CASP3

Gene Summary

Gene:CASP3; caspase 3, apoptosis-related cysteine peptidase
Aliases: CPP32, SCA-1, CPP32B
Location:4q34
Summary:This gene encodes a protein which is a member of the cysteine-aspartic acid protease (caspase) family. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes which undergo proteolytic processing at conserved aspartic residues to produce two subunits, large and small, that dimerize to form the active enzyme. This protein cleaves and activates caspases 6, 7 and 9, and the protein itself is processed by caspases 8, 9 and 10. It is the predominant caspase involved in the cleavage of amyloid-beta 4A precursor protein, which is associated with neuronal death in Alzheimer's disease. Alternative splicing of this gene results in two transcript variants that encode the same protein. [provided by RefSeq, Jul 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:caspase-3
HPRD
Source:NCBIAccessed: 28 February, 2015

Ontology:

What does this gene/protein do?
Show (43)
Pathways:What pathways are this gene/protein implicaed in?
Show (21)

Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 28 February 2015 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • p300-CBP Transcription Factors
  • Osteosarcoma
  • Zinc Oxide
  • Cell Survival
  • Cell Movement
  • MicroRNAs
  • Dose-Response Relationship, Drug
  • Antineoplastic Agents
  • RTPCR
  • Phosphatidylinositol 3-Kinases
  • Triple Negative Breast Cancer
  • Drug Resistance
  • siRNA
  • bcl-2-Associated X Protein
  • Plasmids
  • Temperature
  • Cell Cycle
  • ras GTPase-Activating Proteins
  • Translocation
  • fms-Like Tyrosine Kinase 3
  • Protein Kinase C-delta
  • Cancer Gene Expression Regulation
  • Cell Proliferation
  • Down-Regulation
  • Flow Cytometry
  • Gene Knockdown Techniques
  • Apoptosis Regulatory Proteins
  • VEGFA
  • Lung Cancer
  • Western Blotting
  • Apoptosis
  • X-Linked Inhibitor of Apoptosis Protein
  • Saponins
  • Stomach Cancer
  • bcl-X Protein
  • Zearalenone
  • Chromosome 4
  • rac GTP-Binding Proteins
  • cdc25 Phosphatases
  • Tumor Microenvironment
  • Caspase 3
  • Bladder Cancer
Tag cloud generated 28 February, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: CASP3 (cancer-related)

Fang Q, Fu WH, Yang J, et al.
Knockdown of ZFX suppresses renal carcinoma cell growth and induces apoptosis.
Cancer Genet. 2014 Oct-Dec; 207(10-12):461-6 [PubMed] Related Publications
The ZFX (zinc finger protein, X-linked) gene located on the human X chromosome controls the self-renewal of embryonic and hematopoietic stem cells as a transcriptional regulator. Recently, studies have affirmed that ZFX is associated with several human cancers, including lymphoma, laryngeal squamous cell carcinoma, prostate cancer, and liver cancer, which suggests ZFX as a potential therapeutic target in cancer. However, the functional role of ZFX in human renal cancer remains unclear. Herein, we detected the expression of ZFX in 42 patients with renal cancer and found the expression of ZFX was specifically upregulated in cancer tissues at the mRNA and protein levels. Moreover, we employed lentivirus-mediated short hairpin RNA (shRNA) to knock down ZFX expression in two human renal cell carcinoma cell lines, 786-0 and ACHN. Functional analysis indicated that ZFX silencing significantly inhibited renal cell carcinoma cell proliferation and cell cycle progression, probably because of suppression of CDK4 and cyclin D1, and induced apoptosis via activation of Bax, Caspase 3, and PUMA in a p53-dependent manner. Our findings suggest that knockdown of ZFX by shRNA may be a potential therapeutic approach for the treatment of renal cancer.

Lamy S, Moldovan PL, Ben Saad A, Annabi B
Biphasic effects of luteolin on interleukin-1β-induced cyclooxygenase-2 expression in glioblastoma cells.
Biochim Biophys Acta. 2015; 1853(1):126-35 [PubMed] Related Publications
Success in developing therapeutic approaches to target brain tumor-associated inflammation in patients has been limited. Given that the inflammatory microenvironment is a hallmark signature of solid tumor development, anti-inflammatory targeting strategies have been envisioned as preventing glioblastoma initiation or progression. Consumption of foods from plant origin is associated with reduced risk of developing cancers, a chemopreventive effect that is, in part, attributed to their high content of phytochemicals with potent anti-inflammatory properties. We explored whether luteolin, a common flavonoid in many types of plants, may inhibit interleukin (IL)-1β function induction of the inflammation biomarker cyclooxygenase (COX)-2. We found that IL-1β triggered COX-2 expression in U-87 glioblastoma cells and synergized with luteolin to potentiate or inhibit that induction in a biphasic manner. Luteolin pretreatment of cells inhibited IL-1β-mediated phosphorylation of inhibitor of κB, nuclear transcription factor-κB (NF-κB) p65, extracellular signal-regulated kinase-1/2, and c-Jun amino-terminal kinase in a concentration-dependent manner. Luteolin also inhibited AKT phosphorylation and survivin expression, while it triggered both caspase-3 cleavage and expression of glucose-regulated protein 78. These effects were all potentiated by IL-1β, in part through increased nuclear translocation of NF-κB p65. Finally, luteolin was able to reduce IL-1 receptor gene expression, and treatment with IL-1 receptor antagonist or gene silencing of IL-1 receptor prevented IL-1β/luteolin-induced COX-2 expression. Our results document a novel adaptive cellular response to luteolin, which triggers anti-survival and anti-inflammatory mechanisms that contribute to the chemopreventive properties of this diet-derived molecule.

Ray S, Murmu N, Adhikari J, et al.
Inhibition of Hep G2 hepatic cancer cell growth and CCl₄ induced liver cytotoxicity in Swiss albino mice by Mahua extract.
J Environ Pathol Toxicol Oncol. 2014; 33(4):295-314 [PubMed] Related Publications
Mahua flower extract may provide protective effects against hepatotoxicity. The effect of Mahua flower extract (ME) was investigated on Hep G2 cell line and carbon tetrachloride (CCl4)-induced liver damages in Swiss albino mice. To investigate its cytotoxic effect in liver cancer, Hep G2 cells were treated with different doses of ME, and cell proliferation as well as colony formation assays demonstrated dose-dependent cytotoxicity of ME towards Hep G2 cells in tissue culture. Further gene expression studies showed significant down-regulation of AKT1/2/3, p-AKT, and COX-2 proteins including up-regulation of active caspase-3 in ME treated Hep G2 cells. In in vivo experiments, the mice were pretreated with ME for 15 days. On the 16th day CCl4 was injected intraperitoneally and after 24 h all mice were sacrificed. The antioxidant enzyme activities were measured in liver homogenates. CCl4-induced hepatotoxicity was evidenced by significant increase in lipid peroxidation and decrease in activities of antioxidant enzymes such as GST, GSH, SOD, CAT, and GPx. Histological studies showed CCl4-induced centrilobular necrosis and formation of fatty vacuoles in cirrhotic mice liver. Treatment with ME at a dose of 2 mg and 4 mg/kg exhibited the potential to prevent significant liver toxicity. The expression of active caspase-3 protein was down-regulated in ME treated groups compared to CCl4 exposed animals. This study demonstrated ME mediated antioxidant activity and hepatoprotective effects; therefore it could be used in the future for treating hepatic disorders including liver cancer, especially in combination with chemotherapeutics.

