EXPERIMENTAL STUDY ON THE EFFECT OF INTRACELLULAR ROS LEVEL IN NON-SMALL CELL LUNG CANCER ON RESPONSE TO ABT-263 THERAPY

Liangliang Ouyang^1,#, Yufang Du^2,#, Yujun Yuan¹, Zhaohui Leng¹, Wenjuan Wang¹

¹Department of laboratory, The Affiliated Hospital of Jiujiang University, Jiujiang, Jiangxi, 332000, PR China - ²Department of Operating room, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, PR China

Objective: To investigate the effect of reactive oxygen species (ROS) level in non-small cell lung cancer (NSCLC) on response to ABT-263 therapy. 

Methods: In this study, NSCLC-related cell lines were selected, the responses of different NSCLC cell lines to ABT-263 therapy were analyzed, and the effect of ABT-263 on the apoptosis, MCL-1 ex-pression and ROS level of different cell lines were evaluated. 

Results: Compared with DMSO-treated cells, the positive percentage of annexin V and/or PI in Calu-1, Calu-3 and BID007 cells treated with ABT-263 increased significantly (P<0.05); PARP deg-radation products were observed in Calu-3 and BID007 cells treated with ABT-263, but not in A549 cells; Western blot analysis indicated that the expression levels of MCL-1 in BID007, Calu-1, Calu-3 and A549 cells were similar. MCL-1 gene silencing can improve the responses of PC-9 and A549 cells to ABT-263 therapy; MCL-1 gene silencing didn’t affect the responses of Calu-3 and BID007 cells to ABT-263 therapy; Flow cytometry analysis showed that after ABT-263 treatment, the ROS levels in Calu-1 and Calu-3 cells decreased significantly (P<0.05). Immunofluorescence assay suggested that the ROS levels in Calu-1 and Calu-3 cells were higher than those of H3122 and A549 (P<0.05); The results of MTS test showed that after NAC treatment, the responses of Calu-3 and BID007 cells to ABT-263 therapy decreased significantly (P<0.05). Flow cytometry analysis showed that the ROS level in ABT-263 treated-cells fell significantly when MCL1 gene was silenced (P<0.05). 

Conclusion: ROS level is closely related to the response of NSCLC cell lines to ABT-263 therapy and ROS can effectively improve the sensitivity to ABT-263 therapy.