HMGA1 sensitizes esophageal squamous cell carcinoma to mTOR inhibitors through the ETS1-FKBP12 axis.

Esophageal carcinoma is amongst the prevalent malignancies worldwide, characterized by unclear molecular classifications and varying clinical outcomes. The PI3K/AKT/mTOR signaling, one of the frequently perturbed dysregulated pathways in human malignancies, has instigated the development of various inhibitory agents targeting this pathway, but many ESCC patients exhibit intrinsic or adaptive resistance to these inhibitors. Here, we aim to explore the reasons for the insensitivity of ESCC patients to mTOR inhibitors. We assessed the sensitivity to rapamycin in various ESCC cell lines by determining their respective IC50 values and found that cells with a low level of HMGA1 were more tolerant to rapamycin. Subsequent experiments have supported this finding. Through a transcriptome sequencing, we identified a crucial downstream effector of HMGA1, FKBP12, and found that FKBP12 was necessary for HMGA1-induced cell sensitivity to rapamycin. HMGA1 interacted with ETS1, and facilitated the transcription of FKBP12. Finally, we validated this regulatory axis in in vivo experiments, where HMGA1 deficiency in transplanted tumors rendered them resistance to rapamycin. Therefore, we speculate that mTOR inhibitor therapy for individuals exhibiting a reduced level of HMGA1 or FKBP12 may not work. Conversely, individuals exhibiting an elevated level of HMGA1 or FKBP12 are more suitable candidates for mTOR inhibitor treatment.

HMGA1 regulates trabectedin sensitivity in advanced soft-tissue sarcoma (STS): A Spanish Group for Research on Sarcomas (GEIS) study.

HMGA1 is a structural epigenetic chromatin factor that has been associated with tumor progression and drug resistance. Here, we reported the prognostic/predictive value of HMGA1 for trabectedin in advanced soft-tissue sarcoma (STS) and the effect of inhibiting HMGA1 or the mTOR downstream pathway in trabectedin activity. The prognostic/predictive value of HMGA1 expression was assessed in a cohort of 301 STS patients at mRNA (n = 133) and protein level (n = 272), by HTG EdgeSeq transcriptomics and immunohistochemistry, respectively. The effect of HMGA1 silencing on trabectedin activity and gene expression profiling was measured in leiomyosarcoma cells. The effect of combining mTOR inhibitors with trabectedin was assessed on cell viability in vitro studies, whereas in vivo studies tested the activity of this combination. HMGA1 mRNA and protein expression were significantly associated with worse progression-free survival of trabectedin and worse overall survival in STS. HMGA1 silencing sensitized leiomyosarcoma cells for trabectedin treatment, reducing the spheroid area and increasing cell death. The downregulation of HGMA1 significantly decreased the enrichment of some specific gene sets, including the PI3K/AKT/mTOR pathway. The inhibition of mTOR, sensitized leiomyosarcoma cultures for trabectedin treatment, increasing cell death. In in vivo studies, the combination of rapamycin with trabectedin downregulated HMGA1 expression and stabilized tumor growth of 3-methylcholantrene-induced sarcoma-like models. HMGA1 is an adverse prognostic factor for trabectedin treatment in advanced STS. HMGA1 silencing increases trabectedin efficacy, in part by modulating the mTOR signaling pathway. Trabectedin plus mTOR inhibitors are active in preclinical models of sarcoma, downregulating HMGA1 expression levels and stabilizing tumor growth.

