Several humoral growth factors may contribute to the development and growth of AIDS-associated Kaposi's sarcoma (KS). They are either provided by chronically activated cells of the immune system or in an autocrine/paracrine manner by the neoplastic cells themselves. Transforming growth factor β (TGF-β) may directly enhance the growth of KS cells and tumor matrix formation. To mediate a signal both TGF-β receptors type I and type II (TβR-I and TβR-II) have to be expressed. We investigated the expression of TGF-P, TGF-β receptors types I and II, and endoglin, a nonsignaling-type TβR-III, by means of immunohistochemistry on skin biopsies from patients with AIDS-related KS. We found that the TGF-β ligand was expressed by KS cells in 9 of 11 samples. TβR-II was strongly expressed in 10 of 12 samples, but none of the investigated tumor samples stained for TβR-I. Endoglin was weakly expressed on all KS lesions and stained the endothelium of tumor-associated vessels in 92% of the samples. These findings show that most KS lesions have the ability to produce TGF-β and that KS cells maintain a high expression of TβR-II in the absence of TβR-I, which may allow KS to escape growth inhibitory effects of endocrine or paracrine TGF-β.
|Original language||English (US)|
|Number of pages||6|
|Journal||Clinical Cancer Research|
|State||Published - Oct 1 1995|
ASJC Scopus subject areas
- Cancer Research