High Mobility Group A1 Protein Research Articles

Let-7 reduces the proliferation and migration of oral cancer cells via PI3K/AKT signaling pathway.

The involvement of let-7 in the occurrence and progression of various cancers has been well-documented. However, the precise molecular mechanisms underlying its impact on oral cancer development remain unclear. In this study, we aimed to elucidate the role of let-7 in oral cancer progression and investigate its underlying molecular mechanisms. The expression of let-7 and high mobility group A2 (HMGA2) mRNA was assessed using the quantitative reverse transcription polymerase chain reaction. Western blot analysis was employed to detect the expression of key proteins in the PI3K/AKT signaling pathway as well as HMGA2 protein levels. The targeting relationship between let-7 and HMGA2 was predicted through bioinformatics methods and confirmed via luciferase reporter gene assay. The effects of let-7 and HMGA2 on the functionality of oral cancer cells were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, colony formation assay, Transwell assay, wound healing assay, and Annexin V/PI apoptosis assay. Additionally, the impact of let-7 on the growth of oral cancer cells in vivo was investigated by inducing subcutaneous tumor formation in nude mice. Let-7 effectively suppresses the proliferation, migration, and invasion of oral cancer cells by inhibiting the activation of the PI3K/AKT signaling pathway. HMGA2, a downstream target gene of let-7, exhibits high expression in oral cancer. However, overexpression of HMGA2 diminishes the inhibitory effects induced by let-7 overexpression on the proliferation, migration, and invasion of oral cancer cells. The occurrence and progression of oral cancer cells are inhibited by Let-7 through the downregulation of HMGA2, potentially mediated by the inhibition of PI3K/AKT signaling pathway activation.

Proteomic analysis identifies HMGA2 as a novel biomarker of overall survival in papillary renal cell carcinoma.

Although papillary renal cell carcinoma (PRCC) has a relatively favorable prognosis, a small number of patients with lymph node or distant metastasis have a poor prognosis. Owing to the complex typing and heterogeneity of PRCC, it remains difficult to provide risk stratification. The objective of our research was to identify potential markers of PRCC prognosis. We performed proteomics and bioinformatics analyses on six pairs of formalin-fixed paraffin-embedded tumor and paired normal tissue samples. The Cancer Genome Atlas (TCGA) data were used to analyze the prognostic value of differentially expressed proteins (DEPs) in PRCC. We verified the expression of the major biomarker through immunohistochemistry (IHC) in 91 PRCC tumor specimens. Proteomic analysis revealed 1544 DEPs between tumor and paired normal tissues. PRCC transcriptomic data from the TCGA database revealed that compared to non-tumor tissues, the expression of high-mobility group protein A2 (HMGA2) was upregulated in tumor tissues, and patients with high HMGA2 expression exhibited shorter overall survival times. HMGA2 was associated with PRCC tissue subtype and higher cell pleomorphism. Both TCGA and IHC results showed that HMGA2 expression was associated with lymph node metastasis and clinical stage. HMGA2 was positively correlated with malignant progression and could be a valuable novel prognostic biomarker for PRCC risk stratification.

Reversal of HMGA1-Mediated Immunosuppression Synergizes with Immunogenic Magnetothermodynamic for Improved Hepatocellular Carcinoma Therapy.

Magnetothermodynamic (MTD) therapy can activate antitumor immune responses by inducing potent immunogenic tumor cell death. However, tumor development is often accompanied by multifarious immunosuppressive mechanisms that can counter the efficacy of immunogenic MTD therapy. High-mobility group protein A1 (HMGA1) is overexpressed within hepatocellular carcinoma tissues and plays a crucial function in the generation of immunosuppressive effects. The reversal of HMGA1-mediated immunosuppression could enhance immunogenic tumor cell death-induced immune responses. A ferrimagnetic vortex-domain iron oxide (FVIO) nanoring-based nanovehicle was developed, which is capable of efficiently mediating an alternating magnetic field for immunogenic tumor cell death induction, while concurrently delivering HMGA1 small interfering (si)RNA (siHMGA1) to the cytoplasm of hepatocellular carcinoma Hepa 1-6 cells for HMGA1 pathway interference. Using siHMGA1-FVIO-mediated MTD therapy, the proliferation of hepatocellular carcinoma Hepa 1-6 tumors was inhibited, and the survival of a mouse model was improved. We also demonstrated that siHMGA1-FVIO-mediated MTD achieved synergistic antitumor effects in a subcutaneous hepatocellular carcinoma Hepa 1-6 and H22 tumor model by promoting dendritic cell maturation, enhancing antigen-presenting molecule expression (both major histocompatibility complexes I and II), improving tumor-infiltrating T lymphocyte numbers, and decreasing immunosuppressive myeloid-derived suppressor cells, interleukin-10, and transforming growth factor-β expression. The nanoparticle system outlined in this paper has the potential to target HMGA1 and, in combination with MTD-induced immunotherapy, is a promising approach for hepatocellular carcinoma treatment.