The transcription factor HMGB2 indirectly regulates APRIL expression and Gd-IgA1 production in patients with IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Proliferation-inducing ligand (APRIL) was identified as an important cause of glycosylation deficiency of IgA1 (Gd-IgA1), which can 'trigger' IgAN. Our previous study indicated that high migration group protein B2 (HMGB2) in peripheral blood mononuclear cells from patients with IgAN was associated with disease severity, but the underlying mechanism remains unclear. MATERIALS AND METHODS: The location of HMGB2 was identified by immunofluorescence. qRT-PCR and Western blotting were used to measure HMGB2, HMGA1, and APRIL expression. Gd-IgA1 levels were detected by enzyme-linked immunosorbent assay (ELISA). In addition, we used DNA pull-down, protein profiling, and transcription factor prediction software to identify proteins bound to the promoter region of the APRIL gene. RNA interference and coimmunoprecipitation (Co-IP) were used to verify the relationships among HMGB2, high mobility group AT-hook protein 1 (HMGA1), and APRIL. RESULTS: HMGB2 expression was greater in IgAN patients than in HCs and was positively associated with APRIL expression in B cells. DNA pull-down and protein profiling revealed that HMGB2 and HMGA1 bound to the promoter region of the APRIL gene. The expression levels of HMGA1, APRIL, and Gd-IgA1 were downregulated after HMGB2 knockdown. Co-IP indicated that HMGB2 binds to HMGA1. The Gd-IgA1 concentration in the supernatant was reduced after HMGA1 knockdown. HMGA1 binding sites were predicted in the promoter region of the APRIL gene. CONCLUSION: HMGB2 expression is greater in IgAN patients than in healthy controls; it promotes APRIL expression by interacting with HMGA1, thereby inducing Gd-IgA1 overexpression and leading to IgAN.

LINC00665 target let-7i/HMGA1 promotes the proliferation and invasion of hepatoma cells.

OBJECTIVES: Our group previously found that LINC00665 was upregulated in hepatocellular carcinoma (HCC) tissues through database analysis; however, the potential molecular mechanism of LINC00665 in HCC progression still needs further study. METHODS: qRTPCR was performed to determine the differential expression of LINC00665 and let-7i in HCC cells. Dual-luciferase reporter assays were performed to analyze the interaction of LINC00665 and let-7i. CCK-8 assays, scratch assays, Transwell invasion assays, qRTPCR and western blotting were performed to determine the regulatory mechanism of LINC00665/let-7i/HMGA1 in HCC cells. RESULTS: LINC00665 was upregulated in HCC cells compared with normal hepatocytes. A potential binding site between LINC00665 and let-7i was confirmed by dual-luciferase reporter assay. In HCC cells, inhibition of LINC00665 significantly reduced cell proliferation, migration and invasion ability via the let-7i/HMGA1 signaling axis. CONCLUSION: LINC00665 promotes the proliferation and invasion of HCC cells via the let-7i/HMGA1 signaling axis.

HMGA1 drives chemoresistance in esophageal squamous cell carcinoma by suppressing ferroptosis.

Chemotherapy is a primary treatment for esophageal squamous cell carcinoma (ESCC). Resistance to chemotherapeutic drugs is an important hurdle to effective treatment. Understanding the mechanisms underlying chemotherapy resistance in ESCC is an unmet medical need to improve the survival of ESCC. Herein, we demonstrate that ferroptosis triggered by inhibiting high mobility group AT-hook 1 (HMGA1) may provide a novel opportunity to gain an effective therapeutic strategy against chemoresistance in ESCC. HMGA1 is upregulated in ESCC and works as a key driver for cisplatin (DDP) resistance in ESCC by repressing ferroptosis. Inhibition of HMGA1 enhances the sensitivity of ESCC to ferroptosis. With a transcriptome analysis and following-up assays, we demonstrated that HMGA1 upregulates the expression of solute carrier family 7 member 11 (SLC7A11), a key transporter maintaining intracellular glutathione homeostasis and inhibiting the accumulation of malondialdehyde (MDA), thereby suppressing cell ferroptosis. HMGA1 acts as a chromatin remodeling factor promoting the binding of activating transcription factor 4 (ATF4) to the promoter of SLC7A11, and hence enhancing the transcription of SLC7A11 and maintaining the redox balance. We characterized that the enhanced chemosensitivity of ESCC is primarily attributed to the increased susceptibility of ferroptosis resulting from the depletion of HMGA1. Moreover, we utilized syngeneic allograft tumor models and genetically engineered mice of HMGA1 to induce ESCC and validated that depletion of HMGA1 promotes ferroptosis and restores the sensitivity of ESCC to DDP, and hence enhances the therapeutic efficacy. Our finding uncovers a critical role of HMGA1 in the repression of ferroptosis and thus in the establishment of DDP resistance in ESCC, highlighting HMGA1-based rewiring strategies as potential approaches to overcome ESCC chemotherapy resistance. Schematic depicting that HMGA1 maintains intracellular redox homeostasis against ferroptosis by assisting ATF4 to activate SLC7A11 transcription, resulting in ESCC resistance to chemotherapy.

