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Human pluripotent stem cells can be differentiated into exocrine pancreas progenitor organoids, allowing studies of development and pancreatic cancer modeling. There are few in vitro models of exocrine pancreas development and primary human pancreatic adenocarcinoma (PDAC). We establish three-dimensional culture conditions to induce the differentiation of human pluripotent stem cells into exocrine progenitor organoids that form ductal and acinar structures in culture and in vivo. Expression of mutant KRAS or TP53 in progenitor organoids induces mutation-specific phenotypes in culture and in vivo . Expression of TP53 R175H induces cytosolic SOX9 localization. In patient tumors bearing TP53 mutations, SOX9 was cytoplasmic and associated with mortality. We also define culture conditions for clonal generation of tumor organoids from freshly resected PDAC. Tumor organoids maintain the differentiation status, histoarchitecture and phenotypic heterogeneity of the primary tumor and retain patient-specific physiological changes, including hypoxia, oxygen consumption, epigenetic marks and differences in sensitivity to inhibition of the histone methyltransferase EZH2. Thus, pancreatic progenitor organoids and tumor organoids can be used to model PDAC and for drug screening to identify precision therapy strategies.

The contribution of basal and luminal cells to cancer progression and metastasis is poorly understood. We report generation of reporter systems driven by either keratin-14 (K14) or keratin-8 (K8) promoter that not only express a fluorescent protein but also an inducible suicide gene. Transgenic mice express the reporter genes in the right cell compartments of mammary gland epithelia and respond to treatment with toxins. In addition, we engineered the reporters into 4T1 metastatic mouse tumor cell line and demonstrate that K14+ cells, but not K14- or K8+, are both highly invasive in three-dimensional (3D) culture and metastatic in vivo. Treatment of cells in culture, or tumors in mice, with reporter-targeting toxin inhibited both invasive behavior and metastasis in vivo. RNA sequencing (RNA-seq), secretome, and epigenome analysis of K14+ and K14- cells led to the identification of amphoterin-induced protein 2 (Amigo2) as a new cell invasion driver whose expression correlated with decreased relapse-free survival in patients with TP53 wild-type (WT) breast cancer.

Muthuswamy  et al.  report that in macrophages SCRIB interacts with the NADPH oxidase complex to promote the production of reactive oxygen species needed to kill bacteria. Conversely, loss of SCRIB promotes M1 macrophage polarization and inflammation. The polarity protein Scribble (SCRIB) regulates apical–basal polarity, directional migration and tumour suppression in Drosophila and mammals 1 , 2 , 3 , 4 , 5 , 6 . Here we report that SCRIB is an important regulator of myeloid cell functions including bacterial infection and inflammation. SCRIB interacts directly with the NADPH oxidase (NOX) complex in a PSD95/Dlg/ZO-1 (PDZ)-domain-dependent manner and is required for NOX-induced reactive oxygen species (ROS) generation in culture and in vivo . On bacterial infection, SCRIB localized to phagosomes in a leucine-rich repeat-dependent manner and promoted ROS production within phagosomes to kill bacteria. Unexpectedly, SCRIB loss promoted M1 macrophage polarization and inflammation. Thus, SCRIB uncouples ROS-dependent bacterial killing activity from M1 polarization and inflammatory functions of macrophages. Modulating the SCRIB–NOX pathway can therefore identify ways to manage infection and inflammation with implications for chronic inflammatory diseases, sepsis and cancer.

