Organotypic 3D Cell-Architecture Impacts the Expression Pattern of miRNAs-mRNAs Network in Breast Cancer SKBR3 Cells.

BACKGROUND: Currently, most of the research on breast cancer has been carried out in conventional two-dimensional (2D) cell cultures due to its practical benefits, however, the three-dimensional (3D) cell culture is becoming the model of choice in cancer research because it allows cell-cell and cell-extracellular matrix (ECM) interactions, mimicking the native microenvironment of tumors in vivo. METHODS: In this work, we evaluated the effect of 3D cell organization on the expression pattern of miRNAs (by Small-RNAseq) and mRNAs (by microarrays) in the breast cancer SKBR3 cell line and analyzed the biological processes and signaling pathways regulated by the differentially expressed protein-coding genes (DE-mRNAs) and miRNAs (DE-microRNAs) found in the organoids. RESULTS: We obtained well-defined cell-aggregated organoids with a grape cluster-like morphology with a size up to 9.2 × 105 µm3. The transcriptomic assays showed that cell growth in organoids significantly affected (all p < 0.01) the gene expression patterns of both miRNAs, and mRNAs, finding 20 upregulated and 19 downregulated DE-microRNAs, as well as 49 upregulated and 123 downregulated DE-mRNAs. In silico analysis showed that a subset of 11 upregulated DE-microRNAs target 70 downregulated DE-mRNAs. These genes are involved in 150 gene ontology (GO) biological processes such as regulation of cell morphogenesis, regulation of cell shape, regulation of canonical Wnt signaling pathway, morphogenesis of epithelium, regulation of cytoskeleton organization, as well as in the MAPK and AGE-RAGE signaling KEGG-pathways. Interestingly, hsa-mir-122-5p (Fold Change (FC) = 15.4), hsa-mir-369-3p (FC = 11.4), and hsa-mir-10b-5p (FC = 20.1) regulated up to 81% of the 70 downregulated DE-mRNAs. CONCLUSION: The organotypic 3D cell-organization architecture of breast cancer SKBR3 cells impacts the expression pattern of the miRNAs-mRNAs network mainly through overexpression of hsa-mir-122-5p, hsa-mir-369-3p, and hsa-mir-10b-5p. All these findings suggest that the interaction between cell-cell and cell-ECM as well as the change in the culture architecture impacts gene expression, and, therefore, support the pertinence of migrating breast cancer research from conventional cultures to 3D models.

Cell Survival Is Regulated via SOX9/BCL2L1 Axis in HCT-116 Colorectal Cancer Cell Line.

Colorectal cancer (CRC) is one of the most frequent types of malignancies and one of the major causes of cancer-related death worldwide. Sex-determining region Y (SRY)-box 9 protein (SOX9) is a member of the SOX family of transcription factors which are involved in the regulation of differentiation and development. Recently, several reports suggest an important role of SOX9 in tumorigenesis since its overexpression correlates with tumor progression and poor outcome in several types of cancer; however, its role in CRC is not clear until now. Therefore, in this work, we searched for novel SOX9-regulated genes involved in cell survival of CRC. We silenced SOX9 in the poorly differentiated HCT-116 cell line, using a specific siRNA, to identify differential expressed genes by DNA microarrays and analyzed the role or candidate genes in apoptosis and autophagy. Transcriptome analysis showed that diverse cellular pathways, associated with CRC carcinogenesis such as Wnt/ß-catenin, MAPK, TGF-ß, and mTOR, were modulated after SOX9 silencing. Interestingly, we found that SOX9 silencing promotes downregulation of BCL2L1 and overexpression of CASP3, proteins related to apoptosis, which was further confirmed in SW-480, a moderated-differentiated cell line, but not in HT-29, well-differentiated cell line. Moreover, inhibition of BCL2L1 by ABT-737 (BH3 mimetic) in SOX9-silenced HCT-116 cells resulted in an increased apoptosis percentage. However, downregulation of BCL2L1 was not enough to induce autophagy. This is the first report, suggesting that cell survival in poorly and moderated-differentiated CRC cells lines is regulated by SOX9/BCL2L1 axis, but not in well-differentiated cell lines.

HLA Alleles are Genetic Markers for Susceptibility and Resistance towards Leprosy in a Mexican Mestizo Population.

Despite the use of multidrug therapy, leprosy remains endemic in some countries. The association of several human leucocyte antigen (HLA) alleles and gene polymorphisms with leprosy has been demonstrated in many populations, but the major immune contributors associated to the spectrum of leprosy have not been defined yet. In this study, genotyping of HLA-A, -B, -DR, and -DQ alleles was performed in leprosy patients (n = 113) and control subjects (n = 117) from the region with the highest incidence for the disease in México. The odds of developing leprosy and lepromatous subtype were 2.12- and 2.74-fold higher in carriers of HLA-A*28, and 2.48- and 4.14-fold higher for leprosy and dimorphic subtype in carriers of DQB1*06. Interestingly, DQB1*07 was overrepresented in healthy individuals, compared to patients with leprosy (OR = 0.08) and the lepromatous subtype (OR = 0.06). These results suggest that HLA-A*28 is a marker for predisposition to leprosy and the lepromatous subtype and DQB1*06 to leprosy and the dimorphic subtype, while DQB1*07 might be a resistance marker in this Mestizo population.