Protein Farnesyltransferase Inhibitors Research Articles

Quantitative Structure Activity Relationship (QSAR) Investigations and Molecular Docking Analysis of Plasmodium Protein Farnesyltransferase Inhibitors as Potent Antimalarial Agents

The development of farnesyltransferase inhibitors based on the benzophenone scaffold directed against Plasmodium falciparum is considered a strategy in malaria treatment. In this work, quantitative structure–activity relationship (QSAR) was performed to predict the protein farnesyltransferase (PFT) inhibitory activities for a series of 36 benzophenone derivatives. The data set was divided into two subsets of training and test sets, and the best model using multiple linear regression (MLR), with the values of internal and external validity (R2 = 0.884, R2adj = 0.865, R2pred = 0.821, Q2cv =0.822 and R2p=0.811) was found in agreement with the Tropsha and Golbraikh criteria. The applicability domain (AD) was determined using the Williams plot to describe the chemical space for the model used in this study. The model shows that antimalarial activities of benzophenone depend on logP, bpol, MAXDn, and FMF descriptors. These indications prompted us to design new benzophenones PFT inhibitors and predict the value of their anti-malarial activities based on the MLR equation. Docking results reveal that the newly designed benzophenones bind to the hydrophobic pocket and polar contact with high affinity. The predicted results from this study can help to design novel benzophenone as inhibitors of human PFT with high antimalarial activities.

Abolishing the prelamin A ZMPSTE24 cleavage site leads to progeroid phenotypes with near-normal longevity in mice.

Prelamin A is a farnesylated precursor of lamin A, a nuclear lamina protein. Accumulation of the farnesylated prelamin A variant progerin, with an internal deletion including its processing site, causes Hutchinson-Gilford progeria syndrome. Loss-of-function mutations in ZMPSTE24, which encodes the prelamin A processing enzyme, lead to accumulation of full-length farnesylated prelamin A and cause related progeroid disorders. Some data suggest that prelamin A also accumulates with physiological aging. Zmpste24-/- mice die young, at ∼20 wk. Because ZMPSTE24 has functions in addition to prelamin A processing, we generated a mouse model to examine effects solely due to the presence of permanently farnesylated prelamin A. These mice have an L648R amino acid substitution in prelamin A that blocks ZMPSTE24-catalyzed processing to lamin A. The LmnaL648R/L648R mice express only prelamin and no mature protein. Notably, nearly all survive to 65 to 70 wk, with ∼40% of male and 75% of female LmnaL648R/L648R mice having near-normal lifespans of 90 wk (almost 2 y). Starting at ∼10 wk of age, LmnaL648R/L648R mice of both sexes have lower body masses than controls. By ∼20 to 30 wk of age, they exhibit detectable cranial, mandibular, and dental defects similar to those observed in Zmpste24-/- mice and have decreased vertebral bone density compared to age- and sex-matched controls. Cultured embryonic fibroblasts from LmnaL648R/L648R mice have aberrant nuclear morphology that is reversible by treatment with a protein farnesyltransferase inhibitor. These novel mice provide a model to study the effects of farnesylated prelamin A during physiological aging.

Structure-guided design of Cryptococcus neoformans protein farnesyltransferase inhibitors with antifungal activity

Structure-guided design of <i>Cryptococcus neoformans</i> protein farnesyltransferase inhibitors with antifungal activity

Early Stages of Drug Discovery in an Academic Institution and Involvement of Pharma for Advancing Promising Leads.

In this Viewpoint, we provide a brief description of two efforts to develop drugs to treat diseases caused by tropical parasites (Malaria, human African trypanosomiasis and Chagas disease). These efforts are largely based in a University setting but draw heavily on Pharma for a complete progression from drug hit discovery to advancement toward clinical trials. The first case is the development of protein farnesyltransferase inhibitors, and the second case is a series of benzthiazoles, the target of which is being investigated.

