microRNA-199a/b-5p enhance imatinib efficacy via repressing WNT2 signaling-mediated protective autophagy in imatinib-resistant chronic myeloid leukemia cells

Non-coding RNAs in leukemia drug resistance: new perspectives on molecular mechanisms and signaling pathways

Like almost all cancer types, timely diagnosis is needed for leukemias to be effectively cured. Drug efflux, attenuated drug uptake, altered drug metabolism, and epigenetic alterations are just several of the key mechanisms by which drug resistance develops. All of these mechanisms are orchestrated by up- and downregulators, in which non-coding RNAs (ncRNAs) do not encode specific proteins in most cases; albeit, some of them have been found to exhibit the potential for protein-coding. Notwithstanding, ncRNAs are chiefly known for their contribution to the regulation of physiological processes, as well as the pathological ones, such as cell proliferation, apoptosis, and immune responses. Specifically, in the case of leukemia chemo-resistance, ncRNAs have been recognized to be responsible for modulating the initiation and progression of drug resistance. Herein, we comprehensively reviewed the role of ncRNAs, specifically its effect on molecular mechanisms and signaling pathways, in the development of leukemia drug resistance.

Stem Cell Responsiveness to Imatinib in Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disease characterized by the presence of the BCR-ABL fusion gene, which results from the Philadelphia chromosome. Since the introduction of tyrosine kinase inhibitors (TKI) such as imatinib mesylate (IM), the clinical outcomes for patients with CML have improved significantly. However, IM resistance remains the major clinical challenge for many patients, underlining the need to develop new drugs for the treatment of CML. The basis of CML cell resistance to this drug is unclear, but the appearance of additional genetic alterations in leukemic stem cells (LSCs) is the most common cause of patient relapse. However, several groups have identified a rare subpopulation of CD34+ stem cells in adult patients that is present mainly in the bone marrow and is more immature and pluripotent; these cells are also known as very small embryonic-like stem cells (VSELs). The uncontrolled proliferation and a compromised differentiation possibly initiate their transformation to leukemic VSELs (LVSELs). Their nature and possible involvement in carcinogenesis suggest that they cannot be completely eradicated with IM treatment. In this study, we demonstrated that cells from CML patients with the VSELs phenotype (LVSELs) similarly harbor the fusion protein BCR-ABL and are less sensitive to apoptosis than leukemic HSCs after IM treatment. Thus, IM induces apoptosis and reduces the proliferation and mRNA expression of Ki67 more efficiently in LHSCs than in leukemic LVSELs. Finally, we found that the expression levels of some miRNAs are affected in LVSELs. In addition to the tumor suppressor miR-451, both miR-126 and miR-21, known to be responsible for LSC leukemia-initiating capacity, quiescence, and growth, appear to be involved in IM insensitivity of LVSELs CML cell population. Targeting IM-resistant CML leukemic stem cells by acting via the miRNA pathways may represent a promising therapeutic option.

Microcystin-LR-induced autophagy via miR-282-5p/PIK3R1 pathway in Eriocheir sinensis hepatopancreas

With the intensifying climate warming, blue-green algae blooms have become more frequent and severe, releasing environmental hazards such as microcystin that pose potential threats to human and animal health. Autophagy has been shown to play a crucial role in regulating immune responses induced by environmental hazards, enabling cells to adapt to stress and protect against damage. Although microcystin-LR (MC-LR) has been identified to affect autophagy in mammalian, its impact on aquatic animals has been poorly studied. To investigate the toxicological effects of MC-LR in aquatic ecosystems, we constructed a microRNA profile of acute MC-LR stress in the hepatopancreas of the Chinese mitten crab. Interestingly, we found the MC-LR exposure activated autophagy in the hepatopancreas based on the following evidence. Specifically, mRNA expression level of ATG7, Beclin1 and Gabarap was significantly up-regulated, autophagy regulatory pathways were significantly enriched, and numerous autolysosomes and autophagosomes were observed. Additionally, we found that miR-282-5p and its target gene PIK3R1 played important regulatory roles in autophagy by in vivo and in vitro experiments. Overexpression of miR-282-5p mimicked MC-LR-induced autophagy by inhibiting PIK3R1 expression, while miR-282-5p silencing inhibited autophagy by promoting PIK3R1 expression. Altogether, our findings suggest that MC-LR increases miR-282-5p, which then targets inhibition of PIK3R1 to stimulate autophagy. This study focused on the stress response regulatory mechanisms of juvenile crabs to toxic pollutants in water, offering a potential target for alleviating the toxicity of MC-LR. These findings lay a foundation for reducing the toxicity of MC-LR and environmental hazards in organisms.

