Expression characteristic of CXCR1 in different breast tissues and the relevance between its expression and efficacy of neo-adjuvant chemotherapy in breast cancer

Clinical significance of the CXCL8/CXCR1/R2 signalling axis in patients with invasive breast cancer

The C-X-C motif chemokine ligand 8 (CXCL8)-C-X-C chemokine receptor (CXCR)1/2 signalling axis is among numerous mechanisms which stimulate the immune system to defend against tumour growth and influence the tumour microenvironment to promote tumour growth. This pathway plays an important role in the development of a number of cancers including breast cancer (BC). The aim of the present study was to analyse the levels of the chemokine CXCL8 and its receptors, CXCR1 and CXCR2, in the serum of female patients with invasive BC and to assess the expression of these parameters at the mRNA level, considering molecular subtypes and degrees of cancer malignancy. The study group consisted of 62 patients with histopathologically confirmed invasive BC. The control group consisted of 18 patients with histopathologically confirmed fibroadenoma, a benign breast tumour. The levels of CXCL8, CXCR1 and CXCR2 were determined by sandwich ELISA using the CLOUD-CLONE ELISA kit. CXCL8, CXCR1 and CXCR2 transcript levels were analysed using reverse transcription-quantitative PCR. Results showed that serum CXCL8 levels in female patients with invasive BC were significantly higher compared with those in the control group (P<0.05). In addition, significantly elevated CXCR1 levels were observed in luminal B human epidermal growth factor receptor 2+ carcinoma compared with those in the control group. Analysis of CXCL8 in the serum of female patients with BC showed a statistically significant difference between clinical stage G1 and G2 (P<0.05), G2 and G3 (P<0.01), and G1 and G3 (P<0.0001). On the other hand, the analysis of CXCR1 and CXCR2 levels in the serum of the patients revealed a statistically significant difference between G2 and G3 (P<0.05). The current study showed that abnormalities in the immune response involving the CXCL8-CXCR1/2 signalling axis in patients with invasive BC are involved in the development of these tumours. Moreover, the demonstrated severity of changes occurring at protein level may suggest the potential usefulness of their determination as potential diagnostic markers in the clinic.

CXCR1: A Cancer Stem Cell Marker and Therapeutic Target in Solid Tumors

Therapy resistance is a significant concern while treating malignant disease. Accumulating evidence suggests that a subset of cancer cells potentiates tumor survival, therapy resistance, and relapse. Several different pathways regulate these purported cancer stem cells (CSCs). Evidence shows that the inflammatory tumor microenvironment plays a crucial role in maintaining the cancer stem cell pool. Typically, in the case of the tumor microenvironment, inflammatory pathways can be utilized by the tumor to aid in tumor progression; one such pathway is the CXCR1/2 pathway. The CXCR1 and CXCR2 receptors are intricately related, with CXCR1 binding two ligands that also bind CXCR2. They have the same downstream pathways but potentially separate roles in the tumor microenvironment. CXCR1 is becoming more well known for its role as a cancer stem cell identifier and therapeutic target. This review elucidates the role of the CXCR1 axis as a CSC marker in several solid tumors and discusses the utility of CXCR1 as a therapeutic target.

Tackling Immune Targets for Breast Cancer: Beyond PD-1/PD-L1 Axis

The burden of breast cancer is imposing a huge global problem. Drug discovery research and novel approaches to treat breast cancer have been carried out extensively over the last decades. Although immune checkpoint inhibitors are showing promising preclinical and clinical results in treating breast cancer, they are facing multiple limitations. From an immunological perspective, a recent report highlighted breast cancer as an "inflamed tumor" with an immunosuppressive microenvironment. Consequently, researchers have been focusing on identifying novel immunological targets that can tune up the tumor immune microenvironment. In this context, several novel non-classical immune targets have been targeted to determine their ability to uncouple immunoregulatory pathways at play in the tumor microenvironment. This article will highlight strategies designed to increase the immunogenicity of the breast tumor microenvironment. It also addresses the latest studies on targets which can enhance immune responses to breast cancer and discusses examples of preclinical and clinical trial landscapes that utilize these targets.

