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Abstract Aberrant expression of circRNAs has been proven to play a crucial role in the progression of acute myeloid leukemia (AML); however, its regulatory mechanism remains unclear. Herein, we identified a novel circRNA, Circ_0001187, which is downregulated in AML patients, and its low level contributes to a poor prognosis. We further validated their expression in large-scale samples and found that only the expression of Circ_0001187 was significantly decreased in newly diagnosed (ND) AML patients and increased in patients with hematological complete remission (HCR) compared with controls. Knockdown of Circ_0001187 significantly promoted proliferation and inhibited apoptosis of AML cells in vitro and in vivo, whereas overexpression of Circ _0001187 exerted the opposite effects. Interestingly, we found that Circ_0001187 decreases mRNA m6A modification in AML cells by enhancing METTL3 protein degradation. Mechanistically, Circ_0001187 sponges miR-499a-5p to enhance the expression of E3 ubiquitin ligase RNF113A, which mediates METTL3 ubiquitin/proteasome-dependent degradation via K48-linked polyubiquitin chains. Moreover, we found that the low expression of Circ _0001187 is regulated by promoter DNA methylation and histone acetylation. Collectively, our findings highlight the potential clinical implications of Circ _0001187 as a key tumor suppressor in AML via the miR-499a-5p/RNF113A/METTL3 pathway.

Aberrant expression of circRNAs has been proven to play a crucial role in the progression of acute myeloid leukemia (AML); however, its regulatory mechanism remains unclear. Herein, we identified a novel circRNA, Circ_0001187, which is downregulated in AML patients, and its low level contributes to a poor prognosis. We further validated their expression in large-scale samples and found that only the expression of Circ_0001187 was significantly decreased in newly diagnosed (ND) AML patients and increased in patients with hematological complete remission (HCR) compared with controls. Knockdown of Circ_0001187 significantly promoted proliferation and inhibited apoptosis of AML cells in vitro and in vivo, whereas overexpression of Circ _0001187 exerted the opposite effects. Interestingly, we found that Circ_0001187 decreases mRNA m6A modification in AML cells by enhancing METTL3 protein degradation. Mechanistically, Circ_0001187 sponges miR-499a-5p to enhance the expression of E3 ubiquitin ligase RNF113A, which mediates METTL3 ubiquitin/proteasome-dependent degradation via K48-linked polyubiquitin chains. Moreover, we found that the low expression of Circ _0001187 is regulated by promoter DNA methylation and histone acetylation. Collectively, our findings highlight the potential clinical implications of Circ _0001187 as a key tumor suppressor in AML via the miR-499a-5p/RNF113A/METTL3 pathway. Key points: Circ_0001187 is downregulated in AML patients and contributes to poor prognosis. Circ_0001187 suppresses AML progression by sponging miR-499a-5p to promote RNF113A-mediated METTL3 ubiquitination. [ABSTRACT FROM AUTHOR]

Objective To study the effect of miR-499a-5p on injury induced by chemical hypoxia of pheochromocytoma cell(PC12). Methods PC12 cells were divided into control group, hypoxia group (treated with CoCl2 for 24 h), hypoxia+miR-NC or miR-mimic groups. Cell viability was detected by MTT assay; the expression of miR-499a-5p was detected by RT-qPCR; lactate dehydrogenase (LDH) activity was detected by kit; apoptosis was detected by flow cytometry; the expression of phosphatase and tensin homolog (PTEN) protein was detected by Western blot. The luciferase reporter gene was used to detect whether Pten was a direct target of miR-499a-5p. Results Compared with control group, the cell viability and miR-499a-5p expression decreased (P＜0.01 or P＜0.001), LDH activity and apoptosis increased (P＜0.01 or P＜0.001) in hypoxia group. Over-expression of miR-499a-5p enhanced survival rate and inhibited apoptosis of PC12 cells under hypoxia (P＜0.05 or P＜0.01). Pten was a direct target of miR-499a-5p. Conclusions miR-499a-5p alleviates hypoxic injury of PC12 cells through targeting at Pten.

