Resveratrol-downregulated phosphorylated liver kinase B1 is involved in senescence of acute myeloid leukemia stem cells

Engineered mesenchymal stem cell exosomes loaded with miR-34c-5p selectively promote eradication of acute myeloid leukemia stem cells

Most patients with acute myeloid leukemia (AML) relapse eventually because of the inability to effectively eliminate leukemia stem cells (LSCs), prompting the search of new therapies to eradicate LSCs. Our previous study demonstrated that miR-34c-5p promotes the clearance of LSCs in an AML mouse model, highlighting its potential as a therapeutic target for eradicating LSCs, but the effective delivery of miR-34c-5p to LSCs remains a great challenge. Here, we employed simultaneous two-step modifications to engineer mesenchymal stem cells (MSCs) and MSC-derived exosomes to create exosomes overexpressing the fused protein lysosome-associated membrane protein 2-interleukin 3 (Lamp2b-IL3) and hematopoietic cell E-selectin/L-selectin ligand (HCELL), and demonstrated that the engineered exosomes exhibited an enhanced ability for bone marrow homing and selective targeting of LSCs. Additionally, using a humanized AML mouse model, we confirmed that the engineered exosomes, loaded with miR-34c-5p, could selectively promote eradication of LSCs and impede the AML development in vivo. In summary, we successfully designed an effective delivery system and provided new insights into the development of novel therapies for delivering miRNA or other molecules to LSCs with greater cellular targeting specificity.

MicroRNA-361 reduces the viability and migratory ability of pancreatic cancer cells via mediation of the MAPK/JNK pathway

Previous research has revealed that microRNA-361 (miR-361) functions as a fundamental modulator in non-small-cell lung cancer and esophageal carcinoma. However, its involvement in pancreatic cancer (PC) is yet to be elucidated. Therefore, the present study aimed to examine the mechanism and function of miR-361 during the regulation of PC cell migration and viability. It was demonstrated that miR-361 expression decreased in PC cell lines and tissues, and the overexpression of miR-361 suppressed in vivo PC cell proliferation in mice. Moreover, flow cytometry and MTT assays indicated that the miR-361 mimic decreased the viability and increased the apoptosis of PC cells. Both Transwell migration and wound healing assays identified that miR-361 ameliorated the migratory ability of PC cells. Using dual-luciferase reporter assays, it was found that miR-361 targeted mitogen-activated protein kinase (MAPK)/JNK 3'-untranslated regions, inducing the downregulation of this gene. In PC cells, overexpression of MAPK/JNK diminished the pro-apoptotic effect of the miR-361 mimic, while restoring the migratory activity of PC cells. Collectively, the present results suggested novel molecular mechanisms underlying PC progression and development.

Bone Marrow Mesenchymal Stem Cells-Derived Exosomal miR-425-5p Inhibits Acute Myeloid Leukemia Cell Proliferation, Apoptosis, Invasion and Migration by Targeting WTAP

Introduction

Acute myeloid leukemia (AML) is a predominant blood malignancy with high mortality and severe morbidity. AML is affected by microRNAs (miRNAs) loaded in exosomes derived from bone marrow mesenchymal stem cells (BM-MSCs). MiR-425-5p has been reported to participate in different cancer models. However, the function of BM-MSCs-derived exosomal miR-425-5p in AML is unclear.

Methods

The expression of miR-425-5p was measured by qRT-PCR in clinical AML samples. The immunophenotype of BM-MSCs was analyzed using antibodies against CD44, CD90, and CD105. The exosome was isolated from BM-MSCs. The effect of BM-MSCs-derived exosomal miR-425-5p on AML was analyzed by CCK-8 assay, Edu assay, transwell assay, flow cytometry in AML cells. qRT-PCR, luciferase reporter gene assay and Western blot analysis were also conducted in AML cells.

