HMGA2 gene is a promising target for ovarian cancer silencing therapy

HMGA2 overexpression activates IGF2BP2 to stabilize APLP2 via m6A modification and promote pancreatic cancer progression

Pancreatic cancer is a highly aggressive malignancy of the digestive system, with occult onset, rapid progression, and poor prognosis. The genetic heterogeneity of pancreatic cancer contributes to its highly malignant biological behavior. HMGA2 is overexpressed in tumors and is known to regulate tumor progression in various cancers through the HMGA2-IGF2BP2 axis, but its role and mechanism in pancreatic cancer remain unclear. In this study, we demonstrated that HMGA2 promotes pancreatic cancer progression. We further revealed that HMGA2 upregulates IGF2BP2, which stabilizes APLP2 mRNA via m6A modification, thereby promoting pancreatic cancer progression. These results indicate that HMGA2/IGF2BP2/APLP2 signaling axis regulates the progression of pancreatic cancer.

HMGA2 promotes nasopharyngeal carcinoma progression and is associated with tumor resistance and poor prognosis

Nasopharyngeal carcinoma (NPC), as one of the most prevalent malignancies in the head and neck region, still lacks a complete understanding of its pathogenesis. Presently, radiotherapy, concurrent chemoradiotherapy, and targeted therapy stand as the primary modalities for treating NPC. With advancements in medicine, the cure rates for nasopharyngeal carcinoma have been steadily increasing. Nevertheless, recurrence and metastasis persist as the primary reasons for treatment failure. Consequently, a profound exploration of the molecular mechanisms underlying the occurrence and progression of nasopharyngeal carcinoma, along with the exploration of corresponding therapeutic approaches, becomes particularly imperative in the quest for comprehensive solutions to combat this disease. High mobility group AT-hook 2 (HMGA2) is a pivotal protein capable of altering chromatin structure, regulating gene expression, and influencing transcriptional activity. In the realm of cancer research, HMGA2 exhibits widespread dysregulation, playing a crucial role in nearly all malignant tumors. It is implicated in various tumorigenic processes, including cell cycle regulation, cell proliferation, epithelial-mesenchymal transition, angiogenesis, tumor invasion, metastasis, and drug resistance. Additionally, HMGA2 serves as a molecular marker and an independent prognostic factor in certain malignancies. Recent studies have increasingly unveiled the critical role of HMGA2 in nasopharyngeal carcinoma (NPC), particularly in promoting malignant progression, correlating with tumor resistance, and serving as an independent adverse prognostic factor. This review focuses on elucidating the oncogenic role of HMGA2 in NPC, suggesting its potential association with chemotherapy resistance in NPC, and proposing its candidacy as an independent factor in nasopharyngeal carcinoma prognosis assessment.

Small interference (RNAi) technique: Exploring its clinical applications, benefits and limitations

BACKGROUND

Small interference RNA (siRNA) has emerged as the most desired method for researchers and clinicians who wish to silence a specific gene of interest and has been extensively developed as a therapeutic agent. This review points to collecting all clinical trials on siRNA and understanding its benefits, pharmacokinetics and safety by reading articles published in the last 5 years.

MATERIALS AND METHODS

Searching in the PubMed database using 'siRNA' and 'in vivo' with limits to articles published in the previous 5 years, article type 'clinical trials' and language 'English' to acquire papers on in vivo studies on siRNA approaches. Features of siRNA clinical trials registered at https://clinicaltrials.gov/ were analysed.

RESULTS

So far, 55 clinical studies have been published on siRNA. Many published clinical trials on siRNA showed tolerability, safety and effectiveness in treating cancers like breast, lung, colon, and other organs and other diseases like viral infections and hereditary diseases. Many different routes of administration can silence many genes at the same time. Limitations and uncertainties associated with siRNA treatment include the effectiveness of cellular uptake, precise targeting of the intended tissue or cell and prompt elimination from the body.

CONCLUSIONS

The siRNA or RNAi method will be one of the most critical and influential techniques to fight against many different diseases. Although the RNAi approach has certain advantages, it also has limitations concerning clinical applications. Overcoming these limitations remains a daunting challenge.

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

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

HMGA2 regulation by miRNAs in cancer: affecting cancer hallmarks and therapy response

High mobility group A 2 (HMGA2) is a protein that modulates the structure of chromatin in the nucleus. Importantly, aberrant expression of HMGA2 occurs during carcinogenesis, and this protein is an upstream mediator of cancer hallmarks including evasion of apoptosis, proliferation, invasion, metastasis, and therapy resistance. HMGA2 targets critical signaling pathways such as Wnt/β-catenin and mTOR in cancer cells. Therefore, suppression of HMGA2 function notably decreases cancer progression and improves outcome in patients. As HMGA2 is mainly oncogenic, targeting expression by non-coding RNAs (ncRNAs) is crucial to take into consideration since it affects HMGA2 function. MicroRNAs (miRNAs) belong to ncRNAs and are master regulators of vital cell processes, which affect all aspects of cancer hallmarks. Long ncRNAs (lncRNAs) and circular RNAs (circRNAs), other members of ncRNAs, are upstream mediators of miRNAs. The current review intends to discuss the importance of the miRNA/HMGA2 axis in modulation of various types of cancer, and mentions lncRNAs and circRNAs, which regulate this axis as upstream mediators. Finally, we discuss the effect of miRNAs and HMGA2 interactions on the response of cancer cells to therapy. Regarding the critical role of HMGA2 in regulation of critical signaling pathways in cancer cells, and considering the confirmed interaction between HMGA2 and one of the master regulators of cancer, miRNAs, targeting miRNA/HMGA2 axis in cancer therapy is promising and this could be the subject of future clinical trial experiments.

miR-219-5p attenuates cisplatin resistance of ovarian cancer by inactivating Wnt/β-catenin signaling and autophagy via targeting HMGA2

Our previous study confirmed that miR-219-5p inhibits the progression of ovarian cancer (OC) by targeting high mobility group AT-hook 2 (HMGA2), while the role of miR-219-5p on the chemoresistance of OC is unclear. HMGA2 and miR-219-5p expression in OC tumors and various types of OC cells were determined by reverse transcription-quantitative PCR (RT-qPCR) and western blotting. The miRNA profiles in A2780 and cisplatin-resistant A2780 cells were investigated via bulk miRNA sequencing, and the interactions of miR-219-5p and HMGA2 were determined by luciferase reporter activity assay. Cell function was verified through Cell Counting Kit-8, invasion assay, wound-healing, and TUNEL assays. HMGA2 level is highly expressed in cisplatin-resistant OC cell lines compared to normal OC cells, while the expression trend of miR-219-5p is the opposite. In addition, we found that miR-219-5p is one of the miRNAs that have the most significant reduction in levels in the cisplatin-resistant A2780/DDP cell line compared to A2780 cells. Then, we reveal that miR-219-5p directly targets HMGA2 in cisplatin-resistant OC cells, and upregulation of miR-219-5p significantly reduces the resistance of OC cells to cisplatin both in vitro and in vivo. Finally, our results suggest that Wnt/β-catenin signaling and autophagy pathway is involved in the role of miR-219-5p/HMGA2 on resistance of OC cells to cisplatin via gain-of-function experiments. Collectively, the present study shows that miR-219-5p decreases the resistance of OC cells to cisplatin via Wnt/β-catenin signaling and autophagy by regulating HMGA2, which provides a feasible solution for the resistance of OC to chemotherapy.

Expression and Clinical Significance of High-Mobility Group AT-hook 2 (HMGA2) in Osteosarcoma

Objective

Although high‐mobility group AT‐hook 2 (HMGA2) has been shown to have crucial roles in the pathogenesis and metastasis of various malignancies, its expression and significance in osteosarcoma remain unknown. Here we evaluate the expression, clinical prognostic value, and overall function of HMGA2 in osteosarcoma.

Methods

Sixty‐nine osteosarcoma patient specimens within a tissue microarray (TMA) were analyzed by immunohistochemistry for HMGA2 expression. Demographics and clinicopathological information including age, gender, tumor location, metastasis, recurrence, chemotherapy response, follow‐up time, and disease status were also collected. After validation of expression, we determined whether there was a correlation between HMGA2 expression and patient clinicopathology. HMGA2 expression was also evaluated in osteosarcoma cell lines and patient tissues by Western blot, we analyzed the expression of HMGA2 in the human osteosarcoma cell lines MG63, 143B, U2OS, Saos‐2, MNNG/HOS, and KHOS. HMGA2‐specific siRNA and clonogenic assays were then used to determine the effect of HMGA2 inhibition on osteosarcoma cell proliferation, growth, and chemosensitivity.

