| Fas associated phosphatase-1 (FAP-1) is a kind of important protein-tyrosine phosphatase founded in present years, which can inhibit fas from activation by its binding to the negative regulatory domain of fas (the cytosolic tail of fas i.e. the last 15 C-terminal amino acids of fas) and attenuate fas export from intracellular stores to the cell surface. As a result, it can prevent fas signal transduction and block fas-induced apoptosis. Besides this FAP-1 also can modulate the activities of NF-kB, P75 and caspase8 that are all apoptosis regulative factors, so it seems FAP-1 can resist apoptosis by several ways and be a steady negative regulator of apoptosis. Recently, people have found overexpression of FAP-1 is common in many kinds of malignant tumors, presumably associating with immune escape and drug resistance of cancer cells. But there have few researches about FAP-1 's action in the pathogenesis of ovarian cancer and has no report about treating FAP-1 antisense oligonucleotide (FAP-1 ASODN) as one kind of therapy to ovarian cancer. In the present study, we address the expressions of FAP-1 inovarian cancer tissues and cell lines, and make a primary research of whether FAP-1 has a functional role in ovarian cancer etiology and drug resistance.There are four parts in this experiment: (1) Immunohisto-chemical S-P method, Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis were employed to detect the expression of FAP-1 protein and mRNA in normal ovary, carcinoid and carcinoma ovarian tissues and ovarian cancer cell lines (SKOV3, HO-8910, TC-1 and 3AO). (2) MTT, flow cytometric analysis (FCM) and Ho/PI fluorescein staining methods were used to evaluate the sensitivity to apoptosis of four kinds of ovarian cancer cell lines after induced by agonistic anti-fas antibody (DX2). Furthermore, we compared these results with the FAP-1 expression level, in order to analysis whether there was a correlativity between FAP-1 expression and the sensitivity to fas-induced apoptosis.(3) Transfected SKOV3, a FAP-1 highly expressed cell line, with FAP-1 ASODN and SODN after wrapped by liposome, then detected the FAP-1 protein and mRNA expression by western blot and RT-PCR, and compared the apoptosic levels between SK0V3 cells with or without transfection after being treated by DX2, so as to counterevident whether FAP-1 could decrease the sensitivity to fas-induced apoptosis in SKOV3 cells.(4) we treated SKOV3 cell with FAP-1 ASODN, SODN, carboplatin and FAP-1 ASODN combined with carboplatin for different time and doses, then use MTT, FCM and DNA Ladder analysis to investigate the cell cycles, cell apoptosic rate and growth inhibitive rate, in order to elucidate if there is a cooperative relationship between FAP-1 ASODN and chemo-therapeutic agent carboplatin.The experimental results showed there was no FAP-1 expression in normal ovary and low positive expression rate in carcinoid, but high expression levels were found in ovarian borderline epithelial tumor and carcinoma. Moreover, We also observed that the expression of FAP-1 was markedly associated with patients' FIGO stage and tumor grade (P < 0.05), but not related to tumor histological subtype or metastasis. In our invitro experiments, the results of western blot and RT-PCR are coincident, which showed there were no expression of FAP-1 protein and mRNA in TC-1 and 3AO cells, but positive expression in HO-8910 and SKOV3 cell, and SKOV3 cell is the highest one to express FAP-1 among them. In addition, statistical analysis revealed that the expression level of FAP-1 was noticeably correlative with the sensitivity to Fas-mediated apoptosis induced by DX2 of ovarian cancer cells. The higher expression level the cell has, the lower sensitivity to apoptosis the cell is. In this experiment, SKOV3 is the last sensitive one to react to DX2. When blocked FAP-1 mRNA and protein expressions with FAP-1 ASODN in SKOV3 cell, the apoptosic rate and growth inhibitive rate were increased significantly in the same condition, which means FAP-1 could weaken the...
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