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BRCA1/2 mutation status in epithelial ovarian cancer (EOC) presently relies on genetic testing which is resource consuming. Immunohistochemistry is cheap, fairly reproducible, and may identify gene product alterations due to both germline and somatic mutations and other defects along the BRCA gene pathway (BRCAness phenomenon), which is important when treatment with poly (adenosine-diphosphate-ribose) polymerase (PARP) inhibitors is considered. The aim of this study was to investigate immunohistochemical detection of BRCA1 and PARP expression in EOC and their possible prognostic relevance. Tumor tissue from 170 patients with EOC was stained immunohistochemically with BRCA1 and PARP antibodies. Semiquantitative analyses were performed to determine loss of, equivocal, and retained BRCA1 and high versus low PARP protein expression. These parameters were analyzed for relation with patient and clinicopathologic characteristics and overall survival. BRCA1 expression was reduced in 21.2 % of the tumors and 36.5% showed high PARP expression. No correlation between the 2 parameters or between PARP and clinicopathologic features was found. Overall survival was significantly increased in the BRCA1-reduced and equivocal groups [median survival 2.4 y (95% CI, 1.6-6.6) and 4.9 y (95 % CI, 2.3-6.7) vs. 1.5 y (95% CI, 1.3-1.9); P=0.0002]. Multivariate analysis confirmed these findings; hazard ratio=0.53 (95% CI, 0.34-0.81; P=0.0037; loss of BRCA1 expression). In conclusion, immunohistochemical BRCA1 expression in EOC holds considerable prognostic information, whereas PARP expression did not influence the outcome. The results call for validation in prospective trials.

The combined use of several drugs targeting different cellular functions is one approach to achieve tumor control in cancer. We studied the effects of Pseudomonas exotoxin A (PE)-based immunotoxins (ITs), the 9.2.27PE and the 425.3PE, together with 2 different triphenylmethyl derivatives, triphenylmethyl phosphonates and phosphonochloridates (TPMP)-I-2 and 4BI. Combining the triphenylmethyl derivatives with ITs enhanced the cytotoxic effect of the ITs, with TPMP-I-2 in combination with the 425.3PE (targeting the epidermal growth factor receptor) being the most promising combination. The cytotoxicity involving signs of apoptosis was observed in cancer cells from different origins in vitro. It is interesting to note that treatment with IT, TPMP-I-2, or 4BI alone or in combination resulted in strongly decreased protein levels of stearoyl-CoA desaturase. Stearoyl-CoA desaturase is the rate-limiting enzyme for converting saturated fatty acids into monounsaturated fatty acids needed for membrane genesis. Furthermore, the combination of 425.3PE and TPMP-I-2 prolonged the survival time of nude rats in a simulated micrometastatic cervical cancer model. In addition, we demonstrate that a combination of the 425.3PE and 4BI was more effective in reducing tumor growth in a breast cancer model in nude mice compared with either agent alone.

PARP, poly (adenosine diphosphate-ribose) polymerase, is a damage-sensing protein, which is essential for the repair of DNA single-strand breaks. PARP and p53 function synergistically in repairing DNA damage and suppressing chromosomal rearrangements. The aim of this study was to determine the expression of PARP and p53 in epithelial ovarian cancer (EOC) and to correlate their expression with clinicopathologic characteristics. PARP and p53 were evaluated using immunohistochemistry applied on a tissue microarray of 189 EOC and their expressions were correlated to clinicopathologic variables, including the age of diagnosis, stage, grade, histologic type, optimal debulking, progression-free survival, and overall survival (OS). PARP and p53 expressions were shown in 61% and 54% of cases, respectively. PARP-positive tumors are more likely to have higher grade (P=0.03) and complete response to initial first-line chemotherapy (P=0.009). Patients with positive p53 staining are more likely to be at the advanced stage disease (P=0.004). Finally, there were no significant associations between PARP and p53 expression and no differences in progression-free survival and OS for PARP or p53 expressions. The overexpression of PARP and p53 in high grade, and advanced stage tumors indicated that these 2 markers might serve as an indicator of aggressive disease behavior. Additional studies are warranted to evaluate the role of PARP and PARP inhibitors in the setting of adjuvant chemotherapy.