Antileukemic Activity of hsa-miR-203a-5p by Limiting Glutathione Metabolism in Imatinib-Resistant K562 Cells

Imatinib has been the first and most successful tyrosine kinase inhibitor (TKI) for chronic myeloid leukemia (CML), but many patients develop resistance to it after a satisfactory response. Glutathione (GSH) metabolism is thought to be one of the factors causing the emergence of imatinib resistance. Since hsa-miR-203a-5p was found to downregulate Bcr-Abl1 oncogene and also a link between this oncogene and GSH metabolism is reported, the present study aimed to investigate whether hsa-miR-203a-5p could overcome imatinib resistance by targeting GSH metabolism in imatinib-resistant CML cells. After the development of imatinib-resistant K562 (IR-K562) cells by gradually exposing K562 (C) cells to increasing doses of imatinib, resistant cells were transfected with hsa-miR-203a-5p (R+203). Thereafter, cell lysates from various K562 cell sets (imatinib-sensitive, imatinib-resistant, and miR-transfected imatinib-resistant K562 cells) were used for GC-MS-based metabolic profiling. L-alanine, 5-oxoproline (also known as pyroglutamic acid), L-glutamic acid, glycine, and phosphoric acid (Pi)-five metabolites from our data, matched with the enumerated 28 metabolites of the MetaboAnalyst 5.0 for the GSH metabolism. All of these metabolites were present in higher concentrations in IR-K562 cells, but intriguingly, they were all reduced in R+203 and equated to imatinib-sensitive K562 cells (C). Concludingly, the identified metabolites associated with GSH metabolism could be used as diagnostic markers.

Non-Coding RNAs Are Implicit in Chronic Myeloid Leukemia Therapy Resistance

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm initiated by the presence of the fusion gene BCR::ABL1. The development of tyrosine kinase inhibitors (TKIs) highly specific to p210^BCR-ABL1, the constitutively active tyrosine kinase encoded by BCR::ABL1, has greatly improved the prognosis for CML patients. Now, the survival rate of CML nearly parallels that of age matched controls. However, therapy resistance remains a persistent problem in the pursuit of a cure. TKI resistance can be attributed to both BCR::ABL1 dependent and independent mechanisms. Recently, the role of non-coding RNAs (ncRNAs) has been increasingly explored due to their frequent dysregulation in a variety of malignancies. Specifically, microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs) have been shown to contribute to the development and progression of therapy resistance in CML. Since each ncRNA exhibits multiple functions and is capable of controlling gene expression, they exert their effect on CML resistance through a diverse set of mechanisms and pathways. In most cases ncRNAs with tumor suppressing functions are silenced in CML, while those with oncogenic properties are overexpressed. Here, we discuss the relevance of many aberrantly expressed ncRNAs and their effect on therapy resistance in CML.

Imatinib Mesylate Induces Necroptotic Cell Death and Impairs Autophagic Flux in Human Cardiac Progenitor Cells

The receptor tyrosine kinase inhibitor imatinib improves patient cancer survival but is linked to cardiotoxicity. This study investigated imatinib's effects on cell viability, apoptosis, autophagy, and necroptosis in human cardiac progenitor cells in vitro. Imatinib reduced cell viability (75.9 ± 2.7% vs. 100.0 ± 0.0%) at concentrations comparable to peak plasma levels (10 µM). Imatinib reduced cells' TMRM fluorescence (74.6 ± 6.5% vs. 100.0 ± 0.0%), consistent with mitochondrial depolarisation. Imatinib increased lysosome and autophagosome content as indicated by LAMP2 expression (2.4 ± 0.3-fold) and acridine orange fluorescence (46.0 ± 5.4% vs. 9.0 ± 3.0), respectively. Although imatinib increased expression of autophagy-associated proteins and also impaired autophagic flux, shown by proximity ligation assay staining for LAMP2 and LC3II (autophagosome marker): 48 h of imatinib treatment reduced visible puncta to 2.7 ± 0.7/cell from 11.3 ± 2.1 puncta/cell in the control. Cell viability was partially recovered by autophagosome inhibition by wortmannin, with the viability increasing 91.8 ± 8.2% after imatinib-wortmannin co-treatment (84 ± 1.5% after imatinib). Imatinib-induced necroptosis was associated with an 8.5 ± 2.5-fold increase in mixed lineage kinase domain-like pseudokinase activation. Imatinib-induced toxicity was rescued by RIP1 inhibition: 88.6 ± 3.0% vs. 100.0 ± 0.0% in the control. Imatinib applied to human cardiac progenitor cells depolarises mitochondria and induces cell death through necroptosis, recoverable by RIP1 inhibition, with a partial role for autophagy.

