Prognostic value of HMGB3 expression in patients with non-small cell lung cancer

Systematic analysis of expression profiles of HMGB family members for prognostic application in non-small cell lung cancer

Background: Lung cancer is a significant challenge to human health. Members of the high mobility group (HMG) superfamily (HMGB proteins) are implicated in a wide variety of physiological and pathophysiological processes, but the expression and prognostic value of HMGB family members in non-small cell lung cancer (NSCLC) have not been elucidated.

Methods: In this study, ONCOMINE, UALCAN, GEPIA, Kaplan–Meier Plotter, starBase, OncomiR databases, and GeneMANIA were utilized to evaluate the prognostic significance of HMGB family members in NSCLC.

Results: HMGB2/3 expression levels were higher in NSCLC patients. HMGB1 expression was higher in lung squamous cell carcinoma (LUSC) and was lower in lung adenocarcinoma (LUAD) tissue than in normal lung tissue. HMGB2 expression was related to cancer stage. Increased HMGB1 mRNA expression levels were associated with improved lung cancer prognosis, including overall survival (OS), first-progression survival (FP), and post-progression survival (PPS). There was no significant association between HMGB2 levels and prognostic indicators. HMGB3 expression was associated with poorer OS. GeneMANIA and GO/KEGG pathway analysis showed that HMGB family members mainly associated with chromosome condensation, regulation of chromatin organization, and nucleosome binding in NSCLC. HMGBs expression were closely correlated with infiltrating levels of specific types of immune cells in NSCLC, especially Th2 cells, Th17 cells, and mast cells. hsa-miR-25-3p, hsa-miR-374a-3p, and hsa-miR-93-5p were significantly positively correlated with HMGB1, HMGB2, and HMGB3, respectively. However, hsa-miR-30a-5p was predicted to significantly negatively regulate HMGB3 expression.

Conclusion: Our study revealed that HMGB1 is positively related to the improved prognosis in NSCLC, and demonstrate that HMGB3 might be a risk factor for poorer survival of NSCLC patients.

MicroRNA-18 facilitates the stemness of gastric cancer by downregulating HMGB3 though targeting Meis2

The recurrence and metastasis of gastric cancer are related to the stemness of gastric cancer cells. Researches have shown that miR-18 level is negatively correlated to the occurrence and development of certain cancer types. However, the effects of miR-18 on the stemness of gastric cancer remain uncertain. In this research, gastric cancer cell lines with stable overexpression of miR-18 were constructed through lentivirus infection. CCK-8 assay, RT-qPCR, Western blot, flow cytometry, and in vivo tumorigenesis assays were performed to evaluate the effects of miR-18 on the stemness of gastric cancer cells. Moreover, luciferase reporter assays found that Meis2 was the target of miR-18. Furthermore, we also found that the low-expressed oncogene HMGB3 is involved in this miR-18/Meis2 axis to further promote the stemness of gastric cancer cells. These findings suggest that the miR-18/Meis2/HMGB3 axis may be potential prognostic indicators for patients with gastric cancer.

Circular RNA circFOXO3 facilitate non-small cell lung cancer progression through upregulating HMGB3 via sponging miR-545-3p/miR-506-3p

PURPOSE

Circular RNAs (circRNAs) have emerged as a pivotal regulatory element in the progression of human cancers. Being an important member of circRNAs, circFOXO3 has been implicated in tumor invasion or metastasis of non-small cell lung cancer (NSCLC); however, the molecular mechanism underlying this promoting effect remains an enigma. The present study aims to study the function of circFOXO3 and dissect the relevant intracellular network in the progression and metastasis of NSCLC.

METHODS

Quantitative real time PCR (RT-qPCR) assay and Western blotting were used to quantify the levels of RNAs and proteins respectively. starBase v2.0 and luciferase assay were used to validate the target of circRNAs or miRNAs. Cell Counting Kit-8 (CCK-8) assay was adopted to examine cell viability. Transwell was used to determine cell invasion and migration. Xenograft model was established to detect tumor growth.

RESULTS

RT-qPCR showed that circFOXO3 was overexpressed in NSCLC cells and tissues. Knockdown of circFOXO3 not only inhibited NSCLC cell proliferation, migration and invasion in vitro but also suppressed tumor growth in vivo. starBase v2.0 and luciferase assay results collectively suggested that circFOXO3 sponged miR-545-3p and miR-506-3p. Dual-inhibition of circFOXO3 and its target miRNAs suppressed the reduction of cell proliferation, migration and invasion induced by siRNA of circFOXO3 (si-circFOXO3), demonstrating that the effect of circFOXO3 on NSCLC was dependent on sponging miR-545-3p and miR-506-3p. Further bioinformatic analysis and biochemistry experiments revealed that miR-545-3p and miR-506-3p regulated the expression of a family member of high-mobility group box, HMGB3.

CONCLUSION

Here, we show thatcircFOXO3 in NSCLC promotes the proliferation, migration and invasion of NSCLC cells, thereby promoting tumor growth. We further find that circFOXO3 sponges miR-545-3p/miR-506-3p that bind to 3'-UTR of HMGB3 mRNA, which constitutes the major network fulfilling the circFOXO3's promoting effect. Therefore, we proposed that circFOXO3 could be a potential therapeutic target for NSCLC.

