Abstract 4033: Gene expression of EdU proliferating cells made possible with improved click chemistry.

Abstract

Gene expression profiling of cancer cells has become increasingly common over the past five years. Especially important is identifying changes in gene expression caused by drug treatment leading to side populations with altered pathways. These populations can escape drug treatment and lead to recurrence. Characterizing gene expression of proliferating cells requires a method of identifying proliferation while simultaneously maintaining high quality RNA. Typically, cells are screened in a drug panel in the presence of tritiated thymidine or BrdU to identify the drug resistance in the proliferating population. Proliferation detection with these methods is neither rapid nor does it yield high quality RNA for profiling. A new proliferation method based on click chemistry using an alkyne modified thymidine analog (EdU), which can be used to rapidly identify replicating cells appears ideally suited for this application; however, copper used for the catalysis of the click reaction causes undesired degradation of RNA. Recent improvements to the copper based click reaction are presented here whereby the copper is tightly controlled, resulting in higher quality RNA useful for sequencing.

In this study we demonstrate gene expression changes in the proliferating population of a drug resistant cancer cell line compared to the parental cell lines. Proliferating cells were identified using an improved click reaction comprising of a copper(I) ligand combined with a picolyl modified dye azide detection reagent. Total RNA from these cells was isolated and gene expression was assessed by targeted RNA sequencing using an RNA Apoptosis panel and an RNA Cancer panel using proton based sequencing technology.

Use of an improved copper “safe” click reaction for detection of nascent DNA, allows for detection of incorporated click analog for measuring proliferation and subsequent isolation of high quality RNA for use in sequence analysis.

Citation Format: Scott T. Clarke, Angie Cheng, Aleksey Rukavishnikov, Michelle Yan, Upinder Singh, Kyle Gee, Susan Magdaleno. Gene expression of EdU proliferating cells made possible with improved click chemistry. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4033. doi:10.1158/1538-7445.AM2013-4033