Celastrol Elicits Antitumor Effects through Inducing Immunogenic Cell Death and Downregulating PD-L1 in ccRCC.

BACKGROUND: Targeting immunogenic cell death (ICD) is considered a promising therapeutic strategy for cancer. However, the commonly identified ICD inducers promote the expression of programmed cell death ligand 1 (PD-L1) in tumor cells, thus aiding them to evade the recognition and killing by the immune system. Therefore, the finding of novel ICD inducers to avoid enhanced PD-L1 expression is of vital significance for cancer therapy. Celastrol (CeT), a triterpene isolated from Tripterygium wilfordii Hook. F induces various forms of cell death to exert anti-cancer effects, which may make celastrol an attractive candidate as an inducer of ICD. METHODS: In the present study, bioinformatics analysis was combined with experimental validation to explore the underlying mechanism by which CeT induces ICD and regulates PD-L1 expression in clear cell renal cell carcinoma (ccRCC). RESULTS: The results showed that EGFR, IKBKB, PRKCQ and MAPK1 were the crucial targets for CeT-induced ICD, and only MAPK1 was an independent prognostic factor for the overall survival (OS) of ccRCC patients. In addition, CeT triggered autophagy and up-regulated the expressions of HMGB1 and CRT to induce ICD in 786-O cells in vitro. Importantly, CeT can down-regulate PD-L1 expression through activating autophagy. At the molecular level, CeT suppressed PD-L1 via the inhibition of MAPK1 expression. Immunologically, the core target of celastrol, MAPK1, was tightly correlated with CD8+ T cells and CD4+ T cells in ccRCC. CONCLUSION: These findings indicate that CeT not only induces ICD but also suppresses PD-L1 by down-regulating MAPK1 expression, which will provide an attractive strategy for ccRCC immunotherapy.

Insights into dietary phytochemicals targeting Parkinson's disease key genes and pathways: A network pharmacology approach.

Parkinson's disease (PD) is a complex neurological disease associated with the degeneration of dopaminergic neurons. Oxidative stress is a key player in instigating apoptosis in dopaminergic neurons. To improve the survival of neurons many dietary phytochemicals have gathered significant attention recently. Thus, the present study implements a comprehensive network pharmacology approach to unravel the mechanisms of action of dietary phytochemicals that benefit disease management. A literature search was performed to identify ligands (i.e., comprising dietary phytochemicals and Food and Drug Administration pre-approved PD drugs) in the PubMed database. Targets associated with selected ligands were extracted from the search tool for interactions of chemicals (STITCH) database. Then, the construction of a gene-gene interaction (GGI) network, analysis of hub-gene, functional and pathway enrichment, associated transcription factors, miRNAs, ligand-target interaction network, docking were performed using various bioinformatics tools together with molecular dynamics (MD) simulations. The database search resulted in 69 ligands and 144 unique targets. GGI and subsequent topological measures indicate histone acetyltransferase p300 (EP300), mitogen-activated protein kinase 1 (MAPK1) or extracellular signal-regulated kinase (ERK)2, and CREB-binding protein (CREBBP) as hub genes. Neurodegeneration, MAPK signaling, apoptosis, and zinc binding are key pathways and gene ontology terms. hsa-miR-5692a and SCNA gene-associated transcription factors interact with all the 3 hub genes. Ligand-target interaction (LTI) network analysis suggest rasagiline and baicalein as candidate ligands targeting MAPK1. Rasagiline and baicalein form stable complexes with the Y205, K330, and V173 residues of MAPK1. Computational molecular insights suggest that baicalein and rasagiline are promising preclinical candidates for PD management.

Integrated bioinformatics approaches and expression assays identified new markers in pituitary adenomas.

