Personalized Drug Sensitivity Screening for Bladder Cancer Using Conditionally Reprogrammed Patient-derived Cells.

Many patients with muscle-invasive bladder cancer (BC) are either ineligible for or do not benefit from cisplatin-based chemotherapy, and there is an unmet need to estimate individuals' drug sensitivities. We investigated the suitability of conditionally reprogrammed (CR) cells for the characterization of BC properties and their feasibility for personalized drug sensitivity screening. The CR cultures were established from six BC tumors with varying histology and stage. Four cultures were successfully propagated for genomic, transcriptomic, and protein expression profiling and compared to the parental tumors. Two out of four CR cultures (urothelial carcinoma and small cell neuroendocrine carcinoma [SmCC]) corresponded well to their parental tumors and underwent drug sensitivity screening to identify novel drugs for the respective tumors. Both cultures were sensitive to standard BC chemotherapy agents (eg cisplatin and gemcitabine) and to conventional drugs such as taxanes and inhibitors of topoisomerase and proteasome. The SmCC cells were also sensitive to statins (eg, atorvastatin and pitavastatin). In summary, after confirming their representativeness and origin, we conclude that CR cells are a feasible platform for personalized drug sensitivity testing and might thus add to the approaches used to personalize BC treatment strategies. PATIENT SUMMARY: We investigated the conditional reprogramming method for generating patient-derived bladder cancer cell cultures and studied their feasibility for planning personalized treatment strategies.

Correlation between 18F-1-amino-3-fluorocyclobutane-1-carboxylic acid (18F-fluciclovine) uptake and expression of alanine-serine-cysteine-transporter 2 (ASCT2) and L-type amino acid transporter 1 (LAT1) in primary prostate cancer.

PURPOSE: To evaluate the expression of alanine-serine-cysteine-transporter 2 (ASCT2) and L-type amino acid transporter1 (LAT1) in prostate cancer (PCa) and their impact on uptake of 18F-1-amino-3-fluorocyclobutane-1-carboxylic acid (18F-fluciclovine) which is approved for the detection of recurrent PCa. METHODS: Twenty-five hormone-naïve patients with histologically confirmed PCa underwent PET/CT before prostatectomy. Dynamic imaging was performed immediately after injection of 368 ± 10 MBq of 18F-fluciclovine and the uptake in PCa was expressed as SUVmax at six sequential 4-min time frames and as tracer distribution volume (VT) using Logan plots over 0-24 min. The expression of ASCT2 and LAT1 was studied with immunohistochemistry (IHC) on a tissue microarray (TMA) containing three cores per carcinoma lesion. The TMA slides were scored independently by two trained readers based on visual intensity of ASCT2/LAT1 expression on a four-tiered scale. The correlations between ASCT2/LAT1 staining intensity, SUVmax/VT, and Gleason grade group (GGG) were assessed using Spearman's rank correlation coefficient (ρ). RESULTS: Forty tumor foci (> 0.5 mm in diameter, max. 3 per patient) were available for TMA. In visual scoring, low, moderate, and high staining intensity of ASCT2 was observed in 4 (10%), 24 (60%), and 12 (30%) tumors, respectively. No tumors showed high LAT1 staining intensity while moderate intensity was found in 10 (25%), 25 (63%) showed low, and the remaining 5 (12%) were negative for staining with LAT1. Tumors with GGG > 2 showed significantly higher uptake of 18F-fluciclovine and higher LAT1 staining intensity (p < 0.05). The uptake of 18F-fluciclovine correlated significantly with LAT1 expression (ρ = 0.39, p = 0.01, for SUVmax at 2 min and ρ = 0.39, p = 0.01 for VT). No correlation between ASCT2 expression and 18F-fluciclovine uptake or GGG was found. CONCLUSIONS: Our findings suggest that LAT1 is moderately associated with the transport of 18F-fluciclovine in local PCa not exposed to hormonal therapy. Both high and low Gleason grade tumors express ASCT2 while LAT1 expression is less conspicuous and may be absent in some low-grade tumors. Our observations may be of importance when using 18F-fluciclovine imaging in the planning of focal therapies for PCa.

SORLA regulates endosomal trafficking and oncogenic fitness of HER2.

