ABSTRACT
Purpose@#Glioblastoma (GBM) is one of the most lethal human tumors with a highly infiltrative phenotype. Our previous studies showed that GBM originates in the subventricular zone, and that tumor-derived mesenchymal stem-like cells (tMSLCs) promote the invasiveness of GBM tumorspheres (TSs). Here, we extend these studies in terms of ventricles using several types of GBM patient-derived cells. @*Materials and Methods@#The invasiveness of GBM TSs and ventricle spheres (VSs) were quantified via collagen-based 3D invasion assays. Gene expression profiles were obtained from microarray data. A mouse orthotopic xenograft model was used for in vivo experiments. @*Results@#After molecular and functional characterization of ventricle-derived mesenchymal stem-like cells (vMSLCs), we investigated the effects of these cells on the invasiveness of GBM TSs. We found that vMSLC-conditioned media (CM) significantly accelerated the invasiveness of GBM TSs and VSs, compared to the control and even tMSLC-CM. Transcriptome analyses revealed that vMSLC secreted significantly higher levels of several invasiveness-associated cytokines. Moreover, differentially expressed genes between vMSLCs and tMSLCs were enriched for migration, adhesion, and chemotaxis-related gene sets, providing a mechanistic basis for vMSLC-induced invasion of GBM TSs. In vivo experiments using a mouse orthotopic xenograft model confirmed vMSLCinduced increases in the invasiveness of GBM TSs. @*Conclusion@#Although vMSLCs are non-tumorigenic, this study adds to our understanding of how GBM cells acquire infiltrative features by vMSLCs, which are present in the region where GBM genesis originates.
ABSTRACT
Glioblastoma (GBM) is a disease without any definite cure. Numerous approaches have been tested in efforts to conquer this brain disease, but patients invariably experience recurrence or develop resistance to treatment. New surgical tools, carefully chosen samples, and experimental methods are enabling discoveries at single-cell resolution. The present article reviews the cell-of-origin of isocitrate dehydrogenase (IDH)-wildtype GBM, beginning with the historical background for focusing on cellular origin and introducing the cancer genesis patterned on firework. The authors also review mutations associated with the senescence process in cells of the subventricular zone (SVZ), and biological validation of somatic mutations in a mouse SVZ model. Understanding GBM would facilitate research on the origin of other cancers and may catalyze the development of new management approaches or treatments against IDH-wildtype GBM.
ABSTRACT
There are several dimensions of academic burnout experienced by medical and health science college students. The purpose of this study was to examine the effects of academic relationships on academic burnout. Data was collected from 476 Eulji University students using an online survey over 4 days in April of 2018. Of the 264 respondents, 111 studied medicine (42.0%), 105 studied nursing (39.8%), and 48 studied clinical pathology (18.1%). The questionnaire was composed of the following sections: demographics (four questions), general life characteristics (seven questions), academic enthusiasm (eight questions), academic relationships (15 questions), and academic burnout sub-dimensions (partially revised Maslach Burnout Inventory-Student Survey Scale) (11 questions). T-tests and one-way analysis of variance were performed to illustrate the differences among the three departments. The effects of academic relationships and academic enthusiasm on academic burnout were analyzed using linear regression. Comparing the three departments, academic burnout was not found to be statistically significant (p=0.296). However, medical students' academic enthusiasm was significantly lower (p<0.001) and academic relationships were significantly higher (p<0.001) than nursing and clinical pathology students. The difference in academic burnout among the three departments was not significant. However, medical students have stronger academic relationships, while nursing and clinical pathology students were more focused on academics. Relationships and academic enthusiasm contribute to reducing academic burnout. Therefore, strategies need to be developed to deal with academic burnout considering relationship factors.
Subject(s)
Humans , Demography , Education, Premedical , Health Occupations , Linear Models , Nursing , Pathology, Clinical , Professionalism , Students, Medical , Students, Nursing , Surveys and QuestionnairesABSTRACT
PURPOSE: Current treatment of glioblastoma after surgery consists of a combination of fractionated radiotherapy and temozolomide. However, it is difficult to completely remove glioblastoma because it has uncertain boundaries with surrounding tissues. Moreover, combination therapy is not always successful because glioblastoma has diverse resistances. To overcome these limitations, we examined the combined effects of chemotherapy and knockdown of mitogen-activated protein kinase phosphatase-1 (MKP-1). MATERIALS AND METHODS: We used ten different anti-cancer drugs (cisplatin, cyclophosphoamide, doxorubicin, epirubicin, etoposide, 5-fluorouracil, gemcitabine, irinotecan, mitomycin C, and vincristine) to treat glioblastoma multiforme (GBM) cells. Knockdown of MKP-1 was performed using siRNA and lipofectamine. The basal level of MKP-1 in GBM was analyzed based on cDNA microarray data obtained from the Gene Expression Omnibus (GEO) databases. RESULTS: Anti-cancer drug-induced cell death was significantly enhanced by knockdown of MKP-1, and this effect was most prominent in cells treated with irinotecan and etoposide. Treatment with these two drugs led to significantly increased phosphorylation of c-Jun N-terminal kinase (JNK) in a time-dependent manner, while pharmacological inhibition of JNK partially inhibited drug-induced cell death. Knockdown of MKP-1 also enhanced drug-induced phosphorylation of JNK. CONCLUSION: Increased MKP-1 expression levels could be the cause of the high resistance to conventional chemotherapeutics in human GBM. Therefore, MKP-1 is an attractive target for overcoming drug resistance in this highly refractory malignancy.