Machine learning on large scale perturbation screens for SARS-CoV-2 host factors identifies β-catenin/CBP inhibitor PRI-724 as a potent antiviral

Expanding antiviral treatment options against SARS-CoV-2 remains crucial as the virus evolves under selection pressure which already led to the emergence of several drug resistant strains. Broad spectrum host-directed antivirals (HDA) are promising therapeutic options, however the robust identification of relevant host factors by CRISPR/Cas9 or RNA interference screens remains challenging due to low consistency in the resulting hits. To address this issue, we employed machine learning, based on experimental data from several knockout screens and a drug screen. We trained classifiers using genes essential for virus life cycle obtained from the knockout screens. The machines based their predictions on features describing cellular localization, protein domains, annotated gene sets from Gene Ontology, gene and protein sequences, and experimental data from proteomics, phospho-proteomics, protein interaction and transcriptomic profiles of SARS-CoV-2 infected cells. The models reached a remarkable performance suggesting patterns of intrinsic data consistency. The predicted HDF were enriched in sets of genes particularly encoding development, morphogenesis, and neural processes. Focusing on development and morphogenesis-associated gene sets, we found β-catenin to be central and selected PRI-724, a canonical β-catenin/CBP disruptor, as a potential HDA. PRI-724 limited infection with SARS-CoV-2 variants, SARS-CoV-1, MERS-CoV and IAV in different cell line models. We detected a concentration-dependent reduction in cytopathic effects, viral RNA replication, and infectious virus production in SARS-CoV-2 and SARS-CoV-1-infected cells. Independent of virus infection, PRI-724 treatment caused cell cycle deregulation which substantiates its potential as a broad spectrum antiviral. Our proposed machine learning concept supports focusing and accelerating the discovery of host dependency factors and identification of potential host-directed antivirals.

Immunohistochemical expression of beta-catenin in ampullary adenocarcinoma: a cross-sectional retrospective study

Ampullary carcinomas are uncommon malignant tumours of the digestive system, they usually are adenocarcinomas presenting histologically as three types: intestinal, pancreaticobiliary and mixed. β-catenin is a multifunctional protein involved in physiological homoeostasis and intracellular adhesion. Abnormal nuclear accumulation of β-catenin has been described in many malignancies such as colon, breast, liver and others. The relationships between the immunohistochemical expression of β-catenin and the subtype, the grade and the stage of ampullary carcinoma are studied.

Material and methods

A cross-sectional retrospective study was done on 25 formalin-fixed paraffin-embedded blocks of ampullary carcinoma: Cases were collected from the archives of the pathology department in the Gastroenterology and hepatology teaching hospital, medical city/ Baghdad from January 2019 to March 2022. The data of the patients and the characteristics of the tumour were derived from the pathological reports; additional sections from the block were stained with β-catenin immunohistochemically.

Results

25 paraffin blocks from patients with ampullary carcinoma (12 males, 13 females) were included in the study. 64% of the cases are classified as pancreaticobiliary, 20% as mixed, 12% as intestinal and 4% as adenosquamous type. Eighty-four percent of the cases are moderately differentiated, and the remaining is poorly differentiated. Most cases show strong β-catenin membranous staining and 80% express 3+ staining of cytoplasmic β-catenin. Regarding nuclear β-catenin staining, 56% has negative staining.

Conclusion

No significant association was found between the cytoplasmic and the nuclear expression of β-catenin and the tumour type, size and lymph node status. The grade of the tumour showed a significant correlation with the cytoplasmic expression; while, no correlation was noted with the nuclear expression. This study results do not support the use of beta-catenin as a diagnostic marker or prognostic marker in ampullary cancers.

Millet seed oil activates β-catenin signaling and promotes hair growth

Alopecia, regardless of gender, exacerbates psychological stress in those affected. The rising prevalence of alopecia has fueled a research interest in preventing hair loss. This study investigates the potential of millet seed oil (MSO) in promoting the proliferation of hair follicle dermal papilla cells (HFDPC) and stimulating hair growth in animals with testosterone-dependent hair growth inhibition as part of a study on dietary treatments to improve hair growth. MSO-treated HFDPC significantly increased cell proliferation and phosphorylation of AKT, S6K1, and GSK3β proteins. This induces β-catenin, a downstream transcription factor, to translocate to the nucleus and increase the expression of factors related to cell growth. In a C57BL/6 mice model in which hair growth was inhibited by subcutaneous testosterone injection after shaving the dorsal skin, oral administration of MSO stimulated hair growth in the subject mice by increasing the size and number of hair follicles. These results suggest that MSO is a potent agent that may help prevent or treat androgenetic alopecia by promoting hair growth.

