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. Author manuscript; available in PMC: 2013 May 6.
Published in final edited form as: Nat Med. 2012 Jun;18(6):883–891. doi: 10.1038/nm.2753

Figure 5. Disrupting Rab27a expression reduces exosome release, tumor growth, and metastasis.

Figure 5

(a) QRT-PCR analysis of RAB genes in melanoma (SK-Mel-#), breast cancer (MCF7, MDA-MB-231, SkBr3) and pancreatic adenocarcinoma (AsPc1) human cell lines. Red denotes high (≥ 2—fold), white intermediate (< 2—fold and > 1.5—fold), and blue low (≤ 1.5—fold) RAB expression in melanoma relative to breast cancer and pancreatic cell lines. (b) Measurement of the total protein in the exosomes secreted per million human melanoma cells in culture. (c) QRT-PCR analysis of Rab27a expression after shRNA knockdown of Rab27a in B16-F10 and SK-Mel-28 cell lines. (d) Measurement of exosome protein per million cells after shRNA knockdown of Rab27a in B16-F10 and SK-Mel-28 cell lines. Control scramble shRNA and parental cells were used as a reference. (e) Characterization and densitometric analysis of conditioned medium derived from B16-F10-shScramble and -shRab27a cell lines. (f) Analysis of primary tumor growth and metastasis in shScramble, sh-Rab27a- B16-F10 and SK-Mel28 cell lines subcutaneously injected into the flank of C57BL/6 and NOD SCID mice, respectively. Metastases were macroscopically counted (B16-F10) or quantified by QRT-PCR for mCherry (SK-Mel-28), n = 5 mice per group; error bars represent s.e.m.; ***P < 0.001 by ANOVA. (g) Analysis of BMDCs (GFP+-green) and tumor cells (mCherry-red) in B16-F10-shScramble and -shRab27a primary tumors (upper panel, scale bar, 200 μm) and lungs (lower panels, scale bar, 50 μm). Quantification of the metastatic area and total BMDCs is shown on the right, n = 5 mice per group; Error bars represent s.e.m; P value by ANOVA.