Does Testosterone Therapy Increase the Risk of Prostate Cancer?

ObjectiveTo review factors affecting use of testosterone therapy for hypogonadism including the persistent controversial link between testosterone therapy and prostate cancer.MethodsWe reviewed studies investigating the relationship between testosterone therapy and prostate cancer progression and summarized strategies for hypogonadism management and prostate monitoring.ResultsTrials of up to 36 months in length and longitudinal studies consistently fail to demonstrate an increased prostate cancer risk associated with increased testosterone levels. No evidence of an associated relationship between exogenous testosterone therapy and prostate cancer has emerged from clinical trials or adverse event reports. It does not appear that exogenous testosterone accumulates in the prostate or provokes major biologic change in the prostate gland. In addition, preliminary evidence indicates that low endogenous testosterone may confer an increased risk of prostate cancer.ConclusionsMounting evidence demonstrates that there is a lack of association between testosterone therapy and prostate cancer progression. Testosterone therapy may be prescribed for men for whom it was once not considered. Careful monitoring of patients with hypogonadism who are receiving testosterone therapy is imperative. Well-designed, large-scale prospective clinical trials are necessary to adequately address prostate safety in hypogonadal men receiving testosterone therapy. (Endocr Pract. 2008;14:904-911)     

Andropause or Male Menopause? Rationale for Testosterone Replacement Therapy in Older Men with Low Testosterone Levels

ObjectiveTo provide rationale for testosterone replacement therapy (TRT) in older men with low testosterone levels and symptoms consistent with testosterone deficiency.MethodsThe relevant literature was reviewed using PubMedResultsCross-sectional and longitudinal population-based studies indicate that total and free testosterone levels fall with aging, and they may be accompanied by symptoms consistent with androgen deficiency. Testosterone treatment of younger men with very low testosterone levels and hypothalamic, pituitary, or testicular disease is associated with improvements in symptoms, body composition, bone density, and hematocrit/hemoglobin. Studies evaluating testosterone treatment of older men with low testosterone levels are limited, but they suggest some increase in fat free mass, some decrease in fat mass, and some increase in bone density of the lumbar spine and femoral neck.ConclusionThe Testosterone Trial should provide definitive information regarding the potential benefits of TRT in men ≥ years of age. If efficacy is confirmed, we will still need more information regarding the risks of TRT in older men. (Endocr Pract. 2013;19:847-852)     

Bisphosphonates in the Adjuvant Setting of Breast Cancer Therapy—Effect on Survival: A Systematic Review and Meta-Analysis

Background

The role of bisphosphonates (BP) in early breast cancer (BC) has been considered controversial. We performed a meta-analysis of all randomized controlled trials (RCTs) that appraised the effects of BP on survival in early BC.

Methods

RCTs were identified by searching the Cochrane Library, MEDLINE databases and conference proceedings. Hazard ratios (HRs) of overall survival (OS), disease-free survival (DFS) and relative risks of adverse events were estimated and pooled.

Results

Thirteen trials met the inclusion criteria, evaluating a total of 15,762 patients. Meta-analysis of ten trials which reported OS revealed no statistically significant benefit in OS for BP (HR 0.89, 95% CI = 0.79 to 1.01). Meta-analysis of nine trials which reported the DFS revealed no benefit in DFS (HR 0.95 (0.81–1.12)). Meta-analysis upon menopausal status showed a statistically significant better DFS in the BP-treated patients (HR 0.81(0.69–0.95)). In meta-regression, chemotherapy was negatively associated with HR of survival.

Conclusions

Our meta-analysis indicates a positive effect for adjuvant BP on survival only in postmenopausal patients. Meta-regression demonstrated a negative association between chemotherapy use BP effect on survival. Further large scale RCTs are warranted to unravel the specific subgroups that would benefit from the addition of BP in the adjuvant setting.     

