Nuclear expression of pSTAT3Tyr705 and pSTAT3Ser727 in the stromal compartment of localized hormone-naïve prostate cancer.

BACKGROUND: The signal transducer and activator of transcription 3 (STAT3) is involved in the progression of different tumors including prostate cancer (PCa). The expression of STAT3 in benign and malignant epithelium has been described previously but it has not been described in the stromal compartment. The aim of the present study was to evaluate the nuclear expression and prognostic value of different forms of phosphorylated STAT3 in the stromal compartment of non-cancer and cancer areas of prostatic tissue. MATERIAL AND METHODS: Tissue microarray cores from radical prostatectomy of 225 patients with hormone-naïve localized PCa were immunostained for two phosphorylated forms of STAT3, pSTAT3Tyr705 and pSTAT3Ser727. The prognostic value of the expression levels was studied by Cox regression analysis and biochemical recurrence (BCR)-free survival illustrated by Kaplan-Meier curves. RESULTS: Expression of pSTAT3Tyr705 and pSTAT3Ser727 in the stromal compartment of cancer tissue was lower compared with non-cancer areas. In univariable and multivariable Cox regression analysis, expression levels of pSTAT3Tyr705 and STAT3Ser727 showed similar prognostic value as pathological T-stage, Gleason score and surgical margin status. Kaplan-Meier survival analysis showed that low nuclear expression levels of pSTAT3Tyr705 and pSTAT3Ser727 in stromal cells in cancer compartment and in non-cancer areas were related to BCR-free survival. CONCLUSIONS: Nuclear expression of pSTAT3Tyr705 and pSTAT3Ser727 in the stromal cells mirrors previous findings in the epithelial component in that it displays prognostic value in men undergoing radical prostatectomy for localized hormone-naïve PCa.

Feedback control of the CXCR7/CXCL11 chemokine axis by estrogen receptor α in ovarian cancer.

Ovarian cancer (OC) is one of the most intractable diseases, exhibiting tremendous molecular heterogeneity and lacking reliable methods for screening, resulting in late diagnosis and widespread peritoneal dissemination. Menopausal estrogen replacement therapy is a well-recognized risk factor for OC, but little is known about how estrogen might contribute to this disease at the cellular level. This study identifies chemokine receptor CXCR7/ACKR3 as an estrogen-responsive gene, whose expression is markedly enhanced by estrogen through direct recruitment of ERα and transcriptional active histone modifications in OC cells. The gene encoding CXCR7 chemokine ligand I-TAC/CXCL11 was also upregulated by estrogen, resulting in Ser-118 phosphorylation, activation, and recruitment of estrogen receptor ERα at the CXCR7 promoter locus for positive feedback regulation. Both CXCR7 and CXCL11, but not CXCR3 (also recognized to interact with CXCL11), were found to be significantly increased in stromal sections of microdissected tumors and positively correlated in mesenchymal subtype of OC. Estrogenic induction of mesenchymal markers SNAI1, SNAI2, and CDH2 expression, with a consequent increase in cancer cell migration, was shown to depend on CXCR7, indicating a key role for CXCR7 in mediating estrogen upregulation of mesenchymal markers to induce invasion of OC cells. These findings identify a feed-forward mechanism that sustains activation of the CXCR7/CXCL11 axis under ERα control to induce the epithelial-mesenchymal transition pathway and metastatic behavior of OC cells. Such interplay underlies the complex gene profile heterogeneity of OC that promotes changes in tumor microenvironment and metastatic acquisition.

Effect of neoadjuvant chemotherapy on the immune microenvironment in non-small cell lung carcinomas as determined by multiplex immunofluorescence and image analysis approaches.

