Experimental study of iodine-131 labeling of a novel tumor-targeting peptide, TFMP-Y4, in the treatment of hepatocellular carcinoma with internal irradiation.

Objective: To explore and compare the value of I-TFMP-Y4 and I-Caerin 1.1 in internal irradiation therapy for hepatocellular carcinoma.

Methods: (1) 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis revealed the inhibitory effects of Caerin 1.1 and TFMP-Y4 on Hepg2 and LO2 cell growth. (2) The chloramine-T method was used to prepare I-Caerin 1.1 and I-TFMP-Y4. (3) Uptake and elution assays revealed that Hepg2 cells bound and retained I-Caerin 1.1 and I-TFMP-Y4, and the inhibitory effects on Hepg2 cells were verified with cellular proliferation/toxicity assays. (4) A hormonal nude mouse model was established to study the in vivo therapeutic effects of the peptides alone, I-Caerin 1.1 and I-TFMP-Y4.

Results: (1) Caerin 1.1 inhibited Hepg2 and LO2 cell proliferation in a concentration-dependent manner, and the half-maximal inhibitory concentrations (IC) were 9.34 µg/mL and 22.16 µg/mL, respectively. Moreover, TFMP-Y4 did not inhibit these two cell lines. (2) The labeling rates of I-Caerin 1.1 and I-TFMP-Y4 were high and stable. Both could significantly reduce the activity of Hepg2 cells and inhibit tumor growth in vitro and in vivo.

Conclusion: I-Caerin 1.1 and I-TFMP-Y4 significantly inhibited the proliferation of Hepg2 cells in vitro and in vivo. In addition, I-TFMP-Y4 can reduce adverse reactions during treatment.