[Correlation between clinical phenotypes and genotypes among 46 children with SCN1A-related developmental epileptic encephalopathy].

OBJECTIVE: To explore the correlation between clinical phenotypes and genotypes among 46 children with SCN1A-related developmental epileptic encephalopathy (DEE). METHODS: Clinical data of 46 children with DEE and SCN1A variants identified at the Guangzhou Women and Children's Medical Center between January 2018 and June 2022 were collected. The children were grouped based on their age of onset, clinical manifestations, neurodevelopmental status, and results of genetic testing. The correlation between SCN1A genotypes and clinical phenotypes was analyzed. RESULTS: Among the 46 patients, 2 children (4.35%) had developed the symptoms before 3 months of age, 42 (91.30%) were between 3 to 9 months, and 2 cases (4.35%) were after 10 months. Two cases (4.35%) presented with epilepsy of infancy with migrating focal seizures (EIMFS), while 44 (95.7%) had presented with Dravet syndrome (DS), including 28 cases (63.6%) with focal onset (DS-F), 13 cases (29.5%) with myoclonic type (DS-M), 1 case (2.27%) with generalized type (DS-G), and 2 cases (4.55%) with status epilepticus type (DS-SE). Both of the two EIMFS children had severe developmental delay, and among the DS patients, 7 cases had normal development, while the remaining had developmental delay. A total of 44 variants were identified through genetic sequencing, which included 16 missense variants and 28 truncating variants. All EIMFS children had carried the c.677C>T (p.Thr226Met) missense variant. In the DS group, there was a significant difference in the age of onset between the missense variants group and the truncating variants group (P < 0.05). Missense variants were more common in D1 (7/15, 46.7%) and pore regions (8/15, 53.3%), while truncating variants were more common in D1 (12/28, 42.9%). Children with variants outside the pore region were more likely to develop myoclonic seizures. CONCLUSION: The clinical phenotypes of DEE are diverse. There is a difference in the age of onset between individuals with truncating and missense variants in the SCN1A gene. Missense variants outside the pore region are associated with a higher incidence of myoclonic seizures.

[Genetic analysis of a child with developmental disorder and epilepsy due to a homozygous variant of PIGW gene].

OBJECTIVE: To explore the genetic basis for a child featuring global developmental disorder with epilepsy. METHODS: A child who had presented at Guangzhou Women and Children's Medical Center in July 2022 was selected as the study subject. Clinical data was collected. Potential variant was detected by whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing and bioinformatic analysis. RESULTS: The child, a three-year-old ethnic Zhuang Chinese girl, had presented with global developmental disorder and epilepsy, for which rehabilitation therapy was ineffective. Genetic testing revealed that she has harbored a homozygous c.821T>C (p.Leu274Pro) missense variant of the PIGW gene, for which both of her parents and sister were heterozygous carriers. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as variant of uncertain significance. CONCLUSION: The homozygous c.821T>C (p.Leu274Pro) variant of the PIGW gene probably underlay the onset of disease in this child. Above finding has enriched the mutational spectrum of the PIGW gene.

Increased soluble endoglin levels in newly-diagnosed type 2 diabetic patients are associated with endothelial dysfunction.

Endothelial dysfunction (ED) contributes to the pathologic process underlying macrovascular complications, a common complication of type 2 diabetes mellitus (T2DM). Soluble endoglin (sEng) shed from the extracellular domain of the entire endoglin molecule blocks endothelial protection mediated by transforming growth factor-beta 1 (TGF-ß1). The reactive hyperemia index (RHI), which is determined by reactive hyperemia peripheral arterial tonometry (RH-PAT), is a new index with which to evaluate ED. This study determined the changes in serum sEng levels in newly-diagnosed (untreated) T2DM patients and the correlation with the RHI. The T2DM group included 34 newly-diagnosed T2DM patients, while the control group included 53 healthy adults. The clinical data from the two groups were evaluated retrospectively. The intima-media thickness (IMT) of the common carotid artery (CCA) and the ankle-brachial index (ABI) of both legs were used to assess structural vascular changes. The serum sEng level was determined using an ELISA kit. Endothelial function was assessed using RH-PAT and the RHI was computed. The serum sEng level in the T2DM group was significantly greater than the control group, although the RHI was significantly lower in the T2DM group (p < 0.05). The serum sEng level was negatively correlated with the RHI in T2DM patents (r = 0.354, p = 0.041). The serum sEng level, CCA-IMT, and ABI were not significantly correlated with T2DM (p > 0.05). In summary, among newly-diagnosed T2DM patients, the serum sEng levels were inversely correlated with the RHI, and an elevated sEng level may be associated with ED.