LINC00857 promotes colorectal cancer progression by sponging miR-150-5p and upregulating HMGB3 (high mobility group box 3) expression

Colorectal cancer (CRC) is the third most commonly diagnosed malignant tumor worldwide. LINC00857 has been reported as a dysregulated long non-coding RNAs (lncRNAs) involved in the genesis and development of different cancers. In CRC, accumulating evidence indicates that high mobility group box 3 (HMGB3) is over-expressed and contributes to CRC development. However, the mechanism underlying HMGB3 upregulation in CRC remains unclear. The present work aims to investigate the role of LINC00857 and its functional interaction with HMGB3 in regulating CRC progression. Differential expression of LINC00857 between CRC tissues and normal tissues was identified in TCGA (The Cancer Genome Atlas) database. In vitro functional assays were performed to explore the biological functions of LINC00857 in CRC cells. In vivo xenograft model was employed to investigate the role of LINC00857 in CRC tumorigenesis. We found that LINC00857 was significant upregulated in CRC tissues and cell lines. LINC00857 knockdown significantly inhibited the proliferation, migration and invasion of CRC cells, and also induced apoptosis. Moreover, LINC00857 knockdown suppressed CRC tumorigenesis in vivo. We further demonstrated that the effects of LINC00857 in CRC cells were mediated through miR-150-5p/HMGB3 axis. LINC00857 negatively regulates the activity of miR-150-5p, which releases its inhibition on HMGB3 expression. Our data indicate that LINC00857/miR-150-5p/HMGB3 axis plays a fundamental role in regulating the malignant phenotype and tumorigenesis of CRC. Targeting this axis may serve as novel therapeutic strategies for CRC treatment.

Cancer Cells Retrace a Stepwise Differentiation Program during Malignant Progression

Pancreatic neuroendocrine tumors (PanNET) comprise two molecular subtypes, relatively benign islet tumors (IT) and invasive, metastasis-like primary (MLP) tumors. Until now, the origin of aggressive MLP tumors has been obscure. Herein, using multi-omics approaches, we revealed that MLP tumors arise from IT via dedifferentiation following a reverse trajectory along the developmental pathway of islet β cells, which results in the acquisition of a progenitor-like molecular phenotype. Functionally, the miR-181cd cluster induces the IT-to-MLP transition by suppressing expression of the Meis2 transcription factor, leading to upregulation of a developmental transcription factor, Hmgb3. Notably, the IT-to-MLP transition constitutes a distinct step of tumorigenesis and is separable from the classic proliferation-associated hallmark, temporally preceding accelerated proliferation of cancer cells. Furthermore, patients with PanNET with elevated HMGB3 expression and an MLP transcriptional signature are associated with higher-grade tumors and worse survival. Overall, our results unveil a new mechanism that modulates cancer cell plasticity to enable malignant progression. SIGNIFICANCE: Dedifferentiation has long been observed as a histopathologic characteristic of many cancers, albeit inseparable from concurrent increases in cell proliferation. Herein, we demonstrate that dedifferentiation is a mechanistically and temporally separable step in the multistage tumorigenesis of pancreatic islet cells, retracing the developmental lineage of islet β cells.This article is highlighted in the In This Issue feature, p. 2355.

Insights into Mechanisms of Tumorigenesis in Neuroendocrine Neoplasms

Genomic studies have identified some of the most relevant genetic players in Neuroendocrine Neoplasm (NEN) tumorigenesis. However, we are still far from being able to draw a model that encompasses their heterogeneity, elucidates the different biological effects consequent to the identified molecular events, or incorporates extensive knowledge of molecular biomarkers and therapeutic targets. Here, we reviewed recent insights in NEN tumorigenesis from selected basic research studies on animal models, highlighting novel players in the intergenic cooperation and peculiar mechanisms including splicing dysregulation, chromatin stability, or cell dedifferentiation. Furthermore, models of tumorigenesis based on composite interactions other than a linear progression of events are proposed, exemplified by the involvement in NEN tumorigenesis of genes regulating complex functions, such as MEN1 or DAXX. Although limited by interspecies differences, animal models have proved helpful for the more in-depth study of every facet of tumorigenesis, showing that the identification of driver mutations is only one of the many necessary steps and that other mechanisms are worth investigating.

High mobility group box 3 promotes cervical cancer proliferation by regulating Wnt/β-catenin pathway

Objective

High mobility group box 3 (HMGB3) plays an important role in the development of various cancer. This study aims to explore whether HMGB3 regulates cervical cancer (CC) progression and elucidate the underlying mechanism.

Methods

HMGB3 expression in clinical patients' tumor samples were determined by real-time quantitative polymerase chain reaction (qRT-PCR) and western blot. HMGB3 overexpression/knockdown were used to investigate its function. Cell apoptosis and cycle were detected by Annexin V/PI staining and flow cytometry. In vivo tumor model was made by subcutaneous injection of HeLa cells transfected with shRNAs targeting HMGB3 (sh-HMGB31) into the flank area of nude mice. Western blot was used to detect the levels of β-catenin, c-Myc, and matrix metalloproteinase-7 (MMP-7) in Hela and CaSki cells transfected with sh-HMGB3 or shRNAs targeting β-catenin.

Results

Both messenger RNA and protein levels of HMGB3 were upregulated in CC tissues from patients. High expression level of HMGB3 had positive correlation with serosal invasion, lymph metastasis, and tumor sizes in CC patient. Functional experiments showed that HMGB3 could promote CC cell proliferation both in vitro and in vivo. The expression levels of c-Myc and MMP-7 were increased, resulting in regulating cell apoptosis, cell cycle, and activating Wnt/β-catenin pathway.

Conclusions

Our data indicated that HMGB3 may serve as an oncoprotein. It could be used as a potential prognostic marker and represent a promising therapeutic strategy for CC treatment.

High-mobility group box 3 (HMGB3) silencing inhibits non-small cell lung cancer development through regulating Wnt/β-catenin pathway

It has been reported that high-mobility group box 3 is overexpressed in various cancers. This study aimed to explore its function in non-small cell lung cancer (NSCLC). A546 and H460 cell lines were used for in vivo experiments, scratch healing tests, transwell migration and invasion experiments. It was first found that HMGB3 was highly expressed in tumor tissues in the patients and associated with NSCLC stage. Silencing of HMGB3 significantly slowed the growth, proliferation and invasion of NSCLC in vitro, and repressed cell growth in vivo. Mechanistic studies suggest that the observed effects were mediated by inhibiting the expression of β-catenin/MMP7/c-Myc in Wnt pathway. Our study highlights the role of HMGB3 in NSCLC, which may provide a therapeutic target for the treatment of NSCLC.

