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Nisar S, Hashem S, Macha MA, Yadav SK, Muralitharan S, Therachiyil L, Sageena G, Al-Naemi H, Haris M, Bhat AA. Exploring Dysregulated Signaling Pathways in Cancer. Curr Pharm Des 2020; 26:429-445. [PMID: 31939726 DOI: 10.2174/1381612826666200115095937] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 11/27/2019] [Indexed: 02/08/2023]
Abstract
Cancer cell biology takes advantage of identifying diverse cellular signaling pathways that are disrupted in cancer. Signaling pathways are an important means of communication from the exterior of cell to intracellular mediators, as well as intracellular interactions that govern diverse cellular processes. Oncogenic mutations or abnormal expression of signaling components disrupt the regulatory networks that govern cell function, thus enabling tumor cells to undergo dysregulated mitogenesis, to resist apoptosis, and to promote invasion to neighboring tissues. Unraveling of dysregulated signaling pathways may advance the understanding of tumor pathophysiology and lead to the improvement of targeted tumor therapy. In this review article, different signaling pathways and how their dysregulation contributes to the development of tumors have been discussed.
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Affiliation(s)
- Sabah Nisar
- Translational Medicine, Research Branch, Sidra Medicine, Doha, Qatar
| | - Sheema Hashem
- Translational Medicine, Research Branch, Sidra Medicine, Doha, Qatar
| | - Muzafar A Macha
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, United States.,Department of Biotechnology, Central University of Kashmir, Ganderbal, Jammu and Kashmir, India
| | - Santosh K Yadav
- Translational Medicine, Research Branch, Sidra Medicine, Doha, Qatar
| | | | - Lubna Therachiyil
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | | | - Hamda Al-Naemi
- Laboratory Animal Research Center, Qatar University, Doha, Qatar
| | - Mohammad Haris
- Translational Medicine, Research Branch, Sidra Medicine, Doha, Qatar.,Laboratory Animal Research Center, Qatar University, Doha, Qatar
| | - Ajaz A Bhat
- Translational Medicine, Research Branch, Sidra Medicine, Doha, Qatar
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2
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Particular aspects in the cytogenetics and molecular biology of salivary gland tumours - current review of reports. Contemp Oncol (Pozn) 2016; 20:281-6. [PMID: 27688723 PMCID: PMC5032155 DOI: 10.5114/wo.2016.61847] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 04/24/2015] [Indexed: 12/26/2022] Open
Abstract
Salivary gland tumours are a group of lesions whose heterogeneity of biological and pathological features is widely reflected in the molecular aspect. This is demonstrated by an increasing number of studies in the field of genetics of these tumours. The aim of this study was to collect the most significant scientific reports on the cytogenetic and molecular data concerning these tumours, which might facilitate the identification of potential biomarkers and therapeutic targets. The analysis covered 71 papers included in the PubMed database. We focused on the most common tumours, such as pleomorphic adenoma, Warthin tumour, mucoepidermoid carcinoma, and others. The aim of this study is to present current knowledge about widely explored genotypic alterations (such as PLAG1 gene in pleomorphic adenoma or MECT1 gene in mucoepidermoid carcinoma), and also about rare markers, like Mena or SOX10 protein, which might also be associated with tumourigenesis and carcinogenesis of these tumours.