Patient-derived xenograft (PDX) and their xenograft-derived organoid (XDO) models that recapitulate the genotypic and phenotypic landscape of patient cancers could help to advance research and lead to improved clinical management. PDX models were established from 276 pancreato-duodenal and biliary cancer resections. Initial, passage 0 (P0) engraftment rates were 59% (118/199) for pancreatic, 86% (25/29) for duodenal, and 35% (17/48) for biliary ductal tumors. Pancreatic ductal adenocarcinoma (PDAC), had a P0 engraftment rate of 62% (105/169).  KRAS  mutant and wild-type PDAC models were molecularly profiled, and XDO models were generated to perform initial drug response evaluations. Subsets of PDAC PDX models showed global copy number variants and gene expression profiles that were retained with serial passaging, and they showed a spectrum of somatic mutations represented in patient tumors. PDAC XDO models were established, with a success rate of 71% (10/14). Pathway activation of KRAS-MAPK in PDXs was independent of  KRAS  mutational status. Four wild-type KRAS models were characterized by one with  EGFR  (L747-P753 del), two with BRAF alterations (N486_P490del or V600E), and one with triple negative  KRAS/EGFR/BRAF . Model OCIP256, characterized by BRAF (N486-P490 del), had activated phospho-ERK. A combination treatment of a pan-RAF inhibitor (LY3009120) and a MEK inhibitor (trametinib) effectively suppressed phospho-ERK and inhibited growth of OCIP256 XDO and PDX models. PDAC/duodenal adenocarcinoma have high success rates forming PDX/organoid and retaining their phenotypic and genotypic features. These models may be effective tools to evaluate novel drug combination therapies.

Using spectral filters, Cladonia uncialis and Cladina rangiferina were exposed for seven days to visible light supplemented with two intensities of three different bands of ultraviolet in a growth chamber. The concentrations of lichen secondary products separated by thin-layer chromatography were then determined densitometrically. In Cladonia uncialis, higher intensity exposure to visible light enhanced with UV-A, while UV-B and UV-C were excluded, significantly increased usnic acid concentrations over control levels. However, less usnic acid accumulated under high intensity enhancement of both UV-A and UV-B. The effect of supplemental UV-A and UV-B was the same on atranorin concentrations in Cladina rangiferina. This suggested that UV-A caused increased accumulation of both compounds, but that the effect was negated by UV-B. Concentrations of usnic acid in natural populations of Cladina mitis were significantly lower in spring and summer when UV-B flux is greatest.

This study tested the photolability of lichen products under different bands of ultraviolet (UV) light. Following various UV treatments in a growth chamber, analysis of chromatographically separated secondary compounds of Cladina uncialis through use of a transilluminator and gel documentation system showed higher levels of usnic acid were observed under UV-A and visible light in the absence of UV-B. The greatest concentrations were observed under the greatest flux. After treatment with high intensity UV-A/B from the transilluminator, compounds in acetone extracts of Cladina uncialis, C. rangiferina, Umbilicaria mammulata and Peltigera aphthosa were separated on thin-layer plates. Banding patterns of C. rangiferina, U. mammulata and P. aphthosa extracts were not altered by UV, but those of C. uncialis began to change after approximately 25 minutes of exposure. Intact thalli were also exposed to UV-A/B and phenolics extracted from these were qualitatively compared to UV-exposed isolated extracts. No visual differences in secondary products were observed in UV-exposed lichens suggesting phenolic integrity is better maintained within a thallus than in the isolated form. The effect of UV on usnic acid in intact thalli of C. uncialis was compared in killed and live thalli and the significantly lower concentrations found in dead material indicated that metabolic activity played a role in maintaining usnic acid levels. Comparisons of wet and dry samples revealed that hydrated thalli contained less usnic acid and suggested that degradation was more pronounced when the thallus was wet and perhaps more transparent to light. Lichen compounds are thus relatively stable under UV, but usnic acid is one compound that can be degraded by absorbing UV energy and thus may provide a degree of protection for the thallus.

A densitometric technique was developed that permitted rapid quantification of lichen compounds separated by thin-layer chromatography. Thin-layer plates were scanned in a densitometer using a UV light source and density-dependent absorbance or fluorescence was measured for each compound. The lichen products tested differed with respect to photostability under UV, and thus in the time taken to achieve constant densitometric readings. Minimal exposure times required for stabilization of the compounds tested ranged from 3 min to 2.5 hr.