Role of the Oral Microbiome in Oral Squamous Cell Carcinoma Progression

项目摘要 头颈癌是全球第六大常见恶性肿瘤，口腔鳞状细胞癌 口腔癌(OSCC)是口腔最常见的恶性肿瘤。尽管预后有所改善 对于许多其他人类癌症，口腔鳞癌的存活率几十年来几乎保持不变， 强调迫切需要新的治疗方式。越来越多的证据表明，人类 微生物组在促进多种癌症，包括胃癌、结肠癌和胆囊癌方面起着关键作用。 各种机制。与下消化道相比，口腔的作用和机制 微生物组可能对口腔鳞癌的作用尚不清楚。这个项目的推动力是灵知生鼠 模型与功能转录学相结合，为阐明这种机制提供了强有力的新途径 这是口腔鳞状细胞癌中口腔微生物组致瘤作用的基础。在初步研究中，我们发现 无菌小鼠在微生物群中定居，并受到致癌物4-NQO的挑战，产生了许多 与保持无菌状态的小鼠相比，肿瘤更多、更大。转录过度活跃的候选病原体 它们表达了许多毒力特征，与之前在人类口腔鳞状细胞癌中的发现相似。 肿瘤浸润性白细胞(TIL)似乎被调节为免疫抑制与保护 微生物群定植小鼠的表型。这些发现导致了我们的中心假设，即关键的致病因素 口腔微生物群中的物种促进口腔鳞癌进展，至少部分是通过诱导免疫抑制而不是 保护豁免权。这将通过确定转录活性最高的物种来进行测试 强促进同基因小鼠口腔癌(MOC)细胞株在体内的生长和转移 老鼠的舌头在体内。细菌的代谢途径将以转译组学为特征，而 微生物组调节的免疫以及RNAseq对肿瘤细胞的反应。诱导的免疫反应 致癌病原体将在局部和引流淋巴结内表现特征。Treg和Treg的功能 髓系来源的抑制细胞将在体内通过免疫治疗抗体去除进行评估。 致癌病原体对肿瘤细胞生长和侵袭的直接影响将被确定。我们的目标是 确定主要的口腔致癌细菌及其促进作用的分子机制 口腔鳞癌进展。该项目的成功完成将提出新的以微生物组为重点的干预措施 减少口腔鳞癌的发病和复发，并为开发新一代口腔鳞癌治疗方法做出贡献 这种顽固不化的毁灭性疾病。

Project Abstract Head and neck cancer represents the sixth most common malignancy worldwide, and oral squamous cell carcinomas (OSCC) are the most frequent malignancies in the oral cavity. Despite improvements in prognosis for many other human cancers, survival rates for OSCC have remained nearly unchanged for decades, emphasizing the urgent need for new treatment modalities. Mounting evidence indicates that the human microbiome plays a key role in promoting a variety of cancers, including stomach, colon and gall bladder, via various mechanisms. In contrast to the lower GI tract, the role of, and mechanisms by which, the oral microbiome may contribute to OSCC remain obscure. The impetus for this project is that gnotobiotic mouse models, coupled with functional transcriptomics, offer powerful new approaches to elucidate the mechanisms that underlie the tumorigenic effects of the oral microbiome in OSCC. In preliminary studies we found that germfree mice colonized with microbiomes, and challenged with the carcinogen 4-NQO, developed many more, and larger tumors than mice that remained germfree. Transcriptionally-hyperactive candidate pathogens were identified, which expressed numerous virulence signatures, paralleling previous findings in human OSCC. Tumor-infiltrating leukocytes (TIL) appeared to be modulated to an immunosuppressive vs protective phenotype in microbiome-colonized mice. These findings lead to our central hypothesis, that key pathogenic species in the oral microbiome promote OSCC progression, at least in part by inducing immunosuppression vs protective immunity. This will be tested by determining the transcriptionally-hyperactive species that most strongly promote the growth and metastasis of syngeneic mouse oral cancer (MOC) cell line orthografts in mouse tongues in vivo. Bacterial metabolic pathways will be characterized by metatranscriptomics, and the microbiome-modulated immune as well as tumor cell responses by RNASeq. Immune responses induced by tumorigenic pathogens will be characterized locally and in draining lymph nodes. The function of Treg and myeloid-derived suppressor cells will be evaluated by abrogation with immunotherapeutic antibodies in vivo. Direct effects of tumorigenic pathogens on tumor cell growth and invasion will be determined. The goal is to identify key oral tumorigenic bacteria and their molecular mechanisms that are responsible for promoting OSCC progression. Successful completion of this project will suggest new microbiome-focused interventions to reduce OSCC initiation and recurrence, and contribute to the development of next generation therapeutics for this recalcitrant and devastating disease.