Discriminating healthy from tumor and necrosis tissue in rat brain tissue samples by Raman spectral imaging

The purpose of this study was to investigate molecular changes associated with glioma tissues by Raman microspectroscopy in order to develop its use in clinical practice. Spectroscopic markers obtained from C6 glioma tissues were compared to conventional histological and histochemical techniques. Cholesterol and phospholipid contents were highest in corpus callosum and decreased gradually towards the cortex surface as well as in the tumor. Two different necrotic areas have been identified: a fully necrotic zone characterized by the presence of plasma proteins and a peri-necrotic area with a high lipid content. This result was confirmed by Nile Red staining. Additionally, one structure was detected in the periphery of the tumor. Invisible with histopathological hematoxylin and eosin staining, it was revealed by immunohistochemical Ki-67 and MT1-MMP staining used to visualize the proliferative and invasive activities of glioma, respectively. Hierarchical cluster analysis on the only cluster averaged spectra showed a clear distinction between normal, tumoral, necrotic and edematous tissues. Raman microspectroscopy can discriminate between healthy and tumoral brain tissue and yield spectroscopic markers associated with the proliferative and invasive properties of glioblastoma. Development of in vivo Raman spectroscopy could thus accurately define tumor margins, identify tumor remnants, and help in the development of novel therapies for glioblastoma.     

Brain tissue characterisation by infrared imaging in a rat glioma model

Pathological changes associated with the development of brain tumor were investigated by Fourier transform infrared microspectroscopy (FT-IRM) with high spatial resolution. Using multivariate statistical analysis and imaging, all normal brain structures were discriminated from tumor and surrounding tumor tissues. These structural changes were mainly related to qualitative and quantitative changes in lipids (tumors contain little fat) and were correlated to the degree of myelination, an important factor in several neurodegenerative disorders. Lipid concentration and composition may thus be used as spectroscopic markers to discriminate between healthy and tumor tissues. Additionally, we have identified one peculiar structure all around the tumor. This structure could be attributed to infiltrative events, such as peritumoral oedema observed during tumor development. Our results highlight the ability of FT-IRM to identify the molecular origin that gave rise to the specific changes between healthy and diseased states. Comparison between pseudo-FT-IRM maps and histological examinations (Luxol fast blue, Luxol fast blue-cresyl violet staining) showed the complementarities of both techniques for early detection of tissue abnormalities.     

Brain tissue characterisation by infrared imaging in a rat glioma model

Pathological changes associated with the development of brain tumor were investigated by Fourier transform infrared microspectroscopy (FT-IRM) with high spatial resolution. Using multivariate statistical analysis and imaging, all normal brain structures were discriminated from tumor and surrounding tumor tissues. These structural changes were mainly related to qualitative and quantitative changes in lipids (tumors contain little fat) and were correlated to the degree of myelination, an important factor in several neurodegenerative disorders. Lipid concentration and composition may thus be used as spectroscopic markers to discriminate between healthy and tumor tissues. Additionally, we have identified one peculiar structure all around the tumor. This structure could be attributed to infiltrative events, such as peritumoral oedema observed during tumor development. Our results highlight the ability of FT-IRM to identify the molecular origin that gave rise to the specific changes between healthy and diseased states. Comparison between pseudo-FT-IRM maps and histological examinations (Luxol fast blue, Luxol fast blue-cresyl violet staining) showed the complementarities of both techniques for early detection of tissue abnormalities.     

