Variation Of Focal Adhesion Kinase In Adenoid Cystic Carcinoma And Its Relationship With Invasion

ObjectiveFocal adhesion kinase (pp125FAK or FAK) is a tyrosine phosphorylated protein in cells transformed by the Src oncogene, and was later found to associate with Src via an SH2 domain mediated interaction by Schaller inl992^[6]. The FAK gene is highly conserved across species, and is located on human chromosome 8q24, in proximity to the c - myc locus ^[1.2] . cDNA length of FAK gene is 4285bp, encode 1028 amino acid, and the molecule weight is 125KD. FAK is centcer of signal transduction pathways and may represent the prototype for a tyrosine kinase family involved in many novel signal transduction pathways, such as Src,PTKs,Shc,Grb2,PI -3 kinase. This signal net could activate ERK protein to advance cell division. Adenoid cystic carcinoma is one of the most common maxillofacial malignant tumor. It is 9.95% of salivary tumor, 24% of malignant salivary tumor, and the second of malignant salivary tumor. Adenoid cystic carcinoma often happens in small salivary gland. It occurs in head and neck, and is rare in other part of body. According to WHO, there are 3 types: adenoid type, tubular type and parenchymal type. The three types can happen in one tumor. According to the ratio of constituent, the tumor is typed. It seems that there is clear boundary between adenoid cystic carcinoma and peripheral tissue in salivary gland. But there is no envelope around the tumor, and the tumor often infiltrates peripheral tissue. In a few of cases, there is incomplete envelope around the tumor. Adenoid cystic carcinoma is a kind of infiltrative tumor, andtumor cell can be found in and out of envelope. Near the tumor, such as muscle , bone and periosteum, the infiltrative tumor cells which cannot be found by eye, can be tested under the microscope. So it is difficult to judge the anatomic field of tumor. The rate of distant metastasis is very high. Early metastasis can occur, and lung is the main part involved. Recovery can occur after operation. So it is difficult to treat and it does harm to health of patients. Control of recovery and distant metastasis is an important question in clinical treatment, and now research of pulmonary metastasis of adenoid cystic carcinoma is a focus.MethodFresh material was obtained from 50 patients with salivary adenoid cystic carcinoma and 12 normal oral salivary gland tissuesample. Immunohistochemis-try technique was used to detect FAK protein and PTEN protein expression in SACC and to analyze the relationship with histopatholgy typing. Human SACC -LM and SACC - 83 cell line were cultured in DMEM supplemented with 10% fetal calf serum. Reverse transcriptase polymetase chain reaction ( RT - PCR) was applied to detect ERK mRNA and FAK mRNA;Western blot was applied to detect ERK protein expression and FAK protein expression;FAK and ERK enzyme activity were examined to verify FAK was relative with SACC. Next step, to measure FAK was correlated with invasion of SACC, The tyrosine protein kinase inhibitor Genistein were added to cultured SACC - LM with different density and with different time. Then, RT - PCR was applied to detect ERK mRNA and FAK mRNA;Western blot was applied to detect ERK protein expression and FAK protein expression;MTT colormetric assay and were applied to detect cell proliferation;Transwell mesure the invasion of SACC - LM.RESULT1 . Expression of focal adhesion kinase in SACC 1. Expression of focal adhesion kinase in SACCFocal adhesion kinase is lo-cated in the plasma of SACC. There is no/few expression of focal adhesion ki-nase in normal salivary gland cell, but in plasma and nucleus of ductal cell. In 50 cases of SACC, there are 47 positive cases, and 3 negative cases;in 12 cases of normal tissue, there are 2 positive cases, and 10 negative cases. Through X test, there is obvious difference between them ( P < 0. 01) (table 1). Expression of focal adhesion kinase is high in SACC.2. Relationship between expression of focal adhesion kinase in SACC and pathologic typingThe positive rate of focal adhesion kinase in three types (adenoid type, tubular type and parenchymal type) is 86. 96% ,76. 47% and 80. 00% respectively. Through X2test there is no obvious difference among them( P > 0.05). Positive expression of focal adhesion kinase is not related with pathologic typing of SACC.II ? Activity and expression of focal adhesion kinase in SACC - LM and SACC-831. Activity focal adhesion kinase in SACC - LM and SACC -83 In SACC -LM, the mean activity of focal adhesion kinase is 21. 880pmol/min/|xg. . In SACC -83, the mean activity of protein focal adhesion kinase is 13. 160pmol/ min/u,g. Comparing with SACC -83,activity of focal adhesion kinase is higher inSACC-LM(P<0.01)2. Expression of focal adhesion kinase in SACC - LM and SACC -83In SACC - LM, expression of focal adhesion kinase is higher Comparing with SACC-83.H. Variation of focal adhesion kinase and its relationship with invasion.1. With promotion of concentration of inhibitor, the inhibitory level of focal adhesion kinase and expression of ERK decrease.2. With enlongation of action time, the inhibitory level of focal adhesion kinase and expression of ERK decrease.Conclusion1. The high expression of focal adhesion kinase in adenoid cystic carcinoma is related with occurrence of the tumor.2. Expression of focal adhesion kinase in adenoid cystic carcinoma is not related with tying of histopathology.3. Focal adhesion kinase, especially variation of activity of focal adhesion kinase in nucleus, is related with invasion of adenoid cystic carcinoma.4. Focal adhesion kinase, especially variation of expression of focal adhesion kinase, is related with invasion of adenoid cystic carcinoma.5. In the cell of invasion, the variation of focal adhesion kinase affects the expression of ERK.6. Focal adhesion kinase is positive correlation with invasion...