PCNA

Gene Summary

Gene:PCNA; proliferating cell nuclear antigen
Aliases: ATLD2
Location:20pter-p12
Summary:The protein encoded by this gene is found in the nucleus and is a cofactor of DNA polymerase delta. The encoded protein acts as a homotrimer and helps increase the processivity of leading strand synthesis during DNA replication. In response to DNA damage, this protein is ubiquitinated and is involved in the RAD6-dependent DNA repair pathway. Two transcript variants encoding the same protein have been found for this gene. Pseudogenes of this gene have been described on chromosome 4 and on the X chromosome. [provided by RefSeq, Jul 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:proliferating cell nuclear antigen
HPRD
Source:NCBIAccessed: 20 August, 2015

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 20 August 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.

Tag cloud generated 20 August, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (6)

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: PCNA (cancer-related)

Okoh VO, Garba NA, Penney RB, et al.
Redox signalling to nuclear regulatory proteins by reactive oxygen species contributes to oestrogen-induced growth of breast cancer cells.
Br J Cancer. 2015; 112(10):1687-702 [PubMed] Article available free on PMC after 12/05/2016 Related Publications
BACKGROUND: 17β-Oestradiol (E2)-induced reactive oxygen species (ROS) have been implicated in regulating the growth of breast cancer cells. However, the underlying mechanism of this is not clear. Here we show how ROS through a novel redox signalling pathway involving nuclear respiratory factor-1 (NRF-1) and p27 contribute to E2-induced growth of MCF-7 breast cancer cells.
METHODS: Chromatin immunoprecipitation, qPCR, mass spectrometry, redox western blot, colony formation, cell proliferation, ROS assay, and immunofluorescence microscopy were used to study the role of NRF-1.
RESULTS: The major novel finding of this study is the demonstration of oxidative modification of phosphatases PTEN and CDC25A by E2-generated ROS along with the subsequent activation of AKT and ERK pathways that culminated in the activation of NRF-1 leading to the upregulation of cell cycle genes. 17β-Oestradiol-induced ROS by influencing nuclear proteins p27 and Jab1 also contributed to the growth of MCF-7 cells.
CONCLUSIONS: Taken together, our results present evidence in the support of E2-induced ROS-mediated AKT signalling leading to the activation of NRF-1-regulated cell cycle genes as well as the impairment of p27 activity, which is presumably necessary for the growth of MCF-7 cells. These observations are important because they provide a new paradigm by which oestrogen may contribute to the growth of breast cancer.

Walesky C, Apte U
Role of hepatocyte nuclear factor 4α (HNF4α) in cell proliferation and cancer.
Gene Expr. 2015; 16(3):101-8 [PubMed] Related Publications
Hepatocyte nuclear factor 4α (HNF4α) is an orphan nuclear receptor commonly known as the master regulator of hepatic differentiation, owing to the large number of hepatocyte-specific genes it regulates. Whereas the role of HNF4α in hepatocyte differentiation is well recognized and extensively studied, its role in regulation of cell proliferation is relatively less known. Recent studies have revealed that HNF4α inhibits proliferation not only of hepatocytes but also cells in colon and kidney. Further, a growing number of studies have demonstrated that inhibition or loss of HNF4α promotes tumorigenesis in the liver and colon, and reexpression of HNF4α results in decreased cancer growth. Studies using tissue-specific conditional knockout mice, knock-in studies, and combinatorial bioinformatics of RNA/ChIP-sequencing data indicate that the mechanisms of HNF4α-mediated inhibition of cell proliferation are multifold, involving epigenetic repression of promitogenic genes, significant cross talk with other cell cycle regulators including c-Myc and cyclin D1, and regulation of miRNAs. Furthermore, studies indicate that posttranslational modifications of HNF4α may change its activity and may be at the core of its dual role as a differentiation factor and repressor of proliferation. This review summarizes recent findings on the role of HNF4α in cell proliferation and highlights the newly understood function of this old receptor.

Wang F, Luo Y, Li C, Chen L
Correlation between deregulated expression of PER2 gene and degree of glioma malignancy.
Tumori. 2014 Nov-Dec; 100(6):e266-72 [PubMed] Related Publications
AIMS AND BACKGROUND: Growing evidence indicates that disruption of circadian rhythms may be a risk factor for the development of glioma. However, the molecular mechanisms underlying the genetic regulation of circadian rhythms in glioma cells have yet to be explored.
METHODS AND STUDY DESIGN: Using immunohistochemical staining and methylation-specific PCR techniques, we examined the expression of the period 2 (PER2) gene, one of the most important clock genes, epidermal growth factor receptor (EGFR), and proliferating cell nuclear antigen (PCNA) in 92 gliomas.
RESULTS: Our results revealed disturbances in the expression of PER2 in most (52.17%) glioma cells compared with the expression in nearby noncancerous cells, and indicated that PER2 gene deregulation most likely occurs via methylation of PER2 promoters. The protein expression of PCNA and EGFR was significantly higher in high-grade than low-grade gliomas (P < 0.05). Furthermore, a negative correlation was detected between the protein expression of PER2 and PCNA and EGFR in glioma.
CONCLUSIONS: Because the circadian clock regulates the expression of cell cycle-related genes, we suggest that disturbances in PER2 gene expression may disrupt the regulation of the circadian clock, thus enhancing the survival of cancer cells and promoting carcinogenesis.

Chen R, Zhao Y, Huang Y, et al.
Nanomicellar TGX221 blocks xenograft tumor growth of prostate cancer in nude mice.
Prostate. 2015; 75(6):593-602 [PubMed] Article available free on PMC after 01/05/2016 Related Publications
BACKGROUND: Combination of androgen ablation along with early detection and surgery has made prostate cancer highly treatable at the initial stage. However, this cancer remains the second leading cause of cancer death among American men due to castration-resistant progression, suggesting that novel therapeutic agents are urgently needed for this life-threatening condition. Phosphatidylinositol 3-kinase p110β is a major cellular signaling molecule and has been identified as a critical factor in prostate cancer progression. In a recent report, we established a nanomicelle-based strategy to deliver p110β-specific inhibitor TGX221 to prostate cancer cells by conjugating the surface of nanomicelles with a RNA aptamer against prostate specific membrane antigen (PSMA) present in all clinical prostate cancers. In this study, we tested this nanomicellar TGX221 for its in vivo anti-tumor effect in mouse xenograft models.
METHODS: Prostate cancer cell lines LAPC-4, LNCaP, C4-2 and 22RV1 were used to establish subcutaneous xenograft tumors in nude mice. Paraffin sections from xenograft tumor specimens were used in immunohistochemistry assays to detect AKT phosphorylation, cell proliferation marker Ki67 and proliferating cell nuclear antigen (PCNA), as well as 5-bromo-2-deoxyuridine (BrdU) incorporation. Quantitative PCR assay was conducted to determine prostate-specific antigen (PSA) gene expression in xenograft tumors.
RESULTS: Although systemic delivery of unconjugated TGX221 significantly reduced xenograft tumor growth in nude mice compared to solvent control, the nanomicellar TGX221 conjugates completely blocked tumor growth of xenografts derived from multiple prostate cancer cell lines. Further analyses revealed that AKT phosphorylation and cell proliferation indexes were dramatically reduced in xenograft tumors received nanomicellar TGX221 compared to xenograft tumors received unconjugated TGX221 treatment. There was no noticeable side effect by gross observation or at microscopic level of organ tissue section.
CONCLUSION: These data strongly suggest that prostate cancer cell-targeted nanomicellar TGX221 is an effective anti-cancer agent for prostate cancer.

