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Ma M, Zhu Y, Xiao C, Li R, Cao X, Kang R, Wang X, Li E. Novel insights into RB1 in prostate cancer lineage plasticity and drug resistance. TUMORI JOURNAL 2024; 110:252-263. [PMID: 38316605 DOI: 10.1177/03008916231225576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Prostate cancer is the second most common malignancy among men in the world, posing a serious threat to men's health and lives. RB1 is the first human tumor suppressor gene to be described, and it is closely associated with the development, progression, and suppression of a variety of tumors. It was found that the loss of RB1 is an early event in prostate cancer development and is closely related to prostate cancer development, progression and treatment resistance. This paper reviews the current status of research on the relationship between RB1 and prostate cancer from three aspects: RB1 and prostate cell lineage plasticity; biological behavior; and therapeutic resistance. Providing a novel perspective for developing new therapeutic strategies for RB1-loss prostate cancer.
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Affiliation(s)
- Min Ma
- Institute of Translational Medicine, School of Basic Medical, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Yazhi Zhu
- Institute of Translational Medicine, School of Basic Medical, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Changkai Xiao
- Department of Urology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Ruidong Li
- Department of Urology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Xingyu Cao
- Institute of Translational Medicine, School of Basic Medical, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Ran Kang
- Department of Urology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Xiaolan Wang
- Department of Reproductive Medicine, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China
| | - Ermao Li
- Institute of Translational Medicine, School of Basic Medical, Hengyang Medical School, University of South China, Hengyang, Hunan, China
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Agha‐Hosseini F, Hafezi Motlagh K. The correlation between human papillomavirus and oral lichen planus: A systematic review of the literature. Immun Inflamm Dis 2023; 11:e960. [PMID: 37647448 PMCID: PMC10408375 DOI: 10.1002/iid3.960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/28/2023] [Accepted: 07/13/2023] [Indexed: 09/01/2023] Open
Abstract
INTRODUCTION Oral lichen planus (OLP) is a chronic inflammatory disorder with cell-induced immunopathological responses and is considered a potential malignancy disorder in the oral cavity. Due to the high prevalence of OLP as well as the potential for malignancy, human papillomaviruses (HPVs) may play an important role in it. Although previous studies have explored the possible relationship between HPV and OLP, the findings have been conflicting and nonconclusive. This study aims to review the studies that investigated HPV-16 and HPV-18 in OLP. METHODS AND MATERIALS The research protocol followed the Preferred Reporting Items for Systematic Reviews (PRISMA2020) checklist. The online databases Pubmed, Scopus, Embase, Google Scholar, and Cochrane were searched using the following individual keywords: "OLP" OR "Oral Lichen Planus" OR "HPV" OR "Human Papillomavirus." The search strategy resulted in the selection of 80 articles. The articles were evaluated, and after duplication removal, 53 abstracts were reviewed, resulting in the selection of 25 studies according to inclusion and exclusion criteria. The risk of bias assessment was done by using the Modified Newcastle-Ottawa quality assessment scale. The overall prevalence of HPV in OLP lesions varied from 2.7% to 70%, depending on the type of diagnostic method used. CONCLUSION Despite the studies conducted on the relationship between OLP and HPV infection, there is still no conclusive evidence that HPV can play a role in the etiopathogenesis of OLP, either in clinical manifestations or in the malignant transformation of lesions.
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Affiliation(s)
- Farzaneh Agha‐Hosseini
- Dental Research CenterDentistry Research Institute, Tehran University of Medical SciencesTehranIran
- Department of Oral Medicine, Faculty of DentistryTehran University of Medical SciencesTehranIran
- The Academy of Medical SciencesTehranIran
| | - Kimia Hafezi Motlagh
- Department of Oral Medicine, School of DentistryTehran University of Medical SciencesTehranIran
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3
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López-Ansio M, Ramos-García P, González-Moles MÁ. Prognostic and Clinicopathological Significance of the Loss of Expression of Retinoblastoma Protein (pRb) in Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis. Cancers (Basel) 2023; 15:3132. [PMID: 37370742 DOI: 10.3390/cancers15123132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/02/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
This systematic review and meta-analysis aims to evaluate the scientific evidence on the implications of retinoblastoma protein (pRb) alterations in oral cancer, in order to determine its prognostic and clinicopathological significance. PubMed, Embase, Web of Science, and Scopus were searched for studies published before February 2022, with no restrictions by publication date or language. The quality of the studies using the Quality in Prognosis Studies tool (QUIPS tool). Meta-analysis was conducted to achieve the proposed objectives, as well as heterogeneity, subgroup, meta-regression, and small study-effects analyses. Twenty studies that met the inclusion criteria (2451 patients) were systematically reviewed and meta-analyzed. Our results were significant for the association between the loss of pRb expression and a better overall survival (HR = 0.79, 95%CI = 0.64-0.98, p = 0.03), whereas no significant results were found for disease-free survival or clinico-pathological parameters (T/N status, clinical stage, histological grade). In conclusion, our evidence-based results demonstrate that loss of pRb function is a factor associated with improved survival in patients with OSCC. Research lines that should be developed in the future are highlighted.