Italian Association of Clinical Endocrinologists Statement–Replacement Therapy for Primary Hypothyroidism: A Brief Guide for Clinical Practice

Objective: Hypothyroidism requires life-long thyroid hormone replacement therapy in most patients. Oral levothyroxine (LT4) is an established safe and effective treatment for hypothyroidism, but some issues remain unsettled.Methods: The Italian Association of Clinical Endocrinologists appointed a panel of experts to provide an updated statement for appropriate use of thyroid hormone formulations for hypothyroidism replacement therapy. The American Association of Clinical Endocrinologists' protocol for standardized production of clinical practice guidelines was followed.Results: LT4 is the first choice in replacement therapy. Thyroid-stimulating hormone (TSH) should be maintained between 1.0 and 3.0 mIU/L in young subjects and at the upper normal limit in elderly or fragile patients. Achievement of biochemical targets, patient well-being, and adherence to treatment should be addressed. In patients with unstable serum TSH, a search for interfering factors and patient compliance is warranted. Liquid or gel formulations may be considered in subjects with hampered LT4 absorption or who do not allow sufficient time before or after meals and LT4 replacement. Replacement therapy with LT4 and L-triiodothyronine (LT3) combination is generally not recommended. A trial may be considered in patients with normal values of serum TSH who continue to complain of symptoms of hypothyroidism only after co-existent nonthyroid problems have been excluded or optimally managed. LT3 should be administered in small (LT4:LT3 ratio, 10:1 to 20:1) divided daily doses. Combined therapy should be avoided in elderly patients or those with cardiac risk factors and in pregnancy.Conclusion: LT4 therapy should be aimed at resolution of symptoms of hypothyroidism, normalization of serum TSH, and improvement of quality of life. In selected cases, the use of liquid LT4 formulations or combined LT4/LT3 treatment may be considered to improve adherence to treatment or patient well-being.Abbreviations:AACE = American Association of Clinical EndocrinologistsFT3 = free triiodothyronineFT4 = free thyroxineLT3 = levotriiodothyronineLT4 = levothyroxineMeSH = medicine medical subject headingsQoL = quality of lifeTSH = thyroid-stimulating hormone     

A Hybrid Model of Tumor–Stromal Interactions in Breast Cancer

Ductal carcinoma in situ (DCIS) is an early stage noninvasive breast cancer that originates in the epithelial lining of the milk ducts, but it can evolve into comedo DCIS and ultimately, into the most common type of breast cancer, invasive ductal carcinoma. Understanding the progression and how to effectively intervene in it presents a major scientific challenge. The extracellular matrix (ECM) surrounding a duct contains several types of cells and several types of growth factors that are known to individually affect tumor growth, but at present the complex biochemical and mechanical interactions of these stromal cells and growth factors with tumor cells is poorly understood. Here we develop a mathematical model that incorporates the cross-talk between stromal and tumor cells, which can predict how perturbations of the local biochemical and mechanical state influence tumor evolution. We focus on the EGF and TGF-β signaling pathways and show how up- or down-regulation of components in these pathways affects cell growth and proliferation. We then study a hybrid model for the interaction of cells with the tumor microenvironment (TME), in which epithelial cells (ECs) are modeled individually while the ECM is treated as a continuum, and show how these interactions affect the early development of tumors. Finally, we incorporate breakdown of the epithelium into the model and predict the early stages of tumor invasion into the stroma. Our results shed light on the interactions between growth factors, mechanical properties of the ECM, and feedback signaling loops between stromal and tumor cells, and suggest how epigenetic changes in transformed cells affect tumor progression.     

