Fibrosis-Related Gene Profiling in Liver Biopsies of PiZZ α1-Antitrypsin Children with Different Clinical Courses.

PiZZ (Glu342Lys) α1-antitrypsin deficiency (AATD) is characterized by intrahepatic AAT polymerization and is a risk factor for liver disease development in children. The majority of PiZZ children are disease free, hence this mutation alone is not sufficient to cause the disease. We investigated Z-AAT polymers and the expression of fibrosis-related genes in liver tissues of PiZZ children with different clinical courses. Liver biopsies obtained during 1979-2010 at the Department of Paediatrics, Karolinska University Hospital, Sweden, were subjected to histological re-evaluation, immunohistochemistry and NanoString-based transcriptome profiling using a panel of 760 fibrosis plus 8 bile acid-related genes. Subjects were divided into three groups based on clinical outcomes: NCH (neonatal cholestasis, favourable outcome, n = 5), NCC (neonatal cholestasis, early cirrhosis and liver transplantation, n = 4), and NNCH (no neonatal cholestasis, favourable outcome, n = 5, six biopsies). Hepatocytes containing Z-AAT polymers were abundant in all groups whereas NCC showed higher expression of genes related to liver fibrosis/cirrhosis and lower expression of genes related to lipid, aldehyde/ketone, and bile acid metabolism. Z-AAT accumulation per se cannot explain the clinical outcomes of PiZZ children; however, changes in the expression of specific genes and pathways involved in lipid, fatty acid, and steroid metabolism appear to reflect the degree of liver injury.

Morphological changes without histological myocarditis in hearts of COVID-19 deceased patients.

Objective. Patients with underlying heart diseases have a higher risk of dying from Covid-19. It has also been suggested that Covid-19 affects the heart through myocarditis. Despite the rapidly growing research on the management of Covid-19 associated complications, most of the ongoing research is focused on the respiratory complications of Covid-19, and little is known about the prevalence of myocarditis. Design. This study aimed to characterize myocardial involvement by using a panel of antibodies to detect hypoxic and inflammatory changes and the presence of SARS-CoV-2 proteins in heart tissues obtained during the autopsy procedure of Covid-19 deceased patients. Thirty-seven fatal COVID-19 cases and 21 controls were included in this study. Results. Overall, the Covid-19 hearts had several histopathological changes like the waviness of myocytes, fibrosis, contract band necrosis, infiltration of polymorphonuclear neutrophils, vacuolization, and necrosis of myocytes. In addition, endothelial damage and activation were detected in heart tissue. However, viral replication was not detected using RNA in situ hybridization. Also, lymphocyte infiltration, as a hallmark of myocarditis, was not seen in this study. Conclusion. No histological sign of myocarditis was detected in any of our cases; our findings are thus most congruent with the hypothesis of the presence of a circulating endothelium activating factor such as VEGF, originating outside of the heart, probably from the hypoxic part of the Covid-19 lungs.

Estimating Total Excess Mortality During a Coronavirus Disease 2019 Outbreak in Stockholm, Sweden.

Total excess mortality peaked during a coronavirus disease 2019 (COVID-19) outbreak in Stockholm, but 25% of these deaths were not recognized as COVID-19 related nor occurred in hospitals. Estimate of total excess mortality may give a more comprehensive picture of the total disease burden during a COVID-19 outbreak, and may facilitate managing future outbreaks.

Quantification of low molecular weight selenium metabolites in human plasma after treatment with selenite in pharmacological doses by LC-ICP-MS.

The paper presents an analytical method for quantification of low molecular weight (LMW) selenium compounds in human plasma based on liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS) and post column isotope dilution-based quantification. Prior to analysis, samples were ultrafiltrated using a cut-off value of 3000 Da. The method was validated in aqueous solution as well as plasma using standards of selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), selenite, and the selenosugar Se-methylseleno-N-acetylgalactosamine (SeGal) for linearity, precision, recoveries, and limits of detection and quantitation with satisfactory results. The method was applied for analysis of a set of plasma samples from cancer patients receiving selenite treatment in a clinical trial. Three LMW selenium compounds were observed. The main compounds, SeGal and selenite were tentatively identified by retention time matching with standards in different chromatographic systems, while the third minor compound was not identified. The identity of the selenosugar was verified by ESI-MS-MS product ion scanning, while selenite was identified indirectly as the glutathione (GSH) reaction product, GS-Se-SG.

