High mobility group a proteins as tumor markers

Role of microRNA-363 during tumor progression and invasion

Recent progresses in diagnostic and therapeutic methods have significantly improved prognosis in cancer patients. However, cancer is still considered as one of the main causes of human deaths in the world. Late diagnosis in advanced tumor stages can reduce the effectiveness of treatment methods and increase mortality rate of cancer patients. Therefore, investigating the molecular mechanisms of tumor progression can help to introduce the early diagnostic markers in these patients. MicroRNA (miRNAs) has an important role in regulation of pathophysiological cellular processes. Due to their high stability in body fluids, they are always used as the non-invasive markers in cancer patients. Since, miR-363 deregulation has been reported in a wide range of cancers, we discussed the role of miR-363 during tumor progression and metastasis. It has been reported that miR-363 has mainly a tumor suppressor function through the regulation of transcription factors, apoptosis, cell cycle, and structural proteins. MiR-363 also affected the tumor progression via regulation of various signaling pathways such as WNT, MAPK, TGF-β, NOTCH, and PI3K/AKT. Therefore, miR-363 can be introduced as a probable therapeutic target as well as a non-invasive diagnostic marker in cancer patients.

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.

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

BACKGROUND

About 70%-80% of breast cancers (BCs) express estrogen receptors (ER-positive). MicroRNAs (miRNAs) are a group of small endogenous noncoding RNAs that play a critical regulatory role in cancer development and progression, including in BC. MiRNA deficiency promotes the development of BCs. MiR-143-5p is one of the most commonly dysregulated miRNAs in BC but its role as a tumor suppressor remains unclear.

MATERIALS AND METHODS

MiR-143-3p and -5p expression in breast tissue was analyzed using TCGA and StarBase databases. Expression in BC subclasses and survival analyses were conducted. Clinical samples were collected, cell cultures created, and gene expression assays performed following previous studies. Protein expression, luciferase reporter, wound healing, DAPI staining, cell cycle, colony formation, spheroid, CD44 FACS, and proliferation assays were conducted following various protocols.

RESULTS

Here, we find that both miR-143-3p and miR-143-5p levels are considerably lower in BC tissue compared to normal breast tissue and low miR-143 expression predicts poor prognosis in ER+ BC patients. In-depth analyses identified 3 miR-143-5p binding sites in the 3' untranslated region (UTR) of the DNA binding protein High Mobility Group AT-Hook 2 (HMGA2). Luciferase reporter assays using wild-type and mutant HMGA2 3'UTR sequences and Western blot analyses demonstrated that HMGA2 is a direct and bona fide miR-143-5p target in BC cells. In addition, we show that restoration of miR-143-5p expression suppresses metastasis-related features of ER+ BC cells, including reduced tumor cell migration, increased E-cadherin expression, and decreased vimentin and N-cadherin expression. Furthermore, miR-143-5p reduces cell proliferation, cell cycle entry, and stemness, while promoting apoptosis moderately. Finally, patient sample pathway analyses demonstrated that these mechanisms are also active in BC.

CONCLUSIONS

Altogether, our findings shed new light on miR-143-5p's anticancer biological functions in BC progression by directly targeting HMGA2. This suggests that restoration of miR-143-5p could be a promising new therapeutic approach for the treatment of ER+ BC.

Inhibition of transcription and antiproliferative effects in a cancer cell line using antigene oligonucleotides containing artificial nucleoside analogues

Antigene methods are promising novel therapeutic approaches to suppress abnormal gene expression. One of these methods inhibits transcription by forming triplex DNA against duplex DNA. However, by using natural-type triplex-forming oligonucleotides (TFOs), stable triplex formation is limited to homopurine and homopyrimidine strands in targeted duplex DNA. We recently developed artificial nucleoside analogues with the ability to recognize CG and TA inversion sites. We successfully formed stable unnatural-type triplex DNA for duplex DNA containing a CG base pair and extended the target sequence using TFOs containing 2-amino-3-methylpyridinyl pseudo-dC (3MeAP-ΨdC). Therefore, this present study investigated triplex-forming regions and synthesized antigene TFOs containing 3MeAP-ΨdC. Some of the synthesized antigene TFOs reduced transcription products and inhibited cell proliferation in several types of cultured cancer cells. The antigene effects of antigene TFOs containing artificial nucleic acids were markedly stronger than those of natural-type TFOs, and these results clearly demonstrated the usefulness of incorporating artificial nucleic acids within TFOs.

Circular RNA-mediated ceRNA network was identified in human lung adenocarcinoma by high-throughput sequencing

OBJECTIVES

Aberrantly expressed circular RNAs (circRNAs) have been detected in many types of tumors. Hence, they are currently investigated as candidate biomarkers for diagnostic and potential targets for therapy in cancers. The objective of this study was to assess the expression profile of circRNA in lung adenocarcinoma (LUAD).

METHODS

This study included 14 pairs of postoperative lung adenocarcinoma specimens, including cancer tissues and matched adjacent tissues. Second-generation sequencing was applied to the specimens to determine the circRNA expression in them among the 5242 distinct circRNAs detected.

RESULTS

We identified a total of 18 significantly dysregulated circRNAs in the LUAD tissues: upregulation in four and downregulation in 14. ROC (The receiver operating characteristic curve) further suggested that hsa_circ_0120106, has_circ_0007342, has_circ_0005937, and circRNA_0000826 could potentially be used as biomarkers in the diagnosis of LUAD. Furthermore, study of the circRNA-microRNA (miRNA)-messenger RNA (mRNA) revealed interactions between the 18 dysregulated circRNA and several cancer-related miRNAs. Finally, a further Kyoto Encyclopedia of Genes and Genomes analysis showed that the cell cycle phase transition, p53 signaling pathway, AMP-activated protein kinase (AMPK) relative signaling pathway, and so on were key putative pathways in the process of LUAD.

CONCLUSIONS

These findings demonstrated the correlation between abnormality in circRNA expression and LUAD, which lays the foundation of making CircRNAs candidate biomarkers in the diagnosis of LUAD.

HMGA1 gene expression level in cancer tissue and blood samples of non-small cell lung cancer (NSCLC) patients: preliminary report

The study aimed to assess the HMGA1 gene expression level in NSCLC patients and to evaluate its association with selected clinicopathological features and overall survival of patients. The expression of the HMGA1, coding non-histone transcription regulator HMGA1, was previously proved to correlate with the ability of cancer cells to metastasize the advancement of the disease. The prognostic value of the HMGA1 expression level was demonstrated in some neoplasms, e.g., pancreatic, gastric, endometrial, hepatocellular cancer, but the knowledge about its role in non-small cell lung cancer (NSCLC) is still limited. Thus, the HMGA1 expression level was evaluated by real-time PCR method in postoperative tumor tissue and blood samples collected at the time of diagnosis, 100 days and 1 year after surgery from 47 NSCLC patients. Mean HMGA1 expression level in blood decreased systematically from the time of cancer diagnosis to 1 year after surgery. The blood HMGA1 expression level 1 year after surgery was associated with the tobacco smoking status of patients (p= 0.0230). Patients with high blood HMGA1 expression levels measured 100 days after surgery tend to have worse overall survival than those with low expression levels (p= 0.1197). Tumor HMGA1 expression level was associated with neither features nor the overall survival of NSCLC patients. Moreover, no correlation between HMGA1 expression level measured in tumor tissue and blood samples was stated. Blood HMGA1 mRNA level could be a promising factor in the prognostication of non-small cell lung cancer patients.

