High Mobility Group AT-hook Research Articles

MiR-129 Weakens Proliferation of Non-Small Cell Lung Cancer Cells via Targeted Regulation of High-Mobility Group AT-Hook 2

This study investigated the role of micro ribonucleic acid (miR)-129 in non-small cell lung cancer (NSCLC) by examining its effects on cell proliferation and apoptosis, as well as its relationship with the high-mobility group AT-hook 2 (HMGA2) target gene. Human NSCLC tissues were collected, and cancerous cells and normal cells were isolated and cultured. In vitro cultured NSCLC cells were transfected with miR-129 mimics or HMGA2-small interfering RNA (siRNA). The expression levels of miR-129 and HMGA2 were measured using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), while cell proliferation was assessed using the cell counting kit-8 (CCK-8) assay. The targeted regulation between miR-129 and HMGA2 was examined using a luciferase reporter assay system, and protein expression was determined by Western blotting (WB). Flow cytometry was utilized to measure the cell apoptosis rate. NSCLC tissues and cells exhibited significantly decreased miR-129 expression and increased HMGA2 expression compared to normal tissues and cells. Transfection with miR-129 mimics and HMGA2-siRNA effectively reduced HMGA2 gene and protein expression in NSCLC cells, leading to decreased proliferation and increased apoptosis. The luciferase reporter assay confirmed targeted regulation between miR-129 and HMGA2. In summary, miR-129 may suppress NSCLC cell proliferation and induce apoptosis by targeting HMGA2 expression.

Abstract PR002: Ferroptosis inducers can antagonize prostate cancer-bone interactions

Abstract Prostate cancer (PCa) is a leading cause of mortality, primarily due to its ability to metastasize to the bone. The incidence, rates of metastasis and mortality rates are higher in men of African descent compared to other races. The transcription factor High Mobility Group AT-Hook 2 (HMGA2) plays a crucial role in regulating gene expression and has been implicated in tumorigenesis and the metastatic process. Our recent study revealed that overexpression of the wild-type/full-length HMGA2 isoform in PCa cells promotes cancer progression by triggering epithelial mesenchymal transition (EMT), whereas truncated HMGA2 isoform promotes progression through oxidative stress signaling. Ferroptosis is a regulated form of cell death induced by the accumulation of iron-dependent lipid reactive oxygen species (ROS). Exploiting this oxidative stress pathway offers a promising therapeutic approach for cancer treatment, especially for apoptosis-resistant cancer cells. In our investigation, we aimed to assess the effectiveness of RSL3, a known ferroptosis inducer, in inhibiting interactions between prostate cancer cells and bone. To achieve this, we co-cultured various human PCa cell lines: C4-2B (Caucasian/bone metastatic), C4-2B MDVR (enzalutamide-resistant), MDAPCa-2b (African American/bone metastatic), LNCaP (Caucasian/non-metastatic) that stably overexpresses Neo control, HMGA2 wild-type or truncated isoform with human ground bone matrix powder (GBM) to recapitulate the bone microenvironment. We collected the conditioned media (CM) from these co-cultures and subsequently added it to parental LNCaP cells, with or without RSL3 ferroptosis inducer, plus or minus Ferrostatin-1 (Fer-1) ferroptosis inhibitor. We then assessed cell viability, migration, and lipid ROS levels. Our results demonstrated that LNCaP cells treated with CM from cancer cells co-cultured with GBM exhibited increased cell viability and migration. However, the addition of RSL3 effectively inhibited cell viability by inactivating GPX4 antioxidant and triggering lipid ROS production; this could be reversed by Fer-1. This suggests that ferroptosis inducers such as RSL3 hold potential as a treatment strategy for prostate cancer bone metastasis. Further investigation is necessary to comprehensively evaluate the impact of RSL3 treatments and elucidate the underlying mechanisms involved. By exploring these avenues, we can advance our understanding and potentially develop targeted therapies to combat the devastating effects of prostate cancer bone metastasis. Acknowledgements: These studies were supported by NIH/NIGMS/RISE SR25GM060414 and NIH/NIMHD 2U54MD007590; 5U54MD013376. Citation Format: Precious Elechi Dike, Taaliah Campbell, Valerie Odero-Marah. Ferroptosis inducers can antagonize prostate cancer-bone interactions [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr PR002.

