ABCC4 suppresses glioblastoma progression and recurrence by restraining cGMP-PKG signalling

BACKGROUND

Cyclic nucleotides are critical mediators of cellular signalling in glioblastoma. However, the clinical relevance and mechanisms of regulating cyclic nucleotides in glioblastoma progression and recurrence have yet to be thoroughly explored.

METHODS

In silico, mRNA, and protein level analyses identified the primary regulator of cyclic nucleotides in recurrent human glioblastoma. Lentiviral and pharmacological manipulations examined the functional impact of cyclic nucleotide signalling in human glioma cell lines and primary glioblastoma cells. An orthotopic xenograft mice model coupled with aspirin hydrogels verified the in vivo outcome of targeting cyclic nucleotide signalling.

RESULTS

Elevated intracellular levels of cGMP, instead of cAMP, due to a lower substrate efflux from ATP-binding cassette sub-family C member 4 (ABCC4) is engaged in the recurrence of glioblastoma. ABCC4 gene expression is negatively associated with recurrence and overall survival outcomes in glioblastoma specimens. ABCC4 loss-of-function activates cGMP-PKG signalling, promoting malignancy in glioblastoma cells and xenografts. Hydrogels loaded with aspirin, inhibiting glioblastoma progression partly by upregulating ABCC4 expressions, augment the efficacy of standard-of-care therapies in orthotopic glioblastoma xenografts.

CONCLUSION

ABCC4, repressing the cGMP-PKG signalling pathway, is a tumour suppressor in glioblastoma progression and recurrence. Aspirin hydrogels impede glioblastoma progression through ABCC4 restoration and constitute a viable translational approach.

Cellular and exosomal GPx1 are essential for controlling hydrogen peroxide balance and alleviating oxidative stress in hypoxic glioblastoma

Tumor hypoxia promotes malignant progression and therapeutic resistance in glioblastoma partly by increasing the production of hydrogen peroxide (H2O2), a type of reactive oxygen species critical for cell metabolic responses due to its additional role as a second messenger. However, the catabolic pathways that prevent H2O2 overload and subsequent tumor cell damage in hypoxic glioblastoma remain unclear. Herein, we present a hypoxia-coordinated H2O2 regulatory mechanism whereby excess H2O2 in glioblastoma induced by hypoxia is diminished by glutathione peroxidase 1 (GPx1), an antioxidant enzyme detoxifying H2O2, via the binding of hypoxia-inducible factor-1α (HIF-1α) to GPx1 promoter. Depletion of GPx1 results in H2O2 overload and apoptosis in glioblastoma cells, as well as growth inhibition in glioblastoma xenografts. Moreover, tumor hypoxia increases exosomal GPx1 expression, which assists glioblastoma and endothelial cells in countering H2O2 or radiation-induced apoptosis in vitro and in vivo. Clinical data explorations further demonstrate that GPx1 expression was positively correlated with tumor grade and expression of HIF-1α, HIF-1α target genes, and exosomal marker genes; by contrast, it was inversely correlated with the overall survival outcome in human glioblastoma specimens. Our analyses validate that the redox balance of H2O2 within hypoxic glioblastoma is clinically relevant and could be maintained by HIF-1α-promoted or exosome-related GPx1.

Patient-derived tumor organoids as a platform of precision treatment for malignant brain tumors

Malignant brain tumors consist of malignancies originated primarily within the brain and the metastatic lesions disseminated from other organs. In spite of intensive studies, malignant brain tumors remain to be a medical challenge. Patient-derived organoid (PDO) can recapitulate the biological features of the primary tumor it was derived from and has emerged as a promising drug-screening model for precision therapy. Here we show a proof-of-concept based on early clinical study entailing the organoids derived from the surgically resected tumors of 26 patients with advanced malignant brain tumors enrolled during December 2020 to October 2021. The tumors included nine glioma patients, one malignant meningioma, one primary lymphoma patient, and 15 brain metastases. The primary tumor sites of the metastases included five from the lungs, three from the breasts, two from the ovaries, two from the colon, one from the testis, one of melanoma origin, and one of chondrosarcoma. Out of the 26 tissues, 13 (50%) organoids were successfully generated with a culture time of about 2 weeks. Among these patients, three were further pursued to have the organoids derived from their tumor tissues tested for the sensitivity to different therapeutic drugs in parallel to their clinical care. Our results showed that the therapeutic effects observed by the organoid models were consistent to the responses of these patients to their treatments. Our study suggests that PDO can recapitulate patient responses in the clinic with high potential of implementation in personalized medicine of malignant brain tumors.

