Mammaglobin B (SCGB2A1) is a novel tumour antigen highly differentially expressed in all major histological types of ovarian cancer: implications for ovarian cancer immunotherapy.

BACKGROUND: We studied the genetic fingerprints of ovarian cancer and validated the potential of Mammaglobin b (SCGB2A1), one of the top differentially expressed genes found in our analysis, as a novel ovarian tumour rejection antigen. METHODS: We profiled 70 ovarian carcinomas including 24 serous (OSPC), 15 clear-cell (CC), 24 endometrioid (EAC) and 7 poorly differentiated tumours, and 14 normal human ovarian surface epithelial (HOSE) control cell lines using the Human HG-U133 Plus 2.0 chip (Affymetrix). Quantitative real-time PCR and immunohistochemistry staining techniques were used to validate microarray data at RNA and protein levels for SCGB2A1. Full-length human-recombinant SCGB2A1 was used to pulse monocyte-derived dendritic cells (DCs) to stimulate autologous SCGB2A1-specific cytotoxic T-lymphocyte (CTL) responses against chemo-naive and chemo-resistant autologous ovarian tumours. RESULTS: Gene expression profiling identified SCGB2A1 as a top differentially expressed gene in all histological ovarian cancer types tested. The CD8+ CTL populations generated against SCGB2A1 were able to consistently induce lysis of autologous primary (chemo-naive) and metastatic/recurrent (chemo-resistant) target tumour cells expressing SCGB2A1, whereas autologous HLA-identical noncancerous cells were not lysed. Cytotoxicity against autologous tumour cells was significantly inhibited by anti-HLA-class I (W6/32) monoclonal antibody. Intracellular cytokine expression measured by flow cytometry showed a striking type 1 cytokine profile (i.e., high IFN-γ secretion) in SCGB2A1-specific CTLs. CONCLUSION: SCGB2A1 is a top differentially expressed gene in all major histological types of ovarian cancers and may represent a novel and attractive target for the immunotherapy of patients harbouring recurrent disease resistant to chemotherapy.

Vaginal myofibroblastoma with glands expressing mammary and prostatic antigens.

A case of unusual vaginal myofibroblastoma containing glands which expressed mammary and prostatic markers is described. The tumor occurred in 70-year-old woman in the proximal third of the vagina. It showed morphology and immunophenotype typical of so-called cervicovaginal myofibroblastoma. The peripheral zone of the lesion contained a few groups of glands suggesting vaginal adenosis or prostatic-type glands on initial examination. The glands showed a surprising simultaneous expression of mammary markers mammaglobin and GCDFP-15 and prostatic markers prostate-specific antigen (PSA) and prostate-specific acid phosphatase (PSAP). Immunostains for alpha-smooth muscle actin, p63 and CD10 highlighted the myoepithelial cell layer of the glands. The finding indicates that simultaneous use of both mammary and prostatic markers for examination of unusual glandular lesions in the vulvovaginal location can be helpful for an exact diagnosis, and can contribute to better understanding of prostatic and mammary differentiations in the female lower genital tract.

The Clinical Value of PELP1 for Breast Cancer: A Comparison with Multiple Cancers and Analysis in Breast Cancer Subtypes.

