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Colorectal cancer (CRC) is one of the world's most common cancers with a high mortality rate mainly due to metastasis. Our previous study showed that pristimerin had potent antitumor activities against human CRC cells. In the present study, we further evaluated pristimerin anti-tumor and anti-metastatic properties. MTT assay, Hoechst staining, Annexin V/PI double staining, reactive oxygen species (ROS) measurements were used to assess pristimerin cytotoxicity and apoptotic-inducing effects on HCT-116 cells. Wound healing assay and Transwell assay were used to estimate pristimerin anti-migration and anti-invasion activities on CRC cells. Meanwhile, HCT-116 xenograft model applied for investigating in vivo antitumor activities. Our results showed that pristimerin mediated in vitro HCT-116 cell death, through generation of intracellular ROS and apoptosis induction. Tumor volumes and weights measurements, pathological analysis and Tunnel assay proved that pristimerin inhibited in vivo HCT-116 xenografts growth. Pristimerin was also able to limit CRC invasion and metastasis. It caused downregulation of PI3K/AKT/mTOR pathway and its subsequent downstream p70S6K and E4-BP1 proteins. Collectively, pristimerin exerted both in vitro and in vivo cytotoxic and anti-metastatic effects on HCT-116 cells, suggesting that pristimerin has potential as a new anticancer drug for treatment of colon cancer.

Rhein is an active component of rhubarb; a traditional Chinese medicine reported to induce apoptosis and cause liver toxicity. However, rhein's apoptotic-inducing effects, as well as its molecular mechanisms of action on hepatic cells need to be further explored. In the present study, rhein was found to trigger apoptosis in primary human hepatic HL-7702 cells as showed by annexin V/PI double staining assay and nuclear morphological changes demonstrated by Hoechst 33258 staining. Moreover, it was observed that the mechanism implicated in rhein-induced apoptosis was caspase-dependent, presumably via ER-stress associated pathways, as illustrated by up-regulation of glucose-regulated protein 78 (GRP 78), PKR-like ER kinase (PERK), C-Jun N-terminal kinase (JNK) and CCAAT/enhancer-binding protein homologous protein (CHOP). Meanwhile, caspase-4 as a hallmark of ER-stress, was also showed to be activated following by caspase-3 activation. Furthermore, rhein also promoted intracellular elevation of calcium that contributed in apoptosis induction. Interestingly, pre-treatment with calpain inhibitor I reduced the effects of rhein on apoptosis induction and JNK activation. These data suggested that rhein-induced apoptosis through ER-stress and elevated intracellular calcium level in HL-7702 cells.

Pristimerin is a naturally occurring triterpenoid that has a cytotoxic effect on several cancer cell lines. However, the cytotoxic effects of pristimerin as well as its molecular mechanisms of action against colorectal cancer have never been explored. In the present study, we investigated the anticancer potential of pristimerin, and examined the different signaling pathways affected by its action in three colon cancer cell lines namely HCT-116, COLO-205 and SW-620. Pristimerin was found to possess potent cytotoxic and proliferation inhibitory effects against these cell lines. Cell cycle analysis revealed G1 phase arrest, which was strongly associated with decreased expression of cyclin D1 and cyclin-dependent kinases (cdk4 and cdk6) with concomitant induction of p21. Pristimerin also induced apoptosis in a dose-dependent manner. Cell plasma membrane alterations studied by Annexin V/PI double staining, loss of mitochondrial membrane potential (ΔΨm), measurements of caspase activities and the inhibitory effect of Z-VAD-FMK (a caspase inhibitor) confirmed the apoptotic effect of pristimerin. Moreover, western blot data showed that apoptotic induction was associated with activated caspase-3 and -8, PARP-1 cleavage and modulation of the expression levels of Bcl-2 family proteins. Additionally, pristimerin treatment downregulated the phosphorylated forms of EGFR and HER2 proteins, and subsequently caused a decrease in the phosphorylated forms of Erk1/2, Akt, mTOR and NF-κB proteins. Taken together, these results suggest that pristimerin may have potential as a new targeting therapeutic strategy for the treatment of colon cancer.

