Corrigendum to 'Cancer chemotherapy and beyond: Current status, drug candidates, associated risks and progress in targeted therapeutics' [Genes & Diseases 10 (2023) 1367-1401].

[This corrects the article DOI: 10.1016/j.gendis.2022.02.007.].

Next Generation Mucosal Vaccine Strategy for Respiratory Pathogens.

Inducing humoral and cytotoxic mucosal immunity at the sites of pathogen entry has the potential to prevent the infection from getting established. This is different from systemic vaccination, which protects against the development of systemic symptoms. The field of mucosal vaccination has seen fewer technological advances compared to nucleic acid and subunit vaccine advances for injectable vaccine platforms. The advent of the next-generation adenoviral vectors has given a boost to mucosal vaccine research. Basic research into the mechanisms regulating innate and adaptive mucosal immunity and the discovery of effective and safe mucosal vaccine adjuvants will continue to improve mucosal vaccine design. The results from clinical trials of inhaled COVID-19 vaccines demonstrate their ability to induce the proliferation of cytotoxic T cells and the production of secreted IgA and IgG antibodies locally, unlike intramuscular vaccinations. However, these mucosal vaccines induce systemic immune responses at par with systemic vaccinations. This review summarizes the function of the respiratory mucosa-associated lymphoid tissue and the advantages that the adenoviral vectors provide as inhaled vaccine platforms.

Cancer chemotherapy and beyond: Current status, drug candidates, associated risks and progress in targeted therapeutics.

Cancer is an abnormal state of cells where they undergo uncontrolled proliferation and produce aggressive malignancies that causes millions of deaths every year. With the new understanding of the molecular mechanism(s) of disease progression, our knowledge about the disease is snowballing, leading to the evolution of many new therapeutic regimes and their successive trials. In the past few decades, various combinations of therapies have been proposed and are presently employed in the treatment of diverse cancers. Targeted drug therapy, immunotherapy, and personalized medicines are now largely being employed, which were not common a few years back. The field of cancer discoveries and therapeutics are evolving fast as cancer type-specific biomarkers are progressively being identified and several types of cancers are nowadays undergoing systematic therapies, extending patients' disease-free survival thereafter. Although growing evidence shows that a systematic and targeted approach could be the future of cancer medicine, chemotherapy remains a largely opted therapeutic option despite its known side effects on the patient's physical and psychological health. Chemotherapeutic agents/pharmaceuticals served a great purpose over the past few decades and have remained the frontline choice for advanced-stage malignancies where surgery and/or radiation therapy cannot be prescribed due to specific reasons. The present report succinctly reviews the existing and contemporary advancements in chemotherapy and assesses the status of the enrolled drugs/pharmaceuticals; it also comprehensively discusses the emerging role of specific/targeted therapeutic strategies that are presently being employed to achieve better clinical success/survival rate in cancer patients.

Amyloids and brain cancer: molecular linkages and crossovers.

Amyloids are high-order proteinaceous formations deposited in both intra- and extracellular spaces. These aggregates have tendencies to deregulate cellular physiology in multiple ways; for example, altered metabolism, mitochondrial dysfunctions, immune modulation, etc. When amyloids are formed in brain tissues, the endpoint often is death of neurons. However, interesting but least understood is a close connection of amyloids with another set of conditions in which brain cells proliferate at an extraordinary rate and form tumor inside brain. Glioblastoma is one such condition. Increasing number of evidence indicate a possible link between amyloid formation and depositions in brain tumors. Several proteins associated with cell cycle regulation and apoptotic pathways themselves have shown to possess high tendencies to form amyloids. Tumor suppressor protein p53 is one prominent example that mutate, oligomerize and form amyloids leading to loss- or gain-of-functions and cause increased cell proliferation and malignancies. In this review article, we present available examples, genetic links and common pathways that indicate that possibly the two distantly placed pathways: amyloid formation and developing cancers in the brain have similarities and are mechanistically intertwined together.

Development and Challenges of Diclofenac-Based Novel Therapeutics: Targeting Cancer and Complex Diseases.