MicroRNA-429 acts as a tumor suppressor in colorectal cancer by targeting high mobility group box 3

Colorectal cancer (CRC) is one of the most common solid tumors worldwide and has an extremely poor prognosis. MicroRNA-429 (miR-429) has been reported to participate in the progression of CRC. However, the pathological mechanisms require further investigation. The aim of the present study was to investigate the association between miR-429 and high mobility group box 3 (HMGB3) in CRC and the associated mechanism. The mRNA expression levels of miR-429 and HMGB3 in 65 paired CRC and adjacent tissues were examined by reverse transcription-quantitative PCR. Furthermore, a dual-luciferase reporter assay was performed to identify the association between miR-429 and HMGB3. Finally, the effects of miR-429 and HMGB3 on the proliferation and apoptosis of CRC cells were detected. As a result, it was identified that miR-429 expression was downregulated and HMGB3 expression was upregulated in CRC tissues compared with in adjacent non-cancer tissues, and the expression levels of miR-429 were negatively associated with those of HMGB3. Notably, HMGB3 was demonstrated to be a direct target of miR-429 by dual-luciferase reporter assay. Furthermore, transfection with a miR-429 mimic significantly inhibited HMGB3 expression and led to decreased proliferation and increased apoptosis of CRC cells. On the other hand, transient overexpression of HMGB3 partially inhibited the antitumor effects of miR-429. To the best of our knowledge, the present study demonstrated for the first time that miR-429 regulated the proliferation and apoptosis of CRC cells via HMGB3, suggesting a specific tumor suppressive function of the miR-429/HMGB3 signaling pathway in CRC.

The role of high mobility group protein B3 (HMGB3) in tumor proliferation and drug resistance

The high mobility group protein B (HMGB) family (including HMGB1, HMGB2, HMGB3, and HMGB4) can regulate the mechanisms of DNA replication, transcription, recombination, and repair, and act as cytokines to mediate responses to infection, injury, and inflammation. HMGB1/2/3 has a high similarity in sequence and structure, while HMGB4 has no acidic C-terminal tail. Among them, HMGB3 can regulate the self-renewal and differentiation of normal hematopoietic stem cell population, but the decrease of its expression is easy to induce leukemia. Up-regulation of its expression promotes tumor development and chemotherapy resistance through a variety of mechanisms, and non-coding RNA can regulate to promote tumor cell proliferation, invasion, and migration and inhibit cancer cell apoptosis.

Circular RNA 0001313 Knockdown Suppresses Non-Small Cell Lung Cancer Cell Proliferation and Invasion via the microRNA-452/HMGB3/ERK/MAPK Axis

Background

Non-small cell lung cancer (NSCLC) seriously endangers human health. Circular RNAs (circRNAs) regulate diverse types of cancers, including NSCLC. This study investigated the possible mechanism of circ0001313 in NSCLC.

Materials and Methods

Circ0001313 expression in NSCLC tissues was measured, and its correlation with clinicopathological features was analyzed. The binding relationships among circ0001313, microRNA (miR)-452 and HMGB3 were tested. The gain and loss of functions were performed to examine NSCLC cell malignant behaviors. After HMGB3 overexpression, ERK/MAPK pathway-related protein levels were detected. Subsequently, the rescue experiment was further performed using an ERK/MAPK pathway inhibitor PD98059.

Results

Abnormally elevated circ0001313 and decreased miR-452 in NSCLC cells were observed. Circ0001313 silencing or miR-452 overexpression significantly reduced NSCLC cell proliferation and invasion. Circ0001313 competitively bound to miR-452 to upregulate HMGB3, thus promoting NSCLC cell growth. HMGB3 overexpression activated the ERK/MAPK pathway to contribute to NSCLC development.

Conclusion

We highlighted that silencing of circ0001313 blunted the ERK/MAPK pathway via the miR-452/HMGB3 axis, thereby inhibiting NSCLC cell proliferation and invasion.

CircEPSTI1 Promotes the Progression of Non-Small Cell Lung Cancer Through miR-145/HMGB3 Axis

Background

The high expression of circular RNA circEPSTI1 (hsa_circRNA_000479) has been reported to be associated with the malignant potential of ovarian cancer cells and triple-negative breast cancer cells. However, the expression profile and function of circEPSTI1 in non-small cell lung cancer (NSCLC) are not fully addressed.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to measure the RNA expression of circEPSTI1, relevant microRNAs (miRNAs) and high mobility group box 3 (HMGB3) in NSCLC tissues and cells. Cell counting kit 8 (CCK8) assay, colony formation and transwell assays were conducted to detect the capacities of proliferation, colony formation and metastasis in NSCLC cells. Western blot assay was performed to detect the expression of metastasis-associated proteins and HMGB3. Animal experiment was carried out to confirm the function of circEPSTI1 in vivo. The combination between miR-145 and circEPSTI1 or HMGB3 was verified by dual-luciferase reporter assay, RNA pull-down and RIP assays.

Results

CircEPSTI1 was abnormally up-regulated in NSCLC tissues and cells in comparison with that in normal tissues and cells. The high expression of circEPSTI1 was associated with the low survival rate of NSCLC patients. CircEPSTI1 accelerated the proliferation, colony formation and motility of NSCLC cells in vitro. CircEPSTI1 silencing restrained the NSCLC tumor growth in vivo. miR-145 was validated as a target of circEPSTI1 in NSCLC cells. HMGB3 was a direct downstream target of miR-145 in NSCLC cells. The decreased abilities of proliferation, colony formation and metastasis caused by the silencing of circEPSTI1 were reversed by the depletion of miR-145 or the accumulation of HMGB3 in NSCLC cells.

Conclusion

CircEPSTI1 aggravated the progression of NSCLC through elevating the expression of HMGB3 via sponging miR-145.

