GSE132419
LSF small molecule inhibitors phenocopy LSF-targeted siRNAs causing mitotic defects and senescence in cancer cells
The oncogene LSF has been proposed as a novel target with therapeutic potential for multiple cancers. LSF overexpression correlates with poor prognosis for both liver and colorectal cancers, for which there are currently limited therapeutic treatment options. In particular, molecularly targeted therapies for hepatocellular carcinoma targeting cellular receptors and kinases have yielded disappointing clinical results, providing impetus for targeting distinct mechanisms. LSF small molecule inhibitors, Factor Quinolinone Inhibitors (FQIs), have exhibited robust anti-tumor activity in multiple pre-clinical models of hepatocellular carcinoma, with no observable toxicity. To understand how the inhibitors impact cancer cell proliferation, we characterized the cellular phenotypes that result from loss of LSF activity. Phenotypically, inhibition of LSF activity induced a mitotic delay with condensed, but unaligned, chromosomes. This mitotic disruption resulted in improper cellular division leading to multiple outcomes: multi-nucleation, apoptosis, and cellular senescence. The cellular phenotypes observed upon FQI1 treatment were due specifically to the loss of LSF activity, as siRNA specifically targeting LSF produced nearly identical phenotypes. Taken together, these findings confirm that LSF is a promising therapeutic target for cancer treatment. In order to identify potential LSF target genes in human cells, we performed LSF-ChIP-seq in a LSF-inducible, stable HEK293T cell line. Overall design: Establishment of HA-tagged LSF inducible, permanent HEK293T cell line by using the RheoSwich inducible system---> Crosslinking, followed by micrococcal nuclease digestion to fragment chromatin to yield mono- and di-nucleosomes---> ChIP using antibody against HA tag---> Library preparation separately of DNA-sized fragments representing mono- versus di-nucleosomes---> ChIP-seq analysis.