Abstract

PURPOSE:

Ocular adnexal (OA) sebaceous carcinoma is an aggressive malignancy of the eyelid and ocular adnexa that frequently recurs and metastasizes, and effective therapies beyond surgical excision are lacking. There remains a critical need to define the molecular-genetic drivers of the disease to understand carcinomagenesis and progression and to devise novel treatment strategies.

EXPERIMENTAL DESIGN:

We present next generation sequencing of a targeted panel of cancer-associated genes in 42 and whole transcriptome RNA sequencing from 8 OA sebaceous carcinomas from 29 patients.

RESULTS:

We delineate two potentially distinct molecular-genetic subtypes of OA sebaceous carcinoma. The first is defined by somatic mutations impacting TP53 and/or RB1 (20/29 [70%] patients, including 10 patients whose primary tumors contained co-existing TP53 and RB1 mutations) with frequent concomitant mutations affecting NOTCH genes. These tumors arise in older patients and show frequent local recurrence. The second subtype (9/29 [31%] patients) lacks mutations affecting TP53, RB1, or NOTCH family members, but in 44% (4/9) of these tumors, RNA sequencing and in situ hybridization studies confirm transcriptionally active high-risk human papillomavirus (HPV). These tumors arise in younger patients and have not shown local recurrence.

CONCLUSIONS:

Together, our findings establish a potential molecular-genetic framework by which to understand the development and progression of OA sebaceous carcinoma and provide key molecular-genetic insights to direct the design of novel therapeutic interventions.

Abstract

BACKGROUND:

The LKB1 tumor suppressor gene is commonly inactivated in non-small cell lung carcinomas (NSCLC), a major form of lung cancer. Targeted therapies for LKB1-inactivated lung cancer are currently unavailable. Identification of critical signaling components downstream of LKB1 inactivation has the potential to uncover rational therapeutic targets. Here we investigated the role of INSL4, a member of the insulin/IGF/relaxin superfamily, in LKB1-inactivated NSCLCs.

METHODS:

INSL4 expression was analyzed using global transcriptome profiling, quantitative reverse transcription PCR, western blotting, enzyme-linked immunosorbent assay, and RNA in situ hybridization in human NSCLC cell lines and tumor specimens. INSL4 gene expression and clinical data from The Cancer Genome Atlas lung adenocarcinomas (n = 515) were analyzed using log-rank and Fisher exact tests. INSL4 functions were studied using short hairpin RNA (shRNA) knockdown, overexpression, transcriptome profiling, cell growth, and survival assays in vitro and in vivo. All statistical tests were two-sided.

RESULTS:

INSL4 was identified as a novel downstream target of LKB1 deficiency and its expression was induced through aberrant CRTC-CREB activation. INSL4 was highly induced in LKB1-deficient NSCLC cells (up to 543-fold) and 9 of 41 primary tumors, although undetectable in all normal tissues except the placenta. Lung adenocarcinomas from The Cancer Genome Atlas with high and low INSL4 expression (with the top 10th percentile as cutoff) showed statistically significant differences for advanced tumor stage (P < .001), lymph node metastasis (P = .001), and tumor size (P = .01). The INSL4-high group showed worse survival than the INSL4-low group (P < .001). Sustained INSL4 expression was required for the growth and viability of LKB1-inactivated NSCLC cells in vitro and in a mouse xenograft model (n = 5 mice per group). Expression profiling revealed INSL4 as a critical regulator of cell cycle, growth, and survival.

CONCLUSIONS:

LKB1 deficiency induces an autocrine INSL4 signaling that critically supports the growth and survival of lung cancer cells. Therefore, aberrant INSL4 signaling is a promising therapeutic target for LKB1-deficient lung cancers.

Hepatitis E virus (HEV) infection, particularly HEV genotype 1 (HEV-1), can result in fulminant hepatic failure and severe placental diseases, but mechanisms underlying genotype-specific pathogenicity are unclear and appropriate models are lacking. Here, we model HEV-1 infection ex vivo at the maternal-fetal interface using the decidua basalis and fetal placenta, and compare its effects to the less-pathogenic genotype 3 (HEV-3). We demonstrate that HEV-1 replicates more efficiently than HEV-3 both in tissue explants and stromal cells, produces more infectious progeny virions and causes severe tissue alterations. HEV-1 infection dysregulates the secretion of several soluble factors. These alterations to the cytokine microenvironment correlate with viral load and contribute to the tissue damage. Collectively, this study characterizes an ex vivo model for HEV infection and provides insights into HEV-1 pathogenesis during pregnancy that are linked to high viral replication, alteration of the local secretome and induction of tissue injuries.