Modulation of Myoepithelial-Associated α6β4 Integrin in a Breast Cancer Cell Line Alters Invasive Potential

In normal breast, cell–stromal contact is mediated by myoepithelial cells which strongly express α2β1, α3β1, and α6β4 integrins, while epithelial cells exhibit α2β1 and α3β1 integrins at cell–cell borders, but do not express α6β4 integrin. Breast carcinomas consistently show down-regulation of all integrins. We have investigated the modulatory effect of stromal proteins, hormones, and transforming growth factor β (TGF-β) on integrin expression in breast cancer cell lines MCF-7, T47-D, and MDA-MB 231 using indirect immunofluorescence and confocal laser scanning microscopy. MCF-7 and T47-D cells displayed low levels of both α2β1 and α3β1 integrins, and no α6β4 integrin, and this profile remained unchanged by modulatory agents. The MDA-MB 231 cells exhibited stronger staining for α2β1 and α3β1 integrins and focal staining for α6β4 integrin under control conditions, but markedly enhanced reactivity for the α6β4 complex in the presence of TGF-β. This was associated with acquisition of a spread cellular morphology and localization of α6β4 at the cell periphery in a discrete punctate distribution. There was associated enhanced expression of epiligrin, the ligand for α6β4, with similar localization to the cell periphery. Cell invasion assays through a Matrigel barrier revealed significantly reduced invasive potential of TGF-β-treated cells, an effect largely reversed following preincubation of the treated cells with anti-β4 integrin antibody. We conclude that α6β4 integrin can be up-regulated by TGF-β and has an anti-invasive effect on MDA-MB 231 cells. In addition to α6β4, MDA-MB 231 cells exhibit other myoepithelial markers including cytokeratin 14, vimentin, and weak expression of CALLA. These findings support the concept of a subgroup of breast carcinomas displaying features of myoepithelial differentiation.     

Chemical–Physical Changes in Cell Membrane Microdomains of Breast Cancer Cells After Omega-3 PUFA Incorporation

Epidemiologic and experimental studies suggest that dietary fatty acids influence the development and progression of breast cancer. However, no clear data are present in literature that could demonstrate how n?-?3 PUFA can interfere with breast cancer growth. It is suggested that these fatty acids might change the structure of cell membrane, especially of lipid rafts. During this study we treated MCF-7 and MDA-MB-231 cells with AA, EPA, and DHA to assess if they are incorporated in lipid raft phospholipids and are able to change chemical and physical properties of these structures. Our data demonstrate that PUFA and their metabolites are inserted with different yield in cell membrane microdomains and are able to alter fatty acid composition without decreasing the total percentage of saturated fatty acids that characterize these structures. In particular in MDA-MB-231 cells, that displays the highest content of Chol and saturated fatty acids, we observed the lowest incorporation of DHA, probably for sterical reasons; nevertheless DHA was able to decrease Chol and SM content. Moreover, PUFA are incorporated in breast cancer lipid rafts with different specificity for the phospholipid moiety, in particular PUFA are incorporated in PI, PS, and PC phospholipids that may be relevant to the formation of PUFA metabolites (prostaglandins, prostacyclins, leukotrienes, resolvines, and protectines) of phospholipids deriving second messengers and signal transduction activation. The bio-physical changes after n?-?3 PUFA incubation have also been highlighted by atomic force microscopy. In particular, for both cell lines the DHA treatment produced a decrease of the lipid rafts in the order of about 20-30?%. It is worth noticing that after DHA incorporation lipid rafts exhibit two different height ranges. In fact, some lipid rafts have a higher height of 6-6.5?nm. In conclusion n?-?3 PUFA are able to modify lipid raft biochemical and biophysical features leading to decrease of breast cancer cell proliferation probably through different mechanisms related to acyl chain length and unsaturation. While EPA may contribute to cell apoptosis mainly through decrease of AA concentration in lipid raft phospholipids, DHA may change the biophysical properties of lipid rafts decreasing the content of cholesterol and probably the distribution of key proteins.     

Clinical Implications of TβRII Expression in Breast Cancer

Objective

To explore the relationship between TβRII [type II TGFβ (transforming growth factor β) receptor] expression and clinicopathological characteristics, and to evaluate the prognostic significance of TβRII expression in breast cancer.