MiR-499a-5p was significantly downregulated in degenerative tissues and correlated with apoptosis. Nonetheless, the biological function of miR-499a-5p in acute ischemic stroke has been still unclear. In this study, we found that the plasma levels of miR-499a-5p were significantly downregulated in 64 ischemic stroke patients and negatively correlated with the National Institutes of Health Stroke Scale score. Then, we constructed cerebral ischemia/reperfusion (I/R) injury in rats after middle cerebral artery occlusion and subsequent reperfusion and oxygen–glucose deprivation and reoxygenation (OGD/R)-treated SH-SY5Y cell model. Transfection with miR-499a-5p mimic was accomplished by intracerebroventricular injection in the in vivo I/R injury model. We further found that miR-499a-5p overexpression decreased infarct volumes and cell apoptosis in the in vivo I/R stroke model using TTC and TUNEL staining. PDCD4 was a direct target of miR-499a-5p by luciferase report assay and Western blotting. Knockdown of PDCD4 reduced the infarct damage and cortical neuron apoptosis caused by I/R injury. MiR-499a-5p exerted neuroprotective roles mainly through inhibiting PDCD4-mediated apoptosis by CCK-8 assay, LDH release assay, and flow cytometry analysis. These findings suggest that miR-499a-5p might represent a novel target that regulates brain injury by inhibiting PDCD4-mediating apoptosis. [ABSTRACT FROM AUTHOR]

Abstract Background This study sought to investigate the predictive value and regulatory mechanism of serum miR-499a-5p in sepsis-induced myocardial dysfunction (SIMD). Methods A total of 60 patients with sepsis and 60 healthy volunteers were enrolled in this study. The serum levels of miRNAs (miR-451, miR-378 and miR-499a-5p) were detected. Receiver operating characteristic curve and logistic regression analysis were used to evaluate the diagnostic and prognostic value of miR-499a-5p in SIMD patients. AC16 cells were used to establish SIMD model in vitro using lipopolysaccharide (LPS). An analysis was conducted for miR-499a-5p expression, cell viability, and the concentration of creatine kinase-MB isoform (CK-MB), brain natriuretic peptide (BNP), superoxide dismutase (SOD) and cytochrome C oxidase IV (COX IV). The downstream target of miR-499a-5p was verified. Results Our results revealed a poor expression of miR-499a-5p in the serum of SIMD patients, while no significant difference was evident for miR-451 and miR-378. The level of miR-499a-5p in the survival group was higher than the non-survival group. miR-499a-5p elicited good diagnostic and prognostic value for SIMD. Our findings revealed that miR-499a-5p was decreased significantly in LPS-treated cardiomyocytes. After overexpression of miR-499a-5p, the cell viability increased, and the concentrations of CK-MB and BNP were decreased, while the concentrations of SOD and COX IV were increased. EIF4E was validated as the target of miR-499a-5p. After overexpression of EIF4E, the cell viability was decreased and the concentrations of CK-MB and BNP were increased while the concentrations of SOD and COX IV were decreased. Conclusion The level of miR-499a-5p is weak in SIMD patients. miR-499a-5p has a good diagnostic and prognostic value for SIMD by inhibiting EIF4E transcription.

Background: Our previous study demonstrated that lncRNA GIHCG is upregulated in renal cell carcinoma (RCC) and that knockdown of lncRNA GIHCG suppresses the proliferation and migration of RCC cells. However, the mechanism of lncRNA GIHCG in RCC needs further exploration. Methods: The proliferation, cell cycle, migration, and apoptosis of RCC cells were tested using CCK-8, flow cytometry, wound healing and Annexin-V/-FITC/PI flow cytometry assays, respectively. Dual-luciferase reporter and RNA pull-down or RNA immunoprecipitation assays (RIPs) were performed to analyze the interactions among lncRNA GIHCG, miR-499a-5p and XIAP. A tumour xenograft study was conducted to verify the function of lncRNA GIHCG in RCC development in vivo. Results: Knockdown of lncRNA GIHCG inhibited cell proliferation and migration and induced G0/G1 arrest while promoting apoptosis. Overexpression of lncRNA GIHCG led to the opposite results. LncRNA GIHCG sponged miR-499a-5p and downregulated its expression in RCC cells. MiR-499a-5p overexpression suppressed RCC cell growth. MiR-499a-5p targeted XIAP and inhibited its expression. LncRNA GIHCG knockdown reduced the growth of tumour xenografts in vivo and the expression of XIAP while increasing miR-499a-5p levels. Conclusion: LncRNA GIHCG accelerated the development of RCC by targeting miR-499a-5p and increasing XIAP levels.

