A Carcinogen-induced mouse model recapitulates the molecular alterations of human muscle invasive bladder cancer.

The N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) mouse model is an attractive model system of muscle-invasive bladder cancer (MIBC) as it recapitulates the histology of human tumors in a background with intact immune system. However, it was unknown whether this carcinogen-induced model also mimicked human MIBC at the molecular and mutational level. In our study, we analyzed gene expression and mutational landscape of the BBN model by next-generation sequencing followed by a bioinformatic comparison to human MIBC using data from The Cancer Genome Atlas and other repositories. BBN tumors showed overexpression of markers of basal cancer subtype, and had a high mutation burden with frequent Trp53 (80%), Kmt2d (70%), and Kmt2c (90%) mutations by exome sequencing, similar to human MIBC. Many variants corresponded to human cancer hotspot mutations, supporting their role as driver mutations. We extracted two novel mutational signatures from the BBN mouse genomes. The integrated analysis of mutation frequencies and signatures highlighted the contribution of aberrations to chromatin regulators and genetic instability in the BBN tumors. Together, our study revealed several similarities between human MIBC and the BBN mouse model, providing a strong rationale for its use in molecular and drug discovery studies.

Interleukin 16- (IL-16-) Targeted Ultrasound Imaging Agent Improves Detection of Ovarian Tumors in Laying Hens, a Preclinical Model of Spontaneous Ovarian Cancer.

Limited resolution of transvaginal ultrasound (TVUS) scanning is a significant barrier to early detection of ovarian cancer (OVCA). Contrast agents have been suggested to improve the resolution of TVUS scanning. Emerging evidence suggests that expression of interleukin 16 (IL-16) by the tumor epithelium and microvessels increases in association with OVCA development and offers a potential target for early OVCA detection. The goal of this study was to examine the feasibility of IL-16-targeted contrast agents in enhancing the intensity of ultrasound imaging from ovarian tumors in hens, a model of spontaneous OVCA. Contrast agents were developed by conjugating biotinylated anti-IL-16 antibodies with streptavidin coated microbubbles. Enhancement of ultrasound signal intensity was determined before and after injection of contrast agents. Following scanning, ovarian tissues were processed for the detection of IL-16 expressing cells and microvessels. Compared with precontrast, contrast imaging enhanced ultrasound signal intensity significantly in OVCA hens at early (P < 0.05) and late stages (P < 0.001). Higher intensities of ultrasound signals in OVCA hens were associated with increased frequencies of IL-16 expressing cells and microvessels. These results suggest that IL-16-targeted contrast agents improve the visualization of ovarian tumors. The laying hen may be a suitable model to test new imaging agents and develop targeted anti-OVCA therapeutics.

VEGFR2-Targeted Ultrasound Imaging Agent Enhances the Detection of Ovarian Tumors at Early Stage in Laying Hens, a Preclinical Model of Spontaneous Ovarian Cancer.

Tumor-associated neoangiogenesis (TAN) is an early event in ovarian cancer (OVCA) development. Increased expression of vascular endothelial growth factor receptor 2 (VEGFR2) by TAN vessels presents a potential target for early detection by ultrasound imaging. The goal of this study was to examine the suitability of VEGFR2-targeted ultrasound contrast agents in detecting spontaneous OVCA in laying hens. Effects of VEGFR2-targeted contrast agents in enhancing the intensity of ultrasound imaging from spontaneous ovarian tumors in hens were examined in a cross-sectional study. Enhancement in the intensity of ultrasound imaging was determined before and after injection of VEGFR2-targeted contrast agents. All ultrasound images were digitally stored and analyzed off-line. Following scanning, ovarian tissues were collected and processed for histology and detection of VEGFR2-expressing microvessels. Enhancement in visualization of ovarian morphology was detected by gray-scale imaging following injection of VEGFR2-targeted contrast agents. Compared with pre-contrast, contrast imaging enhanced the intensities of ultrasound imaging significantly (p < 0.0001) irrespective of the pathological status of ovaries. In contrast to normal hens, the intensity of ultrasound imaging was significantly (p < 0.0001) higher in hens with early stage OVCA and increased further in hens with late stage OVCA. Higher intensities of ultrasound imaging in hens with OVCA were positively correlated with increased (p < 0.0001) frequencies of VEGFR2-expressing microvessels. The results of this study suggest that VEGFR2-targeted contrast agents enhance the visualization of spontaneous ovarian tumors in hens at early and late stages of OVCA. The laying hen may be a suitable model to test new imaging agents and develop targeted therapeutics.

