The Role of Rho GTPases in VEGF Signaling in Cancer Cells

Cancer research in Lebanon: Scope of the most recent publications of an academic institution (Review)

Cancer may be considered one of the most interesting areas of study, and although oncology research has grown markedly over the last decade, there is as yet no known cure for cancer. The objective of the present review is to examine various approaches to cancer research from a single institution, summarize their key conclusions and offer recommendations for future evaluations. The review examined 72 cancer-associated studies that were published within six years from 2017 to 2022. Published works in the subject fields of 'cancer' or 'oncology' and 'research' that were indexed in Scopus and Web of Science were retrieved and sorted according to article title, author names, author count, citation count and key words. After screening, a total of 28 in vitro/animal studies and 46 patient-associated published studies were obtained. A large proportion of these studies comprised literature reviews (20/72), while 20 studies were observational in nature. The 72 publications included 23 in which various types of cancer were examined, while the remaining studies focused on specific types of cancer, including lung, breast, colon and brain cancer. These studies aimed to investigate the incidence, prevalence, treatment and prevention mechanisms associated with cancer. Despite the existence of extensive cancer research, scientists seldom contemplate an ultimate cure for cancer. However, it is crucial to continuously pursue research on cancer prevention and treatment in order to enhance the effectiveness and minimize potential side effects of cancer therapy.

Phthalides Isolated from the Endolichenic Arthrinium sp. EL000127 Exhibits Antiangiogenic Activity

Endolichenic fungi (ELF) produce specialized metabolites that have various medicinal properties. Inhibition of tumor angiogenesis efficaciously suppresses many types of cancer. This study aimed to discover novel antiangiogenic agents from specialized metabolite extracts of ELF strains isolated from Korean lichens. The EtOAc extracts of 51 ELF strains were subjected to a screening pipeline consisting of cell viability, scratch wound healing, and Transwell migration assays. The EtOAc extract of Arthrinium sp. EL000127 showed the most potent inhibitory activity against the chemotactic migration of human umbilical vein endothelial cells (HUVEC). Targeted isolation on the major LC-MS peaks exhibited a previously known phthalide, 3-O-methylcyclopolic acid (1), and two unknown analogues of 1, 3-O-phenylethylcyclopolic acid (2) and 3-O-p-hydroxyphenylethylcyclopolic acid (3). The structures were characterized by MS and NMR analyses. All the isolates were acquired and applied to bioassays as racemates due to spontaneous racemization. Among the isolates, compound 3 effectively inhibits HUVEC motility by suppressing mRNA expressions of genes regulating epithelial cell survival and motility, which suggested that compound 3 is a potent antiangiogenic agent suitable for further exploration as a potential novel therapeutic against cancers.

The role of Colchicine on actin polymerization dynamics: as a potent anti-angiogenic factor

Over the years, cancer research has focused on different strategies to discover drugs and therapies to treat the metastatic stage of cancer. This stage depends upon the type, and the cause of cancer. One of the central facts about any cancer invasion is the formation of new blood vessels that provide nutrients to these uncontrollably dividing cells. This phenomenon is called angiogenesis and is responsible for tumor progression and metastasis. Tumor angiogenesis is a sequential process wherein various angiogenic factors produced by tumor cells bind to receptors of endothelial cells. This stimulates the cytoskeletal protein, especially actin to reorganize themselves and undergo the process of canalization. The driving force for such membrane transformation is spatially and temporally-regulated by polymerization of submembrane actin filaments. So far, Colchicine has been studied for its effectiveness in controlling microtubule reorganization during cell division, but its role is far from understood on actin polymerization. In our current study, we report the effect of Colchicine on actin polymerization dynamics using biophysical analysis like Right light scattering (RLS), Dynamic light scattering (DLS), Circular dichroism (CD) analysis, Scanning electron microscopy (SEM) study. Isothermal titration calorimetry (ITC) and kinetic measurements. Isothermal titration calorimetry (ITC) indicates multiple site binding for colchicine with actin aggregates. We have checked the in vivo effect of colchicine using end3 cells of Saccharomyces cerevisiae. We also report the anti-angiogenesis activity of colchicine via ex-ovo chicken chorioallantoic membrane (CAM) assay. We predict the target site of binding for the drug by docking studies. Based on our findings, we suggest the 'drug-repurposed' function for colchicine as a potential anti-angiogenic candidate.Communicated by Ramaswamy H. Sarma.