MicroRNA-199a deficiency relates to higher bone marrow blasts, poor risk stratification and worse prognostication in pediatric acute myeloid leukemia patients

MicroRNA-199a (miR-199a) inhibits the progression of several hematological malignancies and enhances the sensitivity to chemotherapy in acute myeloid leukemia (AML), but its clinical role in AML needs further investigation. This study aimed to explore the correlation of miR-199a with clinical features and prognosis in pediatric AML patients. Totally, 71 pediatric AML patients were enrolled. Their bone marrows (BMs) before and after one course of treatment were collected. Besides, 30 pediatric patients with nonmalignant hematological disease who underwent BM examination were enrolled with their BMs collected. miR-199a expression was detected by reverse transcription-quantitative polymerase chain reaction. miR-199a expression was lower in pediatric AML patients than in controls (p < 0.001). Meanwhile, downregulated miR-199a expression was correlated with the occurrence of FLT3-ITD mutation (p = 0.023), higher BM blasts (p = 0.037), poor NCCN risk stratification (p = 0.012) and unfavorable Chinese Medical Association risk stratification (p = 0.002) but not associated with other clinical features. Additionally, downregulated miR-199a expression was correlated with lower complete response (CR) rate after one course of treatment (p = 0.036). Interestingly, after treatment, miR-199a expression was increased in patients who achieved CR (p < 0.001), but remained unchanged in those who didn't achieve CR (p = 0.163). Moreover, downregulated miR-199a expression was correlated with shorter event-free survival (p = 0.021); meanwhile, it showed a trend of associating with poor OS (p = 0.055), which was not statistically significant. In this series, decreased expression of miR199a was associated with inadequate treatment response and worse OS in pediatric AML patients, indicating its potential as a prognostic biomarker for pediatric AML.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2021.2022045.

The regulation of autophagy by the miR-199a-5p/p62 axis was a potential mechanism of small cell lung cancer cisplatin resistance

BACKGROUND

Autophagy has been found to be involved in the multidrug resistance (MDR) of cancers, but whether it is associated with resistance of small cell lung cancer (SCLC) has not been studied. Here, we hypothesized that a potential autophagy-regulating miRNA, miR-199a-5p, regulated cisplatin-resistant SCLC.

METHODS

We validated the MDR of H446/EP using CCK-8 and LDH. We tested the binding of miR-199a-5p to p62 using the Dual-Luciferase assay and validated the association of miR-199a-5p and p62 in SCLC samples. We overexpressed (OE) and knocked down (KD) miR-199a-5p in H446 and H446/EP and determined the expression of miR-199a-5p, autophagy-related proteins, and the formation of autophagolysosomes using QPCR, western blotting, and MDC staining respectively. These results were validated in an orthotopic H446 mouse model of SCLC.

RESULTS

H446/EP was resistant to cisplatin, etoposide, paclitexal, epirubicin, irinotecan, and vinorelbine. Exposure of cisplatin at 5 μg/ml for 24 h increased LC3II/LC3I, ATG5, p62, and the formation of autophagolysosomes in H446 cells, but not in H446/EP cells. The expression of miR-199a-5p was up-regulated in H446/EP compared to H446. MiR-199a-5p directly targeted the p62 gene. The expression of miR-199a-5p and p62 were correlated in SCLC samples. In H446 and H69PR, the OE of miR-199a-5p increased LC3II/LC3I, p62, and the formation of autophagolysosomes, but not ATG5, while the KD of miR-199a-5p decreased p62, but did not affect LC3II/LC3I, ATG5, and the formation of autophagolysosomes. In H446/EP, the OE of miR-199a-5p decreased p62 only. These results were generally consistent to results in the animal tumor samples.

CONCLUSIONS

The regulation of autophagy by the miR-199a-5p/p62 axis was a potential mechanism of small cell lung cancer cisplatin resistance.

The MicroRNA-Based Strategies to Combat Cancer Chemoresistance via Regulating Autophagy

Chemoresistance frequently occurs in cancer treatment, which results in chemotherapy failure and is one of the most leading causes of cancer-related death worldwide. Understanding the mechanism of chemoresistance and exploring strategies to overcome chemoresistance have become an urgent need. Autophagy is a highly conserved self-degraded process in cells. The dual roles of autophagy (pro-death or pro-survival) have been implicated in cancers and chemotherapy. MicroRNA (miRNA) is a class of small non-coding molecules that regulate autophagy at the post-transcriptional level in cancer cells. The association between miRNAs and autophagy in cancer chemoresistance has been emphasized. In this review, we focus on the dual roles of miRNA-mediated autophagy in facilitating or combating chemoresistance, aiming to shed lights on the potential role of miRNAs as targets to overcome chemoresistance.

