Circ_LDLR promotes the progression of papillary thyroid carcinoma by regulating miR-1294/HMGB3 axis.

Circular RNAs (circRNAs) have been found to be associated with the development and progression of cancers including papillary thyroid carcinoma (PTC). Circ_LDLR has been reported to be highly expressed in PTC, but its underlying mechanism of action has not been fully elucidated. This study aimed to investigate the role of circ_LDLR in PTC. The expression of circ_LDLR, miR-1294 and high mobility group box (HMGB) 3 was detected by quantitative real-time polymerase chain reaction (qRT-PCR). CCK-8 assay and transwell assays were employed to value cell viability, invasion and migration abilities. Western blot assay was to detect HMGB3 protein expression. Luciferase reporter gene and pull down assay were used to validate the interaction between miR-1294 and HMGB3 or circ_LDLR. Circ_LDLR showed high expression levels in PTC tissues and cells and knockdown of it inhibited the growth, invasion, and migration of PTC cells. In addition, miR-1294 was considered as a downstream target of circ_LDLR, and inhibition of miR-1294 partially reversed the inhibitory effects of circ_LDLR knockdown on PTC cells growth, invasion, and migration. More importantly, HMGB3 was identified as a downstream target of miR-1294. Our findings suggest circ_LDLR may plays a promoting role in PTC by downregulating miR-1294 and upregulating HMGB3 expression. Therefore, circ_LDLR may serve as a valuable prognostic biomarker and therapeutic target for PTC.

HMGB3 promotes the malignant phenotypes and stemness of epithelial ovarian cancer through the MAPK/ERK signaling pathway.

BACKGROUND: Ovarian cancer, particularly epithelial ovarian cancer (EOC), is the leading cause of cancer-related mortality among women. Our previous study revealed that high HMGB3 levels are associated with poor prognosis and lymph node metastasis in patients with high-grade serous ovarian carcinoma; however, the role of HMGB3 in EOC proliferation and metastasis remains unknown. METHODS: MTT, clonogenic, and EdU assays were used to assess cell proliferation. Transwell assays were performed to detect cell migration and invasion. Signaling pathways involved in HMGB3 function were identified by RNA sequencing (RNA-seq). MAPK/ERK signaling pathway protein levels were evaluated by western blot. RESULTS: HMGB3 knockdown inhibited ovarian cancer cell proliferation and metastasis, whereas HMGB3 overexpression facilitated these processes. RNA-seq showed that HMGB3 participates in regulating stem cell pluripotency and the MAPK signaling pathway. We further proved that HMGB3 promotes ovarian cancer stemness, proliferation, and metastasis through activating the MAPK/ERK signaling pathway. In addition, we demonstrated that HMGB3 promotes tumor growth in a xenograft model via MAPK/ERK signaling. CONCLUSIONS: HMGB3 promotes ovarian cancer malignant phenotypes and stemness through the MAPK/ERK signaling pathway. Targeting HMGB3 is a promising strategy for ovarian cancer treatment that may improve the prognosis of women with this disease. Video Abstract.

Anxiolytic, Analgesic and Anti-Inflammatory Effects of Peptides Hmg 1b-2 and Hmg 1b-4 from the Sea Anemone Heteractis magnifica.

Acid-sensing ion channels (ASICs) have been known as sensors of a local pH change within both physiological and pathological conditions. ASIC-targeting peptide toxins could be potent molecular tools for ASIC-manipulating in vitro, and for pathology treatment in animal test studies. Two sea anemone toxins, native Hmg 1b-2 and recombinant Hmg 1b-4, both related to APETx-like peptides, inhibited the transient current component of human ASIC3-Δ20 expressed in Xenopus laevis oocytes, but only Hmg 1b-2 inhibited the rat ASIC3 transient current. The Hmg 1b-4 action on rASIC3 as a potentiator was confirmed once again. Both peptides are non-toxic molecules for rodents. In open field and elevated plus maze tests, Hmg 1b-2 had more of an excitatory effect and Hmg 1b-4 had more of an anxiolytic effect on mouse behavior. The analgesic activity of peptides was similar and comparable to diclofenac activity in an acid-induced muscle pain model. In models of acute local inflammation induced by λ-carrageenan or complete Freund's adjuvant, Hmg 1b-4 had more pronounced and statistically significant anti-inflammatory effects than Hmg 1b-2. It exceeded the effect of diclofenac and, at a dose of 0.1 mg/kg, reduced the volume of the paw almost to the initial volume. Our data highlight the importance of a comprehensive study of novel ASIC-targeting ligands, and in particular, peptide toxins, and present the slightly different biological activity of the two similar toxins.