Diclofenac is a highly prescribed non-steroidal anti-inflammatory drug (NSAID) that relieves inflammation, pain, fever, and aches, used at different doses depending on clinical conditions. This drug inhibits cyclooxygenase-1 and cyclooxygenase-2 enzymes, which are responsible for the generation of prostaglandin synthesis. To improve current diclofenac-based therapies, we require new molecular systematic therapeutic approaches to reduce complex multifactorial effects. However, the critical challenge that appears with diclofenac and other drugs of the same class is their side effects, such as signs of stomach injuries, kidney problems, cardiovascular issues, hepatic issues, and diarrhea. In this article, we discuss why defining diclofenac-based mechanisms, pharmacological features, and its medicinal properties are needed to direct future drug development against neurodegeneration and imperfect ageing and to improve cancer therapy. In addition, we describe various advance molecular mechanisms and fundamental aspects linked with diclofenac which can strengthen and enable the better designing of new derivatives of diclofenac to overcome critical challenges and improve their applications.

Complex Inclusion Bodies and Defective Proteome Hubs in Neurodegenerative Disease: New Clues, New Challenges.

A healthy physiological environment of cells represents the dynamic homeostasis of crowded molecules. A subset of cellular proteome forms protein quality control (PQC) machinery to maintain an uninterrupted synthesis of new polypeptides and targeted elimination of old or defective proteins. The process of PQC may get overwhelmed under specific genetic mutations, environmental stress conditions, and aging-associated perturbances. Many of these conditions may lead to the generation of various types of aberrant protein species that may or may not accumulate as large cellular inclusions. These proteinaceous formations, referred to as inclusion bodies (IBs), could be membrane-bound or membrane-less, cytoplasmic, or nuclear. Most importantly, they could either be toxic or protective. Under acute stress conditions, the formation of aggregates may cause proteostasis failure, leading to large-scale changes in the cellular proteome compositions. However, the large insoluble IBs may act as reservoirs for many soluble proteins with high aggregation propensities, which can overwhelm the cellular chaperoning capacity and protein degradation machinery. The kinetic equilibrium between folding and unfolding, misfolding, and refolding; aggregation and degradation is perturbed in one or many neurodegenerative disorders (NDDs) associated with dementia, cognitive impairments, movement, and behavioural losses. However, a detailed interplay of IBs into the manifestation of the NDDs is unknown, and a very primitive knowledge of structural compositions of amyloid inclusions is present. The present article presents a brief evolutionary background of IBs; their functional relevance for prokaryotes, plants, and animals; and associated involvement in neuronal proteostasis.

Natural compounds in the regulation of proteostatic pathways: An invincible artillery against stress, ageing, and diseases.

Cells have different sets of molecules for performing an array of physiological functions. Nucleic acids have stored and carried the information throughout evolution, whereas proteins have been attributed to performing most of the cellular functions. To perform these functions, proteins need to have a unique conformation and a definite lifespan. These attributes are achieved by a highly coordinated protein quality control (PQC) system comprising chaperones to fold the proteins in a proper three-dimensional structure, ubiquitin-proteasome system for selective degradation of proteins, and autophagy for bulk clearance of cell debris. Many kinds of stresses and perturbations may lead to the weakening of these protective cellular machinery, leading to the unfolding and aggregation of cellular proteins and the occurrence of numerous pathological conditions. However, modulating the expression and functional efficiency of molecular chaperones, E3 ubiquitin ligases, and autophagic proteins may diminish cellular proteotoxic load and mitigate various pathological effects. Natural medicine and small molecule-based therapies have been well-documented for their effectiveness in modulating these pathways and reestablishing the lost proteostasis inside the cells to combat disease conditions. The present article summarizes various similar reports and highlights the importance of the molecules obtained from natural sources in disease therapeutics.

Neurodegeneration & imperfect ageing: Technological limitations and challenges?

Cellular homeostasis is regulated by the protein quality control (PQC) machinery, comprising multiple chaperones and enzymes. Studies suggest that the loss of the PQC mechanisms in neurons may lead to the formation of abnormal inclusions that may lead to neurological disorders and defective aging. The questions could be raised how protein aggregate formation precisely engenders multifactorial molecular pathomechanism in neuronal cells and affects different brain regions? Such questions await thorough investigation that may help us understand how aberrant proteinaceous bodies lead to neurodegeneration and imperfect aging. However, these studies face multiple technological challenges in utilizing available tools for detailed characterizations of the protein aggregates or amyloids and developing new techniques to understand the biology and pathology of proteopathies. The lack of detection and analysis methods has decelerated the pace of the research in amyloid biology. Here, we address the significance of aggregation and inclusion formation, followed by exploring the evolutionary contribution of these structures. We also provide a detailed overview of current state-of-the-art techniques and advances in studying amyloids in the diseased brain. A comprehensive understanding of the structural, pathological, and clinical characteristics of different types of aggregates (inclusions, fibrils, plaques, etc.) will aid in developing future therapies.