Xu XC, Zhang YH, Zhang WB, et al.
MicroRNA-133a functions as a tumor suppressor in gastric cancer.
J Biol Regul Homeost Agents. 2014 Oct-Dec; 28(4):615-24 [PubMed] Related Publications
MicroRNAs (miRNAs) are small and highly conserved non-coding RNAs that regulate gene expression of target mRNAs through posttranscriptional inhibition involved in the tumorigenesis and progression of multiple malignancies. Although miR-133a has been shown to function as a tumor suppressor in some cancers, the clinical significance and function of miR-133a in gastric cancer remain unclear. Hence, we were focused on the expression and mechanisms of miR-133a in the development of gastric cancer in this study. It was found that the expression of miR-133a was downregulated (P<0.001), while transgelin-2 (TAGLN2) was upregulated (P<0.05) in primary gastric cancer tissues, compared to the adjacent non-cancerous tissues (ANCT). Furthermore, decreased expression of miR-133a and increased expression of TAGLN2 were both associated with lymph node metastases in patients with gastric cancer (P<0.001; P=0.011). Functional analysis studies revealed that ectopic expression of miR-133a reduced cell proliferation and invasion, and induced cell apoptosis and cycle arrest via suppressing the level of TAGLN2 from transcriptional and translational levels and downregulated the expression of proliferating cell nuclear antigen (PCNA) and matrix metalloproteinase-2 (MMP-2) in gastric cancer cells. In conclusion, these results demonstrate that decreased expression of miR-133a is associated with the lymph node metastases of patients with gastric cancer. Overexpression of miR-133a inhibits cell growth and invasion and induces cell apoptosis and cycle arrest through repressing TAGLN2 gene, suggesting that miR-133a might be used as a biomarker or therapeutic target for the treatment of gastric cancer.

Jiang J, Liu HL, Liu ZH, et al.
Identification of cystatin SN as a novel biomarker for pancreatic cancer.
Tumour Biol. 2015; 36(5):3903-10 [PubMed] Related Publications
Cystatin SN (cystatin 1, CST1) is a member of the cystatin superfamily that inhibits the proteolytic activity of cysteine proteases. CST1 is a tumor biomarker that provides useful information for the diagnosis of esophageal, gastric, and colorectal carcinomas. However, the significance of CST1 in pancreatic cancer is unknown. The aim of this study was to assess whether CST1 is a potential biomarker for early diagnosis of malignant pancreatic neoplasms. Microarray analysis of mRNA extracted from pancreatic cancer and pancreatic normal tissues was performed. Bioinformatics revealed that CST1 was one of the highest expressed genes on the array in pancreatic cancer, compared with normal tissue. In addition, the upregulation of CST1 in pancreatic cancer and several pancreatic cancer cell lines was confirmed using real-time PCR (RT-PCR), immunohistochemistry, and Western blotting. Next, CST1 knockdown using siRNA reduced the expression of the proliferation-related proteins p-AKT and PCNA significantly, as well as colony formation and xenograft development in vitro. Consistent with this, CST1 mRNA overexpression was correlated closely with malignancy-associated proteins such as PCNA, cyclin D1, cyclin A2, and cyclin E in pancreatic cancer cell lines. In conclusion, our data suggest that CST1 might contribute to the proliferation of pancreatic cancer cells and could be a potential biomarker for the early detection of pancreatic cancer.

Nie W, Song W, Zhang W, et al.
miR-1470 mediates lapatinib induced p27 upregulation by targeting c-jun.
J Cell Physiol. 2015; 230(7):1630-9 [PubMed] Related Publications
Our previous study indicated that lapatinib induces p27-dependent G(1) arrest through both transcriptional and post-translational mechanisms. Using miRNA microarray technology and quantitative RT-PCR, we further investigated the potential miRNAs that involved in p27 upregulation and Her-2 signaling pathway alteration with lapatinib treatment. A subset of 7 miRNAs was significantly affected in both 0.5 µM and 2.0 µM and 24 h and 48 h lapatinib treatment. Among them, only miR-1470, miR-126, and miR-1208 were identified in the Her-2 pathway after KEGG pathway analysis. However, luciferase reporter assay confirmed that miR-1470 directly recognized the 3'-untranslated region of c-jun transcripts, which was consistent with TargetScan analysis. miR-1470 significantly decreased c-jun expression, thus miR-1470 may repressc-jun activation of cyclinD1 expression, and consequently promoted the upregulation of p27, a key molecule in the cell cycle arrest. Taken together, the present study provided the first evidences that miR-1470 mediated lapatinib induced p27 upregulation by targeting c-jun.

Akrami H, Aminzadeh S, Fallahi H
Inhibitory effect of ibuprofen on tumor survival and angiogenesis in gastric cancer cell.
Tumour Biol. 2015; 36(5):3237-43 [PubMed] Related Publications
Numerous epidemiological studies have suggested effectiveness of long-term and regular use of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and aspirin, in preventing and treatment of certain cancers including prostate, colon, breast, lung, and gastric cancers. We have studied the potential anti-turmeric effect of ibuprofen in adenocarcinoma gastric cell line (AGS). The effects of ibuprofen were investigated on cell proliferation, apoptosis, angiogenesis, and expression of stemness marker genes using real-time RT-PCR, DNA laddering, and tube formation assays via ECM gel and human umbilical vein endothelial cells (HUVECs). Annexin-V-FLUOS and propidium iodide (PI) were used to stain the apoptotic cells. Our findings indicate that ibuprofen at the concentrations of 100, 200, 300, 400, and 500 μM is able to reduce the cancerous characteristics of the AGS cells by inducing apoptosis, inhibition of cell proliferation, and angiogenesis. Real-time RT-PCR showed that ibuprofen altered the expression of several genes including Akt, P53, PCNA, Bax, and Bcl2 in the AGS cells. In addition, reduction in CD44 and OCT3/4 transcript levels revealed that ibuprofen reduces the stemness of the AGS cells and therefore it could be used as a potential anti-tumor drug.