Histopathological study of breast cancer and normal breast tissue after magnetic resonance-guided cryotherapy ablation

BACKGROUND: Cryotherapy ablation is a minimally invasive procedure being investigated as an alternative to conventional surgery. There are few reports in breast cancer. AIM: Evaluate the histopathology of tumoral and normal breast tissue after cryotherapy. METHODS: Eleven patients with clinically <2.0cm and ultrasound visible tumors were studied. Invasive carcinoma was documented by preoperative mammography, magnetic resonance imaging and biopsies. Cryotherapy needles were inserted in the tumor under magnetic resonance guidance and deep freezed with a CRYO-HIT TM System-3. Lumpectomy was performed within 4-5 weeks following cryoablation and submitted for pathological examination including immunostaining of keratins. RESULTS: The tumoral response after cryoablation was variable. In 4 cases there was no viable invasive carcinoma left and focal DCIS only in 2. In 6 cases, residual invasive carcinoma of various size was present with DCIS inside or outside the cryozone. One case could not be evaluated because the cryozone was adjacent to the tumor due to technical problems. Histologically, the normal breast parenchyma of the cryozone showed dense fibrosis, fat necrosis, xanthogranulomatous reaction, endovascular fibrosis and haemorrhages in all cases. The positive immunostaining of keratins revealed remnants of cytoskeleton of carcinomatous cells in the necrotic areas without any viable tumoral cells on routine stains. Skin ulceration and/or necrosis were observed in five patients. CONCLUSIONS: Cryotherapy allows tumor destruction of variable extent in breast carcinomas <2.0cm in diameter. Immunostaining of keratins is useful to identify cytoskeleton remnants of tumor cells in devitalized areas.     

RECK‐mediated inhibition of glioma migration and invasion

RECK is an anti‐tumoral gene whose activity has been associated with its inhibitory effects regulating MMP‐2, MMP‐9, and MT1‐MMP. RECK level decreases as gliobastoma progresses, varying from less invasive grade II gliomas to very invasive human glioblastoma multiforme (GBM). Since RECK expression and glioma invasiveness show an inverse correlation, the aim of the present study is to investigate whether RECK expression would inhibit glioma invasive behavior. We conducted this study to explore forced RECK expression in the highly invasive T98G human GBM cell line. Expression levels as well as protein levels of RECK, MMP‐2, MMP‐9, and MT1‐MMP were assessed by qPCR and immunoblotting in T98G/RECK+ cells. The invasion and migration capacity of RECK+ cells was inhibited in transwell and wound assays. Dramatic cytoskeleton modifications were observed in the T98G/RECK+ cells, when compared to control cells, such as the abundance of stress fibers (contractile actin–myosin II bundles) and alteration of lamellipodia. T98G/RECK+ cells also displayed phosphorylated focal adhesion kinase (P‐FAK) in mature focal adhesions associated with stress fibers; whereas P‐FAK in control cells was mostly associated with immature focal complexes. Interestingly, the RECK protein was predominantly localized at the leading edge of migrating cells, associated with membrane ruffles. Unexpectedly, introduced expression of RECK effectively inhibited the invasive process through rearrangement of actin filaments, promoting a decrease in migratory ability. This work has associated RECK tumor‐suppressing activity with the inhibition of motility and invasion in this GBM model, which are two glioma characteristics responsible for the inefficiency of current available treatments. J. Cell. Biochem. 110: 52–61, 2010. © 2010 Wiley‐Liss, Inc.     

Molecular and clinical characterization of Galectin-9 in glioma through 1,027 samples

In recent years, research on glioma immunotherapy have grown rapidly. However, the autoimmune-like side effects that are caused by blocking immunological checkpoints hinder their clinical application in gliomas currently. Galectin-9, a ligand for T-cell immunoglobulin mucin 3, has shed a new light on the treatment of malignant glioma. However, the potential mechanism of Galectin-9 is still under discussion. In this study, first, we methodically gathered 1,027 glioma patients with RNA-seq and 986 patients with survival data to explore the role and mechanism of Galectin-9 in gliomas. Second, we analyzed glioma samples from 50 patients in the Department of Neurosurgery, Tianjin Medical University General Hospital. Finally, we found that Galectin-9 was strongly upregulated in glioblastoma multiforme compared with normal brain tissues and lower-grade glioma. Patients with Galectin-9 overexpression had a significantly shorter overall survival. Moreover, the tissue microarray data displayed that the expression of Galectin-9 in the core of tumor is higher than that in the border and was correlated with the shorter survival in glioma patients. Galectin-9 is more highly expressed in the mesenchymal subtype of glioblastoma multiforme than in the other subtypes. Simultaneously, Galectin-9 was closely associated with the immune response and lymphocyte activation, especially T-cell activation. To further determine the underlying role of Galectin-9 in the immune response, we selected seven immune metagenes. Through cluster analysis and correlation analysis, we discovered that Galectin-9 was highly correlated with immune checkpoint molecules and M2 tumor-associated macrophages. In summary, Galectin-9 serves as a potential therapeutic target to treat glioblastoma multiforme.     

