1602

DACH1

dachshund family transcription factor 1;DACH1;dachshund family transcription factor 1

dac homolog|dachshund homolog 1

13q22

protein-coding

Oncogene-mediated signaling to the host environment induces a subset of cytokines and chemokines. The Drosophila Dac gene promotes migration of the morphogenetic furrow during eye development. expression of the cell-fate determination factor Dachshund (DACH1) was lost in poor prognosis invasive breast cancer. Mouse embryo fibroblasts derived from Dach1(-/-) mice demonstrated endogenous Dach1 constitutively represses cellular migration. DACH1 inhibited cellular migration and invasion of oncogene (Ras, Myc, ErbB2, c-Raf)-transformed human breast epithelial cells. An unbiased proteomic analysis identified and immunoneutralizing antibody and reconstitution experiments demonstrated IL-8 is a critical target of DACH1 mediating breast cancer cellular migration and metastasis in vivo. DACH1 bound the endogenous IL-8 promoter in ChIP assays and repressed the IL-8 promoter through the AP-1 and NF-kappaB binding sites. Collectively, our data identify a pathway by which an endogenous cell-fate determination factor blocks oncogene-dependent tumor metastasis via a key heterotypic mediator.

The altered expression of human DACH1, a Drosophila Dachshund homolog, has been associated with tumor progression and metastasis. DACH1 inhibits breast cancer cellular proliferation via cyclin D1. Endometrial cancer is the third most common cancer in women and broad screening for DACH1 expression will further our understanding of this disease. Herein, we screened 126 hysterectomy specimens for DACH1 expression and evaluated the correlation between DACH1 levels and several clinical parameters. Decreased DACH1 expression was significantly correlated with FIGO surgical stages (Stage I-II vs. stage III-IV, p = 0.017), peritoneal cytology (p = 0.044), lymph node positivity (p = 0.035) and histological type (p = 0.007), but not histological grade, depth of myometrial and patient age. Immunostaining was also conducted to examine the expression of cyclin D1, estrogen receptor alpha (ERalpha) and progesterone receptor (PR) in these specimens. Multivariate analysis using the stepwise Cox proportional hazard model showed that FIGO surgical stage, histological grade, lymph node metastasis, and PR expression were correlated with poor survival. Despite the fact that univariate analysis demonstrated that DACH1 positivity is associated with increased 5-year survival in all patients (p = 0.037), decreased expression of DACH1 had no significant value as an independent prognostic factor in predicting survival in endometrial cancers. Our results suggested that loss of DACH1 expression might be involved in endometrial cancer progression.

OBJECTIVE: This study aimed to determine the functional relationship between the levels of dachshund homolog 1 (DACH1) expression and different subtypes of ovarian cancer and to investigate the possible prognostic value of DACH1 in ovarian cancer. METHODS: Immunohistochemical staining was deployed to determine the protein levels of DACH1. Staining was performed on patient samples, for whom the detailed follow-up data have been acquired during the last 10 years. Normal, benign, borderline, cancer, and metastatic ovarian cancer samples were included in this study. RESULTS: The results of our study show that DACH1 protein levels increase with the invasiveness of the ovarian cancer. As the cancer progresses from benign and borderline to metastatic, DACH1 protein expression increases as well. Moreover, with the increase in expression, the subcellular distribution of DACH1 changes from nucleus in normal tissue to cytoplasm in cancer. Finally, DACH1 expression levels were compared with estrogen receptor alpha (ERalpha) levels, and the results showed that overall DACH1 levels were higher, whereas also DACH1 exhibited increased cytoplasmic expression in ERalpha-positive ovarian cancer samples. CONCLUSIONS: These results indicate that DACH1 is highly expressed in metastatic ovarian cancer compared with that of normal, benign, and borderline ovarian tissues and that it could play an important role in cancer growth.