STMN1 Promotes Tumor Metastasis in Non-small Cell Lung Cancer Through Microtubule-dependent And Nonmicrotubule-dependent Pathways.

The relationship between STMN1 and cancer metastasis is controversial. The purpose of this study was to explore the role and mechanism of STMN1 in NSCLC metastasis. In this study, we reported that STMN1 was highly expressed in NSCLC tissues and associated with poor prognosis. Both in vivo and in vitro functional assays confirmed that STMN1 promoted NSCLC metastasis. Further studies confirmed that STMN1 promoted cell migration by regulating microtubule stability. The results of Co-IP and LC‒MS/MS illustrated that STMN1 interacts with HMGA1. HMGA1 decreases microtubule stability by regulating the phosphorylation level of STMN1 at Ser16 and Ser38 after interacting with STMN1. This result suggested that STMN1 could be activated by HMGA1 to further promote NSCLC metastasis. Meanwhile, it has been found that STMN1 could promote cell migration by activating the p38MAPK/STAT1 signaling pathway, which is not dependent on microtubule stability. However, activating p38MAPK can decrease microtubule stability by promoting the dephosphorylation of STMN1 at ser16. A positive feedback loop was formed between STMN1 and p38MAPK to synergistically promote cell migration. In summary, our study demonstrated that STMN1 could promote NSCLC metastasis through microtubule-dependent and nonmicrotubule-dependent mechanisms. STMN1 has the potential to be a therapeutic target to inhibit metastasis.

Anoikis-related gene signature is associated with immune infiltration and predicts the prognosis of non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is the most common histological type of lung cancer. With the in-depth exploration of cell death manners, numerous studies found that anoikis is an important mechanism that associated with treatment. Therefore, we aimed to explore the prognostic value and treatment guidance of anoikis in NSCLC patients. In the current study, we first constructed a prognostic model based on the anoikis-related genes based on bulk RNA-sequencing and single-cell RNA-sequencing (scRNA-seq) dataset. Then, immuno-correlations of anoikis-related risk scores (ARGRS) were analyzed. In addition, HMGA1, a risky gene in ARGRS, was further explored to define its expression and immuno-correlation. Results showed that patients with higher ARGRS had worse clinical outcomes. Moreover, the five genes in the prognostic model were all highly expressed on tumor cells. Moreover, further analysis found that the ARGRS was negatively correlated with ImmuneScore, but positively with tumor purity. Besides, patients in the ARGRS-high group had lower levels of immunological characteristics, such as the immune-related signaling pathways and subpopulations. Additionally, in the immunotherapy cohorts, patients with the ARGRS-high phenotype were more resistant to immunotherapy and tended to not achieve remission after treatment. Last, HMGA1 was chosen as the representative biomarker, and analysis of the in-house cohort showed that HMGA1 was highly expressed in tumor tissues and correlated with decreased T cell infiltration. To sum up, ARGRS was correlated with a desert tumor microenvironment and identified immune-cold tumors, which can be a novel biomarker for the recognition of immunological characteristics and an immunotherapeutic response in NSCLC.

The role of high mobility group AT-hook 1 in viral infections: Implications for cancer pathogenesis.

