Genetic aspects and molecular testing in prostate cancer: a report from a Dutch multidisciplinary consensus meeting

Background: Germline and tumour genetic testing in prostate cancer (PCa) is becoming more broadly accepted, but testing indications and clinical consequences for carriers in each disease stage are not yet well defined.Objective: To determine the consensus of a Dutch multidisciplinary expert panel on the indication and application of germline and tumour genetic testing in PCa.Design, setting, and participants: The panel consisted of 39 specialists involved in PCa management. We used a modified Delphi method consisting of two voting rounds and a virtual consensus meeting.Outcome measurements and statistical analysis: Consensus was reached if >75% of the panellists chose the same option. Appropriateness was assessed by the RAND/UCLA appropriateness method.Results and limitations: Of the multiple-choice questions, 44% reached consensus. For men without PCa having a relevant family history (familial PCa/BRCA-related hered-itary cancer), follow-up by prostate-specific antigen was considered appropriate. For patients with low-risk localised PCa and a family history of PCa, active surveil-lance was considered appropriate, except in case of the patient being a BRCA2 germ -line pathogenic variant carrier. Germline and tumour genetic testing should not be done for nonmetastatic hormone-sensitive PCa in the absence of a relevant family history of cancer. Tumour genetic testing was deemed most appropriate for the identification of actionable variants, with uncertainty for germline testing. For tumour genetic testing in metastatic castration-resistant PCa, consensus was not reached for the timing and panel composition. The principal limitations are as fol-lows: (1) a number of topics discussed lack scientific evidence, and therefore the recommendations are partly opinion based, and (2) there was a small number of experts per discipline.Conclusions: The outcomes of this Dutch consensus meeting may provide further guidance on genetic counselling and molecular testing related to PCa.Patient summary: A group of Dutch specialists discussed the use of germline and tumour genetic testing in prostate cancer (PCa) patients, indication of these tests (which patients and when), and impact of these tests on the management and treatment of PCa.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of European Association of Urology. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/).Experimentele farmacotherapi

Wnt signaling: its transcriptional output in the intestinal crypt and in colon cancer

The transition of an intestinal epithelial cell into a fully transformed, metastatic cancer cell requires mutations in multiple proto-oncogenes and key tumor suppressor genes, including those of the Wnt pathway. We describe a large scale analysis of the downstream genetic program activated by wnt signaling through β-catenin/TCF4 in colorectal cancer cells. Inhibition of wnt signaling in these cells results in a growth arrest with downregulation of genes expressed in the proliferating region of the crypt while forcing these cells into a differentiation program. These results were confirmed by immunohistochemistry on adenomas and early neoplastic lesions in the intestine. This study validated the disruption of the β-catenin/TCF complex as a therapeutic strategy to revert the transformed phenotype in colorectal cancer. Silencing genes that contribute to the survival and progression of tumor cells is a major research objective. Recently RNAi technology for gene knockdown in mammalian cells has been proven to be effective. We describe the generation of a doxycycline-inducible version of a Polymerase III H1-RNA gene promoter driven shRNA vector (pTER). The knockdown of β-catenin/TCF activity by a loss-of-function approach reproduced the phenotypic changes that occur in CRC cells described earlier. This inducible pTER vector is particularly useful for the analysis of genes which functions are difficult to evaluate due to effects on growth or differentiation of cells, like cell-cycle regulators, oncogenes, tumor suppressor genes and genes that control apoptosis. DNA array techniques are rapidly evolving and genome-wide oligonucleotide array platforms are now common use, containing up to 55000 probes. We analyzed the expression profile of LS174 CRC cells stably transfected with inducible dnTCF1 and dnTCF4. The 300-400 selected Wnt responsive genes were subsequently compared to the gene profile of adenomas and adenocarcinomas versus normal colonic epithelium. These genes could be divided into 3 groups based on differential expression in distinct parts of the crypts. Our data demonstrate that in one organ system, the gut, different transcriptional outputs of Wnt signalling correspond with the proposed Wnt functions of maintaining the crypt progenitor phenotype, driving the terminal differentiation of Paneth cells and stem cell renewal, respectively. Mash-2 one of the identified target genes was studied more extensively. In the normal intestine, Mash-2 is expressed at the position of the presumptive crypt stem cell. No Mash-2 expression was found in the TCF4 KO mice and in adenomas of APCmin mice Mash-2 is highly expressed. This confirmed the observation that Mash-2 is indeed a target of the Wnt pathway. To further define the contribution of Mash-2 to the Wnt dependent phenotype in the gut, we generated a Villin-Mash-2-transgenic mouse. Overexpression of Mash-2 in the intestine correlated with overexpression of few wnt target genes implicated in proliferation and in stem cell maintenance, making Mash-2 a possible stem cell regulator. The results described in this thesis has further increased our knowledge of the role of the Wnt pathway. This may be a basis for the ongoing efforts for the development of drugs targeting the inhibition of the Wnt pathway

