High Frequency of TGF-β-Receptor-II Mutations in Microdissected Tissue Samples from Laryngeal Squamous Cell Carcinomas

• Published in: Laboratory investigation Vol. 83; no. 8; pp. 1241 - 1251
• Main Authors: Nerlich, Andreas G, Sauer, Ulrich, Ruoss, Isabell, Hagedorn, Hjalmar G
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-08-2003; Nature Publishing
• Subjects: Aged; Aged, 80 and over; Biological and medical sciences; Carcinoma, Squamous Cell - chemistry; Carcinoma, Squamous Cell - genetics; Carcinoma, Squamous Cell - secondary; Cell Division; DNA Mutational Analysis; DNA Primers - chemistry; DNA, Neoplasm - analysis; Female; Fluorescent Antibody Technique, Indirect; Humans; Laryngeal Neoplasms - chemistry; Laryngeal Neoplasms - genetics; Laryngeal Neoplasms - pathology; Male; Medical sciences; Middle Aged; Otorhinolaryngology (head neck, general aspects and miscellaneous); Otorhinolaryngology. Stomatology; Point Mutation - genetics; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta - analysis; Receptors, Transforming Growth Factor beta - genetics; Tumors; Human; Squamous cell carcinoma; Microdissection; Tumoral tissue; Cytokine; Malignant tumor; Signal transduction; Gene; ENT disease; Tumor necrosis factor β; Larynx; Larynx disease; Mutation; Biological receptor
• ISSN: 0023-6837; 1530-0307
• DOI: 10.1097/01.LAB.0000081389.98880.79

In this study we analyze 105 paraformaldehyde-fixed and paraffin-embedded tumor samples from 12 patients with invasive squamous cell carcinoma of the larynx for the presence of gene mutations of the complete TGF-β-receptor-II (TBR-II) gene. This study was conducted on tissue samples following separation of tumor cell groups from adjacent stroma cell compartments by laser microdissection, resulting in pure tumor cell complexes of approximately 50 to 500 cells. We detected 35 different mutations in 5 of the 12 patients analyzed but none in numerous samples of the normal peritumoral stroma or in normal epithelium. Twelve of the mutations were silent and nonfunctional, whereas the 23 relevant mutations were either bp replacements leading to amino acid exchanges or deletions leading to frame shifts and premature stop codons. Except for the so-called “big polyadenine tract” in exon 3 with several similar mutations, no further mutational hot spot was found. In addition we found a correlation between mutations and a loss of typical TGF-β effects in tumor cells (high cell proliferation rate) but not in the stroma cells (low proliferative capacity, significant de novo deposition of matrix material). This study is the first to identify a high mutational rate of the TBR-II gene in laryngeal squamous cell carcinoma. We show that that only small tumor-cell groups are affected. The molecular abnormalities are variable, and only one hot spot of mutations can be identified (exon 3, big polyadenine tract). These defects and possibly comparable mutations in other proteins of the TGF-β–signaling cascade seem to be associated with enhanced cell proliferation rates and alterations of the peritumoral matrix.