Cancer: An unknown territory; rethinking before going ahead.

Cancer is a disease of altered signaling and metabolism, causing uncontrolled division and survival of transformed cells. A host of molecules, factors, and conditions have been designated as underlying causes for the inception and progression of the disease. An enormous amount of data is available, system-wide interaction networks of the genes and proteins are generated over the years and have now reached up to a level of saturation, where we need to shift our focus to the more advanced and comprehensive methods and approaches of data analysis and visualization. Even with the availability of enormous literature on this one of the most pressing pathological conditions, a successful cure of the disease seems to be obscure. New treatment plans, like immunotherapy and precision medicine, are being employed for different studies. Nevertheless, their actual benefits to the patients would be known only after the evaluation of clinical data over the next few years. Therefore, we need to look at few fundamental challenges that should be addressed in more depth before we could devise better, rigorous, and comprehensive treatment plans and may successfully reach a possible cure of the disease. This article aims at bringing attention towards some fundamental gaps in our approach towards the disease that leads to failure in devising successful therapeutics.

Herpesviruses and the hidden links to Multiple Sclerosis neuropathology.

Herpesviruses like Epstein-Barr virus, human herpesvirus (HHV)-6, HHV-1, VZV, and human endogenous retroviruses, have an age-old clinical association with multiple sclerosis (MS). MS is an autoimmune disease of the nervous system wherein the myelin sheath deteriorates. The most popular mode of virus mediated immune system manipulation is molecular mimicry. Numerous herpesvirus antigens are similar to myelin proteins. Other mechanisms described here include the activity of cytokines and autoantibodies produced by the autoreactive T and B cells, respectively, viral déjà vu, epitope spreading, CD46 receptor engagement, impaired remyelination etc. Overall, this review addresses the host-parasite association of viruses with MS.

Ibuprofen-based advanced therapeutics: breaking the inflammatory link in cancer, neurodegeneration, and diseases.

Ibuprofen is a classical nonsteroidal anti-inflammatory drug (NSAID) highly prescribed to reduce acute pain and inflammation under an array of conditions, including rheumatoid arthritis, osteoarthritis, dysmenorrhea, and gout. Ibuprofen acts as a potential inhibitor for cyclooxygenase enzymes (COX-1 and COX-2). In the past few decades, research on this small molecule has led to identifying other possible therapeutic benefits. Anti-tumorigenic and neuroprotective functions of Ibuprofen are majorly recognized in recent literature and need further consideration. Additionally, several other roles of this anti-inflammatory molecule have been discovered and subjected to experimental assessment in various diseases. However, the major challenge faced by Ibuprofen and other drugs of similar classes is their side effects, and tendency to cause gastrointestinal injury, generate cardiovascular risks, modulate hepatic and acute kidney diseases. Future research should also be conducted to deduce new methods and approaches of suppressing the unwanted toxic changes mediated by these drugs and develop new therapeutic avenues so that these small molecules continue to serve the purposes. This article primarily aims to develop a comprehensive and better understanding of Ibuprofen, its pharmacological features, therapeutic benefits, and possible but less understood medicinal properties apart from major challenges in its future application.KEY POINTSIbuprofen, an NSAID, is a classical anti-inflammatory therapeutic agent.Pro-apoptotic roles of NSAIDs have been explored in detail in the past, holding the key in anti-cancer therapies.Excessive and continuous use of NSAIDs may have several side effects and multiple organ damage.Hyperactivated Inflammation initiates multifold detrimental changes in multiple pathological conditions.Targeting inflammatory pathways hold the key to several therapeutic strategies against many diseases, including cancer, microbial infections, multiple sclerosis, and many other brain diseases.

Cloning, purification, and homology modeling of Histone deacetylase in Leishmania donovani.

Neglected diseases, such as leishmaniasis, are still a major health problem in poor countries. To date, there is a severe lack of effective, safe, and affordable treatment for leishmaniasis. Currently, there are very limited chemotherapeutic options, and the development of vaccines is still underway. Hence, novel therapeutic strategies need to be developed against leishmanial parasites. Histone deacetylases (HDACs), silent regulators of many critical pathways, have been validated as potential therapeutic targets in cancer and several parasitic diseases. In the present work, we have isolated and characterized biologically active Zn2+-dependent HDAC protein from leishmania that can be studied further as a potential anti-leishmanial drug target to develop new therapies against neglected diseases. The nucleotide sequence of the HDAC gene with no intervening sequence was amplified, cloned in a pET-28a vector, and later transformed into the BL21(DE3) competent E. coli bacterial cells. After transformation, the cells were cultured and induced with 0.6 mM of IPTG to express histidine-tagged HDAC protein (LD_HDAC), which was later purified using nickel affinity chromatography. The approximate protein size confirmed with the help of 10% SDS-PAGE was ~48.0 kDa. The enzymatic assay using the purified protein confirmed it as biologically active. A three dimensional structure of LD_HDAC was modeled using the crystal structure of HDAC2 protein of Homo sapiens (PDB ID: 6G3O). This protein can be utilized for the screening of Leishmania-specific HDAC inhibitors.

