Dynamics of the intratumoral immune response during progression of high-grade serous ovarian cancer

PURPOSE: Tumor-infiltrating lymphocytes (TILs) have an established impact on the prognosis of high-grade serous ovarian carcinoma (HGSOC), however, their role in recurrent ovarian cancer is largely unknown. We therefore systematically investigated TIL densities and MHC class I and II (MHC1, 2) expression in the progression of HGSOC. EXPERIMENTAL DESIGN: CD3+, CD4+, CD8+ TILs and MHC1, 2 expression were evaluated by immunohistochemistry on tissue microarrays in 113 paired primary and recurrent HGSOC. TILs were quantified by image analysis. All patients had been included to the EU-funded OCTIPS FP7 project. RESULTS: CD3+, CD4+, CD8+ TILs and MHC1 and MHC2 expression showed significant correlations between primary and recurrent tumor levels (Spearman rho 0.427, 0.533, 0.361, 0.456, 0.526 respectively; P<.0001 each). Paired testing revealed higher CD4+ densities and MHC1 expression in recurrent tumors (Wilcoxon P=.034 and P=.018). There was also a shift towards higher CD3+ TILs levels in recurrent carcinomas when analyzing platinum-sensitive tumors only (Wilcoxon P=.026) and in pairs with recurrent tumor tissue from first relapse only (Wilcoxon P=.031). High MHC2 expression was the only parameter to be significantly linked to prolonged progression-free survival after first relapse (PFS2, log-rank P=.012). CONCLUSIONS: This is the first study that analyzed the development of TILs density and MHC expression in paired primary and recurrent HGSOC. The level of the antitumoral immune response in recurrent tumors was clearly dependent on the one in the primary tumor. Our data contribute to the understanding of temporal heterogeneity of HGSOC immune microenvironment and have implications for selection of samples for biomarker testing in the setting of immune-targeting therapeutics

Roles of the C-terminal domains of topoisomerase II alpha and topoisomerase II beta in regulation of the decatenation checkpoint

Topoisomerase (topo) IIα and IIβ maintain genome stability and are targets for anti-tumor drugs. In this study, we demonstrate that the decatenation checkpoint is regulated, not only by topo IIα, as previously reported, but also by topo IIβ. The decatenation checkpoint is most efficient when both isoforms are present. Regulation of this checkpoint and sensitivity to topo II-targeted drugs is influenced by the C-terminal domain (CTD) of the topo II isoforms and by a conserved non-catalytic tyrosine, Y640 in topo IIα and Y656 in topo IIβ. Deletion of most of the CTD of topo IIα, while preserving the nuclear localization signal (NLS), enhances the decatenation checkpoint and sensitivity to topo II-targeted drugs. In contrast, deletion of most of the CTD of topo IIβ, while preserving the NLS, and mutation of Y640 in topo IIα and Y656 in topo IIβ inhibits these activities. Structural studies suggest that the differential impact of the CTD on topo IIα and topo IIβ function may be due to differences in CTD charge distribution and differential alignment of the CTD with reference to transport DNA. Together these results suggest that topo IIα and topo IIβ cooperate to maintain genome stability, which may be distinctly modulated by their CTDs