Lipolytic and lipoprotein lipase (LPL)-inhibiting activities produced by a human lung cancer cell line responsible for cachexia induction.
Previous studies have shown that five human cancer cell lines, LS180, MKN-1, MMG-1, C32 and LX-1, induced remarkable weight loss in tumor-bearing nude mice. With the aim of identifying novel molecules involved in lipid catabolism, conditioned media of these cancer cell lines were analyzed in terms of lipoprotein lipase (LPL)-inhibiting or lipolytic activities. All conditioned media from the five cell lines significantly suppressed LPL activity in 3T3-L1 cells, while media from LX-1 and C32 promoted lipolytic activity in a dose-dependent manner. RT-PCR and ELISA demonstrated that the major factors responsible for LPL inhibition and lipolysis were not IL-1beta, IL-6, IL-11, TNF-alpha, TGF-beta1 or LIF in all the cancer cell lines except for MMG-1 cells. Preliminary biochemical analysis showed that the LPL-inhibiting factor produced by LX-1 cells was approximately 65 kD and vulnerable to heat, whereas the lipolytic factor was less than 1 kD and heat stable. These results suggested that unknown factors are partially involved in the pathogenesis of cancer cachexia in tumor-bearing nude mice and further purification will be needed.
Nara-Ashizawa
N
N
Growth Factor Division, National Cancer Center Research Institute, Tokyo, Japan. nnara@gan2.res.ncc.go.jp
Akiyama
Y
Y
Maruyama
K
K
Tsukada
T
T
Yamaguchi
K
K
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D002100:Cachexia / Q000201:enzymology / Q000209:etiology / Q000378:metabolism*; D017077:Culture Media, Conditioned; D016207:Cytokines / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D005990:Glycerol / Q000378:metabolism; D006801:Humans; D008066:Lipolysis / Q000187:drug effects / Q000502:physiology; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors*; D008175:Lung Neoplasms / Q000150:complications / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011433:Propranolol / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D000319:Adrenergic beta-Antagonists; D017077:Culture Media, Conditioned; D016207:Cytokines; D011433:Propranolol; D008071:Lipoprotein Lipase; D005990:Glycerol