Reduction of pro-tumorigenic activity of human prostate cancer-associated fibroblasts using Dlk1 or SCUBE1

SUMMARY Human prostatic cancer-associated fibroblasts (CAFs) can elicit malignant changes in initiated but non-tumorigenic human prostate epithelium, demonstrating that they possess pro-tumorigenic properties. We set out to reduce the pro-tumorigenic activity of patient CAFs using the Dlk1 and SCUBE1 molecules that we had previously identified in prostate development. Our hypothesis was that mesenchymally expressed molecules might reduce CAF pro-tumorigenic activity, either directly or indirectly. We isolated primary prostatic CAFs and characterised their expression of CAF markers, expression of Notch2, Dlk1 and SCUBE1 transcripts, and confirmed their ability to stimulate BPH1 epithelial cell proliferation. Next, we expressed Dlk1 or SCUBE1 in CAFs and determined their effects upon tumorigenesis in vivo following recombination with BPH1 epithelia and xenografting in SCID mice. Tumour size was reduced by about 75% and BPH1 proliferation was reduced by about 50% after expression of Dlk1 or SCUBE1 in CAFs, and there was also a reduction in invasion of BPH1 epithelia into the host kidney. Inhibition of Notch signalling, using inhibitor XIX, led to a reduction in BPH1 cell proliferation in CAF-BPH1 co-cultures, whereas inhibition of Dlk1 in NIH3T3-conditioned media led to an increase in BPH1 growth. Our results suggest that pro-tumorigenic CAF activity can be reduced by the expression of developmental pathways

The Efficacy of Sunitinib Treatment of Renal Cancer Cells Is Associated with the Protein PHAX In Vitro

Anti-angiogenic agents, such as the multi-tyrosine kinase inhibitor sunitinib, are key first line therapies for metastatic clear cell renal cell carcinoma (ccRCC), but their mechanism of action is not fully understood. Here, we take steps towards validating a computational prediction based on differential transcriptome network analysis that phosphorylated adapter RNA export protein (PHAX) is associated with sunitinib drug treatment. The regulatory impact factor differential network algorithm run on patient tissue samples suggests PHAX is likely an important regulator through changes in genome-wide network connectivity. Immunofluorescence staining of patient tumours showed strong localisation of PHAX to the microvasculature consistent with the anti-angiogenic effect of sunitinib. In normal kidney tissue, PHAX protein abundance was low but increased with tumour grade (G1 vs. G3/4; p 0.01), consistent with a possible role in cancer progression. In organ culture, ccRCC cells had higher levels of PHAX protein expression than normal kidney cells, and sunitinib increased PHAX protein expression in a dose dependent manner (untreated vs. 100 µM; p 0.05). PHAX knockdown in a ccRCC organ culture model impacted the ability of sunitinib to cause cancer cell death (p 0.0001 untreated vs. treated), suggesting a role for PHAX in mediating the efficacy of sunitinib

The VENUSS prognostic model to predict disease recurrence following surgery for non-metastatic papillary renal cell carcinoma: development and evaluation using the ASSURE prospective clinical trial cohort

Abstract: Background: The current World Health Organization classification recognises 12 major subtypes of renal cell carcinoma (RCC). Although these subtypes differ on molecular and clinical levels, they are generally managed as the same disease, simply because they occur in the same organ. Specifically, there is a paucity of tools to risk-stratify patients with papillary RCC (PRCC). The purpose of this study was to develop and evaluate a tool to risk-stratify patients with clinically non-metastatic PRCC following curative surgery. Methods: We studied clinicopathological variables and outcomes of 556 patients, who underwent full resection of sporadic, unilateral, non-metastatic (T1–4, N0–1, M0) PRCC at five institutions. Based on multivariable Fine-Gray competing risks regression models, we developed a prognostic scoring system to predict disease recurrence. This was further evaluated in the 150 PRCC patients recruited to the ASSURE trial. We compared the discrimination, calibration and decision-curve clinical net benefit against the Tumour, Node, Metastasis (TNM) stage group, University of California Integrated Staging System (UISS) and the 2018 Leibovich prognostic groups. Results: We developed the VENUSS score from significant variables on multivariable analysis, which were the presence of VEnous tumour thrombus, NUclear grade, Size, T and N Stage. We created three risk groups based on the VENUSS score, with a 5-year cumulative incidence of recurrence equalling 2.9% in low-risk, 15.4% in intermediate-risk and 54.5% in high-risk patients. 91.7% of low-risk patients had oligometastatic recurrent disease, compared to 16.7% of intermediate-risk and 40.0% of high-risk patients. Discrimination, calibration and clinical net benefit from VENUSS appeared to be superior to UISS, TNM and Leibovich prognostic groups. Conclusions: We developed and tested a prognostic model for patients with clinically non-metastatic PRCC, which is based on routine pathological variables. This model may be superior to standard models and could be used for tailoring postoperative surveillance and defining inclusion for prospective adjuvant clinical trials

Comprehensive characterization of cell-free tumor DNA in plasma and urine of patients with renal tumors.

