Updated project metadata. Therapy resistance is still a major reason for treatment failure in colorectal cancer (CRC). Previously, we identified the E3 ubiquitin ligase TRIM25 as a novel suppressor of caspase-2 translation, thereby contributing to apoptosis resistance of CRC cells towards chemotherapeutic drugs. We herein report the executioner caspase-7 being a further target of TRIM25. Results from gain and loss-of-function approaches and actinomycin D experiments indicate that TRIM25 attenuates caspase-7 expression mainly through a decrease in mRNA stability. Data from RNA pull-down assays with immunoprecipitated TRIM25 truncations indicate a direct TRIM25 binding to caspase-7 mRNA which is mediated by the PRY/SPRY domain which is also known to be highly relevant for protein-protein interactions. By employing TRIM25 immunoprecipitation, we identified the heterogeneous nuclear ribonucleoprotein H1 (hnRNPH1) as a novel TRIM25 binding protein involved in the control of caspase-7 mRNA stability. Notably, the interaction of both proteins was highly sensitive to RNase A treatment and again depended on the PRY/SPRY domain, thus indicating an indirect interaction of both proteins which is achieved through a common RNA binding. Ubiquitin affinity chromatography showed that hnRNPH1 and TRIM25 are targets of ubiquitin modification. Functionally, the ectopic expression of caspase-7 in CRC cells caused an increase in poly ADP-ribose polymerase (PARP) cleavage concomitant with a significant increase in apoptosis. Collectively, the negative regulation of caspase-7 by TRIM25 via hnRNPH1 implies a novel survival mechanism underlying chemotherapeutic drug resistance of CRC cells. Targeting of TRIM25 could therefore offer a promising strategy for reducing therapy resistance in CRC patients.