Figure 5.

¹³¹I treatment had a poor effect in RAI-resistant PTC cell lines. (a) Continuously treatment of the median-lethal dose of ¹³¹I to TPC-1 cell lines. 1^st generation of TPC-1 was set as normal TPC-1 cell line, and the 8^th as res-TPC-1 (RAI-resistant TPC-1). ¹³¹I radioactivity was calculated with a half-time decay of 8.02 days. The medium was changed every day. (b) Continuously treatment of the median-lethal dose of ¹³¹I to B-CPAP cell lines. 1^st generation of B-CPAP was considered as normal B-CPAP cell line, and the 8^th as res- B-CPAP (RAI-resistant B-CPAP). ¹³¹I radioactivity was calculated with a half-time decay of 8.02 days. The medium was changed every day. (c) MTT assay for sensitive and resistant TPC-1 cell lines treated with ¹³¹I (1.0 mCi/well) for 96 h. (d) MTT assay for sensitive and resistant B-CPAP cell lines treated with ¹³¹I (0.45 mCi/well) for 96 h. (e) Apoptosis assay for TPC-1, res-TPC-1, B-CPAP and res-B-CPAP cell lines treated with ¹³¹I for 12 h by flow cytometry. TPC-1 cells were treated with 1.0 mCi ¹³¹I and B-CPA cells were treated with 0.45 mCi ¹³¹I. The data were from one representative experiment of three identically performed and were expressed as means±SD (Standard Deviation). *** P < 0.001.