Small Extracellular Vesicles and Their Involvement in Cancer Resistance: An Up-to-Date Review

In recent years, tremendous progress has been made in understanding the roles of extracellular vesicles (EVs) in cancer. Thanks to advancements in molecular biology, it has been found that the fraction of EVs called exosomes or small EVs (sEVs) modulates the sensitivity of cancer cells to chemotherapeutic agents by delivering molecularly active non-coding RNAs (ncRNAs). An in-depth analysis shows that two main molecular mechanisms are involved in exosomal modified chemoresistance: (1) translational repression of anti-oncogenes by exosomal microRNAs (miRs) and (2) lack of translational repression of oncogenes by sponging of miRs through long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). At the cellular level, these processes increase the proliferation and survival of cancer cells and improve their ability to metastasize and resist apoptosis. In addition, studies in animal models have shown enhancing tumor size under the influence of exosomal ncRNAs. Ultimately, exosomal ncRNAs are responsible for clinically significant chemotherapy failures in patients with different types of cancer. Preliminary data have also revealed that exosomal ncRNAs can overcome chemotherapeutic agent resistance, but the results are thoroughly fragmented. This review presents how exosomes modulate the response of cancer cells to chemotherapeutic agents. Understanding how exosomes interfere with chemoresistance may become a milestone in developing new therapeutic options, but more data are still required.

Review: New horizons in retinoblastoma treatment: an updated review article

Retinoblastoma (Rb) is a rare childhood intraocular malignancy with an incidence rate of approximately 9000 children per year worldwide. The management of Rb is inherently complex and depends on several factors. The orders of priorities in the treatment of Rb are saving life, globe salvage and vision salvage. Rarity and the young age at diagnosis impede conducting randomized clinical trials (RCTs) for new therapeutic options, and therefore pre-RCTs studies are needed. This review provides an overview of advances in Rb treatment options, focusing on the emergence of new small molecules to treat Rb. Articles related to the management and treatments of Rb were searched in different databases. Several studies and animal models discussing recent advances in the treatment of Rb were included to have a better grasp of the biological mechanisms of Rb. Over the years, the principles of management and treatment of Rb have changed significantly. Innovations in targeted therapies and molecular biology have led to improved patient and ocular survival. However, there is still a need for further evaluation of the long-term effects of these new treatments.

Prognostic Significance of HMGA1 Expression in Lung Cancer Based on Bioinformatics Analysis

High-mobility group protein 1 (HMGA1) participates in the processes of DNA transcription, replication, recombination, and repair. The HMGA1 gene is expressed abundantly during embryogenesis and is reactivated during carcinogenesis. HMGA1 gene expression has been associated with a high degree of malignancy, metastatic tendency, and poor survival in breast, colon, ovary, and pancreatic cancers. However, its prognostic significance in lung cancer remains unclear. Using publicly available data, HMGA1 was shown to be overexpressed in both small and non-small lung tumors, with higher expression compared to both the adjacent non-malignant lung tissues and non-tumor lung tissues of healthy individuals. Elevated HMGA1 expression could result from lowered HMGA1 methylation and was connected with some clinicopathological features like sex, age, and stage of the disease. The high HMGA1 expression level was connected with shorter overall and first progression survival time among lung adenocarcinoma patients, but not lung squamous cell carcinoma patients. HMGA1 could interact with proteins involved in cellular senescence and cell cycle control (TP53, RB1, RPS6KB1, and CDK1), transcription regulation (EP400 and HMGA2), chromatin assembly and remodeling (LMNB1), and cholesterol and isoprene biosynthesis (HMGCR and INSIG1). Taken together, HMGA1 overexpression could be an essential element of lung carcinogenesis and a prognostic feature in lung cancer.

Effects of HMGA2 on the epithelial-mesenchymal transition-related genes in ACHN renal cell carcinoma cells-derived xenografts in nude mice

Background

The architectural transcriptional regulator high-mobility group AT-hook 2 (HMGA2) is an oncofetal protein which has been reported to be ectopically expressed in a variety of cancers. A high expression of HMGA2 in human renal cell carcinoma (RCC) is related with tumor invasiveness and poor prognosis. Recent in vitro studies have shown that HMGA2 knockdown was able to decrease cell proliferation and migration, and regulate the gene expression related to epithelial-mesenchymal transition (EMT).

Methods

To understand the HMGA2’s effect in vivo, HMGA2 expression was knocked down in ACHN cells using small hairpin RNA (shRNA), then the HMGA2-deficient ACHN cells were xenografted into the BALB/c nude mice. Tumor growth was monitored and the expression of EMT-related genes was analyzed.

Results

HMGA2 expression was confirmed to be knocked down in the cultured and xenografted ACHN cells. The xenograft tumor of HMGA2-deficient cells demonstrated a retarded growth pattern compared with the control. The expression of E-cadherin was increased, whereas N-cadherin and Snail were decreased in the HMGA2-deficient xenograft tumors.

Conclusions

In conclusion, to the best of our knowledge, for the first time, we have successfully developed an in vivo experiment using HMGA2-silencing ACHN cells to be grown as xenografts in nude mice. Our findings show that HMGA2 deficiency was sufficient to suppress the xenograft tumor growth in vivo, which support our hypothesis that HMGA2-induced renal carcinogenesis occurs at least in part through the regulation of tumor associated EMT genes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09537-w.

High-Mobility Group AT-Hook 1 Served as a Prognosis Biomarker and Associated with Immune Infiltrate in Hepatocellular Carcinoma

BACKGROUND

The protein high-mobility group AT-hook 1 (HMGA1) has been demonstrated that modulated cellular proliferation, invasion, and apoptosis with a poor prognosis in miscellaneous carcinomas. However, the mechanism of circumstantial carcinogenesis and association with the immune microenvironment of HMGA1 in hepatocellular carcinoma (HCC) had not been extensively explored.

METHODS

The gene expression, clinicopathological correlation, and prognosis analysis were performed in the data obtained from TCGA. The results were further validated by ICGC and GEO database and external validation cohort from Guangxi. The HMGA1 protein expression was further examined in the HPA database. Biological function analyses were conducted by GSEA, STRING database, and Coexpedia online tool. Using TIMER and CIBERSORT method, the relationship between immune infiltrate and HMGA1 was investigated.

RESULTS

In HCC, HMGA1 had much higher transcriptional and proteomic expression than in corresponding paraneoplastic tissue. Patients with high HMGA1 expression had a poor prognosis and unpromising clinicopathological features. High HMGA1 expression was closely related to the cell cycle, tumorigenesis, substance metabolism, and immune processes by regulating complex signaling pathways. Notably, HMGA1 may be associated with TP53 mutational carcinogenesis. Moreover, increased HMGA1 expression may lead to an increase in immune infiltration and a decrease in tumor purity in HCC. CIBERSORT analysis elucidated that the amount of B cell naive, B cell memory, T cells gamma delta, macrophages M2, and mast cell resting decreased when HMGA1 expression was high, whereas T cells follicular helper, macrophages M0, and Dendritic cells resting increased.

CONCLUSION

In conclusions, HMGA1 is a potent prognostic biomarker and a sign of immune infiltration in HCC, which may be a potential immunotherapy target for HCC.

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.

A mechanistic basis for the malignant progression of salivary gland tumors

Salivary gland tumors are diverse neoplasms, likely reflecting differences in the tissue- and cell-of-origin. 80%-90% of tumors arising in the sublingual gland (SLG) are malignant, whereas the other major glands often form benign tumors. Owing to the lack of experimental models to explore the etiology of salivary gland tumors, the cellular and molecular bases of malignancy remain unknown. Here, we generated a murine model of HRASG12V-driven salivary gland tumors amenable to examine tumor onset and malignant progression. We found that HMGA2 marks the tumor onset, and transformed-SOX2+ stem/progenitor cells expand exclusively in SLG tumors. Lineage tracing experiments showed that SLG tumor cells undergo an extensive epithelial-mesenchymal transition (EMT) and TGF-β-responding tumor cells are a source of mesenchymal tumor cells invading the surrounding stroma. This study advances our understanding of the mechanistic basis of salivary gland malignancy and may help combat this highly heterogeneous cancer.

