Rob C.M. Pelger

High Aldehyde Dehydrogenase Activity Identifies Tumor-Initiating and Metastasis-Initiating Cells in Human Prostate Cancer

Metastatic progression of advanced prostate cancer is a major clinical problem. Identifying the cell(s) of origin in prostate cancer and its distant metastases may permit the development of more effective treatment and preventive therapies. In this study, aldehyde dehydrogenase (ALDH) activity was used as a basis to isolate and compare subpopulations of primary human prostate cancer cells and cell lines. ALDH-high prostate cancer cells displayed strongly elevated clonogenicity and migratory behavior in vitro. More strikingly, ALDH-high cells readily formed distant metastases with strongly enhanced tumor progression at both orthotopic and metastatic sites in preclinical models. Several ALDH isoforms were expressed in human prostate cancer cells and clinical specimens of primary prostate tumors with matched bone metastases. Our findings suggest that ALDH-based viable cell sorting can be used to identify and characterize tumor-initiating and, more importantly perhaps, metastasis-initiating cells in human prostate cancer.

Costs of Prostate Cancer, Metastatic to the Bone, in The Netherlands

OBJECTIVE To quantify medical costs associated with bone metastases in patients with prostate cancer. Bone metastases in patients with prostate cancer are associated with considerable morbidity, negatively impact quality of life, and can add substantially to medical costs, given a median survival of 30-35 months from diagnosis of bone metastases. METHODS A retrospective cost analysis from both a community and university hospital in The Netherlands was conducted. Twenty-eight patient records (14 from each hospital) were investigated to assess the impact of skeletal-related events (SREs), including fractures, spinal cord compression, and radiotherapy, on total direct medical costs and cost of hospitalization. Costs are given in EUROS (Euros). RESULTS The average total cost of treatment was Euros 13,051 per patient over the 24-month follow-up period, which includes an average cost of Euros 6973 per patient to treat SREs. Treatment of SREs more than doubled total treatment costs. Patients in this analysis experienced, on average, one SRE per year, and the cost of SREs varied from Euros 1187 to Euros 40,948. CONCLUSIONS Occurrence of SREs contributes significantly to the cost of care for patients with advanced prostate cancer. These data suggest that bisphosphonates, which can reduce pain and SREs, may reduce healthcare costs.

The BMP2/7 heterodimer inhibits the human breast cancer stem cell subpopulation and bone metastases formation.

Accumulating evidence suggests that a subpopulation of breast cancer cells, referred to as cancer stem cells (CSCs), have the ability to propagate a tumor and potentially seed new metastases. Furthermore, stimulation of an epithelial-to-mesenchymal transition by factors like transforming growth factor-β (TGFβ) is accompanied with the generation of breast CSCs. Previous observations indicated that bone morphogenetic protein-7 (BMP7) antagonizes the protumorigenic and prometastatic actions of TGFβ, but whether BMP7 action is mechanistically linked to breast CSCs has remained elusive. Here, we have studied the effects of BMP7, BMP2 and a BMP2/7 heterodimer on the formation of human breast CSCs (ALDHhi/CD44hi/CD24−/low) and bone metastases formation in a preclinical model of intra-cardiac injection of MDA-MB-231 cells in athymic nude (Balb/c nu/nu) mice. The BMP2/7 heterodimer was the most efficient stimulator of BMP signaling and very effectively reduced TGFβ-driven Smad signaling and cancer cell invasiveness. The tested BMPs—particularly the heterodimeric BMP2/7—strongly reduced the size of the ALDHhi/CD44hi/CD24−/low CSC subpopulation. In keeping with these in vitro observations, pretreatment of cancer cells with BMPs for 72 h prior to systemic inoculation of the cancer cells inhibited the formation of bone metastases. Collectively, our data support the notion that breast CSCs are involved in bone metastasis formation and describe heterodimeric BMP2/7 as a powerful TGFβ antagonist with anti-metastatic potency.

Effects of the Bisphosphonate Olpadronate in Patients With Carcinoma of the Prostate Metastatic to the Skeleton

Prostate cancer is predominantly associated with osteoblastic bone metastases, but an increase in bone resorption has been demonstrated consistently, both histologically and biochemically. For this reason, bisphosphonates, which effectively suppress bone resorption, have been used in patients with prostate cancer metastatic to the skeleton. We studied clinical and biochemical responses 5 days and 3 months after administration of the new, potent bisphosphonate, olpadronate, in 28 patients with prostate cancer and bone metastases. All patients received 4 mg of olpadronate intravenously daily for 5 days. No additional treatment was given to the first 12 patients, while treatment was continued with oral olpadronate 200 mg daily in the following 16 patients. Serum alkaline phosphatase (ALP) activity was elevated in 93% of the patients and was positively correlated to urinary hydroxyproline excretion (r = 0.81, p < 0.0001), suggesting a coupling between bone formation and resorption. A rapid and significant suppression of bone resorption was observed in all patients after intravenous treatment. This was sustained for 4-6 weeks in all patients, but reversed thereafter in patients not receiving oral maintenance therapy. No significant changes in serum ALP activity were observed in either group during the 3 months of follow-up. At the start of treatment all patients had severe bone pain and 82% and 36% were using NSAIDs and/or opiates, respectively. Although clinical response was not a primary objective of the study, we observed that intravenous therapy was associated with a decrease in bone pain in 76% of patients and a reduction in the use of analgesics. At 3 months this response was generally sustained only in those patients who were maintained on continuous oral therapy (p < 0.05 compared with the group treated with intravenous olpadronate only). The clinical response thus appeared to parallel the biochemical changes in bone resorption.

