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Uroog L, Zeya B, Imtiyaz K, Ahmad Wani R, Moshahid Alam Rizvi M. FBXW7 polymorphism asserts susceptibility to colorectal cancer. Gene 2024; 901:148181. [PMID: 38244948 DOI: 10.1016/j.gene.2024.148181] [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: 09/21/2023] [Revised: 01/05/2024] [Accepted: 01/17/2024] [Indexed: 01/22/2024]
Abstract
FBXW7, belonging to the F-Box protein family, is considered a candidate cancer susceptibility gene. Our findings indicate that single nucleotide polymorphisms (SNPs) in the FBXW7 gene are linked to cancer risk, strengthening FBXW7's role in the pathogenesis of colorectal cancer. Our case-control study comprised of 450 patients diagnosed with colorectal cancer (CRC) and an equal number of 450 healthy subjects. FBXW7 SNPs rs2255137C>T and rs6842544C>T were genotyped using PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) and Single-Stranded Conformation Polymorphism (SSCP) techniques and further cross-checked by direct sequencing. Linkage disequilibrium and haplotype analyses of these SNPs were also assessed. The in-silico approach was used to reveal the functional analysis between the nonsynonymous variation (rs6842544) and CRC followed by its validation at the protein level by western blotting and reverse transcription-PCR. A significant association of colorectal cancer was detected with rs6842544 SNP. However, there was no association between FBXW7 rs2255137 polymorphism and CRC. The homozygous individuals carrying the C variant in FBXW7 rs6842544 showed a slightly higher risk for colorectal cancer (OR = 1.590, 95%CI = 0.39 ∼ 2.89, p = 0.011). The haplotype CC identified in this study seemed to be associated with good prognosis (OR = 1.22, 95% CI = 1.00 ∼ 1.47, p = 0.0013) whereas the TT haplotype was found to reduce the CRC risk (OR = 0.642, 95%CI = 0.48 ∼ 0.84, p = 0.039). In-silico prediction proposed that the variant R133G is responsible for the lower expression of FBXW7. Additionally, the expression profiling of FBXW7 nonsynonymous SNP was significantly lower in primary CRC tissues than in the paired non-cancerous tissues at protein and mRNA levels. The study indicates that the FBXW7 rs6842544 is associated with the risk of development of CRC and could serve as a molecular biological marker to screen high-risk groups for CRC.
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Affiliation(s)
- Laraib Uroog
- Genome Biology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India
| | - Bushra Zeya
- Genome Biology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India
| | - Khalid Imtiyaz
- Genome Biology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India
| | - Rauf Ahmad Wani
- Department of General Surgery, SKIMS, Srinagar, Jammu and Kashmir, India
| | - M Moshahid Alam Rizvi
- Genome Biology Lab, Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India.
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Snijders AM, Liu Y, Su L, Huang Y, Mao JH. Expression profiling reveals transcriptional regulation by Fbxw7/mTOR pathway in radiation-induced mouse thymic lymphomas. Oncotarget 2016; 6:44794-805. [PMID: 26575021 PMCID: PMC4792592 DOI: 10.18632/oncotarget.6328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 10/23/2015] [Indexed: 01/12/2023] Open
Abstract
The tumor suppressor gene FBXW7 is deleted and mutated in many different types of human cancers. FBXW7 primarily exerts its tumor suppressor activity by ubiquitinating different oncoproteins including mTOR. Here we used gene transcript profiling to gain a deeper understanding of the role of FBXW7 in tumor development and to determine the influence of mTOR inhibition by rapamycin on tumor transcriptome and biological functions. In comparison to tumors from p53 single heterozygous (p53+/−) mice, we find that radiation-induced thymic lymphomas from Fbxw7/p53 double heterozygous (Fbxw7+/−p53+/−) mice show significant deregulation of cholesterol metabolic processes independent of rapamycin treatment, while cell cycle related genes were upregulated in tumors from placebo treated Fbxw7+/−p53+/− mice, but not in tumors from rapamycin treated Fbxw7+/−p53+/− mice. On the other hand, tumors from rapamycin treated Fbxw7+/−p53+/− mice were enriched for genes involved in the integrated stress response, an adaptive mechanism to survive in stressful environments. Finally, we demonstrated that the Fbxw7 gene signatures identified in mouse tumors significantly overlap with FBXW7 co-expressed genes in human cancers. Importantly these common FBXW7 gene signatures between mouse and human are predictive for disease-free survival in human colon, breast and lung adenocarcinoma cancer patients. These results provide novel insights into the role of FBXW7 in tumor development and have identified a number of potential targets for therapeutic intervention.