Zou Y, Xiong H, Xiong H, et al.
A polysaccharide from mushroom Huaier retards human hepatocellular carcinoma growth, angiogenesis, and metastasis in nude mice.
Tumour Biol. 2015; 36(4):2929-36 [PubMed] Related Publications
Mushroom Huaier has become a focus of interest in the treatment of hepatocellular carcinoma (HCC). Presently, we isolated and purified one polysaccharide from this mushroom. This study aimed to investigate the effects of SP1 on tumor growth and metastasis in a HCC xenograft model and explore its possible mechanism of action. Our results showed that SP1 not only significantly inhibited the proliferation of SMMC-7721 cells in vitro at the concentration ranging from 0 to 800 μg/ml but also suppressed the HCC tumor growth and metastatic nodules to the lung in SMMC-7721-bearing mice by oral administration at three doses of 30, 60, and 120 mg/kg. Concomitantly, immunohistochemistry analysis of tumor tissues identified that SP1 administration at three doses significantly inhibited the in vivo cancer cell proliferation and microvessel density (MVD) formation, evidenced by a low proliferating cell nuclear antigen (PCNA) and CD34 expression, but increased the percentage of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells. Keeping in line with this observation, SP1 treatment decreased serum matrix metalloproteinase (MMP) 2 and vascular endothelial growth factor (VEGF) levels, downregulated the protein expression of hypoxia-inducible factor (HIF)-1alpha, VEGF, MMP2, bcl-2, N-cadherin, signal transducer and activator of transcription 3 (STAT3), and metadherin (MTDH), and upregulated bax and NE-cadherin protein expression in tumor tissues. Taken together, our data suggest that SP1 appears to be a promising chemopreventive agent for the tumorigenesis and metastasis in patients with HCC, especially at advanced stages.

El-Mallawany NK, Day N, Ayello J, et al.
Differential proteomic analysis of endemic and sporadic Epstein-Barr virus-positive and negative Burkitt lymphoma.
Eur J Cancer. 2015; 51(1):92-100 [PubMed] Related Publications
BACKGROUND: Burkitt lymphoma (BL) is the most common non-Hodgkin lymphoma in children worldwide and the most common paediatric malignancy in sub-Saharan Africa. The endemic (eBL) and sporadic (sBL) variants have distinct epidemiologic and virologic characteristics. Although gene expression studies have defined the transcriptional profiles of both, their proteomic signatures have not been studied.
METHODS: We compared the proteomic expression profiles using differential mass spectrometry-based isotope tag for relative and absolute quantitation (iTRAQ) analysis of a cell line representing Epstein-Barr virus (EBV)+ eBL, EBV+ and EBV- sBL, and EBV+/- normal B cells from healthy donors.
RESULTS: In total, there were 144 differentially expressed proteins with a statistically significant false discovery rate (FDR) of ⩽0.2. Results revealed over-expression of specific proteins with well-established links to lymphomagenesis such as TUBB2C (FDR 0.05), UCHL1 (FDR 0.05) and HSP90AB1 (FDR 0.1). Distinct characteristics based upon the epidemiologic and virologic subtypes of BL were also identified. In sBL, PCNA (FDR 0.05) and SLC3A2 (FDR 0.1) were significantly over-expressed. In eBL, C1QBP (FDR 0.1) and ENO1 (FDR 0.25) were significantly over-expressed. Comparison of EBV+ to EBV- BL cell lines and B cells revealed significant over-expression of DDX3X (FDR 0.1). Proteins were validated using Western blot analysis.
CONCLUSION: Our results suggest unique signal transduction pathways associated with EBV infection and epidemiological subtype of BL that may contribute to lymphomagenesis. These proteomic findings provide potential diagnostic, prognostic and therapeutic links to BL.

Sun R, Liu Y, Li SY, et al.
Co-delivery of all-trans-retinoic acid and doxorubicin for cancer therapy with synergistic inhibition of cancer stem cells.
Biomaterials. 2015; 37:405-14 [PubMed] Related Publications
Combination treatment through simultaneous delivery of two or more drugs with nanoparticles has been demonstrated to be an elegant and efficient approach for cancer therapy. Herein, we employ a combination therapy for eliminating both the bulk tumor cells and the rare cancer stem cells (CSCs) that have a high self-renewal capacity and play a critical role in cancer treatment failure. All-trans-retinoic acid (ATRA), a powerful differentiation agent of cancer stem cells and the clinically widely used chemotherapy agent doxorubicin (DOX) are simultaneously encapsulated in the same nanoparticle by a single emulsion method. It is demonstrated that ATRA and DOX simultaneous delivery-based therapy can efficiently deliver the drugs to both non-CSCs and CSCs to differentiate and kill the cancer cells. Differentiation of CSCs into non-CSCs can reduce their self-renewal capacity and increase their sensitivity to chemotherapy; with the combined therapy, a significantly improved anti-cancer effect is demonstrated. Administration of this combinational drug delivery system can markedly augment the enrichment of drugs both in tumor tissues and cancer stem cells, prodigiously enhancing the suppression of tumor growth while reduce the incidence of CSC in a synergistic manner.

Huang C, Sheng Y, Jia J, Chen L
Identification of melanoma biomarkers based on network modules by integrating the human signaling network with microarrays.
J Cancer Res Ther. 2014; 10 Suppl:C114-24 [PubMed] Related Publications
BACKGROUND: Melanoma is a leading cause of cancer death. Thus, accurate prognostic biomarkers that will assist rational treatment planning need to be identified.
METHODS: Microarray analysis of melanoma and normal tissue samples was performed to identify differentially expressed modules (DEMs) from the signaling network and ultimately detect molecular markers to support histological examination. Network motifs were extracted from the human signaling network. Then, significant expression-correlation differential modules were identified by comparing the network module expression-correlation differential scores under normal and disease conditions using the gene expression datasets. Finally, we obtained DEMs by the Wilcoxon rank test and considered the average gene expression level in these modules as the classification features for diagnosing melanoma.
RESULTS: In total, 99 functional DEMs were identified from the signaling network and gene expression profiles. The area under the curve scores for cancer module genes, melanoma module genes, and whole network modules are 92.4%, 90.44%, and 88.45%, respectively. The classification efficiency rates for nonmodule features are 71.04% and 79.38%, which correspond to the features of cancer genes and melanoma cancer genes, respectively. Finally, we acquired six significant molecular biomarkers, namely, module 10 (CALM3, Ca 2+ , PKC, PDGFRA, phospholipase-g, PIB5PA, and phosphatidylinositol-3-kinase), module 14 (SRC, Src homology 2 domain-containing [SHC], SAM68, GIT1, transcription factor-4, CBLB, GRB2, VAV2, LCK, YES, PTCH2, downstream of tyrosine kinase [DOK], and KIT), module 16 (ELK3, p85beta, SHC, ZFYVE9, TGFBR1, TGFBR2, CITED1, SH3KBP1, HCK, DOK, and KIT), module 45 (RB, CCND3, CCNA2, CDK4, and CDK6), module 75 (PCNA, CDK4, and CCND1), and module 114 (PSD93, NMDAR, and FYN).
CONCLUSION: We explored the gene expression profile and signaling network in a global view and identified DEMs that can be used as diagnostic or prognostic markers for melanoma.