Sexual Function Improvement Following Surgery for Stress Incontinence: The Relevance of Coital Incontinence

INTRODUCTION Little is known about the impact of surgery for stress urinary incontinence (SUI) on female sexual function, and results are conflicting. AIMS We aimed to clarify the impact of surgery for SUI on female sexual function. METHODS We analyzed data collected from two studies evaluating sexual function in women after placement of the tension-free vaginal tape, tension-free vaginal tape obturator, or transobturator suburethral tape. A nonvalidated sexual questionnaire developed by Lemack, translated into Dutch, was mailed to all patients 3-12 months after the procedure. MAIN OUTCOME MEASURES Pre- and postoperative results of a nonvalidated sexual questionnaire. RESULTS A total of 136 sexually active women completed the questionnaires. Compared with preoperative responses, we observed no significant changes postsurgical regarding frequency of sexual intercourse or satisfaction of sexual intercourse, although a significant postoperative decrease in urinary coital incontinence (P < or = 0.001) was found. Postoperatively, 29 women (21.3%) reported improved sexual intercourse, and eight women (5.9%) complained of a worsening. There was a significant higher rate of preoperative coital incontinence (86.2% women with coital incontinence) in the group of women who reported improved intercourse (P = 0.01). CONCLUSION Women with coital incontinence show a significant higher improvement in sexual function after surgery for SUI compared to women without coital incontinence. Our results suggest that improvement in coital incontinence results in improvement of sexual function. Therefore, coital incontinence is a prognostic factor for improvement of sexual function following incontinence surgery.

The aldehyde dehydrogenase enzyme 7A1 is functionally involved in prostate cancer bone metastasis

High aldehyde dehydrogenase (ALDH) activity can be used to identify tumor-initiating and metastasis-initiating cells in various human carcinomas, including prostate cancer. To date, the functional importance of ALDH enzymes in prostate carcinogenesis, progression and metastasis has remained elusive. Previously we identified strong expression of ALDH7A1 in human prostate cancer cell lines, primary tumors and matched bone metastases. In this study, we evaluated whether ALDH7A1 is required for the acquisition of a metastatic stem/progenitor cell phenotype in human prostate cancer. Knockdown of ALDH7A1 expression resulted in a decrease of the α2hi/αvhi/CD44+ stem/progenitor cell subpopulation in the human prostate cancer cell line PC-3M-Pro4. In addition, ALDH7A1 knockdown significantly inhibited the clonogenic and migratory ability of human prostate cancer cells in vitro. Furthermore, a number of genes/factors involved in migration, invasion and metastasis were affected including transcription factors (snail, snail2, and twist) and osteopontin, an ECM molecule involved in metastasis. Knockdown of ALDH7A1 resulted in decreased intra-bone growth and inhibited experimentally induced (bone) metastasis, while intra-prostatic growth was not affected. In line with these observations, evidence is presented that TGF-β, a key player in cancer invasiveness and bone metastasis, strongly induced ALDH activity while BMP7 (an antagonist of TGF-β signaling) down-regulated ALDH activity. Our findings show, for the first time, that the ALDH7A1 enzyme is functionally involved in the formation of bone metastases and that the effect appeared dependent on the microenvironment, i.e., bone versus prostate.

Integrin αv expression is required for the acquisition of a metastatic stem/progenitor cell phenotype in human prostate cancer.

Integrins participate in multiple cellular processes, including cell adhesion, migration, proliferation, survival, and the activation of growth factor receptors. Recent studies have shown that expression of αv integrins is elevated in the prostate cancer stem/progenitor cell subpopulation compared with more differentiated, committed precursors. Here, we examine the functional role of αv integrin receptor expression in the acquisition of a metastatic stem/progenitor phenotype in human prostate cancer. Stable knockdown of αv integrins expression in PC-3M-Pro4 prostate cancer cells coincided with a significant decrease of prostate cancer stem/progenitor cell characteristics (α2 integrin, CD44, and ALDH(hi)) and decreased expression of invasion-associated genes Snail, Snail2, and Twist. Consistent with these observations, αv-knockdown strongly inhibited the clonogenic and migratory potentials of human prostate cancer cells in vitro and significantly decreased tumorigenicity and metastatic ability in preclinical models of orthotopic growth and bone metastasis. Our data indicate that integrin αv expression is functionally involved in the maintenance of a highly migratory, mesenchymal cellular phenotype as well as the acquisition of a stem/progenitor phenotype in human prostate cancer cells with metastasis-initiating capacity.

