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Biomedical subjects

Yang Ke

Publications and source records attributed to Yang Ke.

39 records · Page 3Linked to original sources

p53 codon 72 polymorphism (C/G) and the risk of human papillomavirus-associated carcinomas in China.

BACKGROUND: Human papillomavirus (HPV) plays an important role in the development of carcinomas at various body sites. It was found previously that the p53 codon 72 polymorphism (C/G) is a high-risk factor for the development HPV-associated cervical carcinoma. However, it still was considered controversial in several studies of cervical and esophageal carcinoma. METHODS: In the current study, the authors used an allele specific polymerase chain reaction (PCR) method to analyze correlation between the p53 codon 72 (C/G) polymorphism and HPV-associated, noncancerous esophageal epithelium as well as esophageal, ovarian, and breast carcinoma in the Chinese population. Esophageal balloon cytology examination samples were obtained from high-incidence and low-incidence populations for esophageal carcinoma in Anyang (Henan Province). RESULTS: Thirty-six of 48 esophageal balloon samples from the high-incidence population were HPV positive, and 13 of 33 esophageal balloon samples from the low-incidence population were HPV positive. Thirty-nine of 62 esophageal carcinoma samples from Anyang Tumor Hospital were HPV positive. Twenty-six of 39 ovarian carcinoma samples from the Second Affiliated Hospital of Inner Mongolia Medical College were HPV positive. Nineteen of 82 breast carcinoma samples from Beijing Cancer Hospital were HPV positive. It is noteworthy that the distribution of the p53 codon 72 Arg homozygous genotype in HPV positive samples of esophageal epithelium, ovarian carcinoma, and breast carcinoma was significantly higher compared with HPV negative tumor samples. (P < 0.05). CONCLUSIONS: The current results suggest that the p53 codon 72 Arg homozygous genotype is one of the high-risk genetic factors for HPV-associated malignancies among the Chinese population.

Alleles↗

Esophageal cancer in Chinese population: no polymorphism in codon 149 of P21(Waf1/Cip1) cyclin dependent kinase gene.

It has recently been suggested that people of the Indian population who carried the codon 149 polymorphism (GAT-->GGT) of P21(Waf1/Cip1) gene were more susceptible to esophageal cancer and oral cancer than the individuals without that polymorphism. Since esophageal cancer is a high incident neoplasm in China, we analysed the same codon of P21(Waf1/Cip1) in the Chinese population. Blood samples from 80 esophageal cancer patients and 80 normal blood donors were collected for DNA extraction. Methods of Polymerase Chain Reaction (PCR) and direct sequencing were used for detection of the polymorphism in codon 149 of P21(Waf1/Cip1). Bioinformatics analysis was also thoroughly performed for this gene. No polymorphism was found in all samples tested. Bioinformatics analysis revealed that the so-called polymorphism of codon 149 reported previously was a wrong one. In conclusion, no polymorphism exists in codon 149 of P21(Waf1/Cip1). It is not appropriate to use it as a susceptible site of the gene in cancer study.

Asian People↗

Human breast carcinoma xenografts in nude mice.

OBJECTIVE: To investigate spontaneous metastasis, micrometastasis and genetic stability in human breast carcinoma xenografts in nude mice. METHODS: Intact tissue from surgical specimens from breast carcinoma patients was xenografted into nude mice and transplanted from generation to generation. Cells from the xenografts were cultured in vitro and retransplanted into nude mice. Microsatellite DNA in the genome of human breast carcinomas, xenotransplanted tumors and metastases in nude mice were analyzed at three microsatellite loci. RESULTS: The tumorigenicity of orthotopic xenotransplantation was 88.6% (31/35), with a metastatic rate of 41.9% (13/31). Cells from xenotransplants were successfully cultured in vitro. The taking rate of retransplantation into nude mice and the spontaneous lung metastasis rate were both 100% (10/10). Microsatellite DNA sequences in the genome of xenotransplanted tumors and metastases in nude mice were identical with that of the original human breast carcinoma at three microsatellite loci. CONCLUSIONS: Tumorigenicity and metastatic potential can be improved in human breast carcinoma xenografts using intact fresh tumor tissue and orthotopic grafts. Xenotransplanted tumors and tumors after serial passage maintained the genetic stability. The detection of microsatellite DNA may identify micrometastases in a nude mouse model.

Aneuploidy↗