Small-molecule CBP/p300 histone acetyltransferase inhibition mobilizes leukocytes from the bone marrow via the endocrine stress response.

Mutations of the CBP/p300 histone acetyltransferase (HAT) domain can be linked to leukemic transformation in humans, suggestive of a checkpoint of leukocyte compartment sizes. Here, we examined the impact of reversible inhibition of this domain by the small-molecule A485. We found that A485 triggered acute and transient mobilization of leukocytes from the bone marrow into the blood. Leukocyte mobilization by A485 was equally potent as, but mechanistically distinct from, granulocyte colony-stimulating factor (G-CSF), which allowed for additive neutrophil mobilization when both compounds were combined. These effects were maintained in models of leukopenia and conferred augmented host defenses. Mechanistically, activation of the hypothalamus-pituitary-adrenal gland (HPA) axis by A485 relayed shifts in leukocyte distribution through corticotropin-releasing hormone receptor 1 (CRHR1) and adrenocorticotropic hormone (ACTH), but independently of glucocorticoids. Our findings identify a strategy for rapid expansion of the blood leukocyte compartment via a neuroendocrine loop, with implications for the treatment of human pathologies.

Overcoming statin resistance in prostate cancer cells by targeting the 3-hydroxy-3-methylglutaryl-CoA-reductase.

Prostate cancer is the most prevalent malignancy in men. While diagnostic and therapeutic interventions have substantially improved in recent years, disease relapse, treatment resistance, and metastasis remain significant contributors to prostate cancer-related mortality. Therefore, novel therapeutic approaches are needed. Statins are inhibitors of the 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the rate-limiting enzyme of the mevalonate pathway which plays an essential role in cholesterol homeostasis. Numerous preclinical studies have provided evidence for the pleiotropic antitumor effects of statins. However, results from clinical studies remain controversial and have shown substantial benefits to even no effects on human malignancies including prostate cancer. Potential statin resistance mechanisms of tumor cells may account for such discrepancies. In our study, we treated human prostate cancer cell lines (PC3, C4-2B, DU-145, LNCaP) with simvastatin, atorvastatin, and rosuvastatin. PC3 cells demonstrated high statin sensitivity, resulting in a significant loss of vitality and clonogenic potential (up to - 70%; p < 0.001) along with an activation of caspases (up to 4-fold; p < 0.001). In contrast, C4-2B and DU-145 cells were statin-resistant. Statin treatment induced a restorative feedback in statin-resistant C4-2B and DU-145 cells through upregulation of the HMGCR gene and protein expression (up to 3-folds; p < 0.01) and its transcription factor sterol-regulatory element binding protein 2 (SREBP-2). This feedback was absent in PC3 cells. Blocking the feedback using HMGCR-specific small-interfering (si)RNA, the SREBP-2 activation inhibitor dipyridamole or the HMGCR degrader SR12813 abolished statin resistance in C4-2B and DU-145 and induced significant activation of caspases by statin treatment (up to 10-fold; p < 0.001). Consistently, long-term treatment with sublethal concentrations of simvastatin established a stable statin resistance of a PC3SIM subclone accompanied by a significant upregulation of both baseline as well as post-statin HMGCR protein (gene expression up to 70-fold; p < 0.001). Importantly, the statin-resistant phenotype of PC3SIM cells was reversible by HMGCR-specific siRNA and dipyridamole. Our investigations reveal a key role of a restorative feedback driven by the HMGCR/SREBP-2 axis in statin resistance mechanisms of prostate cancer cells.

High serum levels of leucine-rich α-2 glycoprotein 1 (LRG-1) are associated with poor survival in patients with early breast cancer.

