Gastric cancer (GC) is the second most frequent cause of cancer-related mortality in the world, with Eastern Asia having the highest incidence rates. E2F is a family of transcription factor proteins that has a variety of functions, which include control of cell cycle, cell differentiation, DNA damage response and cell death. E2F transcription factors are divided into two subfamilies: transcription activators (E2F transcription factors 1 (E2F1), 2 (E2F2) and 3a (E2F3a)) and repressors (E2F3b, E2F transcription factors 4 (E2F4), 5 (E2F5), 6 (E2F6), 7 (E2F7) and 8 (E2F8)). Studies have demonstrated that E2F had prognostic significance in a number of cancers. However, the entirety of the prognostic roles of

Apoptosis is a form of directed programmed cell death with a tightly regulated signalling cascade for the destruction of single cells. MicroRNAs (miRNAs) play an important role as fine tuners in the regulation of apoptotic processes. MiR-493-3p mimic transfection leads to the induction of apoptosis causing the breakdown of mitochondrial membrane potential and the activation of Caspases resulting in the fragmentation of DNA in several ovarian carcinoma cell lines. Ovarian cancer shows with its pronounced heterogeneity a very high death-to-incidence ratio. A target gene analysis for miR-493-3p was performed for the investigation of underlying molecular mechanisms involved in apoptosis signalling pathways. Elevated miR-493-3p levels downregulated the mRNA and protein expression levels of Serine/Threonine Kinase 38 Like (STK38L), High Mobility Group AT-Hook 2 (HMGA2) and AKT Serine/Threonine Kinase 2 (AKT2) by direct binding as demonstrated by luciferase reporter assays. Notably, the protein expression of RAF1 Proto-Oncogene, Serine/Threonine Kinase (RAF1) was almost completely downregulated by miR-493-3p. This interaction, however, was indirect and regulated by STK38L phosphorylation. In addition, RAF1 transcription was diminished as a result of reduced transcription of ETS proto-oncogene 1 (ETS1), another direct target of miR-493-3p. Taken together, our observations have uncovered the apoptosis inducing potential of miR-493-3p through its regulation of multiple target genes participating in the extrinsic and intrinsic apoptosis pathway.

BACKGROUND: Previous studies report that miR-1-3p, a member of the microRNA-1 family (miR-1), and functions as a tumor suppressor in several different cancers. However, little is known regarding the biological role and intrinsic regulatory mechanisms of miR-1-3p in prostate cancer (PCa).
METHODS: In this study, the expression levels of miR-1-3p were first examined in PCa cell lines and tumor tissues by RT-qPCR and bioinformatics. The in vitro and in vivo functional effect of miR-1-3p was examined further. A luciferase reporter assay was conducted to confirm target associations.
RESULTS: We found that miR-1-3p was significantly downregulated in advanced PCa tissues and cell lines. Low miR-1-3p levels were strongly associated with aggressive clinicopathological features and poor prognosis in PCa patients. Ectopic expression of miR-1-3p in 22RV1 and LncaP cells was sufficient to prevent tumor cell growth and cell cycle progression in vitro and in vivo. Further mechanistic studies revealed that miR-1-3p could directly target the mRNA 3'- untranslated region (3'- UTR) of two central cell cycle genes, E2F5 and PFTK1, and could suppress their mRNA and protein expression. In addition, knockdown of E2F5 and PFTK1 mimicked the tumor-suppressive effects of miR-1-3p overexpression on PCa progression. Conversely, concomitant knockdown of miR-1-3p and E2F5 and PFTK1 substantially reversed the inhibitory effects of either E2F5 or PFTK1 silencing alone.
CONCLUSION: These data highlight an important role for miR-1-3p in the regulation of proliferation and cell cycle in the molecular etiology of PCa and indicate the potential for miR-1-3p in applications furthering PCa prognostics and therapeutics.

