Inhibition of RANKL blocks skeletal tumor progression and improves survival in a mouse model of breast cancer bone metastasis.

Bone metastases cause severe skeletal morbidity including fractures and hypercalcemia. Tumor cells in bone induce activation of osteoclasts, which mediate bone resorption and release of growth factors from bone matrix, resulting in a "vicious cycle" of bone breakdown and tumor proliferation. Receptor activator of NF-kappaB ligand (RANKL) is an essential mediator of osteoclast formation, function, and survival, and is blocked by a soluble decoy receptor, osteoprotegerin (OPG).

Conserved microRNA characteristics in mammals.

Short hairpin RNAs (shRNAs) and short interfering RNAs (siRNAs) probably enter different stages of the microRNA (miRNA) pathway for depletion of mRNA and suppression of protein translation. Primary and secondary structural characteristics that are shared between endogenous primary miRNA transcripts (pri-miRNAs) may contribute toward efficient biogenesis and potent silencing. This study investigates known miRNA transcripts for characteristics that are conserved between miRNAs and that distinguish them from random hairpins with similar lengths.