Carbohydrate- Dependent Epithelial Cancer Metastasis

有充分证据表明，上皮细胞的恶性转化与结构性改变有关。 changes in cell surface carbohydrates. Many clinical studies have correlated those cancer-associated 碳水化合物抗原具有不良的临床预后，包括转移。 Carbohydrate-dependent cancer metastasis has been observed, but the mechanisms underlying this process are not yet defined. 我们之前通过以下方法鉴定了模仿抗路易斯 A 抗体表位的 IELLQAR（l 肽）： screening peptide displaying phage libraries.当L-肽注射到野生型小鼠体内时，它们 抑制 sLex 依赖性黑色素瘤肺部定植。 However, lung colonization also occurs in mutant 缺乏E-和P-选择素以及L-肽的小鼠抑制定植，排除以下因素的参与 these selectins in this process.这些发现表明，L-肽干扰定植确实 not require E- and P-selectins. Our preliminary data show that the l-peptide receptors are pre-mRNA splicing factor (Sfrs) and AnnexinAI (Anxal). The PI also studied the in vivo roles of the Golgi processing a-mannosidase II (Mil) and alphamannosidase llx (MX). Mil/MX 双无效小鼠胚胎未显示复杂的 A/- 型聚糖， 表明 Mil 和 MX 一起负责复杂型 N-聚糖的合成。 Mil/MX 双空基因在出生后不久就会致命。根据这些发现，具体目标是： (1) To determine A/-glycan-based L-selectin ligand activity in vivo using conditional Mil/MX double null 老鼠。内皮细胞和造血细胞特异性 Mil/MX 双敲除 (Tie2-Cre:Mllftaxp/floxp/MX-/-) 将生成并分析高内皮小静脉 (HEV) 中的 L-选择素配体活性，(2) 定义 Sfrs 和 Anxal 的碳水化合物结合活性，(3) 以确定是否发生靶向凋亡 Anxal binding. Anxal 已被鉴定为肿瘤特异性内皮标志物，我们鉴定了 IF 肽， which binds preferentially to Anxal. Thus we will develop a method to target apoptosis to 使用 IF-肽对小鼠肿瘤脉管系统的内皮细胞进行分析，并且 (4) 确定 Anxal 是否 expressed on the endothelial surface promotes angiogenesis and identify mechanisms underlying Anxal-dependent endothelial cell activation including binding to heparan sulfate. 这些研究将为更好地理解潜在机制提供信息 碳水化合物依赖性癌症转移并有助于开发新的治疗策略 epithelial cancer.

It is well documented that malignant transformation of epithelial cells is associated with structural changes in cell surface carbohydrates. Many clinical studies have correlated those cancer-associated carbohydrate antigens with poor clinical prognosis, including metastasis. Carbohydrate-dependent cancer metastasis has been observed, but the mechanisms underlying this process are not yet defined. We previously identified IELLQAR (l-peptide) that mimics the epitope of anti-Lewis A antibody by screening peptide displaying phage libraries. When l-peptides were injected into wild type mice, they inhibited sLex-dependent melanoma lung colonization. However, lung colonization also occurs in mutant mice lacking both E- and P-selectins and l-peptide inhibits the colonization, excluding the involvement of these selectins in this process. These findings suggest that l-peptide interference with colonization does not require E- and P-selectins. Our preliminary data show that the l-peptide receptors are pre-mRNA splicing factor (Sfrs) and AnnexinAI (Anxal). The PI also studied the in vivo roles of the Golgi processing a-mannosidase II (Mil) and alphamannosidase llx (MX). Mil/MX double null mouse embryos showed no complex type A/-glycans, indicating that Mil and MX together are responsible for the complex type N-glycan synthesis. Mil/MX double nulls were lethal shortly after birth. Based on these findings, the specific aims are: (1) To determine A/-glycan-based L-selectin ligand activity in vivo using conditional Mil/MX double null mice. Endothelial and hematopoietic cell-specific Mil/MX double knockouts (Tie2-Cre:Mllftaxp/floxp/MX-/-) will be generated and analyzed for L-selectin ligand activity in high endothelial venules (HEVs), (2) to define carbohydrate-binding activity of Sfrs and Anxal, (3) to determine if targeted apoptosis occurs by Anxal binding. Anxal has been identified as a tumor-specific endothelial marker, and we identified IFpeptide, which binds preferentially to Anxal. Thus we will develop a method to target apoptosis to endothelial cells of tumor vasculature in the mouse using IF-peptide, and (4) to determine if Anxal expressed on the endothelial surface promotes angiogenesis and identify mechanisms underlying Anxal-dependent endothelial cell activation including binding to heparan sulfate. These studies will provide information for better understand of the mechanisms underlying carbohydrate-dependent cancer metastasis and help for developing new therapeutic strategies against epithelial cancer.