[Analysis of human papillomavirus 16 E6 oncogene mutation in Xinjiang Uygur women with cervical carcinoma].

BACKGROUND & OBJECTIVE: High-risk human papillomaviruses(HPVs),such as HPV16, and HPV18,are major causes of cervical cancer (CC), and HPV16 was found most frequently in CC patients. HPV16E6 is one of major oncogenes. In some region, specific E6 mutation is considered as dangerous factor causing CC. There is a very high incidence of CC in southern Xinjiang, where the Uygur are the majority. As we reported before, we found HPV16E6 mutation from this district. This study was designed to investigate distribution of the mutation in CC of Xinjiang Uygur women, and the relationship between the mutation and high incidence of CC in southern Xinjiang. METHODS: The tissue DNA was extracted from 35 CC biopsies of Xinjiang Uygur Women. HPV16E6 gene was amplified by polymerase chain reaction (PCR) from the CC tissue DNA. The PCR fragments were sequenced and analyzed. RESULTS: The result of PCR showed that the positive rate of HPV16E6 was 82.86%(29/35); 26 of these 29 PCR fragments were sequenced and analyzed, 15 of them maintained prototype (57.69%), 11 have L83V mutation (34.62%), and 2 have L83V/D63E mutation (7.69%). CONCLUSIONS: There is mutation within the HPV16E6 gene in CC of Xinjiang Uygur women. Our research suggested that the distribution of HPV16 prototype and HPV16E6 mutation might be associated with high incidence of CC in southern Xinjiang.

[Mutations of human papillomavirus (HPV) 16 type L1 genes from cervical carcinoma biopsies in southern Xinjiang Uygur women].

OBJECTIVE: To study the mutations of Human Papillomavirus (HPV) 16 type L1 genes of cervical carcinoma biopsies from Uygur women in Southern Xinjiang, and analyze changes of L1 protein function. METHODS: The tissue DNA was extracted from cervical carcinoma biopsies. HPV16 L1 genes were amplified by PCR from the DNA HPV16 type L1 genes were sequenced and analyzed. RESULTS: The result of PCR showed that the positive rate of HPV16 L1 was 84.21% (16/19). These DNA were sequenced, and we found some mutations in comparison with the previously published sequence of prototype HPV16 L1. Some of the mutations changed the triplet codes, subsequently led to changes of amino acids. The mutations of all thirteen HPV16 L1 fragments formed six patterns (XJL1-1 approximately XJL1-6) at nucleic acid level. Compare to HPV16 prototype, their homology were 99.69% to 99.87%. There were four mutations in nucleic acid sequences of XJL1-1, which occurred also in XJL1-2 approximately XJL1-6. Moreover, there are other mutations in XJL1-2 approximately XJL1-6 besides the four mutations in XJ L1-1. The mutations of all thirteen HPV16 L1 fragments formed four patterns at amino acid level, among the mutations XJL1-1/2/3 was by 76.92% (8/13). CONCLUSION: HPV16 type L1 genes from cervical carcinoma biopsies occurred some mutations in Uygur women from southern Xinjiang, and formed several patterns as well as mainstream pattern. The mutations of L1 proteins changed its hydrophobicity and antigenicity. The research suggested that the mutations of HPV16 type L1 genes associated with HPV16 phylogenesis and escape from immune recognition.

[Sequence analysis of bacterial transposon in NHX gene of Populus euphratica].

The United Nations Environment Program estimates that approximately 20% of agricultural land and 50% of cropland in the world is salt-stressed. The gene NHX (Na+/H+ exchanger) encodes functional protein that catalyzes the countertransport of Na+ and H+ across membranes and may play an important role in plant salt tolerance. To clone the NHX from the wild plant Populus euphratica collected in Tarim basin and Xinjiang Wujiaqu district into a T-vector, designed primer was used to amplify 1kb NHX cDNA fragment with RT-PCR. Total RNA was extracted from Populus euphratica tissue (plant tissue was collected from Tarim basin and Xinjiang Wujiaqu district and stored in liquid nitrogen) according to the Plant RNA Mini Kits of Omega. First cDNAs were synthesized from 1 microg total RNA of Populus euphratica seedling. A pair of primers were used to perform RT-PCR. The amplified DNA fragment was purified and cloned into pMD18-T vector. However, 1kb and 2.3kb fragment were obtained from Tarim basin and Xinjiang Wujiaqu district and named as PtNHX and PwNHX, respectively. Sequence analysis reveals that the cloned PtNHX fragment of Populus euphratica contains partial NHX coding region with 98%, 86%, 84% and 80% identity comparing with Atriplex gemelini, Suaeda maritima, Arabidopsis thaliana and Oryza sativa, respectively. This analysis suggests that NHX gene would be highly conserved in terms of evolution in plant; and it also suggests that the NHX gene of Populus euphratica also would have the similarity with that of Arabidopsis. It may be of great importance in improvement of the plant salt tolerance and breed of crop. At the same time, sequence analysis shows that PwNHX gene includes a coding region about 1350bp with 99% identity comparing with transposon Tn10 IS10-left transposase of Shigella flexneri. On the one hand, the NHX gene may lose its function because it was inserted a fragment in coding region. On the other hand, its product may play a important role in salt tolerance. Populus grow in saline soil. It speculates that it may have other salt tolerance mechanism in Populus. The transposon can be used as transposon tagging to clone other genes and it will help us to understand farther the salt tolerance mechanism.