A variant form of laminin is responsible for the neurite outgrowth-promoting activity in conditioned medium from a squamous carcinoma cell line.
We examined the effects of conditioned medium (CM) obtained from a squamous carcinoma cell line, termed SAS, on chick sympathetic neuritic outgrowth. Neurons grown on a substratum coated with CM extended their neurites. Antisera raised against human laminin and mouse EHS laminin immunoprecipitated the neurite outgrowth-promoting factor in CM. The most purified fraction of CM contained a 740-kDa protein which reacted with the anti-laminin sera and was composed of three polypeptides of 330 kDa, 215 kDa and 195 kDa. The 215-kDa and 195-kDa polypeptides, but not the 330-kDa polypeptide were shown to be antigenically related to mouse laminin and human laminin by immunoblotting. The presence of merosin M chain in SAS cells was ruled out by using the method of reverse transcription polymerase chain reaction (RT-PCR). These results suggest that the 740-kDa protein is a laminin variant having a novel heavy chain of 330 kDa and is responsible for neurite outgrowth-promoting activity in CM.
Yoshida
H
H
Department of Oral Surgery, Chiba University School of Medicine, Japan.
Hasegawa
S
S
Kuromi
H
H
Inagaki
N
N
Seino
S
S
Takahashi
K
K
Sato
K
K
D000818:Animals; D001369:Axons / Q000502:physiology*; D001483:Base Sequence; D002294:Carcinoma, Squamous Cell / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D002465:Cell Movement / Q000502:physiology; D002645:Chickens; D017077:Culture Media, Conditioned / Q000032:analysis* / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006358:Hot Temperature; D006801:Humans; D007106:Immune Sera; D015151:Immunoblotting; D007797:Laminin / Q000032:analysis* / Q000276:immunology / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009414:Nerve Growth Factors / Q000378:metabolism*; D009474:Neurons / Q000502:physiology; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D013564:Sympathetic Nervous System / Q000166:cytology* / Q000502:physiology; D014062:Tongue Neoplasms / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D014407:Tumor Cells, Cultured
D017077:Culture Media, Conditioned; D007106:Immune Sera; D007797:Laminin; D008565:Membrane Proteins; D009414:Nerve Growth Factors; D012333:RNA, Messenger