Eleonora Lippolis

The mammalian heart has no significant endogenous regenerative capacity, as mammalian cardiomyocytes undergo a last round of cell cycle after birth, becoming post-mitotic and polyploid. Consistent with this, cytokinesis inhibition in zebrafish impairs their cardiac regenerative capacity. Notably, re-induction of cell cycle progression or polyploidization reduction through cytokinesis generates proliferative mammalian cardiomyocytes. Thus, a better understanding of cytokinesis is fundamental. Here, we adopted an integrative bioinformatics approach to identify novel common candidate cytokinesis genes by comparing proliferative and non-proliferative cell states. The approach relies on (i) a temporal expression dataset profiling rat ventricles during heart development, (ii) a transcriptomics dataset profiling postnatal rat cardiomyocytes upon stimulation with pro-proliferative compounds, and (iii) an expression dataset profiling mouse embryonic fibroblasts upon knockout of Lin9, a master regulator of cell division. Following prioritization of the identified 236 novel candidate cytokinesis genes and literature-based investigations, Car8, Sox11, Arl6ip1, and Sc5d underwent experimental validation. Protein localization studies in HeLa cells revealed distinct localization patterns during cytokinesis for CA8 and SC5D. Their knockdown in Hct116 cells resulted in increased multinucleation. These findings highlight that leveraging integrative bioinformatics across different proliferative states can uncover novel candidate cytokinesis genes, contributing to the establishment of potential therapeutic targets to treat proliferative diseases and/or to promote regeneration.

Stage pT1 bladder cancer (BC) shows highly diverse outcomes. Predictive markers are required to stratify patients for personalized treatment. The present study aimed to validate immune response quantification as a prognostic marker. Patients with pT1 BC (n = 167) treated by transurethral resection of the bladder (TURB) were enrolled. Formaldehyde-fixed paraffin-embedded material was stained for CD3 and CD8. Corresponding T cells were counted in three regions with the highest immune response. Numbers of tertiary lymphoid structures (TLS) and lymphocyte aggregates (LA) were quantified. High CD3⁺ stroma T-cell infiltration was associated with improved survival (p = 0.045), especially in the G3 subgroup (p = 0.01). Cluster with higher immune response showed less recurrence (p = 0.034) and favorable overall survival (OS) (p = 0.019). In contrast, higher CD3⁺ and CD8⁺ tumor T-cell infiltration seemed to have a negative impact on prognosis. TLS and LA were more frequently observed in G3 tumors, indicating an increased anti-tumoral immune response. We proved the role of immune cell infiltration and showed that higher infiltration numbers of CD3⁺ (not CD8⁺) lymphocytes in the stroma are associated with favorable outcome. Immune cell quantification could be used as a marker to help stratify patients’ risk and therefore, to optimize patients’ management and follow-up examination as well as possible therapies.