Methods

Clinicopathological data and prognostic information of 108 patients with histologically confirmed breast cancer who were surgically treated at China Medical University between January 2007 and September 2008 were reviewed and the association between the clinicopathological characteristics and TβRII expression was analyzed by chi-square test and multivariate analysis. The expression of TβRII was assessed by immunohistochemistry.

Results

Of the 108 patients, 60 cases were TβRII positive and 48 cases were negative. There was no significant association between TβRII expression of the patients older than 40 years and that of the younger than 40 years (56.0% vs 50.0%; P = 0.742). The TβRII expression rate was significantly increased in patients with lymph node metastasis compared to those without lymph node metastasis (67.40% vs 46.8%; P = 0.033). Statistically significant relationships were found between increasing tumor clinical stage and high TβRII expression (P = 0.011). TβRII expression was not associated with the expression of ER(estrogen receptor)、PR, (progesterone receptor)、Her-2 (human epidermal growth factor receptor 2) (P = 0.925,P = 0.861, and P = 0.840, respectively). Patients with high TβRII expression showed poorer 5-year disease-free survival (DFS) compared to those with low expression (66.7% vs 45.6%; P = 0.028) by univariate analysis. Survival analysis demonstrated that TβRII was associated with poor DFS (P = 0.011). Subgroup analysis revealed that TβRII expression was associated with shorter DFS in patients with lymph node metastasis, ER-positive, PR-positive or Her-2-negative tumors (P = 0.006, P = 0.016, P = 0.022, and P = 0.033, respectively). Cox regression analysis revealed that high TβRII expression was related to poor 5-year DFS, and it was an independent factor for predicting the poor outcome for breast cancer patients (P = 0.016).

Conclusions

High levels of TβRII expression were associated with lymph node metastasis, increasing tumor clinical stage, and poorer 5-year DFS in patients with breast cancer. TβRII may be a potential prognostic marker for breast cancer.     

Doxorubicin in Combination with a Small TGFβ Inhibitor: A Potential Novel Therapy for Metastatic Breast Cancer in Mouse Models

Background

Recent studies suggested that induction of epithelial-mesenchymal transition (EMT) might confer both metastatic and self-renewal properties to breast tumor cells resulting in drug resistance and tumor recurrence. TGFβ is a potent inducer of EMT and has been shown to promote tumor progression in various breast cancer cell and animal models.

Principal Findings

We report that chemotherapeutic drug doxorubicin activates TGFβ signaling in human and murine breast cancer cells. Doxorubicin induced EMT, promoted invasion and enhanced generation of cells with stem cell phenotype in murine 4T1 breast cancer cells in vitro, which were significantly inhibited by a TGFβ type I receptor kinase inhibitor (TβRI-KI). We investigated the potential synergistic anti-tumor activity of TβR1-KI in combination with doxorubicin in animal models of metastatic breast cancer. Combination of Doxorubicin and TβRI-KI enhanced the efficacy of doxorubicin in reducing tumor growth and lung metastasis in the 4T1 orthotopic xenograft model in comparison to single treatments. Doxorubicin treatment alone enhanced metastasis to lung in the human breast cancer MDA-MB-231 orthotopic xenograft model and metastasis to bone in the 4T1 orthotopic xenograft model, which was significantly blocked when TβR1-KI was administered in combination with doxorubicin.

Conclusions

These observations suggest that the adverse activation of TGFβ pathway by chemotherapeutics in the cancer cells together with elevated TGFβ levels in tumor microenvironment may lead to EMT and generation of cancer stem cells resulting in the resistance to the chemotherapy. Our results indicate that the combination treatment of doxorubicin with a TGFβ inhibitor has the potential to reduce the dose and consequently the toxic side-effects of doxorubicin, and improve its efficacy in the inhibition of breast cancer growth and metastasis.     

