Fraisinib: a calixpyrrole derivative reducing A549 cell-derived NSCLC tumor in vivo acts as a ligand of the glycine-tRNA synthase, a new molecular target in oncology.

Background and purpose: Lung cancer is the leading cause of death in both men and women, constituting a major public health problem worldwide. Non-small-cell lung cancer accounts for 85%-90% of all lung cancers. We propose a compound that successfully fights tumor growth in vivo by targeting the enzyme GARS1. Experimental approach: We present an in-depth investigation of the mechanism through which Fraisinib [meso-(p-acetamidophenyl)-calix(4)pyrrole] affects the human lung adenocarcinoma A549 cell line. In a xenografted model of non-small-cell lung cancer, Fraisinib was found to reduce tumor mass volume without affecting the vital parameters or body weight of mice. Through a computational approach, we uncovered that glycyl-tRNA synthetase is its molecular target. Differential proteomics analysis further confirmed that pathways regulated by Fraisinib are consistent with glycyl-tRNA synthetase inhibition. Key results: Fraisinib displays a strong anti-tumoral potential coupled with limited toxicity in mice. Glycyl-tRNA synthetase has been identified and validated as a protein target of this compound. By inhibiting GARS1, Fraisinib modulates different key biological processes involved in tumoral growth, aggressiveness, and invasiveness. Conclusion and implications: The overall results indicate that Fraisinib is a powerful inhibitor of non-small-cell lung cancer growth by exerting its action on the enzyme GARS1 while displaying marginal toxicity in animal models. Together with the proven ability of this compound to cross the blood-brain barrier, we can assess that Fraisinib can kill two birds with one stone: targeting the primary tumor and its metastases "in one shot." Taken together, we suggest that inhibiting GARS1 expression and/or GARS1 enzymatic activity may be innovative molecular targets for cancer treatment.

Two calix[4]pyrroles as potential therapeutics for castration-resistant prostate cancer.

Macrocyclic compounds meso-(p-acetamidophenyl)-calix[4]pyrrole and meso-(m-acetamidophenyl)-calix[4]pyrrole have previously been reported to exhibit cytotoxic properties towards lung cancer cells. Here, we report pre-clinical in vitro and in vivo studies showing that these calixpyrrole derivatives can inhibit cell growth in both PC3 and DU145 prostatic cancer cell lines. We explored the impact of these compounds on programmed cell death, as well as their ability to inhibit cellular invasion. In this study we have demonstrated the safety of these macrocyclic compounds by cytotoxicity tests on ex-vivo human peripheral blood mononuclear cells (PBMCs), and by in vivo subcutaneous administration. Preliminary in vivo tests demonstrated no hepato-, no nephro- and no genotoxicity in Balb/c mice compared to controls treated with cisplatin. These findings suggest these calixpyrroles might be novel therapeutic tools for the treatment of prostate cancer and of particular interest for the treatment of androgen-independent castration-resistant prostate cancer.

A novel calix[4]pyrrole derivative as a potential anticancer agent that forms genotoxic adducts with DNA.

meso-(p-acetamidophenyl)-calix[4]pyrrole 3 was found to exhibit remarkable cytotoxicity towards A549 cancer cells. A comparative study including the isomer of 3 meso-(m-acetamidophenyl)-calix[4]pyrrole 5, as well as molecules containing 'fragments' of these structures, demonstrated that both the calix[4]pyrrole and the acetamidophenyl units are essential for high cytotoxicity. Although calix[4]pyrroles and other anion-complexing ionophores have recently been reported to induce apoptosis by perturbing cellular chloride concentrations, in our study an alternative mechanism has emerged, as proven by the isolation of covalent DNA adducts revealed by the 32P postlabelling technique. Preliminary pharmacokinetic studies indicate that 3 is able to cross the Blood-Brain-Barrier, therefore being a potential drug that could kill primary and brain metastatic cancer cells simultaneously.

A calixpyrrole derivative acts as an antagonist to GPER, a G-protein coupled receptor: mechanisms and models.

Estrogens regulate numerous pathophysiological processes, mainly by binding to and activating estrogen receptor (ER)α and ERß. Increasing amounts of evidence have recently demonstrated that G-protein coupled receptor 30 (GPR30; also known as GPER) is also involved in diverse biological responses to estrogens both in normal and cancer cells. The classical ER and GPER share several features, including the ability to bind to identical compounds; nevertheless, some ligands exhibit opposed activity through these receptors. It is worth noting that, owing to the availability of selective agonists and antagonists of GPER for research, certain differential roles elicited by GPER compared with ER have been identified. Here, we provide evidence on the molecular mechanisms through which a calixpyrrole derivative acts as a GPER antagonist in different model systems, such as breast tumor cells and cancer-associated fibroblasts (CAFs) obtained from breast cancer patients. Our data might open new perspectives toward the development of a further class of selective GPER ligands in order to better dissect the role exerted by this receptor in different pathophysiological conditions. Moreover, calixpyrrole derivatives could be considered in future anticancer strategies targeting GPER in cancer cells.

Auxin induces cell proliferation in an experimental model of mammalian renal tubular epithelial cells.

