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Figure 3 | Biomarker Research

Figure 3

From: Prognostic value and functional consequences of cell cycle inhibitor p27Kip1 loss in medulloblastoma

Figure 3

P27 loss is a feature common in human medulloblastomas. Human tumor tissue was obtained from the brain tumor tissue bank at Children’s Hospital in Seattle. These studies had prior approval from the Institutional Review Board and informed consent was obtained for all samples. Control brain samples were from four pediatric subjects (median age 16 yr, range 11-18 yrs) who died from trauma or non-malignant disease. These were from the Maryland Brain Bank, supplied by the laboratory of Dr. Gregory Riggins. (A) Representative P27 staining in the human cerebellum from a pediatric patient that died of non-cancer-related trauma demonstrates P27 expression in over 70% of granule cells. (B-C) Sections from human medulloblastoma samples were stained for P27, with panel (B) representative of the observed P27 protein loss within tumors. (C) Granule neurons within the remaining normal cerebellar architecture from the tumor sample shown in panel (B) exhibit strong, nuclear P27 staining. (D) Kaplan-Meier analysis from the second study of 141 patients enrolled on the SIOP PNET3 study [11, 12]. Patients were grouped into three categories: N, with virtually no (<1%) P27-positive cells (n = 2), F, with less than 10% P27-positive cells and M, with greater than 10% P27-positive cells. Patients from groups F and N were grouped together because they represented only 13 of the 141 patients examined. Because desmoplastic/nodular tumors have a heterogeneous P27 staining pattern with pockets of strong P27 expression among fields of low or variable staining, we analyzed the test data set including and excluding patients with desmoplastic/nodular tumors, but neither analysis revealed prognostic value for P27.

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