CircRNA_102179 promotes the proliferation, migration and invasion in non-small cell lung cancer cells by regulating miR-330-5p/HMGB3 axis

Non-small cell lung cancer (NSCLC) accounting for 85 % of all lung cancer was one of the main causes of death worldwide. In this study, we investigated the role of circRNA_102179 in NSCLC development. The levels of circRNA_102179 in NSCLC tissues and cell lines were determined by quantitative real-time PCR assay (qRT-PCR). CCK8 and colony formation assays were applied to explore the effect of circRNA_102179 on the growth of NSCLC cells in vitro. Transwell assay was utilized to analyze the impact of circRNA_102179 on the migration and invasion of NSCLC cells. Target prediction and luciferase reporter assay were used to identify the interacting miRNA of circRNA_102179. The interaction among circRNA_102179/ miR-330-5p/HMGB3 was further validated by colony formation and Transwell invasion assays. Finally, the mouse xenograft NSCLC model was used to explore the role of circRNA_102179 in the tumor growth of NSCLC cells in vivo. CircRNA_102179 was overexpressed in NSCLC tissues and cells compared with normal lung tissues and human bronchial epithelial cells (HBEs). The down-regulation of circRNA_102179 markedly reduced the proliferation, migration, and invasion of NSCLC cells. Moreover, down-expression of circRNA_102179 significantly increased the level of miR-330-5p/HMGB3 in NSCLC cells. Further functional experiments indicated that over-expression of miR-330-5p reversed the inhibitory effect of circRNA_102179 on NSCLC cells growth, migration, and invasion. Our results reveal that circRNA_102179 facilitates the proliferation, migration, and invasion of NSCLC cell via modulating miR-330-5p/ HMGB3 axis in NSCLC cells.

Proteogenomic Characterization Reveals Therapeutic Vulnerabilities in Lung Adenocarcinoma

To explore the biology of lung adenocarcinoma (LUAD) and identify new therapeutic opportunities, we performed comprehensive proteogenomic characterization of 110 tumors and 101 matched normal adjacent tissues (NATs) incorporating genomics, epigenomics, deep-scale proteomics, phosphoproteomics, and acetylproteomics. Multi-omics clustering revealed four subgroups defined by key driver mutations, country, and gender. Proteomic and phosphoproteomic data illuminated biology downstream of copy number aberrations, somatic mutations, and fusions and identified therapeutic vulnerabilities associated with driver events involving KRAS, EGFR, and ALK. Immune subtyping revealed a complex landscape, reinforced the association of STK11 with immune-cold behavior, and underscored a potential immunosuppressive role of neutrophil degranulation. Smoking-associated LUADs showed correlation with other environmental exposure signatures and a field effect in NATs. Matched NATs allowed identification of differentially expressed proteins with potential diagnostic and therapeutic utility. This proteogenomics dataset represents a unique public resource for researchers and clinicians seeking to better understand and treat lung adenocarcinomas.

Screening of tumor-associated antigens based on Oncomine database and evaluation of diagnostic value of autoantibodies in lung cancer

OBJECTIVES

The purpose of this study is to discover novel tumor-associated antigens (TAAs) to improve the diagnosis of lung cancer (LC).

MATERIALS AND METHODS

Oncomine database was used to discover potential TAAs from LC tissues, enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of autoantibodies against TAAs in two independent sets (identification set, n = 368; validation set, n = 1011).

RESULTS

Analyses of sera from identification set showed that the sensitivity of autoantibodies against five TAAs (HMGB3, ZWINT, GREM1, NUSAP1 and MMP12) reached 57.1%, 42.4%, 38.0%, 36.4% and 20.7%, with area under ROC curve (AUC) of 0.85, 0.75, 0.71, 0.73 and 0.70, respectively. It also validated the diagnostic performances of these autoantibodies with AUC of 0.72, 0.65, 0.61, 0.64 and 0.64, respectively. Autoantibody against HMGB3 exhibited significantly increased frequency in early LC (53.3%) compared to advanced LC (29.3%) (P < .05). The positive rates of autoantibody against HMGB3 and NUSAP1 in serum of LC patients without distant metastasis were significantly higher than that of distant metastatic LC (P < .05). When each of the three protein biomarkers (CEA, CA125 and CYFRA21-1) was combined with anti-HMGB3 autoantibody, the sensitivity of early LC increased to 72.7%, 63.3% and 75.9% from 36.4%, 13.3% and 27.6%, respectively.

CONCLUSION

Autoantibodies against 5 TAAs (HMGB3, ZWINT, GREM1, NUSAP1 and MMP12) might have favorable diagnostic values in LC detection, and autoantibody against HMGB3 has the potential to serve as a serological biomarker in early-stage LC. The combination of protein biomarkers and anti-HMGB3 might contribute to detection of early-stage LC.

Long non-coding RNA HOTTIP promotes hypoxia-induced glycolysis through targeting miR-615-3p/HMGB3 axis in non-small cell lung cancer cells

Increased glycolysis under hypoxic stress is a fundamentally important feature of non-small cell lung cancer (NSCLC) cells, but molecular mechanisms of hypoxia on glycolysis remain elusive. Herein, we aimed to explore whether lncRNAs and miRNAs are involved in the glycolytic reprogramming under hypoxic conditions. The levels of HOXA transcript at the distal tip (HOTTIP), miR-615-3p and high mobility group box 3 (HMGB3) mRNA were assessed by qRT-PCR. Western blot was performed to determine the protein expression of hexokinase 2 (HK-2) and HMGB3. Glucose consumption and lactate production were analyzed using a respective assay kit. The targeted correlation between miR-615-3p and HOTTIP or HMGB3 was verified using dual-luciferase reporter and RNA immunoprecipition assays. Our data revealed that HOTTIP was upregulated and miR-615-3p was downregulated in NSCLC tissues and cells. Hypoxia induced glycolysis, increased HOTTIP and HMGB3 mRNA levels and repressed miR-615-3p expression in NSCLC cells. HOTTIP deficiency or miR-615-3p expression restoration repressed hypoxia-induced glycolysis. Moreover, HOTTIP acted as a molecular sponge for miR-615-3p and HMGB3 was a direct target of miR-615-3p. The inhibitory effect of HOTTIP deficiency on glycolysis under hypoxic exposure was reversed by miR-615-3p restoration. Additionally, HOTTIP regulated HMGB3 expression by acting as a molecular sponge of miR-615-3p in NSCLC cells. In conclusion, our study suggested that HOTTIP might promote glycolysis under hypoxic conditions at least partly through regulating miR-615-3p/HMGB3 axis in NSCLC cells. Targeting HOTTIP might be a promising therapeutic strategy for NSCLC treatment.

