Role of death receptor and mitochondrial pathways in conventional chemotherapy drug induction of apoptosis.

The molecular mechanism underlying chemotherapy-induced apoptosis is often debated because of contradicting reports of its signaling pathway. The focus of this ongoing debate is on the requirement of a death receptor and its role in subsequent activation of caspase-8. Understanding the precise mechanism responsible for apoptosis and identifying molecules targeted by chemotherapy will allow us to develop better therapeutic strategies that target the inherent abnormalities of cancer cells.

Interferon gamma induces neurite outgrowth by up-regulation of p35 neuron-specific cyclin-dependent kinase 5 activator via activation of ERK1/2 pathway.

Interferon gamma (IFN-gamma) is a cytokine predominantly involved in antiproliferative and antiviral responses, immune surveillance, and tumor suppression. However, it has been shown that IFN-gamma is also involved in central nervous system development. Here we studied the underlying mechanism for IFN-gamma-induced neuronal differentiation using the human neuroblastoma Paju cell line.

TRAIL inhibits tumor growth but is nontoxic to human hepatocytes in chimeric mice.

Tumor necrosis factor (TNF) family ligand TNF-alpha and Fas ligand (FasL) can trigger apoptosis in solid tumors, but their clinical usage has been limited by hepatotoxicity. TNF-related apoptosis-inducing ligand (TRAIL) is a newly identified member of the TNF family, and its clinical application currently is under a similar debate. Here, we report a recombinant soluble form of human TRAIL (114 to 281 amino acids) that induces apoptosis in tumor cells but not human hepatocytes.

TRAIL triggers apoptosis in human malignant glioma cells through extrinsic and intrinsic pathways.

Many malignant glioma cells express death receptors for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), yet some of these cells are resistant to TRAIL. Here, we examined signaling events in TRAIL-induced apoptosis and searched for therapeutic agents that could overcome TRAIL resistance in glioma cells. TRAIL induced apoptosis through death receptor 5 (DR5) and was mediated by caspase-8-initiated extrinsic and intrinsic mitochondrial pathways in sensitive glioma cell lines.

Cisplatin down-regulation of cellular Fas-associated death domain-like interleukin-1beta-converting enzyme-like inhibitory proteins to restore tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis in human melanoma cells.

Purpose: Many melanoma cell lines and primary cultures are resistant to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. In this study, we investigated the molecular mechanisms that control melanoma cell resistance and searched for chemotherapeutic drugs that could overcome the TRAIL resistance in melanoma cells.

Experimental Design: We examined 21 melanoma cell lines and 3 primary melanoma cultures for their sensitivity to TRAIL-induced apoptosis, and then tested cisplatin, chemptothecin, and etoposide for their synergistic effects on TRAIL sensitivity in resistant melanoma cells.