Association of Lonafarnib Treatment vs No Treatment With Mortality Rate in Patients With Hutchinson-Gilford Progeria Syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare fatal premature aging disease. There is no approved treatment. To evaluate the association of monotherapy using the protein farnesyltransferase inhibitor lonafarnib with mortality rate in children with HGPS. Cohort study comparing contemporaneous (birth date ≥1991) untreated patients with HGPS matched with treated patients by age, sex, and continent of residency using conditional Cox proportional hazards regression. Treatment cohorts included patients from 2 single-group, single-site clinical trials (ProLon1 [n = 27; completed] and ProLon2 [n = 36; ongoing]). Untreated patients originated from a separate natural history study (n = 103). The cutoff date for patient follow-up was January 1, 2018. Treated patients received oral lonafarnib (150 mg/m2) twice daily. Untreated patients received no clinical trial medications. The primary outcome was mortality. The primary analysis compared treated patients from the first lonafarnib trial with matched untreated patients. A secondary analysis compared the combined cohorts from both lonafarnib trials with matched untreated patients. Among untreated and treated patients (n = 258) from 6 continents, 123 (47.7%) were female; 141 (54.7%) had a known genotype, of which 125 (88.7%) were classic (c.1824C>T in LMNA). When identified (n = 73), the primary cause of death was heart failure (79.4%). The median treatment duration was 2.2 years. Median age at start of follow-up was 8.4 (interquartile range [IQR], 4.8-9.5) years in the first trial cohort and 6.5 (IQR, 3.7-9.0) years in the combined cohort. There was 1 death (3.7%) among 27 patients in the first trial group and there were 9 deaths (33.3%) among 27 patients in the matched untreated group. Treatment was associated with a lower mortality rate (hazard ratio, 0.12; 95% CI, 0.01-0.93; P = .04). In the combined cohort, there were 4 deaths (6.3%) among 63 patients in the treated group and 17 deaths (27.0%) among 63 patients in the matched untreated group (hazard ratio, 0.23; 95% CI, 0.06-0.90; P = .04). Among patients with HGPS, lonafarnib monotherapy, compared with no treatment, was associated with a lower mortality rate after 2.2 years of follow-up. Study interpretation is limited by its observational design.

Survey of plasma proteins in children with progeria pre-therapy and on-therapy with lonafarnib.

BackgroundHutchinson-Gilford progeria syndrome (HGPS) is an ultra-rare, fatal, segmental premature aging syndrome caused by the aberrant lamin A protein, progerin. The protein farnesyltransferase inhibitor, lonafarnib, ameliorates some aspects of cardiovascular and bone disease.MethodsWe performed a prospective longitudinal survey of plasma proteins in 24 children with HGPS (an estimated 10% of the world's population at the time) at baseline and on lonafarnib therapy, compared with age- and gender-matched controls using a multi-analyte, microsphere-based immunofluorescent assay.ResultsThe mean levels for 23/66 (34.8%) proteins were significantly lower and 7/66 (10.6%) were significantly higher in HGPS samples compared with those in controls (P≤0.05). Six proteins whose concentrations were initially lower normalized with lonafarnib therapy: interleukins 1α, 7, and 13, beta-2 microglobulin, C-reactive protein, and myoglobin. Alpha-2 macroglobulin, a protease inhibitor associated with stroke, was elevated at baseline and subsequently normalized with lonafarnib therapy.ConclusionThis is the first study to employ a multi-analyte array platform in HGPS. Novel potential biomarkers identified in this study should be further validated by correlations with clinical disease status, especially proteins associated with cardiovascular disease and those that normalized with lonafarnib therapy.

A Review on Plasmodium falciparum-Protein Farnesyltransferase Inhibitors as Antimalarial Drug Targets.

