Keratin-6 driven ODC expression to hair follicle keratinocytes enhances stemness and tumorigenesis by negatively regulating Notch

KRT13 is upregulated in pancreatic cancer stem-like cells and associated with radioresistance

Pancreatic cancer is one of the most aggressive cancers and the seventh leading cause of cancer-associated death in the world. Radiation is performed as an adjuvant therapy as well as anti-cancer drugs. Because cancer stem-like cells (CSCs) are considered to be radioresistant and cause recurrence and metastasis, understanding their properties is required for the development of novel therapeutic strategies. To investigate the CSC properties of pancreatic cancer cells, we used a pancreatic CSC model, degron (++) cells, which have low proteasome activity. Degron (++) cells displayed radioresistance in comparison with control cells. Using Ribonucleic acid (RNA) sequencing, we successfully identified KRT13 as a candidate gene responsible for radioresistance. Knockdown of KRT13 sensitized the degron (++) cells to radiation. Furthermore, a database search revealed that KRT13 is upregulated in pancreatic cancer cell lines and that high expression of KRT13 is associated with poorer prognosis. These results indicate that a combination therapy of KRT13 knockdown and radiation could hold therapeutic promise in pancreatic cancer.

Hedgehog/GLI1 Transcriptionally Regulates FANCD2 in Ovarian Tumor Cells: Its Inhibition Induces HR-Deficiency and Synergistic Lethality with PARP Inhibition

Ovarian cancer (OC) is one of the most lethal type of cancer in women due to a lack of effective targeted therapies and high rates of treatment resistance and disease recurrence. Recently Poly (ADP-ribose) polymerase inhibitors (PARPi) have shown promise as chemotherapeutic agents; however, their efficacy is limited to a small fraction of patients with BRCA mutations. Here we show a novel function for the Hedgehog (Hh) transcription factor Glioma associated protein 1 (GLI1) in regulation of key Fanconi anemia (FA) gene, FANCD2 in OC cells. GLI1 inhibition in HR-proficient OC cells induces HR deficiency (BRCAness), replication stress and synergistic lethality when combined with PARP inhibition. Treatment of OC cells with combination of GLI1 and PARP inhibitors shows enhanced DNA damage, synergy in cytotoxicity, and strong in vivo anticancer responses.

CircRNA-1926 Promotes the Differentiation of Goat SHF Stem Cells into Hair Follicle Lineage by miR-148a/b-3p/CDK19 Axis

Simple Summary

Cashmere is the fiber derived from cashmere goats. Its textiles have been favored by consumers due to their typical features, like fine, light, softness, and comfort. Circular RNAs (circRNAs) are thought to play roles in cashmere growth of cashmere goats. CircRNA-1926 was previously identified in cashmere goats, but its functional roles are unclear. In this study, we firstly confirmed the expression of circRNA-1926 in secondary hair follicle bulge of cashmere goats with a significantly higher level at anagen than the counterpart of telogen. Next, we showed that circRNA-1926 promotes the differentiation of hair follicle stem cell into hair follicle lineage in cashmere goats. Mechanistically, we found that circRNA-1926 regulated the CDK19 expression via sponging miR-148a/b-3p. Our results have demonstrated that circRNA-1926 promotes the differentiation of secondary hair follicle stem cells into hair follicle lineages in cashmere goats through sponging miR-148a/b-3p to promote the expression of the CDK19 gene. The results from this study provided novel insight into the functional roles of circRNA-1926 in hair follicle regeneration and cashmere growth.

Abstract

Circular RNAs (CircRNAs) are a type of non-coding RNAs, which contain a covalently closed loop structure without 5′ to 3′ free ends. CircRNAs play essential roles in the regeneration of secondary hair follicle (SHF) and cashmere growth in goats. CircRNA-1926 was previously identified in SHF of cashmere goats, but its potential roles are unclear. In this study, we confirmed the expression of circRNA-1926 in SHF bulge of nine cashmere goats with a significantly higher level at anagen than that of telogen. Through the use of both overexpression and siRNA interference, we showed that circRNA-1926 promoted the differentiation of SHF stem cell into hair follicle lineage in cashmere goats which was evaluated via indictor genes Keratin 7 and Keratin 17. Using RNA pull-down, we found that circRNA-1926 bound with miR-148a/b-3p. Additionally, our data indicated that circRNA-1926 promoted the expression of the CDK19 gene. Using dual-luciferase reporter assays, it was revealed that circRNA-1926 positively regulated the CDK19 expression through miR-148a/b-3p. The results from this study demonstrated that circRNA-1926 contributes the differentiation of SHF stem cells into hair follicle lineages in cashmere goats via sponging miR-148a/b-3p to enhance CDK19 expression.

