High-mobility Group AT-hook 2 Overexpression Research Articles

HMGA2 promotes platelet-neutrophil complex formation and pulmonary tissue damage in myelodysplastic syndromes

AbstractHigh mobility group AT-hook 2 (HMGA2) is an architectural transcription factor that functions as an oncogene in various cancers. Although overexpression of HMGA2 has been reported in several myeloid malignancies, its role varies considerably in different disease contexts. Here, we identified a distinct role of HMGA2 as a mediator of noninfectious pneumonia in myelodysplastic syndrome (MDS). The expression level of HMGA2 in CD34+ hematopoietic stem cells and progenitors (HSC/Ps) was significantly associated with the incidence of noninfectious pneumonia, a common systemic complication in patients with MDS. Consistent with this clinical investigation, HMGA2 overexpression in a mouse model of an MDS-associated mutation led to the development of lethal noninfectious pneumonia. Mechanistically, HMGA2 overexpression conferred a megakaryocytic lineage bias to HSC/Ps and contributed to platelet activation in MDS mice. P-selectin–positive activated platelets interacted with MDS clone–derived neutrophils that exhibit increased susceptibility to cell death and formed platelet-neutrophil complexes (PNCs). Both the frequency of PNCs and neutrophil cell death within the lung microenvironment increased in MDS mice overexpressing HMGA2. Genetic inhibition of P-selectin attenuated pulmonary tissue damage in MDS mice. These findings indicate that PNCs could be a new therapeutic target for noninfectious pneumonia in patients with MDS and provide new insights into the mechanistic basis of the systemic complications of MDS.

HMGA2 promotes cancer metastasis by regulating epithelial-mesenchymal transition.

Epithelial-mesenchymal transition (EMT) is a complex physiological process that transforms polarized epithelial cells into moving mesenchymal cells. Dysfunction of EMT promotes the invasion and metastasis of cancer. The architectural transcription factor high mobility group AT-hook 2 (HMGA2) is highly overexpressed in various types of cancer (e.g., colorectal cancer, liver cancer, breast cancer, uterine leiomyomas) and significantly correlated with poor survival rates. Evidence indicated that HMGA2 overexpression markedly decreased the expression of epithelial marker E-cadherin (CDH1) and increased that of vimentin (VIM), Snail, N-cadherin (CDH2), and zinc finger E-box binding homeobox 1 (ZEB1) by targeting the transforming growth factor beta/SMAD (TGFβ/SMAD), mitogen-activated protein kinase (MAPK), and WNT/beta-catenin (WNT/β-catenin) signaling pathways. Furthermore, a new class of non-coding RNAs (miRNAs, circular RNAs, and long non-coding RNAs) plays an essential role in the process of HMGA2-induced metastasis and invasion of cancer by accelerating the EMT process. In this review, we discuss alterations in the expression of HMGA2 in various types of cancer. Furthermore, we highlight the role of HMGA2-induced EMT in promoting tumor growth, migration, and invasion. More importantly, we discuss extensively the mechanism through which HMGA2 regulates the EMT process and invasion in most cancers, including signaling pathways and the interacting RNA signaling axis. Thus, the elucidation of molecular mechanisms that underlie the effects of HMGA2 on cancer invasion and patient survival by mediating EMT may offer new therapeutic methods for preventing cancer progression.

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.

Green Tea Epigallocatechin Gallate Inhibits Preadipocyte Growth via the microRNA-let-7a/HMGA2 Signaling Pathway.

This study investigates the effect of epigallocatechin gallate (EGCG) on white and beige preadipocyte growth and explores the involvement of the miR-let-7a/HMGA2 pathway. 3T3-L1 and D12 cells are treated with EGCG. The effect of EGCG on cell proliferation and viability is evaluated, as well as microRNA (miRNA)-related signaling pathways. EGCG inhibits 3T3-L1 and D12 preadipocyte growth, upregulates miR-let-7a expression, and downregulates high-mobility group AT-hook 2 (HMGA2) mRNA and protein levels in a time- and dose-dependent manner. In addition, overexpression of miR-let-7a significantly inhibits the growth of 3T3-L1 and D12 cells and decreases HMGA2 mRNA and protein levels. MiR-let-7a inhibitor antagonizes the inhibitory effects of EGCG on the number and viability of 3T3-L1 and D12 cells. Furthermore, miR-let-7a inhibitor reverses the EGCG-induced increase in miR-let-7a expression levels and decrease in HMGA2 mRNA and protein levels. HMGA2 overexpression induces an increase in cell number and viability and antagonizes EGCG-suppressed cell growth and HMGA2 expression in 3T3-L1 and D12 preadipocytes. EGCG inhibits the growth of 3T3-L1 and D12 preadipocytes by modulating the miR-let-7a and HMGA2 pathways.

