Project 1: Nanotherapies for Vemurafenib Resistant Melanoma

项目1摘要 皮肤黑色素瘤占皮肤癌死亡的大部分(约75%)。尽管 最近在预防和早期发现方面的改进，大约20%的患者患有 黑色素瘤仍然会死于这些疾病。转移的患者预后很差，而且 预期寿命很短。大约50%的人类黑色素瘤存在BRAFV600突变。 维莫拉非尼(Vem)是一种突变的BRAF的特异性抑制剂，对治疗非常有效 转移性黑色素瘤。不幸的是，在治疗后3-18个月出现耐药性。 涉及到重新激活MEK/ERK通路的替代机制。耐Vem黑色素瘤， 然而，黑色素瘤相关抗原gp100，mart-1和 酪氨酸酶。因此，耐药疾病为两个独立的、尚未 互补的治疗方法，即合成致命性和癌症疫苗。要阻止 另一种Raf激酶，我们发现抑制基因Sprouty4在传递时 通过该小组开发的LPH(脂质-聚阳离子-透明质酸)纳米颗粒(NPs)，可以 有效下调MEK/ERK通路，导致Vem耐药细胞生长速度减慢 黑色素瘤。我们将通过使用一种新发现的基因治疗策略来跟进这一新的基因治疗策略 含有聚二甲双胍的脂多糖(目标1)，以演示合成的机制 致命性(目标2)。聚二甲双胍的毒性比同等的聚乙烯亚胺小得多，而且 抑制mTOR，进一步抑制肿瘤细胞的生存机制。自从我们的Vem 耐药肿瘤也缺乏PTEN，我们还将开发一种siRNA疗法来沉默Akt。在… 与此同时，我们将使用BRAF突变黑色素瘤在同基因小鼠模型中进行研究 使用新的信使核糖核酸疫苗配方抑制肿瘤生长(目标3)。几个基因的mRNAs 黑色素瘤相关抗原，包括那些在Vem耐药肿瘤中上调的抗原，将是 在LCP(脂质-钙-磷酸)纳米粒中配制并输送到 淋巴结。初步数据表明，这种方法在诱导 抗原特异性CTL应答并显著抑制原发AS的生长 以及淋巴结内转移性黑色素瘤。我们将最终将基因/药物结合起来 用疫苗疗法克服黑色素瘤对Vem的耐药性。

Project 1 Abstract Cutaneous melanoma accounts for the majority (~75%) of skin cancer deaths. Despite the recent improvements in prevention and early detection, approximately 20% of patients with melanoma still die from the diseases. Patients with metastases have a poor prognosis and a very short life expectancy. About 50% of human melanoma harbor BRafV600 mutations. Vemurafenib (Vem), a specific inhibitor of the mutated BRaf, is very effective for treating metastatic melanoma. Unfortunately, drug resistance emerges 3-18 months post treatment due to alternative mechanisms that reactivate the MEK/ERK pathway. Vem resistant melanoma, however, exhibits elevated expression of melanoma associated antigens, gp100, MART-1 and Tyrosinase. Thus, the drug resistant disease provides opportunity for two independent, yet complementary, therapeutic approaches, i.e. synthetic lethality and cancer vaccine. To block the alternative Raf kinase, we have discovered that the suppressor gene Sprouty4, when delivered by LPH (lipid-polycation-hyaluronic acid) nanoparticles (NPs) developed in this group, could effectively down-regulate MEK/ERK pathway, leading to reduced growth rate in Vem resistant melanoma. We will follow up this novel gene therapy strategy by using a newly discovered lipopolyplex containing polymetformin (aim 1) to demonstrate the mechanism of the synthetic lethality (aim 2). Polymetformin is much less toxic than the equivalent polyethyleneimine and inhibits mTOR to further suppress the survival mechanism of the tumor cells. Since our Vem resistant tumor is also PTEN deficient, we will also develop a siRNA therapy to silence Akt. At the same time, we will use a BRaf mutant melanoma in a syngeneic mouse model to study tumor growth inhibition using a new mRNA vaccine formulation (aim 3). mRNAs of several melanoma associated antigens, including those up-regulated in Vem resistant tumor, will be formulated in LCP (lipid-calcium-phosphate) NPs and delivered to the dendritic cells in the lymph nodes. Preliminary data indicate that this approach was very effective in inducing an antigen-specific CTL response in the host and significantly inhibited the growth of the primary as well as the metastatic melanoma in the lymph nodes. We will finally combine the gene/drug therapy with the vaccine therapy to overcome Vem resistance in melanoma.