Apoptosis Induction of Human Prostate Carcinoma DU145 Cells by Diallyl Disulfide via Modulation of JNK and PI3K/AKT Signaling Pathways

Diallyl disulfide (DADS), a sulfur compound derived from garlic, has various biological properties, such as anticancer, antiangiogenic and anti-inflammatory effects. However, the mechanisms of action underlying the compound’s anticancer activity have not been fully elucidated. In this study, the apoptotic effects of DADS were investigated in DU145 human prostate carcinoma cells. Our results showed that DADS markedly inhibited the growth of the DU145 cells by induction of apoptosis. Apoptosis was accompanied by modulation of Bcl-2 and inhibitor of apoptosis protein (IAP) family proteins, depolarization of the mitochondrial membrane potential (MMP, ΔΨm) and proteolytic activation of caspases. We also found that the expression of death-receptor 4 (DR4) and Fas ligand (FasL) proteins was increased and that the level of intact Bid proteins was down-regulated by DADS. Moreover, treatment with DADS induced phosphorylation of mitogen-activated protein kinases (MAPKs), including extracellular-signal regulating kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK). A specific JNK inhibitor, SP600125, significantly blocked DADS-induced-apoptosis, whereas inhibitors of the ERK (PD98059) and p38 MAPK (SB203580) had no effect. The induction of apoptosis was also accompanied by inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt and the PI3K inhibitor LY29004 significantly increased DADS-induced cell death. These findings provide evidence demonstrating that the proapoptotic effect of DADS is mediated through the activation of JNK and the inhibition of the PI3K/Akt signaling pathway in DU145 cells.     

The Anti-Proliferative and Apoptotic Effects of Rutaecarpine on Human Esophageal Squamous Cell Carcinoma Cell Line CE81T/VGH In Vitro and In Vivo

The overall five-year survival rate for patients with esophageal cancer is low (15 to 25%) because of the poor prognosis at earlier stages. Rutaecarpine (RTP) is a bioalkaloid found in the traditional Chinese herb Evodia rutaecarpa and has been shown to exhibit anti-proliferative effect on tumor cells. However, the mechanisms by which RTP confer these effects and its importance in esophageal squamous cell carcinoma treatment remain unclear. Thus, in the present study, we first incubated human esophageal squamous cell carcinoma cell line, CE81T/VGH, with RTP to evaluate RTP’s effects on tumor cell growth and apoptosis. We also performed a xenograft study to confirm the in vitro findings. Furthermore, we determined the expression of p53, Bax, bcl-2, caspase-3, caspase-9, and PCNA in CE81T/VGH cells or the tumor tissues to investigate the possible mechanisms. All the effects of TRP were compared with that of cisplatin. The results showed that RTP significantly inhibits CE81T/VGH cell growth, promotes arrest of cells in the G₂/M phase, and induces apoptosis. Consistently, the in vivo study showed that tumor size, tumor weight, and proliferating cell nuclear antigen protein expression in tumor tissue are significantly reduced in the high-dose RTP treatment group. Furthermore, the in vitro and in vivo studies showed that RTP increases the expression of p53 and Bax proteins, while inhibiting the expression of Bcl-2 in cancer cells. In addition, RTP significantly increases the expression of cleaved caspase-9 and cleaved caspase-3 proteins in tumor tissues in mice. These results suggest that RTP may trigger the apoptosis and inhibit growth in CE81T/VGH cells by the mechanisms associated with the regulation of the expression of p53, Bax, Bcl-2, as well as caspase-9 and caspase-3.     

Bisdemethoxycurcumin Induces Cell Apoptosis and Inhibits Human Brain Glioblastoma GBM 8401/Luc2 Cell Xenograft Tumor in Subcutaneous Nude Mice In Vivo

