Antitumor actions of cytokines on new human papillary thyroid carcinoma cell lines

To investigate the in vitro effects of cytokines on the growth of human papillary thyroid carcinoma (PTC) cells, we established six new PTC cell lines, designated BHP 5, 14, 15, 17, 18, and 19, from different patients. We studied the antiproliferative actions of cytokines by using BHP cells, NP cells (PTC cell line), and ARO cells (anaplastic thyroid carcinoma cell line). These cells were treated with various concentrations of tumor necrosis factor-alpha (TNF alpha), interferon-gamma (IFN gamma), interleukin-1 beta (IL-1 beta), and transforming growth factor-beta 1 (TGF beta 1), alone and in combination. Cell proliferation was assessed by [3H]thymidine incorporation and cell number measurement. In BHP cell lines, IFN gamma, IL-1 beta, and TGF beta 1 inhibited [3H]thymidine incorporation and decreased cell number, but TNF alpha stimulated [3H]thymidine incorporation. In NP cells, treatment with each cytokine decreased [3H]thymidine incorporation and cell number. In contrast, the proliferation of ARO cells was either stimulated by or resistant to TNF alpha, IL-1 beta, and TGF beta 1. The effects of these cytokines on [3H]thymidine incorporation were additive in these cell lines. The results suggest that IL-1 beta and TGF beta 1 play a pivotal role in growth inhibition of PTC cells, and the escape from negative control of IL-1 beta and TGF beta 1 may be a step toward anaplastic changes. The additive effects of these cytokines suggest that they act through different pathways.