The Expression And Significance Of CXCR-4 And MMP-2 In Non-small Cell Lung Cancer

Background and ObjectivesThe incidence and mortality of lung cancer is increasing rapidly and it severely endangers human life. Non-small cell lung carcinoma (NSCLC) accounts for 80% to 90% of all lung cancers. Invasiveness and metastasis are the primary cause of treatment failure and death in NSCLC.Crucial event in the Invasiveness and metastasis of cancer cells is the secretion of matrix metalloproteinases (MMPs), which are responsible for the degradation of extracellular matrix (ECM). Among them, matrix metalloproteinase-2 (MMP-2) is a gelatinase, which degrades basement membrane type-Ⅳcollagen. Recent evidence suggests that the chemokine receptor CXCR-4 and its corresponding ligand SDF-Ⅰare involved in the metastasis of many cancers. Same as MMP-2, the research of CXCR-4 in NSCLC is rarely reported. At present, there aren't any correlation reports between MMP-2 and CXCR-4 in NSCLC in the literature.In our study, the expression of CXCR-4 in NSCLC was detected both by immunohistochemical staining S-P method and RT-PCR method, the expression of MMP-2 in NSCLC was detected only by immunohistochemical staining S-P method. We try to explore their roles in invasiveness and metastasis in NSCLC. It may provide basis of research in the gene diagnosis and gene therapy for NSCLC. Materials and methods1 As experimental group,60 cases of NSCLC specimens which were confirmed postoperative by pathological diagnosis were obtained from department of thoracic surgery, the second Clinical College of Zhengzhou University from November 2008 to July 2009. Among the 60 NSCLC cases,36 are male and 24 are female, aged between 38 to 73 years, average age is 55.7. Any chemotherapy or radiotherapy has never been carried out in all cases before operation.23 cases of normal lung tissue were selected as control group, which were obtained from the patients with NSCLC 5 cm far from tumor tissue and confirmed histologically.2 The expression of MMP-2 was detected by immunohistochemical staining S-P method. The expression of CXCR-4 was detected by immunohistochemical staining S-P method and RT-PCR method.3 All statistical analyses were performed by using the Statistical Package for SPSS 10.0. The association of variables was evaluated by usingχ2 test, t-test and Pearson analysis. a=0.05.Results1 MMP-2 protein was detected using immunohistochemical staining S-P method. The expression of MMP-2 protein in experimental group (73.3%) is significantly higher than that of control group (39.1%), there was a significant difference in them (P<0.05). The expression of MMP-2 protein in NSCLC was not correlated with the patients'age, gender and tumor histology(P>0.05). The expression of MMP-2 protein in NSCLC was correlated with lymphatic metastasis, tumor differentiation and the TNM stage (P<0.05).2 CXCR-4 protein was detected using immunohistochemical staining S-P method. The expression of CXCR-4 protein in experimental group (60.5%) is significantly higher than that of control group (26.1%), there was a significant difference in them (P<0.05). The expression of CXCR-4 protein in NSCLC was not correlated with the patients'age, gender and tumor histology (P>0.05). The expression of CXCR-4 protein in NSCLC was correlated with lymphatic metastasis, tumor differentiation and the TNM stage (P<0.05). 3 CXCR-4 protein and MMP-2 protein expression in NSCLC was positively correlated(r=0.269,P=0.037<0.05).4 CXCR-4 mRNA was detected using RT-PCR method. The expression of CXCR-4 mRNA in NSCLC was not correlated with the patients'age, gender and tumor histology(P>0.05). The expression of CXCR-4mRNA in NSCLC was correlated with lymphatic metastasis, tumor differentiation and the TNM stage (P<0.05), same as the results detected by immunohistochemical staining S-P method.Conclusion1 CXCR-4 and MMP-2 play an important role in the occurrence of NSCLC.2 The expression of CXCR-4 and MMP-2 in NSCLC was not correlated with the patients'age, gender and tumor histology. The expression of CXCR-4 and MMP-2 in NSCLC was correlated with the malignance, aggression and metastasis.3 CXCR-4 with MMP-2 plays an important role in the occurrence, development, aggression and metastasis of NSCLC.4 There is a same expression result of CXCR-4 in NSCLC which was detected by immunohistochemical staining S-P method or RT-PCR method.