Integrated ATAC-Seq and RNA-Seq Data Analysis to Reveal OsbZIP14 Function in Rice in Response to Heat Stress.

Transcription factors (TFs) play critical roles in mediating the plant response to various abiotic stresses, particularly heat stress. Plants respond to elevated temperatures by modulating the expression of genes involved in diverse metabolic pathways, a regulatory process primarily governed by multiple TFs in a networked configuration. Many TFs, such as WRKY, MYB, NAC, bZIP, zinc finger protein, AP2/ERF, DREB, ERF, bHLH, and brassinosteroids, are associated with heat shock factor (Hsf) families, and are involved in heat stress tolerance. These TFs hold the potential to control multiple genes, which makes them ideal targets for enhancing the heat stress tolerance of crop plants. Despite their immense importance, only a small number of heat-stress-responsive TFs have been identified in rice. The molecular mechanisms underpinning the role of TFs in rice adaptation to heat stress still need to be researched. This study identified three TF genes, including OsbZIP14, OsMYB2, and OsHSF7, by integrating transcriptomic and epigenetic sequencing data analysis of rice in response to heat stress. Through comprehensive bioinformatics analysis, we demonstrated that OsbZIP14, one of the key heat-responsive TF genes, contained a basic-leucine zipper domain and primarily functioned as a nuclear TF with transcriptional activation capability. By knocking out the OsbZIP14 gene in the rice cultivar Zhonghua 11, we observed that the knockout mutant OsbZIP14 exhibited dwarfism with reduced tiller during the grain-filling stage. Under high-temperature treatment, it was also demonstrated that in the OsbZIP14 mutant, the expression of the OsbZIP58 gene, a key regulator of rice seed storage protein (SSP) accumulation, was upregulated. Furthermore, bimolecular fluorescence complementation (BiFC) experiments uncovered a direct interaction between OsbZIP14 and OsbZIP58. Our results suggested that OsbZIP14 acts as a key TF gene through the concerted action of OsbZIP58 and OsbZIP14 during rice filling under heat stress. These findings provide good candidate genes for genetic improvement of rice but also offer valuable scientific insights into the mechanism of heat tolerance stress in rice.

The Association of Serum Irisin with Bone Mineral Density and Turnover Markers in New-Onset Type 2 Diabetic Patients.

