title: Somatic acquisition of TGFBR1*6A by epithelial and stromal cells during head and neck and colon cancer development.
abstract: TGFBR1*6A is a common hypomorphic variant of the type I transforming growth factor (TGF)-beta receptor (TGFBR1), which transduces TGF-beta growth inhibitory signals less effectively than TGFBR1. Recent studies suggest that TGFBR1*6A confers a selective growth advantage to both normal appearing and cancerous epithelial cells in the presence of TGF-beta. We have previously shown that TGFBR1*6A is somatically acquired in head and neck and colon cancer (10). Using microdissected tissues, we show that TGFBR1*6A is somatically acquired by stromal and epithelial cells adjacent to colorectal and head and neck tumors. Somatic acquisition of the TGFBR1*6A allele is not accompanied by acquisition of other tumor-specific mutations. Furthermore, lymphocytes located within the stroma or the normal appearing epithelium do not have evidence of TGFBR1*6A acquisition. The highest TGFBR1*6A/TGFBR1 allelic ratio is observed at the tumor's edge, and traces of TGFBR1*6A are detected as far as 2 cm away from the tumor, which is suggestive of centrifugal spread of cells that harbor TGFBR1*6A. Assessment of CDH1 and CDH2 expression does not indicate epithelial-mesenchymal transformation. The results suggest that TGFBR1*6A somatic acquisition is a critical event in the early stages of cancer development that is associated with field cancerization. They also represent the first human report of somatically acquired altered stromal TGF-beta signaling during oncogenesis and the first report of a concordant mutation in the stromal and epithelial compartments in colon cancer.
authors: Cancer Genetics Program, Division of Hematology/Oncology, Department of Medicine, Northwestern University, Chicago, IL 60611, USA.
authors: Yansong
authors: Y
authors: Bian
authors: Thomas J
authors: TJ
authors: Knobloch
authors: Maureen
authors: M
authors: Sadim
authors: Virginia
authors: V
authors: Kaklamani
authors: Adekunle
authors: A
authors: Raji
authors: Guang-Yu
authors: GY
authors: Yang
authors: Christopher M
authors: CM
authors: Weghorst
authors: Boris
authors: B
authors: Pasche
mesh_terms: D001483:Base Sequence; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics*; D017154:Stromal Cells / Q000378:metabolism* / Q000473:pathology
chemical_list: D018125:Receptors, Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human