Development of a long term, ex vivo, patient-derived explant model of endometrial cancer.

Incidence of endometrial cancer (EC) is rising in the developed world. The current standard of care, hysterectomy, is often infeasible for younger patients and those with high body mass index. There are limited non-surgical treatment options and a lack of biologically relevant research models to investigate novel alternatives to surgery for EC. The aim of the present study was to develop a long-term, patient-derived explant (PDE) model of early-stage EC and demonstrate its use for investigating predictive biomarkers for a current non-surgical treatment option, the levonorgestrel intra-uterine system (LNG-IUS). Fresh tumour specimens were obtained from patients with early-stage endometrioid EC. Tumours were cut into explants, cultured on media-soaked gelatin sponges for up to 21 days and treated with LNG. Formalin-fixed, paraffin embedded (FFPE) blocks were generated for each explant after 21 days in culture. Tumour architecture and integrity were assessed by haematoxylin and eosin (H&E) and immunohistochemistry (IHC). IHC was additionally performed for the expression of five candidate biomarkers of LNG resistance. The developed ex vivo PDE model is capable of culturing explants from early-stage EC tumours long-term (21 Days). This model can complement existing models and may serve as a tool to validate results obtained in higher-throughput in vitro studies. Our study provides the foundation to validate the extent to which EC PDEs reflect patient response in future research.

Importance of the endometrial immune environment in endometrial cancer and associated therapies.

Endometrial cancer is rising in prevalence. The standard treatment modality of hysterectomy is becoming increasingly inadequate due primarily to the direct link between endometrial cancer and high BMI which increases surgical risks. This is an immunogenic cancer, with unique molecular subtypes associated with differential immune infiltration. Despite the immunogenicity of endometrial cancer, there is limited pre-clinical and clinical evidence of the function of immune cells in both the normal and cancerous endometrium. Immune checkpoint inhibitors for endometrial cancer are the most well studied type of immune therapy but these are not currently used as standard-of-care and importantly, they represent only one method of immune manipulation. There is limited evidence regarding the use of other immunotherapies as surgical adjuvants or alternatives. Levonorgestrel-loaded intra-uterine systems can also be effective for early-stage disease, but with varying success. There is currently no known reason as to what predisposes some patients to respond while others do not. As hormones can directly influence immune cell function, it is worth investigating the immune compartment in this context. This review assesses the immunological components of the endometrium and describes how the immune microenvironment changes with hormones, obesity, and in progression to malignancy. It also describes the importance of investigating novel pathways for immunotherapy.

Co-culture With Human Breast Adipocytes Differentially Regulates Protein Abundance in Breast Cancer Cells.

BACKGROUND/AIM: Recent research highlights the role of cancer-associated adipocytes (CAA) in promoting breast cancer cell migration, invasion and resistance to therapy. This study aimed at identifying cellular proteins differentially regulated in breast cancer cells co-cultured with CAA. MATERIALS AND METHODS: Adipocytes isolated from human breast adipose tissue were co-cultured with hormone receptor-positive (MCF-7) or -negative (MDA-MB-231) breast cancer cells using a transwell co-culture system. Proteomes of co-cultured and control breast cancer cells were compared quantitatively using iTRAQ labelling and tandem mass spectrometry, and the results were validated by western blotting. RESULTS: A total of 1,126 and 1,218 proteins were identified in MCF-7 and MDA-MB-231 cells, respectively. Among these, 85 (MCF-7) and 63 (MDA-MB-231) had an average fold change >1.5 following co-culture. Pathway analysis revealed that CAA-induced enrichment of proteins involved in metabolism, the ubiquitin proteasome, and purine synthesis. CONCLUSION: This study provides a proteomic platform for investigating the paracrine role of CAA in promoting breast cancer cell metastasis and resistance to therapy.

Angiogenesis and host immune response contribute to the aggressive character of non-melanoma skin cancers in renal transplant recipients.

AIMS: The aim of this study was to determine the contribution of tumour angiogenesis to the aggressive growth of non-melanoma skin cancers (NMSCs) in renal transplant recipients (RTRs). METHODS AND RESULTS: The study cohort included RTRs (n = 38) with formalin-fixed paraffin-embedded tumour samples available from first post-transplant NMSC (NMSC1) surgically excised at Christchurch Hospital, New Zealand, from 1997 to 2007. Comparable samples excised from immunocompetent individuals (ICIs) (n = 36) were selected to accommodate confounding factors. Markers of tumour angiogenesis were evaluated by immunohistochemistry, and analysed for associations with clinicopathological variables. As compared with ICIs, RTRs had a higher proportion of tumours with high microvessel density (P = 0.008), high proliferating capillary index (P < 0.0001) and low microvessel pericyte coverage index (P < 0.0001), and RTRs had a shorter cumulative second NMSC (NMSC2)-free interval (P < 0.0001). ICIs had a higher proportion of tumours with a 'marked' number of vascular endothelial growth factor (VEGF)-A-positive leukocytes than RTRs (P = 0.04), and RTRs with a 'moderate/marked' number of VEGF-A-positive leukocytes had longer cumulative NMSC2-free intervals than those with a 'minimum' number (P = 0.02). CONCLUSIONS: This study demonstrates increased tumour angiogenesis in NMSC in RTRs, and suggests a role for VEGF-A-positive peritumoural leukocytes in suppressing NMSC development.