Table 2.
Mutations and polymorphisms of the components of the TGF-β-Smad signaling pathway identified in the HNSCC cell lines.
| Exonic mutations with presumed LOH | ||||||
|---|---|---|---|---|---|---|
| Gene | Exon | Codon | Nucleotide change | Amino acid change | Presence of a wild-type allele | Cell line |
| SMAD2 | 8 | 276 | TCG→TTG | Ser→Leu | No | SCC-15 |
| SMAD4 | 5 | 245 | CAG→TAG | Glu→Stop | No | CAL27 |
| Polymorphic changes in exonic coding regions | ||||
|---|---|---|---|---|
| Gene | Exon | Codon | Nucleotide change | Presence of a wild-type allele (number of cell lines) |
| SMAD3 | 2 | 103 | CTG(leu)→CTA(leu) | No (2) Yes (3) |
| TGFBRI | 1 | 18-26 | del (GCG)3 | Yes (2) |
| Polymorphic changes in intronic sequences | ||||
|---|---|---|---|---|
| Gene | Intron | Nucleotide position | Polymorphic change | Presence of a wild-type allele (number of cell lines) |
| SMAD2 | 3 | −39 to −56 | (T18)del TT | Yes (5) |
| 3 | −39 to −56 | (T18)del T | Yes (3) | |
| SMAD3 | 2 | +59 | C→G | No (3) Yes (2) |
| 7 | +159 | T→C | Yes (1) | |
| SMAD4 | 6 | +30 | del T | Yes (6) |
| 6 | +30 | ins T | Yes (1) | |
| TGFBRI | 7 | +24 | G→A | No (2) Yes (1) |
| 8 | +86 | del CTTTT | No (2) Yes (1) | |
| TGFBRII | 2 | +7 | A→G | No (2) |
| 3 | −4 | T→A | No (1) | |
| 6 | −101 | C→A | Yes (1) | |