Results

The expression levels of miR-425-5p were decreased in CD34 + CD38-AML cells from primary AML patients compared to that from the bone marrow of healthy cases, and were reduced in exosomes from AML patients compared that from healthy cases. Similarly, miR-425-5p was also down-regulated in AML cell lines compared with BM-MSCs. MiR-425-5p was able to express in exosomes from BM-MSCs. CCK-8, Edu, transwell assay and flow cytometry analysis revealed that BM-MSCs-derived exosomal miR-425-5p significantly inhibited cell viability, Edu positive cells, invasion and migration, and induced apoptosis of AML cells. Meanwhile, the expression levels of cleaved PARP and cleaved caspase3 were increased by BM-MSCs-derived exosomal miR-425-5p in cells. MiR-425-5p inhibited the expression of Wilms tumor 1-associated protein (WTAP). Moreover, overexpression of WTAP could reverse the miR-425-5p-induced inhibition effect on AML cell proliferation, apoptosis, migration and invasion.

Conclusion

BM-MSCs-derived exosomal miR-425-5p inhibits proliferation, invasion and migration of AML cells and induced apoptosis of AML cells by targeting WTAP. Therapeutically, BM-MSCs-derived exosomal miR-425-5p may serve as a potential target for AML therapy.

Hsa-circ_0003420 induces apoptosis in acute myeloid leukemia stem cells and impairs stem cell properties

OBJECTIVE

To explore the effect of circular RNA-0003420 (circ_0003420) in acute myeloid leukemia (AML) relapse and leukemia stem cells (LSCs) properties.

MATERIALS AND METHODS

TRIzol reagent was used to extract total RNA from AML tissues or cells. Cell viability was assessed by Cell Counting Kit-8 and EdU staining assays. Cell apoptosis was determined by flow cytometry.

RESULTS

Compared with normal hematopoietic stem cells, circular RNA hsa-circ_0003420 expression was considerably decreased in non-m3 AML stem cells. Furthermore, the lack of hsa-circ_0003420 is correlated with poor clinical results and impaired therapeutic effects in AML. Overexpression of hsa-circ_0003420 via transfection caused LSC death and inhibited the characteristics of leukemia tumor stem cells, including expression of Homeobox B4 (HOXB4), MYB, and aldehyde dehydrogenase 1 family member A1 (ALDH1A1) axis. Furthermore, hsa-circ_0003420 targets the mRNA of insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) and hsa-circ_0003420 expression markedly repressed IGF2BP1 levels in LSCs. Restoration of IGF2BP1 eliminated the effect of hsa-circ_0003420 on the replication, apoptosis, and LSC phenotype of KG-1a cells.

DISCUSSION AND CONCLUSIONS

Up-regulation of hsa-circ_0003420 expression in LSCs caused redox disorder, inflammation and apoptosis, suggesting that this protein could be used as a target for the treatment AML.

MicroRNA-361 suppresses the biological processes of hepatic stellate cells in HBV-relative hepatic fibrosis by NF-kappaB p65

BACKGROUND

This research study explores the effect of miR-361 on the activation of immortalized human and mice hepatic stallate cells (HSCs).

METHODS

10 liver specimens from healthy volunteers and 20 HBV-relevant HCC tissues from patients. The expressions of miR-361 in HCC patients, HBx transgenic mice, HCC cell lines expressing HBx, and human and mouse HSCs were detected. The influences of miR-361 on the biological processes of HSCs were explored. The target of miR-361 and the effects of p65 on miR-361 were also verified and analyzed.

RESULTS

Microarray analysis and quantitative real-time PCR (Q-PCR) indicated that miR-361 was decreased in HBV-relevant HCC tissues, HBx transgenic mice, HBx-transfected HepG2 cells, human and mice HSCs. Bio-informatics prediction and dual-luciferase reporter assay (DLRA) suggested that nuclear factor kappa B subunit p65 gene was a target of miR-361. Furthermore, this study showed that p65 expression was upregulated in the HBV-relevant HCC tissues, HBx transgenic mice, HBx-transfected HepG2 cells. MiR-361 upregulation also caused a reduction in p65 expression in both human and mice HSCs. In addition, p65 overexpression counteracted the effect of miR-361 in human and mice HSCs' biological processes. These findings reveal a latent mechanism underlying p65 modulation by miR-361 which is capable of initiating HSC growth and migration.

CONCLUSION

miR-361 is potentially functioning as a potent marker for HBV-relevant HCC development or liver fibrosis (LF) progression.