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Affiliation(s)
- María López-Ansio
- School of Dentistry, University of Granada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Pablo Ramos-García
- School of Dentistry, University of Granada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Miguel Ángel González-Moles
- School of Dentistry, University of Granada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
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Levin A, Paredes D, Haefeli L, Okoye O, Capasso J, Wyman C, Khetan V. Genetic testing: Getting it right. Oman J Ophthalmol 2023; 16:1-3. [PMID: 37007263 PMCID: PMC10062063 DOI: 10.4103/ojo.ojo_11_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 01/19/2023] [Accepted: 01/19/2023] [Indexed: 02/23/2023] Open
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5
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González-Moles MÁ, Keim-del Pino C, Ramos-García P. Hallmarks of Cancer Expression in Oral Lichen Planus: A Scoping Review of Systematic Reviews and Meta-Analyses. Int J Mol Sci 2022; 23:13099. [PMID: 36361889 PMCID: PMC9658487 DOI: 10.3390/ijms232113099] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 09/05/2023] Open
Abstract
Oral lichen planus (OLP) is a common chronic inflammatory disease of unknown etiology and likely autoimmune nature that is currently considered an oral potentially malignant disorder, implying that patients suffering from this process are at risk of developing oral cancer in their lifetime. The molecular alterations that develop in OLP and that make the affected oral epithelium predisposed to malignancy are unknown, although, as in other autoimmune diseases (ulcerative colitis, primary biliary cirrhosis, etc.), they may be linked to oncogenesis-promoting effects mediated by the inflammatory infiltrate. So far there is no in-depth knowledge on how these hallmarks of cancer are established in the cells of the oral epithelium affected by OLP. In this scoping review of systematic reviews and meta-analyses the state of evidence based knowledge in this field is presented, to point out gaps of evidence and to indicate future lines of research. MEDLINE, Embase, Cochrane Library and Dare were searched for secondary-level studies published before October 2022. The results identified 20 systematic reviews and meta-analyses critically appraising the hallmarks tumor-promoting inflammation (n = 17, 85%), sustaining proliferative signaling (n = 2, 10%), and evading growth suppressors (n = 1, 5%). No evidence was found for the other hallmarks of cancer in OLP. In conclusion, OLP malignization hypothetically derives from the aggressions of the inflammatory infiltrate and a particular type of epithelial response based on increased epithelial proliferation, evasion of growth-suppressive signals and lack of apoptosis. Future evidence-based research is required to support this hypothesis.
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Affiliation(s)
- Miguel Ángel González-Moles
- School of Dentistry, University of Granada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Carmen Keim-del Pino
- School of Dentistry, University of Granada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Pablo Ramos-García
- School of Dentistry, University of Granada, 18071 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
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6
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González-Moles MÁ, Warnakulasuriya S, López-Ansio M, Ramos-García P. Hallmarks of Cancer Applied to Oral and Oropharyngeal Carcinogenesis: A Scoping Review of the Evidence Gaps Found in Published Systematic Reviews. Cancers (Basel) 2022; 14:cancers14153834. [PMID: 35954497 PMCID: PMC9367256 DOI: 10.3390/cancers14153834] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/04/2022] [Accepted: 08/04/2022] [Indexed: 02/07/2023] Open
Abstract
Simple Summary This scoping review of systematic reviews aims to accurately assess the degree of existing scientific evidence on the cancer hallmarks proposed in 2011 by Hanahan and Weinberg, in the form of systematic reviews and meta-analyses, applied to oral potentially malignant disorders, oral cavity and oropharyngeal squamous cell carcinomas, in order to point out gaps in evidence and lines of research that should be implemented in the future to improve the malignant transformation prediction, diagnosis and/or prognosis of these diseases. Abstract In 2000 and 2011, Hanahan and Weinberg published two papers in which they defined the characteristics that cells must fulfil in order to be considered neoplastic cells in all types of tumours that affect humans, which the authors called “hallmarks of cancer”. These papers have represented a milestone in our understanding of the biology of many types of cancers and have made it possible to reach high levels of scientific evidence in relation to the prognostic impact that these hallmarks have on different tumour types. However, to date, there is no study that globally analyses evidence-based knowledge on the importance of these hallmarks in oral and oropharyngeal squamous cell carcinomas. For this reason, we set out to conduct this scoping review of systematic reviews with the aim of detecting evidence gaps in relation to the relevance of the cancer hallmarks proposed by Hanahan and Weinberg in oral and oropharyngeal cancer, and oral potentially malignant disorders, and to point out future lines of research in this field.
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Affiliation(s)
- Miguel Ángel González-Moles
- School of Dentistry, University of Granada, 18011 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Saman Warnakulasuriya
- Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London SE1 9RT, UK
- WHO Collaborating for Oral Cancer, King's College London, London SE1 9RT, UK
| | - María López-Ansio
- School of Dentistry, University of Granada, 18011 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
| | - Pablo Ramos-García
- School of Dentistry, University of Granada, 18011 Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, 18012 Granada, Spain
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Wang WZ, Shulman A, Amann JM, Carbone DP, Tsichlis PN. Small cell lung cancer: Subtypes and therapeutic implications. Semin Cancer Biol 2022; 86:543-554. [DOI: 10.1016/j.semcancer.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/23/2022] [Accepted: 04/04/2022] [Indexed: 12/20/2022]
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Seok JS, Jeong CH, Petriello MC, Seo HG, Yoo H, Hong K, Han SG. Piperlongumine decreases cell proliferation and the expression of cell cycle-associated proteins by inhibiting Akt pathway in human lung cancer cells. Food Chem Toxicol 2018; 111:9-18. [PMID: 29109039 DOI: 10.1016/j.fct.2017.10.058] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 10/20/2017] [Accepted: 10/30/2017] [Indexed: 12/13/2022]
Abstract
Piperlongumine (PL) is an alkaloid of a pepper plant found in Southeast Asia. PL is known to induce selective toxicity towards a variety of cancer cell types. To explore the possible anti-lung cancer effects of PL, A549 cells were treated with PL (0-40 μM) for 24 h. Alterations in the expression of cell cycle-associated proteins (cyclin D1, cyclin-dependent kinase 4 (CDK4), CDK6 and retinoblastoma (Rb)) and intracellular signaling molecules (extracellular signal receptor-activated kinase 1/2 (ERK1/2), Akt, p38 and nuclear factor-κB (NF-κB)) were examined in cells following treatment of PL using Western blot analysis. Results showed that proliferation of cells were significantly decreased by PL in a dose-dependent manner. Flow cytometry results demonstrated increased number of cells in G1 phase in PL (40 μM)-treated group. Reactive oxygen species was significantly increased in cells treated with PL at 20-40 μM. The expression of cyclin D1, CDK4, CDK6 and p-Rb were markedly decreased in cells treated with PL at 40 μM. Treatment of cells with PL suppressed phosphorylation of Akt but increased ERK1/2 phosphorylation. Treatment of PL significantly decreased nuclear translocation of NF-κB p65 in cells. These results suggest that PL possesses antiproliferative properties in A549 cells.
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Affiliation(s)
- Jin Sil Seok
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Republic of Korea
| | - Chang Hee Jeong
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Republic of Korea
| | - Michael C Petriello
- Superfund Research Center, Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Han Geuk Seo
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Republic of Korea
| | - Hyunjin Yoo
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Seoul 05029, Republic of Korea
| | - Kwonho Hong
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Seoul 05029, Republic of Korea
| | - Sung Gu Han
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Republic of Korea.
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Barnoud T, Schmidt ML, Donninger H, Clark GJ. The role of the NORE1A tumor suppressor in Oncogene-Induced Senescence. Cancer Lett 2017; 400:30-36. [PMID: 28455242 PMCID: PMC5502528 DOI: 10.1016/j.canlet.2017.04.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 12/14/2022]
Abstract
The Ras genes are the most frequently mutated oncogenes in human cancer. However, Ras biology is quite complex. While Ras promotes tumorigenesis by regulating numerous growth promoting pathways, activated Ras can paradoxically also lead to cell cycle arrest, death, and Oncogene-Induced Senescence (OIS). OIS is thought to be a critical pathway that serves to protect cells against aberrant Ras signaling. Multiple reports have highlighted the importance of the p53 and Rb tumor suppressors in Ras mediated OIS. However, until recently, the molecular mechanisms connecting Ras to these proteins remained unknown. The RASSF family of tumor suppressors has recently been identified as direct effectors of Ras. One of these members, NORE1A (RASSF5), may be the missing link between Ras-induced senescence and the regulation of p53 and Rb. This occurs both quantitatively, by promoting protein stability, as well as qualitatively via promoting critical pro-senescent post-translational modifications. Here we review the mechanisms by which NORE1A can activate OIS as a barrier against Ras-mediated transformation, and how this could lead to improved therapeutic strategies against cancers having lost NORE1A expression.
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Affiliation(s)
- Thibaut Barnoud
- Program in Molecular and Cellular Oncogenesis, The Wistar Institute, Philadelphia PA 19104, USA
| | - M Lee Schmidt
- Department of Pharmacology and Toxicology, University of Louisville, KY 40202, USA
| | | | - Geoffrey J Clark
- Department of Pharmacology and Toxicology, University of Louisville, KY 40202, USA.
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10
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Abstract
Mutations in the Ras oncogene are one of the most frequent events in human cancer. Although Ras regulates numerous growth-promoting pathways to drive transformation, it can paradoxically promote an irreversible cell cycle arrest known as oncogene-induced senescence. Although senescence has clearly been implicated as a major defense mechanism against tumorigenesis, the mechanisms by which Ras can promote such a senescent phenotype remain poorly defined. We have shown recently that the Ras death effector NORE1A plays a critical role in promoting Ras-induced senescence and connects Ras to the regulation of the p53 tumor suppressor. We now show that NORE1A also connects Ras to the regulation of a second major prosenescent tumor suppressor, the retinoblastoma (Rb) protein. We show that Ras induces the formation of a complex between NORE1A and the phosphatase PP1A, promoting the activation of the Rb tumor suppressor by dephosphorylation. Furthermore, suppression of Rb reduces NORE1A senescence activity. These results, together with our previous findings, suggest that NORE1A acts as a critical tumor suppressor node, linking Ras to both the p53 and the Rb pathways to drive senescence.
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Affiliation(s)
| | | | - Geoffrey J Clark
- Pharmacology and Toxicology, James Graham Brown Cancer Center, Molecular Targets Program, University of Louisville, Louisville, Kentucky 40202
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Abstract
Diffuse anterior retinoblastoma is a rare variant of retinoblastoma seeding in the area of the vitreous base and anterior chamber. Patients with diffuse anterior retinoblastoma are older than those with the classical types, with the mean age being 6.1 years. The original cells of diffuse anterior retinoblastoma are supposed to be cone precursor. Patients most commonly present with pseudouveitis, pseudohypopyon, and increased intraocular pressure. The retina under fundus examination is likely to be normal, and the clinical features mimic the inflammation progress, which can often lead to misdiagnosis. The published diffuse anterior retinoblastoma cases were diagnosed after fine-needle aspiration biopsy running the potential risk of inducing metastasis. The most common treatment for diffuse anterior retinoblastoma is enucleation followed by systematic chemotherapy according to the patient’s presentation and clinical course. This review summarizes the recent advances in etiology (including tumorigenesis and cell origin), pathology, diagnosis, differential diagnosis, and new treatment. The challenges of early diagnosis and prospects are also discussed.
