Mechanism study of benzyl isothiocyanate combined with sorafenib in the treatment of anaplastic thyroid cancer

MA Chunmei; YU Peng; ZHANG Qicheng; YANG Lei; LI Dihua; TAN Jian; MENG Zhaowei

doi:10.11958/20250340

Abstract：Objective To investigate the mechanism of benzyl isothiocyanate(BITC)combined with sorafenib(Sor)in the treatment of anaplastic thyroid cancer(ATC).Methods Two ATC cell lines,8505C and CAL-62,were treated with Sor at concentrations of 0,20,30,40,and 50 μmol/L.The cell survival rate was assessed using CCK-8 assay.The combined dose of BITC and Sor was determined by calculating combination index(CI).CAL-62 and 8505C cells were exposed to 10 μmol/L BITC(BITC group),10 μmol/L Sor(Sor group),or a combination of 10 μmol/L BITC and 10 μmol/L Sor(BITC+Sor group)for 24 hours.The control group was not treated.The effects of Sor and BITC on ATC cell viability were evaluated using the CCK-8 method.Apoptosis was analyzed via flow cytometry.Western blot assay was employed to detect the protein expression levels of LC3B Ⅱ,Beclin-1 and nuclear factor(NF)-κB.Real-time fluorescence quantitative PCR was used to quantify the mRNA levels of LC3B.Additionally,CAL-62 cells were subcutaneously injected into mice to establish tumor xenograft model.Mice were treated with BITC(100 mg/kg,intraperitoneal injection),Sor(30 mg/kg,intragastric administration)or a combination of BITC and Sor every other day for 21 days.Finally,the expression levels of LC3B Ⅱ,Beclin-1 and NF-κB in tumor tissue were analyzed by Western blot assay.Results Sor significantly inhibited the viability of CAL-62 and 8505C cells in a concentration-dependent manner.The combination index(CI)was 0.710 at BITC 10 μmol/L and Sor 10 μmol/L,indicating a moderate synergistic effect between the two drugs.In both 8505C and CAL-62 cells,compared with the control group,treatment with BITC or Sor resulted in the decreased cell viability,as well as reduced expression levels of Beclin-1 and NF-κB proteins(P＜0.05),and the apoptosis rate,LC3B mRNA and LC3B Ⅱ protein expression levels were significantly increased(P＜0.05).When BITC and Sor were combined,the cell viability,Beclin-1 and NF-κB protein expressions were further reduced compared to either drug alone,while the apoptosis rate,LC3B mRNA and LC3B Ⅱ protein expression levels were significantly elevated(P＜0.05).In the mouse xenograft tumor model,the BITC+Sor group exhibited increased LC3B Ⅱ expression,along with decreased Beclin-1 and NF-κB expression levels,tumor volume and tumor mass compared to the BITC or Sor groups(P＜0.05).Conclusion The combination of BITC and Sor can inhibit ATC cells through NF-κB pathway,induce autophagy and promote apoptosis in vitro and in vivo.