Fig. 8: Origin and mechanisms of the lncRNA signature for T-DM1 resistance.

A Schematic diagram of the culture, collection, and processing of exosomes from supernatants and cultured cells. B Western blot analysis of Alix in EVs originating from cell pellets and culture supernatants. C Relative expression levels of the 4-lncRNA signature in exosomes and exosome-free supernatants cultured from primary breast tumor cells. Immune cells were isolated from 10 patients (mean + s.e.m. D BT474 and SKBR3 cells were transduced with ASO-nc, an ASO of four lncRNAs, and then T-DM1 was added to the culture medium at 8.00 μg/ml for 48 h. The relative expression levels of individual lncRNAs were assessed via qRT-PCR. E–G A WST-1 assay was used to assess the growth of treated cells as described in (D) (mean ± s.e.m., n = 3 separate experiments). ***p < 0.001. p values were obtained via two-tailed Student’s t tests. H–K Luciferase reporter assay of SKBR3 cells transfected with the indicated vectors in the presence or absence of the indicated lncRNAs. (mean ± s.e.m., n = 3 separate experiments). ***p < 0.001. p values were obtained via two-tailed Student’s t tests.