Bisdemethoxycurcumin (BDMC) has biological activities, including anticancer effects in vitro; however, its anticancer effects in human glioblastoma (GBM) cells have not been examined yet. This study aimed to evaluate the tumor inhibitory effect and molecular mechanism of BDMC on human GBM 8401/luc2 cells in vitro and in vivo. In vitro studies have shown that BDMC significantly reduced cell viability and induced cell apoptosis in GBM 8401/luc2 cells. Furthermore, BDMC induced apoptosis via inhibited Bcl-2 (anti-apoptotic protein) and increased Bax (pro-apoptotic proteins) and cytochrome c release in GBM 8401/luc2 cells in vitro. Then, twelve BALB/c-nude mice were xenografted with human glioblastoma GBM 8401/luc2 cancer cells subcutaneously, and the xenograft nude mice were treated without and with BDMC (30 and 60 mg/kg of BDMC treatment) every 3 days. GBM 8401/luc2 cell xenografts experiment showed that the growth of the tumors was significantly suppressed by BDMC administration at both doses based on the reduction of tumor size and weights. BDMC did not change the body weight and the H&E histopathology analysis of liver samples, indicating that BDMC did not induce systemic toxicity. Meanwhile, treatment with BDMC up-regulated the expressions of BAX and cleaved caspase-3, while it down-regulated the protein expressions of Bcl-2 and XIAP in the tumor tissues compared with the control group. This study has demonstrated that BDMC presents potent anticancer activity on the human glioblastoma GBM 8401/luc2 cell xenograft model by inducing apoptosis and inhibiting tumor cell proliferation and shows the potential for further development to the anti-GBM cancer drug.     

Ursolic Acid Accelerates Paclitaxel-Induced Cell Death in Esophageal Cancer Cells by Suppressing Akt/FOXM1 Signaling Cascade

Ursolic acid (UA), a pentacyclic triterpenoid extracted from various plants, inhibits cell growth, metastasis, and tumorigenesis in various cancers. Chemotherapy resistance and the side effects of paclitaxel (PTX), a traditional chemotherapy reagent, have limited the curative effect of PTX in esophageal cancer. In this study, we investigate whether UA promotes the anti-tumor effect of PTX and explore the underlying mechanism of their combined effect in esophageal squamous cell carcinoma (ESCC). Combination treatment with UA and PTX inhibited cell proliferation and cell growth more effectively than either treatment alone by inducing more significant apoptosis, as indicated by increased sub-G1 phase distribution and protein levels of cleaved-PARP and cleaved caspase-9. Similar to the cell growth suppressive effect, the combination of UA and PTX significantly inhibited cell migration by targeting uPA, MMP-9, and E-cadherin in ESCC cells. In addition, combination treatment with UA and PTX significantly activated p-GSK-3β and suppressed the activation of Akt and FOXM1 in ESCC cells. Those effects were enhanced by the Akt inhibitor LY2940002 and inverted by the Akt agonist SC79. In an in vivo evaluation of a murine xenograft model of esophageal cancer, combination treatment with UA and PTX suppressed tumor growth significantly better than UA or PTX treatment alone. Thus, UA effectively potentiates the anti-tumor efficacy of PTX by targeting the Akt/FOXM1 cascade since combination treatment shows significantly more anti-tumor potential than PTX alone both in vitro and in vivo. Combination treatment with UA and PTX could be a new strategy for curing esophageal cancer patients.     

Mallotucin D,a Clerodane Diterpenoid from Croton crassifolius,Suppresses HepG2 Cell Growth via Inducing Autophagic Cell Death and Pyroptosis

Hepatocellular carcinoma (HCC) is a major subtype of primary liver cancer with a high mortality rate. Pyroptosis and autophagy are crucial processes in the pathophysiology of HCC. Searching for efficient drugs targeting pyroptosis and autophagy with lower toxicity is useful for HCC treatment. Mallotucin D (MLD), a clerodane diterpenoid from Croton crassifolius, has not been previously reported for its anticancer effects in HCC. This study aims to evaluate the inhibitory effects of MLD in HCC and explore the underlying mechanism. We found that the cell proliferation, DNA synthesis, and colony formation of HepG2 cells and the angiogenesis of HUVECs were all greatly inhibited by MLD. MLD caused mitochondrial damage and decreased the TOM20 expression and mitochondrial membrane potential, inducing ROS overproduction. Moreover, MLD promoted the cytochrome C from mitochondria into cytoplasm, leading to cleavage of caspase-9 and caspase-3 inducing GSDMD-related pyroptosis. In addition, we revealed that MLD activated mitophagy by inhibiting the PI3K/AKT/mTOR pathway. Using the ROS-scavenging reagent NAC, the activation effects of MLD on pyroptosis- and autophagy-related pathways were all inhibited. In the HepG2 xenograft model, MLD effectively inhibited tumor growth without detectable toxicities in normal tissue. In conclusion, MLD could be developed as a candidate drug for HCC treatment by inducing mitophagy and pyroptosis via promoting mitochondrial-related ROS production.     