Pleomorphic Adenoma with a Novel Rearrangement - LINC01606::PLAG1

Abstract Introduction/Objective Pleomorphic adenoma (PA) is characterized by presence of three components including bi- layered ducts, myoepithelial cells, and chondromyxoid/fibrous stroma in varying proportions. Evaluation of molecular aberrations helps recognizing challenging cases. Pleomorphic adenoma gene 1 (PLAG1) and high-mobility group AT- hook 2 (HMGA2) are hallmark genes showing rearrangement with various partner genes. Here, we present a case of myoepithelial cell rich PA, showing PLAG1 rearrangement with a novel partner gene. Methods/Case Report A 77-year-old male with history of slow-growing, right post-auricular mass over 5-year duration, now presented with overlying skin ulceration and bleeding/intermittent oozing. CT scan showed a complex, lobular, enhancing 8.7 x 8.4 x 7.0 cm mass, arising from the right parotid gland. Fine needle aspiration was performed and reported inconclusive with blood and fibrin only. The patient elected to undergo total parotidectomy with cervical lymph node dissection. Histology revealed a circumscribed, cellular salivary neoplasm with extensive hemorrhage/infarction and cystic degeneration. The viable neoplastic cells composed of sheet of spindle and epithelioid/plasmacytoid cells, with focal glandular and cribriform areas. Very focally chondromyxoid change is noted. The tumor cells stained with CK7, S100, and SOX10, few scattered cells positive for SMA, p63, and p40, with Ki67 labeling index of 5-10%. None of the cervical lymph nodes showed metastatic tumor. Overall, the features were compatible with myoepithelial cell rich salivary neoplasm with working diagnosis of cellular pleomorphic adenoma. Next generation RNA sequencing showed a LINC01606::PLAG1 [inv(8;8)(8q12.1;8q12.1)] fusion alteration. Results (if a Case Study enter NA) NA Conclusion PLAG1 is located at 8q12.1 and have been reported to be involved in chromosome rearrangements in various tumors including salivary gland tumors, mainly pleomorphic adenoma. Many fusion partners of PLAG1 have been reported. This report presents LINC01606 gene as a novel fusion partner of PLAG1 in a case of myoepithelial rich PA. This fusion leads to in-frame fusion of exons 1-2 of the LINC01606 gene to exons 3-5 of the PLAG1 gene.

CircDLGAP4 overexpression ameliorates neuronal injury in Parkinson's disease by binding to EIF4A3 and increasing HMGA2 expression.

Parkinson's disease (PD) is a prevalent neurodegenerative disease, and its prevalence increases steadily with age. Circular RNAs (circRNAs) are involved in various neurodegenerative diseases. Here, we aimed to explore the role of circRNA DLG-associated protein 4 (circDLGAP4) in 1-methyl-4-phenylpyridinium ion (MPP+ )-induced neuronal injury in PD. SH-SY5Y cells were treated with MPP+ to establish PD cell models. The levels of circDLGAP4 and high mobility group AT-hook 2 (HMGA2) in SH-SY5Y cells were detected. SH-SY5Y cell viability and apoptosis were detected. The levels of inflammatory damage (IL-1β, IL-6, TNF-α) and oxidative stress (reactive oxygen species, lactate dehydrogenase, superoxide dismutase, and malondialdehyde)-related factors were measured. The binding of eukaryotic initiation factor 4A3 (EIF4A3) to circDLGAP4 and HMGA2 was analyzed using RNA pull-down or RNA immunoprecipitation. The stability of HMGA2 was detected after actinomycin D treatment, and its effects on neuronal injury were tested. CircDLGAP4 expression was decreased in MPP+ -induced SH-SY5Y cells. CircDLGAP4 upregulation restored cell activity, decreased apoptosis, and reduced inflammatory damage and oxidative stress in PD cell models. CircDLGAP4 bound to EIF4A3 to increase HMGA2 expression and stability. Silencing HMGA2 attenuated the protective effect of circDLGAP4 overexpression. Overall, circDLGAP4 upregulated HMGA2 by recruiting EIF4A3, thus increasing the mRNA stability of HMGA2 and alleviating neuronal injury in PD.

HMGA2 directly mediates chromatin condensation in association with neuronal fate regulation

Identification of factors that regulate chromatin condensation is important for understanding of gene regulation. High-mobility group AT-hook (HMGA) proteins 1 and 2 are abundant nonhistone chromatin proteins that play a role in many biological processes including tissue stem-progenitor cell regulation, but the nature of their protein function remains unclear. Here we show that HMGA2 mediates direct condensation of polynucleosomes and forms droplets with nucleosomes. Consistently, most endogenous HMGA2 localized to transposase 5– and DNase I–inaccessible chromatin regions, and its binding was mostly associated with gene repression, in mouse embryonic neocortical cells. The AT-hook 1 domain was necessary for chromatin condensation by HMGA2 in vitro and in cellulo, and an HMGA2 mutant lacking this domain was defective in the ability to maintain neuronal progenitors in vivo. Intrinsically disordered regions of other proteins could substitute for the AT-hook 1 domain in promoting this biological function of HMGA2. Taken together, HMGA2 may regulate neural cell fate by its chromatin condensation activity.

