Value of CXCL8-CXCR1/2 axis in neoadjuvant chemotherapy for triple-negative breast cancer patients: a retrospective pilot study

CMTM4 promotes the motility of colon cancer cells under radiation and is associated with an unfavorable neoadjuvant chemoradiotherapy response and patient survival in rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) is the standard treatment for locally advanced rectal cancer (LARC). Pathological complete regression is closely linked to disease outcomes. However, biomarkers predicting nCRT response and patient survival are lacking for LARC. In the present study, the clinical characteristics and follow-up information of 228 patients with LARC were retrospectively collected. Immunohistochemistry (IHC), reverse transcription-quantitative PCR (RT-qPCR), Kaplan-Meier and multivariate analyses were used to evaluate the expression and predict the role of CKLF-like MARVEL transmembrane domain member 4 (CMTM4) in LARC. Additionally, lentiviral short hairpin (sh)RNA was used to interfere with CMTM4 expression. The phenotype of CMTM4-knockdown LoVo cells was determined by colony formation, migration and invasion assays under irradiation (IR) treatment. RNA-sequencing (RNA-seq) analysis was also used to explore the CMTM4-regulated genes in LoVo-shCMTM4 cells compared with control cells. RT-qPCR was then used to confirm the expression of these CMTM4-regulated genes. CMTM4 expression in pre-nCRT tissues indicated an unfavorable response and a short disease-free survival (DFS) with LARC. The expression of CMTM4 significantly increased following nCRT treatment. Additionally, CMTM4 knockdown increased the proliferation, migration and invasion of colon cancer cells; however, IR disrupted the cell migration and invasion induced by CMTM4 knockdown. RNA-seq analysis, the Tumor Immune Estimation Resource database and RT-qPCR indicated that CMTM4 was involved in different signaling pathways and regulated immune-related genes such as cluster of differentiation 66b, chemokine (CXC motif) ligand 8 (CXCL8) and programmed cell death 1. Furthermore, CXCL8 expression was found to be negatively associated with CMTM4 expression in patients with LARC by IHC and RT-qPCR. CXCL8 expression on invasion margin regions in post-operative tissues was also an inferior predictor of DFS in patients with LARC. In conclusion, CMTM4 may predict the nCRT response and outcomes in patients with LARC.

Recent advances targeting chemokines for breast cancer

Breast cancer (BC) is a complex and heterogeneous disease, and its onset and progression involve the interplay of multiple molecular mechanisms. Chemokines and their receptors are key regulators of cell migration and immune responses and contribute significantly to the pathophysiology of BC. This article reviews the classification, functions, and mechanisms of chemokines and their receptors in the proliferation, migration, invasion, and angiogenesis of BC cells. This study explores the regulatory roles of chemokines and their receptors in the immune microenvironment of BC, particularly the ways they influence the infiltration, polarization, and antitumor immune responses of immune cells. Finally, this article summarizes the current treatment strategies for breast cancer that utilize chemokines and their receptors and provides insights into future research directions and trends in this field.

Exploring the interplay between triple-negative breast cancer stem cells and tumor microenvironment for effective therapeutic strategies

Triple-negative breast cancer (TNBC) is a highly aggressive and metastatic malignancy with poor treatment outcomes. The interaction between the tumor microenvironment (TME) and breast cancer stem cells (BCSCs) plays an important role in the development of TNBC. Owing to their ability of self-renewal and multidirectional differentiation, BCSCs maintain tumor growth, drive metastatic colonization, and facilitate the development of drug resistance. TME is the main factor regulating the phenotype and metastasis of BCSCs. Immune cells, cancer-related fibroblasts (CAFs), cytokines, mesenchymal cells, endothelial cells, and extracellular matrix within the TME form a complex communication network, exert highly selective pressure on the tumor, and provide a conducive environment for the formation of BCSC niches. Tumor growth and metastasis can be controlled by targeting the TME to eliminate BCSC niches or targeting BCSCs to modify the TME. These approaches may improve the treatment outcomes and possess great application potential in clinical settings. In this review, we summarized the relationship between BCSCs and the progression and drug resistance of TNBC, especially focusing on the interaction between BCSCs and TME. In addition, we discussed therapeutic strategies that target the TME to inhibit or eliminate BCSCs, providing valuable insights into the clinical treatment of TNBC.

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.

