In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 35, No. 15_suppl ( 2017-05-20), p. e23216-e23216
Abstract:
e23216 Background: Impairment of stability in chromosomal structure facilitates abnormal segregation of chromosomes, increasing the risk of carcinogenesis. Chromosomal stability during segregation is managed by appropriate methylation in the centromere region of chromosomes, which is associated with heterochromatin structures. Insufficient methylation, or demethylation, results in chromosomal instability. Satellite alpha transcript (Sat-A) is non-coding RNA transcribed from satellite alpha repetitive sequences at centromere, which is overexpressed by demethylated status of centromere. We have reported that increased levels of Sat-A were observed in patients with colorectal cancer, resulting in chromosomal instability. Difference levels of demethylation were reported in breast cancer patients but their association with Sat-A expression and chromosomal instability are not well known. In this study, we determined if Sat-A was involved in the chromosomal instability of breast cancer. Methods: We constructed lentiviral vectors expressing Sat-A and control viruses, which were infected in human mammary epithelial cells. The expression levels of Sat-A were determined by qRT-PCR and copy number alterations were evaluated by array CGH. Demethylation levels of satellite alpha sequences were determined by Methylight PCR. Then, these results were verified by using clinical specimens of 45 breast cancer patients. Results: Array CGH analysis revealed that copy number alterations were frequently seen at specific chromosomes of 8q and 20q in infected cells, despite no alteration in control, which was consistent with results in the clinical specimens. Patients with high levels of Sat-A expression showed more alterations than patients with low. Regression analysis exhibited that levels of Sat-A expression were significantly collated with demethylation levels of satellite alpha sequences. Conclusions: Overexpression of Sat-A impaired stability of chromosome 8q and 20q in human mammary epithelial cells, which was also recognized in clinical specimens of breast cancer patients. Chromosomal instability induced by Sat-A is involved in the development of breast cancer.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2017.35.15_suppl.e23216
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2017
detail.hit.zdb_id:
2005181-5