C2orf48 promotes the progression of nasopharyngeal carcinoma by regulating high mobility group AT-hook 2.

Recurrence and metastasis are the major factors affecting the survival of nasopharyngeal carcinoma (NPC), and the mechanism remains unclear. Long non-coding RNA chromosome 2 open reading frame 48 (C2orf48) has been shown to influence the prognosis of many cancers. However, C2orf48's function in NPC has not been clarified. In this investigation, C2orf48 expression in NPC was measured by quantitative real-time PCR (qRT-PCR) at the cellular and tissue levels, and the association between C2orf48 expression and the prognosis of patients with NPC was examined. Additionally, the effects of C2orf48 and high mobility group AT-hook 2 (HMGA2) upon NPC proliferation, migration, and invasion were examined employing the MTT assay, colony formation assay, and transwell assay, respectively. Furthermore, the association between C2orf48 and HMGA2 in NPC was investigated. Our research demonstrated that C2orf48 was overexpressed in NPC tissues and cell lines, and compared to patients with lower levels of C2orf48 expression, those with higher levels had poorer 5-year overall survival and progression-free survival. Functionally, C2orf48 overexpression accelerated NPC cells proliferation, migration, and invasion. Besides, the tandem mass tag (TMT) quantitative proteomic analysis indicated that HMGA2 may be a target of C2orf48. Moreover, upregulation of C2orf48 could increase HMGA2 expression, and HMGA2 silencing could counteract the proliferation, migration, and invasion changes induced by C2orf48 in NPC cells. These results reveal that overexpression of C2orf48 can promote NPC cells proliferation, migration, and invasion via regulating the expression of HMGA2 and C2orf48 may be a potentially important prognostic marker for NPC.

A novel HMGA2::KITLG fusion in a dedifferentiated liposarcoma with amplification of MDM2 and HMGA2.

High-mobility group AT-hook 2 (HMGA2) is rearranged in various types of mesenchymal tumors, particularly lipomas. HMGA2 is also co-amplified with mouse double minute 2 (MDM2) in well-differentiated liposarcoma/dedifferentiated liposarcoma (WDLPS/DDLPS). We report a case of relapsed DDLPS with a novel in-frame fusion between HMGA2 and KITLG, which encodes the ligand for KIT kinase, a critical protein involved in gametogenesis, hematopoiesis, and melanogenesis. The HMGA2 breakpoint is in intron 3, a commonly observed location for HMGA2 rearrangements, while the KITLG breakpoint is in intron 2, leading to a fusion protein that contains almost the entire coding sequence of KITLG. By immunohistochemical staining, tumor cells expressed KIT and showed phosphorylated MAPK, a major KIT downstream target. We suggest an oncogenic mechanism that involves the overexpression of KITLG caused by its rearrangement with HMGA2, leading to the constitutive activation of KIT kinase. While MDM2 amplification was observed in both the primary tumor and the relapsed tumor, the HMGA2::KITLG was only present in the relapsed tumor, indicating the role of HMGA2::KITLG in disease progression.

M6A-mediated lncRNA NEAT1 plays an oncogenic role in non-small cell lung cancer by upregulating the HMGA1 expression through binding miR-361-3p.

Lung cancer is the most common primary malignant tumor of the lung, and 85% of lung cancer is non-small cell lung cancer (NSCLC). The N6-methyladenosine (m6A) and long noncoding RNAs (lncRNAs) have been widely reported to participate in the development of non-small cell lung cancer. However, the potential molecular mechanisms of m6A-regulated lncRNAs in NSCLC still need further investigation. The expression levels and the role of lncRNA NEAT1 in NSCLC tissues or cells were measured by RT-qPCR, Western blot, cell counting kit 8 (CCK-8), flow cytometry assay. RNA immunoprecipitation (RIP) was used to measure the levels of m6A modification of NEAT1. Bioinformatics analysis and dual-luciferase reporter gene assay were detected the relationship between miR-361-3p and NEAT1/HMGA1. Mouse xenograft tumor models were established to confirm the effects of lncRNA NEAT1 in vivo. In this study, we verified whether m6A-modified lncRNA nuclear enriched abundant transcript 1 (NEAT1) is involved in NSCLC progression via miR-361-3p/HMGA1 axis. Firstly, we found that lncRNA NEAT1 was upregulated in NSCLC, and was associated with a poor survival in NSCLC patients. Methyltransferase like 3 (METTL3)-mediated m6A modification stabilized and upregulated NEAT1 expression. Next, function experiment indicated that depletion of METTL3 and NEAT1 induced cell apoptosis and inhibited cell proliferation, epithelial-mesenchymal transition (EMT). Likewise, in vivo experiments further supported the oncogenic role of NEAT1 in NSCLC. In addition, the molecular mechanism was uncovered in our study, and we found that lncRNA NEAT1 promoted the expression of high-mobility group AT-hook 1 (HMGA1) by sponging miR-361-3p and then promoted tumorigenesis of NSCLC. In conclusion, our findings demonstrated that METTL3-mediated m6A modification accelerated NSCLC progression by regulating the NEAT1/miR-361-3p/HMGA1 axis, which provides important targets for the treatment of NSCLC.

