LncRNAs and the Angiogenic Switch in Cancer: Clinical Significance and Therapeutic Opportunities

Angiogenesis is one of the hallmarks of cancer, and the establishment of new blood vessels is vital to allow for a tumour to grow beyond 1–2 mm in size. The angiogenic switch is the term given to the point where the number or activity of the pro-angiogenic factors exceeds that of the anti-angiogenic factors, resulting in the angiogenic process proceeding, giving rise to new blood vessels accompanied by increased tumour growth, metastasis, and potential drug resistance. Long noncoding ribonucleic acids (lncRNAs) have been found to play a role in the angiogenic switch by regulating gene expression, transcription, translation, and post translation modification. In this regard they play both anti-angiogenic and pro-angiogenic roles. The expression levels of the pro-angiogenic lncRNAs have been found to correlate with patient survival. These lncRNAs are also potential drug targets for the development of therapies that will inhibit or modify tumour angiogenesis. Here we review the roles of lncRNAs in regulating the angiogenic switch. We cover specific examples of both pro and anti-angiogenic lncRNAs and discuss their potential use as both prognostic biomarkers and targets for the development of future therapies.

Recent Advances in Combretastatin A-4 Inspired Inhibitors of Tubulin Polymerization-An Update

Cancer is one of the leading causes of fatality and mortality worldwide. Investigations on developing therapeutic strategies for cancer are supported throughout the world. The massive achievements in molecular sciences involving biochemistry, molecular chemistry, medicine, and pharmacy, and high throughput techniques such as genomics and proteomics have helped to create new potential drug targets for cancer treatment. Microtubules are very attractive targets for cancer therapy because of the crucial roles they play in cell division. In recent years, lots of efforts have been put into the identification of new microtubule-targeting agents (MTAs) in anticancer therapy. Combretastatin A-4 (CA-4) is a natural compound that binds to microtubules’ colchicine binding site and inhibits microtubule polymerization. Due to CA-4’s structural simplicity, many analogs have been synthesized. This article summarizes the new molecule development efforts to reach CA-4 analogs by modifications on its pharmacophore groups, published since 2015.

Visualizing a Convergence of Three Mitochondrial Molecule mRNAs for Drp1/Mfn2/Ucp4 on Soma of Cerebellar Purkinje Cells by RNAscope

We know little about how mitochondrial dynamics regulates in the Purkinje cells. To explore it, we first set up the Gad2-cre:ZsGreen-tdTomatofl/fl mice where Purkinje cells expressed tdTomato in the cerebellum. Secondly, double stainings verified tdTomato cells were Calbinin (CB)-positive Purkinje cells, but colocalized neither with astrocyte marker GFAP nor with microglia marker Iba1. Thirdly, application of RNAscope in situ hybridization with the identification of mRNAs of mitofusin 2 (Mfn2), calcium transporter (Mcu and Nclx) and uncoupling proteins (Ucp2 and Ucp4) were used onto Purkinje cells for specific spatial analysis. Our findings demonstrated that Mfn2 mRNAs expression was evident in Purkinje cells. And few expressions of Ucp4 mRNAs were presented in dendritic shafts of Purkinje cells. It should be noted that Mcu, Nclx, and Ucp2 mRNAs expression were only scattered on both soma and dendrites in Purkinje cells. The double RNAscope profiling of mitochondrial molecules showed Mfn1 mRNAs are presented only in the soma of the Purkinje cells. Double RNAscope showed none of Drp1 mRNAs were co-localized with Mcu mRNAs, as well as almost none of Ucp2 mRNAs were co-localized with Mfn2 mRNAs. All of these results showed the mitochondrial Drp1/Mfn2/Ucp4 convergence on the Purkinje cells. Finally, present research focuses on developing new and more specific molecules tuning the activity of the Purkinje cells activate or inactivate and opening therapeutic windows for Purkinje cells-related diseases. The molecular identification of potential drug targets, mechanism of action, and structural basis of their activity will crucially enable preclinical development.

Decreased glutamate transport in acivicin resistant Leishmania tarentolae

Studies of drug resistance in the protozoan parasites of the genus Leishmania have been helpful in revealing biochemical pathways as potential drug targets. The chlorinated glutamine analogue acivicin has shown good activity against Leishmania cells and was shown to target several enzymes containing amidotransferase domains. We selected a Leishmania tarentolae clone for acivicin resistance. The genome of this resistant strain was sequenced and the gene coding for the amidotransferase domain-containing GMP synthase was found to be amplified. Episomal expression of this gene in wild-type L. tarentolae revealed a modest role in acivicin resistance. The most prominent defect observed in the resistant mutant was reduced uptake of glutamate, and through competition experiments we determined that glutamate and acivicin, but not glutamine, share the same transporter. Several amino acid transporters (AATs) were either deleted or mutated in the resistant cells. Some contributed to the acivicin resistance phenotype although none corresponded to the main glutamate transporter. Through sequence analysis one AAT on chromosome 22 corresponded to the main glutamate transporter. Episomal expression of the gene coding for this transporter in the resistant mutant restored glutamate transport and acivicin susceptibility. Its genetic knockout led to reduced glutamate transport and acivicin resistance. We propose that acivicin binds covalently to this transporter and as such leads to decreased transport of glutamate and acivicin thus leading to acivicin resistance.

