Acute graft-versus-host disease (aGVHD) remains a major complication of allogeneic hematopoietic stem cell transplant (alloHSCT), underscoring the need to further elucidate its mechanisms and develop novel treatments. Based on recent observations that microRNA-155 (miR-155) is up-regulated during T-cell activation, we hypothesized that miR-155 is involved in the modulation of aGVHD.Here we show that miR-155 expression was up-regulated in T cells from mice developing aGVHD after alloHSCT. Mice receiving miR-155-deficient donor lymphocytes had markedly reduced lethal aGVHD, whereas lethal aGVHD developed rapidly in mice recipients of miR-155 overexpressing T cells. Blocking miR-155 expression using a synthetic antimiR-155 after alloHSCT decreased aGVHD severity and prolonged survival in mice. Finally, miR-155 up-regulation was shown in specimens from patients with pathologic evidence of intestinal aGVHD. Altogether, our data indicate a role for miR-155 in the regulation of GVHD and point to miR-155 as a novel target for therapeutic intervention in this disease.

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MicroRNAs are small noncoding RNAs that play an important role in the regulation of various biological processes through their interaction with cellular messenger RNAs. They are frequently dysregulated in cancer and have shown great potential as tissue-based markers for cancer classification and prognostication. microRNAs are also present in extracellular human body fluids such as serum, plasma, saliva, and urine. Most of circulating microRNAs are present in human plasma and serum cofractionate with the Argonaute2 (Ago2) protein. However, circulating microRNAs have been also found in membrane-bound vesicles such as exosomes. Since microRNAs circulate in the bloodstream in a highly stable, extracellular form, they may be used as blood-based biomarkers for cancer and other diseases. A knowledge base of extracellular circulating miRNAs is a fundamental tool for biomedical research. In this work, we present miRandola, a comprehensive manually curated classification of extracellular circulating miRNAs. miRandola is connected to miRò, the miRNA knowledge base, allowing users to infer the potential biological functions of circulating miRNAs and their connections with phenotypes. The miRandola database contains 2132 entries, with 581 unique mature miRNAs and 21 types of samples. miRNAs are classified into four categories, based on their extracellular form: miRNA-Ago2 (173 entries), miRNA-exosome (856 entries), miRNA-HDL (20 entries) and miRNA-circulating (1083 entries). miRandola is available online at: http://atlas.dmi.unict.it/mirandola/index.html.

In the past decade, we have observed exciting advances in lung cancer therapy, including the development of targeted therapies. However, additional strategies for early detection and tumor-based therapy are still essential in improving patient outcomes. EGF receptor (EGFR) and MET (the receptor tyrosine kinase for hepatocyte growth factors) are cell-surface tyrosine kinase receptors that have been implicated in diverse cellular processes and as regulators of several microRNAs (miRNAs), thus contributing to tumor progression. Here, we demonstrate a biological link between EGFR, MET, and the miRNA cluster 23a∼27a∼24-2. We show that miR27a regulates MET, EGFR, and Sprouty2 in lung cancer. In addition, we identify both direct and indirect mechanisms by which miR-27a can regulate both MET and EGFR. Thus, we propose a mechanism for MET and EGFR axis regulation that may lead to the development of therapeutics in lung cancer.cell signaling | epigenetics L ung cancer remains the number one cause of cancer-related deaths among men and women. However, in the past several years, we have witnessed some major advances in therapeutics that have improved outcomes in selected subgroups of patients. Tyrosine kinase receptors continue to be investigated as therapeutic targets in lung cancer. The receptor tyrosine kinase for hepatocyte growth factors, MET, is a membrane receptor for the hepatocyte growth factor (HGF) (1); MET tyrosine kinase is known to promote survival of many cell types following exposure to various apoptotic inducers, including serum starvation, death receptor activation, or genotoxic treatment (2). MET protein expression and phosphorylation have been associated with primary resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI) therapy in non-small cell lung cancer (NSCLC) patients (3). EGFR is a membrane receptor overexpressed in most NSCLC tumors, and its activation and signaling contribute to both the growth and maintenance of epithelial tissues (4-6). MET and EGFR are normally expressed by cells of epithelial origin and, upon ligand stimulation, induce cancer cell invasion, thus increasing metastatic potential. This effect on invasion occurs primarily through increased phosphorylation of both ERK1/2 and the ETS domain containing protein (ELK)1 transcriptional factor (7-9). MET and EGFR protein levels are positively regulated by Sprouty2 protein expression (10-12). Sprouty2 is ubiquitously expressed at different levels in human tissues (13). Sprouty2 expression has been shown to increase MET protein levels in colon adenocarcinoma and also to increase EGFR levels by attenuating EGFR degradation by ubiquitination (10,12,14). MicroRNAs (miRNAs) are small noncoding RNAs of 19-25 nt that can inhibit mRNA translation and/or negatively regulate mRNA stability (15). MiRNA dysregulation is one of the most important factors contributing to cancer development (16) and has been implicated in cancer drug resistance (17). Several miRNAs are indeed involved in cancer initiation and progression such as miR-15 and...

