Biology subjects

Braga, S.

Publications and source records attributed to Braga, S..

3 recordsLinked to original sources

bioRxiv2021

Determination of HLA-DR level in cytotoxic T lymphocytes: a new validated tool to predict breast cancer response to treatment

BackgroundNeoadjuvant chemotherapy (NACT) is the usual treatment for locally-advanced breast cancer (BC). However, more than half of the patients lack an effective response to this treatment. Thus, its urgent to find predictive biomarkers. Recently, we proposed the HLA-DR expression level in cytotoxic T lymphocytes (CTLs) as a robust biomarker to select, in advance, patients that will actually benefit from NACT. Patients and MethodsA total of 202 BC patients, 102 of which submitted to NACT, were enrolled in this study. 61 biopsies and 41 blood samples collected pre-NACT and 100 non-NACT tumor samples were immunophenotyped by flow cytometry. Both NACT and non-NACT patients were followed up for 34 months. Blood-isolated immune cells were cultured with BC cell lines in a 3D system. ResultsHere we confirmed that HLA-DR level in CTLs is a highly sensitive and specific biomarker to predict BC response to NACT, reflected in circulation and independent of the patients age, BC subtype and other tumor-immunological features. Therefore, we developed a predictive probability model, based on the determination of HLA-DR level in tumor-infiltrating CTLs, that could be used to guide therapeutic decisions. Interestingly, this biomarker was also associated with progression-free survival, regardless the treatment. Contrary to HLA-DRnegative CTLs, HLA-DR+ CTLs were able to reduce the viability of tumor cells, in culture, in agreement with their higher expression of activation, proliferation and cytotoxicity-related molecules. Tissue-residency and memory markers were also increased in HLA-DR+ CTLs. These anti-tumor features of HLA-DR+ CTLs may justify the clinical observations. ConclusionHLA-DR level in CTLs is a validated and independent biomarker to predict response to NACT which allow the establishment of a clinical meaningful tool to select in advance patients that will truly benefit from this treatment. Intriguingly, it may be further used as a biomarker of BC patients general prognosis. Highlights- HLA-DR level in cytotoxic T cells is an independent predictive factor of breast cancer response to NACT - A predictive probability model based on this biomarker was developed as a new tool to improve treatment decisions - HLA-DR level in cytotoxic T cells is also reflected systemically - HLA-DR level in cytotoxic T cells is also a prognostic factor, associated with progression-free survival - HLA-DR+ cytotoxic T cells exhibit several phenotypic and functional anti-tumor characteristics

immunology↗

bioRxiv2021

Circulating Low Density Neutrophils of Breast Cancer Patients are Associated with their Worse Prognosis due to the Impairment of T cell Responses

Neutrophils are prominent immune components of solid tumors, which can protect against the onset of cancer (N1) or have pro-tumor activity (N2). Circulating neutrophils, divided into high density neutrophils (HDN) and low density neutrophils (LDN), functionally mirror those N1 and N2 cells, respectively. LDN, a rare subset in non-pathological conditions, have been extensively studied in cancer, due to their frequency in this disease and their pro-tumor phenotype. However, this has been mainly demonstrated in animal models and proper validation in humans is an urgent need. Here, we further enlighten the clinical impact of LDN in a cohort of breast cancer (BC) patients. We observed that LDN were practically absent in healthy donors blood, while were significantly increased in the blood of BC patients, particularly with metastatic disease. Relevant for a clinical translation, within the population of non-metastatic patients, LDN were more prevalent in patients with poor response to neoadjuvant chemotherapy than in responders. The association of a higher incidence of circulating LDN and the worse prognosis of BC patients could be explained by the pro-tumor/immunosuppressive characteristics exhibited by these cells. Namely, there are more LDN expressing the immunosuppressive marker PD-L1, than HDN. Additionally, LDN also showed increased expression of activation markers; a robust formation of neutrophil extracellular traps; an augmented phagocytic activity; and a higher capacity to release reactive oxygen species, which may contribute for tumor development and metastization. Moreover, the percentage of LDN in BC patients blood was negatively correlated with activated cytotoxic T lymphocytes and positively correlated with the immunosuppressive CCR4+ regulatory T cells, corroborating their impairment on the anti-tumor immune responses, which was further demonstrated ex vivo. Hence, this study reveals the potential of LDN as a clinical meaningful biomarker of BC response to treatment and opens new avenues for developing targeted immunotherapies.

immunology↗

bioRxiv2020

Differential expression between African-ancestry and White patients diagnosed with Triple-Negative Breast Cancer: EGFR, Myc, Bcl2 and β-Catenin as ancestry-associated markers

PurposeTriple-negative breast cancer (TNBC) has a higher incidence, a younger age of onset, and a more aggressive behavior in African-ancestry women. Biological disparities have been suggested as an important factor influencing the ancestry-associated TNBC discrepancy. In this study, we sought to identify ancestry-associated differential gene and protein expression between African-ancestry and White TNBC patients, controlling for patients menopause status and pathological staging at diagnosis. MethodsDifferential gene expression analyses (DGEA) were performed using RNA-sequencing data from The Cancer Genome Atlas (TCGA). Gene set enrichment analysis (GSEA) and Ingenuity Pathway Analysis (IPA), with focus on network design, were performed to highlight candidate genes for further validation through immunohistochemistry of TNBC samples from patients followed in Portugal. ResultsWith 52 African-American and 90 White TNBC patients included, TCGAs data corroborate that African-American patients have a higher TNBC incidence (28.42% vs 11.89%, p<0.0001). Particularly, premenopausal and stage II disease African-American patients also have significantly lower survival probability, comparing with White patients (log-rank p=0.019 and 0.0038, respectively). DGEA results suggest that expression profile differences are more associated with TNBC staging than with patients menopause status. Hippo pathway and cellular community gene sets are downregulated, while breast cancer gene set is upregulated in African-Americans, comparing with White TNBC patients. Furthermore, MAPK pathway gene set is upregulated when controlling for stage II disease. Due to their central role in highly scored networks resulted from IPAs network design, EGFR, Myc and Bcl2 genes were selected for further validation through immunohistochemistry. We also included {beta}-Catenin in the validation study as it is consensually reported to be required in TNBC tumorigenesis. Although patients used in the DGEA and in the immunohistochemistry experiments are geographically and culturally distinct, both groups of African-ancestry patients are mostly of western-African ancestry and, interesting, differential gene and protein expression matched. ConclusionsWe found ancestry-associated gene expression patterns between African-ancestry and White TNBCs, particularly when controlling for menopause status or staging. EGFR, Myc, Bcl2 and {beta}-catenin gene and protein differential expression matching results in distinct populations suggest these markers as being important indicators of TNBCs ancestry-associated development.

cancer biology↗