Characterization of Human Keratinocyte Cell Lines for Barrier Studies

Epidermal cell models are critical for studying skin biology. The gold standard used by the scientific community has historically been primary cell cultures from discarded tissue, typically from neonates (foreskin). Although directly applicable to humans, this system suffers from multiple issues, including substantial donor-to-donor variability and a finite number of divisions in culture. As such, we have identified a faithful alternative called N/TERT2G cells. These cells show many of the characteristics of primary cells, including barrier formation, differentiation kinetics and/or protein expression, and pathogenesis. From our observations, N/TERT2G cells can serve as a reproducible and genetically manipulatable platform in studying skin biology.

New insights into the pathophysiology and clinical care of rare primary liver cancers

Hepatocholangiocarcinoma, fibrolamellar carcinoma, hepatic haemangioendothelioma and hepatic angiosarcoma represent less than 5% of primary liver cancers. Fibrolamellar carcinoma and hepatic haemangioendothelioma are driven by unique somatic genetic alterations (DNAJB1-PRKCA and CAMTA1-WWTR1 fusions, respectively), while the pathogenesis of hepatocholangiocarcinoma remains more complex, as suggested by its histological diversity. Histology is the gold standard for diagnosis, which remains challenging even in an expert centre because of the low incidences of these liver cancers. Resection, when feasible, is the cornerstone of treatment, together with liver transplantation for hepatic haemangioendothelioma. The role of locoregional therapies and systemic treatments remains poorly studied. In this review, we aim to describe the recent advances in terms of diagnosis and clinical management of these rare primary liver cancers.

Cell of origin in biliary tract cancers and clinical implications

Biliary tract cancers (BTCs) are aggressive epithelial malignancies that can arise at any point of the biliary tree. Albeit rare, their incidence and mortality rates have been rising steadily over the past 40 years, highlighting the need to improve current diagnostic and therapeutic strategies. BTCs show high inter- and intra-tumour heterogeneity both at the morphological and molecular level. Such complex heterogeneity poses a substantial obstacle to effective interventions. It is widely accepted that the observed heterogeneity may be the result of a complex interplay of different elements, including risk factors, distinct molecular alterations and multiple potential cells of origin. The use of genetic lineage tracing systems in experimental models has identified cholangiocytes, hepatocytes and/or progenitor-like cells as the cells of origin of BTCs. Genomic evidence in support of the distinct cell of origin hypotheses is growing. In this review, we focus on recent advances in the histopathological subtyping of BTCs, discuss current genomic evidence and outline lineage tracing studies that have contributed to the current knowledge surrounding the cell of origin of these tumours.

Occult mucin-producing urothelial-type adenocarcinoma of the prostate with elevated serum levels of carcinoembryonic antigen and carbohydrate antigen 19-9: Report of an autopsy-proven case

Mucin-producing urothelial-type adenocarcinoma of the prostate (MPUAP) is a rare, aggressive neoplasm thought to originate from the prostatic urethral urothelium. Our case is the first reported to show significantly increased serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in MPUAP. An autopsy revealed occult MPUAP with prominent seminal vesicle, perineural, lymphatic vessel, and vascular invasion and extensive bone metastases. Duration of survival in this case was far shorter than average, and extensive bone metastases were rare in previously reported cases. This suggests serum CEA and CA19-9 levels can be an important prognostic factor in MPUAP.

A unique case of a huge mixed squamous cell and glandular papilloma of non-endobronchial origin with a peripheral growth

We report a case of a huge solitary non-endobronchial pulmonary tumor in a 76-year-old male smoker. The tumor measured 11 × 10 × 8 cm. It was ill-defined, and it was located periphery of the right lower lobe with the subpleural cystic spaces. He underwent right lower lobectomy with mediastinal lymph node dissection and is free from tumor 30 months after surgery. Microscopically, it was composed of a proliferation of squamous and ciliated columnar epithelial cells with a few mucous cells. These cells were arranged in a papillary growth fashion extending along the fibrously thickened alveolar septa together with metaplastic bronchiolar and squamous epithelia displaying an usual interstitial pneumonia-pattern. Although the histologic features of the tumor were that of a mixed squamous cell and glandular papilloma (MSCGP), it was peripherally located and showed a lepidic growth, and it was much larger than previously reported MSCGPs. It is possible that the tumor developed in association with bronchial metaplasia in the periphery of the lung, and then extended along the surface of the reconstructed air spaces, which resulted in its unique histologic appearance. Further investigations of respiratory papilloma are needed to clarify the pathogenesis of these lesions.