Critical role of the high mobility group A proteins in hematological malignancies

The high mobility group A (HMGA) protein family is composed of three non‐histone chromatin remodeling proteins that act as architectural transcriptional factors. Indeed, although HMGA proteins lack transcriptional activity per se, they bind the minor groove of DNA at AT‐rich sequences, and, interacting with the transcription machinery, are able to modify chromatin modeling, thus regulating the expression of several genes. HMGA proteins have been deeply involved in embryogenesis process, and a large volume of studies has pointed out their key role in human cancer. Here, we review the studies on the role of the HMGA proteins in human hematological malignancies: they are overexpressed in most of the cases and their expression correlates with a reduced survival. In some cases, such as in acute lymphoblastic leukemia and acute myelogenous leukemia, HMGA2 gene rearrangements have been also described. Finally, recent studies evidence a synergism between HMGA and EZH2 in diffuse B‐cell lymphomas, suggesting an innovative therapy for this disease based on the inhibition of the function of both these proteins.

Mesenchymal stromal cells expressing a dominant-negative high mobility group A1 transgene exhibit improved function during sepsis

High mobility group (HMG)A proteins are nonhistone chromatin proteins that bind to the minor groove of DNA, interact with transcriptional machinery, and facilitate DNA-directed nuclear processes. HMGA1 has been shown to regulate genes involved with systemic inflammatory processes. We hypothesized that HMGA1 is important in the function of mesenchymal stromal cells (MSCs), which are known to modulate inflammatory responses due to sepsis. To study this process, we harvested MSCs from transgenic (Tg) mice expressing a dominant-negative (dn) form of HMGA1 in mesenchymal cells. MSCs harvested from Tg mice contained the dnHMGA1 transgene, and transgene expression did not change endogenous HMGA1 levels. Immunophenotyping of the cells, along with trilineage differentiation revealed no striking differences between Tg and wild-type (WT) MSCs. However, Tg MSCs growth was decreased compared with WT MSCs, although Tg MSCs were more resistant to oxidative stress-induced death and expressed less IL-6. Tg MSCs administered after the onset of Escherichia coli-induced sepsis maintained their ability to improve survival when given in a single dose, in contrast with WT MSCs. This survival benefit of Tg MSCs was associated with less tissue cell death, and also a reduction in tissue neutrophil infiltration and expression of neutrophil chemokines. Finally, Tg MSCs promoted bacterial clearance and enhanced neutrophil phagocytosis, in part through their increased expression of stromal cell-derived factor-1 compared with WT MSCs. Taken together, these data demonstrate that expression of dnHMGA1 in MSCs provides a functional advantage of the cells when administered during bacterial sepsis.

Essential Role of the 14q32 Encoded miRNAs in Endocrine Tumors

BACKGROUND

The 14q32 cluster is among the largest polycistronic miRNA clusters. miRNAs encoded here have been implicated in tumorigenesis of multiple organs including endocrine glands.

METHODS

Critical review of miRNA studies performed in endocrine tumors have been performed. The potential relevance of 14q32 miRNAs through investigating their targets, and integrating the knowledge provided by literature data and bioinformatics predictions have been indicated.

RESULTS

Pituitary adenoma, papillary thyroid cancer and a particular subset of pheochromocytoma and adrenocortical cancer are characterized by the downregulation of miRNAs encoded by the 14q32 cluster. Pancreas neuroendocrine tumors, most of the adrenocortical cancer and medullary thyroid cancer are particularly distinct, as 14q32 miRNAs were overexpressed. In pheochromocytoma and growth-hormone producing pituitary adenoma, however, both increased and decreased expression of 14q32 miRNAs cluster members were observed. In the background of this phenomenon methodological, technical and biological factors are hypothesized and discussed. The functions of 14q32 miRNAs were also revealed by bioinformatics and literature data mining.

CONCLUSIONS

14q32 miRNAs have a significant role in the tumorigenesis of endocrine organs. Regarding their stable expression in the circulation of healthy individuals, further investigation of 14q32 miRNAs could provide a potential for use as biomarkers (diagnostic or prognostic) in endocrine neoplasms.

Expression of PLAG1, HMGA1 and HMGA2 in minor salivary glands tumours

Background

Diagnosis of minor salivary gland (MSG) tumours is often difficult, due to the scarce tissue obtained from bioptic excision and complex histopathological differential diagnosis. In our study we performed an immunohistochemical analysis of PLAG1, HMGA1 and HMGA2 on a series of MSG tumours, in order to develop a new helpful diagnostic panel.

Methods

A retrospective series of 17 surgical specimens of MSG tumours were analysed for the expression of PLAG1, HMGA1 and HMGA2. Three control cases were enrolled and analysed. An intensity and percentage-based approach was performed, creating a combined score panel.

Results

PLAG1 facilitate the diagnosis of benign tumours, discriminating it from malignant histotypes, with a defined cut-off value. Similarly, HMGA1 is significantly higher in benign histotypes than in malignant ones. HMGA2 in our series, did not reveal any association in identifying benign from malignant histotypes.

Conclusions

In this study we assessed the diagnostic role of PLAG1, HMGA1 and HMGA2 immunohistochemical analysis. The score panel facilitate histopathological diagnosis of these rare tumours, helping to distinguish benign tumours from malignant ones and ameliorating the differential diagnosis of specific histotypes.

HMGA1B/2 transcriptionally activated-POU1F1 facilitates gastric carcinoma metastasis via CXCL12/CXCR4 axis-mediated macrophage polarization

Tumor-associated macrophages (TAMs) in the tumor microenvironment contribute to poor prognosis in gastric cancer (GC). However, the underlying mechanism by which TAMs promote GC progression and metastasis remains elusive. Expression of POU1F1 was detected in 60 matched GC-normal tissue pairs using qRT-PCR and immunohistochemistry (IHC) analysis. The correlation between POU1F1 and the clinical-pathological factors of GC patients were further assessed. Cell proliferation was monitored by CCK-8, colony formation, and 5-Ethynyl-2'-deoxyuridine (EdU) incorporation assays. Cell migration and invasion were assessed by transwell assays. The impact on angiogenesis was evaluated by tube formation assay. Xenograft model was generated to investigate the role of POU1F1 on tumor growth and lung metastasis in vivo. GST pull-down and Co-immunoprecipitation (Co-IP) were used to study the interaction between HMGA1B/2 and POU1F1. Chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays were performed to investigate the transcriptional regulation of POU1F1. Flow cytometry was performed to detect the surface expression of macrophage markers. Upregulated POU1F1 observed both in GC tissues and cell lines was positively correlated with poor prognosis. Knockdown of POU1F1 inhibited cell proliferation, migration, invasion, and angiogenesis in vitro, and suppressed tumor growth in vivo. HMGA1B/2 transcriptionally activated-POU1F1. POU1F1 promoted GC progression via regulating macrophage proliferation, migration, polarization, and angiogenesis in a CXCL12/CXCR4-dependent manner. POU1F1 also promoted GC metastasis in lung by modulating macrophage polarization through CXCL12/CXCR4 axis in vivo. HMGA1B/2-upregulated POU1F1 promoted GC metastasis via regulating macrophage polarization in a CXCL12/CXCR4-dependent manner.

