DNA Repair Genes ERCC1 and BRCA1 Expression in Non-Small Cell Lung Cancer Chemotherapy Drug Resistance.
BACKGROUND Surgery combined with chemotherapy is an important therapy for non-small cell lung cancer (NSCLC). However, chemotherapy drug resistance seriously hinders the curative effect. Studies show that DNA repair genes ERCC1 and BRCA1 are associated with NSCLC chemotherapy, but their expression and mechanism in NSCLC chemotherapy drug-resistant cells has not been elucidated. MATERIAL AND METHODS NSCLC cell line A549 and drug resistance cell line A549/DDP were cultured. Real-time PCR and Western blot analyses were used to detect ERCC1 and BRCA1 mRNA expression. A549/DDP cells were randomly divided into 3 groups: the control group; the siRNA-negative control group (scramble group); and the siRNA ERCC1 and BRCA1siRNA transfection group. Real-time PCR and Western blot analyses were used to determine ERCC1 and BRCA1 mRNA and protein expression. MTT was used to detect cell proliferation activity. Caspase 3 activity was tested by use of a kit. Western blot analysis was performed to detect PI3K, AKT, phosphorylated PI3K, and phosphorylated AKT protein expression. RESULTS ERCC1 and BRCA1 were overexpressed in A549/DDP compared with A549 (P<0.05). ERCC1 and BRCA1siRNA transfection can significantly reduce ERCC1 and BRCA1 mRNA and protein expression (P<0.05). Downregulating ERCC1 and BRCA1 expression obviously inhibited cell proliferation and increased caspase 3 activity (P<0.05). Downregulating ERCC1 and BRCA1 significantly decreased PI3K and AKT phosphorylation levels (P<0.05). CONCLUSIONS ERCC1 and BRCA1 were overexpressed in NSCLC drug-resistant cells, and they regulated lung cancer occurrence and development through the phosphorylating PI3K/AKT signaling pathway.
, Shandong University, Jinan, Shandong, China (mainland).
Shuai
S
Wang
, WeiFang Medical University, Weifang, Shandong, China (mainland).
Feng
F
Liu
Department of Oncology, Weifang Traditional Chinese Hospital, Weifang, Shandong, China (mainland).
Jingyan
J
Zhu
Department of Oncology, Weifang Traditional Chinese Hospital, Weifang, Shandong, China (mainland).
Peng
P
Chen
Department of Oncology, Weifang Traditional Chinese Hospital, Weifang, Shandong, China (mainland).
Hongxing
H
Liu
Institute of Oncology, Provincial Hospital Affiliated to Shandong University, Shandong University, Jinan, Shandong, China (mainland).
Qi
Q
Liu
Department of Tumor Research and Therapy Center, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China (mainland).
Junqing
J
Han
D000072283:A549 Cells; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D019313:BRCA1 Protein / Q000096:biosynthesis / Q000235:genetics*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics*; D045744:Cell Line, Tumor; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D015536:Down-Regulation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D004720:Endonucleases / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D014162:Transfection
D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C071447:ERCC1 protein, human; D004720:Endonucleases