Results

HMGA2 expression was elevated in the osteosarcoma patient specimens and human osteosarcoma cell lines. HMGA2 was differentially expressed in human osteosarcoma cell lines. Specifically, a relatively high expression of HMGA2 was present in KHOS, MNNG/HOS, 143B and a relatively low expression was in MG63, U2OS as well as Saos‐2. HMGA2 expression is correlated with metastasis and shorter overall survival. High HMGA2 expression is an independent predictor of poor osteosarcoma prognosis. There was no significant correlation between HMGA2 expression and the age, gender, or tumor site of the patient. HMGA2 expression is predominantly within the nucleus. The expression of HMGA2 also directly correlated to neoadjuvant chemoresistance. There was a significant reduction of HMGA2 expression in the siRNA transfection group. After the use of siRNA, the proliferation of osteosarcoma cells is decreased and the chemosensitivity of osteosarcoma cells is significantly increased.

Conclusion

Our study supports HMGA2 as a potential prognostic biomarker and therapeutic target in osteosarcoma.

HMGA2: A Biomarker in Gynecologic Neoplasia

High Mobility Group A2 gene (HMGA2), an oncofetal protein, is normally expressed in fetal development and completely shuts down in almost all organs and tissue types during adulthood. It is upregulated or overexpressed again in certain mesenchymal neoplasms due to chromosomal translocations and in malignant epithelial tumors through transcription regulation. HMGA2 overexpression can either drive tumor development or promote the aggressiveness of tumor growth. Many gynecologic neoplasms, including uterine smooth muscle tumors and ovarian cancer, are associated with HMGA2 overexpression. In this article, we review recent developments in the study of HMGA2 and its expression as a potential biomarker for gynecologic neoplasms and clinic application.

HMGA2 Supports Cancer Hallmarks in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that exhibits a high proliferation rate and early metastasis leading to a poor prognosis. HMGA2 is a DNA binding transcriptional regulator implicated in tumorigenesis. Here, we demonstrate that the HMGA2 promoter is demethylated in TNBC tumors, leading to increased expression of HMGA2 at both mRNA and protein levels. Importantly, high HMGA2 levels in TNBC tumors are correlated with poor prognosis. To detail the role of HMGA2 in TNBC development and progression, we studied its effect on core cancer phenotypes. Stable knockdown of HMGA2 in TNBC cells revealed that HMGA2 may support cell proliferation, cell migration and invasion. In addition, HMGA2 knockdown decreased cancer stem cell (CSC) features. Importantly, we found that silencing HMGA2 inhibited NF-kB signaling and lead to decreased expression of the downstream molecules IL-6 and IL-8 and reduced STAT3 pathway activation. Our results demonstrate that HMGA2 supports cancer hallmarks in TNBC and may represent a promising target for TNBC treatment.

CDK13-Mediated Cell Cycle Disorder Promotes Tumorigenesis of High HMGA2 Expression Gastric Cancer

The inhibitor of CDK4/6 has been clinically used for treating certain types of cancer which are characterized by G0/G1 acceleration induced by the CDK4/6-RB1 pathway. On the contrary, the cell cycle–related molecules are abnormal in over 50% of the patients with gastric cancer (GC), but the efficiency of inhibiting CDK4/6 does not work well as it is expected. In our study, we found HMGA2 promotes GC through accelerating the S–G2/M phase transition, instead of G0/G1. We also found CDK13 is the direct target gene of HMGA2. Importantly, we analyzed 200 pairs of GC and the adjacent tissue and proved the positive relation between HMGA2 and CDK13; moreover, high expression of both genes predicts a poorer prognosis than the expression of single gene does. We explored the effect of the novel CDK12/13 inhibiting agent, SR-4835, on high HMGA2 expression GC and found inhibition of both genes jointly could reach a satisfied result. Therefore, we suggest that inhibition of CDK13 and HMGA2 simultaneously could be an effective strategy for high HMGA2 expression GC. To detect the expression of both genes simultaneously and individually could be of benefit to predict prognosis for GC.

Regulatory mechanisms of heme regulatory protein BACH1: a potential therapeutic target for cancer

A limited number of overexpressed transcription factors are associated with cancer progression in many types of cancer. BTB and CNC homology 1 (BACH1) is the first mammalian heme-binding transcription factor that belongs to the basic region leucine zipper (bZIP) family and a member of CNC (cap 'n' collar). It forms heterodimers with the small musculoaponeurotic fibrosarcoma (MAF) proteins and stimulates or suppresses the expression of target genes under a very low intracellular heme concentration. It possesses a significant regulatory role in heme homeostasis, oxidative stress, cell cycle, apoptosis, angiogenesis, and cancer metastasis progression. This review discusses the current knowledge about how BACH1 regulates cancer metastasis in various types of cancer and other carcinogenic associated factors such as oxidative stress, cell cycle regulation, apoptosis, and angiogenesis. Overall, from the reported studies and outcomes, it could be realized that BACH1 is a potential pharmacological target for discovering new therapeutic anticancer drugs.

MicroRNAs and Stem-like Properties: The Complex Regulation Underlying Stemness Maintenance and Cancer Development

Embryonic stem cells (ESCs) have the extraordinary properties to indefinitely proliferate and self-renew in culture to produce different cell progeny through differentiation. This latter process recapitulates embryonic development and requires rounds of the epithelial-mesenchymal transition (EMT). EMT is characterized by the loss of the epithelial features and the acquisition of the typical phenotype of the mesenchymal cells. In pathological conditions, EMT can confer stemness or stem-like phenotypes, playing a role in the tumorigenic process. Cancer stem cells (CSCs) represent a subpopulation, found in the tumor tissues, with stem-like properties such as uncontrolled proliferation, self-renewal, and ability to differentiate into different cell types. ESCs and CSCs share numerous features (pluripotency, self-renewal, expression of stemness genes, and acquisition of epithelial-mesenchymal features), and most of them are under the control of microRNAs (miRNAs). These small molecules have relevant roles during both embryogenesis and cancer development. The aim of this review was to recapitulate molecular mechanisms shared by ESCs and CSCs, with a special focus on the recently identified classes of microRNAs (noncanonical miRNAs, mirtrons, isomiRs, and competitive endogenous miRNAs) and their complex functions during embryogenesis and cancer development.

Small interfering-high mobility group A2 attenuates epithelial-mesenchymal transition in thymic cancer cells via the Wnt/β-catenin pathway

Thymus carcinoma is one of the thymic epithelial neoplasms with high metastasis, which does not have any good treatment at present. High mobility group A2 (HMGA2) is highly expressed in a variety of malignant tumors, such as lung cancer, colon cancer and ovarian cancer and is closely related to tumor invasion and metastasis. The present study aimed to investigate the effect and mechanism of HMGA2 on epithelial-mesenchymal transition (EMT) in thymic cancer cells. IU-TAB-1, A549, HCT-116 and 293T cells were screened by testing the protein expression level of HMGA2 though western blotting and subjected to HMGA2 interference [small interfering (si)-HMGA2]. Cell proliferation was evaluated using the Cell Counting Kit-8 assay. Cell migration and invasion were detected using the Transwell assay. Cell apoptosis was examined using flow cytometry and β-catenin expression was observed by immunofluorescence. The levels of E-cadherin, vimentin, Wnt3a, Wnt5a and β-catenin proteins were determined by western blotting. Among the four cell lines tested, IU-TAB-1 cells demonstrated the highest expression of HMGA2 (P<0.05) and were hence selected for subsequent experiments. Compared with the control group (untransfected cells), si-HMGA2 resulted in significantly decreased proliferation, migration and invasion of IU-TAB-1 cells, whereas apoptosis was increased (P<0.05). The protein expression of vimentin, Wnt3a, Wnt5a and β-catenin was significantly decreased by si-HMGA2 compared with the control group (P<0.05), whereas E-cadherin expression was increased (P<0.05). After treatment with si-HMGA2 in combination with Wnt/β-catenin agonists (SKL2001) or inhibitors (XAV-939), EMT was respectively enhanced or inhibited in IU-TAB-1 cells. Overall, si-HMGA2 may attenuate EMT in thymic cancer cells and the mechanism may be related to the Wnt/β-catenin pathway.

