Anti-proliferative effect of leaf extracts of Eucalyptus citriodora against human cancer cells in vitro and in vivo.

Six different extracts from Eucalyptus citriodora leaves were investigated for their anticancer effect. Extracts were prepared using a range of polar and non-polar solvents to leach out maximum active components. Phytochemical analysis of the extracts revealed the presence of anthraquinones, cardiac glycosides, flavonoids, saponins and tannins. Cytotoxic activity of different extracts was tested in vitro against seven human cancer cell lines from seven different tissues, such as SW-620 (colon), HOP-62 (lung), PC-3 (prostate), OVCAR-5 (ovary), HeLa (cervix), IMR-32 (neuroblastoma) and HEP-2 (liver). The ethyl acetate, chloroform and 50% methanolic extract displayed highest anti-proliferative effect in a dose-dependent manner. In vivo anti-tumor activity was evaluated against murine tumor (solid) model of Ehrlich ascites carcinoma and Sarcoma 180. The results showed that ethyl acetate and aqueous extracts suppressed the growth of Ehrlich ascites carcinoma (29.79% and 18.48%, respectively), but showed little growth inhibition in case of Sarcoma 180 (13. 86% and 8.57%, respectively). The activity might be due to the flavonoids, tannins and saponins that are present in all the extracts of the plant. Further investigation is required for the isolation of active principle(s) from the ethyl acetate extract, which has shown significant in vitro and in vivo anticancer potential.

Effect of Small Dose of Radiation on Induction of Apoptosis in Murine Tumors / 대한방사선종양학회지

PURPOSE: To investigate the presence of adaptive response by low dose radiation in murine tumors in relation to radiation induced apoptosis as well as related mechanism. MATERIALS AND METHODS: Syngeneic murine tumors, OCa-I and HCa-I, were given 0.05 Gy pretreatment followed by therapeutic dose of 25 Gy radiation. Induction of apoptosis was analyzed for each treatment group. Regulating molecules of apoptosis, p53, Bcl-2, Bax, Bcl-X, were also analyzed by Western blotting. RESULTS: In 0.05 Gy pretreatment group of OCa-I, 25 Gy-induced apoptosis per 1000 cells was 229, which was estimated at 30% lower level than the expected (p<0.05). In contrast, this reduction in radiation induced apoptosis was not seen in HCa-I. In the expression of apoptosis regulating molecules, p53 increased in both tumors in response to radiation. Bcl-2 and Bax did not show significant change in both tumors however, the expression of Bcl-2 surpassed that of Bax in 0.05 Gy pretreatment group of OCa-I. Bcl-X was not expressed in OCa-I. In HCa-I, Bcl-X showed increased expression even with 0.05 Gy. CONCLUSION: Adaptive response by low dose radiation is shown in one murine tumor, OCa-I, in relation to radiation induced apoptosis. Apoptosis regulating molecules including Bcl-2/Bax and Bcl-X, appear to related. This study shows an evidence that adaptive response is present, but not a generalized phenomenon in vivo.

Potentiation of Antitumor Effect of Radiotherapy by Recombinant Tumor Necrosis Factor-alpha / 대한방사선종양학회지

PURPOSE: To determine whether TNF-alpha increases the antitumor effect of radiotherapy in murine syngeneic tumor system. MATERIALS AND METHODS: Syngeneic murine tumors of MCa-K or MCa-4 (mammary carcinoma), OCa-I (ovarian carcinoma), or HCa-I (hepatocarcinoma were grown in hind legs of C3Hf/HeJ mice. When tumors were grown to 6 mm in mean diameter, mice were treated with TNF-alpha, radiation, or combination of the both. Gamma-radiation was given as a single dose of 30 Gy for HCa-I and 15 Gy for other tumors using Cobalt-60 teletherapy unit. A novel TNF-alpha mutein developed in Korea, was intraperitoneally administered daily at a dose of 10 microgram per mouse for 7 days. In combination of radiation and TNF-alpha, the drug was started 1 hour after radiation. Tumor growth delay assay was used to measure the tumor response to the treatment. RESULTS: Among 4 tested tumors, TNF-alpha alone showed significant antitumor activity in MCa-K and OCa-I tumors, which showed absolute growth delay (AGD) of 5.0 days and 6.5 days, respectively. In combination with radiation, TNF-alpha showed significant delay of AGD (41.1 days) in OCA-I compared to AGDs of TNF-alpha alone and radiation, i.e., 6.5 days and 26.9 days, respectively (p<0.05). Enhancement factor was 1.29 in OCa-I, which showed supraadditive effect. TNF-alpha did not show significant delay of AGDs in the remaining 3 tumors compared to AGDs of TNF-alpha alone and radiation. CONCLUSIONS: TNF-alpha alone showed antitumor effects in MCa-K and OCa-I. In combination with radiation, TNF-alpha acted in supraadditive way in OCa-I only. The results of this study imply that the combination of TNF-alpha and radiation has different therapeutic potential depending on tumor model and further study is advocated.

Construction of retroviral vectors to induce strong hepatoma cell-specific expression of murine tumor necrosis factor gene and the hepatoma-specifie gene therapy mediated by the recombinant retroviral vectors / 中华消化杂志

Murine tumor necrosis factor(mTNF)cDNA was inserted into the polylinker site of MNSM retroviral vector to create pMNSM-SV40-mTNF. Albumin enhancer/promoter (Alb e/p) sequence was used to replace SV40 early region promoter of pMNSM-SV40-mTNF vector to create pMNSM-Alb e/p-mTNF recombinant retroviral vector. The retroviral constructs were introduced into amphotropic retroviral packaging cells PA317. Production of the recombinant retroviruses was accomplished by the lipofectamine-mediated gene transfer procedure. The murine tumor cells were infected with the retroviruses in the presence of polybrene. Dot hybridization of total RNA from modified tumor cell with mTNF cDNA probe and mTNF bioassay demonstrated that transcription and expression of mTNF gene drived by Alb e/p were markedly high in the hepatoma cells which produced albumin, and inhibited in the non-hepatoma tumor cells. The hepatoma cells modified with mTNF gene lost its tumorgenicity and significantly inhibited the growth of the parental hepatoma in vivo. High-titer MNSM-Alb e/p-mTNF retroviruses or the high-titer retroviruses producing packaging cells, after intra-tumoral injection, specifcally inhibited the growth of the hepatoma, and significantly prolonged the survival period of the hepatoma-loaded mice. Biopsy and immunohistochemical assay of the hepatoma during in vivo gene therapy, showed the occurrence of extensive tumor necrosis, bleeding, and CD8+, CD25+, CD4+ lymphocytic infiltration and fibrosis.