Expression of Bioinformatically Candidate miRNAs including, miR-576-5p, miR-501-3p and miR-3143, Targeting PI3K Pathway in Triple-Negative Breast Cancer

A Tiny Viral Protein, SARS-CoV-2-ORF7b: Functional Molecular Mechanisms

This study presents the interaction with the human host metabolism of SARS-CoV-2 ORF7b protein (43 aa), using a protein-protein interaction network analysis. After pruning, we selected from BioGRID the 51 most significant proteins among 2753 proven interactions and 1708 interactors specific to ORF7b. We used these proteins as functional seeds, and we obtained a significant network of 551 nodes via STRING. We performed topological analysis and calculated topological distributions by Cytoscape. By following a hub-and-spoke network architectural model, we were able to identify seven proteins that ranked high as hubs and an additional seven as bottlenecks. Through this interaction model, we identified significant GO-processes (5057 terms in 15 categories) induced in human metabolism by ORF7b. We discovered high statistical significance processes of dysregulated molecular cell mechanisms caused by acting ORF7b. We detected disease-related human proteins and their involvement in metabolic roles, how they relate in a distorted way to signaling and/or functional systems, in particular intra- and inter-cellular signaling systems, and the molecular mechanisms that supervise programmed cell death, with mechanisms similar to that of cancer metastasis diffusion. A cluster analysis showed 10 compact and significant functional clusters, where two of them overlap in a Giant Connected Component core of 206 total nodes. These two clusters contain most of the high-rank nodes. ORF7b acts through these two clusters, inducing most of the metabolic dysregulation. We conducted a co-regulation and transcriptional analysis by hub and bottleneck proteins. This analysis allowed us to define the transcription factors and miRNAs that control the high-ranking proteins and the dysregulated processes within the limits of the poor knowledge that these sectors still impose.

Identification of miR-3182 and miR-3143 target genes involved in the cell cycle as a novel approach in TNBC treatment: A systems biology approach

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with a poor prognosis, lacking therapeutic targets. miRNAs play crucial roles in TNBC through regulating various mechanisms, including cellular growth and proliferation. This study aims to identify critical target genes of two novel miRNAs (miR-3143 and miR-3182) involved in the cell cycle of TNBC as possible therapeutic targets and investigates their regulatory and therapeutic roles through a systems biology approach and in vitro experiment. Datasets related to the TNBC cell line (MDA-MB-231) were screened and retrieved, and Gene regulatory networks were constructed. Significant regulatory motifs were detected and analyzed using the FANMOD and Cytoscape analyzer, and the clusters and seeds were identified using the MCODE. Functional enrichment analysis was also performed using DAVID and STRING. The most critical genes were determined using the analysis of GRN motifs and PPI clusters. The essential genes involved in the cell cycle were selected and verified using the bc-GenExMiner v4.7. We overexpressed miR-3143 and miR-3182 in the MDA-MB-231 cell line using human umbilical cord mesenchymal stem cell (HUCMSC)-miRNA loaded exosomes, and the expression of the critical target genes was investigated using RT-qPCR. We identified eight critical genes as potential therapeutic targets. Their expression decreased by overexpression of miR-3143 and miR-3182 in RT-qPCR. The identified critical genes have probably significant roles in the pathogenesis of TNBC through the cell cycle. We suggest that the overexpression of miR-3143 and miR-3182 could be a new therapeutic candidate in TNBC and is worth more investigation.

miRNA-576-5p promotes endometrial cancer cell growth and metastasis by targeting ZBTB4

PURPOSE

MicroRNAs (miRNAs) have already been shown to have a strong correlation with the invasion and metastasis capacity of tumor cells. The present research examined the function of miRNA-576-5p (miR-576-5p) in the development of endometrial cancer (EC).

METHODS

miR-576-5p and ZBTB4 expression in EC and benign endometrial tissues was measured using quantitative real-time PCR (qRT-PCR) and western blot. To evaluate the proliferation ability of tumor cells in vitro, 2,5-diphenyl-2H-tetrazolium bromide (MTT) and colony formation assays were carried out. The effect of miR-576-5p on the proliferation ability of EC cells in vivo was measured by the tumor formation in nude mice. The migration and invasion ability of tumor cells was determined using the transwell assay. To confirm the association between expressions of miR-576-5p and zinc finger and BTB domain containing four (ZBTB4), western blot, qRT-PCR, and luciferase assay were carried out.

RESULTS

miR-576-5p expression increased significantly in EC samples than in benign endometrial tissues. The level of miR-576-5p was significantly higher in the polymerase ε (POLE) ultramutated subgroup compared to the other three subgroups. High levels of miR-576-5p expression were linked to a shorter progression-free interval time in the copy number high subgroup. Furthermore, upregulated miR-576-5p facilitated EC cell invasion and migration in vitro and promoted the proliferation of EC tumor cell lines both in vitro and in vivo. Moreover, this study showed that the expression of ZBTB4 decreased in patients with EC, and the dual-luciferase reporter assay confirmed that miR-576-5p binds directly to the 3'-UTR of ZBTB4 and inhibits the expression of ZBTB4. An increase in miR-576-5p expression leads to a decrease in the mRNA and protein expression level of ZBTB4. The effects of miR-576-5p can be reversed by overexpression of ZBTB4.

CONCLUSION

miR-576-5p promoted proliferation and metastasis capacity of EC cells by inhibiting ZBTB4 expression. We hypothesized that miR-576-5p could be a prospective therapeutic target for EC.

Assessment of Phenylboronic Acid Nitrogen Mustards as Potent and Selective Drug Candidates for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) has limited treatment options and the worst prognosis among all types of breast cancer. We describe two prodrugs, namely, CWB-20145 (1) and its methyl analogue FAN-NM-CH3 (2) that reduced the size of TNBC-derived tumors. The DNA cross-linking of nitrogen mustard prodrugs 1 and 2 was superior to that of chlorambucil and melphalan once activated in the presence of H2O2. The cellular toxicity of 1 and 2 was demonstrated in seven human cancer cell lines. The TNBC cell line MDA-MB-468 was particularly sensitive toward 1 and 2. Compound 2 was 10 times more cytotoxic than chlorambucil and 16 times more active than melphalan. An evaluation of the gene expression demonstrated an upregulation of the tumor suppressor genes p53 and p21 supporting a transcriptional mechanism of a reduced tumor growth. Pharmacokinetic studies with 1 showed a rapid conversion of the prodrug. The introduction of a methyl group generated 2 with an increased half-life. An in vivo toxicity study in mice demonstrated that both prodrugs were less toxic than chlorambucil. Compounds 1 and 2 reduced tumor growth with an inhibition rate of more than 90% in athymic nude mice xenografted with MDA-MB-468 cells. Together, the in vivo investigations demonstrated that treatment with 1 and 2 suppressed tumor growth without affecting normal tissues in mice. These phenylboronic acid nitrogen mustard prodrugs represent promising drug candidates for the treatment of TNBC. However, the mechanisms underlying their superior in vivo activity and selectivity as well as the correlation between H2O2 level and in vivo efficacy are not yet fully understood.