54940

OCIAD1

OCIA domain containing 1;OCIAD1;OCIA domain containing 1

OCIA domain-containing protein 1|ovarian carcinoma immunoreactive antigen

4p11

protein-coding

OBJECTIVES: To identify proteins unique to metastatic ovarian cancer and test their potential involvement in cell adhesion. METHODS: We purified plasma membrane from paired metastatic and primary tumor tissues from patients with stage IIIC ovarian cancer. Membrane proteins unique to metastases were identified by liquid chromatographic mass spectrometry (LC-MS). The role of one of the identified proteins, ovarian cancer immuno-reactive antigen domain containing 1 (OCIAD1) in cell adhesion was determined in the presence of LPA using both over-expression and down regulation approaches. RESULTS: We identified a differentially expressed 29 kDa protein as OCIAD1 over-expressed in metastatic tissues, when compared to primary tumor tissues. OCIAD1 over-expression in HEY ovarian cancer cells increased LPA-induced, but not basal level cell adhesion to extracellular matrix proteins collagen I and laminin 10/11. This enhancement was not blocked by LY294002 and GF109203X, suggesting that OCIAD1 does not use PKC and PI3K signaling pathways to exert its effect on adhesion. In addition, LPA induced cell adhesion to collagen I was unaffected by paclitaxel (5 microM) in OCIAD1 overexpressing cells. CONCLUSIONS: This is the first report that OCIAD1 is over-expressed in metastatic ovarian cancer tissues. The effect of OCIAD1 on cell adhesion may be related to its function in ovarian cancer. Failure of paclitaxel to affect ovarian cancer cell adhesion in presence of OCIAD1 raises the possibility of OCIAD1s role in tumor metastasis. Ongoing studies using a mouse orthotopic LPA-dependent ovarian cancer metastasis model are focused on strategies to inhibit the potential role of OCIAD1 in tumor metastasis.

AIMS: The biomarkers representing the metastatic potential of well-differentiated thyroid carcinoma remain to be established. A study was undertaken to find whether the expression status of neural cell adhesion molecule (NCAM) and/or ovarian cancer immunoreactive antigen domain containing 1 (OCIAD1) is associated with the metastatic potential of differentiated thyroid carcinoma. METHODS: NCAM and OCIAD1 were analysed by immunohistochemistry on tissue microarrays. RESULTS: Among 214 well-differentiated thyroid carcinomas, 68 patients had distant metastases. Immunohistochemical analyses showed that the majority of benign thyroid lesions expressed NCAM while a significant proportion of thyroid carcinomas lost or had reduced NCAM expression. Both follicular and papillary carcinomas with distant metastasis had a significantly higher frequency of preserving NCAM expression. Hierarchical clustering analysis showed that OCIAD1 had significant differential expression between benign and malignant thyroid lesions. The overall metastatic-to-localised tumour ratio was higher in NCAM-expressing clusters, but the difference between ratios of OCIAD1-positive and OCIAD1-negative subclusters was not significant. CONCLUSIONS: These analyses suggest that the preservation of NCAM expression in well-differentiated thyroid carcinoma is an indicator for a higher risk of distant metastasis. OCIAD1 is a potential biomarker of thyroid carcinoma but had no significant additive effect on the risk of distant metastasis. Further elucidation of the molecular mechanisms underlying the NCAM-mediated cellular processes will be beneficial for the development of effective treatments against the metastasis of thyroid carcinoma.