Phosphorylated SATB1 is associated with the progression and prognosis of glioma

Special AT-rich sequence-binding protein 1 (SATB1) is a global chromatin organizer and gene regulator, and high expression of SATB1 is associated with progression and poor prognosis in several malignancies. Here, we examine the expression pattern of SATB1 in glioma. Microarray analysis of 127 clinical samples showed that SATB1 mRNA was expressed at lower levels in highly malignant glioblastoma multiforme (GBM) than in low-grade glioma and normal brain tissue. This result was further confirmed by real-time RT-PCR in the clinical samples, three GBM cell lines, primary SU3 glioma cells and tumor cells harvested by laser-capture microdissection. Consistent with the mRNA levels, SATB1 protein expression was downregulated in high-grade glioma, as shown by western blotting. However, phospho-SATB1 levels showed an opposite pattern, with a significant increase in these tumors. Immunohistochemical analysis of phospho-SATB1 expression in tissue microarrays with tumors from 122 glioma cases showed that phospho-SATB1 expression was significantly associated with high histological grade and poor survival by Kaplan–Meier analysis. In vitro transfection analysis showed that phospho-SATB1 DNA binding has a key role in regulating the proliferation and invasion of glioma cells. The effect of SATB1 in glioma cell is mainly histone deacetylase (HDAC1)-dependent. We conclude that phospho-SATB1, but not SATB1 mRNA expression, is associated with the progression and prognosis of glioma. By interaction with HDAC1, phospho-SATB1 contributes to the invasive and proliferative phenotype of GBM cells.     

Antitumor Activity of a Polypyridyl Chelating Ligand: In Vitro and In Vivo Inhibition of Glioma

Glioblastoma multiforme is an extremely aggressive and invasive form of central nervous system tumor commonly treated with the chemotherapeutic drug Temozolomide. Unfortunately, even with treatment, the median survival time is less than 12 months. 2,9-Di-sec-butyl-1,10-phenanthroline (SBP), a phenanthroline-based ligand originally developed to deliver gold-based anticancer drugs, has recently been shown to have significant antitumor activity in its own right. SBP is hypothesized to initiate tumor cell death via interaction with non-DNA targets, and considering most glioblastoma drugs kill tumors through DNA damage processes, SBP was tested as a potential novel drug candidate against glial-based tumors. In vitro studies demonstrated that SBP significantly inhibited the growth of rodent GL-26 and C6 glioma cells, as well as human U-87, and SW1088 glioblastomas/astrocytomas. Furthermore, using a syngeneic glioma model in mice, in vivo administration of SBP significantly reduced tumor volume and increased survival time. There was no significant toxicity toward nontumorigenic primary murine and human astrocytes in vitro, and limited toxicity was observed in ex vivo tissues obtained from noncancerous mice. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining and recovery assays suggest that SBP induces apoptosis in gliomas. This exploratory study suggests SBP is effective in slowing the growth of tumorigenic cells in the brain while exhibiting limited toxicity to normal cells and tissues and should therefore be further investigated for its potential in glioblastoma treatment.     

