Understanding and exploiting 5T4 oncofoetal glycoprotein expression.

Oncofoetal antigens are present during foetal development with generally limited expression in the adult but are upregulated in cancer. These molecules can sometimes be used to diagnose or follow treatment of tumours or as a target for different immunotherapies. The 5T4 oncofoetal glycoprotein was identified by searching for shared surface molecules of human trophoblast and cancer cells with the rationale that they may function to allow survival of the foetus as a semi-allograft in the mother or a tumour in its host, potentially influencing growth, invasion or altered immune surveillance of the host. 5T4 tumour selective expression has stimulated the development of 5T4 vaccine, 5T4 antibody targeted-superantigen and 5T4 antibody-drug therapies through preclinical and into clinical studies. It is now apparent that 5T4 expression is a marker of the use (or not) of several cellular pathways relevant to tumour growth and spread. Thus 5T4 expression is mechanistically associated with the directional movement of cells through epithelial mesenchymal transition, facilitation of CXCL12/CXCR4 chemotaxis, blocking of canonical Wnt/beta-catenin while favouring non-canonical pathway signalling. These processes are highly regulated in development and in normal adult tissues but can contribute to the spread of cancer cells. Understanding the differential impact of these pathways marked by 5T4 can potentially improve existing, or aid development of novel cancer treatment strategies.

CXCL12 receptor preference, signal transduction, biological response and the expression of 5T4 oncofoetal glycoprotein.

CXCL12 is a pleiotropic chemokine capable of eliciting multiple signal transduction cascades and functions, via interaction with either CXCR4 or CXCR7. Factors that determine CXCL12 receptor preference, intracellular signalling route and biological response are poorly understood but are of central importance in the context of therapeutic intervention of the CXCL12 axis in multiple disease states. We have recently demonstrated that 5T4 oncofoetal glycoprotein facilitates functional CXCR4 expression leading to CXCL12 mediated chemotaxis in mouse embryonic cells. Using wild type (WT) and 5T4 knockout (5T4KO) murine embryonic fibroblasts (MEFs), we now show that CXCL12 binding to CXCR4 activates both the ERK and AKT pathways within minutes, but while these pathways are intact, they are non-functional in 5T4KO cells treated with CXCL12. Importantly, in the absence of 5T4 expression, CXCR7 is upregulated and becomes the predominant receptor for CXCL12, activating a distinct signal transduction pathway with slower kinetics involving transactivation of the epidermal growth factor receptor (EGFR), eliciting proliferation rather than chemotaxis. Thus the surface expression of 5T4 marks the use of the CXCR4 rather than the CXCR7 receptor, with distinct consequences for CXCL12 exposure, relevant to the spread and growth of a tumour. Consistent with this hypothesis, we have identified human small cell lung carcinoma cells with similar 5T4/CXCR7 reciprocity that is predictive of biological response to CXCL12 and determined that 5T4 expression is required for functional chemotaxis in these cells.

Circulating regulatory T cells in endometrial cancer: a role for age and menopausal status.

Regulatory T cells (Treg) are a sub-population of T cells that suppress self-reactivity and are implicated in immune tolerance towards malignant cells. Circulating Treg cells are increased in several cancers. In endometrial cancer Treg cells have been investigated only in tumour tissues and, in contrast to some other tumours, fewer Treg cells were reported in endometrial cancer compared with benign controls. Flow cytometry was used to determine the frequency of circulating Treg cells in women undergoing hysterectomy for either endometrial cancer (n = 24) or non- cancer-related conditions (n = 21). Circulating Treg cells were more abundant in women with cancer compared to those without (4.68% vs. 3.66%, p = 0.05, Mann-Whitney test). This relationship disappeared, however, when only data from post-menopausal women were included in the analysis. Mean Treg cell frequency was 4.65% in postmenopausal women with cancer (n = 23) and 4.73% in postmenopausal controls (n = 5) (p = 0.9). In women without cancer we found that mean Treg cell frequency was higher in postmenopausal women (4.73%, n = 5) in comparison to premenopausal controls (3.33%, n = 16) (p = 0.02). These results suggest that the increased proportion of Treg cells seen in endometrial cancer patients might be, at least in part, attributed to their postmenopausal status or age.

Integrated multi-omics analysis of ovarian cancer using variational autoencoders.

