CXCR7 contributes to the aggressive phenotype of cholangiocarcinoma cells.

Development of cholangiocarcinoma (CCA) is dependent on a cross-talk with stromal cells, which release different chemokines including CXCL12, that interacts with two different receptors, CXCR4 and CXCR7. The aim of the present study was to investigate the role of CXCR7 in CCA cells. CXCR7 is overexpressed by different CCA cell lines and in human CCA specimens. Knock-down of CXCR7 in HuCCT-1 cells reduced migration, invasion, and CXCL12-induced adhesion to collagen I. Survival of CCA was also reduced in CXCR7-silenced cells. The ability of CXCL12 to induce cell migration and survival was also blocked by CCX733, a CXCR7 antagonist. Similar effects of CXCR7 activation were observed in CCLP-1 cells and in primary iCCA cells. Enrichment of tumor stem-like cells by a 3D culture system resulted in increased CXCR7 expression compared to cells grown in monolayers, and genetic knockdown of CXCR7 robustly reduced sphere formation both in HuCCT-1 and in CCLP-1 cells. In HuCCT-1 cells CXCR7 was found to interact with ß-arrestin 2, which was necessary to mediate CXCL12-induced migration, but not survival. In conclusion, CXCR7 is widely expressed in CCA, and contributes to the aggressive phenotype of CCA cells, inducing cell migration, invasion, adhesion, survival, growth and stem cell-like features. Cell migration induced by CXCR7 requires interaction with ß-arrestin 2.

CXCR4/CXCL12 Signaling and Protumor Macrophages in Primary Tumors and Sentinel Lymph Nodes Are Involved in Luminal B Breast Cancer Progression.

Luminal B breast cancers (BC) have a more aggressive behavior associated with a higher rate of tumor relapse and worse prognosis compared to luminal A tumors. In this study, we evaluated the involvement of specific epithelial-to-mesenchymal transition- (EMT-) and immune-related pathways in the dissemination of luminal B BC cells. The expression of 42 EMT- and immune-related genes was evaluated in matched sentinel lymph nodes (SLNs) analyzed by the one-step nucleic acid amplification assay (OSNA) and primary tumors of 40 luminal B BC patients by gene array and immunohistochemistry. The results were validated in an independent group of 150 luminal B tumors by immunohistochemistry and immunofluorescence and using gene expression data from 315 luminal B BC patients included in the Metabric dataset. We found that the expression of CXCR4 (p = 3.28E - 02) and CD163 (p = 6.92E - 03) was significantly upregulated in SLNs of recurrent luminal B BC patients. Luminal B primary tumors overexpressing CXCR4 were characterized by an increased expression of vimentin and a high content of CD163-positive macrophages. Bioinformatics analysis confirmed the correlation of CXCR4 with CXCL12, VIM, and CD163 expression and LN involvement. Our results suggest that the upregulation of the CXCR4/CXCL12 pathway and the presence of protumor macrophages in the primary tumor and SLNs sustain the aggressiveness of an important subgroup of luminal B BC.

Integrated MicroRNA-mRNA Profiling Identifies Oncostatin M as a Marker of Mesenchymal-Like ER-Negative/HER2-Negative Breast Cancer.

MicroRNAs (miRNAs) simultaneously modulate different oncogenic networks, establishing a dynamic system of gene expression and pathway regulation. In this study, we analyzed global miRNA and messenger RNA (mRNA) expression profiles of 17 cell lines representing different molecular breast cancer subtypes. Spearman's rank correlation test was used to evaluate the correlation between miRNA and mRNA expression. Hierarchical clustering and pathway analysis were also performed. Publicly available gene expression profiles (n = 699) and tumor tissues (n = 80) were analyzed to assess the relevance of key miRNA-regulated pathways in human breast cancer. We identified 39 significantly deregulated miRNAs, and the integration between miRNA and mRNA data revealed the importance of immune-related pathways, particularly the Oncostatin M (OSM) signaling, associated with mesenchymal-like breast cancer cells. OSM levels correlated with genes involved in the inflammatory response, epithelial-to-mesenchymal transition (EMT), and epidermal growth factor (EGF) signaling in human estrogen receptor (ER)-negative/human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Our results suggest that the deregulation of specific miRNAs may cooperatively impair immune and EMT pathways. The identification of the OSM inflammatory pathway as an important mediator of EMT in triple-negative breast cancer (TNBC) may provide a novel potential opportunity to improve therapeutic strategies.

An immune stratification reveals a subset of PD-1/LAG-3 double-positive triple-negative breast cancers.

