Long non-coding RNA MALAT1 regulated ATAD2 to facilitate retinoblastoma progression by sponging miR-655-3p
Background: Long non-coding RNA (lncRNA) metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was reported as an oncogene in many tumors including retinoblastoma (RB). This research mainly focused on the functions and mechanism of MALAT1 in RB.Methods: The levels of MALAT1, microRNA-655-3p (miR-655-3p), and ATPase family AAA domain containing 2 (ATAD2) in RB tissues and cells were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The cell viability and apoptotic
... ility and apoptotic rate were monitored via cell counting kit 8 (CCK8) assay and flow cytometry, respectively. The protein levels of p21, CyclinD1, B-cell lymphoma-2 (Bcl-2), cleaved-casp-3, E-cadherin, Ncadherin, Vimentin, and ATAD2 were detected by Western blot assay. Transwell assay was performed to estimate the abilities of migration and invasion. The interactions between miR-655-3p and MALAT1 or ATAD2 were predicted by starBase. Dual-luciferase reporter assay was constructed to verify these interactions. The mice model experiments were established to validate the effects of MALAT1 in vivo.Results: MALAT1and ATAD2 were significantly increased while the level of miR-655-3p was remarkably decreased in RB tissues and cells. MALAT1 knockdown inhibited cell proliferation, metastasis, and epithelial-mesenchymal transition (EMT) but promoted apoptosis via miR-655-3p in vitro, and blocked xenograft tumor growth in vivo. MALAT1 was validated to sponge miR-655-3p and ATAD2 was verified as a candidate of miR-655-3p. MiR-655-3p overexpression inhibited cell proliferation but promoted apoptosis by targeting ATAD2. MALAT1 silencing affected cell behaviors by regulating ATAD2. MALAT1 depletion down-regulated ATAD2 expression via miR-655-3p in RB cells.Conclusion: MALAT1 positively regulated ATAD2 to accelerate cell proliferation but retard apoptosis by sponging miR-655-3p in RB cells.