Author/Editor     Rijavec, Matija; Šilar, Mira; Triller, Nadja; Kern, Izidor; Čegovnik, Urška; Košnik, Mitja; Korošec, Peter
Title     Expressions of topoisomerase IIalpha and BCRP in metastatic cells are associated with overall survival in small cell lung cancer patients
Type     članek
Source     Pathol Oncol Res
Vol. and No.     Letnik 17, št. 3
Publication year     2011
Volume     str. 691-6
Language     eng
Abstract     The aim of this study was to investigate the mRNA expression levels of multidrug resistance-associated proteins in chemo-naive metastatic lung cancer cells and to determine the correlation with response to chemotherapy and overall survival. Metastatic cells were obtained by transbronchial fine needle aspiration biopsy of enlarged mediastinal lymph nodes in 14 patients with small cell lung cancer (SCLC) and 7 patients with non-small cell lung cancer (NSCLC). After cytological confirmation of lung cancer type, total RNA was extracted from biopsy samples and reverse transcribed to cDNA, and real-time PCR for the genes of interest [P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), breast cancer resistance protein (BCRP), lung resistance protein (LRP) and topoisomerase IIalpha (TOPIIalpha)], was performed. We observed significantly decreased expression of BCRP and significantly increased expression of TOPIIalpha in metastatic SCLC cells compared to NSCLC. Furthermore, in SCLC high topoisomerase IIalpha and low BCRP expression levels positively correlated with longer overall survival. Our results showed higher expression levels of BCRP as well as lower levels of topoisomerase IIalpha in chemo-naive metastatic cells in NSCLC than in SCLC. These results correlate with previous observations that metastatic SCLC cells at the beginning of chemotherapy are potentially more sensitive to chemotherapeutic agents while in metastatic NSCLC cells resistance is usually inherent. We also showed that altered levels of topoisomerase IIalpha and BCRP in SCLC are important factors that contribute to resistance to chemotherapeutics that interfere with the enzyme and/or DNA and are highly associated with overall survival.
Descriptors     LUNG NEOPLASMS
CARCINOMA, SMALL CELL
LYMPHATIC METASTASIS
DNA TOPOISOMERASE (ATP-HYDROLYSING)
BREAST NEOPLASMS
RNA, MESSENGER
BIOPSY
P-GLYCOPROTEIN
DRUG RESISTANCE, MULTIPLE
POLYMERASE CHAIN REACTION
SURVIVAL ANALYSIS