1
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Common J, Barker J, Steensel M. What does acne genetics teach us about disease pathogenesis? Br J Dermatol 2019; 181:665-676. [DOI: 10.1111/bjd.17721] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2019] [Indexed: 12/18/2022]
Affiliation(s)
- J.E.A. Common
- Skin Research Institute of Singapore, Agency for Science, Technology and Research (A*STAR) Singapore
| | - J.N. Barker
- St John's Institute of Dermatology Faculty of Life Sciences and Medicine King's College London London U.K
| | - M.A.M. Steensel
- Skin Research Institute of Singapore, Agency for Science, Technology and Research (A*STAR) Singapore
- Lee Kong Chian School of Medicine Nanyang Technological University Clinical Sciences Building Novena Singapore
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2
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Bao B, Prasad AS. Targeting CSC in a Most Aggressive Subtype of Breast Cancer TNBC. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1152:311-334. [DOI: 10.1007/978-3-030-20301-6_17] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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3
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Jung S, Hartmann A, Del Sol A. RefBool: a reference-based algorithm for discretizing gene expression data. Bioinformatics 2018; 33:1953-1962. [PMID: 28334101 DOI: 10.1093/bioinformatics/btx111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/21/2017] [Indexed: 12/26/2022] Open
Abstract
Motivation The identification of genes or molecular regulatory mechanisms implicated in biological processes often requires the discretization, and in particular booleanization, of gene expression measurements. However, currently used methods mostly classify each measurement into an active or inactive state regardless of its statistical support possibly leading to downstream analysis conclusions based on spurious booleanization results. Results In order to overcome the lack of certainty inherent in current methodologies and to improve the process of discretization, we introduce RefBool, a reference-based algorithm for discretizing gene expression data. Instead of requiring each measurement to be classified as active or inactive, RefBool allows for the classification of a third state that can be interpreted as an intermediate expression of genes. Furthermore, each measurement is associated to a p- and q-value indicating the significance of each classification. Validation of RefBool on a neuroepithelial differentiation study and subsequent qualitative and quantitative comparison against 10 currently used methods supports its advantages and shows clear improvements of resulting clusterings. Availability and Implementation The software is available as MATLAB files in the Supplementary Information and as an online repository ( https://github.com/saschajung/RefBool ). Contact antonio.delsol@uni.lu. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Sascha Jung
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belvaux, Luxembourg
| | - Andras Hartmann
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belvaux, Luxembourg
| | - Antonio Del Sol
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belvaux, Luxembourg
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4
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Shi FT, Yu M, Zloty D, Bell RH, Wang E, Akhoundsadegh N, Leung G, Haegert A, Carr N, Shapiro J, McElwee KJ. Notch signaling is significantly suppressed in basal cell carcinomas and activation induces basal cell carcinoma cell apoptosis. Mol Med Rep 2017; 15:1441-1454. [PMID: 28259916 PMCID: PMC5364965 DOI: 10.3892/mmr.2017.6163] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 09/09/2016] [Indexed: 12/29/2022] Open
Abstract
A subset of basal cell carcinomas (BCCs) are directly derived from hair follicles (HFs). In some respects, HFs can be defined as 'ordered' skin appendage growths, while BCCs can be regarded as 'disordered' skin appendage growths. The aim of the present study was to examine HFs and BCCs to define the expression of common and unique signaling pathways in each skin appendage. Human nodular BCCs, along with HFs and non‑follicular skin epithelium from normal individuals, were examined using microarrays, qPCR, and immunohistochemistry. Subsequently, BCC cells and root sheath keratinocyte cells from HFs were cultured and treated with Notch signaling peptide Jagged1 (JAG1). Gene expression, protein levels, and cell apoptosis susceptibility were assessed using qPCR, immunoblotting, and flow cytometry, respectively. Specific molecular mechanisms were found to be involved in the process of cell self‑renewal in the HFs and BCCs, including Notch and Hedgehog signaling pathways. However, several key Notch signaling factors showed significant differential expression in BCCs compared with HFs. Stimulating Notch signaling with JAG1 induced apoptosis of BCC cells by increasing Fas ligand expression and downstream caspase-8 activation. The present study showed that Notch signaling pathway activity is suppressed in BCCs, and is highly expressed in HFs. Elements of the Notch pathway could, therefore, represent targets for the treatment of BCCs and potentially in hair follicle engineering.
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Affiliation(s)
- Feng-Tao Shi
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada
| | - Mei Yu
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada
| | - David Zloty
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada
| | - Robert H Bell
- Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC V6H 3Z6, Canada
| | - Eddy Wang
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada
| | - Noushin Akhoundsadegh
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada
| | - Gigi Leung
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada
| | - Anne Haegert
- Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, BC V6H 3Z6, Canada
| | - Nicholas Carr
- Department of Surgery, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Jerry Shapiro
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada
| | - Kevin J McElwee
- Department of Dermatology and Skin Science, University of British Columbia, Vancouver, BC V5Z 4E8, Canada
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5
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Ishitsuka Y, Kawachi Y, Maruyama H, Taguchi S, Fujisawa Y, Furuta J, Nakamura Y, Ishii Y, Otsuka F. Pituitary Tumor Transforming Gene 1 Induces Tumor Necrosis Factor-α Production from Keratinocytes: Implication for Involvement in the Pathophysiology of Psoriasis. J Invest Dermatol 2013; 133:2566-2575. [DOI: 10.1038/jid.2013.189] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 03/18/2013] [Accepted: 04/01/2013] [Indexed: 01/25/2023]
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6
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Bao B, Azmi AS, Ali S, Ahmad A, Li Y, Banerjee S, Kong D, Sarkar FH. The biological kinship of hypoxia with CSC and EMT and their relationship with deregulated expression of miRNAs and tumor aggressiveness. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1826:272-96. [PMID: 22579961 PMCID: PMC3788359 DOI: 10.1016/j.bbcan.2012.04.008] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/25/2012] [Accepted: 04/28/2012] [Indexed: 12/13/2022]
Abstract
Hypoxia is one of the fundamental biological phenomena that are intricately associated with the development and aggressiveness of a variety of solid tumors. Hypoxia-inducible factors (HIF) function as a master transcription factor, which regulates hypoxia responsive genes and has been recognized to play critical roles in tumor invasion, metastasis, and chemo-radiation resistance, and contributes to increased cell proliferation, survival, angiogenesis and metastasis. Therefore, tumor hypoxia with deregulated expression of HIF and its biological consequence lead to poor prognosis of patients diagnosed with solid tumors, resulting in higher mortality, suggesting that understanding of the molecular relationship of hypoxia with other cellular features of tumor aggressiveness would be invaluable for developing newer targeted therapy for solid tumors. It has been well recognized that cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT) phenotypic cells are associated with therapeutic resistance and contribute to aggressive tumor growth, invasion, metastasis and believed to be the cause of tumor recurrence. Interestingly, hypoxia and HIF signaling pathway are known to play an important role in the regulation and sustenance of CSCs and EMT phenotype. However, the molecular relationship between HIF signaling pathway with the biology of CSCs and EMT remains unclear although NF-κB, PI3K/Akt/mTOR, Notch, Wnt/β-catenin, and Hedgehog signaling pathways have been recognized as important regulators of CSCs and EMT. In this article, we will discuss the state of our knowledge on the role of HIF-hypoxia signaling pathway and its kinship with CSCs and EMT within the tumor microenvironment. We will also discuss the potential role of hypoxia-induced microRNAs (miRNAs) in tumor development and aggressiveness, and finally discuss the potential effects of nutraceuticals on the biology of CSCs and EMT in the context of tumor hypoxia.
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Affiliation(s)
- Bin Bao
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Asfar S. Azmi
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Shadan Ali
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Aamir Ahmad
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Yiwei Li
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Sanjeev Banerjee
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Dejuan Kong
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Fazlul H. Sarkar
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
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7
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Dereure O. [Stem cells in dermatology: concept and medical interest]. Ann Dermatol Venereol 2012; 139:568-78. [PMID: 22963970 DOI: 10.1016/j.annder.2012.03.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- O Dereure
- Service de dermatologie, Inserm U1058, université Montpellier-I, hôpital St-Éloi, 80, avenue A.-Fliche, 34295 Montpellier cedex 5, France.
