MicroRNA-488 inhibits proliferation, invasion and EMT in osteosarcoma cell lines by targeting aquaporin 3

Targeting IL-11R/EZH2 signaling axis as a therapeutic strategy for osteosarcoma lung metastases

Lung metastases are the primary cause of death for osteosarcoma (OS) patients. We recently validated interleukin-11 receptor α (IL-11Rα) as a molecular target for the inhibition of OS lung metastases. Since there is no clinically approved antibody against this receptor, we sought to identify downstream targets that mediate the effects of IL-11Rα signaling. We used shRNA to deplete IL-11Rα from OS cells; as a complementary approach, we added IL-11 exogenously to OS cells. The resulting changes in gene expression identified EZH2 as a downstream candidate. This was confirmed by knockdown of IL-11Rα in OS cells, which led to increased expression of genes repressed by histone methyltransferase EZH2, including members of the WNT pathway, a known target pathway of EZH2. Exogenous IL-11 increased the global levels of histone H3 lysine 27 trimethylation, evidence of EZH2 activation. Treatment with the EZH2 inhibitor GSK126 significantly reduced in vitro proliferation and increased cell-cycle arrest and apoptosis, which were partially mediated through the WNT pathway. In vivo, treatment of an orthotopic nude mouse model of OS with GSK126 inhibited lung metastatic growth and prolonged survival. In addition, significantly shorter recurrence-free survival was seen in OS patients with high levels of EZH2 in their primary tumors (P < .05). This suggests that IL-11Rα promotes OS lung metastasis via activation of EZH2. Thus, blocking EZH2 activity may be an effective strategy for inhibiting OS lung metastasis and improving prognosis.

miR-488-3p Represses Malignant Behaviors and Facilitates Autophagy of Osteosarcoma Cells by Targeting Neurensin-2

OBJECTIVES

Osteosarcoma (OS) is a primary bone sarcoma that primarily affects children and adolescents and poses significant challenges in terms of treatment. microRNAs (miRNAs) have been implicated in OS cell growth and regulation. This study sought to investigate the role of hsa-miR-488-3p in autophagy and apoptosis of OS cells.

METHODS

The expression of miR-488-3p was examined in normal human osteoblasts and OS cell lines (U2OS, Saos2, and OS 99-1) using RT-qPCR. U2OS cells were transfected with miR-488- 3p-mimic, and cell viability, apoptosis, migration, and invasion were assessed using CCK-8, flow cytometry, and Transwell assays, respectively. Western blotting and immunofluorescence were employed to measure apoptosis- and autophagy-related protein levels, as well as the autophagosome marker LC3. The binding sites between miR-488-3p and neurensin-2 (NRSN2) were predicted using online bioinformatics tools and confirmed by a dual-luciferase assay. Functional rescue experiments were conducted by co-transfecting miR-488-3p-mimic and pcDNA3.1-NRSN2 into U2OS cells to validate the effects of the miR-488-3p/NRSN2 axis on OS cell behaviors. Additionally, 3-MA, an autophagy inhibitor, was used to investigate the relationship between miR- 488-3p/NRSN2 and cell apoptosis and autophagy.

RESULTS

miR-488-3p was found to be downregulated in OS cell lines, and its over-expression inhibited the viability, migration, and invasion while promoting apoptosis of U2OS cells. NRSN2 was identified as a direct target of miR-488-3p. Over-expression of NRSN2 partially counteracted the inhibitory effects of miR-488-3p on malignant behaviors of U2OS cells. Furthermore, miR- 488-3p induced autophagy in U2OS cells through NRSN2-mediated mechanisms. The autophagy inhibitor 3-MA partially reversed the effects of the miR-488-3p/NRSN2 axis in U2OS cells.

CONCLUSION

Our findings demonstrate that miR-488-3p suppresses malignant behaviors and promotes autophagy in OS cells by targeting NRSN2. This study provides insights into the role of miR-488-3p in OS pathogenesis and suggests its potential as a therapeutic target for OS treatment.