Pituitary adenomas (PA) include about one third of primary central nervous tumors in adolescent and young adult. Despite extensive research, the underlying mechanism of PA tumorigenesis is still unknown. In the present study, through bioinformatics analysis of a PA-related dataset downloaded from GEO database, we attempted to identify pair(s) of lncRNA/target mRNA whose expression changes may be involved in the tumorigenesis of PAs. For this end, we evaluated expression of a set of bioinformatically obtained genes in 46 PA tissues against adjacent non-tumor pituitary tissues. The bioinformatics step led to selection of four genes for validation through expression assays. Expression levels of HIF1A and MAPK1 were increased in NFPA tissues (P < 0.0001 and =0.0042, respectively). Expression level of BANCR was significantly decreased in tumor tissues (P < 0.0001). However, expression of STAT3 was not meaningfully different between the two tissue types (P = 0.56). Since there was no significant correlation between MAPK1 and BANCR expressions in either tumor or adjacent normal tissues, the regulatory effect of BANCR on MAPK1 was not confirmed. In conclusion, this study offers information about deregulation of bioinformatically identified genes in PA tumors and indicates that further studies in this field is needed to understand the involved molecular mechanisms.

CETSA-MS-based target profiling of anti-aging natural compound quercetin.

BACKGROUND: Quercetin is widely distributed in nature and abundant in the human diet, which exhibits diverse biological activities and potential medical benefits. However, there remains a lack of comprehensive understanding about its cellular targets, impeding its in-depth mechanistic studies and clinical applications. PURPOSE: This study aimed to profile protein targets of quercetin at the proteome level. METHODS: A label-free CETSA-MS proteomics technique was employed for target enrichment and identification. The R package Inflect was used for melting curve fitting and target selection. D3Pocket and LiBiSco tools were used for binding pocket prediction and binding pocket analysis. Western blotting, molecular docking, site-directed mutagenesis and pull-down assays were used for target verification and validation. RESULTS: We curated a library of direct binding targets of quercetin in cells. This library comprises 37 proteins that show increased thermal stability upon quercetin binding and 33 proteins that display decreased thermal stability. Through Western blotting, molecular docking, site-directed mutagenesis and pull-down assays, we validated CBR1 and GSK3A from the stabilized protein group and MAPK1 from the destabilized group as direct binding targets of quercetin. Moreover, we characterized the shared chemical properties of the binding pockets of quercetin with targets. CONCLUSION: Our findings deepen our understanding of the proteins pivotal to the bioactivity of quercetin and lay the groundwork for further exploration into its mechanisms of action and potential clinical applications.

MAPK1 Mediates MAM Disruption and Mitochondrial Dysfunction in Diabetic Kidney Disease via the PACS-2-Dependent Mechanism.

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease (ESRD). Mitochondrial dysfunction in renal tubules, occurring early in the disease, is linked to the development of DKD, although the underlying pathways remain unclear. Here, we examine diabetic human and mouse kidneys, and HK-2 cells exposed to high glucose, to show that high glucose disrupts mitochondria-associated endoplasmic reticulum membrane (MAM) and causes mitochondrial fragmentation. We find that high glucose conditions increase mitogen-activated protein kinase 1(MAPK1), a member of the MAP kinase signal transduction pathway, which in turn lowers the level of phosphofurin acidic cluster sorting protein 2 (PACS-2), a key component of MAM that tethers mitochondria to the ER. MAPK1-induced disruption of MAM leads to mitochondrial fragmentation but this can be rescued in HK-2 cells by increasing PACS-2 levels. Functional studies in diabetic mice show that inhibition of MAPK1 increases PACS-2 and protects against the loss of MAM and the mitochondrial fragmentation. Taken together, these results identify the MAPK1-PACS-2 axis as a key pathway to therapeutically target as well as provide new insights into the pathogenesis of DKD.

Tumor cells-derived extracellular vesicles carry circ_0064516 competitively inhibit microRNA-6805-3p and promote cervical cancer angiogenesis and tumor growth.

