2017年3月27日，，國際腫瘤學學術期刊《Oncotarget》雜志上在線發(fā)表了中南大學生命科學學院醫(yī)學遺傳學國家重點實驗室梁德生課題組在基因編輯干細胞抑制腫瘤生長研究的新進展，文章題為“Enhanced tumor growth inhibition by mesenchymal stem cells derived from ipsCs with targeted integration of interleukin 24 into rDNA loci”，博士研究生劉博為第一作者，梁德生教授和劉雄昊副教授為共同通訊作者。

間充質干細胞(MSCs)存在于骨髓、血液、脂肪等多種組織中，是一種具有多向分化潛能的成體干細胞。MSCs參與免疫抑制并具有免疫原性低和向炎癥及腫瘤區(qū)域遷移的能力等特性，可作為細胞載體用于腫瘤和自身免疫性疾病的靶向治療而備受關注。然而，個體來源的MSCs數(shù)量有限，在體外擴增中分化潛能及增殖能力的衰減也限制了其臨床應用。近年來人誘導多能干細胞(iPSCs)因其具有無限的增殖和分化潛能而展示了廣泛的應用前景，源自患者自體iPSCs的MSCs已被用于癌癥的自體細胞治療。因此，該課題組嘗試建立高效穩(wěn)定表達抗癌因子的病人特異性ipsCs，誘導分化為MSCs用于腫瘤的自體化基因治療。

研究人員通過構建攜帶白介素24(IL24)基因的新型rDNA區(qū)打靶載體pHrn-IL24，借助自主研發(fā)針對多拷貝位點顯著降低細胞毒性和脫靶效應的人工核酸切口酶TALENickase，將IL-24高效整合到人尿液細胞來源iPSCs的多拷貝rDNA區(qū)。隨后通過優(yōu)化方法將定點整合IL24的iPSCs分化成MSCs(IL24-iMSCs)，并且檢測到外源IL24在細胞中有效表達。在與黑色素瘤細胞體外共培養(yǎng)和小鼠體內(nèi)共注射的實驗中顯示，IL24-iMSCs具有誘導腫瘤細胞凋亡和抑制腫瘤生長的功能。研究結果首次證明通過非病毒基因打靶病人特異性iPSCs獲得自體MSCs用于癌癥治療的可行性，展示了基因編輯ipsCs在腫瘤自體化基因治療領域的臨床應用前景。

梁德生教授課題組長期致力于非病毒基因打靶研究，在自體干細胞核糖體基因(rDNA)區(qū)打靶應用于遺傳病基因治療研究方面取得了系列原創(chuàng)性成果，這是首次將該策略應用于腫瘤的靶向基因治療研究。

原文鏈接：

Enhanced tumor growth inhibition by mesenchymal stem cells derived from ipsCs with targeted integration of interleukin24 into rDNA loci

原文摘要：

Induced pluripotent stem cells (iPSCs) are a promising source of mesenchymal stem cells (MSCs) for clinical applications. In this study， we transformed human iPSCs using a non-viral vector carrying the IL24 transgene pHrn-IL24. PCR and Southern Blotting confirmed IL24 integration into the rDNA loci in four of 68 iPSC clones. We then differentiated a high expressing IL24-iPSC clone into MSCs (IL24-iMSCs) that showed higher expression of IL24 in culture supernatants and in cell lysates than control iMSCs. IL24-iMSCs efficiently differentiated into osteoblasts， chondrocytes and adipocytes. Functionally， IL24-iMSCs induced in vitro apoptosis in B16-F10 melanoma cells more efficiently than control iMSCs when co-cultured in Transwell assays. In vivo tumor xenograft studies in mice demonstrated that IL24-iMSCs inhibited melanoma growth more than control iMSCs did. Immunofluorescence and histochemical analysis showed larger necrotic areas and cell nuclear aggregation in tumors with IL24-iMSCs than control iMSCs， indicating that IL24-iMSCs inhibited tumor growth by inducing apoptosis. These findings demonstrate efficient transformation of ipsCs through gene targeting with non-viral vectors into a rDNA locus. The ability of these genetically modified MSCs to inhibit in vivomelanoma growth is suggestive of the clinical potential of autologous cell therapy in cancer.