Simultaneous induction of other types of programmed cell death, alongside apoptosis, in cancer cells may be considered an attractive strategy for the development of more effective anticancer therapies. The present study aimed to investigate the role of AMP-activated protein kinase (AMPK) in nutrient/serum starvation-induced necroptosis, which is a programmed form of necrosis, in the presence or absence of p53. The present study detected higher cell proliferation and lower cell death rates in the HCT116 human colon cancer cell line containing a p53 null mutation (HCT116 p53 -/-) compared with in HCT116 cells harboring wild-type p53 (HCT116 p53 +/+ ), as determined using a cell viability assay. Notably, western blot analysis revealed a relatively lower level of necroptosis in HCT116 p53 -/cells compared with in HCT116 p53 +/+ cells. Investigating the mechanism, it was revealed that necroptosis may be induced in HCT116 p53 +/+ cells by significantly increasing reactive oxygen species (ROS) and decreasing mitochondrial membrane potential (MMP), whereas little alterations were detected in HCT116 p53 -/cells. Unexpectedly, a much lower level of ATP was detected in HCT116 p53 -/cells compared with in HCT116 p53 +/+ cells. Accordingly, AMPK phosphorylation on the Thr172 residue was markedly increased in HCT116 p53 -/cells. Furthermore, western blot analysis and ROS measurements indicated that AMPK inhibition, using dorsomorphin dihydrochloride, accelerated necroptosis by increasing ROS generation in HCT116 p53 -/cells. However, AMPK activation by AICAR did not suppress necroptosis in HCT116 p53 +/+ cells. In conclusion, these data strongly suggested that AMPK activation may be enhanced in HCT116 p53 -/cells under serum-depleted conditions via a drop in cellular ATP levels. In addition, activated AMPK may be at least partially responsible for the inhibition of necroptosis in HCT116 p53 -/cells, but not in HCT116 p53 +/+ cells.

In attempting to identify effective anticancer drugs from natural products that are harmless to humans, we found that the gomisin J from Schisandra chinensis fruit has anticancer activity. Schisandra chinensis fruits are used in traditional herbal medicine and gomisin J is one of their chemical constituents. In the present study, we examined the anticancer activity of gomisin J in MCF7 and MDA-MB-231 breast cancer cell lines and in MCF10A normal cell line, in a time-and concentration-dependent manner. Our data revealed that gomisin J exerted a much stronger cytotoxic effect on MCF7 and MDA-MB-231 cancer cells than on MCF10A normal cells. Gomisin J suppressed the proliferation and decreased the viability of MCF7 and MDA-MB-231 cells at relatively low (<10 µg/ml) and high (>30 µg/ml) concentrations, respectively. Our data also revealed that gomisin J induced necroptosis, a programmed form of necrosis, as well as apoptosis. Notably, gomisin J predominantly induced necroptosis in MCF7 cells that are known to have high resistance to many pro-apoptotic anticancer drugs, while MDA-MB-231 exhibited a much lower level of necroptosis but instead a higher level of apoptosis. This data indicated the possibility that it may be used as a more effective anticancer drug, especially in apoptosis-resistant malignant cancer cells. In an extended study, gomisin J exhibited a strong cytotoxic effect on all tested various types of 13 cancer cell lines, indicating its potential to be used against a wide range of different types of cancer cells.

Angelica amurensis has traditionally been used to treat various medical problems. In this report, we introduce cis-khellactone as a new anti-cancer agent, which was isolated from the chloroform soluble fraction of the rhizomes of Angelica amurensis. Its anti-cancerous effect was at first tested in MCF7 and MDA-MB-231 breast cell lines, in which MCF7 is well known to be resistant to many anti-cancer drugs; MCF10A normal breast cell line was used as a control. In vitro experiments showed that cis-khellactone suppressed cell growth and proliferation at a relatively low concentrations (<5 μg/ml) and decreased cell viability at high concentrations (>10 μg/ml) in both cancer cell lines in a time- and concentration-dependent manner. This anti-cancerous effect was also checked in additional 16 different types of normal and cancer cell lines. Cis-khellactone treatment significantly suppressed cell proliferation and enhanced cell death in all tested cancer cell lines. Furthermore, Western blot analysis showed that cis-khellactone induced three types of programmed cell death (PCD): apoptosis, autophagy-mediated cell death, and necrosis/necroptosis. Cis-khellactone concentration-dependently decreased cell viability by increasing the level of reactive oxygen species (ROS) and decreasing mitochondrial membrane potential (MMP), which are related to all three types of PCD. Mitochondrial fractionation data revealed that cis-khellactone induced the translocation of BAX and BAK into mitochondria as well as the overexpression of VDAC1, which probably accelerates MMP disruption and finally cell death. Importantly, our extended in vivo studies with xenograft model further confirmed these findings of anti-cancerous effects and showed no harmful effects in normal tissues, suggesting that there would be no side effects in humans.

Hippophae rhamnoides L., which belongs to the Elaegnaceae family, is one of the medically and environmentally valuable berry crops with its high nutritious and bioactive compounds. Despite its high demand in the food, medicinal and agricultural industries, this species has been less studied molecularly. In view of this, an effort has been made in the present study to characterize 24 accessions of H. rhamnoides collected from different geographical regions of Mongoliaa through random amplified polymorphic DNA (RAPD) markers. A total of 10 RAPD primers were used in the present study for their ability to produce clear, scorable amplicons. The RAPD analysis totally generated 87 bands, of which 84 (96.34%) were polymorphic, pointing to a high degree of genetic variation. The similarity coefficient ranged from 0.4-1 with the mean of 0.78. The UPGMA dendrogram was generated using these data grouped accessions into two main clusters. Cluster analysis reflected a relatively close relationship between accessions grown at the same or neighbouring areas. Thus, our data could be informative for further selection and management of germplasm collections and crossing strategies for sea buckthorn.