Wang X, Goldstein D, Crowe PJ, Yang JL
Impact of STAT3 inhibition on survival of osteosarcoma cell lines.
Anticancer Res. 2014; 34(11):6537-45 [PubMed] Related Publications
BACKGROUND/AIM: Osteosarcoma is often a fatal malignancy. Constitutive STAT3 activation is associated with various human cancers and commonly suggests poor prognosis. We aimed to investigate the effect and potential molecular mechanisms of STAT3 inhibition on osteosarcoma.
MATERIALS AND METHODS: STAT3 inhibitor S3I-201 was investigated in six osteosarcoma cell lines. Crystal violet colorimetric, clonogenic, cleaved caspase-3 assays and western blot were performed to measure the effect and mechanisms of STAT3 inhibition.
RESULTS: All osteosarcoma cell lines expressed phosphorylated STAT3. Anti-proliferative effects of S3I-201 were dose- and time-dependent. S3I-201 also inhibited colony-formation and induced apoptosis through the caspase cleavage pathway. Finally, molecular mechanism studies suggested that down-regulation of STAT3 phosphorylation and downstream STAT3-target genes such as cyclin D1 and survivin may contribute to S3I-201-mediated anti-proliferation and apoptosis.
CONCLUSION: Inhibition of STAT3 signalling suppressed osteosarcoma cell growth and induced apoptosis, and indicated that STAT3 targeted-therapy may have therapeutic potential in osteosarcoma.

Kim BG, Kwon HY, Sohn EJ, et al.
Activation of caspases and inhibition of ribosome biogenesis mediate antitumor activity of Chijongdan in A549 non-small lung cancer cells.
BMC Complement Altern Med. 2014; 14:420 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Though herbal medicines have been used for cancer prevention and treatment, their scientific evidences still remain unclear so far. Thus, complementary and alternative medicine (CAM) project has been actively executed to reveal the scientific evidences in the USA and other countries. In the present study, we elucidated antitumor mechanism of Chijongdan, an oriental prescription of Rhus verniciflua, processed Panax ginseng, Persicaria tinctoria and Realgar, that has been traditionally applied for cancer treatment in Korea.
METHODS: Chijongdan was prepared with extracts of Rhus verniciflua, processed Panax ginseng, Persicaria tinctoria and processed Realgar. The cytotoxicity of Chijongdan was measured by MTT colorimetric assay. Cell cycle analysis was performed by FACS. Western blot was performed to see the apoptosis related proteins.
RESULTS: Chijongdan significantly exerted cytotoxicity in A549, H460 and H1299 non-small cell lung carcinoma (NSCLC) cells by MTT assay and also increased the number of ethidium homodimer positively stained cells in A549 NSCLC cells. Also, cell cycle analysis showed that Chijongdan increased sub-G1 population in a concentration dependent manner in A549 cells. In addition, Western blotting revealed that Chijongdan activated cleaved PARP, and caspase 9/3, while attenuated the expression of survival genes such as Bcl-2, Bcl-XL and survivin in A549 cells. Furthermore, Chijongdan suppressed the expression of ribosomal biogenesis related proteins such as upstream binding factor (UBF), Fibrillarin, NPM (B23) and Importin-7 (IPO7) and conversely pan-caspase inhibitor Z--VAD-FMK reversed the apoptotic ability of Chijongdan to cleave PARP and caspase 3 and attenuate the expression of UBF and Fibrillarin in A549 cells.
CONCLUSIONS: These findings suggest that Chijongdan induces apoptosis and inhibits ribosomal biogenesis proteins via caspase activation.

Liu BX, Zhou JY, Li Y, et al.
Hederagenin from the leaves of ivy (Hedera helix L.) induces apoptosis in human LoVo colon cells through the mitochondrial pathway.
BMC Complement Altern Med. 2014; 14:412 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Colorectal cancer has become one of the leading cause of cancer morbidity and mortality throughout world. Hederagenin, a derivative of oleanolic acid isolated from the leaves of ivy (Hedera helix L.), has been shown to have potential anti-tumor activity. The study was conducted to evaluate whether hederagenin could induce apoptosis of human colon cancer LoVo cells and explore the possible mechanism.
METHODS: MTT assay was used for evaluating cell viability while Annexin V-FITC/PI assay and Hoechst 33342 nuclear stainining were used for the determination of apoptosis and mitochondrial membrane potential. DCFH-DA fluorescence staining and flow cytometry were used to measure ROS generation. Real-time PCR and western blot analysis were performed for apoptosis-related protein expressions.
RESULTS: MTT assay showed that hederagenin could significantly inhibit the viability of LoVo cells in a concentration-dependent and time-dependent manner by IC50 of 1.39 μM at 24 h and 1.17 μM at 48 h. The apoptosis ratio was significantly increased to 32.46% and 81.78% by the induction of hederagenin (1 and 2 μM) in Annexin V-FITC/PI assay. Hederagenin could also induce the nuclear changes characteristic of apoptosis by Hoechst 33342 nuclear stainining under fluorescence microscopy. DCFH-DA fluorescence staining and flow cytometry showed that hederagenin could increase significantly ROS generation in LoVo cells. Real-time PCR showed that hederagenin induced the up-regulation of Bax and down-regulation of Bcl-2, Bcl-xL and Survivin. Western blotting analysis showed that hederagenin decreased the expressions of apoptosis-associated proteins Bcl-2, procaspase-9, procaspase-3, and polyADP- ribosepolymerase (PARP) were increased, while the expressions of Bax, caspase-3, caspase-9 were increased. However, there was no significant change on caspase-8.
CONCLUSIONS: These results indicated that the disruption of mitochondrial membrane potential might contribute to the apoptosis of hederagenin in LoVo cells. Our findings suggested that hederagenin might be a promising therapeutic candidate for human colon cancer.