si-MALAT1 attenuates thymic cancer cell proliferation and promotes apoptosis via the miR-145-5p/HMGA2 pathway

Metastasis-associated-lung-adenocarcinoma-transcript-1 (MALAT1) is a long non-coding RNA that is considered a potential tumor marker. The present study aimed to investigate the effect and mechanism of MALAT1 on cell proliferation and apoptosis in thymic cancer cells. IU-TAB-1, A549, HCT-116 and 293T cells were screened by reverse transcription-quantitative PCR to assess high-mobility group AT-hook 2 (HMGA2) expression in various types of cancer cells and were transfected with small interfering (si)RNA targeting MALAT1 (si-MALAT1). Cell proliferation was evaluated by Cell Counting Kit-8 assay. Cell apoptosis and cell cycle were examined using flow cytometry. The protein expression of cyclin D1, cyclin E, Bax, Bcl-2 and HMGA2 was determined by western blot analysis, while the associations between MALAT1 and microRNA (miR)-145-5p and between HMGA2 and miR-145-5p were determined by luciferase reporter assay. Among the four cell lines evaluated, IU-TAB-1 showed the highest expression of MALAT1; thus, IU-TAB-1 cells were selected for subsequent experiments. Compared with the findings in the control group, si-MALAT1 significantly decreased the cell proliferation of IU-TAB-1 cells, whereas the apoptosis levels and number of cells in G₂ phase were increased. The protein expression levels of cyclin D1, cyclin E, Bcl-2 and HMGA2 were significantly decreased in the si-MALAT1 group compared with those in the control group, while Bax levels were significantly increased. After treatment with si-MALAT1 in combination with miR-145-5p mimics or inhibitors, cell proliferation and apoptosis were respectively enhanced and inhibited in IU-TAB-1 cells. miR-145-5p inhibited the luciferase activity of IU-TAB-1 cells transfected with the MALAT1 or HMGA2 3' untranslated region. In conclusion, si-MALAT1 significantly attenuated cell proliferation and apoptosis via the miR-145-5p/HMGA2 pathway in thymic cancer cells.

Matrine inhibits ovarian cancer cell viability and promotes apoptosis by regulating the ERK/JNK signaling pathway via p38MAPK

Ovarian cancer displays the highest mortality rate among all types of gynecological cancer worldwide. The survival of patients with ovarian cancer remains poor due to poor responses to anticancer treatments. The present study aimed to investigate the therapeutic effects and potential mechanism underlying matrine in ovarian cancer tissues, ovarian cancer cells and a CAOV‑3‑derived tumor‑bearing mouse model. MTT, migration, invasion, flow cytometry, immunofluorescence and immunohistochemistry assays were performed to assess the inhibitory effects of matrine on ovarian cancer. A xenograft ovarian cancer mouse model was established and treated with matrine or PBS. The results demonstrated that compared with the control group, matrine significantly induced ovarian cancer cell apoptosis by upregulating caspase‑8 and Fas cell surface death receptor (Fas) expression levels, and downregulating Bcl‑2 and Bcl‑xl expression levels. Moreover, compared with the control group, matrine significantly inhibited ovarian cancer cell viability, migration and invasion by downregulating metastasis associated protein‑1, fibronectin, angiotensin II type 2 receptor-interacting protein 3a and H high mobility group AT‑hook 2 expression levels. Compared with the control group, matrine significantly increased p38MAPK, phosphorylated (p)ERK/ERK and pJNK/JNK expression levels in ovarian cancer cells. p38MAPK knockdown significantly downregulated p38MAPK, pERK/ERK and pJNK/JNK expression levels compared with the control group, which significantly promoted ovarian cancer cell viability, migration and invasion. In vivo experiments demonstrated that compared with the control group, matrine significantly suppressed tumor growth by markedly upregulating p38MAPK, ERK and JNK expression levels. The immunohistochemistry results demonstrated that caspase‑8 and Fas expression levels were notably increased, whereas Bcl‑2 and Bcl‑xl expression levels were obviously decreased in matrine‑treated tumors compared with PBS‑treated tumors. In conclusion, the present study demonstrated that matrine inhibited ovarian cancer cell viability, migration and invasion, but induced cell apoptosis, suggesting that matrine may serve as a promising anticancer agent for the treatment of ovarian cancer.

Curcumin Regulates Cancer Progression: Focus on ncRNAs and Molecular Signaling Pathways

Curcumin [(1E,6E) ‑1,7‑bis(4‑hydroxy‑3‑methoxyphenyl) hepta‑1,6‑diene‑3,5‑ dione] is a natural polyphenol derived from the rhizome of the turmeric plant Curcuma longa. Accumulated evidences have presented curcumin’s function in terms of anti-inflammatory, antioxidant properties, and especially anti-tumor activities. Studies demonstrated that curcumin could exert anti-tumor activity via multiple biological signaling pathways, such as PI3K/Akt, JAK/STAT, MAPK, Wnt/β-catenin, p53, NF-ĸB and apoptosis related signaling pathways. Moreover, Curcumin can inhibit tumor proliferation, angiogenesis, epithelial-mesenchymal transition (EMT), invasion and metastasis by regulating tumor related non-coding RNA (ncRNA) expression. In this review, we summarized the roles of curcumin in regulating signaling pathways and ncRNAs in different kinds of cancers. We also discussed the regulatory effect of curcumin through inhibiting carcinogenic miRNA and up regulating tumor suppressive miRNA. Furthermore, we aim to illustrate the cross regulatory relationship between ncRNA and signaling pathways, further to get a better understanding of the anti-tumor mechanism of curcumin, thus lay a theoretical foundation for the clinical application of curcumin in the future.

HMGA2 as a Critical Regulator in Cancer Development

The high mobility group protein 2 (HMGA2) regulates gene expression by binding to AT-rich regions of DNA. Akin to other DNA architectural proteins, HMGA2 is highly expressed in embryonic stem cells during embryogenesis, while its expression is more limited at later stages of development and in adulthood. Importantly, HMGA2 is re-expressed in nearly all human malignancies, where it promotes tumorigenesis by multiple mechanisms. HMGA2 increases cancer cell proliferation by promoting cell cycle entry and inhibition of apoptosis. In addition, HMGA2 influences different DNA repair mechanisms and promotes epithelial-to-mesenchymal transition by activating signaling via the MAPK/ERK, TGFβ/Smad, PI3K/AKT/mTOR, NFkB, and STAT3 pathways. Moreover, HMGA2 supports a cancer stem cell phenotype and renders cancer cells resistant to chemotherapeutic agents. In this review, we discuss these oncogenic roles of HMGA2 in different types of cancers and propose that HMGA2 may be used for cancer diagnostic, prognostic, and therapeutic purposes.

High mobility group A protein-2 as a tumor cancer diagnostic and prognostic marker: a systematic review and meta-analysis

High mobility group A protein-2 (HMGA2) is an architectural transcription factor that binds to the A/T-rich DNA minor groove and is responsible for regulating transcriptional activity of multiple genes indirectly through chromatin change and assembling enhanceosome. HMGA2 is overexpressed in multiple tumor types, suggesting its involvement in cancer initiation and progression, thus, making it an ideal candidate for cancer diagnostic and prognostic. We performed a systematic review to examine the role of HMGA2 as a universal tumor cancer diagnostic and prognostic marker. We used Reporting Recommendations for Tumor Marker Prognostic Studies to systematically search OvidMedline, PubMed, and the Cochrane Library for English language studies, published between 1995 and June 2019. Meta-analysis provided pooled risk estimates and their 95% confidence intervals (CIs) for an association between overall survival and recurrence of cancers for studies with available estimates. We identified 42 eligible studies with a total of 5123 tumor samples in 15 types of cancer. The pooled percentage of HMGA2 gene expression in tumor samples was 65.14%. Meta-analysis showed that cancer patients with HMGA2 positive have significantly reduced survival, compared to patients without HMGA2 gene [pooled-hazard ratio (HR) = 1.85, 95% CI 1.48-2.22]. There was a positive association between cancer patients with HMGA2 overexpression and cancer recurrence though this association did not reach significance (pooled-HR = 1.44, 95% CI 0.80-2.07). Overexpression of HMGA2 was found in 15 types of cancer. There was an association between HMGA2 overexpression with reduced survival of cancer patients. HMGA2 is thus considered a promising universal tumor marker for prognostics.

