Combination Treatment of Sorafenib and Bufalin Induces Apoptosis in NCI-H292 Human Lung Cancer Cells In Vitro.

BACKGROUND/AIM: Lung cancer notably contributes to tumor-associated mortality worldwide, and standard chemotherapy is used for lung cancer patients. However, its therapeutic efficacy remains unsatisfactory. This study aimed to evaluate the effects and molecular mechanisms of sorafenib and bufalin combination therapy on lung cancer cells in vitro. MATERIALS AND METHODS: NCI-H292 cells were treated with sorafenib, bufalin, and sorafenib in combination with bufalin. Cell viability, ROS production, Ca2+ release, and mitochondrial membrane potential were examined by flow cytometric assay. Annexin V/PI staining and chromatin condensation were examined by the apoptosis assays. Finally the molecular mechanism of apoptosis-associated protein expression was investigated by western blotting. RESULTS: NCI-H292 cells treated with sorafenib in combination with bufalin showed significantly decreased viability, enhanced cellular apoptosis, and DNA condensation when compared to that with sorafenib or bufalin alone. Moreover, the combination treatment exhibited higher reactive oxygen species (ROS) production and lower mitochondrial membrane potential (ΔΨm). The combined treatment resulted in higher expression of SOD but lower catalase compared to sorafenib treatment alone. Compared to sorafenib or bufalin treatment alone, the combination treatment resulted in lower Bcl-2 expression but higher Bax, Bad, APAF-1, caspase-3, and caspase-9. CONCLUSION: Sorafenib in combination with bufalin shows more potent cytotoxic effects and cell apoptosis than sorafenib or bufalin treatment alone in NCI-H292 cells. The combined treatment significantly enhanced apoptotic cell death in NCI-H292 lung cancer cells by activating ROS-, mitochondria-, and caspase-signaling pathways in vitro.

Combinational treatment of all-trans retinoic acid (ATRA) and bisdemethoxycurcumin (BDMC)-induced apoptosis in liver cancer Hep3B cells.

The effects of two-drug combination, all-trans retinoic acid (ATRA) and bisdemethoxycurcumin (BDMC), on apoptosis induction of liver cancer cells were investigated in human liver Hep 3B cells. Two-drug combination caused a more effective decrease in cell viability and in induction of S phase arrest, DNA damage, and cell apoptosis than that of ATRA or BDMC only. Also, the two-drug combination caused more cells to undergo significantly increased ROS productions when compared to that of ATRA or BDMC only. Results of Western blotting demonstrated that two-drug combination increased expressions of Fas, pro-apoptotic proteins, and active form of caspase-3 and -9, but decreased that of anti-apoptotic proteins and XIAP than that of ATRA or BDMC only in Hep 3B cells. In conclusion, ATRA combined with BDMC enhance cell apoptosis and associated protein expression in Hep 3B cells. PRACTICAL APPLICATIONS: Bisdemethoxycurcumin (BDMC) derived from natural plants, turmeric (Curcuma longa), which had been used for Asia food for thousands of years. All-trans retinoid acid (ATRA) is currently used as a primary treatment for patients with acute promyelocytic leukemia. In previous study, ATRA and BDMC were reported to have anti-inflammatory and anticancer effects. Our results showed that treatment of ATRA combined with BDMC showed more effectively apoptosis than that of ATRA or BDMC only in Hep 3B cells. The findings also provided possible pathways concerning the induction of liver cancer cell apoptosis. We conclude that ATRA combined with BDMC may be potent anticancer agents or adjuvants for liver cancer therapy in the future.

Bufalin Induces Apoptotic Cell Death in Human Nasopharyngeal Carcinoma Cells through Mitochondrial ROS and TRAIL Pathways.