BACKGROUND: Leucine-rich α-2 glycoprotein 1 (LRG-1) is a secreted glycoprotein that is mainly produced in the liver. Elevated levels of LRG-1 are found in a multitude of pathological conditions including eye diseases, diabetes, infections, autoimmune diseases, and cancer. In patients with early breast cancer (BC), high intratumoral LRG-1 protein expression levels are associated with reduced survival. In this study, we assessed serum levels of LRG-1 in patients with early BC and investigated its correlation with the presence of disseminated tumor cells (DTCs) in the bone marrow and survival outcomes. METHODS: Serum LRG-1 levels of 509 BC patients were determined using ELISA and DTCs were assessed by immunocytochemistry using the pan-cytokeratin antibody A45-B/B3. We stratified LRG-1 levels according to selected clinical parameters. Using the log-rank (Mantel-Cox) test and multivariate Cox regression analysis, Kaplan-Meier survival curves and prognostic relevance were assessed. RESULTS: Mean serum levels of LRG-1 were 29.70 ± 8.67 µg/ml. Age was positively correlated with LRG-1 expression (r = 0.19; p < 0.0001) and significantly higher LRG-1 levels were found in patients over 60 years compared to younger ones (30.49 ± 8.63 µg/ml vs. 28.85 ± 8.63 µg/ml; p = 0.011) and in postmenopausal patients compared to premenopausal patients (30.15 ± 8.34 µg/ml vs. 26.936.94 µg/ml; p = 0.002). Patients with no DTCs showed significantly elevated LRG-1 levels compared to the DTC-positive group (30.51 ± 8.69 µg/ml vs. 28.51 ± 8.54 µg/ml; p = 0.004). Overall and BC-specific survival was significantly lower in patients with high serum LRG-1 levels (above a cut-off of 33.63 µg/ml) compared to patients with lower LRG-1 levels during a mean follow-up of 8.5 years (24.8% vs. 11.1% BC-specific death; p = 0.0003; odds ratio 2.63, 95%CI: 1.56-4.36). Multivariate analyses revealed that LRG-1 is an independent prognostic marker for BC-specific survival (p = 0.001; hazard ratio 2.61). CONCLUSIONS: This study highlights the potential of LRG-1 as an independent prognostic biomarker in patients with early BC.

Evaluation of circulating Dickkopf-1 as a prognostic biomarker in ovarian cancer patients.

OBJECTIVES: Dickkopf-1 (DKK1) is a secreted protein, known for suppressing the differentiation and activity of bone-building osteoblasts by acting as an inhibitor of Wnt-signalling. Soluble DKK1 (sDKK1) has been proposed as prognostic biomarker for a wide range of malignancies, however, clinical relevance of sDKK1 as potential blood-based marker for ovarian cancer is unknown. METHODS: sDKK1 levels were quantified in a cohort of 150 clinically documented ovarian cancer patients by a commercially available DKK1 ELISA (Biomedica, Vienna, Austria). RESULTS: Median sDKK1 level was significantly elevated at primary diagnosis of ovarian cancer compared to healthy controls (estimated difference (ED) of 7.75 ng/mL (95% CI: 3.01-12.30 ng/mL, p=0.001)). Higher levels of sDKK1 at diagnosis indicated an increased volume of intraoperative malignant ascites (ED 7.08 pmol/L, 95% CI: 1.46-13.05, p=0.02) and predicted suboptimal debulking surgery (ED 6.88 pmol/L, 95% CI: 1.73-11.87, p=0.01). sDKK1 did not correlate with CA125 and higher sDKK1 levels predicted a higher risk of recurrence and poor survival (PFS: HR=0.507, 95% CI: 0.317-0.809; p=0.004; OS: HR=0.561, 95% CI: 0.320-0.986; p=0.044). Prognostic relevance of sDKK1 was partly sustained in wtBRCA patients (PFS: HR=0.507, 95% CI: 0.317-0.809; p=0.004). CONCLUSIONS: This is the first study demonstrating the prognostic relevance of sDKK1 in ovarian cancer patients, including those with wtBRCA1/2 status. Our data encourage further evaluation of sDKK1 in ovarian cancer patients, possibly in terms of a therapy monitoring marker or a response predictor for sDKK1-directed targeted therapies.

The Role of Inflammation in Breast and Prostate Cancer Metastasis to Bone.

