BLRD Research Career Scientist Award Application

根据美国人口普查局的数据，2018年美国退伍军人人数约为19.9人。 万10人中有9人是男性，33%的人在50-69岁之间，这是最高的年龄组 前列腺癌（PCa）VA中央癌症登记处一致表明，PCa是最常见的癌症。 男性退伍军人中经常诊断出癌症，占约50，000例癌症的30%以上 诊断。越来越多的人担心，环境和/或职业暴露于金属离子， 部署和部署后增加退伍军人中PCa的风险。国际癌症研究机构 将无机砷（iAs）归类为致癌物，而铅（Pb）是人类的潜在致癌物。PB 接触是服兵役的一种已知危险，而关于接触iAs的数据则不太可靠。此外，本发明还 退伍军人广泛接触这些金属离子可能是通过吸入，摄入和 皮肤吸收燃烧的油田和废物处理焚烧坑产生的有毒烟雾。砷和/或铅暴露 被认为是PCa的潜在风险因素，但其潜在机制在很大程度上尚不明确。中 在一项小型临床研究中，我们发现PCa患者尿液中的iAs和Pb水平显著升高 与对照相比。使用我们新的2次打击动物模型，我们发现暴露于iAs或Pb增加了（1）PCa 体内风险和（2）从治疗动物分离的前列腺上皮干细胞样细胞（PrESLC）的能力， 在软琼脂中形成菌落，这是细胞转化的标志。在该动物模型中，1个月的金属处理 其次是化学致癌物治疗显著增加PCa和癌前病变的发生率 iAs处理的小鼠中的病变，在Pb处理的动物中具有类似的趋势。重要的是，单细胞RNAseq分析 显示铅与具有上皮谱系的PrESLCs亚群的扩增有关 iAs与一种罕见的，独特的， 类似于“癌症”干细胞的致癌PrESLC亚群。这一提议将检验以下假设： iAs和/或Pb失调特异性的，可能不同的，在亚群的信号传导途径， PrESLCs启动或增加前列腺癌变的风险。这是一个未经验证的假设 在前列腺癌发生和退伍军人健康领域的研究。提出了两个目标。目标1：确定 使用PCa形成的肾移植模型在体内研究金属处理的PrESLC的致癌潜力。我们 将评估金属对免疫缺陷宿主小鼠体内PCa形成的影响， 没有PCa的化学诱导。目的2：用金属特异性转录组学方法表征干细胞样细胞 签名.我们将使用单细胞RNAseq和可视化信息学来识别独特的基因签名， 其表征了PrESLC群体中金属诱导的癌症干细胞的罕见亚群。我们的目标 应用这些基因标签通过FACS富集稀有亚群并评估其致癌潜力。 我们还将利用癌症基因组图谱PCa数据和其他在线数据库， 分类的主要，罕见的，和异质亚型的PrESLCs获得深入了解金属致癌作用。 拟议工作的结果可能涉及与职业和部署后接触有关的问题 并扩展我们对干细胞生物学的知识。成功完成这些研究可能会导致 开发新的PCa预防和治疗策略。计划减少不必要的接触 金属离子可以作为预防PCa的有效策略来证明和实施。药物靶向特异性 干细胞亚群可用作治疗选择，以预防早期PCa发展并减缓PCa的生长。 进展当应用于退伍军人时，这项研究的结果可能会挽救生命，改善健康，并减少 残疾人在这个社区和超越。

According to the United States (US) Census Bureau, the number of veterans in the US in 2018 was around 19.9 million. Nine out of 10 were males, and 33% were between 50-69 years old, an age group that is at the highest risk for prostate cancer (PCa). The VA Central Cancer Registry consistently shows that PCa is the most frequently diagnosed cancers among male veterans, accounting for >30% of the approximately 50,000 cancer diagnoses. There is growing concern that environmental and/or occupational exposure to metal ions during deployment and post-deployment increases PCa risk in veterans. The International Agency for Cancer Research classified inorganic arsenic (iAs) as a carcinogen, while lead (Pb) is a potential carcinogen in humans. Pb exposure is a known hazard of military service, while data for iAs exposure is less well-established. Further, wide-spread exposure to these metal ions in veterans could be mediated through inhalation, ingestion, and dermal adsorption of toxic smoke from burning oil fields and waste disposal burn-pits. iAs and/or Pb exposure have been considered potential risk factors for PCa, but the underlying mechanism is largely undefined. In a small clinical study, we found that iAs and Pb levels were significantly higher in the urine of PCa patients compared to controls. Using our new 2-hit animal model, we found that exposure to iAs or Pb increased (1) PCa risk in vivo and (2) the ability of prostate epithelial stem-like cells (PrESLCs) isolated from treated animals to form colonies in soft agar, a hallmark of cellular transformation. In this animal model, a 1-month metal treatment followed by chemical carcinogen treatment significantly increased the incidence of PCa and pre-cancerous lesions in iAs-treated mice, with similar trends in Pb-treated animals. Importantly, single-cell RNAseq analyses revealed that Pb was associated with the expansion of a subpopulation of PrESLCs with epithelial lineage markers into stroma-like oncogenic cells, while iAs was associated with the emergence of a rare, unique subpopulation of oncogenic PrESLCs similar to “cancer” stem cells. This proposal will test the hypothesis that iAs and/or Pb dysregulate specific, and likely different, signaling pathways in subpopulations of PrESLCs to initiate or increase the risk of carcinogenesis in the prostate. This is an untested hypothesis in the field of prostate carcinogenesis and in military veterans’ health. Two Aims are proposed. Aim 1: Determine the carcinogenic potential of metal treated PrESLCs in vivo using a renal grafting model of PCa formation. We will evaluate the effects of metals on the formation of PCa in vivo in immune-deficient host mice, either with or without chemical induction of PCa. Aim 2: Characterize stem-like cells with metal-specific transcriptomic signatures. We will use single-cell RNAseq and visualization informatics to identify the unique gene signatures that characterize rare subpopulations of metal-induced cancer stem cells within the PrESLC population. We aim to apply these gene signatures to enrich rare subpopulations by FACS and evaluate their carcinogenic potential. We will also leverage The Cancer Genome Atlas PCa data and other online databases to enable accurate classification of major, rare, and heterogeneous subtypes of PrESLCs to gain insights into metal carcinogenesis. Findings from the proposed work may address questions related to occupational and post-deployment exposure and expand our knowledge of stem cell biology. Successful completion of these studies may lead to the development of new PCa prevention and therapeutic strategies. Plans to reduce unnecessary exposure to those metal ions can be justified and implemented as effective strategies for PCa prevention. Drugs targeting specific subpopulations of stem cells may be used as therapeutic options to prevent early PCa development and slow progression. When applied to veterans, the results of this study may save lives, improve health, and decrease disabilities in this community and beyond.