Potential Therapeutic Roles of Tanshinone IIA in Human Bladder Cancer Cells

Tanshinone IIA (Tan-IIA), one of the major lipophilic components isolated from the root of Salviae Miltiorrhizae, has been found to exhibit anticancer activity in various cancer cells. We have demonstrated that Tan-IIA induces apoptosis in several human cancer cells through caspase- and mitochondria-dependent pathways. Here we explored the anticancer effect of Tan-IIA in human bladder cancer cell lines. Our results showed that Tan-IIA caused bladder cancer cell death in a time- and dose-dependent manner. Tan-IIA induced apoptosis through the mitochondria-dependent pathway in these bladder cancer cells. Tan-IIA also suppressed the migration of bladder cancer cells as revealed by the wound healing and transwell assays. Finally, combination therapy of Tan-IIA with a lower dose of cisplatin successfully killed bladder cancer cells, suggesting that Tan-IIA can serve as a potential anti-cancer agent in bladder cancer.     

Inactivation of the Akt/FOXM1 Signaling Pathway by Panobinostat Suppresses the Proliferation and Metastasis of Gastric Cancer Cells

Gastric cancer is the fifth most common cancer and the third leading cause of cancer-related deaths worldwide. Histone deacetylase (HDAC) inhibitors are a new class of cytostatic agents available for the treatment of various cancers and diseases. Although numerous clinical and pre-clinical trials on the anticancer effects of panobinostat have been conducted, only a few reports have investigated its efficacy in gastric cancer. The present study aimed to investigate the effects of panobinostat in gastric cancer cells. Panobinostat significantly inhibited the cell viability and proliferation of the gastric cancer cell lines SNU484 and SNU638 in a dose-dependent manner; it reduced the colony-forming ability of these cells. Moreover, it induced apoptosis as indicated by increased protein levels of cleaved poly ADP-ribose polymerase and cleaved caspase-3. Panobinostat induced the G2/M cell cycle arrest in SNU484 and SNU638 cells and subsequently decreased the G2/M phase regulatory-associated protein expression of p-Wee1, Myt1, and Cdc2. Furthermore, panobinostat significantly inhibited the metastasis of SNU484 and SNU638 cells by regulating the expression of MMP-9 and E-cadherin. Further, it decreased the protein levels of p-Akt and forkhead box protein M1 (FOXM1). These effects were reversed by the Akt agonist SC79 and were accelerated by the Akt inhibitor LY2940002. Moreover, tumor growth in xenograft animal experiments was suppressed by panobinostat. These results indicated that panobinostat inhibits the proliferation, metastasis, and cell cycle progression of gastric cancer cells by promoting apoptosis and inactivating Akt/FOXM1 signaling. Cumulatively, our present study suggests that panobinostat is a potential drug for the treatment of gastric cancer.     

Ruthenium Complexes Induce HepG2 Human Hepatocellular Carcinoma Cell Apoptosis and Inhibit Cell Migration and Invasion through Regulation of the Nrf2 Pathway

Ruthenium (Ru) complexes are currently the focus of substantial interest because of their potential application as chemotherapeutic agents with broad anticancer activities. This study investigated the in vitro and in vivo anticancer activities and mechanisms of two Ru complexes—2,3,7,8,12,13,17,18-Octaethyl-21H,23H-porphine Ru(II) carbonyl (Ru1) and 5,10,15,20-Tetraphenyl-21H,23H-porphine Ru(II) carbonyl (Ru2)—against human hepatocellular carcinoma (HCC) cells. These Ru complexes effectively inhibited the cellular growth of three human hepatocellular carcinoma (HCC) cells, with IC₅₀ values ranging from 2.7–7.3 μM. In contrast, the complexes exhibited lower toxicity towards L02 human liver normal cells with IC₅₀ values of 20.4 and 24.8 μM, respectively. Moreover, Ru2 significantly inhibited HepG2 cell migration and invasion, and these effects were dose-dependent. The mechanistic studies demonstrated that Ru2 induced HCC cell apoptosis, as evidenced by DNA fragmentation and nuclear condensation, which was predominately triggered via caspase family member activation. Furthermore, HCC cell treatment significantly decreased the expression levels of Nrf2 and its downstream effectors, NAD(P)H: quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO1). Ru2 also exhibited potent in vivo anticancer efficacy in a tumor-bearing nude mouse model, as demonstrated by a time- and dose-dependent inhibition on tumor growth. The results demonstrate the therapeutic potential of Ru complexes against HCC via Nrf2 pathway regulation.     

