Identification of Tumor Antigens in Ovarian Cancers Using Local and Circulating Tumor-Specific Antibodies.

Ovarian cancers include several disease subtypes and patients often present with advanced metastatic disease and a poor prognosis. New biomarkers for early diagnosis and targeted therapy are, therefore, urgently required. This study uses antibodies produced locally in tumor-draining lymph nodes (ASC probes) of individual ovarian cancer patients to screen two separate protein microarray platforms and identify cognate tumor antigens. The resulting antigen profiles were unique for each individual cancer patient and were used to generate a 50-antigen custom microarray. Serum from a separate cohort of ovarian cancer patients encompassing four disease subtypes was screened on the custom array and we identified 28.8% of all ovarian cancers, with a higher sensitivity for mucinous (50.0%) and serous (40.0%) subtypes. Combining local and circulating antibodies with high-density protein microarrays can identify novel, patient-specific tumor-associated antigens that may have diagnostic, prognostic or therapeutic uses in ovarian cancer.

Up-regulation of HDAC6 Results in Poor Prognosis and Chemoresistance in Patients With Advanced Ovarian High-grade Serous Carcinoma.

BACKGROUND: Ovarian high-grade serous carcinoma (HGSC) gradually acquires chemoresistance after recurrence. Our previous study on ovarian clear-cell carcinoma found histone deacetylase 6 (HDAC6) overexpression led to chemoresistance. This study aimed to evaluate HDAC6 as a predictor of chemoresistance and a therapeutic target for ovarian HGSC. PATIENTS AND METHODS: The clinical significance of HDAC6 as a predictor of prognosis and chemoresistance in HGSC was immunohistochemically evaluated. In addition, expression of programmed cell death ligand-1 (PD-L1), and hypoxia-inducible factor-1α (HIF1α) were analyzed using clinical samples from 88 patients with ovarian HGSC, and their clinicopathological characteristics were reviewed. RESULTS: Twenty-three patients had high HDAC6 expression, 10 positive PD-L1 expression, and 33 high HIF-1α expression. HDAC6 up-regulation was correlated with not undergoing interval debulking surgery (p<0.001), incomplete surgical resection (p=0.002), and frequent occurrence of stable disease/progressive disease according to the Response Evaluation Criteria in Solid Tumors (p=0.005) criteria. On Kaplan-Meier analysis, high HDAC6 expression was significantly associated with reduced progression-free (p=0.001) and overall (p=0.008) survival. On multivariate analysis, high HDAC6 expression (hazard ratio=1.65, 95% confidence interval 1.03-2.66; p=0.039) and surgery status were independent prognostic factors of progression-free survival. PD-L1 and HIF1α expression positively correlated with that of HDAC6. CONCLUSION: HDAC6 may become a potential therapeutic target in patients with ovarian HGSC since its up-regulation is considered to be associated with a poor prognosis in patients with this cancer.

Hypoxia-inducible Factor-1α Suppression in Ovarian Clear-cell Carcinoma Cells by Silibinin Administration.

BACKGROUND/AIM: Advanced ovarian clear-cell carcinoma (CCC) fails to respond to standard chemotherapy, and has a poor prognosis. Since hypoxia-inducible factor-1 (HIF-1) stimulates various genes involved in cancer, we aimed to examine the efficacy of silibinin, an active component of milk thistle belonging to Asteraceae, in suppressing HIF-1 activity, and elucidate the underlying mechanism in human CCC cell lines. MATERIALS AND METHODS: Human ovarian CCC cell lines HAC-2, OVISE, and RMG-1 were treated with 500 µM silibinin for 4 h under normoxic and hypoxic conditions. Using DNA microarray, we analysed genes whose expression modulated more than 2-fold in response to hypoxia, whereas HIF-1α expression was measured using ELISA. RESULTS: Silibinin treatment decreased HIF-1α protein in all cell lines, and eIF4E2 and RPS6 mRNA in HAC-2 and RMG-1 cells. CONCLUSION: Silibinin suppressed HIF-1α protein under hypoxic conditions in CCC cell lines and could be a potential anti-cancer drug.

