Opposing actions of the progesterone metabolites, 5alpha-dihydroprogesterone (5alphaP) and 3alpha-dihydroprogesterone (3alphaHP) on mitosis, apoptosis, and expression of Bcl-2, Bax and p21 in human breast cell lines.

Previous studies have shown that breast tissues and breast cell lines convert progesterone (P) to 5alpha-dihydroprogesterone (5alphaP) and 3alpha-dihydroprogesterone (3alphaHP) and that 3alphaHP suppresses, whereas 5alphaP promotes, cell proliferation and detachment. The objectives of the current studies were to determine if the 5alphaP- and 3alphaHP-induced changes in cell numbers are due to altered rates of mitosis and/or apoptosis, and if 3alphaHP and 5alphaP act on tumorigenic and non-tumorigenic cells, regardless of estrogen (E) and P receptor status. The studies were conducted on tumorigenic (MCF-7, MDA-MB-231, T47D) and non-tumorigenic (MCF-10A) human breast cell lines, employing several methods to assess the effects of the hormones on cell proliferation, mitosis, apoptosis and expression of Bcl-2, Bax and p21.

The role of progesterone metabolites in breast cancer: potential for new diagnostics and therapeutics.

Proliferative changes in the normal breast are known to be controlled by female sex steroids. However, only a portion of all breast cancer patients respond to current estrogen based endocrine therapy, and with continued treatment nearly all will become unresponsive and experience relapse. Therefore, ultimately for the majority of breast carcinomas, explanations and treatments based on estrogen are inadequate.

Effect of viral preinfection upon cell adherence in some staphylococcus strains from specific infections or carriers.

The adherence of bacteria to eukaryote cells has been largely investigated as an essential step in the occurrence of bacterial infection. Some clinical and epidemiological studies have revealed the frequent association of certain viral infections with bacterial infections originating in the same ecological niche. Therefore, we investigated the effect of the viral preinfection (ADV4) of some cultivated cells (HEp-2 and IC.

IgA monoclonal and polyclonal proteins as regulatory factors of the NK cytotoxic activity.

The presence of receptors for IgA (IgAR) on natural killer (NK) cells was only indirectly suggested yet. To elucidate the presence of IgAR on NK cells and its possible role in modulation of the NK activity, was initiated a preliminary study carried out in a homologous system, using human non adherent lymphocytes (NAL) and human seric or secretory IgA. A proportion of over 20% NK cells (CD16+ CD56+) was determined by flow-cytometry in the NAL-cells population.

Mouse multivalent IgG(2a, b) antibody--ricin A-chain immunotoxins combined with homologous or heterologous interleukin 2 in the treatment of a murine malignant lymphoproliferation (EL4).

Two immunotoxins containing ricin A-chain, staphylococcal protein A and mouse anti-Thy 1.2 antibodies of IgG(2a,b) subclass, were prepared. The two multivalent immunotoxins of 750 and 370 kDa and molar ratio A-chain: IgG of 1:2, were used for the treatment of mice bearing ascitic EL4 lymphoma.

Interleukin 2 enhances the efficiency of immunotoxins in the treatment of mice with ascitic tumors.

Two multivalent immunotoxins (ITs) with cytotoxic potential against Thy 1.2-expressing tumor cells were used in association with mouse interleukin 2 (IL2) for treatment of mice bearing ascitic EL4 lymphomas. The combined treatment, ITs + IL2, induced an enhanced antitumor effect revealed by a significant prolongation of the survival time of mice as compared to the simple treatment with ITs or IL2 alone.