Spatio-temporal analysis of prostate tumors in situ suggests pre-existence of treatment-resistant clones.

The molecular mechanisms underlying lethal castration-resistant prostate cancer remain poorly understood, with intratumoral heterogeneity a likely contributing factor. To examine the temporal aspects of resistance, we analyze tumor heterogeneity in needle biopsies collected before and after treatment with androgen deprivation therapy. By doing so, we are able to couple clinical responsiveness and morphological information such as Gleason score to transcriptome-wide data. Our data-driven analysis of transcriptomes identifies several distinct intratumoral cell populations, characterized by their unique gene expression profiles. Certain cell populations present before treatment exhibit gene expression profiles that match those of resistant tumor cell clusters, present after treatment. We confirm that these clusters are resistant by the localization of active androgen receptors to the nuclei in cancer cells post-treatment. Our data also demonstrates that most stromal cells adjacent to resistant clusters do not express the androgen receptor, and we identify differentially expressed genes for these cells. Altogether, this study shows the potential to increase the power in predicting resistant tumors.

Spatially resolved clonal copy number alterations in benign and malignant tissue.

Defining the transition from benign to malignant tissue is fundamental to improving early diagnosis of cancer1. Here we use a systematic approach to study spatial genome integrity in situ and describe previously unidentified clonal relationships. We used spatially resolved transcriptomics2 to infer spatial copy number variations in >120,000 regions across multiple organs, in benign and malignant tissues. We demonstrate that genome-wide copy number variation reveals distinct clonal patterns within tumours and in nearby benign tissue using an organ-wide approach focused on the prostate. Our results suggest a model for how genomic instability arises in histologically benign tissue that may represent early events in cancer evolution. We highlight the power of capturing the molecular and spatial continuums in a tissue context and challenge the rationale for treatment paradigms, including focal therapy.

Morphological Features Extracted by AI Associated with Spatial Transcriptomics in Prostate Cancer.

Prostate cancer is a common cancer type in men, yet some of its traits are still under-explored. One reason for this is high molecular and morphological heterogeneity. The purpose of this study was to develop a method to gain new insights into the connection between morphological changes and underlying molecular patterns. We used artificial intelligence (AI) to analyze the morphology of seven hematoxylin and eosin (H&E)-stained prostatectomy slides from a patient with multi-focal prostate cancer. We also paired the slides with spatially resolved expression for thousands of genes obtained by a novel spatial transcriptomics (ST) technique. As both spaces are highly dimensional, we focused on dimensionality reduction before seeking associations between them. Consequently, we extracted morphological features from H&E images using an ensemble of pre-trained convolutional neural networks and proposed a workflow for dimensionality reduction. To summarize the ST data into genetic profiles, we used a previously proposed factor analysis. We found that the regions were automatically defined, outlined by unsupervised clustering, associated with independent manual annotations, in some cases, finding further relevant subdivisions. The morphological patterns were also correlated with molecular profiles and could predict the spatial variation of individual genes. This novel approach enables flexible unsupervised studies relating morphological and genetic heterogeneity using AI to be carried out.

SRC-3/AIB-1 may Enhance Hepatic NFATC1 Transcription and Mediate Inflammation in a Tissue-Specific Manner in Morbid Obesity.

BACKGROUND: Obesity is a global epidemic which is associated with several cardiometabolic comorbidities and is characterized by chronic, low grade systemic inflammation. Numerous biomarkers have been implicated in the pathophysiology of the disease, including transcription factors and coregulators. Steroid Receptor Coactivator (SRC)-family represent the master regulators of metabolic pathways and their dysregulation is strongly associated with numerous metabolic disorders. METHODS: 50 morbidly obese patients participated in the present study. Biopsies were collected from visceral adipose tissue, subcutaneous adipose tissue, skeletal muscle, extra-myocellular adipose tissue and liver. We evaluated the differential protein expression of NFATc1, SRC-2/TIF-2, SRC-3/AIB-1 and inflammatory biomarkers CD68 and CD3 by immunohistochemistry. The current study was designed to determine any correlations between the transcription factor NFATc1 and the SRC coregulators, as well as any associations with the inflammatory biomarkers. RESULTS: We identified SRC-3 as a hepatic NFATc1 coactivator and we demonstrated its possible role in energy homeostasis and lipid metabolism. Moreover, we revealed a complex and extensive intraand inter-tissue network among the three main investigated proteins and the inflammatory biomarkers, suggesting their potential participation in the obesity-induced inflammatory cascade. CONCLUSION: Steroid receptor coactivators are critical regulators of human metabolism with pleiotropic and tissue-specific actions. We believe that our study will contribute to the better understanding of the complex multi-tissue interactions that are disrupted in obesity and can therefore lead to numerous cardiometabolic diseases. Further on, our present findings suggest that SRC-3/AIB-1 could constitute possible future drug targets.

