Citral, 3,7-dimethyl-2,6-octadien-1-al, a key component of the lemon-scented essential oils extracted from several herbal plants such as lemon grass (Cymbopogon citratus), melissa (Melissa officinalis), verbena (Verbena officinalis) is used as a food additive and as a fragrance in cosmetics. In this study, we investigated the anti-cancer potential of citral and its mode of action. Concentrations of 44.5 muM, comparable to the concentration of citral in a cup of tea prepared from 1 g of lemon grass, induced apoptosis in several hematopoietic cancer cell lines. Apoptosis was accompanied by DNA fragmentation and caspase-3 catalytic activity induction. Citral activity (22.25 microM) was compared to a reference compound like staurosporine (0.7 microM), in respect to DNA fragmentation and caspase-3 enzymatic activity. The apoptotic effect of citral depended on the alpha,beta-unsaturated aldehyde group.

Taxol is used in chemotherapy regimens against breast and ovarian cancer. Treatment of tumor model cell lines with taxol induces apoptosis, but exact mechanism is not sufficiently understood. Our results demonstrate that in response to taxol, various cell types differentially utilize distinct apoptotic pathways. Using MCF7 breast carcinoma cells transfected with caspase-3 gene, we showed that taxol-induced apoptosis occurred in the absence of caspase-3 and caspase-9 activation. Similar results were obtained with ovarian SKOV3 carcinoma cells, expressing high level of endogenous caspase-3. In contrast, staurosporine-induced apoptosis in these cells was accompanied by proteolytic cleavage of pro-caspase-3 and induction of caspase-3 enzymatic activity. The effect of taxol appears to be cell type-specific, since taxolinduced apoptosis in leukemia U937 cells involved caspase-3 activation step. We conclude that a unique caspase-3 and caspase-9 independent pathway is elicited by taxol to induce apoptosis in human ovarian and breast cancinoma cells.

The enzyme 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) is a progesterone-catabolizing enzyme that is highly expressed in mouse ovaries and adrenals. Although the functional significance of ovarian 20alpha-HSD for the induction of parturition has been defined, regulation and distribution of 20alpha-HSD in the adrenal gland has not been determined. We demonstrate that the expression of adrenal 20alpha-HSD is restricted to the X-zone, a transient zone between the adrenal cortex and the medulla of yet unknown function. Adrenal 20alpha-HSD activity in male mice peaks at 3 wk of age and disappears thereafter, whereas 20alpha-HSD enzyme activity is maintained in adrenals from nulliparous female animals. Testosterone treatment of female mice induces rapid involution of the X-zone that is associated with the disappearance of the 20alpha-HSD-positive cells. Conversely, reappearance of 20alpha-HSD expression and activity in male animals is evident after gonadectomy. Moreover, pregnancy, but not pseudopregnancy, is accompanied by X-zone regression and loss of 20alpha-HSD activity. Pregnancy-induced X-zone regression and -abolished 20alpha-HSD expression is partially restored in animals that were kept from nursing their pups. We found that in addition to its progesterone-reducing activity, 20alpha-HSD also functions as an 11-deoxycorticosterone-catabolizing enzyme. The unaltered growth kinetics of the X-zone in 20alpha-HSD knockout animals suggests that 20alpha-HSD is not required for the regulation of X-zone growth. However, 20alpha-HSD expression and enzymatic activity in all experimental paradigms is closely correlated with the presence of the X-zone. These findings provide the basis for 20alpha-HSD as a reliable marker of the murine X-zone.

