Oral squamous cell carcinoma (OSCC) is the most prevalent and most commonly studied oral cancer. However, there is a void regarding the role that the oral microbiome may play in OSCC. Although the relationship between microbial community composition and OSCC has been thoroughly investigated, microbial profiles of the human microbiome in cancer are understudied. Here we performed a small pilot study of community-wide metatranscriptome analysis to profile mRNA expression in the entire oral microbiome in OSCC to reveal molecular functions associated with this disease. Fusobacteria showed a statistically significantly higher number of transcripts at tumour sites and tumour-adjacent sites of cancer patients compared to the healthy controls analysed. Regardless of the community composition, specific metabolic signatures were consistently found in disease. Activities such as iron ion transport, tryptophanase activity, peptidase activities and superoxide dismutase were over-represented in tumour and tumour-adjacent samples when compared to the healthy controls. The expression of putative virulence factors in the oral communities associated with OSCC showed that activities related to capsule biosynthesis, flagellum synthesis and assembly, chemotaxis, iron transport, haemolysins and adhesins were upregulated at tumour sites. Moreover, activities associated with protection against reactive nitrogen intermediates, chemotaxis, flagellar and capsule biosynthesis were also upregulated in non-tumour sites of cancer patients. Although they are preliminary, our results further suggest that Fusobacteria may be the leading phylogenetic group responsible for the increase in expression of virulence factors in the oral microbiome of OSCC patients.

口腔鳞状细胞癌 (OSCC) 是最普遍和最常研究的口腔癌。然而，关于口腔微生物组在 OSCC 中可能发挥的作用尚无定论。尽管已经彻底研究了微生物群落组成与 OSCC 之间的关系，但对癌症中人类微生物组的微生物谱的研究还不够深入。在这里，我们对社区范围的元转录组分析进行了一项小型初步研究，以分析 OSCC 整个口腔微生物组中的 mRNA 表达，以揭示与这种疾病相关的分子功能。梭杆菌与所分析的健康对照相比，癌症患者的肿瘤部位和肿瘤邻近部位的转录物数量在统计学上显着增加。无论群落组成如何，在疾病中始终发现特定的代谢特征。与健康对照相比，在肿瘤和邻近肿瘤的样本中，铁离子转运、色氨酸酶活性、肽酶活性和超氧化物歧化酶等活性过高。与 OSCC 相关的口腔群落中假定的毒力因子的表达表明，与胶囊生物合成、鞭毛合成和组装、趋化性、铁转运、溶血素和粘附素相关的活动在肿瘤部位上调。此外，与保护活性氮中间体、趋化性、鞭毛和胶囊的生物合成也在癌症患者的非肿瘤部位上调。虽然它们是初步的，但我们的结果进一步表明梭杆菌可能是导致 OSCC 患者口腔微生物组中毒力因子表达增加的主要系统发育组。