Screening For Novel Molecular Markers Of Tumor Cells

Cancer is one of the major human genetic diseases. Carcinogenesis occurs due to abnormal cell cycle, unusual cell proliferation and differentiation as a result of the effects of carcinogenic factors. Expression of tumor markers has been found to be changed in tumor cells, showing a high sensitivity and specificity in tumor tissues. The expression amount of tumor markers in serum has been used to diagnose the tumor tissue clinically. Mutations analysis in different cancer cells showed that there were mutations in both exons and introns in tumor suppressor gene P53 and BRCA1. Mutations in both upstream and downstream intron of exon 3, exon 4, downstream intron of exon 4, upstream intron of both exon 5 and 10, and exon 11 of the P53 gene were found. Mutations were found in upstream intron of both exon 7 and exon 8, exon 10 and 12, downstream intron of exon 17 and upstream intron of exon 20 of the BRCA1 gene. The mutations in the introns may be considered as novel DNA markers for tumor cells. But no mutation in proto-oncogenes Src and N-myc was detected. The proteome pattern in mammary cancer cells MCF-7 was compared with that in mammary epithelial cells MCF-10A by two-dimensional electrophoresis and subsequent mass spectrometry. It was found that cell keratin protein-8,71 kDa heat shock protein,94 kDa glucose regulation protein and the 14-3-3ε protein were up-regulated while cell keratin protein-18,40S ribosomal protein and cell keratin protein-1 were down-regulated in MCF-7 cells relative to the control cells of MCF-10A. Therefore, the 14-3-3ε protein and the 40S ribosomal protein might be used as novel protein markers for early diagnosis of breast cancer.