Changes in the oral microbiome, particularly Fusobacterium nucleatum, are associated with oral squamous cell carcinoma (OSCC). F. nucleatum has been reported to modulate local immunity in cancers. We aimed to assess the association between intratumoral F. nucleatum and clinico-pathological features, relapse, and overall survival (OS) in two independent cohorts of patients with OSCC, and to explore the interplay with immune-related genes. We retrospectively analyzed tissue samples from a first cohort of 122 patients with head and neck squamous cell carcinoma, including 61 OSCC (cohort #1), and a second cohort of 90 additional OSCC (cohort #2). We then performed a sensitivity analysis on the merged cohort of OSCC patients (N = 151). F. nucleatum 16S rRNA gene sequences were quantified using real-time quantitative PCR. The presence of gram-negative bacteria and macrophages was confirmed by LPS and CD163 immunostainings, respectively. F. nucleatum positivity was associated with older age, less alcohol and combined alcohol plus tobacco consumption, and less frequent lymph node invasion. There was a trend for a lower recurrence rate in F. nucleatum-positive cases, with less metastatic relapses compared to F. nucleatum-negative tumors, and significantly longer OS, relapse-free and metastasis-free survival. F. nucleatum status was independently associated with OS in multivariate analysis. Immune-related gene and immunohistochemistry analyses showed that gram-negative bacteria load inversely correlated with M2 macrophages. F. nucleatum-associated OSCC has a specific immune microenvironment, is more frequent in older, non-drinking patients, and associated with a favorable prognosis.

Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer with high risk of relapse and metastasis. TNBC is a heterogeneous disease comprising different molecular subtypes including those with mesenchymal features. The tyrosine kinase AXL is expressed in mesenchymal cells and plays a role in drug resistance, migration and metastasis. We confirm that AXL is more expressed in mesenchymal TNBC cells compared to luminal breast cancer cells, and that its invalidation impairs cell migration while having no or little effect on cell viability. Here, we found that AXL controls directed migration. We observed that AXL displays a polarized localization at the Golgi apparatus and the leading edge of migratory mesenchymal TNBC cells. AXL co-localizes with F-actin at the front of the cells. In migratory polarized cells, the specific AXL inhibitor R428 displaces AXL and F-actin from the leading edge to a lateral area localized between the front and the rear of the cells where both are enriched in protrusions. In addition, R428 treatment disrupts the polarized localization of the Golgi apparatus towards the leading edge in migratory cells. Immunohistochemical analysis of aggressive chemo-resistant TNBC samples obtained before treatment reveals inter- and intra-tumor heterogeneity of the percentage of AXL expressing tumor cells, and a preference of these cells to be in contact with the stroma. Taken together, our study demonstrates that AXL controls directed cell migration most likely by regulating cell polarity.

Toll-like receptors (TLRs) are pattern recognition receptors mainly expressed by cells of the immune system but also by epithelial tumor cells. Little is known about expression patterns of TLR genes in breast tumors, and their clinical significance is unclear. The aim of our study was to investigate expression of TLRs pathway components in pre-invasive breast lesions and invasive breast carcinomas (IBCs). We used RT-PCR assays to quantify mRNA levels of the 10 TLR genes and genes involved in TLR pathways in 350 breast tumors from patients with known clinical/pathological status and long-term outcome. Sets of 158 breast samples were also analyzed by immunochemistry including; 40 early noninvasive breast lesions, 38 IBCs and 80 triple negative carcinomas subtype (TNCs). We identified TLR9 as the major TLR gene family member upregulated in breast tumors and more particularly in TNCs. Immunohistochemical studies demonstrated that TLR9 protein was expressed in tumor epithelial and stromal cells of the TLR9 mRNA-overexpressing tumors. TLR9 overexpression appears very early during breast carcinogenesis. High TLR9 levels were associated with favorable outcome in the TNC sub-group. TLR9 overexpression was associated with alterations of down-stream components of the TLR9 signaling pathway, epithelio-mesenchymal transition (EMT) induction and EGFR pathway deregulation. TNCs with TLR9 overexpression were significantly correlated with development of a fibrous and inflammatory microenvironment with variable status of nuclear phosphoSTAT3. Our results suggest that TLR9 could play a role in TNC carcinogenesis and could be useful as predictive biomarker and therapeutic target.Keywords Toll-like receptor 9 . Breast cancer subtypes .