Comprehensive analysis of the prognostic value and immune function of chemokine-CXC receptor family members in breast cancer

Recently, immune checkpoint inhibitors (ICIs) have been successfully used for treating melanoma. Unfortunately, many breast cancer (BC) patients show low response to ICIs due to the lack of infiltrating immune cells. Previous studies revealed that chemokine-CXC receptors (CXCRs) play a crucial role in leukocyte infiltration and promote cancer cell proliferation, migration, metastasis, and angiogenesis. However, the underlying functions of CXCRs in cancer-immunity cycle remain unclear. In this study, we firstly found that in comparison to normal tissues, BC tissues, especially basal-like BC, showed increased mRNA levels of CXCR3/4/5/6/8, but decreased CXCR1/2/7 expression using UALCAN and TIMER database. Interestingly, it's was found that the mRNA levels of CXCR3/4/5/6 were decreased in lymphocyte depleted of the BC immune subtype. Subsequently, functional enrichment analysis of distinct CXCRs indicated that CXCR3/4/5/6 were strongly associated to immune-related biological functions. Therefore, further analysis using TIMER and TISIDB database suggested that CXCR3/4/5/6 expression were strongly correlated with tumor-infiltrating lymphocytes (TILs) and immune checkpoints in BC. Finally, Kaplan-Meier Plotter analysis indicated that high mRNA expression of CXCR4 predicted worse relapse-free survival (RFS), whereas CXCR3/5/6 indicated better RFS in BC patients. These findings suggest a therapeutic value for CXCR3/4/5/6 in combination with ICIs for the treatment of BC.

Engineering a Nanostructured Nucleolin-Binding Peptide for Intracellular Drug Delivery in Triple-Negative Breast Cancer Stem Cells

Five peptide ligands of four different cell surface receptors (nucleolin, CXCR1, CMKLR1, and CD44v6) have been evaluated as targeting moieties for triple-negative human breast cancers. Among them, the peptide F3, derived from phage display, promotes the fast and efficient internalization of a genetically fused green fluorescent protein (GFP) inside MDA-MB-231 cancer stem cells in a specific receptor-dependent fashion. The further engineering of this protein into the modular construct F3-RK-GFP-H6 and the subsequent construct F3-RK-PE24-H6 resulted in self-assembling polypeptides that organize as discrete and regular nanoparticles. These materials, 15-20 nm in size, show enhanced nucleolin-dependent cell penetrability. We show that the F3-RK-PE24-H6, based on the Pseudomonas aeruginosa exotoxin A (PE24) as a core functional domain, is highly cytotoxic over target cells. The combination of F3, the cationic peptide (RK)n, and the toxin domain PE24 in such unusual presentation appears as a promising approach to cell-targeted drug carriers in breast cancers and addresses selective drug delivery in otherwise difficult-to-treat triple-negative breast cancers.

Insights on CXC chemokine receptor 2 in breast cancer: An emerging target for oncotherapy

Breast cancer is the most common malignant neoplasm in women worldwide, and the treatment regimens currently available are far from optimal. Targeted therapy, based on molecular typing of breast cancer, is the most precise form of treatment, and CXC chemokine receptor 2 (CXCR2) is one of the molecular markers used in targeted therapies. As a member of the seven transmembrane G-protein-coupled receptor family, CXCR2 and its associated ligands have been increasingly implicated in tumor-associated processes. These processes include proliferation, angiogenesis, invasion, metastasis, chemoresistance, and stemness and phenotypic maintenance of cancer stem cells. Thus, the inhibition of CXCR2 or its downstream signaling pathways could significantly attenuate tumor progression. Therefore, studies on the biological functions of CXCR2 and its association with neoplasia may help improve the prognosis of breast cancer. Furthermore, the targeting of CXCR2 could supplement the present clinical approaches of breast cancer treatment strategies. The present review discusses the structures and mechanisms of CXCR2 and its ligands. Additionally, the contribution of CXCR2 to the development of breast cancer and its potential therapeutic benefits are also discussed.

