Octamer-binding Transcription Factor 4 Expression Research Articles

KLF4 expression in the surgical cut margin is associated with disease relapse of oral squamous cell carcinoma

The presence of cancer stem-like cells (CSCs) in the majority of tumors is one of the factors responsible for disease relapse in oral squamous cell carcinoma (OSCC). In this study, we investigated the role of octamer-binding transcription factor 4 (OCT4) and Kruppel-like factor 4 (KLF4) in OSCC progression and disease relapse. In this study, 102 patients with OSCC were included. The expression of β-catenin and CSC markers (KLF4 and OCT4) in surgical cut margin and tumor were investigated through Western blot analysis, immunohistochemistry, and quantitative polymerase chain reaction analysis. The χ2 test was used to evaluate the association of β-catenin, OCT4, and KLF4 expression with clinicopathologic characteristics. Kaplan-Meier and Cox regression analyses were performed to correlate different clinical factors with the prognoses of patients with OSCC. We observed increased expression of OCT4, KLF4, and β-catenin in the cut margins (CMs) in recurrent OSCC. The χ2 test exhibited recurrence as one of the key factors associated with high expression of these markers. Kaplan-Meier and COX regression analyses demonstrated that increased expression of KLF4 in the CM region of recurrent patients was independently associated with a poor prognosis. Our findings indicated that expression of KLF4 can be used for monitoring disease progression and may serve as prognostic marker to predict recurrence.

Glucosamine decreases the stemness of human ALDH+ breast cancer stem cells by inactivating STAT3.

Cancer stem cells (CSCs) are a subpopulation of cancer cells responsible for tumor maintenance and relapse due to their ability to resist various anticancer effects. Owing to the resistance of CSCs to the effects of targeted therapy, an alternative strategy that targets post-translational glycosylation may be an improved approach to treat cancer as it disrupts multiple coordinated signaling that maintains the stemness of CSCs. Glucosamine acts as an anticancer agent possibly by inhibiting N-linked glycosylation. The aim of the present study was to investigate the effect of glucosamine on the stemness of breast CSCs, which is regulated by signal transducer and activator of transcription 3 (STAT3) signaling. Human aldehyde dehydrogenase-positive (ALDH+) breast CSCs and MCF7 cells were treated with various concentrations (0.25, 1 or 4 mM) of glucosamine for 24 h. Subsequently, cell viability was determined by performing a trypan blue exclusion assay, pluripotency gene [ALDH 1 family member A1 (ALDH1A1), octamer-binding transcription factor 4 (OCT-4), and Krüppel-like factor 4 (KLF4)] expression was determined using the reverse transcription-quantitative polymerase chain reaction, and STAT3 and phosphorylated STAT3 (pSTAT3) levels were determined by performing western blot analysis. Furthermore, the number of mammosphere-forming units (MFUs) in ALDH+ breast CSCs and MCF7 cells was determined. It was determined that glucosamine treatment decreased the viability of ALDH+ breast CSCs. Glucosamine treatment also decreased the stemness of ALDH+ breast CSCs and MCF7 cells, as indicated by decreased ALDH1A1, OCT-4 and KLF4 expression level, and a decreased number of MFUs. This effect of glucosamine may be associated with a decreased pSTAT3/STAT3 ratio, indicating that glucosamine inhibited STAT3 activation; therefore, the results of the present study indicated that glucosamine treatment may be an improved approach to target the stemness of CSCs.

Prognostic value of association of OCT4 with LEF1 expression in esophageal squamous cell carcinoma and their impact on epithelial-mesenchymal transition, invasion, and migration.