BACKGROUND: The TGFβ-signaling pathway plays an important role in the pathogenesis of colorectal cancer (CRC). Loss of function of several genes within this pathway, such as bone morphogenetic proteins (BMPs) have been seen as key events in CRC progression.
METHODS: In this study we comprehensively evaluate differential gene expression (RNASeq) of 81 genes in the TGFβ-signaling pathway and evaluate how dysregulated genes are associated with miRNA expression (Agilent Human miRNA Microarray V19.0). We utilize paired carcinoma and normal tissue from 217 CRC cases. We evaluate the associations between differentially expressed genes and miRNAs and sex, age, disease stage, and survival months.
RESULTS: Thirteen genes were significantly downregulated and 14 were significantly upregulated after considering fold change (FC) of > 1.50 or < 0.67 and multiple comparison adjustment. Bone morphogenetic protein genes BMP5, BMP6, and BMP2 and growth differentiation factor GDF7 were downregulated. BMP4, BMP7, INHBA (Inhibin beta A), TGFBR1, TGFB2, TGIF1, TGIF2, and TFDP1 were upregulated. In general, genes with the greatest dysregulation, such as BMP5 (FC 0.17, BMP6 (FC 0.25), BMP2 (FC 0.32), CDKN2B (FC 0.32), MYC (FC 3.70), BMP7 (FC 4.17), and INHBA (FC 9.34) showed dysregulation in the majority of the population (84.3, 77.4, 81.1, 80.2, 82.0, 51.2, and 75.1% respectively). Four genes, TGFBR2, ID4, ID1, and PITX2, were un-associated or slightly upregulated in microsatellite-stable (MSS) tumors while downregulated in microsatellite-unstable (MSI) tumors. Eight dysregulated genes were associated with miRNA differential expression. E2F5 and THBS1 were associated with one or two miRNAs; RBL1, TGFBR1, TGIF2, and INHBA were associated with seven or more miRNAs with multiple seed-region matches. Evaluation of the joint effects of mRNA:miRNA identified interactions that were stronger in more advanced disease stages and varied by survival months.
CONCLUSION: These data support an interaction between miRNAs and genes in the TGFβ-signaling pathway in association with CRC risk. These interactions are associated with unique clinical characteristics that may provide targets for further investigations.

Pancreatic cancer is one of deadly cancers and is responsible for significant mortality and morbidity across the globe. The unavailability of the efficient chemotheruptic drugs and the potent thereuprtic targets forms a bottleneck in the treatment of pancreatic cancer. In this study we explored the potential of MicroRNA-1179 as the therapeutic target for the treatment of pancreatic cancer. The results of this study indicated that the expression of miR-1179 was significantly downregulated in the pancreatic cancer cell lines as compared to the normal pancreatic cells. To unveil the potential role of miR-1179, it was overexpressed in the pancreatic cancer cells. It was observed that ectopic expression of miR-1179 caused reduction in the proliferation of pancreatic cancer cells by triggering G

Previous literature exists on the role of microRNA (miR)-132 in initiation and progression of various malignancies. In this study, we aimed at understanding the relationship of miR-132 of prostate tumorigenesis. We collected 32 prostate cancer tissues and adjacent non-cancerous controls, and detected the expression level of miR-132. Then the miRNA database was searched online and luciferase assay perform to understand the regulatory relationship between miR-132 and E2F5. Moreover, we also conducted real-time PCR and western blot analysis to study the mRNA and protein expression level of E2F5 among different groups (cancerous tissue, n=32; non-cancerous tissue, n=32) or cells treated with scramble control, miR-132 mimics, E2F5 siRNA and miR-132 inhibitors. miR-132 was upregulated in cancerous tissues of prostate cancer patients. E2F5 was the target of miR-132, and negative regulatory relationship between miR-132 and E2F5 was also confirmed by luciferase assay. The mRNA and protein expression level of E2F5 increased in cancerous tissue group. miR-132 decreased the expression of E2F5 in prostate cancer cells, and introduction of miR-132 reduced the viability and E2F5 and promoted the viability of prostate cancer cells. miR-132 inhibited apoptosis and E2F5 accelerated apoptosis. In conclusion, miR-132 was upregulated in cancerous tissue of prostate cancer. E2F5 was a direct target of miR-132, and downregulation of E2F5 caused by upregulation of miR-132 may contribute to the tumorigenesis of prostate cancer.

As a member of the miRNA family, let-7c has been identified as a tumor suppressor in many cancers. However, the molecular biological function of let-7c in glioma has not been elucidated. The aim of this study was to explore let-7c expression levels and evaluate its function in glioma cells. We first measured the expression of let-7c in four glioma cell lines and a normal cell line by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), and the results showed that let-7c was downregulated in glioma cells. By applying gain-of-function and loss-of-function assays, the experiments suggested that dysregulation of let-7c could obviously affect cell proliferation, metastasis, and invasion. Based on online bioinformatics analysis and Dual-Luciferase Reporter assays, we found that E2F5 was a target gene of let-7c and contributed to the function of let-7c in glioma cells. Our investigations indicated that loss of let-7c contributed to the progression of glioma cells.