The aim of this study was to investigate the effects of bufalin on human nasopharyngeal carcinoma NPC-TW 076 cells in vitro. Bufalin is a cardiotonic steroid and a key active ingredient of the Chinese medicine ChanSu. The extracts of Chansu are used for various cancer treatments in China. In the present study, bufalin induced cell morphological changes, decreased total cell viability and induced G2/M phase arrest of cell cycle in NPC-TW 076 cells. Results also indicated that bufalin induced chromatin condensation (cell apoptosis) and DNA damage by DAPI staining and comet assay, respectively. The induced apoptotic cell death was further confirmed by annexin-V/PI staining assay. In addition, bufalin also increased ROS and Ca 2+ production and decreased the levels of ΔΨm . Furthermore, the alterations of ROS, ER stress and apoptosis associated protein expressions were investigated by Western blotting. Results demonstrated that bufalin increased the expressions of ROS associated proteins, including SOD (Cu/Zn), SOD2 (Mn) and GST but decreased that of catalase. Bufalin increased ER stress associated proteins (GRP78, IRE-1 α , IRE-1 ß , caspase-4, ATF-6 α , Calpain 1, and GADD153). Bufalin increased the pro-apoptotic proteins Bax, and apoptotic associated proteins (cytochrome c, caspase-3, -8 and -9, AIF and Endo G) but reduced anti-apoptotic protein Bcl-2 in NPC-TW 076 cells. Furthermore, bufalin elevated the expressions of TRAIL-pathway associated proteins (TRAIL, DR4, DR5, and FADD). Based on these findings, we suggest bufalin induced apoptotic cell death via caspase-dependent, mitochondria-dependent and TRAIL pathways in human nasopharyngeal carcinoma NPC-TW 076 cells.

Casticin Promotes Immune Responses, Enhances Macrophage and NK Cell Activities, and Increases Survival Rates of Leukemia BALB/c Mice.

Casticin, derived from Fructus Viticis, has anticancer properties in many human cancer cells, however, there is no report to show that casticin promotes immune responses and affects the survival rate of leukemia mice in vivo. The aim of this study is to evaluate the effects of casticin on immune responses and the survival rate of WEHI-3 cells generated in leukemia mice in vivo. Animals were divided into six groups: normal control mice, leukemia control mice, mice treated with ATRA (all-trans retinoic acid), and casticin (0.1, 0.2, and 0.4 mg/kg) treated mice. All animals were treated for 14 days and then measured for body weights, total survival rate, cell markers, the weights of liver and spleen, phagocytosis of spleen cells, NK cell activities and cell proliferation. Results show that casticin did not affect animal appearances, however, it increased body weights and decreased the weights of liver at 0.2 mg/kg and 0.4 mg/kg treatment. Casticin also decreased spleen weight at 0.2 mg/kg and 0.4 mg/kg treatment, increased CD3 at 0.1, 0.2 and 0.4 mg/kg doses and increased CD19 at 0.2 mg/kg treatment but decreased CD11b and Mac-3 at 0.1, 0.2 and 0.4 mg/kg treatment. Casticin (0.1, 0.2 and 0.4 mg/kg) increased macrophage phagocytosis from PBMC (peripheral blood mononuclear cell) and peritoneal cavity. Furthermore, casticin increased NK cells' cytotoxic activity and promoted T cell proliferation at 0.1-0.4 mg/kg treatment with or without concanavalin A (Con A) stimulation, but only increased B cell proliferation at 0.1 mg/kg treatment. Based on these observations, casticin could be used as promoted immune responses in leukemia mice in vivo.

Anticancer effects of cantharidin in A431 human skin cancer (Epidermoid carcinoma) cells in vitro and in vivo.