Interleukin 16 expression changes in association with ovarian malignant transformation.

OBJECTIVE: Long-term unresolved inflammation has been suggested as a risk factor for the development of various malignancies. The goal of this study was to examine whether the expression of interleukin (IL)-16, a proinflammatory cytokine, changes in association with ovarian cancer (OVCA) development. STUDY DESIGN: In an exploratory study, changes in IL-16 expression in association with OVCA development and progression were determined using ovarian tissues and serum samples from healthy subjects (n = 10) and patients with benign (n = 10) and malignant ovarian tumors at early (n = 8) and late (n = 20) stages. In the prospective study, laying hens, a preclinical model of spontaneous OVCA, were monitored (n = 200) for 45 weeks with serum samples collected at 15-week interval. Changes in serum levels of IL-16 relative to OVCA development were examined. RESULTS: The frequency of IL-16-expressing cells increased significantly in patients with OVCA (P < .001) compared to healthy subjects and patients with benign ovarian tumors. The concentration of serum IL-16 was higher in patients with benign tumors (P < .05) than in healthy subjects and increased further in patients with early-stage (P < .05) and late-stage (P < .03) OVCA. Increase in tissue expression and serum levels of IL-16 in patients with early and late stages of OVCA were positively correlated with the increase in ovarian tumor-associated microvessels. Prospective monitoring showed that serum levels of IL-16 increase significantly (P < .002) even before ovarian tumors become grossly detectable in hens. CONCLUSION: This study showed that tissue expression and serum levels of IL-16 increase in association with malignant ovarian tumor development and progression.

Enhancement of ovarian tumor detection with αvß3 integrin-targeted ultrasound molecular imaging agent in laying hens: a preclinical model of spontaneous ovarian cancer.

OBJECTIVE: Because of the lack of an effective early detection test, ovarian cancer (OVCA) in most cases is detected at late stages and remains a fatal gynecological malignancy. Molecular imaging provides information on the changes associated with the development of a disease at molecular levels. Because angiogenesis is an early event in tumor development, increased expression of αvß3 integrins by ovarian tumor-associated angiogenic microvessels provides a target for noninvasive ultrasound imaging to detect early-stage OVCA. The goal of this study was to examine the feasibility of αvß3 integrin-targeted molecular imaging agent in enhancing the detection of spontaneous ovarian tumor in laying hens, a preclinical model of OVCA. METHODS: The study was conducted in 2 phases, including a cross-sectional exploratory followed by a prospective monitoring of hens for 45 weeks with targeted ultrasound imaging. Changes in ultrasound signal intensity were determined before and after the injection of αvß3 integrin-targeted imaging agent in hens with spontaneous OVCA. All images were digitally stored. After scanning, ovarian tissues from all hens were collected and processed for histopathologic and immunohistochemical studies. RESULTS: Ultrasound signal intensity was significantly (P < 0.001) higher in hens with early-stage OVCA than in normal hens and increased further in late-stage OVCA. Compared with that in normal cases, ultrasound signal intensities increased approximately 19-fold in early stage and 26-fold in late-stage OVCA. Differences in signal enhancement were not observed among different histologic subtypes of OVCA. Higher signal intensities from targeted imaging of ovarian tumors were associated with increased number of αvß3 integrin-expressing ovarian microvessels. Prospective monitoring of hens with αvß3 integrin-targeted imaging agent detected OVCA at early stage. CONCLUSIONS: These results suggest that αvß3 integrin-targeted imaging agent enhanced the visualization of ovarian tumor-associated angiogenic microvessels in hens with early-stage OVCA and may form a foundation for clinical studies.

Expression of death receptor 6 by ovarian tumors in laying hens, a preclinical model of spontaneous ovarian cancer.

