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Kuppers DA, Schmitt TM, Hwang HC, Samraj L, Clurman BE, Fero ML. The miR-106a~363 Xpcl1 miRNA cluster induces murine T cell lymphoma despite transcriptional activation of the p27 Kip1 cell cycle inhibitor. Oncotarget 2017; 8:50680-50691. [PMID: 28881594 PMCID: PMC5584189 DOI: 10.18632/oncotarget.16932] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 03/22/2017] [Indexed: 12/19/2022] Open
Abstract
The miR-106a~363 cluster encodes 6 miRNAs on the X-chromosome which are abundant in blood cells and overexpressed in a variety of malignancies. The constituent miRNA of miR-106a~363 have functional activities in vitro that are predicted to be both oncogenic and tumor suppressive, yet little is known about their physiological functions in vivo. Mature miR-106a~363 (Mirc2) miRNAs are processed from an intragenic, non-protein encoding gene referred to as Xpcl1 (or Kis2), situated at an X-chromosomal locus frequently targeted by retroviruses in murine lymphomas. The oncogenic potential of miR-106a~363 Xpcl1 has not been proven, nor its potential role in T cell development. We show that miR106a~363 levels normally drop at the CD4+/CD8+ double positive (DP) stage of thymocyte development. Forced expression of Xpcl1 at this stage impairs thymocyte maturation and induces T-cell lymphomas. Surprisingly, miR-106a~363 Xpcl1 also induces p27 transcription via Foxo3/4 transcription factors. As a haploinsufficient tumor suppressor, elevated p27 is expected to inhibit lymphomagenesis. Consistent with this, concurrent p27 Kip1 deletion dramatically accelerated lymphomagenesis, indicating that p27 is rate limiting for tumor development by Xpcl1. Whereas down-regulation of miR-106a~363 is important for normal T cell differentiation and for the prevention of lymphomas, eliminating p27 reveals Xpcl1's full oncogenic potential.
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Affiliation(s)
| | | | | | | | - Bruce E. Clurman
- Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
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Siraj AK, Beg S, Jehan Z, Prabhakaran S, Ahmed M, R Hussain A, Al-Dayel F, Tulbah A, Ajarim D, Al-Kuraya KS. ALK alteration is a frequent event in aggressive breast cancers. Breast Cancer Res 2015; 17:127. [PMID: 26384210 PMCID: PMC4588266 DOI: 10.1186/s13058-015-0610-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 07/07/2015] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION Breast cancer is the most common female malignancy worldwide and, despite improvements in treatment modalities, there are increased chances of recurrence and metastasis in a substantial number of cases and it remains one of the major causes of mortality among female cancer patients. Anaplastic lymphoma kinase (ALK) gene has been found to be altered in several solid and hematologic tumors. We aimed to comprehensively study the prevalence of ALK expression, and changes in copy number and translocation in a large cohort of breast cancer cases in a Middle Eastern population. METHODS ALK protein expression was investigated by immunohistochemistry and numerical and structural variations of the ALK gene were analyzed by fluorescence in situ hybridization (FISH) in a tissue microarray format in a cohort of more than 1000 Middle Eastern breast cancers. The data were correlated with clinicopathologic parameters and other important molecular biomarkers. RESULTS Immunohistochemical analysis showed ALK overexpression in 36.0 % of the breast cancer patients and gene amplification was present in 13.3 % of cases, seen by FISH analyses. ALK overexpression was significantly associated with ALK gene amplification (p = 0.0031). ALK-overexpressing tumors showed significant association with high-grade tumors (p = 0.0039), ductal histologic subtype (p = 0.0076), triple-negative phenotype (p = 0.0034), and high Ki-67 (p = 0.0001) and p-AKT (p <0.0001). CONCLUSIONS Immunohistochemical analysis showed ALK is overexpressed in a substantial proportion of breast cancers and possibly plays a significant role in the aggressive behavior of this cancer. Gene amplification is hypothesized to be a possible cause for a significant proportion of this overexpression. Based on these findings, a potential role for an ALK inhibitor, as a therapeutic agent targeting aggressive subtypes of breast cancer, merits further investigation.
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Affiliation(s)
- Abdul K Siraj
- Department of Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Shaham Beg
- Department of Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Zeenath Jehan
- Department of Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Sarita Prabhakaran
- Department of Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Maqbool Ahmed
- Department of Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Azhar R Hussain
- Department of Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Fouad Al-Dayel
- Department of Pathology, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Asma Tulbah
- Department of Pathology, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Dahish Ajarim
- Oncology Center, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia.
| | - Khawla S Al-Kuraya
- Department of Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, Makkah Al Mukarramah Branch Road, Riyadh, 12713, Saudi Arabia. .,Department of Pathology, Al-Faisal University, Al Zahrawi Street, Riyadh, 11533, Saudi Arabia.
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New developments in the pathology of malignant lymphoma. A review of the literature published from January 2012–July 2012. J Hematop 2012. [DOI: 10.1007/s12308-012-0161-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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