Background: Irisin, an exercise-induced myokine and adipocytokine, has been reported to decrease in type 2 diabetic patients. Recently, several research studies indicated that circulating levels were correlated with bone mineral density (BMD). To evaluate bone metabolism, bone turnover markers (BTMs) should be included. However, with respect to newly diagnosed T2DM patients, the relevance of their irisin levels to their BTMs and BMD remains unclear. The investigation of serum irisin levels in patients who have been newly diagnosed with type 2 diabetes and illumination of the relationship between serum irisin levels and those two indices of BMD and BTMs mentioned above are the intention of this cross-sectional study. Methods: 66 new-onset type 2 diabetic patients (T2DM group), together with 82 control subjects (NGT group), were recruited in this study. Serum irisin concentrations and BTMs (including osteocalcin (OC), procollagen type 1 N-terminal propeptide (P1NP), and ß-C-terminal telopeptides of type I collagen (ß-CTX)) were determined by the enzyme-linked immunosorbent assay (ELISA). Glucose, lipid profile, and insulin were considered as measuring indicators as well. Dual-energy X-ray absorptiometry (DXA) was utilized to evaluate the indicator of BMD. Serum irisin, BTMs, and BMD were compared between diabetic patients and healthy individuals. Pearson and Spearman correlation analyses were applied as well to assess correlations between irisin and BTMs and BMD. Multiple stepwise regression analysis was conducted to identify the independent factors of irisin. ROC curve analyses were carried out for serum irisin prediction for osteoporosis/osteopenia (OP). Results: The serum levels of irisin, procollagen type 1, intact N-terminal propeptide (P1NP), and osteocalcin (OC) were evidently lower in T2DM subjects than in NGT subjects (10.90 ± 1.88 vs .11.69 ± 2.06 ng/mL, P < 0.05; 36.42(25.68,51.70) vs. 44.52(35.73,58.05)ng/ml, P < 0.05; 16.15(12.40,21.66) vs. 18.70(15.56, 23.22)ng/ml, P < 0.05). Among patients with T2DM, the circulating irisin level of those with OP was lower than that of normal BMD (9.98 ± 2.09 vs. 11.39 ± 1.57 ng/ml, P < 0.01); irisin had a negative correlation with ß-C-terminal telopeptides of type I collagen (ß-CTX) (r = -0.496, P < 0.001) and came back unrelated to Lumbar BMD; Lumbar BMD was negatively relevant to OC (r = -0.274, P < 0.05) and ß-CTX (r = -0.410, P < 0.01). Multiple linear regression analyses of stepwise models implied that TG, LDL-C, and ß-CTX were independently associated with serum irisin concentrations (P < 0.01 or P < 0.05). Conclusion: Serum irisin level was declined in patients with type 2 diabetes diagnosed in the near term and had a certain association with bone turnover markers. It is suggested to consider irisin as a potential biomarker of bone metabolic disorder in T2DM patients with the initial diagnosis.

Clinical Analysis of Pediatric Opsoclonus-Myoclonus Syndrome in One of the National Children's Medical Center in China.

Objective: To study the clinical characteristics and treatment of pediatric opsoclonus-myoclonus syndrome (OMS). Methods: We analyzed the clinical data of nine children OMS between June 2017 and Nov 2020. Results: Nine children (M/F = 3:6, median onset age was 18 months) diagnosed with OMS were included in the study. Before onset, human rhinovirus and respiratory syncytial virus were seen in one patient, respectively. And one patient received Japanese encephalitis vaccination. Three patients had neuroblastoma, and one patient had ganglioneuroblastoma. All patients' symptoms were improved after receiving surgery (for four patients with tumor), intravenous human immunoglobulin and pulsed methylprednisolone. However, four patients without mass relapsed and became relapse free after rituximab treatment. The relapse rate was 44.4% (4/9). The OMS severity score at the last follow-up was significantly lower than the OMS severity score at onset (3.0 ± 1.0 vs. 11.0 ± 2.2, paired-samples t-test, P < 0.001). All patients had at least one item of neurological symptoms or neuropsychological disturbances. Conclusion: For pediatric OMS, human rhinovirus infection and respiratory syncytial virus infection can be seen before onset. Rituximab is effective in reducing relapse. Improving recognition and long-term prognosis in OMS is urgent.

A nuclear lncRNA Linc00839 as a Myc target to promote breast cancer chemoresistance via PI3K/AKT signaling pathway.