Cantharidin (CTD), a potential anticancer agent of Traditional Chinese Medicine has cytotxic effects in different human cancer cell lines. The cytotoxic effects of CTD on A431 human skin cancer (epidermoid carcinoma) cells in vitro and in A431 cell xenograft mouse model were examined. In vitro, A431 human skin cell were treated with CTD for 24 and 48 h. Cell phase distribution, ROS production, Ca2+ release, Caspase activity and the level of apoptosis associated proteins were measured. In vivo, A431 cell xenograft mouse model were examined. CTD-induced cell morphological changes and decreased percentage of viable A431 cells via G0/G1 phase arrest and induced apoptosis. CTD-induced G0/G1 phase arrest through the reduction of protein levels of cyclin E, CDK6, and cyclin D in A431 cells. CTD-induced cell apoptosis of A431 cells also was confirm by DNA gel electrophoresis showed CTD-induced DNA fragmentation. CTD reduced the mitochondrial membrane potential and stimulated release of cytochrome c, AIF and Endo G in A431 cells. Flow cytometry demonstrated that CTD increased activity of caspase-8, -9 and -3. However, when cells were pretreated with specific caspase inhibitors activity was reduced and cell viability increased. CTD increased protein levels of death receptors such as DR4, DR5, TRAIL and levels of the active form of caspase-8, -9 and -3 in A431 cells. AIF and Endo G proteins levels were also enhanced by CTD. In vivo studies showed that CTD significantly inhibited A431 cell xenograft tumors in mice. Taken together, these in vitro and in vivo results provide insight into the mechanisms of CTD on cell growth and tumor production. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 723-738, 2017.

Kaempferol induces autophagy through AMPK and AKT signaling molecules and causes G2/M arrest via downregulation of CDK1/cyclin B in SK-HEP-1 human hepatic cancer cells.

Kaempferol belongs to the flavonoid family and has been used in traditional folk medicine. Here, we investigated the antitumor effects of kaempferol on cell cycle arrest and autophagic cell death in SK-HEP-1 human hepatic cancer cells. Kaempferol decreased cell viability as determined by MTT assays and induced a G2/M phase cell cycle arrest in a concentration-dependent manner. Kaempferol did not induce DNA fragmentation, apoptotic bodies or caspase-3 activity in SK-HEP-1 cells as determined by DNA gel electrophoresis, DAPI staining and caspase-3 activity assays, respectively. In contrast, kaempferol is involved in the autophagic process. Double-membrane vacuoles, lysosomal compartments, acidic vesicular organelles and cleavage of microtubule-associated protein 1 light chain 3 (LC3) were observed by transmission electron microscopy, LysoΤracker red staining, GFP-fluorescent LC3 assays and acridine orange staining, respectively. In SK-HEP-1 cells, kaempferol increased the protein levels of p-AMPK, LC3-II, Atg 5, Atg 7, Atg 12 and beclin 1 as well as inhibited the protein levels of CDK1, cyclin B, p-AKT and p-mTOR. Taken together, CDK1/cyclin B expression and the AMPK and AKT signaling pathways contributed to kaempferol-induced G2/M cell cycle arrest and autophagic cell death in SK-HEP-1 human hepatic cancer cells. These results suggest that kaempferol may be useful for long-term cancer prevention.

Induction of cell cycle arrest and apoptosis in human osteosarcoma U-2 OS cells by Solanum lyratum extracts.

This research focused on a Chinese herb medicine, Solanum lyratum Thunb (Solanaceae) by ethanol extracts (SLE) for investigating the molecular anticancer mechanism in vitro for exploring the means of cell death through the effects on mitochondrial function. We found that SLE induced cytotoxic effects in human osteosacroma U-2 OS cells, and these effects include cell morphological changes, a decrease of the percentage of viable cells and induction of apoptosis. The results suggest that cell death induced by SLE is closely related to apoptosis based on the observations of DAPI staining and sub-G1 phase in U-2 OS cells. Flow cytometric assays also showed that SLE promoted the production of reactive oxygen species and nitric oxide but decreased the levels of mitochondrial membrane potential and promoted the activations of caspase-8 and -9 in U-2 OS cells. SLE inhibited the level of Bcl-2 but promoted the Bax level, and both proteins led to the release of cytochrome c from mitochondria to cytosol and activation of caspase-9 and -3, resulting in the apoptotic death which is mediated through the mitochondrial pathway. Taken together, SLE was demonstrated to be effective in killing U-2 OS osteosacroma cells via the ROS-promoted and mitochondria- and caspase-dependent apoptotic pathways.

