vallia
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A biopsy of a brain tumor from a 42-year-old man reveals a glial neoplasm
consisting of atypical astrocytes with scattered mitoses. Besides mitotic
activity, which of the following markers can provide information about
the neoplasm's proliferative activity?
A. bcl-2
B. Glial fibrillary acidic protein (GFAP)
C. Ki-67
D. p53
E. Ubiquitin
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| Ms.Apara
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Ki-67
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| MannMD
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B
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| mildus
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Ki67 is a proliferative marker
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| mjl1717
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so what does GFAP show ?
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| nadiabarati
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ki67?!!! Never heard of it!! How do you guys know it? I think I'm a loser because I didn't study kaplans and Goljan........
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| robin082006
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this patient has Glioblastoma Multiforme
But I do not know about its relationships with the answer choices, making me search by Google.
Answer is Ki67.
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| robin082006
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1: J Neurooncol. 2001 Dec;55(3):195-204. Related Articles, Links href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&itool=PubMed_Abstract&term=%22Reavey%2DCantwell+JF%22%5BAuthor%5D">Reavey-Cantwell JF, Haroun RI, Zahurak M, Clatterbuck RE, Parker RJ, Mehta R, Fruehauf JP, Brem H.
Hunterian Neurosurgical Laboratory, Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Although several studies have examined brain tumor markers for prognostic value, few investigations have stratified analysis based on specific histologic grade. The objective of this study was to evaluate a single histologic grade of glioma, the grade IV glioma or glioblastoma (World Health Organization Classification), with a comprehensive panel of tumor markers in an attempt to identify those with prognostic significance. Tumor samples from a cohort of patients with glioblastoma multiforme (n = 32) were examined for tumor markers, DNA analysis, and clinical variables in an attempt to determine a 'profile' for this tumor. We used univariate and multivariate statistical analysis to determine the prognostic value of tumor cell ploidy, percent S-phase, DNA index, p53, and Ki-67 labeling index, as well as the variables of gender, race, age, location of tumor, history of chemotherapy, and primary versus recurrent tumor. Two additional tumor markers, multidrug resistance gene 1 and glutathione-S-transferase subtype pi, were included in the sample testing, but were not analyzed statistically. Univariate analysis indicated that increasing age had a strong association with decreased survival. Female gender, increasing Ki-67, no chemotherapy before sample collection, and primary glioblastoma showed some association with decreased survival in the univariate model. The univariate results indicated that race, side of tumor, ploidy, S-phase, DNA index, and p53 had no prognostic value. Multivariate modeling demonstrated that age, gender, and Ki-67 were the strongest factors associated with survival. The relevant literature is reviewed.
Publication Types:
PMID: 11859975 [PubMed - indexed for MEDLINE]
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| vallia
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sorry guys, I have been away for a few days, this is the answer.
25The correct answer is C. Ki-67 is a nuclear factor (of uncertain function) whose expression correlates with neoplastic replicative activity. Its expression can be visualized by immunostaining of formalin-fixed, paraffin-embedded sections. Ki-67 labeling correlates with a neoplasm's rate of growth and, therefore, with prognosis.
The bcl-2 gene (choice A) suppresses apoptosis by different mechanisms. Its abnormal activation is involved in the pathogenesis of low-grade lymphomas but not astrocytomas.
GFAP (choice B) is an intermediate cytoskeletal filament (analogue of keratin and vimentin) expressed exclusively by certain types of glial cells, e.g., astrocytes and ependymal cells. Immunohistochemistry for GFAP is used diagnostically to confirm an astrocytic origin of a neoplasm, but gives no information about mitotic or proliferative rate.
The gene p53 (choice D) encodes a protein that blocks the cell cycle when damage to DNA occurs. If the damage is successfully repaired, p53 allows the cell cycle to resume; if not, p53 induces apoptosis, thus eliminating dangerous DNA mutations. Mutations of p53 have been found in the great majority of human neoplasms, including gliomas. However, its expression gives no information concerning neoplastic replicative activity.
Ubiquitin (choice E) is a low-molecular-weight heat-shock protein. Its function is to tag aberrant proteins for degradation. It is present in many abnormal intraneuronal inclusions associated with neurodegenerative disorders, such as Lewy bodies, Pick bodies, and neurofibrillary tangles. It has no relationship with mitotic activity or growth rate.
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