Probes for INS

The CXCL12-CXCR4 axis is proposed to mediate metastasis formation. In this study, we examined CXCL12, CXCR4 and the relative CXCL12-CXCR4 expression as prognostic factors in two cohorts of colon cancer patients. Immunohistochemistry (IHC) and in situ hybridization (ISH) were used to study CXCR4, CXCL12 and relative CXCL12-CXCR4 expression in tissue microarrays. Our study included totally 596 patients, 290 in cohort 1 and 306 in cohort 2. For tumour, node, metastasis (TNM) stage III, low nuclear expression of CXCR4 was a positive prognostic factor for 5-year disease-free survival (DFS) in cohort 1 (P = 0.007) and cohort 2 (P = 0.023). In multivariate analysis for stage III, nuclear expression of CXCR4 in cohort 1 was confirmed as a prognostic factor for DFS (hazard ratio (HR), 0.27; 95 % CI, 0.09 to 0.77). For TNM stage III, high cytoplasmic expression of CXCL12 was associated with better 5-year DFS in both cohorts (P = 0.006 and P = 0.006, respectively). We further validated the positive prognostic value of CXCL12 expression for 5-year DFS in stage III with ISH (P = 0.022). For TNM stage III, the relative CXCL12-CXCR4 expression (CXCL12 > CXCR4 vs CXCL12 = CXCR4 vs CXCL12 < CXCR4) was a prognostic factor for 5-year DFS in cohort 1 (92 % vs 46 % vs 31 %, respectively; P < 0.001) and cohort 2 (92 % vs 66 % vs 30 %, respectively; P = 0.006). In conclusion, CXCL12 and relative CXCL12-CXCR4 expression are independent prognostic factors for 5-year DFS in TNM stage III colon cancer.

High-grade serous ovarian cancers (HGSOC) have been subdivided into molecular subtypes. The mesenchymal HGSOC subgroup, defined by stromal-related gene signatures, is invariably associated with poor patient survival. We demonstrate that stroma exerts a key function in mesenchymal HGSOC. We highlight stromal heterogeneity in HGSOC by identifying four subsets of carcinoma-associated fibroblasts (CAF-S1-4). Mesenchymal HGSOC show high content in CAF-S1 fibroblasts, which exhibit immunosuppressive functions by increasing attraction, survival, and differentiation of CD25+FOXP3+ T lymphocytes. The beta isoform of the CXCL12 chemokine (CXCL12β) specifically accumulates in the immunosuppressive CAF-S1 subset through a miR-141/200a dependent-mechanism. Moreover, CXCL12β expression in CAF-S1 cells plays a crucial role in CAF-S1 immunosuppressive activity and is a reliable prognosis factor in HGSOC, in contrast to CXCL12α. Thus, our data highlight the differential regulation of the CXCL12α and CXCL12β isoforms in HGSOC, and reveal a CXCL12β-associated stromal heterogeneity and immunosuppressive environment in mesenchymal HGSOC.

The chemokine CXCL12 has been shown to regulate breast tumor growth, however, its mechanism in initiating distant metastasis is not well understood. Here, we generated a novel conditional allele of Cxcl12 in mice and used a fibroblast-specific Cre transgene along with various mammary tumor models to evaluate CXCL12 function in the breast cancer metastasis. Ablation of CXCL12 in stromal fibroblasts of mice significantly delayed the time to tumor onset and inhibited distant metastasis in different mouse models. Elucidation of mechanisms using in vitro and in vivo model systems revealed that CXCL12 enhances tumor cell intravasation by increasing vascular permeability and expansion of a leaky tumor vasculature. Furthermore, our studies revealed CXCL12 enhances permeability by recruiting endothelial precursor cells and decreasing endothelial tight junction and adherence junction proteins. High expression of stromal CXCL12 in large cohort of breast cancer patients was directly correlated to blood vessel density and inversely correlated to recurrence and overall patient survival. In addition, our analysis revealed that stromal CXCL12 levels in combination with number of CD31+ blood vessels confers poorer patient survival compared to individual protein level. However, no correlation was observed between epithelial CXCL12 and patient survival or blood vessel density. Our findings describe the novel interactions between fibroblasts-derived CXCL12 and endothelial cells in facilitating tumor cell intrvasation, leading to distant metastasis. Overall, our studies indicate that cross-talk between fibroblast-derived CXCL12 and endothelial cells could be used as novel biomarker and strategy for developing tumor microenvironment based therapies against aggressive and metastatic breast cancer.

Several kinase inhibitors that target aberrant signaling pathways in tumor cells have been deployed in cancer therapy. However, their impact on the tumor immune microenvironment remains poorly understood. The tyrosine kinase inhibitor cabozantinib showed striking responses in cancer clinical trial patients across several malignancies. Here we show that cabozantinib rapidly eradicates invasive, poorly-differentiated PTEN/p53 deficient murine prostate cancer. This was associated with enhanced release of neutrophil chemotactic factors from tumor cells, including CXCL12 and HMGB1, resulting in robust infiltration of neutrophils into the tumor. Critically, cabozantinib-induced tumor clearance in mice was abolished by antibody-mediated granulocyte depletion or HMGB1 neutralization or blockade of neutrophil chemotaxis with the CXCR4 inhibitor, plerixafor. Collectively, these data demonstrate that cabozantinib triggers a neutrophil-mediated anti-cancer innate immune response, resulting in tumor clearance.

Aim: The presence of cells within meningioma (MG) that express embryonic stem cell (ESC) markers has been previously reported. However, the precise location of these cells has yet to be determined.

Methods: 3,3-Diaminobenzidine (DAB) immunohistochemical (IHC) staining was performed on 11 WHO grade I MG tissue samples for the expression of the ESC markers OCT4, NANOG, SOX2, KLF4 and c-MYC. Immunofluorescence (IF) IHC staining was performed to investigate the localization of each of these ESC markers. NanoString and colorimetric in situ hybridization (CISH) mRNA expression analyses were performed on six snap-frozen MG tissue samples to confirm transcriptional activation of these proteins, respectively.

Results: DAB IHC staining demonstrated expression of OCT4, NANOG, SOX2, KLF4, and c-MYC within all 11 MG tissue samples. IF IHC staining demonstrated the expression of the ESC markers OCT4, NANOG, SOX2, KLF4, and c-MYC on both the endothelial and pericyte layers of the microvessels. NanoString and CISH mRNA analyses confirmed transcription activation of these ESC markers.

Conclusion: This novel finding of the expression of all aforementioned ESC markers in WHO grade I MG infers the presence of a putative stem cells population which may give rise to MG.