A Case of a Beta-Catenin-Activated Hepatic Adenoma in a Male Patient With Familial Adenomatous Polyposis

Hepatocellular adenoma is a benign liver tumor often diagnosed incidentally in women of reproductive age who are taking oral contraceptives. In this study, we present a unique case of an 18-year-old man with known familial adenomatous polyposis who presented with sepsis in the setting of a recent total proctocolectomy and was incidentally found to have multiple large hepatic lesions. A biopsy of a liver lesion confirmed the diagnosis of a beta-catenin-activated hepatic adenoma. To the best of our knowledge, this is the first known case of beta-catenin-activated hepatic adenoma in a patient with a known familial adenomatous polyposis mutation. Beta-catenin is one of the many subtypes of hepatocellular adenomas, which carries a high risk of malignant transformation.

Detection of Increased Expression of Claudin-1 in Triple-Negative Breast Cancer: Analysis and Clinical-Pathological Correlation

Background Triple-negative breast cancer (TNBC) is a highly aggressive disease that lacks therapeutic targets and prognostic biomarkers. Claudin-1 is a well-described tight junction protein with prognostic value in many human cancers. Aims The need for the discovery of biomarkers of TNBC disease was a major reason for this study. Claudin-1 is a tight junction protein that has shown promising results in the prognosis and management of cancer in general. In the breast, claudin-1 expression and significance have shown variable results, especially in TNBC patients. Our study assessed expression of claudin-1 in a group of TNBC patients, and correlated this expression with clinical-pathological parameters, and with the expression of β-catenin. Materials and methods Tissues from a group of 52 TNBC patients were retrieved from the archives of the community hospital. All related information including demographical, pathologic and clinical data were retrieved. Immunohistochemistry assays of a rabbit polyclonal antibody anti-human claudin-1 were applied using the avidin-biotin peroxidase methodology. Results A statistically significant majority of TNBC cases positively expressed claudin-1 (81%, χ2=13.705; p<0.001). Most TNBC cases had grade 2 β-catenin expression (77.5%; p<0.001), and positive expression for claudin-1 correlated with that of β-catenin (χ2= 23.757; p<0.001). Claudin-1 and β-catenin expressions within tumour cells shared several features including absent or weakness of membranous expression, and redistribution of both proteins to the cytoplasm of tumour cells, and in some cases to the nuclei of these cells. Claudin-1 expression also correlates with adverse survival outcomes, where only four of 20 claudin-1-positive patients who received neo-adjuvant chemotherapy (NAC) achieved pathological complete response (pCR). Conclusions The above presents a complex role of claudin-1 in TNBC patients. In this study, claudin-1 expression was associated with poor prognostic features including invasion, metastases and adverse clinical outcomes. Claudin-1 expression in TNBC correlated with the expression of β-catenin, an important oncogene and a major contributor to the epithelial mesenchymal transition (EMT) phenomenon. Overall, the above results may serve as an impetus for further mechanistic studies to assess the exact role of claudin-1 in TNBC and its possible use in the management of this subset of breast cancer.

Pharmacological inhibition of FOXO1 promotes lymphatic valve growth in a congenital lymphedema mouse model

Mutations in many genes that regulate lymphatic valve development are associated with congenital lymphedema. Oscillatory shear stress (OSS) from lymph provides constant signals for the growth and maintenance of valve cells throughout life. The expression of valve-forming genes in lymphatic endothelial cells (LECs) is upregulated by OSS. The transcription factor FOXO1 represses lymphatic valve formation by inhibiting the expression of these genes, which makes FOXO1 a potential target for treating lymphedema. Here, we tested the ability of a FOXO1 inhibitor, AS1842856, to induce the formation of new lymphatic valves. Our quantitative RT-PCR and Western blot data showed that treatment of cultured human LECs with AS1842856 for 48 h significantly increased the expression levels of valve-forming genes. To investigate the function of AS1842856 in vivo, Foxc2 +/- mice, the mouse model for lymphedema-distichiasis, were injected with AS1842856 for 2 weeks. The valve number in AS-treated Foxc2+/- mice was significantly higher than that of the vehicle-treated Foxc2+/- mice. Furthermore, since β-catenin upregulates the expression of Foxc2 and Prox1 during lymphatic valve formation, and AS1842856 treatment increased the level of active β-catenin in both cultured human LECs and in mouse mesenteric LECs in vivo, we used the mouse model with constitutive active β-catenin to rescue loss of lymphatic valves in Foxc2 +/- mice. Foxc2 +/- mice have 50% fewer lymphatic valves than control, and rescue experiments showed that the valve number was completely restored to the control level upon nuclear β-catenin activation. These findings indicate that pharmacological inhibition of FOXO1 can be explored as a viable strategy to resolve valve defects in congenital lymphedema.

