Abstract
The traditional definitive diagnosis of brain tumors is performed by needle biopsy under the guidance of imaging-based exams. This paradigm is based on the experience of radiogolists, and ...accuracy could be affected by uncertainty in imaging interpretation and needle placement. Raman spectroscopy has the potential to improve needle biopsy by providing fingerprints of different materials and performing in situ tissue identification. In this paper, we present the development of a supervised machine learning algorithm using random forest (RF) to distinguish the Raman spectrum of different types of tissue. An integral process from raw data collection and preprocessing to model training and evaluation is presented. To illustrate the feasibility of this approach, viable animal tissues were used, including ectocinerea (grey matter), alba (white matter) and blood vessels. Raman spectra were acquired using a custom-built Raman spectrometer. The hyperparameters of the RF model were determined by combining a cross-validation-based algorithm and manually adjusting. The experimental results show the ability of our approach to discriminate different types of tissues with high accuracy.
Even when treated with aggressive current therapies, most patients with glioblastoma survive less than two years. Rapid tumor growth, an invasive nature, and the blood-brain barrier, which limits the ...penetration of large molecules into the brain, all contribute to the poor tumor response associated with conventional therapies. Immunotherapy has emerged as a therapeutic approach that may overcome these challenges. We recently reported that single-walled carbon nanotubes (SWCNTs) can be used to dramatically increase the immunotherapeutic efficacy of CpG oligonucleotides in a mouse model of glioma. Following implantation in the mouse brain, the tumor cell line used in these previous studies (GL261) tends to form a spherical tumor with limited invasion into healthy brain. In order to evaluate SWCNT/CpG therapy under more clinically-relevant conditions, here we report the treatment of a more invasive mouse glioma model (K-Luc) that better recapitulates human disease. In addition, a CpG sequence previously tested in humans was used to formulate the SWCNT/CpG which was combined with temozolomide, the standard of care chemotherapy for glioblastoma patients. We found that, following two intracranial administrations, SWCNT/CpG is well-tolerated and improves the survival of mice bearing invasive gliomas. Interestingly, the efficacy of SWCNT/CpG was enhanced when combined with temozolomide. This enhanced anti-tumor efficacy was correlated to an increase of tumor-specific cytotoxic activity in splenocytes. These results reinforce the emerging understanding that immunotherapy can be enhanced by combining it with chemotherapy and support the continued development of SWCNT/CpG.
There is a pressing need for new therapeutic, diagnostic, and drug delivery approaches for treating brain cancers. Nanotechnology offers a new method for targeted brain cancer therapy and could play ...a major role in gene and drug delivery. The goals of our study were to visualize in vitro ingestion, cytotoxicity, and loading capacity of Multi-Walled Carbon Nanotubes (MWCNTs) in microglia. Furthermore, we investigated internalization differences between microglia and glioma cells. BV2 microglia and GL261 glioma cells were incubated with MWCNTs, which were synthesized through catalytic chemical vapor deposition technique. Real-time RT-PCR, cell proliferation analysis, siRNA and DNA loading, electron microscopy, and flow cytometry were performed. We demonstrated that MWCNTs do not result in proliferative or cytokine changes in vitro, are capable of carrying DNA and siRNA and are internalized at higher levels in phagocytic cells as compared to tumor cells. This study suggests MWCNTs could be used as a novel, non-toxic, and biodegradable nano-vehicles for targeted therapy in brain cancers. Further studies are needed to demonstrate the full capacity of MWCNTs as nanovectors.
Abstract The goal of this study was to evaluate the mechanism of cyclodextrin-based nanoparticle (CDP-NP) uptake into a murine glioma model. Using mixed in vitro culture systems, we demonstrated that ...CDP-NPs were preferentially taken up by BV2 and N9 microglia (MG) cells compared with GL261 glioma cells. Fluorescent microscopy and flow cytometry analysis of intracranial GL261 gliomas confirmed these findings and demonstrated a predominant CDP-NP uptake by macrophages (MPs) and MG within and around the tumor site. Notably, in mice bearing bilateral intracranial tumor, MG and MPs carrying CDP-NPs were able to migrate to the contralateral tumors. In conclusion, these studies better characterize the cellular distribution of CDP-NPs in intracranial tumors and demonstrate that MPs and MG could potentially be used as nanoparticle drug carriers into malignant brain tumors. From the Clinical Editor The goal of this study was to evaluate the mechanism of cyclodextrin-based nanoparticle (CDP-NP) uptake into a murine glioma model. CDP-NP was preferentially taken up microglia (MG) cells as compared to glioma cells. A predominant CDP-NP uptake by macrophages and MG was also shown in and around the tumor site. Macrophages and MG could potentially be used as nanoparticle drug carriers into malignant brain tumors.
•The intake rate of ER+HER2+ tumors is higher than that of ER+HER2- tumors.•The protein signature associated with the rate of ER+PDX intake was identified.•Different protein expression was observed ...between patient tumor samples and paired PDX tumors.•PDX models are valuable in evaluating treatments in a preclinical setting.
