Idarubicin hydrochloride reduced U937 metabolic activity, with a reported 36-h MTT IC50 of 0.2 µM. Relapsed-AML extracellular vesicle co-exposure shifted the reported IC50 to 0.35 µM; annexin V/PI measurements also showed attenuation of apoptosis with AML-derived vesicles. These results are specific to this cellular co-exposure model. [2]
Idarubicin also inhibited growth of nonmalignant human fibroblasts. After 2 h of exposure and 72 h in drug-free medium, MTT IC50 values were 2.69 ± 0.19 µM in WA-1, 5.26 ± 0.08 µM in T-158 and 7.69 ± 0.14 µM in C-5 cells (mean ± SD; five independent experiments). The salt form was unspecified, and these cell-line differences do not establish tumor selectivity or patient sensitivity. [3]
Sequence-dependent DNA cleavage by purified mammalian Top2
Biochemical assay · Purified DNA topoisomerase II from murine P388 nuclei; synthetic 36-bp DNA oligomer [1]
Relative to enzyme alone, idarubicin increased cleavage at several sites and reduced cleavage at others. Control lanes included DNA without enzyme and enzyme without drug; buffer conditions influenced basal cleavage.
Literature-Reported Treatment Conditions
- Treatment concentration
- 0.1 and 1 µM (Figure 1)
- Exposure duration
- 20 min at 37 °C
- Method
- Cell-free DNA cleavage assay; denaturing gel analysis of labeled DNA strands.
- Vehicle
- Freshly prepared in deionized water.
- Co-treatment
- No co-drug.
- Reported limits
- Salt form not specified; no lot-specific identity or purity analysis reported in the read materials section.
Methods and source locations
Compound reported in the paper: Idarubicin; Compound label in the paper: idarubicin
Idarubicin evidence; hydrochloride form was not established in this experiment.
pp. 2275–2276, Materials and Methods; Figure 1; Table I; Results: Sequence specific DNA cleavage
Top2-mediated strand cleavage at defined sites: Figure 1 gel compared with Results; Table I contextualizes buffer-dependent basal cleavage. — p. 2275 Figure 1 and p. 2276 first Results paragraph and Table I
U937 response to idarubicin hydrochloride and attenuation by AML-derived EVs
Cell-based study · Human U937 leukemia cells; comparison with untreated cells and with healthy-donor or AML-derived EV co-exposure [2]
The authors reported a 36-h MTT IC50 of 0.2 µM for IDA alone and 0.35 µM with relapsed-AML EVs. Annexin V/PI readouts supported reduced apoptosis under AML-EV co-exposure. These findings describe a context-dependent cellular response, not a clinical resistance rate.
Literature-Reported Treatment Conditions
- Treatment concentration
- 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5 µM for single-agent MTT assay; Figures 4–5 include 0.2 µM IDA and a separate dose series.
- Exposure duration
- 36 h
- Method
- MTT metabolic-activity assay relative to control; annexin V/PI flow cytometry for apoptosis.
- Vehicle
- PBS is reported for drug stock; a separate passage describes a 0.5 mM stock in RPMI. No separately defined final vehicle-control condition identified.
- Co-treatment
- Healthy-donor, newly diagnosed AML or relapsed-AML EV co-exposure compared with IDA alone; no cytarabine in the adopted experiment.
- Reported limits
- EV amounts alternate between µg and µg/mL in the paper; no normalized EV dose adopted. Stock descriptions are not reconciled. Figure captions use mean ± SE whereas general statistical methods say mean ± SD; no error magnitudes adopted.
Methods and source locations
Compound reported in the paper: Idarubicin hydrochloride; Compound label in the paper: IDA
Nominal concentrations and observed cellular endpoints for the reported hydrochloride material.
Experimental: Drug, Cell culture, MTT assay, Annexin V/PI, Bradford assay; Results: AML-EVS protected U937 cells and Induction of apoptosis; Figures 3–5
Metabolic activity relative to untreated control after 36 h: MTT; reported point value, not an enzyme potency or prescribed treatment dose. — Results: AML-EVS protected U937 cells; Figure 3A and caption
Metabolic activity under relapsed-AML EV co-exposure after 36 h: MTT; restricted to relapsed-EV condition directly depicted, although prose also refers to newly diagnosed AML EVs. — Results: AML-EVS protected U937 cells; Figure 3C
Annexin V/PI apoptotic fraction with AML EV co-exposure relative to IDA alone: Flow cytometry; exact percentages and normalized EV dose not adopted. — Results: Induction of apoptosis in U937 cells; Figures 4–5 with captions
Comparative cytotoxicity in nonmalignant human fibroblast lines
Cell-based study · Human skin fibroblasts: healthy-donor WA-1, trisomy-21 T-158 and type-II-diabetic C-5 lines [3]
After a 2-h drug exposure followed by 72 h in drug-free medium, idarubicin inhibited MTT-based growth in all three lines. The healthy-donor line had the lowest IC50; idarubicin IC50 values were lower than daunorubicin values in each line. These donor-derived cell lines do not establish patient-level sensitivity or tumor selectivity.
Literature-Reported Treatment Conditions
- Treatment concentration
- 0.5–10 µM
- Exposure duration
- 2 h exposure, followed by 72 h drug-free culture; MTT incubation for 4 h.
- Method
- MTT assay; IC50 calculated from linear transformation of dose-response curves.
- Vehicle
- Drug vehicle not specified in the read methods. DMSO was used to solubilize MTT formazan, not identified as drug vehicle.
- Co-treatment
- None; daunorubicin was a separate comparator, not a co-treatment.
- Reported limits
- Salt form and supplier not specified in the read methods; one line represents each donor category.
Methods and source locations
Compound reported in the paper: Idarubicin; Compound label in the paper: IDA
Idarubicin evidence in nonmalignant cell lines; HCl form not established.
p. 184 Methods: Cell lines and Cytotoxicity studies; pp. 185–186 Results: Cytotoxicity assay and Table 1
50% growth inhibition relative to control in WA-1 healthy-donor fibroblasts: 2-h exposure followed by 72-h drug-free culture; MTT. — p. 186 Table 1; p. 184 Cytotoxicity studies
50% growth inhibition relative to control in T-158 trisomy-21 fibroblasts: 2-h exposure followed by 72-h drug-free culture; MTT. — p. 186 Table 1; p. 184 Cytotoxicity studies
50% growth inhibition relative to control in C-5 type-II-diabetic fibroblasts: 2-h exposure followed by 72-h drug-free culture; MTT. — p. 186 Table 1; p. 184 Cytotoxicity studies
Comparator growth-inhibition IC50 values in WA-1, T-158 and C-5, respectively: Separate daunorubicin exposure under the same cytotoxicity design. Table footnote: IDA vs DNR p < 0.05 in each line; T-158/C-5 vs normal p < 0.001. — p. 186 Table 1 and footnotes