circUBAP2 regulates osteosarcoma progression via the miR‑204‑3p/HMGA2 axis

Circular RNA (circRNA/circ)-ubiquitin associated protein 2 (UBAP2), a newly recognized circRNA, serves a functional role in several types of tumor, including ovarian cancer, colorectal cancer and osteosarcoma. However, the precise roles and molecular mechanism under-lying circUBAP2 in osteosarcoma (OS) are not completely understood. In the present study, the expression levels of circUBAP2, microRNA (miR)-204-3p and (HMGA2) were evaluated via reverse transcription-quantitative PCR in OS tissues and cells. OS cell proliferation, migration, invasion and apoptosis were assessed by performing Cell Counting Kit-8, Transwell and flow cytometry assays, respectively. HMGA2 protein expression levels were determined via western blot-ting. Dual-luciferase reporter assays were performed to verify the interaction between circUBAP2 and miR-204-3p, and between miR-204-3p and HMGA2. An RNA immunoprecipitation (RIP) assay was conducted to confirm the interaction between circUBAP2 and miR-204-3p. The results demonstrated that circUBAP2 expression was significantly upregulated in OS tissues and cell lines compared with para-cancerous tissues and hFOB1.19 cells, respectively. In addition, high circUBAP2 expression levels in patients with OS were associated with a lower survival rate compared with lower expression levels in patients with OS. The functional assays revealed that circUBAP2 knockdown significantly inhibited OS cell proliferation, migration and invasion, but increased OS cell apoptosis compared with the small interfering RNA-negative control (si-NC) group. The dual-luciferase reporter and RIP assay results confirmed that circUBAP2 bound to miR-204-3p. Moreover, miR-204-3p expression was significantly downregulated in OS tissues compared with paracancerous tissues, and miR-204-3p expression was negatively correlated with circUBAP2 expression in OS tissues. Collectively, the results demonstrated that miR-204-3p was associated with circUBAP2 knockdown-mediated inhibition of OS cell malignant behavior. Moreover, miR-204-3p was also identified as one of the direct targets of HMGA2. Collectively, the results indicated that compared with the si-NC group, circUBAP2 knockdown significantly inhibited OS cell malignant behavior by binding to miR-204-3p, which subsequently regulated HMGA2 expression. Therefore, the present study demonstrated that circUBAP2 expression was upregulated in OS, and circUBAP2 regulated OS cell malignant behavior via the miR-204-3p/HMGA2 axis.

Deregulation of a Cis-Acting lncRNA in Non-small Cell Lung Cancer May Control HMGA1 Expression

Background

Long non-coding RNAs (lncRNAs) have long been implicated in cancer-associated phenotypes. Recently, a class of lncRNAs, known as cis-acting, have been shown to regulate the expression of neighboring protein-coding genes and may represent undiscovered therapeutic action points. The chromatin architecture modification gene HMGA1 has recently been described to be aberrantly expressed in lung adenocarcinoma (LUAD). However, the mechanisms mediating the expression of HMGA1 in LUAD remain unknown. Here we investigate the deregulation of a putative cis-acting lncRNA in LUAD, and its effect on the oncogene HMGA1.

Methods

LncRNA expression was determined from RNA-sequencing data of tumor and matched non-malignant tissues from 36 LUAD patients. Transcripts with significantly deregulated expression were identified and validated in a secondary LUAD RNA-seq dataset (TCGA). SiRNA-mediated knockdown of a candidate cis-acting lncRNA was performed in BEAS-2B cells. Quantitative real-time PCR was used to observe the effects of lncRNA knockdown on the expression of HMGA1.

Results

We identified the lncRNA RP11.513I15.6, which we refer to as HMGA1-lnc, neighboring HMGA1 to be significantly downregulated in both LUAD cohorts. Conversely, we found HMGA1 significantly overexpressed in LUAD and anticorrelated with HMGA1-lnc. In vitro experiments demonstrated siRNA-mediated inhibition of HMGA1-lnc in immortalized non-malignant lung epithelial cells resulted in a significant increase in HMGA1 gene expression.

Conclusion

Our results suggest that HMGA1-lnc is a novel cis-acting lncRNA that negatively regulates HMGA1 gene expression in lung cells. Further characterization of this regulatory mechanism may advance our understanding of the maintenance of lung cancer phenotypes and uncover a novel therapeutic intervention point for tumors driven by HMGA1.

MiR-590 Suppresses Proliferation and Induces Apoptosis in Pancreatic Cancer by Targeting High Mobility Group A2

BACKGROUND

Pancreatic ductal adenocarcinoma is a common malignancy with high morbidity. MicroRNAs have been demonstrated to be critical posttranscriptional regulators in tumorigenesis. This study aimed to investigate the effect of microRNA-590 on the proliferation and apoptosis of pancreatic ductal adenocarcinoma.

MATERIAL AND METHODS

The expression of microRNA-590 and high mobility group AT-hook 2 were examined in clinical pancreatic ductal adenocarcinoma tissues. Pancreatic ductal adenocarcinoma cell line Capan-2 was employed and transfected with microRNA-590 mimics or inhibitor. The correlation between microRNA-590 and high mobility group AT-hook 2 was verified by luciferase reporter assay. Cell viability and apoptosis were detected by MTT and flow cytometry assay. The protein level of high mobility group AT-hook 2, AKT, p-AKT, mTOR, and phosphorylated mTOR were analyzed by Western blotting.

RESULTS

MicroRNA-590 was found to be negatively correlated with the expression of high mobility group AT-hook 2 in pancreatic ductal adenocarcinoma tissues. Further studies identified high mobility group AT-hook 2 as a direct target of microRNA-590. Moreover, overexpression of microRNA-590 downregulated expression of high mobility group AT-hook 2, reduced cell viability, and promoted cell apoptosis, while knockdown of miR-590 led to an inverse result. MicroRNA-590 also suppressed the phosphorylation of AKT and mTOR without altering total AKT and mTOR levels.

CONCLUSION

Our study indicated that microRNA-590 negatively regulates the expression of high mobility group AT-hook 2 in clinical specimens and in vitro. MicroRNA-590 can inhibit cell proliferation and induce cell apoptosis in pancreatic ductal adenocarcinoma cells. This regulatory effect of microRNA-590 may be associated with AKT signaling pathway. Therefore, microRNA-590 has the potential to be used as a biomarker for predicting the progression of pancreatic ductal adenocarcinoma.

HMGA2 promotes breast cancer metastasis by modulating Hippo-YAP signaling pathway

BACKGROUND

Breast cancer is the most common cancer in women, and triple-negative breast cancer (TNBC) accounts for about 15-20% of all breast cancer. High mobility group AT-hook 2 (HMGA2) is overexpressed in some tumors and closely associated with patients' prognosis. However, the mechanisms involved in the regulation of HMGA2 in TNBC still remain unclear.

METHODS

In this study, HMGA2 level in TNBC cell lines was analyzed by western blot. After knockdown of HMGA2 expression by RNA interference in TNBC cell lines MDA-MB-231 and SUM149, wound healing and transwell assays were conducted to examine the effects of HMGA2 on migration and invasion. Tumor metastasis was assessed in amouse xenograft model invivo. Furthermore, expression levels of epithelial-mesenchymal transition (EMT) biomarkers and involvement of the Hippo-YAP pathway were detected by western blot.

RESULTS

Compared to normal breast epithelial cells, the expression levels of HMGA2 were significantly increased in TNBC cell lines (all P< .05). Downregulation of HMGA2 dramatically inhibited the migration and invasion of MDA-MB-231 and SUM149 cells (all P< .01) invitro, and suppressed the tumor metastasis of nude mice xenograft model invivo. Western blot analysis revealed alterations in EMT biomarkers: the expression of mesenchymal markers N-cadherin, Vimentin and Snail were decreased, while the expression of epithelial marker E-cadherin was increased. Downregulated expression of HMGA2 attenuated Hippo-YAP related protein expression and the stability of YAP.