Comprehensive Serum Glycopeptide Spectra Analysis (CSGSA): A Potential New Tool for Early Detection of Ovarian Cancer.

OBJECTIVES: To conduct a comprehensive glycopeptide spectra analysis of serum between cancer and non-cancer patients to identify early biomarkers of epithelial ovarian cancer (EOC). METHODS: Approximately 30,000 glycopeptide peaks were detected from the digested serum glycoproteins of 39 EOC patients (23 early-stage, 16 advanced-stage) and 45 non-cancer patients (27 leiomyoma and ovarian cyst cases, 18 endometrioma cases) by liquid chromatography mass spectrometry (LC-MS). The differential glycopeptide peak spectra were analyzed to distinguish between cancer and non-cancer groups by employing multivariate analysis including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA) and heat maps. RESULTS: Examined spectral peaks were filtered down to 2281 serum quantitative glycopeptide signatures for differentiation between ovarian cancer and controls using multivariate analysis. The OPLS-DA model using cross-validation parameters R2 and Q2 and score plots of the serum samples significantly differentiated the EOC group from the non-cancer control group. In addition, women with early-stage clear cell carcinoma and endometriomas were clearly distinguished from each other by OPLS-DA as well as by PCA and heat maps. CONCLUSIONS: Our study demonstrates the potential of comprehensive serum glycoprotein analysis as a useful tool for ovarian cancer detection.

Clinicopathological correlation of ARID1A status with HDAC6 and its related factors in ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) is associated with a frequent loss in ARID1A function. ARID1A reportedly suppresses histone deacetylase (HDAC)6 in OCCC directly. Here, we evaluated the clinical significance of HDAC6 expression and its related factors in terms of ARID1A status. Immunohistochemical expression of HDAC6, hypoxia inducible factors-1α (HIF-1α), programmed death-1 ligand (PD-L1), CD44 (cancer stem cell marker), and ARID1A was analysed for 106 OCCC patients. High nuclear HDAC6 expression correlated with patient death (p = 0.038). In the multivariate analysis of overall survival, surgical status (complete or incomplete resection) (hazard ratio (HR) = 17.5; p = <0.001), HDAC6 nuclear expression (HR = 1.68; p = 0.034), and PD-L1 expression (HR = 1.95; p = 0.022) were the independent prognostic factors. HDAC6 upregulation and ARID1A loss did not necessarily occur simultaneously. High HDAC6 expression was associated with poor prognosis in OCCC with ARID1A loss; this was not observed without ARID1A loss. HDAC6 expression showed a significant positive correlation with HIF-1α, PD-L1, and CD44. In OCCC, HDAC6 involvement in prognosis depended on ARID1A status. HDAC6 also led to immuno- and hypoxia- tolerance and cancer stem cell phenotype. HDAC6 is a promising therapeutic target for OCCC with loss of ARID1A.

Impact of TP53 immunohistochemistry on the histological grading system for endometrial endometrioid carcinoma.