Drew JE, Farquharson AJ, Mayer CD, et al.
Predictive gene signatures: molecular markers distinguishing colon adenomatous polyp and carcinoma.
PLoS One. 2014; 9(11):e113071 [PubMed] Article available free on PMC after 01/05/2016 Related Publications
Cancers exhibit abnormal molecular signatures associated with disease initiation and progression. Molecular signatures could improve cancer screening, detection, drug development and selection of appropriate drug therapies for individual patients. Typically only very small amounts of tissue are available from patients for analysis and biopsy samples exhibit broad heterogeneity that cannot be captured using a single marker. This report details application of an in-house custom designed GenomeLab System multiplex gene expression assay, the hCellMarkerPlex, to assess predictive gene signatures of normal, adenomatous polyp and carcinoma colon tissue using archived tissue bank material. The hCellMarkerPlex incorporates twenty-one gene markers: epithelial (EZR, KRT18, NOX1, SLC9A2), proliferation (PCNA, CCND1, MS4A12), differentiation (B4GANLT2, CDX1, CDX2), apoptotic (CASP3, NOX1, NTN1), fibroblast (FSP1, COL1A1), structural (ACTG2, CNN1, DES), gene transcription (HDAC1), stem cell (LGR5), endothelial (VWF) and mucin production (MUC2). Gene signatures distinguished normal, adenomatous polyp and carcinoma. Individual gene targets significantly contributing to molecular tissue types, classifier genes, were further characterised using real-time PCR, in-situ hybridisation and immunohistochemistry revealing aberrant epithelial expression of MS4A12, LGR5 CDX2, NOX1 and SLC9A2 prior to development of carcinoma. Identified gene signatures identify aberrant epithelial expression of genes prior to cancer development using in-house custom designed gene expression multiplex assays. This approach may be used to assist in objective classification of disease initiation, staging, progression and therapeutic responses using biopsy material.

Anand S, Ebner J, Warren CB, et al.
C/EBP transcription factors in human squamous cell carcinoma: selective changes in expression of isoforms correlate with the neoplastic state.
PLoS One. 2014; 9(11):e112073 [PubMed] Article available free on PMC after 01/05/2016 Related Publications
The CCAAT/Enhancer Binding Proteins (C/EBPs) are a family of leucine-zipper transcription factors that regulate physiological processes such as energy metabolism, inflammation, cell cycle, and the development and differentiation of several tissues including skin. Recently, a role for C/EBPs in tumor cell proliferation and differentiation has been proposed, but the incomplete characterization in the literature of multiple translational isoforms of these proteins has made interpretation of these roles difficult. Therefore, we have carefully reexamined C/EBP isoform expression in human non-melanoma skin cancers. C/EBPα, C/EBPβ, and C/EBPδ were analyzed histologically in squamous cell carcinomas (SCC). The individual isoforms of C/EBPα and C/EBPβ were examined by immunofluorescent digital imaging, western blotting and DNA binding activity (electrophoretic mobility shift analysis). Expression of all C/EBP family proteins was decreased in SCC tumors. Suppression was greatest for C/EBPα, less for C/EBPβ, and least for C/EBPδ. Western analyses confirmed that C/EBPα p42 and p30 isoforms were decreased. For C/EBPβ, only the abundant full-length isoform (C/EBPβ-1, LAP*, 55 kD) was reduced, whereas the smaller isoforms, C/EBPβ-2 (LAP, 48 kD) and C/EBPβ-3 (LIP, 20 kD), which are predominantly nuclear, were significantly increased in well- and moderately-differentiated SCC (up to 14-fold for C/EBPβ-3). These elevations correlated with increases in PCNA, a marker of proliferation. Although C/EBPβ displayed increased post-translational modifications in SCC, phosphorylation of C/EBPβ-1 (Thr 235) was not altered. C/EBP-specific DNA binding activity in nuclear and whole-cell extracts of cultured cells and tumors was predominantly attributable to C/EBPβ. In summary, two short C/EBPβ isoforms, C/EBPβ-2 and C/EBPβ-3, represent strong candidate markers for epithelial skin malignancy, due to their preferential expression in carcinoma versus normal skin, and their strong correlation with tumor proliferation.

Zhen Y, Guanghui L, Xiefu Z
Knockdown of EGFR inhibits growth and invasion of gastric cancer cells.
Cancer Gene Ther. 2014; 21(11):491-7 [PubMed] Related Publications
The epidermal growth factor receptor (EGFR) is an oncogenic trans-membranous receptor, which is overexpressed in multiple human cancers. However, the role of EGFR in gastric cancer (GC) is still elusive. In this study, we aimed to investigate the expression and molecular mechanisms of EGFR in GC cells. Forty cases of GC and the corresponding adjacent non-cancerous tissues (ANCT) were collected, and the expression of EGFR was assessed using immunohistochemistry in biopsy samples. Furthermore, EGFR signaling was blocked by constructed recombinant small hairpin RNA lentiviral vector (Lv-shRAGE) used to transfect into human GC SGC-7901 cells. The expression of AKT, proliferating cell nuclear antigen (PCNA) and matrix metallopeptidase-9 (MMP-9) was detected by real-time PCR and western blotting assays. Cell proliferative activities and invasive capability were, respectively, determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) and Transwell assays. Cell apoptosis and cycle distribution were analyzed by flow cytometry. EGFR was found highly expressed in cancer tissues compared with the ANCT and correlated with lymph node metastases. Knockdown of EGFR reduced cell proliferation and invasion of GC with decreased expression of AKT, PCNA and MMP-9 and induced cell apoptosis and cycle arrest. Upregulation of EGFR expression is associated with lymph node metastases of GC, and blockade of EGFR signaling suppresses growth and invasion of GC cells through AKT pathway, suggesting that EGFR may represent a potential therapeutic target for this aggressive malignancy.

