Dysregulation of microRNAs (miRNAs) is involved in the initiation and progression of several human cancers, including breast cancer (BC), as strong evidence has been found that miRNAs can act as oncogenes or tumor suppressor genes. This review presents the state of the art on the role of miRNAs in the diagnosis, prognosis, and therapy of BC. Based on the results obtained in the last decade, some miRNAs are emerging as biomarkers of BC for diagnosis (i.e., miR-9, miR-10b, and miR-17-5p), prognosis (i.e., miR-148a and miR-335), and prediction of therapeutic outcomes (i.e., miR-30c, miR-187, and miR-339-5p) and have important roles in the control of BC hallmark functions such as invasion, metastasis, proliferation, resting death, apoptosis, and genomic instability. Other miRNAs are of interest as new, easily accessible, affordable, non-invasive tools for the personalized management of patients with BC because they are circulating in body fluids (e.g., miR-155 and miR-210). In particular, circulating multiple miRNA profiles are showing better diagnostic and prognostic performance as well as better sensitivity than individual miRNAs in BC. New miRNA-based drugs are also promising therapy for BC (e.g., miR-9, miR-21, miR34a, miR145, and miR150), and other miRNAs are showing a fundamental role in modulation of the response to other non-miRNA treatments, being able to increase their efficacy (e.g., miR-21, miR34a, miR195, miR200c, and miR203 in combination with chemotherapy).

Formation of disul®de bonds, an essential step for the maturation and exit of secretory proteins from the endoplasmic reticulum (ER), is controlled by speci®c ER-resident enzymes. A pivotal element in this process is Ero1a, an oxidoreductin that lacks known ER retention motifs. Here we show that ERp44 mediates Ero1a ER localization through the formation of reversible mixed disul®des. ERp44 also prevents the secretion of an unassembled cargo protein with unpaired cysteines. We conclude that ERp44 is a key element in thiol-mediated retention. It might also favour the maturation of disul®de-linked oligomeric proteins and their quality control.

A complex array of chaperones and enzymes reside in the endoplasmic reticulum (ER) to assist the folding and assembly of and the disulfide bond formation in nascent secretory proteins. Here we characterize a novel human putative ER co-chaperone (ERdj5)

The cancer stem cell hypothesis posits that tumors are derived from a single cancer-initiating cell with stem cell properties. The task of identifying and characterizing a single cancer-initiating cell with stem cell properties has proven technically difficult because of the scarcity of the cancer stem cells in the tissue of origin and the lack of specific markers for cancer stem cells. Here we show that a single LA7 cell derived from rat mammary adenocarcinoma has the following properties: the differentiation potential to generate all of the cell lineages of the mammary gland; the ability to generate branched duct-like structures that recapitulate morphologically and functionally the ductal-alveolar-like architecture of the mammary tree; and the capacity to initiate heterogeneous tumors in nonobese diabetic-SCID mice. In addition, we show that cultured cells derived from tumors generated by a single LA7 cell-injection have properties similar to LA7 cells, can generate all of the cell lineages of the mammary gland, and recapitulate the ductalalveolar-like architecture of the mammary tree. The properties of self-renewal, extensive capacity for proliferation, multilineage differentiation potential, and single-cell tumor-initiation potential suggest that LA7 cells are cancer stem cells and can be used as a model system to study the dynamics of tumor formation at the single-cell level.p21/ WAF1 ͉ mammary gland differentiation ͉ single cell injection I ncreasingly, experimental evidence and clinical data suggest that somatic stem cells may be the targets of transformation during carcinogenesis and that virtually all cancers are clonal and represent the progeny of a single cell (1). This suggests that tumorigenic cancer cells may undergo the processes of selfrenewal and differentiation as normal stem cells.We show here that mammary gland LA7 cells isolated by R.D. (2) from a mammary adenocarcinoma induced in rat using DMBA (3) have the stem cell properties of self-renewal, have the capacity to differentiate into all of the cell lineages of the mammary gland, and form heterogeneous tumors in nonobese diabetic (NOD)-SCID mice at a single-cell level. Demonstrating that a single LA7 cell has the capacity to initiate cancer gives strong support to the hypothesis that recurrence of cancer after remedial therapy can occur if even a single malignant cell survives. Characterization of cells with the property of single-cell tumor-formation potential should contribute to the advancement of appropriate therapies that can effectively target specific individual cancer stem cells that have the capacity to initiate tumors at the single-cell level. Previously, LA7 cells have been used to study mammary gland differentiation (4-10). Exposure of LA7 cells to lactogenic hormones, lipids, or differentiating agents results in the formation of hemispherical polarized dome-shaped structures representing cellular changes that occur in vivo in the mammary gland at pregnancy when alveoli are formed (4, 9).We show here that a single LA7 cell can ...

Disulfide bonds are formed in the endoplasmic reticulum (ER) by sequential interchange reactions: Ero1alpha and Ero1beta transfer oxidative equivalents to protein disulfide isomerase (PDI), which in turn oxidizes cargo proteins. Neither Ero1alpha nor Ero1beta contains known ER localization motif(s), raising the question of how they are retained in this organelle. Here the authors show that, unlike endogenous molecules, overexpressed Ero1alpha and Ero1beta are secreted by HeLa transfectants, suggesting saturation of their normal retention mechanism(s). Co-expression of either PDI or ERp44 prevents Ero1 secretion in a KDEL/RDEL dependent way. Covalent interactions between ERp44 and Ero1 are essential for retention. In contrast, a mutant PDI lacking the four cysteines in the two active sites still inhibits secretion, albeit less efficiently. PDI and ERp44 compete for Ero1 binding. PDI also prevents Ero1 aggregation and dimerization, thus chaperoning its own oxidase. This dynamic retention mechanism of Ero1 may be important for fine-tuning the regulation of ER redox homeostasis and quality control.

