Expression of granulocyte colony-stimulating factor in recurrent glial tumors is inversely correlated with tumor progression

Importance of GFAP isoform-specific analyses in astrocytoma

Gliomas are a heterogenous group of malignant primary brain tumors that arise from glia cells or their progenitors and rely on accurate diagnosis for prognosis and treatment strategies. Although recent developments in the molecular biology of glioma have improved diagnosis, classical histological methods and biomarkers are still being used. The glial fibrillary acidic protein (GFAP) is a classical marker of astrocytoma, both in clinical and experimental settings. GFAP is used to determine glial differentiation, which is associated with a less malignant tumor. However, since GFAP is not only expressed by mature astrocytes but also by radial glia during development and neural stem cells in the adult brain, we hypothesized that GFAP expression in astrocytoma might not be a direct indication of glial differentiation and a less malignant phenotype. Therefore, we here review all existing literature from 1972 up to 2018 on GFAP expression in astrocytoma patient material to revisit GFAP as a marker of lower grade, more differentiated astrocytoma. We conclude that GFAP is heterogeneously expressed in astrocytoma, which most likely masks a consistent correlation of GFAP expression to astrocytoma malignancy grade. The GFAP positive cell population contains cells with differences in morphology, function, and differentiation state showing that GFAP is not merely a marker of less malignant and more differentiated astrocytoma. We suggest that discriminating between the GFAP isoforms GFAPδ and GFAPα will improve the accuracy of assessing the differentiation state of astrocytoma in clinical and experimental settings and will benefit glioma classification.

Altered cellular distribution and subcellular sorting of gamma-tubulin in diffuse astrocytic gliomas and human glioblastoma cell lines

Centrosome amplification is a pivotal mechanism underlying tumorigenesis but its role in gliomas is underinvestigated. The present study specifically examines the expression and distribution of the centrosome-associated cytoskeletal protein gamma-tubulin in 56 primary diffuse astrocytic gliomas (grades II-IV) and in 4 human glioblastoma cell lines (U87MG, U118MG, U138MG, and T98G). Monoclonal anti-peptide antibodies recognizing epitopes in C-terminal or N-terminal domains of the gamma-tubulin molecule were used in immunohistochemical, immunofluorescence, and immunoblotting studies. In tumors in adults (n = 46), varying degrees of localization were detected in all tumor grades, but immunoreactivity was significantly increased in high-grade anaplastic astrocytomas and glioblastomas multiforme as compared to low-grade diffuse astrocytomas (p = 0.0001). A similar trend was noted in diffuse gliomas in children but the sample of cases was too small as to be statistically meaningful. Two overlapping patterns of ectopic cellular localization were identified in both primary tumors and glioblastoma cell lines: A punctate pattern, in which gamma-tubulin was partially co-distributed with pericentrin in the pericentriolar region, and a diffuse pattern, independent of pericentrin staining, denoting a soluble pool of gamma-tubulin. Cellular gamma-tubulin was detected in both soluble and insoluble (nocodazole-resistant) fractions of glioblastoma cells. Divergent localizations of gamma-tubulin and pericentrin suggest a differential distribution of these 2 centrosome-associated proteins in glioblastoma cell lines. Our results indicate that overexpression and ectopic cellular distribution of gamma-tubulin in astrocytic gliomas may be significant in the context of centrosome protein amplification and may be linked to tumor progression and anaplastic potential.

Fibronectin and neuroprotective effect of granulocyte colony-stimulating factor in focal cerebral ischemia

Stroke is one of the leading causes of unnatural death and disability. No effective therapy is available. Recombinant human granulocyte colony-stimulating factor (rhG-CSF), as a mobilizing agent for bone marrow stem cells, can promote stem cell mobilization, homing to brain after cerebral ischemia. In the present study, the administration of G-CSF significantly increased number of CD34(+) cells in the marginal zone of the infarction. Rats receiving G-CSF had higher survival rate and lower infarction volume. Neurological behavior was improved, and the expression of fibronectin in the ischemic brain was increased, as compared to rats treated with vehicle. To mimic the ischemia-reperfusion injury in experimental animals, we employed hippocampal slice cultures that were first treated with oxygen and glucose deprivation (OGD) and then with oxygen-glucose resupply, finding that fibronectin significantly increased the neurite outgrowth of OGD hippocampal slices, upregulated the expression of Bcl-2 protein, and ameliorated the ultrastructure damage of OGD hippocampal slices.

