Research Between Esophageal Carcinomas And HPV,HLA-G,Lin28B In High Risk Regions

Esophageal squamous cell carcinoma (ESCC) is one of the most common chest cancer, with about400,000new cases and300,000deaths all over the world. Most of esophageal cancers occur mainly in the developing countries. China is one region of the highest incidence and mortality of esophageal cancer in the world. Since1990s, the incidence and mortality rate of esophageal cancer declined. ESCC continued to hold the first cause of death in the northern part of Henan province. Xinxiang region in Henan Province is the place with the highest ESCC. In our country, esophageal squamous cell carcinoma is the common types. Research on ESCC is still the key areas of researches of our country. Because the mechanism of carcinoma is not clear, there is still a very long road to go. The development from normal epithelium to ESCC needs a long time. There are a few factors of fungal infection, poor diet, smoking, micronutrient deficiencies, environmental pollution and other factors to be related with ESCC. From normal epithelium to invasive carcinoma, it needs a variety of related genes or independent genes or molecular changes to involve in the mechanism. Although based on the current understanding of the mechanism of carcinoma, the application of targeted drug has made some progress. It is needed that much work and time be put into researchs of this tumor by a lot of researchers.Nowadays, besides of the environmental, dietary, genetic and other factors, it has become a heated topic that Human papillomavirus is suspected of causing cancers, including cancer of colon cancer, cervix cancer. Human papillomavirus (HPV), a double-stranded DNA virus, has a diameter of about40-50nm. HPV infection can make its genome into normal cells DNA, and may activate oncogenes and inactivate anti-oncogene. When HPV integrates host cells, its can evade the host immune system and activate telomerase and make replication. As some progression has made on research, it is known that the oncoproteins E6and E7produced by high-risk HPV genotypes (especially HPV16,18) are necessary for malignant transformation of human cells. These oncoproteins of human papillomavirus can bind to P53, Rb and cell cycle regulatory proteins, then make human cells to produce abnormal proliferation state and malignant transformation. Human leukocyte antigen-G (HLA-G) is a non-classical MHC molecule expressed in human immune-privileged sites. HLA-G is an essential immune tolerance. It does not expressed in normal somatic cells. It can play an important role in the development of maternal tolerance to different fetal tissues. HLA-G can protect the embry from maternal immune system attack through the inhibition of NK cells and T lymphocyte cells. The expression of it was reported in colon cancer, breast and lung cancer, et al. HLA-G may play an important role in immune escape of carcinoma. Lin28is a kind of RNA-binding protein, which was firstly characterized by Ambros V in the nematode Caenorhabditis elegans as an essential regulator of developmental timing. The mammalian homologs of Lin28and Lin28b can bind to let-7and inhibit let-7to regulate micro RNAs at the post-transcriptional level. Then they may control cell proliferation, separatism, differentiation in embryonic stem cells.At present, little is known on the correlation between high risk HPV infection with HLA-G and Lin28b expression in esophageal squamous cell carcinomas. The aim of the study was to investigate the possible roles of HLA-G and Lin28b in tumorigenesis among HPV genotypes positive ESCC.This paper consist of2chapters, as follows: Chapterl:Correlation of high risk HPV infection, HLA-G and Lin28b expression in esophageal squamous cell carcinomas. 1. Objective:To investigate the infection risk of human papillomavirus (HPV) genotypes in esophageal squamous cell carcinomas (ESCC) and paracancerous normal tissue. The aim of this study was to investigate the expression of HLA-G and Lin28b in esophageal squamous cell carcinomas and paracancerous normal tissue.To investigate the relationship between different human papillomavirus (HPV) genotypes, HLA-G and Lin28b with age, gender, differentiation, infiltration depth and lymph node in esophageal squamous cell carcinomas. The aim of this study was to investigate the relationship between different human papillomavirus (HPV) genotypes and the expression of HLA-G and Lin28b in esophageal squamous cell carcinomas and paracancerous normal tissue.2. Methods:HPV typing was carried out by gene chip (high risk HPV genotype of16,18,31,33,35,39,45,51,52,56,58,59and68, low risk HPV genotype of6.11,42,43and44, and Chinese genotype of HPV53,66and