LncRNA OIP5-AS1 Promotes the Autophagy-Related Imatinib Resistance in Chronic Myeloid Leukemia Cells by Regulating miR-30e-5p/ATG12 Axis

Background: Resistance to tyrosine kinase inhibitors (TKIs) in patients with chronic myeloid leukemia (CML) remains a problem in clinical treatment, and the mechanism has not been fully clarified. Autophagy can protect cancer cells under chemotherapeutic stimulation. Long noncoding RNAs (lncRNAs) are critical in drug resistance of CML. The role of lncRNAs in autophagy and drug resistance of CML needs to be further explored. Methods: Western blot and immunofluorescence were used to evaluate the autophagy activity in the drug-resistant CML cell line K562/G01 and its parental cell line K562. Then the sensitivity of K562/G01 cells to the first generation TKI imatinib (IM) after autophagy inhibition was determined by CCK-8 assays. The lncRNA OIP5-AS1 related to the drug resistance of CML cells was determined by Gene Expression Omnibus database analysis. Western blot and drug-sensitivity assays were used to detect changes in autophagy and sensitivity to the IM in resistant CML cells after OIP5-AS1 knockdown. The interactions of OIP5-AS1, miR-30e-5p, and ATG12 were explored by RNA immunoprecipitation and dual-luciferase reporter assays. Results: In this study, we found that autophagy was associated with drug resistance in CML cells. Moreover, the upregulation of OIP5-AS1 in K562/G01 cells was related to the enhancement of autophagy. Knockdown of OIP5-AS1 suppressed autophagy and enhanced the sensitivity of K562/G01 cells to IM. Furthermore, OIP5-AS1 regulated ATG12 by competitively binding miR-30e-5p, thereby affecting autophagy-related drug resistance. Conclusion: Our study reveals that OIP5-AS1 promotes the autophagy-related IM resistance in CML cells by regulating miR-30e-5p/ATG12 axis, providing new insights into the drug resistance mechanism of CML.

Schisandrin B Attenuates Colitis-Associated Colorectal Cancer through SIRT1 Linked SMURF2 Signaling

Colon cancer, a common type of malignant tumor, seriously endangers human health. However, due to the relatively slow progress in diagnosis and treatment, the clinical therapeutic technology of colon cancer has not been substantially improved in the past three decades. The present study was designed to investigate the effects and involved mechanisms of schisandrin B in cell growth and metastasis of colon cancer. C57BL/6 mice received AOM and dextran sulfate sodium. Mice in treatment groups were gavaged with 3.75-30 mg/kg/day of schisandrin B. Transwell chamber migration, enzyme-linked immunosorbent assay (ELISA), Western blot analysis, immunoprecipitation (IP) and immunofluorescence were conducted, and HCT116 cell line was employed in this study. Data showed that schisandrin B inhibited tumor number and tumor size in the AOD+DSS-induced colon cancer mouse model. Schisandrin B also inhibited cell proliferation and metastasis of colon cancer cells. We observed that schisandrin B induced SMURF2 protein expression and affected SIRT1 in vitro and in vivo. SMURF2 interacted with SIRT1 protein, and there was a negative correlation between SIRT1 and SMURF2 expressions in human colorectal cancer. The regulation of SMURF2 was involved in the anticancer effects of schisandrin B in both in vitro and in vivo models. In conclusion, the present study revealed that schisandrin B suppressed SIRT1 protein expression, and SIRT1 is negatively correlated with the induction of SMURF2, which inhibited cell growth and metastasis of colon cancer. Schisandrin B could be a leading compound, which will contribute to finding novel potential agents and therapeutic targets for colon cancer.

miR-199a-5p suppresses epithelial- mesenchymal-transition in anaplastic thyroid carcinoma cells via targeting Snail signals

MicroRNAs (miRNAs) have been validated to play prominent roles in the occurrence and development of anaplastic thyroid carcinoma (ATC). miR-199a-5p was previously reported to act as a tumor suppressor or oncomiRNA in various types of cancer. However, its accurate expression, function, and mechanism in ATC remain unclear. Here, we find that miR-199a-5p is significantly downregulated in ATC tissues compared with adjacent non-cancerous tissues. Overexpression of miR-199a-5p significantly inhibits migration and invasion of ATC cells in vitro, and lung metastasis in vivo. Importantly, miR-199a-5p suppresses epithelial-mesenchymal transition (EMT) both in vitro and in vivo by targeting Snail. Taken together, this study reveals that miR-199a-5p is critical to the EMT progression in ATC cells. Targeting the pathway described here may be a novel approach for inhibiting metastasis of ATC.

