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The scope of conditions for which preimplantation genetic diagnosis (PGD) is licensed has recently been expanded in the United Kingdom to include genetic predisposition to adult-onset cancer. This qualitative interview study explores reproductive decision making, knowledge of and attitudes to reproductive genetic testing (prenatal diagnosis and PGD) with 25 women aged 18-45 years who received a positive BRCA test in the United Kingdom before having children. In this cohort of younger women, BRCA testing was motivated by risk management decisions; for some, BRCA status has affected their later decisions about having children. The perceived severity of hereditary breast/ovarian cancer (HBOC) influences thoughts about passing on the mutation to children and willingness to consider reproductive genetic testing, but most participants do not believe HBOC is a condition for which pregnancy termination is justified. PGD is considered more acceptable and advantageous because it would prevent transmission to future generations, but women have concerns about selecting embryos and the fact that they and affected family members would not have been selected. Women would also be deterred by the need to undergo in vitro fertilisation (IVF) and ovarian stimulation for PGD. Awareness of reproductive testing options was very variable among the cohort. The findings highlight the complexities of reproductive decision making for young women who knowingly carry a BRCA mutation, and the dilemmas inherent to reproductive genetic testing when the condition being tested for also affects a prospective parent. Counselling and psychological support for BRCA-positive women and couples concerning reproductive options are strongly indicated.

Platelet factor 4 (PF-4) inhibits angiogenesis in vitro and in vivo. The mechanism of inhibition is poorly understood. We have investigated the mechanism of inhibition by examining the interaction of PF-4 and the fibroblast growth factor-2 (FGF-2)/fibroblast growth factor receptor (FGFR) system. PF-4 inhibited the binding of FGF-2 to high-affinity and low-affinity binding sites in murine microvascular endothelial cells (LEII cells) and proliferation. Maximum inhibition of binding to endothelial FGF receptors was observed at PF-4 concentrations between 5 and 10 microg/mL (half maximum inhibition at 0.6 micro/mL), and proliferation was completely inhibited at 2 microg/mL. At this concentration, PF-4 reduced internalization of 125I-FGF-2 by threefold and delayed degradation. To gain insight into the mechanism of inhibition, we have analyzed the interaction of PF-4 with FGF-2/FGFR by using mutant heparan sulfate-deficient Chinese hamster ovary (CHO) cells transfected with the FGFR-1 cDNA (CHOm-FGFR-1) and by examining the direct interaction with FGF-2. In the absence of heparin, PF-4 inhibited binding of 125I-FGF-2 to CHOm-FGFR-1 cells in a concentration-dependent manner, although not completely. In the presence of heparin, PF-4 abolished totally the stimulatory effect of heparin. Furthermore, PF-4 complexed to FGF-2 and inhibited endogenous or heparin-induced FGF-2 dimerization. These results indicate that PF-4 interacts with FGF-2 by complex formation, inhibiting FGF-2 dimerization, binding to FGF receptors, and internalization. This mechanism most likely contributes to the antiangiogenic properties of PF-4.

Fibroblast growth factor (FGF)-2 stimulates endothelial cell proliferation and is a potent angiogenic molecule in vitro and in vivo. In this review, we have focused on recent findings that relate to the mechanism of action and function of FGF-2. FGF-2 is expressed as four different isoforms: one 18 kDa FGF-2 form that is mainly cytoplasmic and three high molecular weight (HMW) FGF-2 forms that are preferentially localized in the nucleus. It has been demonstrated that these different isoforms lead to specific cellular phenotypes when expressed in cells. HMW FGF-2 controls proliferation by a receptor-independent mechanism, whereas 18 kDa FGF-2 stimulates migration by autocrine receptor activation. Intracellularly, HMW FGF-2 may directly associate with molecules that are involved in growth control. The action of FGF-2 at the cell surface may be altered by angiogenic inhibitors. Angiogenic inhibitors may directly interfere with FGF receptor activation or downstream signaling and thus inhibit FGF activity.

Angiogenesis, the development of new capillary networks from the normal vasculature, is a fundamental process during embryogenesis. In adulthood, angiogenesis contributes to corpus luteum formation, placental implantation and wound healing and is also required in some pathological conditions such as several intraocular syndromes, growth of solid tumors, and metastasis. Many factors are involved in the regulation of neovascularisation among which FGF-2 (fibroblast growth factor-2) and VEGF (vascular endothelial growth factor) are considered as key inducers. Their biological activity is highly controlled by extracellular matrix components and angiostatic factors. Better understanding of the molecular mechanisms regulating angiogenesis should contribute to the development of new molecules to be used for the treatment of neovascularisation-linked diseases.

Tumor invasion and dissemination is tightly controlled by angiogenesis. In recent years, a number of angiogenic factors and inhibitors have been identified. However, the molecular mechanisms leading to this phenomenon are still incompletely understood. In this review, we focus on recent developments in the angiogenesis field. We will summarize our present knowledge about the molecular mechanisms involved in angiogenesis and about the factors that control this phenomenon. We will then shortly discuss the pharmacological modulation and the therapeutic and clinical implications for cancer biology.

