Development of ELISA to estimate thymosin alpha1, the N terminus of prothymosin alpha, in human tumors
Loidi, L.; Vidal, A.; Zalvide, J.B.; Puente, J.L.; Reyes, F.; Domínguez, F.
Clinical Chemistry 43(1): 59-63
1997
ISSN/ISBN: 0009-9147 PMID: 8990223 Document Number: 470381
We reported that tumor content of prothymosin alpha (ProT alpha) is a proliferation index of human breast tumors that might be used to identify patients at high risk for distant metastasis (Dominguez et al., Eur J Cancer 1993; 29A:893-7). In that study ProT alpha concentrations were measured by a RIA; here we present an alternative nonisotopic assay that could be used in a standard clinical laboratory. Main features of the ELISA are: (a) A recombinant fusion protein glutathione S-transferase (GST)-human ProT alpha was used to coat the microtiter plates; (b) we used a polyclonal antiserum raised in rabbits that detects thymosin alpha-1, the NH-2-terminal fragment of ProT alpha; (c) it is as sensitive as the RIA; (d) it is faster than the RIA. ProT alpha concentrations in various human tumors (skin, esophagus, colorectal, and breast) as assessed by ELISA were comparable with, although twofold greater than, the values previously estimated by RIA.