A histopathological diagnostic marker for human spinal astrocytoma: expression of glial fibrillary acidic protein-δ

Abstract

Although histopathological diagnosis of spinal cord astrocytomas is important for postoperative treatment planning and prognosis, there is a lack of reliable immunohistochemical markers. The purpose of our study was to assess the expression pattern of GFAP-δ in spinal cord astrocytomas in human patients and to evaluate the utility of GFAP-δ as an immunohistochemical diagnostic marker. A total of 22 patients with spinal cord astrocytic tumors were included in this study. Patients were classified according to the WHO designation of human astrocytic tumors; three patients had grade 1 astrocytomas, 14 had grade 2, and five had Grade 3. Normal control spinal cord tissues were obtained at autopsy from the cervical spinal cords of ten patients with no history of cervical trauma or neurological disease. We evaluated BRAF, IDH1, GFAP, and GFAP-δ immunoreactivity in control tissues and astrocytomas. In normal control tissues, GFAP immunoreactivity was detected in astrocytes whereas GFAP-δ immunoreactivity was observed in very few astrocytes adjacent to the subpial layer of the spinal cord. GFAP-δ immunoreactivity was significantly correlated with spinal cord astrocytoma grade in astrocytomas compared to that in normal control tissues. The optical density of GFAP-δ increased significantly with astrocytoma grade (correlation coefficient, R (2) = 0.680). Also, BRAF and IDH1 immunoreactivity were detected in astrocytoma. We suggest that GFAP-δ may be an additional, reliable histopathological diagnostic marker for spinal cord astrocytomas.

Expression of glial acidic fibrillary protein delta and E-cadherin in ependymomas; clinic-pathological and immunohistochemistry correlation

“…Other studies have been suggested that human ependymomas arise from regionally distinct populations of radial glial cells [24,26], with abnormal GFAP-δ positive expression [15]. GFAP-δ increased significantly with tumor grade [27].…”

“…Altogether, these results suggest that GFAP-δ and nestin could be clinically relevant markers associated with tumor invasiveness in cerebral astrocytomas as well as, with ependymomas. Heo DH, et al [12]. Observed that the optical density of GFAP-δ increased significantly with astrocytoma grade and suggest that GFAP-δ may be an additional, reliable histopathological diagnostic marker for spinal cord astrocytomas.…”

“…These mechanisms can also lead to increased filament-filament associations and aggregate formation, but this is usually in the context of disease for GFAP and GFAP-δ highlight an emerging pattern for the assembly of type III IFs in terms of the incorporation of other filament subunits to modulate IF function. For instance, nestin like GFAP-δ have been assembly-compromised in vitro, the distribution of the mutations throughout the GFAP sequence, and possible genotype/phenotype correlations in immature astrocytes [11,12,19,20]. The positive reaction to GFAP-δ and nestin have been reported that reactivity is higher in highly invasive tumors compared with low-invasive tumors [19].…”

“…12 We observed that the loss of expression of E-cadherin was directly related to the abnormal isoform expression of GFAP as well as the expression of neurofilament [22]. The brain tumour stem cells express neural precursor markers, suggesting that they may be derived from normal neural precursors that they are capable of differentiation, and aberrant expressions [24].…”

“…Also they are part of the interme-doi: 10.7243/2055-091X-2-17 diate filaments [10,11], each of these different isoforms are involved in different biological processes, in both protein and filament associations as well as Jnk phosphorylation [10,11]. GFAP-δ in brain tumors assembly and function remains poorly understood [10][11][12][13].…”