Aberrant expression of WWOX protein in epithelial ovarian cancer: a clinicopathologic and immunohistochemical study.
ABSTRACT Epithelial ovarian cancer is the most frequent cause of death from gynecologic cancer. The WW domain-containing oxidoreductase (WWOX) gene is located at 16q23.3-24.1, a region that spans the second most common human fragile site, FRA16D. Abnormalities affecting WWOX at the genomic and/or expression level(s) have been reported in numerous neoplasias and cancer-derived cell lines. The goal of the study was to evaluate WWOX protein expression in epithelial ovarian carcinoma tissues to determine whether they correlated with clincopathologic parameters. We performed WWOX expression analyses by means of immunohistochemistry on 112 epithelial ovarian carcinoma tissues, and ovarian carcinoma-derived SKOV3, 3AO cells. The basic significant level was fixed at P<0.05. Loss of WWOX expression was observed in 32 (28.6%) of 112 ovarian carcinoma samples and was positively correlated with negative estrogen receptor (ER) (P<0.001) and negative progesterone receptor (PR) (P=0.001). A statistically significant correlation was observed between the lack of WWOX expression and the advanced International Federation of Gynecology and Obstetrics (FIGO) stages (P=0.02). Furthermore, negative WWOX staining was significantly correlated with lymph node metastasis (P=0.013), whereas no significant differences were found between WWOX and HER-2/neu staining (P=0.79). WWOX protein expression was moderately detectable in SKOV3 cells but not in 3AO cells. Our results indicate that loss of WWOX expression in epithelial ovarian carcinomas correlates with negative ER, negative PR, advanced FIGO stages, and lymph node metastases.
- [show abstract] [hide abstract]
ABSTRACT: Studies were conducted with the final goal of identifying genes of interest mapping to the chromosome region 16q23.3-24.1, an area commonly affected by allelic losses in breast cancer. To this end we generated a detailed physical map of the genomic region spanning between sequence-tagged site markers D16S518 and D16S516. To identify candidate genes, we used shotgun genomic sequencing as well as isolation and analysis of transcripts mapping to the area of interest. We identified and cloned a novel gene, the genomic structure of which spans the whole region of interest. We named this gene WWOX because it contains two WW domains coupled to a region with high homology to the short-chain dehydrogenase/reductase family of enzymes. The ORF of WWOX is 1245 bp long, encoding a 414-amino acid protein. This gene is composed of nine exons. We performed a mutation screening of WWOX exons in a panel of breast cancer lines, most of which are hemizygous for the 16q genomic region indicated. We found no evidence of mutations, thus indicating that WWOX is probably not a tumor suppressor gene. However, we observed that one case of homozygous deletion as well as two previously described translocation breakpoints map to intronic regions of this gene. We speculate that WWOX may span the yet uncharacterized common fragile site FRA16D region. In expression studies we found overexpression of WWOX in breast cancer cell lines when compared with normal breast cells and tissues. The highest normal expression of WWOX was observed in hormonally regulated tissues such as testis, ovary, and prostate. This expression pattern and the presence of a short-chain dehydrogenase/reductase domain and specific amino acid features suggest a role for WWOX in steroid metabolism. Interestingly, the presence of WW domains in the structure of WWOX indicate the likelihood that this protein physically interacts with other proteins. The unique features of WWOX and its possible association with cancer processes make it an interesting target for further investigation.Cancer Research 05/2000; 60(8):2140-5. · 8.65 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: To evaluate the feasibility, toxicity, and efficacy of single-agent monoclonal antibody therapy targeting the human epidermal growth factor receptor 2 (HER2)/neu receptor in ovarian and primary peritoneal carcinoma. Eligible patients had measurable persistent or recurrent epithelial ovarian or primary peritoneal carcinoma with 2+ or 3+ HER2 overexpression documented by immunohistochemistry. Intravenous trastuzumab was administered initially at a dose of 4 mg/kg, then weekly at 2 mg/kg. Patients without progressive disease or excessive toxicity could continue treatment indefinitely. Those with stable or responding disease at 8 weeks were offered treatment at a higher weekly dose (4 mg/kg) at time of progression. Patient sera were analyzed for the presence of the soluble extracellular domain of HER2, host antibodies against trastuzumab, and trastuzumab pharmacokinetics. A total of 837 tumor samples were screened for HER2 expression, and 95 patients (11.4%) exhibited the requisite 2+/3+ expression level. Forty-five patients, all of whom received prior chemotherapy, were entered, and 41 were deemed eligible and assessable. There were only mild expected toxicities and no treatment-related deaths. Although an elevated level of the soluble extracellular domain of HER2 was detected in eight of 24 patients, serum HER2 was not associated with clinical outcome. There was no evidence of host antitrastuzumab antibody formation. Serum concentrations of trastuzumab gradually increased with continued therapy. An overall response rate of 7.3% included one complete and two partial responses. Median treatment duration was 8 weeks (range, 2 to 104 weeks), and median progression-free interval was 2.0 months. The clinical value of single-agent trastuzumab in recurrent ovarian cancer is limited by the low frequency of HER2 overexpression and low rate of objective response among patients with HER2 overexpression.Journal of Clinical Oncology 02/2003; 21(2):283-90. · 18.04 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The American Society of Clinical Oncology/ College of American Pathologists (ASCO/CAP) guideline recommendations from January 2007 identified many sources of immunohistochemistry (IHC) testing variation. In this current study, we implemented the guidelines and addressed our institution's preanalytic, analytic, and postanalytic variables relating to HER2 testing to improve clinical outcomes. We evaluated core biopsies performed on breast lesions from 2006 through 2007. Prognostic/predictive markers obtained by IHC were correlated with HER2 fluorescence in situ hybridization (FISH). Preanalytic sources of biopsy testing variation were studied by collecting data on the number of biopsies that needed repeat testing because of inconclusive FISH results. In the year preceding implementation of the guidelines, the HER2 IHC and FISH concordance was 98%. In an additional 10.8% of cases, the FISH results were inconclusive. When additional material became available to retest the inconclusive cases, the results were informative. Further evaluation of the inconclusive cases revealed that the core needle biopsies received, on average, 4 hours of formalin fixation. After implementation of a minimum 6 hours of fixation and the ASCO/CAP guideline recommendations, the HER2 IHC and FISH concordance was 98.5%. The number of FISH inconclusive cases decreased from 10.8% to 3.4% (a 64% reduction). Repeat estrogen-receptor IHC requests decreased by 40% from 38 in 2006 to 23 in 2007. We have shown that standardized fixation and adherence to the ASCO/CAP guidelines for HER2 testing has resulted in a greater HER2 IHC and HER2 FISH correlation, decreased numbers of inconclusive FISH cases, decreased repeat estrogen-receptor requests, and financial savings to the Department of Pathology.Archives of pathology & laboratory medicine 06/2009; 133(5):775-80. · 2.78 Impact Factor