BACKGROUND: The current study tried to elucidate the regulatory role of tumor cell-derived exosomes (Exos)-circ_0064516 in angiogenesis and growth of cervical cancer. RESEARCH DESIGN AND METHODS: Related cirRNAs and downstream target genes were identified through bioinformatics analysis. Exos were isolated from cervical cancer cell line CaSki, followed by co-cultured with human umbilical vein endothelial cells (HUVECs). Then, the roles of circ_0064516, miR-6805-3p, and MAPK1 in migration and angiogenesis of HUVECs were assayed. Furthermore, xenografted tumors were transplanted into nude mice for in vivo validation. RESULTS: In vitro assay validated highly expressed circ_0064516 in cervical cancer cells. Tumor cell-derived Exos carried circ_0064516 to HUVECs. circ_0064516 increased MAPK1 expression by binding to miR-6805-3p, thus enhancing migration and angiogenesis. Exos containing circ_0064516 also promoted tumorigenesis of cervical cancer cells in nude mice. CONCLUSIONS: We confirmed the oncogenic role of tumor cell-derived Exos carrying circ_0064516 in cervical cancer progression through miR-6805-3p/MAPK1.

N6-methyladenosine-modified CircPSMA7 enhances bladder cancer malignancy through the miR-128-3p/MAPK1 axis.

Several studies have indicated that circular RNAs (circRNAs) play vital roles in the progression of various diseases, including bladder cancer (BCa). However, the underlying mechanisms by which circRNAs drive BCa malignancy remain unclear. In this study, we identified a novel circRNA, circPSMA7 (circbaseID:has_circ_0003456), showing increased expression in BCa cell lines and tissues, by integrating the reported information with circRNA-seq and qRT-PCR. We revealed that circPSMA7 is associated with a higher tumor grade and stage in BCa. M6A modification was identified in circPSMA7, and IGF2BP3 recognized this modification and stabilized circPSMA7, subsequently increasing the circPSMA7 expression. In vitro and in vivo experiments showed that circPSMA7 promoted BCa proliferation and metastasis by regulating the cell cycle and EMT processes. CircPSMA7 acted as a sponge for miR-128-3p, which showed antitumor effects in BCa cell lines, increasing the expression of MAPK1. The tumor proliferation and metastasis suppression induced by silencing circPSMA7 could be partly reversed by miR-128-3p inhibition. Thus, the METTL3/IGF2BP3/circPSMA7/miR-128-3p/MAPK1 axis plays a critical role in BCa progression. Furthermore, circPSMA7 may be a potential diagnostic biomarker and novel therapeutic target for patients with BCa.

Circ_FNDC3B Promotes Cell Proliferation and Metastasis in Esophageal Squamous Cell Carcinoma via Regulating MAPK1 by Binding to miR-136-5p.

A handful of circular RNAs (circRNAs) associated with cancer progression have been indicated in esophageal squamous cell carcinoma (ESCC). The current study aimed to investigate the functional mechanism of circular RNA Fibronectin type III domain containing 3B (circ_FNDC3B) in ESCC. Circ_FNDC3B, FNDC3B, microRNA-136-5p (miR-136-5p) and mitogen-activated protein kinase 1 (MAPK1) were examined via the quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) and colony formation assays. Transwell assay was performed to measure cell migration and invasion. Protein analysis was implemented by western blot. Cell apoptosis was assessed via flow cytometry. Target interaction was affirmed using dual-luciferase reporter assay. The function analysis of circ_FNDC3B in vivo was explored by xenograft models. The upregulation of circ_FNDC3B was detected in ESCC tissues and cells. Functionally, ESCC cell proliferation and metastasis were repressed but apoptosis was promoted by circ_FNDC3B knockdown. Besides, circ_FNDC3B silence inhibited ESCC progression through MAPK1 downregulation. Further target analysis identified miR-136-5p as a target of circ_FNDC3B and an upstream control of MAPK1. Additionally, the regulation of si-circ_FNDC3B in ESCC was also dependent on targeting miR-136-5p. Moreover, circ_FNDC3B targeted miR-136-5p to affect MAPK1 level. Tumorigenesis in vivo was also suppressed by downregulating circ_FNDC3B to regulate miR-136-5p/MAPK1 axis. Circ_FNDC3B downregulation impeded the development of ESCC via the mediation of miR-136-5p/MAPK1 axis. This report afforded a novel insight into the functional mechanism of circ_FNDC3B in ESCC.

In silico designing of multiepitope-based-peptide (MBP) vaccine against MAPK protein express for Alzheimer's disease in Zebrafish.

