Chen Mei-Chuan, Zhou Bingsen, Zhang Keqiang, Yuan Yate-Ching, Un Frank, Hu Shuya, Chou Chih-Ming, Chen Chun-Han, Wu Jun, Wang Yan, Liu Xiyong, Smith D Lynne, Li Hongzhi, Liu Zheng, Warden Charles D, Su Leila, Malkas Linda H, Chung Young Min, Hu Mickey C-T, Yen Yun
Departments of Molecular Pharmacology (B.Z., K.Z., F.U., S.H., X.L., D.L.S., Y.Y.), Molecular Medicine (Y.-C.Y., H.L., Z.L., C.D.W., L.S.), Molecular and Cellular Biology (L.H.M.), and Division of Comparative Medicine (J.W., Y.W.), City of Hope National Medical Center, Duarte, California; Department of Obstetrics and Gynecology, Division of Gynecologic Oncology Stanford University School of Medicine, Stanford, California; (Y.M.C., M.C.-T.H.); Ph.D. Program for the Clinical Drug Discovery from Botanical Herbs, College of Pharmacy (M.-C.C.), and Graduate Institute of Pharmacognosy, College of Pharmacy, (M.-C.C), Ph.D. Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology (C.-H.C., Y.Y.), and Department of Biochemistry, School of Medicine, College of Medicine (C.-M.C.), Taipei Medical University, Taipei, Taiwan.
Departments of Molecular Pharmacology (B.Z., K.Z., F.U., S.H., X.L., D.L.S., Y.Y.), Molecular Medicine (Y.-C.Y., H.L., Z.L., C.D.W., L.S.), Molecular and Cellular Biology (L.H.M.), and Division of Comparative Medicine (J.W., Y.W.), City of Hope National Medical Center, Duarte, California; Department of Obstetrics and Gynecology, Division of Gynecologic Oncology Stanford University School of Medicine, Stanford, California; (Y.M.C., M.C.-T.H.); Ph.D. Program for the Clinical Drug Discovery from Botanical Herbs, College of Pharmacy (M.-C.C.), and Graduate Institute of Pharmacognosy, College of Pharmacy, (M.-C.C), Ph.D. Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology (C.-H.C., Y.Y.), and Department of Biochemistry, School of Medicine, College of Medicine (C.-M.C.), Taipei Medical University, Taipei, Taiwan
Mol Pharmacol. 2015 Jun;87(6):996-1005. doi: 10.1124/mol.114.094987. Epub 2015 Mar 26.
COH29 [N-(4-(3,4-dihydroxyphenyl)-5-phenylthiazol-2-yl)-3,4-dihydroxybenzamide], a novel antimetabolite drug developed at City of Hope Cancer Center, has anticancer activity that stems primarily from the inhibition of human ribonucleotide reductase (RNR). This key enzyme in deoxyribonucleotide biosynthesis is the target of established clinical agents such as hydroxyurea and gemcitabine because of its critical role in DNA replication and repair. Herein we report that BRCA-1-defective human breast cancer cells are more sensitive than wild-type BRCA-1 counterparts to COH29 in vitro and in vivo. Microarray gene expression profiling showed that COH29 reduces the expression of DNA repair pathway genes, suggesting that COH29 interferes with these pathways. It is well established that BRCA1 plays a role in DNA damage repair, especially homologous recombination (HR) repair, to maintain genome integrity. In BRCA1-defective HCC1937 breast cancer cells, COH29 induced more double-strand breaks (DSBs) and DNA-damage response than in HCC1937 + BRCA1 cells. By EJ5- and DR-green fluorescent protein (GFP) reporter assay, we found that COH29 could inhibit nonhomologous end joining (NHEJ) efficiency and that no HR activity was detected in HCC1937 cells, suggesting that repression of the NHEJ repair pathway may be involved in COH29-induced DSBs in BRCA1-deficient HCC1937 cells. Furthermore, we observed an accumulation of nuclear Rad51 foci in COH29-treated HCC1937 + BRCA1 cells, suggesting that BRCA1 plays a crucial role in repairing and recovering drug-induced DNA damage by recruiting Rad51 to damage sites. In summary, we describe here additional biologic effects of the RNR inhibitor COH29 that potentially strengthen its use as an anticancer agent.
COH29 [N-(4-(3,4-二羟基苯基)-5-苯基噻唑-2-基)-3,4-二羟基苯甲酰胺] 是希望之城癌症中心研发的一种新型抗代谢药物，其抗癌活性主要源于对人类核糖核苷酸还原酶（RNR）的抑制作用。脱氧核糖核苷酸生物合成中的这种关键酶是已上市临床药物如羟基脲和吉西他滨的作用靶点，因为它在DNA复制和修复中起关键作用。在此我们报告，BRCA-1缺陷的人乳腺癌细胞在体外和体内对COH29比野生型BRCA-1细胞更敏感。基因芯片基因表达谱分析表明，COH29降低了DNA修复途径基因的表达，提示COH29干扰了这些途径。众所周知，BRCA1在DNA损伤修复尤其是同源重组（HR）修复中发挥作用，以维持基因组完整性。在BRCA1缺陷的HCC1937乳腺癌细胞中，COH29诱导产生的双链断裂（DSB）和DNA损伤反应比在HCC1937 + BRCA1细胞中更多。通过EJ5和DR-绿色荧光蛋白（GFP）报告基因检测，我们发现COH29可抑制非同源末端连接（NHEJ）效率，且在HCC1937细胞中未检测到HR活性，这表明NHEJ修复途径的抑制可能与COH29诱导BRCA1缺陷的HCC1937细胞中的DSB有关。此外，我们观察到在经COH29处理的HCC1937 + BRCA1细胞中核Rad51灶的积累，提示BRCA1通过将Rad51招募到损伤位点在修复和恢复药物诱导的DNA损伤中起关键作用。总之，我们在此描述了RNR抑制剂COH29的其他生物学效应，这些效应可能会增强其作为抗癌药物的应用。
