Actinomycin D

Actinomycin D (Dactinomycin) is an antibiotic found in Streptomyces microsporum with antibacterial and anti-tumor effects. Actinomycin D is an inhibitor of RNA and protein synthesis. Actinomycin D can inhibit the protein synthesis of bacteria, directly bind to the guanine groups of single-stranded or double-stranded DNA in the transcriptional initiation complex, inhibit the activity of DNA-dependent RNA polymerase, and interfere with the transcription process of DNA, thereby inhibiting mRNA synthesis. Actinomycin D inhibits DNA repair with an IC₅₀ value of 0.42 μM. Actinomycin D is also an autophagy activator. Actinomycin D is promising for research of cancer and cardiovascular diseases^{[1][2][3][4][5][6][7]}. IC50 & Target:IC50: 0.42 μM (DNA repair)^[1] In Vitro:Actinomycin D (80 nM-8 μM, 18-24 h) inhibits the proliferation of vascular smooth muscle cells and arrests the cell cycle at the G1 phase in vascular smooth muscle cells^[2].
Actinomycin D (1-100 ng/mL, 24-96 h) induces cell apoptosis and inhibits the growth of PANC-1 pancreatic cancer cells^[4].
Actinomycin D (0.02-0.08 μM, 48 h) induces apoptosis in chronic lymphocytic leukemia (CLL) cells^[5].
Notes:
1. Passage number, cell state, and cell density can significantly affect experimental outcomes. It is crucial to optimize the cell condition before conducting experiments (HCT 116 adherent cells tend to have smaller morphology and are prone to aggregation at high densities; therefore, ensure an even cell plating is achieved).
2. Different cell lines may exhibit varying sensitivities to cycloheximide, which could result in discrepancies in the detection outcomes. It is recommended to consult the literature and perform preliminary experiments to determine optimal drug treatment times, concentrations, and antibody conditions, ensuring that the experimental protocol is both reasonable and feasible.
3. Drugs should be prepared fresh for each use. Ultrasonic heating may be employed to assist solubilization until the solution appears clear and transparent. Any remaining solution after the initial experiment should be aliquoted and stored at -20°C.
Note: Act D has obvious effects at lower concentrations (CCK8) and within a short period of time (WB). Even a slight change in concentration can cause a significant alteration in cell viability (48 h). When the concentration is too high, cell viability increases, but if the time is too long, it will instead inhibit the expression of MDM2 and p53. It is suggested that there be more detection indicators in the pre-experiment, which will increase the probability of success. 4. Actinomycin D is cytotoxic, which should be prepared and used in a well-ventilated environment, and precautions should be taken. Actinomycin D should be stored away from light and at low temperatures to prevent decomposition and failure. In Vivo:Actinomycin D (0.06 mg/kg, i.p., 14 consecutive days) leads to tumor regression in this mouse model of chronic lymphocytic leukemia^[5].
Actinomycin D (0.05-0.12 mg/kg, i.v. or intramyocardial injection, administered 15 minutes before ischemic preconditioning and during the two reperfusion cycles or administered for 40 minutes before ischemic preconditioning and during the two reperfusion cycles) increases the infarct size and reduces the cardioprotection induced by ischemic preconditioning in male castrated pigs^[6].