AR-42: A Pan-HDAC Inhibitor with Antitumor and Antiangiogenic Activities in Esophageal Squamous Cell Carcinoma

New Insights into the LANCL2- Binding Mode towards the Evaluation of New LANCL Agonists

The lanthionine synthetase C-like (LANCL) proteins include LANCL2, which is expressed in the central nervous system (CNS) and in peripheral tissues. LANCL2 exhibits glutathionylation activity and is involved in the neutralization of reactive electrophiles. Several studies explored LANCL2 activation as a validated pharmacological target for diabetes and inflammatory bowel disease. In this context, LANCL2 was found to bind the natural product abscisic acid (ABA), whose pre-clinical effectiveness in different inflammatory diseases was reported in the literature. More recently, LANCL2 attracted more attention as a valuable resource in the field of neurodegenerative disorders. ABA was found to regulate neuro-inflammation and synaptic plasticity to enhance learning and memory, exhibiting promising neuroprotective effects. Up until now, a limited number of LANCL2 ligands are known; among them, BT-11 is the only compound patented and investigated for its anti-inflammatory properties. To guide the design of novel putative LANCL2 agonists, a computational study including molecular docking and long molecular dynamic (MD) simulations of both ABA and BT-11 was carried out. The results pointed out the main LANCL2 ligand chemical features towards the following virtual screening of a novel putative LANCL2 agonist (AR-42). Biochemical assays on rat H9c2 cardiomyocytes showed a similar, LANCL2-mediated stimulation by BT-11 and by AR-42 of the mitochondrial proton gradient and of the transcriptional activation of the AMPK/PGC-1α/Sirt1 axis, the master regulator of mitochondrial function, effects that are previously observed with ABA. These results may allow the development of LANCL2 agonists for the treatment of mitochondrial dysfunction, a common feature of chronic and degenerative diseases.

Targeting epigenetic deregulations for the management of esophageal carcinoma: recent advances and emerging approaches

Ranking from seventh in incidence to sixth in mortality, esophageal carcinoma is considered a severe malignancy of food pipe. Later-stage diagnosis, drug resistance, and a high mortality rate contribute to its lethality. Esophageal squamous cell carcinoma and esophageal adenocarcinoma are the two main histological subtypes of esophageal carcinoma, with squamous cell carcinoma alone accounting for more than eighty percent of its cases. While genetic anomalies are well known in esophageal cancer, accountability of epigenetic deregulations is also being explored for the recent two decades. DNA methylation, histone modifications, and functional non-coding RNAs are the crucial epigenetic players involved in the modulation of different malignancies, including esophageal carcinoma. Targeting these epigenetic aberrations will provide new insights into the development of biomarker tools for risk stratification, early diagnosis, and effective therapeutic intervention. This review discusses different epigenetic alterations, emphasizing the most significant developments in esophageal cancer epigenetics and their potential implication for the detection, prognosis, and treatment of esophageal carcinoma. Further, the preclinical and clinical status of various epigenetic drugs has also been reviewed.

A quantitative structural analysis of AR-42 derivatives as HDAC1 inhibitors for the identification of promising structural contributors

Alteration and abnormal epigenetic mechanisms can lead to the aberration of normal biological functions and the occurrence of several diseases. The histone deacetylase (HDAC) family of enzymes is one of the prime regulators of epigenetic functions modifying the histone proteins, and thus, regulating epigenetics directly. HDAC1 is one of those HDACs which have important contributions to cellular epigenetics. The abnormality of HDAC is correlated to the occurrence, progression, and poor prognosis in several disease conditions namely neurodegenerative disorders, cancer cell proliferation, metastasis, chemotherapy resistance, and survival in various cancers. Therefore, the progress of potent and effective HDAC1 inhibitors is one of the prime approaches to combat such diseases. In this study, both regression and classification-based molecular modelling studies were conducted on some AR-42 derivatives as HDAC1 inhibitors to elucidate the crucial structural aspects that are responsible for regulating their biological responses. This study revealed that the molecular polarizability, van der Waals volume, the presence of aromatic rings as well as the higher number of hydrogen bond acceptors might affect prominently their inhibitory activity and might be responsible for proper fitting and interactions at the HDAC1 active site to pertain effective inhibition.