Protein farnesyltransferase (PFT) inhibitors have emerged as a potent target for the malaria treatment caused by the Plasmodium falciparum (Pf) parasite. To explore the various scaffolds which are active against Pf-PFT target. Seven inhibitor scaffolds based on ethylenediamine, peptidomimetic, benzophenone, benzamide, tetrahydroquinoline, naphthyridine and oxy-tetrahydroquinoline, have been developed till date. It is concluded that naphthyridine based drugs are the most promising one. Furthermore, introducing the hydrophobic molecules like isoprenyl groups to a protein or a chemical compound facilitate protein-protein and protein-membrane interactions thereby makes them good candidates as new therapeutics. The future research should focus on the disease rather than the infection and the dynamics of its transmission; this will bring a new vision about the disease.

Erratum

British Journal of PharmacologyVolume 174, Issue 6 p. 493-493 ERRATUMFree Access Erratum This article corrects the following: Investigation of the effect of the farnesyl protein transferase inhibitor R115777 on isoprenylation and intracellular signalling by the prostacyclin receptor Sarah J O'Meara, B Therese Kinsella, Volume 143Issue 2British Journal of Pharmacology pages: 318-330 First Published online: February 17, 2009 First published: 24 February 2017 https://doi.org/10.1111/bph.13681AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat The British Journal of Pharmacology is publishing this erratum following formal internal investigations of the Research Paper by O'Meara and Kinsella (2004). During the preparation of Figure 5, lanes 6 in panels b and c were reordered to align them with lane 6 in panel a, where in all cases, lane 6 corresponded to the −RNA control. In carrying out this alignment, an error occurred where part of an adjacent lane in panel 5c was copied over and, hence, was duplicated in error. The authors wish to correct this whereby there is no reordering of the data in panels b or c, as depicted in the corrected version of Figure 5 below. In addition, the legend to Figure 6 incorrectly refers to panels a–e, lane 6, whereas it should correctly refer to panels a–e, lane 5. Reference O'Meara SJ, Kinsella BT (2004). Investigation of the effect of the farnesyl protein transferase inhibitor R115777 on isoprenylation and intracellular signalling by the prostacyclin receptor. Br J Pharmacol 143: 318– 330. DOI: 10.1038/sj.bjp.0705956 Volume174, Issue6March 2017Pages 493-493 ReferencesRelatedInformation

Molecular docking and structure-based virtual screening studies of potential drug target, CAAX prenyl proteases, of Leishmania donovani

Targeting CAAX prenyl proteases of Leishmania donovani can be a good approach towards developing a drug molecule against Leishmaniasis. We have modeled the structure of CAAX prenyl protease I and II of L. donovani, using homology modeling approach. The structures were further validated using Ramachandran plot and ProSA. Active site prediction has shown difference in the amino acid residues present at the active site of CAAX prenyl protease I and CAAX prenyl protease II. The electrostatic potential surface of the CAAX prenyl protease I and II has revealed that CAAX prenyl protease I has more electropositive and electronegative potentials as compared CAAX prenyl protease II suggesting significant difference in their activity. Molecular docking with known bisubstrate analog inhibitors of protein farnesyl transferase and peptidyl (acyloxy) methyl ketones reveals significant binding of these molecules with CAAX prenyl protease I, but comparatively less binding with CAAX prenyl protease II. New and potent inhibitors were also found using structure-based virtual screening. The best docked compounds obtained from virtual screening were subjected to induced fit docking to get best docked configurations. Prediction of drug-like characteristics has revealed that the best docked compounds are in line with Lipinski’s rule. Moreover, best docked protein–ligand complexes of CAAX prenyl protease I and II are found to be stable throughout 20 ns simulation. Overall, the study has identified potent drug molecules targeting CAAX prenyl protease I and II of L. donovani whose drug candidature can be verified further using biochemical and cellular studies.