Selenium induces a multi-targeted cell death process in addition to ROS formation.

Selenium compounds inhibit neoplastic growth. Redox active selenium compounds are evolving as promising chemotherapeutic agents through tumour selectivity and multi-target response, which are of great benefit in preventing development of drug resistance. Generation of reactive oxygen species is implicated in selenium-mediated cytotoxic effects on cancer cells. Recent findings indicate that activation of diverse intracellular signalling leading to cell death depends on the chemical form of selenium applied and/or cell line investigated. In the present study, we aimed at deciphering different modes of cell death in a single cell line (HeLa) upon treatment with three redox active selenium compounds (selenite, selenodiglutathione and seleno-DL-cystine). Both selenite and selenodiglutathione exhibited equipotent toxicity (IC50 5 µM) in these cells with striking differences in toxicity mechanisms. Morphological and molecular alterations provided evidence of necroptosis-like cell death in selenite treatment, whereas selenodiglutathione induced apoptosis-like cell death. We demonstrate that selenodiglutathione efficiently glutathionylated free protein thiols, which might explain the early differences in cytotoxic effects induced by selenite and selenodiglutathione. In contrast, seleno-DL-cystine treatment at an IC50 concentration of 100 µM induced morphologically two distinct different types of cell death, one with apoptosis-like phenotype, while the other was reminiscent of paraptosis-like cell death, characterized by induction of unfolded protein response, ER-stress and occurrence of large cytoplasmic vacuoles. Collectively, the current results underline the diverse cytotoxic effects and variable potential of redox active selenium compounds on the survival of HeLa cells and thereby substantiate the potential of chemical species-specific usage of selenium in the treatment of cancers.

Exploring Selenoprotein P in Liver Cancer: Advanced Statistical Analysis and Machine Learning Approaches.

Selenoprotein P (SELENOP) acts as a crucial mediator, distributing selenium from the liver to other tissues within the body. Despite its established role in selenium metabolism, the specific functions of SELENOP in the development of liver cancer remain enigmatic. This study aims to unravel SELENOP's associations in hepatocellular carcinoma (HCC) by scrutinizing its expression in correlation with disease characteristics and investigating links to hormonal and lipid/triglyceride metabolism biomarkers as well as its potential as a prognosticator for overall survival and predictor of hypoxia. SELENOP mRNA expression was analyzed in 372 HCC patients sourced from The Cancer Genome Atlas (TCGA), utilizing statistical methodologies in R programming and machine learning techniques in Python. SELENOP expression significantly varied across HCC grades (p < 0.000001) and among racial groups (p = 0.0246), with lower levels in higher grades and Asian individuals, respectively. Gender significantly influenced SELENOP expression (p < 0.000001), with females showing lower altered expression compared to males. Notably, the Spearman correlation revealed strong positive connections of SELENOP with hormonal markers (AR, ESR1, THRB) and key lipid/triglyceride metabolism markers (PPARA, APOC3, APOA5). Regarding prognosis, SELENOP showed a significant association with overall survival (p = 0.0142) but explained only a limited proportion of variability (~10%). Machine learning suggested its potential as a predictive biomarker for hypoxia, explaining approximately 18.89% of the variance in hypoxia scores. Future directions include validating SELENOP's prognostic and diagnostic value in serum for personalized HCC treatment. Large-scale prospective studies correlating serum SELENOP levels with patient outcomes are essential, along with integrating them with clinical parameters for enhanced prognostic accuracy and tailored therapeutic strategies.

High risk of primary liver cancer in a cohort of 179 patients with Acute Hepatic Porphyria.