Osteocalcin modulates parathyroid cell function in human parathyroid tumors

INTRODUCTION

The bone matrix protein osteocalcin (OC), secreted by osteoblasts, displays endocrine effects. We tested the hypothesis that OC modulates parathyroid tumor cell function.

METHODS

Primary cell cultures derived from parathyroid adenomas (PAds) and HEK293 cells transiently transfected with the putative OC receptor GPRC6A or the calcium sensing receptor (CASR) were used as experimental models to investigate γ-carboxylated OC (GlaOC) or uncarboxylated OC (GluOC) modulation of intracellular signaling.

RESULTS

In primary cell cultures derived from PAds, incubation with GlaOC or GluOC modulated intracellular signaling, inhibiting pERK/ERK and increasing active β-catenin levels. GlaOC increased the expression of PTH, CCND1 and CASR, and reduced CDKN1B/p27 and TP73. GluOC stimulated transcription of PTH, and inhibited MEN1 expression. Moreover, GlaOC and GluOC reduced staurosporin-induced caspase 3/7 activity. The putative OC receptor GPRC6A was detected in normal and tumor parathyroids at membrane or cytoplasmic level in cells scattered throughout the parenchyma. In PAds, the membrane expression levels of GPRC6A and its closest homolog CASR positively correlated; GPRC6A protein levels positively correlated with circulating ionized and total calcium, and PTH levels of the patients harboring the analyzed PAds. Using HEK293A transiently transfected with either GPRC6A or CASR, and PAds-derived cells silenced for CASR, we showed that GlaOC and GluOC modulated pERK/ERK and active β-catenin mainly through CASR activation.

CONCLUSION

Parathyroid gland emerges as a novel target of the bone secreted hormone osteocalcin, which may modulate tumor parathyroid CASR sensitivity and parathyroid cell apoptosis.

Low-Grade Ovarian Stromal Tumors with Genetic Alterations of the Wnt/β-Catenin Pathway That Is Crucial in Ovarian Follicle Development and Regulation

The Wnt signaling pathway is important in the normal development and regulation of ovarian follicles throughout the lifecycle of females. Dysregulation of the Wnt signaling pathway, genetically or epigenetically, with subsequent activation of β-catenin has been implicated in tumorigenesis of a spectrum of ovarian neoplasms, from benign to malignant. We review the recent findings of the Wnt signaling pathway involved in regulating normal physiologic processes of the ovarian follicle cycle. We also review the β-catenin mutations in a family of low-grade ovarian stromal tumors, focusing on characterizing their shared morphological features and the utility of immunohistochemistry of β-catenin in facilitating the accurate diagnosis of these ovarian stromal tumors. The Wnt signaling pathway is one of the most critical mechanisms in regulating cell proliferation, differentiation, and morphogenesis. The Wnt signaling pathway comprises a diverse group of glycoproteins that serve as ligands and bind to transmembrane Frizzled family receptors. The ligand-receptor interactions activate the pathway and govern the downstream signaling cascades, ultimately affecting the transcriptional control of the cellular cytoskeleton, organelle dynamics, epithelial-mesenchymal interaction, and tissue remodeling in the ovary. Wnt signaling consists of two major pathways: a canonical pathway that is β-catenin-dependent and a non-canonical Wnt pathway that is β-catenin-independent. Canonical Wnt signaling is governed by the interaction of β-catenin with other molecules to regulate cellular decisions related to proliferation and differentiation. Recent studies have demonstrated that the Wnt signaling pathway plays important roles in the development and regulation of ovarian folliculogenesis and oogenesis.

Bilateral breast desmoid-type fibromatosis, case report and literature review

BACKGROUND

Breast desmoid-type fibromatosis (BDF) is a rare mesenchymal tumor accounting for only 0.2% of solid breast tumors. It is classified as an intermediate tumor because it is locally aggressive but has no metastatic potential. Its diagnosis is often difficult because it shares many clinical and radiologic aspects with breast carcinomas and therefore relies on anatomopathological analysis which may be supplemented by genetic analysis. The treatment of BDF has considerably evolved in the past years. While surgery was the cornerstone of the management prior to the 2000s, recent data have shown the value of active surveillance (AS) from the time of diagnosis. Indeed, after 2 years of AS, the progression-free survival (PFS) of the disease is identical or superior to surgery. Moreover, spontaneous regression has been observed in 30% of patients undergoing AS. In case of disease progression, surgery can be considered on a case-by-case basis, as well as systemic treatments.

CASE DESCRIPTION

We present a case of bilateral BDF affecting a 20-year-old woman for whom the first suggested treatment was bilateral mastectomy with reconstruction. After a second opinion, the decision was revised and AS was initiated. Almost 3 years after the onset of AS, tumors have shown a continuous regression.