AKT serine/threonine protein kinase modulates baicalin-triggered autophagy in human bladder cancer T24 cells.

Baicalin is one of the major compounds in the traditional Chinese medicinal herb from Scutellaria baicalensis Georgi. We investigated the molecular mechanisms of cell autophagy induced by baicalin in human bladder cancer T24 cells. Baicalin inhibited cell survival as shown by MTT assay and increased cell death by trypan blue exclusion assay in a concentration-dependent manner. Baicalin did not induce apoptotic cell death in T24 cells by TUNEL and caspase-3 activity assay. Baicalin induced the acidic vesicular organelle cell autophagy marker, manifested by acridine orange (AO) and monodansylcadaverine (MDC) staining and cleavage of microtubule-associated protein 1 light chain 3 (LC3). The protein expression levels of the Atg 5, Atg 7, Atg 12, Beclin-1 and LC3-II were upregulated in T24 cells after baicalin treatment. Inhibition of autophagy by 3-methyl-adenine (an inhibitor of class III phosphatidylinositol-3 kinase; 3-MA) reduced the cleavage of LC3 in T24 cells after baicalin treatment. Furthermore, protein expression levels of phospho-AKT (Ser473) and enzyme activity of AKT were downregulated in T24 cells after baicalin treatment. In conclusion, baicalin triggered cell autophagy through the AKT signaling pathway in T24 cells.

Bufalin increases sensitivity to AKT/mTOR-induced autophagic cell death in SK-HEP-1 human hepatocellular carcinoma cells.

Bufalin is the major component of Chan-Su (a traditional Chinese medicine, TCM) extracts from the venom of Bufo bufo gargarizan. In the present study, we investigated the pharmacological mechanisms of cell cycle arrest and autophagic cell death induced by bufalin in SK-HEP-1 human hepatocellular carcinoma cells in vitro. Bufalin inhibited cell survival by MTT assay and increased cell death by trypan blue exclusion assay in a concentration-dependent manner. In addition, bufalin induced G2/M phase arrest by reducing CDK1 activity. Bufalin triggered DNA fragmentation and apoptotic cell death in SK-HEP-1 cells by DNA gel electrophoresis, TUNEL and caspase-3 activity assay, while bufalin induced autophagic cell death by double-membrane vacuoles (transmission electron microscopy, TEM), acidic vesicular organelles (acridine orange staining) and cleavage of microtubule-associated protein 1 light chain 3 (LC3). Protein expression levels of cyclin A and B, CDK1, phospho-CDK1 (Thr161), Cdc25c, phospho-Cdc25c (Ser198), phospho-AKT (Thr308), phospho-AKT (Ser473), phospho­mTOR (Ser2481) were downregulated. In contrast, protein expression levels of the Chk1, Wee1, LC3-II, Beclin-1, Atg 5, Atg 7 and Atg 12 were upregulated in SK-HEP-1 cells after bufalin treatment. Inhibition of autophagy by 3-methyladenine (an inhibitor of class III phosphatidylinositol-3 kinase; 3-MA) or bafilomycin A1 (an inhibitor of the vacuolar proton pump of lysosomes and endosomes) reduced the effect of bufalin on cell viability and enhanced the effect of bufalin on apoptosis. In conclusion, bufalin triggered autophagic cell death and G2/M phase arrest through the AKT/mTOR signaling pathway in SK-HEP-1 cells. Our findings showed that bufalin may be potentially efficacious in the treatment of human hepatocellular carcinoma.

