Cellular Responses to DNA Damage

我们正在努力建立一个体外系统，用于研究不同试剂激活检查点的情况，这些试剂会导致人类细胞的DNA损伤。这些DNA损伤剂被广泛用于化疗。因此，我们的研究集中在这些化疗药物产生细胞毒性的分子机制以及癌细胞对化疗方法产生耐受的途径上。作为一个模型系统，我们正在研究DNA错配修复蛋白MutSalpha和MutLpha介导的检查点激活，以响应几种DNA损伤剂，包括SN1烷化剂、氟尿嘧啶和顺铂。针对特定类型DNA损伤的DNA损伤传感器激活ATR和ATM蛋白激酶。这进而激活了包括Chk1和Chk2在内的一系列信号通路，最终导致细胞周期停滞在G2/M交界处。我们正在提纯参与这种损伤反应的重组人类蛋白，目的是确定潜在的分子机制。我们还对识别关键蛋白质复合体的成分感兴趣，这些蛋白质复合体具有响应DNA损伤剂而使细胞周期停止的功能。我们正在研究细胞增殖的关键调节因子p21在细胞对顺铂的反应中的作用。最后，我们正在研究核膜蛋白在研究细胞核结构在细胞周期中的动态变化以及对DNA损伤的反应中所起的作用。

We are working to establish an in vitro system for the study of checkpoint activation by various reagents that induce DNA damage in human cells. These DNA damaging agents are widely used in chemotherapy. Thus, our research focuses on molecular mechanisms by which these chemotherapeutic agents confer cytotoxicity as well as pathways by which cancer cells achieve tolerance to chemotherapeutic approaches. As a model system, we are investigating checkpoint activation mediated by the DNA mismatch repair proteins MutSalpha and MutLalpha in response to several DNA damaging agents including SN1 alkylators, fluorouracil, and cisplatin. DNA damage sensors that target specific types of DNA damage activate the ATR and ATM protein kinases. This, in turn, activates a cascade of signaling kinases including Chk1 and Chk2 that ultimately result in cell cycle arrest at the G2/M boundary. We are purifying recombinant human proteins involved in this damage response with the goal of defining the underlying molecular mechanism. We are also interested in identifying components of key protein complexes that function to license cell cycle arrest in response to DNA damaging agents. We are investigating the role of p21, a key regulator of cell proliferation, in the cellular response to cisplatin. Finally, we are examining the role of nuclear membrane proteins to study dynamic changes in nuclear architecture in the cell cycle and in response to DNA damage.