Liquid biopsy reveals KLK3 mRNA as a prognostic marker for progression free survival in patients with metastatic castration-resistant prostate cancer undergoing first-line abiraterone acetate and prednisone treatment

Circulating RNAs extracted from liquid biopsies represent a promising source of cancer- and therapy-related biomarkers. We screened whole blood from patients with metastatic castration-resistant prostate cancer (mCRPC) following their first-line treatment with abiraterone acetate and prednisone (AA-P) to identify circulating RNAs that may correlate with progression-free survival (PFS). In a prospective multicenter observational study, 53 patients with mCRPC were included after they started first-line AA-P treatment. Blood was drawn at baseline, 1, 3, and 6 months after treatment initiation. The levels of predefined circulating RNAs earlier identified as being upregulated in patients with mCRPC (e.g., microRNAs, long noncoding RNAs, and mRNAs), were analyzed. Uni- and multivariable Cox regression and Kaplan-Meier analyses were used to analyze the prognostic value of the various circulating RNAs for PFS along treatment. Detectable levels of kallikrein-related peptidase 3 (KLK3) mRNA at baseline were demonstrated to be an independent prognostic marker for PFS (201 vs 501 days, P = 0.00054). Three months after AA-P treatment initiation, KLK3 could not be detected in the blood of responding patients, but was still detectable in 56% of the patients with early progression. Our study confirmed that KLK3 mRNA detection in whole blood is an independent prognostic marker in mCRPC patients receiving AA-P treatment. Furthermore, the levels of circulating KLK3 mRNA in patients receiving AA-P treatment might reflect treatment response or early signs of progression

RNA Biomarkers as a Response Measure for Survival in Patients with Metastatic Castration-Resistant Prostate Cancer

Treatment evaluation in metastatic castration-resistant prostate cancer is challenging. There is an urgent need for biomarkers to discriminate short-term survivors from long-term survivors, shortly after treatment initiation. Thereto, the added value of early RNA biomarkers on predicting progression-free survival (PFS) and overall survival (OS) were explored. The RNA biomarkers: KLK3 mRNA, miR-375, miR-3687, and NAALADL2-AS2 were measured in 93 patients with mCRPC, before and 1 month after start of first-line abiraterone acetate or enzalutamide treatment, in two prospective clinical trials. The added value of the biomarkers to standard clinical parameters in predicting PFS and OS was tested by Harell's C-index. To test whether the biomarkers were independent markers of PFS and OS, multivariate Cox regression was used. The best prediction model for PFS and OS was formed by adding miR-375 and KLK3 (at baseline and 1 month) to standard clinical parameters. Baseline miR-375 and detectable KLK3 after 1 month of therapy were independently related to shorter PFS, which was not observed for OS. In conclusion, the addition of KLK3 and miR-375 (at baseline and 1 month) to standard clinical parameters resulted in the best prediction model for survival assessment

Health-related quality of life, psychological distress, and fatigue in metastatic castration-resistant prostate cancer patients treated with radium-223 therapy.