MicroRNA-758 inhibits cervical cancer cell proliferation and metastasis by targeting HMGB3 through the WNT/β-catenin signaling pathway

Cervical cancer (CC) remains a highly prevalent cancer and cause of mortality amongst women worldwide. miR-758 has been demonstrated to be associated with tumorigenesis by controlling the expression of oncogenic or tumor suppressor genes. However, the function and mechanisms of miR-758 in CC have not been well illustrated. The present study aimed to dissect the effect of miR-758 on the proliferation, migration and invasion of CC cells and determine the potential underlying molecular mechanism of these effects. qPCR results revealed that the expression of miR-758 was significantly decreased in CC tissues and cell lines compared with that in normal tissues and normal cells. Results of CCK-8, colony formation and Transwell assays revealed that miR-758 overexpression markedly decreased cell viability, proliferation, invasion and migration. However, miR-758 inhibitors significantly increased viability, proliferation, invasion and migration. In the mechanism study, we demonstrated that high mobility group box 3 (HMGB3) was a direct target of miR-758, and HMGB3 overexpression rescued the viability, proliferation, invasion and migration of HeLa cells reduced by an miR-758 mimic. It was demonstrated that HMGB3 regulated the WNT/β-catenin signaling pathway under miR-758 regulation. In summary, these observations suggested that miR-758 is a tumor suppressor gene that can inhibit the metastatic phenotype of CC cells by negatively regulating HMGB3, which may present a path to novel therapeutic stratagems for CC therapy.

Targeting the High-Mobility Group Box 3 Protein Sensitizes Chemoresistant Ovarian Cancer Cells to Cisplatin

Chemotherapeutic regimens for ovarian cancer often include the use of DNA interstrand crosslink-inducing agents (e.g., platinum drugs) or DNA double-strand break-inducing agents. Unfortunately, the majority of patients fail to maintain a durable response to treatment, in part, due to drug resistance, contributing to a poor survival rate. In this study, we report that cisplatin sensitivity can be restored in cisplatin-resistant ovarian cancer cells by targeting the chromatin-associated high-mobility group box 3 (HMGB3) protein. HMGB proteins have been implicated in the pathogenesis and prognosis of ovarian cancer, and HMGB3 is often upregulated in cancer cells, making it a potential selective target for therapeutic intervention. Depletion of HMGB3 in cisplatin-sensitive and cisplatin-resistant cells resulted in transcriptional downregulation of the kinases ATR and CHK1, which attenuated the ATR/CHK1/p-CHK1 DNA damage signaling pathway. HMGB3 was associated with the promoter regions of ATR and CHK1, suggesting a new role for HMGB3 in transcriptional regulation. Furthermore, HMGB3 depletion significantly increased apoptosis in cisplatin-resistant A2780/CP70 cells after cisplatin treatment. Taken together, our results indicate that targeted depletion of HMGB3 attenuates cisplatin resistance in human ovarian cancer cells, increasing tumor cell sensitivity to platinum drugs. SIGNIFICANCE: This study shows that targeting HMGB3 is a potential therapeutic strategy to overcome chemoresistance in ovarian cancer.

Identification of tumor suppressor miRNAs by integrative miRNA and mRNA sequencing of matched tumor-normal samples in lung adenocarcinoma

The roles of miRNAs in lung cancer have not yet been explored systematically at the genome scale despite their important regulatory functions. Here, we report an integrative analysis of miRNA and mRNA sequencing data for matched tumor–normal samples from 109 Korean female patients with non‐small‐cell lung adenocarcinoma (LUAD). We produced miRNA sequencing (miRNA‐Seq) and RNA‐Seq data for 48 patients and RNA‐Seq data for 61 additional patients. Subsequent differential expression analysis with stringent criteria yielded 44 miRNAs and 2322 genes. Integrative gene set analysis of the differentially expressed miRNAs and genes using miRNA–target information revealed several regulatory processes related to the cell cycle that were targeted by tumor suppressor miRNAs (TSmiR). We performed colony formation assays in A549 and NCI‐H460 cell lines to test the tumor‐suppressive activity of downregulated miRNAs in cancer and identified 7 novel TSmiRs (miR‐144‐5p, miR‐218‐1‐3p, miR‐223‐3p, miR‐27a‐5p, miR‐30a‐3p, miR‐30c‐2‐3p, miR‐338‐5p). Two miRNAs, miR‐30a‐3p and miR‐30c‐2‐3p, showed differential survival characteristics in the Tumor Cancer Genome Atlas (TCGA) LUAD patient cohort indicating their prognostic value. Finally, we identified a network cluster of miRNAs and target genes that could be responsible for cell cycle regulation. Our study not only provides a dataset of miRNA as well as mRNA sequencing from the matched tumor–normal samples, but also reports several novel TSmiRs that could potentially be developed into prognostic biomarkers or therapeutic RNA drugs.

