C-X-C ligand 10 and C-X-C receptor 3 status can predict tamoxifen treatment response in breast cancer patients

C-X-C Motif Chemokine Ligand 9 Correlates with Favorable Prognosis in Triple-Negative Breast Cancer by Promoting Immune Cell Infiltration

C-X-C motif chemokine ligand 9 (CXCL9) plays an important role in antitumor immunity through the recruitment, proliferation, and activation of immune cells (IC). Here, we evaluated the expression patterns of CXCL9 and programmed death-ligand 1 (PD-L1) in a cohort of 268 patients with triple-negative breast cancer (TNBC) by tissue microarray (TMA). The correlations between CXCL9 expression in ICs or tumor cells (TC) and clinicopathologic parameters, PD-L1 expression, tumor-infiltrating lymphocytes (TIL) and survival were analyzed in this cohort (n = 268). In addition, we analyzed a TNBC dataset (n = 138) from The Cancer Genome Atlas (TCGA) to identify correlation between CXCL9 expression and other immune gene expression, immune infiltration, and prognosis. The results of the TMA cohort (n = 268) showed that CXCL9 was expressed in 80.6% cases, with elevated expression levels in ICs relative to in TCs (median: 1% vs. 0%). CXCL9 expressed in ≥1% of ICs was categorized as the CXCL9-IC-positive group. CXCL9-IC expression was strongly and positively correlated with the PD-L1 expression, CD3+ TILs, CD4+ TILs, CD8+ TILs, and CD19+ TILs (all P < 0.0001). Survival analyses showed that the CXCL9-IC-positive group demonstrated prolonged disease-free survival (P = 0.038) and overall survival (P = 0.023) compared with the negative group. The analyses from TCGA cohort (n = 138) showed that elevated CXCL9 expression correlated with increased infiltration of B cells, macrophages, natural killer cells, monocytes and increased expression of immune checkpoint molecules and other CXCL family members, including CXCL10 and CXCL11. These findings confirm the regulatory role of CXCL9 in antitumor immunity and suggest a potential role in treatments involving immune checkpoint blockade.

The elusive Luminal B breast cancer and the mysterious chemokines

PURPOSE

Invasive ductal breast cancer (IDC) is heterogeneous. Staging and immunohistochemistry (IH) allow for effective therapy but are not yet ideal. Women with Luminal B tumors show an erratic response to treatment. This prospective study with 81 women with breast cancer aims to improve the prognostic stratification of Luminal B patients.

METHODS

This is a prospective translational study with 81 women with infiltrating ductal carcinoma, grouped by TNM staging and immunohistochemistry, for survival analysis, and their correlations with the chemokines. Serum measurements of 13 chemokines were performed, including 7 CC chemokines [CCL2(MCP1), CCL3(MIP1α), CCL4(MIP1β), CCL5(Rantes), CCL11(Eotaxin), CCL17(TARC), CCL20(MIP3α)], 6 CXC chemokines [CXCL1(GroAlpha), CXCL5(ENA78), CCXCL8(IL-8), CXCL9(MIG), CXCL10(IP10), CXCL11(ITAC)].

RESULTS

Overall survival was significantly dependent on tumor staging and subtypes by immunohistochemistry, with a median follow-up time the 32.87 months (3.67-65.63 months). There were age correlations with IP10/CXCL10 chemokines (r =  0.4360; p = 0.0079) and TARC/CCL17 (Spearman + 0.2648; p = 0.0360). An inverse correlation was found between body weight and the chemokines Rantes/CCL5 (r = - 0.3098; p = 0.0169) and Eotaxin/CCL11 (r = - 0.2575; p = 0.0470). Smokers had a higher concentration of MIP3α/CCL20 (Spearman + 0.3344; p = 0.0267). Luminal B subtype patients who expressed lower concentrations of ENA78/CXCL5 (≤ 254.83 pg/ml) (Log-Rank p = 0.016) and higher expression of MIP1β/CCL4 (> 34.84 pg/ml) (Log-Rank p = 0.014) had a higher risk of metastases.