Tumor metastasis to bone is a common event in multiple forms of malignancy. Inflammation holds essential functions in homeostasis as a defense mechanism against infections and is a strategy to repair injured tissue and to adapt to stress conditions. However, exaggerated and/or persistent (chronic) inflammation may eventually become maladaptive and evoke diseases such as autoimmunity, diabetes, inflammatory tissue damage, fibrosis, and cancer. In fact, inflammation is now considered a hallmark of malignancy with prognostic relevance. Emerging studies have revealed a central involvement of inflammation in several steps of the metastatic cascade of bone-homing tumor cells through supporting their survival, migration, invasion, and growth. The mechanisms by which inflammation favors these steps involve activation of epithelial-to-mesenchymal transition (EMT), chemokine-mediated homing of tumor cells, local activation of osteoclastogenesis, and a positive feedback amplification of the protumorigenic inflammation loop between tumor and resident cells. In this review, we summarize established and evolving concepts of inflammation-driven tumorigenesis, with a special focus on bone metastasis.

Dorsomorphin: A novel inhibitor of Dickkopf-1 in breast cancer.

Advanced stages of breast cancer are frequently complicated by bone metastases which cause substantial cancer-related morbidity and mortality. The Wnt-signaling antagonist Dickkopf-1 (DKK-1) has emerged as a crucial factor in the development and progression of osteolytic bone metastases. Although several signaling pathways have been implicated in promoting DKK-1 production in breast cancer cells, pharmacological interventions that interfere with tumor DKK-1 synthesis still remain scarce. In the current study, using an unbiased approach, we identified the small molecule Dorsomorphin as a potent suppressor of DKK-1 in several breast cancer cell lines (MDA-MB-231, MDA-Bone, MDA-MET and MCF7, respectively). Here, Dorsomorphin suppressed DKK-1 mRNA and protein production by 70 and 90%, respectively (p <0.001). Whereas bone morphogenic protein (BMP)- and AMP activated protein kinase (AMPK)-signaling are two well-established targets of Dorsomorphin, we show that neither pathway is essentially involved in facilitating its inhibitory effects on DKK-1. In summary, we identified Dorsomorphin as a potent pharmacological inhibitor of DKK-1 production in breast cancer cells. Whether Dorsomorphin reflects a valuable therapeutic agent in breast cancer warrants further investigations.

High serum levels of periostin are associated with a poor survival in breast cancer.

PURPOSE: Periostin is a secreted extracellular matrix protein, which was originally described in osteoblasts. It supports osteoblastic differentiation and bone formation and has been implicated in the pathogenesis of several human malignancies, including breast cancer. However, little is known about the prognostic value of serum periostin levels in breast cancer. METHODS: In this study, we analyzed serum levels of periostin in a cohort of 509 primary, non-metastatic breast cancer patients. Disseminated tumor cell (DTC) status was determined using bone marrow aspirates obtained from the anterior iliac crests. Periostin levels were stratified according to several clinical parameters and Pearson correlation analyses were performed. Kaplan-Meier survival curves were assessed by using the log-rank (Mantel-Cox) test. To identify prognostic factors, multivariate Cox regression analyses were used. RESULTS: Mean serum levels of periostin were 505 ± 179 pmol/l. In older patients (> 60 years), periostin serum levels were significantly increased compared to younger patients (540 ± 184 pmol/l vs. 469 ± 167 pmol/l; p < 0.0001) and age was positively correlated with periostin expression (p < 0.0001). When stratifying the cohort according to periostin serum concentrations, the overall and breast cancer-specific mortality were significantly higher in those patients with high serum periostin (above median) compared to those with low periostin during a mean follow-up of 8.5 years (17.7% vs. 11.4% breast cancer-specific death; p = 0.03; hazard ratio 1.65). Periostin was confirmed to be an independent prognostic marker for breast cancer-specific survival (p = 0.017; hazard ratio 1.79). No significant differences in serum periostin were observed when stratifying the patients according to their DTC status. CONCLUSIONS: Our findings emphasize the relevance of periostin in breast cancer and reveal serum periostin as a potential marker for disease prediction, independent on the presence of micrometastases.

Anti-tumor effects of mevalonate pathway inhibition in ovarian cancer.

