Targeting cervical cancer: Is there a role for poly (ADP-ribose) polymerase inhibition?

Patients with metastatic and recurrent cervical cancer (CC) have a poor prognosis with limited palliative treatment options. Increasing understanding of the cellular aberrations inherent to cancer cells has allowed the development of therapies to target biological pathways, an important step toward the individualization of cancer therapy. The poly (ADP-ribose) polymerase (PARP) family of enzymes is important in several DNA repair pathways. Drugs that inhibit these PARP enzymes have been investigated in many types of cancer and their application in the treatment of gynecologic malignancies has rapidly evolved. Although the majority of data for PARPi in gynecologic malignancies has been specifically regarding ovarian cancer, their role in the treatment of uterine and CC is currently being investigated. This review will examine PARP inhibitors in CC, summarizes the critical clinical trials of PARP inhibitors that have been completed, provides an overview of the on-going trials, presents the confirmed conclusions and notes the issues that need to be addressed in future studies.     

The gastric effects of UFP-112, a new nociceptin/orphanin receptor agonist, in physiological and pathological conditions

Nociceptin/orphanin FQ (N/OFQ), the endogenous NOP receptor ligand, centrally modulates gastric motor and secretory functions and prevents ethanol-induced gastric lesions in rats. A recently synthesized N/OFQ analog, [(pF)Phe(4)Aib(7)Arg(14)Lys(15)]N/OFQ-NH(2) (UFP-112), acts as a highly potent and selective peptide agonist for NOP receptors and produces longer-lasting in vitro and in vivo effects in mice than the natural ligand N/OFQ. In this study, we evaluated the effects of centrally (intracerebroventricularly/icv) and peripherally (intraperitoneally/ip) injected UFP-112 on gastric emptying and gastric acid secretion, and on the development of gastric mucosal lesions induced by 50% ethanol in the rat. When injected icv, it dose-dependently delayed gastric emptying of a phenol red meal (by up to 70%), decreased gastric secretion in water-loaded rats after 90 pylorus ligature, and reduced ethanol-induced gastric lesions (by up to 87%). In all three assays, UFP-112 was more effective than N/OFQ. The highly selective NOP receptor antagonist, UFP-101, decreased the efficacy of UFP-112, thus confirming that central NOP receptors mediate inhibitory control on these functional and pathological conditions in rats. Ip injected N/OFQ and UFP-112 induced non-dose-related gastric hypersecretory and antiulcer effects, which UFP-101 partially abolished. Ip N/OFQ appeared equiactive but about 30-100 times less potent than ip UFP-112 in stimulating gastric acid secretion and preventing lesion formation. When ip injected, both UFP-112 and N/OFQ left gastric emptying in rats unchanged, suggesting that peripheral NOP receptors have a role in mediating gastric hypersecretory and antiulcer effects but are not involved in regulating gastric motility. In addition, the inhibitory effects induced by this novel NOP receptor agonist lasted longer than those induced by N/OFQ. In conclusion, UFP-112 is a promising new pharmacological tool for studying the functional roles of the central and peripheral N/OFQ receptor system.     

In vivo evolution of the Rhodococcus sp. strain DS7: selection of recombinants able to desulfurize both dibenzothiophene and benzothiophene

Rhodococcus sp. DS7, isolated from a polluted soil, has shown good desulfurizing activity towards dibenzothiophene (DBT) and its derivatives, but is not able to desulfurize benzothiophene (BT), the other thiophenic molecule recalcitrant to the chemical hydrodesulfurization (HDS) process, and most abundant in gasoline. To select a Rhodococcus DS7 derivative strain able to desulfurize both DBT and BT, we took advantage of the verified capacity of this strain to integrate exogenous DNA randomly, with a good efficiency. Heterologous chromosomal DNA, digested with restriction enzymes, from two BT but not DBT desulfurizing strains, Rhodococcus sp. ATCC 27778 and Gordonia sp. ATCC 19067, was electroporated into Rhodococcus DS7. Selection on minimal medium with BT as sole sulfur source allowed us to isolate several DS7 derivatives with the capacity to desulfurize both thiophenic molecules. Two strains, one derived from the integration and recombination of DNA from ATCC 27778, and the other from ATCC 19067, have been partially characterized. These recombinant microorganisms are an interesting starting point to develop new biodesulfurization processes.     