3'RNA and whole-genome sequencing of archival uterine leiomyomas reveal a tumor subtype with chromosomal rearrangements affecting either HMGA2, HMGA1, or PLAG1.

Uterine leiomyomas, or fibroids, are very common smooth muscle tumors that arise from the myometrium. They can be divided into distinct molecular subtypes. We have previously shown that 3'RNA-sequencing is highly effective in classifying archival formalin-fixed paraffin-embedded (FFPE) leiomyomas according to the underlying mutation. In this study, we performed 3'RNA-sequencing with 111 FFPE leiomyomas previously classified as negative for driver alterations in mediator complex subunit 12 (MED12), high mobility group AT-hook 2 (HMGA2), and fumarate hydratase (FH) by Sanger sequencing and immunohistochemistry. This revealed 43 tumors that displayed expression features typically seen in HMGA2-positive tumors, including overexpression of PLAG1. We explored 12 such leiomyomas by whole-genome sequencing to identify their underlying genomic drivers and to evaluate the feasibility of detecting chromosomal driver alterations from FFPE material. Four tumors with significant HMGA2 overexpression at the protein-level served as controls. We identified chromosomal rearrangements targeting either HMGA2, HMGA1, or PLAG1 in all 16 tumors, demonstrating that it is possible to detect chromosomal driver alterations in archival leiomyoma specimens as old as 18 years. Furthermore, two tumors displayed biallelic loss of DEPDC5 and one tumor harbored a COL4A5-COL4A6 deletion. These observations suggest that instead of only HMGA2-positive leiomyomas, a distinct leiomyoma subtype is characterized by rearrangements targeting either HMGA2, HMGA1, or PLAG1. The results indicate that the frequency of HMGA2-positive leiomyomas may be higher than estimated in previous studies where immunohistochemistry has been used. This study also demonstrates the feasibility of detecting chromosomal driver alterations from archival FFPE material.

Dexmedetomidine disrupts esophagus cancer tumorigenesis by modulating circ_0003340/miR-198/HMGA2 axis.

More and more studies have focused on the regulatory role of circular RNAs (circRNAs) in various cancers. However, it is not clear how dexmedetomidine (DEX) affects esophagus cancer progression by affecting the expression of circRNAs. This study aimed to investigate the role of DEX in esophagus cancer and its underlying mechanism. Cell Counting Kit-8 assay and 5-ethynyl-2'-deoxyuridine assays were conducted to evaluate cell proliferation. Flow cytometry analysis and transwell assay were performed for cell apoptosis and invasion. The protein levels of cleaved caspase-3, matrix metallopeptidase 9, and high mobility group AT-hook 2 (HMGA2) were assessed by western blot assay. The expression levels of circ_0003340 and microRNA-198 (miR-198) were determined by quantitative real-time PCR. Dual-luciferase reporter assay was performed to verify the interaction between miR-198 and circ_0003340 or HMGA2. Murine xenograft model was established to investigate the role of circ_0003340 and DEX in vivo. DEX exerted antitumor effects in esophagus cancer cells. DEX hindered proliferation and invasion while inducing apoptosis of esophagus cancer cells, which was abolished by circ_0003340 elevation, HMGA2 overexpression, or miR-198 silencing. miR-198 directly interacted with circ_0003340 and HMGA2 in esophagus cancer cells. Moreover, knockdown of circ_0003340 could improve the anticancer role of DEX in vivo. DEX constrained cell carcinogenesis by regulating circ_0003340/miR-198/HMGA2 axis in esophagus cancer, providing an effective clinical implication for preventing the development of the esophagus cancer by the DEX.

HMGA2 promotes the migration and invasion of gallbladder cancer cells and HMGA2 knockdown inhibits angiogenesis via targeting VEGFA.

