Mayra Rachele Zarone

Mir-34: A New Weapon Against Cancer?

The microRNA(miRNA)-34a is a key regulator of tumor suppression. It controls the expression of a plethora of target proteins involved in cell cycle, differentiation and apoptosis, and antagonizes processes that are necessary for basic cancer cell viability as well as cancer stemness, metastasis, and chemoresistance. In this review, we focus on the molecular mechanisms of miR-34a-mediated tumor suppression, giving emphasis on the main miR-34a targets, as well as on the principal regulators involved in the modulation of this miRNA. Moreover, we shed light on the miR-34a role in modulating responsiveness to chemotherapy and on the phytonutrients-mediated regulation of miR-34a expression and activity in cancer cells. Given the broad anti-oncogenic activity of miR-34a, we also discuss the substantial benefits of a new therapeutic concept based on nanotechnology delivery of miRNA mimics. In fact, the replacement of oncosuppressor miRNAs provides an effective strategy against tumor heterogeneity and the selective RNA-based delivery systems seems to be an excellent platform for a safe and effective targeting of the tumor.

Non-coding RNAs as a new dawn in tumor diagnosis

The current knowledge about non-coding RNAs (ncRNAs) as important regulators of gene expression in both physiological and pathological conditions, has been the main engine for the design of innovative platforms to finalize the pharmacological application of ncRNAs as either therapeutic tools or as molecular biomarkers in cancer. Biochemical alterations of cancer cells are, in fact, largely supported by ncRNA disregulation in the tumor site, which, in turn, reflects the cancer-associated specific modification of circulating ncRNA expression pattern. The aim of this review is to describe the state of the art of pre-clinical and clinical studies that analyze the involvement of miRNAs and lncRNAs in cancer-related processes, such as proliferation, invasion and metastases, giving emphasis to their functional role. A central node of our work has been also the examination of advantages and criticisms correlated with the clinical use of ncRNAs, taking into account the pressing need to refine the profiling methods aimed at identify novel diagnostic and prognostic markers and the request to optimize the delivery of such nucleic acids for a therapeutic use in an imminent future.

Lipid Nanoparticles to Deliver miRNA in Cancer.

MicroRNAs (miRNAs) are a class of post-transcriptional gene expression modulators. In the past two decades, over 1500 human miRNAs were discovered. These small non-coding RNAs regulate various biological processes, including cell growth, proliferation, differentiation, and cell death. Thus, miRNAs have been proposed as new therapeutical agents in different multifactorial diseases such as cancer. Since miRNAs therapies represent a great promise, many research studies have been focused on the development of delivery strategies to overcome miRNAs biopharmaceutical issues. Lipid delivery systems are undoubtedly the non-viral carriers most largely investigated due to their biocompatibility, biodegradability, easy production, low toxicity and immunogenicity, possibility to easily modify the carriers for targeting strategies. In this mini-review we provide a rapid and updated overview on the lipid delivery system currently used to deliver miRNAs, pointing out the progresses achieved in the optimization of these nanovectors, which led up to the first clinical trial.

MELANOMA ADJUVANT TREATMENT: current insight and clinical features

Melanoma represents 2-3% of all cancers, 95% of them arise from skin, while only 5% are non-cutaneous melanoma. Despite an optimal surgery management, the risk of a local and systemic relapse remains high, particularly in high-risk patients (node-positive or node-negative T3b, T4 a/b). We conducted a systematic review of the main published and ongoing phase I/II/III trials between 2000 and June 2015 on the adjuvant treatment of cutaneous melanoma. The IFN remains the only option currently available for this aim. Ipilimumab represents a possible breakthrough in this setting, considering the positive results of the EORTC 18701 trials in terms of disease free survival (DFS), while data regarding OS are pending. Recent advances in the understanding of the biology of melanoma result in the identification of MAPK pathway role in the melanoma development. Based on these features, B-RAF inhibitors and their combination with immunotherapy could represent the upcoming therapeutic strategy.

