Differences in total mitochondrial proteins and proteins synthesized by mitochondria from rat liver and Morris hepatomas 9618A, 5123C, and 5123tc.
Mitochondria were isolated from a slow-growing (9618A) and two intermediate-to-fast-growing (5123C, 5123tc) Morris hepatomas and host livers. The mitochondrial proteins were solubilized and fractionated on sodium dodecyl sulfate:polyacrylamide slab gels. One Coomassie blue-stained band was absent or reduced in amount in all tumors relative to host livers. In addition, a major mitochondrial enzyme present in normal liver, carbamyl phosphate synthetase, was missing or greatly reduced in the slow-growing, highly differentiated hepatoma 9618A, a tumor that is considered to be similar to normal liver in many biochemical and morphological respects. Incubation of mitochondria with [35S]methionine and a suitable amino acid incorporation system resulted in labeling of specific mitochondrial proteins. Autoradiography of the slab gels disclosed four prominently labeled fractions and a number of minor fractions. Preparations from hepatoma 5123tc demonstrated two labeled bands that were absent or greatly reduced in host liver. Host liver preparations displayed a minor band that was absent or greatly reduced in hepatoma 5123C. However, no single change in labeling pattern was common to all three tumors, suggesting the absence of a causal relationship between carcinogenesis and mutations in mitochondrial DNA.
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000378:metabolism*; D009374:Neoplasms, Experimental / Q000378:metabolism; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D051381:Rats
D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D011506:Proteins