Several non-protein-coding genomic regions, previously marked as "junk DNA", have been reported to be transcriptionally active, giving rise to non-coding RNA species implicated in fundamental ...biological and pathological processes. In particular, microRNAs (miRNAs), a class of small non-coding RNAs mediating post-transcriptional gene silencing, are causally involved in several human diseases, including various cancer types. Extracellular vesicles (EVs) are membranous structures physiologically released by most cell types. Initially, they were considered a "waste-removal" mechanism, through which cells could dispose unnecessary material and organelles. It is now widely demonstrated that EVs also play a critical role in intercellular communication, mediating the horizontal transfer of lipids, proteins, and genetic material. A paradigm shift in the biology of miRNAs was represented by the discovery that EVs, especially from cancer cells, contain miRs. EV-associated miRs act as autocrine, paracrine and endocrine factors, participating in cancer pathogenesis by modulating intercellular communication. Noteworthy, these formerly neglected molecules are now considered the next generation of cancer "theranostic" tools, with strong clinical relevance. In this review, we aim to summarize the most recent findings regarding EV-associated miRs in cancer pathogenesis and in the development of novel anti-neoplastic diagnostic and therapeutic approaches.
Cell survival after DNA damage relies on DNA repair, the abrogation of which causes genomic instability and development of cancer. However, defective DNA repair in cancer cells can be exploited for ...cancer therapy using DNA-damaging agents. DNA double-strand breaks are the major lethal lesions induced by ionizing radiation (IR) and can be efficiently repaired by DNA homologous recombination, a system that requires numerous factors including the recombinase RAD51 (RAD51). Therapies combined with adjuvant radiotherapy have been demonstrated to improve the survival of triple-negative breast cancer patients; however, such therapy is challenged by the emergence of resistance in tumor cells. It is, therefore, essential to develop novel therapeutic strategies to overcome radioresistance and improve radiosensitivity. In this study we show that overexpression of microRNA 155 (miR-155) in human breast cancer cells reduces the levels of RAD51 and affects the cellular response to IR. miR-155 directly targets the 3'-untranslated region of RAD51. Overexpression of miR-155 decreased the efficiency of homologous recombination repair and enhanced sensitivity to IR in vitro and in vivo. High miR-155 levels were associated with lower RAD51 expression and with better overall survival of patients in a large series of triple-negative breast cancers. Taken together, our findings indicate that miR-155 regulates DNA repair activity and sensitivity to IR by repressing RAD51 in breast cancer. Testing for expression levels of miR-155 may be useful in the identification of breast cancer patients who will benefit from an IR-based therapeutic approach.
The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), also known as 2019 novel coronavirus (2019-nCoV), is a highly infectious RNA virus. A percentage of patients develop coronavirus ...disease 2019 (COVID-19) after infection, whose symptoms include fever, cough, shortness of breath and fatigue. Acute and life-threatening respiratory symptoms are experienced by 10-20% of symptomatic patients, particularly those with underlying medical conditions. One of the main challenges in the containment of COVID-19 is the identification and isolation of asymptomatic/pre-symptomatic individuals. A number of molecular assays are currently used to detect SARS-CoV-2. Many of them can accurately test hundreds or even thousands of patients every day. However, there are presently no testing platforms that enable more than 10,000 tests per day. Here, we describe the foundation for the REcombinase Mediated BaRcoding and AmplificatioN Diagnostic Tool (REMBRANDT), a high-throughput Next Generation Sequencing-based approach for the simultaneous screening of over 100,000 samples per day. The REMBRANDT protocol includes direct two-barcoded amplification of SARS-CoV-2 and control amplicons using an isothermal reaction, and the downstream library preparation for Illumina sequencing and bioinformatics analysis. This protocol represents a potentially powerful approach for community screening of COVID-19 that may be modified for application to any infectious or non-infectious genome.
miR-15b/16-2 deletion promotes B-cell malignancies Lovat, Francesca; Fassan, Matteo; Gasparini, Pierluigi ...