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Affiliation(s)
- Jing Yang
- Department of Ophthalmology, The First Affiliated Hospital, Zhengzhou University, Zhengzhou City, Henan Province, People's Republic of China ; Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China ; Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People's Republic of China
| | - Yalong Dang
- Department of Ophthalmology, The First Affiliated Hospital, Zhengzhou University, Zhengzhou City, Henan Province, People's Republic of China ; Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China ; Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People's Republic of China
| | - Yu Zhu
- Department of Ophthalmology, The First Affiliated Hospital, Zhengzhou University, Zhengzhou City, Henan Province, People's Republic of China
| | - Chun Zhang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China ; Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People's Republic of China
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Garfin PM, Min D, Bryson JL, Serwold T, Edris B, Blackburn CC, Richie ER, Weinberg KI, Manley NR, Sage J, Viatour P. Inactivation of the RB family prevents thymus involution and promotes thymic function by direct control of Foxn1 expression. ACTA ACUST UNITED AC 2013; 210:1087-97. [PMID: 23669396 PMCID: PMC3674705 DOI: 10.1084/jem.20121716] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
RB family genes control T cell production and promote thymic involution through reducing Foxn1 expression in thymic epithelial cells. Thymic involution during aging is a major cause of decreased production of T cells and reduced immunity. Here we show that inactivation of Rb family genes in young mice prevents thymic involution and results in an enlarged thymus competent for increased production of naive T cells. This phenotype originates from the expansion of functional thymic epithelial cells (TECs). In RB family mutant TECs, increased activity of E2F transcription factors drives increased expression of Foxn1, a central regulator of the thymic epithelium. Increased Foxn1 expression is required for the thymic expansion observed in Rb family mutant mice. Thus, the RB family promotes thymic involution and controls T cell production via a bone marrow–independent mechanism, identifying a novel pathway to target to increase thymic function in patients.
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Affiliation(s)
- Phillip M Garfin
- Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
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Catela Ivkovic T, Aralica G, Cacev T, Loncar B, Kapitanovic S. miR-106a overexpression and pRB downregulation in sporadic colorectal cancer. Exp Mol Pathol 2012. [PMID: 23178825 DOI: 10.1016/j.yexmp.2012.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Rb1 plays an important role in cell cycle progression and therefore may be involved in malignant transformation of colonic cells. The aim of our research was to define the potential role of Rb1 as a prognostic biomarker in tumorigenesis of sporadic colorectal cancer, and to examine the role of miR-106a in Rb1 regulation as it functionally binds to 3'UTR of transcribed mRNA. We examined LOH and promoter methylation status. Real-time PCR was used for Rb1 mRNA and miR-106a, and immunohistochemistry for protein expression analysis. All the results obtained from patients' samples were correlated with the clinicopathological parameters in order to determine its influence on the sporadic colorectal carcinogenesis. LOH showed no correlation with mRNA and pRb expression. 51.5% of tumor samples were scored negative for pRb staining. Despite this finding, we detected overexpression of Rb1 mRNA in tumor samples in comparison to the adjacent normal tissue (p=0.023). mRNA overexpression was consistent with Rb1 promoter methylation analysis results, which showed no methylation in the investigated samples. Expression analysis of miR-106a in the patients samples showed its overexpression in colorectal cancer (p<10(-4)). Negative pRb score was expected according to the definition of tumor suppressor genes and their proposed role in the malignant transformation of the cells. The observed discrepancy between mRNA and protein expression can be explained by a regulatory mechanism that inhibits translation, such as microRNA silencing. Our results suggest that miR-106a might have a regulatory role for Rb1 in sporadic colorectal cancer.
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Affiliation(s)
- T Catela Ivkovic
- Division of Molecular Medicine, Ruder Boskovic Institute, Bijenicka c. 54, Zagreb, Croatia.
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Abstract
Stem cells play a critical role during embryonic development and in the maintenance of homeostasis in adult individuals. A better understanding of stem cell biology, including embryonic and adult stem cells, will allow the scientific community to better comprehend a number of pathologies and possibly design novel approaches to treat patients with a variety of diseases. The retinoblastoma tumor suppressor RB controls the proliferation, differentiation, and survival of cells, and accumulating evidence points to a central role for RB activity in the biology of stem and progenitor cells. In some contexts, loss of RB function in stem or progenitor cells is a key event in the initiation of cancer and determines the subtype of cancer arising from these pluripotent cells by altering their fate. In other cases, RB inactivation is often not sufficient to initiate cancer but may still lead to some stem cell expansion, raising the possibility that strategies aimed at transiently inactivating RB might provide a novel way to expand functional stem cell populations. Future experiments dedicated to better understanding how RB and the RB pathway control a stem cell's decisions to divide, self-renew, or give rise to differentiated progeny may eventually increase our capacity to control these decisions to enhance regeneration or help prevent cancer development.
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Affiliation(s)
- Julien Sage
- Department of Pediatrics, Department of Genetics, Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford Cancer Institute, Stanford, California 94305, USA.
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Couto SS, Bolon B, Cardiff RD. Morphologic manifestations of gene-specific molecular alterations ("genetic addictions") in mouse models of disease. Vet Pathol 2011; 49:116-29. [PMID: 22173978 DOI: 10.1177/0300985811430962] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Neoplasia in both animals and humans results in part from lasting activation of tumor-promoting genes ("oncogenes") or diminished function of genes responsible for preventing neoplastic induction ("tumor suppressor genes"). The concept of "genetic addiction" has emerged to indicate that neoplastic cells cannot maintain a malignant phenotype without sustained genotypic abnormalities related to aberrant activity of oncogene(s) and/or inactivity of tumor suppressor gene(s). Interestingly, some genetic abnormalities reliably produce distinct morphologic patterns that can be used as structural signatures indicating the presence of a specific molecular alteration. Examples of such consistent genetic/microanatomic pairings have been identified for mutated oncogenes, such as rising mucin-producing capacity with RAS overexpression, and mutated tumor suppressor genes-including PTEN eliciting cell hypertrophy, RB1 dictating neuroendocrine differentiation, and TRP53 encouraging sarcomatous transformation. Familiarity with the concept of genetic addiction, as well as the ability to recognize such regular genomic-phenotypic relationships, are of paramount importance for comparative pathologists who are engaged in phenotyping genetically engineered mice to help unravel genomic intricacies in both health and disease.
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Affiliation(s)
- S S Couto
- University of California–Davis, Center for Comparative Medicine, Davis, CA, USA
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Khetan V, Gupta A, Gopal L. Retinoblastoma: Recent trends A mini review based on published literature. Oman J Ophthalmol 2011; 4:108-15. [PMID: 22279397 PMCID: PMC3263162 DOI: 10.4103/0974-620x.91265] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Retinoblastoma (RB) is the most common intraocular malignancy in children. Recently, there have been significant advances made in the molecular pathology and the management of the disease. Last decade has witnessed better understanding of the genetics of RB, the discovery of new tumor markers expressed by the RB tumors, the identification of high-risk histopathological factors following enucleation, and newer methods of treatment including periocular chemotherapy and superselective intraarterial chemotherapy. All these advances have translated in improved survival rates for the affected children, improved rates of eye salvage, and improved visual outcomes. This article briefly reviews these advances.Method of Literature Search: Literature on the Medline database was searched using the PubMed interface. The search strategy included MeSH and natural language terms using the keywords mentioned. Reference lists in retrieved articles and textbooks were also searched for relevant references.
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Affiliation(s)
- Vikas Khetan
- Bhagwan Mahaveer Vitreoretinal Services, Sankara Nethralaya, 18, College Road, Chennai, India
| | - Aditi Gupta
- Bhagwan Mahaveer Vitreoretinal Services, Sankara Nethralaya, 18, College Road, Chennai, India
| | - Lingam Gopal
- Department of Ophthalmology, National University Health System, Singapore
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Litovchick L, Florens LA, Swanson SK, Washburn MP, DeCaprio JA. DYRK1A protein kinase promotes quiescence and senescence through DREAM complex assembly. Genes Dev 2011; 25:801-13. [PMID: 21498570 PMCID: PMC3078706 DOI: 10.1101/gad.2034211] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 03/01/2011] [Indexed: 12/21/2022]
Abstract
In the absence of growth signals, cells exit the cell cycle and enter into G0 or quiescence. Alternatively, cells enter senescence in response to inappropriate growth signals such as oncogene expression. The molecular mechanisms required for cell cycle exit into quiescence or senescence are poorly understood. The DREAM (DP, RB [retinoblastoma], E2F, and MuvB) complex represses cell cycle-dependent genes during quiescence. DREAM contains p130, E2F4, DP1, and a stable core complex of five MuvB-like proteins: LIN9, LIN37, LIN52, LIN54, and RBBP4. In mammalian cells, the MuvB core dissociates from p130 upon entry into the cell cycle and binds to BMYB during S phase to activate the transcription of genes expressed late in the cell cycle. We used mass spectroscopic analysis to identify phosphorylation sites that regulate the switch of the MuvB core from BMYB to DREAM. Here we report that DYRK1A can specifically phosphorylate LIN52 on serine residue 28, and that this phosphorylation is required for DREAM assembly. Inhibiting DYRK1A activity or point mutation of LIN52 disrupts DREAM assembly and reduces the ability of cells to enter quiescence or undergo Ras-induced senescence. These data reveal an important role for DYRK1A in the regulation of DREAM activity and entry into quiescence.
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Affiliation(s)
- Larisa Litovchick
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | - Selene K. Swanson
- Stowers Institute for Biomedical Research, Kansas City, Missouri 64110, USA
| | - Michael P. Washburn
- Stowers Institute for Biomedical Research, Kansas City, Missouri 64110, USA
- Department of Pathology and Laboratory Medicine, The University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - James A. DeCaprio
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
- Belfer Institute for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
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19
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Haubold M, Weise A, Stephan H, Dünker N. Bone morphogenetic protein 4 (BMP4) signaling in retinoblastoma cells. Int J Biol Sci 2010; 6:700-15. [PMID: 21152263 PMCID: PMC2999847 DOI: 10.7150/ijbs.6.700] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 11/22/2010] [Indexed: 01/01/2023] Open
Abstract
Bone morphogenetic proteins (BMPs) - expressed in the developing retina - are known to be involved in the regulation of cell proliferation and apoptosis in several tumor entities. The objective of this study was to determine the role of the BMP4 pathway in retinoblastoma cells, which are absent in a functional retinoblastoma (RB1) gene. BMP receptors were detected in all retinoblastoma cell lines investigated. A correct transmission of BMP signaling via the Smad1/5/8 pathway could be demonstrated in WERI-Rb1 retinoblastoma cells and application of recombinant human BMP4 resulted in an increase in apoptosis, which to a large extend is caspase independent. Cell proliferation was not affected by BMP4 signaling, although the pRb-related proteins p107 and p130, contributing to the regulation of the same genes, are still expressed. WERI-Rb1 cells exhibit elevated endogenous levels of p21(CIP1) and p53, but we did not detect any increase in p53, p21(CIP1)or p27(KIP1) expression levels. Id proteins became, however, strongly up-regulated upon exogenous BMP4 treatment. Thus, RB1 loss in WERI-Rb1 cells is obviously not compensated for by pRb-independent (e.g. p53-dependent) cell cycle control mechanisms, preventing an anti-proliferative response to BMP4, which normally induces cell cycle arrest.