Understanding the role of the mitogen-activated protein kinases (MAPKs) signalling pathway is essential in advancing treatments for neurodegenerative disorders like Alzheimer's. In this study, we investigate in-silico techniques involving computer-based methods to extract the MAPK1 sequence. Our applied methods enable us to analyze the protein's structure, evaluate its properties, establish its evolutionary relationships, and assess its prevalence in populations. We also predict epitopes, assess their ability to trigger immune responses, and check for allergenicity using advanced computational tools to understand their immunological properties comprehensively. We apply virtual screening, docking, and structure modelling to identify promising drug candidates, analyze their interactions, and enhance drug design processes. We identified a total of 30 cell-targeting molecules against the MAPK1 protein, where we selected top 10 CTL epitopes (PAGGGPNPG, GGGPNPGSG, SAPAGGGPN, AVSAPAGGG, AGGGPNPGS, ATAAVSAPA, TAAVSAPAG, ENIIGINDI, INDIIRTPT, and NDIIRTPTI) for further evaluation to determine their potential efficacy, safety, and suitability for vaccine design based on strong binding potential. The potential to cover a large portion of the world's population with these vaccines is substantial-88.5 % for one type and 99.99 % for another. In exploring the molecular docking analyses, we examined a library of compounds from the ZINC database. Among them, we identified twelve compounds with the lowest binding energy. Critical residues in the MAPK1 protein, such as VAL48, LYS63, CYS175, ASP176, LYS160, ALA61, LEU165, TYR45, SER162, ARG33, PRO365, PHE363, ILE40, ASN163, and GLU42, are pivotal for interactions with these compounds. Our result suggests that these compounds could influence the protein's behaviour. Moreover, our docking analyses revealed that the predicted peptides have a strong affinity for the MAPK1 protein. These peptides form stable complexes, indicating their potential as potent inhibitors. This study contributes to the identification of new drug compounds and the screening of their desired properties. These compounds could potentially help reduce the excessive activity of MAPK1, which is linked to Alzheimer's disease.

METTL3/YTHDC1-medicated m6A modification of circRNA3634 regulates the proliferation and differentiation of antler chondrocytes by miR-124486-5-MAPK1 axis.

BACKGROUND: The deer antler, a remarkable mammalian appendage, has a growth rate surpassing that of any other known osseous organ. Emerging evidence indicates that circRNA and MAPK1 play critical roles in chondrocytes. Thus, exploration of their functions in antler chondrocytes will help us to understand the mechanism regulating the rapid antler growth. METHODS: qRT-PCR, western blot, and immunohistochemistry were used to assess the expression of mRNAs and proteins. CCK-8, EdU, Cell migration, ALP activity detection, and ALP staining examined the effects of MAPK1 in antler chondrocytes. FISH, RIP, and luciferase assays were performed to evaluate the interactions among circRNA3634/MAPK1 and miR-124486-5. RIP and RAP assays proved the binding interaction between circRNA3634 and RBPs. Me-RIP was used to determine the m6A methylation modification of circRNA3634. RESULTS: This study revealed high MAPK1 expression in antler cartilage tissue. Overexpression of MAPK1 promoted the proliferation, migration, and differentiation of antler chondrocytes and increased the expression of MAPK3, RAF1, MEK1, RUNX2, and SOX9. The silencing of MAPK1 had the opposite effect. CircRNA3634 was found to act as a molecular sponge for miR-124486-5, leading to increased MAPK1 expression and enhanced proliferation and migration of antler chondrocytes through competitive miR-124486-5 binding. We discovered that METTL3 mediates m6A modification near the splicing site of circRNA3634 and is involved in the proliferation and differentiation of antler chondrocytes. The m6A reader YTHDC1 facilitated the nuclear export of circRNA3634 in an m6A-dependent manner. Our results indicate that m6A-modified circRNA3634 promotes the proliferation of antler chondrocytes by targeting MAPK1 and show that the nuclear export of circRNA3634 is related to the expression of YTHDC1, suggesting that circRNA3634 could represent a critical regeneration marker for the antler. CONCLUSIONS: Our results revealed a novel m6A-modified circRNA3634 promoted the proliferation and differentiation of antler chondrocytes by regulating MAPK1. The nuclear export of circRNA3634 was related to the expression of YTHDC1.

