Fig 1.
Gross presentation of normal ovaries and ovaries with tumors in laying hens.
A) A normal fully functional ovary in a healthy laying hen showing a hierarchy of preovulatory follicles (F1-F5). B) A normal ovary in an older hen with ceased laying activity. The ovary is regressed, no preovulatory follicle is seen in the ovary and no abnormalities are observed at gross. Functionally, this ovary resembles a postmenopausal ovary in a woman. C) Tumor in ovary involving the fimbria of the infundibulum of the oviduct. The tumor is at early stage and is accompanied with moderate ascites. D) Ovarian cancer (OVCA) at late stage in a hen. Compared with early stage, the tumor in late stage showed extensive metastasis with solid masses formed in distant organs. ASC = Ascites, F1 to F5 = Hierarchical follicles: F1 = The largest follicle destined to ovulate soon followed by F2, F3, so on, FIM = Fimbria, FT = Tumor in fimbria, INT = Intestine, OD = Oviduct, OV = Ovary, OT = Ovarian tumor, Tu = Tumor.
Fig 2.
Spontaneous malignant transformation of chicken oviductal fimbria.
A) Gross presentation of the reproductive system in a hen showing the ovary and different parts of the oviduct including oviductal fimbria (FIM), infundibulum (IN), magnum (MG), isthmus (IS), uterus (UT), vagina (VA). B) Microscopic presentation of chicken normal fimbria showing morphological similarities with that of human. C) Gross presentation of fimbrial tumor at early stage accompanied with ascites (ASC). D) Section of a microscopic tumor in fimbria showing papillary-like structure (P). E) Section of a fully formed tumor in fimbria. Ci = Cilia, CL = Cloaca, E = Surface epithelial layer, F1 to F5 = Hierarchical follicles, INT = Intestine, L = Lumen, M = Mucosa in fimbria, OV = Ovary, OD = Oviduct, S = Stroma, Tu = Tumor. Scale bar = 20μm.
Fig 3.
Changes in WT-1 expression during malignant transformation and tumor development in oviductal fimbriae in hens.
A) Normal fimbria in a healthy hen showing very weak or occasional staining for WT-1 by the apical surface epithelial cells (red arrows are examples). B and C) Fimbria with tumor at early and late stages. In contrast to normal fimbria, malignant cells in fimbriae with tumors showed intense staining for WT-1. D) Intensity of immunohistochemical expression of WT-1. Compared with normal fimbria, the intensity of WT-1 was significantly higher in fimbria with tumor at early stage and increased further in late stages (P<0.001). E) Immunoblotting showed a band of 65kDa for WT-1. The signal for WT-1 expression was very weak in normal fimbria while it was stronger in fimbria with tumor at early stage and strongest in late stage tumor. F and G) semi-quantitative (F) and quantitative (G) gene expression assays showed similar patterns of changes in WT-1 gene expression as observed in immunohistochemistry and immunoblotting. Bars with different letters are significantly different. Intensity or fold change values in (D) and (G), respectively, are arbitrary values presented as mean ± SEM. Bp = Base pair, Ci = Cilia, E = Early, L = Late, N = Normal, S = Stroma, Tu = Tumor. Scale bar = 20μm.
Fig 4.
Detection of abnormality in p53 protein and gene expression in fimbriae with tumor in hens.
A) Section of a normal fimbria in a hen. No staining for p53 is seen in normal fimbria. B and C) Section of a fimbria with tumor at early stage (B) and late stage (C) showing abnormal staining for p53. D) and E) Expression of p53 gene in normal fimbria and fimbria with tumor as detected by semi-quantitative (D) and quantitative (E) PCR (RT-PCR and qRT-PCR, respectively). Gene expression assays detected abnormal expression of p53 gene during malignant transformation which increased further as the tumor progressed to late stages (P<0.001). Fold change values are arbitrary values presented as mean ± SEM. Bars with different letters are significantly different. S = Stroma, Tu = Tumor. Scale bar = 20μm.
Fig 5.
Changes in CA-125 expression during the development and progression of tumor in oviductal fimbriae in hens.
A) Immunoblotting showed weak expression of CA-125 in normal fimbria. Compared with normal fimbria, strong signal for CA-125 was detected in fimbria with tumor at early stage and the signal was stronger in late-stage tumor. B) Quantitative gene expression (qRT-PCR) assays did not show significant increase in CA-125 levels with the progression of the disease to the late stages (P = 0.075). Fold change values are arbitrary values presented as mean ± SEM.
Fig 6.
Changes in PAX2 expression during tumor development in oviductal fimbriae in hens.
A) Section of a normal fimbria in a healthy hen showing strong staining for PAX2 by the surface epithelial cells. (B and C) Sections of fimbriae with tumor at early (B) and late (C) stages. In contrast to normal fimbria, malignant cells in fimbriae with tumors showed weaker staining for PAX2. (D) Intensity of immunohistochemical expression of PAX2. Compared with normal fimbria, the intensity of PAX2 was significantly lower in fimbriae with tumor at early stage and decreased further in late stage (P<0.0001). (E and F) semi-quantitative (E) and quantitative (F) gene expression assays showed significant decrease in PAX2 expression during tumor development and progression (P<0.001). Bars with different letters are significantly different. Intensity or fold change values in (D) and (F), respectively, are arbitrary values presented as mean ± SEM. Ci = Cilia. S = Stroma, Tu = Tumor. Scale bar = 20μm.