针对VEGF和CD47的双靶点联合治疗协同抗胃癌作用机制研究

Gastric cancer has a high incidence in China and there is still lack of effective drug treatment. Vascular endothelial growth factor antagonists often suffer from drug resistance in long-term cancer treatment. It is found that the combination of immunotherapy targeting CD47 provides strong support for the enhancement of anti-angiogenesis therapy and the improvement of drug resistance. Our preliminary results suggest that the combination of anti-VEGF monoclonal antibody and anti-CD47 monoclonal antibody has synergistic anti-tumor effect. However, its mechanism of action remains to be further explored. Therefore, we hypothesize that CD47-MAb may play a synergistic anti-tumor role with VEGF-MAb by overcoming the immune resistance of VEGF-MAb to gastric cancer treatment and relieving the immune suppression of the body. In order to verify this hypothesis, we will explore the synergistic anti-tumor effect of VEGF-MAb/CD47-MAb from molecular, cellular, tissue and animal levels by LDH, Western blot, immunohistochemistry and flow cytometry in human gastric carcinoma cell and Balb/c mouse gastric cancer model, and clarify the synergistic mechanism of VEGF-MAb/CD47-MAb. This study provides new ideas for the treatment of gastric cancer through the combination of anti-angiogenesis and immunotherapy, which has high clinical value for the treatment of malignant tumors.

胃癌在我国发病率高，目前仍缺乏有效的药物治疗手段。现有的VEGF拮抗剂在胃癌长期治疗中常会发生肿瘤耐药等问题。我们的预实验结果发现VEGF单克隆抗体与CD47单克隆抗体联合应用具有协同抗肿瘤作用。但其作用机制还有待进一步探讨。为此，我们提出假说：CD47-MAb可能通过克服VEGF-MAb对胃癌治疗产生的免疫耐药，同时解除机体的免疫抑制，与VEGF-MAb发挥协同抗肿瘤作用。为了验证这一假说，我们将通过人胃癌细胞系和Balb/c小鼠胃癌模型，采用LDH法、Western blot、免疫组化、流式细胞术等手段，从分子、细胞、组织及动物整体水平等多方面探讨VEGF-MAb/CD47-MAb的协同抗肿瘤作用，明确VEGF-MAb/CD47-MAb协同作用机制。本研究通过联合抗血管生成和免疫治疗这个新角度为胃癌的治疗提供新思路，对恶性肿瘤的治疗具有较高的临床价值。

胃癌在我国发病率高，目前仍缺乏有效的药物治疗手段。现有的VEGF拮抗剂在胃癌长期治疗中常会发生肿瘤耐药等问题。本研究通过人胃癌细胞系和Balb/c小鼠胃癌模型，采用免疫组化、流式细胞术、qPCR等手段，从分子、细胞、组织及动物整体水平等多方面探讨了VEGF-MAb/CD47-MAb的协同抗肿瘤作用。本课题研究表明贝伐单抗与Anti-CD47单抗联用，可显著增强贝伐单抗的体内外抗胃癌活性，且可抑制肺转移。二者协同作用机制可能是由于Anti-CD47单抗阻断了CD47-SIRPα通路，提高巨噬细胞吞噬肿瘤细胞的能力，从而避免贝伐单抗治疗引起的肿瘤细胞免疫逃逸；同时Anti-CD47单抗治疗能逆转贝伐单抗治疗引起的巨噬细胞浸润减少，使肿瘤组织中浸润的巨噬细胞增多，进一步发挥抑制肿瘤的功效。本课题通过联合抗血管生成和免疫治疗这个新角度为胃癌的治疗提供新思路，对恶性肿瘤的治疗具有较高的临床价值。项目研究成果在Frontiers in Pharmacology发表论文1篇。