Autophagy inhibition and microRNA‑199a‑5p upregulation in paclitaxel‑resistant A549/T lung cancer cells

Multidrug resistance (MDR) is one of the major reasons for the clinical failure of cancer chemotherapy. Autophagy activation serves a crucial role in MDR. However, the specific molecular mechanism linking autophagy with MDR remains unknown. The results of the present study demonstrated that autophagy was inhibited and microRNA (miR)-199a-5p levels were upregulated in MDR model lung cancer cells (A549/T and H1299/T) compared with those in the parental cell lines. Paclitaxel (PTX) treatment increased the expression levels of miR-199a-5p in parental lung cancer cells compared with those in PTX-untreated cells, and these expression levels were negatively correlated with PTX sensitivity of the cells. miR-199a-5p knockdown in A549/T cells induced autophagy and resensitized cells to multiple chemotherapeutic drugs including PTX, taxotere, topotecan, SN38, oxaliplatin and vinorelbine. By contrast, miR-199a-5p overexpression in A549 cells suppressed autophagy and desensitized cells to these chemotherapeutic drugs. Mechanistically, the results of the present study demonstrated that miR-199a-5p blocked autophagy by activating the PI3K/Akt/mTOR signaling pathway and inhibiting the protein expression of autophagy-related 5. Furthermore, p62 protein was identified as a direct target of miR-199a-5p; miR-199a-5p bound to p62 mRNA to decrease its mRNA and protein expression levels. In conclusion, the results of the present study suggested that miR-199a-5p may contribute to MDR development in lung cancer cells by inhibiting autophagy and targeting p62. The regulatory effect of miR-199a-5p on autophagy may provide novel insights for future multidrug-resistant lung cancer chemotherapy.

Downregulation of miR-383 reduces depression-like behavior through targeting Wnt family member 2 (Wnt2) in rats

This study aimed to evaluate the role of miR-383 in the regulation of Wnt-2 signaling in the rat model of chronic stress. The male SD rats with depressive-like behaviors were stimulated with chronic unpredictable mild stress (CUMS) including ice-water swimming for 5 min, food deprivation for 24 h, water deprivation for 24 h, stimulating tail for 1 min, turning night into day, shaking for 15 min (once/s), and wrap restraint (5 min/time) every day for 21 days. The expression levels of miRNAs were detected by qRT-PCR, and the expression levels of Wnt2, depression-impacted proteins (GFAP, BDNF, CREB), brain neurotransmitters (5-HT, NE, DA) and apoptosis-related proteins (Bax and Bcl-2) were evaluated by qRT-PCR and western blot. Bioinformatic analysis and luciferase reporter assay were performed to determine the relationship between miR-383 and Wnt2. Ethological analysis was evaluated by sugar preference test, refuge island test and open field tests. Rescue experiments including knockdown of miR-383, overexpression and silencing of Wnt2 were performed to determine the role of miR-383. High expression levels of miR-383 were observed in the hippocampus of rats submitted to CUMS model. Downregulation of miR-383 significantly inhibited the apoptosis and inflammatory response of hippocampal neurons, and increased the expression levels of GFAP, BDNF and CREB which were impacted in depression, as well as neurotransmitters, then attenuated neural injury in rats induced by CUMS. Furthermore, Wnt family member 2 (Wnt2) was identified as a target of miR-383, and silencing of Wnt2 obviously attenuated the protective effect of miR-383 inhibitor on the apoptosis and inflammatory response in hippocampal neurons, as well as neural injury in CUMS-induced rats. Downregulation of miR-383 ameliorated the behavioral and neurochemical changes induced by chronic stress in rats by directly targeting Wnt2, indicating that the miR-383/Wnt2 axis might be a potential therapeutic target for MDD.

miRNAs mediated drug resistance in hematological malignancies

Despite improvements in the therapeutic approaches for hematological malignancies in the last decades, refractory disease still occurs, and cancer drug resistance still remains a major hurdle in the clinical management of these cancer patients. The investigation of this problem has been extensive and different mechanism and molecules have been associated with drug resistance. MicroRNAs (miRNAs) have been described as having an important action in the emergence of cancer, including hematological tumors, and as being major players in their progression, aggressiveness and response to treatments. Moreover, miRNAs have been strongly associated with cancer drug resistance and with the modulation of the sensitivity of cancer cells to a wide array of anticancer drugs. Furthermore, this role has also been reported for miRNAs packaged into extracellular vesicles (EVs-miRNAs), which in turn have been described as essential for the horizontal transfer of drug resistance to sensitive cells. Several studies have been suggesting the use of miRNAs as biomarkers for drug response and clinical outcome prediction, as well as promising therapeutic tools in hematological diseases. Indeed, the combination of miRNA-based therapeutic tools with conventional drugs contributes to overcome drug resistance. This review addresses the role of miRNAs in the pathogenesis of hematological malignances, namely multiple myeloma, leukemias and lymphomas, highlighting their important action (either in their cell-free circulating form or within circulating EVs) in drug resistance and their potential clinical applications.

Autophagy-mediating microRNAs in cancer chemoresistance

Chemoresistance is a complex phenomenon responsible for failure in response to chemotherapy agents and more than 90% of deaths in cancer patients. MicroRNAs (miRNAs), as a subgroup of non-coding RNAs with lengths between 21 and 25 nucleotides, are involved in various cancer processes like chemoresistance via interacting with their target mRNAs and suppressing their expression. Autophagy is a greatly conserved procedure involving the lysosomal degradation of cytoplasmic contents and organelles to deal with environmental stresses like hypoxia and starvation. Autophagy contributes to response to chemotherapy agents: autophagy can act as a protective mechanism for mediating the resistance in response to chemotherapy or can induce autophagic cell death and mediate the sensitivity to chemotherapy. On the other hand, one of the processes targeted by microRNAs in the regulation of chemoresistance is autophagy. Hence, we studied the literatures on chemoresistance mechanisms, the miRNAs' role in cancer, and the miRNAs' role in chemoresistance by modulating autophagy. Graphical Abstract.