High Mobility Group AT-Hook 2 (HMGA2) Oncogenicity in Mesenchymal and Epithelial Neoplasia

High mobility group AT-hook 2 (HMGA2) has been associated with increased cell proliferation and cell cycle dysregulation, leading to the ontogeny of varied tumor types and their metastatic potentials, a frequently used index of disease prognosis. In this review, we deepen our understanding of HMGA2 pathogenicity by exploring the mechanisms by which HMGA2 misexpression and ectopic expression induces mesenchymal and epithelial tumorigenesis respectively and distinguish the pathogenesis of benign from malignant mesenchymal tumors. Importantly, we highlight the regulatory role of let-7 microRNA family of tumor suppressors in determining HMGA2 misexpression events leading to tumor pathogenesis and focused on possible mechanisms by which HMGA2 could propagate lymphangioleiomyomatosis (LAM), benign mesenchymal tumors of the lungs. Lastly, we discuss potential therapeutic strategies for epithelial and mesenchymal tumorigenesis based on targeting the HMGA2 signaling pathway.

Gene Expression Signature-Based Approach Identifies Antifungal Drug Ciclopirox As a Novel Inhibitor of HMGA2 in Colorectal Cancer

Human high-mobility group A2 (HMGA2) encodes for a non-histone chromatin protein which influences a variety of biological processes, including the cell cycle process, apoptosis, the DNA damage repair process, and epithelial–mesenchymal transition. The accumulated evidence suggests that high expression of HMGA2 is related to tumor progression, poor prognosis, and a poor response to therapy. Thus, HMGA2 is an important molecular target for many types of malignancies. Our recent studies revealed the positive connections between heat shock protein 90 (Hsp90) and HMGA2 and that the Hsp90 inhibitor has therapeutic potential to inhibit HMGA2-triggered tumorigenesis. However, 43% of patients suffered visual disturbances in a phase I trial of the second-generation Hsp90 inhibitor, NVP-AUY922. To identify a specific inhibitor to target HMGA2, the Gene Expression Omnibus (GEO) database and the Library of Integrated Network-based Cellular Signatures (LINCS) L1000platform were both analyzed. We identified the approved small-molecule antifungal agent ciclopirox (CPX) as a novel potential inhibitor of HMGA2. In addition, CPX induces cytotoxicity of colorectal cancer (CRC) cells by induction of cell cycle arrest and apoptosis in vitro and in vivo through direct interaction with the AT-hook motif (a small DNA-binding protein motif) of HMGA2. In conclusion, this study is the first to report that CPX is a novel potential inhibitor of HMGA2 using a drug-repurposing approach, which can provide a potential therapeutic intervention in CRC patients.

Combined quantitation of HMGA2 mRNA, microRNAs, and mitochondrial-DNA content enables the identification and typing of thyroid tumors in fine-needle aspiration smears

Background

Analysis of molecular markers in addition to cytological analysis of fine-needle aspiration (FNA) samples is a promising way to improve the preoperative diagnosis of thyroid nodules. Nonetheless, in clinical practice, applications of existing diagnostic solutions based on the detection of somatic mutations or analysis of gene expression are limited by their high cost and difficulties with clinical interpretation.

The aim of our work was to develop an algorithm for the differential diagnosis of thyroid nodules on the basis of a small set of molecular markers analyzed by real-time PCR.

Methods

A total of 494 preoperative FNA samples of thyroid goiters and tumors from 232 patients with known histological reports were analyzed: goiter, 105 samples (50 patients); follicular adenoma, 101 (48); follicular carcinoma, 43 (28); Hürthle cell carcinoma, 25 (11); papillary carcinoma, 121 (56); follicular variant of papillary carcinoma, 80 (32); and medullary carcinoma, 19 (12). Total nucleic acids extracted from dried FNA smears were analyzed for five somatic point mutations and two translocations typical of thyroid tumors as well as for relative concentrations of HMGA2 mRNA and 13 microRNAs and the ratio of mitochondrial to nuclear DNA by real-time PCR. A decision tree–based algorithm was built to discriminate benign and malignant tumors and to type the thyroid cancer. Leave-p-out cross-validation with five partitions was performed to estimate prediction quality. A comparison of two independent samples by quantitative traits was carried out via the Mann–Whitney U test.

Results

A minimum set of markers was selected (levels of HMGA2 mRNA and miR-375, − 221, and -146b in combination with the mitochondrial-to-nuclear DNA ratio) and yielded highly accurate discrimination (sensitivity = 0.97; positive predictive value = 0.98) between goiters with benign tumors and malignant tumors and accurate typing of papillary, medullary, and Hürthle cell carcinomas. The results support an alternative classification of follicular tumors, which differs from the histological one.

Conclusions

The study shows the feasibility of the preoperative differential diagnosis of thyroid nodules using a panel of several molecular markers by a simple PCR-based method. Combining markers of different types increases the accuracy of classification.

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.

Long noncoding RNA LSINCT5 promotes endometrial carcinoma cell proliferation, cycle, and invasion by promoting the Wnt/β-catenin signaling pathway via HMGA2

Background:

A review of the evidence has indicated the critical role of long noncoding RNA (lncRNA) LSINCT5 in a large number of human cancers. However, the mechanistic involvement of LSINCT5 in endometrial carcinoma (EC) is still unknown. Here the authors aim to characterize the expression status of LSINCT5 and elucidate its mechanistic relevance to EC.

Methods:

Relative expression of LSINCT5 and HMGA2 were quantified by a real-time polymerase chain reaction. SiRNAs were employed to specifically knockdown endogenous LSINCT5 in EC cells. Cell proliferation was measured with Cell Count Kit-8 kit (CCK-8, Dojindo, Kumamoto, Japan) and cell growth was assessed by a colony formation assay. The cell cycle was analyzed with propidium iodide (PI) staining. Apoptotic cells were determined by flow cytometry after Annexin V/PI double-staining. Cell migration was evaluated by a wound-healing assay, and cell invasion was assessed using a transwell migration assay. The protein levels of HMGA2, Wnt3a, p-β-catenin, c-myc, β-actin, and GAPDH were determined by western blot.

Results:

The authors observed positively correlated and aberrantly up-regulated LSINCT5 and HMGA2 in EC. LSINCT5 deficiency significantly inhibited cell proliferation, cell cycle progression, and induced apoptosis. Meanwhile, cell migration and invasion were greatly compromised by the LSINCT5 knockdown. LSINCT5 stabilized HMGA2, which subsequently stimulated activation of Wnt/β-catenin signaling and consequently contributed to the oncogenic properties of LSINCT5 in EC.

Conclusions:

Our data uncovered the oncogenic activities and highlighted the mechanistic contributions of the LSINCT5-HMGA2-Wnt/β-catenin signaling pathway in EC.

MicroRNA-9 exerts antitumor effects on hepatocellular carcinoma progression by targeting HMGA2

Accumulating evidence has demonstrated that the aberrant expression of microRNAs (miRs or miRNAs) may contribute to the initiation and progression of various types of human cancer and may also constitute biomarkers for cancer diagnosis and therapy. However, the specific function of miR‐9 in hepatocellular carcinoma (HCC) remains unclear, and the mechanisms that underlie HCC are incompletely understood. Here, we report that miR‐9 expression was significantly decreased in clinical tumor tissue samples, as well as in a cohort of HCC cell lines. In addition, it was demonstrated that overexpression of miR‐9 suppressed the proliferative and migratory capacity of HCC cells and impaired cell cycle progression. Furthermore, high mobility group AT‐hook 2 (HMGA2) was verified as a downstream target gene of miR‐9 using a luciferase reporter assay. Quantitative RT‐PCR and western blotting implicated HMGA2 in the miR‐9‐mediated reduction of HCC cell growth. In vivo, transfection with miR‐9 mimics down‐regulated the expression of HMGA2, thus leading to a dramatic reduction in tumor growth in a mouse xenograft model. These results suggest that miR‐9 may exert critical antitumor effects on HCC by directly targeting HMGA2, and the miR9/HMGA2 signaling pathway may be of use for the diagnosis and prognosis of patients with HCC.