Colorectal Cancer Liver Metastasis: Evolving Paradigms and Future Directions

In patients with colorectal cancer (CRC) that metastasizes to the liver, there are several key goals for improving outcomes including early detection, effective prognostic indicators of treatment response, and accurate identification of patients at high risk for recurrence. Although new therapeutic regimens developed over the past decade have increased survival, there is substantial room for improvement in selecting targeted treatment regimens for the patients who will derive the most benefit. Recently, there have been exciting developments in identifying high-risk patient cohorts, refinements in the understanding of systemic vs localized drug delivery to metastatic niches, liquid biomarker development, and dramatic advances in tumor immune therapy, all of which promise new and innovative approaches to tackling the problem of detecting and treating the metastatic spread of CRC to the liver. Our multidisciplinary group held a state-of-the-science symposium this past year to review advances in this rapidly evolving field. Herein, we present a discussion around the issues facing treatment of patients with CRC liver metastases, including the relationship of discrete gene signatures with prognosis. We also discuss the latest advances to maximize regional and systemic therapies aimed at decreasing intrahepatic recurrence, review recent insights into the tumor microenvironment, and summarize advances in noninvasive multimodal biomarkers for early detection of primary and recurrent disease. As we continue to advance clinically and technologically in the field of colorectal tumor biology, our goal should be continued refinement of predictive and prognostic studies to decrease recurrence after curative resection and minimize treatment toxicity to patients through a tailored multidisciplinary approach to cancer care.

Colorectal Cancer Liver Metastasis: Evolving Paradigms and Future Directions

In patients with colorectal cancer (CRC) that metastasizes to the liver, there are several key goals for improving outcomes including early detection, effective prognostic indicators of treatment response, and accurate identification of patients at high risk for recurrence. Although new therapeutic regimens developed over the past decade have increased survival, there is substantial room for improvement in selecting targeted treatment regimens for the patients who will derive the most benefit. Recently, there have been exciting developments in identifying high-risk patient cohorts, refinements in the understanding of systemic vs localized drug delivery to metastatic niches, liquid biomarker development, and dramatic advances in tumor immune therapy, all of which promise new and innovative approaches to tackling the problem of detecting and treating the metastatic spread of CRC to the liver. Our multidisciplinary group held a state-of-the-science symposium this past year to review advances in this rapidly evolving field. Herein, we present a discussion around the issues facing treatment of patients with CRC liver metastases, including the relationship of discrete gene signatures with prognosis. We also discuss the latest advances to maximize regional and systemic therapies aimed at decreasing intrahepatic recurrence, review recent insights into the tumor microenvironment, and summarize advances in noninvasive multimodal biomarkers for early detection of primary and recurrent disease. As we continue to advance clinically and technologically in the field of colorectal tumor biology, our goal should be continued refinement of predictive and prognostic studies to decrease recurrence after curative resection and minimize treatment toxicity to patients through a tailored multidisciplinary approach to cancer care.

Induction of hepatic tissues in multicellular spheroids composed of murine fetal hepatic cells and embedded hydrogel beads

Introduction

Three-dimensional (3D) multicellular spheroids are useful tools for simulation of cellular functions in vitro. However, it is difficult to culture certain epithelial cell types under 3D spheroid conditions because these cells cannot resist autonomous cell death, triggered by disordered cell polarity. The objective of this study was to find a method that enables spheroid culture of such epithelial cells utilizing hydrogel beads without cell death.

Methods

We used murine E14.5 fetal hepatic cells for the spheroid composition because they are sensitive to disorganized structures. Spheroids were formed by injecting 1-μl fresh medium containing 1000 fetal hepatic cells and the same number of alginate hydrogel beads (20 μm in diameter) into a 3% methylcellulose medium in the presence of dexamethasone and oncostatin M to induce hepatic differentiation. After 7 days of culture, microstructures were observed using hematoxylin and eosin staining and immunostaining using anti-CK8/18 antibody. Albumin secretion rate was determined by the enzyme-linked immunosorbent assay method. In addition, polarity-related proteins, E-cadherin, ezrin, and MRP2 were observed with immunostaining.

