Molecular analysis of the INK4A and INK4B gene loci in human breast cancer cell lines and primary carcinomas

Autor: Maria Bisogna, Jacqueline E. Calvano, Gay Hui Ho, Irene Orlow, Carlos Cordón-Cardó, Patrick I. Borgen, Kimberly J. Van Zee
Rok vydání: 2001
Předmět:
Silent mutation
Cancer Research
DNA Mutational Analysis
Breast Neoplasms
Cell Cycle Proteins
Biology
medicine.disease_cause
Viral Proteins
Exon
Tumor Cells
Cultured
Genetics
medicine
Humans
Genes
Tumor Suppressor
Breast
Gene Silencing
RNA
Messenger
RNA
Neoplasm
Molecular Biology
Cyclin-Dependent Kinase Inhibitor p16
Polymorphism
Single-Stranded Conformational
Cyclin-Dependent Kinase Inhibitor p15
Sequence Deletion
Regulation of gene expression
Reverse Transcriptase Polymerase Chain Reaction
Gene Expression Profiling
Genes
p16
Tumor Suppressor Proteins
Carcinoma
DNA
Neoplasm
Exons
DNA Methylation
Cell cycle
Neoplasm Proteins
Gene Expression Regulation
Neoplastic
Gene expression profiling
Blotting
Southern
DNA methylation
Cancer research
CpG Islands
Female
Carrier Proteins
Chromosomes
Human
Pair 9
Carcinogenesis
Breast carcinoma
Zdroj: Cancer Genetics and Cytogenetics. 125:131-138
ISSN: 0165-4608
DOI: 10.1016/s0165-4608(00)00367-8
Popis: The INK4A and INK4B loci are located at 9p21 and have been implicated in the tumorigenesis of various human malignancies. The INK4A gene encodes two cell cycle regulators, p16(INK4A) and ARF, while INK4B encodes p15(INK4B). Previously, we have shown that the p16(INK4) tumor suppressor was not mutated or deleted in primary breast carcinomas. However, primary and metastatic breast carcinomas exhibited a relative hypomethylation of p16(INK4A), which is associated with expression, compared to normal breast tissue. The present study was conducted to determine if inactivation of p15(INK4B) and INK4A exon 1beta (ARF) are common events in breast carcinoma. Mutational analysis was performed by PCR-SSCP, and mRNA expression was evaluated by RT-PCR. Methylation-specific PCR was used to determine the methylation status of the p15(INK4B) promoter. Our results demonstrate that the p15(INK4B) gene was altered in 3 (21%) of the 14 breast cell lines; one had a silent mutation and two had homozygous deletion of the gene. None of the cell lines showed methylation of p15(INK4B). Two (14%) cell lines had homozygous deletion of INK4A exon 1beta. All normal and malignant breast tissue samples were wild-type and non-methylated for p15(INK4B) and wild-type for exon 1beta. Our results show that these structurally and functionally related genes are not invariably affected together, and the most frequently observed alteration at the INK4A and INK4B loci in breast carcinoma appears to be p16(INK4A) hypomethylation.
Databáze: OpenAIRE
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