Krill Oil Perturbs Proliferation and Migration of Mouse Colon Cancer Cells in vitro by Impeding Extracellular Signal-Regulated Protein Kinase Signaling Pathway

The prevalence of colorectal cancer (CRC) continues to increase. Treatment of CRC remains a significant clinical challenge, and effective therapies for advanced CRC are desperately needed. Increasing attention and ongoing research efforts have focused on krill oil that may provide health benefits to the human body. Here we report that krill oil exerts in vitro anticancer activity through a direct inhibition on proliferation, colony formation, migration, and invasion of mouse colon cancer cells. Krill oil inhibited the proliferation and colony formation of CT-26 colon cancer cells by causing G0/G1 cell cycle arrest and apoptosis. Cell cycle arrest was attributable to reduction of cyclin D1 levels in krill oil-treated cells. Further studies revealed that krill oil induced mitochondrial-dependent apoptosis of CT-26 cells, including loss of mitochondrial membrane potential, increased cytosolic calcium levels, activation of caspase-3, and downregulation of anti-apoptotic proteins MCL-1 and BCL-XL. Krill oil suppressed migration of CT-26 cells by disrupting the microfilaments and microtubules. Extracellular signal-regulated protein kinase (ERK) plays crucial roles in regulating proliferation and migration of cancer cells. We found that krill oil attenuated the activation of ERK signaling pathway to exert the effects on cell cycle, apoptosis, and migration of colon cancer cells. We speculate that polyunsaturated fatty acids of krill oil may dampen ERK activation by decreasing the phospholipid saturation of cell membrane. Although findings from in vitro studies may not necessarily translate in vivo, our study provides insights into the possibility that krill oil or its components could have therapeutic potential in colon cancer.     

Apoptosis is Induced in Cancer Cells via the Mitochondrial Pathway by the Novel Xylocydine-Derived Compound JRS-15

The novel compound JRS-15 was obtained through the chemical modification of xylocydine. JRS-15 exhibited much stronger cytotoxic and pro-apoptotic activity than its parent compound in various cancer cell lines, with IC₅₀ values in HeLa, HepG2, SK-HEP-1, PC-3M and A549 cells ranging from 12.42 to 28.25 μM. In addition, it is more potent for killing cancer than non-cancerous cells. Mechanistic studies showed that JRS-15 treatment arrested cell cycle at the G1/S phase, which further triggered the translocation of Bax and Bak to the mitochondria, resulting in mitochondrial membrane potential (MMP) depolarization and the subsequent release of cytochrome c and the second mitochondria-derived activator of caspase (Smac). The sequential activation of caspase-9 and caspase-3/7 and the cleavage of poly (ADP-ribose) polymerase (PARP) were observed following these mitochondrial events. Caspase-8, an initiator caspase that is required to activate the membrane receptor-mediated extrinsic apoptosis pathway was not activated in JRS-15-treated cells. Further analysis showed that the levels of the anti-apoptotic proteins Bcl-xL and XIAP were significantly reduced upon JRS-15 treatment. Furthermore, the caspase-9 inhibitor z-LEHD-fmk, the pan-caspase inhibitor z-VAD-fmk, and Bcl-xL or XIAP overexpression all effectively prevented JRS-15-induced apoptosis. Taken together, these results indicate that JRS-15 induces cancer cell apoptosis by regulating multiple apoptosis-related proteins, and this compound may therefore be a good candidate reagent for anticancer therapy.     

Iron Chelator Induces Apoptosis in Osteosarcoma Cells by Disrupting Intracellular Iron Homeostasis and Activating the MAPK Pathway