Esophageal squamous cell carcinoma (ESCC) is a malignant disease with poor prognosis. Because of early metastasis prior to diagnosis and therapeutic resistance, ESCC has become one of the leading causes of cancer‐related death. Here, we investigated the clinicopathological significance of the association of octamer‐binding transcription factor 4 (OCT4) with lymphoid enhancer‐binding factor 1 (LEF1) expression and the potential molecular mechanism in the epithelial‐mesenchymal transition (EMT), invasion, and migration of ESCC. The expression of OCT4 and LEF1 was detected via immunohistochemistry analysis. High levels of LEF1 expression were observed in 95 ESCC specimens and were obviously associated with aberrant clinicopathological features and poor patient prognosis. Our previous study showed that OCT4 expression level is elevated in ESCC, and statistical analysis showed that the elevated expression of OCT4 and LEF1 in ESCC was significantly associated with histologic grade, lymph node metastasis, TNM stage, and poor patient prognosis. The specific inhibition of OCT4 expression via a lentivirus encoding OCT4‐shRNA (LV‐shOCT4) in Eca109 cells led to decreased levels of OCT4 and LEF1 in vitro. Additionally, we applied a rescue strategy by infecting LV‐shOCT4 Eca109 cells with a LEF1 overexpression plasmid (p‐LEF1) and detected changes in EMT, migration, and invasion. Unsurprisingly, the p‐LEF1 group exhibited greater EMT, invasion, and migration than did the LV‐shOCT4 and negative control groups. This study demonstrates for the first time the relationship between OCT4 and LEF1 expression. The combination of high expression of OCT4 and LEF1 was associated with clinicopathological features of atypical patients, and this combination might be an ideal prognostic factor in ESCC. OCT4 positively regulated LEF1 expression, and LEF1 mediated the effects of OCT4 in cancer cell EMT, invasion, and migration. The data presented here suggest that the inhibition of OCT4‐LEF1 signaling may be a new therapeutic target for the treatment of ESCC.

Octamer-binding transcription factor 4 correlates with complex karyotype, FLT3-ITD mutation and poorer risk stratification, and predicts unfavourable prognosis in patients with acute myeloid leukaemia

ABSTRACTObjectiveTo investigate the correlation of octamer-binding transcription factor 4 (OCT4) expression with clinicopathological features and its predictive value for treatment response as well as survival profiles in de novo acute myeloid leukaemia (AML) patients.MethodOne hundred fifty-two de novo AML patients and 52 non-hematologic malignancy patients were recruited in this prospective cohort study. OCT4 expression was determined in bone marrow sample collected before treatment. Complete response (CR), event free survival (EFS) and overall survival (OS) were evaluated.ResultsCompared with the controls, OCT4 mRNA expression was higher in AML patients (P < .001), and higher OCT4 expression was correlated with presence of complex karyotype (CK) (P = .037), FLT3-ITD mutation (P = .012) and poorer risk stratification (P < .001) in AML patients. As to predictive value, OCT4 mRNA expression was decreased in patients achieved CR compared to non-CR patients (P = .022). Kaplan–Meier (K–M) curves showed that shorter EFS (9.0 (95% CI (7.7–10.3)) months vs. 25.0 (95% CI (17.5–32.5)) months, P < .001) and shorter OS (20.0 (95% CI (17.8–22.2) months vs. 33.0 months, P < .001) were observed in OCT4 mRNA high expression patients compared to OCT4 mRNA low expression patients. Multivariate Cox’s proportional hazards regression analyses revealed that OCT4 mRNA high expression was an independent predictive factor for shorter EFS and OS in AML patients.ConclusionOCT4 correlates with presence of CK, FLT3-ITD mutation and poorer risk stratification, and it could be served as a convincing biomarker for predicting unfavourable prognosis in AML patients.

OCT4 but not SOX2 expression correlates with worse prognosis in surgical patients with triple-negative breast cancer.

Octamer-binding transcription factor 4 (OCT4) and SRY (sex determining region Y)-box 2 (SOX2) are common biomarkers of cancer stem cells, which contribute to the pathological processes of several carcinomas, while little is known about the effects of OCT4 and SOX2 on the prognosis of triple-negative breast cancer (TNBC). The purpose was to evaluate the correlation of tumor tissue OCT4 and SOX2 expressions with clinicopathological features and overall survival (OS) in surgical TNBC patients. 127 surgical patients with TNBC were enrolled in this cohort study. Tumor tissue samples were obtained during the operation. OCT4 and SOX2 expressions were assessed by immunofluorescent staining. 32 (25%) TNBC patients with OCT4 positive expression (OCT4+), 21 (17%) patients with SOX2 positive expression (SOX2+), and 11 (9%) patients with both OCT4+ and SOX2+ were observed. OCT4 expression was positively associated with histologic grade (P<0.001), pathological tumor size (P=0.014), N stage (P<0.001) and TNM stage (P<0.001), while SOX2 expression was positively correlated with histologic grade (P<0.001), pathological tumor size (P=0.033) and Ki-67 expression (P=0.016). Kaplan-Meier (K-M) curves suggested OCT4+ was correlated with shorter OS compared with OCT4- (P<0.001), while no correlation between SOX2+ with OS in all patients (P=0.128) was observed. Multivariate Cox model indicated that OCT4+ (P<0.001) were independent factors for worse OS. Tumor tissue OCT4 but not SOX2 expression was positively correlated with histologic grade, pathological tumor size, N stage and TNM stage, and it could be served as an independent biomarker to predict worse prognosis in surgical patients with TNBC.

