Journal: Signal Transduction and Targeted Therapy

Article Title: Breast cancer-associated fibroblast-derived exosomal miR-1290 promotes triple-negative breast cancer cell proliferation

doi: 10.1038/s41392-026-02922-y

Figure Lengend Snippet: miR-1290 is upregulated in breast cancer and BCAF/MB-231-derived exosomes. a Nanoparticle tracking analysis of exosomes isolated from BCAFs and MB-231 cells showing their size distribution. The mean size and standard deviation (SD) are indicated for each sample. b TEM images of exosomes isolated from BCAFs (upper) and MB-231 cells (lower) showing the characteristic morphology of the exosomes. Scale bar, 100 nm. c Western blot analysis of exosome markers (CD63, CD81, and flotillin-1), CAF markers (α-SMA and FAP) and cellular markers (GM130 and H3) in BCAF cells, MB-231 cells and their derived exosomes. d BCAF-derived exosome uptake by TNBC cells. PKH67-labeled BCAF-derived exosomes (green) were incubated with BT-549 and Hs578T cells for 1 hour. The cell nuclei were stained with Hoechst 33342 (blue). Scale bar, 20 μm. e Heatmap showing miRNA expression profiles in exosomes derived from BCAFs and MB-231 cells. Red indicates high expression, and blue indicates low expression. miR-1290 (highlighted in red) is highly expressed in both exosome types. f Volcano plots showing differentially expressed miRNAs between breast cancer or TNBC samples and normal controls in five independent GEO datasets ( GSE37963 , GSE45666 , GSE45498 , GSE38167 , and GSE61438 ). Red and blue dots represent upregulated and downregulated miRNAs, respectively, selected using fold-change and nominal p value cutoffs (|log2(fold change)| > 0.58 and nominal p < 0.05, two-tailed Welch’s t test). g Venn diagram analysis of upregulated miRNAs across the five GEO datasets revealed four commonly upregulated miRNAs. h Violin plot showing miR-1290 expression levels in serum samples from normal individuals ( N , n = 2686) and breast cancer patients ( P , n = 1280) from the GSE73002 dataset. The expression of miR-1290 was significantly upregulated in the breast cancer patient samples (*** p < 0.001, Mann‒Whitney U test). i Analysis of serum exosomal miR-1290 levels in normal ( N , n = 20) and TNBC patient ( P , n = 39) samples collected at Keimyung University Dongsan Hospital. The results support the potential of miR-1290 as a candidate diagnostic marker in an independent cohort (*** p < 0.001, Mann‒Whitney U test). j Kaplan‒Meier plot of overall survival for TNBC patients based on serum exosomal miR-1290 expression levels from Keimyung University Dongsan Hospital ( p = 0.006, log-rank test)

Article Snippet: Membranes were incubated with the following primary antibodies: CD63 (1:200; ABclonal, A5271), CD81 (1:200; ABclonal, A5270), flotillin-1 (1:1000; ABclonal, A6220), α-SMA (1:1000; ABclonal, A17910), FAP (1:1000; ABclonal, A23789 ), GM130 (1:1000; Abcam, ab52649), H3 (1:1000; Cell Signaling Technology, 4620S), ACTB (1:20,000; ABclonal, AC026), TBC1D4 (1:200; Cell Signaling Technology, 2670S), P70S6K (1:500; Cell Signaling Technology, 9202S), phospho-P70S6K (1:500; ABclonal, AP0564), and Ki67 (1:1000; Abcam, ab16667).

Techniques: Derivative Assay, Exosomes, Analysis, Isolation, Standard Deviation, Morphology, Western Blot, Labeling, Incubation, Staining, Expressing, Two Tailed Test, Blood/Plasma/Serum Samples, Diagnostic Assay, Marker