To ensure that the genetic material is accurately passed down to daughter cells during mitosis, dividing cells must duplicate their chromosomes and centrosomes once and only once per cell cycle. The same key steps-licensing, duplication, and segregation-control both the chromosome and the centrosome cycle, which must occur in concert to safeguard genome integrity. Aberrations in genome content or centrosome numbers lead to genomic instability and are linked to tumorigenesis. Such aberrations, however, can also be part of the normal life cycle of specific cell types. Multiciliated cells best exemplify the deviation from a normal centrosome cycle. They are post-mitotic cells which massively amplify their centrioles, bypassing the rule for once-per-cell-cycle centriole duplication. Hundreds of centrioles dock to the apical cell surface and generate motile cilia, whose concerted movement ensures fluid flow across epithelia. The early steps that control the generation of multiciliated cells have lately started to be elucidated. Geminin and the vertebrate-specific GemC1 and McIdas are distantly related coiled-coil proteins, initially identified as cell cycle regulators associated with the chromosome cycle. Geminin is required to ensure once-per-cell-cycle genome replication, while McIdas and GemC1 bind to Geminin and are implicated in DNA replication control. Recent findings highlight Geminin family members as early regulators of multiciliogenesis. GemC1 and McIdas specify the multiciliate cell fate by forming complexes with the E2F4/5 transcription factors to switch on a gene expression program leading to centriole amplification and cilia formation. Positive and negative interactions among Geminin family members may link cell cycle control to centriole amplification and multiciliogenesis, acting close to the point of transition from proliferation to differentiation. We review key steps of centrosome duplication and amplification, present the role of Geminin family members in the centrosome and chromosome cycle, and discuss links with disease.

Retinoblastoma is a common intraocular malignancy that occurs during childhood. MicroRNAs play critical roles in the regulation of retinoblastoma initiation and progression, and aberrant expression of miR-613 had been reported in various types of cancer. However, the role and mechanism of its function in retinoblastoma are still unclear. In this study, we found that miR-613 was downregulated in retinoblastoma tissues and cell lines. Overexpression of miR-613 suppressed retinoblastoma cell proliferation, migration, and invasion and induced cell cycle arrest in vitro. Additionally, overexpressed miR-613 also inhibited tumor formation of retinoblastoma cells in vivo. We further identified E2F5 as a direct target of miR-613. Reintroduction of E2F5 without 3'-untranslated region reversed the inhibitory effects of miR-613 on cell proliferation and invasion. Our data collectively indicate that miR-613 functions as a tumor suppressor in retinoblastoma through downregulating E2F5, supporting the targeting of the novel miR-613/E2F5 axis as a potentially effective therapeutic approach for retinoblastoma.

Long noncoding RNAs (lncRNAs) have been proved to play important roles in cellular processes of cancer, including the development, proliferation, and migration of cancer cells. In the present study, we demonstrated small nucleolar RNA host gene 16 (SNHG16) as an oncogene on cell migration in breast cancer. Expression levels of SNHG16 were found to be frequently higher in breast cancer tissues than in the paired noncancerous tissues. Gain- and loss-of-function studies proved that SNHG16 significantly promoted breast cancer cell migration. We predicted SNHG16 as a competitive endogenous RNA (ceRNA) of E2F transcription factor 5 protein (E2F5) via competition for the shared miR-98 through bioinformatics analysis, and proved this regulation using relative quantitative real-time PCR (qRT-PCR), western blot, RNA immunoprecipitation (RIP) assay and luciferase reporter assay. In addition, we identified a positive correlation between SNHG16 and E2F5 in breast cancer tissues. Furthermore, we demonstrated that forced expression of miR-98 could partially abrogate SNHG16-mediated increase of breast cancer cells migration, suggesting that SNHG16 promoted cell migration in a miR-98 dependent manner. Taken together, our findings indicated that SNHG16 induces breast cancer cell migration by competitively binding miR-98 with E2F5, and SNHG16 can serve as a potential therapeutic target for breast cancer treatment.

Epithelial ovarian cancer (EOC) generates multicellular aggregates called spheroids that detach from the primary tumor and disseminate through ascites. Spheroids possess a number of characteristics of tumor dormancy including withdrawal from the cell cycle and resistance to chemotherapeutics. This report systematically analyzes the effects of RNAi depletion of 21 genes that are known to contribute to negative regulation of the cell cycle in 10 ovarian cancer cell lines. Interestingly, spheroid cell viability was compromised by loss of some cyclin-dependent kinase inhibitors such as p57

Type 1 iodothyronine deiodinase (DIO1) regulates peripheral metabolism of thyroid hormones that control cellular proliferation, differentiation and metabolism. The significance of DIO1 in cancer is unknown. In this study we hypothesized that diminished expression of DIO1, observed in renal cancer, contributes to the carcinogenic process in the kidney. Here, we demonstrate that ectopic expression of DIO1 in renal cancer cells changes the expression of genes controlling cell cycle, including cyclin E1 and E2F5, and results in inhibition of proliferation. The expression of genes encoding collagens (COL1A1, COL4A2, COL5A1), integrins (ITGA4, ITGA5, ITGB3) and transforming growth factor-β-induced (TGFBI) is significantly altered in renal cancer cells with induced expression of DIO1. Finally, we show that overexpression of DIO1 inhibits migration of renal cancer cells. In conclusion, we demonstrate for the first time that loss of DIO1 contributes to renal carcinogenesis and that its induced expression protects cells against cancerous proliferation and migration.