Su B, Shi B, Tang Y, et al.
HMGN5 knockdown sensitizes prostate cancer cells to ionizing radiation.
Prostate. 2015; 75(1):33-44 [PubMed] Related Publications
BACKGROUND: High Mobility Group N (HMGN) proteins are a family of chromatin structural proteins that specifically bind to nucleosome core particles. HMGN5 is a novel and characteristic member of the HMGN protein family. We have previously found that HMGN5 is upregulated in prostate cancer and its downregulation had been demonstrated to induce apoptosis and G2-M cell cycle arrest.
METHODS: The radiosensitization effect of HMGN5 knockdown on PC3 and DU145 cells was assessed using clonogenic assay, flow cytometry, and comet assay. The DNA double-strand break (DSB) repair kinetics of HMGN5 knockdown and control cells after radiation exposure was evaluated using immunocytofluorescence. The mitochondrial reactive oxygen species (ROS) levels were estimated using Dihydrorhodamine 123 (DHR 123) probes. Expression of mitochondrial antioxidant MnSOD was measured by real-time PCR and Western blot. The expression of antiapoptotic proteins Bcl-2 and Bcl-xL as well as cleavage of caspase-3, caspase-9, and PARP were also measured using Western blot.
RESULTS: HMGN5 knockdown cells exhibit decreased clonogenic survival and increased apoptosis rate in response to 2-8 Gy ionizing radiation (IR). Loss of HMGN5 does not affect the DSB repair kinetics after radiation exposure. HMGN5 knockdown cells demonstrated increased mitochondrial ROS level and suppressed induction of MnSOD upon radiation compared with control cells upon radiation. Further, MnSOD knockdown resulted in inhibited cell viability as well as increased mitochondrial ROS level and apoptosis upon radiation in PC3 and DU145 cells. Finally, HMGN5 knockdown cells showed significantly decreased levels of antiapoptotic proteins Bcl-2 and Bcl-xL as well as increased cleavage of caspase-3, caspase-9, and PARP compared with control cells after radiation.
CONCLUSIONS: HMGN5 knockdown sensitizes prostate cancer cells to ionizing radiation, and the radiosensitization effect may be partially mediated through suppressed induction of MnSOD and enhanced activation of apoptosis pathway in response to IR.

Hou W, Guan J, Lu H, et al.
The effects of dexamethasone on the proliferation and apoptosis of human ovarian cancer cells induced by paclitaxel.
J Ovarian Res. 2014; 7:89 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Dexamethasone (DEX) has been routinely used as a pre-treatment in the clinical application of paclitaxel (PTX) to treat ovarian cancer. However, PTX-induced apoptosis might be inhibited by DEX. This study was undertaken to investigate the effects of DEX on the apoptosis induced by PTX.
METHODS: Both of SKOV-3 and HO-8910 human ovarian cancer cells were divided into four groups: (1) untreated (Con); (2) treated with DEX (0.1 μM) alone; (3) treated with PTX (50 nM); and (4) pre-treated with DEX (0.1 μM), and 24 h later, treated with PTX (DEX + PTX). Cell proliferation was determined by the 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) dye uptake method, while cell apoptosis was analyzed by propidium iodide (PI) staining and flow cytometry. Then, reverse transcription polymerase chain reactions (RT-PCRs) were applied to semi-quantitative analysis, followed by western blot analysis. Statistical analysis was performed, with Fisher's least significant difference test.
RESULTS: Our results demonstrated that DEX can differentially inhibit SKOV-3 and HO-8910 cell proliferation induced by PTX and decrease the apoptosis rates in cancer cells. Pre-treatment with DEX could up-regulate the expressions of members of anti-apoptotic Bcl-2 family (Bcl-2 and Bcl-XL) and members of IAP family (survivin). The expression of cleaved caspase-3 was down-regulated by DEX, shown by semi-quantitative RT-PCRs and western blot analysis.
CONCLUSIONS: Our data gained invaluable insights of the antagonistic mechanisms of DEX on PTX-induced cancer cell death and may provide new methods of using DEX as antineoplastic drugs or agents in the clinical treatment for ovarian cancer patients.

Wang YC, Wang Y, Kong WZ, et al.
Effects and mechanism of suberoylanilide hydroxamic acid on the proliferation and apoptosis of human hepatoma cell line Bel-7402.
J BUON. 2014 Jul-Sep; 19(3):698-704 [PubMed] Related Publications
PURPOSE: To investigate the effects and mechanism of suberoylanilide hydroxamic acid (SAHA) on the proliferation and apoptosis of human hepatoma cell line Bel-7402.
METHODS: SAHA treatment and control groups were designed in this study. To observe the morphological characteristics and the inhibition of cell proliferation, we conducted confocal microscopy and methyl thiazolyl tetrazolium (MTT) assay, respectively. Changes in cell apoptosis and cell cycle were then determined by flow cytometry. Real-time polymerase chain reaction (RT-PCR) was also conducted to detect the mRNA expressions of p53, bcl-2 and bax genes. Caspase-3 protein activity was determined by spectrophotometry.
RESULTS: Cell proliferation in the SAHA treatment group could be inhibited in a time- and dose-dependent manner. FCM analysis showed that the early apoptosis rate in the SAHA treatment group increased significantly. Furthermore, cell cycle was arrested at the S phase. RT-PCR assay confirmed that SAHA could upregulate the mRNA expressions of p53 and bax genes. By comparison, SAHA could downregulate the mRNA expression of bcl-2. SAHA induced apoptosis by activating the caspase-3 pathway.
CONCLUSION: SAHA inhibited cell proliferation and promoted human hepatoma Bel-7402 cell apoptosis by affecting caspase-3 protein activity and mRNA expressions of p53, bcl-2 and bax genes.

Vera-Lozada G, Scholl V, Barros MH, et al.
Analysis of biological and technical variability in gene expression assays from formalin-fixed paraffin-embedded classical Hodgkin lymphomas.
Exp Mol Pathol. 2014; 97(3):433-9 [PubMed] Related Publications
Formalin-fixed paraffin-embedded (FFPE) tissues are invaluable sources of biological material for research and diagnostic purposes. In this study, we aimed to identify biological and technical variability in RT-qPCR TaqMan® assays performed with FFPE-RNA from lymph nodes of classical Hodgkin lymphoma samples. An ANOVA-nested 6-level design was employed to evaluate BCL2, CASP3, IRF4, LYZ and STAT1 gene expression. The most variable genes were CASP3 (low expression) and LYZ (high expression). Total variability decreased after normalization for all genes, except by LYZ. Genes with moderate and low expression were identified and suffered more the effects of the technical manipulation than high-expression genes. Pre-amplification was shown to introduce significant technical variability, which was partially alleviated by lowering to a half the amount of input RNA. Ct and Cy0 quantification methods, based on cycle-threshold and the kinetic of amplification curves, respectively, were compared. Cy0 method resulted in higher quantification values, leading to the decrease of total variability in CASP3 and LYZ genes. The mean individual noise was 0.45 (0.31 to 0.61 SD), indicating a variation of gene expression over ~1.5 folds from one case to another. We showed that total variability in RT-qPCR from FFPE-RNA is not higher than that reported for fresh complex tissues, and identified gene-, and expression level-sources of biological and technical variability, which can allow better strategies for designing RT-qPCR assays from highly degraded and inhibited samples.

