Targets of miR-21 (TIMP3, PDCD4, PTEN, TPM1 and RECK) are also primarily involved in BC promotion and progression, especially invasion, angiogenesis and metastasis. miR-21 expression levels could perhaps be used in conjunction with the standard diagnostic parameters as an indicator of BC presence, and to indicate a phenotype likely to show early invasion/metastasis detection and poor prognosis.
A previous methylome study on breast cancer tissues detected inverse correlation between RECK CpG methylation (in an intron-1 region) and relapse-free survival.
Here we show that the membrane protein RECK (Reversion-inducing cysteine-rich protein with kazal motifs) controls breast cancer metastasis by modulating a novel, non-canonical and convergent signal transducer and activator of transcription factor 3 (STAT3)-dependent angiogenic program.
Higher RECK protein expression levels were detected in more aggressive breast cancer cell lines (T4-2, MDA-MB-231 and Hs578T) than in non-invasive (MCF-7 and T47D) and non-tumorigenic (S1) cell lines.
We analyzed the expression levels of MMP-2, MMP-9 and MMP-14 and their inhibitors (TIMP-1, TIMP-2 and RECK) by quantitative RT-PCR (qRT-PCR) in five human breast cancer cell lines presenting increased invasiveness and metastatic potential, 72 primary breast tumors and 30 adjacent normal tissues.
Therefore, the possibility of applying RECK, a pharmaceutical mimetic, or drugs activating endogenous RECK expression, as possible therapeutic or preventive agents for breast carcinoma should be explored.