Compositions and methods for cancer treatment are disclosed herein. More specifically, the present invention describes an autologous cancer vaccine genetically modified for Furin knockdown and GM-CSF expression. The vaccine described herein attenuates the immunosuppressive activity of TGF-β through the use of bi-functional shRNAs to knock down the expression of furin in cancer cells, and to augment tumor antigen expression, presentation, and processing through expression of the GM-CSF transgene.