Clinicians routinely prescribe adjuvant chemotherapy (ACT) for resected non-small cell lung cancer patients. However, ACT only improves five-year disease-free survival in stage I-III non-small cell lung cancer by 5-15%, with most patients deriving no benefit. Herein, deregulation of the E2F pathway was explored as a biomarker in lung adenocarcinoma patients. An E2F pathway scoring system, based on 74 E2F-regulated genes, was trained for RNA from two platforms: fresh-frozen (FF) or formalin-fixed paraffin-embedded (FFPE) tissues. The E2F score was tested as a prognostic biomarker in five FF-based cohorts and two FFPE-based cohorts. The E2F score was tested as a predictive biomarker in two randomized clinical trials; JBR10 and the NATCH (Neo-Adjuvant Taxol-Carboplatin Hope) trial. The E2F score was prognostic in untreated patients in all seven datasets examined (p < 0.05). Stage-specific analysis of combined cohorts demonstrated that the E2F score was prognostic in stage I patients (p = 0.0495 to <0.001; hazard ratio, HR, =2.04- 2.22) with a similar trend in other stages. The E2F score was strongly predictive in stage II patients from the two combined randomized clinical trials with a significant differential treatment effect (p = 0.015). Specifically, ACT improved survival in stage II patients with high E2F (p = 0.01; HR= 0.21). The 5-year survival increased from 18% to 81%. In contrast, in patients with low E2F, 5-year survival was 57% in untreated patients and 41% in ACT-treated patients with a HR of 1.55 (p = 0.47). In summary, the E2F score provides valuable prognostic information for Stage I and predictive information for Stage II lung adenocarcinoma patients and should be further explored as a decision support tool for their treatment.

Metastatic dissemination is the most frequent cause of death of sporadic colorectal cancer (sCRC) patients. Genomic abnormalities which are potentially characteristic of such advanced stages of the disease are complex and so far, they have been poorly described and only partially understood. We evaluated the molecular heterogeneity of sCRC tumors based on simultaneous assessment of the overall GEP of both coding mRNA and non-coding RNA genes in primary sCRC tumor samples from 23 consecutive patients and their paired liver metastases. Liver metastases from the sCRC patients analyzed, systematically showed deregulated transcripts of those genes identified as also deregulated in their paired primary colorectal carcinomas. However, some transcripts were found to be specifically deregulated in liver metastases (vs. non-tumoral colorectal tissues) while expressed at normal levels in their primary tumors, reflecting either an increased genomic instability of metastatic cells or theiradaption to the liver microenvironment. Newly deregulated metastatic transcripts included overexpression of APOA1, HRG, UGT2B4, RBP4 and ADH4 mRNAS and the miR-3180-3p, miR-3197, miR-3178, miR-4793 and miR-4440 miRNAs, together with decreased expression of the IGKV1-39, IGKC, IGKV1-27, FABP4 and MYLK mRNAS and the miR-363, miR-1, miR-143, miR-27b and miR-28-5p miRNAs. Canonical pathways found to be specifically deregulated in liver metastatic samples included multiple genes related with intercellular adhesion and the metastatic processes (e.g., IGF1R, PIK3CA, PTEN and EGFR), endocytosis (e.g., the PDGFRA, SMAD2, ERBB3, PML and FGFR2), and the cell cycle (e.g., SMAD2, CCND2, E2F5 and MYC). Our results also highlighted the activation of genes associated with the TGFβ signaling pathway, -e.g. RHOA, SMAD2, SMAD4, SMAD5, SMAD6, BMPR1A, SMAD7 and MYC-, which thereby emerge as candidate genes to play an important role in CRC tumor metastasis.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide, and the mechanisms underlying the development of HCC remain to be elucidated. Forkhead box N3 (FOXN3) is an important member of the FOX family of transcription factors that plays an essential role in several cancers but has not been investigated in HCC. In this study, we demonstrate that FOXN3 is downregulated in human primary HCC tissues compared with their matched adjacent liver tissues. Functional tests of FOXN3 demonstrated that FOXN3 inhibits the proliferation of HCC cells in vitro and in vivo. Additionally, FOXN3 repressed the mRNA and protein expression of E2F5, a reported potential oncogene, by inhibiting the promoter activity of E2F5. Collectively, our findings indicate that FOXN3 functions as a tumor suppressor in HCC by downregulating the expression of E2F5.