Proceedings of the National Academy of Sciences - PNAS,
09/2015, Letnik:
112, Številka:
37
Journal Article
Recenzirano
Odprti dostop
The central role of the microRNA (miR) 15a/16-1 cluster in B-cell oncogenesis has been extensively demonstrated, with over two-thirds of B-cell chronic lymphocytic leukemia characterized by the ...deletion of the miR-15a/16-1 locus at 13q14. Despite the well-established understanding of the molecular mechanisms occurring during miR-15a/16-1 dysregulation, the oncogenic role of other miR-15/16 family members, such as the miR-15b/16-2 cluster (3q25), is still far from being elucidated. Whereas miR-15a is highly similar to miR-15b, miR-16-1 is identical to miR-16-2; thus, it could be speculated that both clusters control a similar set of target genes and may have overlapping functions. However, the biological role of miR-15b/16-2 is still controversial. We generated miR-15b/16-2 knockout mice to better understand the cluster’s role in vivo. These mice developed B-cell malignancy by age 15–18 mo with a penetrance of 60%. At this stage, mice showed significantly enlarged spleens with abnormal B cell-derived white pulp enlargement. Flow cytometric analysis demonstrated an expanded CD19+ CD5+ population in the spleen of 40% knockout mice, a characteristic of the chronic lymphocytic leukemia-associated phenotype found in humans. Of note, miR-15b/16-2 modulates theCCND2(Cyclin D2),CCND1(Cyclin D1), andIGF1R(insulin-like growth factor 1 receptor) genes involved in proliferation and antiapoptotic pathways in mouse B cells. These results are the first, to our knowledge, to suggest an important role of miR-15b/16-2 loss in the pathogenesis of B-cell chronic lymphocytic leukemia.
Scorpins in the DNA Damage Response Palmieri, Dario; Tessari, Anna; Coppola, Vincenzo
International journal of molecular sciences,
06/2018, Letnik:
19, Številka:
6
Journal Article
Recenzirano
Odprti dostop
The DNA Damage Response (DDR) is a complex signaling network that comes into play when cells experience genotoxic stress. Upon DNA damage, cellular signaling pathways are rewired to slow down cell ...cycle progression and allow recovery. However, when the damage is beyond repair, cells activate complex and still not fully understood mechanisms, leading to a complete proliferative arrest or cell death. Several conventional and novel anti-neoplastic treatments rely on causing DNA damage or on the inhibition of the DDR in cancer cells. However, the identification of molecular determinants directing cancer cells toward recovery or death upon DNA damage is still far from complete, and it is object of intense investigation.
PRY-
ntaining
AN binding
rote
(
) RANBP9 and RANBP10 are evolutionarily conserved and ubiquitously expressed proteins whose biological functions are still debated. RANBP9 has been previously implicated in cell proliferation, survival, apoptosis and migration. Recent studies also showed that RANBP9 is involved in the Ataxia Telangiectasia Mutated (ATM) signaling upon DNA damage. Accordingly, cells lacking RANBP9 show increased sensitivity to genotoxic treatment. Although there is no published evidence, extensive protein similarities suggest that RANBP10 might have partially overlapping functions with RANBP9. Like RANBP9, RANBP10 bears sites putative target of PIK-kinases and high throughput studies found RANBP10 to be phosphorylated following genotoxic stress. Therefore, this second Scorpin might be another overlooked player of the DDR alone or in combination with RANBP9. This review focuses on the relatively unknown role played by RANBP9 and RANBP10 in responding to genotoxic stress.
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 miR-27a 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.
Context:
MicroRNA (miRNA) are an important class of regulators of gene expression. Altered miRNA expression has been constantly found in human neoplasias and plays an important role in the process of ...carcinogenesis.
Objective:
The aim of this study was to identify specific miRNA whose expression is altered in GH-secreting pituitary adenomas.
Design:
Using a miRNACHIP microarray, we have analyzed the miRNA expression profile of human GH adenomas vs. normal pituitary gland.
Results:
We report the identification of a set of miRNA, including miR-34b, miR-326, miR-432, miR-548c-3p, miR-570, and miR-603, drastically and constantly down-regulated in GH adenomas. We demonstrate that these miRNA target genes such as high-mobility group A1 (HMGA1), HMGA2, and E2F1, whose overexpression and/or activation plays a critical role in pituitary tumorigenesis. We also show that the enforced expression of the down-regulated miRNA has a negative role on the growth regulation of pituitary adenoma cells. Finally, an inverse correlation is found between the expression of these miRNA and HMGA1 and HMGA2 protein levels in GH adenomas.
Conclusion:
Our study identifies a specific subset of miRNA, whose down-regulation might contribute to pituitary tumorigenesis.
