Anti-HSP90 antibody promotes the anticancer effect of cisplatin by inhibiting human gastric cancer stem cells through internalizing eHSP90 / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：探索抗HSP90单克隆抗体28C10通过靶向肿瘤干细胞促进顺铂（cisplatin，DDP）对人胃癌细胞PAMC82恶性生物学行为的抑制效果及其可能的作用机制。方法: 28C10单独或与DDP联合处理人胃癌细胞PAMC82，采用不同实验方法检测该细胞的无血清成球能力、迁移和侵袭能力与克隆形成能力，CCK-8法检测28C10对PAMC82细胞恶性生物学行为和协同DDP抗癌能力的影响。采用细胞免疫荧光及流式细胞术检测PAMC82细胞中HSP90及eHSP90（extracellular HSP90）的表达、定位、eHSP90+亚群比例，以及28C10处理后对ALDH+、CD44+、eHSP90+细胞亚群的影响。采用WB实验检测28C10作用后PAMC82细胞中HSP90、干性相关蛋白以及PI3K/AKT/mTOR信号通路蛋白表达的变化。结果：胃癌细胞PAMC82膜表面表达eHSP90，具有2%~3%的eHSP90+细胞亚群，且eHSP90+细胞多为与ALDH+或CD44+共阳性细胞。28C10处理能显著抑制PAMC82细胞的成球、克隆形成、增殖、耐药、迁移及侵袭能力，而且和DDP联用的效果更明显（P<0.05或P<0.01）。流式细胞术分析发现28C10处理显著抑制PAMC82细胞的eHSP90+、ALDH+和CD44+亚群数量（均P<0.01）。免疫荧光实验发现28C10作用后eHSP90发生内吞，WB实验结果显示eHSP90、CD44、ALDH和干性相关蛋白OCT4、SOX2表达量均降低（P<0.05或P<0.01）。结论：抗HSP90单克隆抗体28C10可靶向胃癌PAMC82细胞的ALDH+、CD44+肿瘤干细胞相关亚群、内化eHSP90且降低细胞总HSP90的水平、抑制PI3K/AKT/mTOR信号通路，从而有效地抑制PAMC82细胞的干性、耐药和其他恶性生物学行为，协同DDP显著提高抗癌效果。

Targeting cancer stem cells for cancer therapy / 中国肿瘤生物治疗杂志

@#[摘 要] 具有独特的分子表达、表面标志物、干性相关信号通路和代谢模式等方面特征的肿瘤干细胞（cancer stem cell, CSC）因其具有高致瘤、高转移、高治疗抵抗能力，可能是多种类型恶性肿瘤生长、转移、治疗抵抗的关键因素，也是肿瘤发生和复发的重要根源。正常干细胞在产生了第一个致癌突变之后将逐步发展成为癌前干细胞和CSC，随后在突变和微环境的共同作用下进一步积累突变增加异质性，并与CSC可塑性转变交织在一起推动肿瘤的发生和进展，促进肿瘤的复发、转移及治疗抵抗。为了更好地治疗肿瘤，现已研发了多种类型的靶向CSC的治疗策略，包括靶向CSC的细胞表面标志物、信号转导途径、微环境、代谢模式等，以及促CSC分化、靶向CSC的免疫治疗等其他策略。多个靶向CSC治疗肿瘤的新药在临床试验中已经展现出良好的治疗效果，然而，也有一些抗肿瘤新药的失败为未来研发提供了值得注意的教训。未来肿瘤治疗中，特异地靶向患者肿瘤中所有异质性的CSC，并同时清除癌前干细胞和子代肿瘤细胞，将会更好地抑制肿瘤生长、转移和复发，从而为治愈肿瘤带来新的希望。

Anti-ENO1 antibody combined with metformin reverses the resistance of human non-small cell lung cancer A549 cells to cetuximab by targeting cancer stem cells / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To explore the effect of anti-ENO1 (enolase 1) antibody and metformin (MET) treatment on the proliferation, migration, invasion and stemness of cetuximab (CTX) -resistant non-small cell lung cancer (NSCLC) cells through targeting cancer stem cells and the possible mechanism. Methods: 10 mmol/L MET combined with 40 μg/ml anti-ENO1 antibody was used to treat CTX(35 µg/ml)-resistant NSCLC A549 cells for 4 d, and the effects of combined treatment on A549 cells were detected with proliferation experiment, colony formation assay, migration and invasion experiments and methylcellulose ball formation experiment. In the meanwhile, FCM was used to detect the effects of CTX, MET and anti-ENO1 antibody single-drug treatment as well as the three-drug combination treatment on ALDH+ and CD44+ lung cancer stem cell subsets. Results: CTX combined with MET and anti-ENO1 antibody treatment significantly inhibited the proliferation, migration, invasion and self-renewal capacity of A549 cells. FCM analysis found that MET could significantly inhibit ALDH+ stem cell subpopulations, while anti-ENO1 antibody could significantly inhibit CD44+ stem cell subpopulations, and the three-drug combination treatment could simultaneously suppress ALDH+ and CD44+ stem cell subpopulations. Conclusion: MET and anti-ENO1 antibody respectively target ALDH+ and CD44+ cancer stem cell subsets, and the combined treatment of MET and anti-ENO1 antibody can effectively reverse the resistance of A549 cells to CTX, and thereby more effectively inhibiting stemness, proliferation, metastasis of A549 cells and tumor recurrence.

Monoclonal antibody 18H12 suppresses the self-renewal and invasion of PAMC-82 gastric cancer stem cells / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To investigate the effect of 18H12, a functional monoclonal antibody that can target gastric cancer stem cells, on the self-renewal and invasion ability of gastric cancer cells. Methods: The gastric cancer cell line PAMC-82 was used as cell model, the expression of ENO1 (enolase-1) on the membrane surface of its parental cells and enriched stem cells by sphere culture was detected by Flow cytometry. Flow cytometry was used to separate ENO1+ cells and ENO1- cells to detect their self-renewal ability and invasion ability. With the commercial ENO1 antigen and antibody as the samples, CoIP (co-immunoprecipitation) was used to verify whether 18H12 antibody targeting ENO1 could able to accurately recognize ENO1. After being treated with 18H12 for 12 h, 24 h and 48 h, the selfrenewal and invasion ability of PAMC-82 cells were detected by methylcellulose pelletization experiment and Transwell chamber assay, respectively. Results: Flow cytometry showed that the expression of ENO1 on the membrane surface of PAMC-82 sphere cells was significantly higher than that of its parental cells (P<0.01), so ENO1 could be a potential target for targeting gastric cancer stem cells. The self-renewal ability and invasion ability of the sorted ENO1+ cells were significantly stronger than those of the ENO1- cells and the parental cells (P<0.05 or P<0.01). 18H12 antibody could accurately recognize ENO1, which was consistent with the commercial antibody recognition band. 18H12 could significantly inhibit self-renewal ability and invasion ability of PAMC-82 cells (P<0.01). Conclusion: Monoclonal antibody 18H12 can significantly inhibit the self-renewal and invasion of gastric cancer stem cells and is expected to be a candidate antibody drug targeting gastric cancer stem cells.