LINC00963 Promotes Cancer Stemness, Metastasis, and Drug Resistance in Head and Neck Carcinomas via ABCB5 Regulation.

Accumulating studies have indicated that long non-coding RNAs (lncRNAs) participate in the regulation of cancer stem cells (CSCs), which are crucial in tumor initiation, metastasis, relapse, and therapy resistance. In the current study, RT-PCR analysis was employed to evaluate the expression of LINC00963 in tumor tissues and oral CSCs. Stemness phenotypes and the expression of CSCs markers in oral cancer cells transfected with sh-LINC00963 were examined. Our results showed that the expression of the lncRNA LINC00963 was up-regulated in oral cancer tissues and CSCs. We found that the downregulation of LINC00963 inhibited CSC hallmarks, such as migration, invasion and colony formation capacity. Moreover, suppression of LINC00963 reduced the activity of stemness marker ALDH1, the percentage of self-renewal, chemoresistance and the expression of multidrug-resistance transporter ABCB5. Most importantly, we demonstrated that knockdown of LINC00963 decreased self-renewal, invasion and colony formation ability via ABCB5. Analysis of TCGA (the Cancer Genome Atlas) datasets suggested that the level of LINC00963 was positively correlated with the expression of the cancer stemness markers (Sox2 and CD44) and drug resistance markers (ABCG2 and ABCB5). Altogether, our results showed that suppression of LINC00963 may be beneficial to inhibit chemoresistance and cancer relapse in oral cancer patients.