A Novel Distal 22Q11.21 Microduplication in a 43-Year-Old Male Patient with Mild Intellectual Disability, Social Cognitive Dysfunctions, and Anxiety.

Objective: The chromosome region 22q11.2 is highly susceptible to genomic rearrangements. It has become clear that genomic instability extends distally to the commonly deleted/duplicated region (Low Copy Repeats [LCR] A-D) and that a clear difference exists between the phenotypic presentation of patients with rearrangements in the common region versus that in the distal region (LCR D-H), particularly with respect to developmental and somatic issues. Microdeletions in the 22q11.2 distal region are typically associated with congenital heart defects whereas distal 22q11.2 microduplications are infrequently described and present with a smaller duplicated region and a rather unspecified phenotype. Method: The present paper provides detailed assessments of a middle-aged male with mild intellectual disability, elsewhere diagnosed with autism spectrum disorder. Because of persisting functional complaints, he was referred for second opinion to a specialized outpatient department. Results: High resolution SNP-based array analysis demonstrated a ~1.5 Mb distal microduplication in chromosome 22 flanked by LCR region 22C and LCR22E encompassing among others the disease gene MAPK1. No remarkable facial dysmorphisms were noticed. Autism spectrum disorder was ruled out and it was concluded that the patient was primarily suffering from mild intellectual disability and social cognitive dysfunctions with anxieties and suspicious social interactions, to be understood as a disorder within the anxiety spectrum. Conclusions: The pattern of psychological and psychiatric phenomena was discussed against the background of findings on psychopathology in the chromosome 22 region demarcated by LCR breakpoints C and E. It was suggested that alterations in the MAPK1 gene due to either a deletion or a duplication enhance the vulnerability to develop a psychiatric disorder within the anxiety spectrum.

Expression and promoter methylation of mitogen-activated protein kinase 1 in tumor and marginal cells of breast cancer.

AIM: In the present study, we sought to explore potential differences in the expression and promoter methylation of mitogen-activated protein kinase 1 (MAPK1) between tumor and marginal cells of breast cancer lesions. METHODS: A total of 50 randomly selected patients with breast cancer (BCa) undergoing needle biopsy were enrolled. Clinical specimens containing both tumor and marginal cells were collected and preserved. After DNA extraction using specific primers, MAPK1 mRNA and promoter methylation were measured with spectrophotometry at 260/280 nm absorption wavelengths. To deliver a comparative analysis, data from The Cancer Genome Atlas (TCGA) program regarding breast cancer (BRCA), were downloaded from Xena Functional Genomics Explorer and separately analyzed. The suitability of MAPK1 expression and promoter methylation as biomarkers for BCa was analyzed with receiver operating characteristic (ROC) curves. RESULTS: We found a positive correlation between tumor stage and MAPK1 expression (P-value: 0.029) in BCa. Likewise, MAPK1 expression was significantly associated with lymph node metastasis (P-value: 0.018). There was a significant difference in the expression of MAPK1 mRNA between tumor and marginal cells of BCa and BRCA (P-value < 0.001). However, we did not find any statistically significant difference in MAPK1 promoter methylation between tumor and marginal cells of both BCa and BRCA. With an area under the curve (AUC) of 0.71, the diagnostic accuracy of MAPK1 expression in BCa and BRCA was validated. However, MAPK1 promoter methylation was not found to be a suitable biomarker. CONCLUSION: Our findings suggest that while MAPK1 expression, might be a promising biomarker for evaluating oncogenic activity in patients suspected of BCa. We were not able to detect a prognostic/diagnostic role for MAPK1 promoter methylation.

Mechanism of Interaction between hsa_circ_0002854 and MAPK1 Protein in PM2.5-Induced Apoptosis of Human Bronchial Epithelial Cells.