Novel roles for HMGA2 isoforms in regulating oxidative stress and sensitizing to RSL3-Induced ferroptosis in prostate cancer cells

Oxidative stress is increased in several cancers including prostate cancer, and is currently being exploited in cancer therapy to induce ferroptosis, a novel nonapoptotic form of cell death. High mobility group A2 (HMGA2), a non-histone protein up-regulated in several cancers, can be truncated due to chromosomal rearrangement or alternative splicing of HMGA2 gene. The purpose of this study is to investigate the role of wild-type vs. truncated HMGA2 in prostate cancer (PCa). We analyzed the expression of wild-type vs. truncated HMGA2 and showed that prostate cancer patient tissue and some cell lines expressed increasing amounts of both wild-type and truncated HMGA2 with increasing tumor grade, compared to normal epithelial cells. RNA-Seq analysis of LNCaP prostate cancer cells stably overexpressing wild-type HMGA2 (HMGA2-WT), truncated HMGA2 (HMGA2-TR) or empty vector (Neo) control revealed that HMGA2-TR cells exhibited higher oxidative stress compared to HMGA2-WT or Neo control cells, which was also confirmed by analysis of basal reactive oxygen species (ROS) levels using 2′, 7′-dichlorofluorescin diacetate (DCFDA) dye, the ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) and NADP/NADPH using metabolomics. This was associated with increased sensitivity to RAS-selective lethal 3 (RSL3)-induced ferroptosis that could be antagonized by ferrostatin-1. Additionally, proteomic and immunoprecipitation analyses showed that cytoplasmic HMGA2 protein interacted with Ras GTPase-activating protein-binding protein 1 (G3BP1), a cytoplasmic stress granule protein that responds to oxidative stress, and that G3BP1 transient knockdown increased sensitivity to ferroptosis even further. Endogenous knockdown of HMGA2 or G3BP1 in PC3 cells reduced proliferation which was reversed by ferrostatin-1. In conclusion, we show a novel role for HMGA2 in oxidative stress, particularly the truncated HMGA2, which may be a therapeutic target for ferroptosis-mediated prostate cancer therapy.

Association between HMGA1 and immunosuppression in hepatocellular carcinoma: A comprehensive bioinformatics analysis.

The high mobility group A1 (HMGA1) gene is overexpressed in malignant tumors, and its expression level correlates with the progression and metastasis of tumors. However, the specific role of HMGA1 in hepatocellular carcinoma (HCC) and relevant influencing approaches in tumor immunity remain unclear. In this study, the expression and clinical significance of HMGA1 in HCC immunity were analyzed. The expression levels of HMGA1 mRNA and protein in HCC tissue and normal liver tissue were analyzed based on the cancer genome atlas, the gene expression omnibus and the Human Protein Atlas databases. The correlation between HMGA1 and clinicopathological factors was analyzed, and survival was estimated based on the expression of HMGA1. Gene set cancer analysis and the TISIDB database were used to identify tumor-infiltrating immune cells and immune inhibitors. Gene set enrichment analysis was performed to determine the involved signaling pathway. The HMGA1 genetic alterations were identified with the cBioPortal for Cancer Genomics. The expression of HMGA1 mRNA and protein was significantly higher in HCC tissue and negatively correlated with survival. Neutrophils, Th17 cells, several immune inhibitors, and signaling pathways were positively correlated with the expression of HMGA1. Amplification was the main type of genetic alteration in HMGA1. These findings demonstrate that HMGA1 can be a therapeutic target and a potential biomarker to predict the prognosis of patients with HCC. HMGA1 may affect the progression of HCC by suppressing the immune function of these patients.

Effect and Mechanism of Dexmedetomidine on Inhibiting Proliferation, Migration and Invasion of Ovarian Cancer Cell Strain SKOV3

