A proteomic approach links decreased pyruvate kinase M2 expression to oxaliplatin resistance in patients with colorectal cancer and in human cell lines.
We aimed to gain further understanding of the molecular mechanisms involved in oxaliplatin resistance in colorectal cancer by using a proteomic approach. A 5-fold oxaliplatin-resistant cell line, HTOXAR3, was compared with its parental cell line, HT29, using two-dimensional PAGE. Mass spectrometry, Western blot, and real-time quantitative PCR confirmed the down-regulation of pyruvate kinase M2 (PK-M2) in HTOXAR3 cells. In a panel of eight colorectal cancer cell lines, we found a negative correlation between oxaliplatin resistance and PK-M2 mRNA levels (Spearman r=-0.846, P=0.008). Oxaliplatin exposure in both HT29 and HTOXAR3 led to PK-M2 mRNA up-regulation. PK-M2 mRNA levels were measured by real-time quantitative PCR in 41 tumors treated with oxaliplatin/5-fluorouracil. Tumors with the lowest PK-M2 levels attained the lowest response rates (20% versus 64.5%, P=0.026). High PK-M2 levels were associated with high p53 levels (P=0.032). In conclusion, the data provided clearly link PK-M2 expression and oxaliplatin resistance mechanisms and further implicate PK-M2 as a predictive marker of response in patients with oxaliplatin-treated colorectal cancer.
Medical Oncology Service, Hospital Universitari Germans Trias i Pujol, Institut Catala Oncologia, Badalona 08916, Barcelona, Spain.
Eva
E
Martinez-Balibrea
Carmen
C
Plasencia
Alba
A
Ginés
Anna
A
Martinez-Cardús
Eva
E
Musulén
Rodrigo
R
Aguilera
José Luis
JL
Manzano
Nouri
N
Neamati
Albert
A
Abad
D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D015153:Blotting, Western; D002945:Cisplatin / Q000494:pharmacology; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000201:enzymology* / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009944:Organoplatinum Compounds / Q000627:therapeutic use*; D000077150:Oxaliplatin; D040901:Proteomics; D011770:Pyruvate Kinase / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D046888:Tissue Array Analysis; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds; D012333:RNA, Messenger; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D000077150:Oxaliplatin; D011770:Pyruvate Kinase; D002945:Cisplatin