Prostate cancer (PC) includes several phenotypes, from indolent to highly aggressive cancer. Actual diagnostic and prognostic tools have several limitations, and there is a need for new biomarkers to stratify patients and assign them optimal therapies by taking into account potential genetic and epigenetic differences. MicroRNAs (miRNAs) are small sequences of non-coding RNA regulating specific genes involved in the onset and development of PC. Stable miRNAs have been found in biofluids, such as serum and plasma; thus, the measurement of PC-associated miRNAs is emerging as a non-invasive tool for PC detection and monitoring. In this study, we conduct an in-depth literature review focusing on miRNAs that may contribute to the diagnosis and prognosis of PC. The role of miRNAs as a potential theranostic tool in PC is discussed. Using a meta-analysis approach, we found a group of 29 miRNAs with diagnostic properties and a group of seven miRNAs with prognostic properties, which were found already expressed in both biofluids and PC tissues. We tested the two miRNA groups on The Cancer Genome Atlas dataset of PC tissue samples with a machine-learning approach. Our results suggest that these 29 miRNAs should be considered as potential panel of biomarkers for the diagnosis of PC, both as in vivo non-invasive test and ex vivo confirmation test.

Previous studies reported that Angiotensin converting enzyme 2 (ACE2) is the main cell receptor of SARS-CoV and SARS-CoV-2. It plays a key role in the access of the virus into the cell to produce the final infection. In the present study we investigated in silico the basic mechanism of ACE2 in the lung and provided evidences for new potentially effective drugs for Covid-19. Specifically, we used the gene expression profiles from public datasets including The Cancer Genome Atlas, Gene Expression Omnibus and Genotype-Tissue Expression, Gene Ontology and pathway enrichment analysis to investigate the main functions of ACE2-correlated genes. We constructed a protein-protein interaction network containing the genes co-expressed with ACE2. Finally, we focused on the genes in the network that are already associated with known drugs and evaluated their role for a potential treatment of Covid-19. Our results demonstrate that the genes correlated with ACE2 are mainly enriched in the sterol biosynthetic process, Aryldialkylphosphatase activity, adenosylhomocysteinase activity, trialkylsulfonium hydrolase activity, acetate-CoA and CoA ligase activity. We identified a network of 193 genes, 222 interactions and 36 potential drugs that could have a crucial role. Among possible interesting drugs for Covid-19 treatment, we found Nimesulide, Fluticasone Propionate, Thiabendazole, Photofrin, Didanosine and Flutamide.While the diagnosis of COVID-19 is based on the amplification of the viral genome in real-time PCR with specific probes, the current treatment of affected individuals is limited to a mixture of a broad-spectrum of antiviral drugs [6]. However, in many cases this pharmacological approach has proven to be totally ineffective.Screening drug studies on pangolin SARS-CoV-2, which is the human-related Coronavirus, demonstrated that three drugs (cepharanthine, selamectin and mefloquine hydrochloride) were effective in inhibiting viral replication, with cepharanthine potently inhibiting coronavirus infection at viral entry and post-entry viral replication [7]. The last drug is an anti-inflammatory and antineoplastic alkaloid approved for leukopenia and it is also proposed to inhibit the human immunodeficiency virus type 1 (HIV) entering in cells by reducing plasma membrane fluidity. In humans, it has a reduced toxicity.Mefloquine is the approved treatment for malaria and has antiviral activity against both MERS-CoV and SARS-CoV [8]. The antiviral mechanism of selamectin is still unknown, as it is used usually as a topical broad-spectrum parasiticide in little animals (e.g., cats and dogs).The entry of the virus in the cells is mediated by spike (S) glycoprotein; in particular, the spike 1 (S1) surface unit allows the attachment of the virus to cellular receptors. To allow the entry of the viral particles, the S protein is cleaved by cellular proteases at the S1/S2 and the S2 site. Then, the viral capside is fused with the cellular membrane, a process driven by the S2 subunit [9]. It has been described that SARS-CoV entrance is ...

Cancer driver gene alterations influence cancer development, occurring in oncogenes, tumor suppressors, and dual role genes. Discovering dual role cancer genes is difficult because of their elusive context-dependent behavior. We define oncogenic mediators as genes controlling biological processes. With them, we classify cancer driver genes, unveiling their roles in cancer mechanisms. To this end, we present Moonlight, a tool that incorporates multiple -omics data to identify critical cancer driver genes. With Moonlight, we analyze 8000+ tumor samples from 18 cancer types, discovering 3310 oncogenic mediators, 151 having dual roles. By incorporating additional data (amplification, mutation, DNA methylation, chromatin accessibility), we reveal 1000+ cancer driver genes, corroborating known molecular mechanisms. Additionally, we confirm critical cancer driver genes by analysing cell-line datasets. We discover inactivation of tumor suppressors in intron regions and that tissue type and subtype indicate dual role status. These findings help explain tumor heterogeneity and could guide therapeutic decisions.