ABERRANT EXPRESSION OF KERATIN PROTEINS AND CROSS-LINKED ENVELOPES IN HUMAN ESOPHAGEAL CARCINOMAS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 44  (3) , 1153-1157
Abstract
When compared to normal esophageal epithelium, marked alterations in keratin protein and cross-linked envelope expression were found in human esophageal carcinomas. Examination of the pattern of keratin proteins extracted from either several primary esophageal tumors or carcinomas xenotransplanted in nude mice revealed a dramatic reduction in the amount of keratin protein, especially in the MW 52,000-61,000 range. In 7 of the 8 primary tumors, the major MW 52,000 and MW 61,000 esophageal keratins were not detected, and the remaining tumor exhibited a marked reduction in these 2 keratins. The major MW 57,000 and minor MW 59,000 esophageal keratins were found in varying but reduced amounts in the different tumors. The major MW 57,000 keratin seemed to be the most conserved keratin of this intermediate-MW keratin class (MW 52,000-61,000). The lower MW keratins (MW 46,000-50,500) were usually conserved in the carcinoma cells and were present at levels approximately that of the nontransformed counterpart. The minor MW 37,000 and 44,000 keratins from normal esophageal epithelium were retained in the tumor cells but often in reduced amounts. The expression of another differentiated function, cross-linked envelopes, in the carcinoma cells varied from unimpaired to severely restricted capacity to form envelopes. Specific alterations in keratin protein and cross-linked envelope expression were found in human esophageal carcinomas.