LRSAM1 E3 ubiquitin ligase promotes proteasomal clearance of E6-AP protein.

Numerous proteins participate and actively contribute to the various cellular mechanisms, where several of them are crucial for regular metabolism, including survival. Thus, to maintain optimal cellular physiology, cells govern protein quality control functions with the assistance of comprehensive actions of molecular chaperones, the ubiquitin-proteasome system, and autophagy. In the ubiquitin-proteasome pathway, few quality control E3 ubiquitin ligases actively participate against misfolded protein aggregation generated via stress conditions. But how these quality control E3s active expression levels returned to basal levels when cells achieved re-establishment of proteostasis is still poorly understood. Our current study demonstrated that LRSAM1 E3 ubiquitin ligase promotes the proteasomal degradation of quality control E3 ubiquitin ligase E6-AP. We have observed the co-localization and recruitment of LRSAM1 with E6-AP protein and noticed that LRSAM1 induces the endogenous turnover of E6-AP. Partial depletion of LRSAM1 elevates the levels of E6-AP and affects overall cell cycle regulatory proteins (p53 and p27) expression, including the rate of cellular proliferation. The current finding also provides an excellent opportunity to better understand the basis of the E6-AP associated pathomechanism of Angelman Syndrome disorder. Additionally, this study touches upon the novel potential molecular strategy to regulate the levels of one quality control E3 ubiquitin ligase with another E3 ubiquitin ligase and restore proteostasis and provide a possible therapeutic approach against abnormal protein aggregation diseases.

The Dichotomous Role of Extracellular Vesicles in the Central Nervous System.

Extracellular vesicles (EVs) are important mediators of intercellular communication. Interest in the role of central nervous system (CNS)-derived EVs has been increasing; however, some skepticism of their importance has persisted because many aspects of their biology remain elusive. This ambiguity is largely due to technical barriers that hamper our ability to achieve a comprehensive understanding of their molecular components and mechanisms responsible for their transmission and uptake. However, accumulating evidence supports the notion that EVs play important roles in basic physiological processes within the CNS during neurodevelopment and synaptic plasticity. Interestingly, EVs also act to spread toxic polypeptides in neurodegenerative diseases. Developing a more profound understanding of the role that EVs play in the CNS could lead to the identification of biomarkers and potential vehicles for drug delivery. Here we highlight our current understanding of CNS EVs and summarize our current understanding of their complex role in the CNS.

Structure of proteins: Evolution with unsolved mysteries.

Evolution of macromolecules could be considered as a milestone in the history of life. Nucleic acids are the long stretches of nucleotides that contain all the possible codes and information of life. On the other hand, proteins are their actual translated outcomes, or reflections of modifications in their structure that have occurred at a slow, but steady rate over a very long period of evolution. Over the years of research, biophysicists, biochemists, molecular and structural biologists have unfurled several layers of the structural convolutions in these chemical molecules; however evolutionists look over their structures through a different prism, which may or may not coincide with others. There remains a need to outline several well-known, but less discussed features of protein structures, like intrinsically disordered states, degron signals and different types of ubiquitin chains providing degradation signals, which help the cellular proteolytic machinery to identify and target the proteins towards degradation pathways. There are several important factors, which are critical for folding of proteins into their native three-dimensional conformations by the cytoplasmic chaperones; but in real time how the chaperones fold the newly synthesized polypeptide sequences into a particular three-dimensional shape within a fraction of second is still a mystery for biologists as well as mathematicians. Multiple similar unsolved or unaddressed questions need to be addressed in detail so that future line of research can dig deeper into the finer details of these structures of the proteins.

Polyphenolic flavonoid (Myricetin) upregulated proteasomal degradation mechanisms: Eliminates neurodegenerative proteins aggregation.