Non‐invasive identification of proteoglycans and chondrocyte differentiation state by Raman microspectroscopy

Proteoglycans (PGs) are crucial extracellular matrix (ECM) components that are present in all tissues and organs. Pathological remodeling of these macromolecules can lead to severe diseases such as osteoarthritis or rheumatoid arthritis. To date, PG‐associated ECM alterations are routinely diagnosed by invasive analytical methods. Here, we employed Raman microspectroscopy, a laser‐based, marker‐free and non‐destructive technique that allows the generation of spectra with peaks originating from molecular vibrations within a sample, to identify specific Raman bands that can be assigned to PGs within human and porcine cartilage samples and chondrocytes. Based on the non‐invasively acquired Raman spectra, we further revealed that a prolonged in vitro culture leads to phenotypic alterations of chondrocytes, resulting in a decreased PG synthesis rate and loss of lipid contents. Our results are the first to demonstrate the applicability of Raman microspectroscopy as an analytical and potential diagnostic tool for non‐invasive cell and tissue state monitoring of cartilage in biomedical research. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Specificity Protein 1 Expression Contributes to Bcl-w-Induced Aggressiveness in Glioblastoma Multiforme

We already had reported that Bcl-w promotes invasion or migration in gastric cancer cells and glioblastoma multiforme (GBM) by activating matrix metalloproteinase-2 (MMP-2) via specificity protein 1 (Sp1) or β-cateinin, respectively. High expression of Bcl-w also has been reported in GBM which is the most common malignant brain tumor and exhibits aggressive and invasive behavior. These reports propose that Bcl-w-induced signaling is strongly associated with aggressive characteristic of GBM. We demonstrated that Sp1 protein or mRNA expression is induced by Bcl-w using Western blotting or RT-PCR, respectively, and markedly elevated in high-grade glioma specimens compared with low-grade glioma tissues using tissue array. However, relationship between Bcl-w-related signaling and aggressive characteristic of GBM is poorly characterized. This study suggested that Bcl-w-induced Sp1 activation promoted expression of glioma stem-like cell markers, such as Musashi, Nanog, Oct4 and sox-2, as well as neurosphere formation and invasiveness, using western blotting, neurosphere formation assay, or invasion assay, culminating in their aggressive behavior. Therefore, Bcl-w-induced Sp1 activation is proposed as a putative marker for aggressiveness of GBM.     

YKL-40在脑胶质母细胞瘤微环境中的作用

胶质母细胞瘤是大脑及其他中枢神经系统最常见的恶性肿瘤,其复杂的肿瘤微环境是胶质母细胞瘤临床治疗的主要挑战,也是胶质母细胞瘤患者复发率高、生存率低的主要原因。YKL-40,这一分泌性蛋白质与多种类型的癌症预后不良相关,且在高级别胶质瘤尤其是胶质母细胞瘤患者中血清水平与肿瘤组织表达水平显著升高,而在低级别胶质瘤中并未发现这一特征。这提示,YKL-40与胶质瘤分级及胶质母细胞瘤恶性发展过程密切相关。针对YKL-40的抗体治疗也被证明能够与电离辐射协同抑制胶质母细胞瘤血管生成及恶性发展。基于YKL-40的临床价值,本文将从肿瘤微环境的角度,归纳总结YKL-40在恶性肿瘤中的相关研究成果,并讨论其在胶质母细胞瘤发生发展中的相关作用及临床应用前景。     

Identification of Plasma Membrane Glycoproteins Specific to Human Glioblastoma Multiforme Cells Using Lectin Arrays and LC‐MS/MS

