Comparing MicroRNA Profilings of Purified HER-2-Negative and HER-2-Positive Cells Validates miR-362-5p/Sema3A as Characteristic Molecular Change in Triple-Negative Breast Cancers

Sema3A Alleviates the Malignant Behaviors of Gastric Cancer Cells by Inhibiting NRP-1

AIMS AND OBJECTIVES

Semaphorin3A (Sema3a) is lowly expressed in the peripheral blood of gastric cancer patients, suggesting Sema3a may be involved in the progression of gastric cancer. Nevertheless, the specific role and the potential regulatory mechanism of Sema3a in gastric cancer is still obscure. Neuropilin-1 (NRP-1) has been reported to interact with Sema3a; herein, we intended to reveal the role and regulatory mechanism of Sema3a/neuropilin-1 (NRP-1) in gastric cancer progression.

METHODS

Cell transfection was carried out to regulate gene expression. CCK-8 and colony formation assays were applied to estimate cell proliferation. Scratch assay and transwell assay were conducted to assess the cell migration and invasion abilities. Angiogenesis ability was assessed using a tubule-forming assay. The expression of corresponding genes and proteins were detected by RT-qPCR and western blot, respectively.

RESULTS

Data showed that Sema3a was downregulated in gastric cancer cells and NRP-1 was upregulated. Sema3a overexpression repressed NRP-1 level in AGS cells. Overexpression of Sema3a inhibited cell proliferation, migration, and invasion abilities as well as epithelial-mesenchymal transition (EMT) of AGS cells. Overexpression of Sema3a inhibited tube formation and reduced the expression of VEGFA/VEGFR2 in AGS cells. However, the effects of Sema3a overexpression on the malignant behaviors in AGS cells were partly reversed by NRP-1 overexpression. Additionally, Sema3a overexpression enhanced the inhibitory effects of Ramucirumab, an anti-VEGFR2 agent, on the proliferative, migratory, and invasive capabilities as well as EMT in AGS cells.

CONCLUSION

In conclusion, Sema3a alleviates the proliferation, migration, invasion, and angiogenesis capabilities of gastric cancer cells via repressing NRP-1. This finding may provide potential targets for gastric cancer therapy.

ER Negative Breast Cancer and miRNA: There Is More to Decipher Than What the Pathologist Can See!

Breast cancer (BC), the most prevalent cancer in women, is a heterogenous disease. Despite advancements in BC diagnosis, prognosis, and therapeutics, survival rates have drastically decreased in the metastatic setting. Therefore, BC still remains a medical challenge. The evolution of high-throughput technology has highlighted gaps in the classification system of BCs. Of particular interest is the notorious triple negative BC, which was recounted as being heterogenous itself and it overlaps with distinct subtypes, namely molecular apocrine (MA) and luminal androgen (LAR) BCs. These subtypes are, even today, still misdiagnosed and poorly treated. As such, researchers and clinicians have been looking for ways through which to refine BC classification in order to properly understand the initiation, development, progression, and the responses to the treatment of BCs. One tool is biomarkers and, specifically, microRNA (miRNA), which are highly reported as associated with BC carcinogenesis. In this review, the diverse roles of miRNA in estrogen receptor negative (ER-) and androgen receptor positive (AR+) BC are depicted. While highlighting their oncogenic and tumor suppressor functions in tumor progression, we will discuss their diagnostic, prognostic, and predictive biomarker potentials, as well as their drug sensitivity/resistance activity. The association of several miRNAs in the KEGG-reported pathways that are related to ER-BC carcinogenesis is presented. The identification and verification of accurate miRNA panels is a cornerstone for tackling BC classification setbacks, as is also the deciphering of the carcinogenesis regulators of ER - AR + BC.

Role of MicroRNA-502-3p in Human Diseases

MicroRNAs (miRNAs) are non-coding RNAs that play a major role in gene regulation in several diseases. MicroRNA-502-3p (MiR-502-3p) has been previously characterized in a variety of human diseases such as osteoporosis, diabetes, tuberculosis, cancers, and neurological disorders. Our studies recently explored the new role of miR-502-3p in regulating synapse function in Alzheimer’s disease (AD). AD is the most common cause of dementia in elderly individuals. Synapse is the initial target that is hit during AD progression. The most common causes of synapse dysfunction in AD are amyloid beta, hyperphosphorylated tau, and microglia activation. MiR-502-3p was found to be localized and overexpressed in the AD synapses. Overexpression of miR-502-3p was correlated with AD severity in terms of Braak stages. Studies have shown that miR-502-3p modulates the glutaminergic and GABAergic synapse function in AD. The current study’s emphasis is to discuss the in-depth roles of miR-502-3p in human diseases and AD and the future possibilities concerning miR-502-3p as a therapeutic for AD treatment.

Alteration of miR-362-5p and miR-454-3p expression elicits diverse responses in breast cancer cell lines

BACKGROUND

The heterogeneity of breast tumors presents a challenge in disease management, necessitating an understanding of the molecular mechanisms driving breast tumorigenesis. Aberrant expression of microRNAs is known to promote tumor growth and progression. Our previous RNA-sequencing dataset revealed the upregulation of miR-362-5p and miR-454-3p in breast tumors. We investigated potential role of miR-362-5p and miR-454-3p in breast cancer using MDAMB231 and MCF7 cell lines.

METHODS AND RESULTS

The expression of miR-362-5p and miR-454-3p were altered in MCF7 and MDAMB231 using mimics and inhibitors. The effect on cell viability, cell cycle progression and migration was assessed using Alamar blue assay, flow cytometry and wound healing assay. Further, the expression of potential target genes were measured using real-time PCR. Our results indicated that an increased expression of miR-362-5p promoted cell growth and survival in MCF7, but decreased cell migration. In contrast, miR-362-5p overexpression reduced cancer cell growth, survival and migration in MDAMB231. Overexpression of miR-454-3p was oncogenic in both cell lines but suppressed migration in the aggressive cell line MDAMB231.

CONCLUSION

Two microRNAs, miR-362-5p and miR-454-3p, were evaluated for functional activity in breast cancer cell lines and they showed increased proliferative signals and tumorigenic properties.

Modulatory Role of microRNAs in Triple Negative Breast Cancer with Basal-Like Phenotype

Development of new research, classification, and therapeutic options are urgently required due to the fact that TNBC is a heterogeneous malignancy. The expression of high molecular weight cytokeratins identifies a biologically and clinically distinct subgroup of TNBCs with a basal-like phenotype, representing about 75% of TNBCs, while the remaining 25% includes all other intrinsic subtypes. The triple negative phenotype in basal-like breast cancer (BLBC) makes it unresponsive to endocrine therapy, i.e., tamoxifen, aromatase inhibitors, and/or anti-HER2-targeted therapies; for this reason, only chemotherapy can be considered an approach available for systemic treatment even if it shows poor prognosis. Therefore, treatment for these subgroups of patients is a strong challenge for oncologists due to disease heterogeneity and the absence of unambiguous molecular targets. Dysregulation of the cellular miRNAome has been related to huge cellular process deregulations underlying human malignancy. Consequently, epigenetics is a field of great promise in cancer research. Increasing evidence suggests that specific miRNA clusters/signatures might be of clinical utility in TNBCs with basal-like phenotype. The epigenetic mechanisms behind tumorigenesis enable progress in the treatment, diagnosis, and prevention of cancer. This review intends to summarize the epigenetic findings related to miRNAome in TNBCs with basal-like phenotype.