Molecular mechanism, regulation, and therapeutic targeting of the STAT3 signaling pathway in esophageal cancer (Review)

Esophageal cancer (EC) is the seventh most common cancer globally, and the overall 5-year survival rate is only 20%. Signal transducer and activator of transcription 3 (STAT3) is aberrantly activated in EC, and its activation is associated with a poor prognosis. STAT3 can be activated by canonical pathways such as the JAK/STAT3 pathway as well as non-canonical pathways including the Wnt/STAT3 and COX2/PGE2/STAT3 pathways. Activated STAT3, present as phosphorylated STAT3 (p-STAT3), can be transported into the nucleus to regulate downstream genes, including VEGF, cyclin D1, Bcl-xL, and matrix metalloproteinases (MMPs), to promote cancer cell proliferation and induce resistance to therapy. Non-coding RNAs, including microRNAs (miRNAs/miRs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), play a vital role in regulating the STAT3 signaling pathway in EC. Several miRNAs promote or suppress the function of STAT3 in EC, while lncRNAs and circRNAs primarily promote the effects of STAT3 and the progression of cancer. Additionally, various drugs and natural compounds can target STAT3 to suppress the malignant behavior of EC cells, providing novel insights into potential EC therapies.

Establishment of prognostic risk model and drug sensitivity based on prognostic related genes of esophageal cancer

At present, the treatment of esophageal cancer (EC) is mainly surgical and drug treatment. However, due to drug resistance, these therapies can not effectively improve the prognosis of patients with the EC. Therefore, a multigene prognostic risk scoring system was constructed by bioinformatics analysis method to provide a theoretical basis for the prognosis and treatment decision of EC. The gene expression profiles and clinical data of esophageal cancer patients were gathered from the Cancer Genome Atlas TCGA database, and the differentially expressed genes (DEGs) were screened by R software. Genes with prognostic value were screened by Kaplan Meier analysis, followed by functional enrichment analysis. A cox regression model was used to construct the prognostic risk score model of DEGs. ROC curve and survival curve were utilized to evaluate the performance of the model. Univariate and multivariate Cox regression analysis was used to evaluate whether the model has an independent prognostic value. Network tool mirdip was used to find miRNAs that may regulate risk genes, and Cytoscape software was used to construct gene miRNA regulatory network. GSCA platform is used to analyze the relationship between gene expression and drug sensitivity. 41 DEGs related to prognosis were pre-liminarily screened by survival analysis. A prognostic risk scoring model composed of 8 DEGs (APOA2, COX6A2, CLCNKB, BHLHA15, HIST1H1E, FABP3, UBE2C and ERO1B) was built by Cox regression analysis. In this model, the prognosis of the high-risk score group was poor (P < 0.001). The ROC curve showed that (AUC = 0.862) the model had a good performance in predicting prognosis. In Cox regression analysis, the comprehensive risk score can be employed as an independent prognostic factor of the EC. HIST1H1E, UBE2C and ERO1B interacted with differentially expressed miRNAs. High expression of HIST1H1E was resistant to trametinib, selumetinib, RDEA119, docetaxel and 17-AAG, High expression of UBE2C was resistant to masitinib, and Low expression of ERO1B made the EC more sensitive to FK866. We constructed an EC risk score model composed of 8 DEGs and gene resistance analysis, which can provide reference for prognosis prediction, diagnosis and treatment of the EC patients.

The role of protein acetylation in carcinogenesis and targeted drug discovery

Protein acetylation is a reversible post-translational modification, and is involved in many biological processes in cells, such as transcriptional regulation, DNA damage repair, and energy metabolism, which is an important molecular event and is associated with a wide range of diseases such as cancers. Protein acetylation is dynamically regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs) in homeostasis. The abnormal acetylation level might lead to the occurrence and deterioration of a cancer, and is closely related to various pathophysiological characteristics of a cancer, such as malignant phenotypes, and promotes cancer cells to adapt to tumor microenvironment. Therapeutic modalities targeting protein acetylation are a potential therapeutic strategy. This article discussed the roles of protein acetylation in tumor pathology and therapeutic drugs targeting protein acetylation, which offers the contributions of protein acetylation in clarification of carcinogenesis, and discovery of therapeutic drugs for cancers, and lays the foundation for precision medicine in oncology.