The Anti-Leukemic Activity of Natural Compounds

The use of biologically active compounds has become a realistic option for the treatment of malignant tumors due to their cost-effectiveness and safety. In this review, we aimed to highlight the main natural biocompounds that target leukemic cells, assessed by in vitro and in vivo experiments or clinical studies, in order to explore their therapeutic potential in the treatment of leukemia: acute myeloid leukemia (AML), chronic myeloid leukemia (CML), acute lymphocytic leukemia (ALL), and chronic lymphocytic leukemia (CLL). It provides a basis for researchers and hematologists in improving basic and clinical research on the development of new alternative therapies in the fight against leukemia, a harmful hematological cancer and the leading cause of death among patients.

circFADS2 protects LPS-treated chondrocytes from apoptosis acting as an interceptor of miR-498/mTOR cross-talking

We aimed to investigate the regulation of circular RNAs in lipopolysaccharide (LPS)-treated chondrocytes isolated from SD rat. In this study, we analyzed how circFADS2 was regulated in LPS-treated chondrocytes and isolates from Rheumatoid arthritis (RA) patients and found that circFADS2 and mTOR were highly expressed whereas miR-498 expression was significantly reduced. We then silenced circFADS2 in LPS-treated chondrocytes; this resulted in a declined expression of type II collagen, but an increase in the expression of MMP-13, COX-2, and IL-6. Overall, silencing circFADS2 caused a significant reduction in the proliferative rate of LPS-treated chondrocytes, increased apoptotic levels, miR-498 upregulation, and mTOR downregulation. Dual-luciferase reporter assay indicated that circFADS2 directly targeted miR-498. In contrast, miR-498 down-regulation affected circFADS2 silencing, promoting extracellular matrix (ECM) degradation and apoptosis. The 3’ UTR of the mTOR gene is targeted by miR-498, and consequently, in cells transfected with miR-498, there was a significant reduction of mTOR expression at the protein and mRNA levels. Silencing mTOR had a similar effect to circFADS2 silencing on type II collagen, MMP-13, COX-2, and IL-6 expression, as well as cell proliferation and apoptosis. In conclusion, circFADS2 may affect LPS-induced chondrocytes properties by regulating the ECM catabolism, inflammation, and apoptosis in chondrocytes.

Long noncoding RNA MALAT1 inhibits the apoptosis and autophagy of hepatocellular carcinoma cell by targeting the microRNA-146a/PI3K/Akt/mTOR axis

Background

Increased long noncoding RNA (lncRNA) expression is characteristic to hepatocellular carcinoma (HCC) and several other neoplasms. The present study aimed to identify the mechanism underlying modulation of HCC development by the lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1).

Methods

Quantitative real-time polymerase chain reaction was used to determine MALAT1 and microRNA (miR)-146a expression in HCC tissues and cell lines. Western blotting was performed to measure PI3K, Akt, and mTOR levels. Dual-luciferase reporter assay was used to validate the direct targeting and negative regulatory interaction between miR-146a and MALAT1. Cell viability, proliferation, and apoptosis were analyzed using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, colony formation assay, and flow cytometry, respectively; autophagy was detected based on LC3B expression.

Results

MALAT1 expression was higher in HCC tissues than in normal tissues. MALAT1 upregulation promoted HCC cell proliferation, whereas MALAT1 downregulation promoted HCC apoptosis and autophagy. Moreover, effects of MALAT1 downregulation on HCC cells were abolished by miR-146a inhibition. miR-146a directly targeted the 3'-untranslated region of PI3K, and PI3K protein level was clearly decreased upon miR-146a mimic transfection.

Conclusions

MALAT1 may modulate HCC cell proliferation, apoptosis, and autophagy via sponging miR-146a, which regulates HCC progression.

EV71 virus reduces Nrf2 activation to promote production of reactive oxygen species in infected cells

BACKGROUND

Emerging evidence closely links Enterovirus 71 (EV71) infection with the generation of reactive oxygen species (ROS). Excess ROS results in apoptosis and exacerbates inflammatory reactions. The Keap1-Nrf2 axis serves as an essential oxidant counteracting pathway.

METHODS

The present study aimed to elucidate the role of the Keap1-Nrf2 pathway in modulating apoptosis and inflammatory reactions triggered by oxidative stress in Vero and RD cells upon EV71 infection.