Lack of Association of the HMGA1 Gene Variants with Metabolic Syndrome Risk and Response to Oral Anti-Diabetic Drugs

Background: Metabolic syndrome (Mets) is partially heritable. High mobility group AT-hook1 (HMGA1), an architectural transcription factor, affects the homeostasis of glucose. The marked inter-individual differences between T2DM patients in response to oral anti-diabetic drugs have become an issue for effective prescribing and dosing. The objective of this study was designed to assess whether different SNPs of the HMGA1 gene are associated with metabolic syndrome, and clarify the effect of these variants on response to combination therapy of metformin, sitagliptin, and glimepiride used by Mets with diabetes patients.
 Methods: From February until Augusts 2022, a total of 91 Iraqi participants (61 patients with metabolic syndrome and 30 controls). The diabetes patients were divided into two groups’ responders and non-responders, based on their HbA1c. Polymorphisms in HMGA1 and genotyping were identified by Sanger sequencing of genomic DNA.
 Results: The high prevalence of CC and GG genotypes of rs1023028442 and rs112081775 respectively was seen in the Iraqi population. Minor allele frequency of rs1023028442 was higher among metabolic patients without diabetes with (MAF=0.08) compared to the control group with (MAF= 0%). While (MAF=0.1) of rs112081775 was seen in metabolic patients without diabetes compared to (MAF=0.02) in the control group. The non-significant difference in genotyping and allele carriage frequencies of the HMGA1 gene was seen between total metabolic syndrome patients and the control group. Based on their response to therapy non-significant difference was seen between those with wild and carrier genotypes.
 Conclusions: This study suggests a lack of association of the rare HMGA1 gene variants with metabolic syndrome risk and response to oral anti-diabetic drugs.

TFAP2A activates HMGA1 to promote glycolysis and lung adenocarcinoma progression

BackgroundLung cancer is the most common cancer in the world. High Mobility Group AT-Hook 1 (HMGA1) is found to be associated with the glycolytic pathway in a variety of cancers, and abnormal glycolysis function is one of the important characteristics of cancer cells. Therefore, this paper discusses the effect of HMGA1 on glycolysis of lung adenocarcinoma (LUAD) cells MethodsThe mRNA expression data were downloaded from TCGA-LUAD database. Groups were set according to the median expression of HMGA1, followed by GSEA enrichment analysis. The upstream transcriptional regulators of HMGA1 were predicted by bioinformatics. The correlation between HMGA1 and Transcription Factor AP-2 Alpha (TFAP2A) and their expression in LUAD tissues were analyzed as well. mRNA expression levels of HMGA1 and TFAP2A were detected by qRT-PCR. The binding of HMGA1 and TFAP2A was demonstrated by ChIP and dual luciferase reporter assays. Cell function experiments were utilized to assay proliferation, apoptosis, glycolysis ability of LUAD cells, and glycolysis-related protein expression in each treatment group. ResultsHMGA1 was highly expressed in LUAD patients’ tissues and enriched in the glycolytic pathway. Additionally, silencing HMGA1 markedly hampered cell proliferation and glycolysis, and promoted cell apoptosis. The upstream transcriptional regulator TFAP2A was predicted to be highly expressed in LUAD. ChIP and dual luciferase reporter assays confirmed the targeted relationship between HMGA1 and TFAP2A. Cell rescue assay confirmed that TFAP2A promoted glycolysis and LUAD progression by activating HMGA1. ConclusionTFAP2A promotes glycolysis, proliferation and hampers apoptosis of LUAD cells by stimulating HMGA1. Hence, TFAP2A/HMGA1 may be a feasible therapeutic target for LUAD. Availability of data and materialsAll the data within this manuscript could be gotten from corresponding author at reasonable request.