CONCLUSION

Patients with Luminal B breast tumors can be better stratified by serum chemokine expression, suggesting that prognosis is dependent on biomarkers other than TNM and IH.

Cxcl10 chemokine induces migration of ING4-deficient breast cancer cells via a novel crosstalk mechanism between the Cxcr3 and Egfr receptors

The chemokine Cxcl10 has been associated with poor prognosis in breast cancer, but the mechanism is not well understood. Our previous study have shown that CXCL10 was repressed by the ING4 tumor suppressor, suggesting a potential inverse functional relationship. We thus investigated a role for Cxcl10 in the context of ING4 deficiencies in breast cancer. We first analyzed public gene expression datasets and found that patients with CXCL10-high/ING4-low expressing tumors had significantly reduced disease-free survival in breast cancer. In vitro, Cxcl10 induced migration of ING4-deleted breast cancer cells, but not of ING4-intact cells. Using inhibitors, we found that Cxcl10-induced migration of ING4-deleted cells required Cxcr3, Egfr, and the Gβγ subunits downstream of Cxcr3, but not Gαi. Immunofluorescent imaging showed that Cxcl10 induced early transient colocalization between Cxcr3 and Egfr in both ING4-intact and ING4-deleted cells, which recurred only in ING4-deleted cells. A peptide agent that binds to the internal juxtamembrane domain of Egfr inhibited Cxcr3/Egfr colocalization and cell migration. Taken together, these results presented a novel mechanism of Cxcl10 that elicits migration of ING4-deleted cells, in part by inducing a physical or proximal association between Cxcr3 and Egfr and signaling downstream via Gβγ. These results further indicated that ING4 plays a critical role in the regulation of Cxcl10 signaling that enables breast cancer progression.

The role of CXCL10 in prognosis of patients with colon cancer and tumor microenvironment remodeling

BACKGROUNG

Tumor microenvironment (TME) has gradually emerged as an important research topic in the fight against cancer. The immune system is a major contributing factor in TME, and investigations have revealed that tumors are partially infiltrated with numerous immune cell subsets.

METHOD

We obtained transcriptome RNA-seq data from the the Cancer Genome Atlas databases for 521 patients with colon adenocarcinoma (COAD). ESTIMATE algorithms are then used to estimate the fraction of stromal and immune cells in COAD samples.

RESULT

A total of 1109 stromal-immune score-related differentially expressed genes were identified and used to generate a high-confidence protein-protein interaction network and univariate COX regression analysis. C-X-C motif chemokine 10 (CXCL10) was identified as the core gene by intersection analysis of data from protein-protein interaction network and univariate COX regression analysis. Then, for CXCL10, we performed gene set enrichment analysis, survival analysis and clinical analysis, and we used CIBERSORT algorithms to estimate the proportion of tumor-infiltrating immune cells in COAD samples.

CONCLUSION

We discovered that CXCL10 levels could be effective for predicting the prognosis of COAD patients as well as a clue that the status of TME is transitioning from immunological to metabolic activity, which provided additional information for COAD therapies.

Role of CXCL10 in the progression of in situ to invasive carcinoma of the breast

Tumor immune microenvironment plays a crucial role in tumor progression. We performed immune profiling to compare immune-related gene expression between ductal carcinoma in situ (DCIS) and invasive carcinoma of the breast using nCounter PanCancer immune Profiling Panel and found that CXCL10 was the most significant gene that had the highest difference in expression between them. Effect of CXCL10 on breast cancer cell proliferation and invasion was examined in vitro, and expression of CXCL10 and its relationship with immune cell infiltration was assessed in breast cancer samples. CXCL10 induced cell proliferation, migration and epithelial-mesenchymal transition in MCF-7 and MDA-MB-231 breast cancer cell lines. We confirmed that CXCL10 mRNA expression was significantly higher in invasive carcinoma than in DCIS, especially in hormone receptor (HR)-negative tumors using a validation set. CXCL10 mRNA expression showed a positive correlation with tumor infiltrating lymphocyte (TIL) density in both DCIS and invasive carcinoma; CXCL10-positive tumors generally showed higher infiltration of CD8+ and FOXP3+TILs as well as PD-L1+ immune cells compared to CXCL10-negative tumors, albeit with different patterns according to HR status. In conclusion, our study showed that CXCL10 promotes tumor cell proliferation, invasion, and immune cell infiltration, implying its contribution in the progression of DCIS to invasive carcinoma of the breast.