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3
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Schneider T, Strehl A, Linz C, Brands R, Hartmann S, Beckford F, Rosenwald A, Kübler AC, Müller-Richter UDA. Phosphorylated epidermal growth factor receptor expression and KRAS mutation status in salivary gland carcinomas. Clin Oral Investig 2015; 20:541-51. [DOI: 10.1007/s00784-015-1541-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 07/20/2015] [Indexed: 01/26/2023]
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Park JT, Johnson N, Liu S, Levesque M, Wang YJ, Ho H, Huso D, Maitra A, Parsons MJ, Prescott JD, Leach SD. Differential in vivo tumorigenicity of diverse KRAS mutations in vertebrate pancreas: A comprehensive survey. Oncogene 2014; 34:2801-6. [PMID: 25065594 PMCID: PMC4836617 DOI: 10.1038/onc.2014.223] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 06/09/2014] [Accepted: 06/15/2014] [Indexed: 12/30/2022]
Abstract
Somatic activation of the KRAS proto-oncogene is evident in almost all pancreatic cancers, and appears to represent an initiating event. These mutations occur primarily at codon 12 and less frequently at codons 13 and 61. While some studies have suggested that different KRAS mutations may have variable oncogenic properties, to date there has been no comprehensive functional comparison of multiple KRAS mutations in an in vivo vertebrate tumorigenesis system. We generated a Gal4/UAS-based zebrafish model of pancreatic tumorigenesis in which the pancreatic expression of UAS-regulated oncogenes is driven by a ptf1a:Gal4-VP16 driver line. This system allowed us to rapidly compare the ability of 12 different KRAS mutations (G12A, G12C, G12D, G12F, G12R, G12S, G12V, G13C, G13D, Q61L, Q61R, and A146T) to drive pancreatic tumorigenesis in vivo. Among fish injected with one of five KRAS mutations reported in other tumor types but not in human pancreatic cancer, 2/79 (0.25%) developed pancreatic tumors, with both tumors arising in fish injected with A146T. In contrast, among fish injected with one of seven KRAS mutations known to occur in human pancreatic cancer, 22/106 (20.8%) developed pancreatic cancer. All eight tumorigenic KRAS mutations were associated with downstream MAPK/ERK pathway activation in preneoplastic pancreatic epithelium, while non-tumorigenic mutations were not. These results suggest that the spectrum of KRAS mutations observed in human pancreatic cancer reflects selection based upon variable tumorigenic capacities, including the ability to activate MAPK/ERK signaling.
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Affiliation(s)
- J T Park
- Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - N Johnson
- Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - S Liu
- Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - M Levesque
- Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Y J Wang
- Graduate Program in Human Genetics, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - H Ho
- Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - D Huso
- Department of Molecular & Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - A Maitra
- Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - M J Parsons
- 1] Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA [2] Graduate Program in Human Genetics, Johns Hopkins Medical Institutions, Baltimore, MD, USA [3] Institute of Genetic Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - J D Prescott
- Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - S D Leach
- 1] Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, MD, USA [2] Graduate Program in Human Genetics, Johns Hopkins Medical Institutions, Baltimore, MD, USA [3] Institute of Genetic Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA
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5
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Chiosea SI, Miller M, Seethala RR. HRAS mutations in epithelial-myoepithelial carcinoma. Head Neck Pathol 2013; 8:146-50. [PMID: 24277618 PMCID: PMC4022927 DOI: 10.1007/s12105-013-0506-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 10/31/2013] [Indexed: 10/26/2022]
Abstract
The molecular profile of epithelial-myoepithelial carcinomas (EMCa) has not been well studied, though a recent association with Harvey rat sarcoma viral oncogene homolog (HRAS) mutations has been noted. To confirm and validate this, we surveyed fifteen EMCa for HRAS codon 61 mutations and correlated HRAS status with clinicopathologic parameters. There were 11 females and 4 males and mean patient age was 64 (range 49-90). Parotid gland was most commonly involved (n = 10) and the most common histologic appearance was that of a 'classic' EMCa (7/15). Four of fifteen (26.7 %) cases demonstrated local recurrence, while 2/15 (13.3 %) demonstrated distant metastases. Other variant morphologies included EMCa arising from pleomorphic adenoma (3/15), and high grade EMCa (2/15). HRAS exon 3, codon 61 mutations, p.Q61R (n = 3) and p.Q61 K (n = 1) were identified in 4 of 15 successfully tested EMCAs (14 patients). Two cases were classic type, while the other cases consisted of one oncocytic variant, and one tumor with myoepithelial overgrowth, the latter of which showed the same mutation in both the primary and recurrence. Of note, the high grade EMCa and EMCa ex pleomorphic adenoma were negative for mutations. Given the small number of cases, there were no significant differences between mutation positive and mutation negative cases in terms of age, gender and outcome.