Belkacemi L, Hebb MO
HSP27 knockdown produces synergistic induction of apoptosis by HSP90 and kinase inhibitors in glioblastoma multiforme.
Anticancer Res. 2014; 34(9):4915-27 [PubMed] Related Publications
BACKGROUND/AIM: The heat-shock proteins HSP27 and HSP90 perpetuate the malignant nature of glioblastoma multiforme (GBM) and offer promise as targets for novel cancer therapeutics. The present study sought to define synergistic antitumor benefits of concurrent HSP27-knockdown and the HSP90 inhibitor, 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) or, comparatively, the non-selective kinase inhibitor, staurosporine, in GBM cells.
MATERIALS AND METHODS: Dose-response relations were determined for 17-AAG and staurosporine in three GBM cell lines. HSP27-targeted siRNA was administered alone or in combination with subtherapeutic concentrations of each drug and cells were evaluated for viability, proliferation and apoptosis.
RESULTS: Adjuvant HSP27 knockdown with 17-AAG or staurosporine produced marked and synergistic decrease in GBM cell viability and proliferation, with robust elevation of apoptotic fractions and caspase-3 activation.
CONCLUSION: HSP27 knockdown confers potent chemosensitization of GBM cells. These novel data support the development of HSP-targeting strategies and, specifically, anti-HSP27 agents for the treatment of GBM.

Matsumoto N, Yoshikawa K, Shimada M, et al.
Effect of light irradiation by light emitting diode on colon cancer cells.
Anticancer Res. 2014; 34(9):4709-16 [PubMed] Related Publications
BACKGROUND/AIM: Recent studies have demonstrated the efficacy of irradiation from light emitting diodes (LED) for wound healing, anti-inflammation and anticancer therapies. However, little is known about the effects of visible light in colon cancer cells. The purpose of this study was to evaluate the biological response (including gene expression changes) of human colon cancer cells to different wavelengths of LED irradiation.
MATERIALS AND METHODS: Human colon cancer cells (HT29 or HCT116) were seeded onto laboratory dishes that were then put on LED irradiation equipment with a 465 nm-, 525 nm-, or 635 nm-LED. Irradiation at 15 or 30 mW was performed 10 min/day, each day for 5 days. The cell counting kit8 was then used to measure cell viability. Apoptosis and expression of several mRNAs (caspase, MAPK and autophagy pathway) in HT29 cultures irradiated with 465 nm LED were evaluated via AnnexinV/PI and RT-PCR, respectively.
RESULTS: Viability of HT29 and HCT116 cells was lower in 465 nm-LED irradiated cultures than in control cultures, but viability of HT29 cells did not differ between control cultures and 525 nm-LED or 635 nm-LED irradiated cultures. Moreover, the expression of FAS, caspase-3, capase-8, and JUK were significantly higher in 465 nm-LED irradiated cultures than in control cultures, and expression of ERK1/2 and LC3 was lower in blue-irradiated cells.
CONCLUSION: LED irradiation at 465 nm inhibited the proliferation of HT29 cells and of HCT116 cells. Notably, LED irradiation at 465 nm promoted apoptosis inHT29 cultures via the extrinsic apoptosis pathway and the MAPK pathway.

Shike M, Doane AS, Russo L, et al.
The effects of soy supplementation on gene expression in breast cancer: a randomized placebo-controlled study.
J Natl Cancer Inst. 2014; 106(9) [PubMed] Related Publications
BACKGROUND: There are conflicting reports on the impact of soy on breast carcinogenesis. This study examines the effects of soy supplementation on breast cancer-related genes and pathways.
METHODS: Women (n = 140) with early-stage breast cancer were randomly assigned to soy protein supplementation (n = 70) or placebo (n = 70) for 7 to 30 days, from diagnosis until surgery. Adherence was determined by plasma isoflavones: genistein and daidzein. Gene expression changes were evaluated by NanoString in pre- and posttreatment tumor tissue. Genome-wide expression analysis was performed on posttreatment tissue. Proliferation (Ki67) and apoptosis (Cas3) were assessed by immunohistochemistry.
RESULTS: Plasma isoflavones rose in the soy group (two-sided Wilcoxon rank-sum test, P < .001) and did not change in the placebo group. In paired analysis of pre- and posttreatment samples, 21 genes (out of 202) showed altered expression (two-sided Student's t-test, P < .05). Several genes including FANCC and UGT2A1 revealed different magnitude and direction of expression changes between the two groups (two-sided Student's t-test, P < .05). A high-genistein signature consisting of 126 differentially expressed genes was identified from microarray analysis of tumors. This signature was characterized by overexpression (>2-fold) of cell cycle transcripts, including those that promote cell proliferation, such as FGFR2, E2F5, BUB1, CCNB2, MYBL2, CDK1, and CDC20 (P < .01). Soy intake did not result in statistically significant changes in Ki67 or Cas3.
CONCLUSIONS: Gene expression associated with soy intake and high plasma genistein defines a signature characterized by overexpression of FGFR2 and genes that drive cell cycle and proliferation pathways. These findings raise the concerns that in a subset of women soy could adversely affect gene expression in breast cancer.

Hui KF, Leung YY, Yeung PL, et al.
Combination of SAHA and bortezomib up-regulates CDKN2A and CDKN1A and induces apoptosis of Epstein-Barr virus-positive Wp-restricted Burkitt lymphoma and lymphoblastoid cell lines.
Br J Haematol. 2014; 167(5):639-50 [PubMed] Related Publications
Epstein-Barr virus (EBV) latent proteins exert anti-apoptotic effects on EBV-transformed lymphoid cells by down-regulating BCL2L11 (BIM), CDKN2A (p16(INK4A) ) and CDKN1A (p21(WAF1) ). However, the potential therapeutic effects of targeting these anti-apoptotic mechanisms remain unexplored. Here, we tested both in vitro and in vivo effects of the combination of histone deacetylase (HDAC) and proteasome inhibitors on the apoptosis of six endemic Burkitt lymphoma (BL) lines of different latency patterns (types I and III and Wp-restricted) and three lymphoblastoid cell lines (LCLs). We found that the combination of HDAC and proteasome inhibitors (e.g. SAHA/bortezomib) synergistically induced the killing of Wp-restricted and latency III BL and LCLs but not latency I BL cells. The synergistic killing was due to apoptosis, as evidenced by the high percentage of annexin V positivity and strong cleavage of PARP1 (PARP) and CASP3 (caspase-3). Concomitantly, SAHA/bortezomib up-regulated the expression of CDKN2A and CDKN1A but did not affect the level of BCL2L11 or BHRF1 (viral homologue of BCL2). The apoptotic effects were dependent on reactive oxygen species generation. Furthermore, SAHA/bortezomib suppressed the growth of Wp-restricted BL xenografts in nude mice. This study provides the rationale to test the novel application of SAHA/bortezomib on the treatment of EBV-associated Wp-restricted BL and post-transplant lymphoproliferative disorder.