Objective: To determine whether soluble HLA-G1 (sHLA-G1) concentrations in maternal serum and in amniotic fluid are lower at term than in the second trimester. Methods: In this prospective study amniotic fluid and maternal serum samples were aspirated from 21 pregnant women during genetic amniocentesis at 16–20 weeks’ gestation, and from 19 women undergoing a cesarean section at term. In the latter group arterial umbilical cord blood was aspirated as well. sHLA-G1 levels were determined using ELISA assay. This assay included the anti-HLA-G monoclonal antibodies 87G and 16G1, both as capture antibodies and horseradish-peroxidase-labeled rabbit anti-human β₂-microglobulin antibodies, as the detection antibody. The relative concentrations of sHLA-G1 were measured from the absorbancy of the blue product at 650 nm. Student’s t test was used for statistical analysis. Results: sHLA-G1 levels in amniotic fluid were significantly lower at term than in the second trimester (0.160 ± 0.05 vs. 0.272 ± 0.150 OD units; p < 0.05). Levels of sHLA-G1 in maternal serum declined toward term, but the difference from the second trimester was not statistically significant (0.266 ± 0.157 vs. 0.205 ± 0.120 OD units; p = 0.193). There was a strong correlation of sHLA-G1 concentrations between cord serum and maternal serum (R² = 0.79; p < 0.001), but not between cord serum and amniotic fluid (R² = 0.00004) or amniotic fluid and maternal serum (R² = 0.02). Conclusions: sHLA-G1 antigen expression is higher in amniotic fluid than in maternal-fetal compartments and significantly decreases toward term. We speculate that the declining amniotic fluid sHLA-G1 levels may stimulate a maternal immunological response against the fetus and contribute to the initiation of parturition.

We have previously demonstrated the pathogenicity of the common anti-DNA idiotype designated 16/6 Id. Immunization of naive mice with the 16/6 Id induced SLE-like disease characterized by serological (e.g. anti-dsDNA and anti-Sm auto-antibodies), clinical (increased ESR, leucopenia and proteinuria), and pathological (16/6 Id deposition in kidneys) parameters. To elucidate further the role of the 16/6 Id in SLE induction the following studies were carried out: BALB/c mice were immunized with SA-1, a human anti-DNA monoclonal antibody carrying the 16/6 Id; TB-68, a mouse monoclonal anti-tuberculosis (TB) glycolipid, which binds dsDNA and carries the 16/6 Id; TB-72, a mouse monoclonal anti-TB glycolipid that binds DNA and does not harbour the 16/6 Id; and 4B4, a human anti-Sm antibody that carries the 16/6 Id. SLE was induced in BALB/c mice only when immunized with SA-1, TB-68, and 4B4, namely antibodies with diverse binding capacities albeit having the 16/6 Id. Our studies further support previous evidence on the pathogenic role attributed to the 16/6 Id in SLE, and suggest that SLE is most probably an idiotype-induced disease.

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Cytokines mediate their effects on growth and maturation of hematopoietic cells by binding to their cognate receptors and activating target genes. Interleukin-3 (IL-3) and erythropoietin (Epo) induce signal transduction via the Jak-Stat pathway. We report here on the identification of several known and novel genes induced by IL-3 and Epo, using a modified version of the PCR-based technique, enhanced differential display (EDD). We modified the technique to facilitate the screening and verification of the differential expression of the genes by using reverse Southern blotting (RS) and PCR-Southern blotting, and we called it EDD-RS. From the initial 110 genetags that were identified as differential expressed genes, 14 contained more than one gene. Among the differentially expressed genes, 24 are known genes and 39 are novel genes. Several of the known genes, such as IRF-1 and P21waf, were previously observed by others to be induced by IL-3 and Epo, but their dependence on Stat5 activation in cytokine-dependent cells was unknown. Other known genes, such as crp and Mssp2/1, were not described previously as target genes for cytokine induction. The results demonstrate that EDD-RS is an efficient method to identify cytokine-induced genes and can be productive in delineating the signal required for their induction.

The sera of various rheumatic and autoimmune diseases were examined for the presence of anti-RNP/Sm activity. An enzyme-linked immunosorbent assay (ELISA) was employed. Anti-RNP Ab's were detected in 18%, 20%, 28%, 16% of the sera of SLE, myasthenia gravis (MG), rheumatoid arthritis (RA) and thyroid diseases respectively. The anti-RNP Ab's belonged to the IgG and IgM isotypes. Most of the IgG anti-Sm antibodies were detected in SLE sera, but they were found also in two sera of MG and in one sera of RA patients. IgM anti-Sm antibodies were not found in SLE sera, but they were detected in low titer in MG, RA and autoimmune thyroid diseases. The activity against RNP and/or Sm was further confirmed by employing immunoblotting assays. In none of the patients, except those with SLE, was any clinical manifestation of SLE noted. The mere presence of anti-Sm antibodies of the IgG isotypes is not sufficient for the development of SLE, however, its presence is highly specific for SLE.