Relationship between expression of apoptosis-related genes and multidrug resistance genes in lung cancer tissues and their clinical significance

Abstract

Multidrug resistance (MDR) of lung cancer is a complex procedure involved in multiple genes and multiple pathways. Besides multidrug resistance genes, there is close relationship between expression of apoptosis-related genes and MDR in lung cancer. The aim of this study is to explore the relationship among the expression of apoptosis-related genes (p53, Bcl-2) and clinicopathological characteristics, and their correlation with multidrug resistance genes such as lung resistance protein (LRP), P-glycoprotein (P-gp), glutathione S-transferase π (GST-π), topoisomerase II (Topo II) and multidrug-resistance-associated protein (MRP) in lung cancer. The expression of P53, Bcl-2, LRP, P-gp, GST-π, Topo II and MRP was detected in 68 lung cancer patients (Bcl-2 for 51 patients) with immunohistochemical staining (Envision method). The positive rate of P53 and Bcl-2 was 75.0% and 33.3% respectively. There was significant difference in P53 expression between non-small cell lung cancer and small cell lung cancer (P=0.001) and among various grades of cell differentiation (P=0.003). There was also significant difference in Bcl-2 expression between squamous cell carcinoma and adenocarcinoma (P=0.002). There was no relationship between the expression of P53 and Bcl-2 (P > 0.05). Spearman analysis showed that there was a positive correlation between the expression of P53 and P-gp (P=0.002), and between P53 and GST-π (P=0.017), and the coexpression rate was 70.6% and 47.1% respectively. There was no correlation between the expression of Bcl-2 and five multidrug resistance factors (P > 0.05). The expression of apoptosis-related gene mutant p53 is significantly related to multidrug resistance factors P-gp and GST-π. It is important to detect both apoptosis-related genes and various multidrug resistance genes.