We conclude that APR-246 is effective in AML cells irrespectively of TP53 mutational status and that it has promising properties for combination studies in AML.

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An internal tandem duplication of FLT3 (FLT3/ITD) occurs in approximately 25% of newly diagnosed AML. PKC412 inhibits the growth of leukemic cell lines with FLT3 mutations such as the MV4-11. This study evaluated the in vitro effects of the combination of PKC412 and ara-C or daunorubicin, studying the effect of co-incubation, pre-incubation and sequential incubation of the drugs in patient samples and cell lines. Thirty-three patients with AML were included. Two cell lines were studied; MV4-11 that expresses the FLT3/ITD and HL-60 that does not. In the patient cells PKC412 exerted its effect at concentrations between 0.1 and 2.0 microM. For MV4-11 cells concentrations down to 1 nM were effective. In patient samples, the results of co-incubation of PKC412 with ara-C were synergistic in 5%, additive in 67%, sub additive in 17% and antagonistic in 11% of the cases. In patient cells, incubations with ara-C and PKC412 resulted in synergistic effects in 17% of the FLT3/ITD positive samples compared to 0% synergistic in the FLT3/ITD negative samples (p < 0.01). Antagonistic effects were more common in the FLT3/ITD negative samples. The timing of the drugs had little impact on the effect. In cell lines, antagonistic effects were seen frequently in HL-60 (90%) and less so in MV4-11 (60%) regardless of sequence or timing of the drugs. The combination of daunorubicin and PKC412 resulted in more synergistic and less antagonistic effects compared to combinations with ara-C, in both patient material and cell lines. The combination of Lonafarnib, a farnesyl-transferase inhibitor (FTI) and PKC412 had additive and synergistic effects in both FLT3/ITD positive and negative cell lines. In conclusion, the combination of PKC412 together with chemotherapeutic drugs is more effective in FLT3/ITD positive AML cells. Antagonistic effects can be seen, especially in patient samples without FLT3/ITD. Also, the combination of PKC412 and the farnesylinhibitor lonafarnib should be further explored.

Exclusive Enteral Nutrition (EEN) is the first-line treatment in children with Crohn’s disease (CD) for induction of remission. However, the mode of action remains conjectural. The aim of this study was to investigate whether the effect of EEN is paralleled by changes in the mucosal cytokine profiles (MCP). Twelve children with new onset inflammatory bowel disease (IBD) received induction treatment with a polymeric EEN. We assessed clinical, endoscopic and histologic scoring before and after EEN. Twelve colonic cytokines were analyzed by Polymerase Chain Reaction (PCR) in six of the IBD patients at onset and after EEN as well as in six non-IBD control children at the diagnostic colonoscopy. Twelve children completed 6 weeks of EEN, except from one child who completed 4 weeks. At the control colonoscopy, 83% were in complete clinical remission. Changes were found in the MCPs of individual patients after EEN. In particular, children with IBD showed significantly higher values of Interleukin (IL)-12β (p = 0.008) and IL-23α (p = 0.02) compared to non-IBD controls at the diagnostic colonoscopy. Furthermore, an overall change in proinflammatory cytokines was noted in the IBD-group after treatment. Further studies are warranted to understand the role of EEN in MCP.

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Pycnogenol®, which is extracted from the bark of French maritime pine, has been shown to have antioxidant and free radical scavenging activities. Thioredoxin reductase (TrxR), glutathione peroxidase (GPx) and glutathione reductase (GR) are three central redox enzymes that are active in endogenous defence against oxidative stress in the cell. Treatment of cells with Pycnogenol® decreased the activity of both TrxR and GPx in cells by more than 50%, but GR was not affected. As previously reported, both enzymes were induced after treatment with hydrogen peroxide and selenite. The presence of Pycnogenol® efficiently decreased selenite‐mediated reactive oxygen species (ROS) production. Addition of Pycnogenol® after selenite treatment reduced the mRNA expression and activity of TrxR to basal levels. In contrast, the GPx activity was completely unaffected. The discrepancy between TrxR and GPx regulation may indicate that transcription of TrxR is induced primarily by oxidative stress. As TrxR is induced in various pathological conditions, including tumours and inflammatory conditions, decreased activity mediated by a non‐toxic agent such as Pycnogenol® may be of great value.

A doxorubicin-resistant subline (U-1285dox(900)) was derived from the human small cell lung carcinoma cell line U-1285. U-1285dox(900) was exposed to a wide range of anticancer agents to determine its resistance profile. In contrast to U-1285 cells, the resistant subline U-1285dox(900) expressed elevated MRP1 mRNA detected by reversed transcriptase-polymerase chain reaction (RT-PCR) and MRP1 protein analyzed with Western blot. Neither MDR1 mRNA nor P-glycoprotein could be detected in the parental cell line or resistant subline. U-1285dox(900) exhibited high resistance to doxorubicin, epirubicin, daunorubicin, and vincristine, an intermediate resistance to mitoxantrone, and a low resistance to etoposide. A collateral sensitivity to cytosine arabinoside, chlorodeoxyadenosine, and melphalan was observed. The resistance could be reversed by buthionine-sulphoximine and verapamil for all tested drugs. Compared with daunorubicin, resistance to idarubicin was very low, 14-fold and 2.6-fold, respectively. This was associated with a higher accumulation due to a slower transport of idarubicin out of U-1285dox(900) cells.