Chemoresistance has become a leading cause of mortality in breast cancer patients and is one of the major obstacles for improving the clinical outcome. Long noncoding RNAs play important roles in breast cancer tumorigenesis and chemoresistance. However, the involvement and regulation of lncRNAs in breast cancer chemoresistance are not completely understood. Here, we reported that Linc00839 was localized in the nucleus and upregulated in chemoresistant breast cancer cells and tissues, and high level of Linc00839 was associated with a poor prognosis. Knockdown of Linc00839 significantly suppressed proliferation, invasion, and migration, sensitized cells to paclitaxel in vitro and inhibited transplant tumor development in vivo. Mechanistically, we found that Myc could directly bind to the promoter region of Linc00839 and activate its transcription. Furthermore, Linc00839 overexpression increased the expression of Myc and the RNA-binding protein Lin28B and activated the PI3K/AKT signaling pathway. We also discovered that Lin28B positively interacted with Linc00839 and was upregulated in breast cancer tissues. Taken together, for the first time, we showed that Linc00839 was activated by Myc and promoted proliferation and chemoresistance in breast cancer through binding with Lin28B. These findings provide new insight into the regulatory mechanism of Linc00839 and propose a Myc/Linc00839/Lin28B feedback loop that could be used as a novel therapeutic target for breast cancer.

Macrophages derived exosomes deliver miR-223 to epithelial ovarian cancer cells to elicit a chemoresistant phenotype.

BACKGROUND: How exosomal microRNAs (miRNAs) derived from macrophages contribute to the development of drug resistance in the context of the hypoxic tumor microenvironment in epithelial ovarian cancer (EOC) remains poorly understood. METHODS: The miRNA levels were detected by qRT-PCR. Protein levels of HIF-1α, CD163 and PTEN-PI3K/AKT pathway were assessed by Western blot (WB) and Immunohistochemistry (IHC). Exosomes were isolated, and then confirmed by Transmission electron microscopy (TEM), Nanoparticle Tracking Analysis (NTA) and WB. Internalization of macrophages-secreted exosomes in EOC cells was detected by Confocal microscope. Subsequently, Dual-luciferase reporter assay verified PTEN was the target of miR-223. Gain- and loss-of-function experiments, rescue experiments, and SKOV3 xenograft models were performed to uncover the underlying mechanisms of miR-223 and PTEN-PI3K/AKT pathway, as well as the exosomal miR-223 in inducing multidrug resistance in vitro and in vivo. RESULTS: Here, we showed hypoxic EOC cells triggered macrophages recruitment and induced macrophages into a tumor-associated macrophage (TAM)-like phenotype; exosomes derived from hypoxic macrophages enhanced the malignant phenotype of EOC cells, miR-223 was enriched in exosomes released from macrophages under hypoxia, which could be transferred to the co-cultivated EOC cells, accompanied by enhanced drug resistant of EOC cells. Besides, results from a functional assay revealed that exosomal miR-223 derived from macrophages promoted the drug resistance of EOC cells via the PTEN-PI3K/AKT pathway both in vivo and in vitro. Furthermore, patients with high HIF-1a expression had statistically higher CD163+ cell infiltration and intertumoral levels of miR-223. Finally, circulating exosomal miR-223 levels were closely related to the recurrence of EOC. CONCLUSIONS: These data indicate a unique role of exosomal miR-223 in the cross-talk between macrophages and EOC cells in chemotherapy resistance, through a novel exosomal miR-223/PTEN-PI3K/AKT signaling pathway.

IL-6R/STAT3/miR-204 feedback loop contributes to cisplatin resistance of epithelial ovarian cancer cells.

Enhanced chemoresistance is, among other factors, believed to be responsible for treatment failure and tumor relapse in patients with epithelial ovarian cancer (EOC). Here, we exposed EOC cells to interleukin-6 (IL-6) to activate oncogenic STAT3, which directly repressed miR-204 via a conserved STAT3-binding site near the TRPM3 promoter region upstream of miR-204. Repression of miR-204 was required for IL-6-induced cisplatin (cDDP) resistance. Furthermore, we identified the IL-6 receptor (IL-6R), which mediates IL-6-dependent STAT3 activation, as a direct miR-204 target. Importantly, the resulting IL-6R/STAT3/miR-204 feedback loop was identified in patients with EOC, and its activity correlated with chemosensitivity. Moreover, exogenous miR-204 blocked this circuit and enhanced cDDP sensitivity both in vitro and in vivo by inactivating IL-6R/STAT3 signaling and subsequently decreasing the expression of anti-apoptotic proteins. Our findings illustrate the function of this feedback loop in cDDP-based therapy and may offer a broadly useful approach to improve EOC therapy.