To investigate the effect and mechanism of dexmedetomidine on SKOV3 proliferation, migration and invasion in ovarian cancer cell strains and the effect on high mobility group protein A2 expression. Western blot was used to detect the protein expression of high mobility group protein A2 in SKOV3 ovarian cancer cells; control group (without any treatment), (dexmedetomidine group 100 ng/ml was treated for 24 h), si-control group (transfection with si-control), si-high mobility group protein A2 group (transfection with si-high mobility group protein A2), dexmedetomidine+plasmid cloning deoxyribonucleic acid group (after transfection with plasmid cloning deoxyribonucleic acid group followed by dexmedetomidine 100 ng/ml treated for 24 h), dexmedetomidine+plasmid cloning deoxyribonucleic acid group-high mobility group protein A2 group (after transfection with plasmid cloning deoxyribonucleic acid-high mobility group protein A2 followed by dexmedetomidine 100 ng/ml treated for 24 h), were all transfected into SKOV3 cells using Lipofectamine; the proliferation of cells was detected by methyl thiazolyl tetrazolium assay; cell migration and invasion were detected by transwell assay; high mobility group protein A2 expression was measured by quantitative reverse transcription-polymerase chain reaction. The proliferation, migration and invasion of SKOV3 cells treated with dexmedetomidine were significantly down-regulated and high mobility group protein A2 expression was significantly down-regulated compared with the control group (p<0.05); knockdown of high mobility group protein A2 significantly inhibited SKOV3 cell proliferation, migration and invasion and overexpression of high mobility group protein A2 reversed the inhibitory effects of dexmedetomidine on ovarian cancer cell proliferation, migration and invasion. Dexmedetomidine can inhibit the proliferation, migration and invasion of ovarian cancer cells SKOV3 and the mechanism may be related to the direct down-regulation of high mobility group protein A2, which will provide a theoretical basis for dexmedetomidine treatment of ovarian cancer.

ER stress-enhanced HMGA2 plays an important role in Cr (VI)-induced glycolysis and inhibited oxidative phosphorylation by targeting the transcription of ATF4

Hexavalent chromium [Cr (VI)] is a proven human carcinogen which is widely used in steel manufacturing and painting. Here, the involvement of high mobility group A2 (HMGA2) in Cr (VI)-mediated glycolysis and oxidative phosphorylation (OXPHOS) was investigated. First, Cr (VI) treatment induced aerobic glycolysis by increasing the expression of GLUT1, HK II, PKM2 and LDHA enzymes, and reduced OXPHOS by decreasing mitochondrial mass, the expression of COX IV and ND1, and increasing Ca2+ content in mitochondria in A549 and HELF cells. And overexpression of HMGA2 induced aerobic glycolysis and decreased OXPHOS. Secondly, using endoplasmic reticulum (ER) stress inhibitor, 4-phenylbutyric acid (4-PBA) and knockdown of activating transcription factor 4 (ATF4) gene by siRNA, we demonstrated that ER stress and ATF4 elevation mediated Cr (VI)-induced glycolysis and inhibited OXPHOS. Furthermore, using tunicamycin (Tm), siHMGA2, transfection of HMGA2 and siATF4, we demonstrated that ER stress-enhanced interaction of HMGA2 and ATF4 resulted in Cr (VI)-induced glycolysis and inhibited OXPHOS. Additionally, ChIP assay revealed that HMGA2 protein could directly bind to the promoter sequence of ATF4 gene, which modulated Cr (VI)-induced ATF4 elevation. Finally, in lung tissues of BALB/c mice injected with HMGA2 plasmids, it is verified that HMGA2 involved in regulation of ATF4, glycolysis and OXPHOS in vivo. Combining, our data discovered that ER stress-enhanced the interaction of HMGA2 and ATF4 played an important role in Cr (VI)-mediated glycolysis and OXPHOS. These results imply a root cause for the carcinogenicity of Cr (VI), and could guide development of novel therapeutics for cancers.

A pan‑cancer analysis of RCC2 and its interaction with HMGA2 protein in an invitro model of colorectal cancer cells.

Regulator of chromosome condensation 2 (RCC2) is highly involved in the development of tumor malignancies. The underlying mechanisms remain to be elucidated. The present study aimed to explore the role of RCC2 in the development of tumor malignancies and explore the underlying mechanisms in colorectal cancer (CRC). RCC2 expression and survival analysis were performed in human pan-cancer. The results of searching its mRNA expression in The Cancer Genome Atlas (TCGA) database showed that RCC2 was highly expressed in different types of cancer. High RCC2 expression levels were significantly correlated with poor survival outcomes by the Kaplan-Meier analysis in the TCGA database. Immunohistochemistry revealed that RCC2 was higher expressed in 36 CRC tissues than in adjacent normal tissues. Co-immunoprecipitation revealed that RCC2 bound to high mobility group A2 (HMGA2). Ectopic expression of RCC2 promoted cell proliferation, migration and invasion, whereas knockdown of HMGA2 exerted the opposite effects. Collectively, the data provided a novel biomarker of RCC2 in various types of cancer. High RCC2 expression levels were correlated with poor prognosis in different types of cancer. In addition, RCC2 may combine with HMGA2 to promote CRC malignancy.

HMGA2 mediates Cr (VI)-induced metabolic reprogramming through binding to mitochondrial D-Loop region.