Osteosarcoma is a common malignant bone tumor in clinical orthopedics. Iron chelators have inhibitory effects on many cancers, but their effects and mechanisms in osteosarcoma are still uncertain. Our in vitro results show that deferoxamine (DFO) and deferasirox (DFX), two iron chelators, significantly inhibited the proliferation of osteosarcoma cells (MG-63, MNNG/HOS and K7M2). The viability of osteosarcoma cells was decreased by DFO and DFX in a concentration-dependent manner. DFO and DFX generated reactive oxygen species (ROS), altered iron metabolism and triggered apoptosis in osteosarcoma cells. Iron chelator-induced apoptosis was due to the activation of the MAPK signaling pathway, with increased phosphorylation levels of JNK, p38 and ERK, and ROS generation; in this process, the expression of C-caspase-3 and C-PARP increased. In an orthotopic osteosarcoma transplantation model, iron chelators (20 mg/kg every day, Ip, for 14 days) significantly inhibited the growth of the tumor. Immunohistochemical analysis showed that iron metabolism was altered, apoptosis was promoted, and malignant proliferation was reduced with iron chelators in the tumor tissues. In conclusion, we observed that iron chelators induced apoptosis in osteosarcoma by activating the ROS-related MAPK signaling pathway. Because iron is crucial for cell proliferation, iron chelators may provide a novel therapeutic strategy for osteosarcoma.     

The Caspase Pathway of Linoelaidic Acid (9t, 12t-C18:2)-Induced Apoptosis in Human Umbilical Vein Endothelial Cells

Trans fatty acids (TFA) are reported to contribute to inflammation and coronary heart disease. The study aim was to investigate the proapoptotic effects of two double bond TFA (TDTFA) on human umbilical vein endothelial cells (HUVEC). The HUVEC were grown in media supplied with linoelaidic acid (9t,12t-C18:2) at 50, 100, 200, 400 μmol/l for 24 or 48 h to examine the effects of TDTFA on the viability and apoptosis of these cells. Flow cytometry analysis and confocal scanning were used to measure apoptosis, cell binding of Annexin V and propidium iodide uptake. Colorimetric assay and RT-PCR were used to analyze enzyme activities and mRNA expression of caspase-3, -8 and -9 in HUVEC. Results showed that 9t,12t-C18:2 inhibited the viability of HUVEC in a dose-dependent and time-dependent manner. The percentages of 9t,12t-C18:2 induced apoptotic and necrotic cells significantly increased compared with that of the control. The activities and mRNA expression of caspase-8, -9 and -3 were significantly increased in 9t,12t-C18:2 treated cells compared to that of the control. Addition of specific inhibitors of caspase-8 (z-IETD-fmk) and caspase-9 (z-LEHD-fmk) to HUVEC was found to completely inhibit 9t,12t-C18:2-induced activation of caspase-3, and z-IETD-fmk inhibited the activation of caspase-9. Meanwhile, it was found that mRNA expression of Bid, Smac/DIABLO and the release of mitochondrial cytochrome c were significantly elevated by 9t,12t-C18:2 treatment. These results suggest that 9t,12t-C18:2 may induce apoptosis of HUVEC through activating caspase-8, -9 and -3. Both the death receptor pathway and the mitochondrial pathway may be involved in the apoptosis induced by 9t,12t-C18:2.     

辛二酰苯胺氧肟酸对人脐静脉内皮细胞增殖及血管形成的影响

目的探讨组蛋白去乙酰化酶抑制剂(Histone deacetylases inhibitor,HDACi)辛二酰苯胺氧肟酸(Suberoy-lanilide hydroxamic acid,SAHA)对人脐静脉内皮细胞(Human umbilical vein endothelial cell,HUVEC)增殖及血管形成能力的影响。方法收集处于对数生长期的HUVEC,以不同浓度的SAHA分别处理24和48 h,另设不加SAHA的对照组,采用CCK-8法检测细胞的增殖活力,并计算增殖抑制率和半数抑制浓度(IC50)。采用流式细胞术检测经15μmol/L SAHA处理48 h的HUVEC凋亡和细胞周期,基质胶体外血管生成试验检测HUVEC的体外成管能力,Western blot法检测HUVEC细胞周期及凋亡相关蛋白的表达水平。结果随着SAHA浓度的增加及作用时间的延长,其对HUVEC增殖的抑制作用增强,SAHA浓度高于80μmol/L时,抑制率增加不明显,24和48 h的IC50值分别为60.53和30.49μmol/L;经15μmol/L SAHA处理48 h,与对照组相比,HUVEC的凋亡率明显增加(P<0.001),S期细胞比例明显升高(P<0.001),G0/G1期比例明显降低(P<0.001),体外成管能力明显下降,P21、caspase-3激活型、caspase-9酶原和激活型蛋白的表达水平均明显升高(P<0.001)。结论 SAHA能够抑制HUVEC增殖及体外血管形成能力,并使P21、caspase-3和caspase-9蛋白水平上调,为肿瘤的治疗提供了一种新的思路。     

