Fig. 5

SPAG5 upregulates MYCBP expression through direct interaction with MYCBP protein. a IP assays suggested that exogenously expressed Flag-SPAG5 specifically interacted with endogenous MYCBP in MDA-MB-231 and BT549 cells. b IF staining experiments showed that SPAG5 mainly localizes in the cytoplasm with MYCBP in MDA-MB-231 and MDA-MB-468 cells. c Western blot results suggested that the protein level of MYCBP was elevated in SPAG5- overexpressing MDA-MB-231 and MDA-MB-468 cells but reduced in SPAG5-knockdown Hs-578t and BT549 cells. d Regression analysis identified a positive relationship between SPAG5 and MYCBP protein expression levels in TNBC tissues. e Representative IHC image of SPAG5 expression and MYCBP expression in breast cancer specimens. f Representative IHC image of SPAG5 expression, MYCBP expression, and Ki-67 staining in xenografted MDA-MB-231 tumor specimens. g MDA-MB-231 cells were transfected with p-SPAG5 plasmid and treated with cycloheximide (CHX). Cells were collected at different time points and immunoblotted with MYCBP antibody. h Hs-578t cells transduced with SPAG5 siRNA were treated with 10 μM MG132 and collected at 6 h and immunoblotted with the MYCBP antibody