Melanoma Chemoprevention by Targeting Mutant (V600E) B-Raf

描述(申请人提供)：恶性黑色素瘤是所有皮肤癌中最致命的。在大约90%的葡萄胎和癌前早期黑色素瘤细胞中，一种名为B-Raf的蛋白质突变为成分活性形式(V600E-B-Raf)。可以制造特异性地降低突变的V600E-B-Raf蛋白表达的siRNA，但不能降低正常野生型蛋白的表达。使用这种siRNA靶向V600E-B-Raf可以抑制早期黑色素瘤的发展，使其成为一种理想的化学预防药物。挑战是开发一种策略，将这种针对V600E-B-Raf的化学预防性siRNA传递到皮肤细胞中，这是该项目的目标。目前，还没有技术或方法利用siRNA作为化学预防药物来抑制早期黑色素瘤的发展。这项研究的中心化学预防假说是，通过新型超声-脂质体技术将针对突变V600E-B-Raf的siRNA输送到含有早期黑素细胞病变的皮肤中，将是逆转或延缓葡萄胎或早期病变发展的有效化学预防性药物。我们根据一个模型的初步发现提出了这一假设，在该模型中，皮肤是在组织培养皿中制作的，组织培养皿中含有来自早期黑色素瘤的细胞，这些黑色素瘤在组织学上发展为类似于早期癌前黑色素瘤的肿瘤。作为原则证明，我们可以证明针对突变V600E-B-Raf的siRNA可以延缓这些早期黑素细胞病变的发展。此外，我们正在开发一种新颖而创新的技术，将皮肤超声波与脂质体输送载体相结合，将siRNA输送到皮肤癌细胞中。我们已经确定突变V600E-B-Raf作为潜在的化学预防靶点，准备进行拟议的研究。此外，我们有使用含有早期黑色素瘤的皮肤重建的初步数据，这些皮肤重建已经被超声处理，并暴露于加载siRNA的脂质体中，显示了这项技术的潜在用途。此外，我们还组建了一个研究团队，该团队独特地结合了黑色素瘤、皮肤重建、siRNA靶向以及超声波和脂质体技术等多学科专家，他们中的每一位都对黑色素瘤和化学预防药物的开发有着长期的研究兴趣。这种化学预防药物的开发将通过减少黑色素瘤的发展而显著影响人类健康，从而直接降低死亡率。

DESCRIPTION (provided by applicant): Malignant melanoma is the most deadly of all skin cancers. A protein called B-Raf is mutated to a constitutively active form (V600E-B-Raf) in approximately 90% of moles and premalignant early melanoma cells. SiRNA can be made that specifically reduces expression of mutant V600E-B-Raf protein but not normal wild-type protein. Targeting V600E-B-Raf using this siRNA inhibits early melanoma development making it an ideal chemopreventive agent. The challenge is to develop a strategy to deliver this chemopreventive siRNA against V600E-B-Raf into cells in the skin, which is the goal of this project. Currently, no technology or approach utilizes siRNA as a chemopreventive agent to inhibit early melanoma development. The central chemoprevention hypothesis for the proposed research is that siRNA against mutant V600E-B-Raf delivered via novel ultrasound-liposome technology into skin containing early melanocytic lesions will be an effective chemopreventive agent for reversing or retarding development of moles or early lesions. We formulated this hypothesis based on preliminary findings using a model in which skin is made in a tissue culture dish that contains cells derived from early-stage melanomas, which develop into tumors histologically resembling early premalignant melanomas. As proof-of-principle, we can show that siRNA against mutant V600E-B-Raf retards development of these early melanocytic lesions. Furthermore, we are developing a novel and innovative technology for delivering siRNA into cancer cells in skin that combines skin ultrasonication together with liposomal delivery vehicles. We are prepared to undertake the proposed research, having identified mutant V600E-B-Raf as a potential chemopreventive target. Furthermore, we have preliminary data using skin reconstructs containing early melanomas, which have been ultrasonicated and exposed to liposomes loaded with siRNA showing the potential utility of this technology. In addition, we have assembled a research team that uniquely combines multidisciplinary experts in melanoma, skin reconstruction, siRNA targeting, as well as ultrasound and liposome technology, each of who has long-standing research interests in melanoma and development of chemopreventive agents. Development of this chemopreventive agent would significantly impact human health by reducing melanoma development, thereby directly decreasing mortality rates.