Abstract A37: Development of screening methods to identify Translesion DNA Synthesis inhibitors

Translesion DNA synthesis (TLS) is a DNA damage tolerance process that employs specialized polymerases to bypass DNA damage during replication. Recent evidence indicates that TLS is a key process that promotes the development of resistance to cancer treatments that induce DNA damage (i.e. Cisplatin). Thus, the inhibition of TLS emerges as a promising strategy for cancer therapy. However, to date, specific chemical inhibitors of TLS are not available.The main goal of our project is to identify specific inhibitors of TLS that can be used as a proof of concept in cancer therapy by developing cell-based assays that explore TLS markers. Our rational is that since TLS polymerases recruitment to sites of DNA damage is a key step for TLS success, we can indirectly monitor TLS efficiency in a given context by studying two key markers of TLS polymerases recruitment: 1) The mono-ubiquitylation of the replication auxiliary factor PCNA and 2) the accumulation of a TLS polymerase into replication foci. We thus developed two screening methods that allow us to promptly identify inhibitors of PCNA ubiquitylation and TLS polymerases recruitment into DNA damage sites. The first marker, PCNA mono-ubiquitylation, is assessed through a western-Blot-based platform where the identification of unmodified PCNA and mono-ubiquitylated PCNA are achieved by two different antibodies coupled to fluorescent infrared detection using a fluorescence scanner. For the second marker, TLS polymerase recruitment to ...
Source: Molecular Cancer Research - Category: Cancer & Oncology Authors: Tags: Replication Stress: Poster Presentations - Proffered Abstracts Source Type: research