Abstract: This document provides methods and materials related to treating cancer. For example, methods and materials that include using CD40L polypeptide, an hsp70 polypeptide, and a cytotoxic polypeptide to trigger an immune response directed against cancer cells are provided.

Abstract: A nucleic acid construct is described which provides cell type-specific expression of a therapeutic transgene. The construct utilizes a cell type-specific promoter which drives expression of the transgene. A positive feedback loop is introduced through the addition of a amplification promoter element operably linked to the therapeutic transgene and by providing, either as part of the same construct, or in a different construct, a transcription activator for activating the amplification promoter element. In one embodiment, the amplification promoter element is a heat shock response element (HSE) and the transcription activator is HSF-1. The construct enables functional targeting of a therapeutic gene while avoiding undesirable effects in non-targeted cells, by combining sufficiently high-level expression to promote a desirable therapeutic outcome with exceptional tissue specificity.

Abstract: This invention relates to a recombinant nucleic acid vector comprising a first expression cassette comprising a first promoter operably linked to a nucleic acid sequence encoding a syncytium-inducing polypeptide, wherein the first expression cassette is flanked on either side by a site recognized by a recombinase. The invention also includes a second expression cassette comprising a tissue-specific promoter operably linked to a nucleic acid sequence encoding a recombinase. The invention also includes cells and compositions including these expression cassettes and methods of reducing tumor volume by expression of these expression cassettes.