PIK3R1Met326Ile germline mutation correlates with cysteine-rich protein 61 expression and poor prognosis in glioblastoma

The matricellular protein Drosophila Cellular Communication Network Factor is required for synaptic transmission and female fertility

Within the extracellular matrix, matricellular proteins are dynamically expressed nonstructural proteins that interact with cell surface receptors, growth factors, and proteases, as well as with structural matrix proteins. The cellular communication network factors family of matricellular proteins serve regulatory roles to regulate cell function and are defined by their conserved multimodular organization. Here, we characterize the expression and neuronal requirement for the Drosophila cellular communication network factor family member. Drosophila cellular communication network factor is expressed in the nervous system throughout development including in subsets of monoamine-expressing neurons. Drosophila cellular communication network factor-expressing abdominal ganglion neurons innervate the ovaries and uterus and the loss of Drosophila cellular communication network factor results in reduced female fertility. In addition, Drosophila cellular communication network factor accumulates at the synaptic cleft and is required for neurotransmission at the larval neuromuscular junction. Analyzing the function of the single Drosophila cellular communication network factor family member will enhance our potential to understand how the microenvironment impacts neurotransmitter release in distinct cellular contexts and in response to activity.

The CCN axis in cancer development and progression

Since the authors first reviewed this subject in 2016 significant progress has been documented in the CCN field with advances made in the understanding of how members of the CCN family of proteins, CCN1-6, contribute to the pathogenesis and progression, positive and negative, of a larger variety of cancers. As termed matricellular proteins, and more recently the connective communication network, it has become clearer that members of the CCN family interact complexly with other proteins in the extracellular microenvironment, membrane signaling proteins, and can also operate intracellularly at the transcriptional level. In this review we expand on this earlier information providing new detailed information and insights that appropriate a much greater involvement and importance of their role in multiple aspects of cancer. Despite all the new information many more questions have been raised and intriguing results generated that warrant greater investigation. In order to permit the reader to smoothly integrate the new information we discuss all relevant CCN members in the context of cancer subtypes. We have harmonized the nomenclature with CCN numbering for easier comparisons. Finally, we summarize what new has been learned and provide a perspective on how our knowledge about CCN1-6 is being used to drive new initiatives on cancer therapeutics.

New insights for precision treatment of glioblastoma from analysis of single-cell lncRNA expression

INTRODUCTION

Glioblastoma (GBM) is a complex disease with high intratumoral heterogeneity, understanding the molecular characteristics of intratumoral heterogeneity accurately is the basis for precision treatment. Although the existing typing strategy based on tumor molecular characteristics has a positive effect, there is still room for improvement, which is mainly because the traditional typing is completed based on the sequencing data of tissue samples, that is, the obtained data are the average level of patient tumor tissues, masking the intratumoral heterogeneity of a single patient and cannot reflect the real level of patient tumor cells. At present, cancer molecular typing is mostly performed based on transcriptome (RNA-seq) without considering lncRNA molecules that are also tissue-specific and developmental stage-specific. Therefore, in this study, we used lncRNAs as typing markers and combined single-cell expression profiles to retype glioblastoma, providing new ideas for GBM molecular typing, and further analyzed the shortcomings of traditional therapies at the singlecell level based on typing results and proposed new precise therapeutic insights.

METHODS

We downloaded GBM single-cell sequencing data from GSE84465 and performed a series of preprocessing. The intratumoral heterogeneity of patients at the single-cell level was revealed using t-SNE, and the room for improvement of the existing traditional histotyping method was revealed using heat map and density curve. Subsequently, to validate the feasibility of lncRNA typing, we compared the similarities and differences of expression patterns between lncRNAs and mRNAs in GBM cells. Then, we used the R package "Seurat" to perform unsupervised clustering of GBM cells for re-typing and performed a detailed analysis of the biological characteristics of each subtype, including differentially expressed lncRNAs and marker lncRNAs. For validation, we performed survival analysis on GBM tissue data from the TCGA database to reveal the impact of different subtypes on patient survival prognosis. Eventually, based on the results, we screened the therapeutic drugs of each subtype by targeting the downstream regulatory genes of lncRNAs and proposed a new precision therapeutic strategy.

