title: Effects of two disiloxanes ALIS-409 and ALIS-421 on chemoprevention in model experiments.
abstract: Morpholino-disiloxane (ALIS-409) and piperazino-disiloxane (ALIS-421) compounds were developed as inhibitors of multidrug resistance of various types of cancer cells. In the present study, the effects of ALIS-409 and ALIS-421 compounds were investigated on cancer promotion and on co-existence of tumor and normal cells. The two compounds were evaluated for their inhibitory effects on Epstein-Barr virus immediate-early antigen (EBV-EA) expression induced by tetradecanoyl-phorbol-acetate (TPA) in Raji cell cultures. The method is known as a primary screening test for antitumor effect, below the (IC50) concentration. ALIS-409 was more effective in inhibiting EBV-EA (100 μg/ml) and tumor promotion, than ALIS-421, in the concentration range up to 1000 μg/ml. However, neither of the compounds were able to reduce tumor promotion significantly, expressed as inhibition of TPA-induced tumor antigen activation. Based on the in vitro results, the two disiloxanes were investigated in vivo for their effects on mouse skin tumors in a two-stage mouse skin carcinogenesis study. The application of dimethyl-benzanthracene (DMBA; 390 nmol) as a tumor initiator was followed by exposure to TPA (1.7 nmol/l) as a tumor promoter. The experiments showed that ALIS-409 at a concentration of 85 nmol/l had a weak EBV-EA inhibitory effect in vitro and a moderate antitumor activity, compared to the positive control of DMBA plus TPA-treated mice. Flow cytometry by differential staining demonstrated interactions in co-cultures of MCF7 breast cancer and MRC5 human lung fibroblasts. The growth rate of tumor cells in mixed populations of MCF7 breast cancer and MRC5 normal fibroblast cells was reduced in the presence of ALIS-409, as compared to the control non-treated cell populations. The two disiloxanes were moderately-effective in chemoprevention in DMBA-induced and TPA-promoted in vivo tumor formation. Authors suggest that the inhibition of tumor cell and fibroblast interaction by ALIS409 might have some perspective in the development of anti-stromal therapy.
authors: Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan.
authors: Harukuni
authors: H
authors: Tokuda
authors: Takashi
authors: T
authors: Maoka
authors: Nobutaka
authors: N
authors: Suzuiki
authors: Judit
authors: J
authors: Hohmann
authors: Andrea
authors: A
authors: Vasas
authors: Helga
authors: H
authors: Engi
authors: Ilona
authors: I
authors: Mucsi
authors: Ulrike
authors: U
authors: Olszewski
authors: Gerhard
authors: G
authors: Hamilton
authors: Leonard
authors: L
authors: Amaral
authors: Joseph
authors: J
authors: Molnar
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000633:toxicity; D000818:Animals; D000956:Antigens, Viral / Q000378:metabolism; D001943:Breast Neoplasms / Q000473:pathology*; D002273:Carcinogens / Q000633:toxicity; D002478:Cells, Cultured; D018920:Coculture Techniques; D004195:Disease Models, Animal; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D009025:Morpholines / Q000627:therapeutic use*; D010212:Papilloma / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D010879:Piperazines / Q000627:therapeutic use*; D012833:Siloxanes / Q000627:therapeutic use*; D012878:Skin Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity
chemical_list: C528072:1,3-dimethyl-1,3-(4-fluorophenyl)-1,3-(3-butyl-(1-piperazinyl)propyl)-1,3-disiloxane; C528071:1,3-dimethyl-1,3-p-fluorophenyl-1,3-(3-morpholinopropyl)-1,3-disiloxane; D000956:Antigens, Viral; D002273:Carcinogens; C033305:Epstein-Barr virus early antigen; D009025:Morpholines; D010879:Piperazines; D012833:Siloxanes; D015127:9,10-Dimethyl-1,2-benzanthracene; D013755:Tetradecanoylphorbol Acetate
keywords: Disiloxanes; EBV-induced early antigen; anti-promotion; chemoprevention; co-existence of tumor and normal cells; two-stage mouse skin carcinogenesis