Lung Cancer Tissue Microarray Preparation And Application

Background & Objective In the past two decades,the incidence of lung cancer has increased quickly in our country. Lung cancer was a multistage processs involving a number of genes.Molecular biolodical studies indicated that abnormal expression of P53 gene cycle and Rb gene cycle is correlated with the development of lung cancer.This study was designed to investigate expression difference and its clinicopathologic significance of eight kinds of Rb-related and P53-related oncogenes and tumor-suppressor genes in lung cancer and normal lung tissues using tissue microarrays technique and immunohistochemistry.Methods: The lung cancer tissue microarrays comprised 226 cases of lung cancer tissues,23 normal lung tissues obtained from autopsy. The diameter of each specimen on tissue microarrays was 1.0mm. Immunohistochemistry was employed to detect the expression of P16, P21, P53, P63,MDM2, Rb,P16,CDK4 genes in tumor and normal lung tissue,respectively. The relationship between the expression of these genes was also analyzed.RESULTS: Three paraffin-embedded lung cancer tissue microarrays were successfully constructed,composed of 105,81,63 tissue dots,respectively.The positive staining rates of the eigh genes in lung cancer and normal tissues were: P16 58.4% and 95.7%,Rb 73.0% and 95.6%,CDK4 62.4% and 0/23, p53 54.4% and 0/23,P63 50.9% and 21.1%, MDM2 54.0% and 17.4%,P14 54.9% and 95.7%,P21 59.3% and 0/23,respectively. Significant difference exists between tumorous tissue and normal tissues(P<0.01).Except P53 and CDK4 genes, the expression of P16,Rb,MDM2,P63,P14 and P21 in NSCLC were statistically significant than that in SCLC. There was significant difference for P53,P21,CDK4,MDM2 positive rate in different histological grades of lung cancer. The expressions of P53,P16,P14,P21and MDM2 in the lung cancer significantly were associated with lymph node metastases. There was significant difference for P14,P21 ,MDM2 and P16 positive rate in different clinical disease stage of lung cancer.CONCLUSION:!.Tissue microarray technique had the advantage of high-throughput in the detection of lung cancer related oncogenes and tumor-suppressorgenes,which can analyze larger amounts of specimens,more target genes,and costless working time.2.P53 gene mutation and the over expression of P63,MDM2,P21 may play important roles in genesis and progression of lung cancer.3.P16 inactivation was detected mainly in NSCLC and Rb inactivation mainly in SCLC.4. There existed low expression of PI6 , P14 proteins and over-expression of mutated P53 protein.Co-expression of these antioncogenes play an important role in metastasis and clinical stage of lung cancer.