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Affiliation(s)
- Maike Haubold
- 1. Institute for Anatomy, Department of Neuroanatomy, University of Duisburg-Essen, Medical Faculty, 45122 Essen, Germany
| | - Andreas Weise
- 1. Institute for Anatomy, Department of Neuroanatomy, University of Duisburg-Essen, Medical Faculty, 45122 Essen, Germany
| | - Harald Stephan
- 2. Division of Haematology and Oncology, Children's Hospital, University of Duisburg-Essen, 45122 Essen, Germany
| | - Nicole Dünker
- 1. Institute for Anatomy, Department of Neuroanatomy, University of Duisburg-Essen, Medical Faculty, 45122 Essen, Germany
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20
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Wirt SE, Adler AS, Gebala V, Weimann JM, Schaffer BE, Saddic LA, Viatour P, Vogel H, Chang HY, Meissner A, Sage J. G1 arrest and differentiation can occur independently of Rb family function. ACTA ACUST UNITED AC 2010; 191:809-25. [PMID: 21059851 PMCID: PMC2983066 DOI: 10.1083/jcb.201003048] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Repression of E2F target genes is required for cell cycle arrest in Rb family (Rb, p107, and p130)-deficient cells. The ability of progenitor cells to exit the cell cycle is essential for proper embryonic development and homeostasis, but the mechanisms governing cell cycle exit are still not fully understood. Here, we tested the requirement for the retinoblastoma (Rb) protein and its family members p107 and p130 in G0/G1 arrest and differentiation in mammalian cells. We found that Rb family triple knockout (TKO) mouse embryos survive until days 9–11 of gestation. Strikingly, some TKO cells, including in epithelial and neural lineages, are able to exit the cell cycle in G0/G1 and differentiate in teratomas and in culture. This ability of TKO cells to arrest in G0/G1 is associated with the repression of key E2F target genes. Thus, G1 arrest is not always dependent on Rb family members, which illustrates the robustness of cell cycle regulatory networks during differentiation and allows for the identification of candidate pathways to inhibit the expansion of cancer cells with mutations in the Rb pathway.
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Affiliation(s)
- Stacey E Wirt
- Department of Pediatrics, Stanford Medical School, Stanford, CA 94305, USA
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21
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Ierardi E, Rosania R, Zotti M, Giorgio F, Prencipe S, Valle ND, Francesco VD, Panella C. From chronic liver disorders to hepatocellular carcinoma: Molecular and genetic pathways. World J Gastrointest Oncol 2010; 2:259-64. [PMID: 21160638 PMCID: PMC2998843 DOI: 10.4251/wjgo.v2.i6.259] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 11/24/2009] [Accepted: 12/01/2009] [Indexed: 02/05/2023] Open
Abstract
Hepatocarcinogenesis is a process attributed to progressive genomic changes that alter the hepatocellular phenotype producing cellular intermediates that evolve into hepatocellular carcinoma (HCC). During the preneoplastic phase, the liver is often the site of chronic hepatitis and/or cirrhosis, and these conditions induce liver regeneration with accelerated hepatocyte cycling in an organ that is otherwise proliferatively at rest. Hepatocyte regeneration is accelerated by upregulation of mitogenic pathways involving molecular and genetic mechanisms. Hepatic growth factors, inhibitors and triggers may also play a role. This process leads to the production of monoclonal populations of aberrant and dysplastic hepatocytes that have telomerase re-expression, microsatellite instability, and occasionally structural aberrations in genes and chromosomes. Development of dysplastic hepatocytes in foci and nodules and the emergence of HCC are associated with the accumulation of irreversible structural alterations in genes and chromosomes even if the genomic basis of the malignant phenotype is largely heterogeneous. Therefore, a malignant hepatocyte phenotype may be produced by changes in genes acting through different regulatory pathways, thus producing several molecular variants of HCC. On these bases, a key point for future research will be to determine whether the deletions are specific, due to particular loci in the minimally deleted regions of affected chromosome arms, or whether they are non-specific with loss of large portions of chromosomes or entire chromosome arms leading to passive deletion of loci. The final aim is the possibility of identifying a step where carcinogenetic processes could be terminated.
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Affiliation(s)
- Enzo Ierardi
- Enzo Ierardi, Rosa Rosania, Mariangela Zotti, Floriana Giorgio, Simonetta Prencipe, Nicola Della Valle, Vincenzo De Francesco, Carmine Panella, Section of Gastroenterology, Department of Medical Sciences, University of Foggia, Ospedali Riuniti, Viale L. Pinto 71100-Foggia, Italy
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22
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Dean JL, Thangavel C, McClendon AK, Reed CA, Knudsen ES. Therapeutic CDK4/6 inhibition in breast cancer: key mechanisms of response and failure. Oncogene 2010; 29:4018-32. [PMID: 20473330 DOI: 10.1038/onc.2010.154] [Citation(s) in RCA: 300] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A hallmark of cancer is the deregulation of cell-cycle machinery, ultimately facilitating aberrant proliferation that fuels tumorigenesis and disease progression. Particularly, in breast cancers, cyclin D1 has a crucial role in the development of disease. Recently, a highly specific inhibitor of CDK4/6 activity (PD-0332991) has been developed that may have efficacy in the treatment of breast cancer. To interrogate the utility of PD-0332991 in treating breast cancers, therapeutic response was evaluated on a panel of breast cancer cell lines. These analyses showed that the chronic loss of Rb is specifically associated with evolution to a CDK4/6-independent state and, ultimately, resistance to PD-0332991. However, to interrogate the functional consequence of Rb directly, knockdown experiments were performed in models that represent immortalized mammary epithelia and multiple subtypes of breast cancer. These studies showed a highly specific role for Rb in mediating the response to CDK4/6 inhibition that was dependent on transcriptional repression manifest through E2F, and the ability to attenuate CDK2 activity. Acquired resistance to PD-03322991 was specifically associated with attenuation of CDK2 inhibitors, indicating that redundancy in CDK functions represents a determinant of therapeutic failure. Despite these caveats, in specific models, PD-0332991 was a particularly effective therapy, which induced Rb-dependent cytostasis. Combined, these findings indicate the critical importance of fully understanding cell-cycle regulatory pathways in directing the utilization of CDK inhibitors in the clinic.