SOX9 and HMGB3 co-operatively transactivate NANOG and promote prostate cancer progression.

BACKGROUND: The homeodomain-containing transcription factor NANOG is overexpressed in prostate adenocarcinoma (PCa) and predicts poor prognosis. The SOX family transcription factor SOX9, as well as the transcription co-activator HMGB3 of the HMGB family, are also overexpressed and may play pivotal roles in PCa. However, it is unknown whether SOX9 and HMGB3 interact with each other, or if they regulate NANOG gene transcription. METHODS: We identified potential SOX9 responsive elements in NANOG promoter, and investigated if SOX9 regulated NANOG transcription in co-operation with HMGB3 by experimental analysis of potential SOX9 binding sites in NANOG promoter, reporter gene transcription assays with or without interference or artificial overexpression of SOX9 and/or HMGB3, and protein-binding assays of SOX9-HMGB3 interaction. Clinicopathologic and prognostic significance of SOX9-HMGB3 overexpression in PCa was analyzed. RESULTS: SOX9 activated NANOG gene transcription by preferentially binding to a highly conserved consensus cis-regulatory element (-573 to -568) in NANOG promoter, and promoted the expression of NANOG downstream oncogenic genes. Importantly, HMGB3 functioned as a partner of SOX9 to co-operatively enhance transactivation of NANOG by interacting with SOX9, predominantly via the HMG Box A domain of HMGB3. Overexpression of SOX9 and/or HMGB3 enhanced PCa cell survival and cell migration and were significantly associated with PCa progression. Notably, Cox proportional regression analysis showed that co-overexpression of both SOX9 and HMGB3 was an independent unfavorable prognosticator for both CRPC-free survival (relative risk [RR] = 3.779，95% confidence interval [CI]: 1.159-12.322, p = 0.028) and overall survival (RR = 3.615，95% CI: 1.101-11.876, p = 0.034). CONCLUSIONS: These findings showed a novel SOX9/HMGB3/NANOG regulatory mechanism, deregulation of which played important roles in PCa progression.

Circ-IGF1R Affects the Progression of Colorectal Cancer by Activating the miR-362-5p/HMGB3-Mediated Wnt/ß-Catenin Signal Pathway.

The aim of this study was to investigate the role of circRNA insulin growth factor 1 receptor (circ-IGF1R) in colorectal cancer (CRC). Glycolytic metabolism was analyzed by glucose uptake and lactate production using the corresponding kits. The protein levels were determined using Western blot. The effect of circ-IGF1R on CRC in vivo was explored by xenograft experiment in mice. Circ-IGF1R was up-regulated in CRC tissues and cells. Knockdown of circ-IGF1R inhibited proliferation, migration, invasion and glycolysis but induced apoptosis of CRC cells. Circ-IGF1R interacted with miR-362-5p and miR-362-5p inhibitor attenuated the anti-tumor effects of circ-IGF1R downregulation on CRC cells. HMGB3 acted as a downstream target for miR-362-5p, and circ-IGF1R facilitated the malignant behaviors of CRC cells by regulating HMGB3. Circ-IGF1R activated the Wnt/ß-catenin pathway via targeting miR-362-5p/HMGB3 axis. Tumor growth in vivo was reduced after knockdown of circ-IGF1R. Circ-IGF1R might be a novel biomolecular target for CRC diagnosis and treatment.

Tanshinone IIA (TSIIA) represses the progression of non-small cell lung cancer by the circ_0020123/miR-1299/HMGB3 pathway.

