西妥昔单抗广泛用于治疗转移性结直肠癌（mCRC）。然而，耐药性对成功治疗提出了重大挑战。最近，细胞凋亡（一种非经典的程序性细胞死亡）因其在抗肿瘤治疗中的潜在应用价值而受到越来越多的关注。我们的目的是确定参与凋亡抑制的重要途径和信号分子，并选择它们作为西妥昔单抗耐药性的治疗靶点。此外，工程外泌体技术被用作兼具靶向性和效应性的药物递送系统。通过比较耐药结肠癌细胞和敏感细胞之间的Paraptosis相关基因的差异表达，观察到西妥昔单抗诱导的Paraptosis水平在耐药细胞中显着下调。京都基因和基因组百科全书 (KEGG) 分析确定粘着斑激酶 (FAK) 信号通路是抑制细胞凋亡的关键通路。通过细胞形态观察、CCK-8测定、集落形成测定、RT-qPCR、Western Blot和功能丧失实验研究FAK在西妥昔单抗耐药细胞中的生物学功能。结果显示，西妥昔单抗耐药结肠癌细胞中FAK信号通路显着上调，针对FAK的siRNA干扰可显着抑制细胞增殖，同时上调凋亡水平。在此基础上，构建了靶向并装载FAK siRNA的外泌体（CT-Exo-siFAK1）的工程结肠癌细胞。体外实验中，CT-Exo-siFAK1能够有效激活细胞凋亡并抑制耐药结肠癌细胞的增殖。体内实验也证实，CT-Exo-siFAK1显着抑制肿瘤生长和转移，同时上调细胞凋亡水平。这项研究表明，FAK信号通路介导的细胞凋亡水平抑制对于西妥昔单抗靶向治疗结肠癌的敏感性至关重要，并且使用工程外泌体递送 FAK siRNA 可能是逆转西妥昔单抗耐药性的有效策略。© 2024。作者。

Cetuximab is extensively used in the treatment of metastatic colorectal cancer (mCRC). However, resistance poses a significant challenge to successful therapy. Recently, paraptosis, a non-classical programmed cell death, has garnered increased attention for its potential application value in antitumor treatments. We aimed to identify the essential pathways and signaling molecules involved in paraptosis inhibition and select them as therapeutic targets in cetuximab resistance. Additionally, engineered exosome technology is used as a drug delivery system with both targeted and effector properties.By comparing the differential expression of paraptosis-related genes between drug-resistant colon cancer cells and sensitive cells, it was observed that the paraptosis level induced by cetuximab was significantly downregulated in drug-resistant cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified the focal adhesion kinase (FAK) signaling pathway as a key pathway involved in the suppression of paraptosis. The biological function of FAK in cetuximab-resistant cells was investigated through cell morphology observation, CCK-8 assay, colony formation assay, RT-qPCR, Western Blot, and loss-of-function experiments. The results showed that the FAK signaling pathway was significantly upregulated in cetuximab-resistant colon cancer cells, and siRNA interference targeting FAK could notably inhibit cell proliferation while upregulating the paraptosis level. Based on this, engineered colon cancer cells targeted and FAK siRNA loaded exosomes (CT-Exo-siFAK1) were constructed. In vitro experiments, CT-Exo-siFAK1 could effectively activate paraptosis and inhibit the proliferation of drug-resistant colon cancer cells. In vivo experiments also confirmed that CT-Exo-siFAK1 significantly suppressed tumor growth and metastasis while upregulating the paraptosis level.This study suggests that FAK signaling pathway-mediated inhibition of paraptosis levels is crucial in the sensitivity of cetuximab targeted therapy in colon cancer, and the use of engineered exosomes to deliver FAK siRNA may be an effective strategy to reverse cetuximab resistance.© 2024. The Author(s).