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Patients with primary HER2-positive breast cancer benefit from HER2-targeted therapies. Nevertheless, a significant proportion of these patients die of disease progression due to mechanisms of drug resistance. MicroRNAs (miRNAs) are emerging as critical core regulators of drug resistance that act by modulating the epithelial- to-mesenchymal transition (EMT) and cancer-related immune responses. In this study, we investigated the association between the expression of a specific subset of 14 miRNAs involved in EMT processes and immune functions and the response to neoadjuvant trastuzumab and chemotherapy in 52 patients with HER2-overexpressing breast tumors. The expression of only a single miRNA, miR-21, was significantly associated with residual disease (p = 0.030) and increased after trastuzumab-chemotherapy (p = 0.012). A target prediction analysis coupled with in vitro and in vivo validations revealed that miR-21 levels inversely correlated with the expression of PTEN (rs = −0.502; p = 0.005) and PDCD4 (rs = −0.426; p = 0.019), which differentially influenced the drug sensitivity of HER2-positive breast cancer cells. However, PTEN expression was only marginally associated with residual disease. We further demonstrated that miR-21 was able to affect the response to both trastuzumab and chemotherapy, triggering an IL-6/STAT3/NF-κB-mediated signaling loop and activating the PI3K pathway. Our findings support the ability of miR-21 signaling to sustain EMT and shape the tumor immune microenvironment in HER2-positive breast cancer. Collectively, these data provide a rationale for using miR-21 expression as a biomarker to select trastuzumab-chemotherapy-resistant HER2-positive breast cancer patients who may benefit from treatments containing PI3K inhibitors or immunomodulatory drugs.

BackgroundStromal tumor-infiltrating lymphocytes (TILs) are a robust prognostic factor in triple-negative breast cancer (TNBC). However, the clinical significance of TILs may be influenced by the complex landscape of the tumor immune microenvironment. In this study, we aimed to evaluate the composition and the functionality of lymphocytic infiltration and checkpoint receptors in TNBC.MethodsFormalin-fixed, paraffin-embedded tissues were retrospectively collected from a cohort of patients with early-stage TNBC treated with adjuvant anthracycline-based chemotherapy (n = 259). Results were validated in an independent cohort of patients with TNBC (n = 104). Stromal TILs were evaluated on hematoxylin-and-eosin-stained sections. The density of CD4+, CD8+, and FOXP3+ lymphocytes, and the expression of the immune checkpoints PD-1 and LAG-3, were assessed by immunohistochemical analysis.ResultsThe presence of elevated TILs positively correlated with the density of all T cell subtypes, especially cytotoxic CD8+ lymphocytes. We showed that increasing stromal TILs assessed as a continuous variable is an independent prognostic marker of prolonged relapse-free survival and overall survival in TNBC. Among immune subpopulations, CD8+ lymphocytes are the main effectors of anti-tumor immune responses. In two independent cohorts, we found that PD-1 and LAG-3 were concurrently expressed in approximately 15% of patients with TNBC. The expression of both checkpoint receptors positively correlated with the presence of TILs, but was not significantly associated with patient outcome.ConclusionsOverall, our data indicate that the evaluation of stromal TILs remains the most reliable immune prognostic marker in TNBC, and support the clinical evaluation of anti-PD-1/PD-L1 and anti-LAG-3 in a subset of patients with TNBC who have concurrent expression of both checkpoint receptors.Electronic supplementary materialThe online version of this article (doi:10.1186/s13058-016-0783-4) contains supplementary material, which is available to authorized users.

Background. Due to its rarity, male breastcancer (mBC) remains an inadequately characterized disease, and current evidence for treatment derives from female breast cancer (FBC). Methods. We retrospectively analyzed the clinicopathological characteristics, treatment patterns, and outcomes of mBCs treated from 2000 to 2013.Results. From a total of 97 patients with mBC, 6 (6.2%) with ductal in situ carcinoma were excluded, and 91 patients with invasive carcinoma were analyzed. Median age was 65 years (range: 25-87 years). Estrogen receptors were positive in 88 patients (96.7%), and progesterone receptors were positive in 84 patients (92.3%). HER-2 was overexpressed in 13 of 85 patients (16%). Median follow-up was 51.5 months (range: 0.5-219.3 months). Five-year progression-free survival (PFS)