Overexpression of miR-758 inhibited proliferation, migration, invasion, and promoted apoptosis of non-small cell lung cancer cells by negatively regulating HMGB

Non-small cell lung cancer (NSCLC) is one of the most fatal types of cancer with significant mortality and morbidity worldwide. MicroRNAs (miRs) have been confirmed to have positive functions in NSCLC. In the present study, we try to explore the role of miR-758 in proliferation, migration, invasion, and apoptosis of NSCLC cells by regulating high-mobility group box (HMGB) 3 (HMGB3.) NSCLC and adjacent tissues were collected. Reverse transcription quantitative PCR (RT-qPCR) was employed to detect expression of miR-758 and HMGB3 in NSCLC and adjacent tissues, in BEAS-2B cells and NSCLC cell lines. The targetted relationship between miR-758 and HMGB3 was identified by dual luciferase reporter gene assay. The effects of miR-758 on proliferation, migration, invasion, cell cycle, and apoptosis of A549 cells. MiR-758 expression was lower in NSCLC tissues, which was opposite to HMGB3 expression. The results also demonstrated that miR-758 can target HMGB3. The cells transfected with miR-758 mimic had decreased HMGB3 expression, proliferation, migration, and invasion, with more arrested cells in G₁ phase and increased apoptosis. Our results supported that the overexpression of miR-758 inhibits proliferation, migration, and invasion, and promotes apoptosis of NSCLC cells by negative regulating HMGB2. The present study may provide a novel target for NSCLC treatment.

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.

Effects of microRNA-513b on cell proliferation, apoptosis, invasion, and migration by targeting HMGB3 through regulation of mTOR signaling pathway in non-small-cell lung cancer

This study aimed to explore the underlying mechanism of miR-513b and HMGB3 in regulating non-small-cell lung cancer (NSCLC). NSCLC tumor, adjacent tissues, and cell lines were extracted, and the expression of miR-513b and HMGB3 were determined by quantitative real-time polymerase chain reaction (RT-qPCR) and western blot analysis. Then, miR-513b was overexpressed in NSCLC cell, and the proliferation, migration, invasion, and apoptosis of cells were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), wound healing, transwell, and flow cytometry, respectively. Regulatory relationship between miR-513b and HMGB3 was determined using luciferase activity reporter assay. Lastly, HMGB3 and/or miR-513b were overexpressed in NSCLC cells, and the proliferation, migration, invasion, and apoptosis of cells were determined. Compared with the controls, the expression of miR-513b was significantly downregulated in the NSCLC tissues and cells lines by RT-qPCR ( p < 0.05). However, the expression of HMGB3 was significantly downregulated at both messenger RNA and protein levels ( p < 0.05). Overexpression of miR-513b could significantly inhibit the proliferation, invasion, migration, and promote apoptosis of NSCLC cells ( p < 0.05). HMGB3 was a target of miR-513b, and overexpression of HMGB3 could obviously reverse the effect of miR-513 on the proliferation, invasion, migration, and apoptosis of NSCLC cells ( p < 0.05). The present results could suggest miR-513b was downregulated in NSCLC and could regulate the proliferation, invasion, migration, and apoptosis of NSCLC cells via HMGB3.

Genomic analyses based on pulmonary adenocarcinoma in situ reveal early lung cancer signature

BACKGROUND

Non-small cell lung cancer (NSCLC) represents more than about 80% of the lung cancer. The early stages of NSCLC can be treated with complete resection with a good prognosis. However, most cases are detected at late stage of the disease. The average survival rate of the patients with invasive lung cancer is only about 4%. Adenocarcinoma in situ (AIS) is an intermediate subtype of lung adenocarcinoma that exhibits early stage growth patterns but can develop into invasion.

METHODS

In this study, we used RNA-seq data from normal, AIS, and invasive lung cancer tissues to identify a gene module that represents the distinguishing characteristics of AIS as AIS-specific genes. Two differential expression analysis algorithms were employed to identify the AIS-specific genes. Then, the subset of the best performed AIS-specific genes for the early lung cancer prediction were selected by random forest. Finally, the performances of the early lung cancer prediction were assessed using random forest, support vector machine (SVM) and artificial neural networks (ANNs) on four independent early lung cancer datasets including one tumor-educated blood platelets (TEPs) dataset.

RESULTS

Based on the differential expression analysis, 107 AIS-specific genes that consisted of 93 protein-coding genes and 14 long non-coding RNAs (lncRNAs) were identified. The significant functions associated with these genes include angiogenesis and ECM-receptor interaction, which are highly related to cancer development and contribute to the smoking-free lung cancers. Moreover, 12 of the AIS-specific lncRNAs are involved in lung cancer progression by potentially regulating the ECM-receptor interaction pathway. The feature selection by random forest identified 20 of the AIS-specific genes as early stage lung cancer signatures using the dataset obtained from The Cancer Genome Atlas (TCGA) lung adenocarcinoma samples. Of the 20 signatures, two were lncRNAs, BLACAT1 and CTD-2527I21.15 which have been reported to be associated with bladder cancer, colorectal cancer and breast cancer. In blind classification for three independent tissue sample datasets, these signature genes consistently yielded about 98% accuracy for distinguishing early stage lung cancer from normal cases. However, the prediction accuracy for the blood platelets samples was only 64.35% (sensitivity 78.1%, specificity 50.59%, and AUROC 0.747).

CONCLUSIONS

The comparison of AIS with normal and invasive tumor revealed diseases-specific genes and offered new insights into the mechanism underlying AIS progression into an invasive tumor. These genes can also serve as the signatures for early diagnosis of lung cancer with high accuracy. The expression profile of gene signatures identified from tissue cancer samples yielded remarkable early cancer prediction for tissues samples, however, relatively lower accuracy for boold platelets samples.

High mobility group box 3 as an emerging biomarker in diagnosis and prognosis of hepatocellular carcinoma

Purpose

High mobility group box 3 (HMGB3) is associated with hepatocytes malignant transformation by our previous work. We continued to investigate the diagnostic and prognostic values of HMGB3 for hepatocellular carcinoma (HCC).