A Comprehensive Review of Ovarian Serous Carcinoma

Although ovarian serous carcinoma is a well-studied human gynecologic malignancy, this high-grade tumor remains fatal. The main purpose of this review is to summarize the accumulated evidence on serous malignant tumors and to clarify the unresolved issues. We discuss the 8 dichotomies of serous carcinoma: high grade versus low grade, ovarian versus extraovarian primary, extrauterine versus uterine primary, sporadic versus hereditary, orthodox versus alternative histology, p53 overexpression versus complete absence of immunophenotype, TP53-mutated versus intact precursor, and therapy responsive versus refractory. In addition, we summarize the molecular classification of high-grade serous carcinoma. This review would lead readers to rapid and parallel developments in understanding high-grade serous carcinoma.

Oncological role of HMGA2 (Review)

The high mobility group A2 (HMGA2) protein is a non‑histone architectural transcription factor that modulates the transcription of several genes by binding to AT‑rich sequences in the minor groove of B‑form DNA and alters the chromatin structure. As a result, HMGA2 influences a variety of biological processes, including the cell cycle process, DNA damage repair process, apoptosis, senescence, epithelial‑mesenchymal transition and telomere restoration. In addition, the overexpression of HMGA2 is a feature of malignancy, and its elevated expression in human cancer predicts the efficacy of certain chemotherapeutic agents. Accumulating evidence has suggested that the detection of HMGA2 can be used as a routine procedure in clinical tumour analysis.

LncRNA ANRIL affects the sensitivity of ovarian cancer to cisplatin via regulation of let-7a/HMGA2 axis

This paper tried to explore ANRIL expression in ovarian cancer and how it affects cisplatin-sensitivity of ovarian cancer cells via regulation of let-7a/high-mobility group protein A2 (HMGA2) axis. qRT-PCR was used to detect ANRIL and let-7a levels in ovarian cancer tissues and cell lines (SKOV3 and SKOV3/DDP). Then cells were randomly assigned into Blank, negative control siRNA, ANRIL siRNA, let-7a inhibitor, and ANRIL siRNA+let-7a-inhibitor groups. CCK-8 assay was applied for assessing cell viability of cells treated with different concentrations of cisplatin. Flow cytometry was employed to test cell apoptosis rate. qRT-PCR and Western blot were performed for related molecules detection. Nude mice transplanted with SKOV3/DDP cells were used to confirm the effects of ANRIL siRNA on the cisplatin-sensitivity. Ovarian cancer tissues and cisplatin-resistant cells had increased ANRIL expression and decreased let-7a expression, and those patients with higher clinical stage and pathological grade showed higher ANRIL and lower let-7a. Dual-luciferase reporter-gene assay confirmed the targeting relationship between ANRIL and let-7a, and between let-7a and HMGA2. The cell viability and cisplatin IC50 were decreased in ANRIL siRNA group exposed to different concentrations of cisplatin, with enhanced apoptosis, as well as elevated let-7a and declined HMGA2, which would be reversed by let-7a inhibitor. Meanwhile, ANRIL down-regulation enhanced the inhibitory effect of cisplatin on tumor growth of nude mice and reduced tumor weight. Silencing ANRIL expression reduced HMGA2 expression to promote the apoptosis and improve cisplatin-sensitivity of ovarian cancer cells via up-regulating let-7a expression.

WITHDRAWN: Long non-coding RNA UCA1 regulates tumor growth by impairing let-7e-dependent HMGA2 repression in bladder cancer

Ahead of Print article withdrawn by publisher.

BTB and CNC homology 1 (Bach1) promotes human ovarian cancer cell metastasis by HMGA2-mediated epithelial-mesenchymal transition

Transcriptional factor BTB and CNC homology 1 (Bach1) has been linked to tumor progression and metastasis, but the mechanisms underlying the effects of Bach1 on tumor growth and metastasis are largely uncharacterized. Here, we report that Bach1 expression was significantly higher in human epithelial ovarian cancer (EOC) tissues than in normal ovarian tissues and that higher levels of Bach1 were associated with tumor stage and poorer overall and progression-free survival. We found that Bach1 enhanced the expression of epithelial-mesenchymal transition (EMT) genes, including Slug and Snail, and promoted cell migration by recruiting HMGA2 in the human EOC cell line A2780. Bach1 overexpression enhanced and Bach1 knockout reduced the expression of Slug and the metastasis of EOC cells in a tumor metastasis mouse model. Bach1 expression was positively correlated with Slug and HMGA2 expression in human ovarian cancer tissues. In addition, Bach1 activated p-AKT and p-p70S6K, increased the expression of cyclin D1, and promoted the growth of ovarian cancer cells in vitro and tumor xenografts in vivo. Together, our findings reveal that Bach1 enhances tumor growth and recruits HMGA2 to promote EMT and ovarian cancer metastasis.

Effects of HMGA2 gene downregulation by siRNA on lung carcinoma cell migration in A549 cell lines

BACKGROUND

Although there are multiple treatments for lung cancer, the death rate of this cancer remains high because of metastasis in earlier stages. So a novel treatment for overcoming metastasis is urgently needed. Overexpression of high-mobility group AT-hook 2 (HMGA2), a nonhistone chromosomal protein has been observed in metastatic cancers. So, we suggested that HMGA2 upregulation may play a critical role in treating lung cancer.

METHODS

The A549 cells were transfected with specific HMGA2 small interfering RNA (siRNA) using transfection reagent. Relative HMGA2 and matrix metallopeptidase 1 (MMP1), C-X-C chemokine receptor type 4 (CXCR4), vimentin, and E-cadherin messenger RNA expression levels were measured by quantitative real-time polymerase chain reaction. To diagnose cytotoxic effect of HMGA2 siRNA and other components of transfection process, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was applied. The migration capacity after transfection with HMGA2 siRNA was detected by wound-healing assay.

RESULTS

HMGA2 siRNA significantly reduced HMGA2 expression in a dose-dependent manner 48 hours after transfection. Expression levels of MMP1, vimentin, and CXCR4 were reduced, but E-cadherin level was not changed meaningfully. HMGA2 knockdown significantly reduced cell survival rate and also led to the inhibition of cell migration.

CONCLUSIONS

Our results indicated that RNA interference by downregulation of HMGA2 gene expression and affecting downstream genes led to the inhibition of cell migration and proliferation. Therefore, HMGA2 siRNA might be an alternative treatment option for metastatic lung cancer.

Prognostic Value of HMGA2 in Human Cancers: A Meta-Analysis Based on Literatures and TCGA Datasets

Background: Emerging evidences have shown that the high-mobility group protein A2 (HMGA2) can aberrantly express in human cancers, and it could be an unfavorable prognostic factor in cancer patients. However, the prognostic value of HMGA2 was still unclear. Therefore, in this study, we explored the potential prognostic value of HMGA2 in human cancers by using meta-analysis based on published literatures and The Cancer Genome Atlas (TCGA) datasets.

Methods: Through searching PubMed, Embase, Web of Science and Cochrane Library databases, we were able to identify the studies evaluating the prognostic value of HMGA2 in cancers. Then, UALCAN and TCGA datasets were used to validate the results of our meta-analysis.

Results: In all, 15 types of cancers were included in this meta-analysis. Pooled results showed that high level of HMGA2 was significantly correlated with poor OS (HR = 1.88, 95% confidence interval (CI) = 1.68-2.11, P < 0.001) and poor DFS (HR = 2.49, 95% CI = 1.44-4.28, P = 0.001) in cancer patients. However, subgroup analyses revealed that the high expressed HMGA2 was associated with poor OS in head and neck cancer, gastric cancer and colorectal cancer, but not esophageal cancer and ovarian cancer. Based on TCGA datasets, we analyzed 9944 patients with 33 types of cancers. Significant association between HMGA2 overexpression and poor OS was found in 14 types of cancers. Taken together, consistent results were observed in clear cell renal cell carcinoma, esophageal adenocarcinoma, head and neck cancer, hepatocellular carcinoma, ovarian carcinoma, and pancreatic ductal adenocarcinoma.

