CAJ | 학술논문

目的观察表皮生长因子受体(EGFR)单克隆抗体西妥昔单抗((225)对裸鼠胃癌移植瘤生长的影响,并探索其分子机制.方法筛选出高表达EGFR的胃癌细胞株SGC-7901,建立裸鼠胃癌移植瘤模型,成瘤后分为治疗组(注射(225)和对照组(注射PBS),绘制肿瘤生长曲线.采用免疫组织化学染色法,评价C225对肿瘤细胞增殖和微血管密度的影响.采用原位末端标记染色(TUNEL)技术,检测肿瘤细胞凋亡.采用免疫组化染色和Western blot技术,检测C225对转录因子Spl及EGFR表达的影响.结果经C225处理后,裸鼠胃癌移植瘤的生长、细胞的增殖能力明显受抑,治疗组和对照组肿瘤细胞的凋亡指数分别为16.4%±0.3%和3.1%±0.9%,差异有统计学意义(P<0.001);而治疗组和对照组肿瘤组织的微血管密度并无明显差异.免疫组化染色和Western blot结果均显示,C225处理后,肿瘤细胞表面EGFR及肿瘤细胞核内Spl的表达均明显上调.结论 C225可有效抑制裸鼠胃癌皮下移植瘤的生长及细胞增殖,促进细胞凋亡,但可反馈性上调肿瘤细胞核内转录因子Spl及该药物靶点EGFR的自身表达.不同信号转导通路间可能通过转录因子Spl介导的阻断-转录激活-代偿机制,导致单一靶点阻断后的获得性耐药或使肿瘤细胞维持恶性表型.
목적 관찰표피생장인자수체(EGFR)단극륭항체서타석단항((225)대라서위암이식류생장적영향,병탐색기분자궤제.방법 사선출고표체EGFR적위암세포주SGC-7901,건립라서위암이식류모형,성류후분위치료조(주사(225)화대조조(주사PBS),회제종류생장곡선.채용면역조직화학염색법,평개C225대종류세포증식화미혈관밀도적영향.채용원위말단표기염색(TUNEL)기술,검측종류세포조망.채용면역조화염색화Western blot기술,검측C225대전록인자Spl급EGFR표체적영향.결과 경C225처리후,라서위암이식류적생장、세포적증식능력명현수억,치료조화대조조종류세포적조망지수분별위16.4%±0.3%화3.1%±0.9%,차이유통계학의의(P<0.001);이치료조화대조조종류조직적미혈관밀도병무명현차이.면역조화염색화Western blot결과균현시,C225처리후,종류세포표면EGFR급종류세포핵내Spl적표체균명현상조.결론 C225가유효억제라서위암피하이식류적생장급세포증식,촉진세포조망,단가반궤성상조종류세포핵내전록인자Spl급해약물파점EGFR적자신표체.불동신호전도통로간가능통과전록인자Spl개도적조단-전록격활-대상궤제,도치단일파점조단후적획득성내약혹사종류세포유지악성표형.
Objective EGFR-mediated tumor proliferation plays an important role in the development of cancer, and is a key candidate for targeted therapy. The aim of this study is to evaluate the impact of EGFR monoclonal antibody Cetuximab (C225 ) on the growth, proliferation and apoptsis of gastric cancer xenograft in nude mice, and its possible mechanisms. Methods A gastric cancer cell line SGC-7901 with high EGFR expression level was screened from 7 gastric cancer cell lines. Gastric cancer xenografts in nude mice were established, and randomly divided into C225 treatment group and PBS control group. Tumor growth curves were calculated, the impact of C225 on the tumor growth, proliferation and angiogenesis was evaluated by immunohistochemical (IHC) staining Ki67 and CD34, respectively. The effect of C225 on apoptosis in the gastric cancer cells was evaluated by TUNEL assay. The expression levels of EGFR and its transcription factor Sial were detected by IHC staining and Western blot. Results After C225 treatment, the proliferation and growth of gastric cancer xenograft in nude mice were significantly decreased. In the contrast, the apopotic indexes in C225 treatment group and PBS control group were (16.4%±0.3%) and (3.1%±0.9%), respectively, with a significant difference (P<0.001). There was no significant difference of the densities of CD34-positive mierovessels between C225 treatment group and control group. Elevated expression of EGFR and Spl after C225 treatment was observed by IHC staining and Western blot assay. Conclusion EGFR monoclonal antibody cetuximab (C225) can effectively inhibit the growth of gastric cancer xenografts in nude mice, and trigger its apoptosis. Yet, C225 treatment may upregulate the expression of EGFR and its transcription factor Sial. A " block-transcription activation-compensation" mechanism may exist to explain the molecular mechanism of acquired resistance of a single target blockade treatment.