Tanshinone IIA (TSIIA), a multi-pharmaceutical compound, has been demonstrated to have anti-tumor properties. This study explores the potential regulatory mechanism of TSIIA on non-small cell lung cancer (NSCLC) progression. The cytotoxicity of TSIIA was evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) and LDH (lactate dehydrogenase) assays. Expression levels of circ_0020123 (hsa_circ_0020123) and microRNA-1299 (miR-1299) were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, migration, invasion, and apoptosis were analyzed by MTT, colony formation, transwell, wound-healing, or flow cytometry assays. The relationship between miR-1299 and circ_0020123 or HMGB3 (high mobility group box 3) was verified by the dual-luciferase reporter and/or RNA immunoprecipitation (RIP) assays. Protein level of HMGB3 was measured by western blotting. The relationship between TSIIA and circ_0020123 was confirmed by xenograft assay. TSIIA reduced xenograft tumor growth in vivo and repressed proliferation, migration, invasion, and facilitated apoptosis of NSCLC cells in vitro. TSIIA reduced circ_0020123 and HMGB3 expression, whereas elevated miR-1299 expression in NSCLC cells. Circ_0020123 knockdown enhanced the repressive influence of TSIIA treatment on the malignancy of NSCLC cells in vitro and in vivo. Circ_0020123 sponged miR-1299 to regulate HMGB3 expression under TSIIA treatment. MiR-1299 inhibitor reversed circ_0020123 knockdown-mediated influence on malignant behaviors of NSCLC cells under TSIIA treatment. HMGB3 elevation offset the suppressive impact of miR-1299 mimic on the malignancy of NSCLC cells under TSIIA treatment. TSIIA curbed NSCLC progression by the circ_0020123/miR-1299/HMGB3 axis, manifesting that the TSIIA/circ_0020123/miR-1299/HMG regulatory network might be a potential treatment strategy for NSCLC.

Translocated HMGB3 is involved in papillary thyroid cancer progression by activating cytoplasmic TLR3 and transmembrane TREM1.

The family of high mobility group box (HMGB) proteins participates in various biological processes including immunity, inflammation, as well as cancer formation and progression. However, its role in thyroid cancer remains to be clarified. We performed quantitative RT-PCR (qRT-PCR), western blot, enzyme-linked immunosorbent, immunohistochemistry, and immunofluorescence assays to evaluate the expression level and subcellular location of HMGB3. The effects of HMGB3 knockdown on malignant biological behaviors of thyroid cancer were determined by cell proliferation assays, cell cycle and apoptosis assays, and transwell chamber migration and invasion assays. Differential expression genes (DEGs) altered by HMGB3 were analyzed using the Ingenuity Pathway Analysis (IPA) and TRRUST v2 database. HMGB3 correlated pathways predicted by bioinformatic analysis were then confirmed using western blot, co-immunoprecipitation, dual-luciferase reporter assay, and flow cytometry. We found that HMGB3 is overexpressed and its downregulation inhibits cell viability, promotes cell apoptosis and cell cycle arrest, and suppresses cell migration and invasion in thyroid cancer. In PTC, both tissue and serum levels of HMGB3 are elevated and are correlated with lymph node metastasis and advanced tumor stage. Mechanistically, we observed the translocation of HMGB3 in PTC, induced at least partially by hypoxia. Cytoplasmic HMGB3 activates nucleic-acid-mediated TLR3/NF-κB signaling and extracellular HMGB3 interacts with the transmembrane TREM1 receptor in PTC. This study demonstrates the oncogenic role of HMGB3 cytoplasmic and extracellular translocation in papillary thyroid cancers; we recommend its future use as a potential circulating biomarker and therapeutic target for PTC.

Designing a humanized immunotoxin based on DELTA-stichotoxin-Hmg2a toxin: an in silico study.

Breast cancer remains the most frequently diagnosed cancer and the principal cause of mortality by malignancy in women. HER2 positive subtype includes 15-20% of breast cancer cases. This receptor could be an appropriate mark for targeting breast cancer cells. Immunotherapy methods compared to current cancer treatment methods have the lowest side effects. DELTA-stichotoxin-Hmg2a is isolated from the sea anemone and kills cells through pore formation. In the current study, we designed and evaluated an immunotoxin composed of pertuzumab and DELTA-stichotoxin-Hmg2a-derived scFv by bioinformatics tools. The designed immunotoxin was constructed using the amino acid sequences. Then, secondary structure and physico-chemical features were studied, and the tertiary structure of the immunotoxin was built according to the homology modeling methods. The validation and allergenicity of the model were assessed. The immunotoxin and receptor were docked and molecular dynamics simulation indicated the construct stability. The analysis results indicated that the construct is a stable protein that could have a natural-like structure and would not be an allergen, so this immunotoxin could effectively target HER2 receptors. Therefore, our designed immunotoxin could be an appropriate immunotoxin against HER2-positive breast cancer and could be a challenging topic for future in vitro and in vivo studies.

Long Noncoding RNA Brain Cytoplasmic RNA 1 Induces Cisplatin-Resistance of Cervical Cancer Cells by Sponging MicroRNA-330-5p and Upregulating High-Mobility Group Box 3.

