2. Academic Validation
  3. Germline Heterozygous Variants in SEC23B Are Associated with Cowden Syndrome and Enriched in Apparently Sporadic Thyroid Cancer

Germline Heterozygous Variants in SEC23B Are Associated with Cowden Syndrome and Enriched in Apparently Sporadic Thyroid Cancer

  • Am J Hum Genet. 2015 Nov 5;97(5):661-76. doi: 10.1016/j.ajhg.2015.10.001.
Lamis Yehia 1,  Farshad Niazi 2,  Ying Ni 3,  Joanne Ngeow 4,  Madhav Sankunny 2,  Zhigang Liu 2,  Wei Wei 5,  Jessica L Mester 2,  Ruth A Keri 6,  Bin Zhang 2,  Charis Eng 7
Affiliations

Affiliations

  • 1 Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
  • 2 Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
  • 3 Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Epidemiology and Biostatistics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
  • 4 Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Division of Medical Oncology, National Cancer Centre, Singapore 169610, Singapore; Oncology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore 169857, Singapore.
  • 5 Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Pediatrics, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China.
  • 6 Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; Division of General Medical Sciences-Oncology, Case Western Reserve University, Cleveland, OH 44106, USA.
  • 7 Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA; CASE Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA. Electronic address: engc@ccf.org.
PMID: 26522472 DOI: 10.1016/j.ajhg.2015.10.001
Abstract

Cancer-predisposing genes associated with inherited Cancer syndromes help explain mechanisms of sporadic carcinogenesis and often inform normal development. Cowden syndrome (CS) is an autosomal-dominant disorder characterized by high lifetime risks of epithelial cancers, such that ∼50% of affected individuals are wild-type for known cancer-predisposing genes. Using whole-exome and Sanger Sequencing of a multi-generation CS family affected by thyroid and Other cancers, we identified a pathogenic missense heterozygous SEC23B variant (c.1781T>G [p.Val594Gly]) that segregates with the phenotype. We also found germline heterozygous SEC23B variants in 3/96 (3%) unrelated mutation-negative CS probands with thyroid Cancer and in The Cancer Genome Atlas (TCGA), representing apparently sporadic cancers. We note that the TCGA thyroid Cancer dataset is enriched with unique germline deleterious SEC23B variants associated with a significantly younger age of onset. SEC23B encodes Sec23 homolog B (S. cerevisiae), a component of coat protein complex II (COPII), which transports proteins from the endoplasmic reticulum (ER) to the Golgi apparatus. Interestingly, germline homozygous or compound-heterozygous SEC23B mutations cause an unrelated disorder, congenital dyserythropoietic anemia type II, and SEC23B-deficient mice suffer from secretory organ degeneration due to ER-stress-associated Apoptosis. By characterizing the p.Val594Gly variant in a normal thyroid cell line, we show that it is a functional alteration that results in ER-stress-mediated cell-colony formation and survival, growth, and invasion, which reflect aspects of a Cancer phenotype. Our findings suggest a different role for SEC23B, whereby germline heterozygous variants associate with Cancer predisposition potentially mediated by ER stress "addiction."

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