Expression Of PTEN, P21, PCNA In Larygeal Carcinoma And Their Clinical Significance

Background: Laryngeal cell carcinoma(LSCC) is a common malignant neoplasm in otolarygology and increasing incidence has been observed in recent years. The complex molecular mechanisms in the malignant transformation and progression of laryngeal carcinoma have still not been well understood like other tumors.However, with the rapid development of tumor molecular biology it has been demonstrated that neoplasm formation was a molecular incidence involved in multiple factors with multiple procedures,which was participated by multiple oncogenes and antioncogenes. Oncogene's activation and tumor suppressor gene's inactivation were considered to be closely related to laryngeal carcinoma. PTEN is a novel tyrosinephosphatase antioncogene.lt has been discovered that the inactivity of PTEN plays very important role in carcinodenesis and progression of tumors.The inactivity of genes shows in the way of mutation or deletion. So far,there is still no report on the expression of PTEN protein in laryngeal carcinoma.P21 is also a kind of antioncogenes.lt may refrain proliferation of cells by preventing the replication of cells in S phase of cell cycle or prior to S phase of cell cycle.PCNA is the affiliated protein of DNA ploymerase 6 .It can be used to evaluated the state of cell proliferation.Objective: In order to evaluate the role of PTEN,P21and PCNA in laryngealcarcinoma as well as their interaction, their expression in laryngeal carcinoma is investigated.It is expected that the study will help us to elucidate the molecular mechanism of laryngeal carcinoma and provide theoretical foundation for genietherapy.Methods: In order to investigate the expression of PTEN,P21 and PCNA in laryngeal carcinoma and the clinicopathological paramaters,the immunohistochemical S-P method was used to examine the expression of three kinds of proteins in 50 cases of laryngeal carcinomas with 20 samples of polyp of vocal cord and 32 samples of laryngeal atypical hyperplasia(LAH) as controls in the study.Results:1. Expression of PTEN protein:(1) The positive expression rates of PTEN in polyp of vocal cord, LAH and LSCC were75.00%, 68.75% and 41.93%, respectively. Comparing the staining rate among those 3 groups,there were significant differences. The positive rates of the polyp of vocal cord and LAH groups were significantly higher than those of the LSCC group(P<0.05).(2) The positive expression rates of PTEN in I - II phase and in III-IV phase were 60.87%, 25.93% repectively. There were significant differences between them.(3) The positive expression rates of PTEN in laryngeal carcinoma with grade I, II, III were 70.00%, 45.83%, 18.75% respectively. There were significantdifferences between the positive rates of grade I and grade III.(4) PTEN was not clearly assoaiated with metastssis of laryngeal carcinoma.(5) There were significant differences of PTEN positive rates between the groups of PCNA(+)and PCNA(++.)2. Expression of P21 protein:(l)There were significant differences among the positive expressionrates of P21 inpolyp of vocal cord , LAH and LSCC.The positive rate of polyp of vocal cord groupwas higher than that of LSCC group.(2) The positive expression rates of PTEN in I -II phase and in III-IV phase were43.47%, 37.04% repectively. There was no significant difference between them.(3)The positive expression rates of PTEN in laryngeal carcinoma with grade I, II, IIIwere 80.00%,41.67%,12.50% respectively. The positive rate of grade I group was lower than that of grade III.(4) P21 was not clearly assoaiated with metastssis of laryngeal carcinoma.(5) There was no significant difference of PTEN positive rates between the groups ofPCNA(+)and PCNA(++.)3. Expression of PCNA protein:(1) There were significant differences among the positive expression rates of PCNA in polyp of vocal cord, LAH and LSCC.(2) The positive expression rates of PCNA in I - II phase and in III- IV phase were 65.22%, 92.59% repectively. There were significant differences between them.(3) The positiv...