CST6 promoter methylation in circulating cell-free DNA of breast cancer patients.

Objectives: We have recently shown that detection of CST6 promoter methylation in primary breast tumors can provide important prognostic information in patients with operable breast cancer and that CST6 promoter is also methylated in Circulating Tumor Cells (CTC). In this study we evaluated the presence of CST6 promoter methylation in cell-free DNA (cfDNA) circulating in plasma of breast cancer patients.

Design And Methods: Our study material consisted of: a) a pilot testing group of 27 patients with stage I-III operable breast cancer, 46 patients with verified metastasis and 37 healthy donors and b) an independent cohort of 123 consecutive stage I-III operable breast cancer patients.

DNA methylation of tumor suppressor and metastasis suppressor genes in circulating tumor cells.

Background: Circulating tumor cells (CTCs) are associated with prognosis in a variety of human cancers and have been proposed as a liquid biopsy for follow-up examinations. We show that tumor suppressor and metastasis suppressor genes are epigenetically silenced in CTCs isolated from peripheral blood of breast cancer patients.

Methods: We obtained peripheral blood from 56 patients with operable breast cancer, 27 patients with verified metastasis, and 23 healthy individuals.

The enzymatic activity of SR protein kinases 1 and 1a is negatively affected by interaction with scaffold attachment factors B1 and 2.

SR protein kinases (SRPKs) phosphorylate Ser/Arg dipeptide-containing proteins that play crucial roles in a broad spectrum of basic cellular processes. Phosphorylation by SRPKs constitutes a major way of regulating such cellular mechanisms. In the past, we have shown that SRPK1a interacts with the nuclear matrix protein scaffold attachment factor B1 (SAFB1) via its unique N-terminal domain, which differentiates it from SRPK1.