Cell lines

HL-60, PC-3, DU145 and LNCaP cells

Preparation method

The solubility of this compound in DMSO is > 10.85 mg/mL. General tips for obtaining a higher concentration: Please warm the tube at 37 ℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below - 20 ℃ for several months.

Reacting condition

0.005 ~ 50 μM; 12 hrs

Applications

In H HL-60, PC-3, DU145 and LNCaP cells, Beta-Lapachone at the doses of 1 ~ 5 μM arrested cells in the G0/G1 phase of the cell cycle. Moreover, Beta-Lapachone induced apoptosis before or at the early stage of DNA synthesis, in a p53-independent manner. The mechanism of Beta-Lapachone-induced apoptosis might be through locking Topo I onto DNA and blocking replication fork movement.

Animal models

Nude mice bearing human ovarian cancer 36M2 cells

Dosage form

25 ~ 50 mg/kg; i.p.

Applications

In nude mice bearing human ovarian cancer 36M2 cells, Beta-Lapachone treatment (50 mg/kg) potently inhibited tumor growth. The combination of Beta-Lapachone and Taxol caused a synergistic induction of apoptosis. In addition, mice treated with both drugs appeared to be healthy without reduction in body weight. No gross abnormalities in internal organs were observed from autopsy as well.

Other notes

Please test the solubility of all compounds indoor, and the actual solubility may slightly differ with the theoretical value. This is caused by an experimental system error and it is normal.

Beta-Lapachone is an inhibitor of DNA topoisomerase I [1].

Beta-Lapachone is found to inhibit the activity of topoisomerase I in a DNA unwinding assay. It inhibits the relaxation at 1μM. The potency of beta-Lapachone can be increased when pretreating topoisomerase I with beta-Lapachone for 5 min at 37℃. Beta-Lapachone is selective for topoisomerase I and shows no inhibition activity for topoisomerase II. Besides, beta-Lapachone is also proved to have no induction in topoisomerase I mediated DNA cleavage [1].

Beta-Lapachone has anti-tumor efficacy in a broad spectrum of human carcinoma cells. It induces cell death of AD2780s, HT-29, DLD, G480 and MCF-7 with IC50 values of 2μM, 5μM, 5μM, 4μM and 2μM, respectively. It is found that beta-Lapachone induces cell death of both apoptosis and necrosis through releasing cytochrome C. Beta-Lapachone is also reported to affect cell cycle. It induces primarily S-phase arrest in SW480 cells, late S- and G2/M-phase arrest in SW620 cells and early S-phase arrest in DLD1 cells [2, 3].

References:
[1] Li CJ, Averboukh L, Pardee AB. beta-Lapachone, a novel DNA topoisomerase I inhibitor with a mode of action different from camptothecin. J Biol Chem. 1993 Oct 25;268(30):22463-8.
[2] Li YZ, Li CJ, Pinto AV, Pardee AB. Release of mitochondrial cytochrome C in both apoptosis and necrosis induced by beta-lapachone in human carcinoma cells. Mol Med. 1999 Apr;5(4):232-9.
[3] Huang L, Pardee AB. beta-lapachone induces cell cycle arrest and apoptosis in human colon cancer cells. Mol Med. 1999 Nov;5(11):711-20.