BACKGROUND: Ovarian cancer remains the most fatal gynecological malignancy. Current therapeutic options are limited due to late diagnosis in the majority of the cases, metastatic spread to the peritoneal cavity and the onset of chemo-resistance. Thus, novel therapeutic approaches are required. Statins and amino-bisphosphonates are inhibitors of the mevalonate pathway, which is a fundamental pathway of cellular metabolism, essential for cholesterol production and posttranslational protein farnesylation and geranylgeranylation. While this pathway has emerged as a promising treatment target in several human malignancies, its potential as a therapeutic approach in ovarian cancer is still not fully understood. METHODS: Human ovarian cancer cell lines (IGROV-1, A2780, A2780cis) were treated with increasing concentrations (0.5-100 µM) of statins (simvastatin, atorvastatin, rosuvastatin) and zoledronic acid. Effects on cell vitality and apoptosis were assessed using Cell Titer Blue®, Caspase 3/7 Glo®, clonogenic assays as well as cleaved poly (ADP-ribose) polymerase (cPARP) detection. The inhibition of the mevalonate pathway was confirmed using Western Blot of unprenylated Ras and Rap1a proteins. Quantitative real-time PCR and ELISA were used to analyze modulations on several key regulators of ovarian cancer tumorigenesis. RESULTS: The treatment of IGROV-1 and A2780 cells with statins and zoledronic acid reduced vitality (by up to 80%; p < 0.001) and induced apoptosis by up to 8-folds (p < 0.001) in a dose-dependent fashion. Rescue experiments using farnesyl pyrophosphate or geranylgeranyl pyrophosphate evidenced that blocked geranylgeranylation is the major underlying mechanism of the pro-apoptotic effects. Gene expression of the tumor-promoting cytokines and mediators, such as transforming growth factor (TGF)-ß1, vascular endothelial growth factor (VEGF), interleukin (IL)-8, and IL-6 were significantly suppressed by statins and zoledronic acid by up to 90% (p < 0.001). For all readouts, simvastatin was most potent of all agents used. Cisplatin-resistant A2780cis cells showed a relative resistance to statins and zoledronic acid. However, similar to the effects in A2780 cells, simvastatin and zoledronic acid significantly induced caspase 3/7 activation (6-folds; p < 0.001). CONCLUSION: Our in vitro findings point to promising anti-tumor effects of statins and zoledronic acid in ovarian cancer and warrant additional validation in preclinical and clinical settings.

Concurrent antitumor and bone-protective effects of everolimus in osteotropic breast cancer.

BACKGROUND: The mammalian target of rapamycin inhibitor everolimus is approved as an antitumor agent in advanced estrogen receptor-positive breast cancer. Surrogate bone marker data from clinical trials suggest effects on bone metabolism, but the mode of action of everolimus in bone biology remains unclear. In this study, we assessed potential bone-protective effects of everolimus in the context of osteotropic tumors. METHODS: The effects of everolimus on cancer cell viability in vitro and on tumor growth in vivo were assessed. Everolimus-regulated osteoclastogenesis and osteoblastogenesis were also assessed in vitro before we assessed the bone-protective effect of everolimus in a model where bone loss was induced in ovariectomized (OVX) mice. Finally, the role of everolimus in the progression of osteolytic bone disease was assessed in an intracardiac model of breast cancer bone metastases. RESULTS: At low concentrations (1 nM) in vitro, everolimus reduced the viability of human and murine cancer cell lines and impaired the osteoclastogenesis of osteoclast progenitors as assessed by quantitative real-time polymerase chain reaction and counting tartrate-resistant acid phosphatase-positive, multinucleated osteoclasts (p < 0.001). Everolimus had little or no deleterious effect on osteoblastogenesis in vitro, with concentrations of 1 and 10 nM increasing the messenger RNA expression of osteoblast marker genes (p ≤ 0.05) and leaving mineralization in differentiated human mesenchymal stem cells unchanged. Everolimus treatment (1 mg/kg body weight/day) prevented the bone loss observed in OVX mice and concurrently inhibited the metastatic growth of MDA-MB-231 cells by 70% (p < 0.002) while preserving bone mass in an intracardiac model of bone metastasis. CONCLUSIONS: These results underline the antitumor effects of everolimus and highlight its bone-protective efficacy, warranting further research on the potential implications on bone health in populations prone to osteoporosis and bone metastases, such as postmenopausal women with breast cancer.