RESULTS

GBM has significant intratumoral heterogeneity at the single-cell level, with more than one traditional subtype highly expressed in each patient, which reflects the shortcomings of traditional histotyping. LncRNAs and mRNAs have similar expression patterns in GBM cells, and the expression coefficient of variation of lncRNAs is higher than that of mRNAs, meaning that lncRNAs will better reflect the intratumoral heterogeneity. GBM was reclassified into four subtypes by unsupervised clustering, with different subtypes having different biological characteristics. Survival analysis showed that patients with different subtype compositions had different prognostic outcomes, so different subtypes had different effects on patient prognosis. Based on this, 47 drugs were screened for treatment. There are both shared and unique drugs between different subtypes. A new precision treatment strategy was proposed: for patients with different subtypes, in addition to the combination of drugs targeting single subtype, drugs targeting multiple subtypes can also be selected.

CONCLUSION

Intratumoral heterogeneity may lead to poor prognosis or recurrence after treatment, and more precise typing of GBM can be performed based on single-cell lncRNA expression profiles. The biological characteristics possessed by different subtypes will have different effects on patients, such as survival time. For different subtypes, there are both drugs targeting single subtype and drugs targeting multiple subtypes, and we prefer drugs targeting multiple subtypes because this strategy can maximize medication efficiency and reduce the types of medication to reduce risks and side effects.

Differentiated glioblastoma cells accelerate tumor progression by shaping the tumor microenvironment via CCN1-mediated macrophage infiltration

Glioblastoma (GBM) is the most lethal primary brain tumor characterized by significant cellular heterogeneity, namely tumor cells, including GBM stem-like cells (GSCs) and differentiated GBM cells (DGCs), and non-tumor cells such as endothelial cells, vascular pericytes, macrophages, and other types of immune cells. GSCs are essential to drive tumor progression, whereas the biological roles of DGCs are largely unknown. In this study, we focused on the roles of DGCs in the tumor microenvironment. To this end, we extracted DGC-specific signature genes from transcriptomic profiles of matched pairs of in vitro GSC and DGC models. By evaluating the DGC signature using single cell data, we confirmed the presence of cell subpopulations emulated by in vitro culture models within a primary tumor. The DGC signature was correlated with the mesenchymal subtype and a poor prognosis in large GBM cohorts such as The Cancer Genome Atlas and Ivy Glioblastoma Atlas Project. In silico signaling pathway analysis suggested a role of DGCs in macrophage infiltration. Consistent with in silico findings, in vitro DGC models promoted macrophage migration. In vivo, coimplantation of DGCs and GSCs reduced the survival of tumor xenograft-bearing mice and increased macrophage infiltration into tumor tissue compared with transplantation of GSCs alone. DGCs exhibited a significant increase in YAP/TAZ/TEAD activity compared with GSCs. CCN1, a transcriptional target of YAP/TAZ, was selected from the DGC signature as a candidate secreted protein involved in macrophage recruitment. In fact, CCN1 was secreted abundantly from DGCs, but not GSCs. DGCs promoted macrophage migration in vitro and macrophage infiltration into tumor tissue in vivo through secretion of CCN1. Collectively, these results demonstrate that DGCs contribute to GSC-dependent tumor progression by shaping a mesenchymal microenvironment via CCN1-mediated macrophage infiltration. This study provides new insight into the complex GBM microenvironment consisting of heterogeneous cells.

Ependyma-expressed CCN1 restricts the size of the neural stem cell pool in the adult ventricular-subventricular zone

Adult neural stem cells (NSCs) reside in specialized niches, which hold a balanced number of NSCs, their progeny, and other cells. How niche capacity is regulated to contain a specific number of NSCs remains unclear. Here, we show that ependyma-derived matricellular protein CCN1 (cellular communication network factor 1) negatively regulates niche capacity and NSC number in the adult ventricular-subventricular zone (V-SVZ). Adult ependyma-specific deletion of Ccn1 transiently enhanced NSC proliferation and reduced neuronal differentiation in mice, increasing the numbers of NSCs and NSC units. Although proliferation of NSCs and neurogenesis seen in Ccn1 knockout mice eventually returned to normal, the expanded NSC pool was maintained in the V-SVZ until old age. Inhibition of EGFR signaling prevented expansion of the NSC population observed in CCN1 deficient mice. Thus, ependyma-derived CCN1 restricts NSC expansion in the adult brain to maintain the proper niche capacity of the V-SVZ.