Clinical value and molecular mechanism of AQGPs in different tumors

Aquaglyceroporins (AQGPs), including AQP3, AQP7, AQP9, and AQP10, are transmembrane channels that allow small solutes across biological membranes, such as water, glycerol, H₂O₂, and so on. Increasing evidence suggests that they play critical roles in cancer. Overexpression or knockdown of AQGPs can promote or inhibit cancer cell proliferation, migration, invasion, apoptosis, epithelial-mesenchymal transition and metastasis, and the expression levels of AQGPs are closely linked to the prognosis of cancer patients. Here, we provide a comprehensive and detailed review to discuss the expression patterns of AQGPs in different cancers as well as the relationship between the expression patterns and prognosis. Then, we elaborate the relevance between AQGPs and malignant behaviors in cancer as well as the latent upstream regulators and downstream targets or signaling pathways of AQGPs. Finally, we summarize the potential clinical value in cancer treatment. This review will provide us with new ideas and thoughts for subsequent cancer therapy specifically targeting AQGPs.

Aquaglyceroporin Modulators as Emergent Pharmacological Molecules for Human Diseases

Aquaglyceroporins, a sub-class of aquaporins that facilitate the diffusion of water, glycerol and other small uncharged solutes across cell membranes, have been recognized for their important role in human physiology and their involvement in multiple disorders, mostly related to disturbed energy homeostasis. Aquaglyceroporins dysfunction in a variety of pathological conditions highlighted their targeting as novel therapeutic strategies, boosting the search for potent and selective modulators with pharmacological properties. The identification of selective inhibitors with potential clinical applications has been challenging, relying on accurate assays to measure membrane glycerol permeability and validate effective functional blockers. Additionally, biologicals such as hormones and natural compounds have been revealed as alternative strategies to modulate aquaglyceroporins via their gene and protein expression. This review summarizes the current knowledge of aquaglyceroporins’ involvement in several pathologies and the experimental approaches used to evaluate glycerol permeability and aquaglyceroporin modulation. In addition, we provide an update on aquaglyceroporins modulators reported to impact disease, unveiling aquaglyceroporin pharmacological targeting as a promising approach for innovative therapeutics.

Processing body (P-body) and its mediators in cancer

In recent years, processing bodies (P-bodies) formed by liquid-liquid phase separation, have attracted growing scientific attention due to their involvement in numerous cellular activities, including the regulation of mRNAs decay or storage. These cytoplasmic dynamic membraneless granules contain mRNA storage and decay components such as deadenylase and decapping factors. In addition, different mRNA metabolic regulators, including m⁶A readers and gene-mediated miRNA-silencing, are also associated with such P-bodies. Cancerous cells may profit from these mRNA decay shredders by up-regulating the expression level of oncogenes and down-regulating tumor suppressor genes. The main challenges of cancer treatment are drug resistance, metastasis, and cancer relapse likely associated with cancer stem cells, heterogeneity, and plasticity features of different tumors. The mRNA metabolic regulators based on P-bodies play a great role in cancer development and progression. The dysregulation of P-bodies mediators affects mRNA metabolism. However, less is known about the relationship between P-bodies mediators and cancerous behavior. The current review summarizes the recent studies on P-bodies mediators, their contribution to tumor development, and their potential in the clinical setting, particularly highlighting the P-bodies as potential drug-carriers such as exosomes to anticancer in the future.

Peptide Nanoparticle-Mediated Combinatorial Delivery of Cancer-Related siRNAs for Synergistic Anti-Proliferative Activity in Triple Negative Breast Cancer Cells

Triple negative breast cancer (TNBC) is one of the deadliest types of cancer for women of different age groups. Frequently this cancer does not respond to conservative treatment. Combinatorial RNAi can be suggested as an advanced approach to TNBC therapy. Due to the fact that TNBC cells overexpress chemokine receptor 4 we used modular L1 peptide-based nanoparticles modified with CXCR4 ligand for combinatorial delivery of siRNAs suppressing major transduction pathways. TNBC cell line MDA-MB-231 was used as a cellular model. Genes encoding the AQP3, CDC20, and COL4A2 proteins responsible for proliferative activity in TNBC cells were selected as RNAi targets. The siRNA binding ability of the carrier was studied at different charge ratios. The silencing specificity was demonstrated for all siRNAs studied. Alamar Blue proliferation assay has shown significant reduction in the anti-proliferative activity after combinatorial siRNA transfection compared to single siRNA delivery. The most significant synergistic effect has been demonstrated for combinatorial transfection of anti-COL4A2 and anti-CDC20 siRNAs what resulted in 1.5-2 fold inhibition of proliferation and migration of TNBC cells. Based on our findings, we have concluded that combinatorial treatment by CXCR4-ligand modified L1-polyplexes formed with AQP3, CDC20, and COL4A2 siRNAs effectively inhibits proliferation of TNBC cells and can be suggested as useful tool for RNAi-mediated cancer therapy.