Adjuvant tamoxifen but not aromatase inhibitor therapy decreases serum levels of the Wnt inhibitor dickkopf-1 while not affecting sclerostin in breast cancer patients.

PURPOSE: Endocrine therapies, including tamoxifen or aromatase inhibitors, are indispensable for the treatment of patients with estrogen receptor (ER)- and/or progesterone-positive breast cancer. Whereas tamoxifen displays partial ER agonistic effects in bone, aromatase inhibitors increase bone resorption and fracture risk. The Wnt inhibitors dickkopf-1 (DKK-1) and sclerostin negatively impact bone formation and are considered targets for the treatment of bone disorders. However, the effect of endocrine therapies on serum DKK-1 and sclerostin levels in patients with primary breast cancer remains elusive. METHODS: Serum DKK-1 and sclerostin levels were measured at primary diagnosis as well as 3-5 days and 12 months after surgery in a cohort of 45 pre- and postmenopausal women with primary estrogen receptor-positive breast cancer treated with adjuvant tamoxifen or aromatase inhibitors. RESULTS: Mean baseline levels ±SD for DKK-1 and sclerostin were 29.7 ± 14.6 and 27.1 ± 16.2 pmol/l, respectively. A significant negative correlation of DKK-1 levels and age was observed (r = -0.32; p < 0.05), but not for sclerostin. Of note, DKK-1 levels were significantly lower in peri- and postmenopausal women compared to premenopausal patients (-47%; p < 0.05). In tamoxifen-treated patients, DKK-1 levels were reduced by 35% (p < 0.01) one year after surgery but remained unaltered in patients treated with aromatase inhibitors. No significant changes were observed for sclerostin. CONCLUSION: DKK-1 serum levels were reduced in breast cancer patients receiving an adjuvant therapy with tamoxifen, possibly contributing to its bone-protective properties.

P38 regulates the Wnt inhibitor Dickkopf-1 in breast cancer.

Dickkopf-1 (DKK-1) is an inhibitor of canonical Wnt signalling and has been associated with the progression of osteolytic bone metastases by impairing osteoblast activity. In addition, there is growing evidence supporting a direct anti-tumour effect of DKK-1. The p38 mitogen-activated protein kinase (MAPK) regulates intracellular responses that have been linked to cell cycle, apoptosis and tumorigenesis. P38 inhibitors are currently under clinical evaluation for the treatment of malignancies. However, the influence of p38 on DKK-1 in breast cancer remains elusive. In this work, we show that p38 inhibition using SB202190 or LY2228820 potently suppressed DKK-1 expression by MDA-231 and MCF-7 breast cancer cell lines as well melanoma derived MDA-435 cells. Vice versa, activation of p38 signalling by anisomycin induced DKK-1 expression. Immunohistochemical analysis of DKK-1 expression in 97 breast cancer samples revealed that high expression of p38 was associated with a higher expression of DKK-1 compared to tumours with low p38 expression. In conclusion, these results support a role of p38 in the regulation of DKK-1 in osteolytic tumours and warrant further research on the potential of p38 inhibition for the treatment of malignant bone disease.

Potentiated suppression of Dickkopf-1 in breast cancer by combined administration of the mevalonate pathway inhibitors zoledronic acid and statins.

The Wnt-inhibitor dickkopf-1 (DKK-1) promotes cancer-induced osteolytic bone lesions by direct inhibition of osteoblast differentiation and indirect activation of osteoclasts. DKK-1 is highly expressed in human breast cancer cells and can be suppressed by inhibitors of the mevalonate pathway such as statins and amino-bisphosphonates. However, supraphysiological concentrations are required to suppress DKK-1. We show that a sequential mevalonate pathway blockade using statins and amino-bisphosphonates suppresses DKK-1 more significantly than the individual agents alone. Thus, the reduction of the DKK-1 expression and secretion in the human osteotropic tumor cell lines MDA-MB-231, MDA-MET, and MDA-BONE by zoledronic acid was potentiated by the combination with low concentrations of statins (atorvastatin, simvastatin, and rosuvastatin) by up to 75% (p < 0.05). The specific rescue of prenylation using farnesyl pyrophosphate or geranylgeranyl pyrophosphate revealed that these effects were mediated by suppressed geranylgeranylation rather than by suppressed farnesylation. Moreover, combining low concentrations of statins (1 µM atorvastatin or 0.25 µM simvastatin) and zoledronic acid at low concentrations resulted in an at least 50% reversal of breast cancer-derived DKK-1-mediated inhibition of osteogenic markers in C2C12 cells (p < 0.05). Finally, the intratumoral injection of atorvastatin and zoledronic acid in as subcutaneous MDA-MB-231 mouse model reduced the serum level of human DKK-1 by 25% compared to untreated mice. Hence our study reveals that a sequential mevalonate pathway blockade allows for the combined use of low concentration of statins and amino-bisphosphonates. This combination still significantly suppresses breast cancer-derived DKK-1 to levels where it can no longer inhibit Wnt-mediated osteoblast differentiation.

