Minimally invasive assessment of tumor angiogenesis by fine needle aspiration and flow cytometry

Abstract

The development of a new, less invasive, and more rapidly implemented method of quantifying endothelial cell density in tumors could facilitate experimental and clinical studies of angiogenesis. Therefore, we evaluated the utility of tumor fine needle aspiration (FNA) coupled with flow cytometry for assessment of tumor angiogenesis. Samples were obtained from cutaneous tumors of mice using FNA, then immunostained and assessed by flow cytometry to determine the number of CD31+ endothelial cells. Results of the FNA/flow cytometry technique were compared with quantification of tumor microvessel density using immunohistochemistry. The ability of the FNA/cytometry technique to quantify the effects of anti-angiogenic therapy and to monitor changes in tumor angiogenesis over time in individual tumors was also determined. We found that endothelial cell percentages determined in tumor tissue aspirates by flow cytometry correlated well with the percentages of endothelial cells determined in whole tumor digests by flow cytometry and with tumor microvessel density measurements by immunohistochemistry. Moreover, we found that repeated FNA sampling of tumors did not induce endothelial cell changes. Interestingly, by employing repeated FNA sampling of the same tumors we were able to observe a sudden and marked decline in tumor angiogenesis triggered when tumors reached a certain size. Thus, we conclude that the FNA/flow cytometry technique is an efficient, reproducible, and relatively non-invasive method of rapidly assessing tumor angiogenesis, which could be readily applied to evaluation of tumor angiogenesis in clinical settings in humans.

Preclinical evaluation of PSMA expression in response to androgen receptor blockade for theranostics in prostate cancer

“…For serial monitoring of PSMA expression, tumor samples were acquired by fine needle aspiration biopsy [ 10 , 12 , 13 ]. Syringes were filled with 500 μl PBS, and a 25-G needle was attached.…”

Depletion of phagocytic myeloid cells triggers spontaneous T cell- and NK cell-dependent antitumor activity

“…To track the distribution and uptake of LC by phagocytic cells in tumor tissues and other tissues, mice were injected with L-PBS labeled with BODIPY cholesterol 64 and tissues were collected 6h later for preparation of single cell suspensions and analysis by flow cytometry. Mice with established s.c. MCA205 tumors were injected i.v.…”

Repeated fine-needle aspiration of solid tumours in mice allows the identification of multiple infiltrating immune cell types

“…We have found only two published papers utilising FNAs combined with flow cytometry for mouse tumours. 1) Sottnik et al (2010) used FNAs to quantify endothelial cells in tumours, and 2) Betka et al (2013) performed FNAs, using a biopsy gun, on mouse tumours to quantify tumour-infiltrating cells (T cells and NK cells) at two time points. While a comparison of survival data between FNA and Non-FNA control mice was presented, there was no statistical analysis provided.…”