Patel AD, Rotenberg S, Messer RL, et al.
Blue light activates phase 2 response proteins and slows growth of a431 epidermoid carcinoma xenografts.
Anticancer Res. 2014; 34(11):6305-13 [PubMed] Related Publications
BACKGROUND: Recent studies suggest that light in the UVA range (320-400 nm) activates signaling pathways that are anti-inflammatory, antioxidative and play a critical role in protection against cancer. These effects have been attributed to NF-E2-related factor (NRF2)-mediated up-regulation of 'phase 2' genes that neutralize oxidative stress and metabolize electrophiles. We had previously shown that small doses of blue light (400-500 nm) had selective toxicity for cultured oral tumor cells and increased levels of peroxiredoxin phase 2 proteins, which led to our hypothesis that blue light activates NRF2 signaling.
MATERIALS AND METHODS: A431 epidermoid carcinoma cells were treated in culture and as nude mouse xenografts with doses of blue light. Cell lysates and tumor samples were tested for NRF2 activation, and for markers of proliferation and oxidative stress.
RESULTS: Blue light activated the phase 2 response in cultured A431 cells and reduced their viability dose dependently. Light treatment of tumors reduced tumor growth, and levels of proliferating cell nuclear antigen (PCNA), and oxidized proteins.
DISCUSSION: Cellular responses to these light energies are worth further study and may provide therapeutic interventions for inflammation and cancer.

Chen XZ, Cao ZY, Li JN, et al.
Ethyl acetate extract from Jiedu Xiaozheng Yin inhibits the proliferation of human hepatocellular carcinoma cells by suppressing polycomb gene product Bmi1 and Wnt/β-catenin signaling.
Oncol Rep. 2014; 32(6):2710-8 [PubMed] Related Publications
Jiedu Xiaozheng Yin (JXY) is a Chinese herbal decoction used to treat hepatocellular carcinoma (HCC). Previous studies have demonstrated that JXY can inhibit HCC cell proliferation via induction of G0/G1 phase arrest. In this study, we investigated whether the inhibitory effect of JXY on HCC cells is associated with the inhibition of the Wnt/β‑catenin pathway and the polycomb gene product Bmi1. Ethyl acetate extract from JXY (EE-JXY) was prepared. Methyl thiazolyl tetrazolium (MTT) and colony formation assays were used to measure cell proliferation. Immunofluorescence was used to analyze the expression and location of β-catenin and Bmi1. Immunohistochemistry was used to examine the expression of proliferating cell nuclear antigen (PCNA), c-myc and cyclin D1. β-catenin, Bmi1, c-myc, cyclin D1 and p16INK4A mRNA levels were detected by RT-PCR. The results demonstrated that EE-JXY inhibited the expression of PCNA, c-myc, cyclin D1 and Bmi1, and upregulated the expression of p16INK4A. We also found that EE-JXY could facilitate β-catenin translocation from the cytoplasm and nuclei to the cytomembrane. Finally, suppression of cell proliferation and expression of Bmi1 and Wnt/β-catenin by EE-JXY was confirmed in a mouse xenograft model of HCC. Thus, EE-JXY can inhibit the proliferation of HCC partially via suppression of the Bmi1 and Wnt/β-catenin signaling pathways.

Weng M, Song F, Chen J, et al.
The high-mobility group nucleosome-binding domain 5 is highly expressed in breast cancer and promotes the proliferation and invasion of breast cancer cells.
Tumour Biol. 2015; 36(2):959-66 [PubMed] Related Publications
The high-mobility group nucleosome-binding domain 5 (HMGN5) is a member of the high-mobility group proteins family. Previous study found that HMGN5 is required for tumorigenesis in vitro, and aberrations in the expression of HMGN5 were found in human osteosarcoma, prostate cancer, and squamous cell carcinoma. Nevertheless, the role of HMGN5 in breast cancer remains unclear. This study aimed to investigate the expression and clinical significance of HMGN5 in human breast cancer, confirm the oncogenic role of HMGN5, and explore the mechanism by which HMGN5 contributes to invasion and metastasis. HMGN5 expression was detected in breast cancer tissues and corresponding adjacent non-cancerous tissues from 43 patients by immunohistochemistry, and the clinicopathologic characteristics of all patients were also analyzed. Next, knockdown of HMGN5 protein in MDA-MB-231 cells was performed through a small interfering RNA (siRNA) technique, and cell viability, apoptosis, and invasion were detected by cell vitality test, flow cytometry, and transwell assay, respectively. Immunohistostaining showed that HMGN5 were highly expressed in the nucleus in all breast cancer tissues as compared with the adjacent non-cancerous tissues (ANCT;(73.5 ± 11 vs. 31.0 ± 5 %, P < 0.01). HMGN5 expression level was associated with the poorly differentiated tumor cells, lymph node involvement tumor, and T4 staging tumor. Knockdown of HMGN5 inhibited cell growth, suppressed invasion, and increased cell apoptosis in human breast cancer MDA-MB-231 cells. Western blot analysis demonstrated that the expressions of PCNA, connective tissue growth factor (CTGF), and MMP-9 were decreased in human breast MDA-MB-231 cells depleted of HMGN5. In addition, the apoptotic markers (cleaved PARP and cleaved caspase-3) were significantly increased by HMGN5 knockdown, but microtubule-associated protein 1 light chain 3-II/I (LC3-II/I) did not alter. HMGN5 plays an oncogenic role in human breast cancer by inhibiting cell proliferation and invasion, and activating apoptosis, which could be exploited as a target for therapy in human breast cancer.