Plasma Levels of CXC Motif Chemokine 1 (CXCL1) and Chemokine 8 (CXCL8) as Diagnostic Biomarkers in Luminal A and B Breast Cancer

Chemokines are involved in the regulation of immune balance and in triggering an immune response. CXCL1 and CXCL8 belong to the ELR-motif-containing group of CXC chemokines, which, in breast cancer (BC), stimulate angiogenesis and increase migration and invasiveness of tumor cells. The aim of this study was to evaluate CXCL1, CXCL8 and comparative marker CA 15-3 plasma concentrations in BC patients with luminal subtypes A and B. The study group consisted of 100 patients with BC, and the control group of 50 subjects with benign breast lesions and 50 healthy women. Chemokines concentrations were determined by ELISA method; CA15-3-by CMIA. Concentrations of CXCL8 and CA15-3 were significantly higher in BC total group and luminal B (for CA15-3 also in luminal A) subtype of BC than in healthy controls and subjects with benign lesions. In the total BC group, the highest SE, PPV and NPV were observed for CXCL8 (70%, 77.78%, 50%, resp.). A combined analysis of tested chemokines with CA 15-3 increased SE and NPV values (96%, 69.23%, resp.). The diagnostic power of the test (measured by area under ROC curve (AUC)) showed the highest value for CXCL8 in the total BC group (0.6410), luminal A (0.6120) and B subgroup of BC (0.6700). For the combined parameter, the AUC was increasing and reached the highest value for CXCL1 + CXCL8 + CA15-3 combination (0.7024). In light of these results, we suggest that CXCL8 could be used as an additional diagnostic marker that would positively influence the diagnostic utility of CA 15-3, especially in luminal B subtype of BC.

The AGEs/RAGE Transduction Signaling Prompts IL-8/CXCR1/2-Mediated Interaction between Cancer-Associated Fibroblasts (CAFs) and Breast Cancer Cells

Advanced glycation end products (AGEs) and the cognate receptor, named RAGE, are involved in metabolic disorders characterized by hyperglycemia, type 2 diabetes mellitus (T2DM) and obesity. Moreover, the AGEs/RAGE transduction pathway prompts a dysfunctional interaction between breast cancer cells and tumor stroma toward the acquisition of malignant features. However, the action of the AGEs/RAGE axis in the main players of the tumor microenvironment, named breast cancer-associated fibroblasts (CAFs), remains to be fully explored. In the present study, by chemokine array, we first assessed that interleukin-8 (IL-8) is the most up-regulated pro-inflammatory chemokine upon AGEs/RAGE activation in primary CAFs, obtained from breast tumors. Thereafter, we ascertained that the AGEs/RAGE signaling promotes a network cascade in CAFs, leading to the c-Fos-dependent regulation of IL-8. Next, using a conditioned medium from AGEs-exposed CAFs, we determined that IL-8/CXCR1/2 paracrine activation induces the acquisition of migratory and invasive features in MDA-MB-231 breast cancer cells. Altogether, our data provide new insights on the involvement of IL-8 in the AGEs/RAGE transduction pathway among the intricate connections linking breast cancer cells to the surrounding stroma. Hence, our findings may pave the way for further investigations to define the role of IL-8 as useful target for the better management of breast cancer patients exhibiting metabolic disorders.

Molecular Mechanisms, Biomarkers and Emerging Therapies for Chemotherapy Resistant TNBC

Triple-negative breast cancer (TNBC) is associated with high recurrence rates, high incidence of distant metastases, and poor overall survival (OS). Taxane and anthracycline-containing chemotherapy (CT) is currently the main systemic treatment option for TNBC, while platinum-based chemotherapy showed promising results in the neoadjuvant and metastatic settings. An early arising of intrinsic or acquired CT resistance is common and represents the main hurdle for successful TNBC treatment. Numerous mechanisms were uncovered that can lead to the development of chemoresistance. These include cancer stem cells (CSCs) induction after neoadjuvant chemotherapy (NACT), ATP-binding cassette (ABC) transporters, hypoxia and avoidance of apoptosis, single factors such as tyrosine kinase receptors (EGFR, IGFR1), a disintegrin and metalloproteinase 10 (ADAM10), and a few pathological molecular pathways. Some biomarkers capable of predicting resistance to specific chemotherapeutic agents were identified and are expected to be validated in future studies for a more accurate selection of drugs to be employed and for a more tailored approach, both in neoadjuvant and advanced settings. Recently, based on specific biomarkers, some therapies were tailored to TNBC subsets and became available in clinical practice: olaparib and talazoparib for BRCA1/2 germline mutation carriers larotrectinib and entrectinib for neurotrophic tropomyosin receptor kinase (NTRK) gene fusion carriers, and anti-trophoblast cell surface antigen 2 (Trop2) antibody drug conjugate therapy for heavily pretreated metastatic TNBC (mTNBC). Further therapies targeting some pathologic molecular pathways, apoptosis, miRNAS, epidermal growth factor receptor (EGFR), insulin growth factor 1 receptor (IGF-1R), and androgen receptor (AR) are under investigation. Among them, phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and EGFR inhibitors as well as antiandrogens showed promising results and are under evaluation in Phase II/III clinical trials. Emerging therapies allow to select specific antiblastics that alone or by integrating the conventional therapeutic approach may overcome/hinder chemoresistance.

