Gompertz tracking of the growth trajectories of the human-liver-cancer xenograft-tumors in nude mice

Abstract

Background and objective: The accurate tracking of the growth trajectories of the human-liver-cancer xenograft-tumors in nude mice is an important prerequisite for the effective use of relevant trial results. Our objective is first to find out whether the Gompertz model can accurately track the growth trajectories of the xenograft-tumors in the non-target control group, Gsk3β knockdown, and c-Myc knockdown groups; secondly, to verify the effect of knocking down Gsk3β or c-Myc on the growth of xenograft-tumors and reveal the mechanism; finally, to demonstrate the 100-day Gompertz growth trajectory, which is a complete growth process with two phases and three stages.

Methods: The 18 male specific-pathogen-free (SPF) BALB/c nude mice were randomly divided into three groups and different interventions were performed to establish the non-target control, Gsk3β knockdown, and c-Myc knockdown groups. The volumes of the xenograft-tumors were measured from day 14 to day 30 after transplantation. The first 30-days and the whole 100-days of Gompertz growth trajectories of the xenograft-tumors were obtained respectively, and the growth assessment indicators of each group were calculated based on the parameters of the Gompertz model.

Results: 1) The Gompertz model can accurately track the growth trajectories of xenograft-tumors in the non-target control, Gsk3β knockdown, and c-Myc knockdown groups; 2) knocking down Gsk3β or c-Myc can inhibit the growth of xenograft-tumors. It is the combined effect of growth-promoting factor, growth inhibitory factor, and the delay of angiogenesis, of which the delay of angiogenesis plays a decisive role; 3) the 100-day Gompertz growth trajectory can provide complete information about the two phases and three stages of xenograft-tumor growth. Therefore, it is strongly recommended that nude mouse trials be extended from 30 days (currently widely accepted) to 100 days.

Conclusions: The Gompertz model can well reveal the growth pattern of the human-liver-cancer xenograft-tumors in nude mice. Combined with the growth assessment indicators obtained from the Gompertz model parameters, one can further clarify the mechanism that affects the growth of xenograft-tumors. The Gompertz tracking of the growth trajectories of the human-liver-cancer xenograft-tumors in nude mice has broad application prospects in the fields of basic research, drug verification, and clinical treatment, etc.

Keywords: Gompertz; Gsk3β; Liver cancer; Xenograft tumor; c-Myc.