Therapeutic potential of antitumorigenic soluble MET variants induced by splicing interference

胃癌(GC)是全球癌症相关死亡的第三大原因，总存活率中位数 对于晚期疾病，限制在1年内。很大一部分GC是由于HGF/MET轴信号异常所致，大多数 通常是由于MET受体基因扩增所致。然而，目前还没有有效的MET靶向疗法， 在最初的反应之后，耐药性经常迅速出现。开发附加的、可供选择的 因此，有效抑制MET和其他RTK的方法是找到治愈方法的必要条件。 我们最近发现了一些新的可溶性诱骗RTK亚型(SdRTK)，由一种替代方案产生 剪接/内含子多聚腺苷酸化(IPA)机制，可作为RTK信号的有效天然抑制物。我们 开发了一种基于反义的方法，在体外特异性和有效地诱导IPA的使用和sdRTKs的表达 在活体内。这些化合物识别出一类新的药物，其优点是同时击倒 病理靶点，同时引入天然显性-负性异构体，从而大大提高其疗效。 我们将应用这种基于反义的方法来促进IPA，并刺激显性-负性表达， 内源可溶性诱骗满足抑制变异体(SdMET)，通常在低水平表达。SdMET编码 胞外配体结合和二聚化结构域，但缺乏跨膜和细胞内激酶域。 我们假设sdMET诱导的化合物通过三种机制抑制HGF/MET信号：a) 直接去除全长MET受体mRNAs，B)MET配体(HGF)的结合和隔离，以及C)非 用残留的MET受体进行高效的异二聚化。我们进一步假设，由于产生的产品是 它们由靶细胞分泌，影响靶细胞和邻近细胞的信号，并干扰 旁分泌和自分泌环路，因此具有放大的效果。由于其作用机制不同于 目前的治疗方法，这种策略应该对所有依赖HGF/MET信号的肿瘤都有效，包括复发 一个。为此，我们将追求以下具体目标： 1)有效抑制sdMET剪接变异体的鉴定和鉴定。 2)反义剪接对胃癌细胞MET剪接/多聚腺苷酸化的重编程 诱导IPA的重定向化合物。 3)sdMET诱导的反义寡核苷酸对多发性胃粘膜病变的治疗作用 体外和体内的癌症模型。 这些结果将对开发强大的新型调查工具和治疗方法具有重要意义 HGF/MET信号轴起决定性作用的任何癌症类型。这项研究的发现将是 在胃癌和其他肿瘤中，可广泛翻译为依赖于其他RTK和癌基因的疾病。类比 事实上，化合物可以被类似地设计成直接针对其他RTK或其他导致耐药性的靶点 和病理信号，或克服各种抗性机制。

Gastric cancer (GC) is the third leading cause of cancer-related death worldwide, with a median overall survival limited to 1 year for advanced disease. A significant fraction of GC is due to aberrant HGF/MET axis signaling, most commonly due to MET receptor gene amplification. However, no effective MET-targeted therapies are currently available, with resistance frequently emerging rapidly, following an initial response. The development of additional, alternative approaches to effectively inhibit MET and other RTKs is therefore a necessity for a cure to be found. We recently identified a number of novel soluble decoy RTKs isoforms (sdRTKs), generated by an alternative splicing/intronic polyadenylation (IPA) mechanism, which can act as potent natural inhibitors of RTK signaling. We developed an antisense-based method to specifically and effectively induce IPA usage and sdRTKs expression in vitro and in vivo. These compounds identify a new class of drugs that carry the advantage of simultaneously knocking down the pathological targets while introducing natural dominant-negative isoforms, thus greatly increasing their efficacy. We will apply this antisense-based approach to promote IPA and stimulate the expression of dominant-negative, endogenous soluble decoy MET inhibitory variants (sdMET), normally expressed at low levels. sdMETs encode the extracellular ligand-binding and dimerization domains, but lack the transmembrane and the intracellular kinase domains. We hypothesize that sdMET-inducing compounds suppress HGF/MET signaling by a three fold-mechanism: A) direct removal of full-length MET receptor mRNAs, B) binding and sequestration of MET ligand (HGF), and C) non- productive hetero-dimerization with residual MET receptors. We further posit that, as the resulting products are secreted from targeted cells, they affect signaling in both targeted and neighboring cells alike and interfere with paracrine and autocrine loops, thus wielding an amplified effect. Since the mechanism of action is different from that of current therapies, this strategy should be effective in all tumors that rely on HGF/MET signaling, including relapsing ones. To this end, we will pursue the following specific aims: 1) Identification and characterization of effective inhibitory sdMET splicing variants. 2) Reprogramming of MET splicing/polyadenylation in gastric cancer cells by antisense-based splicing redirection compounds that induce IPA. 3) Assessment of the therapeutic potential of sdMET-inducing antisense oligonucleotides in multiple gastric cancer models, in vitro and in vivo. These results will be important for the development of powerful novel investigative tools and therapeutic approaches in any cancer type where the HGF/MET signaling axis plays a determinant role. The findings emerging from this study will be broadly translatable to disease dependent on other RTKs and oncogenes, in gastric cancer and other tumors. Analogous compounds can in fact be similarly designed to directly target other RTKs or other targets responsible for drug-resistance and pathological signaling, or to overcome various mechanisms of resistance.