MicroRNA-503-3p affects osteogenic differentiation of human adipose-derived stem cells by regulation of Wnt2 and Wnt7b under cyclic strain

BACKGROUND

MicroRNAs (miRNAs) play a role in regulating osteogenic differentiation (OD) of mesenchymal stem cells by inhibiting mRNAs translation under cyclic strain. miR-503-3p was downregulated in OD of human adipose-derived stem cells (hASCs) in vivo under cyclic strain in our previous study, while it might target the Wnt/β-catenin (W-β) pathway. In this study, we explored miR-503-3p's role in OD of hASCs under cyclic strain.

METHODS

OD of hASCs was induced by cyclic strain. Bioinformatic and dual luciferase analyses were used to confirm the relationship between Wnt2/Wnt7b and miR-503-3p. Immunofluorescence was used to detect the effect of miR-503-3p on Wnt2/Wnt7b and β-catenin in hASCs transfected with miR-503-3p mimic and inhibitor. Mimic, inhibitor, and small interfering RNA (siRNA) transfected in hASCs to against Wnt2 and Wnt7b. Quantitative real-time PCR (RT-PCR) and western blot were used to examine the OD and W-β pathway at the mRNA and protein levels, respectively. Immunofluorescence was performed to locate β-catenin. ALP activity and calcium were detected by colorimetric assay.

RESULTS

Results of immunophenotypes by flow cytometry and multi-lineage potential confirmed that the cultured cells were hASCs. Results of luciferase reporter assay indicated that miR-503-3p could regulate the expression levels of Wnt2 and Wnt7b by targeting their respective 3'-untranslated region (UTR). Under cyclic strain, gain- or loss-function of miR-503-3p studies by mimic and inhibitor revealed that decreasing expression of miR-503-3p could significantly bring about promotion of OD of hASCs, whereas increased expression of miR-503-3p inhibited OD. Furthermore, miR-503-3p high-expression reduced the activity of the W-β pathway, as indicated by lowering expression of Wnt2 and Wnt7b, inactive β-catenin in miR-503-3p-treated hASCs. By contrast, miR-503-3p inhibition activated the W-β pathway.

CONCLUSIONS

Collectively, our findings indicate that miR-503-3p is a negative factor in regulating W-β pathway by Wnt2 and Wnt7b, which inhibit the OD of hASCs under cyclic strain.

Evaluation of LDL receptor and Scavenger Receptor, Class B, Type 1 in the malignant and benign breast tumors: The correlation with the expression of miR-199a-5p, miR-199b-5p and miR-455-5p

AIMS

The purpose of present study was to examine the correlations of LDL (LDLR) and HDL (SR-B1) receptors with lipoproteins, miR-199a-5p, miR-199b-5p, miR-455-5p in the malignant and benign breast tumors.

METHODS

Total cholesterol-rich-lipoproteins and the receptors were determined using enzymatic-homogeneous and ELISA methods. The expression levels of miRNAs were detected by qRT-PCR.

RESULTS

Receptor expressions and lipoproteins concentration were significantly higher in the malignant tumors (p < 0.05). Positive correlation was found for LDLR with Ki67% and Her2+. HDL-C content of TNBC tumors was higher than those of Non-TNBC (p < 0.05). The expression level of miR-199a-5p was found to be downregulated significantly in the malignant tumors of <2 cm, TNBC, HER2- or stage3. The expression of miR-199b-5p was downregulated in the malignant tumors and was negatively associated with TNBC, stage and Her2+. The expression of miR-455-5p was significantly correlated with Her2- (p < 0.05). A positive correlation was observed for SR-B1 or LDLR with HDL-C or LDL-C and also for SR-B1 with LDLR, although a reverse association was detected for the expression of miR-199b-5p with LDLR in the malignant tumors (p < 0.05). No significant correlations were found for miR-199a-5p or miR-455-5p with LDLR or SR-B1 expressions and also for LDL-C and SR-B1 with clinicopathological features (p ≥ 0.05).

CONCLUSIONS

Mechanisms potentially involved in the present findings may be due to the lipid internalization and lipoprotein consumption through LDLR and SR-B1 over expression. It is noteworthy that the expression of miR-199b-5p is negatively correlated with LDLR which may suggest it as a suppressor for LDLR expression in the breast cancer.

