STRESS ACTIVATED PROTEIN KINASES AND CHEMOTHERAPY

已知大多数抗癌药物的主要作用机制是 许多都能诱导细胞凋亡。然而，我们的知识有很大的差距 抗癌药物的作用，特别是损伤和细胞凋亡是如何 分子相连的。此外，细胞死亡并不总是随之而来 损伤，癌细胞可以通过暴露在细胞毒药物中存活 有缺陷的细胞凋亡、其他抵抗机制或修复。一个 理解将损害与反应联系起来的机制可能会提示 改变细胞死亡门槛的方法使癌细胞 对化疗药物敏感。最近，我们已经证明了 阿霉素、长春花碱或依托泊苷激活c-jun氨基末端 人KB中的一种应激激活蛋白激酶--蛋白激酶(JNK) 癌细胞。我们的假设是，JNK介导的信号是一种 应激反应的关键成分在功能上是不同的 可能通过影响或调解而影响结果的抗癌药物 细胞死亡或细胞存活。在具体目标1中，底物 (转录因子)和效应因子(转录激活因子) JNK对化疗药物的反应将被确定。这将是 提供下游分子事件的全面图景 JNK的这一点可能对化疗的整体反应至关重要。 在具体目标2中，几种方法(JNK反义寡核苷酸， SEK1的显性负向抑制因子JNK磷酸酶过表达， Jun或ATF-2)将被用来产生人类癌细胞系 化疗药物引起的JNK信号缺陷。在……里面 具体目标3，JNK信号缺陷细胞系将用于 探讨JNK激活与细胞周期调控的机制关系 化疗药物引起的细胞凋亡。在……里面 具体来说，将确定JNK是否调节该表达 或细胞凋亡调节因子(Bcl2家族)的活性或细胞凋亡效应 (半胱氨酸酶)。在具体目标4中，将确定JNK是否参与 通过调节mdr1的表达而在细胞存活中发挥作用。通过 了解JNK在癌细胞对药物的反应中的作用 抗癌药物，我们或许能找到方法来控制这种情况 信号通路，以增加药物敏感性或预防药物 抵抗。

The primary mechanism of action of most anticancer dugs are known and many induce apoptosis. However, there are large gaps in our knowledge of anticancer drug action, in particular how damage and apoptosis are molecularly linked. Furthermore, cell death does not always follow damage, and cancer cells can survive exposure to cytotoxic drugs through defective apoptosis, other resistance mechanisms, or repair. An understanding of the mechanisms that link damage to response may suggest ways to alter the threshold for cell death to make cancer cells more sensitive to chemotherapeutic drugs. Recently, we have shown that Adriamycin, vinblastine, or etoposide activate c-Jun NH2-terminal protein kinase (JNK), a stress-activated protein kinase, in human KB carcinoma cells. Our hypothesis is that JNK-mediated signaling is a critical component of the stress response to functionally distinct anticancer drugs that might affect outcome by influencing or mediating cell death or cell survival. In Specific Aim 1, the substrates (transcription factors) and effectors (transcriptional activators) of JNK in response to chemotherapeutic drugs will be determined. This will provide a comprehensive picture of molecular events emanating downstream from JNK that may be critical to the overall response to chemotherapy. In Specific Aim 2, several approaches (JNK antisense oligonucleotides, JNK phosphatase overexpression, dominant negative inhibitors of SEK1, Jun or ATF-2) will be used to generate human carcinoma cell lines with defective JNK signaling in response to chemotherapeutic drugs. In Specific Aim 3, the JNK signaling-defective cell lines will be used to explore the mechanistic relationship between JNK activation and apoptotic cell death in response to chemotherapeutic drugs. In particular, it will be determined whether JNK regulates the expression or activity of apoptotic regulators (Bcl-2 family) or apoptotic effects (caspases). In Specific Aim 4, it will be determined whether JNK plays a role in cell survival through regulation of MDR1 expression. By understanding the role of JNK in the response of carcinoma cells to anticancer drugs, we may be able to develop methods to manipulate this signaling pathway in order to increase drug sensitivity or prevent drug resistance.