Liang Jing,1,* Xu Hua,2,* Du Yuanna,3,* Zang Rukun,3 Mou Junjun3 1Department of Gynecology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, People’s Republic of China; 2Department of Obstetrics, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, People’s Republic of China; 3Department of Radiotherapy, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zang Rukun; Mou JunjunDepartment of Radiotherapy, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, No. 20 Yudong Road, Yantai 264000, Shandong, People’s Republic of ChinaEmail zangrukunxiao7@126.com; moujunjun1986@163.comBackground/Aim: The current therapeutic strategies for endometrial cancer are limited and unsatisfactory. Accumulating evidence suggest that microRNAs (miRNAs) participate in tumor growth and metastasis. Mesenchymal stem cells (MSCs) derived exosomes (Exos) are considered as better miRNA delivery vehicles. Here, we investigated the therapeutic effect of exosomal miR-499a-5p (miR-499) in human endometrial cancer metastasis.Methods: Microarray analysis and RT-PCR were performed to detect the relative expression of miR-499 in endometrial cancer tissues and cell lines. MSC-derived Exos were characterized by transmission electron microscope (TEM), Western blot (WB), and nanoparticle tracking analysis (NTA). miR-499 was loading into Exos using electroporation. Cell proliferation and angiogenesis capacity were tested by 5-ethynyl-29-deoxyuridine (EdU) assay and tube formation assay, respectively. Dual-luciferase reporter assay (DLR) was used to confirm the connection of miR-499 and VAV3.Results: We found that the expression of miR-499 was significantly downregulated in cancer tissues compared with adjacent tissues in endometrial cancer patients. Moreover, exosomal miR-499 not only dramatically suppressed endometrial cancer cells proliferation, endothelial cells tube formation in vitro, but also inhibited tumor growth and angiogenesis in vivo. In addition, we confirmed that miR-499 directly targets the 3′UTR sequence of VAV3.Conclusion: The novel identified exosomal miR-499 functions as a tumor suppressor in endometrial cancer though regulating VAV3, and these findings could be a valid molecular target for endometrial cancer therapy.Keywords: endometrial cancer, exosome, miR-499a-5p, VAV3, angiogenesis

Cervical squamous cell carcinoma (CESC) is the most common cancer type of cervical cancer, which threatens women's life seriously. LncRNA DGUOK-AS1has been reported to promote the biologic processes of CESC. We aim to figure out the role of DGUOK-AS1-miR-499a-5p-SPRR1B axis in modulating the CESC progression in vitro. The levels of DGUOK-AS1, miR-499a-5p, and SPRR1B in CESC tissues and cells were examined by RT-qPCR. The interaction of DGUOK-AS1-miR-499a-5p-SPRR1B was verified by luciferase assay. Inhibition of DGUOK-AS1, miR-499a-5p, and SPRR1B was applied for exploring the biological function based on detection of cell viability, proliferation, migration, and apoptosis in CESC SiHa and HeLa cells. DGUOK-AS1 and SPRR1B expressions were obviously elevated, whereas the expression of miR-499a-5p was reduced in both CESC tissues and cells. Silencing of DGUOK-AS1 attenuated cell growth and boosted apoptosis of CESC cells. Notably, DGUOK-AS1 inhibited miR-499a-5p to release SPRR1B, which significantly accelerated the development of CESC. DGUOK-AS1sponging miR-499a-5p facilitated CESC cells progression by releasing SPRR1B in vitro. It provides a new sight for the treatment of CESC patients involving DGUOK-AS1-miR-499a-5p-SPRR1B. • DGUOK-AS1/miR-499a-5p/SPRR1B is a potential regulator of CESC. • DGUOK-AS1- promoted cell growth and migration, but inhibited cell apoptosis of CESC cells. • DGUOK-AS1 interacted with miR-499a-5p in CESC cells. • DGUOK-AS1 sponging miR-499a-5p facilitated cell growth and repressed cell apoptosis of CESC cells. • MiR-499a-5p targeted to SPRR1B and inhibited the expression of SPRR1B in CESC cells. [ABSTRACT FROM AUTHOR]