The crucial role of high mobility group AT-hook 1 (HMGA1) proteins in nuclear processes such as gene transcription, DNA replication, and chromatin remodeling is undeniable. Elevated levels of HMGA1 have been associated with unfavorable clinical outcomes and adverse differentiation status across various cancer types. HMGA1 regulates a diverse array of biological pathways, including tumor necrosis factor-alpha/nuclear factor-kappa B (TNF-α/NF-κB), epidermal growth factor receptor (EGFR), Hippo, Rat sarcoma/extracellular signal-regulated kinase (Ras/ERK), protein kinase B (Akt), wingless-related integration site/beta-catenin (Wnt/beta-catenin), and phosphoinositide 3-kinase/protein kinase B (PI3-K/Akt). While researchers have extensively investigated tumors in the reproductive, digestive, urinary, and hematopoietic systems, mounting evidence suggests that HMGA1 plays a critical role as a tumorigenic factor in tumors across all functional systems. Given its broad interaction network, HMGA1 is an attractive target for viral manipulation. Some viruses, including herpes simplex virus type 1, human herpesvirus 8, human papillomavirus, JC virus, hepatitis B virus, human immunodeficiency virus type 1, severe acute respiratory syndrome Coronavirus 2, and influenza viruses, utilize HMGA1 influence for infection. This interaction, particularly in oncogenesis, is crucial. Apart from the direct oncogenic effect of some of the mentioned viruses, the hit-and-run theory postulates that viruses can instigate cancer even before being completely eradicated from the host cell, implying a potentially greater impact of viruses on cancer development than previously assumed. This review explores the interplay between HMGA1, viruses, and host cellular machinery, aiming to contribute to a deeper understanding of viral-induced oncogenesis, paving the way for innovative strategies in cancer research and treatment.

Cuproptosis/OXPHOS tendency prediction of prognosis and immune microenvironment of esophageal squamous cell carcinoma: Bioinformatics analysis and experimental validation.

BACKGROUND: Cuproptosis is a newly discovered cell death mechanism that relies on mitochondrial respiration, for which oxidative phosphorylation (OXPHOS) is an essential part. However, the detailed mechanisms of cuproptosis associated with OXPHOS in esophageal squamous cell carcinoma (ESCC) and how this correlation affects prognosis still remains unclear. METHODS: scRNA-seq data of ESCC were downloaded from SRA (Sequence Read Archive) database. "AUCell" algorithm was used to grouping epithelial cells according to cuproptosis and OXPHOS score. Cell-cell communication, Pseudo-time Trajectory and transcription factor enrichment analysis were repectively conducted by "CellChat", "monocle3" package and "pySCENIC" algorithm. Univariate and LASSO cox regression analysis were used to construct the prognostic cuproptosis-OXPHOS signature. Finally, CCK-8 assay and DCFH-DA staining assay were respectively validated the sensitive and ROS production of elesclomol. RESULTS: scRNA-seq data were analyzed to identify 10 core cell types. According to the median scores for cuproptosis and OXPHOS, malignant epithelial cells were divided into double high, double low, and mixed groups. The double high group distributed at the end of the pseudo-time trajectory and harbored HMGA1(+) as specific transcriptional regulons. Knockdown of HMGA1 partly reversed the inhibition of cell viability visualized by CCK-8 assay, while reactive oxygen species (ROS) production by elesclomol was enhanced after HMGA1 silencing. Furthermore, the immunosuppressive signal was significantly increased in the double high group detected by 'CellChat' in single-cell data and 'ssGSEA' in bulk data followed by 'CIBERSORTx' algorithm. Finally, a new cuproptosis-OXPHOS prognostic signature (CNN2, ATP6V0E1, PSMD6, CCDC25, IGFBP2, MT1E, and RPS4Y1) was constructed for the prediction of the prognosis, and a high-risk group corresponding to a more sensitive tendency to erlotinib, dasatinib, and bosutinib treatment was identified. CONCLUSIONS: Our study revealed the relationship between OXPHOS and tendency of cuproptosis in ESCC, and malignant cells with this characteristic exerted immunosuppressive signals and indicated poor prognosis. Furthermore, we constructed the regulatory network in high cuproptosis-OXPHOS ESCC and identified HMGA1 as a potential regulator molecule of cuproptosis mediated by elesclomol.

