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Abildgaard AB, Stein A, Nielsen SV, Schultz-Knudsen K, Papaleo E, Shrikhande A, Hoffmann ER, Bernstein I, Gerdes AM, Takahashi M, Ishioka C, Lindorff-Larsen K, Hartmann-Petersen R. Computational and cellular studies reveal structural destabilization and degradation of MLH1 variants in Lynch syndrome. eLife 2019; 8:e49138. [PMID: 31697235 PMCID: PMC6837844 DOI: 10.7554/elife.49138] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/23/2019] [Indexed: 12/13/2022] Open
Abstract
Defective mismatch repair leads to increased mutation rates, and germline loss-of-function variants in the repair component MLH1 cause the hereditary cancer predisposition disorder known as Lynch syndrome. Early diagnosis is important, but complicated by many variants being of unknown significance. Here we show that a majority of the disease-linked MLH1 variants we studied are present at reduced cellular levels. We show that destabilized MLH1 variants are targeted for chaperone-assisted proteasomal degradation, resulting also in degradation of co-factors PMS1 and PMS2. In silico saturation mutagenesis and computational predictions of thermodynamic stability of MLH1 missense variants revealed a correlation between structural destabilization, reduced steady-state levels and loss-of-function. Thus, we suggest that loss of stability and cellular degradation is an important mechanism underlying many MLH1 variants in Lynch syndrome. Combined with analyses of conservation, the thermodynamic stability predictions separate disease-linked from benign MLH1 variants, and therefore hold potential for Lynch syndrome diagnostics.
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Affiliation(s)
- Amanda B Abildgaard
- Department of Biology, The Linderstrøm-Lang Centre for Protein ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Amelie Stein
- Department of Biology, The Linderstrøm-Lang Centre for Protein ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Sofie V Nielsen
- Department of Biology, The Linderstrøm-Lang Centre for Protein ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Katrine Schultz-Knudsen
- Department of Biology, The Linderstrøm-Lang Centre for Protein ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Elena Papaleo
- Department of Biology, The Linderstrøm-Lang Centre for Protein ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Amruta Shrikhande
- DNRF Center for Chromosome Stability, Department of Cellular and Molecular MedicineUniversity of CopenhagenCopenhagenDenmark
| | - Eva R Hoffmann
- DNRF Center for Chromosome Stability, Department of Cellular and Molecular MedicineUniversity of CopenhagenCopenhagenDenmark
| | - Inge Bernstein
- Department of Surgical GastroenterologyAalborg University HospitalAalborgDenmark
| | | | - Masanobu Takahashi
- Department of Medical OncologyTohoku University Hospital, Tohoku UniversitySendaiJapan
| | - Chikashi Ishioka
- Department of Medical OncologyTohoku University Hospital, Tohoku UniversitySendaiJapan
| | - Kresten Lindorff-Larsen
- Department of Biology, The Linderstrøm-Lang Centre for Protein ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Rasmus Hartmann-Petersen
- Department of Biology, The Linderstrøm-Lang Centre for Protein ScienceUniversity of CopenhagenCopenhagenDenmark
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2
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Castillejo A, Vargas G, Castillejo MI, Navarro M, Barberá VM, González S, Hernández-Illán E, Brunet J, Ramón y Cajal T, Balmaña J, Oltra S, Iglesias S, Velasco A, Solanes A, Campos O, Sánchez Heras AB, Gallego J, Carrasco E, González Juan D, Segura A, Chirivella I, Juan MJ, Tena I, Lázaro C, Blanco I, Pineda M, Capellá G, Soto JL. Prevalence of germline MUTYH mutations among Lynch-like syndrome patients. Eur J Cancer 2014; 50:2241-50. [PMID: 24953332 DOI: 10.1016/j.ejca.2014.05.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/17/2014] [Accepted: 05/22/2014] [Indexed: 01/04/2023]
Abstract
BACKGROUND AND AIMS Individuals with tumours showing mismatch repair (MMR) deficiency not linked to germline mutations or somatic methylation of MMR genes have been recently referred as having 'Lynch-like syndrome' (LLS). The genetic basis of these LLS cases is unknown. MUTYH-associated polyposis patients show some phenotypic similarities to Lynch syndrome patients. The aim of this study was to investigate the prevalence of germline MUTYH mutations in a large series of LLS patients. METHODS Two hundred and twenty-five probands fulfilling LLS criteria were included in this study. Screening of MUTYH recurrent mutations, whole coding sequencing and a large rearrangement analysis were undertaken. Age, sex, clinical, pathological and molecular characteristics of tumours including KRAS mutations were assessed. RESULTS We found a prevalence of 3.1% of MAP syndrome in the whole series of LLS (7/225) and 3.9% when only cases fulfilling clinical criteria were considered (7/178). Patients with MUTYH biallelic mutations had more adenomas than monoallelic (P=0.02) and wildtype patients (P<0.0001). Six out of nine analysed tumours from six biallelic MUTYH carriers harboured KRAS-p.G12C mutation. This mutation was found to be associated with biallelic MUTYH germline mutation when compared with reported series of unselected colorectal cancer cohorts (P<0.0001). CONCLUSIONS A proportion of unexplained LLS cases is caused by biallelic MUTYH mutations. The obtained results further justify the inclusion of MUTYH in the diagnostic strategy for Lynch syndrome-suspected patients.