Dickkopf-1 is regulated by the mevalonate pathway in breast cancer.

INTRODUCTION: Amino-bisphosphonates and statins inhibit the mevalonate pathway, and may exert anti-tumor effects. The Wnt inhibitor dickkopf-1 (DKK-1) promotes osteolytic bone lesions by inhibiting osteoblast functions and has been implicated as an adverse marker in multiple cancers. We assessed the effects of mevalonate pathway inhibition on DKK-1 expression in osteotropic breast cancer. METHODS: Regulation of DKK-1 by bisphosphonates and statins was assessed in human breast cancer cell lines, and the role of the mevalonate pathway and downstream targets was analyzed. Moreover, the potential of breast cancer cells to modulate osteoblastogenesis via DKK-1 was studied in mC2C12 cells. Clinical relevance was validated by analyzing DKK-1 expression in the tissue and serum of women with breast cancer exposed to bisphosphonates. RESULTS: DKK-1 was highly expressed in receptor-negative breast cancer cell lines. Patients with receptor-negative tumors displayed elevated levels of DKK-1 at the tissue and serum level compared to healthy controls. Zoledronic acid and atorvastatin potently suppressed DKK-1 in vitro by inhibiting geranylgeranylation of CDC42 and Rho. Regulation of DKK-1 was strongest in osteolytic breast cancer cell lines with abundant DKK-1 expression. Suppression of DKK-1 inhibited the ability of breast cancer cells to block WNT3A-induced production of alkaline phosphates and bone-protective osteoprotegerin in preosteoblastic C2C12 cells. In line with the in vitro data, treatment of breast cancer patients with zoledronic acid decreased DKK-1 levels by a mean of 60% after 12 months of treatment. CONCLUSION: DKK-1 is a novel target of the mevalonate pathway that is suppressed by zoledronic acid and atorvastatin in breast cancer.

High serum levels of Dickkopf-1 are associated with a poor prognosis in prostate cancer patients.

BACKGROUND: The Wnt inhibitor Dickkopf-1 (DKK-1) has been linked to the progression of malignant bone disease by impairing osteoblast activity. In addition, there is increasing data to suggest direct tumor promoting effects of DKK-1. The prognostic role of DKK-1 expression in prostate cancer remains unclear. METHODS: A prostate cancer tissue microarray (n = 400) was stained for DKK-1 and DKK-1 serum levels were measured in 80 patients with prostate cancer. The independent prognostic value of DKK-1 expression was assessed using multivariate analyses. RESULTS: DKK-1 tissue expression was significantly increased in prostate cancer compared to benign disease, but was not correlated with survival. However, high DKK-1 serum levels at the time of the diagnosis were associated with a significantly shorter overall and disease-specific survival. Multivariate analyses defined high serum levels of DKK-1 as an independent prognostic marker in prostate cancer (HR 3.73; 95%CI 1.44-9.66, p = 0.007). CONCLUSION: High DKK-1 serum levels are associated with a poor survival in patients with prostate cancer. In light of current clinical trials evaluating the efficacy of anti-DKK-1 antibody therapies in multiple myeloma and solid malignancies, the measurement of DKK-1 in prostate cancer may gain clinical relevance.

Endocrine health in survivors of adult-onset cancer.