The high mobility group AT-hook 2 (HMGA2) protein has been found to be upregulated in the majority of tumor types and is associated with a poor prognosis. Previous studies have suggested the oncogenic role of HMGA2 in gallbladder cancer (GBC). The present study aimed to investigate the effects of HMGA2 on the invasion, migration and angiogenesis of GBC cells. To achieve this aim, HMGA2 was overexpressed or silenced in the GBC cell line, EH-GB1, and then the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) abilities of EH-GB1 cells were investigated using Cell Counting Kit-8, wound healing, Transwell and western blotting assays. In addition, the expression levels of VEGFA were determined in EH-GB1 cells using western blotting and reverse transcription-quantitative PCR following HMGA2 overexpression or silencing. Furthermore, HMGA2-silenced EH-GB1 cells were transfected with VEGFA overexpression plasmids to evaluate the tube formation ability of HUVECs using tube formation assay. The results demonstrated that HMGA2 silencing inhibited GBC cell proliferation, migration, invasion and EMT, as evidenced by the downregulated expression of Ki67, proliferating cell nuclear antigen, MMP2, MMP9, N-cadherin, snail family transcriptional repressor 2 and zinc finger E-box-binding homeobox 1, and attenuated cell migration and invasion. However, the opposite results were obtained following HMGA2 overexpression. Moreover, HMGA2 knockdown and overexpression downregulated and upregulated VEGFA expression, respectively. In addition, the tube formation ability of HUVECs and the expression levels of CD31, VEGFR1 and VEGFR2 were downregulated following HMGA2 silencing. However, these effects were partially rescued by simultaneous VEGFA overexpression. In conclusion, the findings of the present study revealed that HMGA2 may promote GBC cell migration, invasion, EMT and angiogenesis. Therefore, inhibiting HMGA2 expression could be considered as a possible therapeutic approach for GBC.

CircRNA Circ-CCND1 Aggravates Hepatocellular Carcinoma Tumorigenesis by Regulating the miR-497-5p/HMGA2 Axis.

Circular RNAs (circRNAs) are key regulators in hepatocellular carcinoma (HCC) tumorigenesis and development, yet it is unclear whether circ-CCND1 participates in regulating HCC progression. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for detecting the expressions of circ-CCND1, microRNA (miR) -497-5p, and high mobility group AT-hook 2 (HMGA2) mRNA in HCC tissues and cell lines. Subcellular fractionation assay was used to analyze the localization of circ-CCND1 in HCC cell lines. Loss-of-function experiments were conducted to examine the effects of circ-CCND1 on HCC cell proliferation, migration, and invasion. Dual-luciferase reporter gene assay was employed for detecting the targeting relationships of circ-CCND1 and miR-497-5p, as well as miR-497-5p and HMGA2, respectively. Western blot was used to detect the regulatory functions of circ-CCND1 and miR-497-5p on HMGA1 expression at protein level. Circ-CCND1 and HMGA2 expressions in HCC were significantly up-regulated and miR-497-5p expression was markedly decreased. High circ-CCND1 expression was associated with relatively large tumor size and lymph node metastasis in HCC patients. In addition, circ-CCND1 was mainly distributed in the cytoplasm of HCC cells. Functionally, knockdown of circ-CCND1 remarkably suppressed HCC cell proliferation, migration, and invasion. Mechanistically, miR-497-5p was a direct target of circ-CCND1 and miR-497-5p specifically modulated HMGA2 expression. Furthermore, miR-497-5p inhibitors and or HMGA2 overexpression partially counteracted the suppressing effect induced by si-circ-CCND1 on the malignant phenotype of HCC cells. Circ-CCND1 plays a cancer-promoting role in HCC by modulating the miR-497-5p/HMGA2 axis. Therefore, targeting circ-CCND1 is likely to be a promising therapeutic strategy for HCC.

