| Objective: As the major pathological types of all laryngeal malignancies,laryngeal squamous cell carcinoma (LSCC) has emerged as the secondmost common solid tumor malignancy in the head and neck region. Theincidence is also gradually increasing and patients with LSCC have a poorsurvival. Despite advances in conventional therapy including surgery,chemotherapy and radiotherapy, the5-year survival rate has not beensignificantly improved over the last30years. Currently, the molecularmechanisms in the development and progression of LSCC remain poorlyunderstood. It is of great value in further understanding the molecularmechanisms of LSCC and to find early molecular diagnostic markers andmolecular prognostic factors with high specificity and sensitivity and noveltherapeutic strategies. The oncogenic transformation of human cells requiresthe perturbation of a distinct set of oncogenes and tumor suppressors. As aprotein serine/threonine phosphatase，the tumor suppressor function of proteinphosphatase2A（PP2A）has been well-known. Cancerous inhibitor of proteinphosphatase2A (CIP2A) can stabilize c-Myc protein, and promoteanchorage-independent cell growth and in vivo tumor formation. An increasedexpression of CIP2A has been detected in gastric, breast and colonadenocarcinomas and in head and neck squamous cell carcinomas. However,the association of CIP2A with laryngeal squamous cell carcinoma has not yetbeen established. In addition, the role of CIP2A in laryngeal squamous cellcarcinoma has not been studied thus far. The study was to investigate theexpression of CIP2A and c-Myc in human laryngeal squamous cell carcinoma,and to analyze its relation with the clinicopathologic characteristics of thecarcinoma in order to explore the association between the expression ofCIP2A and tumorigenesis and progression of laryngeal squamous cell carcinoma.Methods: Materials were collected from patients with laryngeal canceradmitted in Department of Otolaryngology from April2009to August2011atthe Hospital Affiliated to Logistics University of Chinese People’s ArmedPolice Forces and the Fourth Central Hospital of Tianjin. There were40casesof laryngeal carcinoma and25cases of the para-carcinoma tissues (at least0.5cm from the tumor margin) as controls. All tumor tissues were confirmed tobe squamous cell carcinoma; the para-carcinoma tissues were confirmed to benormal mucosa pathologically. All the patients had not received preoperativeradiotherapy, chemotherapy and immunotherapy. The specimens were dividedinto two groups immediately after they were cut off, one was immobilized in10%formaldehyde, then Embed it by Paraffin, the other was stored in-80℃.1The expression of CIP2A protein and c-Myc protein were detected byimmunohistochemistry (IHC) method in laryngeal squamous cellcarcinoma and para-carcinoma tissues.2The expression of CIP2A mRNA and c-Myc mRNA were detected byreal-time PCR in laryngeal squamous cell carcinoma and para-carcinomatissues.3The experimental date was analyzed with statistical software of SPSS13.0edition. There was statistical significance when p<0.05.Results:1Result display of immunohistochemistry1.1The positive expression of CIP2A protein which was located in the cellmembrane and cytoplasm in laryngeal squamous cell carcinoma tissues washigher than those in the para-carcinoma tissues. The positive expression rateof CIP2A protein in carcinoma group and para-carcinoma group was70.0%(28/40) and40.0%(10/25)，which was statistically significant(p<0.05).The expression of CIP2A in laryngeal squamous cell carcinomatissue was associate with clinical staging and lymphnode metastasis（p<0.05，p <0.05）, but it was not associate with gender, age of patients, primary siteand tumor differentiation (all p>0.05). 1.2The positive expression of c-Myc which was located in the cell nucleusand cytoplasm in laryngeal squamous cell carcinoma tissue was higher thanthose in the para-carcinoma tissues. The positive expression rate of c-Mycprotein in carcinoma group and para-carcinoma group was75.0%(30/40)and48.0%(12/25),which were statistically significant (p<0.05).1.3The expression of CIP2A protein was positively correlated with theexpression of c-Myc protein in laryngeal squamous cell carcinoma (r=0.378, p<0.05).2The results of real-time PCR2.1The level of mRNA of CIP2A and c-Myc in the laryngeal squamous cellcarcinoma increased significantly compared with the para-carcinoma tissuesand there was statistical significance (p<0.01). The expression of CIP2AmRNA in laryngeal squamous cell carcinoma tissues was associate withclinical staging and lymphnode metastasis（p <0.05，p <0.05）,but it was notassociate with gender, age of patients, primary site and tumordifferentiation(all p>0.05).2.2The expression of CIP2A mRNA was positively correlated with theexpression of c-Myc mRNA in laryngeal squamous cell carcinoma (r=0.603,p<0.01).Conclusions：1The expression of CIP2A and c-Myc in laryngeal squamous cellcarcinoma tissues is higher than those in the para-carcinoma tissues. CIP2Aand c-Myc may play a significant role in carcinogenesis and development oflaryngeal squamous cell carcinoma.2The expression of CIP2A in laryngeal squamous cell carcinoma tissuesis not associate with gender, age of patients, primary site and tumordifferentiation, but it is higher with clinical staging and lymph node metastasis.The results indicate that CIP2A plays an important role in invision andmigration of laryngeal squamous cell carcinoma.3There is positive correlation between the expression of CIP2A andc-Myc in laryngeal squamous cell carcinoma, suggesting that their synergistic effect promote the development, invision and migration of laryngeal squamouscell carcinoma. |
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