M1 Polarization Markers Are Upregulated in Basal-Like Breast Cancer Molecular Subtype and Associated With Favorable Patient Outcome

Background

Breast cancer heterogeneity is an essential element that plays a role in the therapy response variability and the patient's outcome. This highlights the need for more precise subtyping methods that focus not only on tumor cells but also investigate the profile of stromal cells as well as immune cells.

Objectives

To mine publicly available transcriptomic breast cancer datasets and reanalyze their transcriptomic profiling using unsupervised clustering in order to identify novel subsets in molecular subtypes of breast cancer, then explore the stromal and immune cells profile in each subset using bioinformatics and systems immunology approaches.

Materials and Methods

Transcriptomic data from 1,084 breast cancer patients obtained from The Cancer Genome Atlas (TCGA) database were extracted and subjected to unsupervised clustering using a recently described, multi-step algorithm called Iterative Clustering and Guide-gene Selection (ICGS). For each cluster, the stromal and immune profile was investigated using ESTIMATE and CIBERSORT analytical tool. Clinical outcomes and differentially expressed genes of the characterized clusters were identified and validated in silico and in vitro in a cohort of 80 breast cancer samples by immunohistochemistry.

Results

Seven unique sub-clusters showed distinct molecular and clinical profiles between the well-known breast cancer subtypes. Those unsupervised clusters identified more homogenous subgroups in each of the classical subtypes with a different prognostic profile. Immune profiling of the identified clusters showed that while the classically activated macrophages (M1) are correlated with the more aggressive basal-like breast cancer subtype, the alternatively activated macrophages (M2) showed a higher level of infiltration in luminal A and luminal B subtypes. Indeed, patients with higher levels of M1 expression showed less advanced disease and better patient outcomes presented as prolonged overall survival. Moreover, the M1 high basal-like breast cancer group showed a higher expression of interferon-gamma induced chemokines and guanylate-binding proteins (GBPs) involved in immunity against microbes.

Conclusion

Adding immune profiling using transcriptomic data can add precision for diagnosis and prognosis and can cluster patients according to the available modalities of therapy in a more personalized approach.

CXCL10 mediates breast cancer tamoxifen resistance and promotes estrogen-dependent and independent proliferation

Although 70% of estrogen receptor (ER)-positive breast cancer patients can benefit from tamoxifen therapy, the rapid development of tamoxifen resistance hampers the treatment advantage. In this investigation, we found that the serum level of CXCL10 in breast cancer patients was positively correlated with tumor size and ER status. Furthermore, GSE22220 dataset analysis demonstrated that CXCL10 expression in the tumor was correlated with tumor grade and lymphatic metastasis status, and Kaplan-Meier analysis indicated that patients with high CXCL10 expression had a poor prognosis. Estrogen-deprived MCF7 cells were transfected with CXCL10 luciferase reporter plasmid and treated with 10 nM estrogen. Luciferase reporter assay confirmed that CXCL10 was regulated by estrogen. CXCL10 promoted the proliferation of both parental MCF7 cells and tamoxifen-resistant (TamR) MCF7 cells through the AKT pathway, while CXCL10 inhibition restored the sensitivity of TamR cells to tamoxifen. All of these data indicate that CXCL10 could be utilized as a biomarker to predict the prognosis of breast cancer and as a therapeutic target to treat tamoxifen resistant cases.

