CYCLOSPORINE A AND SIGNAL TRANSDUCTION

多效性耐药的特征是细胞的改变 膜特性。已经证明，某些人 化疗药物在一定水平上发挥抗肿瘤作用 膜的作用。环孢素A(CsA)在磷脂中的分配 囊泡和对质膜磷脂的干扰 新陈代谢。它也被证明可以减少运动 膜脂自由与质膜去极化 小鼠淋巴细胞学的潜能。这样做的总体目标是 建议了解CSA对信号的影响 使用肿瘤的转导途径(敏感和 多效性耐药)和正常T细胞和EB病毒诱导的B细胞 台词。研究的具体目的是：(1)比较血浆 敏感的T和B白血病细胞系的膜电位和 其相应的耐药亚系，以及在T和B细胞 来源于正常淋巴细胞的线条。膜电位 将用DiOC5染料进行流式细胞仪研究。(2)审查 环孢素A对细胞内三磷酸肌醇生成的影响 耐药和敏感的白血病细胞系和T、B细胞系 来源于正常的淋巴细胞。(3)体外直接研究 环孢素A对蛋白质激活和转位的影响 肿瘤和正常淋巴细胞来源的T、B细胞中的蛋白激酶C 细胞系。还将进行研究，以审查监管作用 CsA对PMA诱导的激活和易位的影响 通过免疫沉淀和间接测定 免疫荧光，使用PKC同种异体抗体。(4)至 环孢素A对P-半胱氨酸膜磷酸化的影响 180.所研究的将有助于理解 环孢素A在淋巴细胞活化早期的作用机制 以及CsA纠正多效性药物的机制 肿瘤细胞中的耐药性。

Pleiotropic drug resistance is characterized by alterations in cell membrane properties. It has been shown that certain chemotherapeutic agents exert antineoplastic effect at the level of membrane. Cyclosporine A (CsA) partitions into phospholipid vesicles and interferes with plasma membrane phospholipid metabolism. It has also been shown to decrease the motional freedom of membrane lipids and to depolarize plasma membrane potentials in murine lymphoctyes. The overall aim of this proposal is to understand the effects of CsA on signal transduction pathway using both neoplastic (sensitive and pleiotropic drug resistant) and normal T and EBV-induced B cell lines. The specific aims of the study are: (1) To compare plasma membrane potentials in sensitive T and B leukemia cell lines and their corresponding drug resistant sublines, and in T and B cells lines derived from normal lymphocytes. The membrane potentials will be studied with DiOC5 dye using FACS. (2) To examine the effect of CsA on the generation of inositol trisphosphate in resistant and sensitive leukemic cell lines and T and B cell lines derived from normal lymphocytes. (3) To study the in vitro direct effect of CsA on the activation and translocation of protein kinase C (PKC) in tumor and normal lymphocyte-derived T and B cells lines. Studies will also be done to examine regulatory role of CsA on PMA-induced activation and translocation will be measured by immunoprecipitation and indirect immunofluorescence, using an alloantibody against PKC. (4) To examine the effect of CsA on membrane phosphorylation of P- 180. The studied would help in the understanding of the mechanisms of CsA on the early steps of lymphocyte activation and the mechanisms by which CsA corrects the pleiotropic drug resistance in neoplastic cells.