Objective       To study the role of different MG132 doses in prevention and treatment of cancer cachexia.       Methods       A mouse cancer cachexia model was induced by inoculating mouse colon cancer 26 cells into male BALB/c mice．Eighty-eight male BALB/c mice were divided into healthy control (HC) group (n=8)

cancer cachexia (CC) group (n=16)

low concentration MG132 prevention (PL) group (n=8)

moderate MG132 concentration prevention (PM) group (n=16) and high MG132 concentration prevention (PH) group (n=8)

low MG132 concentration treatment (TL) group (n=8)

moderate MG132 concentration treatment (TM) group (n=16) and high MG132 concentration treatment (TH) group (n=8). Their BMI

diet intake and tumor volume were measured daily. Mice in prevention groups and treatment groups were intraperitoneally injected with MG132 (0.01

0.1 and 0.5 mg/kg) on days 5 and 12 after inoculation of colon cancer 26 cells. Eight mice in each group were killed on day 19 after inoculation of colon cancer 26 cells and their tumor

left gastrocnemius muscle and epididymis adipose tissue were weighed. Serum levels of glucose (Glu)

triglyceride (TG)

total protein (TP) and albumin (ALB) were measured. The remaining 8 mice in CC group

PM group and TM group received the original treatment till their death and their survival time was recorded.       Results        The spontaneous activity and non-tumor BMI

the weight of cross-cut gastrocnemius muscle fiber

gastrocnemius muscle and epididymis adipose

and the serum Glu and ALB levels were significantly higher and the survival time was longer whereas the serum TG level was significantly lower in MG132 prevention and treatment groups than in CC group (P0.05). The best effect of MG132 on cancer cachexia was observed in PM and TM groups (P0.05). The tumor growth was significantly inhibited in PH group (P0.05).       Conclusion        MG132 at a moderate dose can rather effectively prevent and improve cancer cachexia

and prolong the survival time of cancer cachexia patients.