Circ_UBAP2 exacerbates proliferation and metastasis of OS via targeting miR-665/miR-370-3p/HMGA1 axis.

Circ_UBAP2 is extensively engaged in regulating the development of various malignancies, containing osteosarcoma (OS). However, its biological significance and function are not fully understood. In this study, we found that circ_UBAP2 and HMGA1 levels were up-regulated, and miR-370-3p and miR-665 expressions were decreased in osteosarcoma tissues. Inhibition of circ_UBAP2 or HMGA1 expression in OS cells, cell viability, invasion and migration abilitities were notably hindered, and cell apoptosis abilities were increased. Bioinformatics analysis predicted that miR-665 and miR-370-3p were the downstream targets of circ_UBAP2, and the dual luciferase experiment demonstrated the correlation between them. In addition, inhibition of miR-665 and miR-370-3p expression could significantly reverse the impact of knocking down circ_UBAP2 on OS cells. HMGA1 was discovered to become the downstream target of both miR-665 and miR-370-3p. It was shown that over-expression of miR-665 or miR-370-3p notably stimulated the cell growth, invasion, and migration of osteosarcoma cells, while hindered cell apoptosis. Nevertheless, this effect could be reversed by concurrent over-expression of HMGA1. Our data strongly prove that circ_UBAP2 makes a vital impact on promoting the proliferation, invasion as well as migration of osteosarcoma cells via down-regulating the level of miR-665 and miR-370-3p, and later up-regulating the level of HMGA1. In conclusion, circ_UBAP2 is upregulated in osteosarcoma, and it competitively adsorbs miR-370-3p and miR-665, resulting in up-regulation of HMGA1, thus promoting OS development.

Integrated bulk and scRNA sequence identified anoikis-related diagnostic biomarkers and potential association with immune infiltration in type A aortic dissection.

Type-A aortic dissection (TAAD) is common life-threatening cardiovascular diseases with high-morbidity and mortality but the concrete etiology of disease remains unclear, which might disturb or delay the early diagnosis for TAAD. Anoikis is a special form of programmed cell-death (PCD) induced by detachment of anchorage-dependent cells from the extracellular matrix (ECM) or neighboring cells, and has been widely applied to identify anoikis-related biomarkers for the prediction and prognosis in oncological fields. However, the specific roles of anoikis-related genes (ARGs) in TAAD remain unclear. In this study, we first identified and validated eight diagnostic ARGs for TAAD based on multiple RNA-sequence datasets, including CHEK2, HIF1A, HK2, HMGA1, SERPINA1, PTPN1, SLC2A1 and VEGFA. The comprehensive functional annotation was evaluated by the integrated functional enrichments analysis. We identified the activation of inflammatory-related pathways, metabolic reprogramming and angiogenesis, and the inhibition of cardiovascular development pathways in TAAD. Immune cell infiltration (ICI) analysis further demonstrated that innate immune-cells were more dominant than adaptive immune-cells in TAAD tissues, especially in macrophages, monocytes, activated-DC, NKT cells and CD56+dim NK cells. The cellular landscape was further validated by single-cell RNA sequence technology with significant associations with anoikis in TAAD patients. Four vital ARGs (HIF1A, HMGA1, SERPINA1 and VEGFA) were ultimately identified along with the changes of differentiation trajectory, and major expressions were conformably concentrated on Macro1-3, Mono1-2 and Mono4 subtypes. These findings provide a promising diagnostic biomarker for the accurately diagnosing the disease and would be helpful to further explore the potential pathogenesis with anoikis process for TAAD.

m6A-mediated lncRNA NEAT1 plays an oncogenic role in non-small cell lung cancer by upregulating the HMGA1 expression through binding miR-361-3p.