Fine particulate matter (PM2.5) pollution increases the risk of respiratory diseases and death, and apoptosis is an important factor in the occurrence of respiratory diseases caused by PM2.5 exposure. In addition, circular RNAs (circRNAs) can interact with proteins and widely participate in physiological and pathological processes in the body. The aim of this study was to investigate the mechanism of circRNA and protein interaction on PM2.5-induced apoptosis of human bronchial epithelial cells (16HBE) in vitro. In this study, we exposed human bronchial epithelial cells to a PM2.5 suspension with different concentration gradients for 24 h. The results showed that apoptosis of 16HBE cells after PM2.5 treatment was accompanied by cell proliferation. After exposure of PM2.5 to 16HBE cells, circRNAs related to apoptosis were abnormally expressed. We further found that the expression of hsa_circ_0002854 increased with the increase in exposure concentration. Functional analysis showed that knocking down the expression of hsa_circ_0002854 could inhibit apoptosis induced by PM2.5 exposure. We then found that hsa_circ_0002854 could interact with MAPK1 protein and inhibit MAPK1 phosphorylation, thus promoting apoptosis. Our results suggest that hsa_circ_0002854 can promote 16HBE apoptosis due to PM2.5 exposure, which may provide a gene therapy target and scientific basis for PM2.5-induced respiratory diseases.

JMJD6-BRD4 complex stimulates lncRNA HOTAIR transcription by binding to the promoter region of HOTAIR and induces radioresistance in liver cancer stem cells.

BACKGROUND: Long non-coding RNA (lncRNA) HOTAIR acts importantly in liver cancer development, but its effect on radioresistance remains poorly understood. Here, our study probed into the possible impact of HOTAIR in radioresistance in liver cancer stem cells (LCSCs) and to elucidate its molecular basis. METHODS: Following sorting of stem and non-stem liver cancer cells, LCSCs were identified and subjected to RNA-seq analysis for selecting differentially expressed genes. Expression of HOTAIR was determined in liver cancer tissues and CSCs. The stemness, proliferation, apoptosis and radioresistance of LCSCs were then detected in response to altered expression of HOTAIR-LSD1-JMJD6-BRD4. RESULTS: Ectopic HOTAIR expression was found to promote radioresistance of LCSCs by maintaining its stemness. Mechanistic investigations indicated that HOTAIR recruited LSD1 to the MAPK1 promoter region and reduced the level of H3K9me2 in the promoter region, thus elevating ERK2 (MAPK1) expression. JMJD6-BRD4 complex promoted HOTAIR transcription by forming a complex and positively regulated ERK2 (MAPK1) expression, maintaining the stemness of LCSCs, and ultimately promoting their radioresistance in vitro and in vivo. CONCLUSION: Collectively, our work highlights the promoting effect of the JMJD6-BRD4 complex on the radioresistance of LCSCs through a HOTAIR-dependent mechanism.

MAPK1 promotes the metastasis and invasion of gastric cancer as a bidirectional transcription factor.

BACKGROUND: The Mitogen-activated protein kinase 1 (MAPK1) has both independent functions of phosphorylating histones as a kinase and directly binding the promoter regions of genes to regulate gene expression as a transcription factor. Previous studies have identified elevated expression of MAPK1 in human gastric cancer, which is associated with its role as a kinase, facilitating the migration and invasion of gastric cancer cells. However, how MAPK1 binds to its target genes as a transcription factor and whether it modulates related gene expressions in gastric cancer remains unclear. RESULTS: Here, we integrated biochemical assays (protein interactions and chromatin immunoprecipitation (ChIP)), cellular analysis assays (cell proliferation and migration), RNA sequencing, ChIP sequencing, and clinical analysis to investigate the potential genomic recognition patterns of MAPK1 in a human gastric adenocarcinoma cell-line (AGS) and to uncover its regulatory effect on gastric cancer progression. We confirmed that MAPK1 promotes AGS cells invasion and migration by regulating the target genes in different directions, up-regulating seven target genes (KRT13, KRT6A, KRT81, MYH15, STARD4, SYTL4, and TMEM267) and down-regulating one gene (FGG). Among them, five genes (FGG, MYH15, STARD4, SYTL4, and TMEM267) were first associated with cancer procession, while the other three (KRT81, KRT6A, and KRT13) have previously been confirmed to be related to cancer metastasis and migration. CONCLUSION: Our data showed that MAPK1 can bind to the promoter regions of these target genes to control their transcription as a bidirectional transcription factor, promoting AGS cell motility and invasion. Our research has expanded the understanding of the regulatory roles of MAPK1, enriched our knowledge of transcription factors, and provided novel candidates for cancer therapeutics.

