33. – GRO/MGSA
Publisher Summary 
The cytokine and growth factor GRO/melanoma growth-stimulatory activity (MGSA) is a member of the cytokines family that was originally associated with either immortal growth of fibroblasts or malignant and benign nevus cells expressing chromosomal abnormalities. The exons of the GRO/MGSA gene family are organized in a very similar pattern to those of the other CXC members of the chemokine family. There is a slight difference among the three GRO genes. All the three members have TATA boxes, and the leader sequence is encoded almost solely within the first exon. The most striking feature of the three genes is the high proportion of ATTTA motifs found within the 3' untranslated regions. The amino-acid (aa) sequences of the three GRO gene products are similar, with GROβ being the most similar to GROα (90% identical) and GROγ showing 86% identity with GROα. Colonic epithelial and bronchial epithelial cells express GROα and GROγ but not GROβ. Synovial fibroblasts express GROα and GROβ but not GROγ. Phorbol ester (PMA)-exposed monocytes express GROβ and GROγ but not GROα, while endotoxin-stimulated monocytes express all three GROs. Retinal pigment epithelial cells exposed to IL-1β or tumor necrosis factor (TNF-α) express all three GROs, while serum-stimulated cells express only GROα and GROγ.