CONCLUSIONS

This case demonstrates the need for experience in the management of mesenchymal tumors to avoid overtreatment by mutilating surgeries which promote recurrence. Moreover, to our knowledge, very few cases of bilateral BDF have been published to date. It thus seemed relevant for us to report this rare case which supports the interest of AS for DF, as recently advised by the Desmoid Tumor Working Group guidelines.

The role of CTNNB1 mutations and matrix metalloproteinases (MMPs) in anti-angiogenesis treatment of endometrial carcinoma

OBJECTIVE

Treatment options and associated biomarkers for advanced and recurrent disease are limited. Endometrial cancers (ECs) with CTNNB1 exon 3 mutations appear to have preferential response to bevacizumab, an anti-angiogenesis treatment, though the mechanism of action is unknown. We aim to identify mediators of bevacizumab-responsive endometrial cancers.

METHODS

We analyzed RNA expression from TCGA and protein expression from CPTAC to identify likely targets for β-catenin overactivity. We then transiently and stably overexpressed β-catenin in EC cells to confirm the results suggested by our in silico analysis. We performed corroborative experiments by silencing CTNNB1 in mutated cell lines to demonstrate functional specificity. We implanted transduced cells into xenograft models to study microvessel density.

RESULTS

CTNNB1-mutated ECs were associated with increased β-catenin and MMP7 protein abundance (P < 0.001), but not VEGF-A protein abundance. Overexpressing β-catenin in EC cells did not increase VEGF-A abundance but did increase expression and secretion of MMP7 (P < 0.03). Silencing CTNNB1 in CTNNB1-mutated cells decreased MMP7 gene expression in EC (P < 0.0001). Microvessel density was not increased.

CONCLUSIONS

These data provide a mechanistic understanding for bevacizumab-response in CTNNB1-mutated ECs demonstrated in GOG-86P. We hypothesize that overexpressed and secreted MMP7 potentially digests VEGFR-1, releasing VEGF-A, and increasing its availability. These activities may drive the formation of permeable vessels, which contributes to tumor progression, metastasis, and immune suppression. This mechanism is unique to EC and advocates for further clinical trials evaluating this treatment-related biomarker.

High glucose impairs osteogenic differentiation of embryonic stem cells via early diversion of beta-catenin from Forkhead box O to T cell factor interaction

BACKGROUND

Diabetes, which is characterized by an increase in blood glucose concentration, is accompanied by low bone turnover, increased fracture risk, and the formation of embryonic skeletal malformations. Yet, there are few studies elucidating the underlying alterations in signaling pathways leading to these osteogenic defects. We hypothesized here that bone formation deficiencies in a high glucose environment result from altered activity of beta-catenin (CTNNB1), a key contributor to osteogenic differentiation, dysregulation of which has also been implicated in the development of diabetes.

METHODS

To test this hypothesis, we used a previously established embryonic stem cell (ESC) model of differentiation that mimics the diabetic environment of the developing embryo. We differentiated murine ESCs within osteogenic-inducing media containing either high (diabetic) or low (physiological) levels of D-glucose and performed time course analyses to study the influence of high glucose on early and late bone cell differentiation.

RESULTS

Endpoint measures for osteogenic differentiation were reduced in a glucose-dependent manner and expression of precursor-specific markers altered at multiple time points. Furthermore, transcriptional activity of the lymphoid enhancer factor (LEF)/T cell factor (TCF) transcription factors during precursor formation stages was significantly elevated while levels of CTNNB1 complexed with Forkhead box O 3a (FOXO3a) declined. Modulation of AKT, a known upstream regulator of both LEF/TCF and FOXO3a, as well as CTNNB1 rescued some of the reductions in osteogenic output seen in the high glucose condition.

CONCLUSIONS

Within our in vitro model, we found a clear involvement of LEF/TCF and FOXO3a signaling pathways in the regulation of osteogenic differentiation, which may account for the skeletal deficiencies found in newborns of diabetic mothers.

Nuclear Dishevelled: An enigmatic role in governing cell fate and Wnt signaling

The Dishevelled gene was first identified in Drosophila mutants with disoriented hair and bristle polarity and subsequent work has now demonstrated its importance in critical and diverse aspects of biology. Since those early discoveries, Dishevelled has been shown to coordinate a plethora of developmental and cellular processes that range from controlling cell polarity during gastrulation to partnering with chromatin modifying enzymes to regulate histone methylation at genomic loci. While the role of DVL in development is well-respected and the cytosolic function of DVL has been studied more extensively, its nuclear role continues to remain murky. In this review we highlight some of the seminal discoveries that have contributed to the field, but the primary focus is to discuss recent advances with respect to the nuclear role of Dishevelled. This nuclear function of Dishevelled is a dimension which is proving to be increasingly important yet remains enigmatic.

