Receptor binding characteristics and cytotoxicity of insulin-methotrexate

Figure 1 HPLC analysis of insulin and insulin-MTX. The condition was described in MATERIALS AND METHODS. Retention time of insulin was 8.81 min. Retention time of insulin-MTX was 12.16 min. A: HPLC analysis of insulin. B: HPLC analysis of insulin-MTX.

Figure 2 Competitive binding curves of ¹²⁵I-insulin against insulin-MTX or insulin. The concentration of ¹²⁵I-insulin was 5 nmol/L. The binding assay was described in the MATERI-ALS AND METHODS.

Figure 3 Concentrations of MTX and insulin-MTX in BEL7402 and HL7702 cells. BEL7402 cells and HL7702 cells having cultured overnight were exposed to insulin-MTX or MTX at the indicated concentration for 24 h, 48 h, 72 h, 96 h, 120 h and 144 h respectively. Cell viability was assessed using MTT assay. Viability was expressed as a percentage of control by dividing the absorbance of each treated well by the average of the untreated control. A: Viability of BEL7402 cells treated with insulin-MTX (mean ± SD, n = 3); B: Viability of BEL7402 cells treated with MTX (mean ± SD, n = 3); C: Viability of HL7702 cells treated with insulin-MTX (mean ± SD, n = 3); D: Viability of HL7702 cells treated with MTX (mean ± SD, n = 3).