The regulatory protein nucleolin controls the expression of a subset of miRNAs involved in breast cancer progression and can be targeted to inhibit breast cancer growth in vivo.

T cell-based therapies have induced cancer remissions, though most tumors ultimately progress, reflecting inherent or acquired resistance including antigen escape. Better understanding of how T cells eliminate tumors will help decipher resistance mechanisms. We used a CRISPR/Cas9 screen and identified a necessary role for Fas-FasL in antigen-specific T-cell killing. We also found that Fas-FasL mediated off-target "bystander" killing of antigen-negative tumor cells. This localized bystander cytotoxicity enhanced clearance of antigen-heterogeneous tumors in vivo, a finding that has not been shown previously. Fas-mediated on-target and bystander killing was reproduced in chimeric antigen receptor (CAR-T) and bispecific antibody T-cell models and was augmented by inhibiting regulators of Fas signaling. Tumoral FAS expression alone predicted survival of CAR-T-treated patients in a large clinical trial (NCT02348216). These data suggest strategies to prevent immune escape by targeting both the antigen expression of most tumor cells and the geography of antigen-loss variants.SigNifiCANCe: This study demonstrates the first report of in vivo Fas-dependent bystander killing of antigen-negative tumors by T cells, a phenomenon that may be contributing to the high response rates of antigen-directed immunotherapies despite tumoral heterogeneity. Small molecules that target the Fas pathway may potentiate this mechanism to prevent cancer relapse. intRoductionT cell-based immunotherapies-including adoptive transfer of engineered T cells, bispecific antibodies, and checkpoint blockade-have revolutionized cancer treatment. However, even with the remarkably high response rates of chimeric antigen receptor (CAR)-T-treated patients, most either progress or relapse within one year (1-3). Microenvironmental factors contributing to T-cell priming (4-6) and T cell-intrinsic factors (7, 8) both influence antitumor immunity, but tumor cell-intrinsic factors have the most abundant clinical evidence for contributing to treatment potency and failures.The clearest such mechanism is target antigen (Ag) modulation-expression downregulation, lineage switching, or emergence of splice variants-which is the most common cause of relapse following CAR-T therapy for B-cell acute

Nonsmall cell lung cancer (NSCLC) is one of the leading causes of death worldwide. TNF-related apoptosis-inducing ligand (TRAIL) has been shown to induce apoptosis in malignant cells without inducing significant toxicity in normal cells. However, several carcinomas, including lung cancer, remain resistant to TRAIL. MicroRNAs (miRNAs) are small noncoding RNAs of ∼24 nt that block mRNA translation and/or negatively regulate its stability. They are often aberrantly expressed in cancer and have been implicated in increasing susceptibility or resistance to TRAIL-induced apoptosis by inhibiting key functional proteins. Here we show that miR-148a is down-regulated in cells with acquired TRAIL-resistance compared with TRAIL-sensitive cells. Enforced expression of miR-148a sensitized cells to TRAIL and reduced lung tumorigenesis in vitro and in vivo through the down-modulation of matrix metalloproteinase 15 (MMP15) and Rho-associated kinase 1 (ROCK1). These findings suggest that miR-148a acts as a tumor suppressor and might have therapeutic application in the treatment of NSCLC.

The epithelial-mesenchymal transition (EMT) and its reversal, MET, are fundamental processes involved in tumor cell invasion and metastasis. SEMA3F is a secreted semaphorin and tumor suppressor downregulated by TGFβ1 and ZEB1-induced EMT. Here we report that NRP2, the high-affinity receptor for SEMA3F and a co-receptor for certain growth factors, is upregulated during TGFβ1-driven EMT in lung cancer cells. Mechanistically, NRP2 upregulation was TβRI-dependent and SMAD-independent, occurring mainly at a post-transcriptional level involving increased association of mRNA with polyribosomes. ERK and AKT inhibition blocked NRP2 upregulation, while RNAi-mediated attenuation of ZEB1 reduced steady-state NRP2 levels. Additionally, NRP2 attenuation inhibited TGFβ1-driven morphologic transformation, migration/invasion, ERK activation, growth suppression and changes in gene expression. In a mouse xenograft model of lung cancer, NRP2 attenuation also inhibited locally invasive features of the tumor and reversed TGFβ1-mediated growth inhibition. In support of these results, in human lung cancer specimens with the highest NRP2 expression were predominantly E-cadherin negative. Furthermore, the presence of NRP2 staining strengthened the association of E-cadherin loss with high-grade tumors. Together, our results demonstrate that NRP2 contributes significantly to TGFβ1-induced EMT in lung cancer.