Sex differences in adrenal cortex beta-catenin immunolocalisation of the Saharan gerbil, Libyan jird (Meriones libycus, Lichtenstein, 1823)

BACKGROUND

The adrenal cortex provides adequate steroidogenic responses to environmental changes. However, in desert rodents, the adrenocortical activity varies according to several factors especially sex, age, and seasonal variations. Herein, we examined the sex differences in the adrenal cortex activity and explored the involvement of sex hormones in the regulation of this function in Libyan jird Meriones libycus.

MATERIALS AND METHODS

Twenty-four adult male and female animals weighing 109-110 g were captured in the breeding season and equally assigned into control and gonadectomised groups. Animal euthanasia was performed 50 days after the gonadectomy. Adrenal gland was processed for structural and immunohistochemistry study of b-catenin, whereas plasma was used for cortisol assay.

RESULTS

The results showed that female adrenal gland weight was heavier than male and gonadectomy reduced this dimorphism. The adrenal cortex thickness was greater in the female than in the male, mainly due to significant development of the zona fasciculata. Females presented higher cell density in fasciculata and reticularis zones. The plasma cortisol was higher in females than in males. The immunolocalisation of beta-catenin showed that the expression was particularly glomerular in both sexes. However, in the female, the immunostaining was present in the zona reticularis while it was absent in the control male. Orchiectomy reduced zona glomerulosa cell density and induced hypertrophy of zona reticularis characterised by strong beta-catenin immunoreactivity.

CONCLUSIONS

Results indicated that sex hormones had a major role in the regulation of the Saharan gerbil's adrenal homeostasis by modulating beta-catenin signalling. Androgens seem to inhibit the Wnt-beta-catenin pathway and oestrogens are activators of the adrenal inner zones.

SOX transcription factors direct TCF-independent WNT/β-catenin responsive transcription to govern cell fate in human pluripotent stem cells

WNT/β-catenin signaling controls gene expression across biological contexts from development and stem cell homeostasis to diseases including cancer. How β-catenin is recruited to distinct enhancers to activate context-specific transcription is unclear, given that most WNT/ß-catenin-responsive transcription is thought to be mediated by TCF/LEF transcription factors (TFs). With time-resolved multi-omic analyses, we show that SOX TFs can direct lineage-specific WNT-responsive transcription during the differentiation of human pluripotent stem cells (hPSCs) into definitive endoderm and neuromesodermal progenitors. We demonstrate that SOX17 and SOX2 are required to recruit β-catenin to lineage-specific WNT-responsive enhancers, many of which are not occupied by TCFs. At TCF-independent enhancers, SOX TFs establish a permissive chromatin landscape and recruit a WNT-enhanceosome complex to activate SOX/ß-catenin-dependent transcription. Given that SOX TFs and the WNT pathway are critical for specification of most cell types, these results have broad mechanistic implications for the specificity of WNT responses across developmental and disease contexts.

Expression level and prognostic potential of beta-catenin-interacting protein in acute myeloid leukemia

Inhibitor of beta-catenin and TCF (ICAT) is a key protein in the Wnt-β-catenin signaling pathway. However, its role in acute myeloid leukemia (AML) remains unknown. In this study, we evaluated its expression level as well as its prognostic value in AML patients. A total of 72 patients with AML and 30 control subjects were enrolled in this study during the period of January 2017 and December 2019 at Zhongshan Hospital of SunYat-sen University. ICAT and β-catenin expression levels in peripheral blood were determined via enzyme-linked immunosorbent assays. ICAT levels in AML patients were significantly lower and β-catenin levels were higher than those of the control group. After the first course of standard chemotherapy, the concentration of ICAT in the partial remission group (93.79 ng/mL) was significantly higher than that in the initial diagnosis group (49.38 ng/mL) and the no response group (39.94 ng/mL). AML subtypes had lower ICAT expression levels than controls, and ICAT levels were significantly correlated with body mass index, bone marrow/peripheral blood blast cell proportions, and white blood cell and red blood cell counts at initial diagnosis. Furthermore, low ICAT expression was found to be associated with poor disease-free survival and overall survival in AML. ICAT is closely associated with AML progression and can be used as an indicator to monitor AML treatment efficacy.

Deleting the β-catenin degradation domain in mouse hepatocytes drives hepatocellular carcinoma or hepatoblastoma-like tumor growth

BACKGROUND & AIMS

One-third of hepatocellular carcinomas (HCCs) harbor mutations activating the β-catenin pathway, predominantly via mutations in the CTNNB1 gene itself. Mouse models of Apc loss-of-function are widely used to mimic β-catenin-dependent tumorigenesis. Given the low prevalence of APC mutations in human HCCs, we aimed to generate liver tumors through CTNNB1 exon 3 deletion (βcat^Δex3). We then compared βcat^Δex3 liver tumors with liver tumors generated via frameshift in exon 15 of Apc (Apc^fs-ex15).