The research was to appraise the utility of the patient-derived tumor xenografts (PDXs) as models of estrogen receptor positive (ER+HER2− and ER+HER2+) breast cancers. We compared protein expression profiles by Reverse Phase Protein Array (RPPA) in tumors that resulted in PDXs compared to those that did not. Our overall PDX intake rate for ER+ breast cancer was 9% (9/97). The intake rate for ER+HER2+ tumors (3/16, 19%) was higher than for ER+HER2− tumors (6/81, 7%). Heat map analyses of RPPA data showed that ER+HER2− tumors were divided into 2 groups by luminal A/B signature protein expression of ER, AR, Bcl-2, Bim (BCL2L11), GATA3 and INPP4b, and this expression signature was also associated with the rate of PDX intake. Cell survival pathways such as the PI3K/AKT signaling and RAS/ERK pathways were more activated in the specimens that could be established as PDX in both classes. Expression of the ER protein itself may have a bearing on the potential success of an ER+ PDX model. In addition, HER2 and its downstream protein expressions were up-regulated in the ER+HER2+ patient tumors that were successfully established as PDX models. Moreover, the comparison of RPPA data between original and PDX tumors suggested that the selection/adaptation process required to grow the tumors in mice is unavoidable for generation of ER+ PDX models, and we identified differences between patient tumor samples and paired PDX tumors. A better understanding of the biological characteristics of ER+PDX would be the key to using PDX models in assessing treatment strategies in a preclinical setting.
Although microglia have been suggested to be a component of the inflammatory reaction to tumors of the central nervous system, their role in glioma biology remains unknown. One obstacle to studying ...the function of microglia is the inability to effectively separate them from macrophages. Because flow cytometry can effectively discern immune cells with similar surface antigens, we evaluated its role in characterizing the mononuclear cell infiltration in experimental gliomas.
Freshly prepared rat C6, 9L, and RG-2 tumor specimens were labeled ex vivo with monoclonal antibodies against CD11b/c, CD45, and CD8a antigens and analyzed by flow cytometry. The extent of microglia (CD11b/c(high), CD45(low)), macrophage (CD11b/c(high), CD45(high)), and lymphocyte (CD11b/c(negative), CD45(high)) infiltration into tumors, tumor periphery, and contralateral tumor-free hemispheres was measured for each glioma type.
Microglia, which accounted for 13 to 34% of viable cells, were distributed throughout the central nervous system and were present in the tumors, tumor periphery, and contralateral tumor-free hemispheres. In contrast, macrophages were less prominent within the tumors and tumor periphery (4.2-12%) and were scarce in the contralateral tumor-free hemispheres (0.9-1.1%). Among the tumor types, RG-2 gliomas had the least microglia/macrophage infiltration. The frequency and the distribution pattern of lymphocytes also varied among tumor models. Whereas lymphocytes accounted for more than one-third of the cells in C6 and 9L tumors, they represented only 1% of cells in RG-2 gliomas.
More abundant than macrophages and scattered throughout the central nervous system, microglia account for a significant component of the inflammatory response to experimental gliomas. A better understanding of microglial function in gliomas may be important in the development of immunotherapy strategies.
Role of microglia in glioma biology Badie, Behnam; Schartner, Jill
Microscopy research and technique,
15 July 2001, Volume:
54, Issue:
2
Journal Article
BackgroundGlioblastoma (GBM) is the most aggressive form of glioma with a median survival rate of less than two years. Despite aggressive standard treatments, GBM remains uniformly fatal with a poor ...prognosis. Achieving responsiveness of GBMs to chimeric antigen receptor (CAR) T cell therapy has been a significant challenge due to the heterogeneity and evasive mechanisms employed by solid tumors, particularly GBM, to resist therapy. Recent studies have highlighted the substantial role of cancer-associated fibroblasts (CAFs) in GBM invasion by depositing various collagen subunits, including COL1A1, COL1A2, COL5A1, COL5A2, and COL8A1, within the extracellular matrix (ECM). This collagen deposition leads to increased ECM stiffness, modulating the tumor microenvironment, inducing immune suppression, and hindering T cell trafficking, ultimately worsening clinical outcomes and patient survival. Additionally, COL1A1 has been implicated in promoting tumor aggressiveness, particularly in GBM cases with wildtype isocitrate dehydrogenase (IDH-wt) status and a poor prognosis. Based on these findings, we investigated whether the expression level of COL1A1 could influence the response to CAR T cell therapy.MethodsWe performed immunofluorescent staining on tissue biopsies obtained from GBM patients to identify a subpopulation of CAFs expressing ACTA2 (alpha smooth muscle actin), PDGFRβ, and COL1A1. Confocal microscopy was used to visualize the stained CAFs. ACTA2 and PDGFRβ serve as markers for a specific subset of CAFs involved in the epithelial-to-mesenchymal transition (EMT), a process associated with immune suppression and tumor growth. The presence of these CAF subpopulations was previously confirmed in GBM patients enrolled in an IL13Ra2 targeted CAR T cell trial through single-cell RNA sequencing. Subsequently, we compared our immunostaining images with flow cytometry data obtained from cerebrospinal fluid (CSF) or tumor fragment (TF) biopsies collected from the same patients after CAR T cell therapy.ResultsOur preliminary analysis revealed an increase in the number of infiltrating CD3+ cells from baseline, particularly within the effector CD8+ subpopulation (characterized by CD27+CD28+ expression), during CAR T cell therapy in patients with low COL1A1 expression. Furthermore, FACS analysis demonstrated a significant increase in the proportion of CD8+ T cells relative to CD4+ T cells in these patients.ConclusionsOngoing experiments are currently investigating the distribution of CAF subpopulations producing COL1A1 and their correlation with the response to CAR T cell therapy.
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