Complete remission of brain metastases in three patients with stage IV melanoma treated with BOLD and G-CSF

BACKGROUND

Brain metastases are the most life-threatening among the secondary localizations of melanoma for their unresponsiveness to the surgical, radiotherapeutic and/or chemotherapeutic treatments.

METHODS

Accidentally, we observed a complete response (CR) in a patient undergoing chemotherapy with bleomycin, vincristine or Oncovin, CCNU or lomustine, dacarbazine (BOLD) regimen for metastatic melanoma including brain metastases, who was also treated with G-CSF to manage a concomitant leukopenia. After this observation, seven more patients with stage IV melanoma with brain metastases were treated with BOLD regimen repeated every 6 weeks with administration of G-CSF in the intervals.

RESULTS

Three patients presented CR (37.5%). Two patients stopped the treatment after two courses for evident progressive disease (25%). The other three patients showed stable disease (SD: 37.5%). Median duration of SD was 24 weeks. Among the eight patients, six (75%) achieved clinical benefit. Median time to progression was 8.5 months (range 0-74+ months). Median survival was 12.5 months (range 4-74+ months). Two patients are still alive and disease-free after 74 and 57 months, respectively.

CONCLUSION

We believe that the brilliant CR, the long duration of the disease-free intervals and the long survival in at least three of eight patients should encourage further research on BOLD with G-CSF for the treatment of advanced melanoma.

G-CSF therapy of ongoing experimental allergic encephalomyelitis via chemokine- and cytokine-based immune deviation

Converging evidence that G-CSF, the hemopoietic growth factor of the myeloid lineage, also exerts anti-inflammatory and pro-Th2 effects, prompted us to evaluate its direct therapeutic potential in autoimmune diseases. Here we report a novel activity of G-CSF in experimental allergic encephalomyelitis, a murine model for multiple sclerosis, driven by Th1-oriented autoaggressive cells. A short 7-day treatment with G-CSF, initiated at the onset of clinical signs, provided durable protection from experimental autoimmune encephalomyelitis. G-CSF-treated mice displayed limited demyelination, reduced recruitment of T cells to the CNS, and very discrete autoimmune inflammation, as well as barely detectable CNS mRNA levels of cytokines and chemokines. In the periphery, G-CSF treatment triggered an imbalance in the production by macrophages as well as autoreactive splenocytes of macrophage inflammatory protein-1alpha and monocyte chemoattractant protein-1, the prototypical pro-Th1 and pro-Th2 CC chemokines, respectively. This chemokine imbalance was associated with an immune deviation of the autoreactive response, with reduced IFN-gamma and increased IL-4 and TGF-beta1 levels. Moreover, G-CSF limited the production of TNF-alpha, a cytokine also associated with early CNS infiltration and neurological deficit. These findings support the potential application of G-CSF in the treatment of human autoimmune diseases such as multiple sclerosis, taking advantage of the wide clinical favorable experience with this molecule.

Evidence of recurrent atypical meningioma with rhabdoid transformation and expression of pyrogenic cytokines in a child presenting with a marked acute-phase response: case report and review of the literature

Children presenting with acute systemic illnesses that lack specific clinical or serological defining features may be diagnosed as having a chronic infection, an atypical systemic vasculitis or a connective tissue disease, but often turn out to have occult neoplasias. Cytokines have been implicated in causing many of the systemic effects in such cases. In this study, we describe the case of a 9-year-old boy presenting at an interval of 18 months with a marked acute-phase response due to a recurrent atypical meningioma with rhabdoid transformation of the tentorium cerebelli. Resection of the recurrent tumor was curative. We evaluated in detail the local and systemic production of cytokines released by the primary and the recurrent tumor. Blood and CSF samples were taken pre-, intra-, and postoperatively, and the production of IL-6, IL-1beta, and TNF-alpha was measured by enzyme-linked immunosorbent assays (ELISA). The level of IL-6 in CSF was about 150-fold increased before tumor resection, normalizing postoperatively. On the contrary, the levels of IL-1beta and TNF-alpha in CSF and of IL-6, IL-1beta, and TNF-alpha in serum were pre-, intra-, and postoperatively within normal limits. Cytokine production was also evaluated immunohistochemically, and confirmed strong IL-6 and TNF-alpha expression in the primary and the recurrent tumor, while expression of IL-1beta was lacking. The scattered MHC class II- and leukocyte common antigen (LCA)-expressing inflammatory cells, which were infiltrating exclusively the tumoral stroma, had no detectable cytokine immunoreactivity. We conclude that chronic IL-6 and TNF-alpha production by the tumor cells in this patient was responsible for the severe systemic illness with which he presented.