Cryopreserved biopsy tissues of rectal cancer liver metastasis for assessment of anticancer drug response in vitro and in vivo.

Living tumors are of great scientific value for clinical medicine and basic research, especially for drug testing. An increasing number of drug tests fail due to the use of imperfect models. The aim of the present study was to develop a novel method combining vitrificationbased cryopreservation of tumor biopsies and precisioncut slice cultivation for the assessment of anticancer drug responses. Biological characteristics of rectal cancer liver metastasis biopsies could be retained by vitrificationbased cryopreservation. The patientderived xenograft models were successfully established using both fresh and warmed biopsy tissues. Precisioncut slicing provided a similar threedimensional architecture and heterogeneity to the original tumor. The positive drug responses in the xenograft model were consistent with those in precisioncut slice cultures in vitro. The present study demonstrated that live tumor biopsies could be preserved using vitrificationbased cryopreservation. The warmed tissues developed xenograft tumors, which were also useful for either in vivo or in vitro anticancer drug testing. Precisioncut slices derived from the warmed tissues provided an efficient tool to assess anticancer drug response in vitro.