3146

HMGB1

high mobility group box 1;HMGB1;high mobility group box 1

Amphoterin|HMG-1|Sulfoglucuronyl carbohydrate binding protein|high mobility group protein 1|high mobility group protein B1|high-mobility group (nonhistone chromosomal) protein 1|high-mobility group box 1

13q12

protein-coding

OBJECTIVE: To investigate the association between high mobility group box1 (HMGB1) and cervical squamous cell carcinoma (CSCC), and explore the role of HMGB1/RAGE pathway in the metastasis of CSCC. METHODS: Levels of HMGB1 mRNA and RAGE mRNA in CSCC and normal cervical tissues were detected by real time quantitative polymerase chain reaction (qRT-PCR), and the level of HMGB1 protein was determined by immunohistochemistry and Western blotting. RESULTS: The mRNA and protein expression of HMGB1 was significantly higher in CSCC than that in normal cervical tissue (P < 0.05), correlated with stage, invasion and metastasis (P < 0.05), but not with tumor size and differentiation (P > 0.05). The levels of RAGE mRNA and HMGB1 mRNA were both significantly higher (r = 0.663, P < 0.05) in metastatic CSCC in comparison with those in the non-metastatic cases. CONCLUSION: HMGB1 is involved in the invasion and metastasis of CSCC, and HMGB1/RAGE pathway plays an important role in the metastasis of CSCC.

BACKGROUND: cancer-secreted high mobility group 1 (HMGB1) induces apoptosis of macrophages and suppresses the host anti-cancer immune system. OBJECTIVE: We here examined the effect of HMGB1 on macrophages in the lymph nodes of colorectal cancer (CRC) patients. METHODS: Regional lymph nodes of 50 Dukes C CRCs were compared with 50 Dukes B CRCs. RESULTS: Dukes C tumors exhibited higher HMGB1 labeling indices and higher HMGB1 concentrations in primary tumors than Dukes B CRCs. Macrophages in the regional lymph nodes were decreased in non-metastasized nodes as well as metastasized nodes in Dukes C cases, whereas macrophage numbers in Dukes B nodes were higher than in Dukes C nodes. Nodal HMGB1 concentration was higher in Dukes C nodes than in Dukes B nodes, being inversely correlated with macrophage numbers. Nodal HMGB1 concentration was correlated with HMGB1 concentration and lymph vessel density in the primary tumors. CONCLUSION: These data suggest that HMGB1 secreted from primary tumors spread to the regional lymph nodes decreases the number of macrophages to attenuate the anti-metastatic defense of the lymph nodes in patients with CRCs.

The objective is to explore the expression of high mobility group box 1 (HMGB1) in esophageal squamous cell carcinoma (ESCC) and its relationship with lymph node metastasis and the prognosis of patients as well as possible mechanism. The expression of HMGB1, vascular endothelial growth factor C (VEGF-C) and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1) in ESCC tissues, which were obtained from 72 patients who underwent radical esophagectomy, was detected through immunohistochemistry, firstly. The correlations between HMGB1 and VEGF-C, and micro-lymphatic vessel density (MLD), and lymph node metastasis, and the prognosis of patients, were analyzed by statistic analysis. The plasmid of small interference RNA (siRNA) targeting HMGB1, giving siHMGB1, was transfected into exponentially growing KYSE150 human esophageal squamous cancer cells and the expression of HMGB1 mRNA and protein was observed by Real-time PCR and Western Blot and the expression of VEGF-C was examined by ELISA. HMGB1 expressed highly in the nuclei and cytoplasm of carcinoma cells as well as the extracellular space in ESCC and was associated with lymph node metastasis, MLD, the expression of VEGF-C, TNM stage and the prognosis of patients (P < 0.05 or P < 0.01). In vitro, siHMGB1 inhibited the expression of HMGB1 mRNA and protein and the secretion of VEGF-C in KYSE150 cells. In ESCC, HMGB1 expresses highly and affects the prognosis of patients through regulating the expression of VEGF-C to promote lymphangiogenesis and lymph node metastasis, and HMGB1 might serve as the marker of progression and potential target for anti-lymphangiogenesis therapy.