Long-term survivors of cancer (ie, the patient who is considered cured or for whom the disease is under long-term control and unlikely to recur) are at an increased risk of developing endocrine complications such as hypothalamic-pituitary dysfunctions, hypogonadisms, osteoporosis, or metabolic disorders, particularly when intensive tumour-directed therapies are applied. Symptom severity associated with these conditions ranges from mild and subclinical to highly detrimental, affecting individual health and quality of life. Although they are usually manageable, many of these endocrine pathologies remain underdiagnosed and untreated for years. To address this challenge, a higher degree of awareness, standardised screening tools, comprehensible treatment algorithms, and a close collaborative effort between endocrinologists and oncologists are essential to early identify patients who are at risk, and to implement appropriate treatment protocols. This Review highlights common symptoms and conditions related to endocrine disorders among survivors of adult-onset cancer, provides a summary of the currently available practice guidelines, and proposes a practical approach to diagnose affected patients among this group.

The social status of the male Nile tilapia (Oreochromis niloticus) influences testis structure and gene expression.

Dominant and territorial behaviour are known social phenomena in cichlids and social stress influences reproduction and growth. The gonadotropic hormones trigger spermatogenesis and subordinate males have typically lower levels of gonadotropins than dominant males. In this study, we compared testis morphology and gene expression of dominant and subordinate Nile tilapia males (d- and s-males) in socially stable communities. The d-males had the highest gonadosomatic index but they were not the largest animals in the majority of studied cases. Long-term d-males showed large groups of Leydig cells and hyperplasia of the tunica albuginea due to numerous cytochrome-P450-11ß-hydroxylase (Cyp11b) expressing myoid cells. Increased Cyp11b expression in d-males was reflected by elevated 11-ketotestosterone plasma values. However, immunofluorescence microscopy and expression analysis of selected genes revealed that most s-males conserved their capability for spermatogenesis and are, therefore, ready for reproduction when the social environment changes. Moreover, in s-males gene expression analysis by quantitative RT-PCR showed increased transcript levels for germ line-specific genes (vasa, sox2 and dmc1) and Sertoli-specific genes (amh, amhrII and dmrt1) whereas gene expression of key factors for steroid production (sf1 and cyp11b) were reduced. The Nile tilapia is a promising model to study social cues and gonadotropic signals on testis development in vertebrates.

Bone Metastases: From Mechanisms to Treatment.

OBJECTIVES: Bone metastases are of high clinical relevance because they are a frequent complication of most types of common cancers, such as breast and prostate. The metastatic process is complex, requiring the completion of several different steps to allow successful dissemination and homing. In addition, preparation of the metastatic niche changes the constant cycle of bone matrix formation and degradation, leading to the clinical phenotypes of lytic and sclerotic lesions. We review our current knowledge on this topic and briefly explain the current treatment landscape of bone metastasis. DATA SOURCES: These include PubMed, international guidelines, and clinician experience. CONCLUSION: Bone metastases remain a clinical challenge that negatively impacts patients prognosis and quality of life. A comprehensive understanding of the complex molecular mechanisms that results in bone metastasis is the basis for successful treatment of affected patients. The disruption of bone matrix metabolism is already recognized as the prerequisite for metastasis formation, but many open questions remain that need to be addressed in future research to establish individually tailored treatment approaches. IMPLICATIONS FOR NURSING PRACTICE: Patient-centered therapy of bone metastases requires suitable pharmacological options, and importantly a holistic approach in care delivery across the multidisciplinary team. Nurses provide the cornerstone of the multidisciplinary team and provide the closest and the most frequent contact to the patient and their families to provide timely intervention. Nurses require a basic understanding of the complex physiology of metastasis to inform practice.

The mevalonate pathway in breast cancer biology.

Breast cancer affects one in eight women during their lifetime. Although diagnostic and therapeutic options have improved, recurrence, metastasis, and therapeutic resistance remain clinical challenges, which affect life quality and prognosis. The mevalonate pathway is an essential part of cellular homeostasis by providing a number of essential isoprenoid products including cholesterol. However, the disturbance of this pathway paralleled by increased bioavailability of its products and their direct involvement in several steps of tumorigenesis has highlighted the mevalonate pathway as a promising hub in cancer treatment. In this review, we will specifically discuss how the mevalonate pathway affects breast cancer biology in terms of supporting and modulating soluble and cellular factors and distinct steps of tumorigenesis. We will further summarize antitumor effects of the mevalonate pathway-inhibiting drugs, statins and amino-bisphosphonates, in breast cancer and discuss how they are used for future precision therapy.