Glioblastoma, also known as glioblastoma multiforme (GBM), is the most malignant type of brain cancer and has poor prognosis with a median survival of less than one year. While the structural changes of tumor cell surface carbohydrates are known to be associated with invasive behavior of tumor cells, the cell surface glycoproteins to differentiate the low‐ and high‐grade glioma cells can be potential diagnostic markers and therapeutic targets for GBMs. In the present study, lectin arrays consisting of eight lectins were employed to explore cell surface carbohydrate expression patterns on low‐grade oligodendroglioma cells (Hs683) and GBM cells (T98G). Griffonia simplicifolia I (GS I) was found to selectively bind to T98G cells and not to Hs683 cells. For identification of the glioblastoma‐specific cell surface markers, the glycoproteins from each cell type were captured by a GS I lectin column and analyzed by LC‐MS/MS. The identified proteins from the two cell types were quantified using label‐free quantitative analysis based on spectral counting. Of cell surface glycoproteins showing significant increases in T98G cells, five proteins were selected for verification of both protein and glycosylation level changes using Western blot and GS I lectin‐based immunosorbent assay.     

Metronomic Doses of Temozolomide Enhance the Efficacy of Carbon Nanotube CpG Immunotherapy in an Invasive Glioma Model

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.     

Modulation of Angiogenic and Inflammatory Response in Glioblastoma by Hypoxia

Glioblastoma are rapidly proliferating brain tumors in which hypoxia is readily recognizable, as indicated by focal or extensive necrosis and vascular proliferation, two independent diagnostic criteria for glioblastoma. Gene expression profiling of glioblastoma revealed a gene expression signature associated with hypoxia-regulated genes. The correlated gene set emerging from unsupervised analysis comprised known hypoxia-inducible genes involved in angiogenesis and inflammation such as VEGF and BIRC3, respectively. The relationship between hypoxia-modulated angiogenic genes and inflammatory genes was associated with outcome in our cohort of glioblastoma patients treated within prospective clinical trials of combined chemoradiotherapy. The hypoxia regulation of several new genes comprised in this cluster including ZNF395, TNFAIP3, and TREM1 was experimentally confirmed in glioma cell lines and primary monocytes exposed to hypoxia in vitro. Interestingly, the cluster seems to characterize differential response of tumor cells, stromal cells and the macrophage/microglia compartment to hypoxic conditions. Most genes classically associated with the inflammatory compartment are part of the NF-kappaB signaling pathway including TNFAIP3 and BIRC3 that have been shown to be involved in resistance to chemotherapy.Our results associate hypoxia-driven tumor response with inflammation in glioblastoma, hence underlining the importance of tumor-host interaction involving the inflammatory compartment.     

Selective Targeting to Glioma with Nucleic Acid Aptamers

Malignant glioma is characterised by a rapid growth rate and high capacity for invasive infiltration to surrounding brain tissue; hence, diagnosis and treatment is difficult and patient survival is poor. Aptamers contribute a promising and unique technology for the in vitro imaging of live cells and tissues, with a potentially bright future in clinical diagnostics and therapeutics for malignant glioma. The binding selectivity, uptake capacity and binding target of two DNA aptamers, SA43 and SA44, were investigated in glioma cells and patient tissues. The binding assay showed that SA43 and SA44 bound with strong affinity (K_d, 21.56 ± 4.60 nM and K_d, 21.11 ± 3.30 nM respectively) to the target U87MG cells. Quantitative analysis by flow cytometry showed that the aptamers were able to actively internalise in U87MG and 1321N1 glioma cells compared to the non-cancerous and non-glioma cell types. Confocal microscopy confirmed staining in the cytoplasm, and co-localisation studies with endoplasmic reticulum, Golgi apparatus and lysosomal markers suggested internalisation and compartmentalisation within the endomembrane system. Both aptamers selectively bound to Ku 70 and Ku 80 DNA repair proteins as determined by aptoprecipitation (AP) followed by mass spectrometry analysis and confirmation by Western blot. In addition, aptohistochemical (AHC) staining on paraffin embedded, formalin fixed patient tissues revealed that the binding selectivity was significantly higher for SA43 aptamer in glioma tissues (grade I, II, III and IV) compared to the non-cancerous tissues, whereas SA44 did not show selectivity towards glioma tissues. The results indicate that SA43 aptamer can differentiate between glioma and non-cancerous cells and tissues and therefore, shows promise for histological diagnosis of glioma.