Tumor-associated neoangiogenesis and suppression of antitumor immunity are hallmarks of tumor development and progression. Death receptor 6 (DR6) has been reported to be associated with suppression of antitumor immunity and tumor progression in several malignancies. However, expression of DR6 by malignant ovarian epithelial tumors at an early stage is unknown. The goals of this study were to determine whether DR6 is expressed by malignant ovarian epithelial tumors at an early stage and to examine whether DR6 expression is associated with ovarian cancer (OVCA) progression in a laying hen model of spontaneous OVCA. Expression of DR6 was examined in normal and malignant ovaries, normal ovarian surface epithelial (OSE) cells, or malignant epithelial cells and in serum of 3-year-old hens. The population of microvessels expressing DR6 was significantly higher in hens with early-stage OVCA than hens with normal ovaries (P < .01) and increased further in late-stage OVCA. The results of this study showed that, in addition to microvessels, tumor cells in the ovary also express DR6 with a significantly higher intensity than normal OSE cells. Similar patterns of DR6 expression were also observed by immunoblot analysis and gene expression studies. Furthermore, DR6 was also detected in the serum of hens. In conclusion, DR6 expression is associated with OVCA development and progression in laying hens. This study may be helpful to examine the feasibility of DR6 as a useful surrogate marker of OVCA, a target for antitumor immunotherapy and molecular imaging and thus provide a foundation for clinical studies.

Expression of Leukocyte Inhibitory Immunoglobulin-like Transcript 3 Receptors by Ovarian Tumors in Laying Hen Model of Spontaneous Ovarian Cancer.

Attempts to enhance a patient's immune response and ameliorate the poor prognosis of ovarian cancer (OVCA) have largely been unsuccessful owing to the suppressive tumor microenvironment. Leukocyte immunoglobulin-like transcript 3 (ILT3) inhibitory receptors have been implicated in immunosuppression in several malignancies. The expression and role of ILT3 in the progression of ovarian tumors are unknown. This study examined the expression and association of ILT3 in ovarian tumors in laying hens, a spontaneous preclinical model of human OVCA. White Leghorn laying hens were selected by transvaginal ultrasound scanning. Serum and normal ovaries or ovarian tumors were collected. The presence of tumors and the expression of ILT3 were examined by routine histology, immunohistochemistry, Western blot analysis, and reverse transcription-polymerase chain reaction. In addition to stromal immune cell-like cells, the epithelium of the ovarian tumors also expressed ILT3 with significantly high intensity than normal ovaries. Among different subtypes of ovarian carcinomas, serous OVCA showed the highest ILT3 staining intensity, whereas endometrioid OVCA had the lowest intensity. Similar to humans, an immunoreactive protein band of approximately 55 kDa for ILT3 was detected in the ovarian tumors in hens. The patterns of ILT3 protein and messenger RNA expression by ovarian tumors in different subtypes and stages were similar to those of immunohistochemical staining. The results of this study suggest that laying hens may be useful to generate information on ILT3-associated immunosuppression in OVCA. This animal model also offers the opportunity to develop and test anti-ILT3 immunotherapy to enhance antitumor immunity against OVCA in humans.

Association of interleukin 16 with the development of ovarian tumor and tumor-associated neoangiogenesis in laying hen model of spontaneous ovarian cancer.

OBJECTIVE: Tumor-associated neoangiogenesis (TAN) is an early event in ovarian tumor development. Interleukin 16 (IL-16) is a proangiogenic cytokine that stimulates production of neoangiogenic factors. The goal of this study was to determine the association of IL-16 with tumor development and ovarian TAN in laying hens, an animal model of spontaneous ovarian cancer (OVCA). METHODS: Sera and ovarian tissues from 3-year-old laying hens were collected and processed for histopathologic, immunoassay, immunohistochemistry, immunoblotting, and molecular biological studies to determine the tissue expression and serum levels of IL-16. Samples were divided into 3 groups based on the diagnosis of the histopathologic ovarian tissue examination, namely, normal (healthy control, n = 81), early (n = 23 including 11 with microscopic OVCA), and late stages (n = 16) of OVCA. RESULTS: Serum levels of IL-16 were significantly higher in hens with microscopic, early, and late stages of OVCA than normal hens (P < 0.0001). The frequencies of IL-16 cells in tumor-bearing ovaries were significantly higher than normal hens (P < 0.05). The expression of IL-16 protein and mRNA were stronger in tumor-bearing ovaries than normal ovaries. In addition to ovarian stroma, IL-16 was also expressed by the epithelial cells of the tumor in OVCA hens. Differences in serum levels and ovarian IL-16 expression were not significant among different histological subtypes of OVCA including serous, endometrioid, and mucinous. Similar to the serum levels and ovarian expression of IL-16, the densities of neoangiogenic microvessels were significantly higher in hens with tumor-bearing ovaries than normal hens. CONCLUSIONS: The results of the study suggest that changes in serum levels of IL-16 are associated with tumor development and TAN. Thus, serum IL-16 levels may be an indicator of ovarian TAN at the early stage of OVCA.