Exploring glyoxalase 1 expression in prostate cancer tissues: targeting the enzyme by ethyl pyruvate defangs some malignancy-associated properties.

BACKGROUND: The glyoxalase (GLO)1 is part of a ubiquitous detoxification system in the glycolytic pathway of normal and tumor cells. It protects against cellular damage caused by cytotoxic metabolites. METHODS: Aiming at exploring the role of GLO1 in prostate cancer, we evaluated and targeted the expression of GLO1 in prostate cancer tissues and cell lines and analyzed its correlation with grading systems and tumor growth indices. RESULTS: Immunohistochemical studies on 37 prostate cancer specimens revealed a positive correlation between Helpap-grading and the cytoplasmic (P = 0.002)/nuclear (P = 0.006) GLO1 level. A positive correlation between Ki-67 proliferation marker and the cytoplasmic GLO1 (P = 0.006) was evident. Furthermore, the highest GLO1 level was detected in the androgen-sensitive LNCaP compared to the androgen-independent Du-145 and PC-3 prostate cell lines and the breast cancer cell MCF-7, both at protein and mRNA level. Treating cancer cells with ethyl pyruvate was found to defang some malignancy-associated properties of cancer cells including proliferation, invasion and anchorage-independent growth. In vitro results revealed that the potency of ethyl pyruvate is increased when cells are metabolically activated by growth stimulators, for example, by fetal calf serum, dihydrotestosterone, tumor growth factor-ß1 and leptin. CONCLUSIONS: The positive correlation of GLO1 expression level in prostate cancer tissues with the pathological grade and proliferation rate may assign GLO1 as a risk factor for prostate cancer development and progression. Furthermore, our data indicate that inhibitors of GLO1 might be useful to decelerate the cancer cell growth by a novel therapeutic approach that we may call "induced metabolic catastrophe."

Altered immune response in mice deficient for the G protein-coupled receptor GPR34.

The X-chromosomal GPR34 gene encodes an orphan G(i) protein-coupled receptor that is highly conserved among vertebrates. To evaluate the physiological relevance of GPR34, we generated a GPR34-deficient mouse line. GPR34-deficient mice were vital, reproduced normally, and showed no gross abnormalities in anatomical, histological, laboratory chemistry, or behavioral investigations under standard housing. Because GPR34 is highly expressed in mononuclear cells of the immune system, mice were specifically tested for altered functions of these cell types. Following immunization with methylated BSA, the number of granulocytes and macrophages in spleens was significantly lower in GPR34-deficient mice as in wild-type mice. GPR34-deficient mice showed significantly increased paw swelling in the delayed type hypersensitivity test and higher pathogen burden in extrapulmonary tissues after pulmonary infection with Cryptococcus neoformans compared with wild-type mice. The findings in delayed type hypersensitivity and infection tests were accompanied by significantly different basal and stimulated TNF-α, GM-CSF, and IFN-γ levels in GPR34-deficient animals. Our data point toward a functional role of GPR34 in the cellular response to immunological challenges.

Reduced food intake and body weight in mice deficient for the G protein-coupled receptor GPR82.

G protein-coupled receptors (GPCR) are involved in the regulation of numerous physiological functions. Therefore, GPCR variants may have conferred important selective advantages during periods of human evolution. Indeed, several genomic loci with signatures of recent selection in humans contain GPCR genes among them the X-chromosomally located gene for GPR82. This gene encodes a so-called orphan GPCR with unknown function. To address the functional relevance of GPR82 gene-deficient mice were characterized. GPR82-deficient mice were viable, reproduced normally, and showed no gross anatomical abnormalities. However, GPR82-deficient mice have a reduced body weight and body fat content associated with a lower food intake. Moreover, GPR82-deficient mice showed decreased serum triacylglyceride levels, increased insulin sensitivity and glucose tolerance, most pronounced under Western diet. Because there were no differences in respiratory and metabolic rates between wild-type and GPR82-deficient mice our data suggest that GPR82 function influences food intake and, therefore, energy and body weight balance. GPR82 may represent a thrifty gene most probably representing an advantage during human expansion into new environments.

Alternatively activated alveolar macrophages in pulmonary fibrosis-mediator production and intracellular signal transduction.

Activated macrophages have been characterized as M1 and M2 according to their inflammatory response pattern. Here we analyzed the M2 marker expression and intracellular signal transduction in the course of cytokine-driven differentiation. We found elevated spontaneous production of the chemokines CCL17, CCL18 and CCL22 and increased expression of CD206 by alveolar macrophages from patients with lung fibrosis. Stimulation of normal human AM with Th2 cytokines IL-4 and/or IL-10 in vitro revealed IL-4 as the most powerful inducer of M2-phenotype in AM and monocytes. Importantly, IL-10 enhanced IL-4-induced expression of CCL18 and IL-1RA in a synergistic fashion. IL-4/IL-10 stimulation induces a strong activation of STAT3 in AM from fibrosis patients. These results suggest an important role for M2 polarized AM in the pathogenesis of pulmonary fibrosis and indicate that both IL-4 and IL-10 account for human AM phenotype shift to M2, as seen in patients with fibrotic interstitial lung diseases.