BACKGROUND: MicroRNAs (miRNAs) are a class of small non-coding RNAs (18-25 nucleotides) which post-transcriptionally regulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs. This study aimed to determine the function of miR-154-5p in prostate cancer (PCa) cells and identify the novel molecular targets regulated by miR-154-5p.
MATERIALS AND METHODS: The effects of forced miR-154-5p expression or E2F transcription factor 5 (E2F5) knockdown on PCa cells were evaluated by cell proliferation, flow cytometry, cell migration and invasion assays as well as by Western blot analysis. Dual-luciferase reporter assay was performed to verify the precise target of miR-154-5p.
RESULTS: The forced expression of miR-154-5p or E2F5 knockdown significantly restrained cell growth, as well as the migratory and invasive capabilities. Such expression also induced G1 cell cycle arrest of PCa cells in vitro. Hence, E2F5 is a direct target gene of miR-154-5p.
CONCLUSIONS: miR-154-5p may play an important role as an inhibitor of proliferation, migration and invasion of PCa by targeting E2F5 in PCa cell lines.

Circular RNAs (circRNAs), a large class of RNAs, have recently shown huge capabilities as gene regulators in mammals. Some of them bind with microRNAs (miRNAs) and act as natural miRNA sponges to inhibit related miRNAs' activities. Here we showed that hsa_circ_001569 acted as a positive regulator in cell proliferation and invasion of colorectal cancer (CRC). Moreover, hsa_circ_001569 was identified as a sponge of miR-145 and up-regulated miR-145 functional targets E2F5, BAG4 and FMNL2. In CRC tissues, circ_001569 negatively correlated with miR-145, and miR-145 correlated negatively with E2F5, BAG4 and FMNL2 expressions. Our study reveals a novel regulatory mechanism of circ_001569 in cell proliferation and invasion in CRC, provides a comprehensive landscape of circ_001569 that will facilitate further biomarker discoveries in the progression of CRC.

Transforming growth factor-β signaling exerts divergent effects on normal and cancer cells, although mechanism underlying this differential behavior remains unclear. In this study, expression of 94 genes pertaining to the TGF-β signaling pathway was compared between tumor and benign tissue samples from the human prostate gland to identify major discriminators driving prostate carcinogenesis. E2F5 was identified as one of the most deregulated genes in prostate cancer tissues, predominantly in samples with Gleason-score 6. Expression of other deregulated components of TGF-β signaling was examined by qRT-PCR, Western blot, and immune-staining. Function of E2F5 and p38 in prostate cancer was investigated using siRNA-treatment of PC3 cell-line followed by analyses of associated components and cell cycle. Observations revealed that E2F5 overexpression was accompanied by significantly higher phosphorylation of SMAD3 at Ser-208 in the linker region (pSMAD3L) and p38 in tumor tissue. A striking difference in SMAD3 phosphorylation, marked by preponderance of pSMAD3L and pSMAD3C (Ser-423 and 425) in tumor and benign tissues, respectively was noted. Co-localization of E2F5 with pSMAD3L in the nuclei of tumor and PC3 cells indicated a functional interface between the proteins. Downregulation of E2F5 and p38 in PC3 cells resulted in marked reduction of phosphorylation of SMAD3 and perturbation of cell cycle with an arrest of cells in G1 . Our findings unearthed that E2F5/p38 axis played a cardinal role in uncontrolled cellular proliferation in prostate cancer through pSMAD3L activation. It also underscores a strong potential for E2F5 to be incorporated as a tool in early detection of prostate cancer. J. Cell. Physiol. 231: 2482-2492, 2016. © 2016 Wiley Periodicals, Inc.

