Function and origin of tumour-associated fibroblasts (TAFs) in human parathyroid neoplasia

Chiara Verdelli; Laura Avagliano; Vito Guarnieri; Alfredo Scillitani; Elena Passini; Leonardo Vicentini; Giovan Battista Steffano; Anna Spada; Gaetano Bulfamante; Sabrina Corbetta

doi:10.1530/endoabs.32.P525

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Endocrine Abstracts (2013) 32 P525 | DOI: 10.1530/endoabs.32.P525

ECE2013 Poster Presentations Endocrine tumours and neoplasia (66 abstracts)

Function and origin of tumour-associated fibroblasts (TAFs) in human parathyroid neoplasia

Chiara Verdelli ¹ , Laura Avagliano ² , Vito Guarnieri ³ , Alfredo Scillitani ⁴ , Elena Passini ⁵ , Leonardo Vicentini ⁶ , Giovan Battista Steffano ⁷ , Anna Spada ⁸ , Gaetano Bulfamante ⁹ & Sabrina Corbetta ⁵

Err

Author affiliations

¹Molecular Biology Laboratory, IRCCS Policlinico san Donato, San Donato Milanese (MI), Italy; ²Department of Obstetrics and Gynecology, DMSD San Paolo, University of Milan, Milan, Italy; ³Medical Genetics, IRCCS Hospital Casa Sollievo della Sofferenza, San Giovanni Rotondo (FG), Italy; ⁴Endocrine Unit, IRCCS Hospital Casa Sollievo della Sofferenza, San Giovanni Rotondo (FG), Italy; ⁵Endocrine Unit, Department of Biomedical Sciences for Health, University of Milan, IRCCS Policlinico San Donato, San Donato Milanese (MI), Italy; ⁶Endocrine Surgery, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico-Milano, Milan, Italy; ⁷Surgery 1, IRCCS Policlinico San Donato, San Donato Milanese (MI), Italy; ⁸Endocrine Unit, Department of Clinical Sciences and Community, University of Milan, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy; ⁹Human Pathology, DMSD San Paolo, San Paolo Hospital Medical School, University of Milan, Milan, Italy.

Tumour-associated fibroblasts (TAFs) are important players in tumour formation, growth, enhancement and metastasis. We firstly investigated the TAFs component in human parathyroid neoplasia from patients with primary hyperparathyroidism. Alpha-smooth muscle actin (alpha-SMA) has been used to identify activated TAFs (myofibroblasts). Culturing explants from parathyroid adenomas (PA, n=5), large spindle-shaped alpha-SMA+ cells outgrew from explants and the expression of activated fibroblasts markers such as vimentin, stromal derived factor-1 (SDF-1/CXCL12) and fibroblast activated protein were detected. Immunohistochemistry showed alpha-SMA+ cells highly represented in normal parathyroid glands (n=3) where they lined the acinar structures. In typical PAs (n=5) alpha-SMA+ cells were variably reduced, though they surrounded new microvessels suggesting a role in neoangiogenesis. Interestingly, in human fetal parathyroids (19–24 weeks of gestation), myofibroblasts were exclusively found lining blood vessels. In atypical adenomas (n=3) and carcinomas (n=3), the chief cells proliferating in sheets were not sustained by myofibroblasts, which were highly represented in the fibrous bands and capsula stroma, suggesting a role of alpha-SMA+ cells in invasiveness. Coculture of human bone-marrow mesenchymal stem cells (hBM-MSCs) with PA-derived explants (n=3) induced significant increases of VEGFa mRNA expression levels in hBM-MSCs. Immunofluorescence (IF) and FACS (n=5) identified 32–63% of PA-derived cells expressing CXCR4, the SDF-1 receptor, whose 47–90% coexpressing PTH and CXCR4. Treatment of cocultures with the CXCR4 antagonist AMD3100 reduced the coculture-stimulated VEGFa mRNA expression in hBM-MSCs, suggesting that the proangiogenic effect might be regulated through the CXCR4/SDF-1 pathway. A subset of alpha-SMA+ cells were shown by IF to co-express the haematopoietic marker CD34 suggesting they might be perivascular adipose-tissue derived mesenchymal progenitors. A subset of alpha-SMA+ cells also co-expressed the parathyroid marker GCM2, and the endodermic transcription factor TBX1, suggesting they might derived from chief cells through epithelial-to-mesenchymal transition. In conclusions, we identified in parathyroid neoplasia cells showing features of activated TAFs that might be involved in tumoral neoangiogenesis and invasiveness.