Gastrointestinal effects of intracerebroventricularly injected nociceptin/orphaninFQ in rats

Nociceptin/orphanin FQ/(N/OFQ), a novel heptadecapeptide recently isolated from porcine and rat brain, is the endogenous ligand of the N/OFQ peptide receptor (NOP, previously known as ORL-1). In this study we examined the effects of intracerebroventricularly (icv) injected N/OFQ on gastric emptying, gastrointestinal transit, colonic propulsion and gastric acid secretion in rats. N/OFQ (0.01-10 nmol/rat) significantly delayed gastric emptying of a phenol red meal, inhibited transit of a non-absorbable charcoal marker through the small intestine and increased the mean colonic bead expulsion time. These N/OFQ-motor effects were abolished by the NOP receptor selective antagonist [NPhe(1)]N/OFQ(1-13)-NH(2) (50 nmol/rat), but were unaltered by the classical opioid receptor antagonist, naloxone (9.2 micromol/kg). Icv injected N/OFQ (10 nmol/rat) decreased gastric acid secretion in 2-h pylorus ligated rats in a naloxone sensitive manner. [NPhe(1)]N/OFQ(1-13)-NH(2) (100 nmol/rat) icv administered alone stimulated gastric acid secretion. These results indicate that N/OFQ activates via NOP receptor stimulation a central inhibitory pathway modulating gastrointestinal propulsive activity and gastric acid secretion in rats.     

Comparison of cardiovascular response to passive tilt in young and elderly men

To test the hypothesis that altered hemodynamic responses to postural changes are associated with aging, cardiovascular responses to head-up tilt (HUT) and head-down tilt (HDT) were examined in 12 healthy young (average age, 24.6 +/- 1.7 years) and 12 healthy elderly (average age, 68.6 +/- 2.2 years) men. Subjects were passively tilted from supine to 30 degrees, 60 degrees, and 90 degrees HUT and HDT. Responses to these perturbations were determined 5 min after tilting with measures of heart rate (HR), blood pressure (SBP, DBP), and echocardiographically determined left ventricular diameter in systole and diastole (LVIDs, LVIDd). In HUT there were no significant age effects. In both young and elderly, SBP decreased significantly (p less than 0.05), and DBP and HR increased significantly. Ejection fraction (EF), mean arterial blood pressure (MABP), and rate-pressure product (RPP) were unchanged in both groups. In HDT, the hemodynamic responses of the young and elderly were in opposite directions and significant age effects were found for SBP, DBP, HR, LVIDs, EF, MABP, and RPP. In HDT, the young appear to increase cardiac output primarily due to an increase in EF and end-diastolic volume (LVIDd), while HR is unchanged and SBP is decreased. MABP is unchanged, suggesting a small decrease in total peripheral resistance. The elderly may increase cardiac output slightly, owing to an increase in LVIDd with no change in EF, and a large increase in HR. Afterload increased markedly, therefore attenuating any increase in cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dissecting the Gene Dose-Effects of the APOE ε4 and ε2 Alleles on Hippocampal Volumes in Aging and Alzheimer’s Disease

Objective

To investigate whether there is a specific dose-dependent effect of the Apolipoprotein E (APOE) ε4 and ε2 alleles on hippocampal volume, across the cognitive spectrum, from normal aging to Alzheimer’s Disease (AD).

Materials and Methods

We analyzed MR and genetic data on 662 patients from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database–198 cognitively normal controls (CN), 321 mild-cognitive impairment (MCI) subjects, and 143 AD subjects–looking for dose-dependent effects of the ε4 and ε2 alleles on hippocampal volumes. Volumes were measured using a fully-automated algorithm applied to high resolution T1-weighted MR images. Statistical analysis consisted of a multivariate regression with repeated-measures model.

Results

There was a dose-dependent effect of the ε4 allele on hippocampal volume in AD (p = 0.04) and MCI (p = 0.02)–in both cases, each allele accounted for loss of >150 mm³ (approximately 4%) of hippocampal volume below the mean volume for AD and MCI subjects with no such alleles (Cohen’s d = −0.16 and −0.19 for AD and MCI, respectively). There was also a dose-dependent, main effect of the ε2 allele (p<0.0001), suggestive of a moderate protective effect on hippocampal volume–an approximately 20% per allele volume increase as compared to CN with no ε2 alleles (Cohen’s d = 0.23).

Conclusion

Though no effect of ε4 was seen in CN subjects, our findings confirm and extend prior data on the opposing effects of the APOE ε4 and ε2 alleles on hippocampal morphology across the spectrum of cognitive aging.     