OBJECTIVES: The aim of the study was to find out the function of long noncoding RNA brain cytoplasmic RNA 1 (BCYRN1) in cisplatin (DDP)-resistance of cervical cancer (CC) cells. Design and Materials, Setting, Methods: BCYRN1 expression in CC and DDP-resistant cells was evaluated, with the association of BCYRN1 and prognosis analyzed. Then, DDP-resistant cells with BCYRN1 knockdown were established and the DDP-resistance of these cells was assessed. BCYRN1 subcellular localization was detected and confirmed. Besides, the binding relations of BCYRN1 and microRNA (miR)-330-5p and between miR-330-5p and high-mobility group box 3 (HMGB3) were examined and verified. Moreover, the role of miR-330-5p and HMGB3 in the mechanism of BCYRN1 modulating DDP-resistance of CC cells was detected. In addition, xenograft transplantation was conducted to confirm the effect of BCYRN1 in CC cell DDP-resistance. RESULTS: BCYRN1 was overexpressed in CC, which resulted in poor prognosis and DDP-resistance. BCYRN1 knockdown in DDP-resistant cells downregulated DDP-resistance. Mechanically, BCYRN1 sponged miR-330-5p to strengthen HMGB3 mRNA level. Besides, miR-330-5p underexpression or HMGB3 overexpression reversed the function of BCYRN1 knockdown in inhibiting DDP-resistance of CC cells. Eventually, BCYRN1 knockdown reduced the DDP-resistance of CC cells in vivo. LIMITATIONS: There are still some deficiencies in the research; for example, whether there are other miRs working as the downstream genes of BCYRN1 in the competing endogenous RNA interaction is not fully clarified, nor the other downstream mechanisms of miR-330-5p. Besides, the experimental findings and their application into practice need extensive validation. CONCLUSIONS: BCYRN1 knockdown could disrupt the DDP-resistance of CC cells through upregulating miR-330-5p to suppress HMGB3 mRNA level.

HMGB3 inhibition by miR-142-3p/sh-RNA modulates autophagy and induces apoptosis via ROS accumulation and mitochondrial dysfunction and reduces the tumorigenic potential of human breast cancer cells.

AIMS: High mobility group box (HMGB) family proteins, HMGB1, HMGB2, HMGB3, and HMGB4 are oncogenic. The oncogenic nature of HMGB1 is characterized by its association with autophagy, ROS, and MMP. Since HMGB3 is its paralog, we hypothesized that it might also modulate autophagy, ROS, and MMP. Hence, we targeted HMGB3 using its shRNA or miR-142-3p and assessed the changes in autophagy, ROS, MMP, and tumorigenic properties of human breast cancer cells. MAIN METHODS: Cell viability was assessed by resazurin staining and annexin-V/PI dual staining was used for confirming apoptosis. Colony formation, transwell migration, invasion and luciferase reporter (for miRNA-target validation) assays were also performed. ROS and MMP were detected using DHE and MitoTracker dyes, respectively. A zebrafish xenograft model was used to assess the role of miR-142-3p on in vivo metastatic potential of breast cancer cells. KEY FINDINGS: Breast cancer tissues from Indian patients and TCGA samples exhibit overexpression of HMGB3. miR-142-3p binds to 3' UTR of HMGB3, leading to its downregulation that subsequently inhibits colony formation and induces apoptosis involving increased ROS accumulation and decreased MMP, phospho-mTOR and STAT3. Our findings show that HMGB3 is directly involved in the miR-142-3p-mediated disruption of autophagy and induction of apoptotic cell death via modulation of LC3, cleaved PARP and Bcl-xL. In addition, miR-142-3p inhibited migration, invasion and metastatic potential of breast cancer cells. SIGNIFICANCE: Our findings highlighted the role of HMGB3, for the first time, in the modulation of autophagy and apoptosis in human breast cancer cells, and these results have therapeutic implications.

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.

miR-142-3p simultaneously targets HMGA1, HMGA2, HMGB1, and HMGB3 and inhibits tumorigenic properties and in-vivo metastatic potential of human cervical cancer cells.

