title: Assessment of in vitro drug resistance of human breast cancer cells subcultured from biopsy specimens.
abstract: The low cellular yield of a breast cancer sample represents a limiting factor for in vitro chemosensitivity/chemoresistance testing. The use of in vitro serially cultured cells can help overcome this obstacle.
  
  
  METHODS
  In vitro drug resistance of cells cultured from mammary carcinomas by the 3T3 feeder-layer technique was tested by the MTT assay. Out of the 33 tested cultures, 9 were derived from cells obtained from true-cut biopsies of primary tumours, with sample volume less than 0.03 cm3. The cultures were treated with 6 anticancer drugs at 6-8 concentrations. The chemoresistance of cultured cells was monitored by the surviving cell fraction as a function of the drug concentration.
  
  
  RESULTS
  The average time to obtain a result was 28 days. The volume of an original sample had no effect on the in vitro resistance of a culture, suggesting minimal alteration of in vitro chemosensitivity of cells by their cultivation. Histopathological grade, estrogen receptor status or expression of the c-erb-B2 protein of the original tumours did not significantly correlate with the resistance of cultures. Individual drugs displayed distinct in vitro effectiveness. Paclitaxel and cisplatin were the most potent drugs. Gemcitabine, vinorelbine and mafosfamide were the least potent drugs. Doxorubicin and gemcitabine most frequently failed to completely metabolically inhibit 100% of cultured cells at any concentration.
  
  
  CONCLUSIONS
  Combination of the optimised feeder-layer cultivation technique and the MTT test permits extensive drug resistance testing from very small breast cancer samples.
authors.affiliation: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Department of Oncology, 1st Medical Faculty, Charles University, Prague, Czech Republic.
authors.forename: Luboslava
authors.initials: L
authors.lastname: Krasna
authors.forename: Irena
authors.initials: I
authors.lastname: Netikova
authors.forename: Alena
authors.initials: A
authors.lastname: Chaloupkova
authors.forename: Eva
authors.initials: E
authors.lastname: Taislova
authors.forename: Martina
authors.initials: M
authors.lastname: Zimovjanova
authors.forename: Pavel
authors.initials: P
authors.lastname: Vesely
authors.forename: Jan
authors.initials: J
authors.lastname: Danes
authors.forename: Lubos
authors.initials: L
authors.lastname: Petruzelka
authors.forename: Eva
authors.initials: E
authors.lastname: Matouskova
mesh_terms: D016475:3T3 Cells; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001706:Biopsy; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D005240:Feasibility Studies; D006801:Humans; D051379:Mice; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue