Clinical and Genetic Predictors of Impaired Fertility in Female Survivors of Childhood Cancer

An important late effect among female survivors of childhood cancer is treatment-related ovarian damage and impaired fertility. While chemotherapy and radiation therapy are associated with impaired fertility, few other risk factors have been identified. Furthermore, little is known about the role of genetic susceptibility to these late effects. Objective: As Anti-Müllerian Hormone (AMH) is a demonstrated marker of ovarian reserve; our objective was to identify clinical and genetic predictors of AMH levels in female survivors of childhood cancer. Methods: Female childhood cancer survivors (n = 181) were recruited from the Texas Children's Cancer Center Long Term Survivor Program (LTSP). AMH (ng/mL) was measured using an enzyme-linked immunosorbent assay. Information on age at diagnosis and enrollment, race, ethnicity, cancer diagnosis, pelvic radiation, and use of alkylating agents was abstracted from medical records. The following single nucleotide polymorphisms (SNPs) were selected based on known or suspected function: AMHR2 rs2002555; CYP2C9*4 rs56165452; CYP2C19*2 rs4244285; and CYP2C19*3 rs4986893. SNPs were genotyped using TaqMan assays. Linear regression was used to determine the association between selected factors and AMH levels. As AMH levels were not normally distributed, the dependent variable was expressed as log10(AMH+1). Results: The mean age at enrollment in the LTSP was 12.4 years. The most common cancer diagnosis was acute lymphoblastic leukemia (47.2%), and a substantial proportion of the population was Hispanic (41.0%). The following variables were significantly associated with lower AMH levels: pelvic radiation (beta = −0.61, P < 0.001) and treatment with alkylating agents (beta = −0.09, P = 0.04). Age at enrollment was associated with higher AMH levels (beta = 0.01, P = 0.04). Hispanic ethnicity was marginally associated with lower AMH levels (beta = −0.08, P = 0.08). There were no significant genetic associations. Conclusions: In one of the largest studies of its kind, our results confirm previous associations between treatment-related factors and ovarian damage. While the SNPs evaluated were not predictive of AMH levels, more work is needed to explain why some survivors experience impaired fertility, while others do not, despite similar therapy.

[Effect of tranilast ophthalmic solution on allergic conjunctivitis in guinea pigs]

The effect of the ophthalmic solution of tranilast, an anti-allergic agent, on allergic conjunctivitis was studied in passively sensitized guinea pigs. We determined the content of uranine dye and histamine in tears and histopathologically examined palpebral conjunctiva. After instillation of antigen into the conjunctival sac, inflammation of the palpebral conjunctiva, an increase in leaked dye and the release of histamine were found. In the histopathological study, tranilast (1.0%) suppressed the appearance of edema and infiltration of inflammatory cells. Tranilast suppressed the leakage of uranine in a dose-dependent manner. A 0.5% solution of diphenhydramine also showed the inhibitory effect on the leakage of uranine. The inhibitory effect of 0.5% tranilast on antigen-induced dye leakage and histamine release lasted for 6 hr. These results suggest that topically applied tranilast is effective for allergic conjunctivitis.

The mechanism involved in the inhibitory action of tranilast on collagen biosynthesis of keloid fibroblasts

Tranilast, an anti-allergic drug inhibiting the release of substances such as histamine and prostaglandins from mast cells, was previously reported to suppress collagen synthesis of fibroblasts derived from keloid tissues. However, the inhibitory mechanism on collagen synthesis is unknown. We studied its inhibitory mechanism on collagen synthesis by culturing fibroblasts from keloid and hypertrophic scar tissues of humans. Collagen synthesis of fibroblasts from keloid and hypertrophic scar tissue is greater than that from healthy human skin. Tranilast (3-100 microM) did not inhibit prolyl hydroxylase (the rate-limiting enzyme in collagen synthesis) activity. Tranilast (3-300 microM) suppressed the collagen synthesis of fibroblasts from keloid and hypertrophic scar tissue but not healthy skin fibroblasts. Tranilast (30-300 microM) inhibited the release of transforming growth factor (TGF)-beta 1 from keloid fibroblasts, which enhances the collagen synthesis of keloid fibroblasts. Anti-TGF-beta 1 antibody (50 microliter/ml) inhibited the collagen synthesis, although diphenhydramine (10 microM) and indomethacin (10 microM) did not show any inhibition. These results suggest that tranilast inhibits collagen synthesis of fibroblasts from keloid and hypertrophic scar tissue through suppressing the release of TGF-beta 1 from the fibroblasts themselves.

