REGULATORS OF EPITHELIAL TUMOR PROGRESSION

上皮性肿瘤的进展涉及细胞与细胞外环境的异常相互作用，如 肿瘤细胞本身固有的异常。皮肤鳞状细胞癌(SCC)发生于 皮肤免受紫外线诱变，因阳光照射而对美国退伍军人造成不成比例的影响 在服兵役。在全国范围内，鳞状细胞癌是第二常见的癌症，每年约有100万新病例。 鳞状细胞癌可以导致毁容，在极少数情况下，还会导致致命的转移。这份功绩评估最近确定了 胶原蛋白是鳞癌中突变最多的基因家族，其中COL11A1基因突变次之 鳞癌中总的突变基因频率为63%。它还发现更多的胶原蛋白基因在高突变 在鳞癌中的频率(&gt；20%)，包括COL17A1和COL4A4，以及COL7A1，其遗传突变 导致大疱性表皮松解症，伴有侵袭性皮肤SCCs。鳞状细胞癌胶原突变集中在 甘氨酸-X-Y(通常带有X和Y)三螺旋序列中的脯氨酸和甘氨酸，变化 已知产生显性负性胶原蛋白，增加了肿瘤分泌突变胶原蛋白的可能性 可能会以一种跨显性的方式导致癌症。与突变体的致癌作用一致 胶原蛋白，敲入鳞状细胞癌相关的COL11A1突变促进体内肿瘤侵袭 与等基因COL11A1野生型对照和内源性突变COL11A1在鳞癌中的比较 肿瘤抑制了体内的肿瘤形成，表明突变的胶原蛋白在功能上促进了肿瘤的发生。 目的我将测试一种模型，在该模型中，分泌的突变型胶原蛋白以非细胞自主方式发挥作用。 以加速肿瘤的形成。首先，它将确定突变的COL11A1是否可以促进肿瘤进展 使用马赛克组织模型对反式肿瘤细胞进行研究。其次，它将量化对表皮肿瘤的影响 鳞状细胞癌中频繁突变的多种额外胶原的突变进展，包括 COL17A1、COL4A4和COL7A1。目的研究COL11A1在表皮肿瘤进展中的作用。 并确定其他反复突变的胶原蛋白是否也能促进鳞状细胞癌。 该项目最近还对一系列人鳞状细胞癌的47,771个细胞进行了单细胞RNA测序 肿瘤，以及患者和部位匹配的正常对照皮肤，以确定肿瘤细胞亚群 SCC。这定义了一种新的肿瘤特异性角质形成细胞(TSK)群体，在正常组织中没有对应的群体 表达COL11A1和其他与细胞通讯和入侵有关的基因。这样的肿瘤 亚群通过细胞表面和分泌的方式相互沟通，从而使肿瘤发生 然而，在活体肿瘤中实际表达的蛋白质组--与RNA相反-- 通过特定的肿瘤亚群来定义一直是一个技术挑战。为了解决这个问题，我们开发了 一种新的识别细胞表面的邻近蛋白质组学方法--分泌蛋白鉴定(SecrID) 和体内异种活体肿瘤组织中感兴趣的离散细胞群中的分泌蛋白 研究肿瘤进展过程中的细胞亚群蛋白。 AIM II基于TSK SCC亚群使用特定蜂窝通信的模型 驱使恶性肿瘤的蛋白质。首先，它将使用SecrID来定义分泌的和细胞表面特定的蛋白质 到TSK细胞亚群，基于这些细胞可能介导促肿瘤细胞 沟通。其次，它将去除TSK亚群特有的基因，包括那些被 SecrID，以确定它们对肿瘤发生的影响，并寻找新的可获得的治疗靶点。AIM II 将表征肿瘤特异的SCC TSK亚群，并确定其用于影响的分子 肿瘤进展。 在拟议的资金周期结束时，我们计划对突变胶原蛋白的作用进行表征 以及新定义的表皮肿瘤进展中的肿瘤细胞亚群。

Epithelial tumor progression involves abnormal cell interactions with the extracellular environment as well abnormalities intrinsic to tumor cells themselves. Cutaneous squamous cell carcinoma (SCC) arises in skin from ultraviolet mutagenesis and disproportionately affects U.S. Veterans due to sun exposure incurred in military service. Nationally, SCC is the second most common cancer, with ~1 million new cases yearly. SCC can lead to disfigurement and, in rare cases, lethal metastases. This Merit Review recently identified collagens as the most highly mutated gene family in SCC, with the COL11A1 gene the second most frequently mutated gene overall in SCC (63%). It also found additional collagen genes mutated at high frequency (>20%) in SCC, including COL17A1 and COL4A4, as well as COL7A1, whose inherited mutation causes forms of epidermolysis bullosa with aggressive skin SCCs. SCC collagen mutations concentrate at prolines and glycines in the Gly-X-Y (with X and Y commonly proline) triple helical sequence, alterations known to produce dominant-negative collagens, raising the possibility that tumor-secreted mutant collagens may enable cancer in a trans-dominant fashion. Consistent with a pro-oncogenic function for mutant collagens, knocking in an SCC-associated COL11A1 mutation enhanced neoplastic invasion in vivo compared to isogenic COL11A1 wild-type control and ablating endogenously mutant COL11A1 in SCC tumors impaired tumorigenesis in vivo, indicating that mutant collagens functionally promote tumorigenesis. Aim I will test a model in which secreted mutant collagen proteins act in a non-cell autonomous fashion to accelerate tumorigenesis. First, it will determine if mutant COL11A1 can promote neoplastic progression of tumor cells in trans using mosaic tissue models. Second, it will quantify the impacts on epidermal tumor progression of mutations in multiple additional collagens that are frequently mutated in SCC, including COL17A1, COL4A4, and COL7A1. Aim I will study the action of COL11A1 in epidermal tumor progression and determine if other recurrently mutated collagens can also promote SCC. This project also recently used single-cell RNA-sequencing of 47,771 cells from a series of human SCC tumors, along with patient and site-matched normal control skin, to identify tumor cell subpopulations in SCC. This defined a new tumor-specific keratinocyte (TSK) population with no counterpart in normal tissue that expressed COL11A1 and other genes linked to cellular communication and invasion. Such tumor subpopulations enable neoplasia by communicating with each other through cell surface and secreted proteins, however, the sets of proteins – as opposed to RNAs – that are actually expressed in living tumors by specific tumor subpopulations have been a technical challenge to define. To address this, we developed a new proximity proteomics method, Secreted Protein Identification (SecrID) that can identify cell surface and secreted proteins within discrete cell populations of interest in heterogenous living tumor tissues in vivo to characterize cell subpopulation proteins in tumor progression. Aim II is based on a model in which the TSK SCC subpopulation uses specific cellular communication proteins to drive malignancy. First, it will use SecrID to define the secreted and cell surface proteins specific to the TSK cell subpopulation, based on the premise that these may mediate pro-neoplastic cellular communication. Second, it will ablate TSK subpopulation-specific genes, including those identified by SecrID, to define their impact on tumorigenesis and to search for new accessible therapeutic targets. Aim II will characterize the tumor-specific SCC TSK subpopulation and identify the molecules it uses to influence tumor progression. At the end of the proposed funding cycle, we plan to have characterized the actions of mutant collagens and newly defined tumor cell subpopulations in epidermal tumor progression.