Carvacrol Suppresses Human Osteosarcoma Cells via the Wnt/β-Catenin Signaling Pathway

BACKGROUND

Carvacrol is a monoterpenic phenol extracted from traditional Chinese herbs, including oregano and thyme. Currently, carvacrol has been widely studied for its therapeutic role in central nervous system diseases, liver diseases and digestive system cancer.

OBJECTIVE

However, the role of carvacrol in osteosarcoma and its underlying molecular mechanism remain elusive. Here, we aimed to examine the anticancer effects of carvacrol on osteosarcoma.

METHODS

The effects of carvacrol on the osteosarcoma proliferation capacity were revealed by CCK-8 and colony formation assays. Flow cytometry and Hoechst assays were used to determine the effects of carvacrol on osteosarcoma cell apoptosis. The effect of carvacrol on migration and invasion of osteosarcoma cells was determined by wound healing and transwell tests. Protein expression was evaluated by WB assays. The suppressive effects of carvacrol on osteosarcoma in vivo were examined by a xenograft animal model, immunohistochemistry and HE staining.

RESULTS

We demonstrated that carvacrol treatment reduced viability and inhibited the colony formation of U2OS and 143B cells in a concentration-dependent manner. Apoptotic cell number increased after exposure to carvacrol. Meanwhile, the expression of Bax increased, and that of Bcl-2 decreased by carvacrol treatment. In addition, the MMP-9 expression and migration and invasion of 143B and U2OS cells were inhibited by carvacrol. We also found that these carvacrol-induced effects on osteosarcoma are associated with the regulation of the Wnt/β-catenin signaling pathway.

CONCLUSION

Our findings suggest that carvacrol suppresses proliferation, migration, invasion and promotes apoptosis in osteosarcoma cells, in part by regulating the Wnt/β-catenin signaling pathway.

LncRNA SNHG16 promotes epithelial-mesenchymal transition by upregulating ITGA6 through miR-488 inhibition in osteosarcoma

BACKGROUND

Osteosarcoma is a primary cause of cancer-associated death in children and adolescents worldwide. Long non-coding RNAs SNHG16 (lncRNA SNHG16) and integrin subunit-a 6 (ITGA6) are recently reported to be involved in the tumorigenesis of osteosarcoma by multiple mechanisms. However, the correlation between SNHG16 and ITGA6 in osteosarcoma remains undetermined.

METHODS

Expression of miR-488, SNHG16 and ITGA6, as well as epithelial-mesenchymal transition (EMT) associated markers in osteosarcoma tissues and cell lines were examined by qRT-PCR or Western blotting. Effects of miR-488, SNHG16 and ITGA6 on cell migration, invasion were evaluated by wound-healing assay and transwell assay. Bioinformatics analysis and dual-luciferase reported assays were applied to assess the interaction among miR-488, SNHG16 and ITGA6. RNA immunoprecipitation (RIP) was also used to verify SNHG16 and miR-488 interaction. Finally, animal study was used to detect the effect of SNHG16 on osteosarcoma in vivo.

RESULTS

SNHG16 and ITGA6 were significantly increased while miR-488 was decreased in osteosarcoma. ITGA6 was screened as a target gene of miR-488, and SNHG16 was sponged by miR-488 in osteosarcoma cells. MiR-488 overexpression and SNHG16 knockdown suppressed migration, invasion and EMT of osteosarcoma cells. Moreover, rescue assays proved that the influences of SNHG16 on osteosarcoma cells migration, invasion and EMT were dependent on miR-488 and ITGA6. In addition, the promotive effects of SNHG16 on osteosarcoma tumor growth and metastasis were further supported by xenograft tumor growth assay.

