The Role of HS-1200 Induced Autophagy in Oral Cancer Cells

Bile acids and synthetic bile acid derivatives induce apoptosis in various kinds of cancer cells and thus have anticancer properties. Recently, it has been suggested that autophagy may play an important role in cancer therapy. However, few data are available regarding the role of autophagy in oral cancers and there have been no reports of autophagic cell death in OSCCs (oral squamous cell carcinoma cells) induced by HS-1200, a synthetic bile acid derivative. We thus examine whether HS-1200 modulates autophagy in OSCCs. Our findings indicate that HS-1200 has anticancer effects in OSCCs, and we observed in these cells that autophagic vacuoles were visible by monodansylcadaverine (MDC)and acridine orange staining. When we analyzed HS-1200-treated OSCC cells for the presence of biochemical markers, we observed that this treatment directly affects the conversion of LC-3II, degradation of p62/SQSTM1 and full-length beclin-1, cleavage of ATG5-12 and the activation of caspase. An autophagy inhibitor suppressed HS-1200-induced cell death in OSCCs, confirming that autophagy acts as a pro-death signal in these cells. Furthermore, HS-1200 shows anticancer activity against OSCCs via both autophagy and apoptosis. Our current findings suggest that HS-1200 may potentially contribute to oral cancer treatment and thus provide useful information for the future development of a new therapeutic agent.

HS-1200 Overcomes the Resistance Conferred by Bcl-2 in Human Leukemic U937 Cells

Bcl-2 protects tumor cells from the apoptotic effects of various anti-neoplastic agents. Increased expression of Bcl-2 has been associated with a poor response to chemotherapy in various malignancies, including leukemia. Hence, bypassing the resistance conferred by anti-apoptotic factors such as Bcl-2 represents an attractive therapeutic strategy against cancer cells, including leukemic cells. This study was undertaken to examine whether the anticancer drug, cisplatin and the synthetic chenodeoxycholic acid (CDCA) derivative, HS-1200 show anti-tumor activity in U937 and U937/Bcl-2 cells. Viability assays revealed that HS-1200 overcomes the resistance conferred by Bcl-2 in human leukemic U937 cells. Various apoptosis assessment assays further demonstrated that HS-1200 overcomes the resistance conferred by Bcl-2 in human leukemic U937 cells by inducing apoptosis. In addition HS-1200, but not cisplatin, overcomes the anti-apoptotic effects of Bcl-2 in Bcl-2 over-expressing human leukemic cells (U937/Bcl-2 cells). Notably, we observed that the HS-1200-induced formation of mature promyelocytic leukemia (PML) nuclear bodies (NBs) correlates with a suppression of the anti-apoptotic effects of Bcl-2 in human leukemic cells over-expressing this protein (U937/Bcl-2 cells). Furthermore, HS-1200 was found to induce the association between PML and SUMO-1, Daxx, Sp100, p53 or CBP in the aggregated PML-NBs of U937/Bcl-2 cells. Thus, PML protein and the formation of mature PML-NBs could be considered as therapeutic targets that may help to bypass the resistance to apoptosis conferred by Bcl-2. Elucidating the exact mechanism by which PML regulates Bcl-2 will require further work.

Apoptotic Effect of Co-treatment with Chios Gum Mastic and HS-1200 on G361 Human Melanoma Cell Line / 대한해부학회지