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Affiliation(s)
- Simion I. Chiosea
- grid.412689.00000000106507433Department of Pathology and Laboratory Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA USA
| | - Megan Miller
- grid.412689.00000000106507433Department of Pathology and Laboratory Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA USA
| | - Raja R. Seethala
- grid.412689.00000000106507433Department of Pathology and Laboratory Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA USA
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Nakano T, Yamamoto H, Hashimoto K, Tamiya S, Shiratsuchi H, Nakashima T, Nishiyama KI, Higaki Y, Komune S, Oda Y. HER2andEGFRgene copy number alterations are predominant in high-grade salivary mucoepidermoid carcinoma irrespective ofMAML2fusion status. Histopathology 2013; 63:378-92. [DOI: 10.1111/his.12183] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 05/02/2013] [Indexed: 01/07/2023]
Affiliation(s)
| | - Hidetaka Yamamoto
- Department of Anatomic Pathology; Graduate School of Medical Sciences; Kyushu University; Fukuoka; Japan
| | | | | | - Hideki Shiratsuchi
- Department of Otolaryngology; Graduate School of Medical Sciences; Kyushu University; Fukuoka; Japan
| | - Torahiko Nakashima
- Department of Otolaryngology; Graduate School of Medical Sciences; Kyushu University; Fukuoka; Japan
| | | | - Yuichiro Higaki
- Department of Head and Neck Surgery; National Kyushu Cancer Center; Fukuoka; Japan
| | - Shizuo Komune
- Department of Otolaryngology; Graduate School of Medical Sciences; Kyushu University; Fukuoka; Japan
| | - Yoshinao Oda
- Department of Anatomic Pathology; Graduate School of Medical Sciences; Kyushu University; Fukuoka; Japan
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Clauditz TS, Gontarewicz A, Bokemeyer C, Sauter G, Knecht R, Münscher A, Wilczak W. Abundant expression of mTOR kinase in salivary gland tumors - potentials as therapy target? J Oral Pathol Med 2013; 42:769-73. [PMID: 23521157 DOI: 10.1111/jop.12064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2013] [Indexed: 12/22/2022]
Abstract
BACKGROUND Salivary gland tumors constitute 3-6% of all head and neck neoplasms in adults. Because of limited advances made in the treatment of metastatic disease, the more important is the role of new therapeutic strategies, including molecular therapy. The mammalian target of rapamycin (mTOR) has recently been established as a therapeutic target for several drugs. MATERIAL Evaluation of phospho-mTOR as a possible therapy target by patients with salivary gland tumors. Immunohistochemical semi-quantitative analyses of the expression of phospho-mTOR(Ser2448) were processed on a tissue microarray containing samples from more than 900 patients. For statistical analysis, contingency table and chi-squared test (likelihood) were used. RESULTS We observed at least weak phospho-mTOR expression in 25.6-41.2% of all 4 histological adenoma and in 36.8-61.6% of all 11 histological carcinoma subtypes analyzed. No association was seen between phospho-mTOR expression and tumor grade in mucoepidermoid carcinomas. CONCLUSION In conjunction with literature data providing the evidence for a functional role of mTOR in salivary gland tumors, we conclude that treatment with mTOR-antagonists might potentially also be efficient in wide variety of salivary gland carcinomas.
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Murugan AK, Munirajan AK, Tsuchida N. Ras oncogenes in oral cancer: the past 20 years. Oral Oncol 2012; 48:383-92. [PMID: 22240207 DOI: 10.1016/j.oraloncology.2011.12.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2011] [Revised: 12/12/2011] [Accepted: 12/15/2011] [Indexed: 12/13/2022]
Abstract
Oral squamous cell carcinoma (OSCC) of head and neck is associated with high morbidity and mortality in both Western and Asian countries. Several risk factors for the development of oral cancer are very well established, including tobacco chewing, betel quid, smoking, alcohol drinking and human papilloma virus (HPV) infection. Apart from these risk factors, many genetic factors such as oncogenes, tumor suppressor genes and regulatory genes are identified to involve in oral carcinogenesis with these risk factors dependent and independent manner. Ras is one of the most frequently genetically deregulated oncogene in oral cancer. In this review, we analyze the past 22years of literature on genetic alterations such as mutations and amplifications of the isoforms of the ras oncogene in oral cancer. Further, we addressed the isoform-specific role of the ras in oral carcinogenesis. We also discussed how targeting the Akt and MEK, downstream effectors of the PI3K/Akt and MAPK pathways, respectively, would probably pave the possible molecular therapeutic target for the ras driven tumorigenesis in oral cancer. Analysis of these ras isoforms may critically enlighten specific role of a particular ras isoform in oral carcinogenesis, enhance prognosis and pave the way for isoform-specific molecular targeted therapy in OSCC.
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Affiliation(s)
- Avaniyapuram Kannan Murugan
- Department of Molecular Cellular Oncology and Microbiology, Tokyo Medical and Dental University, Tokyo, Japan.
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Castellano E, Santos E. Functional specificity of ras isoforms: so similar but so different. Genes Cancer 2011; 2:216-31. [PMID: 21779495 DOI: 10.1177/1947601911408081] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
H-ras, N-ras, and K-ras are canonical ras gene family members frequently activated by point mutation in human cancers and coding for 4 different, highly related protein isoforms (H-Ras, N-Ras, K-Ras4A, and K-Ras4B). Their expression is nearly ubiquitous and broadly conserved across eukaryotic species, although there are quantitative and qualitative differences of expression depending on the tissue and/or developmental stage under consideration. Extensive functional studies have determined during the last quarter century that these Ras gene products are critical components of signaling pathways that control eukaryotic cell proliferation, survival, and differentiation. However, because of their homology and frequent coexpression in various cellular contexts, it remained unclear whether the different Ras proteins play specific or overlapping functional roles in physiological and pathological processes. Initially, their high degree of sequence homology and the observation that all Ras isoforms share common sets of downstream effectors and upstream activators suggested that they were mostly redundant functionally. In contrast, the notion of functional specificity for each of the different Ras isoforms is supported at present by an increasing body of experimental observations, including 1) the fact that different ras isoforms are preferentially mutated in specific types of tumors or developmental disorders; 2) the different transforming potential of transfected ras genes in different cell contexts; 3) the distinct sensitivities exhibited by the various Ras family members for modulation by different GAPs or GEFs; 4) the demonstration that different Ras isoforms follow distinct intracellular processing pathways and localize to different membrane microdomains or subcellular compartments; 5) the different phenotypes displayed by genetically modified animal strains for each of the 3 ras loci; and 6) the specific transcriptional networks controlled by each isoform in different cellular settings.
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Affiliation(s)
- Esther Castellano
- Signal Transduction Laboratory, Cancer Research UK London Research Institute, London, UK
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Liu G, Zheng H, Zhang Z, Wu Z, Xiong H, Li J, Song L. Overexpression of sphingosine kinase 1 is associated with salivary gland carcinoma progression and might be a novel predictive marker for adjuvant therapy. BMC Cancer 2010; 10:495. [PMID: 20846391 PMCID: PMC2949806 DOI: 10.1186/1471-2407-10-495] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 09/16/2010] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Overexpression of sphingosine kinase-1 (SPHK1) has been demonstrated to be associated with the development and progression in various types of human cancers. The current study was to characterize the expression of SPHK1 in salivary gland carcinomas (SGC) and to investigate the association between SPHK1 expression and progression of SGC. METHODS The expression of SPHK1 was examined in 2 normal salivary gland tissues, 8 SGC tissues of various clinical stages, and 5 pairs of primary SGC and adjacent salivary gland tissues from the same patient, using real-time PCR and western blot analysis. Furthermore, the SPHK1 protein expression was analyzed in 159 clinicopathologically characterized SGC cases by immunohistochemistry. Statistical analyses were performed to determine the prognostic and diagnostic associations. RESULTS SPHK1 expression was found to be markedly upregulated in SGC tissues than that in the normal salivary gland tissues and paired adjacent salivary gland tissues, at both mRNA and protein levels. Statistical analysis revealed a significant correlation of SPHK1 expression with the clinical stage (P = 0.005), T classification (P = 0.017), N classification (P = 0.009), M classification (P = 0.002), and pathological differentiation (P = 0.013). Patients with higher SPHK1 expression had shorter overall survival time, whereas patients with lower SPHK1 expression had better survival. Importantly, patients in the group without adjuvant therapy who exhibited high SPHK1 expression had significantly lower overall survival rates compared with those with low SPHK1 expression. Moreover, multivariate analysis suggested that SPHK1 expression might be an independent prognostic indicator for the survival of SGC patients. CONCLUSIONS Our results suggest that SPHK1 expression is associated with SGC progression, and might represent as a novel and valuable predictor for adjuvant therapy to SGC patients.
