Consistent with the demonstration that LARP7 is necessary for the integrity of the 7SK snRNA (He et al., 2008), the reduced LARP7 expression in
invasive breast cancer cell lines was accompanied by a decrease in 7SK snRNA (Figure 1D).
LARP7 was expressed at relatively high levels in the untransformed mammary epithelial
cell lines (MCF10A and EpH4) and noninvasive
breast cancer cell lines (MCF7, BT474, T74D, and ZR75B), but was markedly reduced in all four
invasive and metastatic
cancer lines examined (MDA - MB - 468, BT549, MDA - MB - 231, and MDA - MB - 435; Figure 1D).