Choline phosphate cytidylyltransferase-α is a novel antigen detected by the anti-ERCC1 antibody 8F1 with biomarker value in patients with lung and head and neck squamous cell carcinomas.

BACKGROUND: The determination of in situ protein levels of ERCC1 with the 8F1 monoclonal antibody is prognostic of survival in patients with non-small cell lung cancer (NSCLC). The authors previously demonstrated that 8F1 recognizes a second nuclear antigen. This antigen was identified and its value as a biomarker of clinical outcomes analyzed. METHODS: The second antigen was identified by mass spectrometry. Protein identity and antibody specificity were confirmed through knockdown and overexpression experiments. Immunohistochemistry of 187 early-stage NSCLC samples and 60 head and neck squamous cell carcinomas (HNSCCs) was used to examine the influence of the second antigen on 8F1 immunoreactivity and its association with patient outcomes. RESULTS: Choline phosphate cytidylyltransferase-α (CCTα, also known as phosphate cytidylyltransferase 1 choline alpha [PCYT1A], a phospholipid synthesis enzyme regulated by RAS) is the second antigen recognized by 8F1. In NSCLC samples, CCTα contributed (rho, 0.38) to 8F1 immunoreactivity. In samples of squamous cell carcinomas of the lung, CCTα was found to be the dominant determinant of 8F1 immunoreactivity, whereas its contribution in other subtypes of lung cancer was negligible. High expression of CCTα, but not ERCC1, was found to be prognostic of longer disease-free survival (log-rank P = .002) and overall survival (log-rank P = .056). Similarly, in patients with HNSCC, CCTα contributed strongly to 8F1 immunoreactivity (rho, 0.74), and high CCTα expression was found to be prognostic of survival (log-rank P = .022 for disease-free survival and P = .027 for overall survival). CONCLUSIONS: CCTα is the second antigen detected by 8F1. High CCTα expression appears to be prognostic of survival in patients with NSCLC who are treated by surgery alone and patients with HNSCC. CCTα is a promising biomarker of patient survival and deserves further study.

Pre-treatment tumor expression of ERCC1 in women with advanced stage epithelial ovarian cancer is not predictive of clinical outcomes: a Gynecologic Oncology Group study.

OBJECTIVE: Excision repair cross-complementation group 1 (ERCC1) is required for the repair of platinum-induced DNA damage. This study sought to assess the prognostic value of ERCC1 expression, measured by immunohistochemistry (IHC) using a highly specific antibody, in advanced epithelial ovarian cancer (EOC) patients treated with platinum-based chemotherapy. METHODS: Formalin-fixed, paraffin-embedded tumors were collected from two GOG phase III trials (GOG-172 and GOG-182) of patients with stage III/IV EOC treated with platinum-based chemotherapy. ERCC1 was detected by (IHC) using FL297 polyclonal antibody and tumors were categorized as negative or positive, based on nuclear staining of tumor cells. ERCC1 genotyping was performed as previously reported. Associations between ERCC1 expression and clinical characteristics, platinum responsiveness, progression-free survival (PFS) or overall survival (OS) were evaluated. RESULTS: Of 408 eligible patients, 27% had tumors that were ERCC1 positive. ERCC1 expression was not associated with clinical characteristics or platinum-responsiveness. Women with ERCC1-positive versus -negative tumors had similar median PFS (17.9 months versus 17.5 months, respectively, p=0.59), median OS (52.0 months versus 47.0 months, respectively, p=0.30), risk of disease progression (adjusted hazard ratio [HR]=0.90, 95% confidence interval (CI): 0.71-1.15, p=0.41), and risk of death (adjusted HR=0.81, 95% CI: 0.61-1.07, p=0.14). ERCC1 expression, as measured by IHC, was not associated with single nucleotide polymorphisms (SNPs), in codon 118 and C8092A, of the ERCC1 gene. CONCLUSIONS: ERCC1 expression, measured by IHC in pre-treatment tumor specimens, using a highly specific antibody, has limited clinical value in patients with advanced EOC treated with platinum and taxane based chemotherapy.

Dasatinib (BMS-35482) has synergistic activity with paclitaxel and carboplatin in ovarian cancer cells.