PURPOSE: Proline, glutamic acid, and leucine-rich protein 1 (PELP1), a novel nuclear receptor (NR) co-regulator, is highly expressed in breast cancer. We investigated its expression in breast cancer subtypes, in comparison with other breast markers as well as cancers from different sites. Its prognostic relevance with different subtypes and other NR expression was also examined in breast cancers. METHODS: Immunohistochemical analysis was performed on totally 1,944 cancers from six different organs. RESULTS: PELP1 expression rate was the highest in breast cancers (70.5%) among different cancers. Compared to GATA3, mammaglobin and gross cystic disease fluid protein 15, PELP1 was less sensitive than GATA3 for luminal cancers, but was the most sensitive for non-luminal cancers. PELP1 has low expression rate (<20%) in colorectal cancers, gastric cancers and renal cell carcinomas, but higher in lung cancers (49.1%) and ovarian cancers (42.3%). In breast cancer, PELP1 expression was an independent adverse prognostic factor for non-luminal cancers (disease-free survival [DFS]: hazard ratio [HR], 1.403; p=0.012 and breast cancer specific survival [BCSS]: HR, 1.443; p=0.015). Interestingly, its expression affected the prognostication of androgen receptor (AR). ARposPELP1lo luminal cancer showed the best DFS (log-rank=8.563, p=0.036) while ARnegPELP1hi non-luminal cancers showed the worst DFS (log-rank=9.536, p=0.023). CONCLUSION: PELP1 is a sensitive marker for breast cancer, particularly non-luminal cases. However, its considerable expression in lung and ovarian cancers may limit its utility in differential diagnosis in some scenarios. PELP1 expression was associated with poor outcome in non-luminal cancers and modified the prognostic effects of AR, suggesting the potential significance of NR co-regulator in prognostication.

The Novel Marker GATA3 is Significantly More Sensitive Than Traditional Markers Mammaglobin and GCDFP15 for Identifying Breast Cancer in Surgical and Cytology Specimens of Metastatic and Matched Primary Tumors.

Traditional markers mammaglobin and GCDFP15 show good specificity but lack sensitivity and can be difficult to interpret in small tissue samples. We undertook a comparative study of the novel nuclear marker GATA3 (expression typically restricted to breast and urothelial carcinomas) and GCDFP15 and mammaglobin. We first compared quantitative mRNA expression levels of these 3 markers across a diverse set of over 6000 tumors and 500 normal samples from The Cancer Genome Atlas which showed dramatically higher GATA3 expression (>10-fold higher) in breast cancer as compared with GCDFP15 or mammaglobin (both P<2.2e-16), suggesting that GATA3 may represent a more sensitive marker of breast cancer than GCDFP15 or mammaglobin. We next examined protein expression by immunohistochemistry in 166 cases (including surgical and cytology specimens) of metastatic breast carcinoma and 54 cases with available matched primaries. One whole-slide section from each case was stained for monoclonal GATA3 (L50-823), monoclonal mammaglobin (31A5), and monoclonal GCDFP15 (EP1582Y). Staining intensity (0 to 3+) and extent (0% to 100%) were scored with an H-score calculated (range, 0 to 300). Sensitivities by varying H-score cutoffs for a positive result in metastatic breast carcinoma among GATA3/GCDFP15/mammaglobin, respectively, were as follows: any H-score=95%/65%/78%, H-score>50=93%/37%/47%, H-score>100=90%/25%/27%, H-score>150=86%/21%/19%, H-score>200=73%/18%/9%, H-score>250=66%/14%/6%. Significant staining differences by specimen type, tumor subtype/grade, or ER/PR/HER2 status were not identified. Significantly stronger correlation was observed between primary/metastatic GATA3 expression [Pearson's correlation=0.81 (0.68-0.89)] as compared with the primary/metastatic correlations of GCDFP15 [Pearson's correlation=0.57 (0.33-0.74)] and mammaglobin [Pearson's correlation=0.50 (0.24-0.70)] (both P<0.05). In conclusion, the novel marker GATA3 stains a significantly higher proportion of both primary and metastatic breast carcinomas than GCDFP15 or mammaglobin with stronger and more diffuse staining, helpful in cases with small tissue samples. The matched primary/metastatic expression of GATA3 is also more consistent. We propose that GATA3 be included among a panel of confirmatory markers for metastatic breast carcinoma.

Identification of secretaglobin Scgb2a1 as a target for developmental reprogramming by BPA in the rat prostate.

