STAT3 exerts pro-tumor and anti-autophagy roles in cervical cancer.

BACKGROUND: STAT3 plays an important role in cervical cancer. LC3B, the most potential molecular biomarker of autophagy that may promote or inhibit cancer progression, can be downregulated by STAT3. However the role of STAT3 in the autophagy of cervical cancer remains unclear. PURPOSE: This study aimed to evaluate the relationship between STAT3 and LC3B in protein level, and verify whether STAT3 promotes proliferation, migration and plate colony formation by inhibiting autophagy of cervical cancer cells through bcl2-beclin1 axis. RESULTS: STAT3 was overexpressed in cervical cancer tissues, and negatively correlated with the expression level of LC3B. STAT3 knockout or knockdown significantly increased the autophagy level and decreased proliferation, migration, plate colony formation and subcutaneous tumorigenesis of cervical cancer cells in vitro and in vivo. STAT3 is known to mediate autophagy through Bcl2-Beclin1 complex. Bcl2 was positively whereas Beclin1 negatively correlated with STAT3 expression, indicating that Bcl2-Beclin1 complex involved in this transition. CONCLUSION: STAT3 may upregulate the autophagy level of cervical cancer cells through the Bcl2-Beclin1 axis. This indicates that STAT3 may be an important prognostic and therapeutic target for cervical cancer.

Aberrant expression of microRNA-26b and its prognostic potential in human cervical cancer.

BACKGROUND: microRNA-26b (miR-26b) is reported to be downregulated in many human malignancies and function as a tumor suppressor. However, the roles of miR-26b expression in cervical cancer progression are unclear. The aim of this study was to investigate the clinicopathological or prognostic significance of miR-26b in human cervical cancer. METHODS: A cohort of 88 paired of cervical cancer and the adjacent normal cervical epithelial tissues were collected. Quantitative RT-PCR (qRT-PCR) assay was used to detect the expression of miR-26b and its correlations with clinicopathological factors were statistically analyzed. Finally, the survival was assessed by the Kaplan-Meier method and proportional hazards model. RESULTS: The expression level of miR-26b in cervical cancer tissues was significantly lower than that in the adjacent normal cervical tissues (P<0.001). Reduced miR-26b was observed to be significantly correlated with advanced FIGO stage, higher incidence of lymph node metastasis and recurrence of cervical cancer patients (P=0.002, 0.036 and 0.029, respectively). In addition, patients with low-miR-26b expression showed poorer recurrence-free survival (RFS) and overall survival (OS) than those with high-miR-26b expression (P=0.0043 and 0.0015, respectively). Furthermore, multivariate analyses demonstrated that low miR-26b expression was an independent prognostic factor for predicting the 5-year RFS and OS of cervical cancer patients (P=0.013 and 0.007, respectively). CONCLUSION: Our results showed that reduced miR-26b was correlated with tumor development and poor prognosis in human cervical cancer. The status of miR-26b expression may be a potential prognostic biomarker for cervical cancer patients.

MicroRNA-497 is a potential prognostic marker in human cervical cancer and functions as a tumor suppressor by targeting the insulin-like growth factor 1 receptor.

BACKGROUND: Increasing evidence has shown that microRNAs function as oncogenes or tumor suppressors in human malignancies, but the roles of microRNA (miR)-497 in human cervical cancer still remain unclear. Our aim was to analyze the clinicopathologic and prognostic significance of miR-497 in human cervical cancer and to investigate the effects of miR-497 on the malignant phenotype of cervical cancer cells. METHODS: First, we detected miR-497 expression in the HPV-16-immortalized cervical epithelial cell lines and 4 other cervical cancer cell lines (HeLa, Caski, SiHa, and HeLa-S3). Then the expression of miR-497 was analyzed in cervical cancer tissues and paired nontumor tissues, and its correlation with clinicopathologic features and survival was analyzed. Finally, the roles of miR-497 in regulation of tumor proliferation, apoptosis, migration, invasion, and target gene expression were further investigated. RESULTS: MiR-497 was downregulated in cervical cancer cells or tissues compared with HPV-16-immortalized cervical epithelial cell lines or the paired nontumor tissues. Also, the decrease in miR-497 correlated closely with the criteria of the International Federation of Gynaecology and Obstetrics stage and lymph node metastases in patients with cervical cancer. Multivariate Cox analysis showed that low miR-497 expression appeared to be an unfavorable prognostic factor. Transient forced expression of miR-497 decreased the growth and colony-formation capacity of HeLa and SiHa cells by inducing Caspase-3-dependent apoptosis. Forced expression of miR-497 suppressed the migration and invasiveness of cervical cancer cells. By computational miRNA target prediction and functional analysis, miR-497 was demonstrated to bind to the 3' untranslated regions of IGF-1R mRNA, and upregulation of miR-497 downregulated IGF-1R protein expression. Further investigation showed that small interfering RNA-mediated IGF-1R knockdown could mimic the effect of enforced miR-497 expression on the malignant phenotypes of cervical cancer cells. CONCLUSION: MiR-497 may be a potential prognostic marker and functions as a tumor suppressor in human cervical cancer by post-transcriptionally targeting IGF-1R.

[Effect of gene polymorphism of TNF-beta on the concentration of TNF in serum of patient with endometriosis].

OBJECTIVE: To determine the polymorphism in +252 site of tumor necrosis factor-beta(TNF-beta) gene in patients with or without endometriosis, to evaluate the levels of TNF-alpha and TNF-beta in the serum with or without endometriosis, to explore the relation between polymorphism of TNF-beta gene and the genetic susceptibility of endometriosis, and to explore the pathogenic mechanism of endometriosis at gene level. METHODS: By polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, polymorphism on +252 site of TNF-beta gene was measured in 82 patients with endometriosis (the endometriosis group) and 80 patients without endometriosis (the control group). With the sandwich-enzyme-linked immunosorbent assay (ELISA), the levels of TNF-alpha and TNF-beta in the serum of the two groups were determined. RESULTS: The TNF-beta level in the serum in the endometriosis group with TNF-beta gene +252 site AA genotype significantly increased, compared with GG genotype (t=2.029, P<0.05); while TNF-alpha and TNF-beta level in the serum had no statistical significance in patients with other genotypes in TNF-beta gene +252 site in the endometriosis group and the control group. CONCLUSION: TNF-beta gene +252 site AA genotype might be enhance TNF-beta level in the serum of patients with endometriosis.

[Association of tumor necrosis factors-beta gene polymorphism with endometriosis in women in Guangdong Province].

OBJECTIVE: To study the polymorphism of +252 site in intron 1 of tumor necrosis factor (TNF)-beta gene in relation to genetic susceptibility of endometriosis. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was employed to detect the polymorphism of +252 site in intron 1 of TNF-beta gene in 82 Chinese Han patients with endometriosis in Guangdong Province and 80 Han patients without endometriosis (control group), and the relation between TNF gene polymorphism and the risk of endometriosis was analyzed. RESULTS: The +252 site of TNF-beta allele and genotype distribution showed significant difference between endometriosis and control groups (Chi2=6.562, P<0.05; chi2=6.562, P<0.05), and relative risk of endometriosis in relation to allele A was increased by 1.793 fold. The risk of endometriosis was 3.33-fold higher in women of AA genotype than those of GG genotype (Chi2=6.562, P<0.05). CONCLUSIONS: Allele A in TNF-beta gene +252 site can significantly increase the relative risk of endometriosis in women in Guangdong, among which TNF-beta AA genotype might be one of the genetic susceptible factors for endometriosis.