Munagala R, Aqil F, Jeyabalan J, Gupta RC
Tanshinone IIA inhibits viral oncogene expression leading to apoptosis and inhibition of cervical cancer.
Cancer Lett. 2015; 356(2 Pt B):536-46 [PubMed] Related Publications
Human papilloma virus (HPV) is the well-established etiological factor of cervical cancer. E6 and E7 oncoproteins expressed by HPV are known to inactivate tumor suppressor proteins p53 and pRb, respectively. Tanshinone IIA (Tan IIA) is a diterpenoid naphthoquinone found in the traditional Chinese medicine Danshen (Salvia sp.). Tan IIA has been shown to possess anti-tumor activity against several cancer types. In this study we show that Tan IIA potently inhibited proliferation of the human cervical cancer CaSki, SiHa, HeLa and C33a cells. Mechanistically in HPV positive CaSki cells, Tan IIA was found to (i) downregulate expression of HPV E6 and E7 genes and modulate associated proteins E6AP and E2F1, (ii) cause S phase cell cycle arrest, (iii) induce accumulation of p53 and alter expression of p53-dependent targets, (iv) modulate pRb and related proteins, and (v) cause p53-mediated apoptosis by moderating Bcl2, Bax, caspase-3, and PARP cleavage expressions. In vivo, Tan IIA resulted in over 66% reduction in tumor volume of cervical cancer xenograft in athymic nude mice. Tan IIA treated tumor tissues had lower expression of proliferation marker PCNA and changes in apoptosis targets were in agreement with in vitro studies, further confirming reduced proliferation and involvement of multiple targets behind anti-cancer effects. This is the first demonstration of Tan IIA to possess significant anti-viral activity by repressing HPV oncogenes leading to inhibition of cervical cancer. Together, our data suggest that Tan IIA can be exploited as a potent therapeutic agent for the prevention and treatment of cervical and other HPV-related cancers.

Huan JL, Gao X, Xing L, et al.
Screening for key genes associated with invasive ductal carcinoma of the breast via microarray data analysis.
Genet Mol Res. 2014; 13(3):7919-25 [PubMed] Related Publications
The aim of this study was to identify key genes related to invasive ductal carcinoma (IDC) of the breast by analyzing gene expression data with bioinformatic tools. Microarray data set GSE31138 was downloaded from Gene Expression Omnibus, including 3 breast cancer tissue samples and 3 normal controls. Differentially expressed genes (DEGs) between breast cancer and normal control were screened out (FDR < 0.05 and |logFC| > 2). Coexpression between genes was examined with String, and a network was then constructed. Relevant pathways and diseases were retrieved with KOBAS. A total of 56 DEGs were obtained in the IDC of the breast compared with normal controls. A gene coexpression network including 27 pairs of genes was constructed and all the genes in the network were upregulated. Further study indicated that most of the genes in the coexpression network were enriched in ECM-receptor interaction (COL4A2, FN1, and HMMR) and nucleotide excision repair (CETN2 and PCNA) pathways, and that the most significantly related disease was autoimmune lymphoproliferative syndromes. A number of DEGs were acquired through comparative analysis of gene expression data. These findings are beneficial in promoting the understanding of the molecular mechanisms in breast cancer. More importantly, some key genes were revealed via gene coexpression network analysis, which could be potential biomarkers for IDC of the breast.

Yang J, Kuang XR, Lv PT, Yan XX
Thymoquinone inhibits proliferation and invasion of human nonsmall-cell lung cancer cells via ERK pathway.
Tumour Biol. 2015; 36(1):259-69 [PubMed] Related Publications
Thymoquinone (TQ) is the primary bioactive component of Nigella sativa Linn seed oil and used as anti-inflammatory, anti-oxidant, and anti-neoplastic agent. Previous studies have shown that TQ exhibits inhibitory effects on multiple cancers. However, the detailed antineoplastic effects and its molecular mechanisms of TQ on lung cancer are not entirely elucidated yet. In the present study, we aimed to investigate the effects of TQ on cell proliferation, migration, and invasion as well as its underlying anti-metastatic mechanisms in A549 cells. Lung cancer cell line A549 cells were treated with different concentration of TQ for different period of time, and the growth-inhibitory effects of TQ was measured by MTT and cell count assays; cell cycle was determined by flow cytometry; wound healing and transwell assays were used to assess the cell migration and invasion activities; Western blot and real-time quantitative RT-PCR were used to determine the expression of proliferation and invasion associated genes as well as MAPKs pathway molecules; gelatinase activity was estimated using gelatin zymography assay. The results show that TQ played a role in inhibiting the proliferation, migration, and invasion of A549 lung cancer cells, it also inhibited the expression level of PCNA, cyclin D1, MMP2, and MMP9 mRNA and protein in a dose- and time-dependent manner especially at 10, 20, 40 μmol/L concentrations. The cell cycle inhibitor P16 expression and the gelatinase activities of MMP2 and MMP9 were also inhibited by TQ dramatically. TQ reduced phosphorylation of ERK1/2; however, the proliferation and invasion inhibitory effects of TQ on A549 cells were neutralized by ERK1/2 inhibitor PD98059. In conclusion, our study confirmed that TQ could inhibit A549 cell proliferation, migration, and invasion through ERK1/2 pathway, as proposed the therapeutic potential of TQ as an anti-metastatic agent in human lung cancer treatment.

Xu C, Chen P, Liu W, et al.
Association between the XRCC1 Arg194Trp polymorphism and glioma risk: an updated meta-analysis.
Asian Pac J Cancer Prev. 2014; 15(17):7419-24 [PubMed] Related Publications
Gliomas are the most common type of primary brain tumors. The XRCC1 Arg194Trp variant affects the proliferating cell nuclear antigen( PCNA) binding region, which suggests that this mutation may contribute to gliomagenesis and a number of articles have examine the association between XRCC1 Arg194Trp and the susceptibility to glioma. However, the results were conflicting. Test of heterogeneity, sensitivity analysis, meta- analysis, and assessment of publication bias were all performed in our present meta-analysis, covering a total of 5,407 patients and 7,715 healthy persons. In the overall analysis the XRCC1 Arg194Trp polymorphism showed a significant association with glioma susceptibility in a recessive mode l(for TrpTrp vs ArgArg+ArgTrp: OR=1.918, 95%CI=1.575-2.336, I2=2.3%). In addition, analysis of subgroups presented an increased risk in Asians and populations-based on hospitals. The results suggested that the XRCC1 Arg194Trp polymorphism is a genetic risk factor for glioma, especially in Asian population. To further evaluate gene-gene and gene-environment interactions on XRCC1 polymorphisms and glioma risk, thousands of subjects and tissue-specific biochemical characterizations are required.

