Targeting STAT3 with SH-4-54 suppresses stemness and chemoresistance in cancer stem-like cells derived from colorectal cancer

BACKGROUND Over the years,the numbers of treatment options for colorectal cancer(CRC)have increased,leading to notable improvements in the overall survival of CRC patients.Although therapy may initially yield positive results,the development of drug resistance can result in treatment failure and cancer recurrence.This resistance is often attributed to the presence of cancer stem cells(CSCs).These CSCs not only contribute to therapeutic resistance but also play crucial roles in the initiation and development of tumor metastasis.AIM To investigate the antitumor effects of SH-4-54,which are mediated by targeting CSCs relative to treatment outcomes.METHODS CSCs were enriched by culturing CRC cells in serum-free medium.Hallmarks of stemness and IL-6/JAK2/STAT3 signaling were detected by Western blotting.Indicators of CSC malignancy,including proliferation,invasion,and tumor formation,were measured.RESULTS In this study,we employed SH-4-54,which exhibits anticancer activity in solid tumors through targeting the SH2 domain of both the signal transducer and activator of transcription(STAT)3 and the STAT5,and evaluated its effects on stemness and chemoresistance in colorectal CSCs.As expected,SH-4-54 treatment inhibited the phosphorylation of STAT3(p-STAT3)and decreased the percentage of ALDH1A1-positive CRC cells.The addition of SH-4-54 dissociated colorectal spheroids and decreased the expression of stemness markers,including ALDH1A1,CD44 and Nanog.SH-4-54 treatment decreased IL-6/JAK2/STAT3 signaling by inhibiting p-STAT3 and thus inhibited spheroid formation by SW480 and LoVo cells.Moreover,SH-4-54 treatment inhibited indicators of malignancy,including cell proliferation,invasion,and tumor formation,in CSCs in vitro and in vivo.Notably,SH-4-54 treatment significantly increased chemosensitivity to oxaplatin.CONCLUSION Taken together,these results indicate that SH-4-54 is a promising molecule that exerts antitumor effects on colorectal CSCs by inhibiting STAT3 signaling.

沉默GRAMD1A及抑制STAT5信号通路对肝癌细胞Huh7放射敏感性的影响

目的 探讨沉默GRAMD1A及抑制STAT5信号对肝癌细胞Huh7放射敏感性的影响，旨在为肝癌临床联合治疗提供新思路。方法 慢病素感染构建沉默GRAMD1A的Huh7细胞株，采用qPCR和Western blot进行验证，qPCR和荧光素酶报告实验检测沉默GRAMD1A后对Huh7细胞中STAT5及其下游基因表达的影响；以克隆形成率和细胞凋亡为指标检测沉默GRA株。结果 构建后的Huh7细胞经2 Gy照射后，沉默GRAMD1A联合照射组细胞克隆形成能力较阴性对照联合照射组显著降低，差异有统计学意义（t=8.494，P〈0.05）；沉默GRAMD1A联合照射组细胞凋亡较阴性对照联合照射组显著增加，差异有统计学意义（t=3.560，P〈0.05）。沉默GRAMD1A后Huh7细胞放射敏感性明显增加，且细胞中STAT5及其下游基因表达显著降低。SH-4-54抑制剂联合照射组较二甲基亚砜联合照射组细胞克隆存活能力显著降低，差异有统计学意义（t=8.660，P〈0.05），SH-4-54抑制STAT5通路后，Huh7细胞放射敏感性显著增加。结论 沉默GRAMD1A可能通过STAT5信号通路增强肝癌细胞Huh7的放射敏感性，表明GRAMD1A在肝癌发生发展中起重要作用，将可能为肝癌靶向治疗及联合治疗提供新靶点。