BACKGROUND:Cell-free tumor-derived DNA (ctDNA) allows non-invasive monitoring of cancers, but its utility in renal cell cancer (RCC) has not been established. METHODS:Here, a combination of untargeted and targeted sequencing methods, applied to two independent cohorts of patients (n = 91) with various renal tumor subtypes, were used to determine ctDNA content in plasma and urine. RESULTS:Our data revealed lower plasma ctDNA levels in RCC relative to other cancers of similar size and stage, with untargeted detection in 27.5% of patients from both cohorts. A sensitive personalized approach, applied to plasma and urine from select patients (n = 22) improved detection to ~ 50%, including in patients with early-stage disease and even benign lesions. Detection in plasma, but not urine, was more frequent amongst patients with larger tumors and in those patients with venous tumor thrombus. With data from one extensively characterized patient, we observed that plasma and, for the first time, urine ctDNA may better represent tumor heterogeneity than a single tissue biopsy. Furthermore, in a subset of patients (n = 16), longitudinal sampling revealed that ctDNA can track disease course and may pre-empt radiological identification of minimal residual disease or disease progression on systemic therapy. Additional datasets will be required to validate these findings. CONCLUSIONS:These data highlight RCC as a ctDNA-low malignancy. The biological reasons for this are yet to be determined. Nonetheless, our findings indicate potential clinical utility in the management of patients with renal tumors, provided improvement in isolation and detection approaches

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Novel survival factors and approaches to the treatment of hypoxic prostate cancer

Tumour hypoxia has been demonstrated to cause development of an aggressive tumour phenotype and is associated with increased patient mortality and poorer response to treatments such as chemotherapy and radiotherapy. Previous studies have established that hypoxia exists within a nidus of prostate cancer. Based on the importance of the tumour microenvironment, especially hypoxia, in prostate cancer, the major aims of this thesis were to establish: (a) the role of a novel putative survival factor, dermcidin, in prostate cancer survival under hypoxia/oxidative stress; and (b) the effect of nitric oxide-donating non-steroidal anti-inflammatory drugs (NO-NSAIDS), a new class of drugs, on the killing of prostate cancer cells subjected to hypoxia. A wide-range of confirmatory, cellular and molecular biology techniques were employed in this thesis. The PC-3 hormone-insensitive prostate cancer cell line was used for the majority of studies as this cell line represents hormone-independent prostate cancer, treatment of which is currently palliative. Cell incubation at 0.2% oxygen for 48 hours was established as suitable conditions to stimulate the development of the hypoxia response. Upregulation of nuclear hypoxia-inducible factor-1α protein was the main marker used to assess the hypoxia response. Dermcidin messenger RNA production was found to occur in a range of prostate cancer cell lines; was upregulated in cell lines by both hypoxic and oxidative stress; and found to act as a proliferation, survival and pro-invasion factor under hypoxia and oxidative stress in immortalised prostate cancer cell lines. Furthermore, the portion of the dermcidin molecule responsible for the survival advantage was localised to the proteolysis-inducing factor core peptide subunit. However, subsequent analysis of primary cancer samples from prostate cancer patients revealed that dermcidin was not expressed in these tumours, although dermcidin mRNA was identified in analysis of other primary tumours. As such, the role of dermcidin in prostate cancer was not evaluated further in this thesis. Investigation of NO-sulindac (a NO-NSAID drug) in hypoxic PC-3 cells showed that these agents were significantly more pro-necrotic, pro-apoptotic and anti-invasive than traditional, unnitrated sulindac. NO-sulindac was found to downregulate the hypoxia response mounted by PC-3 cells under hypoxia via the Akt signalling pathway. Finally, analysis of the role of NO-sulindac in radiosensitising hypoxic PC-3 cells showed that NO-sulindac caused significant radiosensitisation under normoxia, but particularly in hypoxic conditions. As such, NO-NSAIDs show great promise as neoadjuvant, concurrent and adjuvant treatments for patients with hypoxic prostate cancer. The findings of this thesis illustrate several potential novel strategies for treatment of hormone-independent prostate cancer.EThOS - Electronic Theses Online ServiceGBUnited Kingdo