The implication and potential applications of high-mobility group box 1 protein in breast cancer.

High-mobility group box 1 protein (HMGB1) is a highly conserved, non-histone and ubiquitous chromosomal protein found enriched in active chromatin forming part of the high mobility group family of proteins and is encoded by the HMGB1 gene (13q12) in human beings. It has various intranuclear and extracellular functions. It plays an important role in the pathogenesis of many diseases including cancer. In 2012, there was approximately 1.67 million new breast cancer cases diagnosed which makes it the second most frequent cancer in the world after lung cancer (25% of all cancers) and the commonest cancer among women. Both pre-clinical and clinical studies have suggested that HMGB1 might be a useful target in the management of breast cancer. This review summarises the structure and functions of HMGB1 and its dual role in carcinogenesis both as a pro-tumorigenic and anti-tumorigenic factor. It also sums up evidence from in vitro and in vivo studies using breast cancer cell lines and samples which demonstrate its influence in radiotherapy, chemotherapy and hormonal therapy in breast cancer. It may have particular importance in HER2 positive and metastatic breast cancer. It might pave the way for new breast cancer treatments through development of novel drugs, use of microRNAs (miRNAs), targeting breast cancer stem cells (CSCs) and breast cancer immunotherapy. It may also play a role in determining breast cancer prognosis. Thus HMGB1 may open up novel avenues in breast cancer management.

HMGB1 Facilitated Macrophage Reprogramming towards a Proinflammatory M1-like Phenotype in Experimental Autoimmune Myocarditis Development.

Macrophages can be reprogramming, such as the classical activated macrophage, M1 or alternative activated macrophages, M2 phenotype following the milieu danger signals, especially inflammatory factors. Macrophage reprogramming is now considered as a key determinant of disease development and/or regression. Experimental autoimmune myocarditis (EAM) is characterized by monocytes/macrophage infiltration, Th17 cells activation and inflammatory factors producing such as high mobility group box 1 (HMGB1). Whether infiltrated macrophages could be reprogramming in EAM? HMGB1 was associated with macrophage reprogramming? Our results clearly demonstrated that infiltrated macrophage was reprogrammed towards a proinflammatory M1-like phenotype and cardiac protection by monocytes/macrophages depletion or HMGB1 blockade in EAM; in vitro, HMGB1 facilitated macrophage reprogramming towards M1-like phenotype dependent on TLR4-PI3Kγ-Erk1/2 pathway; furthermore, the reprogramming M1-like macrophage promoted Th17 expansion. Therefore, we speculated that HMGB1 contributed EAM development via facilitating macrophage reprogramming towards M1-like phenotype except for directly modulating Th17 cells expansion.

Thalidomide Combined with Chemotherapy in Treating Patients with Advanced Colorectal Cancer.

OBJECTIVE: To assess the safety and effectiveness of thalidomide (produced by CHANGZHOU PHARMACEUTICAL FACTORY CO.LTD) combined with chemotherapy in treating patients with advanced colorectal cancer. METHOD: A consecutive cohort of pretreated patients with advanced colorectal cancer were treated with thalidomide combined with chemotherapy. And chemotherapy for patients with advanced colorectal cancer were administered according to the condition of patients. Thalidomide was orally administered at a dosage of 50mg/day to 150 mg/day before sleeping for at least 14 days. After at least 14 days of treatment, safety and side effects were evaluated. RESULTS: There were 12 female and 3 male patients with advanced cancer recruited into this study, including 9 patients with colon, 6 patients with rectal cancer. The median age of patients was 57(41- 82) years. Partial response was observed in 2 patients (2/15), and stable disease in 3 patients(3/15). Incidences of Grade 1 to 2 myelosuppression was observed in 1/15 patients, and Grade 1 to 2 elevation of hepatic enzyme was recorded in 1/15 patients. Adverse effects on the gastrointestinal tract were documented in 1/15 patients, and were Grade 1. No Grade 3-4 toxicities were diagnosed. No treatment related death was found. CONCLUSIONS: Thalidomide combined with chemotherapy was safe and mildly effective in treating patients with advanced colorectal cancer. However, further study should be conducted to clarify the effectiveness of this combination.

