Immune checkpoint CD155 promoter methylation profiling reveals cancer-associated behaviors within breast neoplasia.

BACKGROUND: CD155 immune checkpoint has recently emerged as a compelling immunotherapeutic target. Epigenetic DNA methylation changes are recognized as key molecular mechanisms in cancer development. Hence, the identification of methylation markers that are sensitive and specific for breast cancer may improve early detection and predict prognosis. We speculate that CD155 promoter methylation can be a valuable epigenetic biomarker, based upon strong indications for its immunoregulatory functions. METHODS: Methylation analyses were conducted on 14 CpGs sites in the CD155 promoter region by bisulfite pyrosequencing. To elucidate the related gene expression changes, a transcriptional study using RT-qPCR was performed. Statistical analyses were performed to evaluate correlations of CD155 methylation profiles with mRNA expression together with clinical-pathological features, prognosis and immune infiltrate. RESULTS: CD155 promoter methylation profile was significantly associated with SBR grade, tumor size, molecular subgroups, HER2 and hormonal receptors expression status. Low CD155 methylation rates correlated with better prognosis in univariate cox proportional hazard analysis and appeared as an independent survival predictor in cox-regression multivariate analysis. Further, methylation changes at CD155 specific CpG sites were consistent with CD155 membranous mRNA isoform expression status. Statistical analyses also showed a significant association with immune Natural Killer cell infiltrate when looking at the CpG7, CpG8, CpG9 and CpG11 sites. CONCLUSION: Altogether, our results contribute to a better understanding of the impact of CD155 immune checkpoint modality expression in breast tumors, revealing for the first time that specific CpG sites from CD155 promoter may be a potential biomarker in breast cancer monitoring.

Immune checkpoint molecules B7-H6 and PD-L1 co-pattern the tumor inflammatory microenvironment in human breast cancer.

B7-H6 and PD-L1 belong to the B7 family co-stimulatory molecules fine-tuning the immune response. The present work investigates the clinical effect of B7-H6 protein expression with PD-L1 status and the infiltration of natural killer cells as potential biomarkers in breast tumor inflammatory microenvironment. The expression levels of B7-H6 protein by cancer cells and immune infiltrating cells in human breast cancer tissues and evaluate their associations with PD-L1 expression, NK cell status, clinical pathological features and prognosis were explored. The immunohistochemistry labeling method was used to assess B7-H6 and PD-L1 proteins expression by cancer and immune cells. The associations between immune checkpoint, major clinical pathological variables and survival rates were analyzed. B7-H6 protein was depicted in both breast and immune cells. Results showed that Tumor B7-H6 expression is highly associated with Her-2 over expression. B7-H6 + immune cells are highly related to the Scarff-Bloom-Richardson grade and associated with PD-L1 expression and NK cells status. Survival analysis revealed a better prognosis in patients with low expression of B7-H6 by cancer cells. Conversely, B7-H6 + immune cells were significantly associated with longer survival. Findings strongly suggest an interaction between B7 molecules that contributes to a particular design of the inflammatory microenvironment. This may influence the efficiency of therapies based on antibodies blocking the PD-L1/PD1 pathway and can explain the detection of clinical benefits only in a fraction of patients treated with immune checkpoint inhibitors.

Prognostic Value of Natural Killer Cells Besides Tumor-Infiltrating Lymphocytes in Breast Cancer Tissues.

BACKGROUND: Each subgroup of immune cells has a different prognostic role in breast cancer; however, the prognostic impact of tumor-infiltrating natural killer cells (TINKs) is still not well established. Our aim was to assess the prognostic impact of natural killer (NK) cells in breast carcinomas. MATERIALS AND METHODS: NK cells infiltration were assessed by immunohistochemistry (IHC). Statistical analyses were performed to evaluate the correlation of NK cells with clinical-pathological features and outcome. RESULTS: CD56 IHC was realized in 126 patients. NK cells infiltration showed significant and positive association with tumor high Scarff-Bloom-Richardson (SBR) grade. NK cells were significantly associated with HER2-positive breast cancer and triple-negative breast cancer subtypes. Analyses showed significant and inverse correlation with progesterone and estrogen receptors expression status. High NK cells were significantly related to high Ki-67 labeling index. Our data showed that high NK cells infiltrate was significantly associated with tumor-infiltrating lymphocytes in breast cancer tissues. At a median follow-up of 5.5 years, high CD56 expression (≥ 5 cells/10 high power field) was associated significantly with a good overall survival and with good disease-free survival. CONCLUSION: In this study, we assessed the important prognostic role of TINKs in breast carcinomas, which seems to be evident despite its association with aggressive pathological features. Thus evaluation of NK cells can be standardized and integrated in daily routine.