Lu ZJ, Lu LG, Tao KZ, et al.
MicroRNA-185 suppresses growth and invasion of colon cancer cells through inhibition of the hypoxia‑inducible factor-2α pathway in vitro and in vivo.
Mol Med Rep. 2014; 10(5):2401-8 [PubMed] Related Publications
MicroRNAs (miRs) are small non‑coding RNAs with regulatory roles, which are involved in a broad spectrum of physiological and pathological processes, including cancer development and progression. However, the function of miR‑185 in the development of human colon cancer has not yet been investigated. In this study, the association between miR‑185 expression and the clinicopathological characteristics of patients with colon cancer was analyzed using quantitative polymerase chain reaction (qPCR). Using a gain‑of‑function approach, the effects of miR‑185 overexpression on the expression of hypoxia‑inducible factor‑2α (HIF‑2α), proliferating cell nuclear antigen (PCNA) and matrix metallopeptidase‑2 (MMP‑2) were investigated in SW620 colon cancer cells using qPCR and western blotting. Functional analysis of cellular proliferative activities, by MTT assay, and invasive potential, by Transwell assay, was conducted on SW620 cells expressing low levels of miR‑185. miR‑185 was found to be significantly downregulated in cancer tissues compared with adjacent non‑cancerous tissues, and was negatively correlated with lymph node metastasis of colon cancer (P<0.001). miR‑185 overexpression in vitro impeded cellular proliferation and invasive potential with reduced expression of HIF‑2α, PCNA and MMP‑2 in SW620 cells transfected with an miR‑185 mimic. In addition, the tumor volumes in SW620 subcutaneous nude mouse models treated with miR‑185 were significantly smaller than those of the control group. In conclusion, these findings indicate that miR‑185 as a tumor suppressor may affect the development of colon cancer cells via inhibition of HIF‑2α signaling, suggesting that miR‑185 may serve as a potential therapeutic target in cancer treatment.

Shi ZH, Shi FF, Wang YQ, et al.
Mitochondrial ferritin, a new target for inhibiting neuronal tumor cell proliferation.
Cell Mol Life Sci. 2015; 72(5):983-97 [PubMed] Article available free on PMC after 01/05/2016 Related Publications
Mitochondrial ferritin (FtMt) has a significant effect on the regulation of cytosolic and mitochondrial iron levels. However, because of the deficiency of iron regulatory elements (IRE) in FtMt's gene sequence, the exact function of FtMt remains unclear. In the present study, we found that FtMt dramatically inhibited SH-SY5Y cell proliferation and tumor growth in nude mice. Interestingly, excess FtMt did not adversely affect the development of drosophila. Additionally, we found that the expression of FtMt in human normal brain tissue was significantly higher than that of neuroblastoma, but not higher than that of neurospongioma. However, the expression of transferrin receptor 1 is completely opposite. We therefore hypothesized that increased expression of FtMt may negatively affect the vitality of neuronal tumor cells. Therefore, we further investigated the underlying mechanisms of FtMt's inhibitory effects on neuronal tumor cell proliferation. As expected, FtMt overexpression disturbed the iron homeostasis of tumor cells and significantly downregulated the expression of proliferating cell nuclear antigen. Moreover, FtMt affected cell cycle, causing G1/S arrest by modifying the expression of cyclinD1, cyclinE, Cdk2, Cdk4 and p21. Remarkably, FtMt strongly upregulated the expression of the tumor suppressors, p53 and N-myc downstream-regulated gene-1 (NDRG1), but dramatically decreased C-myc, N-myc and p-Rb levels. This study demonstrates for the first time a new role and mechanism for FtMt in the regulation of cell cycle. We thus propose FtMt as a new candidate target for inhibiting neuronal tumor cell proliferation. Appropriate regulation of FtMt expression may prevent tumor cell growth. Our study may provide a new strategy for neuronal cancer therapy.

Chen G, Liang YX, Zhu JG, et al.
CC chemokine ligand 18 correlates with malignant progression of prostate cancer.
Biomed Res Int. 2014; 2014:230183 [PubMed] Article available free on PMC after 01/05/2016 Related Publications
BACKGROUND AND AIM: CC chemokine ligand 18 (CCL18) promotes malignant behaviors of various human cancer types. However, its involvement in human prostate cancer has not been fully elucidated. The aim of this study was to investigate the role of CCL18 in PCa.
METHODS: Expression of CCL18 at mRNA and protein levels was detected using real-time qRT-PCR and immunohistochemistry analysis. We analyzed the associations of CCL18 expression with clinical features of human PCa. The effects of PCa cell migration, invasion, and apoptosis were tested. The efficiency of CCL18 on prostate tumor growth was assessed in a subcutaneous xenograft model.
RESULTS: CCL18 expression was upregulated (both P < 0.01) in PCa tissues compared with those in noncancerous prostate tissues. CCL18 upregulation was correlated with high Gleason score (P = 0.034) of patients with PCa. rCCL18 stimulation in PCa cells promoted cell migration and invasion but decreased DU145 cells apoptosis rate. Furthermore, subcutaneous homografts models showed the increased tumor growth and tumor vascularization with the CCL18 stimulation, and the expression of Ki67, PCNA, and CD31 in CCL18 stimulation mice was also significantly increased.
CONCLUSIONS: Our data offer the convincing evidence that the upregulation of CCL18 may be involved in the malignant progression of PCa.

Lingeman RG, Hickey RJ, Malkas LH
Expression of a novel peptide derived from PCNA damages DNA and reverses cisplatin resistance.
Cancer Chemother Pharmacol. 2014; 74(5):981-93 [PubMed] Related Publications
BACKGROUND: An 8 amino acid peptide sequence derived from proliferating cell nuclear antigen (PCNA) has been shown to effectively kill several breast cancer and neuroblastoma cell lines when added exogenously to cell cultures.
METHODS: In this study, the expression of the 8 amino acid peptide sequence (caPeptide) was placed under control of a tetracycline responsive promoter in MDA-MB-231 cells.
RESULTS: Endogenous expression of the peptide resulted in an increase in genomic DNA damage. CaPeptide induction combined with treatment of sublethal doses of cisplatin resulted in a marked increase in death of the cisplatin-resistant MDA-MB-231 cell line. CaPeptide was found to interact with POLD3, one of the subunits of DNA polymerase delta necessary for binding to PCNA.
CONCLUSION: These results suggest an important line of inquiry into the possible role that caPeptide might play in the reversal of cisplatin resistance in breast and other cancers. This is of particular interest in those cancers where cisplatin is the first line of chemotherapy and where the acquisition of resistance is a common malady.