CONCLUSION

SNHG16 promoted migration, invasion and EMT of osteosarcoma by sponging miR-488 to release ITGA6.

Aquaporin water channels as regulators of cell-cell adhesion proteins

Aquaporin (AQP) water channels facilitate passive transport of water across cellular membranes following an osmotic gradient. AQPs are expressed in a multitude of epithelia, endothelia, and other cell types where they play important roles in physiology, especially in the regulation of body water homeostasis, skin hydration, and fat metabolism. AQP dysregulation is associated with many pathophysiological conditions, including nephrogenic diabetes insipidus, chronic kidney disease, and congestive heart failure. Moreover, AQPs have emerged as major players in a multitude of cancers where high expression correlates with metastasis and poor prognosis. Besides water transport, AQPs have been shown to be involved in cellular signaling, cell migration, cell proliferation, and regulation of junctional proteins involved in cell-cell adhesion; all cellular processes which are dysregulated in cancer. This review focuses on AQPs as regulators of junctional proteins involved in cell-cell adhesion.

MicroRNA-488-3p Regulates Neuronal Cell Death in Cerebral Ischemic Stroke Through Vacuolar Protein Sorting 4B (VPS4B)

BACKGROUND

Ischemic stroke, which often occurs with high morbidity, disability, and mortality, is a main cause of brain disease. In various types of human diseases, it is found that microRNAs (miRNAs) are considered as gene regulators. Increasing studies have proved that fluctuation of miRNAs, in the pathologies of ischemic stroke, plays a vital role. However, the accurate regulatory mechanism of cerebral ischemic stroke by miRNAs is still unclear. In this research, we investigated the inhibition mechanism of miR-488-3p on neuronal death through targeting vacuolar protein sorting 4B (VPS4B) in cerebral ischemia/reperfusion (I/R) injury.

METHODS

Western blot and qRT-PCR were utilized to detect the miR-488-3p level and VPS4B expression. The cell counting kit-8 (CCK-8) assay was utilized to measure the function of miR-488-3p in cell death induced by oxygen glucose deprivation/reoxygenation (OGD/R). After middle cerebral artery occlusion/reperfusion (MCAO/R), the impact of miR-488-3p on infarct volume in mouse brain was assessed. The targets of miR-488-3p were confirmed by luciferase analysis and bioinformatics software.

RESULTS

The miR-488-3p level remarkably reduced in primary neuronal cells administrated with OGD/R. Similarly, it also decreased in the mouse brain administrated with MCAO/R. Additionally, the up-regulation of miR-488-3p expression suppressed the death of neuronal cells and restrained ischemic brain infarction in ischemia-stroked mice. Besides, the results showed that VPS4B, which could be inhibited by miR-488-3p, was a direct target of miR-488-3p. This research revealed that the inhibition of VPS4B protected the neuronal cells in ischemic stroke both in vitro as well as in vivo. Meanwhile, this inhibition strengthened positive impact generated by miR-488-3p on ischemic injury.

CONCLUSION

Overall, miR-488-3p played a critical role on neuroprotective function via reducing VPS4B protein level. These results performed a new underlying curative target for the treatment of cerebral ischemic stroke.

Combined Systematic Review and Transcriptomic Analyses of Mammalian Aquaporin Classes 1 to 10 as Biomarkers and Prognostic Indicators in Diverse Cancers

