Cytotoxic effects of aptamer-doxorubicin conjugates in an ovarian cancer cell line.

Despite medical advances in treatment strategies over the past 30-years, epithelial ovarian cancer (EOC) continues to be defined by poor patient survival rates and aggressive, drug resistant relapse. Traditional approaches to cancer chemotherapy are typically limited by severe off-target effects on healthy tissue and aggressive drug-resistant recurrence. Recent shifts towards targeted therapies offer the possibility of circumventing the obstacles experienced by these treatments. While antibodies are the pioneering agents in such targeted therapies, several intrinsic characteristics of antibodies limits their clinical translation and efficacy. In contrast, oligonucleotide chemical antibodies, known as aptamers, are ideal for this application given their small size and lack of immunogenicity. This study explored the efficacy of a DNA aptamer, designed to target a well-established cancer biomarker, EpCAM, to deliver a chemotherapeutic drug. The results from this study support evidence that EpCAM aptamers can bind to epithelial ovarian cancer; and offers a valid alternative as a targeting ligand with tuneable specificity and sensitivity. It also supports the growing body of evidence that aptamers show great potential for application-specific, post-SELEX engineering through rational modifications. Through in vitro assays, these aptamers demonstrated cytotoxicity in both monolayer and tumoursphere assays, as well as in tumourigenic enriching assays. Further experimentation based on the results achieved in this project might aid in the development of novel cancer therapeutics and guide the novel designs of drugs for targeted drug delivery.

ADAMTS-15 Has a Tumor Suppressor Role in Prostate Cancer.

Extracellular matrix remodeling has emerged as an important factor in many cancers. Proteoglycans, including versican (VCAN), are regulated via cleavage by the proteolytic actions of A Disintegrin-like And Metalloproteinase domain with Thrombospondin-1 motif (ADAMTS) family members. Alterations in the balance between Proteoglycans and ADAMTS enzymes have been proposed to contribute to cancer progression. Here, we analyzed the expression of ADAMTS-15 in human prostate cancer, and investigated the effects of enforced expression in prostate cancer cell lines. ADAMTS-15 was found to be expressed in human prostate cancer biopsies with evidence of co-localization with VCAN and its bioactive cleavage fragment versikine. Enforced expression of ADAMTS-15, but not a catalytically-inactive version, decreased cell proliferation and migration of the 'castrate-resistant' PC3 prostate cancer cell line in vitro, with survival increased. Analysis of 'androgen-responsive' LNCaP prostate cancer cells in vivo in NOD/SCID mice revealed that ADAMTS-15 expression caused slower growing tumors, which resulted in increased survival. This was not observed in castrated mice or with cells expressing catalytically-inactive ADAMTS-15. Collectively, this research identifies the enzymatic function of ADAMTS-15 as having a tumor suppressor role in prostate cancer, possibly in concert with androgens, and that VCAN represents a likely key substrate, highlighting potential new options for the clinic.

Defining a new model of interdisciplinary cancer cachexia care in regional Victoria, Australia.

PURPOSE: Cachexia is a wasting condition affecting approximately 50% of cancer patients, associated with decreased quality of life and survival. Barwon Health's Cachexia and Nutrition Support Service provides person-centred interdisciplinary care to assist the management of cachexia symptoms. This study describes a novel and effective service model established in a regional cachexia clinic and the patient population it serves. METHODS: A descriptive, retrospective longitudinal study was conducted of records from patients attending Barwon Health between 2008 and 2013 (n = 175), alongside the description of service refinement over this time. Patients with ≥ 2 attendance dates were assessed for anthropometric measures, follow-up intervals, and muscle function outcomes to describe patient trajectory during clinic involvement. RESULTS: This is the first detailed description of a successful interdisciplinary clinic specific to cancer cachexia management, where patients are seen outside established 8- to 12-week structured programs which prevail in other cachexia clinics. Seventy-five patients (43%) attended one appointment only, with almost half of these (n = 33) first attending within 60 days of death. Of the 99 patients with two or more appointments, 49% displayed positive outcomes with > 2-kg weight gain between two consecutive appointments, and > 50% improved functional strength between two consecutive appointments. CONCLUSIONS: The majority of patients attending clinic multiple times maintained or increased weight and functional status during their involvement with the service. However, successes of care provision were muted by high attrition, primarily due to delayed referral and expected high mortality within the study cohort. Planned future analyses with greater patient numbers and cancer stratification will establish cachectic populations most likely to benefit from this novel mode of interdisciplinary care. The Cachexia and Nutrition Support Service provides an effective and efficient service model for the provision of specialist cachexia care to community-dwelling patients in regional Australia.

The extracellular matrix in cancer progression: Role of hyalectan proteoglycans and ADAMTS enzymes.

Remodelling of the extracellular matrix (ECM) has emerged as a key factor in cancer progression. Proteoglycans, including versican and other hyalectans, represent major structural elements of the ECM where they interact with other important molecules, including the glycosaminoglycan hyaluronan and the CD44 cell surface receptor. The hyalectan proteoglycans are regulated through cleavage by the proteolytic actions of A Disintegrin-like And Metalloproteinase domain with Thrombospondin-1 motif (ADAMTS) family members. Alteration in the balance between hyalectan proteoglycans and ADAMTS enzymes has been proposed to be a crucial factor in cancer progression either in a positive or negative manner depending on the context. Further complexity arises due to the formation of bioactive cleavage products, such as versikine, which may also play a role, and non-enzymatic functions for ADAMTS proteins. This research is providing fresh insights into cancer biology and opportunities for the development of new diagnostic and treatment strategies.

