The erythroblastic leukemia viral oncogene homolog (erbB) family of tyrosine kinase growth factor receptors

Previously, we studied the erythroblastic leukemia viral oncogene homolog (erbB) family of tyrosine kinase growth factor receptors in terms of protein expression, modulation and activation in the 3T3-L1 cell line. In the present study, the presence of full-length erbB mRNAs, and splice or proteolytic erbB variants, was evaluated using RT-PCR. Epidermal growth factor receptor (EGFR)/erbB1 expression was confirmed. Wild-type (wt) ErbB2, human erbB2 (HER2)extracellular domain (ECD) and herstatin mRNA expression were analyzed. Restriction analysis confirmed wt expression. 3T3-L1 cells exhibited HER2-ECD and herstatin mRNA expression, although at extremely low levels (compared to the control cell lines). ErbB3 cDNA was amplified using mouse mammary tumors and rat acines as positive controls. ErbB4 was not positively identified in these cells. In conclusion, this study demonstrates that 3T3-L1 cells express EGFR/erbB1, erbB2 and erbB3, and possibly, certain erbB2 splice or proteolytic variants, which are worth pursuing.