Metformin Abrogates Age-Associated Ovarian Fibrosis.

PURPOSE: The ovarian cancer risk factors of age and ovulation are curious because ovarian cancer incidence increases in postmenopausal women, long after ovulations have ceased. To determine how age and ovulation underlie ovarian cancer risk, we assessed the effects of these risk factors on the ovarian microenvironment. EXPERIMENTAL DESIGN: Aged C57/lcrfa mice (0-33 months old) were generated to assess the aged ovarian microenvironment. To expand our findings into human aging, we assembled a cohort of normal human ovaries (n = 18, 21-71 years old). To validate our findings, an independent cohort of normal human ovaries was assembled (n = 9, 41-82 years old). RESULTS: We first validated the presence of age-associated murine ovarian fibrosis. Using interdisciplinary methodologies, we provide novel evidence that ovarian fibrosis also develops in human postmenopausal ovaries across two independent cohorts (n = 27). Fibrotic ovaries have an increased CD206+:CD68+ cell ratio, CD8+ T-cell infiltration, and profibrotic DPP4+αSMA+ fibroblasts. Metformin use was associated with attenuated CD8+ T-cell infiltration and reduced CD206+:CD68+ cell ratio. CONCLUSIONS: These data support a novel hypothesis that unifies the primary nonhereditary ovarian cancer risk factors through the development of ovarian fibrosis and the formation of a premetastatic niche, and suggests a potential use for metformin in ovarian cancer prophylaxis.See related commentary by Madariaga et al., p. 523.

Preeclampsia is a biomarker for vascular disease in both mother and child: the need for a medical alert system.

This paper reviews the literature pertaining to the impact of preeclampsia not only on the mother but particularly on the children. The review points to the higher blood pressure in children born to preeclamptic mothers compared to controls, their increased tendency to suffer strokes, the reduction in their cognitive ability, and their vulnerability to depression. Mechanisms that may induce these changes are emphasized, particularly the placental vascular insufficiency and the resulting hypoxic and proinflammatory environments in which the fetus develops. The hypothesis proposed is that these changes in the fetal-placental environment result in epigenetic programming of the child towards a higher propensity for vascular disease. The review's main recommendation is that, within ethical boundaries, the medical records of individuals born to preeclamptic mothers should clearly indicate this event and should be made available to the affected individuals so that preventive measures against vascular complications and lifestyle changes that may mitigate the latter can be instituted.

Induction of a menopausal state alters the growth and histology of ovarian tumors in a mouse model of ovarian cancer.

OBJECTIVE: Ovarian cancer is often diagnosed in women after menopause when the levels of the serum gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are increased because of the depletion of growing follicles within the ovary. The ability of FSH and LH to modulate the disease has not been well studied owing to a lack of physiologically relevant models of ovarian cancer. In this study, 4-vinylcyclohexene diepoxide (VCD) was used to deplete ovarian follicles and increase the levels of circulating FSH and LH in the tgCAG-LS-TAg mouse model of ovarian cancer. METHODS: VCD-induced follicle depletion was performed either before or after induction of the oncogene SV40 large and small T-antigens in the ovarian surface epithelial cells of tgCAG-LS-TAg mice, which was mediated by the intrabursal delivery of an adenovirus expressing Cre recombinase (AdCre). RESULTS: tgCAG-LS-TAg mice injected with AdCre developed undifferentiated ovarian tumors with mixed epithelial and stromal components and some features of sex cord stromal tumors. Treatment with VCD before or after AdCre injection yielded tumors of similar histology, but with the unique appearance of Sertoli cell nests. In mice treated with VCD before the induction of tumorigenesis, the ovarian tumors tended to grow more slowly. The human ovarian cancer cell lines SKOV3 and OVCAR3 responded similarly to increased levels of gonadotropins in a second model of menopause, growing more slowly in ovariectomized mice compared with cycling controls. CONCLUSIONS: These results suggest that follicle depletion and increased gonadotropin levels can alter the histology and the rate of growth of ovarian tumors.

17beta-estradiol accelerates tumor onset and decreases survival in a transgenic mouse model of ovarian cancer.

Epithelial ovarian cancer is thought to be derived from the ovarian surface epithelium (OSE) but often goes undetected in the early stages, and as a result, the factors that contribute to its initiation and progression remain poorly understood. Epidemiological studies have suggested that the female steroid hormones are involved in ovarian carcinogenesis and that women who use hormone replacement therapy are at increased risk of developing the disease. A novel transgenic mouse model of ovarian cancer (tgCAG-LS-TAg) was developed to examine the role of the female reproductive steroid hormones [17beta-estradiol (E(2)) and progesterone (P(4))] on the initiation, progression, and pathology of ovarian cancer. The mouse model uses the Cre-LoxP system to induce expression of the simian virus 40 large and small T antigens (SV40 TAg). After targeted induction of the oncogene in the OSE, mice develop poorly differentiated ovarian tumors, tumor dissemination to tissues within the abdominal cavity, and a subset develops hemorrhagic ascites. Treatment with P(4) had no impact on the disease, but E(2) altered the pathophysiology, resulting in an earlier onset of tumors, decreased overall survival time, and a distinctive papillary histology. Normal ovaries collected from mice treated with E(2), but lacking expression of SV40 TAg, displayed an increase in the areas of columnar and hyperplastic OSE cells compared to placebo-treated controls. A better understanding of the mechanisms by which E(2) alters the morphology of normal OSE cells and reduces survival in this mouse model may translate into improved prevention and treatment options for women using hormone replacement therapy.

Conditional inactivation of Brca1, p53 and Rb in mouse ovaries results in the development of leiomyosarcomas.