AIMS: High-mobility group (HMG) proteins are oncogenic in different cancers, including cervical cancer; silencing their individual expression using sh-RNAs, siRNAs, and miRNAs has had anti-tumorigenic effects, but the consequences of their collective downregulation are not known. Since multiple gene targeting is generally very effective in cancer therapy, the present study highlighted the consequences of silencing the expression of HMGA1, A2, B1, and B3 using sh-RNAs or miR-142-3p (that can potentially target HMGA1, A2, B1, and B3) in cervical cancer cell lines. MAIN METHODS: 3' UTR luciferase reporter assays were performed to validate HMGA1, A2, B1, and B3 as targets of miR-142-3p in human cervical cancer cells. Annexin V/PI dual staining and flow cytometry analyses were used to detect apoptotic cells. miR-142-3p-mediated regulation of cell death, colony formation, migration, and invasion was investigated in human cervical cancer cells together with in vivo metastasis in zebrafish. KEY FINDINGS: Concurrent knockdown of HMGA1, A2, B1, and B3 through their corresponding sh-RNAs inhibited cell viability and colony formation but induced apoptosis, and these effects were relatively reduced upon their individual knockdown. miR-142-3p targeted HMGA1, A2, B1, and B3 by binding to their 3'UTRs and induced apoptosis but inhibited proliferation, migration, and invasion of human cervical cancer cells. In addition, miR-142-3p expression decreased phospho-p65 and EMT-related proteins in cervical cancer cells and their in vivo metastatic potential upon implantation in zebrafish. SIGNIFICANCE: These findings suggest that miR-142-3p acts as a tumor-suppressive miRNA by targeting HMGA1, A2, B1, and B3 and may serve as a potential therapeutic agent in human cervical cancer.

SYT7 plays a role in promoting thyroid cancer by mediating HMGB3 ubiquitination.

Thyroid cancer is one of the most common endocrine malignancies. It is necessary to discover more effective molecular targets for the treatment of thyroid cancer. The results of immunohistochemical staining, qPCR and Western blot indicated that the expression of SYT7 in thyroid cancer tissues and cells was higher than that in paracarcinoma tissues and normal thyroid cells. Through cell function testing experiments, it was found that SYT7 knockdown inhibited the proliferation and migration of thyroid cancer cells and promoted cell apoptosis, while SYT7 overexpression had the opposite effect. Similarly, SYT7 downregulation also suppressed tumor growth in vivo. HMGB3 was confirmed to be the downstream gene of SYT7 by GeneChip and Ingenuity Pathway Analysis. Besides, through UbiBrowser database predictions and Co-IP assays, we found that SYT7 interacted with BRCA1 to inhibit HMGB3 ubiquitination and thus upregulated the protein level of HMGB3. Similar to SYT7, HMGB3 was significantly upregulated in thyroid cancer. HMGB3 knockdown inhibited the proliferation and migration of thyroid cancer cells and promoted cell apoptosis. Furthermore, HMGB3 knockdown restored the promotion of cell proliferation and migration caused by SYT7 overexpression. SYT7 and HMGB3 were upregulated in thyroid cancer, and SYT7 regulated the expression of HMGB3 through BRCA1-mediated ubiquitination of HMGB3 to promote thyroid cancer progression.

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.

Circ_CLIP2 promotes glioma progression through targeting the miR-195-5p/HMGB3 axis.

BACKGROUND: Circular RNA (circRNA) has been demonstrated to play key roles in regulating glioma progression. Understanding the regulatory mechanism of circRNA in glioma is vital to reveal the pathogenesis of glioma and develop novel therapeutic strategies. Therefore, our study focuses on the role and underlying mechanism of Circ_CLIP2 in glioma. METHODS: The expression of Circ_CLIP2, miR-195-5p and HMGB3 in glioma cells and tissues were analyzed using qRT-PCR. Cell proliferation was determined with colony formation and MTT assays. Cell cycle and apoptosis were examined by flow cytometry. Western blot was conducted for analyzing HMGB3, PCNA, Bax, Bcl-2, cleaved-caspase 3, Wnt-1 and ß-catenin. Dual-luciferase reporter assay was measured to investigate the interaction among Circ_CLIP2, miR-195-5p and HMGB3. RESULTS: The expression of Circ_CLIP2 and HMGB3 were increased while miR-195-5p was down-regulated in glioma cells and patients. Silencing of Circ_CLIP2 inhibited cell proliferation, enhanced cell apoptosis and inhibited the Wnt/ß-catenin signaling pathway. Circ_CLIP2 suppressed miR-195-5p expression by directly sponging miR-195-5p. MiR-195-5p inhibited HMGB3 expression via directly targeting HMGB3. Knockdown of miR-195-5p facilitated cell proliferation, inhibited cell apoptosis and activated Wnt/ß-catenin signaling, which were reversed by silencing of HMGB3. CONCLUSION: Knockdown of Circ_CLIP2 suppresses glioma progression by targeting miR-195-5p/HMGB3 thus inhibiting Wnt/ß-catenin signaling. This study may provide potential therapeutic targets against glioma.

