In situ hybridization study of chromogranin A and B mRNA in carcinoid tumors.
The distribution of the mRNAs for chromogranin A and B was analyzed by in situ hybridization with 35S-labeled oligonucleotide probes in formalin-fixed paraffin-embedded carcinoid tumor tissues. All the 15 mid-gut carcinoid tumors examined contained both mRNAs for chromogranin A and B at high level in tumor cells. Sixteen of 18 bronchial carcinoid tumors but only 2 of 5 rectal carcinoid tumors expressed one or both species of chromogranin mRNAs. The same tendency was seen with the argyrophil reaction according to Grimelius where most of the mid-gut tumor cells were uniformly stained, while considerable variation in reactivity was seen in some of the bronchial and rectal carcinoid tumor cells. The sequential sections were stained with a monoclonal antibody against chromogranin A and a polyclonal antiserum which reacts with both chromogranins. The expression of the mRNA for chromogranin A on the carcinoid tumors was almost concordant with that of chromogranin B as well as with the chromogranin A protein, whereas almost all tumors stained positively with the polyclonal antibodies. Analyses of mRNA expression of chromogranin A before and after interferon therapy on 4 patients with mid-gut carcinoids indicated an inhibition at pre-translational level. In conclusion, the mRNAs for chromogranin A and B are good markers for the carcinoid tumors, especially of mid-gut origin. Fore-gut, mid-gut and rectal carcinoid tumors are different in their endocrine properties regarding the expression of the chromogranins.
Funa
K
K
Ludwig Institute for Cancer Research, University Hospital, Uppsala, Sweden.
Eriksson
B
B
Wilander
E
E
Oberg
K
K
D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D001984:Bronchial Neoplasms / Q000737:chemistry*; D002276:Carcinoid Tumor / Q000737:chemistry*; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis* / Q000235:genetics; D015342:DNA Probes; D006801:Humans; D007414:Intestinal Neoplasms / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000032:analysis*; D012004:Rectal Neoplasms / Q000737:chemistry*
D014408:Biomarkers, Tumor; C506150:CHGA protein, human; D053379:Chromogranin A; D002864:Chromogranins; D015342:DNA Probes; D012333:RNA, Messenger