Indole-3-acetic acid is the main auxin produced by plants and plays a key role in the plant growth and development. This hormone is also present in humans where it is considered as a uremic toxin deriving from tryptophan metabolism. However, beyond this peculiar aspect, the involvement of auxin in human pathophysiology has not been further investigated. Since it is a growth hormone, we evaluated its proliferative properties in an in vitro model of mammalian renal tubular epithelial cells. We employed an experimental model of renal tubular epithelial cells belonging to the LLC-PK1 cell line that is derived from the kidney of healthy male pig. Growth effects of auxin against LLC-PK1 cell lines were determined by a rapid colorimetric assay. Increasing concentrations of auxin (to give a final concentration from 1 to 1000 ng/mL) were added and microplates were incubated for 72 h. Each auxin concentration was assayed in four wells and repeated four times. Cell proliferation significantly increased, compared to control cells, 72 h after addition of auxin to cultured LLC-PK1 cells. Statistically significant values were observed when 100 ng/mL (p < 0.01) and 1000 ng/mL (p < 0.05) were used. In conclusion, auxin influences cell growth not only in plants, where its role is well documented, but also in mammalian cell lines. This observation opens new scenarios in the field of tissue regeneration and may stimulate a novel line of research aiming at investigating whether this hormone really influences human physiology and pathophysiology and in particular, kidney regeneration.

[Evaluation of an internal guideline for the diagnostics of deep vein thrombosis]. / Evaluation einer abteilungsinternen Leitlinie zur Diagnostik der tiefen Beinvenenthrombose.

BACKGROUND AND PURPOSE: In line with the application of evidence-based medicine as part of the day-to-day clinical practice of a community hospital internal guidelines concerning relevant diagnostic or therapeutic problems were developed. The authors retrospectively compared all data of patients with the tentative diagnosis of deep vein thrombosis (DVT), who underwent further diagnostics before and after implementation of an internally developed guideline for the diagnostics of DVT. The aim was to evaluate if the internal guideline was applied by the doctors in the daily routine and if the implementation led to a change and rationalization of the diagnostic process, in particular with regard to reducing invasive examinations. METHODS: In a retrospective controlled cohort study the medical records of in- and outpatients (n = 371) receiving further diagnostics following a tentative diagnosis of DVT were screened. The kind of examinations, the duration of the diagnostic process and the rate of hospitalization for DVT were compared between the intervention group (n = 185), treated in the initial 10 months following guideline implementation, and the control group (n = 186), treated in the 10 months prior to implementation. Furthermore, the physicians' compliance with the internal guideline was assessed. RESULTS: After implementation in 114 of 185 cases (62%) the treating doctors based their diagnostic procedure on the internal guideline. There was a significant decrease of phlebographies (45.4% vs. 74.2%; RR 0.61 [95% CI 0.51; 0.73]). By contrast, the number of D-dimer tests (81.6% vs. 33.3%; RR 2.45 [95% CI 1.98; 3.03]) and of duplex sonographies (42.2% vs. 21.5%; RR 1.96 [95% CI 1.42; 2.71]) increased significantly. A reduction of the hospitalization rate for further diagnostics of primary ambulant patients (51.3% vs. 60.4% of the tentative cases; RR 0.85 [95% CI 0.69; 1,04]) without a significant change in the final number of DVT diagnoses (33.3% vs. 27.6%; RR 0,83 [95% CI 0,61; 1,13]) was found. There was a slight increment in the mean length of diagnostic process (2.12 vs. 1.84 days). CONCLUSION: The implementation of an internal guideline for the diagnostics of DVT led to a significant reduction of the hospitalization rate and to a considerable change of the diagnostic procedure in favor of noninvasive diagnostic tests, for patients presenting with a diagnosis of suspected DVT.

[Donepezil in patients with Alzheimer's disease--a critical appraisal of the AD2000 study]. / Donepezil bei Patienten mit Alzheimer-Demenz Die AD2000-Studie.

The AD2000 study was a randomized placebo-controlled trial, the effects of donepezil, a cholinesterase inhibitor, in patients with Alzheimer's disease. It was the first long-term RCT not sponsored by the pharmaceutical industry. The study did not show any significant effect on patient-relevant outcomes. However, donepezil had a significant effect on cognitive scores. More patients taking donepezil stopped treatment due to adverse events, even when taking only 5 mg once daily. There are major concerns regarding the conduction of the AD2000 study as well as the presentation of the results. Much less patients than previously planned have been recruited, resulting in a low statistical power to detect a significant difference between both treatments. In addition, no true intention-to-treat analysis based on the first randomization is presented. The validity of the AD2000 trial has to be questioned. However, there is still insufficient evidence to support the claim that cholinesterase inhibitors have beneficial effects on patient-relevant outcomes in patients with Alzheimer's disease. The change of cognitive performance as measured by different scales does not necessarily correspond to substantial changes in patient-relevant outcomes. In conclusion, the widespread use of cholinesterase inhibitors in patients with Alzheimer's disease is not supported by current evidence. Long-term-randomized controlled trials focusing on patient-relevant outcomes instead of cognitive scores are urgently needed.