Hmga1-overexpressing lentivirus protects against osteoporosis by activating the Wnt/β-catenin pathway in the osteogenic differentiation of BMSCs.

Postmenopausal osteoporosis is associated with bone formation inhibition mediated by the impaired osteogenic differentiation potential of bone marrow mesenchymal stem cells (BMSCs). However, identifying and confirming the essential genes in the osteogenic differentiation of BMSCs and osteoporosis remain challenging. The study aimed at revealing the key gene that regulated osteogenic differentiation of BMSCs and led to osteoporosis, thus exploring its therapeutic effect in osteoporosis. In the present study, six essential genes related to the osteogenic differentiation of BMSCs and osteoporosis were identified, namely, fibrillin 2 (Fbn2), leucine-rich repeat-containing 17 (Lrrc17), heat shock protein b7 (Hspb7), high mobility group AT-hook 1 (Hmga1), nexilin F-actin-binding protein (Nexn), and endothelial cell-specific molecule 1 (Esm1). Furthermore, the in vivo and in vitro experiments showed that Hmga1 expression was increased during the osteogenic differentiation of rat BMSCs, while Hmga1 expression was decreased in the bone tissue of ovariectomized (OVX) rats. Moreover, the expression of osteogenic differentiation-related genes, the activity of alkaline phosphatase (ALP), and the number of mineralized nodules were increased after Hmga1 overexpression, which was partially reversed by a Wnt signaling inhibitor (DKK1). In addition, after injecting Hmga1-overexpressing lentivirus into the bone marrow cavity of OVX rats, the bone loss, and osteogenic differentiation inhibition of BMSCs in OVX rats were partially reversed, while osteoclast differentiation promotion of BMSCs in OVX rats was unaffected. Taken together, the present study confirms that Hmga1 prevents OVX-induced bone loss by the Wnt signaling pathway and reveals that Hmga1 is a potential gene therapeutic target for postmenopausal osteoporosis.

MicroRNA-143-5p Suppresses ER-Positive Breast Cancer Development by Targeting Oncogenic HMGA2

BackgroundAbout 70%–80% of breast cancers (BCs) express estrogen receptors (ER-positive). MicroRNAs (miRNAs) are a group of small endogenous noncoding RNAs that play a critical regulatory role in cancer development and progression, including in BC. MiRNA deficiency promotes the development of BCs. MiR-143-5p is one of the most commonly dysregulated miRNAs in BC but its role as a tumor suppressor remains unclear. Materials and MethodsMiR-143-3p and -5p expression in breast tissue was analyzed using TCGA and StarBase databases. Expression in BC subclasses and survival analyses were conducted. Clinical samples were collected, cell cultures created, and gene expression assays performed following previous studies. Protein expression, luciferase reporter, wound healing, DAPI staining, cell cycle, colony formation, spheroid, CD44 FACS, and proliferation assays were conducted following various protocols. ResultsHere, we find that both miR-143-3p and miR-143-5p levels are considerably lower in BC tissue compared to normal breast tissue and low miR-143 expression predicts poor prognosis in ER+ BC patients. In-depth analyses identified 3 miR-143-5p binding sites in the 3' untranslated region (UTR) of the DNA binding protein High Mobility Group AT-Hook 2 (HMGA2). Luciferase reporter assays using wild-type and mutant HMGA2 3'UTR sequences and Western blot analyses demonstrated that HMGA2 is a direct and bona fide miR-143-5p target in BC cells. In addition, we show that restoration of miR-143-5p expression suppresses metastasis-related features of ER+ BC cells, including reduced tumor cell migration, increased E-cadherin expression, and decreased vimentin and N-cadherin expression. Furthermore, miR-143-5p reduces cell proliferation, cell cycle entry, and stemness, while promoting apoptosis moderately. Finally, patient sample pathway analyses demonstrated that these mechanisms are also active in BC. ConclusionsAltogether, our findings shed new light on miR-143-5p's anticancer biological functions in BC progression by directly targeting HMGA2. This suggests that restoration of miR-143-5p could be a promising new therapeutic approach for the treatment of ER+ BC.

HDAC3 Impairs Cardiac Function in Chronic Heart Failure Rats via Mediating MicroRNA-26b-3p to Target High Mobility Group AT-Hook 2.