OBJECTIVE: To investigate the expression and biological significance of HMGB1 and VEGF protein in tissue specimens of laryngeal squamous cell carcinoma (LSCC), and further study the correlation between HMGB1 and VEGF protein. METHOD: The expression of HMGB1 and VEGF protein was evaluated by immunohistochemical staining in 69 cases of LSCC specimens and 15 cases of adjacent epithelial tissue samples, and futher correlated with clinicopathologic parameters. RESULT: The positive rates of HMGB1 and VEGF in LSCC tissues were significantly higher than those in adjacent non-cancerous mucosa (P < 0.01), and the expression of these two marks was closely correlated with clinical stage (P < 0.05) and metastasis (P < 0.05) in LSCC. While the expression of HMGB1 and VEGF had no significant correlations with age, sex, histological differentiation and tumor site (P > 0. 05). There was a positive correlation between the expression of HMGB1 and VEGF (P < 0.05). The Kaplan-Meier survival analysis showed that patients with strong expression of HMGB1 or VEGF had poorer overall survival compared with that in patients with relative low HMGB1 or VEGF expression (P < 0.05). Multivariate COX regression analysis revealed that both lymph node metastasis and HMGB1 expression were independent prognostic factors for patients with LSCC. CONCLUSION: This study demonstrated that HMGB1 and VEGF protein overexpression were closely associated with clinical stage, metastasis and poorer prognosis in patients with LSCC. Increased expression of these two proteins in LSCC suggested that HMGB1 and VEGF might play a critical role in the initiation and progression of LSCC.

OBJECTIVE: To investigate the mRNA and protein expressions of high mobility group box-1 (HMGB1) in the tumor tissues and sera of patients with laryngeal squamous cell carcinoma (LSCC) and their clinical significance. METHODS: Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot were used to detected the expressions of HMGB1 mRNA and protein in the tumors and adjacent normal epithelial tissues in 30 patients with LSCC. Serum HMGB1 protein levels in the patients with LSCC and in 10 healthy volunteers were detected with enzyme-linked immunosorbent adsorption experiment (ELISA). RESULTS: RT-PCR demonstrated that the mean relative mRNA expression levels of HMGB1 (HMGB1/GAPDH) in LSCC tissues and in adjacent normal epithelial tissues were 1.25 +/- 0.12 and 0.32 +/- 0.04, respectively (t = 40.27, P < 0.05). Western blot revealed that the mean relative protein expression levels of HMGB1 (HMGB1/beta-actin) were 1.29 +/- 0.10 and 0.34 +/- 0.03 (t = 49.84, P < 0.05), respectively. Both mRNA and protein expression levels of HMGB1 were associated with T stage, clinical stage, lymph node metastasis status and smoking (all P < 0.05), but no significant correlation with age, alcohol consumption and primary tumor grade and location (all P > 0.05). Mean serum HMGB1 protein levels in patients with LSCC and healthy volunteers were (24.80 +/- 14.08) ng/ml and (23.58 +/- 14.69) ng/ml (t = 0.37, P > 0.05). CONCLUSIONS: Both mRNA and protein expressions of HMGB1 were obviously elevated in LSCC, which were associated closely with T stage, clinical stage and lymph node metastasis.

