Anti-CHEK1 (aa 209-220) polyclonal antibody

The DNA damage response kinase ATR and its effector kinase CHEK1 are required for cancer cells to survive oncogene-induced replication stress. ATR inhibitors exhibit synthetic lethal interactions, with deficiencies in the DNA damage response enzymes ATM and XRCC1 and with overexpression of the cell cycle kinase cyclin E. Here, we report a systematic screen to identify synthetic lethal interactions with ATR pathway-targeted drugs, rationalized by their predicted therapeutic utility in the oncology clinic. We found that reduced function in the ATR pathway itself provided the strongest synthetic lethal interaction. In addition, we found that loss of the structure-specific endonuclease ERCC1-XPF (ERCC4) is synthetic lethal with ATR pathway inhibitors. ERCC1-deficient cells exhibited elevated levels of DNA damage, which was increased further by ATR inhibition. When treated with ATR or CHEK1 inhibitors, ERCC1-deficient cells were arrested in S-phase and failed to complete cell-cycle transit even after drug removal. Notably, triple-negative breast cancer cells and non-small cell lung cancer cells depleted of ERCC1 exhibited increased sensitivity to ATR pathway-targeted drugs. Overall, we concluded that ATR pathway-targeted drugs may offer particular utility in cancers with reduced ATR pathway function or reduced levels of ERCC4 activity. Cancer Res; 74(10); 2835-45. (C) 2014 AACR.

OBJECTIVE: The study aimed to identify potential therapeutic biomarkers and agents in multiple myeloma (MM) based on bioinformatics analysis. MATERIALS AND METHODS: The microarray data of GSE36474 were downloaded from Gene Expression Omnibus database. A total of 4 MM and 3 normal bone marrow mesenchymal stromal cells (BM-MSCs) samples were used to identify the differentially expressed genes (DEGs). The hierarchical clustering analysis and functional enrichment analysis of DEGs were performed. Furthermore, co-expression network was constructed by Cytoscape software. The potential small molecular agents were identified with Connectivity Map (cMap) database. RESULTS: A total of 573 DEGs were identified in MM samples comparing with normal samples, including 322 down-and 251 up-regulated genes. The DEGs were separated into two clusters. Down-regulated genes were mainly enriched in cell cycle function, while up-regulated genes were related to immune response. Down-regulated genes such as checkpoint kinase 1 (CHEK1), MAD2 mitotic arrest deficient-like 1 (MAD2L1) and DBF4 zinc finger (DBF4) were identified in cell cycle-related co-expression network. Up-regulated gene of guanylate binding protein 1, interferon-inducible (GBP1) was a hub node in immune response-related co-expression network. Additionally, the small molecular agent vinblastine was identified in this study. CONCLUSIONS: The genes such as CHEK1, MAD2L1, DBF4 and GBP1 may be potential therapeutic biomarkers in MM. Vinblastine may be a potential therapeutic agent in MM.