Mick D. Brown

Measurement of elastic properties of prostate cancer cells using AFM

This communication reports that three prostate cancer cells of differing metastatic potential were discriminated based on their Youngs moduli (LNCaP - 287 +/- 52 N m(-2), PC-3 - 1401 +/- 162 N m(-2) and BPH - 2797 +/- 491 N m(-2)) which were determined using AFM and the Hertz model.

An investigation of the RWPE prostate derived family of cell lines using FTIR spectroscopy.

Interest in developing robust, quicker and easier diagnostic tests for cancer has lead to an increased use of Fourier transform infrared (FTIR) spectroscopy to meet that need. In this study we present the use of different experimental modes of infrared spectroscopy to investigate the RWPE human prostate epithelial cell line family which are derived from the same source but differ in their mode of transformation and their mode of invasive phenotype. Importantly, analysis of the infrared spectra obtained using different experimental modes of infrared spectroscopy produces similar results. The RWPE family of cell lines can be separated into groups based upon the method of cell transformation rather than the resulting invasiveness/aggressiveness of the cell line. The study also demonstrates the possibility of using a genetic algorithm as a possible standardised pre-processing step and raises the important question of the usefulness of cell lines to create a biochemical model of prostate cancer progression.

Whole organ cross-section chemical imaging using label-free mega-mosaic FTIR microscopy

FTIR chemical imaging has been demonstrated as a promising technique to construct automated systems to complement histopathological evaluation of biomedical tissue samples. The rapid chemical imaging of large areas of tissue has previously been a limiting factor in this application. Consequently, smaller areas of tissue have previously had to be sampled, possibly introducing sampling bias and potentially missing diagnostically important areas. In this report a high spatial resolution chemical image of a whole prostate cross section is shown comprising 66 million pixels. Each pixel represents an area 5.5 × 5.5 μm(2) of tissue and contains a full infrared spectrum providing a chemical fingerprint. The data acquisition time was 14 hours, thus showing that a clinical time frame of hours rather than days has been achieved.

Highlighting a need to distinguish cell cycle signatures from cellular responses to chemotherapeutics in SR-FTIR spectroscopy

Previous research has seen difficulties in establishing clear discrimination by principal component analysis (PCA) between drug-treated cells analysed by single point SR-FTIR spectroscopy, relative to multisampling cell monolayers by conventional FTIR. It is suggested that the issue arises due to signal mixing between cellular-response signatures and cell cycle phase contributions in individual cells. Consequently, chemometric distinction of cell spectra treated with multiple drugs is difficult even with supervised methods. In an effort to separate cell cycle chemistry from cellular response chemistry in the spectra, renal carcinoma cells were stained with propidium iodide and fluorescent-activated cell sorted (FACS) after exposure to a number of chemotherapeutic compounds; 5-fluorouracil (5FU) and a set of novel gold-based experimental compounds. The cell spectra were analysed separately by PCA in G(1), S or G(2)/M phase. The mode of action of established drug 5FU, known to disrupt S phase, was confirmed by FACS analysis. The chemical signature of 5FU-treated cells discriminated against both the control and gold-compound (KF0101)-treated cell spectra, suggesting a different mode of action due to a difference in cellular response.

Arachidonic acid induction of Rho-mediated transendothelial migration in prostate cancer

Background:Bone metastases in prostate cancer (CaP) result in CaP-related morbidity/mortality. The omega-6 polyunsaturated fatty acid (PUFA) arachidonic acid (AA) and lipophilic statins affect metastasis-like behaviour in CaP cells, regulating the critical metastatic step of CaP migration to the bone marrow stroma.Methods:Microscopic analysis and measurement of adhesion and invasion of CaP cells through bone marrow endothelial cells (BMEC) was undertaken with AA stimulation and/or simvastatin (SIM) treatment. Amoeboid characteristics of PC-3, PC3-GFP and DU-145 were analysed by western blotting and Rho assays.Results:The CaP cell lines PC-3, PC3-GFP and DU-145 share the ability to migrate across a BMEC layer. Specific amoeboid inhibition decreased transendothelial migration (TEM). AA stimulates amoeboid characteristics, driven by Rho signalling. Selective knock-down of components of the Rho pathway (RhoA, RhoC, Rho-associated protein kinase 1 (ROCK1) and ROCK2) showed that Rho signalling is crucial to TEM. Functions of these components were analysed, regarding adhesion to BMEC, migration in 2D and the induction of the amoeboid phenotype by AA. TEM was reduced by SIM treatment of PC3-GFP and DU-145, which inhibited Rho pathway signalling.Conclusions:AA-induced TEM is mediated by the induction of a Rho-driven amoeboid phenotype. Inhibition of this cell migratory process may be an important therapeutic target in high-risk CaP.