Abstract

BACKGROUND:

In situ hybridization for human papillomavirus (HPV) messenger RNA (HPV RNA ISH) recently was introduced as an ancillary tool in the diagnosis of cervical squamous intraepithelial lesions, and can aid in the distinction between low-grade squamous intraepithelial lesions (LSILs) versus reactive/negative biopsies. Prior work has shown that up to one-half of cases originally diagnosed as LSIL are reclassified as negative/reactive by expert consensus review of morphology, and negative HPV RNA ISH results most often correlate with an expert diagnosis of negative/reactive. Given that LSIL overdiagnoses on biopsy may result in the erroneous clinical impression that a cervical lesion has been sampled appropriately, the authors proposed that HPV RNA ISH can inform cytology-histology correlation for challenging LSIL biopsies.

METHODS:

A total of 92 cervical biopsies originally diagnosed as LSIL were reviewed by 3 gynecologic pathologists and reclassified based on consensus opinion of morphology. ISH was performed for high-risk and low-risk HPV E6/E7 mRNA. Prior/concurrent cytology results were collected.

RESULTS:

Based on expert consensus morphologic review, 49% of biopsies (45 of 92 biopsies) originally diagnosed as LSIL were reclassified as negative, 6.5% (6 of 92 biopsies) were reclassified as high-grade squamous intraepithelial lesion, and 44.5% (41 of 92 biopsies) were maintained as LSIL. The majority of LSIL biopsies reclassified as negative (80%; 36 of 45 biopsies) were HPV RNA negative, whereas 93% of LSIL biopsies (39 of 41 biopsies) and 100% of high-grade squamous intraepithelial lesion biopsies were HPV RNA positive.

CONCLUSIONS:

LSIL often is overdiagnosed by morphology on biopsy, potentially leading to the false impression that a lesion identified on cytology has been sampled. Performing RNA ISH on biopsies decreases histologic LSIL overdiagnosis, and potentially can prompt further sampling when there is cytology-histology discordance.

Estrogen signalling pathways are emerging targets for lung cancer therapy. Unravelling the contribution of estrogens in lung cancer development is a pre-requisite to support the development of sex-based treatments and to identify patients who could potentially benefit from anti-estrogen treatments. In this study, we highlight the contribution of lymphatic and blood endothelia in the sex-dependent modulation of lung cancer. The orthotopic graft of syngeneic lung cancer cells into immunocompetent mice showed that lung tumours grew faster in female mice than in males. Moreover, estradiol (E2) promoted tumour development in female mice and increased lymph/angiogenesis and levels of VEGFA and bFGF in lung tumours of females through an estrogen receptor (ER) alpha-dependent pathway. Furthermore, while treatment with ERbeta antagonist was inefficient, ERalpha antagonist (MPP) and tamoxifen decreased lung tumour volumes, altered blood and lymphatic vasculature and reduced VEGFA and bFGF levels in females, but not in males. Finally, the quantification of lymphatic and blood vasculature of lung adenocarcinoma biopsies from patients aged between 35 to 55 years old revealed more extensive lymphangiogenesis and angiogenesis in tumour samples issued from women than from men. In conclusion, our findings highlight an E2/ERalpha-dependent modulation of lymphatic and blood vascular components of lung tumour microenvironment. Our study has potential clinical implication in a personalised medicine perspective by pointing to the importance of estrogen status or supplementation on lung cancer development that should be considered to adapt therapeutic strategies.

Regulation of cell type-specific gene expression is critical for generating neuronal diversity. Transcriptome analyses have unraveled extensive heterogeneity of transcribed sequences in retinal photoreceptors because of alternate splicing and/or promoter usage. Here we show that Frmpd1 (FERM and PDZ domain containing 1) is transcribed from an alternative promoter specifically in the retina. Electroporation of Frmpd1 promoter region, -505 to +382 bp, activated reporter gene expression in mouse retina in vivo. A proximal promoter sequence (-8 to +33 bp) of Frmpd1 binds to NRL and CRX, two rod-specific differentiation factors, and is necessary for activating reporter gene expression in vitro and in vivo. CRISPR/Cas9-mediated deletion of the genomic region including NRL and CRX binding sites in vivo completely eliminated Frmpd1 expression in rods and dramatically reduced expression in rod bipolar cells, thereby overcoming embryonic lethality caused by germline Frmpd1 deletion. Our studies demonstrate that a cell-type-specific regulatory control region is a credible target for creating loss-of-function alleles of widely-expressed genes.

Abstract

BACKGROUND & AIMS:

The intestinal epithelium is maintained by long-lived intestinal stem cells (ISCs) that reside near the crypt base. Above the ISC zone, there are short-lived progenitors that normally give rise to lineage-specific differentiated cell types but can dedifferentiate into ISCs in certain circumstances. However, the role of epithelial dedifferentiation in cancer development has not been fully elucidated.