Chios gum mastic (CGM) is a resinous exudate obtained from the stem and the main leaves of Pistacia lenticulus tree native to Mediterranean areas. Recently it reported that CGM induce apoptosis in a few cancer cells in vitro. Bile acids and their synthetic derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. It has been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis-inducing activity on various cancer cells in vitro. This study was undertaken to investigate the synergistic apoptotic effect of cotreatment with a natural product, CGM and a CDCA derivative, HS-1200 on G361 human melanoma cells. To investigate whether the co-treatment of CGM and HS-1200 compared with each single treatment efficiently reduced the viability of G361 cells, MTT assay was conducted. To investigate augmentation of apoptosis in G631 cells co-treated with CGM and HS-1200, DNA electrophoresis, Hoechst staining, proteasome activity assay, flow cytometry, Westen blot analyses, immunofluorescent staining and confocal microscopy were performed. In this study, G361 cells co-treated with CGM and HS-1200 showed several lines of apoptotic manifestation such as nuclear condensations, DNA fragmentation, the reduction of MMP and proteasome activity, the decrease of DNA content, the release of cytochrome c into cytosol, the translocation of AIF and DFF40 (CAD) onto nuclei, activation of caspase-9, caspase-3, PARP and DFF45 (ICAD), and up-regulation of Bax whereas each single treated G361 cells did not. Although the single treatment of 40 micro/mL CGM or 25 micro HS-1200 for 24 hrs did not induce apoptosis, the co-treatment of them induced prominently apoptosis. Therefore, combination therapy of CGM and HS-1200 could be considered, in the future, as an alternative therapeutic strategy for human melanoma.

A Synthetic Chenodeoxycholic Acid Derivative, HS-1200-induced Apoptosis of RBL-2H3 Cells / 대한해부학회지

Bile acids and synthetic bile acid derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. Although synthetic chenodeoxycholic acid (CDCA) derivatives have been demonstrated to induce apoptosis of various cancer cells, there is no report on their effect on RBL-2H3 basophilic leukemia cell line to date. Therefore, this study was undertaken to examine in vitro effects of cytotoxicity and growth inhibition, and the molecular mechanism underlying induction of apoptosis in RBL-2H3 cells treated with a synthetic CDCA derivative, HS-1200. The viability and the growth inhibition of RBL-2H3 cells were assessed by MTT assay and clonogenic assay respectively. The Hoechst staining and DNA electrophoresis were conducted to observe RBL-2H3 cells undergoing apoptosis. RBL-2H3 cells were treated with HS-1200, and Western blotting, immunocytochemistry, confocal microscopy, DNA hypoploidy assay, MMP activity and proteasome activity were performed. HS-1200 treatment of RBL-2H3 cells resulted in a time- and does-dependent decrease of cell viability and a does-dependent inhibition of cell growth, and induced apoptotic cell death. Furthermore, HS-1200 treatment result in the alteration of G1 cell cycle-related proteins. And tested RBL-2H3 cells showed several lines of apoptotic manifestation.We presented data indicating that HS-1200 induces apoptois via the proteasome, mitochondria and caspase pathway, and induces the alteration of the G1 cell cycle-related proteins in RBL-2H3 cells. Therefore our data provide the possibility that HS-1200 could be as a novel therapeutic strategy in the allergy treatment.

Apoptotic Effect of Co-Treatment with a Natural Product, Chios Gum Mastic, and a Synthetic Chenodeoxycholic Acid Derivative, HS-1200, on Human Osteosarcoma Cells / 체질인류학회지

Chios gum mastic (CGM) is a resinous exudate obtained from the stem and the main leaves of Pistacia lenticulus tree native to Mediterranean areas. Recently it reported that CGM induced apoptosis in a few cancer cells in vitro. It has been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis-inducing activity on various cancer cells in vitro. This study was undertaken to investigate the synergistic apoptotic effect of co-treatment with a natural product, CGM and a CDCA derivative, HS-1200 on human osteosarcoma (HOS) cells. To investigate whether the co-treatment of CGM and HS-1200 compared with each single treatment efficiently reduced the viability of HOS cells, MTT assay was conducted. Induction and augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining and DNA hypoploidy, Westen blot analysis and immunofluorescent staining were performed to study the alterations of the expression level and translocation of apoptosis-related proteins in co-treatment. Furthermore, proteasome activity and mitochondrial membrane potential (MMP) change were also assayed. In this study, HOS cells co-treated with CGM and HS-1200 showed several lines of apoptotic manifestation whereas each single treated HOS cells did not. Although the single treatment of 40 microgram/mL CGM or 25 micrometer HS-1200 for 24 h did not induce apoptosis, the cotreatment of them induced prominently apoptosis. Therefore our data provide the possibility that combination therapy of CGM and HS-1200 could be considered as a novel therapeutic strategy for human osteosarcoma.