Background: This study sought to investigate the predictive value and regulatory mechanism of serum miR-499a-5p in sepsis-induced myocardial dysfunction (SIMD).Methods: A total of 60 patients with sepsis and 60 healthy volunteers were enrolled in this study. The serum levels of miRNAs (miR-451, miR-378 and miR-499a-5p) were detected. Receiver operating characteristic curve and logistic regression analysis were used to evaluate the diagnostic and prognostic value of miR-499a-5p in SIMD patients. AC16 cells were used to establish SIMD model in vitro using lipopolysaccharide (LPS). An analysis was conducted for miR-499a-5p expression, cell viability, and the concentration of creatine kinase-MB isoform (CK-MB), brain natriuretic peptide (BNP), superoxide dismutase (SOD) and cytochrome C oxidase IV (COX IV). The downstream target of miR-499a-5p was verified.Results: Our results revealed a poor expression of miR-499a-5p in the serum of SIMD patients, while no significant difference was evident for miR-451 and miR-378. The level of miR-499a-5p in the survival group was higher than the non-survival group. miR-499a-5p elicited good diagnostic and prognostic value for SIMD. Our findings revealed that miR-499a-5p was decreased significantly in LPS-treated cardiomyocytes. After overexpression of miR-499a-5p, the cell viability increased, and the concentrations of CK-MB and BNP were decreased, while the concentrations of SOD and COX IV were increased. EIF4E was validated as the target of miR-499a-5p. After overexpression of EIF4E, the cell viability was decreased and the concentrations of CK-MB and BNP were increased while the concentrations of SOD and COX IV were decreased.Conclusion: The level of miR-499a-5p is weak in SIMD patients. miR-499a-5p has a good diagnostic and prognostic value for SIMD by inhibiting EIF4E transcription. [ABSTRACT FROM AUTHOR]

Xiaobin Gu, Meilian Dong, Zheyan Liu, Jing Yang, Yonggang Shi Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People’s Republic of ChinaCorrespondence: Yonggang ShiDepartment of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People’s Republic of ChinaTel/Fax +86 371 6697 0906Email fccshiyg@zzu.edu.cnIntroduction: The present study aimed to explore the role of miR-499a-5p and its molecular mechanism in cervical cancer (CC).Methods: Quantitative real-time PCR (QRT-PCR) and Western blotting were performed to detect the expression of miR-499a-5p and eukaryotic translation initiation factor 4E (eIF4E) in CC tissues and cell lines. The proliferation, migration, and invasion of CC cells were detected by MTT assay, wound healing assay, and Transwell assay. Apoptosis was evaluated by flow cytometry and alterations of apoptosis-related genes. The effect of miR-499a-5p on epithelial–mesenchymal transition (EMT) was examined by determining the protein levels of EMT-associated genes. Then, colony formation assay was used to determine the radiosensitivity of CC cells. A dual-luciferase reporter assay was performed to confirm the direct target of miR-499a-5p.Results: MiR-499a-5p was significantly downregulated in CC tissues and cell lines. Overexpression of miR-499a-5p or eIF4E knockdown markedly inhibited cell proliferation, invasion, migration, and EMT, and enhanced apoptosis. eIF4E was predicted and verified as a target gene of miR-499a-5p. The influence of miR-499a-5p upregulation on proliferation, apoptosis, invasion, migration, EMT, and radiosensitivity was abrogated by eIF4E overexpression. Discussion: MiR-499a-5p promoted the apoptosis and radiosensitivity and inhibited proliferation, invasion, migration, and EMT by directly targeting eIF4E in CC cells.Keywords: cervical cancer, epithelial–mesenchymal transition, eukaryotic translation initiation factor 4E, miR-499a-5p, radiosensitivity