BACKGROUND/AIMS: Previous studies have indicated a high risk of hepatocellular carcinoma in acute hepatic porphyrias. In this retrospective study we present the incidence of primary liver cancer and clinical characteristics in a cohort of 179 acute porphyria patients above the age of 50 years. METHODS: Twenty-three cases with primary liver cancer were found either by a surveillance program or due to clinical suspicion. Standardized rate ratio was used to estimate the relative risk of primary liver cancer after indirect standardization. Survival data were calculated using the Kaplan-Meier method. RESULTS: The mean age at diagnosis was 69 years. Hepatocellular carcinoma was found in 19 patients while four patients had cholangiocarcinoma or a combination of the two. Four patients had underlying cirrhosis. Mean tumour size was 4.3 cm in the surveillance group and 10.3 cm in the non-surveillance group (p = 0.01). The overall relative risk of primary liver cancer was 86 above the age of 50: 150 for women and 37 for men. Mean survival time was 5.7 years. CONCLUSION: Acute hepatic porphyria carries a high risk of primary liver cancer above the age of 50 which warrants ultrasound surveillance. Sex distribution and frequency of cirrhosis differs from more common aetiologies of primary liver cancer.

Selenite induces posttranscriptional blockade of HLA-E expression and sensitizes tumor cells to CD94/NKG2A-positive NK cells.

CD94/NKG2A is an inhibitory receptor that controls the activity of a large proportion of human NK cells following interactions with the nonclassical HLA class Ib molecule HLA-E expressed on target cells. In this study, we show that selenite (SeO(3)(2-)), an inorganic selenium compound, induces an almost complete loss of cell surface expression of HLA-E on tumor cells of various origins. Selenite abrogated the HLA-E expression at a posttranscriptional level, since selenite exposure led to a dose-dependent decrease in cellular HLA-E protein expression whereas the mRNA levels remained intact. The loss of HLA-E expression following selenite treatment was associated with decreased levels of intracellular free thiols in the tumor cells, suggesting that the reduced HLA-E protein synthesis was caused by oxidative stress. Indeed, HLA-E expression and the level of free thiols remained intact following treatment with selenomethionine, a selenium compound that does not generate oxidative stress. Loss of HLA-E expression, but not of total HLA class I expression, on tumor cells resulted in increased susceptibility to CD94/NK group 2A-positive NK cells. Our results suggest that selenite may be used to potentiate the anti-tumor cytotoxicity in settings of NK cell-based immunotherapies.

Combining PD-1/PD-L1 blockade with type I interferon in cancer therapy.

PD-1 and PD-L1 are crucial regulators of immunity expressed on the surface of T cells and tumour cells, respectively. Cancer cells frequently use PD-1/PD-L1 to evade immune detection; hence, blocking them exposes tumours to be attacked by activated T cells. The synergy of PD-1/PD-L1 blockade with type I interferon (IFN) can improve cancer treatment efficacy. Type I IFN activates immune cells boosts antigen presentation and controls proliferation. In addition, type I IFN increases tumour cell sensitivity to the blockade. Combining the two therapies increases tumoral T cell infiltration and activation within tumours, and stimulate the generation of memory T cells, leading to prolonged patient survival. However, limitations include heterogeneous responses, the need for biomarkers to predict and monitor outcomes, and adverse effects and toxicity. Although treatment resistance remains an obstacle, the combined therapeutic efficacy of IFNα/ß and PD-1/PD-L1 blockade demonstrated considerable benefits across a spectrum of cancer types, notably in melanoma. Overall, the phases I and II clinical trials have demonstrated safety and efficiency. In future, further investigations in clinical trials phases III and IV are essential to compare this combinatorial treatment with standard treatment and assess long-term side effects in patients.

Intravenous Infusion of High Dose Selenite in End-Stage Cancer Patients: Analysis of Systemic Exposure to Selenite and Seleno-Metabolites.