MIB2: metal ion-binding site prediction and modeling server

MOTIVATION

MIB2 (metal ion-binding) attempts to overcome the limitation of structure-based prediction approaches, with many proteins lacking a solved structure. MIB2 also offers more accurate prediction performance and more metal ion types.

RESULTS

MIB2 utilizes both the (PS)2 method and the AlphaFold Protein Structure Database to acquire predicted structures to perform metal ion docking and predict binding residues. MIB2 offers marked improvements over MIB by collecting more MIB residue templates and using the metal ion type-specific scoring function. It offers a total of 18 types of metal ions for binding site predictions.

AVAILABILITY AND IMPLEMENTATION

Freely available on the web at http://bioinfo.cmu.edu.tw/MIB2/.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Recognition of a Novel Gene Signature for Human Glioblastoma

Glioblastoma (GBM) is one of the most common malignant and incurable brain tumors. The identification of a gene signature for GBM may be helpful for its diagnosis, treatment, prediction of prognosis and even the development of treatments. In this study, we used the GSE108474 database to perform GSEA and machine learning analysis, and identified a 33-gene signature of GBM by examining astrocytoma or non-GBM glioma differential gene expression. The 33 identified signature genes included the overexpressed genes COL6A2, ABCC3, COL8A1, FAM20A, ADM, CTHRC1, PDPN, IBSP, MIR210HG, GPX8, MYL9 and PDLIM4, as well as the underexpressed genes CHST9, CSDC2, ENHO, FERMT1, IGFN1, LINC00836, MGAT4C, SHANK2 and VIPR2. Protein functional analysis by CELLO2GO implied that these signature genes might be involved in regulating various aspects of biological function, including anatomical structure development, cell proliferation and adhesion, signaling transduction and many of the genes were annotated in response to stress. Of these 33 signature genes, 23 have previously been reported to be functionally correlated with GBM; the roles of the remaining 10 genes in glioma development remain unknown. Our results were the first to reveal that GBM exhibited the overexpressed GPX8 gene and underexpressed signature genes including CHST9, CSDC2, ENHO, FERMT1, IGFN1, LINC00836, MGAT4C and SHANK2, which might play crucial roles in the tumorigenesis of different gliomas.

Gain of CXCR7 function with mesenchymal stem cell therapy ameliorates experimental arthritis via enhancing tissue regeneration and immunomodulation

BACKGROUND

The major barriers to mesenchymal stem cell (MSC) therapy in rheumatoid arthritis (RA) are a low extent of tissue regeneration and insufficient immunomodulation after cell transplantation. In addition, the role of C-X-C chemokine receptor type 7 (CXCR7) and its mechanism of action in MSC-mediated osteogenic or chondrogenic differentiation and immunomodulation are unclear.

METHODS

Gain of CXCR7 function on human MSCs was carried out by lentiviral vector-mediated CXCR7 overexpression or CXCR7 agonist, TC14012. These cells were determined the role and potential mechanisms for CXCR7-regulated MSC differentiation and immunomodulation using cellular and molecular assays. The therapeutic benefits in RA were investigated in rats with collagen-induced arthritis (CIA).

RESULTS

CXCR7 was upregulated in MSCs during the induction of osteogenic or chondrogenic differentiation. Blockage of CXCR7 function inhibited osteogenic or chondrogenic differentiation of MSCs whereas gain of CXCR7 function had the opposite effects. Besides, MSCs with CXCR7 gain-of-function facilitated macrophage apoptosis and regulatory T cell differentiation in a co-culture system. Gain of CXCR7 function also promoted the production of anti-inflammatory soluble factors. A gene expression profiling assay and signaling reporter assays revealed that CXCR7 could regulate several candidate genes related to the PPAR, WNT, Hedgehog or Notch pathways, and their signaling activities, which are known to control cell differentiation and immunomodulation. Finally, MSCs with CXCR7 gain-of-function significantly reduced the articular index scores, ankle circumference, radiographic scores, histologic scores, and inflammation in rats with CIA compared with control MSCs.

