Amplification and the clinical significance of circulating cell-free DNA of PVT1 in breast cancer.

Duplication in the chromosome 8q24 region is a frequent occurrence in carcinomas. The PVT1 oncogene (PVT1), a long non-coding RNA, is found in this locus. PVT1 amplification is a frequent event in cancers, such as in lymphomas, serous ovarian, colorectal and breast cancers. Ectopic PVT1 expression is related with reduced survival duration in cancer patients. in the present study, we proved that PVT1 is markedly augmented in breast cancer tissues compared with adjacent non-tumorous tissues. Thus, PVT1 is an independent prognostic factor for the survival duration of breast cancer patients. Furthermore, PVT1 is pivotal in regulating p21 expression. In addition, we detected PVT1 DNA in serum and found that circulating PVT1 DNA significantly increased in the serum of breast cancer patients. Compared with PVT1 RNA, DNA is the main form of the PVT1-derived segment. These relevant findings collectively demonstrate that PVT1 plays a pivotal role in breast cancer and is a possible target for novel breast cancer therapies. The detection of circulating PVT1 DNA fragments may be a convenient means to predict the prognosis of breast cancer patients.