title: Establishment, characterization and chemosensitivity of three mismatch repair deficient cell lines from sporadic and inherited colorectal carcinomas.
abstract: BACKGROUND
  Colorectal cancer (CRC) represents a morphologic and molecular heterogenic disease. This heterogeneity substantially impairs drug effectiveness and prognosis. The subtype of mismatch repair deficient (MMR-D) CRCs, accounting for about 15% of all cases, shows particular differential responses up to resistance towards currently approved cytostatic drugs. Pre-clinical in vitro models representing molecular features of MMR-D tumors are thus mandatory for identifying biomarkers that finally help to predict responses towards new cytostatic drugs. Here, we describe the successful establishment and characterization of three patient-derived MMR-D cell lines (HROC24, HROC87, and HROC113) along with their corresponding xenografts.
  
  
  METHODS
  MMR-D cell lines (HROC24, HROC87, and HROC113) were established from a total of ten clinicopathological well-defined MMR-D cases (120 CRC cases in total). Cells were comprehensively characterized by phenotype, morphology, growth kinetics, invasiveness, and molecular profile. Additionally, response to clinically relevant chemotherapeutics was examined in vitro and in vivo.
  
  
  RESULTS
  Two MMR-D lines showing CIMP-H derived from sporadic CRC (HROC24: K-ras(wt), B-raf(mut), HROC87: K-ras(wt), B-raf(mut)), whereas the HROC113 cell line (K-ras(mut), B-raf(wt)) was HNPCC-associated. A diploid DNA-status could be verified by flow cytometry and SNP Array analysis. All cell lines were characterized as epithelial (EpCAM(+)) tumor cells, showing surface tumor marker expression (CEACAM(+)). MHC-class II was inducible by Interferon-γ stimulation. Growth kinetics as well as invasive potential was quite heterogeneous between individual lines. Besides, MMR-D cell lines exhibited distinct responsiveness towards chemotherapeutics, even when comparing in vitro and in vivo sensitivity.
  
  
  CONCLUSIONS
  These newly established and well-characterized, low-passage MMR-D cell lines provide a useful tool for future investigations on the biological characteristics of MMR-D CRCs, both of sporadic and hereditary origin. Additionally, matched patient-derived immune cells allow for comparative genetic studies.
authors.affiliation: Division of Molecular Oncology and Immunotherapy, University of Rostock, Rostock, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Maletzki
authors.forename: Saskia
authors.initials: S
authors.lastname: Stier
authors.forename: Ulrike
authors.initials: U
authors.lastname: Gruenert
authors.forename: Michael
authors.initials: M
authors.lastname: Gock
authors.forename: Christiane
authors.initials: C
authors.lastname: Ostwald
authors.forename: Friedrich
authors.initials: F
authors.lastname: Prall
authors.forename: Michael
authors.initials: M
authors.lastname: Linnebacher
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D016207:Cytokines / Q000378:metabolism; D053843:DNA Mismatch Repair / Q000187:drug effects / Q000235:genetics*; D005260:Female; D006801:Humans; D051379:Mice; D009361:Neoplasm Invasiveness; D010641:Phenotype; D011003:Ploidies; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D016207:Cytokines