Inter-tissue expression patterns of the key metabolic biomarker PGC-1α in severely obese individuals: Implication in obesity-induced disease.

OBJECTIVE: PGC-1α is already known as a significant regulator of mitochondrial biogenesis, oxidative phosphorylation and fatty acid metabolism. Our study focuses on the role of PGC1α in morbid obesity, in five different tissues, collected from 50 severely obese patients during planned bariatric surgery. METHODS: The investigated tissues included subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), skeletal muscle (SM), extramyocellular adipose tissue (EMAT) and liver. PGC1α expression was investigated with immunohistochemistry and evaluated with microscopy. RESULTS: Our findings highlighted significant positive inter-tissue correlations regarding PGC-1α expression between several tissue pairs (VAT-SAT, VAT-SM, VAT-EMAT, SAT-SM, SAT-EMAT, SM-EMAT). Moreover, we found significant negative correlations between PGC1α expression in VAT with CD68 expression in skeletal muscle and EMAT, implying a possible protective role of PGC1α against obesity-induced inflammation. CONCLUSION: Unmasking the inter-tissue communication networks regarding PGC-1α expression in morbid obesity, will give more insight into its significant role in obesity-induced diseases. PGC1α could potentially represent a future preventive and therapeutic target against obesity-induced disease, probably through enhancing mitochondrial biogenesis and metabolism.

Spatial maps of prostate cancer transcriptomes reveal an unexplored landscape of heterogeneity.

Intra-tumor heterogeneity is one of the biggest challenges in cancer treatment today. Here we investigate tissue-wide gene expression heterogeneity throughout a multifocal prostate cancer using the spatial transcriptomics (ST) technology. Utilizing a novel approach for deconvolution, we analyze the transcriptomes of nearly 6750 tissue regions and extract distinct expression profiles for the different tissue components, such as stroma, normal and PIN glands, immune cells and cancer. We distinguish healthy and diseased areas and thereby provide insight into gene expression changes during the progression of prostate cancer. Compared to pathologist annotations, we delineate the extent of cancer foci more accurately, interestingly without link to histological changes. We identify gene expression gradients in stroma adjacent to tumor regions that allow for re-stratification of the tumor microenvironment. The establishment of these profiles is the first step towards an unbiased view of prostate cancer and can serve as a dictionary for future studies.

Adhesions and Healing of Intestinal Anastomoses: The Effect of Anti-Adhesion Barriers.

Background Postoperative adhesions are the result of aberrant peritoneal healing. As they are the leading cause of postoperative bowel obstruction, anti-adherence barriers are advocated for their prevention. This study looks into the effect of these biomaterials on the healing of intestinal anastomoses. Materials and Methods Thirty-three New Zealand White rabbits underwent laparotomy, transection of the terminal ileum, and creation of an end-to-end anastomosis. Animals were randomized into 3 groups: the Control group (n = 11); the Icodextrin group, receiving icodextrin 4% intraperitonealy (n = 11); and the HA/CMC group, having the anastomosis wrapped with a hyaluronic acid/carboxymethylcellulose film (n = 11). All animals were sacrificed on the seventh postoperative day. Macroscopic adhesions were graded and anastomotic strength was tested by the burst pressure. Histological healing was assessed in a semiquantitative way for the presence of ulceration, reepithelization, granulation tissue, inflammation, eosinophilic infiltration, serosal inflammation, and microscopic adhesions. Univariate and multivariate analysis was used. Results are given as medians with interquartile range. Results The median adhesion scores were the following: Control 1 (0-3), Icodextrin 0 (0-1), HA/CMC 0 (0-0), P = .017. The burst pressure did not differ between the groups; however, all except one bowel segments tested burst away from the anastomosis. The macroscopic and histological anastomotic healing was comparable in all 3 groups. A poor histological anastomotic healing score was associated with a higher adhesion grade (odds ratio = 1.92; 95% confidence interval = 1.06-3.47; P = .032). Conclusion Adhesion formation was inhibited by the materials tested without direct detrimental effects on anastomotic healing. Poor anastomotic healing provokes adhesions even in the presence of anti-adhesion barriers.

