FOXP3+ Tregs and B7-H1+/PD-1+ T lymphocytes co-infiltrate the tumor tissues of high-risk breast cancer patients: Implication for immunotherapy

<p>Abstract</p> <p>Background</p> <p>Recent studies have demonstrated a direct involvement of B7-H1, PD-1 and FOXP3 molecules in the immune escape of cancer. B7-H1 is an inhibitory molecule that binds to PD-1 on T lymphocytes, while FOXP3 is a marker for regulatory T cells (T_regs). We have previously demonstrated the association of B7-H1-expressing T infiltrating lymphocytes (TIL) with high-risk breast cancer patients while other studies reported the involvement of FOXP3+ T_regsas a bad prognostic factor in breast tumors. Although the co-existence between the two types of cells has been demonstrated <it>in vitro </it>and animal models, their relative infiltration and correlation with the clinicopathological parameters of cancer patients have not been well studied. Therefore, we investigated TIL-expressing the B7-H1, PD-1, and FOXP3 molecules, in the microenvironment of human breast tumors and their possible association with the progression of the disease.</p> <p>Methods</p> <p>Using immunohistochemistry, tumor sections from 62 breast cancer patients were co-stained for B7-H1, PD-1 and FOXP3 molecules and their expression was statistically correlated with factors known to be involved in the progression of the disease.</p> <p>Results</p> <p>A co-existence of B7-H1⁺T lymphocytes and FOXP3⁺T_regswas evidenced by the highly significant correlation of these molecules (<it>P </it>< .0001) and their expression by different T lymphocyte subsets was clearly demonstrated. Interestingly, concomitant presence of FOXP3⁺T_regs, B7-H1⁺and PD-1⁺TIL synergistically correlated with high histological grade (III) (<it>P </it>< .001), estrogen receptor negative status (<it>P </it>= .017), and the presence of severe lymphocytic infiltration (<it>P </it>= .022).</p> <p>Conclusion</p> <p>Accumulation of TIL-expressing such inhibitory molecules may deteriorate the immunity of high-risk breast cancer patients and this should encourage vigorous combinatorial immunotherapeutic approaches targeting T_regsand B7-H1/PD-1 molecules.</p

Translational Implications of Dysregulated Pathways and microRNA Regulation in Quadruple-Negative Breast Cancer

Triple-negative breast cancers (HER2&minus;, ER&minus;, PR&minus;) continue to present a unique treatment challenge and carry unfavorable prognoses. The elucidation of novel therapeutic targets has necessitated the re-evaluation of stratification approaches to best predict prognosis, treatment response and theranostic and prognostic markers. Androgen receptor expression and function have important implications on proliferation, tumor progression, immunity and molecular signaling in breast cancer. Accordingly, there has been increasing support for classification of androgen receptor-negative triple-negative breast cancer or quadruple-negative breast cancer (QNBC). QNBC has unique molecular, signaling and expression regulation profiles, particularly those affected by microRNA regulatory networks. microRNAs are now known to regulate AR-related targets and pathways that are dysregulated in QNBC, including immune checkpoint inhibitors (ICIs), SKP2, EN1, ACSL4 and EGFR. In this review, we explore and define the QNBC tumor subtype, its molecular and clinical distinctions from other subtypes, miRNA dysregulation and function in QNBC, and knowledge gaps in the field. Potential insights into clinical and translational implications of these dysregulated networks in QNBC are discussed

The p53 codon 72 polymorphism is associated with risk and early onset of breast cancer among Saudi women

Breast cancer has a major impact on the health of women worldwide. In the Kingdom of Saudi Arabia (KSA), breast cancer incidence is on the increase and is characterized by early onset and aggressiveness. Owing to the importance of the TP53 gene in breast carcinogenesis, we analyzed the possible link between TP53 single nucleotide polymorphisms (SNPs) and the risk of breast cancer in Saudi women by direct sequencing of the TP53 gene exon 4 from 100 breast cancer tissues. The proportion of the polymorphic forms of SNP72 in the Saudi breast cancer patients were: Arg/Arg (RR), 39%; Pro/Pro (PP), 36%; and Arg/Pro (RP), 25%. The frequencies of these forms in disease-free Saudi women were 7.59, 22.22 and 60.19%, respectively. This indicates that the RR form of the codon 72 polymorphism is a potential risk factor, whereas the RP form is a protection factor against breast cancer among Saudi women (p=0.0001). Moreover, the results have shown that the p53 R72P SNP is significantly associated with the early onset of breast cancer in the Saudi population (p=0.0138). However, the codon 47 polymorphism appears to have no role in this disease among Saudi women. These results indicate that the TP53 gene could play a major role in breast carcinogenesis and the early onset of the disease among Saudi women

