ABSTRACT
Objective To investigate the changes in lung resistance-related protein (LRP) and vascular endothelial growth factor (VEGF) expressions and micro-vessel density (MVD) in non-small cell lung cancer (NSCLC), and to elucidate their possible relationship and mechanism. Methods Immunohistochemistry was used to detect changes in LRP and VEGF expressions, and MVD level in lung tissues of 56 NSCLC cases and 27 normal controls. Results ① LRP expression (66.1%) was concentrated in the cytoplasm of cancer cells, which was significantly higher than that in lung tissues of control group (P<0.01); the significance was not related to the pathological type. There was no significant difference in LRP expression among gender, TNM stage, lymph node metastasis, and two-year survival in NSCLC (P>0.05). ② In comparison to the control group, NSCLC group had significantly increased VEGF expression (P<0.01), which was not related to the pathological type. VEGF expression in NSCLC group had a significant association with TNM stage and lymph node metastasis (P<0.05). ③ The NSCLC group had a significantly higher MVD than the control group (P<0.01), which was not affected by the pathological type or degree. MVD value (18.5±5.8) of stage Ⅲ and Ⅳ in NSCLC group was significantly higher than that (13.8±5.1) of stage Ⅰ (P<0.05); MVD value for patients with lymph node metastasis was higher than that without lymph node metastasis (P<0.05); MVD value for patients with two-year survival was less than those who died within two years (P<0.01). ④ NSCLC group with high VEGF and LRP expressions had a consistently increased MVD value (P<0.05). Conclusion There is a certain relationship between tumor angiogenesis and LRP expression in NSCLC. VEGF is responsible for the high expression of LRP through up-regulating LRP gene and augmenting tumor MVD. Inhibition of angiogenesis in tumor is expected to reduce or inhibit drug resistance to NSCLC.