Subependymal giant cell astrocytoma (SEGA) is a World Health Organization Central Nervous System grade 1 tumor, strongly associated with tuberous sclerosis complex (TSC). Recent research indicates that Glycoprotein Nonmetastatic Melanoma Protein B (GPNMB), regulated by microphthalmia (MiT) family transcription factors may also be modulated by loss-of-function mutations in TSC1/2. We evaluated GPNMB as a diagnostic marker of subependymal giant cell astrocytoma (SEGA). A total of 11 patients with SEGA were included in the study. The control group comprised 185 primary central nervous system tumors, including high-grade and low-grade gliomas and glioneuronal/neuronal tumors. Strong and diffuse (≥ 50% of tumor cells) GPNMB expression was present in all SEGAs. In contrast, TTF-1 expression was detected in nine SEGAs, resulting in a sensitivity of 81.8%. Among the control group, 77 cases (41.6%) were negative for GPNMB and 102 (55.1%) cases were scored as > 1% < 50% positive. Only six control tissues (3.2%) showed diffuse and strong GPNMB expression. Among the tumors with strong GPNMB expression, there were three glioblastomas (GBMs) with morphology potentially mimicking SEGA but lacking TSC1, TSC2, or MTOR mutations. Using a cutoff of diffuse (≥ 50%) and strong positivity, GPNMB demonstrated 100% sensitivity (95% confidence interval: 74.1%-100%) and 96.8% specificity (95% confidence interval: 93.1%-98.5%) for diagnosing SEGA.

• Keywords
• GPNMB, Immunohistochemistry, Subependymal giant cell astrocytoma, TSC1/2, Tuberous sclerosis,
• Publication type
• Journal Article MeSH

Background: Although several prognostic factors for survival have been identified in glioblastoma, there are numerous other potential markers (such as hemoglobin) whose role has not yet been confirmed. The aim of this study was to evaluate a wide range of potential prognostic factors, including HIF-1α and hemoglobin levels, for survival in glioblastoma. A secondary aim was to determine whether hemoglobin levels were associated with HIF-1α expression. Methods: A retrospective study of 136 patients treated for glioblastoma at our institution between 2012 and 2021 was performed. Cox univariate and multivariate analyses were carried out. Kaplan-Meier survival curves were generated. In addition, bivariate non-parametric correlation analyses were performed for key variables. Results: Median survival was 11.9 months (range: 0-119.4). According to the univariate analysis, 13 variables were significantly associated with survival: age, performance status, extent of surgery, tumor depth, tumor size, epilepsy, postoperative chemoradiotherapy, IDH mutations, CD44, HIF-1α, HIF-1β, vimentin, and PDFGR. According to the multivariate regression analysis, only four variables remained significantly associated with survival: age, extent of surgery, epilepsy, and HIF-1α expression. No significant association was observed between hemoglobin levels (low <120 g/L in females or <140 g/L in males vs. high ≥120 or ≥140 g/L) and survival or HIF-1α/HIF-1β expression. Conclusions: In this retrospective study of patients with glioblastoma, four variables-age, extent of surgery, HIF-1α expression, and epilepsy-were significant prognostic factors for survival. Hemoglobin levels were not significantly associated with survival or HIF-1α expression. Although hypoxia is a well-recognized component of the glioblastoma microenvironment, more research is needed to understand the pathogenesis of onset tumor hypoxia and treatment implication.

• Keywords
• HIF, glioblastoma, hemoglobin, prognostic markers,
• Publication type
• Journal Article MeSH

BACKGROUND: Glioblastoma is a malignant and aggressive type of central nevous system malignancy characterized by many distinct biological features including extensive hypoxia. Hypoxia in glioblatoma associates with complex signaling patterns including activation of several pathways such as MAPK, PI3K-AKT/mTOR and IL-6/JAK/STAT3 with the master regulator HIF-1, which in turn drive particular tumor behaviors determining, in the end, treatment outcomes and patients fate. Thus, the present study was designed to investigate the expression of selected hypoxia related factors including STAT3 in a small set of long-term surviving glioma patients. METHODS: The expression of selected hypoxia related factors including STAT3 was evaluated in a time series of formalin fixed paraffin embedded and cryopreserved glioma samples from repeatedly resected patients. In addition, comparative studies were also conducted on primary glioma cells derived from original patient samples, stabilized glioma cell lines and tumor-xenograft mice model. Obtained data were correlated with clinical findings too. RESULTS: Glioblastoma samples of the analyzed patients displayed heterogeneity in the expression of hypoxia- related and EMT markers with most interesting trend being observed in pSTAT3. This heterogeneity was subsequently confirmed in other employed models (primocultures derived from glioblastoma tissue resections, cryopreserved tumor specimens, stabilized glioblastoma cell line in vitro and in vivo) and concerned, in particular, STAT3 expression which remained stable. In addition, subsequent studies on the role of STAT3 in the context of glioblastoma hypoxia demonstrated opposing effects of its deletion on cell viability as well as the expression of hypoxia and EMT markers. CONCLUSIONS: Our results suport the importance of STAT3 expression and activity in the context of hypoxia in malignant glioblastoma long-term surviving glioma patients while emphasizing heterogeneity of biological outcomes in varying employed tumor models.

• Keywords
• Glioblastoma, Hypoxia, Long-surviving patients, Primocultures, STAT3, Temozolomide,
• MeSH
• Adult MeSH
• Glioblastoma metabolism   pathology   genetics   MeSH
• Glioma * metabolism   pathology   genetics   MeSH
• Hypoxia metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Mice MeSH
• Biomarkers, Tumor metabolism   MeSH
• Cell Line, Tumor MeSH
• Brain Neoplasms metabolism   pathology   genetics   MeSH
• Gene Expression Regulation, Neoplastic MeSH
• Aged MeSH
• STAT3 Transcription Factor * metabolism   MeSH
• Animals MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Mice MeSH
• Aged MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Biomarkers, Tumor MeSH
• STAT3 protein, human MeSH Browser
• STAT3 Transcription Factor * MeSH