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Affiliation(s)
- Antoine M Snijders
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yueyong Liu
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Li Su
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yurong Huang
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jian-Hua Mao
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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Kitade S, Onoyama I, Kobayashi H, Yagi H, Yoshida S, Kato M, Tsunematsu R, Asanoma K, Sonoda K, Wake N, Hata K, Nakayama KI, Kato K. FBXW7 is involved in the acquisition of the malignant phenotype in epithelial ovarian tumors. Cancer Sci 2016; 107:1399-1405. [PMID: 27486687 PMCID: PMC5084658 DOI: 10.1111/cas.13026] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/26/2016] [Accepted: 07/28/2016] [Indexed: 12/15/2022] Open
Abstract
FBXW7 is a ubiquitin ligase that mediates ubiquitylation of oncoproteins, such as c‐Myc, cyclin E, Notch and c‐Jun. FBXW7 is a known tumor‐suppressor gene, and mutations in FBXW7 have been reported in various human malignancies. In this study, we examined the sequences of the FBXW7 and p53 genes in 57 ovarian cancer clinical samples. Interestingly, we found no FBXW7 mutations associated with amino acid changes. We also investigated FBXW7 expression levels in 126 epithelial ovarian tumors. FBXW7 expression was negatively correlated with the malignant potential of ovarian tumors. That is to say, FBXW7 expression levels in ovarian cancer samples were significantly lower than those in borderline and benign tumors (P < 0.01). FBXW7 expression levels in serous carcinoma samples were the lowest among four major histological subtypes. In addition, p53‐mutated ovarian cancer samples showed significantly lower levels of FBXW7 expression compared with p53 wild‐type cancer samples (P < 0.001). DNA methylation arrays and bisulfite PCR sequencing experiments revealed that 5′‐upstream regions of FBXW7 gene in p53‐mutated samples were significantly higher methylated compared with those in p53 wild‐type samples (P < 0.01). This data indicates that p53 mutations might suppress FBXW7 expression through DNA hypermethylation of FBXW7 5′‐upstream regions. Thus, FBXW7 expression was downregulated in ovarian cancers, and was associated with p53 mutations and the DNA methylation status of the 5′‐upstream regions of FBXW7.
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Affiliation(s)
- Shoko Kitade
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ichiro Onoyama
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Hiroaki Kobayashi
- Department of Obstetrics and Gynecology, Faculty of Medicine, Kagoshima University, Kagoshima, Japan
| | - Hiroshi Yagi
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Sachiko Yoshida
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masaya Kato
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ryosuke Tsunematsu
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kazuo Asanoma
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kenzo Sonoda
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Norio Wake
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kenichiro Hata
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Keiichi I Nakayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Kiyoko Kato
- Department of Obstetrics and Gynecology, School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Sato M, Rodriguez-Barrueco R, Yu J, Do C, Silva JM, Gautier J. MYC is a critical target of FBXW7. Oncotarget 2015; 6:3292-305. [PMID: 25669969 PMCID: PMC4413654 DOI: 10.18632/oncotarget.3203] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 12/18/2014] [Indexed: 12/22/2022] Open
Abstract
MYC deregulation is a driver of many human cancers. Altering the balance of MYC protein levels at the level of transcription, protein stability, or turnover is sufficient to transform cells to a tumorigenic phenotype. While direct targeting of MYC is difficult, specific genetic vulnerabilities of MYC-deregulated cells could be exploited to selectively inhibit their growth. Using a genome-wide shRNA screen, we identified 78 candidate genes, which are required for survival of human mammary epithelial cells with elevated MYC levels. Among the candidates, we validated and characterized FBXW7, a component of the SCF-like ubiquitin ligase complex that targets MYC for proteasomal degradation. Down-regulation of FBXW7 leads to synergistic accumulation of cellular and active chromatin-bound MYC, while protein levels of other FBXW7 targets appear unaffected. Over a four-week time course, continuous FBXW7 down-regulation and MYC activation together cause an accumulation of cells in S-phase and G2/M-phase of the cell cycle. Under these conditions, we also observe elevated chromatin-bound levels of CDC45, suggesting increased DNA replication stress. Consistent with these results, FBXW7 down-regulation alone decreases the survival of T47D breast cancer cells. These results establish that FBXW7 down-regulation is synthetic lethal with MYC, and that MYC is a critical target of FBXW7 in breast epithelial cells.
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Affiliation(s)
- Mai Sato
- Department of Pathology and Cell Biology, Columbia University, New York, USA
- Institute for Cancer Genetics, Columbia University, New York, USA
| | - Ruth Rodriguez-Barrueco
- Institute for Cancer Genetics, Columbia University, New York, USA
- Department of Pathology, Mount Sinai School of Medicine, New York, USA
| | - Jiyang Yu
- Department of Biomedical Informatics, Columbia University, New York, USA
| | - Catherine Do
- Institute for Cancer Genetics, Columbia University, New York, USA
| | - Jose M. Silva
- Department of Pathology and Cell Biology, Columbia University, New York, USA
- Institute for Cancer Genetics, Columbia University, New York, USA
- Department of Pathology, Mount Sinai School of Medicine, New York, USA
| | - Jean Gautier
- Institute for Cancer Genetics, Columbia University, New York, USA
- Department of Genetics and Development, Columbia University, New York, USA
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Welcker M, Clurman BE. FBW7 ubiquitin ligase: a tumour suppressor at the crossroads of cell division, growth and differentiation. Nat Rev Cancer 2008; 8:83-93. [PMID: 18094723 DOI: 10.1038/nrc2290] [Citation(s) in RCA: 841] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
FBW7 (F-box and WD repeat domain-containing 7) is the substrate recognition component of an evolutionary conserved SCF (complex of SKP1, CUL1 and F-box protein)-type ubiquitin ligase. SCF(FBW7) degrades several proto-oncogenes that function in cellular growth and division pathways, including MYC, cyclin E, Notch and JUN. FBW7 is also a tumour suppressor, the regulatory network of which is perturbed in many human malignancies. Numerous cancer-associated mutations in FBW7 and its substrates have been identified, and loss of FBW7 function causes chromosomal instability and tumorigenesis. This Review focuses on structural and functional aspects of FBW7 and its role in the development of cancer.
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Affiliation(s)
- Markus Welcker
- Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, Washington 98109, USA.
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