Bioinformatic profiling of prognosis-related genes in the breast cancer immune microenvironment

In the microenvironment of breast cancer, immune cell infiltration is associated with an improved prognosis. To identify immune-related prognostic markers and therapeutic targets, we determined the lymphocyte-specific kinase (LCK) metagene scores of samples from breast cancer patients in The Cancer Genome Atlas. The LCK metagene score correlated highly with other immune-related scores, as well as with the clinical stage, prognosis and tumor suppressor gene mutation status (BRCA2, TP53, PTEN) of patients in the four breast cancer subtypes. A weighted gene co-expression network analysis was performed to detect representative genes from LCK metagene-related gene modules. In two of these modules, the levels of the co-expressed genes correlated highly with LCK metagene levels, so we conducted an enrichment analysis to discover their functions. We also identified differentially expressed genes in samples with high and low LCK metagene scores. By examining the overlapping results from these analyses, we obtained 115 genes, and found that 22 of them were independent predictors of overall survival in breast cancer patients. These genes were validated for their prognostic and diagnostic value with external data sets and paired tumor and non-tumor tissues. The genes identified herein could serve as diagnostic/prognostic markers and immune-related therapeutic targets in breast cancer.

CXCR3 is a prognostic marker and a potential target for patients with solid tumors: a meta-analysis

OBJECTIVE

To deeply verify the clinical significance of CXCR3 in prediction of cancer patients' prognosis.

DATA SOURCES

We performed a meta-analysis including 12 studies searched from PubMed, Web of Science, Embase, and Cochrane databases. A total of 1,751 patients were used to analyze the association between CXCR3 and patients' prognosis, based on either overall survival or time to tumor progression.

STUDY SELECTION

Studies evaluating CXCR3 expression for predicting prognosis in human solid tumors were included.

RESULTS

It showed that patients with higher expression of CXCR3 had significantly shorter OS (pooled hazard ratio =2.315, 95% CI: 1.162-4.611, P=0.017). In addition, higher CXCR3 expression was associated with distant metastasis (yes vs no: pooled relative ratio [RR] =1.828, 95% CI: 1.140-2.931, P=0.012) in solid tumors and indicated advanced tumor stage (III/IV vs I/II, RR =2.656, 95% CI: 1.809-3.900, P<0.001) and lymph node metastasis (yes vs no: RR =2.28, 95% CI: 1.61-3.25, P<0.001) in colorectal cancer.

CONCLUSION

Our study highlights the role of CXCR3 as a potential prognostic marker and a promising therapeutic target in solid tumors.

MiR-15a-5p negatively regulates cell survival and metastasis by targeting CXCL10 in chronic myeloid leukemia

Chronic myeloid leukemia (CML) is a common malignant disease from hematopoietic system. Aberrant expression of microRNAs (miRNAs) has been found in CML, however, the roles of many miRNAs including miR-15a-5p in CML are still unknown. In this study, the expression and roles of miR-15a-5p in CML were investigated. We found that restoration miR-15a-5p expression in CML cells decreased cell growth, metastasis and enhanced cell apoptosis. Chemokine ligand 10 (CXCL10) was predicted as a target gene of miR-15a-5p, which was verified by luciferase assay. CXCL10 mRNA and protein was down-regulated in the CML cells with miR-15a-5p overexpression by real time RT-PCR and western blotting. We also found that there were low levels of miR-15a-5p companied with high levels of CXCL10 in blood samples from CML patients. In a conclusion, miR-15a-5p suppresses cell survival and metastasis of CML by targeting CXCL10, which is a therapeutic option for CML patients.

Induction of cathepsin B by the CXCR3 chemokines CXCL9 and CXCL10 in human breast cancer cells

Cathepsin B (CTSB) is a lysosomal cysteine protease that has been linked to the progression of breast cancer, for example by activation of other proteases and tumor-promoting cytokines, thereby supporting tumor invasion and metastasis. Previously, it was shown that CTSB cleaves and inactivates C-X-C motif chemokine receptor 3 (CXCR3) chemokines. As CXCR3 ligands have been demonstrated to induce proteases in cancer cells, the present study hypothesized that they may also affect CTSB in breast cancer cells. The results demonstrated that the human breast cancer tumor cell lines MCF-7 and MDA-MB-231 express the CXCR3 splice variants A and B and CTSB. Upon binding to CXCR3, the two chemokine ligands C-X-C motif chemokine ligand (CXCL) 9 and CXCL10 trigger upregulation of CTSB in these breast cancer cells, whereas the CXCR3-B-specific ligand CXCL4 has no such effect, suggesting the involvement of CXCR3-A in the regulation of CTSB. In early-stage human breast cancer specimens (n=81), overexpression of CXCR3 is associated with statistically significant poorer overall survival, independent of lymph node status, tumor size and nuclear grading (hazard ratio=1.99; 95% confidence interval=1.00–3.97; P=0.050). In conclusion, the data from the current study propose a so far unknown mechanism by which breast cancer cells may exploit tumor-suppressive chemokines to enhance their invasiveness and reduce immune cell infiltration by the degradation of these chemokines. This mechanism may support the established unfavorable prognostic feature of CXCR3 expression in breast cancer.