Results

Control spheroids without the use of alginate hydrogel beads showed extensive internal lack of epithelial hepatic cells. The spheroids containing alginate hydrogel beads exhibited sheet- or cord-like structures of epithelial hepatic cells, and it was clear that cell death of epithelial cells had been prevented. Albumin secretion data also supported the improvement of epithelial hepatic cell viability when alginate hydrogel beads were used. Localization of polarity-related proteins indicated the partial reconstitution of cell polarity in the spheroids using alginate hydrogel beads.

Conclusion

Based on these data, we concluded that the application of alginate hydrogel beads was effective in improving the epithelial hepatic cell culture of multicellular spheroids.

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It was difficult to maintain epithelial fetal hepatic cells in their multicellular spheroids.

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The difficulty to maintain the fetal hepatic cells was overcome by embedding of alginate hydrogel beads into the spheroids.

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Albumin secretion was improved by embedding of the alginate hydrogel beads.

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Cell polarity was partially established in the hybrid spheroids.

Inhibition of CDK-mediated phosphorylation of Smad3 results in decreased oncogenesis in triple negative breast cancer cells

Breast cancer onset and disease progression have been linked to members of the TGFβ superfamily and their downstream signaling components, the Smads. Alterations in Smad3 signaling are associated with the dichotomous role of TGFβ in malignancy, mediating both tumor suppressant and pro-metastatic behaviors. Overexpression of cell cycle regulators, cyclins D and E, renders cyclin-dependent kinases (CDKs) 4/2 hyperactive. Noncanonical phosphorylation of Smad3 by CDK4/2 inhibits tumor suppressant actions of Smad3. We hypothesized that CDK inhibition (CDKi) would restore Smad3 action and help promote cancer cell regression. Treatment of triple-negative breast cancer (TNBC) cell lines (MDA-MB-231, MDA-MB-436, Hs578T) with CDK2i or CDK4i resulted in increased Smad3 activity and decreased cell migration. Transfection with a 5M Smad3 construct containing inhibitory mutations in 5 CDK phosphorylation sites also resulted in decreased TNBC cell migration and invasion. MDA-MB-231 cells treated with CDK2i or CDK4i resulted in decreased Smad3 protein phosphorylation at the CDK phosphorylation T179 site, decreased MMP2 and c-myc expression, and increased p15 and p21 expression. Using a novel transfected cell array, we found that CDK2i treatment decreased activity of the epithelial-to-mesenchymal transition related transcription factors Snail and Twist. In vivo studies in an MDA-MB-231 tumor model showed that individual and combination treatment with paclitaxel and CDK2i resulted in decreased tumor volume and Ki67 staining. Collectively, these data support further investigation of targeted CDK inhibitors as a promising therapeutic strategy for TNBC, a breast cancer subtype with limited treatment options.

A new role for the PI3K/Akt signaling pathway in the epithelial-mesenchymal transition

Tumor metastasis is not only a sign of disease severity but also a major factor causing treatment failure and cancer-related death. Therefore, studies on the molecular mechanisms of tumor metastasis are critical for the development of treatments and for the improvement of survival. The epithelial-mesenchymal transition (EMT) is an orderly, polygenic biological process that plays an important role in tumor cell invasion, metastasis and chemoresistance. The complex, multi-step process of EMT involves multiple regulatory mechanisms. Specifically, the PI3K/Akt signaling pathway can affect the EMT in a variety of ways to influence tumor aggressiveness. A better understanding of the regulatory mechanisms related to the EMT can provide a theoretical basis for the early prediction of tumor progression as well as targeted therapy.

Intrahepatic cholangiocarcinoma masquerading as liver abscess

Malignancy masquerading as liver abscess, and presenting with fever, is mainly described in patients with colorectal cancers with liver metastasis. Primary liver tumors such as hepatocellular carcinoma or intrahepatic cholangiocarcinoma presenting as non-resolving liver abscess is extremely uncommon and carries a dismal prognosis. We present a rare case of non-resolving liver abscess as a presenting manifestation of intrahepatic cholangiocarcinoma.