Patched1 haploinsufficiency severely impacts intermediary metabolism in the skin of Ptch1+/-/ODC transgenic mice

The study of dominantly heritable cancers has provided insights about tumor development. Gorlin syndrome (GS) is an autosomal dominant disorder wherein affected individuals develop multiple basal cell carcinomas (BCCs) of the skin. We developed a murine model of Ptch1 haploinsufficiency on an ornithine decarboxylase (ODC) transgenic background (Ptch1^+/−/ODC^t/C57BL/6) that is more sensitive to BCCs growth as compared with Ptch1^+/+/ODC^t/C57BL/6 littermates. Ptch1^+/−/ODC^t/C57BL/6 mice show an altered metabolic landscape in the phenotypically normal skin, including restricted glucose availability, restricted ribose/deoxyribose flow and NADPH production, an accumulation of α-ketoglutarate, aconitate, and citrate that is associated with reversal of the tricarboxylic acid cycle, coupled with increased ketogenic/lipogenic activity via acetyl-CoA, 3-hydroybutyrate, and cholesterol metabolites. Also apparent was an increased content/acetylation of amino-acids, glutamine and glutamate, in particular. Accordingly, metabolic alterations due to a single copy loss of Ptch1 in Ptch1^+/−/ODC^t/C57BL/6 heterozygous mice may provide insights about the cancer prone phenotype of BCCs in GS patients, including biomarkers/targets for early intervention.

Mutations in TSPEAR, Encoding a Regulator of Notch Signaling, Affect Tooth and Hair Follicle Morphogenesis

Despite recent advances in our understanding of the pathogenesis of ectodermal dysplasias (EDs), the molecular basis of many of these disorders remains unknown. In the present study, we aimed at elucidating the genetic basis of a new form of ED featuring facial dysmorphism, scalp hypotrichosis and hypodontia. Using whole exome sequencing, we identified 2 frameshift and 2 missense mutations in TSPEAR segregating with the disease phenotype in 3 families. TSPEAR encodes the thrombospondin-type laminin G domain and EAR repeats (TSPEAR) protein, whose function is poorly understood. TSPEAR knock-down resulted in altered expression of genes known to be regulated by NOTCH and to be involved in murine hair and tooth development. Pathway analysis confirmed that down-regulation of TSPEAR in keratinocytes is likely to affect Notch signaling. Accordingly, using a luciferase-based reporter assay, we showed that TSPEAR knock-down is associated with decreased Notch signaling. In addition, NOTCH1 protein expression was reduced in patient scalp skin. Moreover, TSPEAR silencing in mouse hair follicle organ cultures was found to induce apoptosis in follicular epithelial cells, resulting in decreased hair bulb diameter. Collectively, these observations indicate that TSPEAR plays a critical, previously unrecognized role in human tooth and hair follicle morphogenesis through regulation of the Notch signaling pathway.

Ectodermal dysplasias refer to a large group of inherited disorders characterized by developmental defects in tissues of ectodermal origin. The study of these conditions has been instrumental in the discovery of biological pathways involved in the regulation of epithelial tissue morphogenesis. In this report, through the delineation of the molecular basis of a novel form of autosomal recessive ectodermal dysplasia, we identified a new key player in ectodermal development. We detected a number of mutations in TSPEAR co-segregating with abnormal hair and tooth development in three families. TSPEAR encodes the thrombospondin-type laminin G domain and EAR repeats (TSPEAR) protein, whose function is poorly understood. TSPEAR was found to be strongly expressed in murine hair and tooth. Using a reporter assay, we showed that it regulates Notch activity. Accordingly, NOTCH1 expression was altered in patient skin, and NOTCH1, as well as many of its known targets, was down-regulated in TSPEAR deficient keratinocytes. Moreover, Tspear silencing in mouse hair follicle organ cultures was found to induce apoptosis in follicular epithelial cells, resulting in decreased hair bulb diameter. Collectively, these observations indicate that TSPEAR plays a critical, previously unrecognized role in human tooth and hair follicle morphogenesis through regulation of the Notch pathway. As such, these new data are likely to lead to further investigations aimed at characterizing the role of Notch signaling pathway in other forms of ectodermal dysplasias as well as acquired hair and tooth pathologies.

KRT6 interacting with notch1 contributes to progression of renal cell carcinoma, and aliskiren inhibits renal carcinoma cell lines proliferation in vitro

Notch signaling is a conserved and widely expressed signaling pathway, which mediates various physiological processes including tumorigenesis. This study aims to explore the potential role and mechanism of notch1 interacting with KRT6B in the progression of RCC. The results indicated that the mRNA and protein expression of notch1 and KRT6 were significantly increased in tumor tissues, and highly positive correlation existed between notch1 and KRT6. Moreover, the patients with high notch1 expression had a significantly poorer prognosis than those of low expression patients. In vitro, KRT6 loss-of-function could inhibit the expression of notch1 and induce renal carcinoma cell death. Eventually, we found that renin inhibitor, aliskiren, could inhibit cell proliferation and decrease the expression of notch1 and KRT6 as well as regulate apoptosis-related protein expression in 786-O and ACHN renal carcinoma cell lines. These results suggested that the upregulation of notch1 and KRT6B might be involved in the development, progression and prognosis of human RCC, and aliskiren could suppress renal carcinoma cell proliferation, at least partially, through downregulation the expression of notch1 and KRT6.