Qiu M, Liu L, Chen L, et al.
microRNA-183 plays as oncogenes by increasing cell proliferation, migration and invasion via targeting protein phosphatase 2A in renal cancer cells.
Biochem Biophys Res Commun. 2014; 452(1):163-9 [PubMed] Related Publications
The aim of this study was to investigate the function of miR-183 in renal cancer cells and the mechanisms miR-183 regulates this process. In this study, level of miR-183 in clinical renal cancer specimens was detected by quantitative real-time PCR. miR-183 was up- and down-regulated in two renal cancer cell lines ACHN and A498, respectively, and cell proliferation, Caspase 3/7 activity, colony formation, in vitro migration and invasion were measured; and then the mechanisms of miR-183 regulating was analyzed. We found that miR-183 was up-regulated in renal cancer tissues; inhibition of endogenous miR-183 suppressed in vitro cell proliferation, colony formation, migration, and invasion and stimulated Caspase 3/7 activity; up-regulated miR-183 increased cell growth and metastasis and suppressed Caspase 3/7 activity. We also found that miR-183 directly targeted tumor suppressor, specifically the 3'UTR of three subunits of protein phosphatase 2A (PP2A-Cα, PP2A-Cβ, and PP2A-B56-γ) transcripts, inhibiting their expression and regulated the downstream regulators p21, p27, MMP2/3/7 and TIMP1/2/3/4. These results revealed the oncogenes role of miR-183 in renal cancer cells via direct targeting protein phosphatase 2A.

Zhang J, He L, Geng XF, et al.
Anti-cancer effects of novel doxorubicin prodrug PDOX in MCF-7 breast cancer cells.
J Huazhong Univ Sci Technolog Med Sci. 2014; 34(4):521-8 [PubMed] Related Publications
Ac-Phe-Lys-PABC-DOX (PDOX) is a smart doxorubicin (DOX) prodrug designed to decrease toxicities while maintaining the potent anticancer effects of DOX. This study was aimed at elucidating the effectiveness and toxicities of DOX and PDOX in patient-derived MCF-7 breast cancer cells in vitro. The MCF-7 cells were exposed to both PDOX and DOX, and cytotoxicities, cell cycle and P53/P21 signaling alterations were studied. Abundant cathepsin B was found in the MCF-7 cells, and treatment with PDOX and DOX triggered dose- and time-dependent cytotoxicity and resulted in a significant reduction in cell viability. The IC50 of PDOX and DOX was 3.91 and 0.94 μmol/L, respectively. Both PDOX and DOX caused an up-regulation of the P53/P21-related signal pathway, and PDOX significantly increased expression of P53 and caspase 3, and arrested the cell cycle at the G1/G2 phase. As compared with DOX, PDOX reduced toxicities, and it may have different action mechanisms on breast cancer cells.

Zhu H, Chen X, Chen B, et al.
Activating transcription factor 4 mediates a multidrug resistance phenotype of esophageal squamous cell carcinoma cells through transactivation of STAT3 expression.
Cancer Lett. 2014; 354(1):142-52 [PubMed] Related Publications
Multidrug resistance (MDR) is a major challenge to the clinical treatment of esophageal cancer. The stress response gene activating transcription factor 4 (ATF4) is involved in homeostasis and cellular protection. However, relatively little is known about the expression and function of ATF4 in esophageal squamous cell carcinoma (ESCC) MDR. In this study, we investigate the potential role and mechanisms of ATF4 in ESCC MDR. We demonstrated that overexpression of ATF4 promotes the MDR phenotype in ESCC cells, while depletion of ATF4 in the MDR ESCC cell line induces drug re-sensitization. We also demonstrated that ATF4 transactivates STAT3 expression by directly binding to the signal transducers and activators of transcription 3 (STAT3) promoter, resulting in MDR in ESCC cells. Significantly, inhibition of STAT3 by small interfering RNA (siRNA) or a selective inhibitor (JSI-124) reintroduces therapeutic sensitivity. In addition, increased Bcl-2, survivin, and MRP1 expression levels were observed in ATF4-overexpressing cells. In conclusion, ATF4 may promote MDR in ESCC cells through the up-regulation of STAT3 expression, and thus is an attractive therapeutic target to combat therapeutic resistance in ESCC.

Kim SM, Lee JH, Sethi G, et al.
Bergamottin, a natural furanocoumarin obtained from grapefruit juice induces chemosensitization and apoptosis through the inhibition of STAT3 signaling pathway in tumor cells.
Cancer Lett. 2014; 354(1):153-63 [PubMed] Related Publications
Persistent activation of signal transducers and activator of transcription 3 (STAT3) has been closely related to growth, survival, proliferation, metastasis, and angiogenesis of various cancer cells, and thus its inhibition can be considered a potential therapeutic strategy. In this study, we investigated the role of bergamottin (BGM) obtained from grapefruit juice in abrogating the constitutive STAT3 activation in multiple myeloma (MM) cells. This suppression was mediated through the inhibition of phosphorylation of Janus-activated kinase (JAK) 1/2 and c-Src. Pervanadate reversed the BGM induced down-regulation of STAT3 activation, suggesting the involvement of a protein tyrosine phosphatase (PTP). Furthermore, BGM induced the expression of the tyrosine phosphatase SHP-1, and gene silencing of the SHP-1 by small interfering RNA abolished the ability of BGM to inhibit STAT3 activation, suggesting a critical role for SHP-1 in the action of BGM. BGM also downregulated the expression of STAT3-regulated gene products such as COX-2, VEGF, cyclin D1, survivin, IAP-1, Bcl-2, and Bcl-xl in MM cells. This correlated with induction of substantial apoptosis as indicated by an increase in the sub-G1 cell population and caspase-3 induced PARP cleavage. Also, this agent significantly potentiated the apoptotic effects of bortezomib and thalidomide in MM cells. Overall, these results suggest that BGM is a novel blocker of STAT3 activation pathway thus may have a potential in therapy of MM and other cancers.

