AIM: Protein kinase Chk1 (hChk1) is essential in human cells for cell cycle arrest in response to DNA damage, and has been shown to play an important role in the G2/M checkpoint. The BRAF mutations have been suggested to be linked with defective mismatch repair in colorectal cancers. The aim of this study was to investigate whether a frameshift mutation within the Chk1 gene contribute to the development or progression of eastern sporadic and hereditary non-polyposis colorectal cancer (HNPCC) with microsatellite instability (MSI). METHODS: We analyzed MSI using the 6 microsatellite markers and a frameshift mutation in the BRAF gene and in poly(A)9 within the Chk1 gene in 51 sporadic colorectal cancer and 14 HNPCC specimens. RESULTS: Eleven of the 51 sporadic colorectal cancers and all of the 14 HNPCCs were MSI-positive. Chk1 frameshift mutations were observed in 2 and 3 sporadic colon cancers and HNPCC, respectively, whereas no BRAF mutations were detected in these samples. Interestingly, all cases with the Chk1 frameshift mutation had high-frequency MSI. CONCLUSION: These results suggest that the Chk1 gene is a target of genomic instability in MSI-positive colorectal cancers and that the Chk1 framshift mutations might be involved in colorectal tumourigenesis through a defect in response to DNA damage in a subset of sporadic colorectal cancers and HNPCCs.
AIM: Protein kinase Chk1 (hChk1) is essential in human cells for cell cycle arrest in response to DNA damage, and has been shown to play an important role in the G2/M checkpoint. The BRAF mutations have been suggested to be linked with defective mismatch repair in colorectal cancers. The aim of this study was to investigate whether a frameshift mutation within the Chk1 gene contribute to the development or progression of eastern sporadic and hereditary non-polyposis colorectal cancer (HNPCC) with microsatellite instability (MSI). METHODS: We analyzed MSI using the 6 microsatellite markers and a frameshift mutation in the BRAF gene and in poly(A)9 within the Chk1 gene in 51 sporadic colorectal cancer and 14 HNPCC specimens. RESULTS: Eleven of the 51 sporadic colorectal cancers and all of the 14 HNPCCs were MSI-positive. Chk1 frameshift mutations were observed in 2 and 3 sporadic colon cancers and HNPCC, respectively, whereas no BRAF mutations were detected in these samples. Interestingly, all cases with the Chk1 frameshift mutation had high-frequency MSI. CONCLUSION: These results suggest that the Chk1 gene is a target of genomic instability in MSI-positive colorectal cancers and that the Chk1 framshift mutations might be involved in colorectal tumourigenesis through a defect in response to DNA damage in a subset of sporadic colorectal cancers and HNPCCs.
Authors: David W Schoppy; Ryan L Ragland; Oren Gilad; Nishita Shastri; Ashley A Peters; Matilde Murga; Oscar Fernandez-Capetillo; J Alan Diehl; Eric J Brown Journal: J Clin Invest Date: 2011-12-01 Impact factor: 14.808
Authors: Ryan M Gobble; Li-Xuan Qin; Elliott R Brill; Christina V Angeles; Stacy Ugras; Rachael B O'Connor; Nicole H Moraco; Penelope L Decarolis; Cristina Antonescu; Samuel Singer Journal: Cancer Res Date: 2011-02-18 Impact factor: 12.701