Activations of Both Extrinsic and Intrinsic Pathways in HCT 116 Human Colorectal Cancer Cells Contribute to Apoptosis through p53-Mediated ATM/Fas Signaling by Emilia sonchifolia Extract, a Folklore Medicinal Plant.

Emilia sonchifolia (L.) DC (Compositae), an herbaceous plant found in Taiwan and India, is used as folk medicine. The clinical applications include inflammation, rheumatism, cough, cuts fever, dysentery, analgesic, and antibacteria. The activities of Emilia sonchifolia extract (ESE) on colorectal cancer cell death have not been fully investigated. The purpose of this study explored the induction of apoptosis and its molecular mechanisms in ESE-treated HCT 116 human colorectal cancer cells in vitro. The methanolic ESE was characterized, and γ-humulene was formed as the major constituent (63.86%). ESE induced cell growth inhibition in a concentration- and time-dependent response by MTT assay. Apoptotic cells (DNA fragmentation, an apoptotic catachrestic) were found after ESE treatment by TUNEL assay and DNA gel electrophoresis. Alternatively, ESE stimulated the activities of caspase-3, -8, and -9 and their specific caspase inhibitors protected against ESE-induced cytotoxicity. ESE promoted the mitochondria-dependent and death-receptor-associated protein levels. Also, ESE increased ROS production and upregulated the levels of ATM, p53, and Fas in HCT 116 cells. Strikingly, p53 siRNA reversed ESE-reduced viability involved in p53-mediated ATM/Fas signaling in HCT 116 cells. In summary, our result is the first report suggesting that ESE may be potentially efficacious in the treatment of colorectal cancer.

Cucurbitacin E Induces G(2)/M Phase Arrest through STAT3/p53/p21 Signaling and Provokes Apoptosis via Fas/CD95 and Mitochondria-Dependent Pathways in Human Bladder Cancer T24 Cells.

Cucurbitacin E, a tetracyclic triterpenes compound extracted from cucurbitaceous plants, has been shown to exhibit anticancer and anti-inflammatory activities. The purpose of this study was to elucidate whether cucurbitacin E promotes cell cycle arrest and induces apoptosis in T24 cells and further to explore the underlying molecular mechanisms. The effects of cucurbitacin E on T24 cell's growth and accompanied morphological changes were examined by MTT assay and a phase-contrast microscope. DNA content, mitochondrial membrane potential (ΔΨ(m)) and annexin V/PI staining were determined by flow cytometry. The protein levels were measured by Western blotting. Our results demonstrated that cucurbitacin E-induced G(2)/M arrest was associated with a marked increase in the levels of p53, p21 and a decrease in phospho-signal transducer and activator of transcription 3 (STAT3), cyclin-dependent kinase 1 (CDK1) and cyclin B. Cucurbitacin E-triggered apoptosis was accompanied with up-regulation of Fas/CD95, truncated BID (t-BID) and a loss of ΔΨ(m), resulting in the releases of cytochrome c, apoptotic protease activating factor 1 (Apaf-1) and apoptosis-inducing factor (AIF), and sequential activation of caspase-8, caspase-9, and caspase-3. Our findings provided the first evidence that STAT3/p53/p21 signaling, Fas/CD95 and mitochondria-dependent pathways play critical roles in cucurbitacin E-induced G(2)/M phase arrest and apoptosis of T24 cells.

Emodin Induces Apoptotic Death in Murine Myelomonocytic Leukemia WEHI-3 Cells In Vitro and Enhances Phagocytosis in Leukemia Mice In Vivo.