The human epidermal growth factor receptor 2 (HER2) is an oncogene targeted by several kinase inhibitors and therapeutic antibodies. While the endosomal trafficking of many other receptor tyrosine kinases is known to regulate their oncogenic signalling, the prevailing view on HER2 is that this receptor is predominantly retained on the cell surface. Here, we find that sortilin-related receptor 1 (SORLA; SORL1) co-precipitates with HER2 in cancer cells and regulates HER2 subcellular distribution by promoting recycling of the endosomal receptor back to the plasma membrane. SORLA protein levels in cancer cell lines and bladder cancers correlates with HER2 levels. Depletion of SORLA triggers HER2 targeting to late endosomal/lysosomal compartments and impairs HER2-driven signalling and in vivo tumour growth. SORLA silencing also disrupts normal lysosome function and sensitizes anti-HER2 therapy sensitive and resistant cancer cells to lysosome-targeting cationic amphiphilic drugs. These findings reveal potentially important SORLA-dependent endosomal trafficking-linked vulnerabilities in HER2-driven cancers.

Loss of PTEN expression in ERG-negative prostate cancer predicts secondary therapies and leads to shorter disease-specific survival time after radical prostatectomy.

The clinical course of prostate cancer is highly variable. Current prognostic variables, stage, and Gleason score have limitations in assessing treatment regimens for individual patients, especially in the intermediate-risk group of Gleason score 7. ERG:TMPRSS2 fusion and loss of PTEN are some of the most common genetic alterations in prostate cancer. Immunohistochemistry of PTEN and ERG has generated interest as a promising method for more precise outcome prediction but requires further validation in population-based cohorts. We studied the predictive value of ERG and PTEN expression by immunohistochemistry in two large radical prostatectomy cohorts comprising 815 patients with extensive follow-up information. Clinical end points were initiation of secondary therapy, overall survival, and disease-specific survival. Predictions of clinical outcomes were also assessed according to androgen receptor (AR) activity. PTEN loss, especially in ERG-negative cancers, predicted initiation of secondary treatments and shortened disease-specific survival time, as well as stratifying Gleason score 7 patients into different prognostic groups with regard to secondary treatments and disease-specific survival. High AR immunoreactivity in ERG-negative cancers with PTEN loss predicted worse disease-specific survival. We also observed that in Gleason score 7 ERG-negative cases with PTEN loss and high AR expression have significantly shorter disease-specific survival time compared with ERG-positive cases. Our conclusion is that loss of PTEN is a strong determining factor for shorter disease-specific survival time and initiation of secondary therapies after radical prostatectomy. The predictive value of PTEN immunoreactivity is further accentuated in ERG-negative cancers with high AR expression. Negative PTEN expression, accompanied by ERG status, can be used to stratify patients with Gleason score 7 into different survival groups. Assessment of PTEN and ERG status could provide an additional tool for initial diagnostics when determining the prognosis and subsequent follow-up regimen for patients treated by radical prostatectomy.

Differential Predictive Roles of A- and B-Type Nuclear Lamins in Prostate Cancer Progression.

BACKGROUND: Prostate cancer (PCa) is the most common cancer among men in western countries. While active surveillance is increasingly utilized, the majority of patients are currently treated with radical prostatectomy. In order to avoid over-treatment, there is an indisputable need for reliable biomarkers to identify the potentially aggressive and lethal cases. Nuclear intermediate filament proteins called lamins play a role in chromatin organization, gene expression and cell stiffness. The expression of lamin A is associated with poor outcome in colorectal cancer but to date the prognostic value of the lamins has not been tested in other solid tumors. METHODS: We studied the expression of different lamins with immunohistochemistry in a tissue microarray material of 501 PCa patients undergoing radical prostatectomy and lymph node dissection. Patients were divided into two staining categories (low and high expression). The correlation of lamin expression with clinicopathological variables was tested and the association of lamin status with biochemical recurrence (BCR) and disease specific survival (DSS) was further analyzed. RESULTS: Low expression of lamin A associated with lymph node positivity (p<0.01) but not with other clinicopathological variables and low expression had a borderline independent significant association with DSS (HR = 0.4; 95% CI 0.2-1.0; p = 0.052). Similarly, low lamin C expression associated with poorer survival (HR = 0.2; 95% CI 0.1-0.6; p = 0.004). Lamin B1 expression did not associate with clinicopathological variables but high expression independently predicted BCR in multivariable Cox regression analysis (HR = 1.8; 95% CI 1.1-2.9; p = 0.023). Low expression of lamin B2 correlated with lymph node positivity (p<0.01) and predicted unfavorable DSS (HR = 0.4; 95% CI 0.2-1.0; p = 0.047). CONCLUSIONS: These results suggest differential roles for lamins in PCa progression. Reduced amounts of lamin A/C and B2 increase risk for lymph node metastasis and disease specific death possibly through increased nuclear deformability while high expression of lamin B1 predicts disease recurrence.