Colorectal cancer (CRC) is one of the most common malignancies. Increasing evidences indicate that dysregulation of miRNAs is a frequent event in CRC and contributes to the pathogenesis of CRC. In this study, we found that over-expression of miR-34a inhibited cell proliferation and invasion, induced a cell cycle arrest and triggered apoptosis, while knockdown of miR-34a showed the opposite effects. Moreover, ectopic miR-34a suppressed tumor growth and metastasis of CRC cells in vivo. FMNL2 and E2F5 were identified as direct targets of miR-34a. Reintroduction of FMNL2 or E2F5 without 3'UTR region reversed the inhibitory effects of miR-34a on cell proliferation and invasion. MiR-34a was down-regulated in CRC cells and inversely correlated with FMNL2 and E2F5 expressions. Our study suggests that miR-34a is an important tumor suppressor of CRC progression by targeting FMNL2 and E2F5, thus providing new insight into the molecular mechanisms underlying CRC progression and establishing a strong potential for the application of miR-34a as a novel therapeutic marker against CRC.

pRb2/p130 is a key tumor suppressor, whose oncosuppressive activity has mainly been attributed to its ability to negatively regulate cell cycle by interacting with the E2F4 and E2F5 transcription factors. Indeed, pRb2/p130 has been found altered in various cancer types in which it functions as a valuable prognostic marker. Here, we analyzed pRb2/p130 expression in gastric cancer tissue samples of diffuse histotype, in comparison with their normal counterparts. We found a cytoplasmic localization of pRb2/p130 in cancer tissue samples, whereas, in normal counterparts, we observed the expected nuclear localization. pRb2/p130 cytoplasmic delocalization can lead to cell cycle deregulation, but considering the emerging involvement of pRb2/p130 in other key cellular processes, it could contribute to gastric tumorigenesis also through other mechanisms. Our data support the necessity of further investigations to verify the possibility of using pRb2/p130 as a biomarker or potential therapeutic target for diffuse gastric cancer.

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.

AIM: To investigate the role of Na(+)/K(+)/2Cl(-) cotransporter 1 (NKCC1) in the regulation of genes involved in cell cycle progression and the clinicopathological significance of its expression in esophageal squamous cell carcinoma (ESCC).
METHODS: An immunohistochemical analysis was performed on 68 primary tumor samples obtained from ESCC patients that underwent esophagectomy. NKCC1 expression in human ESCC cell lines was analyzed by Western blotting. Knockdown experiments were conducted using NKCC1 small interfering RNA, and the effects on cell cycle progression were analyzed. The gene expression profiles of cells were analyzed by microarray analysis.
RESULTS: Immunohistochemical staining showed that NKCC1 was primarily found in the cytoplasm of carcinoma cells and that its expression was related to the histological degree of differentiation of SCC. NKCC1 was highly expressed in KYSE170 cells. Depletion of NKCC1 in these cells inhibited cell proliferation via G2/M phase arrest. Microarray analysis identified 2527 genes with altered expression levels in NKCC1depleted KYSE170. Pathway analysis showed that the top-ranked canonical pathway was the G2/M DNA damage checkpoint regulation pathway, which involves MAD2L1, DTL, BLM, CDC20, BRCA1, and E2F5.
CONCLUSION: These results suggest that the expression of NKCC1 in ESCC may affect the G2/M checkpoint and may be related to the degree of histological differentiation of SCCs. We have provided a deeper understanding of the role of NKCC1 as a mediator and/or a biomarker in ESCC.

Luteolin, a flavonoid extracted from a number of plants with recognized anticancer, anti-inflammatory and anti-oxidative activities, inhibits angiogenic processes and modulates multidrug resistance. However, the efficacy and mechanisms of action of this flavonoid agent are still undergoing study. In order to elucidate whether luteolin exhibits an anticancer effect in cervical cancer cells, HeLa cells were incubated with luteolin and apoptosis was assessed by observing nuclear morphological changes, and performing Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining. Cell cycle analysis, western blotting, RT-PCR and mitochondrial membrane potential measurements were also carried out. Luteolin showed a significant dose-dependent cytotoxic effect only in human papillomavirus (HPV)-positive cervical cancer cells, when compared to its effect on HPV-negative cervical cancer C33A cells. Expression levels of human papilloma virus E6 and E7 oncogenes were suppressed, those of related factors pRb and p53 were recovered and E2F5 was increased by luteolin treatment. Furthermore, luteolin enhanced the expression of death receptors and death receptor downstream factors such as Fas/FasL, DR5/TRAIL and FADD in HeLa cells, and activated caspase cascades. In particular, luteolin enhanced the activity of caspase-3 and -8 in a dose-dependent manner. Activation of caspase-3 induced caspase-8 activity and vice versa. Luteolin also induced mitochondrial membrane potential collapse and cytochrome c release, and inhibited Bcl-2 and Bcl-xL expression. In conclusion, luteolin exerts anticarcinogenic activity through inhibition of E6 and E7 expression and cross-activation of caspase-3 and -8. Taken together, these results suggest that luteolin induces inactivation of HPV-18 oncogene expression and apoptosis by activating the intrinsic and extrinsic pathways.

