CD133 antisense suppresses cancer cell growth and increases sensitivity to cisplatin in vitro.

The increased incidence of cancer in recent years is associated with a high rate of mortality. Numerous types of cancer have a low percentage of CD133(+) cells, which have similar features to stem cells. The CD133 molecule is involved in apoptosis and cell proliferation. The aim of this study was to determine the biological effect of CD133 suppression and its role in the chemosensitization of cancer cell lines. RT-PCR and immunocytochemical analyses indicated that CD133 was expressed in the cancer cell lines B16F10, MCF7 and INER51. Downregulation of CD133 by transfection with an antisense sequence (As-CD133) resulted in a decrease in cancer cell viability of up to 52, 47 and 22% in B16F10, MCF-7 and INER51 cancer cell lines, respectively. This decreased viability appeared to be due to the induction of apoptosis. In addition, treatment with As-CD133 in combination with cisplatin had a synergic effect in all of the cancer cell lines analyzed, and in particular, significantly decreased the viability of B16F10 cancer cells compared with each treatment separately (3.1% viability for the combined treatment compared with 48% for 0.4 µg As-CD133 and 25% for 5 ng/µl cisplatin; P<0.05). The results indicate that the downregulation of CD133 by antisense is a potential therapeutic target for cancer and has a synergistic effect when administered with minimal doses of the chemotherapeutic drug cisplatin, suggesting that this combination strategy may be applied in cancer treatment.

Gender as a factor of susceptibility to infection in experimental hydatidosis.

We developed an experimental model of hydatidosis in BALB/c mice with six groups, a group of females and another group of males was infected with PSC of Echinococcus, granulosus. Another two groups were gonadectomised and infected with PSC. and another two groups were healthy controls. They were all bled and sacrificed after sixteen weeks post-infection. The cysts in the abdominal cavity were count, and samples were taken from liver. A microscopic study was made of the tissue around the cyst to evaluate the chronic inflammatory response. In addition the seric levels of estradiol and testosterone by means of radioimmunoassay (RIA) were determined. The results were that the females presented a greater number of cysts in liver than the males, in addition the levels to estradiol almost rose to the double in males and females after 16 weeks post-infection, and the testosterone diminished. The granulomatous response around the cysts was greater in the females than in the males. The gonadectomization affected the susceptibility to the infection in females, diminishing in number of hepatic cysts found. One concluded that the females are more susceptible to the infection by metacestode of E. granulosrus, than the males. The female displayed one better granulomatous answer than the males. Nevertheless this was not sufficient to eliminate the parasite or to inhibit its growth. The levels of estradiol and testosterone undergo an imbalance, observing that estradiol increased in chronic stages of the infection whereas the testosterone diminishes, which would indicate to us that probably the parasite causes hormonal imbalance in chronic stages, to be able to remain by long periods in its host.