Aquaporin (AQP) channels enable regulated transport of water and solutes essential for fluid homeostasis, but they are gaining attention as targets for anticancer therapies. Patterns of AQP expression and survival rates for patients were evaluated by systematic review (PubMed and Embase) and transcriptomic analyses of RNAseq data (Human Protein Atlas database). Meta-analyses confirmed predominantly negative associations between AQP protein and RNA expression levels and patient survival times, most notably for AQP1 in lung, breast and prostate cancers; AQP3 in esophageal, liver and breast cancers; and AQP9 in liver cancer. Patterns of AQP expression were clustered for groups of cancers and associated with risk of death. A quantitative transcriptomic analysis of AQP1-10 in human cancer biopsies similarly showed that increased transcript levels of AQPs 1, 3, 5 and 9 were most frequently associated with poor survival. Unexpectedly, increased AQP7 and AQP8 levels were associated with better survival times in glioma, ovarian and endometrial cancers, and increased AQP11 with better survival in colorectal and breast cancers. Although molecular mechanisms of aquaporins in pathology or protection remain to be fully defined, results here support the hypothesis that overexpression of selected classes of AQPs differentially augments cancer progression. Beyond fluid homeostasis, potential roles for AQPs in cancers (suggested from an expanding appreciation of their functions in normal tissues) include cell motility, membrane process extension, transport of signaling molecules, control of proliferation and apoptosis, increased mechanical compliance, and gas exchange. AQP expression also has been linked to differences in sensitivity to chemotherapy treatments, suggesting possible roles as biomarkers for personalized treatments. Development of AQP pharmacological modulators, administered in cancer-specific combinations, might inspire new interventions for controlling malignant carcinomas.

Differential Expression of MicroRNAs in Silent and Functioning Corticotroph Tumors

The potential role of miRNAs in the silencing mechanisms of pituitary neuroendocrine tumors (PitNETs) has not been addressed. The aim of the present study was to evaluate the expression levels and the potential associated role of some miRNAs, pathways, and transcription factors in the silencing mechanisms of corticotroph tumors (CTs). Accordingly, the expression of miR-375, miR-383, miR-488, miR-200a and miR-103; of PKA, MAP3K8, MEK, MAPK3, NGFIB, NURR1, PITX1, and STAT3 were analyzed via qRT-PCR in 23 silent and 24 functioning CTs. miR-200a and miR-103 showed significantly higher expression in silent than in functioning CTs, even after eliminating the bias of tumor size, therefore enabling the differentiation between the two variants. Additionally, miR-383 correlated negatively with TBX19 in silent CTs, a transcription factor related with the processing of POMC that can participate in the silencing mechanisms of CTs. Finally, the gene expression levels of miR-488, miR-200a, and miR-103 were significantly higher in macroadenomas (functioning and silent) than in microadenomas. The evidence from this study indicates that miRNAs could be involved in the pathophysiology of CTs. The translational implications of these findings suggest that pharmacological treatments specifically targeting these miRNAs could become a promising therapeutic option for these patients.

Hypoxia-Induced Aquaporin-3 Changes Hepatocellular Carcinoma Cell Sensitivity to Sorafenib by Activating the PI3K/Akt Signaling Pathway

Purpose

Hypoxia-induced changes are primarily activated in patients with hepatocellular carcinoma (HCC) and long-term sorafenib exposure, thereby reducing the sensitivity to the drug. Aquaporin-3 (AQP3), a member of the aquaporin family, is a hypoxia-induced substance that affects the chemosensitivity of non-hepatocellular tumors. However, its expression and role in the sensitivity of hypoxic HCC cells to sorafenib-induced apoptosis remain unclear. The purpose of this study was to detect changes in AQP3 expression in hypoxic HCC cells and to determine whether these changes alter the sensitivity of these cells to sorafenib.

Materials and Methods

Huh7 and HepG2 hypoxic cell models were established and AQP3 expression was detected using quantitative real-time polymerase chain reaction (qPCR) and Western blotting. Furthermore, the role of AQP3 in cell sensitivity to sorafenib was evaluated via flow cytometry, Western blotting, and a CCK-8 assay.

Results

The results of qPCR and Western blotting showed that AQP3 was overexpressed in the Huh7 and HepG2 hypoxic cell models. Furthermore, AQP3 protein levels were positively correlated with hypoxia-inducible factor-1α (HIF-1α) levels. Compared with cells transfected with lentivirus-GFP (Lv-GFP), hypoxic cells transfected with lentivirus-AQP3 (Lv-AQP3) were less sensitive to sorafenib-induced apoptosis. However, the sensitivity to the drug increased in cells transfected with lentivirus-AQP3RNAi (Lv-AQP3RNAi). Akt and Erk phosphorylation was enhanced in Lv-AQP3-transfected cells. Compared with UO126 (a Mek1/2 inhibitor), LY294002 (a PI3K inhibitor) attenuated the AQP3-induced insensitivity to sorafenib observed in hypoxic cells transfected with Lv-AQP3. Combined with LY294002-treated cells, hypoxic cells transfected with Lv-AQP3RNAi were more sensitive to sorafenib.