Visualization of HIV-1 interactions with penile and foreskin epithelia: clues for female-to-male HIV transmission.

To gain insight into female-to-male HIV sexual transmission and how male circumcision protects against this mode of transmission, we visualized HIV-1 interactions with foreskin and penile tissues in ex vivo tissue culture and in vivo rhesus macaque models utilizing epifluorescent microscopy. 12 foreskin and 14 cadaveric penile specimens were cultured with R5-tropic photoactivatable (PA)-GFP HIV-1 for 4 or 24 hours. Tissue cryosections were immunofluorescently imaged for epithelial and immune cell markers. Images were analyzed for total virions, proportion of penetrators, depth of virion penetration, as well as immune cell counts and depths in the tissue. We visualized individual PA virions breaching penile epithelial surfaces in the explant and macaque model. Using kernel density estimated probabilities of localizing a virion or immune cell at certain tissue depths revealed that interactions between virions and cells were more likely to occur in the inner foreskin or glans penis (from local or cadaveric donors, respectively). Using statistical models to account for repeated measures and zero-inflated datasets, we found no difference in total virions visualized at 4 hours between inner and outer foreskins from local donors. At 24 hours, there were more virions in inner as compared to outer foreskin (0.0495 +/- 0.0154 and 0.0171 +/- 0.0038 virions/image, p = 0.001). In the cadaveric specimens, we observed more virions in inner foreskin (0.0507 +/- 0.0079 virions/image) than glans tissue (0.0167 +/- 0.0033 virions/image, p<0.001), but a greater proportion was seen penetrating uncircumcised glans tissue (0.0458 +/- 0.0188 vs. 0.0151 +/- 0.0100 virions/image, p = 0.099) and to significantly greater mean depths (29.162 +/- 3.908 vs. 12.466 +/- 2.985 µm). Our in vivo macaque model confirmed that virions can breach penile squamous epithelia in a living model. In summary, these results suggest that the inner foreskin and glans epithelia may be important sites for HIV transmission in uncircumcised men.

Reducing psychological distress and obesity in Australian farmers by promoting physical activity.

BACKGROUND: Studies have confirmed that the rate of mental illness is no higher in rural Australians than that of urban Australians. However, the rate of poor mental health outcomes, and in particular suicide, is significantly raised in rural populations. This is thought to be due to lack of early diagnosis, health service access, the distance-decay effect, poor physical health determinants and access to firearms. Research conducted by the National Centre for Farmer Health between 2004 and 2009 reveals that there is a correlation between obesity and psychological distress among the farming community where suicide rates are recognised as high. Chronic stress overstimulates the regulation of the hypothalamic-pituitary-adrenal (HPA) axis that is associated with abdominal obesity. Increasing physical activity may block negative thoughts, increase social contact, positively influence brain chemistry and improve both physical and mental health. This paper describes the design of the Farming Fit study that aims to identify the effect of physical activity on psychological distress, obesity and health behaviours such as diet patterns and smoking in farm men and women. METHODS/DESIGN: For this quasi-experimental (convenience sample) control-intervention study, overweight (Body Mass Index ≥25 kg/m(2)) farm men and women will be recruited from Sustainable Farm Families™ (SFF) programs held across Victoria, Australia. Baseline demographic data, health data, depression anxiety stress scale (DASS) scores, dietary information, physical activity data, anthropometric data, blood pressure and biochemical analysis of plasma and salivary cortisol levels will be collected. The intervention group will receive an exercise program and regular phone coaching in order to increase their physical activity. Analysis will evaluate the impact of the intervention by longitudinal data (baseline and post intervention) comparison of intervention and control groups. DISCUSSION: This study is designed to examine the effect of physical activity on psychological health and other co-morbidities such as obesity, impaired glucose tolerance, hypertension and dyslipidaemia within a high-risk cohort. The outcomes of this research will be relevant to further research and service delivery programs, in particular those tailored to rural communities. TRIAL REGISTRATION: ACTRN12610000827033.

Potential HIV-1 target cells in the human penis.

OBJECTIVES: To study the distribution of HIV-1 receptors and degree of keratinization in the human penis. DESIGN: Formalin-fixed penises were obtained from nine uncircumcised cadavers. Foreskins were obtained from 21 healthy adult men undergoing elective circumcision for social reasons. Uncircumcised penises were obtained within 24 h of death from eight men. All tissues were stained for keratin and HIV-1 receptors. METHODS: Penises from nine formalin fixed cadavers aged 64-80 years were obtained from the Department of Anatomy, University of Melbourne. Foreskins were obtained from 21 men aged 18-64 years following circumcision performed at either the Freemason's or Mercy Private Hospitals, Melbourne, Australia. Fresh penile necropsy specimens from eight uncircumcised men aged 23-63 years were obtained from the Victorian Institute of Forensic Medicine, Melbourne. The degree of keratinization was scored, and the distribution of HIV-1 susceptible cells was mapped in the glans penis, penile urethra, urethral meatus, frenulum and foreskin. RESULTS: Cells with HIV-1 receptors were present in all penile epithelia, but Langerhans' cells were most superficial in the inner foreskin and frenulum. The inner foreskin had a significantly thinner keratin layer (1.8 +/- 0.1 units), than the outer foreskin (3.3 +/- 0.1), or glans penis (3.3 +/- 0.2), P < 0.05. CONCLUSIONS: Superficial Langerhans' cells on the inner aspect of the foreskin and frenulum are poorly protected by keratin and thus could play an important role in primary male infection. These findings provide a possible anatomical explanation for the epidemiologically observed protective effect of male circumcision.