MiRNA regulates OCT4 expression in breast cancer cells.

Breast cancer cell infiltration, migration, and proliferation significantly affect its curative effect. Stemness gene octamer-binding transcription factor 4 (OCT4) upregulated in breast cancer tissue compared with normal control. MiRNA exhibits regulatory role in gene expression. This study adopted bioinformatics to predict the miRNA to regulate OCT4 gene and investigated its impact on breast cancer cell infiltration, migration, and proliferation. MirBase database was analyzed to explore the potential miRNA in regulating OCT4 based on human OCT4 gene sequence. MiRNA mimics and inhibitor were synthetized and transfected to BS524 cells. qRT-PCR was applied to test miRNA and OCT4 mRNA expressions in cells at 12 h, 24 h, and 48 h after transfection. Western blot was selected to detect OCT4 protein expression. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was selected to determine cell proliferation. Scratch assay was adopted to evaluate cell migration. Transwell assay was used to analyze cell infiltration. MiR-145 may regulate OCT4 gene with score 82. OCT4 mRNA and protein increased at 12 h after transfection (p > 0.05). OCR4 gene significantly upregulated, cell proliferation, migration, and infiltration enhanced by miR-145 transfection compared with control (p < 0.05). OCT4 gene downregulated, while cell proliferation, infiltration, and migration markedly weakened in miR-145 inhibitor group compared with control (p < 0.05). MiR-145 affects breast cancer BS524 cell proliferation, infiltration, and migration via positively regulating OCT4 gene expression.

Clinicopathological and prognostic significance of OCT4 in patients with hepatocellular carcinoma: a meta-analysis.

Background and aimsOctamer-binding transcription factor 4 (OCT4) has been implicated in the development of hepatocellular carcinoma (HCC), although the findings are controversial. We conducted a meta-analysis to assess the correlation between OCT4 and the clinicopathological characteristics and the prognostic value in HCC.MethodsAn electronic search for relevant articles was conducted in PubMed, Cochrane Library, Web of Science, EMBASE database, Chinese CNKI, and Chinese WanFang database. Correlations between OCT4 expression and clinicopathological features and survival outcomes were analyzed. Pooled odds ratios and hazard ratios with 95% CIs were calculated using STATA 14.2 software.ResultsA total of 10 trials with 985 patients were included. Positive OCT4 expression was correlated with tumor size, tumor numbers, differentiation, and TNM stage. OCT4 expression was not correlated with gender, age, hepatitis B surface antigen, alfa-fetoprotein, liver cirrhosis, vascular invasion, or tumor encapsulation. OCT4 expression was associated with poor 3- and 5-year overall survival, and disease-free survival rate.ConclusionOCT4 expression was associated with tumor size, tumor numbers, differentiation, and TNM stage in HCC. OCT4 may be a useful prognostic biomarker for HCC.

Correlation of Cancer Stem-Cell Markers OCT4, SOX2, and NANOG with Clinicopathological Features and Prognosis in Operative Patients with Rectal Cancer.