Clinical impact of soluble Neuropilin-1 in ovarian cancer patients and its association with its circulating ligands of the HGF/c-MET axis.

Background: Neuropilin (NRP) is a transmembrane protein, which has been shown to be a pro-angiogenic mediator and implicated as a potential driver of cancer progression. NRP-1 up-regulation in ovarian cancer tissue predicts poor prognosis. However, the clinical relevance of the soluble form of NRP-1 (sNRP-1) as a circulating biomarker in ovarian cancer patients is unknown. Methods/patients cohort: sNRP-1 levels were quantified in a cohort of 88 clinically documented ovarian cancer patients by a commercially available sNRP-1 enzyme-linked immunosorbent assay (ELISA) kit (Biomedica, Vienna, Austria). Patients (81.8% with FIGOIII/IV) received primary cytoreductive surgery with the aim of macroscopic complete resection (achieved in 55.7% of patients) and the recommendation of adjuvant chemotherapy in line with national guidelines. Results: Higher levels of sNRP-1 reflected more advanced disease (FIGO III/IV) and indicated a trend towards suboptimal surgical outcome, i.e. any residual tumor. sNRP-1 was neither related to the patients' age nor the BRCA1/2 mutational status. Patients with higher sNRP-1 levels at primary diagnosis had a significantly reduced progression-free survival (PFS) (HR = 0.541, 95%CI: 0.304 - 0.963; p = 0.037) and overall survival (OS) (HR = 0.459, 95%CI: 0.225 - 0.936; p = 0.032). Principal component analysis showed that sNRP-1 levels were unrelated to the circulating hepatocyte growth factor (HGF) and the soluble ectodomain of its receptor the tyrosine kinase mesenchymal-epithelial transition (c-MET), suggesting that there is no proportional serological concentration gradient of soluble components of the NRP-1/HGF/c-MET signaling axis. Conclusions: In line with the previously shown tissue-based prognostic role, we demonstrated for the first time that sNRP-1 can also act as a readily accessible, prognostic biomarker in the circulation of patients with ovarian cancer at primary diagnosis. Given its known role in angiogenesis and conferring resistance to the poly ADP-ribose polymerase (PARP) inhibitor olaparib in vitro, our results encourage more detailed investigation into sNRP-1 as a potential predictive biomarker for bevacizumab and/or PARP-inhibitor treatment.

Decoding Single Cell Morphology in Osteotropic Breast Cancer Cells for Dissecting Their Migratory, Molecular and Biophysical Heterogeneity.

Breast cancer is a heterogeneous disease and the mechanistic framework for differential osteotropism among intrinsic breast cancer subtypes is unknown. Hypothesizing that cell morphology could be an integrated readout for the functional state of a cancer cell, we established a catalogue of the migratory, molecular and biophysical traits of MDA-MB-231 breast cancer cells, compared it with two enhanced bone-seeking derivative cell lines and integrated these findings with single cell morphology profiles. Such knowledge could be essential for predicting metastatic capacities in breast cancer. High-resolution microscopy revealed a heterogeneous and specific spectrum of single cell morphologies in bone-seeking cells, which correlated with differential migration and stiffness. While parental MDA-MB-231 cells showed long and dynamic membrane protrusions and were enriched in motile cells with continuous and mesenchymal cell migration, bone-seeking cells appeared with discontinuous mesenchymal or amoeboid-like migration. Although non-responsive to CXCL12, bone-seeking cells responded to epidermal growth factor with a morphotype shift and differential expression of genes controlling cell shape and directional migration. Hence, single cell morphology encodes the molecular, migratory and biophysical architecture of breast cancer cells and is specifically altered among osteotropic phenotypes. Quantitative morpho-profiling could aid in dissecting breast cancer heterogeneity and in refining clinically relevant intrinsic breast cancer subtypes.