IFN-γ-producing Th17 cells bias by HMGB1-T-bet/RUNX3 axis might contribute to progression of coronary artery atherosclerosis.

BACKGROUND: IFN-γ-producing Th17 cells have been implicated in autoimmune disorders, but their properties in humans are known only partially. The molecular mechanisms and external factors that govern IFN-γ-producing Th17-cell bias are incompletely understood. The present work was to clarify whether (i) IFN-γ-producing Th17 cells are present in the peripheral circulation of patients with coronary atherosclerosis (CA); (ii) high mobility group box (HMGB)1 in circulation is associated with IFN-γ-producing Th17-cell bias. METHODS: Thirty-six patients (17 females and 19 males; 45-84 years) diagnosed as having atherosclerosis after coronary angiography for suspected or known CA were included the study cohort. Samples of peripheral blood were collected from healthy volunteers and patients, and classical tests (flow cytometry, RT-qPCR) were used to measure blood components. RESULTS AND CONCLUSION: Our results clearly demonstrated that HMGB1 were up-regulated in different progressive CA patients: 5.38 ± 1.48 ng/ml, 6.30 ± 1.53 ng/ml and 5.86 ± 1.12 ng/ml vs1.45 ± 0.65 ng/ml for only atherosclerotic plaque (AP), atherosclerotic plaque and some plaque rupture, no thrombosis (PR), plaque rupture and accompanying thrombosis (TH) and volunteers, respectively, p < 0.05. The frequency of IFN-γ-producing Th17 cells was 2.33 ± 0.58%, 1.93 ± 0.2% and 2.21 ± 0.65% vs 0.38 ± 0.21% for AP, PR, TH and volunteers, p < 0.05, respectively. Furthermore, HMGB1 contributed to IFN-γ-producing Th17-cell bias by controlling expression of T-bet and RUNX3. We demonstrated, for the first time, that HMGB1 is a potential inducer of IFN-γ-producing Th17-cell bias, and that IFN-γ-producing Th17 cells might be one of the pathogenic factors in atherosclerosis.

[The supernatant of 4T1 breast cancer cell culture increases arginase 1 content in ANA-1 macrophages].

OBJECTIVE: To explore the effect of the supernatant of 4T1 murine breast cancer cell culture on arginase 1 (Arg-1) in ANA-1 macrophages in vitro by simulating the microenvironment of breast cancer. METHODS: The experimental ANA-1 macrophages were treated with the supernatant of 4T1 culture, and meanwhile, the control cells were cultured in the absence of the supernatant. Morphological changes of the ANA-1 macrophages were observed with a light microscope at 6, 8, 10, 24 hours, respectively. Real-time quantitative PCR (qRT-PCR) was performed to detect the levels of inducible nitric oxide synthase (iNOS) and Arg-1 mRNAs. Immunofluorescence and Western blotting were used to determine the levels of iNOS and Arg-1 proteins. RESULTS: The qRT-PCR indicated that the level of iNOS mRNA decreased in the experiment group compared with the control group, while Arg-1 mRNA level significantly increased compared with the control group and it reached a peak at the 8th hour. The immunofluorescence and Western blotting also demonstrated that Arg-1 protein expression was enhanced in the experimental group compared with the control group. However, iNOS protein expression was no significantly different between the experiment group and the control group. CONCLUSION: The supernatant of 4T1 cell culture increases Arg-1 production in ANA-1 macrophages.

[Detection and correlation analysis of miRNAs and myeloid-derived suppressor cells in ovarian cancer-bearing mice].