Inhibitory action of tranilast, an anti-allergic drug, on the release of cytokines and PGE2 from human monocytes-macrophages

Tranilast, an anti-allergic drug that inhibits the release of substances such as histamine and prostaglandins from mast cells, has been reported to improve keloids and hypertrophic scars which originate from the abnormal proliferation and excessive collagen accumulation of fibroblasts. It has been considered that various chemical mediators produced by inflammatory cells play important roles in the development of keloids and hypertrophic scars. We therefore studied the effect of tranilast on the release of chemical mediators including transforming growth factor (TGF)-beta 1, interleukin (IL)-1 beta and prostaglandin (PG) E2 which are produced by the human monocytes-macrophages, and estimated whether these mediators induce collagen synthesis and cell proliferation of normal skin fibroblasts. Tranilast inhibited the release of TGF-beta 1, IL-1 beta and PGE2 from the human monocytes-macrophages. TGF-beta 1 (25-200 pM) enhanced the collagen synthesis by fibroblasts. IL-1 (0.1-1 U/ml) increased the proliferation and conversely decreased the collagen synthesis. PGE2 (2 micrograms/ml) enhanced the collagen synthesis. These results suggest that tranilast suppresses collagen synthesis by fibroblasts through inhibiting TGF-beta 1 and PGE2 production and cell proliferation by fibroblasts through inhibiting IL-1 production by inflammatory cells such as macrophages.

[Effect of tranilast, an anti-allergic drug, on the human keloid tissues]

We studied the inhibitory effects of tranilast, an anti-allergic drug, on the human keloid tissues implanted into the dorsal skin of athymic nude mice and on the growth of keloid fibroblast in vitro. In the keloid tissue-implanted model, tranilast (50-200 mg/kg, p.o.) decreased the weight of the keloid tissue as triamcinolone (25 mg/kg, p.o.) did. Tranilast (200 mg/kg, p.o.) reduced the hydroxyproline content of implanted tissues. Tranilast (3-300 microM) also inhibited the collagen synthesis by keloid fibroblast in vitro. Only a high concentration of tranilast (300 microM) suppressed the glycosaminoglycan synthesis and cell proliferation of keloid fibroblasts. Moreover, tranilast scarcely affected the fibronectin production. Triamcinolone (10 microM) also inhibited glycosaminoglycan synthesis and cell proliferation. These results suggest that the inhibitory effect of tranilast on the keloid tissues is related to its inhibition of the collagen synthesis of fibroblasts. Tranilast would be useful as a therapeutic drug for the treatment of keloids.

[Effect of tranilast, an anti-allergic drug, on carrageenin-induced granulation and capillary permeability in rats]

We studied the effect of tranilast on the growth of carrageenin-induced granulation and the increase in capillary permeability induced by inflammatory agents in rats. In the carrageenin-induced granulation model, tranilast (50 or 100-200 mg/kg, p.o.) decreased significantly and dose-dependently the weight and the hydroxyproline content of the granulation tissue. Tranilast, however, showed no effect on the healing day of locally wounded dorsal skin of rats. Triamcinolone (10 mg/kg, p.o.) also showed an inhibitory effect on the carrageenin-induced granulation model. Tranilast (50-400 mg/kg, p.o.) dose-dependently inhibited the enhancement of capillary permeability induced by the Ca ionophore A23187, bradykinin and xanthine oxidase. Moreover, tranilast (30 and 300 microM) suppressed superoxide production induced by FMLP in human neutrophils, but did not act as a superoxide scavenger. Considering that hypertrophic scar and keloid are conditions characterized by abnormal cell proliferation and excessive collagen accumulation accompanied with itch and pain, these results suggest that tranilast is useful as a therapeutic drug for hypertrophic scars and keloids.