Tumor-associated macrophages-mediated CXCL8 infiltration enhances breast cancer metastasis: Suppression by Danirixin

Breast cancer is the most frequent cancer among females and the second most common cause of cancer deaths worldwide. Tumor-associated macrophages (TAMs) are the most abundant immune cell population in the tumor microenvironment, including breast cancer. Breast cancer stem cells (BCSCs) play an important role in regulating breast cancer growth and metastasis, which still remains an obstacle for successful treatment of breast cancer and requires further investigation, as well as the potential therapeutic strategies. Cytokine array validated that C-X-C motif chemokine ligand 8 (CXCL8) is a pivotal chemokine secreted by TAMs, and CXCL8 could enhance breast cancer migration, invasion ability, and epithelial-mesenchymal transition (EMT) in both animal and human breast cancer. In this study, the clinical data firstly indicated that high CXCL8 expression was significantly associated with metastasis and tumor growth in breast cancer patients. Then, we showed that TAMs-released CXCL8 could markedly elevate the migration, invasion and EMT events in breast cancer cells, as well as the self-renewal of BCSCs in vitro. These processes were markedly abrogated by the treatment of Danirixin, a reversible and selective antagonist of CXC chemokine receptor 2 (CXCR2). Consistently, the in vivo analysis confirmed that CXCL8 suppression using Danirixin effectively reduced the tumor growth, lung metastasis and repressed the self-renewal of BCSCs. Collectively, TAMs/CXCL8 could enhance BCSCs self-renewal and breast cancer metastasis, and these effects could be markedly abolished by Danirixin treatment, suppressing breast cancer progression consequently. Therefore, Danirixin could be considered as a novel and effective therapeutic strategy for breast cancer treatment without obvious toxicity to major organs.

Prognostic value of using glucosylceramide synthase and cytochrome P450 family 1 subfamily A1 expression levels for patients with triple-negative breast cancer following neoadjuvant chemotherapy

Neoadjuvant chemotherapy (NACT) has been considered to be the preferred treatment option for early operable triple-negative breast cancer (TNBC). However, resistance to drugs remains to be the barrier to the efficacy of NACT. Glucosylceramide synthase (GCS) and cytochrome P450 family 1 subfamily A1 (CYP1A1) have been previously associated with drug resistance in breast cancer. The present study aimed to explore whether the expression levels of GCS and/or CYP1A1 are associated with the prognosis of TNBC after NACT. Immunohistochemistry was used to detect and measure GCS and CYP1A1 expression. Associations between GCS or CYP1A1 expression and the clinicopathological characteristics, pathological complete response (pCR), clinical complete response (cCR) and disease-free survival (DFS) were analyzed. GCS expression was found to be associated with tumor size (P=0.021) and TNM staging (P=0.042), whilst CYP1A1 expression was associated with lymph node metastasis (P = 0.026) and TNM staging (P=0.034). The expression levels of GCS (P=0.024) and CYP1A1 (P=0.027) were upregulated after NACT. GCS and CYP1A1 expression were positively correlated (P=0.003; r=0.327). No difference was observed between the GCS⁺ (P=0.188) or CYP1A1⁺ group (P=0.073) and the GCS^- or CYP1A1^- group in terms of pCR. However, compared with that in the GCS⁺CYP1A1⁺ group, the pCR was markedly increased in the GCS^-CYP1A1^- group (P=0.031). The cCR was lower in the GCS⁺ (P=0.021) and CYP1A1⁺ groups (P=0.016) compared with in the GCS^- or CYP1A1^- group. The DFS rate (57.9 vs. 65.4%; P=0.049) was lower in the GCS⁺CYP1A1⁺ group compared with that in the GCS^-CYP1A1^- group. However, there was no statistical significance after P-value was adjusted for multiple comparisons using Bonferroni correction. In conclusion, co-expression of GCS and CYP1A1 was associated with pCR and DFS in TNBC, which may serve a role in the prediction of the prognosis of patients with TNBC following treatment with NACT.