ABSTRACT
@#Objective: To investigate whether long non-coding RNA (lncRNA) FOXD2-AS1 targets miR-506-5p to regulate proliferation and apoptosis of cervical cancer cells. Methods: Human normal cervical cells Ect1/E6E7 and cervical cancer cell lines (HeLa, Siha and Caski) were cultured in vitro, and the expression levels of FOXD2-AS1 and miR-506-5p in cells were detected by qPCR. The cervical cancer cells with FOXD2-AS1 knockdown and miR-506-5p over-expression were constructed by liposome transfection technology, and the proliferation and apoptosis of cells were detected by MTT assay and flow cytometry respectively, the expression of proliferation-related proteins CyclinD1, p21, p27 and apoptosis-related proteins Bcl-2, BAX, cleaved-capase-3 were detected by WB. Dual luciferase reporter assay was used to verify whether FOXD2-AS1 would target miR-506-5p; and the effects of simultaneous inhibition of FOXD2-AS1 and miR-506-5p on proliferation and apoptosis of cervical cancer cells were also analyzed. Results: Compared with Ect1/E6E7 cells, the expression of FOXD2-AS1 significantly increased while the expression of miR-506-5p significantly decreased in cervical cancer HeLa, Siha and Caski cells (all P<0.01). FOXD2-AS1 knockdown significantly inhibited the protein expressions of CyclinD1, Bcl-2 and cell proliferationin cervical cancer cells, but promoted the protein expressions of p21, p27, BAX, cleavedcapase-3, and cell apoptosis (all P<0.01). miR-506-5p over-expression significantly inhibited the protein expressions of CyclinD1, Bcl2 and cell proliferation in cervical cancer cells, but promoted the protein expressions of p21, BAX, and cell apoptosis (all P<0.01). Dual luciferase reporter gene assay confirmed that FOXD2-AS1 negatively regulated the expression of miR-506-5p in cervical cancer cells (P<0.01). Inhibition of miR-506-5p expression reversed the effect of FOXD2-AS1 knockdown on proliferation and apoptosis of cervical cancer cell (P<0.01). Conclusion: FOXD2-AS1 modulates proliferation and apoptosis of cervical cancer cells by negatively regulating the expression of miR-506-5p.
ABSTRACT
@# Objective: To investigate the molecular mechanism of lncRNA FOXD2-AS1 participating in apatinib resistance in gastric cancer cells by regulating miR-185-5p/CCND2 axis. Methods: The gastri cancer tissues and corresponding paracancerous tissues of 25 patients with gastric cancer were collected from April 2016 to December 2017 in the Fifth People’s Hospital of Wuxi City. The expressions of FOXD2-AS1, miR-185-5p, and cyclin D2 (CCND2) in gastric cancer tissues or cell lines were examined by quantitative realtime polymerase chain reaction (qRT-PCR). CCK-8 assay, Transwell assay and Annexin V-FITC/PI double staining flow cytometry assay were applied to assess the sensitivity of gastric cancer cells to apatinib. The interaction between FOXD2-AS1, miR-185-5p and CCND2 was explored by dual luciferase reporter gene assay, which was then confirmed by qRT-PCR, and Western blotting. Results: FOXD2-AS1 was highly expressed in gastric cancer tissues and apatinib-resistant gastric cancer cells. Over-expression of FOXD2-AS1 promoted apatinib-resistance of MGC-803/AP cells. Dual luciferase reporter gene assay confirmed that FOXD2-AS1 directly interacted with miR-185-5p and suppressed its expression. miR-185-5p significantly abolished the promotion effect of FOXD2-AS1 on apatinibresistance via inhibiting cell proliferation, invasion and promoting apoptosis of gastric MGC-803/AP cells. miR-185-5p could negatively regulate CCND2 expression; and FOXD2-AS1 promoted the cell proliferation, invasion and inhibited apoptosis of MGC-803/AP cells via down-regulating the inhibition effect of miR-185-5p on CCND2, thus further enhanced the apatinib-resistance of gastric cancer cells. Conclusion: FOXD2-AS1 induced apatinib-resistance of gastric cancer cells by regulating miR-185-5p/CCND2 axis.