Construction of colonic cancer drug-resistant cell line COLO and its relationship with tumor stem cells / 国际肿瘤学杂志

ABSTRACT

Objective To construct a colon cancer chemotherapy-resistant cell line COLO,and study its characteristics and its relationship with tumor stem cells.Methods We constructed two 5-fluorouraci (5-FU)-resistant colon cancer cell line COLO/5-FU-1 and COLO/5-FU-2, which were resistant to 0.1 0 μmol/ml and 0.20 μmol/ml 5-FU respectively through gradiently increased drug concentration.The cha-racteristics of 5-FU-resistant cell lines were compared with parental colon cancer cell line COLO related to proli-feration,colony forming ability,migration and invasion,sphere forming ability,expression of stemness genes and cross drug-resistance.Results In the cell viability assay,4 days after regular training,the absorbancy of colon cancer 5-FU-resistant cell lines COLO/5-FU-2,COLO/5-FU-1 and parental colon cancer cell line COLO were 0.61 ±0.1 3,0.54 ±0.07 and 0.41 ±0.09 respectively,with significant difference (F =63.43,P =0.033).With the increased concentration of 5-FU,5-FU-resistant cell lines presented increasing clonality. The cloning efficiency of COLO/5-FU-2,COLO/5-FU-1 and parental colon cancer cell line COLO were (87.6 ±1 2.7)%,(65.3 ±9.7)% and (38.5 ±7.6)% respectively,with significant difference (F =33.64, P =0.01 7).In each high power field of vision,the cell numbers of migration through the basement membrane of COLO/5-FU-2,COLO/5-FU-1 and parental colon cancer cell line COLO were 482 ±39,434 ±45 and 373 ±38 respectively;and the cell numbers of invasion through the basement membrane were 1 74 ±42,1 1 2 ± 31 and 87 ±29 respectively,with significant differences (F =1 09.61 ,P =0.009;F =67.31 ,P =0.032). Compared with parental colon cancer cell line COLO,5-FU-resistant cell lines had higher expression of stem-ness genes (F =47.31 ,P =0.042).5-FU-resistant cell lines were cross-resistant to other chemotherapeutic drugs such as mitoxantrone.For example,after incubation for 96 hours,inhibition rate of mitoxantrone to parent colon cancer cell line COLO was higher significantly than COLO/5-FU-1 and COLO/5-FU-2 (0.749 ± 0.042,0.423 ±0.024,0.342 ±0.01 8),with significant difference (F =1 2.61 ,P =0.028).The micro-sphere forming rates of COLO/5-FU-2,COLO/5-FU-1 and parental colon cancer cell line COLO were (8.90 ± 0.97)%,(6.20 ±0.75)% and (3.90 ±0.32)% respectively,with significant difference (F =1 64.32,P =0.006).Conclusion Colon cancer drug-resistant cell line COLO possess tumor stem cell-like characteristics, which are enriched in cancer stem cells.