Exosomes Promote Survival in Squamous Head and Neck Cancer Cells after Ionizing Radiation
Poster Jul 12, 2016
Lisa Mutschelknaus, Carsten Peters, Klaudia Winkler, Ramesh Yentrapalli, Theresa Heider, Michael J. Atkinson, Simone Moertl
Exosomes were isolated from conditioned medium of irradiated as well as non-irradiated head and neck cancer cells (BHY and FaDu) by serial ultracentrifugation. Quantification by NanoSight technology indicates an increased exosome release from irradiated compared to non-irradiated cells 24 hours after treatment. To test whether the released exosomes influence the radiation response, exosomes isolated from non-irradiated and irradiated donor cells were transferred on non-irradiated and irradiated recipient cells. We find an enhanced uptake of exosomes, when transferred to irradiated recipient cells compared to the transfer to non-irradiated cells. Functional analyses after exosome transfer indicate that exosomes increase not only the proliferation but also the survival after irradiation in recipient cells. These findings mesh with an increased DNA double strand break repair after the transfer of exosomes isolated from irradiated cells.
Our results demonstrate that radiation increases exosome abundance and influences their effects on recipient cells. This study indicates a functional role for exosomes in the response of tumor cells to therapeutic radiation exposure, suggests that radiotherapy modified exosomes influence the cancer progression and encourages that exosomes might be a useful tool to improve therapy strategies.
P450 Induction in Cryopreserved Hepatocytes from PXR and CAR Nuclear Receptor Knock-out RatsPoster
The nuclear receptors pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are closely related transcription factors that regulate the expression of phase I (cytochrome P450s), phase II metabolizing enzymes and transporter genes in response to xenobiotics, including prescription drugs.READ MORE
A new method for generating arrayed RNAi screening tools for any organismPoster
RNA interference (RNAi) using small interfering RNAs (siRNAs) is an important technology for down-regulation of gene expression and a powerful tool to study cellular processes and pathways. Previously, large collections of siRNAs were available only for traditional experimental model systems, such as human and mouse, and predominantly provided as chemically synthesized libraries.READ MORE
Hepatocellular Carcinoma with Small Cell Histology: A Rare Mimic of Metastatic Tumors Involving the LiverPoster
Two cases of hepatocellular carcinoma (HCC) with small cell histology, a rare morphologic variant of HCC, are presented.READ MORE