Exosomes in HNSCC Progression

外泌体是由多囊泡分泌的小的细胞外囊泡（EV）。 核内体（MVE），并且最近已被认识到促进癌症转移。 外泌体携带生物活性蛋白质、脂质和核酸，是一种重要但很差的 了解肿瘤微环境的组成部分。我们最近发现富含肌动蛋白 称为侵袭伪足的侵袭性结构是癌细胞中MVE的关键对接位点，导致 增强外泌体分泌。此外，我们还发现侵袭足的关键调节因子 coronin增强MVE对接和外泌体分泌。值得注意的是，coronin是基因扩增的， 并且在许多癌症中过度表达，特别是在头颈部鳞状细胞癌中， 癌（HNSCC）。此外，HNSCC中corn的过度表达与 降低患者存活率和增加转移。根据这些数据，我们假设， coronin过度表达导致HNSCC预后不良，因为它在HNSCC中的关键作用是， 促进外泌体分泌。此外，我们假设关键的外泌体货物 与coronin协同促进肿瘤诱导血管生成、淋巴管生成 和转移。具体地说，我们已经确定EphB-ephrinB信号作为关键的血管生成因子。 轴由HNSCC分泌的外泌体调节。因此，我们建议，数量和 外泌体的分子货物以协同方式驱动侵袭性HNSCC行为。我们 将测试这些假设，并利用我们的工作来识别潜在的外泌体血液， 区域和远处转移的基于组织的生物标志物。

Exosomes are small extracellular vesicles (EVs) that are secreted from multivesicular endosomes (MVE) and have been recently recognized to promote cancer metastasis. Exosomes carry bioactive proteins, lipids and nucleic acids and are an important but poorly understood component of the tumor microenvironment. We recently discovered that actin-rich invasive structures called invadopodia are key docking sites for MVE in cancer cells, leading to enhanced exosome secretion. Furthermore, we found that the key invadopodia regulator cortactin enhances MVE docking and exosome secretion. Notably, cortactin is gene amplified and overexpressed in a number of cancers, especially in head and neck squamous cell carcinoma (HNSCC). Furthermore, cortactin overexpression in HNSCC is correlated with decreased patient survival and increased metastasis. Based on these data, we hypothesize that cortactin overexpression drives poor prognosis in HNSCC due to its key role in promoting exosome secretion. Furthermore, we hypothesize that key exosome cargoes synergize with cortactin to promote tumor-induced angiogenesis, lymphangiogenesis, and metastasis. Specifically, we have identified EphB-ephrinB signaling as a key angiogenic axis regulated by HNSCC-secreted exosomes. Thus, we propose that both the number and molecular cargo of exosomes drive aggressive HNSCC behavior in a synergistic manner. We will test these hypotheses and leverage our work to identify potential exosomal blood-and tissue-based biomarkers of regional and distant metastasis.