METHODS

We used hepatocyte-specific and inducible mouse models generated through either a Cre-Lox or a CRISPR/Cas9 approach using adeno-associated virus vectors. Tumors generated by the Cre-Lox models were phenotypically analyzed using immunohistochemistry and were selected for transcriptomic analysis by RNA-sequencing (RNAseq). Mouse RNAseq data were compared to human RNAseq data (8 normal tissues, 48 HCCs, 9 hepatoblastomas) in an integrative analysis. Tumors generated via CRISPR were analyzed using DNA sequencing and immuno-histochemistry.

RESULTS

Mice with CTNNB1 exon 3 deletion in hepatocytes developed liver tumors indistinguishable from Apc^fs-ex15 liver tumors. Both Apc^fs-ex15 and βcat^Δex3 mouse models induced growth of phenotypically distinct tumors (differentiated or undifferentiated). Integrative analysis of human and mouse tumors showed that differentiated mouse tumors cluster with well-differentiated human CTNNB1-mutated tumors. Conversely, undifferentiated mouse tumors cluster with human mesenchymal hepatoblastomas and harbor activated YAP signaling.

CONCLUSION

Apc^fs-ex15 and βcat^Δex3 mouse models both induce growth of tumors that are transcriptionally similar to either well-differentiated and β-catenin-activated human HCCs or mesenchymal hepatoblastomas.

LAY SUMMARY

New and easy-to-use transgenic mouse models of primary liver cancers have been generated, with mutations in the gene encoding beta-catenin, which are frequent in both adult and pediatric primary liver cancers. The mice develop both types of cancer, constituting a strong preclinical model.

The Low-density Lipoprotein Receptor-related Protein 6 Pathway in the Treatment of Intestinal Barrier Dysfunction Induced by Hypoxia and Intestinal Microbiota through the Wnt/β-catenin Pathway

Our study is to explore the key molecular of Low-density lipoprotein receptor-related protein 6 (LRP6) and the related Wnt/β-catenin pathway regulated by LRP6 during the intestinal barrier dysfunction. Colorectal protein profile analysis showed that LRP6 expression was decreased in dextran sulfate sodium (DSS)-induced colitis mice, and mice received fecal bacteria transplantation from stroke patients. Mice with intestinal hypoxia and intestinal epithelial cells cultured in hypoxia showed decreased expression of LRP6. Overexpression of LPR6 or its N-terminus rescued the Wnt/β-catenin signaling pathway which was inhibited by hypoxia and endoplasmic reticulum stress. In mice overexpressing of LRP6, the expression of β-catenin and DKK1 increased, Bcl2 decreased, and Bax increased. Mice with LRP6 knockout showed an opposite trend, and the expression of Claudin2, Occludin and ZO-1 decreased. Two drugs, curcumin and auranofin could alleviate intestinal barrier damage in DSS-induced colitis mice by targeting LRP-6. Therefore, gut microbiota dysbiosis and hypoxia can inhibit the LRP6 and Wnt/β-catenin pathway, and drugs targeting LRP6 can protect the intestinal barrier.

Signaling Pathways in Neurovascular Development

During development, the central nervous system (CNS) vasculature grows to precisely meet the metabolic demands of neurons and glia. In addition, the vast majority of the CNS vasculature acquires a unique set of molecular and cellular properties-collectively referred to as the blood-brain barrier-that minimize passive diffusion of molecules between the blood and the CNS parenchyma. Both of these processes are controlled by signals emanating from neurons and glia. In this review, we describe the nature and mechanisms-of-action of these signals, with an emphasis on vascular endothelial growth factor (VEGF) and beta-catenin (canonical Wnt) signaling, the two best-understood systems that regulate CNS vascular development. We highlight foundational discoveries, interactions between different signaling systems, the integration of genetic and cell biological studies, advances that are of clinical relevance, and questions for future research.

Targeted Therapy in the Management of Modern Craniopharyngiomas

BACKGROUND

The proximity of craniopharyngiomas (CPs) to critical neurovascular structures can lead to a host of neurologic and endocrine complications that lead to difficulty with surgical management. In this review, we examine the molecular and genetic markers implicated in CP, their involvement in tumorigenic pathways, and their impact on CP prognosis and treatment.

METHODS

We undertook a focused review of relevant articles, clinical trials, and molecular summaries regarding CP.

