Expression of progranulin (Acrogranin/PCDGF/Granulin-Epithelin Precursor) in benign and malignant ovarian tumors and activation of MAPK signaling in ovarian cancer cell line

It has been recently demonstrated that progranulin is overexpressed in ovarian cancer and that this protein is involved in the stimulation of cell proliferation, malignancy, and chemoresistance in ovarian cancer. The goal of the present study was to establish the differences in progranulin expression among normal, benign, and malignant ovarian tissues and to identify the signal transduction pathways activated by progranulin in an ovarian cancer cell line. Compared with benign tumors and normal ovarian tissue, progranulin mRNA and protein were overexpressed in malignant tumors. Survival analysis by the Kaplan-Meier method showed a correlation between high mRNA expression levels with poor survival outcome. Progranulin activated the MAPK-signaling pathway in NIH-OVCAR-3 cells. Progranulin expression may be potentially involved in the pathogenesis and malignant progression of ovarian cancer, and thus may represent a therapeutic target for this particular malignancy.

Functional relationships between capacitation-dependent cell signaling and compartmentalized metabolic pathways in murine spermatozoa

Spermatozoa are highly polarized cells with specific metabolic pathways compartmentalized in different regions. Previously, we hypothesized that glycolysis is organized in the fibrous sheath of the flagellum to provide ATP to dynein ATPases that generate motility and to protein kinases that regulate motility. Although a recent report suggested that glucose is not essential for murine sperm capacitation, we demonstrated that glucose (but not lactate or pyruvate) was necessary and sufficient to support the protein tyrosine phosphorylation events associated with capacitation. The effect of glucose on this signaling pathway was downstream of cAMP, and appeared to arise indirectly as a consequence of metabolism as opposed to a direct signaling effect. Moreover, the phosphorylation events were not affected by uncouplers of oxidative respiration, inhibitors of electron transfer, or by a lack of substrates for oxidative respiration in the medium. Further experiments aimed at identifying potential regulators of sperm glycolysis focused on a germ cell-specific isoform of hexokinase, HK1-SC, which localizes to the fibrous sheath. HK1-SC activity and biochemical localization did not change during sperm capacitation, suggesting that glycolysis in sperm is regulated either at the level of substrate availability or by downstream enzymes. These data support the hypothesis that ATP specifically produced by a compartmentalized glycolytic pathway in the principal piece of the flagellum, as opposed to ATP generated by mitochondria in the mid-piece, is strictly required for protein tyrosine phosphorylation events that take place during sperm capacitation. The relationship between these pathways suggests that spermatozoa offer a model system for the study of integration of compartmentalized metabolic and signaling pathways.

A reliable endocrine test with human menopausal gonadotropins for diagnosis of true hermaphroditism in early infancy

In true hermaphroditism diverse phenotypes and karyotypes are found; there are no distinctive laboratory features that can distinguish it from other intersex disorders, thus the diagnosis is made by the histological findings. Existence of Leydig cells is demonstrated by testosterone levels above the female range; however, presence of ovarian tissue cannot be ascertained because of the absence of a reliable functional test. Unless appropriate biopsies are performed or the whole gonad is removed, there is a risk of not diagnosing true hermaphroditism. To find a reliable test that can differentiate patients with true hermaphroditism from those with other intersex disorders, we investigated the estradiol (E2) response to human menopausal gonadotropins (hMG) in infants with genital ambiguity. These results were correlated with the histological findings. Eleven infants with genital ambiguity and four with a high scrotal testis were stimulated every 12 h with 2 IU/kg hMG. If E2 rose above 80 pg/mL (cut-off point), the test was discontinued; if after 7 days E2 remained below 80 pg/mL, the hMG dose was doubled and stimulation extended for 7 additional days. In five patients in whom true hermaphroditism was later histologically demonstrated, E2 rose above 80 pg/mL. In two of them, ovarian tissue was removed and hMG stimulation repeated; no response above our cut-off point was observed during the second test. The maximal E2 response to hMG in the remaining 10 individuals was 43 pg/mL; after laparotomy or gonadal biopsies no ovarian tissue was found. The hMG stimulation test can be considered a reliable and safe dynamic procedure for demonstrating the presence or absence of ovarian tissue in infants with genital ambiguity.