The Expression And Activity Of Protein Kinase A I In Oral Squamous Cell Carcinoma

PrefaceAmong the oral and maxillofacial malignant tumors, oral squamous cell carcinoma is the most common ( about 80% ). The tissue structure, malignant extent, metastasis and treatment of oral squamous cell carcinoma vary along with the location of carcinogenesis does.Protein kinase A (PKA) is the cAMP dependent protein kinase. It can transmit the exocellular signal, phosphorylate the membrane protein and regulate the proliferation, differentiation and apoptosis of cell. So the disorder of PKA regulation plays an important role in the abnormal proliferation and growth of cell. There are two subtypes of PKA: PKA Ⅰ and PKA Ⅱ . Many researches show that PKA Ⅰ overexpress in carcinoma cell lines, primary and malignant tumors. In our experiment we investigated the expression of PKA Ⅰ in Oral Squamous Cell Carcinomas and normal tissues by immunohistochemistry and Western Blot. We also detected the activity of PKA Ⅰ and analyzed the correlations of the expression and activity. We hoped to find the relationship of PKA Ⅰ and oral squamous cell carcinoma and discuss the possibility of PKA Ⅰas the biological parameter of oral squamous cell carcinoma.Materials and Methods1. Tissue specimens: A total of 44 oral squamous cell carcinoma tissue specimens and 15 normal tissues were collected from the pathological department of the First Affiliated Hospital of China Medical University. All the specimens were confirmed by two pathological professors and definited the clinical stagesunder the standard of UICC in 2002. 20 fresh specimens of oral squamous cell carcinomas were collected from the operational resection in the department of o-ral and maxillofacial surgery of The Affiliated Hospital China Medical University. Fresh tumors and adjacent normal tissues were resected and reserved in the - 70℃ refrigerator.2. Reagents: [γ -32P] ATP, Fetal bovine serum(FCS) , HRP - IgG, Nitrocellulose filter, Arcylamide, N,N methylene bisacry - lamide, Sodium dode-cylsulphate ( SDS) , Trishydroxyl aminomethane, Antibody of PKA Ⅰ , SP kit etc.3. Test methods: In order to detect the expression and distribution of Protein Kinase A Ⅰ ( PKA Ⅰ ) in Oral Squamous Cell Carcinoma as well as its clini-calpathological significance. We investigated the expression of PKA Ⅰ in 40 Oral Squamous Cell Carcinomas and 15 normal tissues by immunohistochemistry. We also investigated the expression of PKA Ⅰ in 20 human oral squamous cell carcinomas and adjacent normal tissues by Western Blot and detect the activity of PKA Ⅰ.4. Statistic analyze: We chose SPSS for windows software for use.Experimental Results1. Immunohistochemical staining: The expression of PKA Ⅰ was significantly higher in oral squamous cell carcinomas than in normal tissues ( P < 0. 05 ). The PKA Ⅰ positive cells had yellow particles in the plasma and existed in the prickle cell layer and basal cell layer of oral epithelium mucosa and the rim of nest cancer. There were no differences both in the degree of histodifferentiation and the clinical phases( P > 0.05 ).2. Western blot: The positive cells existed both in the normal tissues and oral squamous cell carcinomas. But the expression of PKA Ⅰ was significantly higher in oral squamous cell carcinomas than in adjacent normal tissues(P <0. 01).3. The activity of PKA Ⅰ : The activity of PKA I was significantly higher in oral squamous cell carcinomas than in adjacent normal tissues (P <0. 01) and...