RESULTS

Genetic and immunological markers show variable expression in different types of CP. BRAF is implicated in tumorigenesis in papillary CP (pCP), whereas CTNNB1 and EGFR are often overexpressed in adamantinomatous CP (aCP) and VEGF is overexpressed in aCP and recurrent CP. Targeted treatment modalities inhibiting these pathways can shrink or halt progression of CP. In addition, EGFR inhibitors may sensitize tumors to radiation therapy. These drugs show promise in medical management and neoadjuvant therapy for CP. Immunotherapy, including anti-interleukin-6 (IL-6) drugs and interferon treatment, are also effective in managing tumor growth. Ongoing clinical trials in CP are limited but are testing BRAF/MET inhibitors and IL-6 monoclonal antibodies.

CONCLUSIONS

Genetic and immunological markers show variable expression in different subtypes of CP. Several current molecular treatments have shown some success in the management of this disease. Additional clinical trials and targeted therapies will be important to improve CP patient outcomes.

Targeting β-catenin in acute myeloid leukaemia: past, present, and future perspectives

Acute myeloid leukaemia (AML) is an aggressive disease of the bone marrow with a poor prognosis. Evidence suggests long established chemotherapeutic regimens used to treat AML are reaching the limits of their efficacy, necessitating the urgent development of novel targeted therapies. Canonical Wnt signalling is an evolutionary conserved cascade heavily implicated in normal developmental and disease processes in humans. For over 15 years its been known that the central mediator of this pathway, β-catenin, is dysregulated in AML promoting the emergence, maintenance, and drug resistance of leukaemia stem cells. Yet, despite this knowledge, and subsequent studies demonstrating the therapeutic potential of targeting Wnt activity in haematological cancers, β-catenin inhibitors have not yet reached the clinic. The aim of this review is to summarise the current understanding regarding the role and mechanistic dysregulation of β-catenin in AML, and assess the therapeutic merit of pharmacologically targeting this molecule, drawing on lessons from other disease contexts.

Impaired Wnt/beta-catenin and protein patched homolog 1 signaling in extraocular sebaceous carcinoma: A clinical and histopathological study

Sebaceous carcinoma (SC) is a rare malignant neoplasm with sebaceous differentiation. SC is classified into eyelid and extraocular SC clinically. Most studies have focused on the eyelid SC in terms of pathogenesis, treatment, and prognosis. In skin, Wnt/beta-catenin and hedgehog signaling are two major pathways in sebaceous differentiation. We aimed to characterize the clinical and histopathological features of extraocular SC and to measure the expression of beta-catenin, lymphoid enhancer-binding factor 1 (LEF1), sonic hedgehog (Shh), and protein patched homolog 1 (PTCH) in extraocular SC. Ten cases of extraocular SC were identified from 2007 to 2020. The clinical features, microscopic findings, and prognosis were analyzed. Immunohistochemical stain for beta-catenin, LEF1, Shh, and PTCH were performed in extraocular SC and other benign sebaceous tumors including sebaceous hyperplasia, sebaceous adenoma, and sebaceoma. The male:female ratio was 4:6. The median onset age was 73.5 years (range, 43-88). Seven patients out of 10 were diagnosed after 60 years. Most extraocular SC were located on the head and neck with indurated plaque. Two patients had concurrent internal cancers and three patients showed lymph node metastasis at time of presentation. Five-year overall-survival was 40%. Beta-catenin was expressed membranously in all sebaceous hyperplasia, but was expressed variably in extraocular SC (1/5). While LEF1 was unequivocally expressed in normal hair follicles, LEF1 expression was absent in all extraocular SC and benign sebaceous tumors. Regarding the sonic hedgehog signaling, Shh and PTCH were all expressed in the cytoplasm of sebaceous hyperplasia, sebaceous adenoma, and sebaceoma. In contrast, PTCH was absent in all cases of extraocular SC and only 50% of the extraocular SC expressed cytoplasmic Shh. To conclude, extraocular SC commonly affects facial skin in the elderly. Inactivated Wnt/beta-catenin and aberrant hedgehog pathway may contribute to the carcinogenesis of extraocular SC. Further studies may be required to elucidate the causative mechanism of these pathways in extraocular SC.

Cross-Talk between p53 and Wnt Signaling in Cancer

Targeting cancer hallmarks is a cardinal strategy to improve antineoplastic treatment. However, cross-talk between signaling pathways and key oncogenic processes frequently convey resistance to targeted therapies. The p53 and Wnt pathway play vital roles for the biology of many tumors, as they are critically involved in cancer onset and progression. Over recent decades, a high level of interaction between the two pathways has been revealed. Here, we provide a comprehensive overview of molecular interactions between the p53 and Wnt pathway discovered in cancer, including complex feedback loops and reciprocal transactivation. The mutational landscape of genes associated with p53 and Wnt signaling is described, including mutual exclusive and co-occurring genetic alterations. Finally, we summarize the functional consequences of this cross-talk for cancer phenotypes, such as invasiveness, metastasis or drug resistance, and discuss potential strategies to pharmacologically target the p53-Wnt interaction.