Comprehensive Analysis of Core Genes and Potential Mechanisms in Rectal Cancer

Rectal cancer is a common type of colorectal cancer with high mortality and morbidity. The objective of this study was to identify gene signatures and uncover the potential mechanisms during rectal cancer samples. The gene expression profiles of GSE87211 data set were downloaded from GEO (Gene Expression Omnibus) database. The GSE87211 data set contained 2363 samples, including 203 rectal cancer samples and 160 matched mucosa control samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted, and protein-protein interaction network of differentially expressed genes (DEGs) was performed by Cytoscape. Then, Gene Expression Profiling Interactive Analysis (GEPIA) was applied to get the hub genes expression level and survival analysis between rectum adenocarcinoma (READ) tissues and normal tissues. In total, 846 DEGs were identified, including 402 upregulated genes and 444 downregulated genes. GO analysis showed that upregulated DEGs were enriched in inflammatory response, signal transduction, cell adhesion, immune response, and positive regulation of cell proliferation. KEGG pathway analysis showed that upregulated DEGs were enriched in cytokine-cytokine receptor interaction, Pi3K-Akt signaling pathway, and chemokine signaling pathway. The top 20 hub genes contained IL8, CXCR1, SSTR2, SST, CXCR2, GALR1, GAL, CXCL1, SSTR1, NPY1R, NPY, AGT, PPY, PPBP, CXCL2, CXCL6, CXCL11, CXCL3, GNG4, and GNGT1, and only four genes significantly increased expression levels with obvious changes of survival analysis in READ tissues based on GEPIA. Our study indicated that identified DEGs might promote our understanding of molecular mechanisms, which might be used as molecular targets or diagnostic biomarkers for the treatment of rectal cancer.

EGFR and CXCR1 expression in thyroid carcinoma in Qassim Region-Saudi Arabia: Correlation with clinicopathological parameters

AIMS

Recent evidence indicates an increased incidence of thyroid carcinoma, especially papillary thyroid carcinoma (PTC), in Saudi Arabia. EGFR and CXCR1 were reported to have increased expression in several human neoplasms. The goals of the present research was to investigate EGFR and CXCR1 expression in thyroid carcinoma and correlate the results to the established prognostic factors.

METHODS

Immunohistochemical study for both EGFR and CXCR1 was performed on formalin-fixed paraffin-embedded thyroid carcinomas tissues sections applying Labeled Streptavidin-biotin method (LSAB).

RESULTS

Remarkable high expression of EGFR and CXCR1 were observed in PTC cases (56% and 63% respectively). There was association between EGFR expression in PTC and each of histologic subtype, lymph node metastasis (LNM), distant metastasis (DM), TNM staging and tumor relapse. There was statistical significant correlation between CXCR1 expression in PTC and each of histologic subtype, LNM, and tumor relapse. A significant correlation was detected between concomitant EGFR and CXCR expression and LNM, DM, increasing stage and tumor relapse.

CONCLUSIONS

The results of the present study demonstrated, a statistically positive correlation of EGFR and CXCR1 expression in PTC compared to normal thyroid tissues and nodular hyperplasia in Qassim Region- Saudi Arabia. Concomitant high expression of both receptors were strongly correlated with LNM, DM, TNM stage and tumor relapse than did each alone. These findings suggest that EGFR and CXCR1 play crucial roles in PTC and serve as predictors of poor prognosis, biomarkers of tumor diagnosis, and potential targets of cancer therapeutics.

Chemokines Modulate Immune Surveillance in Tumorigenesis, Metastasis, and Response to Immunotherapy

Chemokines are small secreted proteins that orchestrate migration and positioning of immune cells within the tissues. Chemokines are essential for the function of the immune system. Accumulating evidence suggest that chemokines play important roles in tumor microenvironment. In this review we discuss an association of chemokine expression and activity within the tumor microenvironment with cancer outcome. We summarize regulation of immune cell recruitment into the tumor by chemokine-chemokine receptor interactions and describe evidence implicating chemokines in promotion of the "inflamed" immune-cell enriched tumor microenvironment. We review both tumor-promoting function of chemokines, such as regulation of tumor metastasis, and beneficial chemokine roles, including stimulation of anti-tumor immunity and response to immunotherapy. Finally, we discuss the therapeutic strategies target tumor-promoting chemokines or induce/deliver beneficial chemokines within the tumor focusing on pre-clinical studies and clinical trials going forward. The goal of this review is to provide insight into comprehensive role of chemokines and their receptors in tumor pathobiology and treatment.