The high-mobility group box 1 (HMGB1) signaling pathway plays a crucial role in tumorigenesis and progression of many malignant cancers. The present study aimed to investigate the expression and clinical significance of HMGB1 in human primary liver cancer, and further explore the molecular mechanisms of HMGB1 in tumor growth and metastasis. Forty cases of human liver cancer and normal liver tissues were collected. The expression of HMGB1 was assessed using RT-PCR and western blot assays in biopsy samples. The HMGB1 pathway in vitro was blocked using transfection of the recombinant small hairpin RNA adenovirus vector rAd5-HMGB1 into the human liver cancer cell line SMMC-7721. The expression of HMGB1, phosphorylated AKT (p-AKT), Ki-67 and matrix metallopeptidase-2 (MMP-2) was detected by Real-PCR and western blot assays. Cell proliferative activities and metastatic capability were determined by MTT and Transwell assays. Cell cycle distribution and apoptosis were detected by flow cytometry. A subcutaneous xenograft tumor model was established, validating the effects of rAd5-HMGB1 on tumor growth in vivo. As a consequence, HMGB1 was found to be highly expressed in liver cancer compared with normal tissues, and was positively associated with pathological grade and distant metastases of liver cancer. Knockdown of HMGB1 downregulated the expression of p-AKT, Ki-67 and MMP-2, inhibited the proliferative activities and metastatic potential of SMMC-7721 cells, induced cell cycle arrest and apoptosis, and slowed the growth of xenograft tumors. Altogether, the expression of HMGB1 is closely correlated with pathological grade and distant metastases of liver cancer, and knockdown of HMGB1 inhibits liver cancer growth and metastasis, suggesting that HMGB1 may be involved in liver cancer development and progression through AKT-mediated regulation of Ki-67 and MMP-2 expression, and represent a potential therapeutic target for this aggressive malignancy.

Since its identification a third of a century ago, the high-mobility group box-1 (HMGB1) protein has been linked to varied diverse cellular processes, including release from necrotic cells and secretion by activated macrophages engulfing apoptotic cells. Initially described as solely chromatin-associated, HMGB1 was additionally discovered in the cytoplasm of several types of cultured mammalian cells 6 years later. In addition to its intracellular role, HMGB1 has been identified extracellularly as a putative leaderless cytokine and differentiation factor. In the years since its discovery, HMGB1 has also been implicated in disease states, including Alzheimer's, sepsis, ischemia-reperfusion, arthritis, and cancer. In cancer, overexpression of HMGB1, particularly in conjunction with its receptor for advanced glycation end products, has been associated with the proliferation and metastasis of many tumor types, including breast, colon, melanoma, and others. This review focuses on current knowledge and speculation on the role of HMGB1 in the development of cancer, metastasis, and potential targets for therapy.

High-mobility group box 1 (HMGB1), a proinflammatory cytokine, plays an important role in inflammatory diseases, including severe sepsis and arthritis. This recent discovery of the extracellular role of HMGB1 as a multifunctional cytokine involved in tumorigenesis, tumor angiogenesis as well as metastasis has opened up a new field of research to study the role of HMGB1 in tumors. However, its molecular mechanism in lymphangiogenesis remains poorly understood. In this study, human lymphatic endothelial cells (LECs) were treated with human recombinant HMGB1 (rHMGB1) and recombinant VEGF-C (rVEGF-C). Changes in cell proliferation, migration, and the capillary-like tube formation were assessed by MTT assay, transwell chamber assay, and a Matrigel model, respectively. Human rHMGB1 induced LEC proliferation, migration, and tube formation in a dose- and time-dependent manner with the maximal effect at a concentration of 2 mug/ml. As a specific lymphangiogenes factor, the role of rVEGF-C in promoting lymphangiogenesis was significant. These data indicate, for the first time, that HMGB1 might contribute to tumor lymphangiogenesis and lymphatic metastasis, and it might ultimately represent a therapeutic target in tumor patients.

