Untargeted LC-MS/MS Metabolomics Study of HO-AAVPA and VPA on Breast Cancer Cell Lines

Breast cancer (BC) is one of the biggest health problems worldwide, characterized by intricate metabolic and biochemical complexities stemming from pronounced variations across dysregulated molecular pathways. If BC is not diagnosed early, complications may lead to death. Thus, the pursuit of novel therapeutic avenues persists, notably focusing on epigenetic pathways such as histone deacetylases (HDACs). The compound N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA), a derivative of valproic acid (VPA), has emerged as a promising candidate warranting pre-clinical investigation. HO-AAVPA is an HDAC inhibitor with antiproliferative effects on BC, but its molecular mechanism has yet to be deciphered. Furthermore, in the present study, we determined the metabolomic effects of HO-AAVPA and VPA on cells of luminal breast cancer (MCF-7) and triple-negative breast cancer (MDA-MB-231) subtypes. The LC-MS untargeted metabolomic study allowed for the simultaneous measurement of multiple metabolites and pathways, identifying that both compounds affect glycerophospholipid and sphingolipid metabolism in the MCF-7 and MDA-MB-231 cell lines, suggesting that other biological targets were different from HDACs. In addition, there are different dysregulate metabolites, possibly due to the physicochemical differences between HO-AAVPA and VPA.

Hepatotoxic Evaluation of N-(2-Hydroxyphenyl)-2-Propylpentanamide: A Novel Derivative of Valproic Acid for the Treatment of Cancer

Valproic acid (VPA) is a drug that has various therapeutic applications; however, it has been associated with liver damage. Furthermore, it is interesting to propose new compounds derived from VPA as N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA). The HO-AAVPA has better antiproliferative activity than the VPA in different cancer cell lines. The purpose of this study was to evaluate the liver injury of HO-AAVPA by acute treatment (once administration) and repeated doses for 7 days under intraperitoneal administration. The median lethal dose value (LD50) was determined in rats and mice (females and males) using OECD Guideline 425. In the study, male rats were randomly divided into 4 groups (n = 7), G1: control (without treatment), G2: vehicle, G3: VPA (500 mg/kg), and G4: HO-AAVPA (708 mg/kg, in equimolar ratio to VPA). Some biomarkers related to hepatotoxicity were evaluated. In addition, macroscopic and histological studies were performed. The LD50 value of HO-AAVPA was greater than 2000 mg/kg. Regarding macroscopy and biochemistry, the HO-AAVPA does not induce liver injury according to the measures of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, glutathione peroxidase, glutathione reductase, and catalase activities. Comparing the treatment with HO-AAVPA and VPA did not show a significant difference with the control group, while malondialdehyde and glutathione-reduced levels in the group treated with HO-AAVPA were close to those of the control (p ≤ 0.05). The histological study shows that liver lesions caused by HO-AAVPA were less severe compared with VPA. Therefore, it is suggested that HO-AAVPA does not induce hepatotoxicity at therapeutic doses, considering that in the future it could be proposed as an antineoplastic drug.

Decrease in Cell Viability of Breast Cancer Cells by a Di-Hydroxylated Derivative of N-(2-hydroxyphenyl)-2-Propylpentanamide

BACKGROUND

A preliminary study of the biotransformation by cytochrome P450 enzymes (CYP) of N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA), an HDAC inhibitor, led to the synthesis of two hydroxylated derivatives: N-(2,4-dihydroxyphenyl)-2-propylpentanamide (5a) and N-(2,5-dihydroxyphenyl)-2-propylpentanamide (5b).

OBJECTIVE

The study aims to evaluate the anti-proliferative activity of these di-hydroxylated derivatives in breast cancer cell lines.

METHODS

MTT assays were conducted in MCF-7 and MDA-MB-231 cell lines. Additionally, in silico studies were carried out to evaluate the affinity of these derivatives with the HDAC1 enzyme.

RESULTS

Results showed that only 5b possess an enhanced anti-proliferative effect in breast cancer cell lines MCF-7 and MDA-MB-231. Docking studies revealed that the presence of hydroxyl groups, as well as the position of the additional hydroxyl groups, could have an impact on HDAC1 affinity and could explain the lack of activity of compound 5a.

CONCLUSION

A priori, these results hypothesize that anti-proliferative activity of 5b could be related to HDAC1 inhibition and thus anti-proliferative activity in breast cancer cells.

Apoptotic Effects of N-(2-Hydroxyphenyl)-2-Propylpentanamide on U87-MG and U-2 OS Cells and Antiangiogenic Properties

BACKGROUND AND OBJECTIVE

Histone Deacetylases (HDACs) are important therapeutic targets for many types of human cancers. A derivative of valproic acid, N-(2-hydroxyphenyl)-2-propylpentanamide (HOAAVPA), has antiproliferative properties on some cancer cell lines and inhibits the HDAC1 isoform.