BACKGROUND: Stromal tumor-infiltrating lymphocytes (TILs) are a robust prognostic factor in triple-negative breast cancer (TNBC). However, the clinical significance of TILs may be influenced by the complex landscape of the tumor immune microenvironment. In this study, we aimed to evaluate the composition and the functionality of lymphocytic infiltration and checkpoint receptors in TNBC. METHODS: Formalin-fixed, paraffin-embedded tissues were retrospectively collected from a cohort of patients with early-stage TNBC treated with adjuvant anthracycline-based chemotherapy (n = 259). Results were validated in an independent cohort of patients with TNBC (n = 104). Stromal TILs were evaluated on hematoxylin-and-eosin-stained sections. The density of CD4+, CD8+, and FOXP3+ lymphocytes, and the expression of the immune checkpoints PD-1 and LAG-3, were assessed by immunohistochemical analysis. RESULTS: The presence of elevated TILs positively correlated with the density of all T cell subtypes, especially cytotoxic CD8+ lymphocytes. We showed that increasing stromal TILs assessed as a continuous variable is an independent prognostic marker of prolonged relapse-free survival and overall survival in TNBC. Among immune subpopulations, CD8+ lymphocytes are the main effectors of anti-tumor immune responses. In two independent cohorts, we found that PD-1 and LAG-3 were concurrently expressed in approximately 15% of patients with TNBC. The expression of both checkpoint receptors positively correlated with the presence of TILs, but was not significantly associated with patient outcome. CONCLUSIONS: Overall, our data indicate that the evaluation of stromal TILs remains the most reliable immune prognostic marker in TNBC, and support the clinical evaluation of anti-PD-1/PD-L1 and anti-LAG-3 in a subset of patients with TNBC who have concurrent expression of both checkpoint receptors.

Targeting microRNAs as key modulators of tumor immune response.

The role of immune response is emerging as a key factor in the complex multistep process of cancer. Tumor microenvironment contains different types of immune cells, which contribute to regulate the fine balance between anti and protumor signals. In this context, mechanisms of crosstalk between cancer and immune cells remain to be extensively elucidated. Interestingly, microRNAs (miRNAs) have been demonstrated to function as crucial regulators of immune response in both physiological and pathological conditions. Specifically, different miRNAs have been reported to have a role in controlling the development and the functions of tumor-associated immune cells. This review aims to describe the most important miRNAs acting as critical modulators of immune response in the context of different solid tumors. In particular, we discuss recent studies that have demonstrated the existence of miRNA-mediated mechanisms regulating the recruitment and the activation status of specific tumor-associated immune cells in the tumor microenvironment. Moreover, various miRNAs have been found to target key cancer-related immune pathways, which concur to mediate the secretion of immunosuppressive or immunostimulating factors by cancer or immune cells. Modalities of miRNA exchange and miRNA-based delivery strategies are also discussed. Based on these findings, the modulation of individual or multiple miRNAs has the potential to enhance or inhibit specific immune subpopulations supporting antitumor immune responses, thus contributing to negatively affect tumorigenesis. New miRNA-based strategies can be developed for more effective immunotherapeutic interventions in cancer.

AXL-associated tumor inflammation as a poor prognostic signature in chemotherapy-treated triple-negative breast cancer patients.

A subgroup of triple-negative breast cancer (TNBC) shows epithelial-to-mesenchymal transition (EMT) features, which are sustained by the interaction between cancer cells and tumor-associated macrophages (TAMs). In this study, the clinical relevance of 30 EMT-related kinases and the potential cross-talk with TAMs were investigated in a cohort of 203 TNBC patients treated with adjuvant chemotherapy. The prognostic value of the evaluated markers was validated in two independent cohorts of TNBC patients treated with adjuvant chemotherapy (N=95; N=137). In vitro, we investigated the potential synergism between cancer cells and TAMs. We found that the EMT-related kinase AXL showed the highest correlation with the frequency of CD163-positive macrophages (rS=0.503; P<0.0001). Relapsing TNBC patients presented high expression of AXL (P<0.0001) and CD163 (P<0.018), but only AXL retained independent prognostic significance in multivariate analysis (relapse-free survival, P=0.002; overall survival P=0.001). In vitro analysis demonstrated that AXL-expressing TNBC cells were able to polarize human macrophages towards an M2-like phenotype, and modulate a specific pattern of pro-tumor cytokines and chemokines. Selective AXL inhibition impaired the activity of M2-like macrophages, reducing cancer cell invasiveness, and restoring the sensitivity of breast cancer cells to chemotherapeutic drugs. These data suggest that the EMT-related kinase AXL overexpressed in cancer cells has prognostic significance, and contributes to the functional skewing of macrophage functions in TNBC. AXL inhibition may represent a novel strategy to target cancer cells, as well as tumor-promoting TAMs in TNBC.

FOLFIRI and Cetuximab Every Second Week for First-Line Treatment of KRAS Wild-Type Metastatic Colorectal Cancer According to Phosphatase and Tensin Homolog Expression: A Phase II Study.

