As to date, more than 49 million confirmed cases of Coronavirus Disease 19 (COVID-19) have been reported worldwide. Current diagnostic protocols use qRT-PCR for viral RNA detection, which is expensive and requires sophisticated equipment, trained personnel and previous RNA extraction. For this reason, we need a faster, direct and more versatile detection method for better epidemiological management of the COVID-19 outbreak. In this work, we propose a direct method without RNA extraction, based on the Loop-mediated isothermal amplification (LAMP) and Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated protein (CRISPR-Cas12) technique that allows the fast detection of SARS-CoV-2 from patient samples with high sensitivity and specificity. We obtained a limit of detection of 16 copies/μL with high specificity and at an affordable cost. The diagnostic test readout can be done with a real-time PCR thermocycler or with the naked eye in a blue-light transilluminator. Our method has been evaluated on a small set of clinical samples with promising results.

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Several neurodegenerative diseases present Tau accumulation as the main pathological marker. Tau posttranslational modifications such as phosphorylation and acetylation are increased in neurodegeneration.Here, we show that Tau hyper-acetylation at residue 174 increases its own nuclear presence and is the result of DNA damage signaling or the lack of SIRT6, both causative of neurodegeneration. Tau-K174ac is deacetylated in the nucleus by SIRT6. However, lack of SIRT6 or chronic DNA damage results in nuclear Tau-K174ac accumulation. Once there, it induces global changes in gene expression, affecting protein translation, synthesis, and energy production. Concomitantly, Alzheimer's disease (AD) case subjects show increased nucleolin and a decrease in SIRT6 levels. AD case subjects present increased levels of nuclear Tau, particularly Tau-K174ac. Our results suggest that increased Tau-K174ac in AD case subjects is the result of DNA damage signaling and SIRT6 depletion. We propose that Tau-K174ac toxicity is due to its increased stability, nuclear accumulation, and nucleolar dysfunction.

The information presented in this review is important to encourage new directed studies that consider microRNAs as a good tool to improve the diagnostic and treatment alternatives in breast cancer.

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Oxygen or nutrient deprivation of early stage tumoral spheroids can be used to reliably mimic the initial growth of primary and metastatic cancer cells. However, cancer cell growth during the initial stages has not been fully explored using a genome-wide approach. Thus, in the present study, we investigated the transcriptome of breast cancer cells during the initial stages of tumoral growth using RNAseq in a model of Multicellular Tumor Spheroids (MTS). Network analyses showed that a metastatic signature was enriched as several adhesion molecules were deregulated, including EPCAM, E-cadherin, integrins and syndecans, which were further supported by an increase in cell migration. Interestingly, we also found that the cancer cells at this stage of growth exhibited a paradoxical hyperactivation of oxidative mitochondrial metabolism. In addition, we found a large number of regulated (long non coding RNA) lncRNAs, several of which were co-regulated with neighboring genes. The regulatory role of some of these lncRNAs on mRNA expression was demonstrated with gain of function assays. This is the first report of an early-stage MTS transcriptome, which not only reveals a complex expression landscape, but points toward an important contribution of long non-coding RNAs in the final phenotype of three-dimensional cellular models.

Multicellular Tumor Spheroids develop a heterogeneous micromilieu and different cell populations, thereby constituting a cancer model with intermediate characteristics between in vitro bi-dimensional cultures and in vivo tumors. Multicellular Tumor Spheroids also acquire tumor aggressiveness features due to transcription modulation of coding and non-coding RNA. Utilizing microarray analyses, we evaluated the microRNAs expression profile in MCF-7 breast cancer cells cultured as Multicellular Tumor Spheroids. The expression data was used to predict associated cellular and molecular functions using different software tools. The biological importance of two dysregulated miRNAs (miR-221-3p and miR-187) was studied by functional assays. Finally, the clinical relevance of these dysregulated miRNAs was explored using previously reported data. Thirty-three dysregulated microRNAs were found in MCF-7 Multicellular Tumor Spheroids. miRNA expression changes were closely linked with growth, proliferation, and cell development. miRNA-221-3p and miR-187 were implicated in the acquisition of migration/invasion capacities, sensitivity to the deprivation of growth factors, cell cycle phase regulation, and cell death. A panel of 5 miRNAs, including miR-187, showed a good predictive value in discriminating between low and high-risk groups of breast cancer.

BACKGROUND: Long-non-coding RNAs, a class of transcripts with lengths > 200 nt, play key roles in tumour progression. Previous reports revealed that LINC00052 (long intergenic non-coding RNA 00052) was strongly downregulated during breast cancer multicellular spheroids formation and suggested a role in cell migration and oxidative metabolism. OBJECTIVE: To examine the function of LINC00052 in MCF-7 breast cancer cells. METHODS: Loss-of-function studies were performed to evaluate LINC00052 role on MCF-7 breast cancer cells. Microarray expression assays were performed to determine genes and cellular functions modified after LINC00052 knockdown. Next, the impact of LINC00052 depletion on MCF-7 cell respiration and migration was evaluated. RESULTS: 1,081 genes were differentially expressed upon LINC00052 inhibition. Gene set enrichment analysis, Gene Ontology and Key Pathway Advisor analysis showed that signalling networks related to cell migration and oxidative phosphorylation were enriched. However, whereas LINC00052 knockdown in MCF-7 cells revealed marginal difference in oxygen consumption rates when compared with control cells, LINC00052 inhibition enhanced cell migration in vitro and in vivo, as observed using a Zebrafish embryo xenotransplant model. CONCLUSION: Our data show that LINC00052 modulates MCF-7 cell migration. Genome-wide microarray experiments suggest that cancer cell migration is affected by LINC00052 through cytoskeleton modulation and Notch/β-catenin/NF-κB signalling pathways.