Tumour-associated fibroblasts contribute to neoangiogenesis in human parathyroid neoplasia.

Autor: Verdelli, C., Avagliano, L., Creo, P., Guarnieri, V., Scillitani, A., Vicentini, L., Steffano, G. B., Beretta, E., Soldati, L., Costa, E., Spada, A., Bulfamante, G. P., Corbetta, S.
Předmět:
Zdroj: Endocrine-Related Cancer; Feb2015, Vol. 22 Issue 1, p87-98, 12p
Abstrakt: Components of the tumour microenvironment initiate and promote cancer development. In this study, we investigated the stromal component of parathyroid neoplasia. Immunohistochemistry for alpha-smooth muscle actin (a-SMA) showed an abundant periacinar distribution of α-SMAC cells in normal parathyroid glands (n = 3). This pattern was progressively lost in parathyroid adenomas (PAds; n = 6) where α-SMA+ cells were found to surround new microvessels, as observed in foetal parathyroid glands (n= 2). Moreover, in atypical adenomas (n = 5) and carcinomas (n = 4), α-SMA+ cells disappeared from the parenchyma and accumulated in the capsula and fibrous bands. At variance with normal glands, parathyroid tumours (n = 37) expressed high levels of fibroblast-activation protein (FAP) transcripts, a marker of tumour-associated fibroblasts. We analysed the ability of PAd-derived cells to activate fibroblasts using human bone-marrow mesenchymal stem cells (hBM-MSCs). PAd-derived cells induced a significant increase in FAP and vascular endothelial growth factor A (VEGFA) mRNA levels in co-cultured hBM-MSCs. Furthermore, the role of the calcium-sensing receptor (CASR) and of the CXCL12/CXCR4 pathway in the PAd-induced activation of hBM-MSCs was investigated. Treatment of co-cultures of hBM-MSCs and PAd-derived cells with the CXCR4 inhibitor AMD3100 reduced the stimulated VEGFA levels, while CASR activation by the R568 agonist was ineffective. PAd-derived cells co-expressing parathyroid hormone (PTH)/CXCR4 and PTH/CXCL12 were identified by FACS, suggesting a paracrine/autocrine signalling. Finally, CXCR4 blockade by AMD3100 reduced PTH gene expression levels in PAd-derived cells. In conclusion, i) PAd-derived cells activated cells of mesenchymal origin; ii) PAd-associated fibroblasts were involved in tumuor neoangiogenesis and iii) CXCL12/CXCR4 pathway was expressed and active in PAd cells, likely contributing to parathyroid tumour neoangiogenesis and PTH synthesis modulation. [ABSTRACT FROM AUTHOR]
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