In vitro and in vivo anti-cancer effects of hibernating common carp (Cyprinus carpio) plasma on metastatic triple-negative breast cancer

Abstract

Uncontrollable proliferation is a hallmark of cancer cells. Cell proliferation and migration are significantly depressed during hibernation state. Many studies believe some factors in the plasma of hibernating animals cause these effects. This study aimed to assess the anti-cancer effects of hibernating common carp (Cyprinus carpio) plasma on 4T1 cancer cells in vitro and in vivo. The effect of hibernating plasma on cell viability, morphology, migration, apoptosis rate, and cell cycle distribution of 4T1 cells was investigated in vitro and in vivo. Hibernating plasma at a concentration of 16 mg/ml significantly reduced the viability of 4T1 cancer cells, without any toxicity on L929 normal fibroblast cells. It could change the morphology of cancer cells, induced apoptosis and cell cycle arrest at the G2/M phase, and inhibited migration. Furthermore, intratumoral injection of hibernating plasma (200 µl, 16 mg/ml) in the tumor-bearing mice caused a significant inhibition of 4T1 breast tumors volume (46.9%) and weight (58.8%) compared with controls. A significant decrease in the number of metastatic colonies at the lungs (80%) and liver (52.8%) of hibernating plasma-treated animals was detected which increased the survival time (21.9%) compared to the control groups. Immunohistochemical analysis revealed a considerable reduction in the Ki-67-positive cells in the tumor section of the hibernating plasma-treated animals compared with controls. Taken together, the SDS-PAGE and mass spectrometry analysis indicated the alpha-2-macroglobulin level in the hibernating fish plasma was significantly increased. It could exert an anti-cancer effect on breast cancer cells and suggested as a novel cancer treatment strategy.

Alpha-2-Macroglobulin Is a Novel Anticancer Agent

“…Amini et al's study [1] describes a significant antimelanoma activity of proteins from hibernating common carpa-derived plasma (HCCP). Other studies indicate alpha-2-macroglobulin (A2MG) as responsible of HCCP anticancer effects [2,3] likely due to the potent inhibitory activity on proteases, necessary for the metastatic progression [4]. Such data are in line with our previous study, showing that sera from melanoma mice and from melanoma patients contain significantly lower A2MG levels than controls [5].…”

“…Therefore, A2MG may exert different functions on cancer cells depending on specific tumor microenvironments, as shown by different roles played by some metalloproteases in cancers [11]. Further, it is noteworthy that cold treatment is crucial for HCCP preparation [1][2][3], and similarly, cooling down is among the denaturation treatments required to highlight structural alterations in serum proteins from melanoma mice or melanoma human patients [5]. Interestingly, A2MG-binding activities were reported to be temperature dependent [12].…”