LINC00319 promotes cancer stem cell-like properties in laryngeal squamous cell carcinoma via E2F1-mediated upregulation of HMGB3.

Laryngeal squamous cell carcinoma (LSCC) is one of the most common subtypes of head and neck malignancies worldwide. Long intervening/intergenic noncoding RNAs (LINCRNAs) have been recently implicated in various biological processes that take place in the setting of laryngeal cancer, but the regulatory role of LINC00319 in LSCC remains largely unknown. The current study aimed to elucidate the regulatory effect of LINC00319 on the development and progression of LSCC via high-mobility group box 3 (HMGB3). Microarray-based analysis was initially conducted to identify differentially expressed long noncoding RNAs, after which the expression of LINC00319 and HMGB3 in LSCC tissues and cells was determined accordingly. CD133+CD144+ TU177 cells were subsequently isolated and transfected with LINC00319 overexpression vector (oe-LINC00319), short hairpin RNA (sh)-LINC00319, sh-HMGB3, sh-E2F transcription factor 1 (E2F1), and oe-E2F1, as well as their corresponding controls. The proliferative, invasion, self-renewal, and tumorigenic abilities of CD133+CD144+ TU177 cells were then evaluated. Our in vitro findings were further confirmed following subcutaneous injection of cells expressing the corresponding plasmids into nude mice. LINC00319 and HMGB3 expressions were elevated in LSCC cells and tissues. LINC00319 increased HMGB3 expression by recruiting E2F1. Furthermore, the stimulatory role of LINC00319 on the proliferation, invasion, self-renewal ability, and tumorigenicity of CD133+CD144+ TU177 cells was achieved by upregulating HMGB3 via recruitment of E2F1. The in vitro findings were also confirmed by in vivo experiments. Taken together, these data show that downregulating LINC00319 in CD133+CD144+ TU177 cells may serve as a potential anticancer regimen by inhibiting the proliferation and invasion of cancer stem cells in LSCC.

Down-regulation of SNHG16 alleviates the acute lung injury in sepsis rats through miR-128-3p/HMGB3 axis.

BACKGROUND: Long noncoding RNAs contribute to various inflammatory diseases, including sepsis. We explore the role of small nucleolar RNA host gene 16 (SNHG16) in sepsis-mediated acute lung injury (ALI) and inflammation. METHODS: A sepsis-induced ALI rat model was constructed by the cecal ligation and perforation method. The profiles of SNHG16, miR-128-3p, and high-mobility group box 3 (HMGB3) were monitored by quantitative reverse transcription PCR and Western blot. The pathologic changes of lung tissues were evaluated by Hematoxylin-Eosin staining, immunohistochemistry, and dry and wet method. Meanwhile, the pro-inflammatory factors and proteins were determined by ELISA and Western blot. In contrast, a sepsis model in BEAS-2B was induced with lipopolysaccharide (LPS) to verify the effects of SNHG16/miR-128-3p/HMGB3 on lung epithelial cell viability and apoptosis. RESULTS: As a result, SNHG16 and HMGB3 were up-regulated, while miR-128-3p was down-regulated in sepsis-induced ALI both in vivo and in vitro. Inhibiting SNHG16 reduced the apoptosis and inflammation in the sepsis-induced ALI model. Overexpressing SNHG16 promoted LPS-mediated lung epithelial apoptosis and inhibited cell viability and inflammation, while miR-128-3p had the opposite effects. Mechanistically, SNHG16 targeted miR-128-3p and attenuated its expression, while miR-128-3p targeted the 3' untranslated region of HMGB3. CONCLUSIONS: Overall, down-regulating SNHG16 alleviated the sepsis-mediated ALI by regulating miR-128-3p/HMGB3.

Accumulation of CD45RO+CD8+ T cells is a diagnostic and prognostic biomarker for clear cell renal cell carcinoma.