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8
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Abstract
This is a chronicle of concepts in the field of epidermal stem cell biology and a historic look at their development over time. The past 25 years have seen the evolution of epidermal stem cell science, from first fundamental studies to a sophisticated science. The study of epithelial stem cell biology was aided by the ability to visualize the distribution of stem cells and their progeny through lineage analysis studies. The excellent progress we have made in understanding epidermal stem cell biology is discussed in this article. The challenges we still face in understanding epidermal stem cells include defining molecular markers for stem and progenitor sub-populations, determining the locations and contributions of the different stem cell niches, and mapping regulatory pathways of epidermal stem cell proliferation and differentiation. However, our rapidly evolving understanding of epidermal stem cells has many potential uses that promise to translate into improved patient therapy.
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Affiliation(s)
- Ruby Ghadially
- Department of Dermatology and Epithelial Section, UCSF Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, California 94121, USA.
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9
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Ragina NP, Schlosser K, Knott JG, Senagore PK, Swiatek PJ, Chang EA, Fakhouri WD, Schutte BC, Kiupel M, Cibelli JB. Downregulation of H19 improves the differentiation potential of mouse parthenogenetic embryonic stem cells. Stem Cells Dev 2011; 21:1134-44. [PMID: 21793658 DOI: 10.1089/scd.2011.0152] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Parthenogenetic embryonic stem cells (P-ESCs) offer an alternative source of pluripotent cells, which hold great promise for autologous transplantation and regenerative medicine. P-ESCs have been successfully derived from blastocysts of several mammalian species. However, compared with biparental embryonic stem cells (B-ESCs), P-ESCs are limited in their ability to fully differentiate into all 3 germ layers. For example, it has been observed that there is a differentiation bias toward ectoderm derivatives at the expense of endoderm and mesoderm derivatives-muscle in particular-in chimeric embryos, teratomas, and embryoid bodies. In the present study we found that H19 expression was highly upregulated in P-ESCs with more than 6-fold overexpression compared with B-ESCs. Thus, we hypothesized that manipulation of the H19 gene in P-ESCs would alleviate their limitations and allow them to function like B-ESCs. To test this hypothesis we employed a small hairpin RNA approach to reduce the amount of H19 transcripts in mouse P-ESCs. We found that downregulation of H19 led to an increase of mesoderm-derived muscle and endoderm in P-ESCs teratomas similar to that observed in B-ESCs teratomas. This phenomenon coincided with upregulation of mesoderm-specific genes such as Myf5, Myf6, and MyoD. Moreover, H19 downregulated P-ESCs differentiated into a higher percentage of beating cardiomyocytes compared with control P-ESCs. Collectively, these results suggest that P-ESCs are amenable to molecular modifications that bring them functionally closer to true ESCs.
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Affiliation(s)
- Neli P Ragina
- Department of Animal Science, Michigan State University, East Lansing, MI 48824, USA
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10
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Winder MJ, Tanase FJ, Rostad S, Mayberg MR. Intracranial sebaceous neoplasm: a case report. Neurosurgery 2011; 70:E1608-12. [PMID: 21788919 DOI: 10.1227/neu.0b013e31822e5a3c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND IMPORTANCE Sebaceous neoplasms range from hyperplastic hamartomas to malignant tumors and are most commonly cutaneous lesions. We describe the first reported case of an intracranial sebaceous neoplasm, discussing the differential diagnosis and possible pathogenesis in relation to the current literature. CLINICAL PRESENTATION A 58-year-old man presented with evolving neck stiffness, facial pain, and progressively worsening diplopia. Magnetic resonance imaging identified a moderate-sized lesion intimately related to the left cavernous sinus, which had extended into the posterior fossa. The patient underwent endoscopic, transnasal subtotal resection of the neoplasm with significant improvement. Histologically, the tumor was identified as a sebaceous neoplasm previously unreported intracranially. Follow-up imaging at 6 months revealed no further recurrence. CONCLUSION This is the first reported case of an intracranial sebaceous neoplasm. Careful follow-up is required to help elucidate the biology of this tumor in an effort to determine the role of adjuvant therapy.