METHODS:

We performed studies with Bhlha15-CreERT, Lgr5-DTR-GFP, Apcflox/flox, LSL-Notch (IC), and R26-reporter strains of mice. Some mice were given diphtheria toxin to ablate Lgr5 mRNA-positive cells, irradiated, or given 5-fluorouracil, hydroxyurea, doxorubicin, or dextran sodium sulfate to induce intestinal or colonic tissue injury. In intestinal tissues we analyzed the fate of progeny that expressed Bhlha15 mRNA. We used microarrays and reverse-transcription PCR to analyze gene expression patterns in healthy and injured intestinal tissues and in tumors. We analyzed gene expression patterns in human colorectal tumors using the TCGA dataset.

RESULTS:

Bhlha15 identified Paneth cells and short-lived secretory precursors (including pre-Paneth label-retaining cells) located just above the ISC zone in the intestinal epithelium. Bhlha15+ cells had no plasticity after loss of Lgr5-positive cells or irradiation. However, Bhlha15+ secretory precursors started to supply the enterocyte lineage after doxorubicin-induced epithelial injury in a Notch-dependent manner. Sustained activation of Notch converts Bhlha15+ secretory precursors to long-lived enterocyte progenitors (EPs). Administration of doxorubicin and expression of an activated form of Notch resulted in a gene expression pattern associated with EPs, whereas only sustained activation of Notch altered gene expression patterns in Bhlha15+ precursors, towards that of ISCs. Bhlha15+ EPs with sustained activation of Notch formed intestinal tumors with serrated features in mice with disruption of Apc. In the colon, Bhlha15 marked secretory precursors that became stem-like, cancer-initiating cells following dextran sodium sulfate-induced injury, via activation of Src and YAP signaling. In analyses of human colorectal tumors, we associated activation of Notch with chromosome instability-type tumors with serrated features in the left colon.

CONCLUSION:

In mice, we found that short-lived precursors can undergo permanent reprogramming by activation of Notch and YAP signaling. These cells could mediate tumor formation, in addition to traditional ISCs.

Abstract

BACKGROUND & AIMS:

Intestinal fibrosis is a long-term complication in inflammatory bowel diseases (IBD) frequently resulting in functional damage, bowel obstruction, and surgery. Interleukin 36 (IL36) is a group of cytokines in the IL1 family with inflammatory effects. We studied expression of IL36 and its receptor, interleukin 1 receptor like 2 (IL1RL2 or IL36R) in development of intestinal fibrosis in human tissues and mice.

METHODS:

We obtained intestinal tissues from 92 patients with Crohn´s disease (CD), 48 patients with ulcerative colitis (UC), and 26 patients without inflammatory bowel diseases (controls). Tissues were analyzed by histology to detect fibrosis and immunohistochemistry to determine the distribution of fibroblasts and levels of IL36R ligands. Human and mouse fibroblasts were incubated with IL36 or control medium, and transcriptome-wide RNA sequences were analyzed. Mice were given neutralizing antibodies against IL36R and we studied intestinal tissues from Il1rl2-/- mice; colitis and fibrosis was induced in mice by repetitive administration of DSS or TNBS. Bone marrow cells were transplanted from Il1rl2-/- to irradiated wild-type mice and intestinal tissues were analyzed. Antibodies against IL36R were applied to mice with established chronic colitis and fibrosis and intestinal tissues were studied.

RESULTS:

Mucosal and submucosal tissues from patients with CD or UC had higher levels of collagens including type VI collagen compared to tissues from controls. In tissues from patients with fibrostenotic CD, significantly higher levels of IL36A were noted, which correlated with high numbers of activated fibroblasts that expressed alpha smooth muscle actin. IL36R activation of mouse and human fibroblasts resulted in expression of genes that regulate fibrosis and tissue remodeling, as well as expression of collagen type VI. Il1rl2-/- mice and mice given injections of an antibody against IL36R developed less severe colitis and fibrosis following administration of DSS or TNBS, but bone marrow cells from Il1rl2-/- mice did not prevent induction of colitis and fibrosis. Injection of antibodies against IL36R significantly reduced established fibrosis in mice with chronic intestinal inflammation.

CONCLUSION:

We found higher levels of IL36A in fibrotic intestinal tissues from patients with IBD, compared with controls. IL36 induced expression of genes that regulate fibrogenesis in fibroblasts. Inhibition or knockout of the IL36R in mice reduces chronic colitis and intestinal fibrosis. Agents designed to block IL36R signaling could be developed for prevention and treatment of intestinal fibrosis in patients with IBD.

