日本群马大学研究人员日前发表论文说，人体内一种特殊蛋白质能促使癌症恶化，抑制这种蛋白质发挥作用，将成为今后抗癌药物新的研究方向。
研究人员在新一期美国《分子细胞》杂志网络版上发表论文说，这种特殊蛋白质名为“Hsp90”，能加强聚合酶“Polη”的功能。“Polη”容易使DNA（脱氧核糖核酸）在复制过程中发生错误，从而导致基因变异。癌细胞的基因如果因“Polη”而反复发生变异，将导致癌症恶化，还会导致癌细胞对放化疗的耐受性增强。
研究人员发现，如果使用药剂让“Hsp90”无法发挥作用，“Polη”就会被分解或者失效，癌症恶化速度就会明显放缓。
参与这项研究的群马大学教授山下孝之说，以前的癌症治疗都是抑制癌细胞本身的增殖，这次的发现将使抑制蛋白质“Hsp90”成为主攻方向。（生物谷Bioon.com）
生物谷推荐原始出处：
Molecular Cell, Volume 37, Issue 1, 79-89, 15 January 2010
The Molecular Chaperone Hsp90 Regulates Accumulation of DNA Polymerase η at Replication Stalling Sites in UV-Irradiated Cells
Takayuki Sekimoto, Tsukasa Oda, Franklin Mayca Pozo, Yoshiki Murakumo, Chikahide Masutani, Fumio Hanaoka, Takayuki Yamashita
DNA polymerase η (Pol η) is a member of the mammalian Y family polymerases and performs error-free translesion synthesis across UV-damaged DNA. For this function, Pol η accumulates in nuclear foci at replication stalling sites via its interaction with monoubiquitinated PCNA. However, little is known about the posttranslational control mechanisms of Pol η, which regulate its accumulation in replication foci. Here, we report that the molecular chaperone Hsp90 promotes UV irradiation-induced nuclear focus formation of Pol η through control of its stability and binding to monoubiquitinated PCNA. Our data indicate that Hsp90 facilitates the folding of Pol η into an active form in which PCNA- and ubiquitin-binding regions are functional. Furthermore, Hsp90 inhibition potentiates UV-induced cytotoxicity and mutagenesis in a Pol η-dependent manner. Our studies identify Hsp90 as an essential regulator of Pol η-mediated translesion synthesis.