Investigating cellular responses to novel chemotherapeutics in renal cell carcinoma using SR-FTIR spectroscopy.

SR-FTIR spectroscopy was evaluated as a technique to discriminate spectral signals of cellular response at the single cell level, when cancer cells are exposed to chemotherapeutics. 5-Fluorouracil, an established drug of known mode of action, was tested against a renal carcinoma cell line (Caki-2), along with two experimental analogues of gold-based compounds. The use of unsupervised principal component analysis (PCA) failed to clearly define any distinction between control and drug treated cell spectra. Supervised principal component linear discriminant analysis (PC-LDA) did have some potential to reveal signatures of cell response and repair but again failed to distinctly discriminate groups of spectra with different drug treatments. Alternatively, clear PCA discrimination was observed in spectra from average cell populations via single point benchtop spectroscopy, probing several cells simultaneously with an increased aperture. The Caki-2 cell line initially appeared to be sensitive to the novel compounds, inducing a cellular response prior to subsequential cell recovery which was assessed by both PCA and cell viability assays.

Automated high-throughput assessment of prostate biopsy tissue using infrared spectroscopic chemical imaging

Fourier transform infrared (FT-IR) chemical imaging has been demonstrated as a promising technique to complement histopathological assessment of biomedical tissue samples. Current histopathology practice involves preparing thin tissue sections and staining them using hematoxylin and eosin (H&E) after which a histopathologist manually assess the tissue architecture under a visible microscope. Studies have shown that there is disagreement between operators viewing the same tissue suggesting that a complementary technique for verification could improve the robustness of the evaluation, and improve patient care. FT-IR chemical imaging allows the spatial distribution of chemistry to be rapidly imaged at a high (diffraction-limited) spatial resolution where each pixel represents an area of 5.5 × 5.5 μm2 and contains a full infrared spectrum providing a chemical fingerprint which studies have shown contains the diagnostic potential to discriminate between different cell-types, and even the benign or malignant state of prostatic epithelial cells. We report a label-free (i.e. no chemical de-waxing, or staining) method of imaging large pieces of prostate tissue (typically 1 cm × 2 cm) in tens of minutes (at a rate of 0.704 × 0.704 mm2 every 14.5 s) yielding images containing millions of spectra. Due to refractive index matching between sample and surrounding paraffin, minimal signal processing is required to recover spectra with their natural profile as opposed to harsh baseline correction methods, paving the way for future quantitative analysis of biochemical signatures. The quality of the spectral information is demonstrated by building and testing an automated cell-type classifier based upon spectral features.

Stroma-induced Jagged1 expression drives PC3 prostate cancer cell migration : disparate effects of RIP-generated proteolytic fragments on cell behaviour and Notch signaling

The Notch ligand Jagged1 is subject to regulated intramembrane proteolysis (RIP) which yields a soluble ectodomain (sJag) and a soluble Jagged1 intracellular domain (JICD). The full-length Jagged1 protein enhances prostate cancer (PCa) cell proliferation and is highly expressed in metastatic cells. However, little is known regarding the mechanisms by which Jagged1 or its RIP-generated fragments might promote PCa bone metastasis. In the current study we show that bone marrow stroma (BMS) induces Jagged1 expression in bone metastatic prostate cancer PC3 cells and that this enhanced expression is mechanistically linked to the promotion of cell migration. We also show that RIP-generated Jagged1 fragments exert disparate effects on PC3 cell behaviour and Notch signaling. In conclusion, the expression of both the full-length ligand and its RIP-generated fragments must be considered in tandem when attempting to regulate Jagged1 as a possible PCa therapy.