Conclusion: Our meta-analysis showed the significance of HMGA2 and its prognostic value in various cancers. High level of HMGA2 could be associated with poor OS in patients with clear cell renal cell carcinoma, head and neck cancer, hepatocellular carcinoma and pancreatic ductal adenocarcinoma, but not esophageal adenocarcinoma and ovarian carcinoma.

Origins based clinical and molecular complexities of epithelial ovarian cancer

Ovarian cancer is the most lethal of all common gynaecological malignancies in women worldwide. Ovarian cancer comprises of >15 distinct tumor types and subtypes characterized by histopathological features, environmental and genetic risk factors, precursor lesions and molecular events during oncogenesis. Recent studies on gene signature profiling of different subtypes of ovarian cancer have revealed significant genetic heterogeneity between and within each ovarian cancer histological subtype. Thus, an immense interest have shown towards a more personalized medicine for understanding the clinical and molecular complexities of four major types of epithelial ovarian cancer (serous, endometrioid, clear cell, and mucinous). As such, further in depth studies are needed for identification of molecular signalling network complexities associated with effective prognostication and targeted therapies to prevent or treat metastasis. Therefore, understanding the metastatic potential of primary ovarian cancer and therapeutic interventions against lethal ovarian cancer for the development of personalized therapies is very much indispensable. Consequently, in this review we have updated the key dysregulated genes of four major subtypes of epithelial carcinomas. We have also highlighted the recent advances and current challenges in unravelling the complexities of the origin of tumor as well as genetic heterogeneity of ovarian cancer.

HMGA2 promotes glioma invasion and poor prognosis via a long-range chromatin interaction

To identify the function and underlying mechanisms of HMGA2 on the prognosis and invasion of gliomas, HMGA2 was detected by immunohistochemistry. The Kaplan‐Meier and Cox's regression analysis results showed that higher HMGA2 level predicted the poorer outcomes of glioma patients. ChIP‐qPCR, DNA electrophoretic mobility shift assay, chromosome conformation capture, and co‐immunoprecipitation were applied to identify HMGA2‐activated target sites, which were further verified by mRNA and protein expression detection. Transwell and orthotopic implantation were used to investigate the roles of HMGA2 in glioma cells. HMGA2 shRNA transfection inhibited glioblastoma invasion. Mechanistically, we first discovered that HMGA2, together with GCN5, facilitated the invasion of glioma cells via inducing chromatin conformational remodeling of the MMP2 gene promoter and epigenetically activating MMP2 gene transcription. Our results indicated that HMGA2, as a novel GCN5 recognition partner and histone acetylation modulator, may be novel prognostic indicator and promising glioma treatment target.

Let-7c inhibits migration and epithelial-mesenchymal transition in head and neck squamous cell carcinoma by targeting IGF1R and HMGA2

To elucidate the molecular mechanisms underlying the progression of head and neck squamous cell carcinoma (HNSCC), we investigated the function of let-7c as a tumor suppressor. Let-7c expression was significantly down-regulated in HNSCC tumor tissues and cell lines. In vitro and in vivo studies revealed that let-7c negatively regulated HNSCC proliferation, migration and epithelial–mesenchymal transition (EMT). To explore the underlying mechanisms that affect these molecular events achieved by let-7c, we predicted its target genes. We performed luciferase assay and confirmed that insulin-like growth factor 1 receptor (IGF1R) and high mobility group AT-hook 2 (HMGA2) were the direct targets of let-7c. Knocking down of IGF1R and HMGA2 inhibited HNSCC progression, including proliferation, migration and EMT in HNSCC cells. Re-expression of these genes overcame let-7c–mediated inhibition. Taken together, our finding suggests that let-7c inhibits HNSCC progression by targeting IGF1R and HMGA2 and might be a novel target for HNSCC treatment.

Roles of microRNA let-7b in papillary thyroid carcinoma by regulating HMGA2

The incidence of thyroid cancer has increased significantly in the last decade, and the most frequent type of this cancer is papillary thyroid carcinoma. MicroRNAs have been demonstrated to be abnormally expressed in tumors and associated with the development of the tumors. Our aim was to analyze the role and molecular mechanisms of tumor suppressor let-7b in the papillary thyroid carcinoma. Expression of let-7b and high-mobility group A2 in papillary thyroid carcinoma tissues and cell lines was assessed using quantitative reverse transcription polymerase chain reaction and western blot analysis. To explore the role of let-7b or high-mobility group A2 in the BCPAP and TPC-1 cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell methods were used. Let-7b expression was significantly downregulated while expression of high-mobility group A2 was upregulated dramatically in papillary thyroid carcinoma tissues and cells compared with that in normal thyroid tissues and cells. In addition, overexpression of let-7b or knockdown of high-mobility group A2 inhibited cell migration and invasion compared with that of control. Besides, high-mobility group A2 was negatively regulated by let-7b in BCPAP cells. Moreover, high-mobility group A2 reintroduction reversed the anti-proliferation, anti-migration, and anti-invasion roles of let-7b. Let-7b might function as a tumor suppressor in papillary thyroid carcinoma by suppressing the expression of high-mobility group A2, and therefore might provide a promising therapeutic target for patients with papillary thyroid carcinoma.

Angiotensin II type 2 receptor-interacting protein 3a inhibits ovarian carcinoma metastasis via the extracellular HMGA2-mediated ERK/EMT pathway

Local migration and long-distance metastasis is the main reason for higher mortality of ovarian cancer. Microtubule-associated tumor suppressor 1/angiotensin II type 2 receptor-interacting protein is associated with tumor initiation and progression and exerts anti-tumor effects. High mobility group AT-hook 2 is overexpressed in majority of metastatic carcinomas, which contributes to carcinomas metastasis through Snail-induced epithelial-to-mesenchymal transition signal pathway. The purpose of this study was to investigate the signal pathway of microtubule-associated tumor suppressor 1/angiotensin II type 2 receptor-interacting protein-mediated anti-tumor effects. Our data observed that ovarian carcinoma cells exhibited lower expression of angiotensin II type 2 receptor-interacting protein 3a and higher expression of high mobility group AT-hook 2 compared to normal ovarian cells. Restoration of angiotensin II type 2 receptor-interacting protein 3a expression in ovarian carcinoma cells inhibited high mobility group AT-hook 2 expression and exhibited anti-proliferative effects. In addition, angiotensin II type 2 receptor-interacting protein 3a treatment suppressed the phosphorylation of epithelial-to-mesenchymal transition and extracellular signal-regulated kinase in ovarian carcinoma cells. We also observed that angiotensin II type 2 receptor-interacting protein 3a restoration downregulated expression of Snail, E-Cadherin, N-Cadherin, and Vimentin in ovarian carcinoma cells, whereas angiotensin II type 2 receptor-interacting protein 3a knockdown enhanced the phosphorylation of extracellular signal-regulated kinase and epithelial-to-mesenchymal transition. In vivo assay indicated that angiotensin II type 2 receptor-interacting protein 3a inhibited ovarian tumor growth and elevated survival of tumor-bearing immunodeficient mice. Tumor histological analysis indicated that Snail, E-Cadherin, N-Cadherin, and Vimentin expression levels were downregulated via decreasing high mobility group AT-hook 2 expression. Furthermore, upregulation of angiotensin II type 2 receptor-interacting protein 3a impaired the phenotype of extracellular signal-regulated kinase and epithelial-to-mesenchymal transition in ovarian carcinoma cells and tumor tissues. Taken together, angiotensin II type 2 receptor-interacting protein 3a presents potential in suppressing the proliferation and aggressiveness of ovarian carcinoma cells through the high mobility group AT-hook 2-mediated extracellular signal-regulated kinase/epithelial-to-mesenchymal transition signal pathway.

Clinicopathological and prognostic significance of HMGA2 overexpression in gastric cancer: a meta-analysis

Background

High mobility group protein A2 (HMGA2) overexpression has been reported to be closely related to tumor progression [1-4] and indicate significantly worse overall survival in gastric cancer [5-8]. However, a final consensus regarding this issue has not yet been reached. Thus, we conducted a meta-analysis to evaluate the association between HMGA2 expression and prognosis of gastric cancer patients.