Diagnostic Investigation of the Pelvic Floor: A Helpful Tool in the Approach in Patients with Complaints of Micturition, Defecation, and/or Sexual Dysfunction

INTRODUCTION Pelvic floor dysfunction is recognized to be related to lower urinary tract dysfunction and to lower gastrointestinal symptoms, and is an influential factor in dysfunction and subsequent behavior of the genital system in both men and women. Caregivers should be informed regarding normal pelvic floor function in general and should be able to identify specific aspects of pelvic floor dysfunction in patients with related symptoms. In our hospital, this diagnostic consultation is indicated as Diagnostic Investigation of Pelvic Floor Function (DIPFF). AIM This study looked at pelvic floor dysfunction related to specific complaints. METHODS DIPFF consists of a medical history, a physical examination, including the International Continence Society (ICS) pelvic organ prolapse quantification system in female patients, and a biofeedback registration using a vaginal or anal probe. Based on our experience, we defined an elevated rest tone as greater than 2 microV using intravaginal or intra-anal electromyography. MAIN OUTCOME MEASURES Stratification of patients with a single complaint, a combination of two or three complaints of the micturition, defecation or sexual (all compartments of the pelvic floor) resulted in subgroups of respectively 30, 74, and 133 patients. RESULTS A total of 238 patients with complaints of micturition, defecation, and/or sexual function were included in this study. Electromyographic analysis revealed an elevated rest tone of the pelvic floor in 141 patients. In 184 patients, we found an involuntary relaxation of the pelvic floor. CONCLUSION In our retrospective study, we found that 77.2% of patients who presented to the clinic with urinary, gastro or sexual complaints had measurable pelvic floor dysfunction (69.3% overactive rest tone and 7.9% under active rest tone). In relation to the ICS terminology, there is a need for a well-defined normal vs. elevated rest tone of the pelvic floor.

Real-Time Cancer Cell Tracking by Bioluminescence in a Preclinical Model of Human Bladder Cancer Growth and Metastasis

BACKGROUND Bladder cancer is the fifth most common malignancy in the Western world and the second most frequently diagnosed genitourinary tumor. In the majority of cases, death from bladder cancer results from metastatic disease. Understanding the multistep process of carcinogenesis and metastasis in urothelial cancers is pivotal to the development of new therapeutic strategies. Molecular imaging of cancer growth and metastasis in preclinical models provides the essential link between cell-based experiments and clinical translation. OBJECTIVE Develop preclinical models for sensitive bladder cancer cell tracking during tumor progression and metastasis. DESIGN, SETTING, AND PARTICIPANTS A human transitional cell carcinoma UM-UC-3 cell line was generated that stably expresses luciferase 2 (UM-UC-3luc2), a mammalian codon-optimized firefly luciferase with superior expression. Preclinical models were developed with human UM-UC-3luc2 cells xenografted into the bladder (orthotopic model with metastases) or inoculated into the left cardiac ventricle (bone metastasis model) of immunocompromised mice. MEASUREMENTS Noninvasive, sensitive bioluminescent imaging of human firefly luciferase 2-positive bladder cancer in mice using the IVIS100 imaging system. RESULTS AND LIMITATIONS In the orthotopic model (intravesical inoculation), tumor growth could be followed directly after inoculation of UM-UC-3luc2 cells. Importantly, micrometastatic lesions originating from orthotopically implanted cancer cells could be detected in the locoregional lymph nodes and in distant organs. In addition, the superior bioluminescent indicator firefly luciferase 2 allows the detection and monitoring of micrometastatic lesions in real time after intracardiac inoculation of human bladder cancer cells in mice. The main disadvantage is the lack of T-cell immunity in the preclinical models. CONCLUSIONS The new bioluminescence-based preclinical bladder cancer models enable superior, noninvasive, and real-time tracking of cancer cells, tumor progression, and micrometastasis. Because of the significant improvement in detection of small cell numbers, the presented models are ideally suited for functional studies dealing with minimal residual disease as well as real-time imaging of drug response.

A review of the positive and negative effects of cardiovascular drugs on sexual function: a proposed table for use in clinical practice.

Several antihypertensive drugs, such as diuretics and β-blockers, can negatively affect sexual function, leading to diminished quality of life and often to noncompliance with the therapy. Other drug classes, however, such as angiotensin II receptor blockers (ARBs) are able to improve patients’ sexual function. Sufficient knowledge about the effects of these widely used antihypertensive drugs will make it possible for cardiologists and general practitioners to spare and even improve patients’ sexual health by switching to different classes of cardiac medication. Nevertheless, previous data (part I) indicate that most cardiologists lack knowledge about the effects cardiovascular agents can have on sexual function and will thus not be able to provide the necessary holistic patient care with regard to prescribing these drugs. To be able to improve healthcare on this point, we aimed to provide a practical overview, for use by cardiologists as well as other healthcare professionals, dealing with sexual dysfunction in their clinical practices. Therefore, a systematic review of the literature was performed. The eight most widely used classes of antihypertensive drugs have been categorised in a clear table, marking whether they have a positive, negative or no effect on sexual function.