Comprehensive Computational Analysis of Honokiol Targets for Cell Cycle Inhibition and Immunotherapy in Metastatic Breast Cancer Stem Cells

Breast cancer stem cells (BCSCs) play a critical role in chemoresistance, metastasis, and poor prognosis of breast cancer. BCSCs are mostly dormant, and therefore, activating them and modulating the cell cycle are important for successful therapy against BCSCs. The tumor microenvironment (TME) promotes BCSC survival and cancer progression, and targeting the TME can aid in successful immunotherapy. Honokiol (HNK), a bioactive polyphenol isolated from the bark and seed pods of Magnolia spp., is known to exert anticancer effects, such as inducing cell cycle arrest, inhibiting metastasis, and overcoming immunotherapy resistance in breast cancer cells. However, the molecular mechanisms of action of HNK in BCSCs, as well as its effects on the cell cycle, remain unclear. This study aimed to explore the potential targets and molecular mechanisms of HNK on metastatic BCSC (mBCSC)-cell cycle arrest and the impact of the TME. Using bioinformatics analyses, we predicted HNK protein targets from several databases and retrieved the genes differentially expressed in mBCSCs from the GEO database. The intersection between the differentially expressed genes (DEGs) and the HNK-targets was determined using a Venn diagram, and the results were analyzed using a protein-protein interaction network, hub gene selection, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, genetic alteration analysis, survival rate, and immune cell infiltration levels. Finally, the interaction between HNK and two HNK-targets regulating the cell cycle was analyzed using molecular docking analysis. The identified potential therapeutic targets of HNK (PTTH) included CCND1, SIRT2, AURKB, VEGFA, HDAC1, CASP9, HSP90AA1, and HSP90AB1, which can potentially inhibit the cell cycle of mBCSCs. Moreover, our results showed that PTTH could modulate the PI3K/Akt/mTOR and HIF1/NFkB/pathways. Overall, these findings highlight the potential of HNK as an immunotherapeutic agent for mBCSCs by modulating the tumor immune environment.

Receptor tyrosine kinases as a therapeutic target by natural compounds in cancer treatment

Background

Receptor tyrosine kinases (RTKs) are single-pass transmembrane proteins that play significant roles in regulating cellular processes, including cell division and growth. Overexpression and mutations of RTKs have been found in clinical manifestations of different forms of cancer. Therefore, RTKs have received considerable interest as a therapeutic biomarker in the treatment of cancer cells.

Main body of the abstract

Comprehensive data on RTKs, pharmacological and biological properties of natural compounds were systematically searched up to 2021 using relevant keywords from various databases, such as Google Scholar, PubMed, Web of Science, and Scopus. The scientific search by various standard electronic resources and databases unveils the effectiveness of medicinal plants in the treatment of various cancers. In vitro and in vivo studies suggested that bioactive compounds such as flavonoids, phenols, alkaloids, and many others can be used pharmacologically as RTKs inhibitors (RTKI) either by competing with ATP at the ATP binding site of the tyrosine kinase domain or competing for the receptor extracellular domain. Additionally, studies conducted on animal models indicated that inhibition of RTKs catalytic activity by natural compounds is one of the most effective ways to block the activation of RTKs signaling cascades, thereby hampering the proliferation of cancer cells. Furthermore, various pharmacological experiments, transcriptomic, and proteomic data also reported that cancer cells treated with different plants extracts or isolated phytochemicals exhibited better anticancer properties with minimal side effects than synthetic drugs. Clinically, natural compounds have demonstrated significant anti-proliferative effect via induction of cell apoptosis in cancer cell lines.

Short conclusion

An in-depth knowledge of the mechanism of inhibition and structural characterization of RTKs is important to the design of novel and selective RTKIs. This review focuses on the molecular mechanisms and structures of natural compounds RTKI targeting vascular endothelial growth factor, epidermal growth factor receptor, insulin receptor, and platelet-derived growth factor while also giving future directions to ameliorate the scientific burden of cancer.