Histone deacetylase 3 (HDAC3) has been studied in chronic heart failure (CHF), while the regulatory mechanism of HDAC3 on the development of CHF in regulating microRNA (miR)-26b-3p/high mobility group AT-hook 2 (HMGA2) axis has not been extensively investigated. This study aimed to probe the effects of HDAC3, miR-26b-3p and HMGA2 on CHF. CHF rat models were established using aortic coarctation. HDAC3, miR-26b-3p and HMGA2 levels in CHF rats were examined. Thereafter, the CHF rats were injected with relative oligonucleotides and plasmids of HDAC3, miR-26b-3p and HMGA2 to detect the cardiac function, inflammatory reaction, myocardial tissue pathological changes, and cardiomyocyte apoptosis. The binding relationship between miR-26b-3p and HMGA2 and the interaction between HDAC3 and miR-26b-3p were validated. HDAC3 and HMGA2 were elevated, while miR-26b-3p was decreased in CHF rats. The reduced HDAC3 or HMGA2 or enriched miR-26b-3p attenuated cardiac dysfunction, inflammatory reaction, myocardial tissue pathological changes and cardiomyocyte apoptosis in CHF rats, while the reduction of miR-26b-3p exerted the opposite effects. Furthermore, the inhibition of the miR-26b-3p or elevation of HMGA2 reversed the effect of reduced HDAC3 on mitigating CHF progression. Mechanically, miR-26b-3p targeted HMGA2 and HDAC3 bound to miR-26-3p. Downregulation of HDAC3 relieves cardiac function in CHF rats via mediating miR-26b-3p/HMGA2 axis. This study provides novel theory references and a distinct direction for the therapy strategies of CHF.

Epigenetic reprogramming-induced guanidinoacetic acid synthesis promotes pancreatic cancer metastasis and transcription-activating histone modifications

BackgroundPancreatic ductal adenocarcinoma (PDAC) tends to undergo distant metastasis, especially liver metastasis, leading to a poor prognosis. Metabolic remodelling and epigenetic reprogramming are two important hallmarks of malignant tumours and participate in regulating PDAC tumorigenesis and metastasis. However, the interaction between these two processes during PDAC metastasis has not been fully elucidated.MethodsWe performed metabolomics analysis to identify the critical metabolites associated with PDAC liver metastasis and focused on guanidinoacetic acid (GAA). Intracellular GAA content was significantly increased in liver metastatic PDAC cells compared to primary cancer cells in mouse xenograft tumour models. The effects of GAA supplementation and glycine amidinotransferase (GATM) knockdown on PDAC metastasis were assessed by analysing cell migration, filopodia formation, epithelial-mesenchymal transition (EMT), and in vivo metastasis in different cell and animal models. Next, ChIP‒qPCR, 3C‒qPCR, and CRISPRi/dCas9-KRAB experiments were used to validate the “epigenome-metabolome" mechanism. Finally, the results of in vitro approaches, including RNA-seq, CUT&RUN, RT‒qPCR, and western blot analyses, as well as luciferase reporter gene assay and transwell assay, revealed the GAA-c-Myc-HMGA axis and transcription-activating histone modifications reprogramming.ResultsA high level of intracellular GAA was associated with PDAC liver metastasis. GAA could promote the migration, EMT, and liver metastasis of pancreatic cancer cells in vitro and in vivo. Next, we explored the role of GATM-mediated de novo GAA synthesis in pancreatic cancer metastasis. High expression of GATM was positively correlated with advanced N stage in PDAC. Knockdown of GATM significantly reduced the intracellular level of GAA, suppressed EMT, and inhibited PDAC liver metastasis, and these effects were attenuated by GAA supplementation. Mechanistically, we identified the active enhancers looped to the Gatm gene locus that promoted GATM expression and PDAC liver metastasis. Furthermore, we found that GAA promoted cell migration and EMT by regulating c-Myc-mediated high mobility group AT-hook protein expression. Moreover, GAA increased the H3K4me3 modification level by upregulating histone methyltransferases, which induced the transcription of metastasis-related genes, including Myc.ConclusionsThese findings revealed the critical role of the epigenome-metabolome interaction in regulating PDAC liver metastasis and suggested potential therapeutic strategies targeting GAA metabolism and epigenetic regulatory mechanisms.

The FGFR inhibitor PD173074 binds to the C-terminus of oncofetal HMGA2 and modulates its DNA-binding and transcriptional activation functions.

The architectural chromatin factor high-mobility group AT-hook 2 (HMGA2) is causally involved in several human malignancies and pathologies. HMGA2 is not expressed in most normal adult somatic cells, which renders the protein an attractive drug target. An established cell-based compound library screen identified the fibroblast growth factor receptor (FGFR) inhibitor PD173074 as an antagonist of HMGA2-mediated transcriptional reporter gene activation. We determined that PD173074 binds the C-terminus of HMGA2 and interferes with functional coordination of the three AT-hook DNA-binding domains mediated by the C-terminus. The HMGA2-antagonistic effect of PD173074 on transcriptional activation may therefore result from an induced altered DNA-binding mode of HMGA2. PD173074 as a novel HMGA2-specific antagonist could trigger the development of derivates with enhanced attributes and clinical potential.

