文摘
The 9p21 gene cluster, harboring growth suppressive genes p14ARF, p15INK4b, and p16INK4a, is one of the major aberration hotspots in head and neck cancers. We try to elucidate specific aberrations affecting this region, throughout methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay. Methylation of the gene was investigated by MS-MLPA in a well-characterized series of 27 laryngeal squamous cell carcinomas and 20 samples of healthy mucosa. Aberrant promoter hypermethylation was confirmed using and methylation-specific. All samples studied except 3 (11 %) presented losses at 9p21 segment. The most common finding was the small deletion (exon 1α) of the p16INK4a locus (44 %). Deletion of the 9p21 gene cluster was identified in 5 cases (18 %). We only found methylation in 8 samples (30 %) for p15IK4b-exon 1. Promoter methylation of p14ARF, p15IK4b and p16INK4a was not detected in any tumor sample. Methylation-specific polymerase chain reaction confirmed the results. Our data indicate that there may be a subgroup of patients in which epigenetic regulation of 9p21 segment might have little relevance. Nevertheless, MS-MLPA could not be suitable for the study of methylation at this region and further research is required.