High-mobility group box 1 (HMGB1) is a versatile protein with intranuclear and extracellular functions. It is involved in invasion and metastasis in various human malignancies. However, the role of HMGB1 in non-small cell lung cancer (NSCLC) is unclear. We hypothesized that HMGB1 expression is a determinant of cellular invasiveness and metastasis in lung cancer. We examined HMGB1 expression in 48 NSCLC specimens by quantitative real-time PCR. High HMGB1 expression was significantly associated with clinically advanced stages (stage III-IV) (P < 0.05) and was correlated to expression of matrix metalloproteinase-9 (MMP-9) (P < 0.05). Patients with high levels of HMGB1 expression had poorer clinical prognosis. The expression level of MMP-9 and metastatic ability in vitro were significantly higher in an HMGB1-overexpressing human NSCLC cell lines (A549 and H23). The treatment with HMGB1 small interfering RNA reduced MMP-9 expression and the cellular metastatic ability in NSCLC cells. We also demonstrated that phosphoinositide 3-kinase/Akt and NF-kappaB-related pathways contributed to the HMGB1-induced MMP-9 expression and cellular metastatic ability.

High-mobility group box 1 (HMGB1), a nuclear and extracellular protein, is implicated in the development and progression of some types of cancers. However, no information is available to date regarding the function of HMGB1 in ovarian cancer. In this study, we performed cDNA microarray analysis and identified HMGB1 as a gene dramatically elevated in the highly invasive subclone S1 compared with the low invasive subclone S21 derived from the same cell line SKOV3. Then lentivirus vector with HMGB1 shRNA was constructed and infected the highly invasive cell line S1, A1, and HO8910PM. Real-time RT-PCR, Western blot, and IHC results confirmed the down-regulation of HMGB1 expression by its shRNA was about 80-90% at both the mRNA and protein levels. Knockdown of HMGB1 significantly suppressed ovarian cancer cell proliferation and induced cell cycle arrest at the G1/G0 phase, which was accompanied by decreased expressions of cyclin D1 and PCNA. Furthermore, knockdown of HMGB1 induced ovarian cancer cell apoptosis, which was mediated by increased expression of Bax and decreased expression of Bcl-2. Finally, knockdown of HMGB1 significantly inhibited ovarian cancer cell invasion and metastasis, which was regulated by decreased expressions of MMP2 and MMP9. Serum HMGB1 levels in patients with epithelial ovarian cancer were significantly higher than that in patients with benign ovarian tumor and healthy controls. These results indicate that HMGB1 is a newly identified gene associated with ovarian cancer growth and metastasis. HMGB1 may serve as a new therapeutic target for the treatment of ovarian cancer in the future.

Amphoterin, the major product of the high mobility group-1 gene, is a ligand associated with cancer invasion and metastasis through activation of the receptor for advanced glycation end products (RAGE). expression of amphoterin and RAGE was examined in prostatectomy specimens from 40 patients with pT3 prostate cancer (18 non-metastatic and 22 metastatic) preoperatively treated with lutenizing hormone-releasing hormone (LH-RH) agonist. Amphoterin expression was detected in tumor cells of 6 (27%) metastatic and 0 non-metastatic cases (p<0.0001). Amphoterin was also detected in prostatic stromal cells of 14 (63%) metastatic cases and 2 (11%) non-metastatic cases (p=0.0010). RAGE production was detected in cancer cells of 16 (73%) metastatic and 6 (33%) non-metastatic cases (p=0.0244). A total of 2 (22%) non-metastatic and 16 (73%) metastatic cases showed co-expression of amphoterin and RAGE in tumor cells or in tumor cells and stromal cells (p=0.0001). The in vitro invasive capacity of PC-3, a prostatic cancer cell line that co-expressed amphoterin and RAGE, was suppressed by treatment with amphoterin antisense S-oligodeoxynucleotide (ODN). Primary cultured human prostatic stromal cells secreted no amphoterin; however, amphoterin secretion was induced by androgen deprivation. The conditioned medium of human prostatic stromal cells deprived of androgen recovered the in vitro invasive capacity of PC-3 cells suppressed by amphoterin antisense S-ODN. These results suggest that androgen deprivation provides a paracrine interaction between cancer and stromal cells through the RAGE-amphoterin system in advanced prostate cancer.