Let‑7b‑5p promotes cell apoptosis in Parkinson's disease by targeting HMGA2

Parkinson's disease (PD), a common multifactorial neurodegenerative disease, is characterized by irreversible loss of dopaminergic neurons in the substantia nigra. In-depth study of the pathogenesis of PD is of great importance. High-mobility group AT-hook 2 (HMGA2) has been proposed to be implicated with neuronal differentiation and impairment of cognitive function. However, whether HMGA2 plays a role in PD is rarely explored. In the present study, N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated PD mice models and N-methyl-4- phenylpyridinium (MPP+)-treated SH-SY5Y cell models were established. Reverse transcription-quantitative PCR showed that HMGA2 displayed low levels in brain tissues of MPTP-treated mice and MPP+-treated SH-SY5Y cells. Moreover, HMGA2 overexpression suppressed SH-SY5Y cell apoptosis. Additionally, let-7b-5p bound with HMGA2 3′ untranslated region (UTR), and its expression was negatively correlated with HMGA2 level. Moreover, let-7b-5p presented high levels in brain tissues of PD mice and MPP+-treated SH-SY5Y cells, and knockdown of let-7b-5p inhibited SH-SY5Y cell apoptosis. Rescue assays illustrated that HMGA2 neutralized the promotive effects of let-7b-5p mimics on SH-SY5Y cell apoptosis. In conclusion, the present study demonstrated that let-7b-5p contributes to cell apoptosis in PD by targeting HMGA2, which offers a potential theoretical basis for the study of effective therapy in PD.

Circ-RPPH1 knockdown retards breast cancer progression via miR-328-3p-mediated suppression of HMGA2

BackgroundCircular RNA Ribonuclease P RNA Component H1 (circ-RPPH1) was confirmed to act as an oncogene in many cancers to promote cancer progression. However, the exact function and mechanism of circ-RPPH1 in breast cancer (BC) remain vague. MethodsThe expression of circ-RPPH1, microRNA (miR)-328-3p and high-mobility group AT-hook 2 (HMGA2) was detected using quantitative real-time polymerase chain reaction and western blot. Cell viability, apoptosis, migration and invasion were determined using cell counting kit-8 assay, flow cytometry and transwell assay, respectively. Glucose metabolism was calculated by detecting glucose uptake and lactate production. The target correlations between miR-328-3p and circ-RPPH1 or HMGA2 were confirmed by dual-luciferase reporter assay. The murine xenograft model was established to conduct in vivo experiments. ResultsCirc-RPPH1 expression was elevated and miR-328-3p was decreased in BC tissues and cells. Circ-RPPH1 knockdown or miR-328-3p re-expression suppressed cell proliferation, migration, invasion and glycolysis but induced apoptosis in BC in vitro. Circ-RPPH1 was a sponge of miR-328-3p, and silencing of miR-328-3p reversed the inhibitory effects of circ-RPPH1 knockdown on BC cell malignant phenotypes and glycolysis. MiR-328-3p directly targeted HMGA2, and HMGA2 overexpression abolished the action of miR-328-3p in BC cells. Besides, circ-RPPH1 could regulate HMGA2 expression by miR-328-3p in BC cells. Moreover, murine xenograft model analysis suggested circ-RPPH1 knockdown inhibited tumor growth in vivo. ConclusionCirc-RPPH1 knockdown retarded cell malignant phenotypes and glycolysis via miR-328-3p/HMGA2 axis in BC, providing a potential therapeutic target for BC treatment.

MiR-532-3p Suppresses Nucleus Pulposus Cells Proliferation and Extracellular Matrix Production, Promotes Cell Apoptosis via Targeting High Mobility Group AT-Hook 2

The present study aimed to investigate the function and mechanism of microRNA (miR)-532-3p in intervertebral disc degeneration (IDD). Further, whether miR-532-3p regulates HMGA2 in nucleus pulposus (NP) cells was explored. We collected human nucleus pulposus (NP) tissues from the patients with IDD, and detected miR-532-3p in NP tissues using RT-qPCR. MiR-532-3p mimic and inhibitor were constructed, and they were transfected into the human nucleus pulposus cells (HNPCs) by Lipofectamine 3000. MTT assay was conducted to determine cell proliferation. Cell apoptosis and extracellular matrix remodeling were examined by flow cytometric, Caspase 3/8 Assay Kits and Western blot. A dual-luciferase reporter assay was applied to investigate whether miR-532-3p targets High mobility group AT-hook 2 (HMGA2). We found miR-532-3p expression level was significantly increased in NP tissues of IDD patients, comparing with the controls. MiR-532-3p exerted an inhibitory effect on HNPCs proliferation; however, cell apoptosis and the degradation of extracellular matrix were induced by miR-532-3p. MiR-532-3p directly targets HMGA2, and HMGA2 overexpression reversed the role of miR-532-3p mimic in HNPCs proliferation, apoptosis, and extracellular matrix remodeling. Our study is the first to report that miR-532-3p might suppress NP cell proliferation, promote cell apoptosis and inhibit ECM production of NP cells via targeting HMGA2, thus facilitating the progression of IDD. MiR-532-3p was supposed to be a novel target for the treatment of IDD.

