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J K Mackey

Publications and source records attributed to J K Mackey.

24 records · Page 2Linked to original sources
PubMed1976

A unique pattern of integrated viral genes in hamster cells transformed by highly oncogenic human adenovirus 12.

We have analyzed the viral DNA sequences persisting in HE C19, a clonal line of hamster embryo cells transformed in vitro by human adenovirus 12 (Ad 12), a member of highly oncogenic group A. Saturation-hybridization of in vitro labeled Ad 12 DNA (2-4 x 10(8) cpm/mug) with HE C19 DNA showed that 93-100% of viral DNA sequences are present in the transformed cell. Reassociation of Ad 12 32P-DNA in the presence of HE C19 DNA detected 8 viral genome equivalents per diploid quantity of cell DNA. REannealing each of the six Ad 12 EcoRl restriction DNA fragments with HE C19 DNA indicated that the sequences of each fragment are present in near equimolar quantities, 8-10.5 copies per cell. HE C19 DNA "networks" were prepared and shown to contain the same viral DNA sequences and in the same amounts as present in unfractionated transformed cell DNA; these data provide the first direct evidence that human adenovirus genes are covalently linked to cellular DNA. The presence of most, if not all, of the viral genes was demonstrated also in the Ad 12 hamster tumor cell line, HT-2. The pattern of integrated viral genes in these nonpermissive hamster cells transformed by Ad 12 is different from that described for cells transformed by group C and B human adenoviruses and for SV40.

Adenoviridae↗
PubMed1976

Do highly oncogenic group A human adenoviruses cause human cancer? Analysis of human tumors for adenovirus 12 transforming DNA sequences.

Adenovirus 12 (Ad12) (Huie) (highly oncogenic group A) readily induces tumors in newborn rodents. Since Ad12 is isolated from human fecal samples, we investigated whether it plays a role in the etiology of human gastrointestinal cancer. If Ad12 is a causal agent of human cancer, then human tumors should contain Ad12 transforming genes, as indicated by studies of cells transformed in vitro and in vivo by oncogenic viruses. Ad12 DNA and the Ad12 transforming restriction fragment (EcoRI-C fragment, left 16% of the viral genome) were labeled in vitro to 10(7) to 4 X 10(8) cpm/mug by the nick translation reaction of DNA polymerase of Escherichia coli. The fidelity and sensitivity of these probes were established by (i) analysis of DNA from Ad12-transformed cells and from hamsters with tumors induced by Ad12, (ii) reconstruction experiments with added Ad12 DNA and EcoRI restriction fragments, and (iii) comparison of annealing characteristics with Ad12 probes labeled in vivo. With Ad12 [3H]DNA as probe, no viral DNA sequences were detected in 18 normal gastrointestinal tissues and 34 gastrointestinal tumors, including cancers of the colon, rectum, small intestine, and stomach, under conditions that would detect 0.1 copy of the Ad12 genome per tumor cell. Similar analyses of Ad12-transformed hamster cells and Ad12 primary hamster tumors indicated 6-18 copies per cell of over 90% of the viral genome. With the Ad12 EcoRI-C transforming fragment as probe, no hybridization was detected with 32 human gastrointestinal tumors and five normal tissues; this result excludes 1-2% of the Ad12 genome per tumor cell. Our date are strong evidence that Ad12 is not a major cause of human gastrointestinal cancer. The Ad12 transforming EcoRI-C fragment hybridized (50-68% efficiency) with other Ad12 isolates and with Ad18 and 31 (members of oncogenic group A), but not at all with 28 other human Ad serotypes (manuscript in preparation). Thus other group A members probably are also not involved in human gastrointestinal cancer. No viral DNA sequences were detected in 12 normal lungs and 22 lung tumors, suggesting that respiratory cancer does not involve an Ad12 etiology.

Adenoviruses, Human↗
PubMed1968

Activities of arginine dihydrolase and phosphatase in Streptococcus faecalis and Streptococcus faecium.

Strains of Streptococcus faecalis and S. faecium are known to produce ammonia from arginine, but only S. faecalis couples the adenosine triphosphate (ATP) produced through the arginine dihydrolase pathway to growth processes. The specific activities of the arginine dihydrolase enzymes were found to be much lower in S. faecium (0.01 to 0.10) than in S. faecalis (0.24 to 1.60). Phosphatase activities in both strains were similar (up to 0.11), but equaled or exceeded the activities of the arginine dihydrolase enzymes in S. faecium. The failure of S. faecium to show increased growth in arginine media is explained on the basis of low activities of the arginine dihydrolase enzymes coupled with sufficient phosphatase activity to negate any benefit from ATP formed.

Adenosine Triphosphatases↗