Cancer is one of the main causes of human death globally and novel chemotherapeutics are desperately required. As a simple selenium oxide, selenite is a very promising chemotherapeutic because of pronounced its dose-dependent tumor-specific cytotoxicity. We previously published a first-in-man systematic phase I clinical trial in patients with cancer (from IV to end-stage) (the SECAR trial) showing that selenite is safe and tolerable with an unexpectable high maximum tolerated dose (MTD) and short half-life. In the present study, we analyzed the selenium species in plasma samples, from the patients participating in the SECAR trial and from various time points and dose cohorts using LC-ICP-MS. In conclusion, selenite, selenosugars, and 1-2 unidentified peaks that did not correspond to any standard, herein denoted ui-selenium, were detected in the plasma. However, trimethylated selenium (trimethylselenonoium) was not detected. The unidentified ui-selenium was eluting close to the selenium-containing amino acids (selenomethionine and selenocysteine) but was not part of a protein fraction. Our data demonstrate that the major metabolite detected was selenosugar. Furthermore, the identification of selenite even long after the administration is remarkable and unexpected. The kinetic analysis did not support that dosing per the body surface area would reduce interindividual variability of the systemic exposure in terms of trough concentrations.

Exploration of Patient-Derived Pancreatic Ductal Adenocarcinoma Ex Vivo Tissue for Treatment Response.

Patient-derived tissue culture models are valuable tools to investigate drug effects and targeted treatment approaches. Resected tumor slices cultured ex vivo have recently gained interest in precision medicine, since they reflect the complex microenvironment of cancer tissue. In this study, we examined the treatment response to an internally developed ex vivo tissue culture model from pancreatic ductal adenocarcinoma (PDAC) and in vitro analysis. Seven PDAC tissues were cultured and subsequently treated with indole-3-pyruvic acid (IPA). IPA, which is known as an agonist of the aryl hydrocarbon receptor (AHR) pathway, has antioxidant properties. Genome-wide transcriptome sequencing analysis revealed activation of AHR pathway genes (CYP1A1 and CYP1B1, p ≤ 0.05). Additionally, significant upregulation of AHR repressor genes AHRR and TiPARP was also observed (p ≤ 0.05), which is indicative of the negative feedback loop activation of AHR pathway signaling. The overall transcriptomic response to IPA indicated that the tissues are biologically active and respond accordingly to exogenous treatment. Cell culture analysis confirmed the significant induction of selected AHR genes by IPA. A morphological examination of the paraffin-embedded formalin-fixed tissue did not show obvious signs of IPA treatment related to tumor cell damage. This study is a proof of concept that ex vivo patient-derived tissue models offer a valuable tool in precision medicine to monitor the effect of personalized treatments.

FPR2 Shapes an Immune-Excluded Pancreatic Tumor Microenvironment and Drives T-cell Exhaustion in a Sex-Dependent Manner.

Sex-driven immune differences can affect tumor progression and the landscape of the tumor microenvironment. Deeper understanding of these differences in males and females can inform patient selection to improve sex-optimized immunotherapy treatments. In this study, single-cell RNA sequencing and protein analyses uncovered a subpopulation of myeloid cells in pancreatic lesions associated with an immune-excluded tumor phenotype and effector T-cell exhaustion exclusively in females. This myeloid subpopulation was positively correlated with poor survival and genetic signatures of M2-like macrophages and T-cell exhaustion in females. The G-protein coupled receptor formyl peptide receptor 2 (FPR2) mediated these immunosuppressive effects. In vitro, treatment of myeloid cells with a specific FPR2 antagonist prevented exhaustion and enhanced cytotoxicity of effector cells. Proteomic analysis revealed high expression of immunosuppressive secretory proteins PGE2 and galectin-9, enriched integrin pathway, and reduced proinflammatory signals like TNFα and IFNγ in female M2-like macrophages upon FPR2 agonist treatment. In addition, myeloid cells treated with FPR2 agonists induced TIM3 and PD-1 expression only in female T cells. Treatment with anti-TIM3 antibodies reversed T-cell exhaustion and stimulated their ability to infiltrate and kill pancreatic spheroids. In vivo, progression of syngeneic pancreatic tumors was significantly suppressed in FPR2 knockout (KO) female mice compared with wild-type (WT) female mice and to WT and FPR2 KO male mice. In female mice, inoculation of tumors with FPR2 KO macrophages significantly reduced tumor growth compared with WT macrophages. Overall, this study identified an immunosuppressive function of FPR2 in females, highlighting a potential sex-specific precision immunotherapy strategy. SIGNIFICANCE: FPR2 is a sex-dependent mediator of macrophage function in pancreatic cancer and can be targeted to reprogram macrophages and stimulate antitumor immunity in females.