Methyl Sartortuoate Inhibits Colon Cancer Cell Growth by Inducing Apoptosis and G2/M-Phase Arrest

The potential anti-neoplastic activity of terpenoids is of continued interest. In this study, we investigate whether methyl sartortuoate, a terpenoid isolated from soft coral, induced cell cycle arrest and apoptosis in a human colon cancer cell line. Culture studies found that methyl sartortuoate inhibited colon cancer cell (LoVo and RKO) growth and caused apoptotic death in a concentration- and time-dependent manner, by activation of caspase-8, caspase-9, caspase-3, p53 and Bax, and inactivation of B-cell lymphoma 2 (Bcl-2) apoptosis regulating proteins. Methyl sartortuoate treatment led to reduced expression of cdc2 and up-regulated p21 and p53, suggesting that Methyl sartortuoate induced G2-M arrest through modulation of p53/p21/cdc2 pathways. Methyl sartortuoate also up-regulated phospho-JNK and phospho-p38 expression levels. This resulted in cell cycle arrest at the G2-M phase and apoptosis in LoVo and RKO cells. Treatment with the JNK inhibitor SP600125 and the p38 MAPK inhibitor SB203580 prevented methyl sartortuoate-induced apoptosis in LoVo cells. Moreover, methyl sartortuoate also prevented neoplasm growth in NOD-SCID nude mice inoculated with LoVo cells. Taken together, these findings suggest that methyl sartortuoate is capable of leading to activation of caspase-8, -9, -3, increasing p53 and Bax/Bcl-2 ratio apoptosis through MAPK-dependent apoptosis and results in G2-M phase arrest in LoVo and RKO cells. Thus, methyl sartortuoate may be a promising anticancer candidate.     

Allyl Isothiocyanate (AITC) Induces Apoptotic Cell Death In Vitro and Exhibits Anti-Tumor Activity in a Human Glioblastoma GBM8401/luc2 Model

Some clinically used anti-cancer drugs are obtained from natural products. Allyl isothiocyanate (AITC), a plant-derived compound abundant in cruciferous vegetables, has been shown to possess an anti-cancer ability in human cancer cell lines in vitro, including human brain glioma cells. However, the anti-cancer effects of AITC in human glioblastoma (GBM) cells in vivo have not yet been examined. In the present study, we used GBM8401/luc2 human glioblastoma cells and a GBM8401/luc2-cell-bearing animal model to identify the treatment efficacy of AITC. Here, we confirm that AITC reduced total cell viability and induced cell apoptosis in GBM8401/luc2 cells in vitro. Furthermore, Western blotting also showed that AITC induced apoptotic cell death through decreased the anti-apoptotic protein BCL-2, MCL-1 expression, increased the pro-apoptotic protein BAX expression, and promoted the activities of caspase-3, -8, and -9. Therefore, we further investigated the anti-tumor effects of AITC on human GBM8401/luc2 cell xenograft mice. The human glioblastoma GBM8401/luc2 cancer cells were subcutaneously injected into the right flank of BALB/c nude mice to generate glioblastoma xenograft mice. The animals were randomly divided into three groups: group I was treated without AITC (control); group II with 0.1 mg/day of AITC; and group III with 0.2 mg/day of AITC every 3 days for 27 days. Bodyweight, and tumor volume (size) were recorded every 3 days. Tumors exhibiting Luc2 intensity were measured, and we quantified intensity using Living Image software on days 0, 12, and 24. After treatment, tumor weight from each mouse was recorded. Tumor tissues were examined for histopathological changes using H&E staining, and we analyzed the protein levels via immunohistochemical analysis. Our results indicate that AITC significantly inhibited tumor growth at both doses of AITC due to the reduction in tumor size and weight. H&E histopathology analysis of heart, liver, spleen, and kidney samples revealed that AITC did not significantly induce toxicity. Body weight did not show significant changes in any experiment group. AITC significantly downregulated the protein expression levels of MCL-1, XIAP, MMP-9, and VEGF; however, it increased apoptosis-associated proteins, such as cleaved caspase-3, -8, and -9, in the tumor tissues compared with the control group. Based on these observations, AITC exhibits potent anti-cancer activity in the human glioblastoma cell xenograft model via inhibiting tumor cell proliferation and the induction of cell apoptosis. AITC may be a potential anti-GBM cancer drug that could be used in the future.     

