Background: Bladder tumor is the fifth most prevalent tumor in men, yet its pathogenesis remains to be fully identified. Albeit a host of long noncoding RNAs (lncRNA) are emerging as new players involved in bladder tumor, the functions of many lncRNAs are still enigmatic. Reports on the deluge of studies on lncRNA ADAMTS9-AS2  have been convincingly associated with various tumors, but without mention of its roles in bladder tumor. Therefore, the roles of ADAMTS9-AS2  in bladder tumor cells were explored in our study.
Materials and Methods: Quantitative real-time PCR assays and bioinformatic tools were applied in bladder tumor cells to identify the ADAMTS9-AS2  and ADAMTS9  expression. Western blot assays were performed to obtain the protein levels of bladder tumor related key molecules. CCK8, clonogenic assay, scratch wound healing, and transwell assays were separately applied to identify the functional roles of ADAMTS9-AS2  on proliferation, migration, and invasion in bladder tumor cells.
Results: First, ADAMTS9-AS2  downregulation in bladder tumor cells was identified. Overexpression and knockdown experiments showed that ADAMTS9-AS2  expression was positively related to ADAMTS9 , which is in accordance with the results from GEO database. Second, ADAMTS9-AS2  contributed to the inhibition of proliferation, migration, and invasion in bladder tumor cells. Third, ADAMTS9-AS2  was linked with PI3K /AKT /mTOR pathway related-molecules, several key autophagy, and apoptotic proteins.
Conclusion: Conjointly, our findings suggested that ADAMTS9-AS2  might function as a tumor suppressor to restrain the proliferation, migration, and invasion in bladder tumor cells. The potential mechanism of ADAMTS9-AS2  related to PI3K /AKT /mTOR signal pathway was further identified. Of note, we found that ADAMTS9-AS2  has a significant effect on several key autophagy and apoptotic proteins. Therefore, these observations will provide supportive evidence to ADAMTS9-AS2  as a potential biomarker in patients with bladder tumor.
Keywords: lncRNA ADAMTS9-AS2, proliferation, PI3K/AKT/mTOR, bladder tumor