Yamada T, Okuda Y, Kushida M, et al.
Human hepatocytes support the hypertrophic but not the hyperplastic response to the murine nongenotoxic hepatocarcinogen sodium phenobarbital in an in vivo study using a chimeric mouse with humanized liver.
Toxicol Sci. 2014; 142(1):137-57 [PubMed] Related Publications
High doses of sodium phenobarbital (NaPB), a constitutive androstane receptor (CAR) activator, have been shown to produce hepatocellular tumors in rodents by a mitogenic mode of action (MOA) involving CAR activation. The effect of 1-week dietary treatment with NaPB on liver weight and histopathology, hepatic CYP2B enzyme activity and CYP2B/3A mRNA expression, replicative DNA synthesis and selected genes related to cell proliferation, and functional transcriptomic and metabolomic analyses was studied in male CD-1 mice, Wistar Hannover (WH) rats, and chimeric mice with human hepatocytes. The treatment of chimeric mice with 1000-1500-ppm NaPB resulted in plasma levels around 3-5-fold higher than those observed in human subjects given therapeutic doses of NaPB. NaPB produced dose-dependent increases in hepatic CYP2B activity and CYP2B/3A mRNA levels in all animal models. Integrated functional metabolomic and transcriptomic analyses demonstrated that the responses to NaPB in the human liver were clearly different from those in rodents. Although NaPB produced a dose-dependent increase in hepatocyte replicative DNA synthesis in CD-1 mice and WH rats, no increase in replicative DNA synthesis was observed in human hepatocyte-originated areas of chimeric mice. In addition, treatment with NaPB had no effect on Ki-67, PCNA, GADD45β, and MDM2 mRNA expression in chimeric mice, whereas significant increases were observed in CD-1 mice and/or WH rats. However, increases in hepatocyte replicative DNA synthesis were observed in chimeric mice both in vivo and in vitro after treatment epidermal growth factor. Thus, although NaPB could activate CAR in both rodent and human hepatocytes, NaPB did not increase replicative DNA synthesis in human hepatocytes of chimeric mice, whereas it was mitogenic to rat and mouse hepatocytes. As human hepatocytes are refractory to the mitogenic effects of NaPB, the MOA for NaPB-induced rodent liver tumor formation is thus not relevant for humans.

Han R, Liang H, Qin ZH, Liu CY
Crotoxin induces apoptosis and autophagy in human lung carcinoma cells in vitro via activation of the p38MAPK signaling pathway.
Acta Pharmacol Sin. 2014; 35(10):1323-32 [PubMed] Article available free on PMC after 01/05/2016 Related Publications
AIM: Crotoxin (CrTX) is the primary toxin in South American rattlesnake (Crotalus durissus terrificus) venom, and exhibits antitumor and other pharmacological actions in vivo and in vitro. Here, we investigated the molecular mechanisms of the antitumor action of CrTX in human lung carcinoma cells in vitro.
METHODS: Human lung squamous carcinoma SK-MES-1 cells were tested. The cytotoxicity of CrTX was evaluated in both MTT and colony formation assays. Cell cycle was investigated with flow cytometry. Cell apoptosis was studied with Hoechst 33258 and Annexin V-FITC staining. The levels of relevant proteins were analyzed using Western blot assays.
RESULTS: CrTX (25, 50, 100 μmol/L) inhibited the growth and colony formation of SK-MES-1 cells in dose- and time-dependent manners. CrTX increased the proportion of S phase cells and dose-dependently induced cell apoptosis, accompanied by down-regulating the expression of proliferating cell nuclear antigen (PCNA), and increasing the level of cleaved caspase-3. Furthermore, CrTX dose-dependently increased the expression of autophagy-related proteins LC3-II and beclin 1, and decreased the level of p62 in the cells. Moreover, CrTX (50 μmol/L) significantly increased p38MAPK phosphorylation in the cells. Pretreatment of the cells with SB203580, a specific inhibitor of p38MAPK, blocked the inhibition of CrTX on cell proliferation, as well as CrTX-induced apoptosis and cleaved caspase-3 expression.
CONCLUSION: The p38MAPK signaling pathway mediates CrTX-induced apoptosis and autophagy of human lung carcinoma SK-MES-1 cells in vitro.

Chen B, Zhao AG, Shao J, et al.
The effects of PTBP3 silencing on the proliferation and differentiation of MKN45 human gastric cancer cells.
Life Sci. 2014; 114(1):29-35 [PubMed] Related Publications
AIMS: PTBP3 overexpression inhibits the differentiation of leukemia cells; however, its effects on the differentiation and proliferation of solid cancer cells remain unclear. Thus, the impact of PTBP3 on the differentiation and proliferation of gastric cancer cells was investigated.
MAIN METHODS: PTBP3 expression was analyzed in normal and tumor tissues using immunohistochemistry. A xenograft model was established in nude mice by subcutaneous injection of untransfected human gastric cancer MKN45 cells or those expressing a control vector or PTBP3 siRNA. We analyzed the tumor inhibition rate, the expression of PTBP3, the PCNA-positive rate and the serum levels of CEA, CA199, CA125, LDH, ALP and γ-GT in different groups.
KEY FINDINGS: The tumor weights in the PTBP3 siRNA group were significantly lower than that of the MKN45 cell control group (P<0.001). Immunohistochemistry analysis of PCNA expression revealed that it was markedly reduced after PTBP3 silencing. ELISAs showed that the serum levels of CEA and CA199 tumor markers as well as LDH and ALP were reduced after PTBP3 silencing. Transmission electron microscopy revealed that MKN45 cells expressing PTBP3 siRNA had reduced nuclear-to-cytoplasmic ratio and regular nuclei, suggesting differentiation.
SIGNIFICANCE: PTBP3 may promote proliferation and inhibit the differentiation of human gastric cancer MKN45 cells.

Bi WW, Zhang WH, Yin GH, et al.
Analysis of indoleamine 2-3 dioxygenase (IDO) and EGFR co-expression in breast cancer tissue by immunohistochemistry.
Asian Pac J Cancer Prev. 2014; 15(14):5535-8 [PubMed] Related Publications
BACKGROUND: To determine the amount of co-expression of IDO and EGFR in breast cancer patients.
MATERIALS AND METHODS: In order to obtain the distribution of co-expression of IDO and EGFR in breast cancer, we tested 110 breast cancer paraffin tissue blocks with immunohistochemical methods. Then we investigated the relationship between the diagnostic and pathologic characteristics (tumor size, lymph node status, histologic grade, the gene expression of ER, PR, HER2, p53, Ki67 and PCNA) with the situation of co-expression of IDO and EGFR by reviewing the medical records of 32 breast cancer patients.
RESULTS: Among 110 breast cancers, 32 cases demonstrated IDO and EGFR co-expression (29.1%), IDO and EGFR synchronous co-expression being found in 19.1% and asynchronous in 10.0%.
CONCLUSIONS: IDO and EGFR were co-expressed in breast cancer, including synchronous and asynchronous co-expression. The results suggest that considering IDO and EGFR as two indicators for breast cancer treatment or prognosis analysis provides a potential option of individual treatment for the portion of breast cancer patients with co-expression of IDO and EGFR.

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Cite this page: Cotterill SJ. PCNA: Proliferating cell nuclear antigen, Cancer Genetics Web: http://www.cancer-genetics.org/PCNA.htm Accessed:

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