Characterisation of high-level cisplatin-resistant cell lines established from a human hepatoma cell line and human KB adenocarcinoma cells: cross-resistance and protein changes

Br J Cancer. 1995 Apr;71(4):676-83. doi: 10.1038/bjc.1995.134.


Human liver carcinoma cells (BEL-7404) and human KB adenocarcinoma cells were selected by stepwise increases in cisplatin. Drug sensitivity assays indicated that the IC50 value for 7404-CP7.5 cells was 49 micrograms ml-1 cisplatin, 111-fold higher than for the parental hepatoma cells. The IC50 value for KB-CP10 cells was 38 micrograms ml-1 cisplatin, which is 1152-fold higher than for the parental KB cells. The 7404-CP7.5 cells were cross-resistant to methotrexate (39 x), 5-fluorouracil (23 x) and 6-mercaptopurine (13 x), but were sensitive to drugs which are known substrates for the multidrug transporter (P-glycoprotein), including colchicine, vinblastine and actinomycin D. Similar cross-resistance patterns were observed for KB-CP10 cells. No evidence of DNA amplification or expression of the MDR1 gene was found. One-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed increases in 52 kDa protein(s) in both the soluble cytosolic and crude membrane fractions in 7404-CP(r) cells and in KB-CP(r) cells. The amount of 52 kDa protein was proportional to the degree of resistance of the 7404-CP(r) cells to cisplatin. Two-dimensional gel analysis demonstrated that two polypeptides of molecular mass 52 and 50 kDa were overexpressed in the membrane fractions in both 7404-CP20 and KB-CP20 cells. Using amino acid microsequencing and Western blotting, major 52 kDa protein was identified as the mitochondrial heat shock protein hsp60. Two-dimensional gels of [35S]methionine-labelled polypeptides showed many other changes, including reduction in soluble proteins of approximately 57 kDa molecular weight in KB-CP20 cells, and of 35 kDa in both 7404-CP20 and KB-CP20 cells. These results suggest that alterations of certain proteins occur commonly in cisplatin-resistant cells, particularly proteins of molecular weight 52 and 50 kDa.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Antineoplastic Agents / toxicity*
  • Blotting, Western
  • Carcinoma, Hepatocellular
  • Cell Survival / drug effects
  • Cisplatin / toxicity*
  • Clone Cells
  • Cytosol / metabolism
  • Drug Resistance*
  • Electrophoresis, Gel, Two-Dimensional
  • Electrophoresis, Polyacrylamide Gel
  • Humans
  • KB Cells
  • Liver Neoplasms
  • Methionine / metabolism
  • Molecular Weight
  • Neoplasm Proteins / biosynthesis*
  • Neoplasm Proteins / chemistry
  • Neoplasm Proteins / isolation & purification
  • Tumor Cells, Cultured


  • Antineoplastic Agents
  • Neoplasm Proteins
  • Methionine
  • Cisplatin