The interaction of folate-modified Bletilla striata polysaccharide-based micelle with bovine serum albumin

We fabricated an amphiphilic folate-modified Bletilla striata polysaccharide (FA-BSP-SA) copolymer that exhibited good biocompatibility and superior antitumor effects. This study investigated the affinity between FA-BSP-SA and bovine serum albumin (BSA) via multispetroscopic approaches. Changes in the morphology and particle size showed that FA-BSP-SA formed a blurry "protein corona". Stern-Volmer equation demonstrated that FA-BSP-SA micelles decreased the fluorescence of BSA via static quenching. The measurement results of thermodynamic parameters (entropy change, enthalpy change, and Gibbs free energy) suggested that the binding between FA-BSP-SA and BSA was spontaneous in which Van der Waals forces and hydrogen bonding played major roles. The results from synchronous fluorescence, circular dichroism, and UV spectra also revealed that BSA conformation was slightly altered by decreasing α-helical contents. In addition, the antitumor effects in vitro of Dox@FA-BSP-SA micelles and the cellular uptake behavior of micelles in 4T1 cells were decreased after incubating with BSA.

Fumonisin B1 triggers carcinogenesis via HDAC/PI3K/Akt signalling pathway in human esophageal epithelial cells

Fumonisin B1 (FB1) is a contaminant that commonly present in the global environment, especially in food and feed. Epidemiologic studies have shown that esophageal cancer is associated with fumonisin toxicity. However, the molecular mechanism of FB1-induced esophageal cancer is unclear. In this research, the molecular mechanism of FB1-induced cell carcinogenesis in human esophageal epithelial cells line (HEEC) was explored. We found that FB1 (0.3125-5 μM) could promote cell proliferation, and the same phenomenon was found in a 3D cell model. FB1 could also accelerate cell migration. The expression levels of DNA damage markers were significantly increased after FB1 exposure. Meanwhile, the expression levels of cell cycle-regulated proteins and cancer-related genes were abnormal. Furthermore, FB1 significantly upregulated the histone deacetylase (HDAC) expression and activated the phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt) signalling pathway. The HDAC inhibitor trichostatin A (TSA) could repressed FB1-promoted cell proliferation and abnormal phenomenon induced by FB1. Moreover, myriocin (ISP-1) could relieve FB1-enhanced HDAC expression and cell proliferation, which implied that ISP-1 may be used to block the fumonisin toxicity in the future. Our findings suggested that the HDAC/PI3K/Akt signalling pathway is a novel mechanism for FB1-induced cell carcinogenesis in HEEC and provided new ideas for the prevention and control of fumonisin toxicity, subsequently avoiding adverse effects on the ecosystem and human health.

Long non‑coding RNA BANCR promotes proliferation, invasion and migration in esophageal squamous cell carcinoma cells via the Raf/MEK/ERK signaling pathway

Esophageal squamous cell carcinoma (ESCC) is a major histological type of esophageal cancer, identified as a leading cause of tumor-associated death worldwide. In addition, long non-coding RNA (lncRNA) BRAF-activated non-coding RNA (BANCR) expression is increased in the plasma of patients with ESCC, which can be reversed by tumor resection. Thus, the aim of the present study was to investigate the underlying mechanism of BANCR in ESCC progression. The relative mRNA expression of BANCR was determined via reverse transcription-quantitative PCR. The cell behaviors of Eca-109 cells were detected using Cell Counting Kit-8, colony formation, wound healing and Transwell chamber assays. Finally, the expression levels of proteins involved in the Raf/MEK/ERK signaling pathway and cell metastasis were analyzed with western blotting. The results revealed that lncRNA BANCR was highly expressed in ESCC cells compared with in normal esophageal cells. BANCR overexpression enhanced proliferation, migration and invasion of ESCC cells, and BANCR silencing exerted opposite effects. Moreover, BANCR overexpression induced activation of the Raf/MEK/ERK signaling pathway in ESCC cells. Notably, U0126, a specific MEK inhibitor, decreased MEK and ERK expression, and blocked the promotive effects of BANCR overexpression on the proliferation, migration and invasion of ESCC cells. Overall, lncRNA BANCR facilitated the proliferation, migration and invasion of ESCC cells via the Raf/MEK/ERK signaling pathway. Thus, lncRNA BANCR may be a promising target for inhibiting ESCC growth and metastasis.