Triptolide is the major bioactive component isolated from the Chinese Medicinal plant Tripterygium wilfordii. Despite the growing interest and the plethora of reports discussing the pharmacological activity of this diterpenoid, no clear consensus regarding its cellular targets and full mechanism of action has been reached. In the present work, a combined in vitro and in silico approach was used to evaluate the biological activity of Triptolide on Non-small cell lung cancer (NSCLC). In vitro, Triptolide treatment induced apoptosis in NSCLC cell lines and down-regulated the phosphorylation of AKT, mTOR, and p70S6K. Triptolide also impacted cellular glycolysis as well as the antioxidant response through the impairment of glucose utilization, HKII, glutathione, and NRF2 levels. Molecular docking results examined the possible interactions between Triptolide and AKT and predicted an allosteric binding to AKT-1 structure. Molecular dynamics simulations were further used to evaluate the stability of the complex formed by Triptolide's best conformer and AKT. These findings provide an insightful approach to the anticancer effect of Triptolide against NSCLC and highlight a possible new role for AKT/mTOR HKII inhibition.

// Mounia Guerram 1 , Zhen-Zhou Jiang 1, 2 , Bashir Alsiddig Yousef 1 , Aida Mejda Hamdi 1 , Hozeifa Mohamed Hassan 1 , Zi-Qiao Yuan 1 , Hou-Wei Luo 3 , Xiong Zhu 4 , Lu-Yong Zhang 1, 5 1 Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009, China 2 Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China 3 Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009, China 4 Medical and Chemical Institute, China Pharmaceutical University, Nanjing 210009, China 5 State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China Correspondence to: Zhen-Zhou Jiang, e-mail: beaglejiang@cpu.edu.cn Lu-Yong Zhang, e-mail: lyzhang@cpu.edu.cn Keywords: ATA, breast cancer, metabolism, HER2, signaling pathways Received: February 15, 2015 Accepted: May 14, 2015 Published: May 28, 2015 ABSTRACT Increased lipogenesis and protein synthesis is a hallmark of cancer cell proliferation, survival, and metastatic progression and is under intense investigation as a potential antineoplastic target. Acetyltanshinone IIA (ATA) is a compound that was obtained from chemical modifications of tanshinone IIA (TIIA), a potent anticancer agent extracted from the dried roots of the Chinese herbal medicine Salvia miltiorrhiza Bunge. A previous investigation indicated that ATA is more effective in inhibiting the growth of breast cancer especially cells with HER2 overexpression. However, the molecular mechanism(s) mediating this cytotoxic effect on HER2-positive breast cancer remained undefined. Studies described here report that ATA induced G1/S phase arrest and apoptosis in the HER2-positive MDA-MB-453, SK-BR-3, and BT-474 breast cancer cell lines. Mechanistic investigations revealed that the ATA-induced apoptosis effect is associated with remarkably down-regulation of receptor tyrosine kinases (RTKs) EGFR/HER2 and inhibition of their downstream pro-survival signaling pathways. Interestingly, ATA was found to trigger oxidative and endoplasmic reticulum (ER) stresses and to activate AMP activated protein kinase (AMPK) leading to inactivation of key enzymes involved in lipid and protein biogenesis. Intraperitoneal administration of ATA significantly inhibited the growth of MDA-MB-453 xenografts in athymic mice without causing weight loss and any other side effects. Additionally, transwell migration, invasion, and wound healing assays revealed that ATA could suppress tumor angiogenesis in vitro . Taken together, our data suggest that ATA may have broad utility in the treatment of HER2-overexpressed breast cancers.

Background Deoxypodophyllotoxin (DPT) is a semi-synthetic compound derived from the extract of Dysosma versipellis (Hance) M. Cheng, one of the most popular Chinese herbal medicines. The present study evaluates the in vitro cytotoxicity of DPT on a wide panel of human cancer cell lines and investigates its molecular mechanism of action on high grade glioma U-87 MG and SF126 cells. Methods The growth inhibitory effect of DPT on different types of human cancer cells was measured by the Cell Counting Kit-8 (CCK-8) assay. For the elucidation of the nature of the cellular response to DPT-treatment; flow cytometry-based assays, light and fluorescent microscopy, caspase colorimetric and inhibition assays, and Western blot analysis were performed. Results Our data show that DPT possesses a potent growth-inhibitory action, with IC 50 values in nanomolar ranges. Cell cycle analysis revealed G2/M phase arrest in a dose- and time-dependent manner before cell death occurred. Additional studies indicated that DPT induced G2 arrest in U-87 MG cells by decreasing the expression of Cdc2, cyclin B1, and Cdc25C proteins. In contrast, DPT failed to down-regulate these cell cycle regulatory molecules in SF126 glioblastoma cells and stopped the cell cycle at M phase. Interestingly, morphological changes and biochemical markers such as phosphatydylserine externalization, DNA fragmentation, and caspase activation, confirmed that DPT-treatment resulted in an induction of apoptosis in both examined cell lines via caspase-dependent pathways. Conclusions Taken together, our data demonstrated that DPT possesses a potent in vitro cytotoxic activity and exerts its effect via G2/M arrest and apoptosis.