Secretoglobins are a superfamily of secreted proteins thought to participate in inflammation, tissue repair, and tumorigenesis. Secretoglobin family 2A member 1 (Scgb2a1) is a component of prostatein, a major androgen-binding protein secreted by the rat prostate. Using a rat model for developmental reprogramming of susceptibility to prostate carcinogenesis, we identified, by RNA-seq, that Scgb2a1 is significantly upregulated (>100-fold) in the prostate of adult rats neonatally exposed to bisphenol A (BPA), with increased gene expression confirmed by quantitative RT-PCR and chromatin immunoprecipitation for histone H3 lysine 9 acetylation. Bisulfite analysis of both CpG islands located within 10 kb of the Scgb2a1 promoter identified significant hypomethylation of the CpG island upstream of the transcription start site of this gene in the reprogrammed prostate. These data suggest that expression of Scgb2a1 in the adult prostate could be epigenetically reprogrammed by BPA exposure during prostate development, with potential implications for cancer risk and response to chemotherapeutics associated with prostatein binding.

SCGB2A1 is a novel prognostic marker for colorectal cancer associated with chemoresistance and radioresistance.

We recently showed that liver metastatic tissue from patients with colorectal cancer (CRC) was a useful model for identifying novel, hypoxia-inducible genes and prognostic markers. We showed that the expression of secretoglobin, family 2A, member 1 (SCGB2A1) was a potential prognostic factor for CRC. Here, we further evaluated the prognostic impact and function of SCGB2A1 in 222 patients with CRC. The impact of SCGB2A1 expression on disease-free survival (DFS) and overall survival (OS) was assessed with mRNA expression profiling. The function of SCGB2A1 was analyzed by evaluating mRNA expression profiles in cells derived from patients with CRC and by testing the effects of transfecting SCGB2A1 into different CRC-derived cell lines. We evaluated the effects of SCGB2A1 on proliferation, chemosensitivity, radiation sensitivity and sphere formation. Univariate and multivariate analyses indicated that the expression of SCGB2A1 was an independent prognostic factor for CRC (p<0.05), together with lymph node metastasis (p<0.05). Enforced expression of SCGB2A1 in CRC-derived cell lines promoted proliferation (DLD1, SW480 and LoVo cells; p<0.05), decreased chemosensitivity to 5-fluorouracil and oxaliplatin (DLD1 and SW480 cell lines; p<0.05), and significantly increased the viability of irradiated cells (DLD1, SW480 and LoVo cell lines; p<0.05). SCGB2A1 expression was also correlated to cancer stemness-related genes (Wnt, Zeb1 and Twist). Consistent with this correlation, SCGB2A1 expressing cells (SW480) showed increased sphere formation (p<0.05). These results indicated that SCGB2A1 represented a novel, prognostic factor for CRC, and that expression of SCGB2A1 correlated with chemoresistance, radioresistance and cancer cell stemness.

Expression of mammaglobin and gross cystic disease fluid protein-15 in breast carcinomas.

Immunohistochemical analysis of gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin (MGB) is frequently used in routine practice for assessment of metastases or regional recurrences of breast origin. Breast cancer is highly heterogeneous. Expression of these 2 markers in various breast cancer subtypes has not been well studied. In addition, the usefulness of these two markers in combination in detecting breast origin has not been explored. In this study, a large cohort of breast cancers was evaluated for GCDFP-15 and MGB expression, both individually and combined. Their expression was correlated with cancer subtypes, other biomarkers and clinicopathologic parameters. A higher sensitivity for MGB (42.3%) than GCDFP-15 (31.6%) in detecting cancers of breast origin was observed. Combining both increased the sensitivity further, both for primary tumor (53.0%) and for nodal metastases (69.0%). GCDFP-15 was associated significantly with a breast cancer profile of good prognosis tumors, including lower grade (P < .001), pN (P = .029) and Ki-67 (P < .001) as well as negative basal markers expression (P = .043, .009, and .049 for c-Kit, CK5/6 and epidermal growth factor receptor, respectively) and, thus, may not be sensitive for detection of poor prognosis tumors. MGB has the highest expression in HER2-overexpressing cancers (56.6%), and may be a potentially useful marker for this subtype. Nonetheless, both markers showed low expression in the basal like (BLBC) subtype (11.9% and 21.4% for GCDFP-15 and MGB respectively), therefore, the detection of BLBC remains problematic. Negative results need to be interpreted with caution, and correlation with other clinical findings may be required to exclude the possibility of metastatic BLBC.