Investigating the mechanisms of indocyanine green (ICG) cellular uptake in sarcoma

作者：Corey D. Chan, Marcus J. Brookes, Riya Tanwani, Chloe Hope, Toni A. Pringle, James C. Knight, Kenneth S. Rankin · 发表于：bioRxiv (Cold Spring Harbor Laboratory) · 年份：2021 · DOI：10.1101/2021.04.05.438013 · 被引用次数：16 · 研究领域：Nanoplatforms for cancer theranostics、Angiogenesis and VEGF in Cancer、Nanoparticle-Based Drug Delivery

Abstract Introduction Indocyanine green (ICG) is a near infrared (NIR) dye which has been used clinically for over 50 years and has recently been utilised for fluorescence guided surgery in a number of cancer types, including sarcoma. ICG is taken up and retained by sarcoma tumours to a greater extent than normal tissue, demonstrating its potential to aid in visualisation of tumour margins. However, the mechanisms surrounding preferential ICG uptake in tumours are poorly understood. Methods In vitro ICG cellular uptake studies were performed across a panel of four sarcoma cell lines and one breast cancer cell line, exhibiting varying proliferation rates and phenotypes. The effects of ICG concentration, incubation time, inhibition of clathrin mediated endocytosis and cell line proliferation rate on the cellular uptake of ICG were investigated using fluorescence microscopy and flow cytometry. The spatial orientation of ICG was also assessed in a patient specimen. Results The level of ICG cellular uptake was dependent on ICG concentration and incubation time. Cell line proliferation rate correlated significantly to ICG uptake within 30 minutes (Rs= 1, p<0.001), whilst retention of ICG after 24hrs did not (Rs= 0.3, p=0.624). From our data, the primary mechanism of ICG uptake in sarcoma cells is via clathrin mediated endocytosis. Following the resection of a grade 3 leiomyosarcoma, ICG signal was detectable macroscopically and on 3μm sections, whilst being negative on the muscl...