Methods

The Cochrane Library, Embase, PubMed, Web of Science and China Biology Medicine databases were searched to identify eligible literature published prior to September 2016. In the included studies, the level of HMGA2 amplification was evaluated by immunohistochemistry. We performed a meta-analysis, and pooled relative risk (RRs), hazard ratio (HRs), and 95% confidence intervals (CIs) were analyzed using Review Manager 5.3.

Results

Six studies [5-7, 9-11] involving 712 gastric cancer patients were included and stratified by HMGA2 amplification magnitude. The results of the analysis indicated that higher HMGA2 levels were associated with several clinicopathological parameters and predicted poor prognosis in terms of overall survival (OS).

Conclusions

The results of the present study indicate that higher HMGA2 levels were significantly associated with TNM stage, lymph node status, vascular invasion, and poor OS in patients with gastric cancer. In conclusion, HMGA2 may serve as a promising prognostic biomarker in gastric cancer.

HMGA2 plays an important role in Cr (VI)-induced autophagy

Cr (VI) is mutagenic and carcinogenic, but the mechanism is unclear. In this study, the involvement of high mobility group A2 (HMGA2) in Cr (VI)-induced autophagy was investigated. Cr (VI) treatment induced formation of autophagosomes, increased expression of LC3II, Atg12-Atg5, Atg4, Atg10, HMGA1 and HMGA2 proteins, and decreased the expression of p62 in A549 cells. Silencing of HMGA2 gene by siRNA blocked Cr (VI)-induced formation of autophagosomes, expression of LC3II, Atg12-Atg5, Atg10 and reduction of p62. Overexpression of HMGA2 in HEK 293 and HeLa cells could induce the expression of LC3II, Atg12-Atg5 and Atg10, and decrease the expression of p62. Although the protein level of Atg12-Atg5 conjugation changed after Cr (VI) treatment, silencing of HMGA2 and overexpression of HMGA2, both the proteins and mRNA levels of Atg12 and Atg5 were not changed significantly. ChIP assay demonstrated that HMGA2 protein directly bound to the promoter sequence of Atg10 gene, which modulated the conjugation of Atg12-Atg5. Interestingly, 3-MA markedly prevented Cr (VI)-induced cell growth of A549 cells. Our further in vivo study confirmed that the expression of HMGA1, HMGA2, LC3II, Atg12-Atg5, Atg4, Atg5, Atg7, Atg10, Atg12, Beclin 1 were increased and p62 was reduced in lung tissues of Cr (VI)-treated BALB/c mice. Combining, our data demonstrated that HMGA2 plays an important role in Cr (VI)-induced autophagy and the mechanism underlies Atg12-Atg5 conjugation modulated by HMGA2-dependent transcriptional regulation of Atg10. This suggests that HMGA2 might be an important biomarker in Cr (VI)-induced autophagy, cell-growth or other toxicities.

Aberrant let7a/HMGA2 signaling activity with unique clinical phenotype in JAK2-mutated myeloproliferative neoplasms

High mobility group AT-hook 2 (HMGA2) is an architectural transcription factor that is negatively regulated by let-7 microRNA through binding to it’s 3′-untranslated region. Transgenic mice expressing Hmga2 with a truncation of its 3′-untranslated region has been shown to exhibit a myeloproliferative phenotype. To decipher the let-7-HMGA2 axis in myeloproliferative neoplasms, we employed an in vitro model supplemented with clinical correlation. Ba/F3 cells with inducible JAK2V617F expression (Ton.JAK2.V617F cells) showed upregulation of HMGA2 with concurrent let-7a repression. Ton.JAK2.V617F cells treated with a let-7a inhibitor exhibited further escalation of Hmga2 expression, while a let-7a mimic diminished the Hmga2 transcript level. Hmga2 overexpression conferred JAK2-mutated cells with a survival advantage through inhibited apoptosis. A pan-JAK inhibitor, INC424, increased the expression of let-7a, downregulated the level of Hmga2, and led to increased apoptosis in Ton.JAK2.V617F cells in a dose-dependent manner. In samples from 151 patients with myeloproliferative neoplasms, there was a modest inverse correlation between the expression levels of let-7a and HMGA2. Overexpression of HMGA2 was detected in 29 (19.2%) of the cases, and it was more commonly seen in patients with essential thrombocythemia than in those with polycythemia vera (26.9% vs. 12.7%, P=0.044). Patients with upregulated HMGA2 showed an increased propensity for developing major thrombotic events, and they were more likely to harbor one of the 3 driver myeloproliferative neoplasm mutations in JAK2, MPL and CALR. Our findings suggest that, in a subset of myeloproliferative neoplasm patients, the let-7-HMGA2 axis plays a prominent role in the pathogenesis of the disease that leads to unique clinical phenotypes.

MiR-4500 is epigenetically downregulated in colorectal cancer and functions as a novel tumor suppressor by regulating HMGA2

This study aimed to understand the exact function and potential mechanism of miR-4500 in colorectal cancer (CRC). In this study, the expression of miR-4500 was decreased in both CRC cells and tissues, and downregulated miR-4500 indicated advanced tumor stage and poor survival. By bisulfite sequencing analysis, we found that the CpG island in the promoter region of miR-4500 was hypermethylated in CRC cells and tissues compared with normal control cells and non-tumor tissues, respectively. Functionally, gain- and loss-of-function analyses indicated the tumor suppressor role of miR-4500: it suppressed cell proliferation, cell cycle progression, migration, and invasion. Predictive algorithms and experimental analyses identified HMGA2 as a direct target of miR-4500. Reintroducing HMGA2 impaired the inhibitory effects of miR-4500 on cell growth and motility. Clinically, higher HMGA2 protein expression in CRC tissues was associated with advanced tumor stage and poor survival. An inverse correlation was found between miR-4500 levels and HMGA2 protein expression. Taken together, this study provides the first evidence that miR-4500 functions as a novel tumor suppressor in the miR-4500/HMGA2 axis in colorectal carcinogenesis, and restoring miR-4500 expression might represent a promising therapeutic strategy for CRC.

Silencing of High Mobility Group Isoform I-C (HMGI-C) Enhances Paclitaxel Chemosensitivity in Breast Adenocarcinoma Cells (MDA-MB-468)

PURPOSE

HMGI-C (High Mobility Group protein Isoform I-C) protein is a member of the high-mobility group AT-hook (HMGA) family of small non-histone chromosomal protein that can modulate transcription of an ample number of genes. Genome-wide studies revealed up regulation of the HMGI-C gene in many human cancers. We suggested that HMGI-C might play a critical role in the progression and migration of various tumors. However, the exact role of HMGI-C in breast adenocarcinoma has not been cleared.

METHODS

The cells were transfected with siRNAs using transfection reagent. Relative HMGI-C mRNA and protein levels were measured by quantitative real-time PCR and Western blotting, respectively. The cytotoxic effects of HMGI-C siRNA, Paclitaxel alone and combination on breast adenocarcinoma cells were determined using MTT assay. The migration after treatment by HMGI-C siRNA, Paclitaxel alone and combination were detected by wound-healing respectively.

RESULTS

HMGI-C siRNA significantly reduced both mRNA and protein expression levels in a 48 hours after transfection and dose dependent manner. We observed that the knockdown of HMGI-C led to the significant reduced cell viability and inhibited cells migration in MDA-MB-468 cells in vitro.

CONCLUSION

These results propose that HMGI-C silencing and Paclitaxel treatment alone can inhibit the proliferation and migration significantly, furthermore, synergic effect of HMGI-C siRNA and Paclitaxel showed higher inhibition compared to mono treatment. Taken together, HMGI-C could be used as a promising therapeutic agent in the treatment of human breast adenocarcinoma. Therefore HMGI-C siRNA may be an effective adjuvant in human breast adenocarcinoma.

HMGI-C suppressing induces P53/caspase9 axis to regulate apoptosis in breast adenocarcinoma cells

PURPOSE

The HMGI-C (high mobility group protein isoform I-C) protein is a member of the high-mobility group AT-hook (HMGA) family of small non-histone chromosomal proteins that can modulate transcription of an ample number of genes. Genome-wide studies reveal upregulation of the HMGI-C gene in many human cancers, which suggests that HMGI-C might play a critical role in the progression of various tumors. However, the exact role of HMGI-C in breast adenocarcinoma has not been made clear.

