Establishment of a novel method to evaluate peritoneal microdissemination and therapeutic effect using luciferase assay

Abstract

Peritoneal dissemination is a major cause of recurrence in patients with malignant tumors in the peritoneal cavity. Effective anticancer agents and treatment protocols are necessary to improve outcomes in these patients. However, previous studies using mouse models of peritoneal dissemination have not detected any drug effect against peritoneal micrometastasis. Here we used the luciferase assay to evaluate peritoneal micrometastasis in living animals and established an accurate mouse model of early peritoneal microdissemination to evaluate tumorigenesis and drug efficacy. There was a positive correlation between luminescence intensity in in vivo luciferase assay and the extent of tumor dissemination evaluated by ex vivo luciferase assay and mesenteric weight. This model has advantages over previous models because optimal luciferin concentration without cell damage was validated and peritoneal microdissemination could be quantitatively evaluated. Therefore, it is a useful model to validate peritoneal micrometastasis formation and to evaluate drug efficacy without killing mice.

An improved mouse orthotopic bladder cancer model exhibiting progression and treatment response characteristics of human recurrent bladder cancer

“…The non-treatment group (normal) comprised eight mice that did not receive any transplants and injections. Reportedly, in mice, 10 and 240 mg/kg are the maximum tolerable doses of CDDP and GEM, respectively, for weekly treatment (25,26). We euthanized and dissected mice from each group under anesthesia on day 21 after transplantation to examine treatment responses.…”

FF‐10832 enables long survival via effective gemcitabine accumulation in a lethal murine peritoneal dissemination model

“…Thirty mice were intraperitoneally inoculated with Colon26 cells (1 × 10 6 cells in 0.5 mL PBS) (day 0). Mice were randomly divided into 3 groups on day 3 according to the intensity of luminescence, as described previously : vehicle‐treated group (n = 10), GEM‐treated group (240 mg/kg Eli Lilly, n = 10) and FF‐10832‐treated group (3 mg/kg, Fujifilm, n = 10). In our lethal model mice, we had already validated the establishment of tumor inoculation on peritoneal cavity pathologically on day 5 after intraperitoneal injection (data not shown).These drugs were administered to the mice on day 5 by intravenous injection.…”

“…We plotted body weight until day 22 following transplantation and Kaplan‐Meier survival curves until day 56 following transplantation in each group. On day 56 following transplantation, surviving mice were killed to evaluate the peritoneal tumor conditions using an ex vivo luciferase assay, as previously described . The peritoneal tumors in each group were observed using H&E staining.…”

Firefly Luciferase‐based Fusion Proteins and their Applications in Bioanalysis

“…Moreover, firefly luciferin is very stable and nontoxic substance . This leads to very low background signal of bioluminescent reaction and permits the successfull application of firefly luciferase in different in vitro and in vivo systems . Fusion of luciferase with specific domains provides possibility of its fixation on the surface of investigated target to detect ATP locally as well as for application in immunoanalysis, hybridization analysis of DNA and RNA, for investigation of DNA modifications, protein–protein interactions and regulation of pathways.…”