PurposeTo investigate the association of cancer stem-cell markers [octamer-binding transcription factor 4 (OCT4), sex determining region Y-box 2 (SOX2), and Nanog homebox (NANOG)] expression with clinicopathological properties and overall survival (OS) in operative rectal cancer (RC) patients receiving adjuvant therapy.Materials and Methods153 patients with primary RC receiving surgery were enrolled. Tumor tissue and paired adjacent normal tissue sample were collected, and OCT4, SOX2, and NANOG expressions were assessed by immunofluorescent staining. The median follow-up duration was 5.2 years, and the last follow-up date was August 2016.ResultsTumor tissue OCT4 (p<0.001), SOX2 (p=0.003), and NANOG (p<0.001) expressions were higher than those in adjacent tissue. OCT4 expression was positively correlated with pathological grade (R=0.185, p=0.022), tumor size (R=0.224, p=0.005), and N stage (R=0.170, p=0.036). NANOG expression was positively associated with tumor size (R=0.169, p=0.036). Kaplan-Meier suggested that OCT4+ was associated with worse OS compared with OCT4− (p<0.001), while no association of SOX2 (p=0.121) and NANOG expressions (p=0.195) with OS was uncovered. Compared with one or no positive marker, at least two positive markers were associated with shorter OS (p<0.001), while all three positive markers were correlated with worse OS compared with two or less positive markers (p<0.001). Multivariate Cox's analysis revealed that OCT4+ (p<0.001) and N stage (p=0.046) were independent factors for shorter OS.ConclusionTumor tissue OCT4 expression was correlated with poor differentiation, tumor size, and N stage, and it can serve as an independent prognostic biomarker in operative patients with RC receiving adjuvant therapy.

TASK-1 induces gefitinib resistance by promoting cancer initiating cell formation and epithelial-mesenchymal transition in lung cancer.

Cancer initiating cell (CIC) formation and epithelial-mesenchymal transition (EMT) are pivotal events in lung cancer cell invasion and metastasis. They have been shown to occur in gefitinib resistance. Studying the molecular mechanisms of CICs, EMT and acquired gefitinib resistance will enhance the understanding of the pathogenesis and progression of the disease and offer novel targets for effective therapies. TWIK-related acid-sensitive K(+) (TASK-1) is expressed in a subset of non-small-cell lung cancer (NSCLC) cell lines, where it promotes cell proliferation while inhibiting apoptosis. In the present study, TASK-1 was demonstrated to induce gefitinib resistance in the A549 NSCLC cell line. Overexpression of TASK-1 promoted the acquisition of CIC-like traits by A549 cells. CD133, octamer-binding transcription factor 4 (OCT-4) and Nanog have been suggested to be markers of CICs in lung cancer. It was demonstrated that overexpression of TASK-1 promoted CD133, OCT-4 and Nanog protein expression in A549 cells. Increased formation of stem cell-like populations results in EMT of cancer cells. The present study found that overexpression of TASK-1 promoted EMT of A549 cells. Thus, downregulation of TASK-1 may represent a novel strategy for EMT reversal, decreasing CIC-like traits and increasing gefitinib sensitivity of NSCLCs.

High-mobility-group protein 2 regulated by microRNA-127 and small heterodimer partner modulates pluripotency of mouse embryonic stem cells and liver tumor initiating cells.

High‐mobility‐group protein 2 (HMGB2) expression is up‐regulated in human liver cancer; however, little is known about its regulatory function. Here, we establish HMGB2 as a new modulator of the pluripotency of mouse embryonic stem cells. Similar to octamer‐binding transcription factor 4 (OCT4) and sex‐determining region Y‐box 2 (SOX2), HMGB2 protein is highly expressed in undifferentiated CGR8 cells, whereas it undergoes rapid decline during embryonic body formation. HMGB2 interacts with OCT4, increases protein expression of OCT4 and SOX2, and enhances their transcriptional activities. We also show that microRNA (miRNA)‐127 is a translational repressor of HMGB2 protein expression by targeting its 3′ untranslated region. We further elucidate a transcriptional mechanism controlling HMGB2 messenger RNA expression by the nuclear receptor small heterodimer partner (SHP) and transcription factor E2F1. Diminishing HMGB2 expression by ectopic expression of miR‐127 or SHP or treatment with the small molecule inhibitor inflachromene decreases OCT4 and SOX2 expression and facilitates CGR8 differentiation. In addition, HMGB2 is markedly induced in liver tumor initiating cells. Diminishing HMGB2 expression by short hairpin RNA for HMGB2 (shHMGB2), miR‐127, or SHP impairs spheroid formation. Importantly, HMGB2 expression is elevated in various human cancers. Conclusion: HMGB2 acts upstream of OCT4/SOX2 signaling to control embryonic stem cell pluripotency. Diminishing HMGB2 expression by miR‐127 or SHP may provide a potential means to decrease the pluripotency of tumor initiating cells. (Hepatology Communications 2017;1:816–830)

Transcriptional factor OCT4 promotes esophageal cancer metastasis by inducing epithelial-mesenchymal transition through VEGF-C/VEGFR-3 signaling pathway.