Hexavalent chromium [Cr (VI)] exists environmentally and occupationally. It has been shown to pose a carcinogenic hazard in certain occupations. This study was to investigate the role of high mobility group A2 (HMGA2) in Cr (VI)-induced metabolism reprogramming from oxidative phosphorylation (OXPHOS) to glycolysis in A549 and HELF cells. First, knockdown of HMGA2 by siHMGA2 significantly attenuated Cr (VI)-reduced expression of OXPHOS-related proteins (COX IV and ND1) and mitochondrial mass, indicating that HMGA2 was involved in Cr (VI)-reduced OXPHOS. Overexpression of HMGA2 by transfection of HMGA2-DNA plasmids reduced the expression of COX IV, ND1 and mitochondrial mass, suggesting the negative role of HMGA2 in OXPHOS. Secondly, both CCCP, the inhibitor of mitochondrial function, and the ER stress inhibitor, 4-phenylbutyric acid (4-PBA), decreased the level of HMGA2, indicating that the interaction of mitochondrial dysfunction and ER stress resulted in Cr (VI)-induced HMGA2 expression. Further study demonstrated that ER stress/HMGA2 axis mediated the metabolism rewiring from OXPHOS to aerobic glycolysis. Notably, Cr (VI) induced the accumulation of HMGA2 proteins in mitochondria and ChIP assay demonstrated that HMGA2 proteins could bind to D-loop region of mitochondrial DNA (mtDNA), which provided the proof for HMGA2-modulating OXPHOS. Taken together, our results suggested that the interaction of mitochondria and ER stress-enhanced HMGA2 played an important role in Cr (VI)-induced metabolic reprogramming from OXPHOS to glycolysis by binding directly to D-loop region of mtDNA. This work informs on the potential mode of action for Cr (VI)-induced tumors and builds on growing evidence regarding the contribution of cellular metabolic disruption contributing to carcinogenicity.

KRAS-G12D mutation drives immune suppression and the primary resistance of anti-PD-1/PD-L1 immunotherapy in non-small cell lung cancer.

BackgroundAlthough immune checkpoint inhibitors (ICIs) against programmed cell death protein 1 (PD‐1) and its ligand PD‐L1 have demonstrated potency towards treating patients with non‐small cell lung carcinoma (NSCLC), the potential association between Kirsten rat sarcoma viral oncogene homolog (KRAS) oncogene substitutions and the efficacy of ICIs remains unclear. In this study, we aimed to find point mutations in the KRAS gene resistant to ICIs and elucidate resistance mechanism.MethodsThe association between KRAS variant status and the efficacy of ICIs was explored with a clinical cohort (n = 74), and confirmed with a mouse model. In addition, the tumor immune microenvironment (TIME) of KRAS‐mutant NSCLC, such as CD8+ tumor‐infiltrating lymphocytes (TILs) and PD‐L1 level, was investigated. Cell lines expressing classic KRAS substitutions were used to explore signaling pathway activation involved in the formation of TIME. Furthermore, interventions that improved TIME were developed to increase responsiveness to ICIs.ResultsWe observed the inferior efficacy of ICIs in KRAS‐G12D‐mutant NSCLC. Based upon transcriptome data and immunostaining results from KRAS‐mutant NSCLC, KRAS‐G12D point mutation negatively correlated with PD‐L1 level and secretion of chemokines CXCL10/CXCL11 that led to a decrease in CD8+ TILs, which in turn yielded an immunosuppressive TIME. The analysis of cell lines overexpressing classic KRAS substitutions further revealed that KRAS‐G12D mutation suppressed PD‐L1 level via the P70S6K/PI3K/AKT axis and reduced CXCL10/CXCL11 levels by down‐regulating high mobility group protein A2 (HMGA2) level. Notably, paclitaxel, a chemotherapeutic agent, upregulated HMGA2 level, and in turn, stimulated the secretion of CXCL10/CXCL11. Moreover, PD‐L1 blockade combined with paclitaxel significantly suppressed tumor growth compared with PD‐L1 inhibitor monotherapy in a mouse model with KRAS‐G12D‐mutant lung adenocarcinoma. Further analyses revealed that the combined treatment significantly enhanced the recruitment of CD8+ TILs via the up‐regulation of CXCL10/CXCL11 levels. Results of clinical study also revealed the superior efficacy of chemo‐immunotherapy in patients with KRAS‐G12D‐mutant NSCLC compared with ICI monotherapy.ConclusionsOur study elucidated the molecular mechanism by which KRAS‐G12D mutation drives immunosuppression and enhances resistance of ICIs in NSCLC. Importantly, our findings demonstrate that ICIs in combination with chemotherapy may be more effective in patients with KRAS‐G12D‐mutant NSCLC.

LncRNA HIT000218960 enhances resistance to 5-fluorouracil by promoting HMGA2 and activating the AKT/mTOR/P70S6K pathway in gastric cancer cells.