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Affiliation(s)
- Guanglin Liu
- State Key Laboratory of Oncology in Southern China, Department of Experimental Research, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, China
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Lujan B, Hakim S, Moyano S, Nadal A, Caballero M, Diaz A, Valera A, Carrera M, Cardesa A, Alos L. Activation of the EGFR/ERK pathway in high-grade mucoepidermoid carcinomas of the salivary glands. Br J Cancer 2010; 103:510-6. [PMID: 20664595 PMCID: PMC2939786 DOI: 10.1038/sj.bjc.6605788] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Background: Mucoepidermoid carcinoma (MEC) shows differences in biological behaviour depending mainly on its histological grade. High-grade tumours usually have an aggressive biological course and they require additional oncological treatment after surgery. Methods: In a series of 43 MECs of the salivary glands, we studied the epidermal growth factor receptor (EGFR) gene by using dual-colour chromogenic in situ hybridisation (CISH). Moreover, we assessed the protein expressions of the EGFR and the activated extracellular signal-regulated kinases (pERK1/2) by using immunohistochemistry. These results were correlated with the histological grade of the tumours and the outcome of the patients. Results: The CISH study demonstrated a high-EGFR gene copy number, with balanced chromosome 7 polysomy, in 8 out of 11 high-grade MECs (72.7%), whereas 27 low-grade and 15 intermediate-grade tumours had a normal EGFR gene copy number (P<0.001). The EGFR gene gains correlated with disease-free interval (P=0.003) and overall survival of the patients (P=0.019). The EGFR protein expression had a significant correlation with the histological grade of the tumours but not with the outcome of the patients. The pERK1/2 expression correlated with histological grade of tumours (P<0.001), disease-free interval (P=0.004) and overall survival (P=0.001). Conclusions: The EGFR/ERK pathway is activated in high-grade MECs with aggressive behaviour. Patients with these tumours who require oncological treatment in addition to surgery could benefit from EGFR and mitogen-activated protein kinase pathway inhibitors.
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Affiliation(s)
- B Lujan
- Department of Pathology, Hospital Clínic, IDIBAPS, University of Barcelona, Villarroel, 170, Barcelona 08036, Spain
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A case of epithelial–myoepithelial carcinoma of the bronchus – A review of reported cases and a comparison with other salivary gland-type carcinomas of the bronchus. Pathol Res Pract 2010; 206:121-9. [DOI: 10.1016/j.prp.2009.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 03/10/2009] [Accepted: 03/11/2009] [Indexed: 11/23/2022]
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KRAS status and epidermal growth factor receptor expression as determinants for anti-EGFR therapies in salivary gland carcinomas. Oral Oncol 2009; 45:826-9. [DOI: 10.1016/j.oraloncology.2009.01.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 01/21/2009] [Accepted: 01/22/2009] [Indexed: 11/22/2022]
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Abstract
The three closely related mammalian ras genes, Hras, Nras and Kras, have each been implicated in human tumorigenesis by virtue of mutational activation. However, while these genes encode proteins with very similar biochemical properties, activating ras alleles corresponding to the various isoforms have been linked to particular malignancies. Accumulating evidence suggests that these proteins exert distinct activities in a tissue-specific context, apparently reflecting developmental lineage-specific roles for the various ras isoforms. Some of these distinct functions appear to reflect differences in their C-termini, which determine distinct subcellular localization, thereby suggesting a role for compartmentalized signaling. In this review, we discuss the biological functions of the ras isoforms in the context of tissue-specific function as it relates to ras function in development and human cancer.
