ABSTRACT
PURPOSE: Telomerase is considered a molecular marker for malignancy. The aim of this study was to determine telomerase activity (TA) as a prognostic factor at diagnosis and as a marker for minimal residual disease during therapy and follow-up in nonmetastatic Ewing family of tumors (EFT). PATIENTS AND METHODS: Primary tumor specimens and 97 peripheral blood (PBL) samples from 31 EFT patients were analyzed for TA by the Telomeric Repeat Amplification Protocol (TRAP assay). The telomerase catalytic subunit (human telomerase reverse transcriptase [hTERT]) gene expression was evaluated by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and telomere length was determined by Southern blotting. The presence of the EFT chimeric transcripts was analyzed by RT-PCR. Correlations with progression-free survival were evaluated. RESULTS: At diagnosis, TA in primary tumors did not correlate with outcome. During therapy and follow-up, highly significant correlation was observed between high TA in PBL samples and adverse prognosis (P <.0001). None of the patients harboring low TA progressed, with a long follow-up (median, 60 months) and a progression-free survival (PFS) of 100%. In nine patients, high TA actually could predict relapse, long before overt clinical relapse. The group of patients with high TA and positive RT-PCR had the most adverse outcome; PFS of 20% (P =.0025). TA was found to be a better prognostic factor than RT-PCR and histopathologic response at surgery. CONCLUSION: The results suggest that TA is a significant prognostic variable, superior to the established clinical prognostic parameters during therapy and tumor surveillance. It could be used in combination with RT-PCR for a new risk classification.
Subject(s)
Sarcoma, Ewing/enzymology , Telomerase/blood , Adolescent , Biomarkers, Tumor/blood , Child , DNA-Binding Proteins , Female , Follow-Up Studies , Humans , Male , Neoplasm, Residual/blood , Prognosis , Reverse Transcriptase Polymerase Chain Reaction , Sarcoma, Ewing/diagnosisABSTRACT
To evaluate possible genomic instability and possible random aneuploidy, we applied comparative genomic hybridization and fluorescence in situ techniques, and evaluated telomerase activity in 16 cases of Ewing sarcoma (EWS) and compared the results to 7 controls. Common secondary aberrations (gains of chromosomes 8 and 12) were found in the study group. There was a direct correlation between the detection of random aneuploidy and development of tumor relapse (P = 0.0047). Other detectable abnormal parameters (secondary) and high telomerase activity were also more common among the cases with relapse but did not reach a statistical significance (probably because of the small sample size). In EWS, the detection of random aneuploidy seems to be a sensitive parameter in the prediction of tumor relapse.
Subject(s)
Aneuploidy , Bone Neoplasms/genetics , Sarcoma, Ewing/genetics , Adolescent , Adult , Bone Neoplasms/enzymology , Bone Neoplasms/mortality , Bone Neoplasms/pathology , Cell Transformation, Neoplastic/genetics , Child , Chromosomes, Human/ultrastructure , Disease-Free Survival , Female , Humans , In Situ Hybridization, Fluorescence , Life Tables , Male , Neoplasm Metastasis , Neoplasm Proteins/analysis , Neoplasm Recurrence, Local , Nucleic Acid Hybridization , Sarcoma, Ewing/enzymology , Sarcoma, Ewing/mortality , Sarcoma, Ewing/pathology , Telomerase/analysisABSTRACT
The insulin receptor is synthesized as a single chain of 190 kiloDaltons, which is processed to disulfide-linked mature alpha- and beta- subunits, containing N- and O-linked oligosaccharides and fatty acids. Previously (Collier E, Carpentier J-L, Beitz L, Caro LHP, Taylor SI, Gorden P: Biochemistry 32:7818-23, 1993), site directed mutagenesis of the asparagine in the first four sites of N-linked glycosylation to glutamine resulted in a receptor that was retained in the endoplasmic reticulum and not processed past the proreceptor form. In this study, mutation of these sites individually and in various combinations is studied. Mutation in the first or second glycosylation site does not significantly impair processing of the receptor; the receptor is found on the cell surface and binds insulin normally. If both the first and second sites are mutated, a significant reduction occurs in the amount of receptor found on the cell surface and in insulin binding. There is some processing of the receptor in cells expressing this mutant compared with the four-part mutant. If only the third and fourth sites are mutated, processing is impaired less than in the mutant with the first and second sites mutated. However, the amount of receptor found on the cell surface is less than in the mutant of only the first or only the second site. In all of these glycosylation mutants, the amount of receptor on the cell surface correlates with the level of 125I-labeled insulin binding on the cell surface.(ABSTRACT TRUNCATED AT 250 WORDS)
Subject(s)
DNA Mutational Analysis , Receptor, Insulin/metabolism , 3T3 Cells , Animals , Asparagine , Binding Sites , Cell Membrane/metabolism , Chromatography, High Pressure Liquid , Cloning, Molecular , Glutamine , Glycosylation , Humans , Insulin/metabolism , Macromolecular Substances , Mice , Mutagenesis, Site-Directed , Peptide Fragments/isolation & purification , Peptide Mapping , Phosphorylation , Receptor, Insulin/biosynthesis , Restriction Mapping , TrypsinABSTRACT
The Kromayer lamp is one of the most effective instruments in the production of therapeutic ultraviolet rays (Linct; 1967; Scott; 1973). Experts who recommend its technique and use say that at a distance of 4 inches it produces a First-degree erythema dose (E1) on the human skin in 10 seconds (Scott; 1973). A total of 30 blacks (Nigerians) patients were recruited at the dressing section of the out-patient department of Obafemi Awolowo University Teaching Hospital Complex; Ile-Ife; for this study; the purpose being to test whether the above parameters are applicable in our environment