LncRNA HCP5 knockdown inhibits high glucose-induced excessive proliferation, fibrosis and inflammation of human glomerular mesangial cells by regulating the miR-93-5p/HMGA2 axis

BackgroundLong non-coding RNAs (lncRNAs) are widely reported to be involved in the development of human diseases. HLA complex P5 (HCP5) deregulation is associated with various diseases. However, the function of HCP5 in diabetic nephropathy (DN) is unclear.MethodsHuman glomerular mesangial cells (HGMCs) were treated with high glucose (HG) to establish DN cell models. The expression of HCP5, miR-93-5p and high mobility group AT-hook 2 (HMGA2) mRNA was detected using quantitative polymerase chain reaction (QPCR). Cell proliferation and cell apoptosis were assessed using cell counting kit-8 (CCK-8) assay and flow cytometry assay, respectively. The expression of apoptosis- and fibrosis-related proteins and HMGA2 protein was quantified by western blot. The release of pro-inflammatory factor was checked using enzyme-linked immunosorbent assay (ELISA). The predicted relationship between miR-93-5p and HCP5 or HMGA2 was verified using dual-luciferase reporter assay, pull-down assay or RNA immunoprecipitation (RIP) assay.ResultsThe expression of HCP5 and HMGA2 was enhanced, while the expression of miR-93-5p was declined in DN serum samples and HG-treated HGMCs. HCP5 knockdown or miR-93-5p restoration ameliorated HG-induced HGMC proliferation, fibrosis and inflammation. MiR-93-5p was a target of HCP5, and miR-93-5p inhibition reversed the effects caused by HCP5 knockdown. Moreover, HMGA2 was a target of miR-93-5p, and HMGA2 overexpression abolished the effects of miR-93-5p restoration. HCP5 knockdown inhibited the AKT/mTOR signaling pathway.ConclusionHCP5 was implicated in DN progression by modulating the miR-93-5p/HMGA2 axis, which provided new insights into the understanding of DN pathogenesis.

CircARL8B Contributes to the Development of Breast Cancer Via Regulating miR-653-5p/HMGA2 Axis.

Circular RNAs (circRNAs) act as essential regulators in breast cancer (BC) progression. In this paper, we aimed to investigate the functions of circARL8B in BC. The levels of circARL8B, ADP Ribosylation Factor Like GTPase 8B (ARL8B), miR-653-5p and high-mobility group AT-hook 2 (HMGA2) mRNA were examined by qRT-PCR. The stability of circARL8B was determined by RNase R assay and Actinomycin D assay. Cell viability and metastasis were evaluated by Cell Counting Kit-8 (CCK-8) assay and transwell assay, respectively. The levels of cellular phospholipids and triglycerides were measured using relevant kits. Protein levels were measured by western blot analysis. The association between miR-653-5p and circARL8B or HMGA2 was verified by dual-luciferase reporter assay. A murine xenograft model was established to explore the function of circARL8B in vivo. CircARL8B was increased in BC tissues and cells. CircARL8B silencing inhibited cell viability, migration, invasion and fatty acid metabolism in BC cells in vitro and blocked tumor growth in vivo. MiR-653-5p was identified as the target of circARL8B and miR-653-5p was negatively modulated by circARL8B. The suppressive role of circARL8B silencing in BC cell progression was abolished by miR-653-5p downregulation. Moreover, HMGA2 was the target gene of miR-653-5p. HMGA2 overexpression abrogated the effect of miR-653-5p on BC cell development. In addition, circARL8B knockdown might block PGE2/PI3K/AKT/GSK-3β/Wnt/β-catenin pathway. Silencing of circARL8B inhibited cell viability, migration, invasion and fatty acid metabolism via miR-653-5p/HMGA2 axis in BC.

Circ_0109046 Promotes the Progression of Endometrial Cancer via Regulating miR-136/HMGA2 Axis.