The aim of the present study was to investigate the effect of the long noncoding RNA HIT000218960 on gastric cancer cell resistance to 5-fluorouracil (5-FU) and to explore the underlying molecular mechanism. HIT000218960 expression was measured in gastric cancer tissues and cells lines using reverse transcription-quantitative PCR and western blotting. Gastric cancer cell lines with overexpressed or repressed HIT000218960 levels were generated to study its influence on apoptosis induced by 5-FU, which was analyzed using flow cytometry analysis. Compared with those in normal gastric mucosal tissues and non-cancerous gastric mucosal epithelial cells, HIT000218960 and high mobility group A2 (HMGA2) proteins were found to be upregulated in gastric cancer tissues and cells. Additionally, a positive correlation was found between the expression of HIT000218960 and HMGA2 in gastric cancer tissues. In patients with gastric cancer, HIT000218960 expression was revealed to associate negatively with the efficacy of chemotherapy and 3-year overall survival rate. Overexpression of HIT000218960 suppressed apoptosis in SNU-5 cells, whilst HIT000218960 knockdown increased the apoptosis of NCI-N87 cells following 5-FU treatment. Downstream, HIT000218960 was demonstrated to promote HMGA2 protein expression in gastric cancer cells. In these cells, knocking down HMGA2 expression significantly increased apoptosis in addition to reducing AKT, mTOR and P70S6 kinase (P70S6K) phosphorylation after 5-FU treatment. In conclusion, HIT000218960 is overexpressed in gastric cancer tissues and cells, which is associated with the efficacy of chemotherapy. Mechanistically, this may be mediated by the upregulation HMGA2 expression and AKT/mTOR/P70S6K signaling.

Hsa_circ_0039569 facilitates the progression of endometrial carcinoma by targeting the miR-197/high mobility group protein A1 axis

ABSTRACT Circular RNAs are novel regulators in endometrial carcinoma. Hsa_circ_0039569 was reportedly upregulated in endometrial carcinoma; however, the functional roles and mechanisms of hsa_circ_0039569 need further investigation. Therefore, we used quantitative real-time PCR (qRT–PCR) to determine the mRNA levels of hsa_circ_0039569, miR-197 and high mobility group protein A1 (HMGA1). The protein level of HMGA1 was determined by Western blot. Cell Counting Kit-8 and colony formation assays were used to assess cell proliferation. Cell migration was measured via wound healing and Transwell assays. Transwell assay was also performed to determine cell invasion ability. Direct binding of the indicated molecules were verified by RNA binding protein immunoprecipitation (RIP) assay and dual luciferase reporter assay. The results revealed that hsa_circ_0039569 and HMGA1 were elevated, while miR-197 was downregulated in endometrial carcinoma. Moreover, hsa_circ_0039569 was positively correlated with the expression of HMGA1 and was negatively correlated with the level of miR-197. In addition, hsa_circ_0039569 facilitated the proliferation, migration and invasion of endometrial carcinoma cells. The underlying mechanism is that hsa_circ_0039569 serves as a sponge of miR-197 to repress the inhibitory effect of miR-197 on HMGA1. Furthermore, the miR-197/HMGA1 axis was implicated in endometrial carcinoma progression accelerated by hsa_circ_0039569. Collectively, hsa_circ_0039569 may promote the development of endometrial carcinoma by serving as an endogenous sponge of miR-197, increasing HMGA1 expression and identifying a novel target for endometrial carcinoma treatment.

Upregulation of exosomal circPLK1 promotes the development of non-small cell lung cancer through the miR-1294/ high mobility group protein A1 axis

ABSTRACT CircRNAs (circular RNAs) have been implicated in the development and progression of a variety of cancers. The molecular pathways underlying the progression of NSCLC (Non-Small Cell Lung Cancer) and the associated regulation of circRNAs in NSCLC remain to be fully elucidated. In this study, we found that circPLK1 expression was upregulated in serum exosomes and tissues from NSCLC patients. The Kaplan–Meier survival analysis revealed that a high expression level of circPLK1 was associated with a poorer prognosis in NSCLC patients. Exosomes extracted from NSCLC serum could promote the replication, migration, and invasion of NSCLC cells and suppress apoptotic cell death. The overexpression of circPLK1 also promotes the malignant phenotype of NSCLC cells. Molecular analyses demonstrated that circPLK1 directly targets miR-1294 and negatively regulates its activity. And circPLK1 overexpression facilitates the progression of NSCLC by negatively regulating miR-1294 level and maintaining a high-level expression of HMGA1 (High Mobility Group Protein A1). Our study suggests that circPLK1 upregulation plays an important role in NSCLC progression by targeting miR-1294/HMGA1 axis. These data provide a theoretical basis for the development of therapeutic strategy targeting exosomal circPLK1 in NSCLC treatment.

