Lnc SMAD5-AS1 as ceRNA inhibit proliferation of diffuse large B cell lymphoma via Wnt/β-catenin pathway by sponging miR-135b-5p to elevate expression of APC

Abstract

Diffuse large B cell lymphoma (DLBCL) is a common and fatal hematological malignancy. Long noncoding RNAs (lncRNAs) have emerged as crucial biomarkers and regulators in many cancers. Novel lncRNA biomarker in DLBCL needs to be investigated badly, as well as its function and molecular mechanism. To further explore, microarray analysis was performed to identify the differentially expressed lncRNAs in DLBCL tissues. To investigate the biological functions of SMAD5-AS1, we performed gain- and loss-of-function experiments in vitro and in vivo. Furthermore, bioinformatics analysis, dual-luciferase reporter assays, Argonaute 2-RNA immunoprecipitation (AGO2-RIP), RNA pull-down assay, quantitative PCR arrays, western blot assay, TOPFlash/FOPFlash reporter assay, and rescue experiments were conducted to explore the underlying mechanisms of competitive endogenous RNAs (ceRNAs). We found that SMAD5-AS1 was down-regulated in DLBCL tissues and cell lines. Functionally, SMAD5-AS1 downregulation promoted cell proliferation in vitro and in vivo, whereas SMAD5-AS1 overexpression could lead to the opposite effects in vitro and in vivo. Bioinformatics analysis and luciferase assays revealed that miR-135b-5p was a direct target of SMAD5-AS1, which was validated by dual-luciferase reporter assays, AGO2-RIP, RNA pull-down assay, and rescue experiments. Also, dual-luciferase reporter assays and rescue experiments demonstrated that miR-135b-5p targeted the adenomatous polyposis coli (APC) gene directly. SMAD5-AS1/miR-135b-5p inhibits the cell proliferation via inactivating the classic Wnt/β-catenin pathway in the form of APC dependency. Our results indicated that SMAD5-AS1 inhibits DLBCL proliferation by sponging miR-135b-5p to up-regulate APC expression and inactivate classic Wnt/β-catenin pathway, suggesting that SMAD5-AS1 may act as a potential biomarker and therapeutic target for DLBCL.

Silencing of Long Non-coding RNA SMAD5-AS1 Reverses Epithelial Mesenchymal Transition in Nasopharyngeal Carcinoma via microRNA-195-Dependent Inhibition of SMAD5

“…Previous evidence has revealed that Raf-1 is a new direct target of miR-195, and the expression of Raf-1 is markedly decreased by miR-195 (34). Similarly, SMAD5-AS1 is reported to be a ceRNA of miR-135b-5p to upregulate APC expression in diffuse large B cell lymphoma (35). Subsequently, the findings of this study showed that SMAD5-AS1 upregulated SMAD5 via competitively binding to miR-195 in NPC.…”

Long non‐coding RNA SNHG16 promotes proliferation and inhibits apoptosis of diffuse large B‐cell lymphoma cells by targeting miR‐497‐5p/PIM1 axis

“…n = three independent repeats, *P < .05 SMAD5-AS1 plays a tumour suppressive role in DLBCL by inhibiting cell proliferation in vitro and repressing tumour growth in vivo. 39 LncRNA PANDA leads to cell cycle arrest at G0/G1 phase in DLBCL cells. 40 Conversely, lncRNA MALAT-1 contributes to proliferation and cell cycle progression, and it represses apoptosis of DLBCL cells.…”

“…Recent studies have demonstrated that lncRNAs function as oncogenes or tumour suppressors in DLBCL. For instance, lncRNA SMAD5‐AS1 plays a tumour suppressive role in DLBCL by inhibiting cell proliferation in vitro and repressing tumour growth in vivo . LncRNA PANDA leads to cell cycle arrest at G0/G1 phase in DLBCL cells .…”

lncRNA-TINCR Functions as a Competitive Endogenous RNA to Regulate the Migration of Mesenchymal Stem Cells by Sponging miR-761

“…To date, numerous studies have revealed its important roles in cellular processes, such as X chromosome inactivation, splicing, imprinting, epigenetic control, and gene transcription regulation [1][2][3]. Moreover, some have shown that lncRNAs could function as a competing endogenous RNA (ceRNA) to sponge miRNAs, thereby preventing microRNAs from binding to their target genes [4][5][6][7].…”