[Chloroquine enhances cisplatin-induced apoptosis of nasopharyngeal carcinoma cells by inhibiting autophagy via upregulating miR129]

OBJECTIVE

To investigate the role of miR129 in mediating the effect of chloroquine to enhance cisplatin- induced apoptosis in nasopharyngeal carcinoma cells (HNE1).

METHODS

MTT assay was used to detect the viability of HNE1 cells treated with different concentrations of cisplatin. Colony formation of HNE1 cells treated with cisplatin and chloroquine, alone or in combination, was observed using crystal violet staining. BALB/C unde mice were inoculated with HNE1 cells and randomly divided into 4 groups with 6 mice in each group. The mice received intraperitoneal injections of cisplatin and chloroquine, alone or in combination once every 3 days for 4 consecutive weeks, and the tumor growth was observed in each group. The expression of miR129 in HNE1 cells treated with chloroquine, cisplatin, or both was detected with qPCR. The effects of miR129 suppression with a miR129 inhibitor on the expressions of autophagy related proteins p62, LC3B, Beclin1 and the drug-resistant related protein P-glycoprotein (P-gp) were examined using Western blotting in HNE1 cells treated with chloroquine, cisplatin, or both; the changes in cell apoptosis were detected Annexin V/PI double staining.

RESULTS

Chloroquine combined with cisplatin significantly inhibited HNE1 cell proliferation in vitro and the growth of HNE1 cell-derived tumor in nude mice as compared with cisplatin alone (P < 0.01). In cultured HNE1 cells, inhibition of the expression of miR129 significantly promoted autophagy and up-regulated P-gp expression (P < 0.01); Chloroquine obviously inhibited cisplatin-induced autophagy and up-regulated the expression of miR129 in HNE1 cells (P < 0.01). Transfection of the cells with the miR129 inhibitor abolished the inhibitory effect of chloroquine on cisplatin-induced autophagy, and significantly increased the cell survival rate (P < 0.05) and lower the cell apoptotic rate (P < 0.01) after combined treatment with chloroquine and cisplatin.

CONCLUSIONS

Chloroquine enhances the pro-apoptotic effect of cisplatin by up-regulating miR129 to inhibit autophagy and drug resistance in HNE1 cells.

Circ_0009910 promotes imatinib resistance through ULK1-induced autophagy by sponging miR-34a-5p in chronic myeloid leukemia

BACKGROUND

The occurrence in drug resistance of chronic myeloid leukemia (CML) was accompanied by autophagy activation. Abnormal circular RNAs (circRNAs) participated in this progression. This study attempted to investigate the potential role of circ_0009910 in imatinib resistance of CML cells.

METHODS

The expression of circ_0009910 and miR-34a-5p was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The characterization of circ_0009910 was investigated using oligo (dT)18 primers, Actinomycin D and RNase R. Cell viability (IC₅₀ value) and apoptosis were assessed by Cell Counting Kit-8 (CCK8) assay and flow cytometry assay, respectively. The relative protein expression was quantified by western blot. The relationship among miR-34a-5p, circ_0009910 and ULK1 was predicted by online bioinformatics tool, and verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP).

RESULTS

The expression of circ_0009910 was up-regulated in the serum of imatinib-resistance CML patients and K562/R cells, and associated with unfavorable clinicopathologic features. Circ_0009910 in K562 and K562/R cells was mainly localized in the cytoplasm. Circ_0009910 knockdown inhibited cell proliferation and autophagy, but induced apoptosis in K562/R cells. Circ_0009910 targeted miR-34a-5p to regulate ULK1. MiR-34a-5p depression rescued the effects of circ_0009910 knockdown on apoptosis and autophagy in K562/R cells.

CONCLUSION

Circ_0009910 accelerated imatinib-resistance in CML cells by modulating ULK1-induced autophagy via targeting miR-34a-5p, providing a potential target in imatinib resistance of CML.

miR-199a-5p Represses Protective Autophagy and Overcomes Chemoresistance by Directly Targeting DRAM1 in Acute Myeloid Leukemia

Chemotherapy resistance is still a primary clinical obstacle to the successful treatment of acute myeloid leukemia (AML). The underlying mechanisms of drug resistance are complicated and have not been fully understood. Here, we found that miR-199a-5p levels were significantly reduced in refractory/relapsed AML patients compared to those who achieved complete remission after chemotherapy. Consistently, miR-199a-5p was markedly decreased in Adriamycin-resistant AML K562/ADM cells in contrast with Adriamycin-sensitive K562 cells, and its decrement dramatically correlated with the chemoresistance of AML cells. Furthermore, we demonstrated that the basic and Adriamycin-induced autophagic activity in K562/ADM cells was higher than that in K562 cells. This inducible autophagy played a prosurvival role and contributed to the development of acquired drug resistance. Importantly, we investigated that miR-199a-5p could negatively regulate autophagy, at least in part, by inhibiting damage regulator autophagy modulator (DRAM1) expression at both the transcriptional and posttranscriptional level. miR-199a-5p bound directly to the 3'-UTR of DRAM1 mRNA which was a functional target of miR-199a-5p. Indeed, downregulation of DRAM1 gene by siRNA in K562/ADM cells resulted in autophagy suppression and chemosensitivity restoration. These results revealed that the miR-199a-5p/DRAM1/autophagy signaling represented a novel pathway regulating chemoresistance, indicating a potential therapeutic strategy for the intervention in drug-resistant AML.