Long non-cording RNA XIST promoted cell proliferation and suppressed apoptosis by miR-423-5p/HMGA2 axis in diabetic nephropathy.

This research studied the effect of long non-coding RNA X-inactive-specific transcript (XIST) on DN. The effect of high glucose (HG) on the expression of XIST and miR-423-5p was detected by quantitative real-time PCR (qRT-PCR) in human kidney (HK) cells (human glomerular mesangial cells (HMCs) and human kidney-2 (HK-2) cells). The effect of XIST depletion and miR-423-5p inhibition or overexpression on high mobility group protein A2 (HMGA2) protein level was examined by western blot in HG-induced HK cells. The impacts of XIST depletion on viability and apoptosis were assessed by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) and flow cytometry assays in HG-induced HK cells. We found the expression of XIST and HMGA2 protein was significantly upregulated in DN tissues and cells. Moreover, HG treatment induced the upregulation of XIST and HMGA2 protein level in HK cells. Besides, both XIST depletion and HMGA2 depletion decreased cell proliferation but increased apoptosis in HG-treated HK cells. Furthermore, HMGA2 upregulation or miR-423-5p inhibition partly eliminated the effects of XIST depletion on cell proliferation, apoptosis of HG-treated HK cells. Interestingly, HMGA2 upregulation partly reversed miR-423-5p overexpression-mediated suppression on viability and promotion on apoptosis in HG-treated HK cells. Mechanistically, XIST sponged miR-423-5p to regulate HMGA2 expression in DN cells. Taken together, XIST depletion suppressed proliferation and promoted apoptosis via miR-423-5p/HMGA2 axis in HG-treated HK cells, which may provide a potential therapeutic target for DN.

Silencing of HMGA2 by siRNA Loaded Methotrexate Functionalized Polyamidoamine Dendrimer for Human Breast Cancer Cell Therapy.

The transcription factor high mobility group protein A2 (HMGA2) plays an important role in the pathogenesis of some cancers including breast cancer. Polyamidoamine dendrimer generation 4 is a kind of highly branched polymeric nanoparticle with surface charge and highest density peripheral groups that allow ligands or therapeutic agents to attach it, thereby facilitating target delivery. Here, methotrexate (MTX)- modified polyamidoamine dendrimer generation 4 (G4) (G4/MTX) was generated to deliver specific small interface RNA (siRNA) for suppressing HMGA2 expression and the consequent effects on folate receptor (FR) expressing human breast cancer cell lines (MCF-7, MDA-MB-231). We observed that HMGA2 siRNA was electrostatically adsorbed on the surface of the G4/MTX nanocarrier for constructing a G4/MTX-siRNA nano-complex which was verified by changing the final particle size and zeta potential. The release of MTX and siRNA from synthesized nanocomplexes was found in a time- and pH-dependent manner. We know that MTX targets FR. Interestingly, G4/MTX-siRNA demonstrates significant cellular internalization and gene silencing efficacy when compared to the control. Besides, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay demonstrated selective cell cytotoxicity depending on the FR expressing in a dose-dependent manner. The gene silencing and protein downregulation of HMGA2 by G4/MTX-siRNA was observed and could significantly induce cell apoptosis in MCF-7 and MDA-MB-231 cancer cells compared to the control group. Based on the findings, we suggest that the newly developed G4/MTX-siRNA nano-complex may be a promising strategy to increase apoptosis induction through HMGA2 suppression as a therapeutic target in human breast cancer.

Microrna-145 Inhibits EMT and Fibrosarcoma Cell Proliferation, Migration and Invasion by Targeting HMGA2

