Search

Chronic infection with the blood fluke, Schistosoma haematobium, is associated with squamous cell carcinoma of the bladder. Previously, it has been shown that soluble extracts of mixed sex adult S. haematobium worms (SWAP) are tumourigenic, both in vitro and in vivo. In addition, oestrogen-related molecules in SWAP of S. haematobium down-regulate oestrogen receptors (ERs) alpha and beta in oestrogen responsive cells. Moreover, schistosome oestrogens occur in sera of persons with schistosomiasis haematobia and repress transcription of ERs in urothelial cells. Given that eggs of S. haematobium are the developmental stage directly responsible for urogenital disease during schistosomiasis haematobia, we suspected that soluble antigens from S. haematobium eggs exhibit similar or more potent tumorigenic capacity. Here we investigated the tumorigenic potential of soluble egg antigens (Sh-SEA) of S. haematobium and the endocrine system in favouring parasitism by schistosomes. The findings confirmed that 6.25μg/ml of Sh-SEA was enough to stimulate cell proliferation, reduce apoptosis and increase oxidative stress of Sh-SEA-exposed urothelial cells. In addition, genotoxic effects of Sh-SEA on these cells were determined by using alkaline single-cell gel electrophoresis (Comet). Furthermore, Liquid Chromatography Diode Array Detection Electron Spray Ionisation Mass Spectrometry indicated the presence of catechol-oestrogens in S. haematobium SEA. A prospective oestrogen-DNA adduct mediated pathway in S. haematobium egg induced bladder cancer is also discussed., (Copyright © 2012 Australian Society for Parasitology Inc. All rights reserved.)

We recently reported the expression of an estradiol-like molecule by a trematode parasite Schistosoma haematobium. We further established that this estradiol-like molecule is an antagonist of estradiol, repressing the transcriptional activity of the estrogen receptor (ER) in estrogen-responsive MCF7 cells and also that S. haematobium total antigen (Sh) contains estrogenic molecules detected by mass spectrometry. In the present study, we used HCV29 cells, a cell line derived from normal urothelial cells, as well as an in vivo model to evaluate the expression of ER in the bladders of Sh-instilled animals. We show that, similarly to MCF7 cells, Sh down-regulates the transcriptional activity of ER in HCV29 cells and also in the bladders of Sh-treated mice. The antiestrogenic activity of the S. haematobium extract and its repressive role in ER could have implications in the carcinogenic process in bladders with S. haematobium infection.

Estradiol is a steroid hormone secreted principally by the ovarian follicles in vertebrate animals. We have identified the production of an estradiol-related molecule in the trematodes Schistosoma haematobium and Schistosomiasis mansoni. We show in this work that this molecule related to estradiol is present in schistosome worm extracts. The detection method ELISA specific for estradiol, revealed the expression of this estradiol-related molecule in schistosome worm extracts, but not in Fasciola hepatica worm extracts. Our results demonstrate for the first time the production of an estradiol-related compound by a human parasite of the genus Schistosoma.

This work reports the detection of specific immunoglobulins (Ig) against rFh8, a recombinant Fasciola hepatica adult worm excretion-secretion antigen, in sera from experimentally (rabbit, Wistar rat, cattle, and sheep), or naturally (human) infected hosts. In the case of laboratory experimental models the study revealed significant differences between rabbits, which recognized the recombinant antigen all along the infection, and Wistar rats, which showed high anti-rFh8 Ig levels only for a short period of the infection. Available sera from experimentally infected cattle and sheep, as well as sera from naturally F. hepatica-infected humans, also contained significant levels of Ig against rFh8, suggesting that Fh8 was produced by F. hepatica at a very early stage of infection in all hosts so far analyzed and that the rFh8 antigen could be used as a tool for the diagnosis of F. hepatica infections.