The octamer-binding transcription factor 4 (OCT4) can promote cancer proliferation and metastasis. Esophageal carcinoma (ECC) harbors different quantities of OCT4-positive cancer cells. These cells are highly malignant and prone to metastasis; however, the mechanism remains unknown. In this study, we found that OCT4 enhances vascular endothelial growth factor C (VEGF-C) promoter activity to promote VEGF-C expression and activates VEGF receptor 3 (VEGFR-3) in ECC cells, thereby inducing cancer cell epithelial-mesenchymal transition (EMT). Studies using xenograft models showed that OCT4 promoted xenograft growth and intraperitoneal implantation metastasis of ECC cells. Downregulation of OCT4 expression could inhibit cancer metastasis. OCT4- and VEGF-C-positive ECC presented more malignant biological behaviors and the corresponding patients exhibited a poor prognosis. The study confirmed that the OCT4/VEGF-C/VEGFR-3/EMT signaling plays a role in the progression of ECC. Understanding of how OCT4 regulates EMT and how ECC metastasis occurs will provide useful targets for the biological treatment of ECC.

Differentiation of cardiomyocytes from amniotic fluid‑derived mesenchymal stem cells by combined induction with transforming growth factor β1 and 5‑azacytidine.

As a novel type of seed cell, amniotic fluid-derived mesenchymal stem cells (AFMSCs) are promising for the regeneration of myocardial cells. A focus of cardiovascular regenerative medicine is to improve the efficiency of AFMSC differentiation. The present study replaced the traditional method of AFMSC differentiation with a combined induction method, in order to improve the efficiency of directional differentiation. AFMSCs were obtained from rabbit amniotic fluid samples, and western blot analysis was performed to analyze the expression of octamer-binding transcription factor 4 (OCT4), and tumorigenicity experiments were conducted. AFMSCs were divided into the following 4 groups: Induction with transforming growth factor β1 (TGFβ1); induction with 5-azacytidine (5Aza); induction with TGFβ1 and 5Aza combined; and untreated controls. Reverse transcription-quantitative polymerase chain reaction was performed to analyze the expression of cardiac-specific GATA binding protein 4 (GATA4), and immunofluorescence was employed to analyze the expression of cardiac troponin T (cTnT). In addition, western blotting was performed to analyze the expression of connexin 43, and transmission electron microscopy was used to observe the ultrastructure of the differentiated cells. AFMSCs exhibited positive OCT4 expression and were not observed to induce tumor development in nude mice. The expression levels of GATA4, cTnT, and connexin 43 in the combined induction group were markedly higher when compared with the remaining groups. Transmission electron microscopy analysis revealed that differentiated cells exhibited myocardial cell characteristics. In conclusion, AFMSCs are multipotent, non-tumorigenic cells that are capable of differentiating into cardiomyocyte-like cells. This combined induction method may improve the efficiency of directed differentiation.

BEX3 contributes to cisplatin chemoresistance in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) can develop cisplatin‐resistant phenotype. Research has revealed that enriched in cancer stem cell population is involved in developing cisplatin‐resistant phenotype. CD271 is a candidate stem cell maker in head and neck cancers. The CD receptor does not possess any enzymatic property. Signal transduction function of CD271 is mediated by the cellular receptor‐associated protein. Our data showed that Brain‐expressed X‐linked 3 (BEX3), a CD271 receptor‐associated protein, was overexpressed in NPC. BEX3 overexpression was a unique event in cancer developed in the head and neck regions, especially NPC. BEX3 expression was inducible by cisplatin in NPC. In cisplatin‐resistant NPC xenograft, treatment with nontoxic level of cisplatin led to a remarkable increase in BEX3 level. High BEX3 expression was accompanied with high octamer‐binding transcription factor 4 (OCT4) expression in cisplatin‐resistant NPC. To confirm the inducing role of BEX3 on OCT4 expression, we knockdown BEX3 using siRNA and compared the expression of OCT4 with mock transfectants. Suppressing BEX3 transcripts led to a significant reduction in OCT4. In addition, targeting BEX3 using shRNA could increase the sensitivity of NPC cells to cisplatin. In summary, our results indicated a unique functional role of BEX3 in mediating the sensitivity of NPC cells to cisplatin. Targeting or blocking BEX3 activity might be useful in reversing the cisplatin‐resistant phenotype in NPC.