Development and Validation of Nomograms for Predicting Overall and Breast Cancer–Specific Survival in Young Women with Breast Cancer: A Population-Based Study

INTRODUCTION: The objective of current study was to develop and validate comprehensive nomograms for predicting the survival of young women with breast cancer. METHODS: Women aged <40 years diagnosed with invasive breast cancer between 1990 and 2010 were selected from the Surveillance, Epidemiology, and End Results database and randomly divided into training (n = 12,465) and validation (n = 12,424) cohorts. A competing-risks model was used to estimate the probability of breast cancer–specific survival (BCSS). We identified and integrated significant prognostic factors for overall survival (OS) and BCSS to construct nomograms. The performance of the nomograms was assessed with respect to calibration, discrimination, and risk group stratification. RESULTS: The entire cohort comprised 24,889 patients. The 5- and 10-year probabilities of breast cancer–specific mortality were 11.6% and 20.5%, respectively. Eight independent prognostic factors for both OS and BCSS were identified and integrated for the construction of the nomograms. The calibration curves showed optimal agreement between the predicted and observed probabilities. The C-indexes of the nomograms in the training cohort were higher than those of the TNM staging system for predicting OS (0.724 vs 0.694; P < .001) and BCSS (0.733 vs 0.702; P < .001). Additionally, significant differences in survival were observed in patients stratified into different risk groups within respective TNM categories. CONCLUSIONS: We developed and validated novel nomograms that can accurately predict OS and BCSS in young women with breast cancer. These nomograms may help clinicians in making decisions on an individualized basis.     

Nanoemulsions in Translational Research—Opportunities and Challenges in Targeted Cancer Therapy

Nanoemulsion dosage form serves as a vehicle for the delivery of active pharmaceutical ingredients and has attracted great attention in drug delivery and pharmacotherapy. In particular, nanoemulsions act as an excellent vehicle for poorly aqueous soluble drugs, which are otherwise difficult to formulate in conventional dosage forms. Nanoemulsions are submicron emulsions composed of generally regarded as safe grade excipients. Particle size at the nanoscale and larger surface area lead to some very interesting physical properties that can be exploited to overcome anatomical and physiological barriers associated in drug delivery to the complex diseases such as cancer. Along these lines, nanoemulsions have been engineered with specific attributes such as size, surface charge, prolonged blood circulation, target specific binding ability, and imaging capability. These attributes can be tuned to assist in delivering drug/imaging agents to the specific site of interest, based on active and passive targeting mechanisms. This review focuses on the current state of nanoemulsions in the translational research and its role in targeted cancer therapy. In addition, the production, physico-chemical characterization, and regulatory aspects of nanoemulsion are addressed.     

Rapid Immunochromatographic Detection of Serum Anti-α-Galactosidase A Antibodies in Fabry Patients after Enzyme Replacement Therapy

We developed an immunochromatography-based assay for detecting antibodies against recombinant α-galactosidase A proteins in serum. The evaluation of 29 serum samples from Fabry patients, who had received enzyme replacement therapy with agalsidase alpha and/or agalsidase beta, was performed by means of this assay method, and the results clearly revealed that the patients exhibited the same level of antibodies against both agalsidase alpha and agalsidase beta, regardless of the species of recombinant α-galactosidase A used for enzyme replacement therapy. A conventional enzyme-linked immunosorbent assay supported the results. Considering these, enzyme replacement therapy with agalsidase alpha or agalsidase beta would generate antibodies against the common epitopes in both agalsidase alpha and agalsidase beta. Most of the patients who showed immunopositive reaction exhibited classic Fabry phenotype and harbored gene mutations affecting biosynthesis of α-galactosidase A. As immunochromatography is a handy and simple assay system which can be available at bedside, this assay method would be extremely useful for quick evaluation or first screening of serum antibodies against agalsidase alpha or agalsidase beta in Fabry disease with enzyme replacement therapy.     

