A Study Of The Relationship Between Lung Cancer Sensitivity And Gene Polymorphisms Of MMP-1,-9

The development of cancer is a complex, multistage process during which a normal cell undergoes genetic changes that result in phenotypic alterations and the acquisition of the ability to invade and colonize distant sites. Although many factors are involved in tumor development, interactions between neoplastic cells and the surrounding microenvironment are crucial to each step of tumorigenesis. Molecular analysis of the microenvironment and its deregulation during neoplasia has opened a new direction of cancer research that will provide insight into the microenvironmental effectors that control cell phenotype.One of the proteins that play an essential role in the dynamics of maintaining the cellular microenvironment is the MMP family. The MMP family comprises 20 enzymes that are associated with the degradaion of the ECM, including the basement membrane, as their name implies. Disruption of basement membrane integrity, a feature of invasive tumors, allows tumors to spread locally and distantly. Therefore, it was believed that the MMPs, via breakdown of the physical barrier, were primarily involved in tumor invasion, bloodvessel penetration and metastasis. However, in addition to fostering cellular invasion by disrupting ECM barriers, MMP can influence the microenvironment by altering cellular signals. More importantly, most MMPs are synthesized not only by the genetically altered cancer cells but also by adjacent and intervening stromal cells. There is also growing evidence to support an expanded role of MMP in creating and maintaining a microenvironment that facilitates the initial stages of tumor development.Among the MMPs, MMP-1 is the most highly expressed interstitial collagenase degrading fibrillar collagens, and the most abundant protein in the human body. Overexpression of MMP-1 has been demonstrated in tissue of tumors and has been suggested to be associated with tumor invasion and metastasis. The expression of MMP-1 is partly regulated by the upstream promoter sequences of this gene. MMP-1 gene -1607bp (1G/2G) polymorphic site has been located in a core recognition sequence of the binding sites for transcription factors that modify the level of MMP-1 expression. Promoters containing the 2G allele display significantly higher transcriptional activity than 1G promoters. Gene polymorphism could be caused by many factors, including differences between study populations in ethnic and geographic origin. We took the Chinese residents of Han nationality of Shan'xi province as study subjects. The expression of MMP-1 protein was detected in 70 NSCLC tissues and 30 normal lung tissues as a control by immunochemistry and Western blotting followed by image analysis to detect the A value of expression. The PCR-RFLP assay was used to determine the MMP-1 genotypes. Results 1. The positive rate of MMP-1 expression in NSCLC tissues was 47.1 (33/70), which was higher than that in normal lung tissue23.3%(7/30). 2. The A value of MMP-1 expression in NSCLC tissues of HI stage was significantly higher than that in NSCLC tissues of I, II stage (/X0.05). 3.The A value of MMP-1 expression in NSCLC tissues of N ij2;3 groups was significantly higher than that in NSCLC tissues of No group (/K0.05). 4. There was no significantly difference in MMP-1 expression between NSCLC tissues of squamous cell carcinoma and adenocarcinoma(p>0.05).5.Among the Chinese population of Han nationality of Shan'xi province.There is a single nucleotide polymorphism (-1607, \G~*2G) located in the promoter region of MMP-1, forming three genotypes: 1G/1G, 1G/2G, 2G/2G The genotype frequency of lung cancer cases was higher than controlsC X 2= 5.896,P < 0.05), and individuals with the 2G/2G genotype had 1.81-fold increased lung cancer risk. Non-smokers with 2G/2G genotype had no risk for lung cancer. Current smokers with 2G/2G genotype exhibited 3.20-fold elevated risk for lung cancer (OR, 3.20; 95% CI, 1.50-6.82) .The two metalloproteinases, MMP-2 and MMP-9 (72 kDa and 92 kDa type IV collagenases or gelatinase A and gelatinase B) are associated with tumor invasion and metastasis. Zhang et al showed that a cytosine to thymine (C-*T) polymorphism at position -1562 of the MMP9 promoter has a functional effect on transcription. The T allele was associated with higher levels of expression. Minematsu et al examined the association between the MMP9 promoter polymorphism -1562(C —T) and the development of pulmonary emphysema in JapanescThe emphysematous changes were more conspicuous in individuals with C/T or T/T than those with the C/C genotype. It was indicated that the -1562 C-*T polymorphism acted as a genetic factorfor the development of pulmonary emphysema in Japanese patients. Gene polymorphism could be caused by many factors, including differences between study populations in ethnic and geographic origin. The expressions of MMP-2, MMP-9 protein were detected in 70 NSCLC tissues and 30 normal lung tissues as a control by immunochemistry, and Western blotting followed by image analysis in order to detect the A value of expression. The MMP-9 genotypes were determined using PCR-RFLP assay. Results: l.The positive rate of MMP-2, MMP-9 protein expression in NSCLC tissues respectively was 65.7% (46/70) and 78.6%(55/70), which was higher than that in normal lung tissue. 2. The A values of MMP-2, MMP-9 expression in NSCLC tissues of IH stage were significantly higher than those in NSCLC tissues of K II stages ( p<0.05). 3. The A values of MMP-2, MMP-9 expression in NSCLC tissues of Ni^ groups were significantly higher than those in NSCLC tissues of No group ( /K0.05). 4. The expressions of MMP-2 and MMP-9 in NSCLC tissues of adenocarcinoma were significantly higher than those in NSCLC tissues of squamous cell carcinoma. 5. hi the Chinese population of Han nationality of Shan'xi province, there is a single Nucleotide polymorphism (-1562,C-T) located in the promoter region of MMP-9, forming three genotypes: C/C,C/T,T/T. 6. The genotype frequency of lung cancer cases was higher than controls (J^=9.556vP<0.05) individuals with the T genotype had 40-fold increased lung cancer risk, compared with C genotype (OR,2.40;95% CI, 1.36-4.08). 7.Current smokers with 2G/2G genotype exhibited 2.68-fold elevated risk for lung cancer (OR, 2.68; 95% CL 1.36—4.08) .Conclusions: 1. The expressions of MMP-1, MMP-2, and MMP-9...