1.1 Aim: Fibrosarcoma is a rare malignant tumor of subcutaneous tissue characterized by slow infiltrative growth and a high rate of local recurrence. The participation of microRNAs (miRNAs/miRs) in the pathogenesis of human diseases and the vital role of miR-145 in different types of cancer. However, the role of miR-145 in fibrosarcoma remains unclear. The present study aimed to investigate the effect of miR-145 in the progression of fibrosarcoma and its potential application as a new therapeutic target. 1.2. Methods: The present study screened out a differential gene named high mobility group protein A2 (HMGA2) via bioinformatics analysis. In the present study, the gene expression profiles of fibrosarcoma cells and normal cells were downloaded from GEO Datasets GSE10021 and GSE1774. The human fibrosarcoma cell line HT1080 were transfected with miR-145 mimics, mimic negative control (NC), pCMV6 vector, overexpression plasmid vector of HMGA2, (si)RNA-HMGA2 or siRNA-NC. Reverse transcription-quantitative PCR and western blot analysis were performed to examine the mRNA (miR-145) and protein (HMGA2, N-cadherin, Vimentin and E-cadherin) expression levels in HT1080 cells. Cell Counting Kit-8, wound healing and Transwell assays were used to examine the TH1080 cell viability, proliferation and migratory capacities, respectively. Bioinformatics prediction and luciferase reporter assay were performed to investigate the relationship between miR145 and its potential target gene (HMGA2). 1.3. Results: The results demonstrated that overexpression of HMGA2 promoted cell proliferation, migration and invasion of HT1080 fibrosarcoma cells, whereas HMGA2 knockdown had no effect on the proliferation of HT1080 fibrosarcoma cells. However, overexpression of miR-145 reversed the facilitating effects of HMGA2 in tumor progression via epithelial-to-mesenchymal transition (EMT) modulation. Mechanistically, miR-145 exerted its inhibitory role in fibrosarcoma by directly binding to the 3’-untranslated region of HMGA2. 1.4. Conclusion: miR-145 plays an inhibitory role in fibrosarcoma progression by directly suppressing HGMA2 expression and EMT progression. Thus, miR-145 may act as a potential therapeutic target for malignant fibrosarcoma therapy

The utility of high-mobility group A2 overexpression for predicting the prognosis of gastric cancer patients and its contribution to poor prognosis via chemoresistance and the propensity for the occurrence of carcinomatosis peritonei

The aim of this study was to elucidate the correlation of high-mobility group protein A2 overexpression with gastric cancer prognosis and compare its prognostic power with that of pre-existing markers. Malignant tissues from 396 patients with gastric cancer who underwent gastrectomy from 2008 to 2012 were examined. High-mobility group protein A2 expression was assessed by immunohistochemistry and the sensitivity and specificity for predicting disease progression and overall survival of high-mobility group protein A2 and the prognostic biomarkers p53, Ki-67, human epidermal growth factor receptor 2, cyclooxygenase-2, and epidermal growth factor receptor were compared. A total of 95 samples (24.1%) showed high-mobility group protein A2 overexpression, which was related to advanced stage, undifferentiated histology, and lymphatic and perineural invasion. Additionally, high-mobility group protein A2 overexpression was an independent prognostic factor in multivariate analysis for disease progression and overall survival. Based on Kaplan-Meier survival analysis disease progression and overall survival, the high-mobility group protein A2-overexpressing patients showed worse survival. The recurrence pattern of peritoneal dissemination was more frequently observed in high-mobility group protein A2-positive group. Moreover, chemoresistance was more frequently observed in the high-mobility group protein A2-positive group. High-mobility group protein A2 exhibited a better ability for predicting disease progression and overall survival than other markers, and the prognostic power was enhanced when high-mobility group protein A2 was used with these markers. High-mobility group protein A2 overexpression is associated with chemoresistance and a propensity for carcinomatosis peritonei after surgery in patients with gastric cancer. The power to predict the prognosis of patients with gastric cancer can be enhanced with the use of preexisting biomarkers and high-mobility group protein A2.

P300-dependent acetylation of histone H3 is required for epidermal growth factor receptor-mediated high-mobility group protein A2 transcription in hepatocellular carcinoma.

High‐mobility group protein A2 (HMGA2) is highly expressed in hepatocellular carcinoma (HCC) cells and contributes to tumor metastasis and poor patient survival. However, the molecular mechanism through which HMGA2 is transcriptionally regulated in HCC cells remains largely unclear. Here, we showed that the expression HMGA2 was upregulated in HCC, and that elevated HMGA2 could promote tumor metastasis. Incubation of HCC cells with epidermal growth factor (EGF) could promote the expression of HMGA2 mRNA and protein. Mechanistic studies suggested that EGF can phosphorylate p300 at Ser1834 residue through the PI3K/Akt signaling pathway in HCC cells. Knockdown of p300 can reverse EGF‐induced HMGA2 expression and histone H3‐K9 acetylation, whereas a phosphorylation‐mimic p300 S1834D mutant can stimulate HMGA2 expression as well as H3‐K9 acetylation in HCC cells. Furthermore, we identified that p300‐mediated H3‐K9 acetylation participates in EGF‐induced HMGA2 expression in HCC. In addition, the levels of H3‐K9 acetylation positively correlated with the expression levels of HMGA2 in a chemically induced HCC model in rats and human HCC specimens.

KCNQ1OT1/miR-18b/HMGA2 axis regulates high glucose-induced proliferation, oxidative stress, and extracellular matrix accumulation in mesangial cells.