Comparison of deformable and elastic foundation finite element simulations for predicting knee replacement mechanics

Rigid body total knee replacement (TKR) models with tibiofemoral contact based on elastic foundation (EF) theory utilize simple contact pressure-surface overclosure relationships to estimate joint mechanics, and require significantly less computational time than corresponding deformable finite element (FE) methods. However, potential differences in predicted kinematics between these representations are currently not well understood, and it is unclear if the estimates of contact area and pressure are acceptable. Therefore, the objectives of the current study were to develop rigid EF and deformable FE models of tibiofemoral contact, and to compare predicted kinematics and contact mechanics from both representations during gait loading conditions with three different implant designs. Linear and nonlinear contact pressure-surface overclosure relationships based on polyethylene material properties were developed using EF theory. All other variables being equal, rigid body FE models accurately estimated kinematics predicted by fully deformable FE models and required only 2% of the analysis time. As expected, the linear EF contact model sufficiently approximated trends for peak contact pressures, but overestimated the deformable results by up to 30%. The nonlinear EF contact model more accurately reproduced trends and magnitudes of the deformable analysis, with maximum differences of approximately 15% at the peak pressures during the gait cycle. All contact area predictions agreed in trend and magnitude. Using rigid models, edge-loading conditions resulted in substantial overestimation of peak pressure. Optimal nonlinear EF contact relationships were developed for specific TKR designs for use in parametric or repetitive analyses where computational time is paramount. The explicit FE analysis method utilized here provides a unique approach in that both rigid and deformable analyses can be run from the same input file, thus enabling simple selection of the most appropriate representation for the analysis of interest.     

Structural Insights into the Quinolone Resistance Mechanism of Mycobacterium tuberculosis DNA Gyrase

Mycobacterium tuberculosis DNA gyrase, an indispensable nanomachine involved in the regulation of DNA topology, is the only type II topoisomerase present in this organism and is hence the sole target for quinolone action, a crucial drug active against multidrug-resistant tuberculosis. To understand at an atomic level the quinolone resistance mechanism, which emerges in extensively drug resistant tuberculosis, we performed combined functional, biophysical and structural studies of the two individual domains constituting the catalytic DNA gyrase reaction core, namely the Toprim and the breakage-reunion domains. This allowed us to produce a model of the catalytic reaction core in complex with DNA and a quinolone molecule, identifying original mechanistic properties of quinolone binding and clarifying the relationships between amino acid mutations and resistance phenotype of M. tuberculosis DNA gyrase. These results are compatible with our previous studies on quinolone resistance. Interestingly, the structure of the entire breakage-reunion domain revealed a new interaction, in which the Quinolone-Binding Pocket (QBP) is blocked by the N-terminal helix of a symmetry-related molecule. This interaction provides useful starting points for designing peptide based inhibitors that target DNA gyrase to prevent its binding to DNA.     

Molecular modelling studies,synthesis and biological activity of a series of novel bisnaphthalimides and their development as new DNA topoisomerase II inhibitors

A series of bisnaphthalimide derivatives were synthesized and evaluated for growth-inhibitory property against HT-29 human colon carcinoma. The N,N′-bis[2-(5-nitro-1,3-dioxo-2,3-dihydro-1H-benz[de]-isoquinolin-2-yl)]propane-2-ethanediamine (9) and the N,N′-Bis[2-(5-nitro-1,3-dioxo-2,3-dihydro-1H-benz[de]-isoquinolin-2-yl)]butylaminoethyl]-2-propanediamine (12) derivatives emerged as the most potent compounds of this series. Molecular modelling studies indicated that the high potency of 12, the most cytotoxic compound of the whole series, could be due to larger number of intermolecular interactions and to the best position of the naphthalimido rings, which favours π–π stacking interactions with purine and pyrimidine bases in the DNA active site. Moreover, 12 was designed as a DNA topoisomerase II poison and biochemical studies showed its effect on human DNA topoisomerase II. We then selected the compounds with a significant cytotoxicity for apoptosis assay. Derivative 9 was able to induce significantly apoptosis (40%) at 0.1 μM concentration, and we demonstrated that the effect on apoptosis in HT-29 cells is mediated by caspases activation.     

Mesoglycan induces keratinocyte activation by triggering syndecan-4 pathway and the formation of the annexin A1/S100A11 complex

Wound healing is a dynamic process comprising multiple events, such as inflammation, re-epithelialization, and tissue remodeling. Re-epithelialization phase is characterized by the engagement of several cell populations, mainly of keratinocytes that sequentially go through cycles of migration, proliferation, and differentiation to restore skin functions. Troubles can arise during the re-epithelialization phase of skin wound healing particularly in keratinocyte migration, resulting in chronic non-healing lesions, which represent a serious clinical problem. Over the last decades, the efforts aimed to find new pharmacological approaches for wound care were made, yet almost all current therapeutic strategies used remain inadequate or even ineffective. As such, it is crucial to identify new drugs that can enable a proper regeneration of the epithelium in wounded skin. Here, we have investigated the effects of the fibrinolytic drug mesoglycan, a glycosaminoglycans mixture derived from porcine intestinal mucosa on HaCaT human keratinocytes that were used as in vitro experimental model of skin re-epithelialization. We found that mesoglycan induces keratinocyte migration and early differentiation by triggering the syndecan-4/PKCα pathway and that these effects were at least in part, because of the formation of the annexin A1/S100A11 complex. Our data suggest that mesoglycan may be useful as a new pro-healing drug for skin wound care.