Circ_0005736 promotes tenogenic differentiation of tendon-derived stem cells through the miR-636/MAPK1 axis.

BACKGROUND: Tendon-derived stem cells (TDSCs) are one of stem cells characterized by greater clonogenicity, tenogenesis, and proliferation capacity. Circ_0005736 has been shown to be decreased in Rotator cuff tendinopathy. Here, we investigated the function and relationship of circ_0005736 in TDSC tenogenic differentiation. METHODS: Transforming growth factor ß1 (TGF-ß1) was used to induce the tenogenic differentiation in TDSC. Cell proliferation, invasion and migration were evaluated by Cell Counting Kit-8, 5-Ethynyl-2'-deoxyuridine, transwell, and wound healing assays, respectively. The detection of the levels of genes and proteins was performed by qRT-PCR and Western blot. The binding between miR-636 and circ_0005736 or MAPK1 (Mitogen-Activated Protein Kinase 1) was verified using dual-luciferase reporter assay and RIP assays. RESULTS: TGF-ß1 induced tenogenic differentiation by enhancing the production of tendon-specific markers and TDSC proliferation, invasion and migration. TGF-ß1 treatment promoted circ_0005736 expression, knockdown of circ_0005736 abolished TGF-ß1-induced tenogenic differentiation in TDSCs. Mechanistically, circ_0005736 acted as a sponge for miR-636 to up-regulate the expression of MAPK1, which was confirmed to be a target of miR-636 in TDSCs. Further rescue assays showed that inhibition of miR-636 could rescue circ_0005736 knockdown-induced suppression on TGF-ß1-caused tenogenic differentiation in TDSCs. Moreover, forced expression of miR-636 abolished TGF-ß1-caused tenogenic differentiation in TDSCs, which was rescued by MAPK1 up-regulation. CONCLUSION: Circ_0005736 enhanced TGF-ß1-induced tenogenic differentiation in TDSCs via increasing the production of tendon-specific markers and TDSC proliferation, invasion and migration through miR-636/MAPK1 axis.

miR-125b-5p-MAPK1-C/EBPα feedback loop regulates all-trans retinoic acid resistance in acute promyelocytic leukemia.

BACKGROUND: Various studies have highlighted the significance of miR-125b-5p in tumour chemotherapy resistance; However, whether miR-125b-5p is associated with all-trans retinoic acid (ATRA) resistance in acute promyelocytic leukemia (APL) has not been reported. METHODS: Drug-resistance-related factors in APL were predicted using the DRESIS database. The expression levels of miR-125b-5p in ATRA-sensitive and ATRA-resistant APL cells were determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR). A nitrotetrazolium blue (NBT) reduction assay and flow cytometry (FCM) were used to detect the effect of miR-125b-5p on ATRA resistance in APL cells. An APL xenograft tumour mouse model was established to determine the effect of miR-125b-5p on ATRA resistance. A dual-luciferase gene reporter assay, qRT-PCR, and western blotting verified the regulation by miR-125b-5p of its target gene, MAPK1, and the MAPK1 downstream factor, C/EBPα. An NBT reduction assay and FCM were used to detect the effect of C/EBPα on ATRA resistance in APL cells. Western blotting and qRT-PCR were used to assess the regulation of miR-125b-5p and MAPK1 by C/EBPα. RESULTS: miR-125b-5p expression levels were dramatically increased in ATRA-resistant APL cells. Both in vitro and in vivo experiments revealed that miR-125b-5p overexpression enhanced ATRA resistance in APL. miR-125b-5p promoted ATRA resistance by sponging MAPK1. C/EBPα was negatively regulated by miR-125b-5p, which in addition, regulated ATRA resistance in APL cells. C/EBPα also regulated the miR-125b-5p-MAPK1 axis. CONCLUSION: The findings of this study indicate that the miR-125b-5p-MAPK1-C/EBPα feedback loop regulated ATRA resistance in APL. Thus, miR-125b-5p may be a promising target for treating ATRA resistance in APL.