Socioeconomic Disparity in Breast Cancer Detection in Hong Kong – A High Income City: Retrospective Epidemiological Study Using the Breast Cancer Registry

Background

It is not known whether socioeconomic disparities affect the detection of breast cancer in Asian countries where the incidence of breast cancer is a rising trend. In this study, we explore the socioeconomic profiles of women and the stage of the disease at the time of diagnosis in breast cancer patients aged 40 or over in Hong Kong.

Method

During the period 2008 to 2011, 5393 breast cancer patients registered with the Hong Kong Breast Cancer Registry. Participants and their clinicians were asked to complete standardised questionnaires including patient socio-demographics, health history and risk factors, the course of the disease, post-treatment physical discomfort and psychosocial impact, follow-up recurrence and survival status.

Results

Monthly household incomes, educational levels and the practice of regular screening are independently associated with the stage of the disease at diagnosis. Higher socioeconomic status and a higher educational level were associated with an earlier stage of the disease at the time of diagnosis. Yearly clinical examinations, ultrasound and mammographic screening every 2 to 3 years were significantly associated with the earlier detection of breast cancer.

Conclusion

There were socioeconomic disparities among Hong Kong women who were found to have breast cancer. Population-based screening policies, including raising awareness among women at risk, should be implemented.     

Curcumin Prevents Palmitoylation of Integrin β4 in Breast Cancer Cells

Curcumin has been shown to mitigate cancer phenotypes such as invasive migration, proliferation, and survival by disrupting numerous signaling pathways. Our previous studies showed that curcumin inhibits integrin β4 (ITG β4)-dependent migration by blocking interaction of this integrin with growth factor receptors in lipid rafts. In the current study, we investigated the possibility that curcumin inhibits ITG β4 palmitoylation, a post-translational modification required for its lipid raft localization and signaling activity. We found that the levels of ITG β4 palmitoylation correlated with the invasive potential of breast cancer cells, and that curcumin effectively reduced the levels of ITG β4 palmitoylation in invasive breast cancer cells. Through studies of ITG β4 palmitoylation kinetics, we concluded curcumin suppressed palmitoylation independent of growth factor-induced phosphorylation of key ITG β4 Ser and Tyr residues. Rather, curcumin blocked autoacylation of the palmitoyl acyltransferase DHHC3 that is responsible for ITG β4 palmitoylation. Moreover, these data reveal that curcumin is able to prevent the palmitoylation of a subset of proteins, but not indiscriminately bind to and block all cysteines from modifications. Our studies reveal a novel paradigm for curcumin to account for much of its biological activity, and specifically, how it is able to suppress the signaling function of ITG β4 in breast cancer cells.     

γ-Secretase-Dependent Cleavage of E-Cadherin by Staurosporine in Breast Cancer Cells

E-cadherin is a transmembrane protein that serves as a cell adhesion molecule component of the adherens junction. We previously showed that cadmium induced γ-secretase-dependent E-cadherin cleavage via oxidative stress. In this study, we report that staurosporine (STS)-induced apoptosis induces caspase-2 and/or -8-dependent E-cadherin cleavage. STS increased γ-secretase-dependent cleavage of E-cadherin in breast cancer cells through caspase activation. The ability of the γ-secretase inhibitor DAPT and the caspase inhibitor zVAD-FMK to block E-cadherin cleavage provided support for these results. The cleavage of E-cadherin was blocked by caspase-2 and -8 inhibitors. Immunofluorescence analysis confirmed that, along with the disappearance of E-cadherin staining at the cell surface, the E-cadherin cytoplasmic domain accumulated in the cytosol. In the presence of an inhibitor of γ-secretase or caspase, the cleavage of E-cadherin was partially blocked. Our findings suggest that activation of caspase-2/-8 stimulated the disruption of cadherin-mediated cell–cell contacts in apoptotic cells via γ-secretase activation.