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- HLA-DR in Cytotoxic T lymphocytes predicts breast cancer patients' response to neoadjuvant chemotherapyPublication . Saraiva, Diana P.; Jacinto, António; Borralho, Paula; Braga, Sofia; Cabral, M. GuadalupePrediction of breast cancer response to Neoadjuvant Chemotherapy (NACT) is an urgent need to promptly direct non-responder patients to alternative therapies. Infiltrating T lymphocytes, namely cytotoxic T lymphocytes (CTLs) have been appointed as predictors of response. However, cancer cells have the ability to dampen CTLs' activity and thus, the prognostic value of the CTLs, per se, is debatable. Here, we disclose that more than the occurrence of CTLs, it is their activation state, revealed by HLA-DR expression, that can accurately predict response to NACT. Flow cytometry analysis of breast cancer biopsies showed that the frequency of CTLs and other lymphocytes were similar regardless disease stage and between NACT responders and non-responders. However, only breast cancer patients without axillary lymph node metastasis and NACT responders have HLA-DRhi CTLs. Interestingly, HLA-DR levels in tumor CTLs is correlated with HLA-DR levels in systemic CTLs. These HLA-DR+ CTLs produce IFN-γ and Granzyme B, enlightening their effector and probable anti-tumor activity profile. Moreover, the level of HLA-DR in CTLs is negatively correlated with the level of HLA-DR in T regulatory lymphocytes and with immunosuppressive and pro-tumor molecules in the tumor microenvironment. Hence, HLA-DR levels in CTLs is a highly sensitive and specific potential predictive factor of NACT-response, which can be assessed in blood to guide therapeutic decisions.
- Clinical and Molecular Methods in Drug Development: Neoadjuvant Systemic Therapy in Breast Cancer as a Model.Publication . Braga, SofiaNeoadjuvant chemotherapy (NACT), neoadjuvant endocrine therapy (NAET), and neoadjuvant targeted therapy (NATT), more recently, have been adopted worldwide as standard of care in locally advanced and inoperable BC. These modalities, collectively called neoadjuvant systemic therapy (NAST), are also used for organ preservation and for mechanistic biological studies on drug response and resistance, drug development, and clinical trials. Furthermore, the response to NACT is a valuable indicator of long-term survival. In this work, the advantages and pitfalls of using NAST in BC for studying drug response and resistance for drug development and clinical trials are discussed as well as practical points on how to set up a NAST clinical trial in BC.
- Relationship between primary tumor location and mortality in stage II colon cancerPublication . Pinto-Torres, S.; Malheiro, M.; Rato, J.; Andre, T.; Gradil, A.; João, A.; Braga, Sofia; Xavier, A. T.; Martins, A.; Fiuza, T.
- Resistance to targeted therapies in breast cancerPublication . Braga, SofiaSeventy five percent of all breast cancer (BC) patients express estrogen receptor (ER) but a quarter to half of patients with ER positive BC relapse on ET (endocrine therapy), tamoxifen, aromatase inhibitors (AIs), surgical castration, amongst other treatment strategies. ER positive BC at relapse loses ER expression in 20 % of cases and reduces quantitative ER expression most of the time. ER is not the only survival pathway driving ER positive BC and escape pathways intrinsic or acquired are activated during ET. This overview gives an account of ligand-independent ER activation, namely by receptor networks cross talk, and by the various genomic factors and mechanisms leading to ET response failure. Also the mechanisms of Her1 and Her2 inhibition resistance are dealt within this overview, along with the therapeutic indications and limitations of tyrosine kinase inhibitors, PARP inhibitors, PI3K/AKT/mTOR inhibitors, RAS/RAF/MEK/ERK/MAPK inhibitors, and antiangiogenic drugs. In spite of the many advances in controlling the division of BC cells and the progression of BC tumors these still remain the main cause of death among women in age range of 20-50 years requiring even more efforts in new therapeutic approaches besides the drugs within the scope of the overview.