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Affiliation(s)
- Margaret P Quinlan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
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Elledge R. Current concepts in research related to oncogenes implicated in salivary gland tumourigenesis: a review of the literature. Oral Dis 2009; 15:249-54. [PMID: 19317835 DOI: 10.1111/j.1601-0825.2009.01529.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Salivary gland tumours are relatively uncommon and there exists considerable difficulty in decisions regarding prognosis and management, as well as diagnostic uncertainty that has implications for treatment. METHOD Literature pertaining to individual oncogenes has been reviewed and commented upon, specifically looking at the role of these as diagnostic and prognostic markers and as potential targets for treatments. RESULTS kit, PLAG1, Mect1-Maml2, HMGIC, HER2/neu, ras, c-fos and Sox-4 all have seminal small-scale studies in the literature with potential for further research and eventual clinical applications. CONCLUSION A wide variety of oncogenes are implicated in salivary gland tumourigenesis, with evidence being confined to small murine or in vitro studies more often than not. There are possible roles for different oncogenes in therapeutics, prognosis and management of specific salivary gland tumours.
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Affiliation(s)
- R Elledge
- Locum Trust SpR Oral and Maxillofacial Surgery, Royal Shrewsbury Hospital, Mytton Oak Road, Shrewsbury SY3 8XQ, UK.
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Activated Kras, but not Hras or Nras, may initiate tumors of endodermal origin via stem cell expansion. Mol Cell Biol 2008; 28:2659-74. [PMID: 18268007 DOI: 10.1128/mcb.01661-07] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The three closely related human Ras genes, Hras, Nras, and Kras, are all widely expressed, engage a common set of downstream effectors, and can each exhibit oncogenic activity. However, the vast majority of activating Ras mutations in human tumors involve Kras. Moreover, Kras mutations are most frequently seen in tumors of endodermally derived tissues (lung, pancreas, and colon), suggesting that activated Kras may affect an endodermal progenitor to initiate oncogenesis. Using a culture model of retinoic acid (RA)-induced stem cell differentiation to endoderm, we determined that while activated HrasV12 promotes differentiation and growth arrest in these endodermal progenitors, KrasV12 promotes their proliferation. Furthermore, KrasV12-expressing endodermal progenitors fail to differentiate upon RA treatment and continue to proliferate and maintain stem cell characteristics. NrasV12 neither promotes nor prevents differentiation. A structure-function analysis demonstrated that these distinct effects of the Ras isoforms involve their variable C-terminal domains, implicating compartmentalized signaling, and revealed a requirement for several established Ras effectors. These findings indicate that activated Ras isoforms exert profoundly different effects on endodermal progenitors and that mutant Kras may initiate tumorigenesis by expanding a susceptible stem/progenitor cell population. These results potentially explain the high frequency of Kras mutations in tumors of endodermal origin.
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Abstract
Mucoepidermoid carcinoma (MEC) is a malignant epithelial neoplasm composed of varying proportions of mucous, epidermoid, intermediate, columnar, and clear cells and often demonstrates prominent cystic growth. MEC is usually subclassified as low, intermediate, or high grade on the basis of its histologic features, including the presence of cystic spaces, cellular differentiation, proportion of mucous cells, growth pattern, type of invasion, and cytologic atypia. Because even low-grade neoplasms may metastasize, the term mucoepidermoid tumor is inappropriate. The 3-level grading approach to tumor classification has found general acceptance among pathologists; differences in biologic behavior can be demonstrated even though clinical stage has become a better prognosticator. However, in the case of MEC, no universal agreement exists regarding which histologic grading criteria are most the useful, and grading has varied. These issues have led to the investigation of more subjective systems. We describe these new schemes, the histologic variants of MEC, and the ancillary methods that allow for further stratification of patients with MEC, especially for patients with grade 2 tumors, which have a variable and unpredictable clinical course.
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Affiliation(s)
- Mario A Luna
- Department of Pathology, Unit 85, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
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