Effects of redox modulation by inhibition of thioredoxin reductase on radiosensitivity and gene expression.

The thioredoxin system is a promising target when aiming to overcome the problem of clinical radiation resistance. Altered cellular redox status and redox sensitive thiols contributing to induction of resistance strongly connect the ubiquitous redox enzyme thioredoxin reductase (TrxR) to the cellular response to ionizing radiation. To further investigate possible strategies in combating clinical radiation resistance, human radio-resistant lung cancer cells were subjected to a combination of single fractions of γ-radiation at clinically relevant doses and non-toxic levels of a well-characterized thioredoxin reductase inhibitor, the phosphine gold(I) compound [Au(SCN)(PEt(3))]. The combination of the TrxR-inhibitor and ionizing radiation reduced the surviving fractions and impaired the ability of the U1810 cells to repopulate by approximately 50%. In addition, inhibition of thioredoxin reductase caused changes in the cell cycle distribution, suggesting a disturbance of the mitotic process. Global gene expression analysis also revealed clustered genetic expression changes connected to several major cellular pathways such as cell cycle, cellular response to stress and DNA damage. Specific TrxR-inhibition as a factor behind the achieved results was confirmed by correlation of gene expression patterns between gold and siRNA treatment. These results clearly demonstrate TrxR as an important factor conferring resistance to irradiation and the use of [Au(SCN)(PEt(3))] as a promising radiosensitizing agent.

The value of thioredoxin family proteins and proliferation markers in dysplastic and malignant gallbladders in patients with primary sclerosing cholangitis.

BACKGROUND AND AIMS: Patients with primary sclerosing cholangitis (PSC) have an increased risk for biliary and gallbladder malignancy and markers of early malignancy in PSC are lacking. The aims were to evaluate biomarkers to look for premalignancy/malignancy. METHODS: All available gallbladder specimens (n = 53) in patients with PSC at Karolinska University Hospital between 1985 and 2006 were reviewed. Immunohistochemical staining for p53, Ki-67, Cyclin D1 and the thioredoxin family redox proteins; Thioredoxin reductase 1 (TrxR1), isoform-TrxR1-v.2.3.5, Thioredoxin (Trx1) and Glutaredoxin1 (Grx1) was performed on tissues from patients with carcinoma (n = 6), dysplasia (n = 7) and non-cancerous gallbladder epithelium (n = 6). RESULTS: Dysplasia and carcinoma were found in 16/53 (30%) cases. Inflammation and fibrosis of the gallbladder wall were more common in tissue with gallbladder dysplasia/carcinoma than in benign tissue 12/25 (48%) versus 4/28 (12%) (p < 0.01) and in 13/21 (62%) versus 3/32 (9%) (p < 0.0001), respectively. Immunoreactivity for p53, Ki67, Cyclin D1 was detected in significantly more cases of dysplasia/carcinoma of the gallbladder than in non-cancerous epithelium. 2/19 (11%) of the samples were positive in non-cancerous epithelium versus 7/17 (41%) in dysplasia/carcinoma (p < 0.05) for TrxR1-v.2.3.5. Grx1 was down regulated; more specifically 15/19 (79%) positive cases in non-cancerous epithelium versus 7/17 (41%) in dysplasia/carcinoma. CONCLUSION: PSC patients have a frequency of gallbladder dysplasia/carcinoma of 30% in operative specimens. The overexpression of TrxR1-v2,3,5 and down regulation of Grx1 in dysplastic gallbladder epithelium suggest that these proteins should be further evaluated as possible future immunohistochemical markers in the early diagnosis of biliary malignancy in PSC.

