title: Upregulation of glycolytic enzymes in proteins secreted from human colon cancer cells with 5-fluorouracil resistance.
abstract: 5-Fluorouracil (5-FU) is the most commonly used chemotherapeutic agent for colorectal cancer (CRC). However, resistance to this drug is a major obstacle in CRC chemotherapy. Accurate prediction of response to 5-FU would avoid unnecessary chemotherapy and allow the selection of other effective drugs. To identify a candidate predictor of 5-FU resistance, we isolated secreted proteins that were up- or downregulated in a 5-FU-resistant cancer cell line, compared with the parent cell line (SNU-C4), using a stable isotope-coded labeling protocol. For validating the clinical applicability of this method, levels of the identified proteins were determined in the sera of 46 patients treated with 5-FU. In total, 238 proteins with molecular weights ranging from 50 to 75 kDa were identified. Among these, 45 and 35 secreted proteins were up- and downregulated in the 5-FU-resistant cell line, respectively. We observed significant upregulation of glycolytic enzymes, including glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase M2 (PK-M2), transketolase, and NADP(+)-dependent malic enzyme 1. In particular, the level of PK-M2, a key enzyme in the glycolytic pathway, showed an increasing tendency in both sera and tissues from CRC patients displaying no response to 5-FU-based chemotherapy (progressive and stable disease cases), compared with that in complete or partial responders to 5-FU-based chemotherapy; however, it did not reach the statistical significance. In conclusion, increasing pattern of PK-M2 observed with 5-FU resistance induced in vitro and in sera and tissues from CRC patients displaying poor response to 5-FU-based chemotherapy suggest the relevance of dysregulated glycolysis and 5-FU-resistant CRC.
authors: Research Institute and Hospital, National Cancer Center, Korea.
authors: Young-Kyoung
authors: YK
authors: Shin
authors: Byong Chul
authors: BC
authors: Yoo
authors: Yong Sang
authors: YS
authors: Hong
authors: Hee Jin
authors: HJ
authors: Chang
authors: Kyung Hae
authors: KH
authors: Jung
authors: Seung-Yong
authors: SY
authors: Jeong
authors: Jae-Gahb
authors: JG
authors: Park
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000201:enzymology* / Q000378:metabolism; D015536:Down-Regulation; D019008:Drug Resistance, Neoplasm; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000494:pharmacology*; D006019:Glycolysis / Q000187:drug effects; D006801:Humans; D000077146:Irinotecan; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000378:metabolism; D020543:Proteome / Q000378:metabolism; D011770:Pyruvate Kinase / Q000378:metabolism; D015203:Reproducibility of Results; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D009363:Neoplasm Proteins; D020543:Proteome; D000077146:Irinotecan; D011770:Pyruvate Kinase; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin