Expression Profiling of Ovarian Cancer: markers and targets for therapy

Ovarian cancer is the leading cause of death from gynecological cancer in the Western world. The initial response of the primary tumor to taxane and platinum-based chemotherapy is high, however 20% of patients never achieve a clinical response and the majority of the patients will relapse and eventually die of drug-resistant disease. Chapter 1 includes a general overview of ovarian cancer, its epidemiology, histology, typing and the different therapies. The major drawback in the treatment of ovarian cancer is late detection and therapy failure due to intrinsic and acquired chemotherapy resistance and several mechanisms involved in the platinum-based chemotherapy resistance are described. Furthermore, the importance of expression profiling (mRNA or protein) in the search for tumor markers suitable for early detection of ovarian cancer, response prediction, progression monitoring and identification of targets for therapy is discussed. Chapter 2A The expression profiling of 24 ovarian carcinomas led to the discovery of a discriminating 69-gene signature from which a predictive nine-gene set was extracted. The nine-gene set predicted the resistance in an independent validation set (n=72) with a sensitivity of 89% (95% CI: 0.68-1.09) and a specificity of 59% (95% CI: 0.47-0.71)(OR=0.09, p=0.026). The predictive nine-gene set consists of the following genes, FN1, TOP2A, LBR, ASS, COL3A1, STK6, SGPP1, ITGAE and PCNA. Interestingly, three of these nine genes are already direct or indirect targets for therapy, i.e. topoisomerase 2A (TOP2A), serine/threonine kinase 6 (STK6) and argininosuccinate synthetase (ASS). The predictive power of the nine-gene set needs to be further validated in larger independent multicenter study before this model can be implemented in the clinical practice. Chapter 2B In their â?~letter to the editorâ?T, Gevaert et al. suggest that in clinical practice, a higher specificity would have been more successful assuming that patients predicted not to respond are given a different treatment not containing platinum drugs. We agree that the predictive gene signature needs further validation before implementation in the clinical practice can be advised. However, it is was not our intention to withhold platinum treatment from patients predicted not to respond, but to tailor the treatment based on the expression profile. An overexpression of TOP2A indicates that adding a TOP2A inhibitor, like etoposide, to the conventional platinum treatment, might proof to be beneficial for the patient. Chapter 2C Underexpression of one of the nine genes from the predictive gene set, i.e. Argininosuccinate synthetase (ASS) was associated with platinum-based chemotherapy resistance. To determine if this observed association was functional, ASS was downregulated with siRNA in three ovarian cancer cell lines that were relatively sensitive to cisplatin. For all three cell lines, this did not result in a reduced response to cisplatin measured with an MTT assay. However, due to differences between cell lines and carcinomas, we cannot exclude that ASS might still play a role in platinum-based chemotherapy resistance in ovarian cancer patients. Chapter 3 One of the nine genes of the predictive gene set i.e. proliferating cell nuclear antigen (PCNA), is involved in the DNA mismatch repair (MMR). In vitro, a relationship between MMR deficiency and platinum-drug resistance was suThe full text of this item cannot yet be made available, due to a publisher's embarg

Clinical outcome comparison of Grade Group 1 and Grade Group 2 prostate cancer with and without cribriform architecture at the time of radical prostatectomy

Aims: Invasive cribriform and intraductal carcinoma are associated with aggressive disease in Grade Group 2 (GG2) prostate cancer patients. However, the characteristics and clinical outcome of patients with GG2 prostate cancer without cribriform architecture (GG2−) as compared with those with Grade Group 1 (GG1) prostate cancer are unknown. The aim of this study was to investigate the clinical and pathological characteristics of GG1 and GG2− prostate cancer in radical prostatectomy specimens. Methods and results: We reviewed 835 radical prostatectomy specimens for Grade Group, pT stage, surgical margin status, and the presence of cribriform architecture. Biochemical recurrence-free survival and metastasis were used as clinical outcomes. GG1 prostate cancer was seen in 207 patients, and GG2 prostate cancer was seen in 420 patients, of whom 228 (54%) showed cribriform architecture (GG2+) and 192 (46%) did not. GG2− patients had higher prostate-specific antigen levels (9.4 ng/ml versus 7.0 ng/ml; P < 0.001), more often had extraprostatic extension (36% versus 11%; P < 0.001) and had more positive surgical margins (27% versus 17%; P = 0.01) than GG1 patients. GG2− patients ha

Mismatch repair and treatment resistance in ovarian cancer

BACKGROUND: The treatment of ovarian cancer is hindered by intrinsic or acquired resistance to platinum-based chemotherapy. The aim of this study is to determine the frequency of mismatch repair (MMR) inactivation in ovarian cancer and its association with resistance to platinum-based chemotherapy. METHODS: We determined, microsatellite instability (MSI) as a marker for MMR inactivation (analysis of BAT25 and BAT26), MLH1 promoter methylation status (methylation specific PCR on bisulfite treated DNA) and mRNA expression of MLH1, MSH2, MSH3, MSH6 and PMS2 (quantitative RT-PCR) in 75 ovarian carcinomas and eight ovarian cancer cell lines RESULTS: MSI was detected in three of the eight cell lines i.e. A2780 (no MLH1 mRNA expression due to promoter methylation), SKOV3 (no MLH1 mRNA expression) and 2774 (no altered expression of MMR genes). Overall, there was no association between cisplatin response and MMR status in these eight cell lines. Seven of the 75 ovarian carcinomas showed MLH1 promoter methylation, however, none of these showed MSI. Forty-six of these patients received platinum-based chemotherapy (11 non-responders, 34 responders, one unknown response). The resistance seen in the eleven non-responders was not related to MSI and therefore also not to MMR inactivation. CONCLUSION: No MMR inactivation was detected in 75 ovarian carcinoma specimens and no association was seen between MMR inactivation and resistance in the ovarian cancer cell lines as well as the ovarian carcinomas. In the discussion, the results were compared to that of twenty similar studies in the literature including in total 1315 ovarian cancer patients. Although no association between response and MMR status was seen in the primary tumor the possible role of MMR inactivation in acquired resistance deserves further investigation

miR-634 restores drug sensitivity in resistant ovarian cancer cells by targeting the Ras-MAPK pathway

Background: Drug resistance hampers the efficient treatment of malignancies, including advanced stage ovarian cancer, which has a 5-year survival rate of only 30 %. The molecular processes underlying resistance have been extensively studied, however, not much is known about the involvement of microRNAs. Methods: Differentially expressed microRNAs between cisplatin sensitive and resistant cancer cell line pairs were determined using microarrays. Mimics were used to study the role of microRNAs in drug sensitivity of ovarian cancer cell lines and patient derived tumor cells. Luciferase reporter constructs were used to establish regulation of target genes by microRNAs. Results: MiR-634 downregulation was associated with cisplatin resistance. Overexpression of miR-634 affected cell cycle progression and enhanced apoptosis in ovarian cancer cells. miR-634 resensitized resistant ovarian cancer cell lines and patient derived drug resistant tumor cells to cisplatin. Similarly, miR-634 enhanced the response to carboplatin and doxorubicin, but not to paclitaxel. The cell cycle regulator CCND1, and Ras-MAPK pathway components GRB2, ERK2 and RSK2 were directly repressed by miR-634 overexpression. Repression of the Ras-MAPK pathway using a MEK inhibitor phenocopied the miR-634 effects on viability and chemosensitivity. Conclusion:miR-634 levels determine chemosensitivity in ovarian cancer cells. We identify miR-634 as a therapeutic candidate to resensitize chemotherapy resistant ovarian tumors

Concordance of cribriform architecture in matched prostate cancer biopsy and radical prostatectomy specimens

Aims: Invasive cribriform and/or intraductal carcinoma have been identified as independent adverse parameters for prostate cancer outcome. Little is known on biopsy undersampling of cribriform architecture. Our aim was to determine the extent of cribriform architecture undersampling and to find predictive factors for identifying false cribriform-negative cases. Methods and results: We reviewed 186 matched prostate biopsies and radical prostatectomy specimens. Of 97 biopsy grade group 2 (Gleason score 3 + 4 = 7) patients, 22 (23%) had true cribriform-negative (TN), 39 (40%) false-negative (FN) and 36 (37%) true-positive (TP) biopsies. Patients with FN biopsies had higher, although not statistically significant (P = 0.06), median PSA levels than patients with TP biopsies (12 versus 8 ng/ml). A PI-RADS 5 lesion was present in nine of 16 (54%) FN and three of 11 (27%) TN biopsies (P = 0.05). Positive biopsy rate (P = 0.47), percentage Gleason pattern 4 (P = 0.55) and glomeruloid architecture (P = 1.0) were not different. Logistic regression identified PSA as an independent pr

Health Policy for Prostate Cancer Early Detection in the European Union and the Impact of Opportunistic Screening:PRAISE-U Consortium

With the new policy recommendation in 2022 to explore the possibilities of screening for prostate cancer by the European Commission, the landscape for prostate cancer early detection is evolving. In line with this recommendation, the PRAISE-U project aims to evaluate the early detection and diagnosis of prostate cancer through customised and risk-based screening programmes, with the goal to align protocols across European Union member states. This systematic review is part of the PRAISE-U project, with the goal to review the policy, medical guideline recommendations, and the current level of opportunistic screening presented in the scientific literature on prostate cancer early detection from 2016 to 2023 in European Union member states. An extensive literature search was performed on 1 June 2023 in a large number of databases, including Embase.com, Medline (Ovid), Web of Science Core Collection, Google Scholar, and Policy Commons. We identified 318 articles (qualitative, quantitative, and reviews), of which 41 were included in the full-text screening. Seventeen articles were ultimately identified as eligible for inclusion. The included articles revealed significant variations towards PSA-based early detection policies for prostate cancer in nine European countries. Despite official recommendations, opportunistic screening was prevalent across all nine countries regardless of recommendations for or against PSA-based early detection. This systematic review suggests that the current early detection policies are not fit for purpose. High levels of opportunistic screening and overdiagnosis persist, prompting policy recommendations for standardised guidelines, informed decision making, and increased awareness to improve efficiency and effectiveness in early detection.</p

Intraoperative assessment and reporting of radical prostatectomy specimens to guide nerve-sparing surgery in prostate cancer patients (NeuroSAFE)

AIMS: Radical prostatectomy for prostate cancer is frequently complicated by urinary incontinence and erectile dysfunction. Nerve-sparing surgery reduces the risk of post-operative complications and can be optimized using intraoperative frozen sections of the adjacent neurovascular structure (NeuroSAFE). The aim of t

Ovarian cancer cell line panel (OCCP): Clinical importance of in vitro morphological subtypes

Epithelial ovarian cancer is a highly heterogeneous disease and remains the most lethal gynaecological malignancy in the Western world. Therapeutic approaches need to account for inter-patient and intra-tumoural heterogeneity and detailed characterization of in vitro models representing the different histological a

TP53 Mutations in Serum Circulating Cell-Free Tumor DNA As Longitudinal Biomarker for High-Grade Serous Ovarian Cancer

The aim of this study was to determine an optimal workflow to detect TP53 mutations in baseline and longitudinal serum cell free DNA (cfDNA) from high-grade serous ovarian carcinomas (HGSOC) patients and to define whether TP53 mutations are suitable as biomarker for disease. TP53 was investigated in tissue and archived serum from 20 HGSOC patients by a next-generation sequencing (NGS) workflow alone or combined with digital PCR (dPCR). AmpliSeq™-focused NGS panels and customized dPCR assays were used for tissue DNA and longitudinal cfDNAs, and Oncomine NGS panel with molecular barcoding was used for baseline cfDNAs. TP53 missense mutations were observed in 17 tissue specimens and in baseline cfDNA for 4/8 patients by AmpliSeq, 6/9 patients by Oncomine, and 4/6 patients by dPCR. Mutations in cfDNA were detected in 4/6 patients with residual disease and 3/4 patients with disease progression within six months, compared to 5/11 patients with no residual disease and 6/13 patients with progression after six months. Finally, mutations were detected at progression in 5/6 patients, but not during chemotherapy. NGS with molecular barcoding and dPCR were most optimal workflows to detect TP53 mutations in baseline and longitudinal serum cfDNA, respectively. TP53 mutations were undetectable in cfDNA during treatment but re-appeared at disease progression, illustrating its promise as a biomarker for disease monitoring