The Effect Of HPV Infection On The Expression Of P53 And PCNA Protein In Laryngeal Carcinoma

Laryngeal carcinoma is a common malignant tumor in laryngopharynx. Its morbility is the second in the primary malignant tumors of head and neck. Most of these carcinomas are well-differentiated squamous cell carcinomas and the operation is selected as the main treatment. Generally speaking, the occurrences of laryngeal carcinoma are related to smoking and drinking, while recently the viral infection is paid more attention to. The pathogenesis of human papilloma virus (HPV) has been one of the important aspects of the study for etiology of laryngeal carcinoma virus. The p53 gene is a tumor suppressor, the encoding protein of which can negatively regulate the cell growth, promote cell differentiation and induce cell apoptosis. The encoding protein of p53mut gene not only loses its normal functions, but also propels cell malignant transformation. Proliferating cell nuclear antigen (PCNA) participates in the regulation of cell generation cycle. The PCNA expression level is an adoptable and objective index to reflect the cell proliferation ability and the tumor malignancy. This paper analyzed the relationship of the HPV infection to the occurrence of laryngeal carcinoma; and the relationship of laryngeal carcinoma to the over expression of P53mut and PCNA; and the relationship of HPV infection and expression of P53mut and PCNA to the location, differentiation, metastasis and recurrence of laryngeal carcinoma; and the relationship of the HPV infection to the over expression of P53mut and PCNA. Hoping to explore the carcinogenesis of the HPV in laryngeal carcinomas, and provide useful information for the predication and treatment of laryngeal carcinoma as early as possible.Objective: This study aims to detect the expressions of HPV infections, P53mut protein and PCNA in laryngeal carcinomas; explore the relationshipbetween laryngeal carcinomas occurrences and HPV infections, and the viral molecular mechanism of laryngeal carcinomas carcinogenesis to offer theory help for clinical warning, early diagnosis and treatment.Methods: laryngectomy specimens (58 cases) collected from 2003 to 2005 in Dalian were all squamous cell carcinomas, all the case providers receiving no chemotherapy and radiotherapy prior to operation. Through paraffin embedding, the specimens were made into tissue sections. After HE staining and microscopy, pathologic diagnosis and sampling parts were ascertained. In situ hybridization and immunohistochemical method were applied to detect HPV infection in tumor cells, while immunohistochemical method was employed to detect the expressions of P53mut protein and PCNA. Furthermore, we observed laryngeal carcinoma HPV infection rate and the correlation of virus protein to P53mut protein and PCNA. The experiment results were analyzed withχ² test by applying SPSS 11.0 statistic software, and P<0.05 was used as the criteria of marked differentia.Results:1. Status of HPV infection.â‘´The HPV Infection rate of laryngeal carcinoma, cancer adjacent tissues and polyp of vocal cord was 39.66%(23/58),40.00%(2/5)and 0.00%(0/5)respectively through in situ hybridization detection, while the positive expression rate of HPV protein was 36.21%(21/58),40.00%(2/5)and 0.00%(0/5)respectively through immunohistochemical detection. The HPV infection of laryngeal carcinoma and cancer adjacent tissues was significantly higher than that of polyp of vocal cord(P<0.05), however, the difference between laryngeal carcinoma and cancer adjacent tissues was not significant.⑵The positive expression rates of HPV infection with in situ hybridization and immunohistochemical method showed no significant difference (P>0.05,χ²=2.228, P =0.136).2. Expressions of P53^mut protein and PCNA protein. In laryngeal carcinoma, cancer adjacent tissues and polyp of vocal cord , the positive expression rate of P53^mut protein was 77.59% (45/58), 0.00% (0/5) and 0.00% (0/5) respectively ,which in laryngeal carcinoma was significantly higher than in cancer adjacent tissues and polyp of vocal cord (P<0.05); while the positive expression rate of PCNA was 70.69% (41/58), 0.00% (0/5) and 0.00% (0/5) respectively, which in laryngeal carcinoma wassignificantly higher than in cancer adjacent tissues and polyp of vocal cord(P<0.05),too.3. Correlation of HPV infection, P53mut, PCNA to clinical-pathologic characteristics of laryngeal carcinoma. No matter we used immunohistochemical detection or in situ hybridization detection, we acquired the same result: HPV infection was not correlated with clinical classification, clinical stages, differentiation, metastasis, as well as recurrence. Three subglottic carcinoma cases displayed negative expressions. The expression of P53mut protein in non-lymph node metastasis group(77.21%,34/44)was significantly different from that of lymph node metastasis group(64.29%,9/14)(P<0.05), but it was not correlated with clinical classification, clinical stages, differentiation or recurrence. Positive expression of PCNA in I-II stage(60.00%,24/40) was significantly different from that of III-IV stage (94.44% , 17/18) (P < 0.05), that of well-differentiated squamous cell carcinomas(60.53%,23/38) was significantly different from that of moderately or poorly differentiated cases (92.31%,12/13,85.71%,6/7) (P<0.05); that without lymph node metastasis (65.91%,29/44) from that with lymph node metastasis (92.86%,13/14) (P<0.05), and that without recurrence (66.00%,33/50)from that with recurrence(100 %,9/9) (P<0.05).4. Relationship of HPV infection to the expressions of P53mut protein and PCNA protein. The positive expression rates of P53mut protein both of the groups with HPV infection and without HPV infection were 100% (23/23) and 62.86% (22/35) respectively (P<0.05), while those of PCNA were 100% (23/23) and 51.43% (18/35) respectively (P<0.05).Conclusions:1. HPV infection is one of the inducing agents of laryngeal carcinoma.2. The occurrence of laryngeal carcinoma was probably correlated with the mutation of p53 gene.3. There were up regulated expression of PCNA protein in the cells of laryngeal carcinoma.4. HPV could promote the mutation of p53 gene and up regulation the expression of PCNA.5. Joint detections of HPV infection, P53^mut protein and PCNA protein could do contribution to the clinical predication of laryngeal carcinoma.