MicroRNA‑4530 suppresses cell proliferation and induces apoptosis by targeting RASA1 in human umbilical vein endothelial cells

Negative Regulation of ULK1 by microRNA-106a in Autophagy Induced by a Triple Drug Combination in Colorectal Cancer Cells In Vitro

Colorectal cancer (CRC) is among the top three most deadly cancers worldwide. The survival rate for this disease has not been reduced despite the treatments, the reason why the search for therapeutic alternatives continues to be a priority issue in oncology. In this research work, we tested our successful pharmacological combination of three drugs, metformin, doxorubicin, and sodium oxamate (triple therapy, or TT), as an autophagy inducer. Firstly, we employed western blot (WB) assays, where we observed that after 8 h of stimulation with TT, the proteins Unc-51 like autophagy activating kinase 1(ULK1), becline-1, autophagy related 1 protein (Atg4), and LC3 increased in the CRC cell lines HCT116 and SW480 in contrast to monotherapy with doxorubicin. The overexpression of these proteins indicated the beginning of autophagy flow through the activation of ULK1 and the hyperlipidation of LC3 at the beginning of this process. Moreover, we confirm that ULK1 is a bona fide target of hsa-miR-106a-5p (referred to from here on as miR-106a) in HCT116. We also observed through the GFP-LC3 fusion protein that in the presence of miR-106a, the accumulation of autophagy vesicles in cells stimulated with TT is inhibited. These results show that the TT triggered autophagy to modulate miR-106a/ULK1 expression, probably affecting different cellular pathways involved in cellular proliferation, survivance, metabolic maintenance, and cell death. Therefore, considering the importance of autophagy in cancer biology, the study of miRNAs that regulate autophagy in cancer will allow a better understanding of malignant tumors and lead to the development of new disease markers and therapeutic strategies.

Role of RASA1 in cancer: A review and update (Review)

Ras p21 protein activator 1 (RASA1) is a regulator of Ras GDP and GTP and is involved in numerous physiological processes such as angiogenesis, cell proliferation, and apoptosis. As a result, RASA1 also contributes to pathological processes in vascular diseases and tumour formation. This review focuses on the role of RASA1 in multiple tumours types in the lung, intestines, liver, and breast. Furthermore, we discuss the potential mechanisms of RASA1 and its downstream effects through Ras/RAF/MEK/ERK or Ras/PI3K/AKT signalling. Moreover, miRNAs are capable of regulating RASA1 and could be a novel targeted treatment strategy for tumours.

miR-132-3p priming enhances the effects of mesenchymal stromal cell-derived exosomes on ameliorating brain ischemic injury

Backgrounds/aims

Mesenchymal stromal cell-derived exosomes (MSC-EXs) could exert protective effects on recipient cells by transferring the contained microRNAs (miRs), and miR-132-3p is one of angiogenic miRs. However, whether the combination of MSC-EXs and miR-132-3p has better effects in ischemic cerebrovascular disease remains unknown.

Methods

Mouse MSCs transfected with scrambler control or miR-132-3p mimics were used to generate MSC-EXs and miR-132-3p-overexpressed MSC-EXs (MSC-EXs^miR-132-3p). The effects of EXs on hypoxia/reoxygenation (H/R)-injured ECs in ROS generation, apoptosis, and barrier function were analyzed. The levels of RASA1, Ras, phosphorylations of PI3K, Akt and endothelial nitric oxide synthesis (eNOS), and tight junction proteins (Claudin-5 and ZO-1) were measured. Ras and PI3K inhibitors were used for pathway analysis. In transient middle cerebral artery occlusion (tMCAO) mouse model, the effects of MSC-EXs on the cerebral vascular ROS production and apoptosis, cerebral vascular density (cMVD), Evans blue extravasation, brain water content, neurological deficit score (NDS), and infarct volume were determined.

Results

MSC-EXs could deliver their carried miR-132-3p into target ECs, which functionally downregulated the target protein RASA1, while upregulated the expression of Ras and the downstream PI3K phosphorylation. Compared to MSC-EXs, MSC-EXs^miR-132-3p were more effective in decreasing ROS production, apoptosis, and tight junction disruption in H/R-injured ECs. These effects were associated with increased levels of phosphorylated Akt and eNOS, which could be abolished by PI3K inhibitor (LY294002) or Ras inhibitor (NSC 23766). In the tMCAO mouse model, the infusion of MSC-EXs^miR-132-3p was more effective than MSC-EXs in reducing cerebral vascular ROS production, BBB dysfunction, and brain injury.