MicroRNA-145 sensitizes cervical cancer cells to low-dose irradiation by downregulating OCT4 expression.

Poor elucidation of the mechanisms involved in regulating the radiosensitivity of cancers prevents the extensive application of low-dose radiotherapy in clinical settings. The present study was conducted to investigate the role of microRNA-145 (miR-145) in the modulation of cervical cancer cell radiosensitivity, as well as to identify the underlying target of miR-145 during this process. Cervical cancer tera cells were initially exposed to doses of radiation between 1 and 6 Gy before the assessments of the cell viability and apoptosis rate. Irradiation at dose of 1 Gy was screened as optimum dose and used in subsequent experiments. A dual luciferase reporter assay was performed to demonstrate that octamer-binding transcription factor 4 (OCT4) is a target of miR-145 in cervical cancer. Consequently, OCT4 was suggested to be a target of miR-145, as a dual luciferase vector that was ligated to a fragment corresponding to the predicted target site of miR-145 in OCT4 3'-UTR showed an 83% reduction in fluorescence. Following exposure to 1 Gy irradiation, tera cells transfected with miR-145 mimics, which showed downregulation of OCT4 and cyclin D1, had lower cell viability and cell migration rate and higher apoptosis rate compared to non-transfected cells. However, the co-transfection of miR-145 mimics and OCT4 expression vector restored OCT4 and cyclin D1 expression levels and made no significant difference in terms of cell viability, cell migration rate and apoptosis rate. The present results indicate that miR-145 increases the radiosensitivity of cervical cancer cells by silencing OCT4, that cyclin D1 is putatively under the positive regulation of OCT4 and mediates miR-145 function.

Liver receptor homolog 1 influences blastocyst hatching in pigs.

Liver receptor homolog 1 (Lrh1, also known as Nr5a2) belongs to the orphan nuclear receptor superfamily and has diverse functions in development, metabolism, and cell differentiation and death. Lrh1 regulates the expression of Oct4, which is a key factor of early embryonic differentiation. However, the role of Lrh1 in early development of mammalian embryo is unknown. In the present study, the localization, Lrh1 mRNA expression, and LRH1 protein levels in porcine early parthenotes were examined by immunofluorescence and real-time reverse-transcription polymerase chain reaction. To determine the role of Lrh1 in porcine early embryo development, the parthenotes were treated with the specific LRH1 antagonist 505601. The immunofluorescence signal for LRH1 was only observed in the nucleus of blastocysts. The blastocyst developmental rate in the presence of 50 and 100 μM 505601 was significantly lower than that in the control group. The blastocyst hatching rate was also reduced in the presence of 50 and 100 μM 505601 than that under control conditions. The latter effect was possibly due to the decreased expression of hatching-related genes such as Fn1, Itgα5, and Cox2 upon the inhibition of Lrh1. Incubation with the LRH1 antagonist also increased the number of apoptotic cells among the blastocysts. Moreover, LRH1 inhibition enhanced the expression of the pro-apoptotic genes Bax and Casp3, and reduced the expression of the anti-apoptotic gene Bcl2. Lrh1 inhibition also led to significant decrease in the expression levels of Oct4 mRNA and octamer-binding transcription factor 4 (OCT4) protein in the blastocysts. In conclusion, Lrh1 affects blastocyst formation and hatching in porcine embryonic development through the regulation of OCT4 expression and cell apoptosis.

