Calderon-Aparicio Ali, Cornejo Alejandro, Orue Andrea, Rieber Manuel
These authors contributed equally to this work.
Instituto Venezolano de Investigaciones Cientificas, Tumor Cell Biology Laboratory, Caracas 1020-A, Venezuela.
Ecancermedicalscience. 2019 Jan 8;13:890. doi: 10.3332/ecancer.2019.890. eCollection 2019.
Ammonium tetrathiomolybdate (TTM) and disulfiram (DSF) are copper (Cu) chelators in cancer clinical trials partly because Cu chelation: a) restricts the activity of Cu-binding MEK1/2 enzymes which drive tumourigenesis by KRAS or BRAF oncogenic mutations and b) enhances uptake of oxaliplatin (OxPt), clinically used in advanced KRAS-mutant colorectal carcinomas (CRC). Whereas TTM decreases intracellular Cu trafficking, DSF can reach other Cu-dependent intracellular proteins. Since the use of individual or combined Cu chelation may help or interfere with anti-cancer therapy, this study investigated whether TTM modifies the response to DSF supplemented with: 1) UO126, a known MEK1/2 inhibitor; 2) other Cu chelators like neocuproine (NC) or 1, 10-o-phenanthroline (OPT) in wt p53 melanoma cells differing in BRAF or KRAS mutations; 3) OxPt in mutant p53 CRC cells devoid of KRAS and BRAF mutations or harbouring either KRAS or BRAF mutations. TTM was not toxic against A375 and C8161 melanoma cells. Moreover, TTM protected both melanoma types from toxicity induced by DSF, NC and co-treatment with sub-lethal levels of DSF and the MEK inhibitor, UO126. Toxicity by co-treatment with DSF+OPT was poorly reversed by TTM in C8161 melanoma cells. In contrast to the greater toxicity of 0.1 μM DSF against mutant p53 CRC cells irrespective of their KRAS mutation, TTM did not protect SW620 CRC from DSF+OxPt compared to Caco-2 CRC. Our results show that DSF co-treatment with: a) MEK inhibitors may enhance tumour suppression; b) OxPt in CRC may counteract impaired response to cetuximab by KRAS/BRAF mutations and c) as a single treatment, TTM may be less effective than DSF and decreases the efficacy of the latter.
Potentiation of melanoma antitumour toxicity of DSF by MEK inhibitor is reversed by TTM.KRAS/c-MYC dysregulation attenuates TTM reversion of melanoma toxicity by DSF + OPT.KRAS/c-MYC dysregulation increases melanoma NC toxicity reversed by TTM.BRAF mutation and lower c-MYC may attenuate toxicity by DSF ± OxPt in colorectal cancer cells.
四硫代钼酸铵（TTM）和双硫仑（DSF）是癌症临床试验中的铜（Cu）螯合剂，部分原因是铜螯合作用：a）限制与铜结合的MEK1/2酶的活性，这些酶通过KRAS或BRAF致癌突变驱动肿瘤发生；b）增强奥沙利铂（OxPt）的摄取，奥沙利铂临床上用于治疗晚期KRAS突变型结直肠癌（CRC）。虽然TTM减少细胞内铜的转运，但DSF可以作用于其他依赖铜的细胞内蛋白质。由于单独或联合使用铜螯合剂可能有助于或干扰抗癌治疗，本研究调查了TTM是否会改变对补充有以下物质的DSF的反应：1）UO126，一种已知的MEK1/2抑制剂；2）其他铜螯合剂，如新铜试剂（NC）或1,10-邻菲罗啉（OPT），在具有BRAF或KRAS突变的野生型p53黑色素瘤细胞中；3）在缺乏KRAS和BRAF突变或携带KRAS或BRAF突变的突变型p53 CRC细胞中加入OxPt。TTM对A375和C8161黑色素瘤细胞无毒。此外，TTM保护这两种黑色素瘤细胞免受DSF、NC以及亚致死剂量的DSF与MEK抑制剂UO126联合处理所诱导的毒性。在C8161黑色素瘤细胞中，TTM对DSF + OPT联合处理所产生的毒性的逆转作用较差。与0.1μM DSF对突变型p53 CRC细胞（无论其KRAS突变情况如何）具有更大毒性相反，与Caco-2 CRC相比，TTM不能保护SW620 CRC免受DSF + OxPt的影响。我们的结果表明，DSF与以下物质联合处理：a）MEK抑制剂可能增强肿瘤抑制作用；b）CRC中的OxPt可能抵消KRAS/BRAF突变导致的对西妥昔单抗反应受损；c）作为单一治疗，TTM可能比DSF效果更差，并降低后者的疗效。
MEK抑制剂增强DSF对黑色素瘤的抗肿瘤毒性作用被TTM逆转。KRAS/c-MYC失调减弱TTM对DSF + OPT诱导的黑色素瘤毒性的逆转作用。KRAS/c-MYC失调增加TTM可逆转的黑色素瘤NC毒性。BRAF突变和较低的c-MYC可能减弱DSF ± OxPt对结肠癌细胞的毒性。