A novel trans-acting lncRNA of ACTG1 that induces the remodeling of ovarian follicles

Previous studies have implicated the attractive role of long noncoding RNAs (lncRNAs) in the remodeling of mammalian tissues. The migration of granulosa cells (GCs), which are the main supporting cells in ovarian follicles, stimulates the follicular remodeling. Here, with the cultured GCs as the follicular model, the actin gamma 1 (ACTG1) was observed to significantly promote the migration and proliferation while inhibit the apoptosis of GCs, suggesting that ACTG1 was required for ovarian remodeling. Moreover, we identified the trans-regulatory lncRNA of ACTG1 (TRLA), which was epigenetically targeted by histone H3 lysine 4 acetylation (H3K4ac). Mechanistically, the 2–375 nt of TRLA bound to ACTG1's mRNA to increase the expression of ACTG1. Furthermore, TRLA facilitated the migration and proliferation while inhibited the apoptosis of GCs, thereby accelerating follicular remodeling. Besides, TRLA acted as a ceRNA for miR-26a to increase the expression of high-mobility group AT-hook 1 (HMGA1). Collectively, TRLA induces the remodeling of ovarian follicles via complementary to ACTG1's mRNA and regulating miR-26a/HMGA1 axis in GCs. These observations revealed a novel and promising trans-acting lncRNA mechanism mediated by H3K4ac, and TRLA might be a new target to restore follicular remodeling and development.

Circular RNA circBNC2 facilitates glycolysis and stemness of hepatocellular carcinoma through the miR-217/high mobility group AT-hook 2 (HMGA2) axis

Hepatocellular cancer (HCC) accounts for approximately 90% of primary liver carcinoma and is a significant health threat worldwide. Circular RNA basonuclin 2 (circBNC2) is implicated with the progression of several cancers. However, its roles in carcinogenesis and glycolysis are still unclear in HCC. In this study, the levels of circBNC2 and high mobility group AT-hook 2 (HMGA2) were highly expressed, while these of miR-217 were poorly expressed in HCC tissues and cells. Upregulation of circBNC2 was related to poor prognosis and tumor node metastasis (TNM) stage. Knockdown of circBNC2 inhibited the HCC progression. Moreover, knockdown of circBNC2 suppressed the levels of Ras, ERK1/2, PCNA, HK2, and OCT4. Notably, circBNC2 functioned as a molecular sponge of microRNA 217 (miR-217) to upregulate the HMGA2 expression. The inhibitory effects of the circBNC2 silence on the growth and stemness of HCC cells, and levels of PCNA, HK2 and OCT4 were aggravated by the miR-217 overexpression, but neutralized by the HMGA2 overexpression. Besides, silencing of circBNC2 blocked the tumor growth through upregulating the expression of miR-217 and downregulating the levels of HMGA2, PCNA2, HK2 and OCT4 in vivo. Thus, the current data confirmed that circBNC2 sponged miR-217 to upregulate the HMGA2 level, thereby contributing to the HCC glycolysis and progression. These findings might present novel insight into the pathogenesis and treatment of HCC.

HMGA2 knockdown alleviates the progression of nonalcoholic fatty liver disease (NAFLD) by downregulating SNAI2 expression

Non-alcoholic fatty liver disease (NAFLD) is a complex disease that is considered as the next major health epidemic with alarmingly increasing global prevalence. To explore the pathogenesis of NAFLD, data from GSE118892 were analyzed. High mobility group AT-hook 2 (HMGA2), a member of the high mobility group family, is declined in liver tissues of NAFLD rats. However, its role in NAFLD remains unknown. This study attempted to identify the multiple roles of HMGA2 in NAFLD process. NAFLD was induced in rats using a high-fat diet (HFD). In vivo, HMGA2 knockdown using adenovirus system attenuated liver injury and liver lipid deposition, accompanied by decreased NAFLD score, increased liver function, and decreased CD36 and FAS, indicating the deceleration of NAFLD progression. Moreover, HMGA2 knockdown restrained liver inflammation by decreasing the expression of related inflammatory factors. Importantly, HMGA2 knockdown attenuated liver fibrosis via downregulating the expression of fibrous proteins, and inhibiting the activation of TGF-β1/SMAD signaling pathway. In vitro, HMGA2 knockdown relieved palmitic acid (PA)-induced hepatocyte injury and attenuated TGF-β1-induced liver fibrosis, consistent with in vivo findings. Strikingly, HMGA2 activated the transcription of SNAI2, which was evidenced by the dual luciferase assays. Moreover, HMGA2 knockdown largely downregulated SNAI2 levels. Indeed, SNAI2 overexpression effectively blocked the inhibitory effect of HMGA2 knockdown on NAFLD. Totally, our findings reveal that HMGA2 knockdown alleviates the progression of NAFLD by directly regulating the transcription of SNAI2. HMGA2 inhibition may emerge as a potential therapeutic target for NAFLD.