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Affiliation(s)
- J L Dean
- Kimmel Cancer Center, Philadelphia, PA, USA
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23
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Rivadeneira DB, Mayhew CN, Thangavel C, Sotillo E, Reed CA, Graña X, Knudsen ES. Proliferative suppression by CDK4/6 inhibition: complex function of the retinoblastoma pathway in liver tissue and hepatoma cells. Gastroenterology 2010; 138:1920-30. [PMID: 20100483 PMCID: PMC2860048 DOI: 10.1053/j.gastro.2010.01.007] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 12/01/2009] [Accepted: 01/11/2010] [Indexed: 12/31/2022]
Abstract
BACKGROUND & AIMS Hepatocellular carcinoma is the third leading cause of cancer mortality worldwide; current chemotherapeutic interventions for this disease are largely ineffective. The retinoblastoma tumor suppressor (RB) is functionally inactivated at relatively high frequency in hepatocellular carcinoma and hepatoma cell lines. Here, we analyzed the ability of CDK4/6 inhibition to inhibit hepatocyte proliferation and the effect of RB status on this process. METHODS Hepatoma cell lines and xenograft models harboring RB knockdown and mice harboring liver-specific Rb deletion were used to define the role of RB function in response to CDK4/6 inhibition. RESULTS Our study shows that CDK4/6-dependent cell cycle progression in hepatoma cells was readily arrested by inhibition of CDK4/6 by PD-0332991 or p16ink4a irrespective of RB status. Interestingly, upon CDK4/6 inhibition, p107 protein stability was dramatically increased as a function of RB loss. This engagement of compensatory mechanisms was critical for cell cycle inhibition in the absence of RB, because both the E1A oncoprotein and overexpression of E2F proteins were capable of overcoming the effect of CDK4/6 inhibition. These findings were recapitulated in xenograft models. Furthermore, to determine how these findings relate to hepatocyte proliferation in vivo, mice were exposed to carbon tetrachloride to induce liver regeneration followed by treatment with PD-0332991. This treatment significantly inhibited hepatocyte proliferation. Strikingly, this facet of PD-0332991 function was retained even in RB-deficient livers. CONCLUSIONS These data show that CDK4/6 inhibition is a potent mediator of cytostasis and that RB loss can be readily compensated for in the context of both hepatoma cell lines and liver tissue.
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Affiliation(s)
- Dayana B Rivadeneira
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107,Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Christopher N Mayhew
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center. Cincinnati, Ohio 45229
| | - Chellappagounder Thangavel
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107,Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Elena Sotillo
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine. Philadelphia, Pennsylvania 19140,Department of Biochemistry, Temple University School of Medicine. Philadelphia, Pennsylvania 19140
| | - Christopher A Reed
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107,Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Xavier Graña
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine. Philadelphia, Pennsylvania 19140,Department of Biochemistry, Temple University School of Medicine. Philadelphia, Pennsylvania 19140
| | - Erik S Knudsen
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107,Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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24
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Ho VM, Schaffer BE, Karnezis AN, Park KS, Sage J. The retinoblastoma gene Rb and its family member p130 suppress lung adenocarcinoma induced by oncogenic K-Ras. Oncogene 2009; 28:1393-9. [PMID: 19151761 DOI: 10.1038/onc.2008.491] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mutations of the retinoblastoma tumor suppressor gene RB are frequently observed in human cancers, but rarely in non-small cell lung carcinomas (NSCLCs). Emerging evidence also suggests that the RB-related gene p130 is inactivated in a subset of human NSCLCs. To directly test the specific tumor suppressor roles of RB and p130 in NSCLC, we crossed Rb and p130 conditional mutant mice to mice carrying a conditional oncogenic K-Ras allele. In this model, controlled oncogenic K-Ras activation leads to the development of adenocarcinoma, a major subtype of NSCLC. We found that loss of p130 accelerated the death of mice, providing direct evidence in vivo that p130 is a tumor suppressor gene, albeit a weak one in this context. Loss of Rb increased the efficiency of lung cancer initiation and resulted in the development of high-grade adenocarcinomas and rapid death. Thus, despite the low frequency of RB mutations in human NSCLCs and reports that K-Ras activation and loss of RB function are rarely found in the same human tumors, loss of Rb clearly cooperates with activation of oncogenic K-Ras in lung adenocarcinoma development in mice.