Castration radiosensitizes prostate cancer tissue by impairing DNA double-strand break repair.

Chemical castration improves responses to radiotherapy in prostate cancer, but the mechanism is unknown. We hypothesized that this radiosensitization is caused by castration-mediated down-regulation of nonhomologous end joining (NHEJ) repair of DNA double-strand breaks (DSBs). To test this, we enrolled 48 patients with localized prostate cancer in two arms of the study: either radiotherapy first or radiotherapy after neoadjuvant castration treatment. We biopsied patients at diagnosis and before and after castration and radiotherapy treatments to monitor androgen receptor, NHEJ, and DSB repair in verified cancer tissue. We show that patients receiving neoadjuvant castration treatment before radiotherapy had reduced amounts of the NHEJ protein Ku70, impaired radiotherapy-induced NHEJ activity, and higher amounts of unrepaired DSBs, measured by γ-H2AX foci in cancer tissues. This study demonstrates that chemical castration impairs NHEJ activity in prostate cancer tissue, explaining the improved response of patients with prostate cancer to radiotherapy after chemical castration.

Expression of ERß and its co-regulators p300 and NCoR in human transitional cell bladder cancer.

OBJECTIVE: Several data support a possible role of estrogens in bladder carcinogenesis, mediated mainly through estrogen receptor-ß (ERß). We study the expression of ERß and its co-regulators p300 and nuclear co-repressor (NCoR) in patients with bladder cancer. PATIENTS AND METHODS: One hundred and eleven consecutive patients (74 males and 37 females), aged 23-90 years (mean 70 ± 10) diagnosed with transitional cell bladder cancer were included in this study. The control group consisted of 29 patients that underwent transurethral prostatectomy and consented to simultaneous bladder biopsies. Immunohistochemical studies took place on formalin-fixed, paraffin-embedded sections from the TUR (transurethral resection) specimens. We studied the expression of ERß, p300 and NCoR.χ(2) test was used to evaluate the relationship between the histological grade and ERß expression, grade and co-regulators expression and grade and gender. Spearman rank correlation coefficient (r) was used in order to estimate the direction and strength of correlations between histological grade and ERß-p300-NCoR expressions. The Cochran-Armitage test for trend was applied in order to examine possible trends across the ordered levels of histological grade. RESULTS: ERß was more frequently expressed in the nucleus of normal bladder epithelium compared to malignant bladder epithelium with statistical significant association (r = -0.25, p = 0.003). The p300 was expressed only in the nucleus of bladder cancer cells and a positive correlation between molecular expression and cancer progression was demonstrated (r = 0.55, p < 0.001). NCoR immunostaining was demonstrated in the nuclei of bladder cells. Nuclear staining was significantly higher in normal tissue than in cancer cells (r = -0.33, p < 0.001), with negative correlation. Furthermore, its expression in grade I tumors was significantly higher than in grade II (r = -0.46, p < 0.001) and grade III tumors (r = -0.51, p < 0.001). Thus, like ERß, NCoR expression in bladder epithelium decreased during cancer progression and loss of cell differentiation. There was no correlation between the levels of expression of the three proteins in normal bladder epithelium, but there was an inverse correlation between the nuclear expression of ERß and p300 in carcinomas (r = -3.88, p = 0.042). Statistical significant association was established when correlating ERß expression with NCoR expression (r = 0.273, p = 0.005), while co-regulators' nuclear expression did not correlate with each other (p > 0.05). CONCLUSIONS: In bladder carcinogenesis, we demonstrated inhibition in the expression of ERß and its co-repressor NCoR as well as increased expression of the co-activator p300.