CAV2 promotes the growth of renal cell carcinoma through the EGFR/PI3K/Akt pathway

Background

Caveolin-2 (CAV2) is reported to have an important role in cancer. The following study investigated the expression and function of CAV2 in kidney cancer in vitro and in vivo.

Materials and methods

Real-time PCR, immunohistochemistry and Western blotting analysis were used to determine CAV2, epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) in kidney cancer cell line OS-RC-2 and clinical specimens. The role of CAV2 in maintaining kidney cancer malignant phenotype was examined by wound healing assay, Matrigel invasion assays and mouse orthotopic xenograft model.

Results

Higher expression of CAV2 was found in renal cell carcinoma tissue compared to normal tissue. Furthermore, increased expression of CAV2 was associated with cancer progression. Also, silencing of CAV2 inhibited the proliferation, migration and invasion, as well as the expression of EGFR, PI3K and p-Akt in OS-RC-2 cells in vitro, and OS-RC-2 xenograft growth in vivo.

Conclusion

Our results revealed that CAV2 promotes the growth of renal cell carcinoma through EGFR/PI3K/Akt pathway.

ALG3 Is Activated by Heat Shock Factor 2 and Promotes Breast Cancer Growth

BACKGROUND Previous research found that ALG3 is associated with cervical cancer, but the role of ALG3 in breast cancer was still unknown. MATERIAL AND METHODS The expression of ALG3 in breast carcinoma tissues was determined by immunochemistry. The ability of cellular proliferation, migration, and invasion was determined by CCK-8 assay, wound healing migration assay, and cell invasion assays, respectively. The binding between HSF2 and promoter of ALG3 was determined by ChIP assay. RESULTS There was an increased expression of ALG3 in breast cancer tissues compared to normal breast tissues (p<0.05). High expression of ALG3 was significantly correlated with poor OS (p<0.05). ALG3 expression was significantly increased in cancer samples with advanced stages (stage III/IV) compared with those in the early stages of disease (stage I/II) (p<0.05). The staining intensity of ALG3 was significantly correlated to the tumor grade (grades 2-3 versus 1, p<0.05). Silencing ALG3 or HSF2 inhibited the proliferation, migration, and invasion abilities of MCF-7 cells. Silencing ALG3 retarded the growth of MCF-7 cells in vivo. CONCLUSIONS Silencing ALG3 inhibited MCF-7 cells growth in vitro and in vivo. HSF2 activated ALG3 and promoted the growth of breast carcinoma.

SPP1 promotes ovarian cancer progression via Integrin β1/FAK/AKT signaling pathway

OBJECTIVES

Ovarian cancer is one of the most lethal malignant tumors in women. Secreted phosphoprotein 1 (SPP1) plays an important role in some cancer types. Therefore, the role of SPP1 in ovarian cancer was determined and the potential mechanism was elucidated.

MATERIALS AND METHODS

The expression of SPP1 in ovarian cancer was determined by immunohistochemistry in ovarian cancer tissues and normal ovarian tissues. Cellular proliferation, migration, and invasion were determined by cell counting kit-8 assay, wound healing assay, and Matrigel invasion assay in SKOV3 and A2780 cells. The protein expression of SPP1, integrin subunit β1 (Integrin β1), focal adhesion kinase (FAK), and phosphorylation protein kinase B (p-AKT) was detected by Western blotting in SKOV3 cells after silencing SPP1. The expression of SPP1 was determined in SKOV3 cells after transfecting with miR-181a mimics or inhibitors. The growth of SKOV3 cells in vivo was determined in a nude mouse model of ovarian cancer after silencing SPP1.

RESULTS

The expression of SPP1 was higher in epithelial ovarian cancer tissues than in normal ovarian tissues. Silencing SPP1 decreased the cell proliferation, migration, and invasion. Ectopic expression of SPP1 increased the cell proliferation, migration, and invasion. Silencing SPP1 prevented ovarian cancer growth in mice. Silencing SPP1 inhibited Integrin β1/FAK/AKT pathway. In agreement, ectopically expressed SPP1 activated Integrin β1/FAK/AKT pathway. Also, SPP1 was regulated by miR-181a.

CONCLUSION

SPP1 is a biomarker for the prognosis of ovarian cancer. It is also oncogenic and a potential target for ovarian cancer therapy.