CD155 expression in human breast cancer: Clinical significance and relevance to natural killer cell infiltration.

AIMS: CD155 is a ligand of the NK activating receptor DNAM-1, it has been described in a variety of human malignancies, but its expression in breast cancer remains unclear and poorly studied. MAIN METHODS: CD155 expression and NK cells infiltration were investigated in 158 patients with breast cancer by immunohistochemistry (IHC). Statistical analyses were performed to evaluate correlations of CD155 expression with clinical-pathological features, prognosis and tumor immunity. KEY FINDINGS: Tumor cytoplasmic CD155 (cyt-CD155) was associated with lymphovascular invasion (p = 0.011), and membranous CD155 (m-CD155) was strongly correlated with the presence of Tumor Infiltrating natural killer cells (NK-TILs) (p = 0.0003). Survival analysis demonstrated that patients with high cyt-CD155 had a significantly worse overall survival (p < 0.001) and death free survival (p = 0.014) than those with low expression, while high levels of m-CD155 correlated with a better prognosis (p = 0.037). Furthermore, we found that patients with m-CD155Low/NKLow tumors had a significantly reduced overall survival (p = 0.012). Multivariate analysis showed that positive tumor m-CD155 status was a significant independent marker of good prognosis. Meanwhile, high cyt-CD155 expression was identified as an independent poor prognostic predictor, suggesting a key role in this malignancy. SIGNIFICANCE: Altogether, our results revealed that cyt-CD155 was associated with invasiveness and poorer prognosis, but the concomitant presence of m-CD155 and NK-TILs had an opposite prognostic relevance in breast cancer. These results raised the importance of CD155 IHC analysis to elucidate biomarker localization, leading to better understand and design therapeutic molecule targeting CD155 in breast tumors.

Imipenem toxicity in male reproductive organs as a result of inflammatory microenvironment and oxidative stress in germinal cells.

Imipenem is a beta-Lactam antibiotic characterized by a broad spectrum of activity. It is prescribed to treat severe infections. Our goal is to investigate toxicity induced in male rat reproductive systems following exposure to this drug (15, 50 or 100 mg/kg) compared to gentamicin (50 mg/kg) treatment. Effects of imipenem on reproductive organ weights, histoarchitecture, sperm parameters, and oxidative stress parameters were evaluated. Serum testosterone levels were measured. Apoptosis and inflammatory behaviors were investigated by immunohistochemical proteins expression analysis of apoptosis regulator BAX (Bax), B-cell lymphoma 2 (Bcl-2), and interleukin-1 beta (IL-1 beta) in testis. Results showed a significant decrease in male fertility parameters including sperm count, sperm motility, reproductive organ weights and serum testosterone levels after imipenem administration as compared to the control and gentamicin treated groups. Increased sperm abnormality was significant in animals treated with high doses of imipenem. Oxidative stress analysis revealed an expressed increase in lipid peroxidation and carbonyl groups levels in testicular tissues compared to control. Similar results were observed with superoxide dismutase and catalase activities from testicular tissues. In addition, severe testicular lesions were observed in the seminiferous tubules as well as important impairments in spermatogenesis testifying an inflammatory microenvironment confirmed by the intensive expression of IL1-beta and Bax protein by germinal cells and Bcl-2 by Leydig cells. In conclusion, imipenem treatment with high doses was found to lead to oxidative stress in male reproductive organs and an inflammatory microenvironment leading to spermatogenesis dysfunction and histopathological changes in the testis.