Most p53 mutations in human cancers are missense mutations resulting in a full-length mutant p53 protein. Besides losing tumor suppressor activity, some hotspot p53 mutants gain oncogenic functions. This effect is mediated in part, through gene expression changes due to inhibition of p63 and p73 by mutant p53 at their target gene promoters. Here, we report that the tumor suppressor microRNA let-7i is downregulated by mutant p53 in multiple cell lines expressing endogenous mutant p53. In breast cancer patients, significantly decreased let-7i levels were associated with missense mutations in p53. Chromatin immunoprecipitation and promoter luciferase assays established let-7i as a transcriptional target of mutant p53 through p63. Introduction of let-7i to mutant p53 cells significantly inhibited migration, invasion and metastasis by repressing a network of oncogenes including E2F5, LIN28B, MYC and NRAS. Our findings demonstrate that repression of let-7i expression by mutant p53 has a key role in enhancing migration, invasion and metastasis.

BACKGROUND: Accumulating evidence showed that microRNAs are involved in development and progression of multiple tumors. Recent studies have found that miR-181a were dysregulated in several types of cancers, however, the function of miR-181a in hepatocellular carcinoma (HCC) remains unclear. In this study we assessed the potential association between miR-181a, HBV and HCC.
METHODS: The expression of miR-181a in HBV-expressing cells was determined by using qRT-PCR. Dual-Luciferase reporter Assay, qRT-PCR and western blot were performed to investigate the target genes of miR-181a. The effects of miR-181a on HCC proliferation were analyzed by MTS and colony formation assay. Tumor growth assay was used to analyze the effect of miR-181a on tumor formation.
RESULTS: HBV up-regulated miR-181a expression by enhancing its promoter activity. Overexpression of miR-181a in hepatoma cells promoted cell growth in vitro and tumor formation in vivo. Conversely, inhibition of miR-181a suppressed the proliferation of HBV-expressing cells. Mechanism investigation revealed that miR-181a inhibited the expression of transcription factor E2F5 by specifically targeting its mRNA 3'UTR. Moreover, E2F5 inhibition induced cell growth and rescued the suppressive effect of miR-181a inhibitor on the proliferation of SMMC-7721 cells. Interestingly, we also discovered that HBV could down-regulate E2F5 expression.
CONCLUSIONS: Those results strongly suggested that HBV down-regulated E2F5 expression, in part, by up-regulating the expression of miR-181a. Up-regulation of miR-181a by HBV in hepatoma cells may contribute to the progression of HCC possibly by targeting E2F5, suggesting miR-181a plays important role in HCC development.

In mammalian cells, E2F family of transcription factors (E2Fs) traditionally modulates assorted cellular functions related to cell cycle progression, proliferation, apoptosis and differentiation. Eight members, E2F1 E2F8 have been recognized of this family so far, and the members of this family are generally divided into activator E2F (E2F1--E2F3a), repressor E2F (E2F3b--E2F5) and inhibitor E2F (E2F6--E2F8) subclasses based on their structur-e and function. Studies have showed that the mammalian E2F family members represent a recent evolutionary adaptation to malignancies besides hepatocellular carcinoma (HCC), and a growing body of evidence has validated that the individual members of the family develop a close relationship with HCC. E2F1 was identified to play overlapping roles in HCC, while E2F2--E2F8 (except E2F6 and E2F7) showed to be tumor-promoter in HCC. However, the mechanism underlying the mammalian E2Fs associated with HCC is still unknown and needs further research. The aim of this review is to sum up the collective knowledge of E2F family and the roles of each member of this family in HCC. Moreover, we will discuss some novel therapeutic target for HCC based on the complicated functions of mammalian E2Fs.

OBJECTIVE: To investigate the effects of miR-106b on malignant characteristics of gastric cancer cells, and explore possible mechanisms.
METHODS: Expression of miR-106b, p21 and E2F was determined by real-time PCR. Transfection with miR-106b mimics was conducted, and gastric cancer cells with miR-106b overexpression were obtained. Cells transfected with mimic mutants and those without transfection served as negative and blank controls, respectively. Flow cytometry and transwell assays were adopted to detect the effects of miR-106b overexpression on cell cycle, migration and invasion of gastric cancer cells.
RESULTS: . The expression of miR- 106b in gastric cancer cells was significantly higher than that in normal gastric mucosa cells. Furthermore, the expression level of miR-106b rose according to the degree of malignacy among the three GC cell strains (MKN- 45 > SGC-7901 > MKN-28). Overexpression of miR-106b shortened the G0/G1 phase and accelerated cell cycle progression, while reducing p21 and E2F5, without any significant effects on the capacity for migration and invasion of gastric cancer cells.
CONCLUSIONS: miR-106b may promote cell cycling of gastric cancer cells through regulation of p21 and E2F5 target gene expression.