Long noncoding RNA DLEU2 and ROR1 pathway induces epithelial-to-mesenchymal transition and cancer stem cells in breast cancer

Abstract Breast cancer (BC) patient who receives chemotherapy for an extended length of time may experience profound repercussions in terms of metastases and clinical outcomes due to the involvement of the epithelial-to-mesenchymal transition (EMT) mechanism and enriched cancer stem cells (CSCs). BC cells that express high levels of lncRNA deleted in lymphocytic leukemia-2 (lncRNA DLEU2) and type I tyrosine kinase-like orphan receptor ROR1 (ROR1) may play roles in the enhanced ability of the activation EMT and CSC induction. Here we find that lncRNA DLEU2 and ROR1 are specifically upregulated in tumor tissues compared to their normal counterparts in TCGA, PubMed GEO datasets, and samples from archived breast cancer tumor tissues. Following chemotherapy, lncRNA DLEU2 and ROR1 were enhanced in BC tumor cells, coupled with the expression of CSCs, EMT-related genes, and BMI1. Mechanistically, ROR1 and lncRNA DLEU2 overexpression led to enhanced tumor cell proliferation, inhibition of apoptosis, cell-cycle dysregulation, chemoresistance, as well as BC cell’s abilities to invade, migrate, develop spheroids. These findings imply that the role of lncRNA DLEU2 and ROR1 in BC therapeutic failure is largely attributed to EMT, which is intricately linked to enriched CSCs. In conclusion, our findings indicate that a lncRNA DLEU2 and ROR1-based regulatory loop governs EMT and CSC self-renewal, implying that targeting this regulatory pathway may improve patients’ responses to chemotherapy and survival

p16INK4A Represses Breast Stromal Fibroblasts Migration/Invasion and Their VEGF-A-dependent Promotion of Angiogenesis through Akt Inhibition

Stromal fibroblasts, the most abundant and probably the most active cellular component of breast cancer-associated stroma, become active and promote angiogenesis through paracrine effects. However, it still unclear how these processes are regulated. Here, we have shown that down-regulation of the tumor suppressor p16INK4A protein enhances the migration/invasion abilities of breast stromal fibroblasts, which form dendritic network of extensions into matrigel. Furthermore, we present clear evidence that p16INK4A represses the expression/secretion of the proangiogenesis protein vascular endothelial growth factor A (VEGF-A). Consequently, p16INK4A-deficient breast stromal fibroblasts and mouse embryonic fibroblasts enhanced endothelial cell differentiation into capillary-like structures in a paracrine manner. This effect was suppressed by adding bevacizumab, a specific VEGF-A inhibitor. Additionally, p16INK4A-defective mouse embryonic fibroblasts enhanced angiogenesis in breast cancer xenografts in mice. Furthermore, we have shown that p16INK4A suppresses the Akt/mammalian target of rapamycin (mTOR) signaling pathway and its downstream effector hypoxia-inducible factor 1-alpha (HIF-1α), which transactivates VEGF-A. Consequently, Akt inactivation suppressed both the p16INK4A-dependent autocrine effect on fibroblast migration/invasion and the paracrine effect on angiogenesis, showing the important role of this protein kinase in mediating the various effects related to p16INK4A deficiency. These results indicate that p16INK4A is an efficient inhibitor of the migration/invasion abilities of breast stromal fibroblasts and also their paracrine proangiogenic effects, through inhibition of Akt. Therefore, pharmacologic restoration of p16INK4A level in stromal fibroblasts may be exploited as therapeutic strategy to help eradicate tumor cells and/or prevent their recurrence, through suppressing cell non-autonomous procarcinogenic mediators