Evidence of novel miR-34a-based therapeutic approaches for multiple myeloma treatment

MiR-34a acts as tumor suppressor microRNA (miRNA) in several cancers, including multiple myeloma (MM), by controlling the expression of target proteins involved in cell cycle, differentiation and apoptosis. Here, we have investigated the combination between miR-34a and γ-secretase inhibitor (γSI), Sirtinol or zoledronic acid (ZOL) in order to enhance the inhibitory action of this miRNA on its canonical targets such as Notch1 and SIRT1, and on Ras/MAPK-dependent pathways. Our data demonstrate that miR-34a synthetic mimics significantly enhance the anti-tumor activity of all the above-mentioned anti-cancer agents in RPMI 8226 MM cells. We found that γSI enhanced miR-34a-dependent anti-tumor effects by activating the extrinsic apoptotic pathway which could overcome the cytoprotective autophagic mechanism. Moreover, the combination between miR-34a and γSI increased the cell surface calreticulin (CRT) expression, that is well known for triggering anti-tumor immunological response. The combination between miR-34a and Sirtinol induced the activation of an intrinsic apoptotic pathway along with increased surface expression of CRT. Regarding ZOL, we found a powerful growth inhibition after enforced miR-34a expression, which was not likely attributable to neither apoptosis nor autophagy modulation. Based on our data, the combination of miR-34a with other anti-cancer agents appears a promising anti-MM strategy deserving further investigation.

Anti-cancer activity of dose-fractioned mPE +/− bevacizumab regimen is paralleled by immune-modulation in advanced squamous NSLC patients

Background Results from the BEVA2007 trial, suggest that the metronomic chemotherapy regimen with dose-fractioned cisplatin and oral etoposide (mPE) +/- bevacizumab, a monoclonal antibody to the vascular endothelial growth factor (VEGF), shows anti-angiogenic and immunological effects and is a safe and active treatment for metastatic non-small cell lung cancer (mNSCLC) patients. We carried out a retrospective analysis aimed to evaluate the antitumor effects of this treatment in a subset of patients with squamous histology. Methods Retrospective analysis was carried out in a subset of 31 patients with squamous histology enrolled in the study between September 2007 and September 2015. All of the patients received chemotherapy with cisplatin (30 mg/sqm, days 1-3q21) and oral etoposide (50 mg, days 1-15q21) (mPE) and 14 of them also received bevacizumab 5 mg/kg on the day 3q21 (mPEBev regimen). Results This treatment showed a disease control rate of 71% with a mean progression free survival (PFS) and overall survival (OS) of 13.6 and 17 months respectively. After 4 treatment courses, 6 patients showing a remarkable tumor shrinkage, underwent to radical surgery, attaining a significant advantage in term of survival (P=0.048). Kaplan-Meier and log-rank test identified the longest survival in patients presenting low baseline levels in neutrophil-to-lymphocyte ratio (NLR) (P=0.05), interleukin (IL) 17A (P=0.036), regulatory-T-cells (Tregs) (P=0.020), and activated CD83+ dendritic cells (DCs) (P=0.03). Conclusions These results suggest that the mPE +/- bevacizumab regimen is feasible and should be tested in comparative trials in advanced squamous-NSCLC (sqNSCLC). Moreover, its immune-biological effects strongly suggest the investigation in sequential combinations with immune check-point inhibitors.

Possible roles of transglutaminases in molecular mechanisms responsible for cancer and human neurodegenerative diseases

Transglutaminases are a family of Ca2+- dependent enzymes which catalyze posttranslational modifications of proteins. The main activity of these enzymes is the crosslinking of glutaminyl residues of a protein/peptide substrate to lysyl residues of a protein/peptide co-substrate. In addition to lysyl residues, other second nucleophilic co-substrates may include monoamines or polyamines (to form mono- or bi-substituted/ crosslinked adducts) or -OH groups (to form ester linkages). In absence of co-substrates, the nucleophile may be water, resulting in the net deamidation of the glutaminyl residue. Transglutaminase activity has been suggested to be involved in molecular mechanisms responsible for either physiological or pathological processes. In particular, transglutaminase activity has been shown to be responsible for human autoimmune diseases and Celiac Disease is just one of them. Interestingly, cancer and neurodegenerative diseases, such as Alzheimer’s Disease, Parkinson’s Disease, supranuclear palsy and Huntington’s Disease, are characterized in part by aberrant transglutaminase activity and by increased cross-linked proteins in affected tissues. This review describes the possible molecular mechanisms by which these enzymes could be responsible for such diseases and the possible use of transglutaminase inhibitors for patients with diseases characterized by aberrant transglutaminase activity.