Renal cell carcinoma is characterized by high immunogenicity and infiltration of immune cells. CD45RO+CD8+ T cells are well known as a critical role in host defense of the immune environment. However, their role in clear cell renal carcinoma (ccRCC) remains unknown. To elucidate the clinical importance of CD45RO+CD8+ T cells in ccRCC as well as its underlying mechanism, we analyzed several types of peripheral immune cells from 274 patients with ccRCC who have received radical or partial nephrectomy and 350 healthy people. Flow cytomety assays showed there was no significant difference in the proportions of CD8+ T cells and its subtypes other than CD45RO+/CD45RA+CD8+ cells. Both gene and protein expression levels of CD45RO in ccRCC tissues were decreased. CD45RO+CD8+ T cells showed increased proliferative abilities but decreased apoptotic abilities through MAPK signaling activation in ccRCC. High expression level of CD45RO+CD8+ T cells inhibited ccRCC progression, including proliferation, invasion, as well as autophagy of ccRCC through many signaling pathways. Bioinformatics and immunohistochemical chip analysis measured gene and protein levels of CD45RO and other related proteins. The combination of UCHL1, HMGB3, and CD36 has diagnostic value in ccRCC and is able to predict prognosis. Collectively, CD45RO+CD8+ T cells play a critical role in ccRCC progression and may be regarded as clinical indicators.

Nuclear exosome HMGB3 secreted by nasopharyngeal carcinoma cells promotes tumour metastasis by inducing angiogenesis.

Distant metastasis accompanied by angiogenesis is the main cause of nasopharyngeal carcinoma (NPC)-related death. Nuclear exosomes (nEXOs) are potential tumour biomarkers. High mobility group box 3 (HMGB3), a nuclear protein, is known to be overexpressed in cancers. However, its role in NPC has not been elucidated. Here, we explore for the first time the function of nEXO HMGB3 in tumour angiogenesis involved in NPC metastasis using a series of in vitro experiments with NPC cell lines and clinical specimens and in vivo experiments with tumour xenograft zebrafish angiogenesis model. We found a high expression of HMGB3 in NPC, accompanied by the formation of micronuclei, to be associated with metastasis. Furthermore, the NPC-secreted HMGB3 expression was associated with tumour angiogenesis. Moreover, HMGB3-containing nEXOs, derived from the micronuclei of NPC cells, were ingested by the human umbilical vein endothelial cells (HUVECs), and accelerated angiogenesis in vitro and in vivo. Importantly, western blotting and flow cytometry analysis showed that circulating nEXO HMGB3 positively correlated with NPC metastasis. In summary, nEXO HMGB3 can be a significant biomarker of NPC metastasis and provide a novel basis for anti-angiogenesis therapy in clinical metastasis.

Integrated analysis of ceRNA network and tumor-infiltrating immune cells in esophageal cancer.

BACKGROUND: Esophageal cancer (ESCA) is one of the most commonly diagnosed cancers in the world. Tumor immune microenvironment is closely related to tumor prognosis. The present study aimed at analyzing the competing endogenous RNA (ceRNA) network and tumor-infiltrating immune cells in ESCA. METHODS: The expression profiles of mRNAs, lncRNAs, and miRNAs were downloaded from the Cancer Genome Atlas database. A ceRNA network was established based on the differentially expressed RNAs by Cytoscape. CIBERSORT was applied to estimate the proportion of immune cells in ESCA. Prognosis-associated genes and immune cells were applied to establish prognostic models basing on Lasso and multivariate Cox analyses. The survival curves were constructed with Kaplan-Meier method. The predictive efficacy of the prognostic models was evaluated by the receiver operating characteristic (ROC) curves. RESULTS: The differentially expressed mRNAs, lncRNAs, and miRNAs were identified. We constructed the ceRNA network including 23 lncRNAs, 19 miRNAs, and 147 mRNAs. Five key molecules (HMGB3, HOXC8, HSPA1B, KLHL15, and RUNX3) were identified from the ceRNA network and five significant immune cells (plasma cells, T cells follicular helper, monocytes, dendritic cells activated, and neutrophils) were selected via CIBERSORT. The ROC curves based on key genes and significant immune cells all showed good sensitivity (AUC of 3-year survival: 0.739, AUC of 5-year survival: 0.899, AUC of 3-year survival: 0.824, AUC of 5-year survival: 0.876). There was certain correlation between five immune cells and five key molecules. CONCLUSION: The present study provides an effective bioinformatics basis for exploring the potential biomarkers of ESCA and predicting its prognosis.