Table 1. Immunohistochemical expression of Met protein and methylation of MET promoter in papillary carcinoma and in other pathological conditions of the thyroid.
| Histology | No. cases | Age mean±s.d. | Sex F/M | Met-positive cases | MET promoter methylation |
|---|---|---|---|---|---|
| Papillary carcinoma | 61 | 41±12 | 49/12 | 61 | 0/6b |
| Peritumoral normal thyroid tissue | 45 | −/+c | 0/6 | ||
| Insular carcinoma | 3 | 42±20 | 2/1 | 3 | nd |
| Anaplastic carcinoma | 3 | 67±2 | 3/0 | 3 | nd |
| Follicular carcinoma | 4 | 34±6 | 3/1 | 4 | nd |
| Oncocytic carcinoma | 4 | 47±13 | 4/0 | 2/4 | nd |
| Medullary carcinoma | 1 | 51 | 0/1 | 0 | nd |
| Follicular adenoma | 20 | 45±14 | 14/6 | 4/20 | nd |
| Thyroiditis | 3 | 49±5 | 3/0 | 2/3 | nd |
| Nodular hyperplasia | 38 | 52±11 | 32/6 | 7/38 | 0/2 |
a
Frozen sections were immunostained with DO24 mouse monoclonal antibody.
b
Methylation status of 43 CpGs of the Met promoter in six cases of papillary carcinoma, in the corresponding normal thyroid tissue, and in two cases of hyperplastic goitre was investigated. Sodium bisulphite modification of genomic DNA and PCR were performed according to Frommer's method (see Materials and Methods).
c
A weaker staining was present in the rim of peritumoral normal follicles with tall epithelium; whereas normal follicles with flat epithelium were not stained.
nd=not determined.