Cdh1 Gene Methylation And Lung Cancer Research

Lung cancer is a common malignancy and with the development of industrialization, it is the major determinant of overall cancer mortality in all over countries. Resent advances in molecular biology showed that lung cancers have accumulated by many different genetic or epigenetic abnormalities of oncogenes and/or tumor suppressor genes. DNA methylation is the most major form of epigenetic alterations .In higher order eukaryotes, DNA is methylated only at cytosines located to guanosine in the CpG dinucleotide. This modification has important regulatory effects on gene expression, especially when involving CpG-rich areas known as CpG islands, located in the promoter regions of many genes. Methylation of the promoter region within CpG islands is considered to be critical for gene silencing given that the promoter region is essential for transcriptional regulation . On the basis of Knudsons two-hit" hypothesis, both alleles of tumor suppressor genes have to be nactivated for loss of expression. Allelic loss of one copy is often associated with methylation, mutation, or some other form of inactivation of the second allele. Aberrant methylation of the promoter regions of tumor suppressor genes seems to be the major mechanism of gene silencing in human tumors .The CDH1 (Cadherin1) gene is located on human chromosome 16q22.1, This gene is a classical member of the cadherin superfamily. It encodes a cell-surface adhesion protein that plays a crucial role in homotypic cell-cell adhesion and maintenance of epithelial morphology. It also helps in controlling cell growth and differentiation. Loss of it' s function is thought to contribute to progression in cancer by increasing proliferation, invasion, and/or metastasis. In molecular biology fields, early researches focused on genetic alterations such as mutation and biallelic deletions, however, resent advanced researches show that epigenetic abnormalities have played a crucial role in proliferation, invasion, and/or metastasis of tumors. Methylation-specific polymerase chain reaction (MSP) is frequently used to screen DNA methylation state. It's a qualitative method that it only can detect the methylation exist or not. In order to study whether the CDH1' s methylation state had changed or not in lung cancer, and...