Highly improved antiparasitic activity after introduction of an N-benzylimidazole moiety on protein farnesyltransferase inhibitors

In our search for new protein farnesyltransferase inhibitors with improved antiparasitic activities, we modified our previously developed 3-arylthiophene series of inhibitors by replacing the thioisopropyl group by different substituted imidazolylmethanamino moieties. Twenty four new derivatives were synthesized and evaluated against human and parasite farnesyltransferases, and their anti-parasitic activity was determined against Plasmodium falciparum, Trypanosoma brucei, Trypanosoma cruzi, and Leishmania donovani. Introduction of a N-p-substituted-benzylimidazole led to significantly increase the inhibition of parasite proliferation in the submicromolar range. The structure of the best inhibitors was parasite dependent. Three compounds possess IC50 values at the same range as the reference miltefosine against L. donovani proliferation and other new derivatives display high level of anti-trypanosomal activity against T. cruzi, higher or in the same order of magnitude as the reference compounds benznidazole and nifurtimox.

Statins alter IL-33-mediated cytokine production in mouse mast cell (HYP4P.315)

Abstract Statins are HMG-CoA reductase inhibitors widely used to reduce hypercholesterolemia. Recent publications have shown that statins can act as immune suppressors by decreasing pro-inflammatory functions of APCs and T cells. We have found that the statin drug Fluvastatin suppresses IgE-mediated pro-inflammatory cytokine release from mast cells, likely by the decreasing prenylation of small G proteins. We extended these studies to the mast cell activator IL-33. Similar to previous studies, Atorvastatin decreased IL-33-mediated pro-inflammatory cytokine production. Unexpectedly, we have found that Fluvastatin increased TNF and IL-6 production upon IL-33-activation. This augmentation is dependent on stem cell factor (SCF), since in the absence of SCF Fluvastatin does not increase cytokine production. Suppressing G protein prenylation by treating mast cells with farnesyl protein transferase and geranylgeranyl transferase inhibitors did not mimic the effects of Fluvastatin. Furthermore, the product of HMG-CoA reductase, melvalonic acid, was unable to reverse Fluvastatin-mediated inhibition. These data suggest that the pro-inflammatory effects of Fluvastatin are an “off target” effect. Examining the effect of statins in IL-33-activated mast cells will elucidate how innate immunity may be altered by commonly prescribed medications.

Recent Advances in Oral Anticancer Agents for Colon Cancer

To provide therapeutic alternatives to intravenous colon chemotherapy major recent research is focusing on the development of oral chemotherapeutic agents with the intention to improve the quality of life of patients. Initially 5-fluorouracil was most commonly used for the treatment of colorectal cancer but currently oxaliplatin and irinotecan are also available. The majority of these new drugs are pyrimidines and their analogs. The rationale for using oral anticancer agents is discussed and new drugs, such as farnesyl protein transferase inhibitor S-1, rubitecan, ZD9331, MMI-166, eflornithine, sulindac, and oral camptothecin analogs, among others, are presented with the results of their preclinical and clinical developments. This article focuses on the advancement of clinical development and also discusses the relative merits and demerits of these agents. The accelerated approval of these agents by regulatory authorities is supported by survival benefit, response rate and time to progression.

Synthesis and biological evaluation of a new series of N-ylides as protein farnesyltransferase inhibitors

A new family of 30 benzoylated N-ylides 4 and 5 was synthesized and evaluated for the inhibitory activity on human protein farnesyltransferase. Most of these novel compounds possessed in vitro inhibition potencies in the micromolar range. The nature of the substituents on the pyridine and phenyl units proved to be important in determining inhibitory activity and generally, the replacement of the cyanoacrylonitrile function by a cyanoethylacrylate group decreased the biological potential on farnesyltransferase. These results completed our SAR study on this original class of N-ylides.