PURPOSE: To explore the activity of dasatinib alone and in combination with paclitaxel and carboplatin in ovarian cancer cells and to determine if dasatinib activity can be predicted based on evaluation of the SRC pathway. EXPERIMENTAL DESIGN: Microarray analysis was performed for IGROV1, OVCAR3, A2780 and SKOV3 ovarian cancer cells and the status of the genomic SRC signature pathway was determined. Cells were treated with carboplatin, paclitaxel and dasatinib individually and in combination. Pre- and post-treatment phospho-SRC (pSRC) and SRC protein expression was determined. Dose-response curves were constructed, and drug interaction was assessed by the Combination Index (CI) method. RESULTS: SRC protein expression levels reflected the SRC pathway genomic signature in the cell lines with the lowest (SKOV3) and highest (IGROV1) pathway expression, but not in those with intermediate expression (OVCAR3, A2780). Dasatinib treatment caused loss of pSRC in all cell lines, with 50% growth inhibition for IGROV1 at 70 nM, OVCAR3 at 34 nM, A2780 at 4.1 µM and SKOV3 at 530 nM. Dasatinib combined with cytotoxics yielded a synergistic effect (CI=0.46 to 0.79) in all cell lines except SKOV3. CONCLUSION: Dasatinib in combination with standard chemotherapeutic agents appears to interact in a synergistic manner in some ovarian cancer cell lines. Further research is needed to evaluate tumor cell characteristics which predict response to dasatinib.

Independent prognostic relevance of microvessel density in advanced epithelial ovarian cancer and associations between CD31, CD105, p53 status, and angiogenic marker expression: A Gynecologic Oncology Group study.

OBJECTIVES: The aims of this study were to examine prognostic significance of microvessel density (MVD) in previously-untreated, advanced epithelial ovarian cancer (EOC) and explore associations between MVD and factors that affect angiogenesis. METHODS: MVD was determined by immunohistochemical expression of CD31 or CD105 in tumor sections from 106 women treated on GOG randomized phase III trials. Average MVD hotspots were quantified by light microscopy at high power (x400) and categorized as low (or=upper quartile). Immunoblot expression of MASPIN, THBS-1, bFGF, VEGF, VEGFR-1 and p53 status (mutation and overexpression) was previously determined. RESULTS: Of 106 evaluable cases, 25% exhibited high CD31-MVD (>24.25 vessels/high power field [HPF]) or high CD105-MVD (>19.25 vessels/HPF). After adjusting for age and stratifying by GOG performance status, stage, cell type, grade, debulking status and treatment regimen, high versus low CD105-MVD was associated with increased risk of disease progression (hazard ratio [HR]=1.873; 95% confidence interval [CI]: 1.102-3.184; p=0.020), but not death (HR=1.125; 95% CI: 0.654-1.935; p=0.670) whereas CD31-MVD was not associated with risk of disease progression (HR=1.578; 95% CI=0.918-2.711; p=0.099) or death (HR=1.678; 95% CI=0.957-2.943; p=0.071). CD31-MVD was correlated with CD105-MVD (p=0.001) and MASPIN (p=0.016). Neither CD31-MVD nor CD105-MVD was associated with p53 status, THBS-1, bFGF, VEGF or VEGFR-1. CONCLUSIONS: High MVD assessed using CD105, a marker of proliferating endothelial cells and neoangiogenesis, but not CD31 a pan-endothelial marker, appeared to be an independent prognostic factor for worse progression-free survival in women with advanced EOC after adjusting for prognostic clinical covariates.

Evaluation of biomarker panels for early stage ovarian cancer detection and monitoring for disease recurrence.

OBJECTIVE: To determine the utility of novel combinations of biomarkers, using both a one-step and two-step assay format, to distinguish serum of early ovarian cancer patients from that of healthy controls and to discern the utility of these biomarkers in a monitoring capacity. METHODS: For ovarian cancer detection, HE4, Glycodelin, MMP7, SLPI, Plau-R, MUC1, Inhibin A, PAI-1, and CA125 were evaluated in a cohort of 200 women with ovarian cancer and 396 healthy age-matched controls. Each biomarker was assessed by serum-based immunoassays utilizing novel monoclonal antibody pairs or commercial kits. For detection of disease recurrence, HE4, Glycodelin, MMP7 and CA125 were evaluated in 260 samples from 30 patients with OC monitored longitudinally after diagnosis. RESULTS: Based upon ROC curve analysis, the sensitivity/specificity of specific biomarker combination algorithms ranged from 59.0%/99.7% to 80.5%/96.5% for detection of early stage ovarian cancer and 76.9%/99.7% to 89.2%/97.2% for detection of late stage cancer. In monitoring evaluation of 27 patients who experienced recurrence of OC, sensitivity for predicting recurrence was 100% for the biomarker panel and 96% for CA125. At least one of the panel biomarkers was elevated earlier (range 6-69 weeks) than CA125 and prior to clinical evidence of recurrence in 14/27 (52%) patients. CONCLUSIONS: We have developed and demonstrated the utility of several one- and two-step multi-marker combinations with acceptable test characteristics for possible use in an ovarian cancer screening population. A subset of this panel may also provide adjunctive information to rising CA125 levels in disease monitoring.