BACKGROUND: Retrospective studies have suggested that phosphatase and tensin homolog (PTEN) expression might predict the efficacy of cetuximab in patients with KRAS wild-type metastatic colorectal cancer (mCRC). The present study was designed to prospectively evaluate the efficacy of first-line irinotecan, fluorouracil, and folinate (FOLFIRI) plus cetuximab every second week according to PTEN expression. PATIENTS AND METHODS: Originally, patients with KRAS wild-type mCRC were randomly assigned to receive either FOLFIRI or cetuximab plus FOLFIRI (FOLFIRI-C). After a protocol amendment, the FOLFIRI arm was discontinued, and additional patients received FOLFIRI-C. Cox proportional hazard models were used to investigate the effect of PTEN and MET expression and BRAF and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit α mutations on progression-free survival (PFS) and overall survival (OS). RESULTS: A total of 35 and 54 patients received FOLFIRI and FOLFIRI-C, respectively. For the patients assigned to FOLFIRI and FOLFIRI-C, the median OS was 17.7 and 23.3 months and the median PFS was 8.2 and 6.6 months, respectively. For patients receiving FOLFIRI-C, the loss of PTEN expression did not affect PFS or OS. Significant interactions for PFS were detected between the MET expression levels (P = .047) and BRAF mutation (P = .018) and treatment. On univariate analysis, BRAF mutation was significantly associated with shorter OS for patients receiving either FOLFIRI-C (P = .016) or FOLFIRI (P = .035). Multivariate analysis confirmed the independent prognostic value of BRAF mutation on OS and that of MET expression levels on PFS (P = .025) and OS (P = .028) but only in the patients receiving FOLFIRI alone. Adverse events with FOLFIRI-C were consistent with those expected from FOLFIRI plus weekly cetuximab. CONCLUSION: Although prospective analysis of PTEN did not allow a validation of the prognostic value of this biomarker, an every second week cetuximab schedule, in addition to first-line FOLFIRI, was effective and well tolerated. The possible predictive value of MET expression levels warrants additional investigation.

TRIP: a pathological score for transarterial chemoembolization resistance individualized prediction in hepatocellular carcinoma.

BACKGROUND & AIMS: Although potentially very useful in optimizing patient selection and follow-up, the individual response to transarterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) is generally unpredictable. The aim of this study was to identify tissue predictors of tumour resistance to TACE for use in clinical practice on pretreatment biopsies. METHODS: We investigated the association of residual tumour in post-TACE-resected HCC with pathological and immunophenotypical features, mainly related to hypoxia and angiogenesis. Comparison of tumour phenotype between post-TACE HCC and both paired pre-TACE biopsies and control TACE-untreated HCC was performed. Cases showing >50% residual tumour (RT) were defined as TACE-resistant. RESULTS: A consecutive series of 108 HCC from 41 patients was studied. Overall, 45/108 (44%) HCC were classified as TACE-resistant. Among these, 32 (71%) and 40 (89%) showed diffuse CD34 vascular staining and negative VEGF staining respectively (p<0.05). The association of these two parameters in a weighted score (TRIP) was able to predict TACE resistance with 81% accuracy, 89% sensitivity and 59% specificity. The effectiveness of TRIP was validated in an independent series of 28 HCC biopsies from patients subsequently treated with TACE and for whom radiological follow-up was available. CONCLUSIONS: This study demonstrates the potential value of pretreatment tumour biopsy as predictors of TACE resistance in HCC.

YAP activation is an early event and a potential therapeutic target in liver cancer development.

BACKGROUND & AIMS: Although the growth suppressing Hippo pathway has been implicated in hepatocellular carcinoma (HCC) pathogenesis, it is unknown at which stage of hepatocarcinogenesis its dysregulation occurs. We investigated in rat and human preneoplastic lesions whether overexpression of the transcriptional co-activator Yes-associated protein (YAP) is an early event. METHODS: The experimental model used is the resistant-hepatocyte (R-H) rat model. Gene expression was determined by qRT-PCR or immunohistochemistry. Forward genetic experiments were performed in human HCC cells and in murine oval cells. RESULTS: All foci of preneoplastic hepatocytes, generated in rats 4weeks after diethylnitrosamine (DENA) treatment, displayed YAP accumulation. This was associated with down-regulation of the ß-TRCP ligase, known to mediate YAP degradation, and of microRNA-375, targeting YAP. YAP accumulation was paralleled by the up-regulation of its target genes. Increased YAP expression was also observed in human early dysplastic nodules and adenomas. Animal treatment with verteporfin (VP), which disrupts the formation of the YAP-TEAD complex, significantly reduced preneoplastic foci and oval cell proliferation. In vitro experiments confirmed that VP-mediated YAP inhibition impaired cell growth in HCC and oval cells; notably, oval cell transduction with wild type or active YAP conferred tumorigenic properties in vitro and in vivo. CONCLUSIONS: These results suggest that (i) YAP overexpression is an early event in rat and human liver tumourigenesis; (ii) it is critical for the clonal expansion of carcinogen-initiated hepatocytes and oval cells, and (iii) VP-induced disruption of the YAP-TEAD interaction may provide an important approach for the treatment of YAP-overexpressing cancers.