MATERIALS AND METHODS

In this work, HO-AAVPA was tested as an antiproliferative agent in U87-MG (human glioblastoma) and U-2 OS cells (human osteosarcoma), which are types of cancer that are difficult to treat, and its antiangiogenic properties were explored.

RESULTS

HO-AAVPA had antiproliferative effects at 48h with an IC₅₀=0.655mM in U87-MG cells and an IC₅₀=0.453mM in U-2 OS cells. Additionally, in the colony formation assay, HO-AAVPA decreased the number of colonies by approximately 99% in both cell lines and induced apoptosis by 31.3% in the U-2 OS cell line and by 78.2% in the U87-MG cell line. Additionally, HO-AAVPA reduced the number of vessels in Chorioallantoic Membranes (CAMs) by approximately 67.74% and IL-6 levels in both cell lines suggesting that the biochemical mechanism on cancer cell of HO-AAVPA is different compared to VPA.

CONCLUSION

HO-AAVPA has antiproliferative effects on glioblastoma and osteosarcoma and antiangiogenic properties.

Anti-epileptic activity, toxicity and teratogenicity in CD1 mice of a novel valproic acid arylamide derivative, N-(2-hydroxyphenyl)-2-propylpentanamide

N-(2-hydroxyphenyl)-2-propylpentamide (HO-AAVPA) is a novel arylamide derivative of valproic acid (VPA) designed in silico, with better antioxidant and antiproliferative effect on cancer cell lines than VPA. This study was aimed to evaluate the anticonvulsant activity, the toxicity and teratogenicity produced in HO-AAVPA-treated CD1 mice using VPA as positive control. With the maximal electroshock (MES)- and pentylenetetrazole (PTZ)-induced seizure models, HO-AAVPA reduced the time of hind limb extension, stupor and recovery, the number of clonic and tonic seizures and the mortality rate in a dose-dependent manner, obtaining an ED₅₀ of 370 and 348 mg/kg for MES and PTZ, respectively. On the rotarod test, mice administered with 600 mg/kg HO-AAVPA manifested reduced locomotor activity (2.78%); while HO-AAVPA at 300 mg/kg and VPA at 500 mg/kg gave a similar outcome (∼60%). The LD₅₀ of 936.80 mg/kg herein found for HO-AAVPA reflects moderate toxicity. Concerning teratogenicity, the administration of HO-AAVPA to pregnant females at 300 and 600 mg/kg on gestation day (GD) 8.5 generated less visceral and skeletal alterations in the fetuses, as well as, minor rate of modifications in the expression pattern of the neuronal marker Tuj1 and endothelial marker PECAM1 in embryos, that those induced by VPA administration. Altered embryonic development occurred with less frequency and severity with HO-AAVPA at 600 mg/kg than VPA at 500 mg/kg. In conclusion, the protective effect against convulsions provided by HO-AAVPA was comparable to that of VPA in the MES and PZT seizure models, showed lower toxicity and less damage to embryonic and fetal development.

Exploring the biotransformation of N-(2-hydroxyphenyl)-2-propylpentanamide (an aryl valproic acid derivative) by CYP2C11, using in silico predictions and in vitro studies

OBJECTIVES

N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA), a derivative of valproic acid (VPA), has been proposed as a potential anticancer agent due to its improved antiproliferative effects in some cancer cell lines. Although there is evidence that VPA is metabolized by cytochrome P450 2C11 rat isoform, HO-AAVPA CYP-mediated metabolism has not yet been fully explored. Therefore, in this work, the biotransformation of HO-AAVPA by CYP2C11 was investigated.

METHODS

Kinetic parameters and spectral interaction between HO-AAVPA and CYP were evaluated using rat liver microsomes. The participation of CYP2C11 in metabolism of HO-AAVPA was confirmed by cimetidine (CIM) inhibition assay. Docking and molecular dynamics simulations coupled to MMGBSA methods were used in theoretical study.

KEY FINDINGS

HO-AAVPA is metabolized by CYP enzymes (K_M  = 38.94 µm), yielding a hydroxylated metabolite according to its HPLC retention time (5.4 min) and MS analysis (252.2 m/z). In addition, CIM inhibition in rat liver microsomes (K_i  = 59.23 µm) confirmed that CYP2C11 is mainly involved in HO-AAVPA metabolism. Furthermore, HO-AAVPA interacts with CYP2C11 as a type I ligand. HO-AAVPA is stabilized at the CYP2C11 ligand recognition site through a map of interactions similar to other typical CYP2C11 substrates.

CONCLUSION

Therefore, rat liver CYP2C11 isoform is able to metabolize HO-AAVPA.