CP8304) in114cases of formalin-fixed and paraffin-embedded esophageal squamous cell carcinomas specimens and50cases of paracancerous normal tissue from Xinxiang. A totle of114cases of esophageal carcinomas and50cases of paracancerous normal tissue were assayed for expression of HLA-G and Lin28b by immunohistochemistry.SPSS13.0for windows software was used to analyse the data. Difference of the ratio between groups were calculated by χ2test or Fisher’s exact test. Correlation between HPV infection with HLA-G and Lin28b expression was analyased by R×C χ2test and Spearman test. The significant difference was considered when the P value was less than0.05.3. Results:Overall, HPV prevalence were63.2%,6%among the esophageal carcinomas and paracancerous normal tissue in this study (x2=45.753, P<0.001). HPV-16,18and52were detected by34.2%.16.7%and12.3%in the tumors. HPV infection was positively correlated with tumor differentiation degree (χ2=6.793, P=0.009).HLA-G was mainly expressed in the cytoplasm. The positive expression rate in normal epithelium and ESCC were63.2%,6%,(χ2=45.753, P=0.000); Lin28b was mainly expressed in the cytoplasm. Lin28b prevalence were63.2%、6%and66.7%,2%among the esophageal carcinomas and paracancerous normal tissue (χ2=62.121, P<0.001). HLA-G protein expression was correlated with tumor differentiation degree (χ2=12.131, P<0.001). Lin28b protein expression was correlated with tumor differentiation degree (χ2=11.225, P=0.001), tumor infiltration depth (χ2=4.342, P=0.037), lymph node metastasis (χ2=21.658, P<0.001).HPV infection was correlated with HLA-G in esophageal squamous cell carcinomas (rs=0.318). HPV infection was correlated with Lin28b in esophageal squamous cell carcinomas (rs=0.347)Chpter2:The research between human papillomavirus infection and esophageal carcinoma in Xinxiang and Chaozhou regions.1. Objective:To investigate the infection risk of human papillomavirus (HPV) genotypes between esophageal squamous cell carcinomas (ESCC) and paracancerous normal tissue in Xinxiang and Chaozhou regions.To examine the difference of human papillomavirus (HPV) genotype in esophageal squamous cell carcinoma (ESCC) specimens collected from Xinxiang and Chaozhou regions, respectively.2. Methods:HPV and its genotype was detected using gene chip technology to examine114and105formalin-fixed and paraffin-embedded ESCC specimens from Xinxiang and Chaozhou regions, respectively. HPV and its genotype was detected using gene chip in50cases of paracancerous normal tissue from Xinxiang and Chaozhou regions, too.SPSS13.0for windows software was used to analyse the data. Difference of the ratio between groups were calculated by χ2test or Fisher’s exact test. Correlation was analyased by χ2test between HPV and HLA-G or Lin28b. The significant difference was considered when the P value was less than0.05. 3. Results:HPV prevalence were63.2%、6%among the esophageal carcinomas and paracancerous normal tissue in Xinxiang region(χ2=45.753, P<0.001), HPV-16,18and52were detected34.2%,16.7%and12.3%in ESCC. HPV prevalence were35.2%and4%among the esophageal carcinomas and normal esophageal tissue in ChaoZhoug region (χ2=17.552, P<0.001, HPV16and18were detected by23.8%and11.4%in ESCC. HPV was detected in219ESCC specimens (49.8%). ESCC cases from Xinxiang had a higher prevalance of HPV than in Chaozhou (63.2%vs35.2%) with stastical significance (χ2=17.043, P<0.001).HPV infection was positively correlated with differentiation degree of tumor in XinXiang region (χ2=6.793, P=0.009). HPV infection was not correlated with differentiation degree of tumor in Chaozhou region (P>0.05).Conclusion1. There is HPV infection in ESCC specimens collected from Xinxiang and Chaozhou regions. HPV16,18and52genotypes can be found in ESCC specimens collected from Xinxiang region; HPV16and18genotypes can be found in ESCC specimens collected from Chaozhou region.2. HLA-G was mainly expressed in the cytoplasm. HLA-G protein expression was correlated with tumor differentiation degree.3. Lin28b was mainly expressed in the cytoplasm. Lin28b protein expression was correlated with tumor differentiation degree, tumor infiltration depth, lymph node metastasis.4. HPV was correlated with HLA-G and Lin28b in esophageal squamous cell carcinomas.5. It supports the hypothesis that HPV, HLA-G and Lin28b may play important roles in the activation of carcinogenesis and malignant transformation of esophageal neoplasia. But their exact mechanism in cancerization of paracancerous normal tissue need to be furtherly studied.6. Combinative detecting the infection of HPV genotype and expression of HLA-G and Lin28b may provide some information in the research of cancerization mechanism of paracancerous normal tissue.