Manumycin A inhibits triple-negative breast cancer growth through LC3-mediated cytoplasmic vacuolation death

Therapy resistance can be attributed to acquisition of anti-apoptotic mechanisms by the cancer cells. Therefore, developing approaches that trigger non-apoptotic cell death in cancer cells to compensate for apoptosis resistance will help to treat cancer effectively. Triple-negative breast cancers (TNBC) are among the most aggressive and therapy resistant to breast tumors. Here we report that manumycin A (Man A), an inhibitor of farnesyl protein transferase, reduces cancer cell viability through induction of non-apoptotic, non-autophagic cytoplasmic vacuolation death in TNBC cells. Man A persistently induced cytoplasmic vacuolation and cell death through the expression of microtubule-associated protein 1 light chain 3 (LC3) and p62 proteins along with endoplasmic reticulum (ER) stress markers, Bip and CHOP, and accumulation of ubiquitinated proteins. As inhibitors of apoptosis and autophagy failed to block cytoplasmic vacuolation and its associated protein expression or cell death, it appears that these processes are not involved in the death induced by Man A. Ability of thiol antioxidant, NAC in blocking Man A-induced vacuolation, death and its related protein expression suggests that sulfhydryl homeostasis may be the target of Man A. Surprisingly, normal human mammary epithelial cells failed to undergo cytoplasmic vacuolation and cell death, and grew normally in presence of Man A. In conjunction with its in vitro effects, Man A also reduced tumor burden in vivo in xenograft models that showed extensive cytoplasmic vacuoles and condensed nuclei with remarkable increase in the vacuolation-associated protein expression together with increase of p21, p27, PTEN and decrease of pAkt. Interestingly, Man A-mediated upregulation of p21, p27 and PTEN and downregulation of pAkt and tumor growth suppression were also mimicked by LC3 knockdown in MDA-MB-231 cells. Overall, these results suggest novel therapeutic actions by Man A through the induction of non-apoptotic and non-autophagic cytoplasmic vacuolation death by probably affecting ER stress, LC3 and p62 pathways in TNBC but not in normal mammary epithelial cells.

Introduction of methionine mimics on 3-arylthiophene: influence on protein farnesyltransferase inhibition and on antiparasitic activity

In the course of our search for new protein farnesyltransferase inhibitors with antiparasitic activity, we found that addition of a methionine residue at position 2 of 3-arylthiophenes greatly improved enzyme inhibition. To investigate the influence of this methionine residue on FTase and antiparasitic activities, 29 novel tetrasubstituted thiophenes bearing methionine or analogous moieties were synthesised. These new derivatives were evaluated on human and Trypanosoma brucei protein farnesyltransferases and on proliferation of 4 protozoan parasites: Plasmodium falciparum, Trypanosoma brucei brucei, Trypanosoma cruzi and Leishmania donovani. Some compounds showed promising low micromolar or submicromolar activities on T. b. brucei and L. donovani confirming the potential of this new class as antiparasitic agents.

Resveratrol Rescues SIRT1-Dependent Adult Stem Cell Decline and Alleviates Progeroid Features in Laminopathy-Based Progeria

Abnormal splicing of LMNA gene or aberrant processing of prelamin A results in progeroid syndrome. Here we show that lamin A interacts with and activates SIRT1. SIRT1 exhibits reduced association with nuclear matrix (NM) and decreased deacetylase activity in the presence of progerin or prelamin A,leading to rapid depletion of adult stem cells (ASCs) in Zmpste24(-/-) mice. Resveratrol enhances the binding between SIRT1 and A-type lamins to increases its deacetylase activity. Resveratrol treatment rescues ASC decline, slows down body weight loss, improves trabecular bone structure and mineral density, and significantly extends the life span in Zmpste24(-/-) mice. Our data demonstrate lamin A as an activator of SIRT1 and provide a mechanistic explanation for the activation of SIRT1 by resveratrol. The link between conserved SIRT1 longevity pathway and progeria suggests a stem cell-based and SIRT1 pathway-dependent therapeutic strategy for progeria.

Synthesis and biological evaluation of a new series of phenothiazine-containing protein farnesyltransferase inhibitors

Two new families of human farnesyltransferase inhibitors 13a–m and 14a–d, based on a phenothiazine scaffold, were synthesized. Compounds 14a and 14b were the most promising inhibitors of human farnesyltransferase with IC50 values of 0.7 and 0.6 μM, respectively.

