Journal of Carcinogenesis & Mutagenesis

Abstract

In vitro growth-inhibitory effects of DMTAP-containing cationic hybrid liposomes (DMTAP-cHL) on cholangiocarcinoma cells

Masaki Okumura, Tomoya Hashimoto, Tomoaki Sakoda, Yoko Matsumoto and Hideaki Ichihara*

Cholangiocarcinoma is difficult to detect at an early stage and is one of the most intractable cancers with a poor prognosis. Because current treatments are associated with problems such as adverse effects and therapeutic resistance, the development of new, highly selective therapeutic approaches is required. In this study, we prepared 1,2-Dimyristoyl-3-Trimethylammonium-Propane (DMTAP)-containing cationic Hybrid Liposomes, designated DMTAP-cHL, and investigated their in vitro anticancer effects on Human Cholangiocarcinoma (HuCCT-1) cells.

DMTAP-cHL were prepared by sonication using DMPC, the Polyethylene Glycol (PEG)-based surfactant C12(EO)21, and the cationic lipid DMTAP. Dynamic light scattering analysis revealed that DMTAP-cHL had a hydrodynamic diameter of approximately 30 nm and remained stable for 35 days. Fluorescence polarization analysis showed that DMTAP-cHL exhibited membrane fluidity comparable to that of L-α-Dimyristoylphosphatidylcholine (DMPC) liposomes and HL21. In the WST-8 assay, the IC50 value of DMTAP-cHL was 262 μM, indicating a stronger antiproliferative effect than DMPC liposomes and HL21. Furthermore, Propidium Iodide (PI) staining demonstrated an increase in the DNA fragmentation rate, and activation of caspase-3, caspase-8, and caspase-9 was observed, suggesting that DMTAP-cHL induced caspase-dependent apoptosis.

After treatment with DMTAP-cHL, HuCCT-1 cells showed a rapid increase in plasma membrane fluidity. Confocal laser microscopy revealed that DMTAP-cHL/1-palmitoyl-2-{12-[(7-Nitro-2-1,3-Benzoxadiazol-4-yl)amino]Dodecanoyl}- sn-glycero-3-Phosphocholine (NBD-PC) rapidly fused with and accumulated in HuCCT-1 cells. In contrast, no clear fusion or accumulation was observed in normal bile duct cells. These results indicate that DMTAP-cHL selectively fuse with and accumulate in cholangiocarcinoma cells and induce apoptosis through alteration of cellular membrane fluidity. Therefore, DMTAP-cHL may be useful as a novel cancer-regulating nanomaterial for cholangiocarcinoma.

Published Date: 2026-08-10; Received Date: 2026-07-10