The Role and Therapeutic Targeting of CCR5 in Breast Cancer

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.

Targeting CCR5: A central approach to HIV treatment and cure strategies

CCR5, a co-receptor critical for R5-tropic HIV entry into host cells, remains a key target for therapeutic interventions. HIV utilizes CCR5, expressed on T cells and macrophages, to facilitate viral entry. Genetic variants, such as the CCR5Δ32 homozygous mutation that confers protection to HIV infection, have made CCR5 a main target for gene-editing technologies, small-molecule inhibitors, and monoclonal antibody-based therapies. Recent studies emphasize the importance of regulating CCR5 expression at transcriptional and post-transcriptional levels and integrating this approach with traditional therapies. Particularly, the role of heterozygous CCR5Δ32 carriers who are HIV seropositive highlights the potential for targeting CCR5 in combination with other immune-regulatory mechanisms. This may lead to more effective treatment strategies and, ultimately, a functional cure for HIV. This minireview discusses the role of CCR5 in HIV pathogenesis and explores the potential of genetic and therapeutic interventions targeting CCR5 as an innovative strategy in the continued battle against HIV.

Association of the SNPs in CCL2 and CXCL12 genes with the susceptibility to breast cancer: a case-control study in China

Background

Chemokines are well-known for playing an essential role in the development of cancer. However, the association between SNPs in the CCL2 and CXCL12 genes and the susceptibility to breast cancer remains unclear.

Methods

A case-control study was conducted in southeast China, including 1855 breast cancer patients and 1838 cancer-free controls. The association between single nucleotide polymorphisms (SNPs) in the CCL2 and CXCL12 genes and the susceptibility to breast cancer was investigated using logistic regression models. The association between plasma CCL2 and CXCL12 with breast cancer was further examined in 72 patients and 75 controls.

Results

The CXCL12 SNP rs3740085 was associated with breast cancer in the additive model (OR=1.15, 95%CI=1.01-1.32), particularly in postmenopausal women. The association between rs1024611 in CCL2 and breast cancer was only found in women with a BMI of ≥24kg/m2. SNPs in the CCL2 gene were mainly associated with PR-positive breast cancer, whereas rs1144471 in CXCL12 was associated with ER-negative (OR=0.43, 95% CI=0.23-0.84), PR-negative (OR=0.38, 95% CI=0.19-0.74), and HER-2-positive (OR=1.27, 95% CI=1.03-1.56) breast cancer. The interaction between rs1801157 and rs3740085 in CXCL12 SNPs was statistically significant, and rs3740085 was also associated with breast cancer survival. Additionally, we found a strong association between plasma CXCL12 and breast cancer.

Conclusion

CCL2 and CXCL12 SNPs are associated with breast cancer susceptibility in overweight and postmenopausal women, and the effect varies according to subtypes. The interaction of SNPs within CXCL12 gene and the association with breast cancer survival further suggest potential targets for improved risk assessment and treatment strategies.

Development of a Sensitive Anti-Mouse CCR5 Monoclonal Antibody for Flow Cytometry

C-C chemokine receptor 5 (CCR5), a member of the G protein-coupled receptor family, is the most common coreceptor for the human immunodeficiency virus type 1. CCR5 is also involved in the pathogenesis of tumors and inflammatory diseases. The CCR5 antagonists including monoclonal antibodies (mAbs) have been developed and evaluated in clinical trials. In this study, we developed novel mAbs for mouse CCR5 (mCCR5) using the Cell-Based Immunization and Screening (CBIS) method. One of the established anti-mCCR5 mAbs, C5Mab-2 (rat IgG2b, kappa), reacted with mCCR5-overexpressed Chinese hamster ovary-K1 (CHO/mCCR5) and an endogenously mCCR5-expressing cell line (L1210) by flow cytometry. Using flow cytometry, the dissociation constant (KD) of C5Mab-2 for CHO/mCCR5 was determined as 4.3 × 10-8 M. These results indicated that C5Mab-2 is useful for the detection of mCCR5 in flow cytometry and may be applicable to obtain the proof of concept in preclinical studies.

Development of Sensitive Anti-Mouse CCR5 Monoclonal Antibodies Using the N-Terminal Peptide Immunization

One of the G protein-coupled receptors, C-C chemokine receptor 5 (CCR5), is an important regulator for the activation of T and B lymphocytes, dendritic cells, natural killer cells, and macrophages. Upon binding to its ligands, CCR5 activates downstream signaling, which is an important regulator in the innate and adaptive immune response through the promotion of lymphocyte migration and the secretion of proinflammatory cytokines. Anti-CCR5 monoclonal antibodies (mAbs) have been developed and evaluated in clinical trials for tumors and inflammatory diseases. In this study, we developed novel mAbs for mouse CCR5 (mCCR5) using the N-terminal peptide immunization. Among the established anti-mCCR5 mAbs, C5Mab-4 (rat IgG2a, kappa) and C5Mab-8 (rat IgG1, kappa), recognized mCCR5-overexpressing Chinese hamster ovary-K1 (CHO/mCCR5) and an endogenously mCCR5-expressing cell line (L1210) by flow cytometry. The dissociation constant (KD) values of C5Mab-4 and C5Mab-8 for CHO/mCCR5 were determined as 3.5 × 10-8 M and 7.3 × 10-9 M, respectively. Furthermore, both C5Mab-4 and C5Mab-8 could detect mCCR5 by western blotting. These results indicated that C5Mab-4 and C5Mab-8 are useful for detecting mCCR5 by flow cytometry and western blotting and provide a possibility to obtain the proof of concept in preclinical studies.

In ovarian cancer maraviroc potentiates the antitumoral activity and further inhibits the formation of a tumor-promoting microenvironment by trabectedin

Ovarian cancer (OC) is the fifth most frequent cause of cancer-related death in women. Chemotherapy agent trabectedin, affecting cancer cells and tumor microenvironment, has been approved for the treatment of relapsed platinum-sensitive OC patients. CCR5-antagonist maraviroc inhibits tumor growth, metastasis, and enhances the antitumoral activity of DNA-damaging drugs. Here, we found that OC cells expressed CCR5 receptor but did not secret CCR5-ligands. Maraviroc treatment did not affect OC cell viability, but strongly potentiated the antiproliferative activity, apoptosis induction, cell cycle blockage, DNA damage, and ROS formation by trabectedin. In A2780cis cisplatin-resistant cells, the cross-resistance to trabectedin was overcame by the combination with maraviroc. Maraviroc enhanced trabectedin cytotoxicity in OC 3Dimensional spheroids and THP-1-monocytes. Both maraviroc and trabectedin interact with drug efflux pump MDR1/P-gp, overexpressed in recurrent OC patients. Maraviroc increased trabectedin intracellular accumulation and the MDR1-inhibitor verapamil, like maraviroc, increased trabectedin cytotoxicity. In OC tumor xenografts the combination with maraviroc further reduced tumor growth, angiogenesis, and monocyte infiltration by trabectedin. In conclusion, this study offers a preclinical rationale for the use of maraviroc as new option to improve trabectedin activity in relapsed chemoresistant OC patients.