The calcineurin/NFAT pathway is activated in diagnostic breast cancer cases and is essential to survival and metastasis of mammary cancer cells

Nuclear factor of activated T cells 1 (NFAT1) expression has been associated with increased migratory/invasive properties of mammary tumor-derived cell lines in vitro. It is unknown, however, if NFAT activation actually occurs in breast cancer cases and whether the calcineurin/NFAT pathway is important to mammary tumorigenesis. Using a cohort of 321 diagnostic cases of the major subgroup of breast cancer, we found Cn/NFAT pathway activated in ER⁻PR⁻HER2⁻ triple-negative breast cancer subtype, whereas its prevalence is less in other subgroups. Using a small hairpin RNA-based gene expression silencing approach in murine mammary tumor cell line (4T1), we show that not only NFAT1 but also NFAT2 and their upstream activator Cn are essential to the migratory and invasive properties of mammary tumor cells. We also demonstrate that Cn, NFAT1 and NFAT2 are essential to the tumorigenic and metastatic properties of these cells in mice, a phenotype which coincides with increased apoptosis in vivo. Finally, global gene expression analyses identified several NFAT-deregulated genes, many of them being previously associated with mammary tumorigenesis. In particular, we identified the gene encoding a disintegrin and metalloproteinase with thrombonspondin motifs 1, as being a potential direct target of NFAT1. Thus, our results show that the Cn/NFAT pathway is activated in diagnostic cases of breast cancers and is essential to the tumorigenic and metastatic potential of mammary tumor cell line. These results suggest that pharmacological inhibition of the Cn/NFAT pathway at different levels could be of therapeutical interest for breast cancer patients.

Divergent roles of CXCR3 isoforms in promoting cancer stem-like cell survival and metastasis

There is growing evidence that several chemokine receptors including CXCR3 contribute to metastasis of breast and other cancers, however, in order to target CXCR3 effectively, it is critical to understand the relative contribution of each CXCR3 isoform. Furthermore, the possible contribution of either major CXCR3 isoform (CXCR3-A, CXCR3-B) to cancer stem cell behavior has not been reported. We employed primary invasive ductal carcinomas, a panel of breast cell lines, and a xenograft model of metastatic breast cancer to examine the role of CXCR3 isoforms in the behavior of breast cancer stem-like cells and the contribution of each isoform to metastasis. In primary human breast cancer specimens as well as established breast cancer cell lines, CXCR3-A is more highly expressed than CXCR3-B. Conversely, immortalized normal MCF10A cells express more CXCR3-B relative to CXCR3-A. Overexpression of CXCR3-B in MDA-MB-231 basal-like cells inhibits CXCR3 ligand-stimulated proliferation, which is accompanied by reduced ligand-mediated activation of ERK1/2 and p38 kinases. Likewise, metastatic capacity is reduced in vivo by higher levels of CXCR3-B, and migratory and invasive properties are inhibited in vitro; conversely, silencing of CXCR3-B enhances lung colonization. In contrast to the anti-metastatic and anti-proliferative roles of CXCR3-B in the non-stem cell population, this isoform supports a cancer stem-like cell phenotype. CXCR3-B is markedly elevated in mammosphere-forming parental cells and overexpressing CXCR3-B further enhances mammosphere-forming potential as well as growth in soft agar; stem-like behavior is inhibited in MDA-MB-231shCXCR3-B cells. Targeting of both CXCR3 isoforms may be important to block the stem cell-promoting actions of CXCR3-B, while inhibiting the pro-proliferative and metastasis-promoting functions of CXCR3-A.