ABSTRACT
Objective: To screen and identify oxaliplatin-resistance-associated proteins in CRC (colorectal cancer) cell lines using proteomics technologies in order to find new biomarkers for individual therapy of CRC. Methods: Oxaliplatin-resistant human CRC cell line HT-29/L-OHP (oxaliplatin) was established. The total proteins in HT-29 and HT-29/L-OHP cells were extracted. The differentially expressed proteins between HT-29 and HT-29/L-OHP cells were screened and identified using 2-DE (two-dimensional gel electrophoresis) and MALDI-TOF-MS (matrix assisted laser desorption-ionization time-of-flight tandem mass spectrometry). Some proteins obtained were validated by Western blotting. Results: The 2-DE maps of total proteins in HT-29 and HT-29/L-OHP cells were established. Of the 38 protein spots identified as differentially expressed proteins (over two-fold, P < 0.05) between HT-29 and HT-29/L-OHP cells, 37 protein spots were positively identified by MALDI-TOF-MS (17 proteins were up-regulated and 20 proteins were down-regulated as compared with the parental HT-29 cells). The result of Western blotting showed that the PCBP1 [poly (C)-binding protein-1] and TUBB2A (tubulin beta 2A ) proteins were up-regulated while ANXA3 (annexin A3) and STIP1 (stress-induced-phosphoprotein 1) proteins were down-regulated in HT-29/L-OHP cells. The result of Western blotting was consistent with that of proteomics. Conclusion: There were 37 oxaliplatin-resistance-associated proteins in CRC identified in this study which may provide useful evidence in further research on mechanism of oxaliplatin-resistance in CRC. Copyright © 2013 by TUMOR.
ABSTRACT
This study was aimed to investigate the effect of homoharringtonine (HHT) on K562 cell proliferation, apoptosis and expression of BCL-2 and NF-κB proteins. The cells proliferation was assayed with MTT method, the cell apoptosis, cell cycle and BCL-2 expression were analyzed with flow cytometry, NF-κB protein expression was detected with Western blot. The results showed that HHT concentration-dependently inhibited proliferation of K562 cells, the IC50 at 48 h was 43.89 ng/ml. Treated with HHT 10 ng/ml for 48 h, K562 cell apoptosis significantly increased, cell cycle was blocked at G0/G1, the expression level of BCL-2 and NF-κB proteins was lower than that in control group (P < 0.05). It is concluded that HHT may inhibit the proliferation of K562 cells, and down-regulating expression levels of BCL-2 and NF-κB may be one of its anti-CML mechanisms.