WP760, a melanoma selective drug.

Purpose: Our goal was to perform studies on the specificity and antimelanoma mechanism of a novel bis-anthracycline, WP760. WP760 initially identified in the NCI 160 screen as anti-melanoma.

Methods: The methyl thiazolyl tetrazolium reduction (MTT) assay was used to test tumor cell growth inhibition; confocal microscopy to view WP760 intracellular distribution; flow cytometry for cell-cycle arrest and apoptosis; and Western blotting was employed to identify and compare quantities and kinetics of cell growth related molecule levels.

Cytokine induction of interleukin-24 in human peripheral blood mononuclear cells.

Interleukin-24 (IL-24) is a recently identified member of the IL-10 family of cytokines. It was originally identified as a tumor suppressor molecule, melanoma differentiation-associated gene 7, and then renamed IL-24 and classified as a cytokine, based on its chromosomal location in the IL-10 locus, its mRNA expression in leukocytes, and its secretory sequence elements. Here, we correlate the kinetics of IL-24 mRNA and protein expression in human peripheral blood mononuclear cells (PBMC) stimulated by polyclonal activators phytohemagglutinin (PHA) and lipopolysaccharide (LPS) or by allogeneic major histocompatibility complex.

Inhibition of nuclear factor-kappaB and nitric oxide by curcumin induces G2/M cell cycle arrest and apoptosis in human melanoma cells.

Curcumin (diferuloylmethane) inhibits tumour cell growth by inducing apoptosis in many tumour types, including melanoma, via complex and ill-defined pathways. Recent studies have shown that curcumin is both a nitric oxide scavenger and an inhibitor of inducible nitric oxide synthase (iNOS) expression, low levels of which correlate with antiapoptotic function and poor survival and which may be regulated by inhibition of nuclear factor-kappaB (NFkappaB) activation. To elucidate the mechanisms by which curcumin inhibits melanoma proliferation, we tested the in vitro effects of curcumin on specific cell cycle pathways and melanoma cell survival, including NFkappaB activation.

Dominant negative signal transducer and activator of transcription 2 (STAT2) protein: stable expression blocks interferon alpha action in skin squamous cell carcinoma cells.

We have demonstrated previously that suppression of some or all of the IFN-stimulated gene factor 3 (ISGF-3) proteins in skin squamous cell carcinomas is an early event in squamous skin carcinogenesis. This finding led to the hypothesis that suppressed expression of ISGF-3 proteins may lead to reduced IFN responsiveness, which in turn may contribute to skin malignancy by conferring a growth and/or survival advantage. To test this hypothesis, we have developed a skin cell-based model for inhibiting the IFN-alpha signaling pathway through the forced expression of a dominant negative-acting signal transducer and activator of transcription 2 (dnSTAT2) protein.

Suppression of type I interferon signaling proteins is an early event in squamous skin carcinogenesis.

Purpose: IFN-based therapy has been shown to be active in the treatmentof squamous cell carcinoma (SCC) of the skin, the most aggressive form of non-melanoma skin cancer. Based largely on this activity, we began programmatically examining the expression of IFN-stimulated gene factor 3 (ISGF-3) proteins (signal transducers and activators of transcription 1alpha/beta, signal transducers and activators of transcription 2, and p48), which are important mediators of IFN-alpha signaling, in skin premalignancy and SCC. Our previous preliminary studies suggested suppression of some or all of the ISGF-3 proteins in skin SCC.