Emodin is one of major compounds in rhubarb (Rheum palmatum L.), a plant used as herbal medicine in Chinese population. Although many reports have shown that emodin exhibits anticancer activity in many tumor cell types, there is no available information addressing emodin-affected apoptotic responses in the murine leukemia cell line (WEHI-3) and modulation of the immune response in leukemia mice. We investigated that emodin induced cytotoxic effects in vitro and affected WEHI-3 cells in vivo. This study showed that emodin decreased viability and induced DNA fragmentation in WEHI-3 cells. Cells after exposure to emodin for 24 h have shown chromatin condensation and DNA damage. Emodin stimulated the productions of ROS and Ca(2+) and reduced the level of ΔΨ(m) by flow cytometry. Our results from Western blotting suggest that emodin triggered apoptosis of WEHI-3 cells through the endoplasmic reticulum (ER) stress, caspase cascade-dependent and -independent mitochondrial pathways. In in vivo study, emodin enhanced the levels of B cells and monocytes, and it also reduced the weights of liver and spleen compared with leukemia mice. Emodin promoted phagocytic activity by monocytes and macrophages in comparison to the leukemia mice group. In conclusions, emodin induced apoptotic death in murine leukemia WEHI-3 cells and enhanced phagocytosis in the leukemia animal model.

Diallyl trisulfide (DATS) inhibits mouse colon tumor in mouse CT-26 cells allograft model in vivo.

Our earlier studies showed that DATS induced apoptosis in human colon cancer HT29 and colo 205 cell lines in vitro. However, there is no report to show that DATS induced apoptosis in vitro and inhibited CT26 cancer cells in vivo on a murine allograft animal model. In vitro studies, the results indicated that DATS induced morphological changes and induction of apoptosis in CT26 cells. In vivo studies, CT26 cancer cells were implanted into BALB/c mice and groups of mice were treated with vehicle, DATS (10 and 50 mg/kg of body weight). DATS were injected once per four days intraperitoneally (i.p.), with treatment starting 4 weeks prior to cells inoculation. Treatment with vehicle or with 10 and 50 mg/kg of DATS resulted in a reduction in tumor volume and weight. Tumor volume and total hemoglobin in allograft mice treated with 50 mg/kg DATS were significantly smaller than that in the control group. These findings indicated that DATS inhibits tumor growth in an allograft animal model. Thus, DATS may represent a colon cancer preventive agent and can be used in the future.

Cantharidin induces G2/M phase arrest and apoptosis in human colorectal cancer colo 205 cells through inhibition of CDK1 activity and caspase-dependent signaling pathways.

Cantharidin (CTD) is a traditional Chinese medicine and an effective component isolated from blister beetle, and it has been demonstrated to have anticancer, antibiotic, antivirus activities and immune-regulated functions. It has been reported that CTD induces cell cycle arrest and apoptosis in many cancer cell types. However, there are no reports showing that CTD would induce cell cycle arrest and apoptosis in human colorectal cancer colo 205 cells. In this study, we studied colo 205 cells which were treated with CTD and demonstrated its molecular mechanisms in apoptosis. CTD induced growth inhibition, G2/M phase arrest and apoptosis in colo 205 cells. The IC50 is 20.53 µM in CTD-treated colo 205 cells. DAPI/TUNEL double staining and Annexin V assays were used to confirm the apoptotic cell death in colo 205 cells after CTD exposure. CTD caused G2/M arrest, down-regulated CDK1 activity, decreased Cyclin A, Cyclin B, CDK1 and increased CHK1 and p21 protein levels. Colorimetric assays also indicated that CTD triggered activities of casapse-8, -9 and -3 in colo 205 cells. Moreover, CTD increased ROS production and decreased the level of mitochondrial membrane potential (ΔΨm) in colo 205 cells. Consequently, CTD-induced growth inhibition was significantly attenuated by N-acetylcysteine (NAC, a scavenger). CTD stimulated the protein levels of Fas/CD95, the caspase-3 active form, cytochrome c and Bax, but suppressed the protein levels of pro-caspase-8, pro-caspase-9 and Bcl-2, determined by Western blot analysis. Based on our observations, we suggest that CTD is able to induce G2/M phase arrest and apoptosis in colo 205 cells through inhibition of CDK1 activity and caspase-dependent signaling pathways.

