Study Of The Viral Carcinogenesis In Nasopharyngeal And Laryngeal Carcinomas

Nasopharyngeal carcinoma and laryngeal carcinoma are the two most common malignant tumors in laryngopharynx. Nasopharyngeal carcinoma occupied 50% of the head and neck primary malignant tumors, and its incidence is high in the south of China. The ages of most patients when found having the carcinomas are from 40 to 50. Most of nasopharyngeal carcinomas are poor differentiated squamous cell carcinomas with the ability of early invasion and metastasis, and therefore the radiotherapy is selected as the first treatment. The incidence of laryngeal carcinoma is the second in head and neck primary malignant tumors, and that of man is about 10 times of that of woman, the high occurrence ages are from 50 to 70, however most of the carcinomas are well differentiated squamous cell carcinomas. Compared with nasopharyngeal carcinoma, most of laryngeal carcinomas have the characteristics of slow growth and late metastasis, so the operation is selected as the main treatment. Generally speaking, the occurrences of the two carcinomas are related to smoking and drinking, but recently the role of viral infection in the occurrence of the two tumors is paid more attention to, and virus has been considered as the 3rd etiological factor following smoking and drinking, inducing these carcinomas. It is considered that Epstein-Barr virus (EBV) is assossiated with the occurrence of nasopharyngeal carcinomas, while human papilloma virus (HPV) with that of laryngeal carcinomas. The anatomical positions of nasopharynx and larynx are close to each other, and their mucosa are squamous epithelia, but why is the virus infected different? Are there any differences in the pathogenesis between the two tumors? The infection rates of EBV and HPV are different in different regions, and the methods used also influence the detective results. It may be helpful to understand viral carcinogenesis of the two carcinomas using the same method to detect the viral infection of people in the same region under standard conditions. The p53 gene (wtp53) is a tumor suppressor gene, the protein encoded can negatively regulate the cell growth, whose main biological functions are to block cell cycle, promote cell differentiation and induce cell apoptosis. The protein(P53) encoded by mutant p53 gene (mtp53) not only losses these functions, but also make cell malignant transformation. Proliferating cell nuclear antigen (PCNA) as the necessary polypeptide of DNA synthesis in cell nucleus, participates in the regulation of cell generation cycle, whose expression increases obviously as cell proliferation. The PCNA expression level is a useful index to reflect the cell proliferation ability and the tumor malignancy. Whether are the occurrences of the two carcinomas related to the expressions of P53 and PCNA? Whether do the HPV and EBV infections influence the expressions of P53 and PCNA, and what role does that play in the carcinogenesis of the two carcinomas? All the questions should be answered. Aiming directly at the above-mentioned questions, using the nasopharyngeal and laryngeal carcinoma of patients in Dalian, the north of China, as the research objects, we analyzed the relationship between the occurrence of the two carcinomas and the infections of the two vira, and explored the carcinogenesises of the two vira in nasopharyngeal and laryngeal carcinomas. We hope to provide some help for the prediction and treatment of the two carcinomas as early as possible. Objective: To detect the expressions of HPV, EBV infections, mutant P53 protein and PCNA in nasopharyngeal and laryngeal carcinomas; explore the relationship of occurrencee of nasopharyngeal and laryngeal carcinomas to HPV, EBV infections, and the viral molecular mechanism of carcinogenesis of the two carcinomas; offer theory help for early diagnosis and treatment. We also explore the usable feasibility of self-made tissue chips in the detection of protein and nucleic acid with immunohistochemistry and in situ hybridization. Methods: The specimens of 47 nasopharyngeal carcinoma cases from 1997to 1998 and 58 larynge...