BACKGROUND: 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. OBJECTIVE: However, the potential molecular mechanisms of m6A-regulated lncRNAs in NSCLC still need further investigation. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

TFAP2A activates HMGA1 to promote glycolysis and lung adenocarcinoma progression.

BACKGROUND: Lung 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 METHODS: The 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. RESULTS: HMGA1 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. CONCLUSION: TFAP2A 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 MATERIALS: All the data within this manuscript could be gotten from corresponding author at reasonable request.

YWHAH activates the HMGA1/PI3K/AKT/mTOR signaling pathway by positively regulating Fra-1 to affect the proliferation of gastric cancer cells.

Fos-related antigen 1 (Fra-1) is a nuclear transcription factor that regulates cell growth, differentiation, and apoptosis. It is involved in the proliferation, invasion, apoptosis and epithelial mesenchymal transformation of malignant tumor cells. Fra-1 is highly expressed in gastric cancer (GC), affects the cycle distribution and apoptosis of GC cells, and participates in GC occurrence and development. However, the detailed mechanism of Fra-1 in GC is unclear, such as the identification of Fra-1-interacting proteins and their role in GC pathogenesis. In this study, we identified tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein eta (YWHAH) as a Fra-1-interacting protein in GC cells using co-immunoprecipitation combined with liquid chromatography-tandem mass spectrometry. Experiments showed that YWHAH positively regulated Fra-1 mRNA and protein expression, and affected GC cell proliferation. Whole proteome analysis showed that Fra-1 affected the activity of the high mobility group AT-hook 1 (HMGA1)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway in GC cells. Western blotting and flow cytometry confirmed that YWHAH activated HMGA1/PI3K/AKT/mTOR signaling pathway by positively regulating Fra-1 to affect GC cell proliferation. These results will help to discover new molecular targets for the early diagnosis, treatment, and prognosis prediction of GC.

Proteomics screening uncovers HMGA1 as a promising negative regulator for γ-globin expression in response to decreased ß-globin levels.

Reactivation of fetal hemoglobin (HbF) is a critical goal for the treatment of patients with hemoglobinopathies. ß-globin disorders can trigger stress erythropoiesis in red blood cells (RBCs). Cell-intrinsic erythroid stress signals promote erythroid precursors to express high levels of fetal hemoglobin, which is also known as γ-globin. However, the molecular mechanism underlying γ-globin production during cell-intrinsic erythroid stress remains to be elucidated. Here, we utilized CRISPR-Cas9 to model a stressed state caused by reduced levels of adult ß-globin in HUDEP2 human erythroid progenitor cells. We found that a decrease in ß-globin expression correlates with the upregulation of γ-globin expression. We also identified transcription factor high-mobility group A1 (HMGA1; formerly HMG-I/Y) as a potential γ-globin regulator that responds to reduced ß-globin levels. Upon erythroid stress, there is a downregulation of HMGA1, which normally binds -626 to -610 base pairs upstream from the STAT3 promoter, to downregulate STAT3 expression. STAT3 is a known γ-globin repressor, so the downregulation of HMGA1 ultimately upregulates γ-globin expression. SIGNIFICANCE: This study demonstrated HMGA1 as a potential regulator in the poorly understood phenomenon of stress-induced globin compensation, and after further validation these results might inform new strategies to treat patients with sickle cell disease and ß-thalassemia.

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.

Targeting HMGA1 contributes to immunotherapy in aggressive breast cancer while suppressing EMT.

Metastasis is an obstacle to the clinical treatment of aggressive breast cancer (BC). Studies have shown that high mobility group A1 (HMGA1) is abnormally expressed in various cancers and mediates tumor proliferation and metastasis. Here, we provided more evidence that HMGA1 mediated epithelial to mesenchymal transition (EMT) through the Wnt/ß-catenin pathway in aggressive BC. More importantly, HMGA1 knockdown enhanced antitumor immunity and improved the response to immune checkpoint blockade (ICB) therapy by upregulating programmed cell death ligand 1 (PD-L1) expression. Simultaneously, we revealed a novel mechanism by which HMGA1 and PD-L1 were regulated by the PD-L1/HMGA1/Wnt/ß-catenin negative feedback loop in aggressive BC. Taken together, we believe that HMGA1 can serve as a target for the dual role of anti-metastasis and enhancing immunotherapeutic responses.