Cancer is a complex disease that deregulates cellular functions at various molecular levels (e.g., DNA, RNA, and proteins). Integrated multi-omics analysis of data from these levels is necessary to understand the aberrant cellular functions accountable for cancer and its development. In recent years, Deep Learning (DL) approaches have become a useful tool in integrated multi-omics analysis of cancer data. However, high dimensional multi-omics data are generally imbalanced with too many molecular features and relatively few patient samples. This imbalance makes a DL based integrated multi-omics analysis difficult. DL-based dimensionality reduction technique, including variational autoencoder (VAE), is a potential solution to balance high dimensional multi-omics data. However, there are few VAE-based integrated multi-omics analyses, and they are limited to pancancer. In this work, we did an integrated multi-omics analysis of ovarian cancer using the compressed features learned through VAE and an improved version of VAE, namely Maximum Mean Discrepancy VAE (MMD-VAE). First, we designed and developed a DL architecture for VAE and MMD-VAE. Then we used the architecture for mono-omics, integrated di-omics and tri-omics data analysis of ovarian cancer through cancer samples identification, molecular subtypes clustering and classification, and survival analysis. The results show that MMD-VAE and VAE-based compressed features can respectively classify the transcriptional subtypes of the TCGA datasets with an accuracy in the range of 93.2-95.5% and 87.1-95.7%. Also, survival analysis results show that VAE and MMD-VAE based compressed representation of omics data can be used in cancer prognosis. Based on the results, we can conclude that (i) VAE and MMD-VAE outperform existing dimensionality reduction techniques, (ii) integrated multi-omics analyses perform better or similar compared to their mono-omics counterparts, and (iii) MMD-VAE performs better than VAE in most omics dataset.

Lower-limb lymphedema and vulval cancer: feasibility of prophylactic compression garments and validation of leg volume measurement.

OBJECTIVES: Leg lymphedema remains a significant health problem after treatment of vulval cancer. This pilot study explored the feasibility of conducting a larger trial to investigate whether the early use of compression stockings is effective in preventing leg lymphedema. METHODS: Fourteen patients undergoing inguinofemoral lymphadenectomy for vulval cancer were randomized to either best supportive care or best supportive care plus the use of graduated compression stockings for 6 months. RESULTS: Six of 7 patients in the treatment group complied with the study protocol. The incidence of clinically significant lymphedema was not different between both groups; however, there was a greater increase in mean leg volume in the control group (953 vs 607 mL, P = 0.010). Furthermore, patients in the treatment group showed better performance as judged by leg symptoms (P = 0.031, at 3 months) and clinical examination (P = 0.039 at 4 weeks and P = 0.004 at 6 months). There was no difference in the incidence of groin wound dehiscence, infection, or lymphocyst formation. We detected no difference between both groups' scores when using a validated quality-of-life questionnaire. Intraobserver and interobserver variabilities of leg-volume measurement technique were investigated using the principles of repeatability and reproducibility statistics. Intraobserver variability was estimated at 270 mL, whereas interobserver variability was 1000 mL. CONCLUSIONS: The prophylactic use of stockings in this population is feasible, and further larger studies are justified to investigate its role in reducing the incidence of leg lymphedema. The design of these studies should take into account the observer-related variability in measuring leg volume or consider alternative methods.

Preserving fertility in pseudomyxoma peritonei, a novel approach.

BACKGROUND: Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is the gold standard treatment for patients with pseudomyxoma peritonei (PMP) but involves routine bilateral salpingo-oophorectomy. Young women wishing to maintain fertility may be reluctant to pursue this. An alternative strategy in women with low-grade PMP has been explored in the form of laparoscopic evacuation of pelvic and ovarian mucin with resection of the appendiceal tumour. METHODS: Between January 2012 and January 2015, four young women (aged 28-35 years) with PMP seeking to maintain fertility underwent laparoscopy, appendicectomy and pelvic mucinous evacuation and washout. Data regarding intra-operative and histopathological findings were collected. Endpoints were fertility-related outcomes and oncological follow-up. RESULTS: Infertility was a presenting symptom in three of the four women. All four had significant pelvic mucinous disease on radiological imaging and were offered CRS and HIPEC as definitive treatment, but chose laparoscopy with appendicectomy and copious irrigation and washout of the pelvis with stripping of mucinous disease off the ovarian surfaces. Postoperative histology demonstrated a low-grade appendiceal mucinous neoplasm (LAMN) in all patients with acellular mucin or low-grade mucinous carcinoma peritonei in the peritoneal cavity. All patients successfully conceived subsequently and gave birth to healthy babies. After 12-29 months follow-up, all women are well with no radiological or laparoscopic evidence of disease recurrence. CONCLUSIONS: In patients with low-grade PMP, initial therapeutic laparoscopy can restore fertility, whilst providing short- to medium-term disease control. This modality in young women wishing to have children appears to be a feasible alternative to immediate CRS and HIPEC.