Conclusion

The study results show that AQP3 is a potential therapeutic target for improving the sensitivity of hypoxic HCC cells to sorafenib.

miR-874 directly targets AQP3 to inhibit cell proliferation, mobility and EMT in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is a major type of lung cancer with high morbidity and high mortality. miR-874 has been determined to play a role in tumor suppression in several cancers. The purpose of our study was to detect the biological mechanisms of miR-874 and AQP3 in NSCLC.

METHODS

CCK-8 and Transwell assays were utilized to perform cell invasion.Western blot was employed to evaluate the protein expression.

RESULTS

The expression of miR-874 was lower in NSCLC tissues than that of corresponding adjacent nontumor tissues. Downregulation of miR-874 predicted a poor prognosis in NSCLC. The cell proliferation and mobility were suppressed by overexpression of miR-874, which were promoted by knockdown of miR-874 in A549 and H1299 cells. miR-874 mediated the expression of AQP3 by directly binding to the 3'-untranslated regions (UTR) of AQP3 mRNA in NSCLC cells. Moreover, miR-874 inhibited the proliferation and mobility by targeting AQP3 and inhibited the PI3K/AKT signaling pathway in A549 cells. miR-874 inhibited the growth of NSCLC in vivo.

CONCLUSIONS

In conclusion, miR-874 inhibited proliferation and mobility by regulating AQP3 in NSCLC. The newly identified miR-874/AQP3 axis provides novel insight into the pathogenesis of NSCLC.

Antitumor effects and mechanisms of pyropheophorbide‑α methyl ester‑mediated photodynamic therapy on the human osteosarcoma cell line MG‑63

Photodynamic therapy (PDT) is a promising treatment for osteosarcoma, and pyropheophorbide-α methyl ester (MPPa) is a second-generation photosensitizer for tumor treatment. The present study aimed to determine the efficacy and possible mechanisms of MPPa-PDT in the treatment of osteosarcoma MG-63 cells. Flow cytometry and western blotting were used to detect cell cycle-related indicators Cyclin D1, Cyclin E, Cyclin A and Cyclin B1. Cell migration and invasion abilities were detected using wound-healing and Transwell chamber assays. Cellular endoplasmic reticulum stress (ERS), autophagy and apoptosis-related indicators were detected by flow cytometry and western blotting. The results demonstrated that MPPa-PDT blocked the MG-63 cell cycle and inhibited cell migration and invasion. Additionally, MPPa-PDT inhibited the activation of the Akt/mammalian target of rapamycin (mTOR) pathway. MG-63 cells underwent ERS-induced apoptosis following MPPa-PDT treatment. Pretreatment with the mTOR phosphorylation inhibitor rapamycin affected the autophagy of MPPa-PDT-induced osteosarcoma MG-63 cells and enhanced apoptosis through targeting mTOR.

Inhibitors of Mammalian Aquaporin Water Channels

Aquaporins (AQPs) are water channel proteins that are essential to life, being expressed in all kingdoms. In humans, there are 13 AQPs, at least one of which is found in every organ system. The structural biology of the AQP family is well-established and many functions for AQPs have been reported in health and disease. AQP expression is linked to numerous pathologies including tumor metastasis, fluid dysregulation, and traumatic injury. The targeted modulation of AQPs therefore presents an opportunity to develop novel treatments for diverse conditions. Various techniques such as video microscopy, light scattering and fluorescence quenching have been used to test putative AQP inhibitors in both AQP-expressing mammalian cells and heterologous expression systems. The inherent variability within these methods has caused discrepancy and many molecules that are inhibitory in one experimental system (such as tetraethylammonium, acetazolamide, and anti-epileptic drugs) have no activity in others. Some heavy metal ions (that would not be suitable for therapeutic use) and the compound, TGN-020, have been shown to inhibit some AQPs. Clinical trials for neuromyelitis optica treatments using anti-AQP4 IgG are in progress. However, these antibodies have no effect on water transport. More research to standardize high-throughput assays is required to identify AQP modulators for which there is an urgent and unmet clinical need.