Synthetic Chenodeoxycholic Acid Derivative HS-1200-induced Apoptosis of Human Melanoma Cells / 체질인류학회지

Bile acids and their synthetic derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. It has been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis-inducing activity on various cancer cells in vitro. It wasn't discovered those materials have apoptosis-inducing effects on G361 human melanoma cells. The present study was done to examine the synthetic bile acid derivatives, HS-1199 and HS-1200, induced apoptosis on G361 cells and such these apoptosis events. The viability of G361 cells was assessed by the MTT assay. Induction of apoptosis was confirmed by DNA electrophoresis and Hoechst staining. Westen blot analysis and immunofluorescent staining were performed to study the alterations in expression level and translocation of apoptosis-related proteins. Proteasome activity and mitochondrial membrane potential (MMP) change were also assayed. Tested G361 cells showed several lines of apoptotic manifestation such as activation of caspase-3, DFF and PARP, DNA degradation (HS-1200 only), nuclear condensation, inhibition of proteasome activity, reduction of mitochondrial membrane potential, and the release of cytochrome c and AIF to cytosol. Between two synthetic derivatives, HS-1200 showed stronger apoptosis-inducing effect than HS-1199 did. Taken collectively, we here demonstrated for the first time that synthetic CDCA dedrivatives induce apoptosis of human melanoma cells through the proteasome, mitochondria and caspase pathway. Therefore our data provide the possibility that HS-1200 could be considered as a novel therapeutic strategy for human melanoma cells from its powerful apoptosis-inducing activity.

A Novel Chenodeoxycholic Derivative HS-1200 Enhances Radiation-induced Apoptosis in Human MCF-7 Breast Cancer Cells / 대한방사선종양학회지

PURPOSE: To examine whether a synthetic bile acid derivatives (HS-1200) sensitizes the radiation-induced apoptosis in human breast cancer cells (MCF-7) and to investigate the underlying mechanism. MATERIALS AND MEHTODS: Human breast cancer cells (MCF-7) in exponential growth phase were treated with HS-1200 for 24 hours at 37degrees C with 5% CO2 in air atmosphere. After removal of HS-1200, cells were irradiated with 2~8 Gy X-ray, and then cultured in drug-free media for 24-96 hours. The effect of radiation on the clonogenicity of MCF-7 cells was determined with clonogenic cell survival assay with 16muM of HS-1200. The induction of apoptosis was determined using agarose gel electrophoresis and Hoechst staining. The expression level of apoptosis-related molecules, such as PARP, Bax, Bcl-2, Bak and AIF, were assayed by Western blotting analysis with 40muM of HS-1200 combined with 8 Gy irradiation. To examine the cellular location of cytochrome c, bax and AIF immunofluorescent stainings were undertaken RESULTS: Treatment of MCF-7 cells with 40muM of HS-1200 combined with 8 Gy irradiation showed several changes associated with enhanced apoptosis by agarose gel electrophoresis and Hoechst staining. HS-1200 combined with 8 Gy irradiation treatment also enhanced production of PARP cleavage products and increased Bax/Bcl-2 ratio by Western blotting. Loss of mitochondrial membrane potential (delta psi m) and increased cytochrome c staining indicated that cytochrome c had been released from the mitochondria in HS-1200 treated cells. CONCLUSION: We demonstrated that combination treatment with a synthetic chenodeoxycholic acid derivative HS-1200 and irradiation enhanced radiation-induced apoptosis of human breast cancer cells (MCF-7). We suggest that the increased Bax/Bcl-2 ratio in HS-1200 co-treatment group underlies the increased radiosensitivity of MCF-7 cells. Further futures studies are remained elusive.