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Affiliation(s)
- V M Ho
- Department of Pediatrics and Genetics, Stanford Medical School, Stanford, CA 94305-5149, USA
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25
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Rb/Cdk2/Cdk4 triple mutant mice elicit an alternative mechanism for regulation of the G1/S transition. Proc Natl Acad Sci U S A 2009; 106:486-91. [PMID: 19129496 DOI: 10.1073/pnas.0804177106] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The G(1)/S-phase transition is a well-toned switch in the mammalian cell cycle. Cdk2, Cdk4, and the rate-limiting tumor suppressor retinoblastoma protein (Rb) have been studied in separate animal models, but interactions between the kinases and Rb in vivo have yet to be investigated. To further dissect the regulation of the G(1) to S-phase progression, we generated Cdk2(-/-)Cdk4(-/-)Rb(-/-) (TKO) mutant mice. TKO mice died at midgestation with major defects in the circulatory systems and displayed combined phenotypes of Rb(-/-) and Cdk2(-/-)Cdk4(-/-) mutants. However, TKO mouse embryonic fibroblasts were not only resistant to senescence and became immortal but displayed enhanced S-phase entry and proliferation rates similar to wild type. These effects were more remarkable in hypoxic compared with normoxic conditions. Interestingly, depletion of the pocket proteins by HPV-E7 or p107/p130 shRNA in the absence of Cdk2/Cdk4 elicited a mechanism for the G(1)/S regulation with increased levels of p27(Kip1) binding to Cdk1/cyclin E complexes. Our work indicates that the G(1)/S transition can be controlled in different ways depending on the situation, resembling a regulatory network.
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26
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Abstract
The retinoblastoma (RB) tumour suppressor gene is functionally inactivated in a broad range of paediatric and adult cancers, and a plethora of cellular functions and partners have been identified for the RB protein. Data from human tumours and studies from mouse models indicate that loss of RB function contributes to both cancer initiation and progression. However, we still do not know the identity of the cell types in which RB normally prevents cancer initiation in vivo, and the specific functions of RB that suppress distinct aspects of the tumorigenic process are poorly understood.
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Affiliation(s)
- Deborah L Burkhart
- Cancer Biology Program, Stanford University School of Medicine, Stanford, California 94305, USA
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27
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Burkhart DL, Viatour P, Ho VM, Sage J. GFP reporter mice for the retinoblastoma-related cell cycle regulator p107. Cell Cycle 2008; 7:2544-52. [PMID: 18719374 DOI: 10.4161/cc.7.16.6441] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The RB tumor suppressor gene is mutated in a broad range of human cancers, including pediatric retinoblastoma. Strikingly, however, Rb mutant mice develop tumors of the pituitary and thyroid glands, but not retinoblastoma. Mouse genetics experiments have demonstrated that p107, a protein related to pRB, is capable of preventing retinoblastoma, but not pituitary tumors, in Rb-deficient mice. Evidence suggests that the basis for this compensatory function of p107 is increased transcription of the p107 gene in response to Rb inactivation. To begin to address the context-dependency of this compensatory role of p107 and to follow p107 expression in vivo, we have generated transgenic mice carrying an enhanced GFP (eGFP) reporter inserted into a bacterial artificial chromosome (BAC) containing the mouse p107 gene. Expression of the eGFP transgene parallels that of p107 in these transgenic mice and identifies cells with a broad range of expression level for p107, even within particular organs or tissues. We also show that loss of Rb results in the upregulation of p107 transcription in specific cell populations in vivo, including subpopulations of hematopoietic cells. Thus, p107 BAC-eGFP transgenic mice serve as a useful tool to identify distinct cell types in which p107 is expressed and may have key functions in vivo, and to characterize changes in cellular networks accompanying Rb deficiency.
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Affiliation(s)
- Deborah L Burkhart
- Department of Pediatrics and Genetics, Cancer Biology Program, Stanford Medical School, Stanford, California, USA
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28
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Blais A, van Oevelen CJC, Margueron R, Acosta-Alvear D, Dynlacht BD. Retinoblastoma tumor suppressor protein-dependent methylation of histone H3 lysine 27 is associated with irreversible cell cycle exit. ACTA ACUST UNITED AC 2008; 179:1399-412. [PMID: 18166651 PMCID: PMC2373492 DOI: 10.1083/jcb.200705051] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The retinoblastoma tumor suppressor protein (pRb) is involved in mitotic exit, promoting the arrest of myoblasts, and myogenic differentiation. However, it is unclear how permanent cell cycle exit is maintained in differentiated muscle. Using RNA interference, expression profiling, and chromatin immunoprecipitations, we show that pRb is essential for cell cycle exit and the differentiation of myoblasts and is also uniquely required to maintain this arrest in myotubes. Remarkably, we also uncover a function for the pRb-related proteins p107 and p130 as enforcers of a G2/M phase checkpoint that prevents progression into mitosis in cells that have lost pRb. We further demonstrate that pRb effects permanent cell cycle exit in part by maintaining trimethylation of histone H3 lysine 27 (H3K27) on cell cycle genes. H3K27 trimethylation silences other genes, including Cyclin D1, in a pRb-independent but polycomb-dependent manner. Thus, our data distinguish two distinct chromatin-based regulatory mechanisms that lead to terminal differentiation.
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Affiliation(s)
- Alexandre Blais
- Department of Biochemistry, Microbiology, and Immunology, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa K1H 8M5, Canada
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30
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Abstract
The completely assembled human genome has made it possible for modern medicine to step into an era rich in genetic information and high-throughput genomic analysis. These novel and readily available genetic resources and analytical tools may be the key to unravel the molecular basis of hepatocellular carcinoma (HCC). Moreover, since an efficient treatment for this disease is lacking, further understanding of the genetic background of HCC will be crucial in order to develop new therapies aimed at selected targets. We report on the current status and recent developments in HCC genetics. Special emphasis is given to the genetics and regulation of major signalling pathways involved in HCC such as p53, Wnt-signalling, TGFβ, Ras, and Rb pathways. Furthermore, we describe the influence of chromosomal aberrations as well as of DNA methylation. Finally, we report on the rapidly developing field of genomic expression profiling in HCC, mainly by microarray analysis.
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Affiliation(s)
- Andreas Teufel
- Department of Medicine, Johannes Gutenberg University, Building 301, Langenbeckstr. 1, 55101 Mainz, Germany.
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