Numerous studies have described the altered expression and the causal role of microRNAs (miRNAs) in human cancer. However, to date, efforts to modulate miRNA levels for therapeutic purposes have been ...challenging to implement. Here we find that nucleolin (NCL), a major nucleolar protein, posttranscriptionally regulates the expression of a specific subset of miRNAs, including miR-21, miR-221, miR-222, and miR-103, that are causally involved in breast cancer initiation, progression, and drug resistance. We also show that NCL is commonly overexpressed in human breast tumors and that its expression correlates with that of NCL-dependent miRNAs. Finally, inhibition of NCL using guanosine-rich aptamers reduces the levels of NCL-dependent miRNAs and their target genes, thus reducing breast cancer cell aggressiveness both in vitro and in vivo. These findings illuminate a path to novel therapeutic approaches based on NCL-targeting aptamers for the modulation of miRNA expression in the treatment of breast cancer.
Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor with a variable incidence among different countries. Occupational asbestos exposure is the most important etiological factor and a ...very long latency period is widely reported. In the early phase of the disease, clinical signs are absent or not specific. For this reason, the diagnosis is frequently achieved only in the advanced stages. The histopathological diagnosis
is also very complex, and no known factor can predict the prognosis with certainty. Nonetheless, current survival rates remain very low, despite the use of standard treatments, which include surgery, chemotherapy and radiotherapy. The identification of new prognostic and/or diagnostic biomarkers, and the discovery of therapeutic targets is a priority and could lead to a real significant impact on the management of malignant pleural mesothelioma. In this scenario, the role of microRNAs is becoming increasingly relevant, with the promise of a quick translation in the current clinical practice. Despite the relative novelty of this field, the number of works and candidate microRNAs that are present in literature is striking. Unfortunately, to date the microRNAs with the most clinical relevance for MPM are still matter of debate, probably due to the variety of approaches, techniques, and collected samples. Although specific microRNAs (e.g., let-7, miR-15 and miR-16, miR-21, miR-34a, and the miR-200 family) have been reported several times from different groups, the heterogeneity of published data reinforces the need of more comprehensive and unified studies on this topic. In this review we collect and discuss the studies focused on the involvement of microRNAs in different aspects of MPM, from their biological role in tumorigenesis and progression, to their possible application as diagnostic, prognostic and predictive biomarkers. Lastly, we examine their potential value as for the design of therapeutic approaches that could benefit MPM patients.
Because of its selective expression on the surface of a variety of different cancer cells, but not on their normal counterparts, nucleolin (NCL) represents an attractive target for antineoplastic ...treatments. However, previously described NCL-targeting molecules, although promising, still suffer from intrinsic limitations. Here, we describe the identification of the first fully human anti-NCL immune-based agent displaying antineoplastic activity against solid tumors, both in vitro and in vivo. This molecule could represent the prototype of a novel class of NCL-targeting drugs with enormous clinical potential as tools for the diagnosis and therapy of a wide range of human cancers.
Nucleolin (NCL) is a nucleocytoplasmic protein involved in many biological processes, such as ribosomal assembly, rRNA processing, and mRNA stabilization. NCL also regulates the biogenesis of specific microRNAs (miRNAs) involved in tumor development and aggressiveness. Interestingly, NCL is expressed on the surface of actively proliferating cancer cells, but not on their normal counterparts. Therefore, NCL is an attractive target for antineoplastic treatments. Taking advantage of phage-display technology, we engineered a fully human single-chain fragment variable, named 4LB5. This immunoagent binds NCL on the cell surface, it is translocated into the cytoplasm of target cells, and it abrogates the biogenesis of NCL-dependent miRNAs. Binding of 4LB5 to NCL on the cell surface of a variety of breast cancer and hepatocellular carcinoma cell lines, but not to normal-like MCF-10a breast cells, dramatically reduces cancer cell viability and proliferation. Finally, in orthotopic breast cancer mouse models, 4LB5 administration results in a significant reduction of the tumor volume without evident side effects. In summary, here we describe, to our knowledge, the first anti-NCL single-chain fragment variable displaying antineoplastic activity against established solid tumors, which could represent the prototype of novel immune-based NCL-targeting drugs with clinical potential as diagnostic and therapeutic tools in a wide variety of human cancers.
PDF
