PREFERENTIAL REDUCTION OF NM23-H1 GENE-PRODUCT IN METASTATIC TISSUES FROM PAPILLARY AND FOLLICULAR CARCINOMAS OF THE THYROID

The nm23 gene product is a possible mediator of cancer invasion and me tastasis, and has been divided into two distinct gene products, NM23-H 1 and NM23-H2. It has been shown previously that expression of nm23-H1 messenger RNA is reduced in metastatic lymph nodes from patients with papillary carcinoma of the thyroid (Am J Pathol 142:1938-1944, 1993). Since mAb H1-229 specific for NM23-H1 is now available, we further ex tended our study to examine the expression of nm23-H1 gene product in various types of thyroid cancer (37 cases of papillary carcinoma, 42 c ases of follicular carcinoma, 17 cases of anaplastic carcinoma, and 3 cases of medullary carcinoma). NM23-H1 was expressed in primary papill ary and follicular carcinomas (14/15 and 21/22), but weakly or hardly expressed in metastatic lymph nodes and metastatic bone marrow (6/23 a nd 1/4) (P < 0.01). Expression of NM23-H1 was low or absent in anaplas tic and medullary carcinoma (3/17 and 0/3) (P < 0.01).