miRNA expression during early, mid and late breast cancer disease progression in mammary glands from MMTV-PyMT transgenic mice. Mus musculus

MicroRNAs (miRNAs) are small noncoding RNAs that typically inhibit the translation and stability of messenger RNAs (mRNAs), controlling genes involved in a variety of cellular processes. miRNA dysregulation is recognized to play an essential role in the development and progression of cancer. MMTV-PyMT mice (Jax Strain: FVB/N-Tg(MMTV-PyVT)634Mul/J) are a well-characterized transgenic mouse model of breast cancer. Upon activation of the MMTV-PyVT transgene (mouse mammary tumor virus (MMTV) long terminal repeat upstream of a cDNA sequence encoding the Polyoma Virus middle T antigen (PyVT)) female carriers develop palpable mammary tumors as early as 5 weeks of age. We performed miRNA microarrays on samples from the MMTV-PyMT transgenic mouse model to investigate the differential expression of miRNAs during development of malignant disease in this model. Overall design: Mammary glands from MMTV-PyMT +/- mice were selected at successive stages of breast cancer progression for RNA extraction and hybridization on Affymatrix miRNA microarrays. Samples in biological triplicate were analyzed from time points representing early (4 weeks), mid (8 weeks) and late (13 weeks) stage breast cancer disease progression.