OBJECTIVE: Glioma is a common aggressive cancer and a major public health problem worldwide, with high incidence, recurrence, and mortality. Circular RNA (circRNA) has been reported to be involved in glioma, but the role of circ_0079593 in glioma is still unclear. MATERIALS AND METHODS: The real-time quantitative polymerase chain reaction (RT-qPCR) was performed to quantify the expression levels of circ_0079593, miR-499a-5p, and karyopherin alpha 2 (KPNA2) in glioma tissues or cells. The protein expression level of KPNA2 was assessed by Western blot. 3-(4, 5-dimethylthiazol- 2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT), flow cytometry, and transwell assays were conducted to evaluate proliferation, apoptosis, migration and invasion of glioma cells, respectively. The relationship between miR-499a-5p and circ_0079593 or KPNA2 was analyzed by bioinformatics database and confirmed by Dual-Luciferase reporter analyses, respectively. The effects of circ_0079593 silencing in vivo were measured by a xenograft experiment. RESULTS: Circ_0079593 and KPNA2 were elevated in glioma tissues and cells. Loss-of functional experiments revealed that knockdown of circ_0079593 hampered the progression of glioma by repressing proliferation, motility and inducing apoptosis in vitro and declining tumor growth in vivo. Similarly, suppression of KPNA2 impeded the process of glioma by inhibiting proliferation, motility and increasing apoptosis. MiR-499a-5p, interacting with KPNA2, was a target gene of circ_0079593. In addition, overexpression of KPNA2 could reverse the effects of circ_0079593 knockdown on proliferation, apoptosis, migration and invasion of glioma cells. Mechanistically, circ_0079593 mediated proliferation, motility and apoptosis of glioma cells by regulating KPNA2 expression via sponging miR- 499a-5p. CONCLUSIONS: Circ_0079593 stimulated the pathological process of glioma via acting as competing endogenous RNA to sponge miR- 499a-5p. [ABSTRACT FROM AUTHOR]

Background: The current study aims to explore the clinical value of serum miR-499a-5p in the diagnosis of pancreatic cancer. Methods: One hundred twenty-four patients with pancreatic cancer (cancer group), 100 patients with benign pancreatic diseases (benign control group), and 100 healthy people (healthy control group) were selected as the observation objects from January 2017 to June 2017. Fasting venous blood samples were collected to detect the levels of CA199 and the relative expression of miR-499a-5p in serum, and to evaluate the diagnostic value for pancreatic cancer. Results: The expression of CA199 in the benign control group and cancer group was significantly higher than that in the healthy control group. However, the expression of miR-499a-5p in the cancer group was significantly higher than that in the benign control group and the healthy control group. But no difference of serum miR-499a-5p level was found in the benign control group and the healthy control group. Receiver operating characteristic (ROC) analysis showed that when used alone, the sensitivity and specificity of miR-499a-5p in the diagnosis of pancreatic cancer were better than that of CA199 (p < 0.05). Moreover, when serum miR-499a-5p was combined with CA199, the diagnostic value for pancreatic cancer increased significantly (p < 0.05). Dual luciferase reporter assay showed that PTEN was a target gene of miR-499a-5p. Conclusions: In summary, miR-499a-5p is a new, non-invasive biomarker, and the combination of miR-499a-5p and CA199 can improve the diagnostic sensitivity of pancreatic cancer. [ABSTRACT FROM AUTHOR]

Emerging evidence suggests that microRNAs (miRNAs, miRs) play important roles in the development of intervertebral disc degeneration (IVDD). Nonetheless, the expression level and biological function of miR-499a-5p in IVDD are still unclear. In this study, we found that miR-499a-5p was significantly downregulated in degenerative tissues of the human nucleus pulposus (NP) compared with healthy tissues. Knockdown of miR-499a-5p promoted NP cell (NPC) apoptosis, stimulated caspase activation, enhanced MMP3 and MMP13 expression, and downregulated aggrecan and type II collagen. Furthermore, TNF-α–treated NPCs showed increased apoptosis and induced an imbalance between anabolism and catabolism of the extracellular matrix (ECM); these changes were attenuated by miR-499a-5p overexpression. Research into possible mechanisms revealed that miR-499a-5p suppressed the expression of SOX4 both at mRNA and protein levels and directly bound to the 3′ untranslated region of SOX4 mRNA. Ectopic expression of SOX4 attenuated the negative effect of miR-499a-5p on NPC apoptosis and the positive effect on ECM synthesis. Taken together, these results indicate that miR-499a-5p may attenuate TNF-α–induced NPC apoptosis and an imbalance between anabolism and catabolism of the ECM by downregulating SOX4.

