Loss of USP28 and SPINT2 expression promotes cancer cell survival after whole genome doubling

Background Whole genome doubling is a frequent event during cancer evolution and shapes the cancer genome due to the occurrence of chromosomal instability. Yet, erroneously arising human tetraploid cells usually do not proliferate due to p53 activation that leads to CDKN1A expression, cell cycle arrest, senescence and/or apoptosis. Methods To uncover the barriers that block the proliferation of tetraploids, we performed a RNAi mediated genome-wide screen in a human colorectal cancer cell line (HCT116). Results We identified 140 genes whose depletion improved the survival of tetraploid cells and characterized in depth two of them: SPINT2 and USP28. We found that SPINT2 is a general regulator of CDKN1A transcription via histone acetylation. Using mass spectrometry and immunoprecipitation, we found that USP28 interacts with NuMA1 and affects centrosome clustering. Tetraploid cells accumulate DNA damage and loss of USP28 reduces checkpoint activation, thus facilitating their proliferation. Conclusions Our results indicate three aspects that contribute to the survival of tetraploid cells: (i) increased mitogenic signaling and reduced expression of cell cycle inhibitors, (ii) the ability to establish functional bipolar spindles and (iii) reduced DNA damage signaling

Aneuploidy renders cancer cells vulnerable to mitotic checkpoint inhibition

Selective targeting of aneuploid cells is an attractive strategy for cancer treatment(1). Here, we mapped the aneuploidy landscapes of ~1,000 human cancer cell lines, and analyzed genetic and chemical perturbation screens(2–9) to reveal aneuploidy-associated cellular vulnerabilities. We identified and validated an increased sensitivity of aneuploid cancer cells to genetic perturbation of core components of the spindle assembly checkpoint (SAC), which ensures the proper segregation of chromosomes during mitosis(10). Surprisingly, we also found aneuploid cancer cells to be less sensitive to short-term exposures to multiple SAC inhibitors. Indeed, aneuploid cancer cells became increasingly more sensitive to SAC inhibition (SACi) over time. Aneuploid cells exhibited aberrant spindle geometry and dynamics, and kept dividing in the presence of SACi, resulting in accumulating mitotic defects, and in unstable and less fit karyotypes. Therefore, although aneuploid cancer cells could overcome SACi more readily than diploid cells, their long-term proliferation was jeopardized. We identified a specific mitotic kinesin, KIF18A, whose activity was perturbed in aneuploid cancer cells. Aneuploid cancer cells were particularly vulnerable to KIF18A depletion, and KIF18A overexpression restored their response to SACi. Our study reveals a novel, therapeutically-relevant, synthetic lethal interaction between aneuploidy and the SAC

Kombinierter Verkehr Ostdeutschland. Einsatzmoeglichkeiten neuer Technologien. Anhang 3 Bericht zum AP 3000. Einsatzmoeglichkeiten der Doppelstocktechnologien im Containerverkehr. Schlussbericht

SIGLEAvailable from TIB Hannover: F93B1158 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman