Nestin in Human Cerebellar Development and Tumorigenesis of Medulloblastoma

Jyoti Mishra; Srijan Srivastav; Mayank Gupta; Geeta Deshmukh

Volume : X, Issue : VI, June - 2020

Nestin in Human Cerebellar Development and Tumorigenesis of Medulloblastoma

Jyoti Mishra, Srijan Srivastav, Mayank Gupta, Geeta Deshmukh

Abstract :

Background & Objectives: The aim of this study was to see the localization and migration of neural stem cells (NSC’s) in developing human cerebellum and neuroectodermal tumors of cerebellum by the expression pattern of Nestin, a neuroepithelial stem cell marker. It was observed that the stem cells decreased during the progressive maturation of the progeny, still some persisted postnatally. In our study the higher Nestin expression was observed in desmoplastic medulloblastomas as compared to classic medulloblatosmas which provided a credible evidence that this tumor originates from these neuroectodermal stem cells. Methods: Nestin immunohistochemistry (IHC) was conducted and quantitatively analysed on a) Eighteen human fetal cerebellum ranging from 17 to 36 weeks of gestational age (GA) – three fetuses each in age groups of 14–17, 18–21, 22–25, 26–29, 30–33 & 34–36 weeks b) Forty cases of childhood medulloblastomas (34 cases of classical and 6 of desmoplastic variants) Results: The results tabulated reflected that a) With the increase in gestational age, Nestin expression decreased in external germinal layer (EGL), periventricular zone (PVZ) and internal granular layer (IGL) while increased in ventricular layer (VL). However, still Nestin positivity persisted in small percentages in each layer. b) The tumor cells showed perivascular and diffuse (<50%) Nestin staining in classical variant as compared to focal nodular and diffuse (>50%) in desmoplastic variant. Interpretation & Conclusions: The careful per–lustration indicated that there was a significant reduction in the neural progenitor cells and increase of these cells in the VL. The Nestin positive cells present in EGL, PVZ, VL and IGL suggested the origin of medulloblastoma from these neural stem cells. The desmoplastic variant of medulloblastomas showing higher Nestin expression in comparison to classical variant points that the desmoplastic variant is more primitive and hence with poor prognosis.