Epithelial ovarian cancer (EOC) is thought to arise in part from the ovarian surface epithelium (OSE); however, the molecular events underlying this transformation are poorly understood. Germline mutations in the BRCA1 tumor suppressor gene result in a significantly increased risk of developing EOC and a large proportion of sporadic EOCs display some sort of BRCA1 dysfunction. To generate a model in which Brca1-mediated transformation can be studied, we previously inactivated Brca1 alone in murine OSE, which resulted in an increased accumulation of premalignant changes, but no tumor formation. In this study, we examined tumor formation in mice with conditionally expressed alleles of Brca1, p53 and Rb, alone or in combination. Intrabursal injection of adenovirus expressing Cre recombinase to inactivate p53 resulted in tumors in 100% of mice. Tumor progression was accelerated in mice with concomitant inactivation of Brca1 and p53, but not Rb and p53. Immunohistologic analyses classified the tumors as leiomyosarcomas that may be arising from the ovarian bursa. Brca1 inactivation in primary cultures of murine OSE cells led to a suppression of proliferation that could be rescued by concomitant inactivation of p53 and/or Rb. Brca1-deficient OSE cells displayed an increased sensitivity to the DNA damaging agent cisplatin, and this effect could be modulated by inactivation of p53 and/or Rb. These results indicate that Brca1 deficiency can accelerate tumor development and alter the sensitivity of OSE cells to chemotherapeutic agents. Intrabursal delivery of adenovirus intended to alter gene expression in the ovarian surface epithelium may, in some strains of mice, result in more rapid transformation of adjacent cells, resulting in leiomyosarcomas.

Phase II evaluation of imatinib mesylate in the treatment of recurrent or persistent epithelial ovarian or primary peritoneal carcinoma: a Gynecologic Oncology Group Study.

PURPOSE: This phase II trial assessed the activity and tolerability of an oral dose of imatinib mesylate 400 mg twice daily in patients with recurrent or persistent epithelial ovarian or primary peritoneal carcinoma. The association between the expression of certain markers and clinical outcome was investigated. PATIENTS AND METHODS: Primary measure of clinical efficacy was progression-free survival (PFS) at 6 months. Mutational analysis of KIT, immunohistochemistry (IHC) and enzyme-linked immunosorbent assay for markers (KIT, platelet-derived growth factor [PDGF] receptor [-R], AKT2, phosphorylated AKT [p-AKT], stem cell factor [SCF], and PDGF) were performed. RESULTS: Fifty-six eligible patients were evaluated. Nine patients were progression free for at least 6 months including one complete responder. The median PFS and survival were 2 and 16 months, respectively. The most common grade 3 and 4 toxicities were neutropenia, GI, dermatologic effects, pain, and electrolyte disturbances. At least one target of imatinib (KIT, PDGFR-alpha, or PDGFR-beta) was expressed in all tumors, and most tumors expressed all three receptors. Higher expression of p-AKT and PDGFR-beta were associated with shorter PFS, and higher IHC scores (% immunopositive cells x staining intensity) of SCF and p-AKT were associated with decreased overall survival. No sequence mutations were detected in the KIT gene. Higher pretreatment plasma concentrations of PDGF-AB, PDGF-BB, and vascular endothelial growth factor (VEGF) were individually associated with shorter PFS and survival. CONCLUSION: Imatinib mesylate was well tolerated but had minimal single-agent activity in patients with recurrent ovarian or primary peritoneal carcinoma. No marker was identified that would predict activity of imatinib; however, tumor p-AKT and plasma VEGF levels were associated with poor outcome.

Characterization of intraperitoneal, orthotopic, and metastatic xenograft models of human ovarian cancer.

Improvement of ovarian cancer patient outcome requires well-characterized animal models in which to evaluate novel therapeutics. Xenograft models are frequently used, but with little discussion of disease histology. The objectives of this study were to inject 11 ovarian cancer cell lines intraperitoneally (ip), and a subset intrabursally (ib; orthotopic), into nude mice and to analyze the resulting pathologies. Eight of 11 lines injected ip formed tumors within 3 months at variable rates with the following histological subtype distribution: one endometrioid, one serous, one clear cell, and five undifferentiated. Only mice injected with A2780-cp cells presented with ovarian-specific metastases (11 of 88), and the survival time of these animals was significantly shorter, which may be attributed to the higher proliferation rate as determined by Ki67 positivity. Additional analysis of the influence of the ovarian microenvironment on cell characteristics was conducted with ib injection of two cell lines (OVCA 429 and ES-2). The site of injection did not affect the tumor histology, the effect on proliferation was cell-type dependent, and the tumor take rate (cell survival) was negatively affected for OVCA 429 cells. The animal models described herein represent histologically distinct models of both early and late stage ovarian cancer useful for evaluation of therapeutics.

Detailed account of confounding factors in interpretation of FTIR spectra of exfoliated cervical cells.

The confounding variables that can potentially lead to a misinterpretation of FTIR spectroscopy of exfoliated cervical cells is described. A detailed account of the spectral effects of the following variables in FTIR spectroscopic screening of exfoliated cervical cells is presented: polymorphs; Cell degradation; and impurities such as endocervical columnar cells, metaplastic cells, cervical mucus, red cells, and debris. The interpretation of the spectra of exfoliated cervical cells must be done with subtraction analysis, which includes these factors. This is essential to prevent unacceptable false-positive rates. The above techniques are subsequently applied to two clinic populations: a dysplasia clinic in follow-up patients with negative cytology and two general gynecology clinics with patients with negative cytology. In the dysplasia clinic group 250 sequential patients with negative smears were tested. Thirty had false-positive smears as defined by the IR spectroscopy using the above methodology. Twenty of those patients subsequently had one follow-up and six had a positive abnormal smear. In the community clinic group 656 sequential patients were examined who had negative smears, of which 27 had false-positive FTIR spectra.