Identification of signature genes and drug candidates for primary plasma cell leukemia: An integrated system biology approach.

BACKGROUND: Plasma cell leukemia (PCL) is one of the rare cancer which is characterized by the uncontrolled proliferation of plasma cells in peripheral blood and bone marrow. The aggressive behavior of the disease and high mortality rate among PCL patients makes it a thirst area to be explored. METHODS: The dataset for PCL was obtained from the GEO database and was analyzed using GEO2R for differentially expressed genes. Further, the functional enrichment analysis was carried out for DEGs using DAVID. The protein-protein interactions (PPI) for DEGs were obtained using STRING 11.5 and were analyzed in Cytoscape 3.7.2. to obtain the key hub genes. These key hub genes were investigated for their interaction with suitable drug candidates using DGIdb, DrugMAP, and Schrodinger's version 2022-1. RESULTS: Out of the total of 104 DEGs, 39 genes were up-regulated whereas 65 genes were down-regulated. A total of 11 biological processes, 2 cellular components, and 5 molecular functions were enriched along with the 7 KEGG pathways for the DEGs. Further, a total of 11 hub genes were obtained from the PPI of DEGs of which TP53, MAPK1, SOCS1, MBD3, and YES1 were the key hub genes. Oxaliplatin, mitoxantrone, and ponatinib were found to have the highest binding affinity towards the p53, MAPK1, and YES1 proteins respectively. CONCLUSION: TP53, MAPK1, SOCS1, MBD3, and YES1 are the signature hub genes that might be responsible for the aggressive prognosis of PCL leading to poor survival rate. However, p53, MAPK1, and YES1 can be targeted with oxaliplatin, mitoxantrone, and ponatinib.

Mutation in the Common Docking Domain Affects MAP Kinase ERK2 Catalysis and Stability.

The extracellular-signal-regulated kinase 2 (ERK2), a mitogen-activated protein kinase (MAPK) located downstream of the Ras-Raf-MEK-ERK signal transduction cascade, is involved in the regulation of a large variety of cellular processes. The ERK2, activated by phosphorylation, is the principal effector of a central signaling cascade that converts extracellular stimuli into cells. Deregulation of the ERK2 signaling pathway is related to many human diseases, including cancer. This study reports a comprehensive biophysical analysis of structural, function, and stability data of pure, recombinant human non-phosphorylated (NP-) and phosphorylated (P-) ERK2 wild-type and missense variants in the common docking site (CD-site) found in cancer tissues. Because the CD-site is involved in interaction with protein substrates and regulators, a biophysical characterization of missense variants adds information about the impact of point mutations on the ERK2 structure-function relationship. Most of the P-ERK2 variants in the CD-site display a reduced catalytic efficiency, and for the P-ERK2 D321E, D321N, D321V and E322K, changes in thermodynamic stability are observed. The thermal stability of NP-ERK2 and P-ERK2 D321E, D321G, and E322K is decreased with respect to the wild-type. In general, a single residue mutation in the CD-site may lead to structural local changes that reflects in alterations in the global ERK2 stability and catalysis.

Rosai-Dorfman: Rare Manifestations of a Rare Disease.

Rosai-Dorfman disease (RDD) is an exceedingly rare non-Langerhans cell histiocytosis of uncertain etiology that most commonly presents in children as self-limited, painless, massive cervical lymphadenopathy. However, extranodal disease occurs in 43% of cases and has a wide range of phenotypic presentations. The pathogenesis has not been clearly understood in the literature and coupled with a wide range of clinical manifestations, early diagnosis and initiation of an appropriate treatment modality have been challenging. Herein, we describe a cohort of five cases that occurred at the same institution within a 12-month period. These cases highlight unique and atypical presentations of an already rare disease, outline the varying and tailored diagnostic and therapeutic approaches, and propose a novel environmental predisposing factor given the exceptionally high incidence at our institution over a short period of time. We emphasize the need for further investigation of predisposing factors and to discern targeted therapies that may offer benefits.