We report here that basic fibroblast growth factor (FGF-2), a potent mitogen for adrenocortical cells, stimulates the expression of alpha 2-macroglobulin by these cells at a transcriptional level and is synergistic with TGF beta 1 for this effect. This is supported by the following observations: (i) Treatment of adrenocortical cells by FGF-2 resulted in a time-dependent and dose-dependent increase of alpha 2M synthesis, (ii) FGF-2 did not modify alpha 2M secretion rate; (iii) The induction of alpha 2M synthesis by FGF-2 was not observed in the presence of the transcription inhibitor DRB; (iv) The amount of alpha 2M mRNA was increased by 2 to 3 fold under either FGF-2 or TGF beta 1 treatment; (v) Optimal doses of TGF beta and FGF-2 synergistically increased alpha 2M synthesis. Since alpha 2M is a growth factor-binding protein, its regulation by FGF-2 may represent an important feedback mechanism controlling the bioactivity of autocrine regulators (FGF-2, TFG beta) of adrenocortical functions.

Adrenocortical differentiated functions are under the control of both endocrine hormones such as ACTH and local factors such as transforming growth factor beta (TGF beta) or basic fibroblast growth factor (bFGF). Besides their regulatory actions on the synthesis of corticosteroids, these two classes of factors also exert some important effects on the cellular environment. We have examined here the regulation by ACTH and TGF beta of adrenocortical cell proteoglycan synthesis and secretion. Under basal conditions, adrenocortical cells synthesized and secreted several species of sulfated proteoglycans, 80% of them being recovered in solution in the culture medium. When analyzed by ion exchange chromatography, the cell extracts and the media from cells metabolically labeled with 35S-sulfate were found to contain two and three species of radioactive sulfated proteoglycans, respectively. All species were proteoheparan-sulfates. Treatment of adrenocortical cells with TGF beta 1 or ACTH resulted in a significant increase of the incorporation of 35S into both secreted and cell-associated proteoglycans. ACTH stimulated more than three times the amount of secreted proteoglycans eluting from DEAE-Trisacryl as peak B, whereas TGF beta preferentially increased the amount of peak C. No important modification of the size of the synthesized proteoglycans was observed. The subpopulation of heparan sulfate proteoglycans capable to bind bFGF was also largely increased after ACTH or TGF beta treatment and paralleled the variation in overall proteoheparan sulfate synthesis. Thus those effects of TGF beta and ACTH on proteoglycan synthesis may participate in an increased ability of adrenocortical cells to bind and respond to bFGF.

Transforming growth factor beta 1 (TGF beta 1) is a member of a large family of structurally related regulatory polypeptides which comprises both functionally similar (TGF beta 1, TGF beta 2, TGF beta 3, TGF beta 4 and TGF beta 5) and functionally distinct proteins. In the past few years, TGF beta 1 has emerged as a multifunctional protein. One of its remarkable properties is its capacity to negatively modulate the differentiated, steroidogenic adrenocortical functions. We present here a review of the results from our recent work related to the effects of TGF beta 1 on bovine adrenocortical cell (zona fasciculata-reticularis) functions. We identified the steroid 17 alpha-hydroxylase (P-450 17 alpha) biosynthetic enzyme and the angiotensin II receptor as major targets whose expression are negatively regulated by TGF beta 1 in these cells. We characterized TGF beta 1 receptors at the surface of adrenocortical cells (mainly type I and type III receptors) and observed that their number is increased under ACTH treatment. Furthermore, we could detect the presence of immunoreactive TGF beta 1 in the bovine adrenal cortex whereas it was undetectable in the adrenal medulla and in the capsule. We also observed that adrenocortical cells secrete TGF beta 1 under a latent form together with large amounts of alpha 2-macroglobulin, a protease inhibitor known to be implied in the latency of TGF beta in serum. Taken together, these observations led us to a working hypothesis, proposing TGF beta 1 as an autocrine and/or paracrine regulator of adrenocortical steroidogenic functions. This concept points out the physiological activation of the latent TGF beta 1 complex as the important limiting step controlling its action in the adrenal cortex.

We reported previously that transforming growth factor beta (TGF-beta) does not influence the proliferation of bovine adrenocortical cells but is a very potent inhibitor of their steroidogenic functions (Feige et al.: Journal of Biological Chemistry 262:13491-13495, 1987). In the present study, we addressed the question of whether these cells modify the synthesis of their extracellular matrix (in particular of fibronectin) in response to TGF-beta 1, similarly to the changes observed in cell types whose growth is modified by this factor (e.g., fibroblasts). Immunofluorescence studies using anti-fibronectin antibodies revealed that TGF-beta 1 treatment in serum-free medium induced the formation of fibronectin-containing fibrils associated with adrenocortical cells. Metabolic labeling of adrenocortical cells with [35S]-methionine showed that fibronectin synthesis and secretion were highly stimulated by low concentrations of TGF-beta 1. Half-maximal stimulation was observed for TGF-beta 1 concentrations in the range of 0.1 to 0.5 ng/ml and maximal stimulation reached 35-fold over control at the concentration of 2 ng/ml. The earlier detectable effect was observed after 8 h of treatment (6-fold stimulation) and the maximal increase was reached after 24 h of treatment. Stimulation of adrenocortical fibronectin synthesis by TGF-beta 1 appeared to imply a transcriptional event since it was no longer observed in the presence of DRB, a potent inhibitor of RNA polymerases, and because the level of fibronectin mRNA was stimulated under TGF-beta 1 treatment. Taken together, these results indicate that the increased expression of fibronectin is not closely related to growth-regulatory effects of TGF-beta 1 since it is also observed in adrenocortical cells, whose proliferation is unaffected by TGF-beta 1.