CONCLUSIONS

HMGA2 is highly expressed in TNBC cells. Downregulation of HMGA2 inhibits the migration and invasion of TNBC and invivo tumor metastasis mediated through inhibition of EMT and Hippo-YAP pathway.

High HMGA2 expression without gene rearrangement in meningiomas

High mobility group AT-hook 2 (HMGA2) is a non-histone transcriptional regulator protein. Aberrant expression of the HMGA2 gene (HMGA2) and structural rearrangement at the chromosomal region 12q14 with HMGA2 involvement have been reported in several mesenchymal tumors. We analyzed truncated and full-length HMGA2 expression in 55 cases of meningioma, the most common brain tumor of mesenchymal origin. Fluorescence in situ hybridization and 3'-rapid amplification of cDNA ends were used to investigate the possibility of gene rearrangements. Moreover, the relationship between HMGA2 expression and clinicopathological features was assessed. Compared with normal brain tissues, 95% of the meningioma tissues exhibited increased HMGA2 expression. In 14 cases, the expression of truncated HMGA2 was more than two-fold higher than that of paired full-length HMGA2. Chromosomal translocation involving the chromosomal region 12q14 was undetectable. No significant correlation was found between the Ki-67 labeling index and HMGA2 expression and between the HMGA2 expression and the clinicopathological features. The majority of the meningioma cases displayed increased HMGA2 expression, which was not attributed to the chromosomal rearrangement at the corresponding region. Similar to that in the other mesenchymal tumors, increased HMGA2 expression was not associated with tumor cell proliferation in meningiomas.

HMGA Proteins in Hematological Malignancies

The high mobility group AT-Hook (HMGA) proteins are a family of nonhistone chromatin remodeling proteins known as "architectural transcriptional factors". By binding the minor groove of AT-rich DNA sequences, they interact with the transcription apparatus, altering the chromatin modeling and regulating gene expression by either enhancing or suppressing the binding of the more usual transcriptional activators and repressors, although they do not themselves have any transcriptional activity. Their involvement in both benign and malignant neoplasias is well-known and supported by a large volume of studies. In this review, we focus on the role of the HMGA proteins in hematological malignancies, exploring the mechanisms through which they enhance neoplastic transformation and how this knowledge could be exploited to devise tailored therapeutic strategies.

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.

HMGA1-Regulating microRNAs Let-7a and miR-26a are Downregulated in Human Seminomas

Background: Recent studies have underlined HMGA protein’s key role in the onset of testicular germ cell tumors, where HMGA1 is differently expressed with respect to the state of differentiation, suggesting its fine regulation as master regulator in testicular tumorigenesis. Several studies have highlighted that the HMGA1 transcript is strictly regulated by a set of inhibitory microRNAs. Thus, the aim of this study is to test whether HMGA1 overexpression in human seminomas may be induced by the deregulation of miR-26a and Let-7a—two HMGA1-targeting microRNAs. Methods: HMGA1 mRNA and Let-7a and miR-26a levels were measured in a seminoma dataset available in the Cancer Genome Atlas database and confirmed in a subset of seminomas by qRT-PCR and western blot. A TCam-2 seminoma cell line was then transfected with Let-7a and miR-26a and tested for proliferation and motility abilities. Results: an inverse correlation was found between the expression of miR-26a and Let-7a and HMGA1 expression levels in seminomas samples, suggesting a critical role of these microRNAs in HMGA1 levels regulation. Accordingly, functional studies showed that miR-26a and Let-7a inhibited the proliferation, migration and invasion capabilities of the human seminoma derived cell line TCam-2. Conclusions: these data strongly support that the upregulation of HMGA1 levels occurring in seminoma is—at least in part—due to the downregulation of HMGA1-targeting microRNAs.

HMGA2 Antisense Long Non-coding RNAs as New Players in the Regulation of HMGA2 Expression and Pancreatic Cancer Promotion

Background: Natural antisense long non-coding RNAs (lncRNAs) are regulatory RNAs transcribed from the opposite strand of either protein coding or non-coding genes, able to modulate their own sense gene expression. Hence, their dysregulation can lead to pathologic processes. Cancer is a complex class of diseases determined by the aberrant expression of a variety of factors, among them, the oncofetal chromatin architectural proteins High Mobility Group A (HMGA) modulate several cancer hallmarks. Thus, we decided to investigate the presence of natural antisense lncRNAs in HMGA1 and HMGA2 loci, and their possible involvement in gene expression regulation.

Methods: We used FANTOM5 data resources, FANTOM-CAT genome browser and Zenbu visualization tool, which employ 1,829 human CAGE and RNA-sequencing libraries, to determine expression, ontology enrichment, and dynamic regulation of natural antisense lncRNAs in HMGA1 and HMGA2 loci. We then performed qRT-PCR in different cancer cell lines to validate the existence of HMGA2-AS1 transcripts. We depleted HMGA2-AS1 transcripts with siRNAs and investigated HMGA2 expression by qRT-PCR and western blot analyses. Moreover, we evaluated cell viability and migration by MTS and transwell assays, and EMT markers by qRT-PCR and immunofluorescence. Furthermore, we used bioinformatics approaches to evaluate HMGA2 and HMGA2-AS1 correlation and overall survival in tumor patients.

Results: We found the presence of a promoter-associated lncRNA (CATG00000088127.1) in the HMGA1 gene and three antisense genes (RPSAP52, HMGA2-AS1, and RP11-366L20.3) in the HMGA2 gene. We studied the uncharacterized HMGA2-AS1 transcripts, validating their existence in cancer cell lines and observing a positive correlation between HMGA2 and HMGA2-AS1 expression in a cancer-derived patient dataset. We showed that HMGA2-AS1 transcripts positively modulate HMGA2 expression and migration properties of PANC1 cells through HMGA2. In addition, Kaplan-Meier analysis showed that high level of HMGA2-AS1 is a negative prognostic factor in pancreatic cancer patients.

Conclusions: Our results describe novel antisense lncRNAs associated with HMGA1 and HMGA2 genes. In particular, we demonstrate that HMGA2-AS1 is involved in the regulation of its own sense gene expression, mediating tumorigenesis. Thus, we highlight a new layer of complexity in the regulation of HMGA2 expression, providing new potential targets for cancer therapy.

HMGA Proteins in Stemness and Differentiation of Embryonic and Adult Stem Cells

HMGA1 and HMGA2 are chromatin architectural proteins that do not have transcriptional activity per se, but are able to modify chromatin structure by interacting with the transcriptional machinery and thus negatively or positively regulate the transcription of several genes. They have been extensively studied in cancer where they are often found to be overexpressed but their functions under physiologic conditions have still not been completely addressed. Hmga1 and Hmga2 are expressed during the early stages of mouse development, whereas they are not detectable in most adult tissues. Hmga overexpression or knockout studies in mouse have pointed to a key function in the development of the embryo and of various tissues. HMGA proteins are expressed in embryonic stem cells and in some adult stem cells and numerous experimental data have indicated that they play a fundamental role in the maintenance of stemness and in the regulation of differentiation. In this review, we discuss available experimental data on HMGA1 and HMGA2 functions in governing embryonic and adult stem cell fate. Moreover, based on the available evidence, we will aim to outline how HMGA expression is regulated in different contexts and how these two proteins contribute to the regulation of gene expression and chromatin architecture in stem cells.

