Abstract 3587: Multiplexed nuclear area and micronucleus screening identifies SKP1 as a human chromosome instability gene

Abstract

Abstract Chromosome instability (CIN) is defined as an increase in the rate at which whole chromosomes or large chromosomal fragments are gained or lost. It is hallmark of cancer that occurs frequently in both solid and liquid tumors. In addition, CIN is associated with highly aggressive tumors, the acquisition of multi-drug resistance, tumor recurrence and poor patient prognosis. Despite this, the majority of human CIN genes have yet to be elucidated, highlighting the need for studies aimed at identifying the defective genes that underlie CIN. In this study we utilized two complementary, image-based approaches capable of detecting CIN-associated phenotypes following RNAi-based silencing of candidate CIN genes. The first assay involves quantifying nuclear areas following silencing, where changes in mean nuclear area relative to controls act as a surrogate marker of CIN. The second approach monitors micronucleus (MN) formation where increases in the number of micronuclei are indicative of DNA damage or the mitotic defects that underlie CIN. These assays were employed in a high-content screen of 164 human candidate CIN genes in two unrelated cell lines, HT1080 and hTERT. In HT1080, the nuclear area and MN enumeration assays identified 88 and 96 putative CIN genes, respectively. In hTERT, the nuclear area and MN assays identified 112 and 19 putative CIN genes, respectively. Promising putative CIN genes such as SKP1 were identified and prioritized for subsequent validation based on the number of assays that identified the gene, and the strength of the CIN phenotype. Preliminary data collected through Western blotting, mitotic chromosome spreads and flow cytometry, provides evidence to support the validation of SKP1 as a bona fide human CIN gene. Identification and characterization of human CIN genes will provide critical insights into CIN and tumorigenesis, as well as identify potential targets that could be exploited in novel, precision medicine approaches for superior cancer treatment. Citation Format: Laura Thompson, Allison Baergen, Zelda Lichtensztejn, Kirk McManus. Multiplexed nuclear area and micronucleus screening identifies SKP1 as a human chromosome instability gene. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3587.