Mir-29b in Breast Cancer: A Promising Target for Therapeutic Approaches

lncRNAs and cyclin-dependent kinases: Unveiling their critical roles in cancer progression

Long non-coding RNAs (lncRNAs) are a diverse class of RNA molecules that do not code for proteins but play critical roles in gene regulation. One such role involves the modulation of cell cycle progression and proliferation through interactions with cyclin-dependent kinases (CDKs), key regulators of cell division. Dysregulation of CDK activity is a hallmark of cancer, contributing to uncontrolled cell growth and tumor formation. These lncRNA-CDK interactions are part of a complex network of molecular mechanisms underlying cancer pathogenesis, involving various signaling pathways and regulatory circuits. Understanding the interplay between lncRNAs, CDKs, and cancer biology holds promise for developing novel therapeutic strategies targeting these molecular targets for more effective cancer treatment. Furthermore, targeting CDKs, key cell cycle progression and proliferation regulators, offers another avenue for disrupting cancer pathways and overcoming drug resistance. This can open new possibilities for individualized treatment plans and focused therapeutic interventions.

Exploring the interplay between triple-negative breast cancer stem cells and tumor microenvironment for effective therapeutic strategies

Triple-negative breast cancer (TNBC) is a highly aggressive and metastatic malignancy with poor treatment outcomes. The interaction between the tumor microenvironment (TME) and breast cancer stem cells (BCSCs) plays an important role in the development of TNBC. Owing to their ability of self-renewal and multidirectional differentiation, BCSCs maintain tumor growth, drive metastatic colonization, and facilitate the development of drug resistance. TME is the main factor regulating the phenotype and metastasis of BCSCs. Immune cells, cancer-related fibroblasts (CAFs), cytokines, mesenchymal cells, endothelial cells, and extracellular matrix within the TME form a complex communication network, exert highly selective pressure on the tumor, and provide a conducive environment for the formation of BCSC niches. Tumor growth and metastasis can be controlled by targeting the TME to eliminate BCSC niches or targeting BCSCs to modify the TME. These approaches may improve the treatment outcomes and possess great application potential in clinical settings. In this review, we summarized the relationship between BCSCs and the progression and drug resistance of TNBC, especially focusing on the interaction between BCSCs and TME. In addition, we discussed therapeutic strategies that target the TME to inhibit or eliminate BCSCs, providing valuable insights into the clinical treatment of TNBC.

Profiling canine mammary tumors: A potential model for studying human breast cancer

Despite all clinical progress recorded in the last decades, human breast cancer (HBC) remains a major challenge worldwide both in terms of its incidence and its management. Canine mammary tumors (CMTs) share similarities with HBC and represent an alternative model for HBC. The utility of the canine model in studying HBC relies on their common features, include spontaneous development, subtype classification, mutational profile, alterations in gene expression profile, and incidence/prevalence. This review describes the similarities between CMTs and HBC regarding genomic landscape, microRNA expression alteration, methylation, and metabolomic changes occurring during mammary gland carcinogenesis. The primary purpose of this review is to highlight the advantages of using the canine model as a translational animal model for HBC research and to investigate the challenges and limitations of this approach.

miRNAs: Potential as Biomarkers and Therapeutic Targets for Cancer

MicroRNAs (miRNAs) are single-stranded, non-coding RNA molecules that regulate gene expression post-transcriptionally by binding to messenger RNAs. miRNAs are important regulators of gene expression, and their dysregulation is implicated in many human and canine diseases. Most cancers tested to date have been shown to express altered miRNA levels, which indicates their potential importance in the oncogenic process. Based on this evidence, numerous miRNAs have been suggested as potential cancer biomarkers for both diagnosis and prognosis. miRNA-based therapies have also been tested in different cancers and have provided measurable clinical benefits to patients. In addition, understanding miRNA biogenesis and regulatory mechanisms in cancer can provide important knowledge about resistance to chemotherapies, leading to more personalized cancer treatment. In this review, we comprehensively summarized the importance of miRNA in human and canine cancer research. We discussed the current state of development and potential for the miRNA as both a diagnostic marker and a therapeutic target.

Discovering the Biological Significance and Therapeutic Potential of miR-29b-3p in Triple-Negative Breast Cancer

The lack of estrogen or progesterone receptors and absence of HER2 amplification/overexpression in triple-negative breast cancer (TNBC) restricts therapeutic options used in clinical management. MicroRNAs (miRNAs) are small, non-coding transcripts which affect important cellular mechanisms by regulating gene expression at the post-transcriptional level. Among this class, attention was focused on miR-29b-3p with a high profile in TNBC and correlated with the overall survival rates, as TCGA data revealed. This study aims to investigate the implication of the miR-29b-3p inhibitor in TNBC cell lines by identifying a potential therapeutic transcript, improving the clinical outcomes of this disease. The experiments were performed on two TNBC cell lines (MDA-MB-231 and BT549) as in vitro models. An established dose of 50 nM was used for all functional assays performed on the miR-29b-3p inhibitor. A decreased level of miR-29b-3p determined a significant reduction in cell proliferation and colony-forming capacity. At the same time, the changes occurring at the molecular and cellular levels were highlighted. We observed that, when inhibiting the expression level of miR-29b-3p, processes such as apoptosis and autophagy were activated. Further, microarray data revealed that the miRNA expression pattern was altered after miR-29b-3p inhibition, pointing out 8 overexpressed and 11 downregulated miRNAs specific for BT549 cells and 33 upregulated and 10 downregulated miRNAs that were specific for MDA-MB-231 cells. As a common signature for both cell lines, three transcripts were observed, two downregulated, miR-29b-3p and miR-29a, and one upregulated, miR-1229-5p. According to DIANA miRPath, the main predicted targets are related to ECM (extracellular matrix) receptor interaction and TP53 signaling. An additional validation step through qRT-PCR was performed, which showed an upregulation of MCL1 and TGFB1. By inhibiting the expression level of miR-29b-3p, it was shown that complex regulatory pathways targeted this transcript in TNBC cells.