Histone lysine methyltransferase SMYD3 promotes oral squamous cell carcinoma tumorigenesis via H3K4me3-mediated HMGA2 transcription

BackgroundEpigenetic dysregulation is essential to the tumorigenesis of oral squamous cell carcinoma (OSCC). SET and MYND domain-containing protein 3 (SMYD3), a histone lysine methyltransferase, is implicated in gene transcription regulation and tumor development. However, the roles of SMYD3 in OSCC initiation are not fully understood. The present study investigated the biological functions and mechanisms involved in the SMYD3-mediated tumorigenesis of OSCC utilizing bioinformatic approaches and validation assays with the aim of informing the development of targeted therapies for OSCC.Results429 chromatin regulators were screened by a machine learning approach and aberrant expression of SMYD3 was found to be closely associated with OSCC formation and poor prognosis. Data profiling of single-cell and tissue demonstrated that upregulated SMYD3 significantly correlated with aggressive clinicopathological features of OSCC. Alterations in copy number and DNA methylation patterns may contribute to SMYD3 overexpression. Functional experimental results suggested that SMYD3 enhanced cancer cell stemness and proliferation in vitro and tumor growth in vivo. SMYD3 was observed to bind to the High Mobility Group AT-Hook 2 (HMGA2) promoter and elevated tri-methylation of histone H3 lysine 4 at the corresponding site was responsible for transactivating HMGA2. SMYD3 also was positively linked to HMGA2 expression in OSCC samples. Furthermore, treatment with the SMYD3 chemical inhibitor BCI-121 exerted anti-tumor effects.ConclusionsHistone methyltransferase activity and transcription-potentiating function of SMYD3 were found to be essential for tumorigenesis and the SMYD3–HMGA2 is a potential therapeutic target in OSCC.

Giant Cell Tumors With HMGA2::NCOR2 Fusion : Clinicopathologic, Molecular, and Epigenetic Study of a Distinct Entity.

Giant cell tumors (GCTs) with high mobility group AT-Hook 2 ( HMGA2 )::nuclear receptor corepressor 2 ( NCOR2 ) fusion are rare mesenchymal tumors of controversial nosology, which have been anecdotally reported to respond to CSFR1 inhibitors. Here, we performed a comprehensive study of 6 GCTs with HMGA2::NCOR2 fusion and explored their relationship with other giant cell-rich neoplasms. Tumors occurred in 4 females and 2 males ranging in age from 17 to 32 years old (median 24). Three lesions originated in subcutaneous soft tissue and 3 in bone. Tumor size ranged from 20 to 33mm (median 27mm). The lesions had a nodular/multinodular architecture and were composed of sheets of mononuclear "histiocytoid" cells with uniform nuclei intermingled with multinucleated giant cells. Mitotic activity was low and nuclear atypia and metaplastic bone were absent. Variable findings included necrosis, cystic degeneration, lymphocytic infiltrate (sometimes forming nodules), and xanthogranulomatous inflammation. On immunohistochemistry, all cases focally expressed pan-keratin and were negative with SATB2 and H3.3G34W. Whole RNA-sequencing was performed in all cases of GCT with HMGA2::NCOR2 fusion and a subset of giant cell-rich tumors (tenosynovial-GCT, n = 19 and "wild-type" GCT of soft tissue, n = 9). Hierarchical clustering of RNA-sequencing data showed that GCT with HMGA2::NCOR2 fusion formed a single cluster, independent of the other 2 entities. Methylome profiling showed similar results, but the distinction from "wild-type" GCT of soft tissue was less flagrant. Gene expression analysis showed similar levels of expression of the CSF1/CSFR1 axis between GCT with HMGA2::NCOR2 fusion and tenosynovial-GCT, supporting their potential sensitivity to CSFR1 inhibitors. Clinical follow-up was available for 5 patients (range: 10 to 64mo; median 32mo). Three patients (60%) experienced local recurrences, whereas none had distant metastases or died of disease. Overall, our study confirms and expands previous knowledge on GCT with HMGA2::NCOR2 fusion and supports its inclusion as an independent entity.