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-ß 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.

Exosomal delivery of 7SK long non-coding RNA suppresses viability, proliferation, aggressiveness and tumorigenicity in triple negative breast cancer cells.

AIMS: RN7SK (7SK), a highly conserved non-coding RNA, serves as a transcription regulator via interaction with a few proteins. Despite increasing evidences which support the cancer-promoting roles of 7SK-interacting proteins, limited reports address the direct link between 7SK and cancer. To test the hypothetic suppression of cancer by overexpression of 7SK, the effects of exosomal 7SK delivery on cancer phenotypes were studied. MATERIALS AND METHODS: Exosomes derived from human mesenchymal stem cells were loaded with 7SK (Exo-7SK). MDA-MB-231, triple negative breast cancer (TNBC), cell line was treated with Exo-7sk. Expression levels of 7SK were evaluated by qPCR. Cell viability was assessed via MTT and Annexin V/PI assays as well as qPCR assessment of apoptosis-regulating genes. Cell proliferation was evaluated by growth curve analysis, colony formation and cell cycle assays. Aggressiveness of TNBCs was evaluated via transwell migration and invasion assays and qPCR assessment of genes regulating epithelial to mesenchymal transition (EMT). Moreover, tumor formation ability was assessed using a nude mice xenograft model. KEY FINDINGS: Treatment of MDA-MB-231 cells with Exo-7SK resulted in efficient overexpression of 7SK; reduced viability; altered transcription levels of apoptosis-regulating genes; reduced proliferation; reduced migration and invasion; altered transcription of EMT-regulating genes; and reduced in vivo tumor formation ability. Finally, Exo-7SK reduced mRNA levels of HMGA1, a 7SK interacting protein with master gene regulatory and cancer promoting roles, and its bioinformatically-selected cancer promoting target genes. SIGNIFICANCE: Altogether, as a proof of the concept, our findings suggest that exosomal delivery of 7SK may suppress cancer phenotypes via downregulation of HMGA1.

Establishment and characterization of a novel cancer stem-like cell of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is an aggressive malignant tumor of bile duct epithelia. Recent evidence suggests the impact of cancer stem cells (CSC) on the therapeutic resistance of CCA; however, the knowledge of CSC in CCA is limited due to the lack of a CSC model. In this study, we successfully established a stable sphere-forming CCA stem-like cell, KKU-055-CSC, from the original CCA cell line, KKU-055. The KKU-055-CSC exhibits CSC characteristics, including: (1) the ability to grow stably and withstand continuous passage for a long period of culture in the stem cell medium, (2) high expression of stem cell markers, (3) low responsiveness to standard chemotherapy drugs, (4) multilineage differentiation, and (5) faster and constant expansive tumor formation in xenograft mouse models. To identify the CCA-CSC-associated pathway, we have undertaken a global proteomics and functional cluster/network analysis. Proteomics identified the 5925 proteins in total, and the significantly upregulated proteins in CSC compared with FCS-induced differentiated CSC and its parental cells were extracted. Network analysis revealed that high mobility group A1 (HMGA1) and Aurora A signaling through the signal transducer and activator of transcription 3 pathways were enriched in KKU-055-CSC. Knockdown of HMGA1 in KKU-055-CSC suppressed the expression of stem cell markers, induced the differentiation followed by cell proliferation, and enhanced sensitivity to chemotherapy drugs including Aurora A inhibitors. In silico analysis indicated that the expression of HMGA1 was correlated with Aurora A expressions and poor survival of CCA patients. In conclusion, we have established a unique CCA stem-like cell model and identified the HMGA1-Aurora A signaling as an important pathway for CSC-CCA.