Fig. 5: High numbers of pericyte FAK-negative blood vessels are associated with enhanced tumour size and progression in human melanoma.
a Representative images of human melanoma showing both pericyte FAK-positive (arrows) and FAK–negative (arrowheads) blood vessels. Scale bar, 40 μm. b Chart represents the range of percentages of blood vessels that are pericyte-FAK negative for individual patients. n = 28 patient samples. c Tumour blood vessel density is increased in human melanoma where more than 50% of tumour blood vessels are pericyte FAK-negative. Chart represents mean ± s.e.m., n = 28 clinical samples, *p = 0.048. d Breslow thickness, an indicator of tumour burden is significantly increased in human melanoma where more than 50 % of tumour blood vessels are mural FAK negative. Chart represents mean Breslow thickness (mm) ± s.e.m., ****p < 0.0001; n = 28 clinical samples. e The incidence of metastasis is significantly increased when more than 50% of tumour blood vessels are PC FAK-negative. Chart represents incidence of metastasis (%); n = 14 clinical samples. f Schematic diagram of proposed molecular mechanism of FAKKO pericyte regulation of tumour growth. Loss of pericyte FAK elevates pPyk2-Gas6-Axl-AKT signalling and subsequent Cyr61 expression that enhances angiogenesis. In parallel, Cyr61 is sufficient to enhance TF expression in tumour cells, thus enhancing tumour growth. c, d Two-sided Students t-test. Source data are provided as a Source data file.
