Discovery of bioactive molecules that target integrins has implicated their role in tumor angiogenesis, tumor growth, metastasis, and other pathological angiogenesis processes. Integrins are members of a family of cell surface receptors that play a critical role in the angiogenesis process. Tetraiodothyroacetic acid (tetrac), a deaminated derivative of l-thyroxine (T4), is a “thyrointegrin” antagonist that blocks the actions of l-triiodothyronine (T3) and T4 with an interaction site that is located at or near the RGD recognition site identified on integrin αvβ3’s binding pocket (thyrointegrin αvβ3 receptors). We have enhanced the biological activity of a tetrac-based inhibitor via significantly improving its αvβ3 receptor binding affinity by introducing a triazole ring on the outer ring of tetrac and covalently conjugating to polymer to increase the product’s hydrophilicity via PEGylation. The product, P-bi-TAT, was restricted from nuclear translocation and demonstrated high blood brain barrier permeability and retention in contrast to the non-PEG conjugated derivative. Results of biological activity indicated that this macromolecule new chemical entity P-bi-TAT has greater than 400-fold potent integrin αvβ3 affinity versus the parent compound tetrac and has potent anticancer/anti-angiogenesis efficacy against glioblastoma multiforme (GBM). P-bi-TAT administered subcutaneously once daily for 21 days at 1–10 mg/kg mouse body weight resulted in a dose-dependent suppression of GBM tumor growth and viability as monitored with IVIS imaging (P < 0.001). GBM tumors had >95% volume loss and maximal loss of GBM cell viability during the 21 days ON-treatment experiment as well as in the 21 days ON followed by 21 days OFF-treatment experiment (P < 0.001). In conclusion, P-bi-TAT is a promising lead clinical candidate effective in the treatment of human GBM.
靶向整合素的
生物活性分子的发现表明它们在肿瘤血管生成、肿瘤生长、转移和其他病理性血管生成过程中的作用。整合素是细胞表面受体家族的成员,在血管生成过程中发挥着关键作用。四
碘甲状腺
乙酸 (tetrac) 是 L-
甲状腺素 (T4) 的脱
氨基衍
生物,是一种“甲状腺整合素”拮抗剂,可通过位于 RGD 识别位点或附近的相互作用位点阻断 L-
三碘甲状腺原氨酸 (T3) 和 T4 的作用在整合素 αvβ3 的结合口袋(甲状腺整合素 αvβ3 受体)上鉴定。我们通过在 tetrac 的外环上引入三唑环并与聚合物共价结合以通过 P
EG 化增加产品的亲
水性,显着提高其 αvβ3 受体结合亲和力,从而增强了基于 tetrac 的
抑制剂的
生物活性。与非 P
EG 缀合衍
生物相比,该产品 P-bi-TAT 的核易位受到限制,并表现出高血脑屏障渗透性和保留性。
生物活性结果表明,这种大分子新
化学实体P-bi-TAT的整合素αvβ3亲和力是母体化合物tetrac的400倍以上,并且对多形性胶质母细胞瘤(GBM)具有有效的抗癌/抗血管生成功效。 P-bi-TAT 以 1-10 mg/kg 小鼠体重每天皮下注射一次,持续 21 天,结果对 GBM 肿瘤生长和活力产生剂量依赖性抑制(通过 IVIS 成像监测)(P < 0.001)。在21天ON治疗实验以及21天ON后21天OFF治疗实验中,GBM肿瘤的体积损失>95%,并且GBM细胞活力最大损失(P < 0.001)。总之,P-bi-TAT 是一种有效治疗人类 GBM 的有前途的主要临床候选药物。