Most ovarian cancers originate from the ovarian surface epithelium and are characterized by aneuploid karyotypes. Aneuploidy, a consequence of chromosome instability, is an early event during the development of ovarian cancers. However, how aneuploid cells are evolved from normal diploid cells in ovarian cancers remains unknown. In the present study, cytogenetic analyses of a mouse syngeneic ovarian cancer model revealed that diploid mouse ovarian surface epithelial cells (MOSECs) experienced an intermediate tetraploid cell stage, before evolving to aneuploid (mainly near-tetraploid) cells. Using long-term live-cell imaging followed by fluorescence in situ hybridization (FISH), we demonstrated that tetraploid cells originally arose from cytokinesis failure of bipolar mitosis in diploid cells, and gave rise to aneuploid cells through chromosome mis-segregation during both bipolar and multipolar mitoses. Injection of the late passage aneuploid MOSECs resulted in tumor formation in C57BL/6 mice. Therefore, we reveal a pathway for the evolution of diploid to aneuploid MOSECs and elucidate a mechanism for the development of near-tetraploid ovarian cancer cells.

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Background CCR10 and CCL27 are the most skin-specific chemokine receptor/ligand pair implicated in skin allergy and inflammatory diseases including atopic dermatitis and psoriasis. This pair is thought to regulate migration and/or maintenance of skin T cells and suggested as therapeutic targets for treatment of skin diseases. However, the functional importance of CCR10/CCL27 in vivo remains elusive. Objective We sought to determine expression and function of CCR10 in different subsets of skin T cells under both homeostatic and inflammatory conditions to gain a mechanistic insight into potential roles of CCR10 during skin inflammation. Methods Using heterozygous and homozygous CCR10-knockout/EGFP-knockin mice, we assessed expression of CCR10 on regulatory and effector T cells of healthy and inflamed skin induced by chemicals, pathogens and auto-reactive T cells. In addition, we assessed the effect of CCR10-knockout on the maintenance and functions of different T cells and inflammatory status in the skin during different phases of the immune response. Results CCR10 expression is preferentially induced on memory-like skin-resident T cells and their progenitors for their maintenance in homeostatic skin but not expressed on most skin-infiltrating effector T cells during inflammation. In CCR10-knockout mice, the imbalanced presence and dysregulated function of resident regulatory and effector T cells result in over-reactive and prolonged innate and memory responses in the skin, leading to increased clearance of Leishmamia infection in the skin. Conclusion CCR10 is a critical regulator of skin immune homeostasis.