ABSTRACT
@#[Abstract] Objective: To explore the regulatory effect of lncRNA maternal imprinting gene 3 (MEG3) on proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of cervical cancer cells via miR-9-5p/SOCS5 axis. Methods: A total of 20 pairs of cancer and para-cancerous tissue specimens resected from cervical cancer patients in Chongqing Hospital of Traditional Chinese Medicine from January 2017 to June 2019 were collected for this study. Using liposome transfection technology, pcDNA3.1-MEG3,si-MEG3, miR-9-5p mimics, miR-9-5p inhibitor and their control plasmids were transfected into cervical cancer HeLa and SiHa cells respectively to construct overexpression and silence cell model. qPCR was used to detect the expression levels of MEG3, miR-9-5p and SOCS5 in cervical cancer tissues and cell lines. CCK-8 method and Transwell chamber method were used to detect cell proliferation, migration and invasion ability. The expression levels of E-cadherin and vimentin in cells were detected by cellular immunofluorescence experiments. Target genes were predicted through the Online Bioinformatics TargetScan database. Dual luciferase reporter gene assay was used to verify the targeting relationship between miR-9-5p and MEG3, SOCS5, respectively. Results: Compared with para-cancerous tissues and cervical epithelial HcerEpic cells, the expressions of MEG3 and SOCS5 were significantly down-regulated and the expression of miR-9-5p was significantly up-regulated in cervical cancer tissues and cell lines (all P<0.01). TargetScan database analysis and Dual luciferase reporter gene assay confirmed the targeting relationship between miR-9-5p and MEG3 or SOCS5. MEG3 and SOCS5 significantly inhibited while miR-9-5p significantly promoted cell proliferation, migration and invasion ability (all P<0.01). MEG3 and SOCS5 promoted E-cadherin expression and inhibited vimentin expression, while miR-9-5p inhibited E-cadherin expression and promoted vimentin expression (P<0.05 or P<0.01). Conclusion: lncRNA MEG3 regulates proliferation, migration, invasion and EMT of cervical cancer cells via miR-9-5p/SOCS5 axis.
ABSTRACT
@#Objective: To investigate the role of exosome (EXO) transporting Let-7a to regulate MYC gene in the malignant biological behaviors of triple negative breast cancer (TNBC) cell, and to explore the underlying mechanism. Methods: After the completion of cell culture, the gene and protein expressions of MYC and Let-7a in TNBC MDA-MB-231cells were detected by qPCR and WB, respectively. Recombinant lenti-virus vector carrying Let-7a and Crisper/Cas-9 system with MYC knockdown were transfected into MDA-MB-231 cells; MTT assay, Transwell assay and Scratch healing assay were performed to examine the proliferation, invasion and migration of MDA-MB-231 cells. Luciferase activity assay was performed to validate the binding between MYC and Let-7a. EXO was isolated and identified by transmission electron microscopy and WB assay in wild-type and Let-7a over-expressed MDA-MB-231 cells, respectively. After co-incubation of two types of EXO and MDA-MB-231 cells, the effects of Let-7a on biological behaviors of MDAMB-231 cells via EXO were detected by qPCR, WB, MTT and Transwell etc. Results: Let-7a was negatively correlated with MYC in breast cancer tissues and cell lines (all P<0.05); MYC promoted while Let-7a inhibited the proliferation, migration and invasion of breast cancer cells (all P<0.01); Let-7a silenced MYC by acting on 3'UTR of MYC gene, thereby reducing the expression of MYC protein (P<0.05); Let-7a was enveloped by EXO and transported to cancer cells, there by inhibiting the proliferation, migration and invasion of MDA-MB-231 cells. Conclusion: EXO some mediated Let-7a silences MYC gene by acting on its 3'UTR region, thus inhibiting the proliferation, migration and invasion of MDA-MB-231 cells.