PARP-1 expression is increased in colon adenoma and carcinoma and correlates with OGG1

The ethiology of colon cancer is largely dependent on inflammation driven oxidative stress. The analysis of 8-oxodeoxyguanosine (8-oxodGuo) level in leukocyte DNA of healthy controls (138 individuals), patients with benign adenomas (AD, 137 individuals) and with malignant carcinomas (CRC, 169 individuals) revealed a significant increase in the level of 8-oxodGuo in leukocyte DNA of AD and CRC patients in comparison to controls. The counteracting mechanism is base excision repair, in which OGG1 and PARP-1 play a key role. We investigated the level of PARP-1 and OGG1 mRNA and protein in diseased and marginal, normal tissues taken from AD and CRC patients and in leukocytes taken from the patients as well as from healthy subjects. In colon tumors the PARP-1 mRNA level was higher than in unaffected colon tissue and in polyp tissues. A high positive correlation was found between PARP-1 and OGG1 mRNA levels in all investigated tissues. This suggests reciprocal influence of PARP-1 and OGG1 on their expression and stability, and may contribute to progression of colon cancer. PARP-1 and OGG1 proteins level was several fold higher in polyps and CRC in comparison to normal colon tissues. Individuals bearing the Cys326Cys genotype of OGG1 were characterized by higher PARP-1 protein level in diseased tissues than the Ser326Cys and Ser326Ser genotypes. Aforementioned result may suggest that the diseased cells with polymorphic OGG1 recruit more PARP protein, which is necessary to remove 8-oxodGuo. Thus, patients with decreased activity of OGG1/polymorphism of the OGG1 gene and higher 8-oxodGuo level may be more susceptible to treatment with PARP-1 inhibitors.

Ketanserin, an antagonist of 5-HT2A receptor of serotonin, inhibits testosterone secretion by rat Leydig cells in vitro

The effect of ketanserin, an antagonist of 5-HT2A receptor of serotonin, added to the culture medium, on basal and LH-stimulated testosterone secretion was studied in primary cultures of adolescent rat Leydig cells. Ketanserin decreased the basal secretion of testosterone but showed an insignificant influence on the LH-stimulated process. It can be concluded that ketanserin may affect the testosterone-secreting cells by an indirect action at the vascular level as well as directly at the level of Leydig cells, at least in adolescent rats, leading to down-regulation of the basal testosterone secretion.

[Preparation and clinical assays of Cl esterase inhibitors]

Seven preparation of Cl-estrase inhibitor (Clinh) were prepared from the serum form which factor IX had been absorbed previously. Despite always the same technique and conditions of isolation the degree of Clinh recovery differed, being sometimes fairly low, and ranging from 24% to 56% in relation to the initial plasma. The preparations contained cartain amounts of other proteins from the groups of alpha- and beta-globulins, particularly coeruloplasmin and components of complement C3, C4 and C9. The concentration of these components was low in relation to the concentration of the inhibitor. Some preparations contained also low amount of albumins. The preparation (about 20 thousand Clinh units) was transfused to a patient with congenital deficiency of Cl-esterase inhibitor at the time free of symptoms. The investigation of the blood obtained 30 minutes after transfusion showed complete inhibition of C-L-esterase. Administration of the preparation to the patient at the time of acute oedema caused in 5 episodes rapid regression of oedema or inhibition of its increase, in two cases no evident positive effect was obtained.