Biopsy of diffuse midline glioma is safe and impacts targeted therapy: a systematic review and meta-analysis

PURPOSE

To quantify the safety and utility of biopsy of pediatric diffuse midline glioma (DMG).

METHODS

This study was conducted in accordance with PRISMA guidelines. PubMed, Embase, Scopus, and Web of Science were queried for relevant articles from inception until June 2023. Two reviewers identified all articles that included diagnostic yield, morbidity, and mortality rates for pediatric DMG patients. Studies that did not present original data or were not in English or peer-reviewed were excluded. Meta-analysis was conducted in R using Freeman-Tukey or logit transformation and DerSimonian-Laird random-effects models. The risk of bias was assessed using the Newcastle-Ottawa Scale. A protocol for this review was not registered.

RESULTS

We identified 381 patients from ten studies that met all criteria. DMG biopsy is safe overall (0% mortality, 95% CI: 0-0.6%; 11.0% morbidity, 95% CI: 4.8-18.9%) and has a high diagnostic yield (99.9%, 95% CI: 98.5-100%). The use of stereotactic biopsy is a significant moderator of morbidity (p = 0.0238). Molecular targets can be identified in approximately 53.4% of tumors (95% CI: 37.0-69.0%), although targeted therapies are only delivered in about 33.5% of all cases (95% CI: 24.4-44.1%). Heterogeneity was high for morbidity and identification of targets. The risk of bias was low for all studies.

CONCLUSION

We conducted the first meta-analysis of DMG biopsy to show that it is safe, effective, and able to identify relevant molecular targets that impact targeted therapy.

The landscape of current research on pediatric diffuse midline glioma: a quantitative analysis of shifts, leaders, and future avenues

PURPOSE

Diffuse midline glioma (DMG) has seen a surge of research interest in recent years with the growth in knowledge of new avenues for potential treatments. However, no bibliometric review of the field has been conducted to visualize the current state of the field. Here, we use bibliometric mapping to visualize the knowledge structure, collaborations, and trends in the field.

METHODS

A total of 1079 original and review articles from 1996 to 2023 on diffuse midline glioma were extracted from the Web of Science Core Collection on June 3, 2023. These files were analyzed with R and VOSviewer to construct bibliometric visualizations.

RESULTS

Research interest in DMG has continued to grow, driven by publications of original research. Molecular characterization of DMG has been a key focus of recent literature, and terms relating to novel small molecules, mutations, immunotherapy, the blood-brain barrier, and liquid biopsy may be areas for future growth in the literature. Collaborating nations have generally been the North American and European nations, but other nations have begun to make their mark in the field. Leading and rising institutions and journals are described.

CONCLUSION

Research in DMG may continue to focus on molecular characterization and new therapeutics based on this knowledge. Novel collaborations between rising nations and institutions in the field may aid in accelerating this research.

Characterization hiPSC-derived neural progenitor cells and neurons to investigate the role of NOS1AP isoforms in human neuron dendritogenesis

Abnormal dendritic arbor development has been implicated in a number of neurodevelopmental disorders, such as autism and Rett syndrome, and the neuropsychiatric disorder schizophrenia. Postmortem brain samples from subjects with schizophrenia show elevated levels of NOS1AP in the dorsolateral prefrontal cortex, a region of the brain associated with cognitive function. We previously reported that the long isoform of NOS1AP (NOS1AP-L), but not the short isoform (NOS1AP-S), negatively regulates dendrite branching in rat hippocampal neurons. To investigate the role that NOS1AP isoforms play in human dendritic arbor development, we adapted methods to generate human neural progenitor cells and neurons using induced pluripotent stem cell (iPSC) technology. We found that increased protein levels of either NOS1AP-L or NOS1AP-S decrease dendrite branching in human neurons at the developmental time point when primary and secondary branching actively occurs. Next, we tested whether pharmacological agents can decrease the expression of NOS1AP isoforms. Treatment of human iPSC-derived neurons with d-serine, but not clozapine, haloperidol, fluphenazine, or GLYX-13, results in a reduction in endogenous NOS1AP-L, but not NOS1AP-S, protein expression; however, d-serine treatment does not reverse decreases in dendrite number mediated by overexpression of NOS1AP isoforms. In summary, we demonstrate how an in vitro model of human neuronal development can help in understanding the etiology of schizophrenia and can also be used as a platform to screen drugs for patients.

Cloning, Prokaryotic Expression and Purification of CpfS1 Gene from Arabidopsis Thaliana

CpfS1 Gene cloned from arabidopsis thaliana was expressed in Escherichia coli DH5α. A cDNA fragment about 320 bp was amplified from the total RNA of arabidopsis thaliana seeds by reverse transcription PCR (RT-PCR) with a pair of specific primers based on the sequences of the AtCpfS1 gene. The recombinant prokaryotic expression vector pET30a-AtCpfS1 was constructed by inserting the cDNA fragment encoding the mature peptide into the prokaryotic expression vector pET30a, and then transformed into E. coli DH5α. Sequence analysis showed that the fragment length was 346 bp containing a full coding region of 332 bp encoding 76 amino acid residues with a molecular mass of 21.5 kD. The SDS-PAGE electrophoresis analysis showed that the best expression was induced by 21oC and 3.6×10-3 mol/L IPTG, under which a relative molecular weight of 82.5 kD recombinant protein was produced. The nickel chelating resin was used to purify the protein in size exclusion chromatography (SEC) and the results indicated that AtCpfS1 protein was present in the form of tetramer.

Arabidopsis thaliana SEPALLATA3 protein prokaryotic expression and purification

SEPALLATA3 (SEP3) can be attributed to E class gene of the ABCE model of floral organ development. In order to reveal how SEP3 proteins form polymers, and the relationship between the polymers and their biological functions, the experiments of Arabidopsis thaliana AtSEP3 protein soluble expression in vitro were performed to construct a vector of prokaryotic expression, and investigate induced expression of recombinant proteins in Escherichia coli cells. The protein soluble expression was analyzed through the aspects of different protein domains, induction time, induction temperature, etc. Different structural domains and expression conditions were screened, and 0.1% IPTG inducing at 22 oC for 15 h was estimated as an optimal expression strategy. The nickel chelating resin was used to purify the protein in size exclusion chromatography (SEC) and the results indicated that AtSEP3 protein was present in the form of tetramer.

A microfabricated fluorescence-activated cell sorter

We have demonstrated a disposable microfabricated fluorescence-activated cell sorter (microFACS) for sorting various biological entities. Compared with conventional FACS machines, the microFACS provides higher sensitivity, no cross-contamination, and lower cost. We have used microFACS chips to obtain substantial enrichment of micron-sized fluorescent bead populations of differing colors. Furthermore, we have separated Escherichia coli cells expressing green fluorescent protein from a background of nonfluorescent E. coli cells and shown that the bacteria are viable after extraction from the sorting device. These sorters can function as stand-alone devices or as components of an integrated microanalytical chip.