A subgroup of triple-negative breast cancer (TNBC) shows epithelial-to-mesenchymal transition (EMT) features, which are sustained by the interaction between cancer cells and tumor-associated macrophages (TAMs). In this study, the clinical relevance of 30 EMT-related kinases and the potential cross-talk with TAMs were investigated in a cohort of 203 TNBC patients treated with adjuvant chemotherapy. The prognostic value of the evaluated markers was validated in two independent cohorts of TNBC patients treated with adjuvant chemotherapy (N=95; N=137). In vitro, we investigated the potential synergism between cancer cells and TAMs. We found that the EMT-related kinase AXL showed the highest correlation with the frequency of CD163-positive macrophages (rS=0.503; P<0.0001). Relapsing TNBC patients presented high expression of AXL (P<0.0001) and CD163 (P<0.018), but only AXL retained independent prognostic significance in multivariate analysis (relapse-free survival, P=0.002; overall survival P=0.001). In vitro analysis demonstrated that AXL-expressing TNBC cells were able to polarize human macrophages towards an M2-like phenotype, and modulate a specific pattern of pro-tumor cytokines and chemokines. Selective AXL inhibition impaired the activity of M2-like macrophages, reducing cancer cell invasiveness, and restoring the sensitivity of breast cancer cells to chemotherapeutic drugs. These data suggest that the EMT-related kinase AXL overexpressed in cancer cells has prognostic significance, and contributes to the functional skewing of macrophage functions in TNBC. AXL inhibition may represent a novel strategy to target cancer cells, as well as tumor-promoting TAMs in TNBC.

Mutations in isocitrate dehydrogenase (IDH)1 and its homolog IDH2 are considered an earliest “driver” genetic event during gliomagenesis, representing now the molecular hallmark of lower-grade gliomas (LGGs). IDH-mutated genes encode for a neomorphic enzyme that converts α-ketoglutarate to the oncometabolite D-2-hydroxyglutarate (2-HG), which accumulates to high concentrations and alters cellular epigenetics and metabolism. Targeting IDH mutations is the first attempt to apply “precision oncology” in LGGs. Two distinct strategies have been proposed so far and are under intense clinical investigation: (i) reducing the amount of intratumoral 2-HG by directly blocking the function of mutant IDH enzyme; (ii) exploiting the selective epigenetic and metabolic cellular vulnerabilities as a consequence of 2-HG accumulation. The present review describes the physiopathological mechanisms by which IDH mutations lead to tumorigenesis, discussing their prognostic significance and pivotal role in the gliomas diagnostic classification system. We critically review preclinical evidence and available clinical data of first-generation mutant-selective IDH inhibitors and novel IDH-targeted vaccines. Finally, as an alternative and attractive approach, we present the rationale to take advantage of selective 2-HG related epigenetic and metabolic weaknesses. The results of ongoing clinical trials will help us clarify the complex scenario of IDH-targeted therapeutic approaches in gliomas.

Multiple myeloma (MM) is a neoplastic disorder. It results from proliferation of clonal plasma cells in bone marrow with production of monoclonal proteins, which are detectable in serum or urine. MM is clinically characterized by destructive bone lesions, anemia, hypercalcemia and renal insufficiency. Its prognosis is severe, with a median survival after diagnosis of approximately 3 years due to frequent relapses. Treatments for patients with relapsed/refractory MM include hematopoietic cell transplantation, a rechallenge using a previous chemotherapy regimen or a trial of a new regimen. The introduction of new drugs such as thalidomide, lenalidomide and bortezomib has markedly improved MM outcomes. When relapse occurs, the clinician’s challenge is to select the optimal treatment for each patient while balancing efficacy and toxicity. Patients with indolent relapse can be first treated with a 2-drug or a 3-drug combination. Patients with more aggressive relapse often require therapy with a combination of multiple active agents. Autologous stem cell transplantation should be considered as salvage therapy at first relapse for patients who have cryopreserved stem cells early in the disease course. The aim of this review is to provide an overview on the pharmacological and molecular action of treatments used for patients with relapsed/refractory multiple myeloma.

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