Endometrial endometrioid carcinoma is usually divided into three histological subgroups: grade 1 (G1), grade 2 (G2), and grade 3 (G3). Most cases of endometrial endometrioid carcinoma G1/2 have a favorable prognosis, although some can have unfavorable outcomes, especially when they involve elderly patients, with similarities to endometrioid carcinoma G3 and serous carcinoma. This retrospective study evaluated whether TP53 abnormalities in endometrial endometrioid carcinoma could be used to supplement the current grading system and improve its ability to predict clinical outcomes. Immunohistochemical expression of TP53 was analyzed using tissue microarrays from the surgically resected specimens of 475 patients with endometrial endometrioid carcinoma. Weak or moderate expression was defined as TP53-normal expression, while absent or strongly positive expression was defined as TP53-aberrant expression. The endometrial endometrioid carcinomas had originally been diagnosed as G1 (69%), G2 (18%), and G3 (13%). Univariate analyses revealed that TP53-aberrant expression was associated with poor survival in G1 and G2 cases, but not G3 cases. In addition, age (<60 years vs. ≥60 years) was correlated with TP53-aberrant expression in G1 cases (3% vs. 16%, p = 0.001), but not in G2 or G3 cases. Based on immunohistochemical TP53 expression, the endometrial endometrioid carcinomas were reclassified using a prognostic grading system as high-grade (G1 or G2 with TP53- aberrant expression, and G3 with TP53-normal or -aberrant expression) or low-grade (G1 or G2 with TP53-normal expression). The multivariate analyses revealed that the prognostic grading system (using histological grade and TP53 expression) could independently predict poor progression-free survival (hazard ratio: 2.91, p < 0.001) and overall survival (hazard ratio: 3.62, p < 0.001). Therefore, combining immunohistochemical TP53 expression with the traditional histological grading system for endometrial endometrioid carcinoma may help improve its ability to accurately predict the patient's prognosis.

Association of the hypoxia-inducible factor-1α (HIF-1α) gene polymorphisms with prognosis in ovarian clear cell carcinoma.

BACKGROUND: Ovarian clear cell carcinoma (OCCC) is the second most common ovarian cancer after serous carcinoma in Japan. OCCC has a more unfavorable clinical outcome due to a poor response to platinum-based chemotherapy, compared with serous carcinoma. Hypoxia inducible factor-1α (HIF-1α) is a key regulator of cellular response to hypoxia and plays an important role in tumor growth, and HIF-1α gene single-nucleotide polymorphisms (SNPs) adversely affect the outcome in some cancers. Herein, we investigated the association of the HIF-1α gene SPNs with clinical outcome in OCCCs. Eighty-nine patients with OCCC were recruited in whom pathological diagnosis was confirmed with surgically resected specimen. RESULTS: The SNPs of C1772T and G1790A in the HIF-1α gene occurred in 23.6 and 3.3% of the patients, respectively. In the univariate analysis, overall survival was associated with stage and surgical residual tumor but not with the SNPs C1772T, G1790A, C1772T and/or G1790A. In the multivariate survival analysis, a significant association was observed between outcome and FIGO stage and/or surgical residual tumor; however, no association was obtained between HIF-1α gene SNPs and these factors. CONCLUSION: In conclusion, unlike the other cancers in which HIF-1α gene SNPs were demonstrated to be associated with the outcome, OCCC prognosis may not be affected by HIF-1α gene SNPs. Further studies need to be performed to clarify the association of HIF-1α expression with the unfavorable prognosis in OCCCs, in terms of transcriptional/translational activity, nuclear translocation of the protein, and protein degradation.

Association of histone deacetylase expression with histology and prognosis of ovarian cancer.

Histone deacetylase (HDAC) inhibitor is known to have a cytotoxic effect on ovarian cancer cell lines. The present study analyzed the association between immunohistochemical HDAC expression and clinicopathological findings, in particular, the association with histological type and effect of chemotherapy. The histology of the 201 ovarian cancers addressed was as follows: Serous carcinoma (SEC), 100 cases; clear cell carcinoma (CCC), 56 cases; endometrioid carcinoma (EMC), 36 cases; and mucinous carcinoma (MUC), 9 cases. Immunohistochemical analyses of HDACs 1, 2, 3, 4, 5, 6 and 7 expression levels were performed using tissue microarrays, composed of 201 primary tumors and 38 tumors following chemotherapy. Overexpression of HDAC1 was detected in the nucleus of all cases with MUC, followed by CCC (80%), SEC (73%), and EMC (53%). CCC specifically demonstrated HDAC7 expression in both the nucleus (27%) and the cytoplasm (54%), and HDAC6 expression in the nucleus (34%). The comparison between prior to and following chemotherapy revealed a nuclear expression increase in HDAC1 (76% vs. 92%; P=0.03) and HDAC7 (0.0 vs. 16%; P=0.01), and cytoplasmic expression increase in HDAC6 (40 vs. 74%; P=<0.01) and HDAC7 (16 vs. 66%; P=<0.01). HDAC1 nuclear expression adversely affected overall survival in SEC (P=0.02) and EMC (P=0.03), and HDAC7 cytoplasmic expression in CCC was associated with a poor prognosis (P=0.06). In multivariate analysis, HDAC6 nuclear expression was determined as a poor prognostic factor (hazard ratio=3.51; 95% confidence interval, 1.49 to 8.27, P=<0.01). In the subgroup analysis, HDAC6 nuclear expression was associated with a poor prognosis in CCC (P=0.07), International Federation of Obstetrics and Gynecology stage III/IV (P=0.07), and suboptimal surgery (P=<0.01). In conclusion, HDACs may be associated with the prognosis of ovarian cancers, depending on the histological subtypes, and upregulated following chemotherapy. HDAC1, 6 and 7 may therefor act as promising therapeutic targets in the future.