Moghadamtousi SZ, Kadir HA, Paydar M, et al.
Annona muricata leaves induced apoptosis in A549 cells through mitochondrial-mediated pathway and involvement of NF-κB.
BMC Complement Altern Med. 2014; 14:299 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Annona muricata leaves have been reported to have antiproliferative effects against various cancer cell lines. However, the detailed mechanism has yet to be defined. The current study was designed to evaluate the molecular mechanisms of A. muricata leaves ethyl acetate extract (AMEAE) against lung cancer A549 cells.
METHODS: The effect of AMEAE on cell proliferation of different cell lines was analyzed by MTT assay. High content screening (HCS) was applied to investigate the suppression of NF-κB translocation, cell membrane permeability, mitochondrial membrane potential (MMP) and cytochrome c translocation from mitochondria to cytosol. Reactive oxygen species (ROS) formation, lactate dehydrogenase (LDH) release and activation of caspase-3/7, -8 and -9 were measured while treatment. The western blot analysis also carried out to determine the protein expression of cleaved caspase-3 and -9. Flow cytometry analysis was used to determine the cell cycle distribution and phosphatidylserine externalization. Quantitative PCR analysis was performed to measure the gene expression of Bax and Bcl-2 proteins.
RESULTS: Cell viability analysis revealed the selective cytotoxic effect of AMEAE towards lung cancer cells, A549, with an IC50 value of 5.09 ± 0.41 μg/mL after 72 h of treatment. Significant LDH leakage and phosphatidylserine externalization were observed in AMEAE treated cells by fluorescence analysis. Treatment of A549 cells with AMEAE significantly elevated ROS formation, followed by attenuation of MMP via upregulation of Bax and downregulation of Bcl-2, accompanied by cytochrome c release to the cytosol. The incubation of A549 cells with superoxide dismutase and catalase significantly attenuated the cytotoxicity caused by AMEAE, indicating that intracellular ROS plays a pivotal role in cell death. The released cytochrome c triggered the activation of caspase-9 followed by caspase-3. In addition, AMEAE-induced apoptosis was accompanied by cell cycle arrest at G0/G1 phase. Moreover, AMEAE suppressed the induced translocation of NF-κB from cytoplasm to nucleus.
CONCLUSIONS: Our data showed for the first time that the ethyl acetate extract of Annona muricata inhibited the proliferation of A549 cells, leading to cell cycle arrest and programmed cell death through activation of the mitochondrial-mediated signaling pathway with the involvement of the NF-kB signalling pathway.

Verma V, Sharma V, Singh V, et al.
Designed modulation of sex steroid signaling inhibits telomerase activity and proliferation of human prostate cancer cells.
Toxicol Appl Pharmacol. 2014; 280(2):323-34 [PubMed] Related Publications
The predominant estrogen-receptor (ER)-β signaling in normal prostate is countered by increased ER-α signaling in prostate cancer (CaP), which in association with androgen-receptor (AR) signaling results in pathogenesis of the disease. However CaP treatments mostly target AR signaling which is initially effective but eventually leads to androgen resistance, hence simultaneous targeting of ERs has been proposed. A novel series of molecules were designed with multiple sex-steroid receptor modulating capabilities by coalescing the pharmacophores of known anti-CaP molecules that act via modulation of ER(α/β) and/or AR, viz. 3,3'diindolylmethane (DIM), mifepristone, toremifene, tamoxifen and raloxifene. N,N-diethyl-4-((2-(4-methoxyphenyl)-1H-indol-3-yl)methyl) aniline (DIMA) was identified as the most promising structure of this new series. DIMA increased annexin-V labelling, cell-cycle arrest and caspase-3 activity, and decreased expression of AR and prostate specific antigen in LNCaP cells, in vitro. Concurrently, DIMA increased ER-β, p21 and p27 protein levels in LNCaP cells and exhibited ~5 times more selective binding for ER-β than ER-α, in comparison to raloxifene. DIMA exhibited a dose-dependent ER-β agonism and ER-α antagonism in classical gene reporter assay and decreased hTERT (catalytic subunit of telomerase) transcript levels in LNCaP at 3.0 μM (P<0.05). DIMA also dose-dependently decreased telomerase enzyme activity in prostate cancer cells. It is thus concluded that DIMA acts as a multi-steroid receptor modulator and effectively inhibits proliferation of prostate cancer cells through ER-β mediated telomerase inhibition, by countering actions of ER-α and AR. Its unique molecular design can serve as a lead structure for generation of potent agents against endocrine malignancies like the CaP.

Veyer DL, Maluquer de Motes C, Sumner RP, et al.
Analysis of the anti-apoptotic activity of four vaccinia virus proteins demonstrates that B13 is the most potent inhibitor in isolation and during viral infection.
J Gen Virol. 2014; 95(Pt 12):2757-68 [PubMed] Article available free on PMC after 01/12/2015 Related Publications
Vaccinia virus (VACV) is a large dsDNA virus encoding ~200 proteins, several of which inhibit apoptosis. Here, a comparative study of anti-apoptotic proteins N1, F1, B13 and Golgi anti-apoptotic protein (GAAP) in isolation and during viral infection is presented. VACVs strains engineered to lack each gene separately still blocked apoptosis to some degree because of functional redundancy provided by the other anti-apoptotic proteins. To overcome this redundancy, we inserted each gene separately into a VACV strain (vv811) that lacked all these anti-apoptotic proteins and that induced apoptosis efficiently during infection. Each protein was also expressed in cells using lentivirus vectors. In isolation, each VACV protein showed anti-apoptotic activity in response to specific stimuli, as measured by immunoblotting for cleaved poly(ADP ribose) polymerase-1 and caspase-3 activation. Of the proteins tested, B13 was the most potent inhibitor, blocking both intrinsic and extrinsic stimuli, whilst the activity of the other proteins was largely restricted to inhibition of intrinsic stimuli. In addition, B13 and F1 were effective blockers of apoptosis induced by vv811 infection. Finally, whilst differences in induction of apoptosis were barely detectable during infection with VACV strain Western Reserve compared with derivative viruses lacking individual anti-apoptotic genes, several of these proteins reduced activation of caspase-3 during infection by vv811 strains expressing these proteins. These results illustrated that vv811 was a useful tool to determine the role of VACV proteins during infection and that whilst all of these proteins have some anti-apoptotic activity, B13 was the most potent.

Gao H, Gong XC, Chen ZD, et al.
Induction of apoptosis in hormone-resistant human prostate cancer PC3 cells by inactivated Sendai virus.
Biomed Environ Sci. 2014; 27(7):506-14 [PubMed] Related Publications
OBJECTIVE: Inactivated Sendai virus particle [hemagglutinating virus of Japan envelope (HVJ-E)] has a potential oncolytic effect due to its ability to induce apoptosis in tumor cells. However, the molecular mechanism of apoptosis induction in cancer cells mediated by HVJ-E has not been fully elucidated. This paper aims to investigate the underlying mechanism of apoptosis induction by HVJ-E in prostate cancer cells (PC3).
METHODS: PC3 cells were treated with HVJ-E at various MOI, and then interferon-β (IFN-β) production, and the cell viability and apoptosis were detected by ELISA, MTT-based assay and flow cytometry, respectively. Next, the roles of Jak-Stat, MAPK and Akt pathways played in HVJ-E-induced apoptosis in PC3 cells were analyzed by immunoblot assay. To further evaluate the cytotoxic effect of HVJ-E on PC3 cells, HVJ-E was intratumorally injected into prostate cancers on BALB/c-nude mice, and the tumor volume was monitored for 36 days.
RESULTS: HVJ-E induced IFN-β production and activated Jak-Stat signaling pathway, which resulted in the activation of caspase-8, caspase-3, and PARP in PC3 prostate cancer cells post HVJ-E treatment. Furthermore, we observed for the first time that p38 and Jnk MAPKs in PC3 cells contributed to HVJ-E-induced apoptosis. In addition, intratumoral HVJ-E treatment displayed a direct inhibitory effect in an in vivo BALB/c nude mouse prostate cancer model.
CONCLUSION: Our findings have provided novel insights into the underlying mechanisms by which HVJ-E induces apoptosis in tumor cells.