Tumor stroma-derived factors skew monocyte to dendritic cell differentiation toward a suppressive CD14+ PD-L1+ phenotype in prostate cancer

Tumor-associated stromal myofibroblasts are essential for the progression and metastatic spread of solid tumors. Corresponding myeloid cell infiltration into primary tumors is a negative prognostic factor in some malignancies. The aim of this study was to define the exact role of stromal myofibroblasts and stromal factors in early prostate carcinoma (PCa) regulating monocyte infiltration and differentiation into dendritic cells (DCs). Epithelial and stromal primary cultures were generated from PCa biopsies and their purity confirmed. Stromal cells produced significantly more of the (C-C) motif chemokine ligand 2 (CCL2), interleukin 6 (IL-6) and transforming growth factor β (TGFβ) than epithelial cells. Monocyte chemoattraction was predominantly due to stromal-derived factors, mainly CCL2. DCs generated in the presence of stromal (but not epithelial) factors upregulated CD209, but failed to downregulate the monocyte marker CD14 in a signal transducer and activator of transcription 3 (STAT3)-dependent manner. Monocytes exposed to stromal factors did not produce detectable amounts of IL-10, however, upon lipopolysaccharide stimulation, stromal factor generated dendritic cells (sDC) produced significantly more IL-10 and less IL-12 than their conventional DC counterparts. sDC failed to cross-present tumor-antigen to CD8⁺ T cells and suppressed T-cell proliferation. Most importantly, sDC expressed significantly elevated levels of programmed cell death ligand-1 (PD-L1) in a primarily STAT3 and IL-6-dependent manner. In parallel with our findings in vitro, tumor-infiltrating CD14⁺ cells in situ were found to express both PD-L1 and CD209, and a higher percentage of tumor-associated CD3⁺ T cells expressed programmed cell death-1 (PD-1) molecules compared to T cells in blood. These results demonstrate a hitherto undescribed, fundamental contribution of tumor-associated stromal myofibroblasts to the development of an immunosuppressive microenvironment in early PCa.

Characterization of the liver-macrophages isolated from a mixed primary culture of neonatal swine hepatocytes

We recently developed a novel procedure to obtain liver-macrophages in sufficient number and purity using a mixed primary culture of rat and bovine hepatocytes. In this study, we aim to apply this method to the neonatal swine liver. Swine parenchymal hepatocytes were isolated by a two-step collagenase perfusion method and cultured in T75 culture flasks. Similar to the rat and bovine cells, the swine hepatocytes retained an epithelial cell morphology for only a few days and progressively changed into fibroblastic cells. After 5–13 days of culture, macrophage-like cells actively proliferated on the mixed fibroblastic cell sheet. Gentle shaking of the culture flask followed by the transfer and brief incubation of the culture supernatant resulted in a quick and selective adhesion of macrophage-like cells to a plastic dish surface. After rinsing dishes with saline, the attached macrophage-like cells were collected at a yield of 10⁶ cells per T75 culture flask at 2–3 day intervals for more than 3 weeks. The isolated cells displayed a typical macrophage morphology and were strongly positive for macrophage markers, such as CD172a, Iba-1 and KT022, but negative for cytokeratin, desmin and a-smooth muscle actin, indicating a highly purified macrophage population. The isolated cells exhibited phagocytosis of polystyrene microbeads and a release of inflammatory cytokines upon lipopolysaccharide stimulation. This shaking and attachment method is applicable to the swine liver and provides a sufficient number of macrophages without any need of complex laboratory equipments.

Study designs to investigate Nox1 acceleration of neoplastic progression in immortalized human epithelial cells by selection of differentiation resistant cells

To investigate the role of NADPH oxidase homolog Nox1 at an early step of cell transformation, we utilized human gingival mucosal keratinocytes immortalized by E6/E7 of human papillomavirus (HPV) type 16 (GM16) to generate progenitor cell lines either by chronic ethanol exposure or overexpression with Nox1. Among several cobblestone epithelial cell lines obtained, two distinctive spindle cell lines - FIB and NuB1 cells were more progressively transformed exhibiting tubulogenesis and anchorage-independent growth associated with increased invasiveness. These spindle cells acquired molecular markers of epithelial mesenchymal transition (EMT) including mesenchymal vimentin and simple cytokeratins (CK) 8 and 18 as well as myogenic alpha-smooth muscle actin and caldesmon. By overexpression and knockdown experiments, we showed that Nox1 on a post-translational level regulated the stability of CK18 in an ROS-, phosphorylation- and PKCepilon-dependent manner. PKCepilon may thus be used as a therapeutic target for EMT inhibition. Taken together, Nox1 accelerates neoplastic progression by regulating structural intermediate filaments leading to EMT of immortalized human gingival epithelial cells.