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Affiliation(s)
- Adela Castillejo
- Molecular Genetics Laboratory, Elche University Hospital, Elche, Alicante, Spain
| | - Gardenia Vargas
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | | | - Matilde Navarro
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | | | - Sara González
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | | | - Joan Brunet
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IdIBGI, Girona, Spain
| | | | | | - Silvestre Oltra
- Genetics Department, La Fe University Hospital, Valencia, Spain
| | - Sílvia Iglesias
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Angela Velasco
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IdIBGI, Girona, Spain
| | - Ares Solanes
- Hereditary Cancer Program, Catalan Institute of Oncology, Badalona, Barcelona, Spain
| | - Olga Campos
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Ana Beatriz Sánchez Heras
- Genetic Counselling in Cancer, Hereditary Cancer Program, Elche University Hospital, Elche, Alicante, Spain; Department of Medical Oncology, Elche University Hospital, Elche, Alicante, Spain
| | - Javier Gallego
- Department of Medical Oncology, Elche University Hospital, Elche, Alicante, Spain
| | | | | | - Angel Segura
- Genetic Counselling in Cancer, Hereditary Cancer Program, La Fe University Hospital, Valencia, Spain
| | - Isabel Chirivella
- Genetic Counselling in Cancer, Hereditary Cancer Program, Clinical University Hospital of Valencia, Valencia, Spain
| | - María José Juan
- Genetic Counselling in Cancer, Hereditary Cancer Program, Valencian Institute of Oncology, Valencia, Spain
| | - Isabel Tena
- Genetic Counselling in Cancer, Hereditary Cancer Program, Provincial Hospital of Castellón, Castellón, Spain
| | - Conxi Lázaro
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Ignacio Blanco
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain; Hereditary Cancer Program, Catalan Institute of Oncology, Badalona, Barcelona, Spain
| | - Marta Pineda
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Gabriel Capellá
- Hereditary Cancer Program, Catalan Institute of Oncology, ICO-IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - José Luis Soto
- Molecular Genetics Laboratory, Elche University Hospital, Elche, Alicante, Spain.
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Gu GL, Zhu XQ, Wei XM, Ren L, Li DC, Wang SL. Epithelial-mesenchymal transition in colorectal cancer tissue of patients with Lynch syndrome. World J Gastroenterol 2014; 20:250-257. [PMID: 24415879 PMCID: PMC3886016 DOI: 10.3748/wjg.v20.i1.250] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 10/29/2013] [Accepted: 11/19/2013] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the epithelial-mesenchymal transition (EMT) in tissue from patients with Lynch syndrome, and to interpret biological behaviour of Lynch syndrome.
METHODS: Sixty-eight formalin-fixed and paraffin embedded tissue blocks were analyzed in this study, including tissues from Lynch syndrome (n = 30), sporadic colorectal carcinoma (CRC) (n = 30), and tumor-adjacent tissues (n = 8). Tissue sections were stained for human mutS homolog 2 (hMSH2), human mutL homolog 1 (hMLH1), transforming growth factor-β type II receptor (TGFβRII), E-cadherin, β-catenin, matrix metalloproteinase-7 (MMP-7) and tissue inhibitor of metalloproteinase-2 (TIMP-2) by immunohistochemical staining. Furthermore, clinical data such as age, gender and tumor-node-metastasis stage were also collected retrospectively.
RESULTS: The positive expression rates of hMSH2, hMLH1, TGFβRII, E-cadherin, β-catenin, MMP-7 and TIMP-2 were significantly related to the depth of invasion and lymph node metastasis, but not to sex or tumour size or location. The differences in the positive expression rates of hMSH2, hMLH1, TGFβRII, E-cadherin, cytomembrane β-catenin, cytoplasmic β-catenin, MMP-7 and TIMP-2 were significant between sporadic CRC and Lynch syndrome. The expression of hMSH2 had a positive correlation with that of hMLH1 in Lynch syndrome and sporadic CRC. The expression of TGFβRII had a positive correlation with that of hMSH2, hMLH1 and MMP-7, and a negative correlation with that of TIMP-2. The expression of MMP-7 had a negative correlation with that of TIMP-2 in Lynch syndrome and sporadic CRC. The expression of E-cadherin was positively correlated with that of cytomembrane β-catenin. However, the expression of cytomembrane β-catenin was negatively correlated with that of cytoplasmic β-catenin, and the expression of cytoplasmic β-catenin was positively correlated with that of MMP-7.
CONCLUSION: EMT may play an important role in the development and progression of Lynch syndrome. Lynch syndrome was caused by the mutations of mismatch repair genes, mainly hMSH2 and hMLH1, which also beget the mutational inactivation of TGFβRII. Therefore, the colorectal cancer of Lynch syndrome can escape the inhibitory effect of TGFβ1. However, TGFβ1 can up-regulate the expression of MMP-7 and down-regulate the expression of TIMP-2 in tumors by disassembling the E-cadherin/β-catenin complex in the cytomembrane.
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