METHODS

HMGI-C mRNA expression in breast cancer samples and marginal normal tissues was characterized using qRT-PCR. The cytotoxic effects of HMGI-C siRNA on breast adenocarcinoma cells were determined using MTT assay. Relative HMGI-C mRNA and protein levels were measured by quantitative real-time PCR and western blotting, respectively. Apoptosis detection was done using TUNEL and Annexin-V/PI assays, P53, caspase 3, 9, 8 and Bcl2 proteins evaluated by protein gel blot and miR34a, Let-7a genes investigates by QRT-PCR assay. Cell cycle was analyzed by flow cytometry assay using propidium iodide DNA staining.

RESULTS

An overexpression of HMGA2 was revealed with highly statistically significant differences between breast cancer samples and marginal normal tissues (P < 0.0001). HMGI-C siRNA significantly reduced both mRNA and protein expression levels in a 48-hour period after transfection and in a dose-dependent manner. We observed that the knockdown of HMGI-C led to the significant induction of apoptosis via mitochondrial pathway by inducing miR34a and cell cycle arrest in MDA-MB-468 cells in vitro.

CONCLUSIONS

These results propose that HMGI-C might play a critical role in the progression of breast adenocarcinoma. Here we introduced HMGI-C as a potential therapeutic target for trigger apoptosis and cell cycle arrest in human breast adenocarcinoma. Therefore HMGI-C siRNA may be an effective adjuvant in human breast adenocarcinoma.

Stromal dynamic reciprocity in cancer: intricacies of fibroblastic-ECM interactions

Stromal dynamic reciprocity (SDR) consists of the biophysical and biochemical interplay between connective tissue elements that regulate and maintain organ homeostasis. In epithelial cancers, chronic alterations of SDR result in the once tumor-restrictive stroma evolving into a 'new' tumor-permissive environment. This altered stroma, known as desmoplasia, is initiated and maintained by cancer associated fibroblasts (CAFs) that remodel the extracellular matrix (ECM). Desmoplasia fuels a vicious cycle of stromal dissemination enriching both CAFs and desmoplastic ECM. Targeting specific drivers of desmoplasia, such as CAFs, either enhances or halts tumor growth and progression. These conflicting effects suggest that stromal interactions are not fully understood. This review highlights known fibroblastic-ECM interactions in an effort to encourage therapies that will restore cancer-restrictive stromal cues.

The transcriptional modulator HMGA2 promotes stemness and tumorigenicity in glioblastoma

Glioblastoma (GBM) contains a population of stem-like cells that promote tumor invasion and resistance to therapy. Identifying and targeting stem cell factors in GBM may lead to the development of more effective therapies. High Mobility Group AT-hook 2 (HMGA2) is a transcriptional modulator that mediates motility and self-renewal in normal and cancer stem cells. We identified increased expression of HMGA2 in the majority of primary human GBM tumors and cell lines compared to normal brain. Additionally, HMGA2 expression was increased in CD133+ GBM neurosphere cells compared to CD133- cells. Targeting HMGA2 with lentiviral short hairpin RNA (shRNA) led to decreased GBM stemness, invasion, and tumorigenicity. Ectopic expression of HMGA2 in GBM cell lines promoted stemness, invasion, and tumorigenicity. Our data suggests that targeting HMGA2 in GBM may be therapeutically beneficial.

The oncogenic triangle of HMGA2, LIN28B and IGF2BP1 antagonizes tumor-suppressive actions of the let-7 family

The tumor-suppressive let-7 microRNA family targets various oncogene-encoding mRNAs. We identify the let-7 targets HMGA2, LIN28B and IGF2BP1 to form a let-7 antagonizing self-promoting oncogenic triangle. Surprisingly, 3′-end processing of IGF2BP1 mRNAs is unaltered in aggressive cancers and tumor-derived cells although IGF2BP1 synthesis was proposed to escape let-7 attack by APA-dependent (alternative polyadenylation) 3′ UTR shortening. However, the expression of the triangle factors is inversely correlated with let-7 levels and promoted by LIN28B impairing let-7 biogenesis. Moreover, IGF2BP1 enhances the expression of all triangle factors by recruiting the respective mRNAs in mRNPs lacking AGO proteins and let-7 miRNAs. This indicates that the downregulation of let-7, largely facilitated by LIN28B upregulation, and the protection of let-7 target mRNAs by IGF2BP1-directed shielding in mRNPs synergize in enhancing the expression of triangle factors. The oncogenic potential of this triangle was confirmed in ovarian cancer (OC)-derived ES-2 cells transduced with let-7 targeting decoys. In these, the depletion of HMGA2 only diminishes tumor cell growth under permissive conditions. The depletion of LIN28B and more prominently IGF2BP1 severely impairs tumor cell viability, self-renewal and 2D as well as 3D migration. In conclusion, this suggests the targeting of the HMGA2-LIN28B-IGF2BP1 triangle as a promising strategy in cancer treatment.

Heat shock protein 90 is involved in the regulation of HMGA2-driven growth and epithelial-to-mesenchymal transition of colorectal cancer cells

High Mobility Group AT-hook 2 (HMGA2) is a nonhistone chromatin-binding protein which acts as a transcriptional regulating factor involved in gene transcription. In particular, overexpression of HMGA2 has been demonstrated to associate with neoplastic transformation and tumor progression in Colorectal Cancer (CRC). Thus, HMGA2 is a potential therapeutic target in cancer therapy. Heat Shock Protein 90 (Hsp90) is a chaperone protein required for the stability and function for a number of proteins that promote the growth, mobility, and survival of cancer cells. Moreover, it has shown strong positive connections were observed between Hsp90 inhibitors and CRC, which indicated their potential for use in CRC treatment by using combination of data mining and experimental designs. However, little is known about the effect of Hsp90 inhibition on HMGA2 protein expression in CRC. In this study, we tested the hypothesis that Hsp90 may regulate HMGA2 expression and investigated the relationship between Hsp90 and HMGA2 signaling. The use of the second-generation Hsp90 inhibitor, NVP-AUY922, considerably knocked down HMGA2 expression, and the effects of Hsp90 and HMGA2 knockdown were similar. In addition, Hsp90 knockdown abrogates colocalization of Hsp90 and HMGA2 in CRC cells. Moreover, the suppression of HMGA2 protein expression in response to NVP-AUY922 treatment resulted in ubiquitination and subsequent proteasome-dependant degradation of HMGA2. Furthermore, RNAi-mediated silencing of HMGA2 reduced the survival of CRC cells and increased the sensitivity of these cells to chemotherapy. Finally, we found that the NVP-AUY922-dependent mitigation of HMGA2 signaling occurred also through indirect reactivation of the tumor suppressor microRNA (miRNA), let-7a, or the inhibition of ERK-regulated HMGA2 involved in regulating the growth of CRC cells. Collectively, our studies identify the crucial role for the Hsp90-HMGA2 interaction in maintaining CRC cell survival and migration. These findings have significant implications for inhibition HMGA2-dependent tumorigenesis by clinically available Hsp90 inhibitors.

Amplified HMGA2 promotes cell growth by regulating Akt pathway in AML

PURPOSE

The aim of this study was to investigate how the amplification of HMGA2 contributes to acute myeloid leukemia (AML) cell proliferation.

METHODS

The amplification and expression of HMGA2 were examined by FISH, qRT-PCR and Western blot in AML cases. The effect of HMGA2 knockdown on cell proliferation was analyzed with XTT, colony-forming assays and BrdUrd incorporation assays. The effects of HMGA2 knockdown on cell cycle were studied by flow cytometry analysis. The progression of AML cells in vivo was examined by the xenografted tumor model. The interaction between Akt pathway and HMGA2 was examined by Western blot.

RESULTS

HMGA2 is amplified in AML, and the levels of HMGA2 messenger RNA (mRNA) and protein expressed in AML cells were significantly higher than those in normal cells, which may be related to NR and prognosis of AML patients. Reduction in HMGA2 expression in AML cells inhibited cell proliferation through a decrease in the protein expression of pAkt and pmTOR, compared with control cells.

CONCLUSIONS

HMGA2 is predominantly amplified and expressed in AML cells, and that aberrant expression of HMGA2 induces AML cell proliferation through the PI3K/Akt/mTOR signaling pathway. Inhibition of HMGA2 expression represents an attractive target for AML therapy.