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11
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Buitrago W, Joseph AK. Sebaceous carcinoma: the great masquerader: emgerging concepts in diagnosis and treatment. Dermatol Ther 2009; 21:459-66. [PMID: 19076624 DOI: 10.1111/j.1529-8019.2008.00247.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Sebaceous carcinoma (SC) is a rare tumor with a high rate of local recurrence and metastasis to lymph nodes and organs. The majority of SCs occur in the periocular region frequently presenting as painless, round subcutaneous nodules with a high tendency of diffuse and invasive growth in the eyelid and conjunctiva. It frequently masquerades as inflammatory conditions or as other tumors leading to delay in diagnosis, inappropriate treatment and increased morbidity and mortality. Sebaceous carcinoma is associated with Muir-Torre syndrome, a genetic condition presenting with sebaceous skin tumors associated with internal malignancy. Therefore, SC patients must be carefully evaluated and referred to an internist or gastroenterologist when indicated. Surgery is the definitive therapy for SC. In recent years, less radical surgical strategies are being used with improved outcomes. Current studies demonstrate that Mohs micrographic surgery (MMS) provides maximal tissue conservation and lower recurrence rates. Greater awareness and understanding of SC and its behavior has led to earlier diagnosis and appropriate treatment.
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Affiliation(s)
- William Buitrago
- Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA
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12
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Ogawa E, Okuyama R, Egawa T, Nagoshi H, Obinata M, Tagami H, Ikawa S, Aiba S. p63/p51-induced onset of keratinocyte differentiation via the c-Jun N-terminal kinase pathway is counteracted by keratinocyte growth factor. J Biol Chem 2008; 283:34241-9. [PMID: 18849344 DOI: 10.1074/jbc.m804101200] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
p63/p51, a homolog of the tumor suppressor protein p53, is chiefly expressed in epithelial tissues, including the epidermis. p63 affects cell death similar to p53, and also plays important roles in the development of epithelial tissues and the maintenance of epithelial stem cells. Because it remains unclear how p63 regulates epithelial cell differentiation, we examined the function(s) of p63 in keratinocyte differentiation through the use of a keratinocyte culture system. DeltaNp63alpha (DeltaNp51B), a p63 isoform specifically expressed in basal keratinocytes, suppressed the differentiation of specific late-stage proteins, such as filaggrin and loricrin. In contrast, DeltaNp63alpha induced keratin 1 (K1), which is expressed at the start of differentiation, via c-Jun N-terminal kinase (JNK)/AP-1 activation. However, p63 did not induce K1 expression in the basal layer in vivo, although basal keratinocytes had high levels of p63. This discrepancy was explained by the suppression of K1 expression by dermis-secreted keratinocyte growth factor. This suppression occurred via extracellular signal-related kinase (ERK) signaling, and counteracted the p63-mediated induction of K1. Thus, a precise balance between p63 and keratinocyte growth factor mediates the onset of epithelial cell differentiation, through JNK and ERK signaling. These data may provide mechanistic explanations for the pathological features of skin diseases, including psoriasis.
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Affiliation(s)
- Eisaku Ogawa
- Department of Dermatology, Tohoku University Graduate School of Medicine, Sendai, Japan
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13
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Partridge M, Costea D, Huang X. The changing face of p53 in head and neck cancer. Int J Oral Maxillofac Surg 2007; 36:1123-38. [DOI: 10.1016/j.ijom.2007.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2006] [Accepted: 06/29/2007] [Indexed: 02/04/2023]
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14
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Nieuwenhuis E, Barnfield PC, Makino S, Hui CC. Epidermal hyperplasia and expansion of the interfollicular stem cell compartment in mutant mice with a C-terminal truncation of Patched1. Dev Biol 2007; 308:547-60. [PMID: 17631878 DOI: 10.1016/j.ydbio.2007.06.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 06/07/2007] [Accepted: 06/20/2007] [Indexed: 12/31/2022]
Abstract
Hedgehog (Hh) signaling is conserved from flies to humans and is indispensable in embryogenesis and adulthood. Patched (Ptc) encodes a receptor for Hh ligands and functions as a tumor suppressor. PTCH1 mutations in humans are found in basal cell carcinoma (BCC) and irradiated Ptc1(+/-) mice recapitulate this phenotype. However, due to embryonic lethality associated with the Ptc1 null mutation, its normal function in embryonic and adult skin remains unknown. Here we describe the epidermal phenotypes of a spontaneous and viable allele of Ptc1, Ptc1(mes), in which the C-terminal domain (CTD) is truncated. Ptc1(mes/mes) embryos display normal epidermal and hair follicle development. Postnatal Ptc1(mes/mes) skin displays severe basal cell layer hyperplasia and increased proliferation, while stratification of the suprabasal layers is mostly normal. Interestingly, truncation of the Ptc1 CTD did not result in skin tumors. However, long term labeling studies revealed a greater than three-fold increase in label-retaining cells in the interfollicular epidermis of Ptc1(mes/mes) adults, indicating possible expansion of the epidermal stem cell compartment. Increased expression of regulators of epidermal homeostasis, c-Myc and p63, was also observed in Ptc1(mes/mes) adult skin. These results suggest that the CTD of Ptc1 is involved in regulating epidermal homeostasis in mature skin.
