Inhibition of mammalian target of rapamycin signaling by everolimus induces senescence in adult T-cell leukemia/lymphoma and apoptosis in peripheral T-cell lymphomas.

HTLV-I-associated adult T-cell leukemia/lymphoma (ATL) and human T-cell lymphotropic virus type I (HTLV-I)-negative peripheral T-cell lymphomas carry poor prognosis mainly because of acquired resistance to chemotherapy. We have shown that this disease is responsive to the combination of zidovudine and interferon-α. However, long-term maintenance therapy with this combination is associated with side effects affecting patient quality of life and hence more tolerated alternatives are needed.

Purified salograviolide A isolated from centaurea ainetensis causes growth inhibition and apoptosis in neoplastic epidermal cells.

Many of the best-selling anticancer drugs are plant-derived. We tested for the anticancer properties of extracts isolated from Centaurea ainetensis, a plant species endemic to Lebanon and which is often used in folk medicine. We performed bioassay-guided fractionation of Centaurea ainetensis extracts using a panel of normal and neoplastic murine cells to identify a component that is associated with antitumor activities.

Human T-cell lymphotropic virus type I-transformed T-cells have a partial defect in ceramide synthesis in response to N-(4-hydroxyphenyl)retinamide.

Treatment with the synthetic retinoid HPR [N-(4-hydroxyphenyl)-retinamide] causes growth arrest and apoptosis in HTLV-I (human T-cell lymphotropic virus type-I)-positive and HTLV-I-negative malignant T-cells. It was observed that HPR-mediated growth inhibition was associated with ceramide accumulation only in HTLV-I-negative cells. The aim of the present study was to investigate the mechanism by which HPR differentially regulates ceramide metabolism in HTLV-I-negative and HTLV-I-positive malignant T-cells.

Regulation of ultraviolet B radiation-mediated activation of AP1 signaling by retinoids in primary keratinocytes.

The main cause of skin cancer and photo-aging is chronic exposure to ultraviolet B (UVB) radiation. Such damage can be ameliorated by retinoid treatment. UVB-radiation-induced skin carcinogenesis is associated with the induction of activator protein 1 (AP1) signaling and factors, namely FOS and JUN family members.

Stage-specific effect of N-(4-hydroxyphenyl)retinamide on cell growth in squamous cell carcinogenesis.

Squamous cell carcinoma (SCC) is the most prevalent form of epithelial cancer. SCC results when normal epithelial cells undergo multiple neoplastic changes that culminate in the evolution of an invasive cancer. Retinoids are commonly used as chemopreventive and treatment agents in skin cancer; however, SCC progression is accompanied by a gradual loss of retinoid responsiveness.