BACKGROUND: xCT is a component of the cysteine/glutamate transporter, which plays a key role in glutathione synthesis. The objectives of the present study were to investigate the role of xCT in the regulation of genes involved in cell cycle progression and the clinicopathological significance of its expression in esophageal squamous cell carcinoma (ESCC).
METHODS: xCT expression in human ESCC cell lines was analyzed by Western blotting and immunofluorescent staining. Knockdown experiments were conducted with xCT siRNA, and the effect on cell cycle was analyzed. The cells' gene expression profiles were analyzed by microarray analysis. An immunohistochemical analysis of 70 primary tumor samples obtained from ESCC patients that had undergone esophagectomy was performed.
RESULTS: xCT was highly expressed in TE13 and KYSE170 cells. In these cells, the knockdown of xCT using siRNA inhibited G1-S phase progression. Microarray analysis identified 1652 genes whose expression levels in TE13 cells were altered by the knockdown of xCT. Pathway analysis showed that the top-ranked canonical pathway was the G1/S checkpoint regulation pathway, which involves TP53INP1, CDKN1A, CyclinD1/cdk4, and E2F5. Immunohistochemical staining showed that xCT is mainly found in the nuclei of carcinoma cells, and that its expression is an independent prognostic factor.
CONCLUSIONS: These observations suggest that the expression of xCT in ESCC cells might affect the G1/S checkpoint and impact on the prognosis of ESCC patients. As a result, we have a deeper understanding of the role played by xCT as a mediator and/or biomarker in ESCC.

The copy number gain of genes in chromosomal region 8q21-24 has been demonstrated to be associated with genesis and progression of prostate cancer (PCa). The aim of this study was to identify novel and effective molecular markers in this chromosomal region for PCa. The differentially expressed genes in PCa specimens were screened by gene microarray analysis, which was validated by RT-QPCR analysis. Then, the DNA qPCR analysis was carried out to detect the copy number changes of these differentially expressed genes. Moreover, the clinical significance of candidate markers (MYC and E2F5) in PCa were further determined. E2F5 and MYC were identified as candidate markers in PCa tissues and PCa cell lines. The DNA qPCR revealed the significant copy number gains of E2F5 and MYC in PCa tissues but not in PCa cell lines. In addition, Western blot analysis and immunohistochemical staining both found the significant higher expression of E2F5 and MYC proteins in PCa tissues than those in adjacent benign specimens (all P < 0.01). Moreover, the overexpression of E2F5 protein was significantly associated with a high Gleason score (P < 0.01), an advanced clinical stage (P = 0.01), a positive metastasis (P < 0.01) and PSA Failure (P < 0.01). The overexpression of MYC was more frequently found in PCa tissues with positive metastasis (P = 0.02) and PSA failure (P = 0.02). Interestingly, there was a close correlation in the expression level of MYC in PCa tissues with that of E2F5 (r ( s ) = 0.5, P ≤ 0.001). Our data offers the convincing evidence that the copy number gains of E2F5 and MYC may play an important role in genesis and progression of PCa. Especially, E2F5 may be a novel potential candidate marker for malignant PCa.

The dormancy-inducing factors of bacteria inhibit tumor cell growth. In the present study, we evaluated the antitumor effects of the dormancy-inducing factor 4-hexylresorcinol (4-HR) using real-time cell electronic sensing (RT-CES) in SCC-9 cells (tongue squamous cell carcinoma cells). Treatment with 4-HR suppressed the growth of SCC-9 cells in a dose-dependent manner. We used a DNA microarray to identify genes that showed a significant change in expression upon 4-HR administration in SCC-9 cells. Among the differentially expressed genes, the protein expression of several cell proliferation related factors, including E2F1, E2F2, E2F3, E2F4, E2F5, E2F6, Sp1 and Sp3, were determined by western blot analyses. Treatment with 4-HR strongly suppressed E2F2 and slightly suppressed E2F3 but did not change the expression of E2F1, E2F4, E2F5 and E2F6 relative to no treatment. Furthermore, 4-HR increased Sp1 expression in a dose-dependent manner and decreased Sp3 expression. Therefore, the ratio of Sp1 to Sp3, an important driving force of epithelial cell differentiation, was drastically increased. Consistent with this observation, 4-HR increased the expression of the epithelial cell differentiation markers involucrin and keratin 10. Together, our results indicate that 4-HR induces the differentiation of SCC-9 via the modulation of the E2F-mediated signaling pathway.