RESULTS

Elevated ROS production was identified in EV71 infected Vero and RD cells. The percentage of dead cells and expression of inflammation-promoting cytokines were increased in these cells. EV71 infected cells also displayed reinforced Keap1 expression and abrogated Nrf2 expression. Keap1 silencing resulted in the downstream aggregation of the Nrf2 protein and heme oxygenase-1 HO-1. Keap1 silencing repressed ubiquitination and reinforced Nrf2 nuclear trafficking. Furthermore, silencing Keap1 expression repressed ROS production, cell death, and inflammatory reactions in EV71 infected RD and Vero cells. In contrast, silencing of both Keap1 and Nrf2 restored ROS production, cell death, and inflammatory reactions. Nrf2 and Keap1 modulated the stimulation of the Akt sensor and extrinsic as well as intrinsic cell death pathways, resulting in EV71-triggered cell death and inflammatory reactions.

CONCLUSIONS

EV71 infection can trigger ROS production, cell death, and inflammatory reactions by modulating the Nrf2 and Keap1 levels of infected cells.

Combination of metformin and berberine represses the apoptosis of sebocytes in high-fat diet-induced diabetic hamsters and an insulin-treated human cell line

Obesity and insulin resistance affect metabolic reactions, but their ensuing contributions to macrophage metabolism remain insufficiently understood. We investigated the contributions of berberine and metformin combination to the inhibition of sebocyte apoptosis in high-fat diet-induced diabetic hamsters and an insulin-treated human cell line. Golden hamsters were fed a high-glucose high-fat diet and administered a 6-week treatment with a combination of metformin and two concentrations of berberine (100 or 50 mg·kg^-1 ). Body weights of treated hamsters were remarkably reduced compared with those of controls. Histological examination indicated that berberine repressed liver fat accumulation. Moreover, insulin and glucose concentrations were noticeably decreased by the combination treatments. In glucose tolerance tests, hamsters receiving berberine displayed higher tolerance to glucose, compared with the control group. Sebocytes isolated from high-fat diet-induced diabetic hamsters and insulin-treated human sebocytes displayed elevated cell death rates, which were attenuated by berberine and metformin treatments. Further studies showed that the effects of metformin and berberine on cellular apoptosis were mediated via the Bik pathway. Thus, berberine may effectively decrease circulating glucose levels, ameliorate insulin resistance, reduce body weight, and attenuate sebocyte apoptosis in diabetic hamsters, potentially decreasing vulnerability to the cardiovascular complications of diabetes. SIGNIFICANCE OF THE STUDY: The present data indicate that insulin stimulates changes in the expression levels of cell death-associated proteins, which participate in sebaceous gland diseases during obesity or diabetes. The anti-apoptotic effects of BBR and MET in sebaceous gland cells are regulated partially by Bik expression. To the best of our knowledge, this study is the first to suggest cell death counteracting effects of BBR in hamster and human sebocytes as well as to propose BBR as an innovative therapeutic agent for insulin-related sebaceous gland diseases, including acne.

MicroRNA‑506 regulates apoptosis in retinoblastoma cells by targeting sirtuin 1

BACKGROUND

MicroRNAs have been reported to participate in the initiation and progression of retinoblastoma (RB), most common malignancy in children. The refractory mechanisms of chemoresistance and the toxicity of chemotherapies hindered the treatment especially on young children. Novel RB therapies are urgently required. MiR-506 is probed to be associated with the tumorigenesis of various cancers whilst the role of this miR in RB remains unclear.

METHODS

Here, the impact of miR-506 on RB cell survival in vitro and tumorigenesis in vivo was examined. MiR-506 expression was examined in human RB samples and cell lines as compared with healthy tissues and non-RB cells. EdU staining and colony formation assay were performed to determine the effect of miR-506 on RB cell growth. TdT-mediated dUTP nick end labeling (TUNEL) staining and flow cytometry analysis were applied to detect the apoptotic cell number after miR-506 was downregulated in RB cells. Furthermore, dual-luciferase reporter assay was utilized to confirm the direct interaction between miR-506 and SIRT1 gene.