Differential Angiogenic Gene Expression in TP53 Wild-Type and Mutant Ovarian Cancer Cell Lines.

OBJECTIVES: Underlying mechanisms regulating angiogenesis in ovarian cancer have not been completely elucidated. Evidence suggests that the TP53 tumor suppressor pathway and tumor microenvironment play integral roles. We utilized microarray technology to study the interaction between TP53 mutational status and hypoxia on angiogenic gene expression. METHODS: Affymetrix U133A arrays were analyzed for angiogenic gene expression in 19 ovarian cancer cell lines stratified both by TP53 mutation status and A2780 wild-type (wt) TP53 vs. mutated (m) TP53 cell lines after treatment under hypoxic conditions or with ionizing radiation. RESULTS: Twenty-eight differentially expressed angiogenic genes were identified in the mTP53 cell lines compared to wtTP53 lines. Five genes were upregulated in mTP53 cells: 40% involved in extracellular matrix (ECM) degradation [matrix metalloproteinase 10 (MMP10)/15] and 60% in angiogenesis (fibroblast growth factor receptor 3/VEGFA/ephrin receptor-B4). Twenty-three genes were upregulated in wtTP53: nearly 22% were ECM constituents or involved in ECM degradation; over 40% were growth factors or mediators of angiogenesis. Five genes were upregulated in the A2780mTP53 cells: 40% involved in ECM remodeling (MMP10, ADAMTS1), 40% with pro-angiogenic activity (EFNB2, factor 2 receptor), and 20% with anti-angiogenic properties (ADAMTS1). Three genes were upregulated in hypoxia treated cells compared to controls: one with anti-angiogenic activity (angiopoietin-like 4) and two with pro-angiogenic activity (VEGFA, EFNA3). No significant gene fold changes were noted after exposure to radiation. Four genes continued to demonstrate significant differential expression (p ≤ 0.05) after adjusting for multiple comparisons. These genes included endoglin upregulation in wt lines (pro-angiogenesis) and upregulation of FGF20 (growth factor), ADAMTS1 (anti-angiogenesis) and MMP10 (ECM degradation) in mTP53 cell lines. CONCLUSION: Our exploratory findings indicate that non-overlapping angiogenic pathways may be altered by TP53 mutations and hypoxic conditions in the tumor microenvironment. Further evaluation is needed for confirmation.

Development of metastatic endometrial endometrioid adenocarcinoma while on progestin therapy for endometrial hyperplasia.

BACKGROUND: Conservative treatment with progestins is a reasonable treatment option for endometrial complex atypical hyperplasia and, in the experimental setting, for some women with grade 1 endometrial endometrioid adenocarcinoma. The risk of progression to a high-stage endometrial cancer is quite low, with only two previously reported cases in the English literature. CASE: A 40-year-old woman with endometrial complex atypical hyperplasia diagnosed by dilatation and curettage was managed conservatively with progestin therapy (initially, megesterol acetate; then, a combination oral contraceptive). More than 2 years after her original diagnosis, she developed endometrial endometrioid adenocarcinoma, FIGO grade 2, with lymph node metastasis. The tumor was microsatellite instability-high due to methylation of MLH1 and loss of MLH1 protein. CONCLUSION: Currently, there are no good criteria for predicting which patients with complex atypical hyperplasia/grade 1 endometrioid adenocarcinoma will optimally respond to progestin therapy. There is some evidence that endometrial complex hyperplasia demonstrating loss of MLH1 protein by immunohistochemistry is strongly related to subsequent or concurrent endometrial cancer, especially tumors of higher grade and stage. In a woman with a biopsy diagnosis of endometrial hyperplasia, evaluation of MLH1 protein status by immunohistochemistry may provide useful information when medical management is being considered.