Jiang XR, Yu XY, Fan JH, et al.
RFT2 is overexpressed in esophageal squamous cell carcinoma and promotes tumorigenesis by sustaining cell proliferation and protecting against cell death.
Cancer Lett. 2014; 353(1):78-86 [PubMed] Related Publications
Human riboflavin transporter 2 (RFT2, also termed as SLC52A3) was recently identified as a susceptibility gene to esophageal squamous cell carcinoma (ESCC), however, its expression and biologic function has remained unclear in ESCC. In this study, we demonstrated that RFT2 was frequently overexpressed in tumor samples compared with normal adjacent tissue in ESCC patients. Knockdown of RFT2 in ESCC cells resulted in decreases of intracellular flavin status, mitochondrial membrane potential and cellular ATP levels, and inhibitions of cell proliferation, colony formation and anchorage-independent growth. Knockdown of RFT2 increased p21 and p27 protein levels, decreased their downstream targets cyclin E1 and Cdk2 protein levels and caused pRb hypophosphorylation, leading to cell cycle arrest at G1-G1/S. Knockdown of RFT2 also reduced anti-apoptotic proteins Bcl-2, Bcl-xl and survivin levels, caused activation of caspase-3 and apoptosis. In contrast, ectopic overexpression of RFT2 in ESCC cells promoted cell proliferation under restricted conditions (soft agar), conferred resistance to cisplatin, and enhanced tumorigenicity in nude mice. These results suggest that RFT2 contributes to ESCC tumorigenesis and may serve as a potential therapeutic target.

Scholtysik R, Kreuz M, Hummel M, et al.
Characterization of genomic imbalances in diffuse large B-cell lymphoma by detailed SNP-chip analysis.
Int J Cancer. 2015; 136(5):1033-42 [PubMed] Related Publications
The pathogenesis of diffuse large B-cell lymphomas (DLBCL) is only partly understood. We analyzed 148 DLBCL by single nucleotide polymorphism (SNP)-chips to characterize genomic imbalances. Seventy-nine cases were of the germinal center B-cell like (GCB) type of DLBCL, 49 of the activated B-cell like (ABC) subtype and 20 were unclassified DLBCL. Twenty-four regions of recurrent genomic gains and 38 regions of recurrent genomic losses were identified over the whole cohort, with a median of 25 imbalances per case for ABC-DLBCL and 19 per case for GCB-DLBCL. Several recurrent copy number changes showed differential frequencies in the GCB- and ABC-DLBCL subgroups, including gains of HDAC7A predominantly in GCB-DLBCL (38% of cases) and losses of BACH2 and CASP8AP2 predominantly in ABC-DLBCL (35%), hinting at disparate pathogenetic mechanisms in these entities. Correlating gene expression and copy number revealed a strong gene dosage effect in all tumors, with 34% of probesets showing a concordant expression change in affected regions. Two new potential tumor suppressor genes emerging from the analysis, CASP3 and IL5RA, were sequenced in ten and 16 candidate cases, respectively. However, no mutations were found, pointing to a potential haploinsufficiency effect of these genes, considering their reduced expression in cases with deletions. Our study thus describes differences and similarities in the landscape of genomic aberrations in the DLBCL subgroups in a large collection of cases, confirming already known targets, but also discovering novel copy number changes with possible pathogenetic relevance.

Zhang H, Sun L, Xiao X, et al.
Krüppel-like factor 8 contributes to hypoxia-induced MDR in gastric cancer cells.
Cancer Sci. 2014; 105(9):1109-15 [PubMed] Related Publications
We previously reported that hypoxia-induced MDR in gastric cancer (GC) cells is hypoxia-inducible factor-1 (HIF-1)-dependent. However, the exact mechanisms are still unknown. Our previous study revealed that Krüppel-like factor 8 (KLF8), a novel transcription factor, was associated with malignant phenotype in GC cells. KLF8 is overexpressed in clear cell renal carcinoma lacking von Hippel-Lindau protein function, which resulted in HIF-1 stabilization. Given this association, we hypothesized that KLF8 contributed to hypoxia-induced MDR in GC cells. Initial experiments revealed that hypoxia could increase KLF8 and HIF-1α expressions in GC cells, and KLF8 levels in GC drug-resistant cell lines were higher than in parental cell lines. Subsequent experiments showed that in normoxia, exogenous KLF8 could promote the MDR phenotype; however, blocking KLF8 expression could effectively reverse the MDR phenotype induced by hypoxia. Overexpressed KLF8 increased resistance-associated gene MDR1 mRNA levels, Bcl-2 and P-gp protein levels, and decreased Bax and caspase-3 protein levels in GC cells, and knockout KLF8 reversed these effects. Dual luciferase reporter and ChIP assays showed that KLF8 could promote MDR1 transcriptional activity by combining with KLF8 binding sites located in the upstream of MDR1 transcriptional start site. These results suggest that KLF8 is involved in hypoxia-induced MDR through inhibiting apoptosis and increasing the drug release rate by directly regulating MDR1 transcription.

Ruggieri S, Tamma R, Marzullo A, et al.
Translocation of the proto-oncogene Bcl-6 in human glioblastoma multiforme.
Cancer Lett. 2014; 353(1):41-51 [PubMed] Related Publications
Bcl-6 translocation is a genetic alteration that is commonly detected in Primary Central Nervous System Lymphoma. The role of this protein in cerebral tumors is unclear. In this study we investigated Bcl-6 translocation and its transcriptional and translational levels in formalin-fixed, paraffin-embedded cerebral tissue sections from glioblastoma (GBM), low-grade glioma (Astrocytoma grade II and III), and meningioma patients, and correlated them with apoptotic processes and p53 and caspase-3 expression. The results showed a frequency of 36.6% of Bcl-6 translocation in GBM patients and a decreased expression in low-grade glioma patients, correlated with the severity of the disease. Bcl-6 translocation induced an overexpression of both Bcl-6 protein and messenger in GBM, inhibiting apoptotic processes and caspases 3 expression. On the contrary, in low-grade gliomas and meningiomas Bcl-6 expression was reduced, resulting in an increase of apoptotic processes. Finally, p53 expression levels in brain tumors were comparable to Bcl-6 levels. Overall, these data demonstrate, for the first time, that the Bcl-6 gene translocates in GBM patients and that its translocation and expression are correlated with apoptosis inhibition, indicating a key role for this gene in the control of cellular proliferation. This study offers further insights into glioblastoma biology, and supports Bcl-6 as a new diagnostic marker to evaluate the disease severity.

