CA19-9 epitope a possible marker for MUC-1/Y protein.
It has been reported that MUC-1 molecules devoid of the tandem repeat region (MUC-1/Y) are detected preferentially in carcinoma cells and are associated with their progression. However, its clinical significance is still unknown. We constructed a mouse colon adenocarcinoma cell line (MC-38) transduced with either MUC-1/Y cDNA defecting the tandem repeat region (Y-MC-38) or MUC-1/R cDNA containing ten tandem repeats (R-MC-38). RT-PCR of mRNAs derived from Y-MC-38 cells using the specific primers to MUC-1/Y mRNAs, proved the existence of 600 bp RT-PCR products generated only from MUC-1/Y mRNAs. DF3 and CA19-9 epitopes out of the MUC-1-related tumor-associated antigens, have been reported to be involved in the prognosis of cancer patients. We examined the expression of DF3 and CA19-9 epitopes on Y-MC-38 and R-MC-38 cells. Fluorescence-activated cell sorting (FACS) analysis of R-MC-38 and Y-MC-38 cells using two monoclonal antibodies against DF3 (mAb DF3) and CA19-9 (mAb CA19-9) epitopes revealed that R-MC-38 cells expressed DF3 but not CA19-9 [DF3(+)CA19-9(-)], while Y-MC-38 cells expressed CA19-9 but not DF3 [DF3(-)CA19-9(+)]. On Western blot, a 40 kDa protein product was recognized by mAb CA19-9 but not by mAb DF3 on cell lysates of Y-MC-38 cells, whereas a 70 kDa protein product was recognized by mAb DF3 but not by mAb CA19-9 on the cell lysates of R-MC-38. Further, we analyzed the expression of MUC-1/Y mRNAs by RT-PCR on various human cancer cell lines: the gastric cancer cell line AZ521, the pancreatic cancer cell lines PANC-1 and Capan-1, the gall bladder cell line GBK-1, the breast cancer cell line MCF-7, and the colon cancer cell lines HT-29 and Colo205. HT-29 and Capan-1 cells producing the 600 bp RT-PCR product, were positive for mAb CA19-9. These results demonstrate that CA19-9 epitope is produced only on MUC-1/Y core protein, suggesting that CA19-9 epitope may be a specific marker for MUC-1/Y protein.
Akagi
J
J
National Kumamoto-Minami Hospital, Kumamoto 869-0593, Japan.
Takai
E
E
Tamori
Y
Y
Nakagawa
K
K
Ogawa
M
M
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000595:Amino Acid Sequence; D000818:Animals; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D015153:Blotting, Western; D018395:CA-19-9 Antigen / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D017931:DNA Primers / Q000737:chemistry; D019084:Fluorescent Antibody Technique, Indirect; D005822:Genetic Vectors; D006801:Humans; D008969:Molecular Sequence Data; D018396:Mucin-1 / Q000235:genetics / Q000378:metabolism*; D011379:Prognosis; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014407:Tumor Cells, Cultured
D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D017931:DNA Primers; D018396:Mucin-1