Inter-observer agreement for the histological diagnosis of invasive lobular breast carcinoma

Invasive lobular breast carcinoma (ILC) is the second most common breast carcinoma (BC) subtype and is mainly driven by loss of E‐cadherin expression. Correct classification of BC as ILC is important for patient treatment. This study assessed the degree of agreement among pathologists for the diagnosis of ILC. Two sets of hormone receptor (HR)‐positive/HER2‐negative BCs were independently reviewed by participating pathologists. In set A (61 cases), participants were provided with hematoxylin/eosin (HE)‐stained sections. In set B (62 cases), participants were provided with HE‐stained sections and E‐cadherin immunohistochemistry (IHC). Tumor characteristics were balanced. Participants classified specimens as non‐lobular BC versus mixed BC versus ILC. Pairwise inter‐observer agreement and agreement with a pre‐defined reference diagnosis were determined with Cohen's kappa statistics. Subtype calls were correlated with molecular features, including CDH1/E‐cadherin mutation status. Thirty‐five pathologists completed both sets, providing 4,305 subtype calls. Pairwise inter‐observer agreement was moderate in set A (median κ = 0.58, interquartile range [IQR]: 0.48–0.66) and substantial in set B (median κ = 0.75, IQR: 0.56–0.86, p < 0.001). Agreement with the reference diagnosis was substantial in set A (median κ = 0.67, IQR: 0.57–0.75) and almost perfect in set B (median κ = 0.86, IQR: 0.73–0.93, p < 0.001). The median frequency of CDH1/E‐cadherin mutations in specimens classified as ILC was 65% in set A (IQR: 56–72%) and 73% in set B (IQR: 65–75%, p < 0.001). Cases with variable subtype calls included E‐cadherin‐positive ILCs harboring CDH1 missense mutations, and E‐cadherin‐negative ILCs with tubular elements and focal P‐cadherin expression. ILCs with trabecular growth pattern were often misclassified as non‐lobular BC in set A but not in set B. In conclusion, subtyping of BC as ILC achieves almost perfect agreement with a pre‐defined reference standard, if assessment is supported by E‐cadherin IHC. CDH1 missense mutations associated with preserved E‐cadherin protein expression, E‐ to P‐cadherin switching in ILC with tubular elements, and trabecular ILC were identified as potential sources of discordant classification.

Matrix remodeling controls a nuclear lamin A/C-emerin network that directs Wnt-regulated stem cell fate

Skeletal stem cells (SSCs) reside within a three-dimensional extracellular matrix (ECM) compartment and differentiate into multiple cell lineages, thereby controlling tissue maintenance and regeneration. Within this environment, SSCs can proteolytically remodel the surrounding ECM in response to growth factors that direct lineage commitment via undefined mechanisms. Here, we report that Mmp14-dependent ECM remodeling coordinates canonical Wnt signaling and guides stem cell fate by triggering an integrin-activated reorganization of the SCC cytoskeleton that controls nuclear lamin A/C levels via the linker of nucleoskeleton and cytoskeleton (LINC) complexes. In turn, SSC lamin A/C levels dictate the localization of emerin, an inner nuclear membrane protein whose ability to regulate β-catenin activity modulates Wnt signaling while directing lineage commitment in vitro and in vivo. These findings define a previously undescribed axis wherein SSCs use Mmp14-dependent ECM remodeling to control cytoskeletal and nucleoskeletal organization, thereby governing Wnt-dependent stem cell fate decisions.

Impact of bacterial infection and intestinal microbiome on colorectal cancer development

ABSTRACT

Accumulating evidence suggests that intestinal bacteria play an important role in the pathogenesis of colorectal cancer (CRC). Due to the complexity of the intestinal microbiome, identification of the specific causative microbial agents in CRC remains challenging, and the search for the causative microbial agents is intense. However, whether bacteria or their products can induce inflammation that results in tumorigenesis or directly causes CRC in humans is still not clear. This review will mainly focus on the progress of bacterial infection and CRC, and introduce the microbial contribution to the hallmarks of cancer. This article uses Salmonella and its chronic infection as an example to investigate a single pathogen and its role in the development of CRC, based on laboratory and epidemiological evidence. The bacterial infection leads to an altered intestinal microbiome. The review also discusses the dysfunction of the microbiome and the mechanism of host-microbial interactions, for example, bacterial virulence factors, key signaling pathways in the host, and microbial post-translational modifications in the tumorigenesis. Colonic carcinogenesis involves a progressive accumulation of mutations in a genetically susceptible host leading to cellular autonomy. Moving forward, more human data are needed to confirm the direct roles of bacterial infection in CRC development. Insights into the inhibiting infection will help to prevent cancer and develop strategies to restore the balance between host and microorganisms.