Extracellular thiol-assisted selenium uptake dependent on the x(c)- cystine transporter explains the cancer-specific cytotoxicity of selenite.

The selenium salt selenite (SeO(3)(2-)) is cytotoxic in low to moderate concentrations, with a remarkable specificity for cancer cells resistant to conventional chemotherapy. Our data show that selenium uptake and accumulation, rather than intracellular events, are crucial to the specific selenite cytotoxicity observed in resistant cancer cells. We show that selenium uptake depends on extracellular reduction, and that the extracellular environment is a key factor specific to selenite cytotoxicity. The extracellular reduction is mediated by cysteine, and the efficacy is determined by the uptake of cystine by the x(c)(-) antiporter and secretion of cysteine by multidrug resistance proteins, both of which are frequently overexpressed by resistant cancer cells. This mechanism provides molecular evidence for the existence of an inverse relationship between resistance to conventional chemotherapy and sensitivity to selenite cytotoxicity, and highlights the great therapeutic potential in treating multidrug-resistant cancer.

Soluble PD-L1 Expression After Intravenous Treatment of Cancer Patients With Selenite in Phase I Clinical Trial.

A high expression level of programmed death-ligand 1 (PD-L1) is observed in different types of cancers (particularly lung cancer). Soluble (s)PD-L1 may be used as a prognostic marker and a target for anti-cancer immunity, as well as, predicting gene therapy or systemic immunotherapy in blocking the PD-1 and PD-L1 checkpoint. Studies that evaluate the effects of the immune regulator selenium on PD-L1 expression show ambiguous results. Thus, we aimed to analyze sPD-L1 levels in samples from patients who underwent different dosages of selenite treatment in phase I clinical trial. We hypothesized that selenite modulates the sPD-L1 levels in the plasma as a consequence of the suggested mode of action of selenotherapy in cancer patients. In conclusion, our results support the view that selenotherapy does not substantially affect the PD-1/PD-L1 axis judged by sPD-L1 analysis. Furthermore, no significant correlation was observed between the survival and sPD-L1 expression nor sPD-L1 changes. However, due to a dynamic individual sPD-L1 profile and a high variation in survival, we suggest that further studies are needed to identify whether individual patients can be benefited from combinational seleno- and anti-PD-L1 therapy.

Methods for accurate and reproducible studies of pharmacological effects of selenium in cancer.

Selenium compounds have pronounced effects on cell growth and proliferation. Nutritional levels induce selenoproteins. However, the antineoplastic effects of supra-nutritional selenium levels are not mediated by selenoproteins. The most studied compound, selenite, was shown in a clinical trial to possess extraordinary pharmacological properties. The uptake of selenite as for GS-Se-SG and selenocystine is dependent on the extracellular reducing environment maintained by the Xc- cystine transporter (xc- antiporter) ensuring a high level of extracellular cysteine. The expression of the xc- antiporter is vital for selenium cytotoxicity and any xenobiotic or media constituents modulating the expression of this antiporter will greatly affect the cellular response. Cytotoxicity determinations are often difficult to interpret and repeat due to differences in culture conditions. In the current chapter, factors influencing the cellular response, e.g., media composition, cell culturing conditions, assays for key enzymes of importance for selenium metabolism and effects, along with selenium mediated modulation of microRNA expression and immune responses are treated.

Proteomic Analysis of Pleural Effusions from COVID-19 Deceased Patients: Enhanced Inflammatory Markers.

