Abnormal centrosome number is correlated with a loss of spatial segregation of homologous chromosome 19 in a renal carcinoma cell line

Student: Kieran Chiddix

Faculty Mentor: Lisa Hua

Biology

College of Science, Technology, and Business

In non-diseased human endothelial cells, homologous chromosomes are spatially separated along an axis defined by subcellular structures, the centrosomes. This spatial segregation is proposed to reduce abnormal pairing between homologs, which has been linked to gene misregulation in a renal cancer cell line, Caki1. Caki-1 cells display a loss of homologous chromosome segregation and abnormal pairing of chromosome 19. However, it is unknown whether an abnormal centrosome number in Caki1 cells may contribute to the loss of homologous chromosome organization. To determine if an abnormal centrosome number is correlated with pairing of chromosome 19 in Caki-1 cells, we performed immunofluorescence to γ-tubulin to visualize centrosomes and a DNA counterstain. High-resolution confocal microscopy and 3D image analysis showed 18.2% of Caki-1 cells with an abnormal centrosome number as compared to 0% of non-diseased human umbilical vein endothelial cells (HUVECs). This data suggests that Caki-1 cells exhibit an abnormal centrosome number that may be correlated with a loss of homologous chromosome segregation. Thus, centrosomes may be involved in maintaining the spatial segregation of homologous chromosomes. Our study provides new insight into chromosome organization and its implication in cancer cell biology.