BACKGROUND: Radium-223 is a registered treatment option for symptomatic bone metastatic castration-resistant prostate cancer (mCRPC). Aim of this multicenter, prospective observational cohort study was to evaluate health-related quality of life (HR-QoL), psychological distress and fatigue in mCRPC patients treated with radium-223. METHODS: Primary endpoint was cancer-specific and bone metastases-related HR-QoL, as measured by the EORTC QLQ-C30 and BM-22 questionnaires. Secondary endpoints were psychological distress and fatigue, evaluated by the HADS and CIS-Fatigue questionnaires. Outcomes were analyzed for the total cohort and between subgroups (1-3 versus 4-5 versus 6 radium-223 injections). A trajectory analysis was performed to explore HR-QoL patterns over time. RESULTS: In total, 122 patients were included for analysis. Baseline HR-QoL, pain intensity, psychological distress and fatigue were worse in patients who did not complete radium-223 therapy. In patients who completed therapy, stabilization of HR-QoL was perceived and psychological distress and fatigue remained stable, whereas clinically meaningful and statistically significant deterioration of HR-QoL, psychological distress and fatigue over time was observed in patients who discontinued radium-223 therapy. Trajectory analysis revealed that HR-QoL deterioration over time was more likely in patients with baseline opioid use, low hemoglobin and high alkaline phosphatase levels. CONCLUSIONS: Patients who discontinued radium-223 therapy showed worse HR-QoL, psychological distress and fatigue at baseline and more frequent deterioration of HR-QoL, psychological distress and fatigue over time when compared to patients who completed therapy. Specific attention with regard to HR-QoL during follow-up is indicated in patients with opioid use, low hemoglobin and high alkaline phosphatase levels before radium-223 therapy initiation. CLINICAL TRIAL REGISTRATION NUMBER: NCT04995614

Transcription factor achaete scute-like 2 controls intestinal stem cell fate.

The small intestinal epithelium is the most rapidly self-renewing tissue of mammals. Proliferative cells are confined to crypts, while differentiated cell types predominantly occupy the villi. We recently demonstrated the existence of a long-lived pool of cycling stem cells defined by Lgr5 expression and intermingled with post-mitotic Paneth cells at crypt bottoms. We have now determined a gene signature for these Lgr5 stem cells. One of the genes within this stem cell signature is the Wnt target Achaete scute-like 2 (Ascl2). Transgenic expression of the Ascl2 transcription factor throughout the intestinal epithelium induces crypt hyperplasia and ectopic crypts on villi. Induced deletion of the Ascl2 gene in adult small intestine leads to disappearance of the Lgr5 stem cells within days. The combined results from these gain- and loss-of-function experiments imply that Ascl2 controls intestinal stem cell fate.

Genetic Aspects and Molecular Testing in Prostate Cancer: A Report from a Dutch Multidisciplinary Consensus Meeting

BACKGROUND: Germline and tumour genetic testing in prostate cancer (PCa) is becoming more broadly accepted, but testing indications and clinical consequences for carriers in each disease stage are not yet well defined. OBJECTIVE: To determine the consensus of a Dutch multidisciplinary expert panel on the indication and application of germline and tumour genetic testing in PCa. DESIGN SETTING AND PARTICIPANTS: The panel consisted of 39 specialists involved in PCa management. We used a modified Delphi method consisting of two voting rounds and a virtual consensus meeting. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Consensus was reached if ≥75% of the panellists chose the same option. Appropriateness was assessed by the RAND/UCLA appropriateness method. RESULTS AND LIMITATIONS: Of the multiple-choice questions, 44% reached consensus. For men without PCa having a relevant family history (familial PCa/BRCA-related hereditary cancer), follow-up by prostate-specific antigen was considered appropriate. For patients with low-risk localised PCa and a family history of PCa, active surveillance was considered appropriate, except in case of the patient being a BRCA2 germline pathogenic variant carrier. Germline and tumour genetic testing should not be done for nonmetastatic hormone-sensitive PCa in the absence of a relevant family history of cancer. Tumour genetic testing was deemed most appropriate for the identification of actionable variants, with uncertainty for germline testing. For tumour genetic testing in metastatic castration-resistant PCa, consensus was not reached for the timing and panel composition. The principal limitations are as follows: (1) a number of topics discussed lack scientific evidence, and therefore the recommendations are partly opinion based, and (2) there was a small number of experts per discipline. CONCLUSIONS: The outcomes of this Dutch consensus meeting may provide further guidance on genetic counselling and molecular testing related to PCa. PATIENT SUMMARY: A group of Dutch specialists discussed the use of germline and tumour genetic testing in prostate cancer (PCa) patients, indication of these tests (which patients and when), and impact of these tests on the management and treatment of PCa