Dysregulation of long non‐coding RNAs (lncRNAs) confirm that it plays a crucial role in tumourigenesis and malignant progression of glioma. The present study demonstrated that LncRNA secretory carrier membrane protein 1 (SCAMP1) was up‐regulated and functioned as an oncogene in glioma cells. In addition, miR‐499a‐5p was down‐regulated meanwhile exerted tumour‐suppressive function in glioma cells. Subsequently, inhibition of SCAMP1 significantly restrained the cell proliferation, migration and invasion, as well as promoted apoptosis by acting as a molecular sponge of miR‐499a‐5p. Transcription factor LIM homeobox transcription factor 1, alpha (LMX1A) was overexpressed in glioma tissues and cells. Moreover, miR‐499a‐5p targeted LMX1A 3′‐UTR in a sequence‐specific manner. Hence, down‐regulation of SCAMP1 remarkably reduced the expression level of LMX1A, indicating that LMX1A participated in miR‐499a‐5p‐induced tumour‐suppressive effects on glioma cells. Furthermore, knockdown of LMX1A decreased NLR family, CARD domain containing 5 (NLRC5) mRNA and protein expression levels through directly binding to the NLRC5 promoter region. Down‐regulation of NLRC5 obviously inhibited malignant biological behaviours of glioma cells through attenuating the activity of Wnt/β‐catenin signalling pathway. In conclusion, our study clarifies that SCAMP1/miR‐499a‐5p/LMX1A/NLRC5 axis plays a critical role in modulating malignant progression of glioma cells, which provide a novel therapeutic strategy for glioma treatment. [ABSTRACT FROM AUTHOR]

MicroRNA (miR)-499a-5p has been reported to regulate the progression of various tumours. However, the role of miR-499a-5p in breast cancer is unclear. The purpose of this study was to investigate the role and mechanism of miR-499a-5p in breast cancer. The growth effect of miR-499a-5p on breast cancer cells was investigated by the CCK-8 assay, wound healing assay and Transwell invasion assay. The luciferase activity assay was used to verify the downstream targets of miR-499a-5p. The levels of GSH, MDA, and ROS were detected by kits. Quantitative real-time PCR and Western blot were used to determine the expression levels of TMEM189, COX-2, GPX4, and other related genes in cells. miR-499a-5p was down-regulated in MDA-MB-231 cells and was shown to reduced the viability, migration and invasion of MDA-MB-231 cells. Further studies revealed that TMEM189 is a target of miR-499a-5p. miR-499a-5p inhibited breast cancer cell growth by downregulating TMEM189. Furthermore, the down-regulation of TMEM189 promotes ferroptosis in breast cancer cells. The low expression of TMEM189 inhibited the development of breast cancer through the ferroptosis pathway. We have demonstrated for the first time that miR-499a-5p inhibits breast cancer progression by targeting the TMEM189-mediated ferroptosis pathway., Competing Interests: No potential conflicts of interest were disclosed., (Copyright © 2023 JCBN.)

Background: Our previous study demonstrated that lncRNA GIHCG is upregulated in renal cell carcinoma (RCC) and that knockdown of lncRNA GIHCG suppresses the proliferation and migration of RCC cells. However, the mechanism of lncRNA GIHCG in RCC needs further exploration., Methods: The proliferation, cell cycle, migration, and apoptosis of RCC cells were tested using CCK-8, flow cytometry, wound healing and Annexin-V/-FITC/PI flow cytometry assays, respectively. Dual-luciferase reporter and RNA pull-down or RNA immunoprecipitation assays (RIPs) were performed to analyze the interactions among lncRNA GIHCG, miR-499a-5p and XIAP. A tumour xenograft study was conducted to verify the function of lncRNA GIHCG in RCC development in vivo., Results: Knockdown of lncRNA GIHCG inhibited cell proliferation and migration and induced G0/G1 arrest while promoting apoptosis. Overexpression of lncRNA GIHCG led to the opposite results. LncRNA GIHCG sponged miR-499a-5p and downregulated its expression in RCC cells. MiR-499a-5p overexpression suppressed RCC cell growth. MiR-499a-5p targeted XIAP and inhibited its expression. LncRNA GIHCG knockdown reduced the growth of tumour xenografts in vivo and the expression of XIAP while increasing miR-499a-5p levels., Conclusion: LncRNA GIHCG accelerated the development of RCC by targeting miR-499a-5p and increasing XIAP levels., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