CONCLUSIONS

CXCR7 promotes the osteogenic and chondrogenic differentiation of MSCs and MSC-mediated immunomodulation by regulating several signaling pathways and anti-inflammatory soluble factors. MSCs with CXCR7 gain-of-function significantly ameliorate arthritic symptoms in a CIA model.

Transforaminal Endoscopic Lumbar Discectomy for L5-S1 Disc Herniation With High Iliac Crest: Technical Note and Preliminary Series

With the trend of minimally invasive spine surgery, full-endoscopic lumbar discectomy (FELD) has evolved with the advancement of the optics and instruments. Regarding the techniques, the transforaminal and interlaminar approach remain the major accesses in FELD. Transforaminal endoscopic lumbar discectomy (TELD) is an effective and safe treatment for herniation of the lumbar disc. More and more evidence supports the TELD in enhancing recovery and decreasing surgical complications. However, the learning curve of TELD remains steep, especially at the L5-S1 level. The iliac crest height is an essential factor in the operability of TELD at the L5-S1 level. In the situation of the high iliac crest, TELD is technically challenging even for an experienced surgeon. Therefore, the authors report their techniques of TELD with foraminoplasty step-by-step and the preliminary results in this report.

Long-Term Follow-up in Patients with Spontaneous Intracerebral Hemorrhage Treated With or Without Surgical Intervention: a Large-Scale Retrospective Study

Debates regarding the most beneficial medical or surgical procedures for patients with spontaneous intracerebral hemorrhage (sICH) are still ongoing. We aimed to evaluate the risk of subsequent vascular disease and mortality in patients with sICH treated with and without surgical intervention, in a large-scale Asian population. Patients hospitalized within 2000 to 2013 who were newly diagnosed with sICH were identified using the National Health Insurance Research Database of Taiwan. Neuroendoscopy and craniotomy groups comprised patients who underwent surgical treatment within 1 week, while those in the control group did not undergo early surgical treatment. Outcomes included subsequent hemorrhagic and ischemic stroke, following acute myocardial infarction, congestive heart failure, and mortality. After propensity score matching, there were 663 patients in each group. Compared to that in the control group, the neuroendoscopy and craniotomy groups had a significantly higher risk of secondary vascular events at 1 to 3 months of follow-up (adjusted HR, 2.08 and 1.95; 95% CI, 1.21-3.58 and 1.13-3.35; p < 0.01 and p < 0.05, respectively), but a significantly lower risk after 3 years of follow-up (adjusted HR, 0.52 and 0.52; 95% CI, 0.35-0.78 and 0.35-0.77; p < 0.01 and p < 0.01, respectively). The mortality rate was higher in the craniotomy group at 6 to 12 months of follow-up (adjusted HR, 2.18; 95% CI, 1.06-4.49; p < 0.05) compared to that in the control group. Thus, a timely surgical intervention for hematoma evacuation is advantageous in preventing secondary vascular events and improving outcomes in the long term. However, greater attention to secondary ischemic stroke following the initial sICH episode is needed.

Risk of subsequent stroke, with or without extracranial-intracranial bypass surgery: a nationwide, retrospective, population-based study

OBJECTIVEAlthough no benefits of extracranial-intracranial (EC-IC) bypass surgery in preventing secondary stroke have been identified previously, the outcomes of initial symptomatic ischemic stroke and stenosis and/or occlusion among the Asian population in patients with or without bypass intervention have yet to be discussed. The authors aimed to evaluate the subsequent risk of secondary vascular disease and cardiac events in patients with and without a history of this intervention.METHODSThis retrospective nationwide population-based Taiwanese registry study included 205,991 patients with initial symptomatic ischemic stroke and stenosis and/or occlusion, with imaging data obtained between 2001 and 2010. Patients who underwent EC-IC bypass (bypass group) were compared with those who had not undergone EC-IC bypass, carotid artery stenting, or carotid artery endarterectomy (nonbypass group). Patients with any previous diagnosis of ischemic or hemorrhagic stroke, moyamoya disease, cancer, or trauma were all excluded.RESULTSThe risk of subsequent ischemic stroke events decreased by 41% in the bypass group (adjusted hazard ratio [HR] 0.59, 95% CI 0.46-0.76, p < 0.001) compared with the nonbypass group. The risk of subsequent hemorrhagic stroke events increased in the bypass group (adjusted HR 2.47, 95% CI 1.67-3.64, p < 0.001) compared with the nonbypass group.CONCLUSIONSBypass surgery does play an important role in revascularization of the ischemic brain, while also increasing the risk of hemorrhage in the early postoperative period. This study highlights the fact that the high risk of bypass surgery obscures the true benefit of revascularization of the ischemic brain and also emphasizes the importance of developing improved surgical technique to treat these high-risk patients.