High mobility group AT-hook 2 and c-MYC as potential prognostic factors in pancreatic ductal adenocarcinoma

The present study investigated if c-MYC and high mobility group AT-hook 2 (HMGA2) expression was associated with prognosis of patients with pancreatic ductal adenocarcinoma (PDAC). A total of 102 patients undergoing surgery for PDAC were retrospectively reviewed. Immunohistochemistry was used to detect c-MYC and HMGA2 protein expression in PDAC and peritumoral tissue samples. Expression of c-MYC and HMGA2 was associated with clinicopathological characteristics and prognoses of patients with PDAC using multivariate analysis. HMGA2 and c-MYC protein expression was significantly higher in PDAC tissues compared with peritumoral tissue (P<0.001). HMGA2 and c-MYC expression was also significantly higher in patients with PDAC who had lymph node metastasis, invasion of regional tissues and tumor node metastasis (TNM) stage III or IV disease compared with those who had no lymph node metastasis, no invasion of regional tissues and TNM stage I or II disease (P<0.001). Multivariate logistic regression analysis was used to identify TNM stage (P=0.007) and invasion (P=0.003) as significant independent predictors of c-MYC expression (model AUC=0.8201), and lymph node metastasis (P=0.002) and invasion (P=0.003) as significant independent predictors of HMGA2 expression (model AUC=0.7638). Cox multivariate analysis showed that expression of c-MYC (P=0.019) and HMGA2 (P<0.001), TNM stage (P=0.014) and lymph node metastasis (P=0.032) were associated with reduced overall survival time. HMGA2 and c-MYC may be important biological markers and potential therapeutic targets involved in the tumorigenesis, metastasis, invasion and prognosis of PDAC.

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.

Transcription Factors That Govern Development and Disease: An Achilles Heel in Cancer

Development requires the careful orchestration of several biological events in order to create any structure and, eventually, to build an entire organism. On the other hand, the fate transformation of terminally differentiated cells is a consequence of erroneous development, and ultimately leads to cancer. In this review, we elaborate how development and cancer share several biological processes, including molecular controls. Transcription factors (TF) are at the helm of both these processes, among many others, and are evolutionarily conserved, ranging from yeast to humans. Here, we discuss four families of TFs that play a pivotal role and have been studied extensively in both embryonic development and cancer—high mobility group box (HMG), GATA, paired box (PAX) and basic helix-loop-helix (bHLH) in the context of their role in development, cancer, and their conservation across several species. Finally, we review TFs as possible therapeutic targets for cancer and reflect on the importance of natural resistance against cancer in certain organisms, yielding knowledge regarding TF function and cancer biology.

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.

LINC00473 promotes hepatocellular carcinoma progression via acting as a ceRNA for microRNA-195 and increasing HMGA2 expression

Hepatocellular carcinoma (HCC) is a most aggressive malignant tumor. Nevertheless, the molecular mechanisms underlying HCC are still completely unclear. LINC00473 is identified as a tumor promoter in many cancers. In this investigation, the function of LINC00473 was specifically focused on. We exhibited that LINC00473 was obviously elevated in HCC cells compared to QSG-7701 cells. Functionally, down-regulation of LINC00473 could prevent HCC cell viability and cell proliferation. For another, HCC cell colony formation capacity was greatly restrained while cell apoptosis was triggered by loss of LINC00473. Meanwhile, would-healing assay and transwell invasion experiments were employed in our present study. As demonstrated, we observed that HCC cell migratory and invasive ability were obviously suppressed by the silence of LINC00473. Apart from these, mechanistic investigations implied miR-195 was a sponge target of LINC00473. It is widely established miR-195 is a famous tumor inhibitory gene regulator in various cancers. Here, we confirmed the binding correlation between LINC00473 and miR-195 using RIP assay. Subsequently, in vivo experiments were employed and it was manifested that LINC00473 was able to promote HCC tumor growth via acting as a ceRNA to inhibit miR-195. HMGA2 is a kind of nuclear-binding protein and it is involved in various cancers. We predicted it as a target of miR-195 and we confirmed their correlation. In addition, HMGA2 was repressed by loss of LINC00473, which was rescued by miR-195 inhibitors. Then, we found that angiogenic fator vascular endothelial growth factor (VEGF) was inhibited by loss of LINC00473 whereas anti-angiogenic factor EPN2 was induced in vivo. Taken all these together, our study revealed the significance of LINC00473/miR-195/HMGA2 signaling axis for the first time in HCC progression. It was suggested the potential possibility of LINC00473 as an indicator for HCC.

Emerging Role of USP8, HMGA, and Non-Coding RNAs in Pituitary Tumorigenesis

Two novel molecular mechanisms with a driver role in pituitary tumorigenesis have been recently identified. They are (a) mutations in the Ubiquitin-Specific Protease 8 (USP8) gene in corticotroph tumors and (b) overexpression of the HMGA1 and HMGA2 genes in most of the pituitary tumors. Moreover, deregulated expression of the non-coding RNAs has been very frequently observed in this neoplasia. The aim of this review is to better elucidate the role, the mechanisms, and the possible clinical impact of these novel alterations in the development of pituitary neoplasia.

Oncofetal HMGA2 attenuates genotoxic damage induced by topoisomerase II target compounds through the regulation of local DNA topology

Rapidly dividing cells maintain chromatin supercoiling homeostasis via two specialized classes of enzymes, DNA topoisomerase type 1 and 2 (TOP1/2). Several important anticancer drugs perturb this homeostasis by targeting TOP1/2, thereby generating genotoxic DNA damage. Our recent studies indicated that the oncofetal chromatin structuring high‐mobility group AT‐hook 2 (HMGA2) protein plays an important role as a DNA replication fork chaperone in coping with DNA topological ramifications that occur during replication stress, both genomewide and at fragile sites such as subtelomeres. Intriguingly, a recent large‐scale clinical study identified HMGA2 expression as a sole predicting marker for relapse and poor clinical outcomes in 350 acute myeloid leukemia (AML) patients receiving combinatorial treatments that targeted TOP2 and replicative DNA synthesis. Here, we demonstrate that HMGA2 significantly enhanced the DNA supercoil relaxation activity of the drug target TOP2A and that this activator function is mechanistically linked to HMGA2's known ability to constrain DNA supercoils within highly compacted ternary complexes. Furthermore, we show that HMGA2 significantly reduced genotoxic DNA damage in each tested cancer cell model during treatment with the TOP2A poison etoposide or the catalytic TOP2A inhibitor merbarone. Taken together with the recent clinical data obtained with AML patients targeted with TOP2 poisons, our study suggests a novel mechanism of cancer chemoresistance toward combination therapies administering TOP2 poisons or inhibitors. We therefore strongly argue for the future implementation of trials of HMGA2 expression profiling to stratify patients before finalizing clinical treatment regimes.

AP-1 Signaling by Fra-1 Directly Regulates HMGA1 Oncogene Transcription in Triple-Negative Breast Cancers

The architectural chromatin protein HMGA1 and the transcription factor Fra-1 are both overexpressed in aggressive triple-negative breast cancers (TNBC), where they both favor epithelial-to-mesenchymal transition, invasion, and metastasis. We therefore explored the possibility that Fra-1 might be involved in enhanced transcription of the HMGA1 gene in TNBCs by exploiting cancer transcriptome datasets and resorting to functional studies combining RNA interference, mRNA and transcriptional run-on assays, chromatin immunoprecipitation, and chromosome conformation capture approaches in TNBC model cell lines. Our bioinformatic analysis indicated that Fra-1 and HMGA1 expressions positively correlate in primary samples of patients with TNBC. Our functional studies showed that Fra-1 regulates HMGA1 mRNA expression at the transcriptional level via binding to enhancer elements located in the last two introns of the gene. Although Fra-1 binding is required for p300/CBP recruitment at the enhancer domain, this recruitment did not appear essential for Fra-1-stimulated HMGA1 gene expression. Strikingly, Fra-1 binding is required for efficient recruitment of RNA Polymerase II at the HMGA1 promoter. This is permitted owing to chromatin interactions bringing about the intragenic Fra-1-binding enhancers and the gene promoter region. Fra-1 is, however, not instrumental for chromatin loop formation at the HMGA1 locus but rather exerts its transcriptional activity by exploiting chromatin interactions preexisting to its binding. IMPLICATIONS: We demonstrate that Fra-1 bound to an intragenic enhancer region is required for RNA Pol II recruitement at the HMGA1 promoter. Thereby, we provide novel insights into the mechanisms whereby Fra-1 exerts its prooncogenic transcriptional actions in the TNBC pathologic context.

