ABSTRACT
Prostate cancer (PCa) is one of the most common malignancies in Western countries. Studies have shown that androgen contributes to the progression of PCa, but how androgen promotes PCa remains largely unknown. Here, we demonstrated that androgen suppressed the expression of miR-760 depending on the interaction between androgen and androgen receptor (AR). miR-760 was downregulated in prostate cancer tissues compared with normal tissues. Functional experiments showed that miR-760 downregulation promoted the proliferation and growth of LNCaP and 22rv1 cells. In contrast, miR-760 ectopic expression inhibited the proliferation of LNCaP and 22rv1 cells. DNA synthesis was suppressed by miR-760. Mechanistically, miR-760 bound to the 3'UTR of interleukin 6 (IL6 ). A mutation in the binding site disrupted their interaction. In addition, silencing ofIL 6 suppressed the proliferation of LNCaP and 22rv1 cells. IL6 was upregulated in PCa tissues. Our study reveals that androgen downregulates miR-760 to promote the growth of PCa cells by regulating IL6.
ABSTRACT
Background: MicroRNAs (miRNAs) are considered as new biomarkers related to cancer treatment. Studies have shown that miR-760 plays an important role in the development of colorectal cancer. Aims: To investigate the regulatory effect and mechanism of miR-760 on proliferation, cycle, migration and invasion of colon cancer cells. Methods: qRT-PCR was used to detect the expression of miR-760 in colon cancer tissue and colon cancer cell lines HCT116, HT29, SW480 and SW620. The targeted relationship between miR-760 and STIM1 was verified by dual luciferase reporter gene test. Expression of STIM1 in colon cancer cells and tissue was detected by Western blotting and immunohistochemistry, respectively. CCK-8 assay was used to detect cell proliferation ability, flow cytometry was used to detect cell cycle, and Transwell assay was used to detect cell migration and invasion. The xenograft model of colon cancer in nude mice was constructed, and the effect of miR-760 on tumor growth was measured. Results: Expression of miR-760 was significantly decreased in colon cancer tissue and colon cancer cells, while expression of STIM1 was significantly increased in colon cancer tissue and colon cancer cells. MiR-760 inhibited expression of STIM1 by complementary binding to the 3'-UTR of STIM1. Overexpression of miR-760 inhibited colon cancer cell proliferation, S-phase arrest, migration and invasion, and up-regulation of STIM1 reversed the inhibitory effect. In the xenograft model of colon cancer in nude mice, overexpression of miR-760 down-regulated expression of STIM1 and inhibited tumor growth. Conclusions: MiR-760 is involved in the regulation of biological behavior of colon cancer cells by targeting STIM1, and plays a role in tumor inhibition of colon cancer.
ABSTRACT
Objective • To detect the effects of miR-760 on proliferation, apoptosis, migration and invasion of human esophageal squamous cell carcinoma (ESCC) TE-10 cells and to analyse the underlying mechanism. Methods • The mRNA and protein expression levels of miR-760 and c-Myc in five ESCC cell lines (normal esophageal epithelial cells as control) and 14 pieces of ESCC tissue specimens (paracancerous tissues as control) were detected by using reverse transcription quantitative PCR (RT-qPCR) and Western blotting. TE-10 cells were transfected with miR-760 mimics, miR-760 inhibitor (miR-mimics/miR-inhibitor group) and corresponding negative controls (mimics-NC/inhibitor-NC group), in which the overexpression and inhibition efficiency of miR-760 and the expression of c-Myc were verified by RT-qPCR. The effect of miR-760 on the proliferation of TE-10 cells was assessed by CCK-8 and colony formation assay. Changes of cell cycle distribution and proportion of apoptotic cells were measured by flow cytometry. Expression levels of cell cycle-, apoptosis-, migration-, and invasion-associated proteins as well as c-Myc were analyzed by Western blotting. The targeting relationship between miR-760 and c-Myc was verified by using the dual luciferase reporter assay. Results • The expressions of miR-760 were down-regulated and the expressions of c-Myc mRNA and protein were up-regulated in five ESCC cell lines compared with those in the normal esophageal epithelial cells. In 14 cases of ESCC tissue specimens, the expressions of miR-760 were down-regulated but the expressions of c-Myc were up-regulated compared with those in the cancer-adjacent tissues. The proliferation ability of TE-10 cells in the miR-mimics group was markedly attenuated, and colony numbers were also decreased. Flow cytometry assay showed that the proportion of cells in G1 phase was notably augmented, and the proportion of apoptotic cells was also increased. The miR-mimics group cells had weaker migration and invasion potential compared with mimics-NC group. Western blotting analysis conformed that expression levels of cyclin D1, B cell lymphoma 2, matrix metalloproteinase 2 and vimentin were decreased, but expression levels of cleaved-caspase3, E-cadherin and β-catenin were elevated. The miR-inhibitor group showed opposite results compared with the miR-mimics group. The dual luciferase reporter assay validated the direct targeted binding of miR-760 to the 3'UTR of c-Myc. Conclusion • miR-760 can suppress proliferation, migration and invasion, and induce apoptosis of TE-10 cells by directly targeting c-Myc.
ABSTRACT
@#Objective: To investigate the expression of microRNA(miR) -760 in human cervical squamous cell carcinoma (CSCC) tissues and cells, and it’s effects on the proliferation, apoptosis, invasion, migration and epithelial-mesenchymal transition (EMT) of SiHa cells, as well as its molecular mechanism. Methods: Eighty pairs of CSCC cancerous and corresponding para-cancerous tissue specimens which were pathologically confirmed and 40 cases of normal cervical tissue specimens obtained by myomectomy in Liaocheng Maternal and Child Health Hospital of Shandong Province from April 2015 to August 2018 were selected. The expression of miR-760 in CSCC tissues, para-cancerous tissues and normal cervical tissues, human CSCC cell lines (SiHa, HCC94) and human cervical squamous epithelial immortalized H8 cells were detected by qPCR, and the relationship between miR-760 and clinicopathological characteristics of CSCC patients was analyzed. miR-760 mimics and NC-mimics plasmids were transfected into SiHa cells by liposome transfection. The expression of miR-760 in SiHa cells was detected by qPCR, the proliferation activity and apoptosis rate were detected by CCK-8 test and flow cytometry, respectively. The invasion and migration of SiHa cells were detected by Transwell assay. The expressions of EMT-related proteins, such as E-cadherin, vimentin and N-cadherin, in SiHa cells were detected by WB. Bioinformatics was used to predict the targeting relationship between FOXA1 and miR-760, and double luciferase reporter gene assay was used to verify the direct regulation of miR-760 on FOXA1. Results: The expression of miR-760 in CSCC tissues was significantly lower than that in para-cancerous tissues and normal cervical tissues (all P<0.01), and the expression of miR-760 was closely related to lymphnode metastasis and clinical stage (all P<0.01). The expression of miR-760 in SiHa and HCC94 cells was significantly lower than that in H8 cells (all P<0.01). Up-regulation of the expression of miR-760 could significantly inhibit the proliferation, invasion and migration of SiHa cells (all P<0.01), promote apoptosis (P<0.01), up-regulate the expression of E-cadherin protein (P<0.01), and down-regulate the protein expressions of vimentin and N-cadherin (all P<0.01).FOXA1 was a direct target gene of miR-760 (P<0.01). Up-regulation of miR760 significantly inhibited the mRNA and protein expressions of FOXA1 in SiHa cells (all P<0.05). Conclusion: The expression of miR-760 is down-regulated in CSCC tissues and cells, and it can regulate the proliferation, invasion, migration and apoptosis of CSCC cells by targeting FOXA1. ··