The dysregulated long noncoding RNAs (lncRNAs) are associated with the pathogenesis of diabetic nephropathy (DN). LncRNA potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (KCNQ1OT1) plays an important role in diabetes, but the role and mechanism of KCNQ1OT1 in DN are largely unknown. Serum samples were collected from 30 DN patients and normal volunteers. High glucose (HG)-challenged human mesangial cells (HMCs) were used as a cell model of DN. KCNQ1OT1, microRNA-18b (miR-18b), and high mobility group protein A2 (HMGA2) abundances were examined via quantitative reverse transcription polymerase chain reaction or western blot. Cell proliferation was assessed via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide. Oxidative stress was assessed via the levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and SOD2. Extracellular matrix (ECM) accumulation was investigated by the levels of fibronectin (FN), collagen I (Col I), and Col IV. The relationship between miR-18b and KCNQ1OT1 or HMGA2 was determined via dual-luciferase reporter analysis, RNA immunoprecipitation, and pull-down. KCNQ1OT1 expression was increased and miR-18b expression was decreased in DN patients and HG-challenged HMCs. miR-18b was targeted via KCNQ1OT1. Knockdown of KCNQ1OT1 weakened HG-caused proliferation, oxidative stress, and ECM accumulation of HMCs by increasing miR-18b. HMGA2 was targeted via miR-18b. miR-18b alleviated HG-induced cell proliferation, oxidative stress, and ECM accumulation by decreasing HMGA2. Silence of KCNQ1OT1 reduced HMGA2 expression via miR-18b. KCNQ1OT1 knockdown attenuated HG-induced proliferation, oxidative stress, and ECM accumulation of HMCs by regulating miR-18b/HMGA2 axis.

Abstract 297: HMGA1 induces FGF-19 to foster tumor-stromal cell crosstalk and drive tumor progression in pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinomas (PDACs) are highly lethal tumors characterized by a dense desmoplastic stroma comprised of cancer associated fibroblasts (CAFs) and fibrotic scar tissue. While stromal CAFs provide a barrier to therapy and release signals that foster tumor growth and invasion, the stroma also restrains tumor growth in murine models. The High Mobility Group A1 (HMGA1) chromatin remodeling gene encodes an oncofetal protein and epigenetic regulator that amplifies signals from the microenvironment to foster stem cell properties within intestinal epithelium. HMGA1 is also highly expressed during embryogenesis and in adult stem cells, but silenced postnatally in most differentiated cells. In diverse, aggressive cancers, HMGA1 becomes aberrantly re-expressed where high levels portend adverse clinical outcomes. In PDAC, HMGA1 protein is detected in late stage precursor lesions and invasive tumors, but not in normal pancreas nor in early precursor lesions. Furthermore, high HMGA1 levels correlate with poor differentiation status and decreased patient survival. Here, we discovered a novel epigenetic program mediated by HMGA1 that recruits CAFs to drive PDAC progression. We discovered that silencing HMGA1 in multiple PDAC cell lines halts proliferation and disrupts oncogenic properties, including migration, invasion, clonogenicity, and xenograft tumorigenesis. HMGA1 silencing also impairs three-dimensional sphere formation and depletes tumor initiator cells in limiting dilution assays. Through RNA sequencing analysis comparing PDAC cells overexpressing HMGA1 to those with HMGA1 silencing, we identified FGF-19 as a potential transcriptional target of HMGA1. HMGA1 binds specifically to the FGF-19 promoter and recruits the active histone mark, H3K4me3, to activate its expression. HMGA1 is also required for FGF-19 secretion from PDAC cells. Similar to HMGA1, silencing FGF-19 blocks oncogenic and cancer stem cell properties in vitro while disrupting tumorigenesis and depleting tumor initiator cells in vivo. In co-culture experiments, HMGA1 expressed in PDAC cells amplifies FGF-19 secretion, thereby stimulating CAF migration to tumor cells across a membrane. Silencing HMGA1 or FGF-19 prevents CAF recruitment to PDAC tumor cells. Furthermore, CAF recruitment is blocked by either FGF-19 blocking antibodies or an inhibitor to the FGF-19 receptor (FGR4). In murine models, silencing HMGA1 also decreases formation of a fibroblastic stroma. Moreover, overexpression of HMGA1 together with that of FGF-19 predict decreased survival in primary human PDAC. Our results reveal a novel paradigm whereby PDAC cells collaborate with stromal CAFs via HMGA1 and FGF-19 to drive tumor progression. These data also provide insight into mechanisms for tumor progression and illuminate FGF-19 as a rational therapeutic target in PDACs with up-regulation of HMGA1 and FGF-19. Citation Format: Lionel Chia, Shuai Shuai, Lingling Xian, Jung-Hyun Kim, Ruitao Zhang, Tait Huso, David Huso, Leslie Cope, Karen Reddy, Linda Resar. HMGA1 induces FGF-19 to foster tumor-stromal cell crosstalk and drive tumor progression in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 297.