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Affiliation(s)
- Erica Nieuwenhuis
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, University of Toronto, Toronto Medical Discovery Towers, 101 College Street, Toronto, Ontario, Canada M5G1L7
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15
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Tiede S, Kloepper JE, Bodò E, Tiwari S, Kruse C, Paus R. Hair follicle stem cells: walking the maze. Eur J Cell Biol 2007; 86:355-76. [PMID: 17576022 DOI: 10.1016/j.ejcb.2007.03.006] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 03/20/2007] [Accepted: 03/21/2007] [Indexed: 12/17/2022] Open
Abstract
The discovery of epithelial stem cells (eSCs) in the bulge region of the outer root sheath of hair follicles in mice and man has encouraged research into utilizing the hair follicle as a therapeutic source of stem cells (SCs) for regenerative medicine, and has called attention to the hair follicle as a highly instructive model system for SC biology. Under physiological circumstances, bulge eSCs serve as cell pool for the cyclic regeneration of the anagen hair bulb, while they can also regenerate the sebaceous gland and the epidermis after injury. More recently, melanocyte SCs, nestin+, mesenchymal and additional, as yet ill-defined "stem cell" populations, have also been identified in or immediately adjacent to the hair follicle epithelium, including in the specialized hair follicle mesenchyme (connective tissue sheath), which is crucial to wound healing. Thus the hair follicle and its adjacent tissue environment contain unipotent, multipotent, and possibly even pluripotent SC populations of different developmental origin. It provides an ideal model system for the study of central issues in SC biology such as plasticity and SC niches, and for the identification of reliable, specific SC markers, which distinguish them from their immediate progeny (e.g. transient amplifying cells). The current review attempts to provide some guidance in this growing maze of hair follicle-associated SCs and their progeny, critically reviews potential or claimed hair follicle SC markers, highlights related differences between murine and human hair follicles, and defines major unanswered questions in this rapidly advancing field.
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Affiliation(s)
- Stephan Tiede
- Department of Dermatology, University Hospital Schleswig-Holstein, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany
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Liu G, Moro A, Zhang JJR, Cheng W, Qiu W, Kim PCW. The role of Shh transcription activator Gli2 in chick cloacal development. Dev Biol 2006; 303:448-60. [PMID: 17239843 DOI: 10.1016/j.ydbio.2006.10.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 09/19/2006] [Accepted: 10/27/2006] [Indexed: 12/25/2022]
Abstract
Patterning and differentiation along the dorsal-ventral (D-V) axis lead to cloacal partitioning into ventral urinary and dorsal alimentary tracts in most mammals, but not birds and fish. We previously reported that the major activator of Sonic hedgehog (Shh) signaling transcription factor Gli2 plays an essential role in cloacal partitioning along the D-V axis in a mouse model. Here, we report that chick cloacal patterning and differentiation is along the anterior-posterior axis. During chick cloacal formation, Shh is expressed strongly in hindgut endoderm; Gli2 is very weakly detected in the surrounding hindgut mesoderm. In the mesoderm of the cloacal region, the over-expression of the constitutively active form of mouse Gli2 has been shown to: not induce cloacal partitioning along the D-V axis; induce expression of Ptch1, Gli2, bmp4, wnt5a, and hoxd-13, which have been previously shown to play a role in hindgut patterning; increase cell proliferation; and reduce apoptosis. Interestingly, p63 expression in the cloacal endoderm is also up-regulated, suggesting an interaction between the Shh and p63 pathways. In conclusion, Gli2 alone is insufficient to induce partitioning along the D-V axis in the chick embryo. However, Gli2 regulates both epithelial and mesenchymal cell proliferation and apoptosis during cloacal development.