Langerhans cell histiocytosis in monozygotic twins with central diabetes insipidus and hypophyseal masses

Langerhans cell histiocytosis (LCH) is a systemic disease mainly affecting children and young adults. It can manifest as single system disorder or multi-system involvement. When the central nervous system is involved, the hypothalamic–pituitary axis is the most common location affected. Herein we report a rare case of Langerhans cell histiocytosis in monozygotic twins both with central diabetes and hypophyseal masses. This is the first report about LCH in monozygotic twins with hypophyseal lesions.

A web-based audiometry database system

To establish a real-time, web-based, customized audiometry database system, we worked in cooperation with the departments of medical records, information technology, and otorhinolaryngology at our hospital. This system includes an audiometry data entry system, retrieval and display system, patient information incorporation system, audiometry data transmission program, and audiometry data integration. Compared with commercial audiometry systems and traditional hand-drawn audiometry data, this web-based system saves time and money and is convenient for statistics research.

Cerebrolysin enhances cognitive recovery of mild traumatic brain injury patients: double-blind, placebo-controlled, randomized study

In adults, mild traumatic brain injury (MTBI) frequently results in impairments of cognitive functions which would lead to psychological consequences in the future. Cerebrolysin is a nootropic drug, and can significantly improve cognitive function in patients with Alzheimer's disease and stroke. The purpose of this study was to investigate how Cerebrolysin therapy enhances cognitive recovery for mild traumatic brain injury patients using a double-blinded, placebo-controlled, randomized phase II pilot study. Patients having head injury within 24 h sent to our hospital were screened and recruited if patients were alert and conscious, and had intracranial contusion haemorrhage. From July 2009 to June 2010, totally, thirty-two patients were recruited in the double-blinded, placebo-controlled, and randomized study. Patients were randomized to receive Cerebrolysin (Group A, once daily intravenous infusion of 30 mL Cerebrolysin over a 60-min period for 5 days) or placebo (Group B, same dosage and administration of normal saline as Group A). The primary outcome measures were differences of cognitive function including Mini-Mental Status Examination (MMSE), and Cognitive Abilities Screening Instrument (CASI) scores between baseline and week 1, between baseline and week 4, and between baseline and week 12. Thirty-two patients completed the trial. For Group A, the CASI score difference between baseline and week 12 was 21.0 ± 20.4, a significantly greater change than that of Group B (7.6 ± 12.1) (p = 0.0461). Besides, drawing function (one of the domains of CASI; p = 0.0066) on week 4 and both drawing function (p = 0.0472) and long-term memory (one of the domains of CASI; p = 0.0256) on week 12 were also found to be significantly improved in the patients receiving Cerebrolysin treatment. Our results suggest that Cerebrolysin improves the cognitive function of the MTBI in patients at 3rd month after injury, especially for long-term memory and drawing function.

Preliminary experience of titanium mesh cages for pathological fracture of middle and lower cervical vertebrae

The advantages and disadvantages of titanium mesh cages (TMCs) assisted by anterior cervical plates (ACPs) for interbody fusion following cervical corpectomy were investigated. Between January 2002 and September 2006, 17 patients with cervical radiculomyelopathy caused by metastasis-induced pathologic fractures were selected for anterior corpectomy. TMCs were inserted into the post-corpectomy defect and stabilized by placement of ACPs filled with Triosite. Post-operative plain X-ray films indicated maintenance of spinal stability. No ceramic, donor site or surgery-related complications were observed. True trabeculation was observed in axial and reconstructive CT scans in all surviving patients one year after surgery. Neurological recovery, pain control, and good quality of life were achieved. Short hospital stays, minimal blood loss, short operation times and brief periods of bed confinement were also observed. We conclude that a TMC assisted by an ACP is safe and effective for interbody fusion following cervical corpectomy for pathological fractures resulting from cervical vertebral metastases.