| Cervical carcinoma is one of the most common malignancy among women in developing country. The incidence and the rate of death of cervical carcinoma are very high. There are some high-incidence areas of cervical carcinoma in china, such as Hubei, Jiangxi, and Xinjiang Province. The infection with high-risk type human papillomavirus such as HPV16 or HPV18 was ever regarded as the major etiological factor for cervical carcinoma, but the alter of genetic factors is also important during the occurrence of cervical carcinoma. Therefore, some researchers of our lab analysed the cervical carcinoma specimen with the oncogene and anti-oncogene cDNA microarray. And after doing some experiments, theseresearchers discovered a candidate tumor suppressor gene for cervical carcinoma--Homosapiens bladder cancer associated protein (BLCAP) gene.Since the character and function of BLCAP gene is unknown, we firstly analyzed BLCAP gene through bioinformatic means. The results showed that there were several genes that were highly resembled with BLCAP gene. The comparability between the sequences of BLCAP gene and Homo sapiens mRNA (DKFZp564M053) or BC10 was 99% and 87% respectively. The protein encoded by BLCAP were composite of Leu(19.5%), pro(9.19%), ser(8.04%), cys(8.04%) and other amino acids. The N-terminal of the protein which was encoded by BLCAP gene was an alpha helix. At the C-terminal, it was beta sheet and in the middle, it was coil. The two terminal regions were more hydrophobile than the middle region. Between 45-65aa, there was a transmembrane region. Therefore, we forecasted that BLCAP gene was a member of transmembrane protein I. By analyzing the signal peptide of BLCAP gene with the program of SignalP (V2.0), we found a cleavage site in 63-64aa. By using the program of Netpho, we predicted that there might be three phospholate sites: 68aa, 73aa and 78aa. In 78-8laa, we found a typical [ST]-X(2)-[DE] structure-the phospholate site of Tyrosine protein kinase, Which might be related to its function. Bioinformatic studies of BLCAP gene provided foundation for the functionalresearch of BLCAP gene in laboratory.Secondly, in order to prove that BLCAP gene was a tumor suppressor gene associated with cervical carcinoma, we examined the expressional level of BLACP gene mRNA in human normal cells and different rumor cells, investigated the tumorigenicity in nude mice of HeLa stably-transfected with BLCAP gene, and also took the DNA ladder experiment. The results showed: (a) the expressional level of BLACP gene mRNA in tumor cells was lower than that in human normal cells, (b) BLCAP gene showed suppressor ability in HeLa tumorigenicity. (c) apoptosis could be investigated in HeLa after it was stably-transfected with BLCAP gene. Basing on the data above, we can think that the abnormal expression of BLACP gene was related to malignant proliferation and anchorage independent growth of human cervical carcinoma cells.Finally, we studied two single nucleotide polymorphisms (SNPs) within BLCAP gene in this experiment, in order to make out the function of BLCAP gene in the occurrence of human cervical carcinoma. We analyzed 30 unrelated cervical carcinoma cases and 60 control subjects, which matched to the cervical carcinoma cases in age and residence, by means of dynamic allele specific hybridization (DASH). Significant results were obtained from one SNP site (rs3795147), which was located at 711bp down-stream of BLCAP gene. SNP rs3795147 had three kinds of genotype: AA, AC and CC, and results of x2test showed that the frequencies of different genotypes resulted in cervical carcinoma cases and control subjects were significantly different (P (0.05 ) . The result had proved again that BLCAP gene may play a certain role in the development of cervical carcinoma, for the SNP site rs3795147 may influence the expression of BLCAP gene.In conclusion, BLCAP gene was a tumor suppressor gene associated with cervical carcinoma, and the different genotypes of SNP rs3795147 had a close relationship with the occurrence of cervical carcino... |
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