OCT4 mediates FSH-induced epithelial–mesenchymal transition and invasion through the ERK1/2 signaling pathway in epithelial ovarian cancer

Our previous study showed that Octamer-binding transcription factor 4 (OCT4) expression was upregulated and significantly associated with histological grade through the analysis of OCT4 expression in 159 ovarian cancer tissue samples, and OCT4 mediated follicle-stimulating hormone (FSH)-induced anti-apoptosis in epithelial ovarian cancer. Nevertheless, whether OCT4 participates in FSH-induced invasion in ovarian cancer is still unknown. Therefore, the present study aimed to define whether FSH-induced ovarian cancer invasion is mediated by OCT4. In present study, we showed that FSH induced not only the epithelial–mesenchymal transition (EMT) and invasive phenotype but also the upregulation of OCT4 expression in a dose- and time-dependent manner in epithelial ovarian cancer cells. In addition, the expression of FSH receptor (FSHR) was upregulated by FSH induction, and knockdown of FSHR inhibited FSH-stimulated OCT4 expression. ERK1/2 signaling pathway participated in the enhanced expression of OCT4 and Snail induced by FSH. We further showed that the activated expression of Snail and N-cadherin, the suppressed expression of E-cadherin and the morphological change of the cells stimulated by FSH were blocked by OCT4-specific small interfering RNA. Moreover, our results showed that OCT4 mediated the increase in invasive capacity induced by FSH in ovarian cancer cells. Taken together, our work reveals that OCT4 is an essential mediator in FSH-induced EMT and invasion in epithelial ovarian cancer and may act as a potential therapeutic target.

Transcription factor OCT4 promotes cell cycle progression by regulating CCND1 expression in esophageal carcinoma

The CCND1 gene is overexpressed in esophageal cancer and accelerates cell cycle progression. However, the mechanism whereby the upstream genes or factors directly regulate CCND1 expression remains unknown. By analyzing the 5′-UTR region of the CCND1 gene, we found that this region contains an octamer motif (ATTTTGCAT), which suggests that the expression of CCND1 might be directly associated with octamer-binding transcription factor 4 (OCT4). In this study, the wild-type and the octamer motif-mutanted CCND1 promoters were cloned, and their corresponding luciferase reporter vectors were then constructed to study the molecular mechanism by which OCT4 regulates the expression of CCND1 and influences the biological behaviors of esophageal cancer cells. The results indicated that suppressing the expression of CCND1 and OCT4 in esophageal cancer cells reduced cell proliferative and invasive abilities, induced cell cycle G1-phase arrest, and slowed the growth of xenografts in nude mice. Suppression of OCT4 expression significantly decreased the wild-type CCND1 promoter activity and down-regulated the expression of CCND1, but did not affect the activity of the mutant promoter. Whereas, suppression of CCND1 did not affect OCT4 expression, suggesting that OCT4 regulates CCND1 expression by activating the CCND1 promoter and subsequently promoting cell cycle progression. The results revealed and confirmed that OCT4 is the upstream factor that directly binds to the CCND1 promoter to regulate CCND1 expression, then to promote cell cycle progression and accelerate the proliferation and invasion of esophageal cancer cells. This finding may significantly contribute to elucidating the regulatory mechanism involved in the cell cycle progression of esophageal cancer cells and may aid in screening potential gene targets for the biological therapy of esophageal cancer.

Knockdown of OCT4 suppresses the growth and invasion of pancreatic cancer cells through inhibition of the AKT pathway.

Octamer-binding transcription factor 4 (OCT4) is one of the factors associated with self-renewal and differentiation in cancer stem cells, and is crucial for the progression of various types of human malignancy. However, the expression and function of OCT4 in human pancreatic cancer has not been fully elucidated. The purpose of the present study was to investigate the function and molecular mechanisms of OCT4 in pancreatic cancer cells. The clinical significance of OCT4 expression was assessed by an immunohistochemical assay using a tissue microarray procedure in pancreatic cancer tissues and cells with different degrees of differentiation. A loss-of-function approach was used to examine the effects of a lentivirus-mediated OCT4 small hairpin RNA vector on biological behaviors, including cell proliferative activity and invasive potential. The results demonstrated that the expression levels of OCT4 protein in cancer tissues were significantly elevated compared with those in adjacent non-cancerous tissues (65.0 vs. 42.5%; P=0.005), which was correlated with tumor differentiation (P=0.008). The knockdown of OCT4 inhibited the proliferation and invasion of pancreatic cancer cells (Panc-1) expressing high levels of OCT4, accompanied with decreased expression of AKT, proliferating cell nuclear antigen (PCNA) and matrix metalloproteinase-2 (MMP-2). In conclusion, the present study reveals that the increased expression of OCT4 is correlated with the differentiation of pancreatic cancer, while knockdown of OCT4 suppresses the growth and invasion of pancreatic cancer cells through inhibition of AKT pathway-mediated PCNA and MMP-2 expression, suggesting that OCT4 might serve as a potential therapeutic target for the treatment of pancreatic cancer.