Synthesis and biological evaluation of new phenothiazine derivatives bearing a pyrazole unit as protein farnesyltransferase inhibitors

A new family of protein farnesyltransferase inhibitors, based on a phenothiazine scaffold, was designed and synthesized. The biological evaluation of these products showed that compounds 28 and 30 were the most active, with protein farnesyltransferase inhibition potencies in the low micromolar range. Compounds were also evaluated for their antiproliferative activity on a NCI-60 cancer cell line panel. Indenopyrazole 30 exhibited the most potent in vitro cytostatic activity inhibiting the growth of HCT-116, LOX IMVI and SK-MEL-5 cell lines.

Blocking farnesylation of the prelamin A variant in Hutchinson-Gilford progeria syndrome alters the distribution of A-type lamins

Mutations in the lamin A/C gene that cause Hutchinson-Gilford progeria syndrome lead to expression of a truncated, permanently farnesylated prelamin A variant called progerin. Blocking farnesylation leads to an improvement in the abnormal nuclear morphology observed in cells expressing progerin, which is associated with a re-localization of the variant protein from the nuclear envelope to the nuclear interior. We now show that a progerin construct that cannot be farnesylated is localized primarily in intranuclear foci and that its diffusional mobility is significantly greater than that of farnesylated progerin localized predominantly at the nuclear envelope. Expression of non-farnesylated progerin in transfected cells leads to a redistribution of lamin A and lamin C away from the nuclear envelope into intranuclear foci but does not significantly affect the localization of endogenous lamin B1 at nuclear envelope. There is a similar redistribution of lamin A and lamin C into intranuclear foci in transfected cells expressing progerin in which protein farnesylation is blocked by treatment with a protein farnesyltransferase inhibitor. Blocking farnesylation of progerin can lead to a redistribution of normal A-type lamins away from the inner nuclear envelope. This may have implications for using drugs that block protein prenylation to treat children with Hutchinson-Gilford progeria syndrome. These findings also provide additional evidence that A-type and B-type lamins can form separate microdomains within the nucleus.

Pharmacological Characterization, Structural Studies, and In Vivo Activities of Anti-Chagas Disease Lead Compounds Derived from Tipifarnib

Chagas disease, caused by the protozoan pathogen Trypanosoma cruzi, remains a challenging infection due to the unavailability of safe and efficacious drugs. Inhibitors of the trypanosome sterol 14α-demethylase enzyme (CYP51), including azole antifungal drugs, are promising candidates for development as anti-Chagas disease drugs. Posaconazole is under clinical investigation for Chagas disease, although the high cost of this drug may limit its widespread use. We have previously reported that the human protein farnesyltransferase (PFT) inhibitor tipifarnib has potent anti-T. cruzi activity by inhibiting the CYP51 enzyme. Furthermore, we have developed analogs that minimize the PFT-inhibitory activity and enhance the CYP51 inhibition. In this paper, we describe the efficacy of the lead tipifarnib analog compared to that of posaconazole in a murine model of T. cruzi infection. The plasma exposure profiles for each compound following a single oral dose in mice and estimated exposure parameters after repeated twice-daily dosing for 20 days are also presented. The lead tipifarnib analog had potent suppressive activity on parasitemia in mice but was unsuccessful at curing mice, whereas posaconazole as well as benznidazole cured 3 of 5 and 4 of 6 mice, respectively. The efficacy results are consistent with posaconazole having substantially higher predicted exposure than that of the tipifarnib analog after repeat twice-daily administration. Further changes to the tipifarnib analogs to reduce plasma clearance are therefore likely to be important. A crystal structure of a trypanosomal CYP51 bound to a tipifarnib analog is reported here and provides new insights to guide structure-based drug design for further optimized compounds.