BackgroundEndometrial cancer (EC) is one of the most common gynecological malignancies. Circular RNAs (circRNAs) play crucial roles in the occurrence and development of tumors. This research aimed to explore the function and potential mechanism of human serum albumin (hsa)_circ_0109046 in EC.Materials and MethodsThe abundance of circ_0109046, microRNA-136 (miR-136) and high-mobility group AT-hook 2 (HMGA2) was detected by quantitative real-time polymerase chain reaction or Western blot. Cell counting kit-8 (CCK-8) and colony formation assays were employed to assess cell proliferation. Transwell assay was used to measure cell migration and invasion. The levels of E-cadherin, Vimentin and N-cadherin were examined by Western blot. The binding association among circ_0109046, miR-136 and HMGA2 was verified by dual-luciferase reporter assay, RNA pull-down assay and RNA immunoprecipitation assay. Xenograft assay was performed to test tumor growth in vivo.ResultsCirc_0109046 and HMGA2 were up-regulated, and miR-136 was down-regulated in EC tissues and cells. Knockdown of circ_0109046 impeded the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of EC cells. Moreover, miR-136 knockdown reversed the suppression of circ_0109046 silencing on EC development. HMGA2 overexpression abolished the inhibition of miR-136 on EC progression. Besides, depletion of circ_0109046 inhibited EC growth in vivo.ConclusionCirc_0109046 accelerated EC progression via modulating miR-136/HMGA2 axis, indicating that circ_0109046 might be a promising therapeutic target for EC.

MicroR-26b Targets High Mobility Group, AT-hook 2 to Ameliorate Myocardial Infarction-induced Fibrosis by Suppression of Cardiac Fibroblasts Activation.

Myocardial Fibrosis (MF) is an important physiological change after myocardial infarction (MI). MicroRNA-26b (MiR-26b) has a certain inhibitory effect on pulmonary fibrosis. However, the role of miR-26b in MI-induced MF rats and underlying molecular mechanisms remain unknown. Forty male Sprague Dawley (SD) rats weighing 200-250 g were divided into four groups (n=10): Sham group, MF group, MF + negative control (NC) agomir group and MF + miR-26b agomir group. Cardiac fibroblasts were isolated from cardiac tissue. Fibrosis levels were detected by MASSON staining, while the expression of related genes was detected by RT-qPCR, Western blotting and Immunohistochemistry, respectively. TargetScan and dual-luciferase reporter assay were utilized to predict the relationship between miR-26b and high mobility group, AT-hook 2 (HMGA2). The study found the expression of miR-26b to be down-regulated in the myocardium of MF rats (P<0.01). miR-26b overexpression in vitro significantly reduced the survival rate of cardiac fibroblasts and inhibited the expression of the fibrillar-associated protein (α-SMA alphasmooth muscle actin (α-SMA) and collagen I) (P<0.01). TargetScan indicated that HMGA2 was one of the target genes of miR-26b; dual-luciferase reporter assay further confirmed the targeted regulatory relationship (P<0.01). Moreover, miR-26b overexpression significantly reduced the expression of HMGA2 (P<0.01). Notably, HMGA2 overexpression reversed the inhibitory effect of miR-26b overexpression on cardiac fibroblast viability and the expression of α-SMA and collagen I (P<0.01). Animal experiments further indicated that miR-26b overexpression inhibited MIinduced rat MF by inhibiting the expression of HMGA2 (P<0.05, P<0.01). In short, these findings indicate that miR-26b targets HMGA2 to ameliorate MI-induced fibrosis by suppression of cardiac fibroblasts activation.

155 A biomarker function of HMGA2 in cutaneous squamous cell carcinoma development

The high mobility group AT-hook 2 (HMGA2) gene encodes a transcription factor that is expressed during embryonic development but down-regulated in adult tissues. Re-expression of HMGA2 in adult tissues is often associated with both benign and malignant tumor formation. HMGA2 has been identified as a biomarker of melanoma progression and prognosis, but its role in non-melanoma skin cancer development remains controversial. In this study, we measured HMGA2 expression in normal human keratinocytes and found a significant decrease in HMGA2 mRNA expression in adult keratinocytes compared to neonatal keratinocytes. HMGA2 is highly expressed in human cutaneous squamous cell carcinoma (SCC) cell lines and primary human SCC tumors, but not detected in adjacent normal skin. In mouse skin, Hmga2 has been found to be translocated from the cell membrane into the nucleus during DMBA/TPA-induced skin tumorigenesis. While Hmga2 expression is absent in the hair follicle in non-UV-irradiated mouse, UV irradiation increased Hmga2 expression in both the epidermis and hair follicles. In agreement, we found enhanced Hmga2 expression in UV-induced mouse skin SCCs and also Hmga2 reactivation in the dermis from UV-irradiated mice. Furthermore, oncogene depletion such as FOXM1 and TRIP13 in human SCC cell lines using CRISPR/Cas9 decreased the expression of HMGA2 coupled with decreased cell proliferation and survival. Taken together, these results demonstrate that the upregulation of HMGA2 is an important biomarker of skin SCC tumorigenesis. Moreover, understanding of the mechanism for HMGA2 overexpression in skin hair follicle cells can develop the new drug for skin cancer treatment.

