Vascular Pericyte Density and Angiogenesis Associated with Adenocarcinoma of the Prostate

Abstract

Background/Aims: Angiogenesis facilitates metabolism, proliferation and metastasis of adenocarcinoma cells in the prostate, as without the development of new vasculature tumor growth cannot be sustained. However, angiogenesis is variable with the well-known phenomenon of vascular ‘hotspots’ seen associated with viable tumor cell mass. With the recent recognition of pericytes as molecular regulators of angiogenesis, we have examined the interaction of these cells in actively growing new vessels. Methods: Pericyte interactions with developing new vessels were examined using transmission electron microscopy. Pericyte distribution was mapped from α-SMA+ immunostained histological sections and quantified using image analysis. Data was obtained from peripheral and more central regions of 27 cases with Gleason scores of 4–9. Results: Pericyte numbers were increased around developing new vessel sprouts at sites of luminal maturation. Numbers were reduced around the actively growing tips of migrating endothelial cells and functional new vessels. Tumor regions internal to a 500-µm peripheral band showed higher microvessel pericyte density than the peripheral region. Conclusion: Pericytes were found to be key cellular components of developing new vessels in adenocarcinoma of the prostate. Their numbers increased at sites of luminal maturation with these cells displaying an activated phenotype different to quiescent pericytes. Increased pericyte density was found internal to the peripheral region, suggesting more mature vessels lie more centrally.

Improved Functionality of the Vasculature during Conventionally Fractionated Radiation Therapy of Prostate Cancer

“…In addition, in the normal prostate, the perimeter of micro-vessels was consistently desmin+/SMA–, whereas SMA expression was strictly restricted to large, inter-acini vessels. This vascular hierarchy is also found in human samples [28]. In contrast, irradiated tumor micro-vessels (≈ 10 µm diameter) gained perivascular SMA expression.…”

3D scaffolds co-seeded with human endothelial progenitor and mesenchymal stem cells: Evidence of prevascularisation within 7 days

“…Of particular interest, the same was observed when EPCs were added to the MM cell fraction (EPC-depleted). Previous investigations on neovascular scaffolding (Maier et al, 2010;Killingsworth and Wu, 2011) revealed the affiliation of CD146-positive pericytes as an important part of the neovascular structure. This is in line with Au et al (Au et al, 2008) who described the contribution of MSCs to the overall stability of newly formed capillaries as providing the structure with perivascular cells.…”

Expression of Angiogenic and Vasculogenic Factors in Human Lymphedematous Tissue

“…Pericytes are involved with vessel maturation; their loss is associated with neovascularization. 26,27 ANG-1 stabilizes endothelial cells by preventing VEGF expression and the recruitment of pericytes. 28 In contrast, ANG-2 promotes endothelial sprouting by destabilizing endothelialpericyte contact.…”