In situ analysis of biomarkers is essential for clinical diagnosis and research purposes. The increasing need to understand the molecular signature of pathologies has led to the blooming of ultrasensitive and multiplexable techniques that combine in situ hybridization (ISH) and immunohistochemistry or immunocytochemistry (IHC or ICC). Most protocols are tailored to formalin-fixed paraffin embedded (FFPE) tissue sections. However, methods to perform such assays on non-adherent cell samples, such as patient blood-derived PBMCs, rare tumor samples, effusions or other body fluids, dissociated or sorted cells, are limited. Typically, a laboratory would need to invest a significant amount of time and resources to establish one such assay. Here, we describe a method that combines ultrasensitive RNAscope-ISH with ICC on cytospin cell preparations. This method allows automated, sensitive, multiplex ISH-ICC on small numbers of non-adherent cells. We provide guidelines for both chromogenic and fluorescent ISH/ICC combinations that can be performed either in fully automated or in manual settings. By using a CD8+ T cells in vitro stimulation paradigm, we demonstrate that this protocol is sensitive enough to detect subtle differences in gene expression and compares well to commonly used methods such as RT-qPCR and flow cytometry with the added benefit of visualization at the cellular level.

Successful embryo implantation requires a receptive endometrium. Poor uterine receptivity can account for implantation failure in women who experience recurrent pregnancy loss or multiple rounds of unsuccessful in vitro fertilization cycles. Here, we demonstrate that the transcription factor Forkhead Box O1 (FOXO1) is a critical regulator of endometrial receptivity in vivo. Uterine ablation of Foxo1 using the progesterone receptor Cre (PgrCre) mouse model resulted in infertility due to altered epithelial cell polarity and apoptosis, preventing the embryo from penetrating the luminal epithelium. Analysis of the uterine transcriptome after Foxo1 ablation identified alterations in gene expression for transcripts involved in the activation of cell invasion, molecular transport, apoptosis, β-catenin (CTNNB1) signaling pathway, and an increase in PGR signaling. The increase of PGR signaling was due to PGR expression being retained in the uterine epithelium during the window of receptivity. Constitutive expression of epithelial PGR during this receptive period inhibited expression of FOXO1 in the nucleus of the uterine epithelium. The reciprocal expression of PGR and FOXO1 was conserved in human endometrial samples during the proliferative and secretory phase. This demonstrates that expression of FOXO1 and the loss of PGR during the window of receptivity are interrelated and critical for embryo implantation.

Haematopoietic stem and progenitor cells (HSPCs) give rise to all blood lineages that support the entire lifespan of vertebrates1. After HSPCs emerge from endothelial cells within the developing dorsal aorta, homing allows the nascent cells to anchor in their niches for further expansion and differentiation2-5. Unique niche microenvironments, composed of various blood vessels as units of microcirculation and other niche components such as stromal cells, regulate this process6-9. However, the detailed architecture of the microenvironment and the mechanism for the regulation of HSPC homing remain unclear. Here, using advanced live imaging and a cell-labelling system, we perform high-resolution analyses of the HSPC homing in caudal haematopoietic tissue of zebrafish (equivalent to the fetal liver in mammals), and reveal the role of the vascular architecture in the regulation of HSPC retention. We identify a VCAM-1+ macrophage-like niche cell population that patrols the inner surface of the venous plexus, interacts with HSPCs in an ITGA4-dependent manner, and directs HSPC retention. These cells, named 'usher cells', together with caudal venous capillaries and plexus, define retention hotspots within the homing microenvironment. Thus, the study provides insights into the mechanism of HSPC homing and reveals the essential role of a VCAM-1+ macrophage population with patrolling behaviour in HSPC retention.

Understanding the neural framework behind appetite control is fundamental to developing effective therapies to combat the obesity epidemic. The paraventricular hypothalamus (PVH) is critical for appetite regulation, yet, the real-time, physiological response properties of PVH neurons to nutrients are unknown. Using a combination of fiber photometry, electrophysiology, immunohistochemistry, and neural manipulation strategies, we determined the population dynamics of four molecularly delineated PVH subsets implicated in feeding behavior: glucagon-like peptide 1 receptor (PVHGlp1r), melanocortin-4 receptor (PVHMc4r), oxytocin (PVHOxt), and corticotropin-releasing hormone (PVHCrh). We identified both calorie- and state-dependent sustained activity increases and decreases in PVHGlp1r and PVHCrh populations, respectively, while observing transient bulk changes of PVHMc4r, but no response in PVHOxt, neurons to food. Furthermore, we highlight the role of PVHGlp1r neurons in orchestrating acute feeding behavior, independent of the anti-obesity drug liraglutide, and demonstrate the indispensability of PVHGlp1r and PVHMc4r, but not PVHOxt or PVHCrh neurons, in body weight maintenance.