RESULTS

MiR-506 expression was upregulated in 20 human RB samples from patients as well as in human RB cell lines, WERI-Rb1 and Y79, as compared to that in healthy tissues and non-RB cells. In contrast, the expression of sirtuin 1 (SIRT1), known as NAD-dependent deacetylase, was downregulated in RB samples and cell lines. Aberrant reduced miR-506 expression impaired survival and proliferation of WERI-Rb1 and Y79 cells. The depletion of miR-506 expression promoted apoptosis of the two RB cell lines. The results of bioinformatics analysis and dual-luciferase assay exhibited that miR-506 targeted the 3'-untranslated region of SIRT1 on silencing purpose. The SIRT1 silencing lessened the miR-506 inhibition on RB cell proliferation and undermined apoptosis.

CONCLUSION

The results provided an insight into the role of miR-506 during RB development and offered potential pharmaceutical strategy for RB diagnosis.

LncRNA MALAT1 mediates proliferation of LPS treated-articular chondrocytes by targeting the miR-146a-PI3K/Akt/mTOR axis

The study aimed to investigate the regulation of long noncoding RNA (lncRNA), Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in osteoarthritis (OA) development. Isolated rat chondrocytes treated with lipopolysaccharide (LPS) were used as OA cell model. Results from quantitative real-time PCR (Q-PCR) showed that, in OA patients and OA cell model, the expression of MALAT1 and PI3K was clearly reduced, while the miR-146a levels were increased. Next, MALAT1 was silenced in LPS-treated chondrocytes. Following with MALAT1 silencing, the generation of Cyclooxygenase-2 (COX-2), Interleukin-6 (IL-6) and Matrix metallopeptidase-13 (MMP-13) were promoted, while the level of type II collagen (COL2) was inhibited. Moreover, MALAT1 silencing caused a significant reduction in the proliferative rate of LPS-treated chondrocytes through inducing apoptosis. Bioinformatics prediction and dual-luciferase reporter assay (DLRA) results showed that MALAT1 targets miR-146a. MALAT1 silencing also resulted in the upregulation of miR-146a. Further studies revealed that miR-146a has the opposite effect on MALAT1, and its inhibition can antagonize the function of MALAT1 silencing on cell proliferation and apoptosis. Additionally, the 3'-UTR of the Phosphoinositide 3-kinase (PI3K) gene was found to be a target of miR-146a, while PI3K protein and mRNA expression, as well as the activation of downstream Akt and mammalian target of rapamycin (mTOR) were clearly reduced upon transfection with a miR-146a mimic. These results show that MALAT1 can modulate ECM catabolism, inflammation, and especially apoptosis in chondrocytes treated with LPS, which targets PI3K/Akt/mTOR to eventually regulate the progression of OA. Our findings provide a novel regulatory mechanism of MALAT1 in OA.

microRNA-1225 inhibit apoptosis of pancreatic cancer cells via targeting JAK1

The microRNA miRNA-1225-5p (miR-1225) is known as an essential modulator of the development of multiple cancers and other biological reactions. However, the understanding of its contribution to pancreatic cancer (PC) is insufficient. The effects of miR-1225 on PC cell survival and tumorigenesis in vivo as well as on the modulation of cell apoptosis were investigated. The expression of miR-1225 was upregulated in 20 human LC samples from acute myeloid leukemia patients with adverse prognosis and poor responses to therapy as well as in several human PC cell lines, as compared to that in healthy tissues, normal tissues, and normal pancreatic cells. In contrast, Janus kinase 1 (JAK1) expression was downregulated in human-derived PC samples and PC cell lines. EdU staining demonstrated that the aberrant expression of miR-1225 impaired the proliferation and survival of these two PC cell lines. The depletion of miR-1225 expression increased the apoptosis of both PANC-1 and AsPC-1 cells, as revealed by the TdT-mediated dUTP nick end labeling (TUNEL) staining and flow cytometry results. The results of dual-luciferase reporter assay indicated that miR-1225 targeted the 3'-untranslated region of JAK1 for silencing. Silencing of JAK1 expression counteracted the suppressive influence of miR-1225 depletion in PC cells. Thus, these results offer an insight into the biological and molecular mechanisms underlying the development of PC and provide potential strategies for PC treatment.

