MMP9 and central nervous system cancer: Hence, as the first step towards understanding the signal transduction in DDR in DSB repair, in the present study, we have used human glioma xenograft cells and treated them with MMP9+uPAR (pMU) and MMP9+cathepsin B (pMC) bicistronic plasmid shRNA constructs in both in vitro and in vivo models.