Effect of miR-181d on chemo-sensitivity in human small cell lung cancer / 中国肿瘤临床

ABSTRACT

Objective:To investigate the possible role of miR-181d in regulating the multidrug resistance (MDR) of small cell lung cancer (SCLC) and its clinical significance. Methods: Quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) and Western blot were used to investigate the differential expression of miR-181d and BCL2 from mRNA and protein levels in the chemo-sensitivity cell H69 and the chemo-resistance cell H69AR. The miR-181d expression in H69AR was then upregulated. More-over, CCK8 assay was employed to detect the sensitivities of the cells to chemotherapy drugs, such as ADM, DDP, and VP-16. Mean-while, the expression of miR-181d in the specimens of 87 cases with SCLC were detected using QRT-PCR. All patients received the chemotherapeutic regimen of EP (etoposide+cisplatin). Correlation of the miR-181d expression with clinicopathological features, prog-nosis, and survival time of the patients was studied. Results:miR-181d was downregulated in the SCLC multidrug-resistant cell line H69AR and chemo-resistant patients. Moreover, miR-181d was concurrent with the upregulation of BCL2 protein compared with the parental H69 cell line and chemo-sensitive patients (P<0.001). miR-181d expression in H69 cells resistant to chemotherapy drugs (ADM, DDP, and VP-16) was inhibited (P<0.01). Enforced miR-181d expression reduced the BCL2 protein level and sensitized H69AR cells to chemotherapy drugs (P<0.01). miR-181d expression was associated with tumor stage, sensitivity of chemotherapy, and survival time (all P<0.001). Patients with high miR-181d expression had longer overall survival and progress-free survival time com-pared with those with low miR-181d expression (P<0.001). Conclusion: miR-181d may play a role in the development of MDR in SCLC and may be a potential predictive factor for treatment efficacy.