Lineage survival oncogenes are activated by somatic DNA alterations in cancers arising from the cell lineages in which these genes play a role in normal development.1,2 Here we show that a peak of genomic amplification on chromosome 3q26.33, found in squamous cell carcinomas (SCCs) of the lung and esophagus, contains the transcription factor gene SOX2—which is mutated in hereditary human esophageal malformations3 and necessary for normal esophageal squamous development4, promotes differentiation and proliferation of basal tracheal cells5 and co-operates in induction of pluripotent stem cells.6,7,8 SOX2 expression is required for proliferation and anchorage-independent growth of lung and esophageal cell lines, as shown by RNA interference experiments. Furthermore, ectopic expression of SOX2 cooperated with FOXE1 or FGFR2 to transform immortalized tracheobronchial epithelial cells. SOX2-driven tumors show expression of markers of both squamous differentiation and pluripotency. These observations identify SOX2 as a novel lineage survival oncogene in lung and esophageal SCC.

Importance Evidence indicates a complex link between gut microbiome, immunity, and intestinal tumorigenesis. To target the microbiota and immunity for colorectal cancer prevention and therapy, a better understanding of the relationship between microorganisms and immune cells in the tumor microenvironment is needed. Experimental evidence suggests that Fusobacterium nucleatum may promote colonic neoplasia development by down-regulating antitumor T-cell-mediated adaptive immunity. Objective To test the hypothesis that higher amount of Fusobacterium nucleatum in colorectal carcinoma tissue is associated with lower density of T-cells in tumor tissue. Design A cross-sectional analysis was conducted on colorectal carcinoma cases in two U.S. nationwide prospective cohort studies. The amount of Fusobacterium nucleatum in colorectal carcinoma tissue was measured by quantitative polymerase chain reaction assay; we equally dichotomized positive cases (high versus low). Multivariable ordinal logistic regression analysis was conducted to assess associations of the amount of Fusobacterium nucleatum with densities (quartiles) of T-cells in tumor tissue, controlling for clinical and tumor molecular features, including microsatellite instability, CpG island methylator phenotype, LINE-1 methylation, and KRAS, BRAF, and PIK3CA mutation status. We adjusted two-sided α level to 0.013 for multiple hypothesis testing. Setting The Nurses’ Health Study and the Health Professionals Follow-up Study. Participants 598 colon and rectal carcinoma cases. Main outcomes and measures Densities of CD3+, CD8+, CD45RO (PTPRC)+, and FOXP3+ T-cells in tumor tissue, determined by tissue microarray immunohistochemistry and computer-assisted image analysis. Results Fusobacterium nucleatum was detected in colorectal carcinoma tissue in 76 (13%) of 598 cases. Compared with Fusobacterium nucleatum-negative cases, Fusobacterium nucleatum-high cases were inversely associated with the density of CD3+ T-cells (for a unit increase in quartile categories of CD3+ T-cells as an outcome: multivariable odds ratio, 0.47; 95% confidence interval, 0.26 to 0.87; Ptrend = 0.006). The amount of Fusobacterium nucleatum was not significantly associated with the density of CD8+, CD45RO+, or FOXP3+ T-cells (Ptrend > 0.013). Conclusions and relevance The amount of tissue Fusobacterium nucleatum is inversely associated with CD3+ T-cell density in colorectal carcinoma tissue. Upon validation, our human population data may provide an impetus for further investigations on potential interactive roles of Fusobacterium and host immunity in carcinogenesis.