Triptolide induces apoptosis in human adrenal cancer NCI-H295 cells through a mitochondrial-dependent pathway.

Triptolide, the main active component obtained from Tripterygium wilfordii Hook. f, has been reported to present potent immunosuppressive and anti-inflammatory biological activities. It has been previously shown that due to the cytotoxicity of triptolide it has a limited use in the clinic. Although numerous studies have shown that triptolide induced apoptosis in many human cancer cells there is no report to show triptolide-induced apoptosis in human adrenal cancer cells. We treated the human adrenal cancer NCI-H295 cells with triptolide in vitro and investigated its cytotoxic effects. The cytotoxicity was examined and quantitated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay and the viability of inhibition and apoptosis was determined by flow cytometric assay, using propidium iodide (PI) staining for apoptosis. Flow cytometric assay also used for the determination of reactive oxygen species (ROS) production and the levels of mitochondrial membrane potential (ΔΨm), and the caspase-3 and -9 activation in NCI-H295 cells. Western blotting was used for examining the changes of apoptotic associated proteins. The results indicated that triptolide induced cytotoxicity (decreased the percentage of viable cells) and induced sub-G1 phase (apoptosis) occurring in NCI-H295 cells and those effects are dose-dependent. Results also showed that triptolide promoted the production of ROS and decreased the levels of ΔΨm in examined NCI-H295 cells. The results showed that triptolide promoted the levels of cytochrome c, Apaf-1, AIF, Endo G, caspase-9 and -3 which were analyzed by Western blotting. These results suggest that triptolide is able to induce apoptosis on NCI-H295 cells through the mitochondrial-dependent signal pathway.

The quinolone derivative CHM-1 inhibits murine WEHI-3 leukemia in BALB/c mice in vivo.

CHM-1 [2-(2-fluorophenyl)-6,7-methylenedioxyquinolin-4-one] is a quinolone derivative that has been reported to induce apoptosis and inhibit invasion of cancer cells. However, there is no available information to address the effects of CHM-1 on leukemia cells in vivo. Therefore, the present study examined the effects of CHM-1 using a mouse model of leukemia. We established leukemia in mice by injecting WEHI-3 cells into BALB/c mice. Mice were then treated with or without CHM-1 (5 and 10 mg/kg). CHM-1 promoted the total survival rate of leukemic mice and these effects were dose-dependent. CHM-1 increased body weight and decreased spleen weight, but did not affect liver weight. The levels of cell markers Mac-3 and CD11b were reduced by CHM-1, indicating that the differentiation of macrophage precursor cells was inhibited. Levels of CD3 and CD19 were induced by CHM-1, suggesting that the differentiation of precursors of T and B cells was promoted in PBMC. Results of the present study indicate that CHM-1 has an inhibitory effect on leukemia induced in mice in vivo and warrants further study as to the mechanisms and effects in other types of cancer.

Rhein induced apoptosis through the endoplasmic reticulum stress, caspase- and mitochondria-dependent pathways in SCC-4 human tongue squamous cancer cells.

Rhein, an anthraquinone compound, can be found in the rhizome of rhubarb, a traditional Chinese medicine herb showing antitumor activity. In this study, it was observed that rhein induced S-phase arrest through the inhibition of p53, cyclin A and E and it induced apoptosis through the endoplasmic reticulum stress by the production of reactive oxygen species (ROS) and Ca2+ release, mitochondrial dysfunction, and caspase-8, -9 and -3 activation in human tongue cancer cell line (SCC-4). The most efficient induction of apoptosis was observed at 30 microM for 24 h. Mechanistic analysis demonstrated that rhein induced changes in the ratio of Bax/Bcl-2 based on the decrease of Bcl-2 levels, the loss of mitochondrial membrane potential, cytochrome c release from the mitochondria and the activation of caspase-9 and -3. The data demonstrated that rhein induces apoptosis in SCC-4 cells via caspase, ROS and mitochondrial death pathways.