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Affiliation(s)
- Guodong Liu
- Department of Surgery, Programs of Infection, Immunity, Injury and Repair, The Hospital for Sick Children, 555 University Ave, Suite 1526, Toronto, Ontario, Canada M5G 1X8
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Abstract
Current understanding of the biology of epidermal stem cells opens a totally new perspective in the function of the epidermis and adjacent epithelial structures. A number of pathogenetic as well as clinical-therapeutic approaches against a variety of dermatoses may become possible with knowledge about keratinocyte proliferation, differentiation and regeneration. The reservoir of epidermal stem cells is located in the interfollicular epidermis, the hair follicle area and the germinal hair follicle matrix. Endogenous stem cell clones exist here, giving rise to transient amplifying cells and postmitotic cells. The stem cell clones are organized in clusters and display high expression of adhesion proteins, which guarantee their stability in a specific environment consisting of different cell types and extracellular substrates in the stratum basale. Differentiation is determined by a specific cascade of chemical signals from the stem cell environment and from the genetic program of the cell. The clinical relevance of stem cells lies primarily in their therapeutic potential with reconstruction of epithelia by reimplantation of autologous stem cells or gene therapeutic applications such as targeted transfection. However, the benefit-to-risk ratio cannot yet be accurately estimated.
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Affiliation(s)
- Karin Rzepka
- Institut für angewandte Dermatopharmazie, Martin-Luther-Universität Halle-Wittenberg
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19
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Johnson J, Lagowski J, Sundberg A, Kulesz-Martin M. P53 Family Activities in Development and Cancer: Relationship to Melanocyte and Keratinocyte Carcinogenesis. J Invest Dermatol 2005; 125:857-64. [PMID: 16297181 DOI: 10.1111/j.0022-202x.2004.23920.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jodi Johnson
- Department of Dermatology, Oregon Health & Science University, School of Medicine, Portland, Oregon, USA
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20
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Chaturvedi V, Sitailo LA, Qin JZ, Bodner B, Denning MF, Curry J, Zhang W, Brash D, Nickoloff BJ. Knockdown of p53 levels in human keratinocytes accelerates Mcl-1 and Bcl-xL reduction thereby enhancing UV-light induced apoptosis. Oncogene 2005; 24:5299-312. [PMID: 15940268 DOI: 10.1038/sj.onc.1208650] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ultraviolet (UV) light exposure is a common cause of epithelial-derived skin cancers, and the epidermal response to UV-light has been extensively studied using both mouse models and cultured human keratinocytes (KCs). Elimination of cells with UV-induced DNA damage via apoptosis provides a powerful mechanism to minimize retention or expansion of genetically abnormal cells. This cell editing function has largely been ascribed to the biological role of the p53 tumor suppressor gene, as mutations or deletions involving p53 have been linked to skin cancer development. Rather than introducing mutations, or using cells with complete loss of wild-type p53, we used an siRNA-based approach to knockdown, but not eliminate, p53 levels in primary cultures of human KCs followed by UV-irradiation. Surprisingly, when p53 levels were reduced by 50-80% the apoptosis induced by exposure to UV-light was accelerated and markedly enhanced (two- to three- fold) compared to control siRNA treated KCs. The p53 siRNA treated KCs were characterized by elevated E2F-1 levels accompanied by accelerated elimination of the Mcl-1 and Bcl-x(L) antiapoptotic proteins, as well as enhanced Bax oligomerization. Forced overexpression of either Mcl-1 or Bcl-x(L) reduced the UV-light enhanced apoptotic response in p53 siRNA treated KCs. We conclude that p53 not only can provide proapoptotic signals but also regulates a survival pathway influencing Mcl-1 and Bcl-x(L) levels. This overlooked survival function of p53 may explain previous paradoxical responses noted by investigators using p53 heterozygous and knockout mouse models, and opens up the possibility that not all liaisons within the cell involving p53 necessarily represent fatal attractions.
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Affiliation(s)
- Vijaya Chaturvedi
- Department of Pathology, Oncology Institute, Loyola University Medical Center, Maywood, IL 60153, USA
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