Mao K, Zhang J, He C, et al.
Restoration of miR-193b sensitizes Hepatitis B virus-associated hepatocellular carcinoma to sorafenib.
Cancer Lett. 2014; 352(2):245-52 [PubMed] Related Publications
BACKGROUND: Chronic infection with Hepatitis B virus (HBV) is the major risk factor of Hepatocellular Carcinoma (HCC). This study is to explore the mechanism of sorafenib resistance and find an effective strategy to sensitize HBV-associated HCC to sorafenib.
METHODS: Cytotoxicity to sorafenib was evaluated in HBV-positive/negative HCC cell lines. Expression of miR-193b and myeloid cell leukemia-1 (Mcl-1) protein were assessed by Q-PCR, in situ hybridization and western blot, immunohistochemistry, respectively. A luciferase reporter of Mcl-1 3'-UTR was used for validation as a target of miR-193b. Cell apoptosis was measured by flow cytometry, caspase-3 activity assay and DAPI staining.
RESULT: The IC50 to sorafenib was significantly higher in HBV-positive HCC cells than those without HBV infection. Significant downregulation of miR-193b and a higher level of Mcl-1 were observed in HBV-positive HCC cells and tissues. The activity of Mcl-1 3'-UTR reporter was inhibited by co-transfection with miR-193b mimic. Restoring the expression of miR-193b sensitized HBV-associated HCC cells to sorafenib treatment and facilitated sorafenib-induced apoptosis.
CONCLUSIONS: Modulation of miRNAs expression might be a potential way to enhance response to sorafenib in HBV-associated HCC.

Thomas P, Pang Y, Dong J, Berg AH
Identification and characterization of membrane androgen receptors in the ZIP9 zinc transporter subfamily: II. Role of human ZIP9 in testosterone-induced prostate and breast cancer cell apoptosis.
Endocrinology. 2014; 155(11):4250-65 [PubMed] Article available free on PMC after 01/11/2015 Related Publications
Recently, we discovered a cDNA in teleost ovarian follicle cells belonging to the zinc transporter ZIP9 subfamily (SLC39A9) encoding a protein with characteristics of a membrane androgen receptor (mAR). Here, we demonstrate that human ZIP9 expressed in MDA-MB-468 breast cancer cells and stably overexpressed in human prostate cancer PC-3 cells (PC-3-ZIP9) also displays the ligand binding and signaling characteristics of a specific, high-affinity mAR. Testosterone treatment of MDA-MB-468 and PC-3-ZIP9 cells caused activation of G proteins and second messenger pathways as well as increases in intracellular free zinc concentrations that were accompanied by induction of apoptosis. [1,2,6,7-(3)H]-testosterone binding and these responses were abrogated in MDA-MB-468 cells after ZIP9 small interfering RNA (siRNA) treatment and absent in PC-3 cells transfected with empty vector, confirming that ZIP9 functions as an mAR. Testosterone treatment caused up-regulation of proapoptotic genes Bax (Bcl-2-associated X protein), p53 (tumor protein p53), and JNK (c-Jun N-terminal kinases) in both cell lines and increased expression of Bax, Caspase 3, and cytochrome C proteins. Treatment with a zinc chelator or a MAPK inhibitor blocked testosterone-induced increases in Bax, p53, and JNK mRNA expression. The results suggest that both androgen signaling and zinc transporter functions of ZIP9 mediate testosterone promotion of apoptosis. ZIP9 is widely expressed in human tissues and up-regulated in malignant breast and prostate tissues, suggesting that it is a potential therapeutic target for treating breast and prostate cancers. These results provide the first evidence for a mechanism mediated by a single protein through which steroid and zinc signaling pathways interact to regulate physiological functions in mammalian cells.

Yong FL, Wang CW, Roslani AC, Law CW
The involvement of miR-23a/APAF1 regulation axis in colorectal cancer.
Int J Mol Sci. 2014; 15(7):11713-29 [PubMed] Article available free on PMC after 01/11/2015 Related Publications
Recent advances in microRNAome have made microRNAs (miRNAs) a compelling novel class of biomarker in cancer biology. In the present study, the role of miR-23a in the carcinogenesis of colorectal cancer (CRC) was investigated. Cell viability, apoptosis, and caspase 3/7 activation analyses were conducted to determine the potentiality of apoptosis resistance function of miR-23a in CRC. Luciferase assay was performed to verify a putative target site of miR-23a in the 3'-UTR of apoptosis protease activating factor 1 (APAF1) mRNA. The expression levels of miR-23a and APAF1 in CRC cell lines (SW480 and SW620) and clinical samples were assessed using reverse transcription-quantitative real-time PCR (RT-qPCR) and Western blot. We found that the inhibition of miR-23a in SW480 and SW620 cell lines resulted in significant reduction of cell viability and promotion of cell apoptosis. Moreover, miR-23a up-regulation was coupled with APAF1 down-regulation in CRC tissue samples. Taken together, miR-23a was identified to regulate apoptosis in CRC. Our study highlights the potential application of miR-23a/APAF1 regulation axis in miRNA-based therapy and prognostication.

Takeda D, Hasegawa T, Ueha T, et al.
Transcutaneous carbon dioxide induces mitochondrial apoptosis and suppresses metastasis of oral squamous cell carcinoma in vivo.
PLoS One. 2014; 9(7):e100530 [PubMed] Article available free on PMC after 01/11/2015 Related Publications
Squamous cell carcinoma (SCC) is the main histological type of oral cancer. Its growth rate and incidence of metastasis to regional lymph nodes is influenced by various factors, including hypoxic conditions. We have previously reported that transcutaneous CO2 induces mitochondrial apoptosis and decreases lung metastasis by reoxygenating sarcoma cells. However, previous studies have not determined the sequential mechanism by which transcutaneous CO2 suppresses growth of epithelial tumors, including SCCs. Moreover, there is no report that transcutaneous CO2 suppresses lymphogenous metastasis using human cell lines xenografts. In this study, we examined the effects of transcutaneous CO2 on cancer apoptosis and lymphogenous metastasis using human SCC xenografts. Our results showed that transcutaneous CO2 affects expressions of PGC-1α and TFAM and protein levels of cleavage products of caspase-3, caspase-9 and PARP, which relatives mitochondrial apoptosis. They also showed that transcutaneous CO2 significantly inhibits SCC tumor growth and affects expressions of HIF-1α, VEGF, MMP-2 and MMP-9, which play essential roles in tumor angiogenesis, invasion and metastasis. In conclusion, transcutaneous CO2 suppressed tumor growth, increased mitochondrial apoptosis and decreased the number of lymph node metastasis in human SCC by decreasing intra-tumoral hypoxia and suppressing metastatic potential with no observable effect in vivo. Our findings indicate that transcutaneous CO2 could be a novel therapeutic tool for treating human SCC.

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