Here, we report that the analysis of RNP granule content purified from U2OS cells treated with sodium arsenite—a known inducer of both SG and P-bodies [24]—and RK-33, a small molecule inhibitor of DDX3 ATPases activity shown to be effective in breast cancer bone metastasis patients [25], reveals alterations in the non-coding RNA pools of both RNP granules and the cytoplasm. Here, RNPC3 is linked to metastasis.