Circ_100565 promotes proliferation, migration and invasion in non-small cell lung cancer through upregulating HMGA2 via sponging miR-506-3p

BackgroundCircular RNAs (circRNAs) play a vital role in the development of various cancers. Circ_100565 was found to be a highly expressed circRNA in non-small cell lung cancer (NSCLC) tissues screened by microarray profiles of circRNAs. However, the role of circ_100565 in NSCLC still remains unknown.MethodsMicroarray analysis was used to screen for differentially expressed circRNAs in NSCLC tissues. The expression levels of circ_100565, microRNA-506-3p (miR-506-3p) and high mobility group AT-hook 2 (HMGA2) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was detected by cell counting kit-8 (CCK-8) and colony formation assays. Transwell assay was used to determine the migration and invasion of cells. Besides, Western blot (WB) analysis was performed to assess the levels of proliferation and metastasis-related proteins and HMGA2 protein. Moreover, animal experiments were used to confirm the effect of circ_100565 on NSCLC tumor growth in vivo. In addition, the interaction between miR-506-3p and circ_100565 or HMGA2 was confirmed by dual-luciferase reporter, RNA immunoprecipitation (RIP) assay or biotin-labeled pull-down assay.ResultsCirc_100565 was upregulated in NSCLC, and its high expression was positively associated with the poor overall survival of NSCLC patients. Silencing of circ_100565 suppressed the proliferation, migration and invasion of NSCLC cells in vitro and reduced the tumor growth of NSCLC in vivo. Circ_100565 could sponge miR-506-3p, and miR-506-3p could target HMGA2. Moreover, miR-506-3p inhibitor or HMGA2 overexpression could reverse the inhibition effect of circ_100565 knockdown on NSCLC progression.ConclusionCirc_100565 increased HMGA2 expression to promote proliferation, migration and invasion in NSCLC via absorbing miR-506-3p. Our findings provided a new biomarker for NSCLC therapy.

Downregulation of lncRNA HOTTIP Suppresses the Proliferation, Migration, and Invasion of Oral Tongue Squamous Cell Carcinoma by Regulation of HMGA2-Mediated Wnt/β-Catenin Pathway.

Background: Oral tongue squamous cell carcinoma (OTSCC) is a common type of oral tumor. LncRNAs (long noncoding RNAs) and miRNAs (microRNAs) were identified as regulators in many human cancers. This study aims to explore the molecular basis of HOXA transcript at the distal tip (HOTTIP) in regulating OTSCC progression. Materials and Methods: The expression of HOTTIP, miR-124-3p, and high-mobility group AT-hook 2 (HMGA2) was detected by quantitative real-time polymerase chain reaction. Next, the proliferation was evaluated by 3-(4,5-dimethylthiazole-2-y1)-2,5-biphenyl tetrazolium bromide (MTT) assay. The migration and invasion were assessed by transwell assay. Furthermore, dual-luciferase reporter assay was performed to confirm the combination between HOTTIP and miR-124-3p, miR-124-3p, and HMGA2. Protein levels of HMGA2, β-catenin, c-Myc, and E-cadherin were examined by Western blot. The nude mice model was employed to test the tumor growth in vivo. Results: HOTTIP was upregulated in OTSCC tissues and cells, and was highly expressed in positive lymph node metastasis and late-stage OTSCC patients. Silencing HOTTIP impeded proliferation, migration, and invasion of OTSCC cells. Moreover, HOTTIP knockdown inhibited proliferation, migration, and invasion of OTSCC cells by targeting miR-124-3p. Besides, miR-124-3p targeted HMGA2 to block proliferation, migration, and invasion. HMGA2 could rescue the inhibitory effects of HOTTIP interference on proliferation, migration, and invasion. In addition, HMGA2 overexpression reversed the downregulation of β-catenin and c-Myc protein levels and upregulation of E-cadherin level affected by HOTTIP silencing. Finally, HOTTIP silencing repressed tumor growth and resulted in a great rise on miR-124-3p and E-cadherin expression and a distinct fall on HMGA2, β-catenin, and c-Myc protein levels. Conclusions: HOTTIP knockdown restrained proliferation, migration, and invasion of OTSCC cells by miR-124-3p/HMGA2 axis through Wnt/β-catenin pathway.

