Molecular cloning, characterization and isolation of novel spliced variants of the human ortholog of a rat estrogen-regulated membrane-associated protein, UO-44.

We have previously reported the characterization of an estrogen-regulated rat uterine-ovarian-specific complementary DNA (UO-44). To understand the involvement of this protein in the initiation and progression of human ovarian and uterine cancers, we now report the cloning and characterization of the human ortholog (HuUO-44). HuUO-44 is mapped to chromosome 10q26.13 and contains nine exons. Multiple tissue Northern blot detected two HuUO-44 transcripts of approximately 2 and 3 kb in the pancreas. RT-PCR demonstrated that HuUO-44 undergoes a complex series of alternative splicing events between exons 2 and 6 that yielded four novel splice variants, HuUO-44A, HuUO-44B, HuUO-44C and HuUO-44D. Putative functional motifs identified in HuUO-44 are two CUB domains and a zona-pellucida domain. Transfection studies demonstrated the membrane-associated nature of HuUO-44. By immunohistochemistry, HuUO-44 was located to the normal ovarian and ovarian tumor epithelial cells; in NIH-OVCAR3 ovarian cancer cells, HuUO-44 was detected only at the leading edge of the dividing cells. Most importantly, a marked loss in cell attachment and proliferation was observed in NIH-OVCAR3 cells cultured in the presence of a polyclonal HuUO-44 antiserum. These findings suggest the potential role of HuUO-44 in cell motility, cell-cell interactions and/or interactions with the extracellular matrices.

Reduction of CWR22 prostate tumor xenograft growth by combined tamoxifen-quercetin treatment is associated with inhibition of angiogenesis and cellular proliferation.

Combination chemotherapy is increasingly practiced for the treatment of malignant prostate cancers. The aim of this study was to evaluate the in vivo efficacy of combined tamoxifen and quercetin in prostate tumor xenografts. Severe combined immune deficient (SCID) mice inoculated with CWR22 prostate tumor cells were treated with either tamoxifen (10 mg/kg/week), quercetin (200 mg/kg/day) or combined tamoxifen-quercetin for 28 days. Tamoxifen or quercetin alone exhibited a moderate antitumor activity. Tamoxifen decreased the Ki-67 index by 52.4%, reduced the vascular endothelial growth factor (VEGF) 121 and VEGF165 mRNA by 18.6 and 21.8%, respectively, and suppressed the blood vessel formation, while quercetin modulated the expression and phosphorylation of cdc-2 and cyclin B1, and inhibited the Ki-67 index by 66.0%. Combined tamoxifen-quercetin effectively delayed the appearance of tumors, inhibited the final tumor volume by 73.3% and reduced the endpoint tumor weight by 67.1% (p<0.05). The Ki-67 index, VEGF121, VEGF165 mRNA and microvessel density (MVD) were decreased by 66.9, 22.1, 40.1 and 59.0%, respectively, by the combined treatment. These findings indicate that tamoxifen inhibits CWR22 prostate tumor by modulating the angiogenesis and its antineoplastic effects can be potentiated by combined use with quercetin.