Ziyuglycoside II Inhibits the Growth of Human Breast Carcinoma MDA-MB-435 Cells via Cell Cycle Arrest and Induction of Apoptosis through the Mitochondria Dependent Pathway

Ziyuglycoside II is one of the major active compounds of Sanguisorba officinalis L., which has a wide range of clinical applications including hemostasis, antibiosis, anti-inflammation and anti-oxidation. This study investigated the effect of ziyuglycoside II on the growth of human breast carcinoma MDA-MB-435 cells for the first time. The results showed that ziyuglycoside II could significantly inhibit the growth of MDA-MB-435 cells through blocking cell cycle progression at G0/G1 and S phase as well as via inducing cell apoptosis. Accumulation of reactive oxygen species (ROS) was observed in the progression of cell cycle arrest, which was associated with the increased expression of cell cycle regulating factors, p53 and p21. Subsequent apoptosis induced by ziyuglycoside II was accompanied with the activation of mitochondrial pathway, in particular a decreased mitochondrial membrane potential (MMP) as well as increased Bax/Bcl-2 ratio, cytochrome c release and the activity of caspase-3 and caspase-9. In conclusion, our study was the first to report that ziyuglycoside II has inhibitory effect on the growth of MDA-MB-435 cells, which might become a potential therapeutic approach of breast cancer in the future.     

Metformin and Dichloroacetate Suppress Proliferation of Liver Cancer Cells by Inhibiting mTOR Complex 1

The Warburg effect is important for cancer cell proliferation. This phenomenon can be flexible by interaction between glycolysis and mitochondrial oxidation for energy production. We aimed to investigate the anticancer effects of the pyruvate dehydrogenase kinase inhibitor, dichloroacetate (DCA) and the mitochondrial respiratory complex I inhibitor metformin in liver cancer cells. The anticancer effect of DCA and/or metformin on HepG2, PLC/PRF5 human liver cancer cell lines, MH-134 murine hepatoma cell lines, and primary normal hepatocytes using MTT assay. Inhibition of lactate/ATP production and intracellular reactive oxygen species generation by DCA and metformin was investigated. Inhibition of PI3K/Akt/mTOR complex I was evaluated to see whether it occurred through AMPK signaling. Anticancer effects of a combination treatment of DCA and metformin were evaluated in HCC murine model. The results showed that metformin and DCA effectively induced apoptosis in liver cancer cells. A combination treatment of metformin and DCA did not affect viability of primary normal hepatocytes. Metformin upregulated glycolysis in liver cancer cells, thereby increasing sensitivity to the DCA treatment. Metformin and DCA inhibited mTOR complex I signaling through upregulated AMPK-independent REDD1. In addition, metformin and DCA increased reactive oxygen species levels in liver cancer cells, which induced apoptosis. A combination treatment of metformin and DCA significantly suppressed the tumor growth of liver cancer cells using in vivo xenograft model. Taken together, the combined treatment of metformin and DCA suppressed the growth of liver cancer cells. This strategy may be effective for patients with advanced liver cancer.     

Potential Chemotherapeutic Effect of Selenium for Improved Canceration of Esophageal Cancer

Esophageal squamous cell carcinoma is the most common type of esophageal cancer and accounts for 5% of malignant tumor deaths. Recent research suggests that chronic inflammation and DNA damage may drive the onset of esophageal squamous cell carcinoma, implying that lowering chronic inflammation and DNA damage compounds may provide chemo-prevention. According to epidemiological and experimental evidence, selenium is linked to a lower risk of several malignancies, including esophageal squamous cell carcinoma. However, its exact mechanism is still unclear. In the present study, we used cell lines and a 4-NQO mice model to explore the anti-cancer mechanism of four types of selenium. Our findings indicated that selenium inhibited the proliferation, colony formation, and ROS level of ESCC cell lines in a time-dependent manner. Intriguingly, selenium treatment impeded 4-NQO-induced high-grade intraepithelial neoplasia and reduced the number of positive inflammatory cells by preserving DNA from oxidative damage. In addition, selenium significantly decreased the expression of Ki-67 and induced apoptosis. This study demonstrates that selenium has a significant chemo-preventive effect on ESCC by reducing high-grade dysplasia to low-grade dysplasia. For the first time, selenium was shown to slow down the progression of esophageal cancer by lowering inflammation and oxidative DNA damage.