OBJECTIVE: To detect the levels of miR-21a-5p, miR-155-5p, miR-218-5p, miR-222-3p, miR-494-3p in ovarian cancer tissues and the number of myeloid-derived suppressor cells (MDSCs) in peripheral blood and spleen in ovarian cancer-bearing mice, and explore their clinical significance and correlations. METHODS: The mRNA expressions of miR-21a-5p, miR-155a-5p, miR-218-5p, miR-222-3p, miR-494-3p were detected by real-time quantitative PCR (qRT-PCR) in tumor tissues and tumor-adjacent normal tissues from 12 ovarian cancer-bearing mice. The frequency of MDSCs in the peripheral blood and spleen from the 12 tumor-bearing mice was measured by flow cytometry. Spearman correlation analysis was used to find out the correlations between MDSCs and miRNAs. RESULTS: Compared with the normal mice, the number of MDSCs in the peripheral blood and spleen of the tumor-bearing mice significantly increased. The levels of miR-21a-5p, miR-218-5p and miR-222-3p in tumor tissues were significantly higher than those in tumor-adjacent normal tissues; conversely, miR-155a-5p and miR-494-3p levels in the former were significantly lower than those in the latter. There was no correlation between miR-222-3p and MDSCs, but miR-494-3p had a negative correlation with MDSCs. The expression differences of miR-21a-5p, miR-155a-5p, miR-218-5p between tumor tissues and tumor-adjacent normal tissues had positive correlations with the number of MDSCs. CONCLUSION: The levels of miR-21a-5p, miR-155a-5p, miR-218-5p, miR-494-3p in tumor tissues had correlations with the number of MDSCs in the peripheral blood and spleen of ovarian cancer-bearing mice.

HMGB1 modulates Lewis cell autophagy and promotes cell survival via RAGE-HMGB1-Erk1/2 positive feedback during nutrient depletion.

Autophagy is a self-digesting mechanism responsible for the removal of long-lived proteins and damaged organelles by lysosomes. It also allows cells to survive during nutrient depletion and/or in the absence of growth factors. High-mobility group protein 1 (HMGB1) is a highly-conserved nuclear protein that has been associated with cell autophagy; however, the mechanisms responsible for this role remain unclear. Many reports have demonstrated that autophagy represents a survival strategy for tumor cells during nutrient depletion, oxidative stress and DNA damage. In the present study, we explored the mechanisms whereby HMGB1 regulates tumor cell autophagy during nutrient depletion (the cells were cultured in Hank's balanced salt solution, HBSS). HMGB1 expression in Lewis cells increased and the protein was shuttled from the nucleus to the cytoplasm and was secreted, coincident with up-regulation of autophagy. Prevention of HMGB1 binding to the receptor for advanced glycation end products (RAGE) or knock-down of HMGB1 expression led to inhibition of autophagy and increased apoptosis. These results demonstrated a positive feedback pathway whereby starvation of Lewis cells promoted HMGB1 secretion, allowing cells to survive by regulating autophagy via a RAGE-HMGB1-extracellular signal-regulated kinase1/2-dependent pathway. These results also implicate HMGB1 as a potential risk factor for cancer growth and metastasis.

HMGB1 silence could promote MCF-7 cell apoptosis and inhibit invasion and metastasis.

High mobility group box 1 (HMGB1), a non-histone nuclear protein, was associated with a variety of biological important processes, such as transcription, differentiation, extracellular signaling. As a cytokine or inflammatory mediator, more and more data showed that HMGB1 was involved in inflammatory diseases, cancers or autoimmune disease. However, few data focused on nucleic or cytoplasmic function of HMGB1. Therefore, the present study focused on cancer cells biological characteristics following HMGB1 silence. HMGB1 siRNAs were designed and chemically synthesized, and then transfected into the breast cancer cell line MCF-7 with lipofectamine 2000. The transcription and translation level of HMGB1 expression, proliferation, apoptosis, migration of MCF-7 were determined. The results demonstrated that HMGB1 silence inhibit invasion and migration and promote apoptosis of human breast cells; which indicated that HMGB1 silence might be a potential therapy targets.