Background and Purpose: Poly(ADP-ribose) polymerase-1 (PARP-1) is involved in ischemic preconditioning of the heart and cultured neurons, but its role in brain ischemic preconditioning is unknown. Summary of Report- We report that 5-minute bilateral common carotid artery occlusion (BCCAO) in the mouse prompted reduction of infarct volumes triggered 24 hours later by 20-minute middle cerebral artery occlusion (MCAO). Pharmacological PARP-1 inhibition between BCCAO and MCAO did not impair preconditioning. The contents of the PARP-1 substrate NAD, those of its product poly(ADP-ribose), caspase-3 activation, and PARP-1 expression did not change after BCCAO within the preconditioned tissue. PARP-1 KO mice were similarly protected by the 5-minute BCCAO., Conclusions: Data demonstrate that, at variance with the heart, PARP-1 is dispensable for brain ischemic preconditioning.

Immunohistochemical techniques revealed a significant increase of poly(ADP-ribose) polymerase (PARP)-containing nuclei in the dopaminergic neurons of the substantia nigra (SN) in Parkinson disease and in diffuse Lewy body disease as compared with a group of patients with other neurodegenerative diseases and normal controls. The nuclear translocation of nuclear factor kappa B (NF-kappa B) was also noted in the same cells. The over-activation of PARP and the transcriptional activation of NF-kappa B can contribute to the pathomechanism of the disease specific lesion of the neurons in the SN. However, in another subgroup of dopaminergic cells of the SN an increased parvalbumin content was detected reflecting a natural protective mechanism against the putative increase of intracellular calcium caused by excitotoxic injury and oxidative stress.

To assess the significance of damaged nuclear DNA in autopsy brain tissue in Lewy body disease (LBD), we examined the patterns of expression of two DNA repair enzymes (PARP and DNA-PKCS), TUNEL and caspase-3 activation, in sections of midbrain and frontal cortex from nine patients with LBD who had not received L-DOPA, and from five neurologically normal controls. In LBD but not controls, many neurons and glia in the midbrain had translocated DNA-PKCS and PARP from the cytoplasm into the nucleus, particularly in the substantia nigra. LBD midbrains contained sparse TUNEL-positive neurons. Caspase-3 activity was largely restricted to microglia but was detected in an occasional nigral neuron. Nuclear DNA damage occurs in vivo in LBD but only rarely indicates neuronal apoptosis.

The aim of the present study was to investigate the effects of tempol, a membrane-permeable radical scavenger, in rats subjected to splanchnic artery occlusion shock (SAO). Rats subjected to SAO developed a significant decrease in mean arterial blood pressure, a significant increase in tissue myeloperoxidase activity, and a marked injury to the distal ileum. SAO shock resulted in 100% mortality at 2 h after reperfusion. At 60 min after reperfusion, a marked increase in the immunoreactivity to nitrotyrosine and to poly (ADP-ribose) synthetase was observed in the necrotic ileum of rats with SAO. Staining of sections of the ileum obtained from SAO-shocked rats with anti-intercellular adhesion molecule (ICAM-1) and anti-P-selectin antibodies resulted in diffuse staining. Tempol (30 mg/kg bolus injection 5 min prior to reperfusion, followed by an infusion of 30 mg/kg/h intravenously) attenuated 1) the infiltration of the reperfused intestine with neutrophils, 2) the lipid peroxidation, 3) the production of peroxynitrite, 4) the degree of P-selectin and ICAM-1 staining in tissue sections from SAO-shocked rats, 5) histological signs of bowel injury, and 6) mortality at 2 h after reperfusion. Taken together, our results clearly demonstrate that the intracellular radical scavenger tempol reduces the intestinal injury of rats subjected SAO shock.

We examined the timing of apoptosis and the expression of the DNA repair proteins poly(ADP-ribose) polymerase (PARP) and Ku80 in sections of frontal and temporal lobes from patients who had suffered severe brain ischaemia due to a cardiac arrent. In situ end-labelling (ISEL) was used to detect apoptotic cells, and immunohistochemistry to assess PARP and Ku80. ISEL of scattered neurons and glia was demonstrable predominantly during the first 24 h after ischaemia. PARP and Ku80 immunoreactivity increased markedly after cerebral ischaemia, PARP particularly in the regions of greatest susceptibility to hypoxic injury: the CA1 field of the hippocampus and the depths of neocortical sulci. The up-regulation of PARP is in keeping with experimental observations concerning the key role of this enzyme in mediating ischaemic cell death.