Effect of ectopic OCT4 expression on canine adipose tissue-derived mesenchymal stem cell proliferation.

Enhancing the proliferative capacity of mesenchymal stem cells (MSCs) is critical for increasing their therapeutic potential in a variety of diseases. We hypothesized that lentivirus-mediated overexpression of canine octamer-binding transcription factor 4 (OCT4) might influence the proliferation of canine adipose tissue-derived MSCs (cATMSCs). cOCT4-cATMSCs were generated by transducing cATMSCs with a cOCT4-lentiviral vector. Increased expression of cOCT4 was confirmed using RT-PCR and immunoblotting. Immunophenotypic characterization using flow cytometry indicated that the CD29, CD44, CD73, CD90, and CD105 surface markers were highly expressed by both cOCT4- and mock-transduced cATMSCs (mock-cATMSCs), whereas the CD31 and CD45 markers were absent. We performed the osteogenic differentiation assay to evaluate the effects of cOCT4 overexpression on the osteogenic differentiation potential of cATMSCs. The results showed that cOCT4-cATMSCs had a much higher potential for osteogenic differentiation than mock-cATMSCs. Next, the proliferative capacities of cOCT4- and mock-cATMSCs were evaluated using a WST-1 cell proliferation assay and trypan blue exclusion. cOCT4-cATMSCs showed a higher proliferative capacity than mock-cATMSCs. Cell cycle analysis indicated that overexpression of cOCT4 in cATMSCs induced an increase in the proportion of cells in S and G2/M phases. Consistent with this, immunoblot analysis showed that cyclin D1 expression was increased in cOCT4-cATMSCs. In conclusion, our results indicate that lentivirus-mediated overexpression of cOCT4 increased the proliferative capacity of cATMSCs. OCT4-mediated enhancement of cell proliferation may be a useful method for expanding MSC population rapidly without loss of stemness.

Forthcoming prognostic markers for esophageal cancer: a systematic review and meta-analysis.

The incidence of esophageal cancer is rising, and survival rates remain poor. This meta-analysis summarizes five molecular mechanisms of disease progression, which are related to prognosis. A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. Original data was abstracted from each study and used to calculate a pooled event rate and 95% confidence interval (95% CI). Our analysis included five octamer-binding transcription factor 4 (OCT4) studies (564 patients), six sex determining region Y-box 2 (SOX2) studies (336 patients), five oestrogen receptor (ER) studies (367 patients), seven MET or MNNG HOS Transforming gene (c-Met) studies (1,015 patients) and six insulin like growth factor receptor studies (764 patients). Incidence of OCT4 in SCC was 53.60% (95% CI: 0.182-0.857) and the overall hazard ratio for poor clinic outcome was 2.9 (95% CI: 1.843-4.565). The incidence of SOX2 in SCC was 69.2% (95% CI: 0.361-0.899) however, was associated with significant heterogeneity of 90.94%. The prevalence of Oestrogen receptor α and β in SCC were 37.90% (95% CI: 0.317-0.444) and 67.20% (95% CI: 0.314-0.901) respectively. The prevalence of MET in EAC was 33.20% (95% CI: 0.031-0.884) and the incidence of insulin-like growth factor-1 receptor (IGF-1R) in EAC was 67.70% (95% CI: 0.333-0.898). Our results show that the status of ER, OCT4 and SOX2 expression correlates with the unfavourable prognosis in patients with esophageal squamous cell carcinoma (ESCC). This study also highlights the potential impact of the IGF-1R on the biology of EAC and the expression of Met was recognised as a significant prognostic factor. Our data supports the concept of IGF axis, ER, Met, OCT4 and SOX2 inhibition as (neo-) adjuvant treatment.