Fully sialylated alpha-chain of complement 4-binding protein (A2160): a novel prognostic marker for epithelial ovarian carcinoma.

PURPOSE: Fully sialylated alpha-chain of complement 4-binding protein (A2160) is a member of the glycoprotein family and has recently been identified as a diagnostic biomarker for epithelial ovarian cancer. This study examined the utility of A2160 as a prognostic biomarker for this disease. METHODS: This is a retrospective analysis of prospectively collected plasma samples from 93 women with stage I-IV epithelial ovarian cancer who underwent primary cytoreductive surgery between 2009 and 2014. Pretreatment A2160 levels were correlated to clinico-pathological factors and survival outcome. RESULTS: Women with advanced-stage disease had significantly higher 2160 levels compared to those with early stage disease (stage I-II versus III-IV, median 2.17-2.70 versus 5.31-8.70 U/mL, P < 0.01). Women with high-grade serous ovarian carcinoma had higher A2160 levels compared to other histologies (6.60 versus 3.01 U/mL, P = 0.05). Women who had suboptimal cytoreduction had significantly higher A2160 levels than those who achieved optimal/complete cytoreduction (7.02 versus 2.30-3.17 U/mL, P < 0.01). On univariable analysis, higher A2160 levels were significantly associated with decreased progression-free survival (64-100 versus 1-33%ile, 5-year rates 53.4 versus 78.9%, P = 0.029). After controlling for age, CA-125 level, cytoreductive status, histology, and stage, higher A2160 levels remained an independent prognostic factor for decreased progression-free survival (adjusted-hazard ratio (HR) 2.48, 95% confidence interval (CI) 1.01-6.11, P = 0.049). Similarly, higher A2160 levels were independently associated with decreased cause-specific survival on multivariable analysis (adjusted-HR 3.07, 95% CI 1.19-7.93, P = 0.021). CONCLUSION: Our study suggests that A2160 may be a useful prognostic biomarker for epithelial ovarian cancer, and higher pretreatment levels of A2160 predicts poor survival outcome.

Relationship between immune function and serum vitamin A in Japanese black beef cattle.

This study evaluated the relationship between the serum vitamin A level and immune function in seventy non-diseased Japanese Black (JB) cattle during their fattening stages. The animals were divided into two groups, a Low Vitamin A (VA) group (N=9) with below 30 IU/dl of serum VA and a Control group (N=61). Blood samples were collected for biochemical analysis and examination of the leukocyte population and cytokine mRNA expression. The numbers of CD3(+)WC1(+) T cells and MHC class-ll(+)CD14(-) B cells were significantly lower in the Low VA group than in the Control group (P<0.05). The IFN-gamma/IL-4 rate was significantly lower in the Low VA group, while IL-4 was higher and IFN-gamma was lower in the Low group compared with the Control group. This study indicated that immune function imbalance was present in JB cattle with low serum VA levels during the fattening stage.