Patients and methods

Circulating HMGB3 levels were quantitatively detected in a cohort of 225 patients with chronic liver diseases by ELISA and compared with alpha-fetoprotein by the receiver operating characteristic curve. HMGB3 expression in tissues of 170 HCC was detected by tissue microarray and immunohistochemistry. Relationship between HMGB3 level and HCC prognosis was evaluated by the Kaplan-Meier curves and Cox regression model.

Results

The incidence of serum HMGB3 >2.0 ng/mL was 75.6% in HCC (96/127), 20.8% in liver cirrhosis (10/48), 16.0% in chronic hepatitis (8/50), and none in healthy controls (0/49). Significant difference (P<0.001) of circulating HMGB3 level was found between HCC and benign liver diseases. Total diagnostic sensitivity of serum HMGB3 plus alpha-fetoprotein was up to 89.0% for HCC. Higher HMGB3 expression was confirmed to be 73.5% in HCC tissues (125/170) >30.6% in their paracancerous tissues (52/170). HMGB3 expression was closely related to tumor size, TNM stage, poor survival, and high recurrence, suggesting an independent prognosis factor for HCC.

Conclusion

HMGB3 with aberrant expression could be a novel diagnostic and prognostic marker for HCC.

Abnormal expression of HMGB-3 is significantly associated with malignant transformation of hepatocytes

AIM

To explore the relationship between dynamic expression of high mobility group box-3 (HMGB3) and malignant transformation of hepatocytes.

METHODS

Expression of HMGB family proteins were observed in rat hepatocarcinogenesis models induced with 2-acetylaminofluorene. Alterations of HMGB3 were analyzed at the mRNA level by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and at the protein level by immunohistochemistry or Western blotting. HMGB3 in human liver cancer tissues were evaluated using bioinformatics databases from GEO, TCGA, and Oncomine. A specific HMGB3-shRNA was used to knock down HMGB3 expression in order to investigate its effects on proliferation and cell cycle in vitro and in vivo.

RESULTS

Elevated HMGB3 levels were first reported in hepatocarcinogenesis, with increasing expression from normal liver to cancer. Bioinformatic databases showed that HMGB3 expression in hepatocellular carcinoma tissues was significantly higher than that in normal liver tissues. Higher HMGB3 expression was discovered in liver cancer cells compared with LO2 cells in vitro. According to gene set enrichment analysis, HMGB3 mRNA levels were correlated with cell cycle and DNA replication pathways. Knocking down HMGB3 by specific shRNA significantly inhibited proliferation of HepG2 cells by cell cycle arrest and downregulating DNA replication related genes (cyclin B1, FEN1, and PCNA) at the mRNA and protein level. Furthermore, silencing HMGB3 significantly inhibited xenograft tumor growth (measured by Ki67) in vivo.

CONCLUSION

HMGB3 is involved in malignant transformation of hepatocytes and could be a useful biomarker for diagnosis and a potential target for therapy of liver cancer.

Potential new biomarkers for squamous carcinoma of the uterine cervix

Aim

An in silico pathway analysis was performed in an attempt to identify new biomarkers for cervical carcinoma.

Methods

Three publicly available Affymetrix gene expression data sets (GSE5787, GSE7803, GSE9750) were retrieved, vouching for a total 9 cervical cancer cell lines, 39 normal cervical samples, 7 CIN3 samples and 111 cervical cancer samples. An Agilent data set (GSE7410; 5 normal cervical samples, 35 samples from invasive cervical cancer) was selected as a validation set. Predication analysis of microarrays was performed in the Affymetrix sets to identify cervical cancer biomarkers. We compared the lists of differentially expressed genes between normal and CIN3 samples on the one hand (n=1923) and between CIN3 and invasive cancer samples on the other hand (n=628).

Results

Seven probe sets were identified that were significantly overexpressed (at least 2 fold increase expression level, and false discovery rate <5%) in both CIN3 samples respective to normal samples and in cancer samples respective to CIN3 samples. From these, five probes sets could be validated in the Agilent data set (P<0.001) comparing the normal with the invasive cancer samples, corresponding to the genes DTL, HMGB3, KIF2C, NEK2 and RFC4. These genes were additionally overexpressed in cervical cancer cell lines respective to the cancer samples. The literature on these markers was reviewed.

Conclusion

Novel biomarkers in combination with primary human papilloma virus (HPV) testing may allow complete cervical screening by objective, non-morphological molecular methods, which may be particularly important in developing countries.

HMGB3 promotes growth and migration in colorectal cancer by regulating WNT/β-catenin pathway

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths and a major health problem. High mobility group box 3 (HMGB3), a member of the high-mobility group box (HMGB) family, was reported to be over-expressed in gastric carcinoma and bladder cancer. However, the function of HMGB3 in CRC remains unclear. Here, we found that HMGB3 was up-regulated in CRC at both mRNA and protein levels. qRT-PCR results showed that high expression of HMGB3 had positive correlation with serosal invasion, lymph metastasis, and tumor–node–metastasis (TNM) stage in CRC patient. Functional experiments showed that HMGB3 can promote CRC cells proliferation and migration in vitro. Moreover, we found HMGB3 can active WNT/β-catenin pathway to increase the expression level of c-Myc and MMP7. These results may be the reason for HMGB3 oncogene role in CRC. In summary, our data indicated that HMGB3 may serve as an oncoprotein and could be used as a potential prognostic marker in CRC.

Knockdown of High Mobility Group-Box 3 (HMGB3) Expression Inhibits Proliferation, Reduces Migration, and Affects Chemosensitivity in Gastric Cancer Cells

Background

High mobility group-box 3 (HMGB3) has been shown to affect tumor initiation and progression. This research aimed to investigate the role of HMGB3 in gastric cancer (GC) cell proliferation, migration, invasion, chemoresistance, and its potential molecular mechanisms.