Oncolytic Herpes Virus Armed with Vasculostatin in Combination with Bevacizumab Abrogates Glioma Invasion via the CCN1 and AKT Signaling Pathways

Anti-VEGF treatments such as bevacizumab have demonstrated convincing therapeutic advantage in patients with glioblastoma. However, bevacizumab has also been reported to induce invasiveness of glioma. In this study, we examined the effects of rapid antiangiogenesis mediated by oncolytic virus (RAMBO), an oncolytic herpes simplex virus-1 expressing vasculostatin, on bevacizumab-induced glioma invasion. The effect of the combination of RAMBO and bevacizumab in vitro was assessed by cytotoxicity, migration, and invasion assays. For in vivo experiments, glioma cells were stereotactically inoculated into the brain of mice. RAMBO was intratumorally injected 7 days after tumor inoculation, and bevacizumab was administered intraperitoneally twice a week. RAMBO significantly decreased both the migration and invasion of glioma cells treated with bevacizumab. In mice treated with bevacizumab and RAMBO combination, the survival time was significantly longer and the depth of tumor invasion was significantly smaller than those treated with bevacizumab monotherapy. Interestingly, RAMBO decreased the expression of cysteine-rich protein 61 and phosphorylation of AKT, which were increased by bevacizumab. These results suggest that RAMBO suppresses bevacizumab-induced glioma invasion, which could be a promising approach to glioma therapy.

δ-Catenin Promotes Bevacizumab-Induced Glioma Invasion

The combination of bevacizumab with temozolomide and radiotherapy was shown to prolong progression-free survival in newly diagnosed patients with glioblastoma, and this emphasizes the potential of bevacizumab as a glioma treatment. However, although bevacizumab effectively inhibits angiogenesis, it has also been reported to induce invasive proliferation. This study examined gene expression in glioma cells to investigate the mechanisms of bevacizumab-induced invasion. We made a human glioma U87ΔEGFR cell xenograft model by stereotactically injecting these cells into the brain of animals. We administered bevacizumab intraperitoneally three times per week. At 18 days after tumor implantation, the brains were removed for histopathology and mRNA was extracted. In vivo, bevacizumab treatment increased glioma cell invasion. qRT-PCR array analysis revealed upregulation of δ-catenin (CTNND2) and several other factors. In vitro, bevacizumab treatment upregulated δ-catenin expression. A low concentration of bevacizumab was not cytotoxic, but tumor cell motility was increased in scratch wound assays and two-chamber assays. Overexpression of δ-catenin increased the tumor invasion in vitro and in vivo However, δ-catenin knockdown decreased glioma cell invasiveness. The depth of tumor invasion in the U87ΔEGFR cells expressing δ-catenin was significantly increased compared with empty vector-transfected cells. The increase in invasive capacity induced by bevacizumab therapy was associated with upregulation of δ-catenin expression in invasive tumor cells. This finding suggests that δ-catenin is related to tumor invasion and migration.

Mutation Frequencies in Endometrial Cancer Patients of Different Ethnicities and Tumor Grades: An Analytical Study

Background:

Endometrial carcinoma is a predominant health problem for women worldwide. However, there is a lack of data on genetic mutation frequencies in endometrial cancer patients of different ethnicities and tumor grades.

Objective:

The objective of this study is to provide data regarding mutation frequencies in endometrial cancer patients of different ethnic groups and tumor grades by analyzing large-scale cancer genomic datasets of a database.

Materials and Methods:

The following databases of cBioPortal were explored for possible mutation frequency variations in endometrial cancer patients: the Uterine Corpus Endometrial Carcinoma (TCGA, PanCancer Atlas) database for ethnicity-based studies; the Uterine Corpus Endometrial Carcinoma (TCGA, Nature 2013) database for tumor grade-based study; and GDC Data Portal database for calculating survival rates using the Kaplan–Meier method.

Results:

PTEN mutation frequency was almost identical in all ethnic groups studied (White, Black/African American, Asian, Native Hawaiian or other Pacific Islander, and American Indian or Asian Native). PIK3CA and ARID1A mutation frequencies were higher in White and Asian patients compared with other ethnicities; TP53 and FAT1 mutation frequencies were higher in Black/African Americans; and CTNNB1 and RYR2 mutation frequencies were higher Native Hawaiians or Asian Natives. TTN mutation frequency was lower in Asian patients. With regards to mutation frequencies at different tumor stages, in all genes, >50% of the mutations occurred during the first stage, except in TP53 and POLQ. In terms of prognosis in endometrial cancer considering the 10 most frequently mutated genes, PIK3CA and ARID1A mutations were correlated with good prognosis, whereas TP53 and PIK3R1 mutations were correlated with poor prognosis; mutations in all other genes did not show significant differences.

Conclusion:

This study revealed a new mutation frequency profile for different ethnicities and tumor grades in endometrial cancer patients. However, because this is a retrospective study, future prospective studies should be conducted including large sample sizes and more controlled measurements.