Conclusion

Our results suggest that miR-132-3p promotes the beneficial effects of MSC-EXs on brain ischemic injury through protecting cerebral EC functions.

Differential Secretion of Angiopoietic Factors and Expression of MicroRNA in Umbilical Cord Blood from Healthy Appropriate-For-Gestational-Age Preterm and Term Newborns-in Search of Biomarkers of Angiogenesis-Related Processes in Preterm Birth

Objectives: Premature birth, defined as less than 37 weeks gestation, affects approximately 12% of all live births around the world. Advances in neonatal care have resulted in the increased survival of infants born prematurely. Although prematurity is a known risk factor for different cardiovascular diseases, little is known about the pathophysiology of vasculature during premature gestation and angiopoietic factors network during premature birth. Aims: The objective of this study was to determine whether the profile of several pro-angiogenic and anti-angiogenic factors in umbilical cord blood (UCB) is different in healthy appropriate-for-gestational-age preterm newborns and normal term babies. The second aim of this study was to investigate the microRNA (miRNAs) expression profile in UCB from preterm labor and to detect miRNAs potentially taking part in control of angogenesis-related processes (Angio-MiRs). Methods: Using an immunobead Luminex assay, we simultaneously measured the concentration of Angiogenin, Angiopoietin-1, FGF-acidic, FGF-basic, PDGF-aa, PlGF, VEGF, VEGF-D, Endostatin, Thrombospondin-2, NGF, BDNF, GDNF, and NT-4 in UCB samples collected from the preterm (n = 27) and term (n = 52) delivery. In addition, the global microRNA expression in peripheral blood mononuclear cells (PBMCs) circulating in such UCB samples was examined in this study using microarray MiRNA technique. Results: The concentrations of five from eight measured pro-angiogenic factors (VEGF, Angiopoietin-1, PDGF-AA, FGF-a, and FGF-b) were significantly lower in UCB from preterm newborns. On the contrary, two angiostatic factors (Endostatin and Thrombospondin-2) were significantly up-regulated in preterm UCB. Among analyzed neurotrophins in preterm newborns, the elevated UCB concentration was found only in the case of GDNF, whereas BDNF was significantly reduced. Moreover, two angiopoietic factors, VEGF-D and PlGF, and two neurotrophins, NT4 and NGF, did not differ in concentration in preterm and term babies. We also discovered that among the significantly down-regulated miRNAs, there were several classical Angio-MiRs (inter alia MiR-125, MiR-126, MiR-145, MiR-150, or MiR155), which are involved in angiogenesis regulation in newborn after preterm delivery. Conclusions: This is the first report of simultaneous measurements of several angiopoietic factors in UCB collected from infants during preterm and term labor. Here, we observed that several pro-angiogenic factors were at lower concentration in UCB collected from preterm newborns than term babies. In contrast, the two measured angiostatic factors, Endostatin and Thrombospondin-2, were significantly higher in UCB from preterm babies. This can suggest that distinct pathophysiological contributions from differentially expressed various angiopoietic factors may determine the clinical outcomes after preterm birth. Especially, our angiogenesis-related molecules analysis indicates that preterm birth of healthy, appropriate-for-gestational-age newborns is an “anti-angiogenic state” that may provide an increased risk for improper development and function of cardiovascular system in the adulthood. This work also contributes to a better understanding of the role of miRNAs potentially involved in angiogenesis control in preterm newborns.

miR‑342 inhibits glioma cell proliferation by targeting GPRC5A

Accumulating evidence suggests that microRNAs (miRNAs) play a key role in the biological behaviors and progression of glioma. However, the function and bio-molecular mechanisms of miR-342 in glioma remain largely unclear. In the present study, reverse transcription quantitative-polymerase chain reaction and western blotting were performed to determine the mRNA and protein expression levels of the factors investigated. MTT assay was performed to examine the proliferation rates. Luciferase reporter assay was performed to test the binding between miRNA-342 and its putative target. Data indicated that miR-342 expression was markedly decreased in human glioma tissues and cell line U87, and reduced miR-342 expression significantly promoted cell proliferation. In order to explore the mechanisms, G-protein coupled receptor family C group 5 member A (GPRC5A) was identified as a target of miR-342 and depletion of GPRC5A suppressed cell proliferation. Our findings demonstrated that miR-342 regulates the cell proliferation of glioma by targeting GPRC5A, which indicates that miR-342 is a target of interest regarding the treatment of refractory glioma, and it may provide a promising prognostic and therapeutic strategy for glioma treatment.