Knockdown of lncRNA ZFAS1-suppressed non-small cell lung cancer progression via targeting the miR-150-5p/HMGA2 signaling.

Non-small cell lung cancer (NSCLC) is the main type of lung malignancy. Early diagnosis and treatments for NSCLC are far from satisfactory due to the limited knowledge of the molecular mechanisms regarding NSCLC progression. Long noncoding RNA (lncRNA) ZNFX1 antisense RNA1 (ZFAS1) has been implicated for its functional role in the progression of malignant tumors. This study aimed to determine the ZFAS1 expression from lung cancer clinical samples and to explore the molecular mechanisms underlying ZFAS1-modulated NSCLC progression. Experimental assays revealed that clinical samples and cell lines of lung malignant tumors showed an upregulation of ZFSA1. ZFAS1 expression was markedly upregulated in the lung tissues from patients with advanced stage of this malignancy. The loss-of-function assays showed that knockdown of ZFAS1-suppressed NSCLC cell proliferative, as well as invasive potentials, increased NSCLC cell apoptotic rates in vitro and also attenuated tumor growth of NSCLC cells in the nude mice. Further experimental evidence showed that ZFAS1 inversely affected miR-150-5p expression and positively affected high-mobility group AT-hook 2 (HMGA2) expression in NSCLC cell lines. MiR-150-5p inhibition or HMGA2 overexpression counteracted the effects of ZFAS1 knockdown on NSCLC cell proliferative, invasive potentials and apoptotic rates. In light of examining the clinical lung cancer samples, miR-150-5p expression was downregulated and the HMGA2 expression was highly expressed in the lung cancer tissues compared with normal ones; the ZFAS1 expression showed a negative correlation with miR-150-5p expression but a positive correlation with HMGA2 expression in lung cancer tissues. To summarize, we, for the first time, demonstrated the inhibitory effects of ZFAS1 knockdown on NSCLC cell progression, and the results from mechanistic studies indicated that ZFAS1-mediated NSCLC progression cells via targeting miR-150-5p/HMGA2 signaling.

An Integrated Bioinformatics Analysis Repurposes an Antihelminthic Drug Niclosamide for Treating HMGA2-Overexpressing Human Colorectal Cancer.

Aberrant overexpression of high mobility group AT-hook 2 (HMGA2) is frequently found in cancers and HMGA2 has been considered an anticancer therapeutic target. In this study, a pan-cancer genomics survey based on Cancer Cell Line Encyclopedia (CCLE) and The Cancer Genome Atlas (TCGA) data indicated that HMGA2 was mainly overexpressed in gastrointestinal cancers including colorectal cancer. Intriguingly, HMGA2 overexpression had no prognostic impacts on cancer patients’ overall and disease-free survivals. In addition, HMGA2-overexpressing colorectal cancer cell lines did not display higher susceptibility to a previously identified HMGA2 inhibitor (netroposin). By microarray profiling of HMGA2-driven gene signature and subsequent Connectivity Map (CMap) database mining, we identified that S100 calcium-binding protein A4 (S100A4) may be a druggable vulnerability for HMGA2-overexpressing colorectal cancer. A repurposing S100A4 inhibitor, niclosamide, was found to reverse the HMGA2-driven gene signature both in colorectal cancer cell lines and patients’ tissues. In vitro and in vivo experiments validated that HMGA2-overexpressing colorectal cancer cells were more sensitive to niclosamide. However, inhibition of S100A4 by siRNAs and other inhibitors was not sufficient to exert effects like niclosamide. Further RNA sequencing analysis identified that niclosamide inhibited more cell-cycle-related gene expression in HMGA2-overexpressing colorectal cancer cells, which may explain its selective anticancer effect. Together, our study repurposes an anthelminthic drug niclosamide for treating HMGA2-overexpression colorectal cancer.