Diagnostic and prognostic value of WNT family gene expression in hepatitis B virus‑related hepatocellular carcinoma

The aim of the present study was to investigate the diagnostic and prognostic value of Wingless-type MMTV integration site (WNT) gene family expression in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). The clinical data of the patients and gene expression levels were downloaded from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Receiver operating characteristic curve analysis was used to investigate the diagnostic value of WNT genes. Cox proportional hazard regression analysis and Kaplan-Meier survival analysis were performed to evaluate the association of WNT gene expression level with overall survival (OS) and recurrence-free survival (RFS). A nomogram was constructed for the prediction of prognosis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. Diagnostic receiver operating characteristic curve analysis suggested that WNT2 had a high diagnostic value, with an area under the curve (AUC) of >0.800 (P<0.0001, AUC=0.810, 95% CI: 0.767–0.852). Survival analysis indicated that the expression level of WNT1 was significantly associated with OS and RFS (adjusted P=0.033, adjusted HR=0.607, 95% CI: 0.384–0.960; and adjusted P=0.007, adjusted HR=0.592, 95% CI: 0.404–0.868, respectively). In the TCGA validation cohort, we also observed that WNT2 was significantly differentially expressed between HCC tissues and adjacent non-tumor tissues, and WNT1 was associated with both the OS and RFS of HCC. Therefore, through the GSE14520 HBV-related HCC cohort we concluded that WNT2 may serve as a diagnostic biomarker and WNT1 may serve as a prognostic biomarker. These results may also be extended to TCGA HCC verification cohort.

Micro-ribonucleic acid expression signature of metastatic castration-resistant prostate cancer: Regulation of NCAPH by antitumor miR-199a/b-3p

OBJECTIVES

To identify oncogenes regulated by micro-ribonucleic acid, miR-199a/b-3p, in metastatic castration-resistant prostate cancer.

METHODS

Advanced ribonucleic acid sequencing technologies were applied to construct a micro-ribonucleic acid expression signature using metastatic castration-resistant prostate cancer autopsy specimens. Ectopic expression of mature micro-ribonucleic acids or small-interfering ribonucleic acids were applied to functional assays for cancer cell lines. Genome-wide gene expression and in silico database analyses were carried out to predict micro-ribonucleic acid targets.

RESULTS

Ectopic expression of miR-199a/b inhibited cancer cell aggressiveness. The gene coding for non-structural maintenance of chromosomes condensin I complex subunit H was directly regulated by miR-199a/b-3p. High expression of condensin I complex subunit H was significantly associated with poor disease-free survival by The Cancer Genome Atlas database analysis (P < 0.0001). Overexpression of condensin I complex subunit H was detected in hormone-sensitive prostate cancer and castration-resistant prostate cancer specimens, and knockdown assays showed that its expression enhanced cancer cell migration and invasive abilities.

CONCLUSIONS

Small ribonucleic acid sequencing of metastatic castration-resistant prostate cancer specimens showed the presence of several antitumor micro-ribonucleic acids whose targets are involved in hormone-sensitive prostate cancer and metastatic castration-resistant prostate cancer pathogenesis. Condensin I complex subunit H seems to be a promising diagnostic marker and therapeutic target for this disease. Our approach, based on the roles of anti-tumor micro-ribonucleic acids and their targets, will contribute to an improved understanding of the molecular pathogenesis of hormone-sensitive prostate cancer and metastatic castration-resistant prostate cancer.

MicroRNA-mediated redox regulation modulates therapy resistance in cancer cells: clinical perspectives

BACKGROUND

Chemotherapy and radiation therapy are the most common types of cancer therapy. The development of chemo/radio-resistance remains, however, a major obstacle. Altered redox balances are among of the main factors mediating therapy resistance. Therefore, redox regulatory strategies are urgently needed to overcome this problem. Recently, microRNAs have been found to act as major redox regulatory factors affecting chemo/radio-resistance. MicroRNAs play critical roles in regulating therapeutic resistance through the regulation of antioxidant enzymes, redox-sensitive signaling pathways, cancer stem cells, DNA repair mechanisms and autophagy.

CONCLUSIONS

Here, we summarize current knowledge on microRNA-mediated redox regulatory mechanisms underlying chemo/radio-resistance. This knowledge may form a basis for a better clinical management of cancer patients.