Effects of resveratrol, curcumin, berberine and other nutraceuticals on aging, cancer development, cancer stem cells and microRNAs

Natural products or nutraceuticals have been shown to elicit anti-aging, anti-cancer and other health-enhancing effects. A key target of the effects of natural products may be the regulation of microRNA (miR) expression which results in cell death or prevents aging, diabetes, cardiovascular and other diseases. This review will focus on a few natural products, especially on resveratrol (RES), curcumin (CUR) and berberine (BBR). RES is obtained from the skins of grapes and other fruits and berries. RES may extend human lifespan by activating the sirtuins and SIRT1 molecules. CUR is isolated from the root of turmeric (Curcuma longa). CUR is currently used in the treatment of many disorders, especially in those involving an inflammatory process. CUR and modified derivatives have been shown to have potent anti-cancer effects, especially on cancer stem cells (CSC). BBR is also isolated from various plants (e.g., Coptis chinensis) and has been used for centuries in traditional medicine to treat diseases such as adult- onset diabetes. Understanding the benefits of these and other nutraceuticals may result in approaches to improve human health.

miR-34c-5p promotes eradication of acute myeloid leukemia stem cells by inducing senescence through selective RAB27B targeting to inhibit exosome shedding

Leukemia stem cells (LSCs) are responsible for acute myeloid leukemia (AML) chemotherapy resistance and relapse. Here, we discovered that miR-34c-5p, a microRNA central to the senescence regulation network, was significantly down-regulated in AML (non-acute promyelocytic leukemia, non-APL) stem cells compared to that in normal hematopoietic stem cells (HSCs). The lower expression of miR-34c-5p in LSCs was closely correlated to the adverse prognosis and poor responses to therapy of AML patients. Increased miR-34c-5p expression induced LSCs senescence ex vivo, prevented leukemia development and promoted the eradication of LSCs in immune deficient mice. Mechanistically, forced expression of miR-34-5p induced senescence in LSCs through p53-p21^Cip1-Cyclin-dependent kinase (CDK)/Cyclin or p53-independent CDK/Cyclin pathways. Exosome-mediated transfer of miR-34c-5p was one of the reasons for miR-34c-5p deficiency in LSCs. Furthermore, miR-34c-5p could increase its intracellular level by inhibiting exosome-mediated transfer via a positive feedback loop through RAB27B, a molecule that promotes exosome shedding. Overall, this study establishes a new strategy for treatment of AML patients by targeting LSCs to reinitiate senescence via increased miR-34c-5p expression. This miRNA-mediated tumor stem cell senescence could also have important therapeutic value in other malignancies.

Downregulation of LKB1 promotes tumor progression and predicts unfavorable prognosis in patients with glioma

The liver kinase B1 (LKB1)/5′-adenosine monophosphate-activated protein kinase pathway has been reported to facilitate glioma cell growth by improving growth conditions. To investigate the clinical significance of LKB1 in human gliomas western blot analysis and quantitative polymerase chain reaction experiments were performed. The present study demonstrated that LKB1 expression was markedly decreased at the messenger RNA and protein levels in 30 freshly prepared glioma tissues, compared with non-neoplastic brain tissues (P<0.001). Subsequently, immunohistochemical analysis demonstrated that LKB1 immunostaining in 180 glioma tissues was significantly decreased compared with that in the corresponding non-neoplastic brain tissues (P<0.001). Notably, this downregulation frequently occurred in high-grade gliomas, and statistical analysis revealed that low LKB1 expression was significantly associated with large tumor size (P=0.02), advanced World Health Organization grade (P=0.006) and low Karnofsky performance scale (P=0.01). The prognostic value of LKB1 expression in patients with glioma was additionally evaluated using Kaplan-Meier survival curves and Cox proportional hazards regression models. As a result, the overall survival time of patients with glioma with low LKB1 expression was shorter compared with that of patients with high LKB1 expression (P<0.001), and low LKB1 expression also indicated decreased survival time in patients with high-grade glioma (P<0.001). Collectively, the present data indicated that the downregulation of LKB1 was closely associated with the malignant degree of human gliomas, exhibiting lower expression at a higher grade. Notably, LKB1 may serve as a potential prognostic biomarker for patients with glioma following surgery.

Histone deacetylase inhibitors for the treatment of cancer stem cells

HDAC inhibitors are a promising group of epigenetic drugs that show the ability to induce apoptosis in cancer stem cells.