title: Internalization properties of the anti-tumor α-lactalbumin-oleic acid complex.
abstract: α-Lactalbumin (α-LA) can bind oleic acid (OA) to form the anti-tumor α-LA-OA complex. Previous studies suggested α-LA-OA induced apoptosis or autophagy in an independent way. Furthermore, as a large molecule, α-LA-OA could enter tumor cells and accumulated in the nucleus, which was speculated as the basis of its anti-tumor activity. In this study, we evaluated the internalization property of α-LA-OA with and without endocytosis inhibitors using flow cytometry and laser scanning confocal microscopy. It was shown α-LA-OA transported from the cell membrane to the cytoplasm, then accumulated around the nucleus, which consequently began to shrink and condense. The α-LA component only located in the membrane whereas the OA component entered cytoplasm. When pre-treated cells with these inhibitors, the internalization of OA would all decrease while the interaction of α-LA with membrane did not influence. As for the complex, the internalization of α-LA-OA was completely blocked at 4°C and significantly decreased in the presence of cytochalasin D, an inhibitor of phagocytosis (p<0.01). In conclusion, the anti-tumor activity of α-LA-OA was mainly dependent on the OA component whereas the internalization mechanism was related to the α-LA component to be temperature-dependent and have a close relationship with the phagocytosis pathway.
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100083, China; Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China. Electronic address: 49631263@qq.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Fang
authors.affiliation: School of Food Science and Chemical Engineering, Beijing Technology and Business University, Beijing, 100048, China; Beijing Laboratory for Food Quality and Safety, China Agricultural University, Beijing, 100083, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Military General Hospital of Beijing PLA, Beijing, 100700, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Wu
authors.affiliation: Beijing Laboratory for Food Quality and Safety, China Agricultural University, Beijing, 100083, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Fan
authors.affiliation: Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
authors.forename: Fazheng
authors.initials: F
authors.lastname: Ren
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001692:Biological Transport; D002417:Cattle; D004705:Endocytosis / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D007768:Lactalbumin / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D019301:Oleic Acid / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D019301:Oleic Acid; D007768:Lactalbumin
keywords: Caveolae-mediated endocytosis; Clathrin-mediated endocytosis; Energy; Macropinocytosis; Phagocytosis; Temperature