Relationship between p62 expression in cisplatin-resistant liver cancer cells and sensitivity to cisplatin
ZHENG Zhiming
ZOU Haipeng
LIN Bihua
LONG Bingqing
Abstract：Objective To investigate the expression of p62 in cisplatin-resistant liver cancer cells and the chemothera-peutic sensitivity of p62-silenced cisplatin-resistant liver cancer cells to cisplatin. Methods Human liver cancer cell lines HepG2 and Huh7 were used to induce cisplatin-resistant cell lines by slowly increasing cisplatin concentrations. The protein expression of p62 was detected in parental cells and cisplatin-resistant cells by Western blotting. The liver cancer cisplatin-resistant cell lines (HepG2 / CDDP and Huh7 / CDDP)were divided into the p62-silenced group and cisplatin-re-sistant group,and were treated by p62 siRNA and siRNA Negative Controls,respectively. After 48-hour transfection,MTT assay was applied to detect cell viability of the two groups at 0,1,2,3,4,and 5 d. Apoptotic nuclear changes were eval-uated with Hochest 33258 staining,and apoptotic cells were quantified. Meanwhile,the apoptosis rate was calculated by Annexin V-FITC/ PI flow cytometry at 48 h after transfection. The protein expression of NF-E2-related factor 2 (Nrf2)and the mRNA expression of its target genes glutamate cysteine ligase (GCL),glutathione S transferase (GST),quinone oxi-doreductase 1 (NQO1),glutathione S transferase (GST),heme oxygenase-1(HQ-1)and multidrug resistance-associated protein (Mrp)was evaluated by Western blotting and RT-PCR,respectively. Results The cisplatin-resistant cells (HepG2 and Huh7)expressed much higher protein levels of p62 than their parental cells (all P < 0. 05). The cell viability of the two groups at 0,1,2,3,4,and 5 d of the p62-silenced group was lower than that of the cisplatin-resistant cells (all P < 0. 05),and the apoptosis of cisplatin-resistant group increased as compared with that of the p62-silenced group (all P< 0. 05). The expression of Nrf2 protein and its target genes NQO1,GCL,GST,HO-1,and Mrp mRNA of the p62-si-lenced group was lower than that of the cisplatin-resistant group (all P < 0. 05). Conclusions The protein level of p62 is up-regulated in cisplatin-resistant liver cancer cells. Silencing p62 increases the sensitivity of liver cancer cells to cispla-tin by down-regulating the expression of Nrf2 and its target genes.
Keywords：liver carcinomaliver cancer cellsdrug resistancecisplatinp62gene silencingNF-E2-related fac-tor 2
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 1-5 )