Critically ill COVID-19 patients with pleural effusion experience longer hospitalization, multisystem inflammatory syndrome, and higher rates of mortality. Generally, pleural effusion can serve as a diagnostic value to differentiate cytokine levels. This study aimed to evaluate the pleural effusions of COVID-19 deceased patients for 182 protein markers. Olink® Inflammation and Organ Damage panels were used to determine the level of 184 protein markers, e.g., ADA, BTC, CA12, CAPG, CD40, CDCP1, CXCL9, ENTPD2, Flt3L, IL-6, IL-8, LRP1, OSM, PD-L1, PTN, STX8, and VEGFA, which were raised significantly in COVID-19 deceased patients, showing over-stimulation of the immune system and ravaging cytokine storm. The rises of DPP6 and EDIL3 also indicate damage caused to arterial and cardiovascular organs. Overall, this study confirms the elevated levels of CA12, CD40, IL-6, IL-8, PD-L1, and VEGFA, proposing their potential either as biomarkers for the severity and prognosis of the disease or as targets for therapy. Particularly, this study reports upregulated ADA, BTC, DPP6, EDIL3, LIF, ENTPD2, Flt3L, and LRP1 in severe COVID-19 patients for the first time. Pearson's correlation coefficient analysis indicates the involvement of JAK/STAT pathways as a core regulator of hyperinflammation in deceased COVID-19 patients, suggesting the application of JAK inhibitors as a potential efficient treatment.

Can laboratory x-ray virtual histology provide intraoperative 3D tumor resection margin assessment?

Purpose: Surgery is an essential part of the curative plan for most patients affected with solid tumors. The outcome of such surgery, e.g., recurrence rates and ultimately patient survival, depends on several factors where the resection margin is of key importance. Presently, the resection margin is assessed by classical histology, which is time-consuming (several days), destructive, and basically only gives two-dimensional information. Clearly, it would be advantageous if immediate feedback on tumor extension in all three dimensions were available to the surgeon intraoperatively. Approach: We investigate a laboratory propagation-based phase-contrast x-ray computed tomography system that provides the resolution, the contrast, and, potentially, the speed for this purpose. The system relies on a liquid-metal jet microfocus source and a scintillator-coated CMOS detector. Our study is performed on paraffin-embedded non-stained samples of human pancreatic neuroendocrine tumors, liver intrahepatic cholangiocarcinoma, and pancreatic serous cystic neoplasm (benign). Results: We observe tumors with distinct and sharp edges having cellular resolution ( ∼ 10 µ m ) as well as many assisting histological landmarks, allowing for resection margin assessment. All x-ray data are compared with classical histology. The agreement is excellent. Conclusion: We conclude that the method has potential for intraoperative three-dimensional virtual histology.

Drug-induced tumor-specific cytotoxicity in a whole tissue ex vivo model of human pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer. PDAC has a dismal prognosis and an inherent resistance to cytostatic drugs. The lack of reliable experimental models is a severe limitation for drug development targeting PDAC. We have employed a whole tissue ex vivo culture model to explore the effect of redox-modulation by sodium selenite on the viability and growth of PDAC. Drug-resistant tumors are more vulnerable to redox-active selenium compounds because of high metabolic activity and redox imbalance. Sodium selenite efficiently and specifically reduced PDAC cell viability (p <0.02) (n=8) and decreased viable de novo tumor cell outgrowth (p<0.05) while preserving non-neoplastic tissues. Major cellular responses (damaged tumor cells > 90%, tumor regression grades III-IV according to Evans) were observed for sodium selenite concentrations between 15-30 µM. Moreover, selenium levels used in this study were significantly below the previously reported maximum tolerated dose for humans. Transcriptome data analysis revealed decreased expression of genes known to drive PDAC growth and metastatic potential (CEMIP, DDR2, PLOD2, P4HA1) while the cell death-inducing genes (ATF3, ACHE) were significantly upregulated (p<0.0001). In conclusion, we report that sodium selenite has an extraordinary efficacy and specificity against drug-resistant pancreatic cancer in an organotypic slice culture model. Our ex vivo organotypic tissue slice culture model can be used to test a variety of drug candidates for swift and reliable drug responses to individual PDAC cases.