Figure 1

Malten and maltonis effect on DNA structure and sarcoma cell growth. (A) Effects of the two compounds on electrophoretic migration of plasmid DNA. After 2 hours incubation in presence of 4 mM malten, 4 mM maltonis or 25 μM CDDP, circular plasmid DNA (pLL3.7) was separated by agarose gel electrophoresis. Supercoiled (white arrow), open circular (black arrow) plasmid form and high molecular weight DNA complexes formation (black bar) are indicated. (B) PCR inhibition assay. Amplification delay (folds) was calculated for each set of primers (for details see Additional file 3) as the difference between the Ct values of treated and untreated samples. Graphical representation of the exponential decrease of the number of amplifiable DNA sequences after incubation with malten, maltonis or CDDP. (C) Histogram showing IC50 values for malten (light bars) and maltonis (dark bars) in a panel of sarcoma cell lines. RMS, rhabdomyosarcoma; OS, osteosarcoma; ES, Ewing sarcoma. Values are expressed as mean of three independent experiments ± SE. (D) Maltol derived compounds inhibit tumour growth in anchorage-independent conditions: columns are the mean of three independent experiments ± SE performed on RD/18 (seeded cells: 10,000/dish), U-2OS(seeded cells: 10,000/dish) and TC-71 (seeded cells: 3,300/dish) cells. Statistical analysis was performed by Student’s t test: *P < 0.05; **P < 0.01. (E) Fold increase in drug resistance to conventional drugs (light grey) or to maltonis (black): fold resistance is calculated on the values of IC50 of each resistant cell line against its respective sensitive parental one. Values are representative of three independent experiments.