HnRNP K and PDI marked response to chemotherapy to human colorectal cancer cells.
5-Fluorouracil has been the chemotherapy agent of first-choice for colorectal cancer for many years, but since there are no proven predictors of a patient's response to therapy, all patients receive similar treatment. Consequently, identification of biomarkers for therapeutic effect is crucial for the development of novel therapeutic strategies. Two human colorectal cancer cell lines of different metastatic potential (LoVo and SW480) were studied. IC50 of 5-FU for both cell lines were measured by 3-(4,5-dimethy-lthiazol-2-yl)-2,5-diphenyltetrazolium assay and validated by cell cycle analysis. Then the cell lines were treated with 5-FU at IC50 concentration and protein was extracted for 2-DE. Differential protein spots were examined by MALDI-TOF/TOF MS. The expression levels of the different proteins were further confirmed by Western blot and immunofluorescence analyses. Eleven proteins were identified. Expression of heterogeneous nuclear ribonucleoprotein K (hnRNP K) in LoVo cells was higher than in SW480 cells, while protein disulfide isomerase (PDI) displayed the opposite trend. After treatment with 5-FU, the expression of hnRNP K in LoVo decreased more significantly than in SW480, while PDI in SW480 increased more significantly than in LoVo cells.


CONCLUSIONS
hnRNP K and PDI in the two cell lines have different expression characteristics. The sensitivity to 5-FU is not consistent in tumor progression. It may assist in development of novel treatment strategies for colorectal cancer metastasis.
Zhang
Peng
P
Department of Surgery, Sixth People's Hospital Affiliated to Shanghai JiaoTong University, Shanghai, PR China.
Huang
Long
L
Ma
Yan-lei
YL
Peng
Jia-yuan
JY
Shen
Tong-yi
TY
Chen
Hong-qi
HQ
Zhou
Yu-kun
YK
Zhang
Ming
M
Chu
Zhao-xin
ZX
Qin
Huan-long
HL
D015153:Blotting, Western; D002453:Cell Cycle; D045744:Cell Line, Tumor; D002470:Cell Survival; D015179:Colorectal Neoplasms / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D005472:Fluorouracil / Q000378:metabolism; D034641:Heterogeneous-Nuclear Ribonucleoprotein K / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D019704:Protein Disulfide-Isomerases / Q000378:metabolism*; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D011506:Proteins; D019704:Protein Disulfide-Isomerases; D005472:Fluorouracil