Differential Expression of HMGA1 and HMGA2 in pituitary neuroendocrine tumors

Defining biomarkers for invasive pituitary neuroendocrine tumors (PitNETs) is highly desirable. The high mobility group A (HMGA) proteins are among the most widely expressed cancer-associated proteins. Indeed, their overexpression is a frequent feature of human malignancies, including PitNETs. We show that nonfunctioning PitNETs (NF-PitNETs) express significantly higher levels of HMGA1 than somatotropinomas (GHs) and corticotropinomas (ACTHs). Furthermore, HMGA2 expression was detected only in NF-PitNETs and was significantly higher in larger tumors than in smaller tumors. HMGA expression analysis generally focuses on nuclear staining. Here, cytoplasmic HMGA staining was also found. PitNETs displayed strong nuclear HMGA1 and strong cytoplasmic HMGA2 immunoreactivity. Interestingly, the HMGA1 and HMGA2 nuclear expression levels were significantly higher in invasive adenomas than in noninvasive adenomas. The highest levels of nuclear HMGA2 were found in GHs. In conclusion, we show that overexpression of nuclear HMGA proteins could be a potential biomarker of invasive PitNETs, particularly HMGA2 for GHs. HMGA2 might be a reliable biomarker for NF-PitNETs.

HMGA2 Contributes to Distant Metastasis and Poor Prognosis by Promoting Angiogenesis in Oral Squamous Cell Carcinoma

The highly malignant phenotype of oral squamous cell carcinoma (OSCC), including the presence of nodal and distant metastasis, reduces patient survival. High-mobility group A protein 2 (HMGA2) is a non-histone chromatin factor that is involved in advanced malignant phenotypes and poor prognosis in several human cancers. However, its biological role in OSCC remains to be elucidated. The purpose of this study was to determine the clinical significance and role of HMGA2 in the malignant potential of OSCC. We first investigated the expression pattern of HMGA2 and its clinical relevance in 110 OSCC specimens using immunohistochemical staining. In addition, we examined the effects HMGA2 on the regulation of vascular endothelial growth factor (VEGF)-A, VEGF-C, and fibroblast growth factor (FGF)-2, which are related to angiogenesis, in vitro. High expression of HMGA2 was significantly correlated with distant metastasis and poor prognosis. Further, HMGA2 depletion in OSCC cells reduced the expression of angiogenesis genes. In OSCC tissues with high HMGA2 expression, angiogenesis genes were increased and a high proportion of blood vessels was observed. These findings suggest that HMGA2 plays a significant role in the regulation of angiogenesis and might be a potential biomarker to predict distant metastasis and prognosis in OSCC.

Knockdown of high mobility group box 3 impairs cell viability and colony formation but increases apoptosis in A549 human non-small cell lung cancer cells

Previous research has linked high mobility group box 3 (HMGB3) overexpression to the malignant progression and poor prognosis of non-small cell lung cancer (NSCLC). The present study investigated the role of HMGB3 in cell survival and colony formation of NSCLC cells. Stable knockdown of HMGB3 in A549 cells was achieved by lentiviral-based shRNA interference and verified by detection of the transcriptional and translational level of HMGB3 with reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. The influence of HMGB3 knockdown on A549 cell viability and apoptotic rate was evaluated by Cell Counting Kit-8 assay and flow cytometry following annexin V staining, respectively. The proliferative capacity of A549 cells with or without HMGB3 knockdown was compared by measuring their colony forming efficiency. The results of the current study revealed that HMGB3 knockdown significantly reduced cell viability and colony forming efficiency while promoting apoptosis in A549 cells, indicating that HMGB3 may be pivotal for the survival and colony formation of A549 cells, serving a notable role in NSCLC progression.

MicroRNA‑363‑3p inhibits hepatocarcinogenesis by targeting HMGA2 and is associated with liver cancer stage

The importance of microRNAs (miRNAs) in cancer development has been widely recognized in recent decades. In the present study, the function and mechanism of miRNA-363-3p (miR-363-3p), formerly characterized as a tumor suppressor, in the hepatocarcinogenesis of liver cancer cells was investigated. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to detect the expression of miR-363-3p in liver cancer tissues. Cell proliferation, survival and migration capacities were determined by MTT, colony formation and wound-healing assays, respectively. The targeting of high mobility group AT-hook 2 (HMGA2) mRNA by miR-363-3p was confirmed by bioinformatics analysis, and RT-qPCR, luciferase reporter and western blot assays. The correlation between the expression levels of HMGA2 and miR-363-3p was analyzed. The RT-qPCR results revealed that the levels of miR-363-3p were downregulated in liver cancer tissues. Cellular assays validated that miR-363-3p exerted tumor suppressing functions, including the inhibition of cell proliferation, survival and migration abilities in two liver cancer cell lines. Bioinformatics prediction and subsequent experiments demonstrated that HMGA2 was a direct target of miR-363-3p. Restoration of the expression of HMGA2 in miR-363-3p mimic-transfected cells reversed the tumor suppressing effects caused by miR-363-3p. Finally, there was a significant negative correlation between the expression levels of HMGA2 and miR-363-3p in liver cancer tissues. miR-363-3p was identified as an important tumor suppressor in liver cancer via targeting HMGA2, which may have potential benefits in liver cancer therapy.

The regulatory roles of lncRNAs in the process of breast cancer invasion and metastasis

Breast cancer (BC) is the most common cancer and principal cause of death among females worldwide. Invasion and metastasis are major causes which influence the survival and prognosis of BC. Therefore, to understand the molecule mechanism underlying invasion and metastasis is paramount for developing strategies to improve survival and prognosis in BC patients. Recent studies have reported that long non-coding RNAs (lncRNAs) play critical roles in the regulation of BC invasion and metastasis through a variety of molecule mechanisms that endow cells with an aggressive phenotype. In this article, we focused on the function of lncRNAs on BC invasion and metastasis through participating in epithelial-to-mesenchymal transition, strengthening cancer stem cells generation, serving as competing endogenous lncRNAs, influencing multiple signaling pathways as well as regulating expressions of invasion-metastasis related factors, including cells adhesion molecules, extracellular matrix, and matrix metallo-proteinases. The published work described has provided a better understanding of the mechanisms underpinning the contribution of lncRNAs to BC invasion and metastasis, which may lay the foundation for the development of new strategies to prevent BC invasion and metastasis.

Hmga2 is dispensable for pancreatic cancer development, metastasis, and therapy resistance

Expression of the chromatin-associated protein HMGA2 correlates with progression, metastasis and therapy resistance in pancreatic ductal adenocarcinoma (PDAC). Hmga2 has also been identified as a marker of a transient subpopulation of PDAC cells that has increased metastatic ability. Here, we characterize the requirement for Hmga2 during growth, dissemination, and metastasis of PDAC in vivo using conditional inactivation of Hmga2 in well-established autochthonous mouse models of PDAC. Overall survival, primary tumour burden, presence of disseminated tumour cells in the peritoneal cavity or circulating tumour cells in the blood, and presence and number of metastases were not significantly different between mice with Hmga2-wildtype or Hmga2-deficient tumours. Treatment of mice with Hmga2-wildtype and Hmga2-deficient tumours with gemcitabine did not uncover a significant impact of Hmga2-deficiency on gemcitabine sensitivity. Hmga1 and Hmga2 overlap in their expression in both human and murine PDAC, however knockdown of Hmga1 in Hmga2-deficient cancer cells also did not decrease metastatic ability. Thus, Hmga2 remains a prognostic marker which identifies a metastatic cancer cell state in primary PDAC, however Hmga2 has limited if any direct functional impact on PDAC progression and therapy resistance.

