Reversion of transformed phenotype of human adenocarcinoma A549 cells by expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase complementary DNA.
3-Hydroxy-3-methylglutaryl CoA reductase (HMG-CoA reductase) plays a rate-limiting role in isoprenoid biosynthesis and is associated with cell proliferation and transformation. Although an elevated level of HMG-CoA reductase activity is consistently detected in cancer cell lines and tumors, the question remains whether HMG-CoA reductase activity may have a causative role in cell transformation. We have stably transfected the A549 human adenocarcinoma cells with both bicistronic and retroviral expression vectors, including the whole cDNA of human HMG-CoA reductase. Stably transfected cells showed strong morphological changes and disorganization in the filamentous actin architecture, became contact inhibited, and had a lower doubling time. Moreover, they exhibited anchorage-independent growth reduction and lost their capability to induce tumors in nude mice. Surprisingly, no quantitative modification of enzyme activity was observed following transfection, although expression of HMG-CoA reductase cDNA was shown by Northern blot analysis. When endogenous and transfected reductase activity was bypassed by the addition of mevalonate and compactin, a competitive inhibitor, the filamentous actin distribution in HMG-CoA reductase-transfected cells became very similar to that of control cells, demonstrating the role of exogenous HMG-CoA reductase activity in this process. All of our data together strongly suggest that phenotype reversion is dependent on exogenous HMG-CoA reductase expression and that enzymatic activity is implied in this mechanism. HMG-CoA reductase cDNA expression, by expression of a particular form of reductase, might be a negative regulator of cell growth and thus reverse the phenotype of tumor cells.
Seronie-Vivien
S
S
Laboratoire de Ciblage en Thérapeutique, UFR des Sciences Pharmaceutiques, Toulose, France.
Pradines
A
A
Couderc
B
B
Clamagirand
C
C
Berg
D
D
Soula
G
G
Favre
G
G
D000214:Acyl Coenzyme A / Q000235:genetics* / Q000378:metabolism; D000230:Adenocarcinoma / Q000201:enzymology*; D000362:Agar; D000818:Animals; D002455:Cell Division / Q000502:physiology; D002461:Cell Line, Transformed; D003001:Cloning, Molecular; D003599:Cytoskeleton / Q000201:enzymology; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007700:Kinetics; D008175:Lung Neoplasms; D051379:Mice; D008819:Mice, Nude; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D012333:RNA, Messenger / Q000032:analysis; D014170:Transformation, Genetic; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000201:enzymology
D000214:Acyl Coenzyme A; D018076:DNA, Complementary; D012333:RNA, Messenger; C008047:3-hydroxy-3-methylglutaryl-coenzyme A; D000362:Agar; D010088:Oxidoreductases