Evelien W. Duiker

The extrinsic apoptosis pathway and its prognostic impact in ovarian cancer

OBJECTIVE Death ligand FasL, its agonistic receptor Fas, tumor necrosis factor related apoptosis inducing ligand (TRAIL) and its agonistic death receptors DR4 and DR5 are implied in carcinogenesis, tumor immune surveillance and response to chemotherapy. TRAIL receptor agonists are evaluated as anti-cancer agents. This study aimed to relate expression of death ligands/receptors and downstream initiator caspase 8 and its anti-apoptotic homologue FLICE like inhibitory protein (c-FLIP) in ovarian cancers to chemotherapy response and survival. METHODS Fas, FasL, TRAIL, DR4, DR5, caspase 8 and c-FLIP were determined immunohistochemically on a tissue microarray containing 382 ovarian cancers. Protein expression profiles were correlated with clinicopathologic variables, chemotherapy response and survival. RESULTS Most tumors expressed DR4, DR5, caspase 8 and c-FLIP. High c-FLIP expression was associated with expression of caspase 8 and both TRAIL receptors. TRAIL and Fas were associated with low tumor grade and better progression-free survival (HR 0.63, p=.018 and HR 0.54, p=.012), respectively, and Fas with disease-specific survival (HR 0.49, p=0.009) in univariate analysis. CONCLUSIONS Fas and TRAIL loss is associated with dedifferentiation and worse prognosis. Expression of DR4, DR5, caspase 8 and c-FLIP by most ovarian cancers does not correlate with survival. High c-FLIP expression should be taken into account for death receptor targeted therapies.

Enhanced Antitumor Efficacy of a DR5-Specific TRAIL Variant over Recombinant Human TRAIL in a Bioluminescent Ovarian Cancer Xenograft Model

Purpose: Recombinant human tumor necrosis factor-related apoptosis-inducing ligand (rhTRAIL) is clinically evaluated as novel anticancer drug. rhTRAIL-DR5, a rhTRAIL variant that specifically binds to DR5 receptor, has recently been developed. We investigated whether rhTRAIL-DR5 is more efficient than rhTRAIL in combination with cisplatin in DR5-expressing human A2780 ovarian cancer cells. Design: Effect of cisplatin alone or in combination with rhTRAIL or rhTRAIL-DR5 on DR5 surface expression, apoptosis, and cell survival of A2780 was measured. Biodistribution analysis was done in mice with 125I-rhTRAIL administered intravenously versus intraperitoneally. Antitumor efficacy of rhTRAIL-DR5 versus rhTRAIL was determined in an intraperitoneally growing bioluminescent A2780 xenograft model. Results: Cisplatin strongly enhanced DR5 surface expression. Both rhTRAIL and rhTRAIL-DR5 in combination with cisplatin induced high levels of caspase-3 activation, apoptosis, and cell kill, with rhTRAIL-DR5 being most potent. Intraperitoneal administration of 125I-rhTRAIL resulted in a 1.7-fold higher area under the curve in serum, increased tumor exposure, and more caspase-3 activation in the tumor than intravenous administration. Intraperitoneal administration of rhTRAIL-DR5 delayed A2780 tumor progression, reflected in a mean light reduction of 68.3% (P = 0.015), whereas rhTRAIL or rhTRAIL-DR5 plus cisplatin resulted in 85% (P = 0.003) and 97% (P = 0.002) reduction compared with A2780 tumor progression in vehicle-treated animals. Combination of rhTRAIL-DR5 with cisplatin was more effective than cisplatin alone (P = 0.027). Conclusion: rhTRAIL-DR5 was superior over rhTRAIL in vitro and in vivo against DR5-expressing ovarian cancer also in combination with cisplatin. Intraperitoneal administration of rhTRAIL-DR5 warrants further exploration in ovarian cancer.

Drug-induced caspase 8 upregulation sensitises cisplatin-resistant ovarian carcinoma cells to rhTRAIL-induced apoptosis

Background:Drug resistance is a major problem in ovarian cancer. Triggering apoptosis using death ligands such as tumour necrosis factor-related apoptosis inducing ligand (TRAIL) might overcome chemoresistance.Methods:We investigated whether acquired cisplatin resistance affects sensitivity to recombinant human (rh) TRAIL alone or in combination with cisplatin in an ovarian cancer cell line model consisting of A2780 and its cisplatin-resistant subline CP70.Results:Combining cisplatin and rhTRAIL strongly enhanced apoptosis in both cell lines. CP70 expressed less caspase 8 protein, whereas mRNA levels were similar compared with A2780. Pre-exposure of particularly CP70 to cisplatin resulted in strongly elevated caspase 8 protein and mRNA levels. Caspase 8 mRNA turnover and protein stability in the presence or absence of cisplatin did not differ between both cell lines. Cisplatin-induced caspase 8 protein levels were essential for the rhTRAIL-sensitising effect as demonstrated using caspase 8 small-interfering RNA (siRNA) and caspase-8 overexpressing constructs. Cellular FLICE-inhibitory protein (c-FLIP) and p53 siRNA experiments showed that neither an altered caspase 8/c-FLIP ratio nor a p53-dependent increase in DR5 membrane expression following cisplatin were involved in rhTRAIL sensitisation.Conclusion:Cisplatin enhances rhTRAIL-induced apoptosis in cisplatin-resistant ovarian cancer cells, and induction of caspase 8 protein expression is the key factor of rhTRAIL sensitisation.

Treatment regimen, surgical outcome and T cell differentiation influence prognostic benefit of tumor-infiltrating lymphocytes in high grade serous ovarian cancer

Purpose: Tumor-infiltrating lymphocytes (TIL) are associated with a better prognosis in high-grade serous ovarian cancer (HGSC). However, it is largely unknown how this prognostic benefit of TIL relates to current standard treatment of surgical resection and (neo-)adjuvant chemotherapy. To address this outstanding issue, we compared TIL infiltration in a unique cohort of patients with advanced-stage HGSC primarily treated with either surgery or neoadjuvant chemotherapy. Experimental Design: Tissue microarray slides containing samples of 171 patients were analyzed for CD8+ TIL by IHC. Freshly isolated CD8+ TIL subsets were characterized by flow cytometry based on differentiation, activation, and exhaustion markers. Relevant T-cell subsets (CD27+) were validated using IHC and immunofluorescence. Results: A prognostic benefit for patients with high intratumoral CD8+ TIL was observed if primary surgery had resulted in a complete cytoreduction (no residual tissue). By contrast, optimal (<1 cm of residual tumor) or incomplete cytoreduction fully abrogated the prognostic effect of CD8+ TIL. Subsequent analysis of primary TIL by flow cytometry and immunofluorescence identified CD27 as a key marker for a less-differentiated, yet antigen-experienced and potentially tumor-reactive CD8+ TIL subset. In line with this, CD27+ TIL were associated with an improved prognosis even in incompletely cytoreduced patients. Neither CD8+ nor CD27+ cell infiltration was of prognostic benefit in patients treated with neoadjuvant chemotherapy. Conclusions: Our findings indicate that treatment regimen, surgical result, and the differentiation of TIL should all be taken into account when studying immune factors in HGSC or, by extension, selecting patients for immunotherapy trials. Clin Cancer Res; 22(3); 714–24. ©2015 AACR.

Biobanking of patient and patient-derived xenograft ovarian tumour tissue: efficient preservation with low and high fetal calf serum based methods.

Using patient-derived xenografts (PDXs) for preclinical cancer research demands proper storage of tumour material to facilitate logistics and to reduce the number of animals needed. We successfully established 45 subcutaneous ovarian cancer PDXs, reflecting all histological subtypes, with an overall take rate of 68%. Corresponding cells from mouse replaced human tumour stromal and endothelial cells in second generation PDXs as demonstrated with mouse-specific vimentin and CD31 immunohistochemical staining. For biobanking purposes two cryopreservation methods, a fetal calf serum (FCS)-based (95%v/v) “FCS/DMSO” protocol and a low serum-based (10%v/v) “vitrification” protocol were tested. After primary cryopreservation, tumour take rates were 38% and 67% using either the vitrification or FCS/DMSO-based cryopreservation protocol, respectively. Cryopreserved tumour tissue of established PDXs achieved take rates of 67% and 94%, respectively compared to 91% using fresh PDX tumour tissue. Genotyping analysis showed that no changes in copy number alterations were introduced by any of the biobanking methods. Our results indicate that both protocols can be used for biobanking of ovarian tumour and PDX tissues. However, FCS/DMSO-based cryopreservation is more successful. Moreover, primary engraftment of fresh patient-derived tumours in mice followed by freezing tissue of successfully established PDXs is the preferred way of efficient ovarian cancer PDX biobanking.

CD103+ intraepithelial T cells in high-grade serous ovarian cancer are phenotypically diverse TCRαβ+ CD8αβ+ T cells that can be targeted for cancer immunotherapy

CD103+ tumor-infiltrating lymphocytes (TIL) have been linked to specific epithelial infiltration and a prolonged survival in high-grade serous epithelial ovarian cancer (HGSC). However, whether these cells are induced as part of an ongoing anti-HGSC immune response or represent non-specifically expanded resident or mucosal lymphocytes remains largely unknown. In this study, we first confirmed that CD103+ TIL from HGSC were predominantly localized in the cancer epithelium and were strongly correlated with an improved prognosis. We further demonstrate that CD103+ TIL were almost exclusively CD3+ TCRαβ+ CD8αβ+ CD4- T cells, but heterogeneously expressed T cell memory and differentiation markers. Activation of peripheral T cells in the presence of HGSC was sufficient to trigger induction of CD103 in over 90% of all CD8+ cells in a T cell receptor (TCR)- and TGFβR1-dependent manner. Finally, CD103+ TIL isolated from primary HGSC showed signs of recent activation and dominantly co-expressed key immunotherapeutic targets PD-1 and CD27. Taken together, our data indicate CD103+ TIL in HGSC are formed as the result of an adaptive anti-tumor immune response that might be reactivated by (dual) checkpoint inhibition.

Development of a radioiodinated apoptosis-inducing ligand, rhTRAIL, and a radiolabelled agonist TRAIL receptor antibody for clinical imaging studies.

BACKGROUND AND PURPOSE The TNF‐related apoptosis inducing ligand (TRAIL) induces apoptosis through activation of the death receptors, TRAIL‐R1 and TRAIL‐R2. Recombinant human (rh) TRAIL and the TRAIL‐R1 directed monoclonal antibody mapatumumab are currently clinically evaluated as anticancer agents. The objective of this study was to develop radiopharmaceuticals targeting the TRAIL‐R1, suitable for clinical use to help understand and predict clinical efficacy in patients.

Integrative kinome profiling identifies mTORC1/2 inhibition as treatment strategy in ovarian clear cell carcinoma

Purpose: Advanced-stage ovarian clear cell carcinoma (OCCC) is unresponsive to conventional platinum-based chemotherapy. Frequent alterations in OCCC include deleterious mutations in the tumor suppressor ARID1A and activating mutations in the PI3K subunit PIK3CA. In this study, we aimed to identify currently unknown mutated kinases in patients with OCCC and test druggability of downstream affected pathways in OCCC models. Experimental Design: In a large set of patients with OCCC (n = 124), the human kinome (518 kinases) and additional cancer-related genes were sequenced, and copy-number alterations were determined. Genetically characterized OCCC cell lines (n = 17) and OCCC patient–derived xenografts (n = 3) were used for drug testing of ERBB tyrosine kinase inhibitors erlotinib and lapatinib, the PARP inhibitor olaparib, and the mTORC1/2 inhibitor AZD8055. Results: We identified several putative driver mutations in kinases at low frequency that were not previously annotated in OCCC. Combining mutations and copy-number alterations, 91% of all tumors are affected in the PI3K/AKT/mTOR pathway, the MAPK pathway, or the ERBB family of receptor tyrosine kinases, and 82% in the DNA repair pathway. Strong p-S6 staining in patients with OCCC suggests high mTORC1/2 activity. We consistently found that the majority of OCCC cell lines are especially sensitive to mTORC1/2 inhibition by AZD8055 and not toward drugs targeting ERBB family of receptor tyrosine kinases or DNA repair signaling. We subsequently demonstrated the efficacy of mTORC1/2 inhibition in all our unique OCCC patient–derived xenograft models. Conclusions: These results propose mTORC1/2 inhibition as an effective treatment strategy in OCCC. Clin Cancer Res; 24(16); 3928–40. ©2018 AACR.

Nuclear COMMD1 Is Associated with Cisplatin Sensitivity in Ovarian Cancer.

Copper metabolism MURR1 domain 1 (COMMD1) protein is a multifunctional protein, and its expression has been correlated with patients’ survival in different types of cancer. In vitro studies revealed that COMMD1 plays a role in sensitizing cancer cell lines to cisplatin, however, the mechanism and its role in platinum sensitivity in cancer has yet to be established. We evaluated the role of COMMD1 in cisplatin sensitivity in A2780 ovarian cancer cells and the relation between COMMD1 expression and response to platinum-based therapy in advanced stage high-grade serous ovarian cancer (HGSOC) patients. We found that elevation of nuclear COMMD1 expression sensitized A2780 ovarian cancer cells to cisplatin-mediated cytotoxicity. This was accompanied by a more effective G2/M checkpoint, and decreased protein expression of the DNA repair gene BRCA1, and the apoptosis inhibitor BCL2. Furthermore, COMMD1 expression was immunohistochemically analyzed in two tissue micro-arrays (TMAs), representing a historical cohort and a randomized clinical trial-based cohort of advanced stage HGSOC tumor specimens. Expression of COMMD1 was observed in all ovarian cancer samples, however, specifically nuclear expression of COMMD1 was only observed in a subset of ovarian cancers. In our historical cohort, nuclear COMMD1 expression was associated with an improved response to chemotherapy (OR = 0.167; P = 0.038), although this association could not be confirmed in the second cohort, likely due to sample size. Taken together, these results suggest that nuclear expression of COMMD1 sensitize ovarian cancer to cisplatin, possibly by modulating the G2/M checkpoint and through controlling expression of genes involved in DNA repair and apoptosis.

HER2 immunohistochemistry in endometrial and ovarian clear cell carcinoma: discordance between antibodies and with in-situ hybridisation

Treatment with anti‐HER2 therapy could be beneficial for patients with HER2‐positive endometrial and ovarian clear cell carcinoma (CCC). We studied HER2 overexpression by immunohistochemistry (IHC) using three different antibodies, including concordance with amplification by in‐situ hybridisation (ISH).