The aim is to investigate the mechanism of miR-499a-5p on the damage of cardiomyocyte induced by hypoxia/reoxygenation. The activity of lactate dehydrogenase (LDH), apoptosis rate and the expression of miR-499a-5p and cluster of differentiation 38 (CD38) in hypoxia-reoxygenation model cells were detected by LDH Cytotoxicity Assay Kit, flow cytometry, real-time polymerase chain reaction, and Western blot analysis, respectively. Apoptosis, the activity of LDH was detected after overexpression of miR-499a-5p or silencing of CD38 in H9c2 cells. The target relationship between miR-499a-5p and CD38 was verified by Targetscan online prediction and dual-luciferase assay. Apoptosis, the activity of LDH was detected after overexpression of miR-499a-5p and CD38. Apoptosis, the activity of LDH and the expression of CD38 were increased (P < .05) while expression of miR-499a-5p was decreased (P < .05) in hypoxia/reoxygenation model cells. Apoptosis and the activity of LDH in H9c2 cells after overexpression of miR-499a-5p or silence of CD38 were decreased (P < .05). The results of Targetscan online prediction and dual-luciferase assay indicated that CD38 was a potential target gene of miR-499a-5p. Overexpression of CD38 could reverse the inhibition of miR-499a-5p on LDH activity and apoptosis in H9c2 cells. miR-499a-5p could relief the injury of cardiomyocytes induced by hypoxia/reoxygenation via targeting CD38., (© 2019 Wiley Periodicals, Inc.)

The aberrant expression of microRNA is an important regulator in the tumorigenesis of non-small cell lung cancer. In this study, we found that miR-499a-5p was notably downregulated in non-small cell lung cancer tissues and cell lines. Decreased miR-499a-5p expression was associated with larger tumor size and higher TNM stage. Non-small cell lung cancer patients with low expression of miR-499a-5p exhibited a worse overall survival rate compared with those patients with high expression of miR-499a-5p. Ectopic expression of miR-499a-5p significantly suppressed non-small cell lung cancer cell proliferation and colony formation, and hampered cell cycle at G0/G1 phase in vitro . Conversely, knockdown of miR-499a-5p promoted non-small cell lung cancer cell proliferation and colony formation, and induced cell cycle at S phase. Furthermore, in vivo experiments revealed that overexpression of miR-499a-5p inhibited the tumor formation in a nude mouse xenograft model. Mechanistic studies showed that fibroblast growth factor 9 was a direct target gene of miR-499a-5p. miR-499a-5p directly bound to fibroblast growth factor 9 mRNA 3'-UTR, therefore led to the reduction in fibroblast growth factor 9 protein expression. Finally, rescue experiments confirmed that silencing of fibroblast growth factor 9 partially reversed the phenotypes of miR-499a-5p knockdown on non-small cell lung cancer cell proliferation. In conclusion, our study demonstrates that downregulation of miR-499a-5p predicts a worse prognosis of patients with non-small cell lung cancer and restrains the tumorigenesis by targeting fibroblast growth factor 9. These findings may provide valuable clues for the future development of therapeutic strategies against this cancer.

Highlights • MiR-499a-5p is downregulated in degenerative NP tissues. • MiR-499a-5p suppresses NPC apoptosis. • MiR-499a-5p enhances ECM synthesis in NPCs. • MiR-499a-5p directly targets SOX4 mRNA and decreases its amount in NPCs. • MiR-499a-5p exerts its action in human NPCs by targeting SOX4 Mrna. Abstract Emerging evidence suggests that microRNAs (miRNAs, miRs) play important roles in the development of intervertebral disc degeneration (IVDD). Nonetheless, the expression level and biological function of miR-499a-5p in IVDD are still unclear. In this study, we found that miR-499a-5p was significantly downregulated in degenerative tissues of the human nucleus pulposus (NP) compared with healthy tissues. Knockdown of miR-499a-5p promoted NP cell (NPC) apoptosis, stimulated caspase activation, enhanced MMP3 and MMP13 expression, and downregulated aggrecan and type II collagen. Furthermore, TNF-α–treated NPCs showed increased apoptosis and induced an imbalance between anabolism and catabolism of the extracellular matrix (ECM); these changes were attenuated by miR-499a-5p overexpression. Research into possible mechanisms revealed that miR-499a-5p suppressed the expression of SOX4 both at mRNA and protein levels and directly bound to the 3′ untranslated region of SOX4 mRNA. Ectopic expression of SOX4 attenuated the negative effect of miR-499a-5p on NPC apoptosis and the positive effect on ECM synthesis. Taken together, these results indicate that miR-499a-5p may attenuate TNF-α–induced NPC apoptosis and an imbalance between anabolism and catabolism of the ECM by downregulating SOX4. [ABSTRACT FROM AUTHOR]