Biology subjects

Al Hrout, A.

Publications and source records attributed to Al Hrout, A..

2 recordsLinked to original sources

bioRxiv2022

Assessing extracellular vesicles in human biofluids using flow-based analyzers

Extracellular vesicles (EVs) are increasingly being analyzed by flow cytometry. Yet, their miniscule size and low refractive index, causes the scatter intensity of most EVs to fall below the detection limit of most flow cytometers. A new class of devices, known as spectral flow analyzers, are becoming standards in cell phenotyping studies. Largely, due to their unique capacity of detecting a vast panel of markers with higher sensitivity for light scatter detection. Another class of devices, known as nano-analyzers, provides high resolution detection of sub-micron sized particles. Here, we aim to compare the EVs phenotyping performance between the Aurora (Cytek) spectral cell analyzer and the NanoFCM (nFCM) nanoflow analyzer. These two devices were specifically chosen given their lead in becoming gold standards in their respective fields. Immune cell-derived EVs remain poorly characterized despite their clinical potentials. We therefore, used B- and T- cell line-derived EVs and donor-matched human biofluid-derived EVs from serum, urine, and saliva in combination with a panel of established immune markers for this comparative study. A comparative evaluation of both cytometry platforms was performed, discussing their potential and suitability for different applications. We found that nFCM can accurately i) analyze small EVs (40 to 200 nm) matching the size accuracy of electron microscopy; ii) measure concentration of single EV particle per volume; iii) identify underrepresented EV marker subsets; and iv) provide co-localization of EV surface markers. We could also show that human sample biofluids have unique EV marker signatures that could have future clinical relevance.

immunology↗

bioRxiv2021

Modelling liver cancer microenvironment: novel 3D culture system as a potential anti-cancer drug screening tool

The tumor microenvironment and its contribution to tumorigenesis has been a focal highlight in recent years. A two-way communication between the tumor and the surrounding microenvironment sustains and contributes to the growth and metastasis of tumors. Progression and metastasis of hepatocellular carcinoma have been reported to be exceedingly influenced by diverse microenvironmental cues. In this study, we present a 3D-culture model of liver cancer to better mimic in vivo tumor settings. By creating novel 3D co-culture model that combines free-floating and scaffold based 3D-culture techniques of liver cancer cells and fibroblasts, we aimed to establish a simple albeit reproducible ex vivo cancer microenvironment model that captures tumor-stroma interactions. The model presented herein exhibited unique gene expression and protein expression profiles when compared to 2D and 3D mono-cultures of liver cancer cells. Our results showed that in vivo like conditions cannot be mimicked by simply growing cancer cells as spheroids, but by co-culturing them with 3D fibroblast with which they were able to cross-talk. This was evident by the upregulation of several pathways involved in HCC, and the increase in secreted factors by co-cultured cancer cells, many of which are also involved in tumor-stroma interactions. Compared to the conventional 2D culture, the proposed model exhibits an increase in the expression of genes associated with development, progression, and poor prognosis of HCC. Our results correlated with an aggressive outcome that better mirrors in vivo HCC, and therefore, a more reliable platform for molecular understanding of HCC and possibly better anti-cancer drug screening.

cancer biology↗