|
COPYRIGHT 2007 The Townsend Letter Group
Introduction
Objective of the Study
The aim of this study was to investigate the combined action of Haelan 951 and the drug doxorubicin on the breast cancer cell line BT474. The analyses mainly focused on how these substances altered the expression of selected genes as a consequence of treatment. In succession to a former study done at Gemeinschaftspraxis Recklinghausen, which covered the effects of Haelan 951 on four different tumor cell lines, the present work should elucidate the following:
* the effects of doxorubicin in monotherapy on the expression of selected genes in cultured BT474 cells;
* the effects of doxorubicin combined with Haelan 951 on the expression of the selected genes in BT474 cells;
* the possibility of reducing the dosage of doxorubicin when combined with Haelan 951 to achieve comparable efficacy of higher doses of doxorubicin alone.
Characteristics of Doxorubicin
Doxorubicin (adriamycin) is pharmacologically an antibiotic cytostatic agent and belongs to the substance-class of anthracyclines. It is used as a chemotherapeutic drug for treatment of metastatic breast cancer and several other tumor types. Anthracyclines are DNA intercalating agents and interfere with the function of topoisomerase II. Topoisomerases are nuclear enzymes that regulate DNA topology during multiple DNA functions (including transcription, replication, and recombination), mediated by cleavage and relegation of DNA strands. Drug interference with these functions leads to lethal DNA damage like double-strand breaks (Wiese L, 2001).
Tumor cells with an enhanced proliferation rate and impaired repair functions are particularly vulnerable to cytostatic drugs. However, these drugs are also harmful to rapidly proliferating normal cells like bone marrow or hair follicle, leading to serious side effects. Moreover, anthracyclines like doxorubicin are mutagenic and teratogenic.
Characteristics of Haelan 951
Haelan 951 is a fluidic, concentrated soy protein beverage, manufactured from specially cultured soybeans. The phytochemical substances contained in the soybeans are broken down into their molecular units by a patented fermentation process to achieve an improved bioavailability for the human organism. For one bottle of Haelan 951, 12 kg of soybean are processed.
Among other components, Haelan 951 contains the bioactive isoflavones genistein, daidzein, and genistin, as well as the saturated branched-chain fatty acid MDT-13 [13-methyl-tetradecanoic acid] (Kousidou O et al., 2006). The active agent MDT-13 has been shown to induce apoptosis in tumor cells and to possess antitumor activity (Yang Z et al., 2000).
Description and Function of the Selected Genes of This Study
The study focused on induction of differential gene expression by treatment of the cell line BT474 with test-substances doxorubicin and/or Haelan 951. The genes included in the analysis are summarized in Table 1.
Material and Methods
Test-Substances/Drugs
Haelan 951: Organic NON-GMO Soy. Fermented Soy Beverage. Made in China. Distributed by Haelan Products, Inc., 18568 142nd Ave. N.E., Bldg. F. Woodinville, WA 98072 USA; www.Haelan951.com.
Doxorubicin: Doxorubicin 10 HEXAL solution. Active agent: doxorubicin hydrochloride 10 mg in 5 ml bottle (2 [micro]g/[micro]l). Antibiotic, anti-tumor agent. HEXAL AG. 83607 Holzkirchen, Germany.
Cell Lines
The cell line BT474 was purchased from the German National Resource Centre for Biological Material, DSMZ (Deutsche Stammsammlung fur Mikroorganismen und Zellinien). The characteristics of the BT474 cell line are summarized in Table 2.
Culturing Conditions of Cell Lines
The BT474 cells were cultured according to the recommendations of the supplier (Table 2). Cells were precultured in tissue culture flasks and harvested by trypsination when subconfluent. The number of cells was determined by microscopic visual counting in a Neubauer hemocytometer. The cell suspensions were then distributed in 24-well tissue culture plates (Cellstar, Greiner, Germany) at a density of 1 x 105 cells per well. Medium containing the test-substances was added, and the cells were grown at 37[degrees]C, 5% C02 for three days (72h). Afterwards, cells were harvested by trypsination and ribonucleic acids extracted. The culturing was regularly monitored microscopically for morphologic changes induced by the test-substances.
Extraction of Ribonucleic Acids (RNA) and Reverse Transcription
Total RNA was extracted from the cells with the commercial Qiamp RNA Blood Minikit (Qiagen, Germany), employing Qia-shredder- and Qia-spin-columns according to the protocol of the manufacturer. Eluted total RNA was reverse transcribed into cDNA using...
Read the full article for free courtesy of your local library.
|
Bookmark this article
Print this article
Link to this article
Email this article
Digg It!
Add to del.icio.us
RSS