Abstract 4350: Prognostic potential of epithelial to mesenchymal transition in prostate cancer at first presentation

Introduction and Objective: Metastatic progression of prostate cancer requires a change of state, epithelial to mesenchymal transition (EMT), reducing cell to cell adherence and contact, with associated cell motility and invasion. EMT is one of the hallmarks of cancer and characterisation of the EMT process has defined a panel of EMT biomarkers. Here we investigate the potential of an EMT panel of biomarkers in an unscreened population at first presentation with prostate cancer. Methods: A prostate Tissue Micro Array (TMA) comprising 2,450 cores containing normal adjacent, prostatic intraepithelial neoplasia and malignant prostate tissue from 524 diagnostic biopsies, linked to an extensive clinical database with long-term outcome, was studied. Expression of a panel of EMT biomarkers, including E-cadherin and vimentin, was assessed using an automated, high throughput fluorescent staining (Leica BOND-MAX), image capture (Carl Zeiss Microimaging Mirax scanner) and quantitative image analysis (Definiens Tissue Studio) protocol. Definiens H-Score was converted to pathological scores prior to univariate and multivariate Cox proportional hazards regression analysis in SPSS. Results: Expression of an EMT profile predicted a significant reduction in both overall and cancer specific survival. In univariate analysis, low or negative E-cadherin staining was associated with a reduction in median overall survival by 45 months (95% CI: 10.4-79.6; P Conclusions: Loss of E-cadherin and concomitant expression of the EMT marker vimentin are powerful predictors of prostate cancer outcome at first presentation. Citation Format: Ahmad Al-Sukaini, Claire Hart, Richard Robinson, Mick Brown, Noel Clarke. Prognostic potential of epithelial to mesenchymal transition in prostate cancer at first presentation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4350. doi:10.1158/1538-7445.AM2015-4350

Primary Mutational Landscape Linked with Pre-Docetaxel Lactate Dehydrogenase Levels Predicts Docetaxel Response in Metastatic Castrate-Resistant Prostate Cancer

BACKGROUND Docetaxel chemotherapy is a standard of care for metastatic castrate-resistant prostate cancer (mCRPC): 40-50% of patients achieve a biochemical response. However, there is a lack of response predictive biomarkers. OBJECTIVE To assess lactate dehydrogenase (LDH) as a docetaxel response biomarker in mCRPC and to examine the association of LDH with genomic alterations in primary diagnostic biopsies. DESIGN, SETTING, AND PARTICIPANTS Clinical and associated primary tumour-targeted next-generation sequencing data from matched training (n=150) and test (n=120) cohorts of progressive mCRPC patients receiving docetaxel therapy were analysed. Data were correlated with large-scale prostate cancer genomic datasets. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Prostate-specific antigen (PSA) response, radiographic response, biochemical progression-free survival (PFS), overall survival (OS), genomic analysis of primary biopsies, and genomic datasets (Memorial Sloan Kettering Cancer Center [MSKCC] and SU2C/PCF). RESULTS AND LIMITATIONS Serum LDH ≥450U/l is a reliable prognostic biomarker (area under the curve: 0.757 [standard deviation 0.054, 95% confidence interval [CI] 0.650-0.864, p<0.001]) in progressive mCRPC, predicting PFS at 3 mo. Patients with LDH ≥450U/l were poorer PSA responders, with shorter PFS (213 vs 372 d, hazard ratio [HR] 1.876, 95% CI 1.289-2.7300) and OS (362 vs 563 d, HR 1.630, 95% CI 1.127-2.357). High LDH is an independent surrogate marker for survival following docetaxel and predicts a poor radiological response (p=0.043). Of the 14 patients with LDH ≥450U/l available for next-generation sequencing, nine (64.3%) were more likely to have DNA repair gene mutation(s) (BRCA1/2, ATM, CHEK2, Fanconi anaemia gene) in their primary biopsy. Cross correlation with MSKCC and SU2C/PCF databases revealed a positive correlation between LDHA, PARP1 (r=0.667, p<0.01), and other DNA repair genes. CONCLUSIONS Genomic abnormalities of LDHA and DNA repair in primary biopsies link to high pretreatment LDH and poor response to docetaxel in mCRPC. PATIENT SUMMARY The presence of mutations of the lactate dehydrogenase and DNA repair pathways are associated with aggressive prostate cancer and poor response to chemotherapy later in the disease.