In situ detection of c-myc mRNA in adenocarcinomas, adenomas, and mucosa of human colon.
We used a sensitive RNA:RNA in situ hybridization technique to study steady-state levels of c-myc proto-oncogene mRNA in primary human colon adenocarcinomas, villous adenomas, and normal mucosa samples. Frozen tissue sections, fixed in 4% buffered paraformaldehyde, were hybridized to 35S-labeled anti-sense transcripts of a c-myc clone and processed for autoradiography. The specificity of the hybridization was controlled by using 35S-labeled plasmid transcripts as a negative control, while RNA preservation in the tissue sample was assessed by using 35S-labeled anti-sense transcripts of a murine 28S rRNA clone. c-myc RNA was detectable in all the carcinomas (eight) and villous adenomas (four), but steady-state levels varied from high to low in different tumors with similar histology. Low levels of c-myc RNA were detected in epithelial stem cells of some of the normal mucosa samples (five). No genetic alterations of the c-myc locus were found by Southern analysis of DNAs extracted from the carcinomas.
Mariani-Costantini
R
R
Laboratory of Tumor Immunology and Biology, National Cancer Institute, Bethesda, Maryland 20892.
Theillet
C
C
Hutzell
P
P
Merlo
G
G
Schlom
J
J
Callahan
R
R
D000230:Adenocarcinoma / Q000032:analysis*; D000236:Adenoma / Q000032:analysis*; D015152:Blotting, Northern; D003106:Colon / Q000032:analysis; D003110:Colonic Neoplasms / Q000032:analysis*; D015342:DNA Probes; D006801:Humans; D007413:Intestinal Mucosa / Q000032:analysis*; D009693:Nucleic Acid Hybridization; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis*
D015342:DNA Probes; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D015347:RNA Probes; D012333:RNA, Messenger