Targeting HMGA protein inhibits retinoblastoma cell proliferation

We describe a novel synthetic strategy for conjugating HMGA2 siRNA and the HMGA aptamer to the nucleolin aptamer and nucleolin antibody, respectively. Our studies demonstrate that these conjugates inhibit cell proliferation in retinoblastoma cells.

A novel approach to target HMGA proteins in retinoblastoma using HMGA2 siRNA–nucleolin aptamer and HMGA aptamer–nucleolin antibody conjugates was developed.

Integrative Analysis of Proteome and Ubiquitylome Reveals Unique Features of Lysosomal and Endocytic Pathways in Gefitinib-Resistant Non-Small Cell Lung Cancer Cells

Non-small cell lung cancer (NSCLC) patients carrying EGFR activating mutations treated with gefitinib, a tyrosine kinase inhibitor, will develop drug resistance. Ubiquitylation is one of major posttranslational modifications of proteins affecting the stability or function of proteins. However, the role of protein ubiquitylation in gefitinib resistance is poorly understood. To systematically identify the global change in protein expression and ubiquitylation during gefitinib resistance, a quantitative global proteome and ubiquitylome study in a pair of gefitinib-resistant and sensitive NSCLC cells is carried out. Altogether, changes in expression of 3773 proteins are quantified, and changes in ubiquitylation of 2893 lysine sites in 1415 proteins are measured in both cells. Interestingly, lysosomal and endocytic pathways, which are involved in autophagy regulation, are enriched with upregulated proteins or ubiquitylated proteins in gefitinib-resistant cells. In addition, HMGA2 overexpression or ALOX5 knockdown suppresses gefitinib resistance in NSCLC cells by inhibiting autophagy. Overall, these results reveal the previously unknown global ubiquitylome and proteomic features associated with gefitinib resistance, uncover the opposing roles of HMGA2 or ALOX5 in regulating gefitinib resistance and autophagy, and will help to identify new therapeutic targets in overcoming gefitinib resistance.

High expression of HMGA2 independently predicts poor clinical outcomes in acute myeloid leukemia

In acute myeloid leukemia (AML), risk stratification based on cytogenetics and mutation profiling is essential but remains insufficient to select the optimal therapy. Accurate biomarkers are needed to improve prognostic assessment. We analyzed RNA sequencing and survival data of 430 AML patients and identified HMGA2 as a novel prognostic marker. We validated a quantitative PCR test to study the association of HMGA2 expression with clinical outcomes in 358 AML samples. In this training cohort, HMGA2 was highly expressed in 22.3% of AML, mostly in patients with intermediate or adverse cytogenetics. High expression levels of HMGA2 (H + ) were associated with a lower frequency of complete remission (58.8% vs 83.4%, P < 0.001), worse 3-year overall survival (OS, 13.2% vs 43.5%, P < 0.001) and relapse-free survival (RFS, 10.8% vs 44.2%, P < 0.001). A positive HMGA2 test also identified a subgroup of patients unresponsive to standard treatments. Multivariable analyses showed that H + was independently associated with significantly worse OS and RFS, including in the intermediate cytogenetic risk category. These associations were confirmed in a validation cohort of 260 patient samples from the UK NCRI AML17 trial. The HMGA2 test could be implemented in clinical trials developing novel therapeutic strategies for high-risk AML.

High expression of HMGA2 independently predicts poor clinical outcomes in acute myeloid leukemia

In acute myeloid leukemia (AML), risk stratification based on cytogenetics and mutation profiling is essential but remains insufficient to select the optimal therapy. Accurate biomarkers are needed to improve prognostic assessment. We analyzed RNA sequencing and survival data of 430 AML patients and identified HMGA2 as a novel prognostic marker. We validated a quantitative PCR test to study the association of HMGA2 expression with clinical outcomes in 358 AML samples. In this training cohort, HMGA2 was highly expressed in 22.3% of AML, mostly in patients with intermediate or adverse cytogenetics. High expression levels of HMGA2 (H + ) were associated with a lower frequency of complete remission (58.8% vs 83.4%, P < 0.001), worse 3-year overall survival (OS, 13.2% vs 43.5%, P < 0.001) and relapse-free survival (RFS, 10.8% vs 44.2%, P < 0.001). A positive HMGA2 test also identified a subgroup of patients unresponsive to standard treatments. Multivariable analyses showed that H + was independently associated with significantly worse OS and RFS, including in the intermediate cytogenetic risk category. These associations were confirmed in a validation cohort of 260 patient samples from the UK NCRI AML17 trial. The HMGA2 test could be implemented in clinical trials developing novel therapeutic strategies for high-risk AML.

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.

Individualised Multimodal Treatment Strategies for Anaplastic and Poorly Differentiated Thyroid Cancer

The prognosis of anaplastic (ATC) and poorly differentiated thyroid cancer (PDTC) is poor, due to their radioiodine refractoriness (RAI-R), high metastatic potential and current lack of effective treatment strategies. We aimed to examine the efficacy of the tyrosine kinase inhibitors (TKIs) sorafenib and selumetinib and the histone deacetylase inhibitor (HDACI) panobinostat in patient-derived tumor tissue (PDTT) of ATCs/PDTCs, the expression of sodium iodide symporter (NIS) and radioiodine up-take (RAI-U). High Mobility Group AT-Hook 2 (HMGA2) and associated miRNAs expression was correlated with the clinical course of the patients. Inhibitory effects of panobinostat, sorafenib and selumetinib were measured by real time cell analyser xCELLigence in five PDTTs and human foreskin fibroblasts (HF) used as control. Expression of NIS, HMGA2 and associated miRNAs hsa-let-7f-5p, hsa-let-7b-5p, hsa-miR-146b-5p and hsa-miR-146b-3p was performed by RT-qPCR and Western blot. RAI-U was performed by Gamma Counter with I-131. Panobinostat showed the strongest cytotoxic effect (10 nM) in all PDTTs and HF and caused a significant over-expression of NIS transcript. TKIs were able to up-regulate NIS transcript in patient 5 and in HF. RAI-U was up-regulated after 24 h of treatment with TKIs and panobinostat in all PDTT and HF, except in patient 5. Selumetinib caused a significant suppression of HMGA2 in PDTT 1, 2, 4, 5 and HF; whereas sorafenib caused no change of HMGA2 expression. Panobinostat suppressed significantly HMGA2 in PDTT 2, 4 and HF. The expression of miRNAs hsa-let-7f-5p, has-let-7b-5p hsa-miR-146b-5p and hsa-miR-146b-3p was modulated heterogeneously. NIS protein level was over-expressed in three PDTTs (patients 1, 3 and 4) after 24 h of treatment with selumetinib, sorafenib and in particular with panobinostat. HF showed a stable NIS protein level after treatment. Panobinostat showed the strongest cytotoxicity in all treated PDTTs at the lowest dosage in comparison with TKI. All three compounds were able to modulate differently NIS, HMGA2 and related miRNAs. These factors represent valuable markers in PDTT for new treatment strategies for patients suffering from ATC/PDTC. Thus, the establishment of PDTT could be a useful tool to test the efficacy of compounds and to develop new and individualised multimodal treatment options for PDTCs and ATCs.