Secretases Related to Amyloid Precursor Protein Processing

Alzheimer’s disease (AD) is a common neurodegenerative disease whose prevalence increases with age. An increasing number of findings suggest that abnormalities in the metabolism of amyloid precursor protein (APP), a single transmembrane aspartic protein that is cleaved by β- and γ-secretases to produce β-amyloid protein (Aβ), are a major pathological feature of AD. In recent years, a large number of studies have been conducted on the APP processing pathways and the role of secretion. This paper provides a summary of the involvement of secretases in the processing of APP and the potential drug targets that could provide new directions for AD therapy.

Forced association of SARS-CoV-2 proteins with the yeast proteome perturb vesicle trafficking

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the highly infectious coronavirus disease COVID-19. Extensive research has been performed in recent months to better understand how SARS-CoV-2 infects and manipulates its host to identify potential drug targets and support patient recovery from COVID-19. However, the function of many SARS-CoV-2 proteins remains uncharacterised. Here we used the Synthetic Physical Interactions (SPI) method to recruit SARS-CoV-2 proteins to most of the budding yeast proteome to identify conserved pathways which are affected by SARS-CoV-2 proteins. The set of yeast proteins that result in growth defects when associated with the viral proteins have homologous functions that overlap those identified in studies performed in mammalian cells. Specifically, we were able to show that recruiting the SARS-CoV-2 NSP1 protein to HOPS, a vesicle-docking complex, is sufficient to perturb membrane trafficking in yeast consistent with the hijacking of the endoplasmic-reticulum–Golgi intermediate compartment trafficking pathway during viral infection of mammalian cells. These data demonstrate that the yeast SPI method is a rapid way to identify potential functions of ectopic viral proteins.

Cellular Genome-scale Metabolic Modeling Identifies New Potential Drug Targets Against Hepatocellular Carcinoma

Hepatocellular carcinoma is the third leading cause of cancer related mortality worldwide. Often this hepatic cancer is associated with fatty liver disease and insulin resistance with genetic predisposition are its major driver. Genome-scale metabolic modeling (GEM) is a promising approach to understand cancer metabolism and to identify new drug targets. Here, we used TRFBA-CORE, an algorithm generating a model using key growth-correlated reactions. Specifically, we generated a HepG2 cell-specific GEM by integrating this cell line transcriptomic data with a generic human metabolic model to predict potential drug targets for hepatocellular carcinoma (HCC). A total of 108 essential genes for growth were predicted by TRFBA-CORE. These genes were enriched for metabolic pathways involved in cholesterol, sterols and steroids biosynthesis. Furthermore, we silenced a predicted essential gene, 11-beta dehydrogenase hydroxysteroid type 2 (HSD11B2), in HepG2 cells resulting in a reduction in cell viability. To further identify novel potential drug targets in HCC, we examined the effect of 9 drugs targeting the essential genes, and observed that most drugs inhibited the growth of HepG2 cells. Interestingly, some of these drugs in this model performed better than Sorafenib, the first line therapeutic against HCC.

Identification of a Novel Therapeutic Target against XDR Salmonella Typhi H58 Using Genomics Driven Approach Followed Up by Natural Products Virtual Screening

Typhoid fever is caused by a pathogenic, rod-shaped, flagellated, and Gram-negative bacterium known as Salmonella Typhi. It features a polysaccharide capsule that acts as a virulence factor and deceives the host immune system by protecting phagocytosis. Typhoid fever remains a major health concern in low and middle-income countries, with an estimated death rate of ~200,000 per annum. However, the situation is exacerbated by the emergence of the extensively drug-resistant (XDR) strain designated as H58 of S. Typhi. The emergence of the XDR strain is alarming, and it poses serious threats to public health due to the failure of the current therapeutic regimen. A relatively newer computational method called subtractive genomics analyses has been widely applied to discover novel and new drug targets against pathogens, particularly drug-resistant ones. The method involves the gradual reduction of the complete proteome of the pathogen, leading to few potential and novel drug targets. Thus, in the current study, a subtractive genomics approach was applied against the Salmonella XDR strain to identify potential drug targets. The current study predicted four prioritized proteins (i.e., Colanic acid biosynthesis acetyltransferase wcaB, Shikimate dehydrogenase aroE, multidrug efflux RND transporter permease subunit MdtC, and pantothenate synthetase panC) as potential drug targets. Though few of the prioritized proteins are treated in the literature as the established drug targets against other pathogenic bacteria, these drug targets are identified here for the first time against S. Typhi (i.e., S. Typhi XDR). The current study aimed at drawing attention to new drug targets against S. Typhi that remain largely unexplored. One of the prioritized drug targets, i.e., Colanic acid biosynthesis acetyltransferase, was predicted as a unique, new drug target against S. Typhi XDR. Therefore, the Colanic acid was further explored using structure-based techniques. Additionally, ~1000 natural compounds were docked with Colanic acid biosynthesis acetyltransferase, resulting in the prediction of seven compounds as potential lead candidates against the S. Typhi XDR strain. The ADMET properties and binding energies via the docking program of these seven compounds characterized them as novel drug candidates. They may potentially be used for the development of future drugs in the treatment of Typhoid fever.