Graphic abstract

In vivo Functional Genomics for Undiagnosed Patients: The Impact of Small GTPases Signaling Dysregulation at Pan-Embryo Developmental Scale

While individually rare, disorders affecting development collectively represent a substantial clinical, psychological, and socioeconomic burden to patients, families, and society. Insights into the molecular mechanisms underlying these disorders are required to speed up diagnosis, improve counseling, and optimize management toward targeted therapies. Genome sequencing is now unveiling previously unexplored genetic variations in undiagnosed patients, which require functional validation and mechanistic understanding, particularly when dealing with novel nosologic entities. Functional perturbations of key regulators acting on signals' intersections of evolutionarily conserved pathways in these pathological conditions hinder the fine balance between various developmental inputs governing morphogenesis and homeostasis. However, the distinct mechanisms by which these hubs orchestrate pathways to ensure the developmental coordinates are poorly understood. Integrative functional genomics implementing quantitative in vivo models of embryogenesis with subcellular precision in whole organisms contribute to answering these questions. Here, we review the current knowledge on genes and mechanisms critically involved in developmental syndromes and pediatric cancers, revealed by genomic sequencing and in vivo models such as insects, worms and fish. We focus on the monomeric GTPases of the RAS superfamily and their influence on crucial developmental signals and processes. We next discuss the effectiveness of exponentially growing functional assays employing tractable models to identify regulatory crossroads. Unprecedented sophistications are now possible in zebrafish, i.e., genome editing with single-nucleotide precision, nanoimaging, highly resolved recording of multiple small molecules activity, and simultaneous monitoring of brain circuits and complex behavioral response. These assets permit accurate real-time reporting of dynamic small GTPases-controlled processes in entire organisms, owning the potential to tackle rare disease mechanisms.

Orofacial clefts embryology, classification, epidemiology, and genetics

Orofacial clefts (OFCs) rank as the second most common congenital birth defect in the United States after Down syndrome and are the most common head and neck congenital malformations. They are classified as cleft lip with or without cleft palate (CL/P) and cleft palate only (CPO). OFCs have significant psychological and socio-economic impact on patients and their families and require a multidisciplinary approach for management and counseling. A complex interaction between genetic and environmental factors contributes to the incidence and clinical presentation of OFCs. In this comprehensive review, the embryology, classification, epidemiology and etiology of clefts are thoroughly discussed and a "state-of-the-art" snapshot of the recent advances in the genetics of OFCs is presented.

Dysregulation of Rho GTPases in orofacial cleft patients-derived primary cells leads to impaired cell migration, a potential cause of cleft/lip palate development

Cleft lip and/or palate are a split in the lip, the palate or both. This results from the inability of lip buds and palatal shelves to properly migrate and assemble during embryogenesis. By extracting primary cells from a cleft patient, we aimed at offering a better understanding of the signaling mechanisms and interacting molecules involved in the lip and palate formation and fusion. With Rho GTPases being indirectly associated with cleft occurrence, we investigated the role of the latter in both. First, whole exome sequencing was conducted in a patient with cleft lip and palate. Primary fibroblastic cells originating from the upper right gingiva region were extracted and distinct cellular populations from two individuals were obtained: a control with no cleft phenotype and a patient with a cleft lip and palate. The genetic data showed three candidate variables in ARHGEF18, EPDR1, and CUL7. Next, the molecular data showed no significant change in proliferation rates between healthy patient cells and CL/P patient cells. However, CL/P patient cells showed decreased migration, increased adhesion and presented with a more elongated phenotype. Additionally, RhoA activity was upregulated in these cells, whereas Cdc42 activity was downregulated, resulting in loss of polarity. Our results are suggestive of a possible correlation between a dysregulation of Rho GTPases and the observed phenotype of cleft lip and palate patient cells. This insight into the intramolecular aspect of this disorder helps link the genetic defect with the observed phenotype and offers a possible mechanism by which CL/P occurs.