Expression of apoptosis regulatory proteins in the skeletal muscle of tumor-bearing rabbits

Citation
H. Yoshida et al., Expression of apoptosis regulatory proteins in the skeletal muscle of tumor-bearing rabbits, JPN J CANC, 92(6), 2001, pp. 631-637
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Onconogenesis & Cancer Research
Journal title
JAPANESE JOURNAL OF CANCER RESEARCH
ISSN journal
0910-5050 → ACNP
Volume
92
Issue
6
Year of publication
2001
Pages
631 - 637
Database
ISI
SICI code
0910-5050(200106)92:6<631:EOARPI>2.0.ZU;2-A
Abstract
We reported finding that apoptosis occurred in skeletal muscle in the early stage after implantation. In the present study, we investigated expression of the apoptosis-related proteins Bar and Bcl-2 to determine the mechanism of the apoptosis, In the early stage of tumor bearing, 20 days after impla ntation, lean body mass (LBM) was reduced by 5.06 +/-1.10% in the tumor-bea ring group, compared with an increase of 4.96 +/-1.26% in the control group , The apoptotic index (AI) of the skeletal muscle in the tumor-bearing grou p increased to 40.5 +/-3.20% but was 0% in the control group, and pax expre ssion was strongly positive in 5 of the 10 rabbits in the tumor-bearing gro up, and significantly stronger than in the control group (P=0.0002). In the late stage of tumor bearing, 40 days after implantation, the AI had declin ed to 0.93 +/-0.96% in the tumor-hearing group, but was still 0% in the con trol group, Ras expression was rarely detected in either the tumor-bearing group or the control group, and there was no significant difference between the two groups (P=0.706). No significant changes in Bcl-2 were observed in either group. The above results showed that apoptosis via pas played a rol e in muscle wasting associated with progression of the malignant tumor. How ever, the apoptosis and expression of Bax were seen only in the early stage , within 20 days after implantation, not in the late stage. This suggested that the muscle wasting in the early stage might he caused by a different m echanism from that in the late stage.