In Vitro Optimization of Non-Small Cell Lung Cancer Activity with Troxacitabine,l-1,3-Dioxolane-cytidine, Prodrugs

A novel drug repurposing approach for non-small cell lung cancer using deep learning

Drug repurposing is an attractive and pragmatic way offering reduced risks and development time in the complicated process of drug discovery. In the past, drug repurposing has been largely accidental and serendipitous. The most successful examples so far have not involved a systematic approach. Nowadays, remarkable advances in drugs, diseases and bioinformatic knowledge are offering great opportunities for designing novel drug repurposing approach through comprehensive understanding of drug information. In this study, we introduced a novel drug repurposing approach based on transcriptomic data and chemical structures using deep learning. One strong candidate for repurposing has been identified. Pimozide is an anti-dyskinesia agent that is used for the suppression of motor and phonic tics in patients with Tourette's Disorder. However, our pipeline proposed it as a strong candidate for treating non-small cell lung cancer. The cytotoxicity of pimozide against A549 cell lines has been validated.

Anomalous interaction of tri-acyl ester derivatives of uridine nucleoside with a l-α-dimyristoylphosphatidylcholine biomembrane model: a differential scanning calorimetry study

OBJECTIVES

Uridine was conjugated with fatty acids to improve the drug lipophilicity and the interaction with phospholipid bilayers.

METHODS

The esterification reaction using carbodiimides compounds as coupling agents and a nucleophilic catalyst allowed us to synthesize tri-acyl ester derivatives of uridine with fatty acids. Analysis of molecular interactions between these tri-acyl ester derivatives and l-α-dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles (MLV) - as a mammalian cell membrane model - have been performed by differential scanning calorimetry (DSC).

KEY FINDINGS

The DSC thermograms suggest that nucleoside and uridine triacetate softly interact with phospholipidic multilamellar vesicles which are predominantly located between the polar phase, whereas the tri-acyl ester derivatives with fatty acids (myristic and stearic acids) present a strongly interaction with the DMPC bilayer due to the nucleoside and aliphatic chains parts which are oriented towards the polar and lipophilic phases of the phospholipidic bilayer, respectively. However, the effects caused by the tri-myristoyl uridine and tri-stearoyl uridine are different.

CONCLUSIONS

We show how the structural changes of uridine modulate the calorimetric behaviour of DMPC shedding light on their affinity with the phospholipidic biomembrane model.

Synthesis and interaction of sterol-uridine conjugate with DMPC liposomes studied by differential scanning calorimetry

Differential scanning calorimetry (DSC) is a thermoanalytical technique which provides information on the interaction between drugs and models of cell membranes. Studies on the calorimetric behavior of hydrated phospholipids within liposomes are employed to shed light on the changes in the physico-chemical properties when interacting with drugs. In this report, new potential anti-cancer drugs such as uridine and uridine derivatives (acetonide and its succinate), 3β-5α,8α-endoperoxide-cholestan-6-en-3-ol (5,8-epidioxicholesterol) and conjugate (uridine acetonide-epidioxicholesterol succinate) have been synthesized. Steglich esterification method using coupling agents allowed to obtain the uridine acetonide-sterol conjugate. The study on the interaction between the drugs and dimiristoyl-phophatidilcholine (DMPC) liposomes has been conducted by the use of DSC. The analysis of the DSC curves indicated that the uridine and derivatives (acetonide and its succinate) present a very soft interaction with the DMPC liposomes, whereas the 5,8-epidioxicholesterol and the conjugate showed a strong effect on the thermotropic behavior. Our results suggested that the lipophilic character of uridine acetonide-sterol conjugate improves the affinity with the DMPC liposomes.

Synthesis and antiviral evaluation of 2-amino-6-carbamoylpurine dioxolane nucleoside derivatives and their phosphoramidates prodrugs

The synthesis of 9-(β-d-1,3-dioxolan-4-yl)2,6-diaminopurine nucleoside phosphoramidate prodrugs as well as various 2-amino-6-carbamoylpurine dioxolane derivatives and their phosphoramidates prodrugs is reported. Their ability to block HIV and HBV replication along with their cytotoxicity toward HepG2, human lymphocyte, CEM and Vero cells was also assessed.

Pharmacological reversal of histone methylation presensitizes pancreatic cancer cells to nucleoside drugs: in vitro optimization and novel nanoparticle delivery studies

We evaluated the potential of an investigational histone methylation reversal agent, 3-deazaneplanocin A (DZNep), in improving the chemosensitivity of pancreatic cancer to nucleoside analogs (i.e., gemcitabine). DZNep brought delayed but selective cytotoxicity to pancreatic cancer cells without affecting normal human pancreatic ductal epithelial (HPDE) cells. Co-exposure of DZNep and gemcitabine induced cytotoxic additivity or synergism in both well- and poorly-differentiated pancreatic cell lines by increased apoptosis. In contrast, DZNep exerted antagonism with gemcitabine against HPDE cells with significant reduction in cytotoxicity compared with the gemcitabine-alone regimen. DZNep marginally depended on purine nucleoside transporters for its cytotoxicity, but the transport dependence was circumvented by acyl derivatization. Drug exposure studies revealed that a short priming with DZNep followed by gemcitabine treatment rather than co-treatment of both agents to produce a maximal chemosensitization response in both gemcitabine-sensitive and gemcitabine-resistant pancreatic cancer cells. DZNep rapidly and reversibly decreased trimethylation of histone H3 lysine 27 but increased trimethylation of lysine 9 in an EZH2- and JMJD1A/2C-dependent manner, respectively. However, DZNep potentiation of nucleoside analog chemosensitization was found to be temporally coupled to trimethylation changes in lysine 27 and not lysine 9. Polymeric nanoparticles engineered to chronologically release DZNep followed by gemcitabine produced pronounced chemosensitization and dose-lowering effects. Together, our results identify that an optimized DZNep exposure can presensitize pancreatic cancer cells to anticancer nucleoside analogs through the reversal of histone methylation, emphasizing the promising clinical utilities of epigenetic reversal agents in future pancreatic cancer combination therapies.

Lipophilic prodrugs and formulations of conventional (deoxy)nucleoside and fluoropyrimidine analogs in cancer

Many drugs that are currently used for the treatment of cancer have limitations, such as induction of resistance and/or poor biological half-life, which reduce their clinical efficacy. To overcome these limitations, several strategies have been explored. Chemical modification by the attachment of lipophilic moieties to (deoxy)nucleoside analogs should enhance the plasma half-life, change the biodistribution, and improve cellular uptake of the drug. Attachment of a lipophilic moiety to a phosphorylated (deoxy)nucleoside analog will improve the activity of the drugs by circumventing the rate-limiting activation step of (deoxy)nucleoside analogs. Encapsulating drugs in nanoparticles or liposomes protects the drug against enzymatic breakdown in the plasma and makes it possible to get lipophilic compounds to the tumor site. In this review, we discuss the considerable progress that has been made in increasing the efficacy of classic (deoxy)nucleoside and fluoropyrimidine compounds by chemical modifications and alternative delivery systems.

QSAR AND ACTION MECHANISM OF TROXACITABINE PRODRUGS WITH ANTITUMOR ACTIVITY

The quantitative structure–activity relationship (QSAR) of troxacitabine prodrugs with antitumor activity has been studied by using the density functional theory (DFT), molecular mechanics (MM2), and statistical methods. The established QSAR model shows not only significant statistical quality, but also predictive ability, with the square of adjusted correlation coefficient [Formula: see text] and the square of the cross-validation coefficient (q2 = 0.807). The antitumor activity is expressed as p IC50, which is defined as the negative value of the logarithm of necessary molar concentration of a compound to cause 50% growth inhibition against the human non-small-cell lung cancer cell line SW1573. It appears to be mainly governed by two factors (or original variables), i.e. the calculated hydrophobic coefficient (C log P) of whole molecule and the net charges of the first atom of substituent R (Q FR ), although three descriptors, i.e. C log P, (C log P)2, and Q FR , were selected in our multiple linear regression model. The factor C log P shows parabolic relation to p IC50 and its suitable range is around 5.6, and the other factor Q FR shows a significant negative correlation with p IC50. In this paper, a detailed discussion on these two factors was carried out, and their close correlation with the action mechanism of these prodrugs was reasonably revealed. Such results can offer some useful theoretical references for understanding the action mechanism and directing the molecular design of this kind of compound with antitumor activity.

Troxacitabine prodrugs for pancreatic cancer

Troxacitabine is a cytotoxic deoxycytidine analogue with an unnatural L-configuration, which is activated by deoxycytidine kinase (dCK). The configuration is responsible for differences in the uptake and metabolism of troxacitabine compared to other deoxynucleoside analogues. The main drawback in the use of most nucleoside anticancer agents originates from their hydrophilic nature, which property requires a high and frequent dosage for an intravenous administration. To overcome this problem several troxacitabine prodrugs modified in the aminogroup with a linear aliphatic chain with a higher lipophilicity were developed. To determine whether these prodrugs have an advantage over Troxacitabine pancreatic cancer cell lines were exposed to Troxacitabine and the lipophilic prodrugs. The addition of linear aliphatic chains to troxacitabine increased sensitivity of pancreatic cancer cell lines to the drug > 100-fold, possibly due to a better uptake and retention of the drug.