title: Targeting Chk2 improves gastric cancer chemotherapy by impairing DNA damage repair.
abstract: Our results demonstrate that the addition of cisplatin after paclitaxel-induced mitotic arrest was more effective than individual treatment on gastric adenocarcinoma cells (MKN45). However, the treatment did not induce benefits in cells derived from lymph node metastasis (ST2957). Time-lapse microscopy revealed that cell death was caused by mitotic catastrophe and apoptosis induction, as the use of the caspase inhibitor z-VAD-fmk decreased cell death. We propose that the molecular mechanism mediating this cell fate is a slippage suffered by these cells, given that our Western blot (WB) analysis revealed premature cyclin B degradation. This resulted in the cell exiting from mitosis without undergoing DNA damage repair, as demonstrated by the strong phosphorylation of H2AX. A comet assay indicated that DNA repair was impaired, and Western blotting showed that the Chk2 protein was degraded after sequential treatment (paclitaxel-cisplatin). Based on these results, the modulation of cell death during mitosis may be an effective strategy for gastric cancer therapy.
authors.affiliation: Department of Biochemistry, School of Medicine, UAM, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Gutiérrez-González
authors.forename: C
authors.initials: C
authors.lastname: Belda-Iniesta
authors.forename: J
authors.initials: J
authors.lastname: Bargiela-Iparraguirre
authors.forename: G
authors.initials: G
authors.lastname: Dominguez
authors.forename: P
authors.initials: P
authors.lastname: García Alfonso
authors.forename: R
authors.initials: R
authors.lastname: Perona
authors.forename: I
authors.initials: I
authors.lastname: Sanchez-Perez
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D064447:Checkpoint Kinase 2; D002945:Cisplatin / Q000627:therapeutic use; D019926:Cyclin B / Q000378:metabolism; D004260:DNA Repair / Q000187:drug effects*; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology; D008938:Mitosis / Q000187:drug effects*; D017239:Paclitaxel; D017346:Protein Serine-Threonine Kinases / Q000187:drug effects* / Q000378:metabolism; D013274:Stomach Neoplasms / Q000188:drug therapy*; D043823:Taxoids / Q000627:therapeutic use
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D019926:Cyclin B; D043823:Taxoids; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases; D017239:Paclitaxel; D002945:Cisplatin