Material/Methods

GC MGC803 and BGC823 cells were transfected with siRNA targeting the HMGB3 gene. The expressions of HMGB3 protein in MGC803 and BGC823 cells after transfection were detected by Western blot assays. We detected cell proliferation and cell cycle by MTT and flow cytometry assay. Cell migration and invasion were determined by wound scratch and transwell assay. MGC803 and BGC823 cells were treated with various concentrations of oxaliplatin, cisplatin, and paclitaxel. After 24 hours of drug exposure, we performed MTT assays to investigate chemoresistance in both groups. Western blot assays were used to detect related proteins expression.

Results

Silencing of HMGB3 inhibited cell proliferation and induced G0/G1 phase arrest of GC cells partly via modulating p53 and p21 pathways, and downregulating Bcl-2/Bax ratio. RNA interference of HMGB3 inhibited cell invasion and migration by downregulating MMP2 and MMP9. Silencing of HMGB3 enhanced sensitive to cisplatin and paclitaxel, and reduced sensitive to oxaliplatin.

Conclusions

These findings suggest the importance of HMGB3 in the regulation of growth, migration, and apoptosis of GC, improve our understanding of the mechanisms of GC pathogenesis, and may promote the development of novel targeted therapies.

Overexpression of HMGB3 protein promotes cell proliferation, migration and is associated with poor prognosis in urinary bladder cancer patients

Human urinary bladder cancer (UBC) is the fourth most common cancer and the eighth most common cause of cancer death in the USA. High mobility group box 3 (HMGB3), a member of a family of proteins containing one or more high mobility group DNA binding motifs, was reported to be overexpressed in a variety of human cancers. However, the expression and role of HMGB3 in human UBC remains unclear. Here, we found that UBC patients had upregulated HMGB at both mRNA and protein levels. Immunochemistry (IHC) evaluation of HMGB3 expression in 113 UBC clinical specimens showed that high expression of HMGB3 had positive correlation with UBC tumor size (P = 0.019), tumor WHO grade (P = 0.031), stage (P = 0.028), and lymph node metastasis (P = 0.017). Moreover, patients with higher HMGB3 expression showed a poorer overall survival rate than those with relatively low HMGB3 (P = 0.0079, log-rank test). Multivariate analysis revealed that HMGB3 expression is an independent prognostic marker. The UBC cancer cell proliferation and migration ability were measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and wound healing assays, respectively. RNA interference of HMGB3 in UBC cell lines inhibited cancer cell growth and migration, along with the downregulation of PCNA and MMP2 protein levels. In sum, our data suggests HMGB3 may serve as an important oncoprotein and indicate that overexpression of HMGB3 in UBC could be used as a potential prognostic marker.

HMGB1 in health and disease

Complex genetic and physiological variations as well as environmental factors that drive emergence of chromosomal instability, development of unscheduled cell death, skewed differentiation, and altered metabolism are central to the pathogenesis of human diseases and disorders. Understanding the molecular bases for these processes is important for the development of new diagnostic biomarkers, and for identifying new therapeutic targets. In 1973, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and termed high-mobility group (HMG) proteins. The HMG proteins include three superfamilies termed HMGB, HMGN, and HMGA. High-mobility group box 1 (HMGB1), the most abundant and well-studied HMG protein, senses and coordinates the cellular stress response and plays a critical role not only inside of the cell as a DNA chaperone, chromosome guardian, autophagy sustainer, and protector from apoptotic cell death, but also outside the cell as the prototypic damage associated molecular pattern molecule (DAMP). This DAMP, in conjunction with other factors, thus has cytokine, chemokine, and growth factor activity, orchestrating the inflammatory and immune response. All of these characteristics make HMGB1 a critical molecular target in multiple human diseases including infectious diseases, ischemia, immune disorders, neurodegenerative diseases, metabolic disorders, and cancer. Indeed, a number of emergent strategies have been used to inhibit HMGB1 expression, release, and activity in vitro and in vivo. These include antibodies, peptide inhibitors, RNAi, anti-coagulants, endogenous hormones, various chemical compounds, HMGB1-receptor and signaling pathway inhibition, artificial DNAs, physical strategies including vagus nerve stimulation and other surgical approaches. Future work further investigating the details of HMGB1 localization, structure, post-translational modification, and identification of additional partners will undoubtedly uncover additional secrets regarding HMGB1's multiple functions.

Upregulation of miR-513b inhibits cell proliferation, migration, and promotes apoptosis by targeting high mobility group-box 3 protein in gastric cancer

The high mobility group-box 3 (HMGB3) protein belongs to the high mobility group box (HMG-box) subfamily, and recent studies have shown that HMGB3 is an oncogene for leukemia. HMGB3 is also expressed at a high level in the progression phase of breast and gastric cancer (GC). Using bioinformatic analyses, we found that HMGB3 is a potential target for miR-513b. However, the pathophysiological role of miR-513b and its relevance to the growth and development of GC have yet to be investigated. This study focuses on whether miR-513b acts as a tumor suppressor in GC. Compared with non-malignant adjacent tissues samples, qRT-PCR data showed significant downregulation of miR-513b in 74 GC tissue samples (P < 0.01). Furthermore, western blotting revealed that HMGB3 protein was overexpressed in tumor samples relative to matched, non-malignant adjacent tissues. Western blotting and qRT-PCR results showed that high expression of HMGB3 and low expression of miR-513b were both significantly associated with primary tumors, lymph node metastases, and the clinical stage (P < 0.01). MiR-513b was shown to not only inhibit the proliferation and migration of gastric cancer cells (MKN45 and SGC7901) in the CCK-8 and transwell assays, but also to promote cell apoptosis in a flow-cytometric apoptosis assay. In western blot and luciferase assays, HMGB3 was identified as a major target of miR-513b. Moreover, we also found that the expression of HMGB3 lacking in 3' UTR could abrogate the anti-migration and pro-apoptosis function of miR-513b. These findings suggest the importance of miR-513b targeting of HMGB3 in the regulation of growth, migration and apoptosis of GC, improve our understanding of the mechanisms of GC pathogenesis, and may promote the development of novel targeted therapies.