ABSTRACT
Background/aim: The aims of this study were to detect CCND1 , C-MYC , and FGFR1 amplification using qPCR, confirmation with FISH, and to further assess their clinicopathological relevance. Materials and methods: Thirty-five breast tumor samples were analyzed for amplification of the selected genes using modified SYBR Green qPCR. The accuracy of the qPCR was assessed by FISH as a gold-standard method. Results: CCND1 , C-MYC , and FGFR1 amplifications were observed in 34.28%, 28.57%, and 17.14% of the 35 samples, respectively. qPCR results were significantly confirmed by FISH and qPCR and FISH showed excellent correlation (P = 0.000). CCND1 amplification with tumor stage (P = 0.044), positive metastatic status (P = 0.042), positive family history (P = 0.042), and C-MYC status (P = 0.005); C-MYC amplification with tumor size (P = 0.021), tumor grade (P = 0.018), tumor stage (P = 0.032), and FGFR1 status (P < 0.000); and FGFR1 amplification with tumor size (P = 0.041) and positive ER status (P = 0.042) were statistically associated. Conclusion: Our findings revealed that the applied qPCR approach could precisely quantify the relative gene copy number. More studies with a larger sample size are suggested to confirm the clinicopathological value of CCND1 , C-MYC , and FGFR1 amplification.
Subject(s)
Breast Neoplasms/genetics , Carcinoma, Ductal, Breast/genetics , Cyclin D1/genetics , DNA-Binding Proteins/genetics , Gene Amplification , Real-Time Polymerase Chain Reaction/methods , Receptor, Fibroblast Growth Factor, Type 1/genetics , Transcription Factors/genetics , Adolescent , Adult , Benzothiazoles , Breast Neoplasms/pathology , Diamines , Female , Gene Dosage , Humans , In Situ Hybridization, Fluorescence/methods , Middle Aged , Neoplasm Grading , Neoplasm Staging , Organic Chemicals , Quinolines , Reproducibility of Results , Young AdultABSTRACT
BACKGROUND: Astrocytoma and meningioma are the most common primary brain tumors. MYCN as a member of MYC proto-oncogenes has recently appeared as an attractive therapeutic target. Functions of MYCN are critical for growth of nervous system and neural differentiation. OBJECTIVE: We examined MYCN amplification and protein expression in astrocytoma and meningioma cases. METHODS: In this study, we used real-time PCR, FISH assay and flowcytometry to analyze DNA amplification and protein expression of MYCN. RESULTS: Among 30 samples of brain tumor, 14 cases (46.6%) revealed MYCN amplification. High-protein expression of MYCN was also observed in 43.3% of patients. There was a significant correlation between MYCN gene amplification and protein expression (r= 0.523; p= 0.003), interestingly five case showed discrepancy between the gene amplification and protein expression. Although MYCN amplification fails to show correlation with poor prognosis (p= 0.305), protein high-expression of MYCN significantly reduce disease-free survival (p= 0.019). CONCLUSIONS: Our results challenge the concept of the neural specificity of MYCN by demonstrating contribution of MYCN in meningioma. Moreover, this study highlights the importance of research at both level of DNA and protein, to determine the biological functions and medical impacts of MYCN.
Subject(s)
Astrocytoma/genetics , Brain Neoplasms/genetics , Meningioma/genetics , N-Myc Proto-Oncogene Protein/genetics , Adult , Astrocytoma/metabolism , Astrocytoma/pathology , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Female , Gene Amplification , Humans , Male , Meningioma/metabolism , Meningioma/pathology , Middle Aged , N-Myc Proto-Oncogene Protein/biosynthesis , PrognosisABSTRACT
Ataxia telangiectasia mutated (ATM) is a key gene in DNA double-strand break (DSB), and therefore, most of its disabling genetic alterations play an important initiative role in many types of cancer. However, the exact role of ATM gene and its epigenetic alterations, especially promoter methylation in different grades of brain tumors, remains elusive. The current study was conducted to query possible correlations among methylation statue of ATM gene, ATM/ retinoblastoma (RB) protein expression, D1853N ATM polymorphism, telomere length (TL), and clinicopathological characteristics of various types of brain tumors. Isolated DNA from 30 fresh tissues was extracted from different types of brain tumors and two brain tissues from deceased normal healthy individuals. DNAs were treated with bisulfate sodium using DNA modification kit (Qiagen). Methylation-specific polymerase chain reaction (MSP-PCR) was implicated to determine the methylation status of treated DNA templates confirmed by promoter sequencing. Besides, the ATM and RB protein levels were determined by immunofluorescence (IF) assay using monoclonal mouse antihuman against ATM, P53, and RB proteins. To achieve an interactive correlation, the methylation data were statistically analyzed by considering TL and D1853N ATM polymorphism. More than 73% of the brain tumors were methylated in ATM gene promoter. There was strong correlation between ATM promoter methylation and its protein expression (p < 0.001). As a triangle, meaningful correlation was also found between methylated ATM promoter and ATM protein expression with D1853N ATM polymorphism (p = 0.01). ATM protein expression was not in line with RB protein expression while it was found to be significantly correlated with ATM promoter methylation (p = 0.01). There was significant correlation between TL neither with ATM promoter methylation nor with ATM protein expression nor with D1853N polymorphism. However, TL has shown strong correlation with patient's age and tumor grade (p = 0.01). Given the important role of cell cycle checkpoint proteins as well as RB and ATM in TL and cancer evolution, further assessment is warranted to shed more light on the pathway linking the telomere instability to tumor progression. High ATM methylation rate in brain tumor patients could open a new avenue toward early screening and cancer therapy.
