Background: Chemotherapy constitutes one of the most important adjuvant treatments for bladder cancer. However, many patients usually develop chemoresistance during chemotherapy. At present, lncRNA has been confirmed not only to be involved in tumorigenesis and progression, but also in tumor chemoresistance. However, the relationship between lncRNAs and chemoresistance of bladder cancer have been rarely reported.
Methods: The novel lncRNA-KMU15 was screened by lncRNAs microarray and determination of IC50 in bladder cancer. The expression of KMU15 was evaluated by qRT-PCR. The correlation between KMU15 and clinicopathological parameters was analyzed from clinical cases. The effects of KMU15 on the biological behavior and chemoresistance were investigated by [3H]-TdR incorporation assay and other experiments. The effects of KMU15 on the growth of xenograft tumors and the survival of nude mice under cisplatin were examined in a xenograft mouse model.
Results: We confirmed that KMU15 was expressed higher in bladder cancer tissues than paired control tissues. Moreover, the expression of KMU15 was significantly positively correlated with the grade, stage, metastasis, and recurrence of bladder cancer and was significantly negatively correlated with the prognosis. In addition, KMU15 knockdown could significantly inhibit bladder cell proliferation, adhesion, migration, and chemoresistance and promoted apoptosis. Knockdown of KMU15 inhibited the growth of xenografts in nude mice and significantly prolonged the survival of tumor-bearing mice under cisplatin.
Conclusions: The novel lncRNA KMU15, which is highly expressed in bladder cancer tissues, could promote the proliferation and progression and was closely related to the malignant degree of bladder cancer. It could also significantly enhance the chemoresistance of bladder cancer cells. Therefore, it was expected to be a new therapy target for bladder cancer and a potential prognosis biomarker for chemotherapy.