BACKGROUND: The clinical efficacy observed with inhibitors of programed cell death 1/programed cell death ligand 1 (PD-L1/PD-1) in cancer therapy has prompted studies to characterize the immune response in several tumor types, including lung cancer. However, the immunological profile of non-small cell lung carcinoma (NSCLC) treated with neoadjuvant chemotherapy (NCT) is not yet fully characterized, and it may be therapeutically important. The aim of this retrospective study was to characterize and quantify PD-L1/PD-1 expression and tumor-associated immune cells (TAICs) in surgically resected NSCLCs from patients who received NCT or did not receive NCT (non-NCT). METHODS: We analyzed immune markers in formalin-fixed, paraffin-embedded tumor tissues resected from 112 patients with stage II/III NSCLC, including 61 non-NCT (adenocarcinoma [ADC] = 33; squamous cell carcinoma [SCC] = 28) and 51 NCT (ADC = 31; SCC = 20). We used multiplex immunofluorescence to identify and quantify immune markers grouped into two 6-antibody panels: panel 1 included AE1/AE3, PD-L1, CD3, CD4, CD8, and CD68; panel 2 included AE1/AE3, PD1, granzyme B, FOXP3, CD45RO, and CD57. RESULTS: PD-L1 expression was higher (> overall median) in NCT cases (median, 19.53%) than in non-NCT cases (median, 1.55%; P = 0.022). Overall, density of TAICs was higher in NCT-NSCLCs than in non-NCT-NSCLCs. Densities of CD3+ cells in the tumor epithelial compartment were higher in NCT-ADCs and NCT-SCCs than in non-NCT-ADCs and non-NCT-SCCs (P = 0.043). Compared with non-NCT-SCCs, NCT-SCCs showed significantly higher densities of CD3 + CD4+ (P = 0.019) and PD-1+ (P < 0.001) cells in the tumor epithelial compartment. Density of CD68+ tumor-associated macrophages (TAMs) was higher in NCT-NSCLCs than in non-NCT-NSCLCs and was significantly higher in NCT-SCCs than in non-NCT-SCCs. In NCT-NSCLCs, higher levels of epithelial T lymphocytes (CD3 + CD4+) and epithelial and stromal TAMs (CD68+) were associated with better outcome in univariate and multivariate analyses. CONCLUSIONS: NCT-NSCLCs exhibited higher levels of PD-L1 expression and T-cell subset regulation than non-NCT-NSCLCs, suggesting that NCT activates specific immune response mechanisms in lung cancer. These results suggest the need for clinical trials and translational studies of combined chemotherapy and immunotherapy prior to surgical resection of locally advanced NSCLC.

Protease-activated receptor 2 suppresses lymphangiogenesis and subsequent lymph node metastasis in a murine pancreatic cancer model.

Protease-activated receptor-2 (PAR-2) is a G protein-coupled receptor that functions as a cell-surface sensor for coagulation factors and other proteases associated with the tumour microenvironment. Pancreatic cancer cells express high levels of PAR-2 and activation of PAR-2 may induce their proliferation and migration. Interestingly, however, PAR-2 expression is increased in stroma-rich pancreatic cancer regions, suggesting a potential role of PAR-2 in the tumour microenvironment. Here, we assessed the importance of PAR-2 in the stromal compartment by utilizing an orthotopic pancreatic cancer model, in which tumour cells are PAR-2-positive, whereas stromal cells are PAR-2-negative. We assessed tumour weight and volume and analysed proliferation and (lymph)angiogenesis both in vivo and in vitro. We show that genetic ablation of PAR-2 from the stromal compartment inhibits primary tumour growth, which is accompanied by reduced vascularization in primary tumours and reduced in tube formation of vascular endothelial cells in vitro. In contrast to smaller primary tumours, the number of lymph node metastases was increased in PAR-2-deficient animals, which was accompanied by an increased number of lymphatic vessels. In vitro tube-formation assays show that PAR-2 does not inhibit the intrinsic tube-forming capacity of lymphatic endothelial cells, but that PAR-2 actually inhibits cancer cell-induced tube formation. Overall, stromal PAR-2 thus plays a dual role in pancreatic cancer development by potentiating primary tumour growth but limiting lymphangiogenesis and subsequent lymph node metastasis. Our data identify a novel role of PAR-2 in the tumour microenvironment and pinpoint PAR-2 as a negative regulator of lymphangiogenesis.