Major neurodegenerative disorders are characterized by the formation of misfolded proteins aggregates inside or outside the neuronal cells. Previous studies suggest that aberrant proteins aggregates play a critical role in protein homeostasis imbalance and failure of protein quality control (PQC) mechanism, leading to disease conditions. However, we still do not understand the precise mechanisms of PQC failure and cellular dysfunctions associated with neurodegenerative diseases caused by the accumulation of protein aggregates. Here, we show that Myricetin, a flavonoid, can eliminate various abnormal proteins from the cellular environment via modulating endogenous levels of Hsp70 chaperone and quality control (QC)-E3 ubiquitin ligase E6-AP. We have observed that Myricetin treatment suppresses the aggregation of different aberrant proteins. Myricetin also enhances the elimination of various toxic neurodegenerative diseases associated proteins from the cells, which could be reversed by the addition of putative proteasome inhibitor (MG132). Remarkably, Myricetin can also stabilize E6-AP and reduce the misfolded proteins inclusions, which further alleviates cytotoxicity. Taken together these findings suggested that new mechanistic and therapeutic insights based on small molecules mediated regulation of disturbed protein quality control mechanism, which may result in the maintenance of the state of proteostasis.

LRSAM1 E3 ubiquitin ligase: molecular neurobiological perspectives linked with brain diseases.

Cellular protein quality control (PQC) plays a significant role in the maintenance of cellular homeostasis. Failure of PQC mechanism may lead to various neurodegenerative diseases due to accumulation of aberrant proteins. To avoid such fatal neuronal conditions PQC employs autophagy and ubiquitin proteasome system (UPS) to degrade misfolded proteins. Few quality control (QC) E3 ubiquitin ligases interplay an important role to specifically recognize misfolded proteins for their intracellular degradation. Leucine-rich repeat and sterile alpha motif-containing 1 (LRSAM1) is a really interesting new gene (RING) class protein that possesses E3 ubiquitin ligase activity with promising applications in PQC. LRSAM1 is also known as RING finger leucine repeat rich (RIFLE) or TSG 101-associated ligase (TAL). LRSAM1 has various cellular functions as it modulates the protein aggregation, endosomal sorting machinery and virus egress from the cells. Thus, this makes LRSAM1 interesting to study not only in protein conformational disorders such as neurodegeneration but also in immunological and other cancerous disorders. Furthermore, LRSAM1 interacts with both cellular protein degradation machineries and hence it can participate in maintenance of overall cellular proteostasis. Still, more research work on the quality control molecular functions of LRSAM1 is needed to comprehend its roles in various protein aggregatory diseases. Earlier findings suggest that in a mouse model of Charcot-Marie-Tooth (CMT) disease, lack of LRSAM1 functions sensitizes peripheral axons to degeneration. It has been observed that in CMT the patients retain dominant and recessive mutations of LRSAM1 gene, which encodes most likely a defective protein. However, still the comprehensive molecular pathomechanism of LRSAM1 in neuronal functions and neurodegenerative diseases is not known. The current article systematically represents the molecular functions, nature and detailed characterization of LRSAM1 E3 ubiquitin ligase. Here, we review emerging molecular mechanisms of LRSAM1 linked with neurobiological functions, with a clear focus on the mechanism of neurodegeneration and also on other diseases. Better understanding of LRSAM1 neurobiological and intracellular functions may contribute to develop promising novel therapeutic approaches, which can also propose new lines of molecular beneficial targets for various neurodegenerative diseases.

Ag(I) and Au(III) Mercaptobenzothiazole complexes induced apoptotic cell death.

2-Mercaptobenzothiazole (MBT) complexes of Ag(I) and Au(III) were synthesized by wet chemical method. The structural, optical, 1HNMR, ICP - MS and electrochemical studies of the complexes were carried out. The TUNEL assay studies of Ag(I)MBT and Au(III)MBT complexes on A549 cell line indicated induced apoptosis in the cells. TUNEL assay showed 60% cell viability for Ag(I)MBT whereas 80% for Au(III)MBT. Thus Ag(I)MBT can induce cell apoptosis in cells at a higher rate than Au(III)MBT. Therefore these complexes studied here can be a viable option as anti - proliferating agent.

Targeted delivery of YSA-functionalized and non-functionalized polymeric nanoparticles to injured pulmonary vasculature.

Ephrin type-A receptor 2 (EphA2) is a transmembrane receptor which is upregulated in injured lungs, including those treated with bleomycin. YSA peptide (YSAYPDSVPMMS), a mimic of ephrin ligands, binds to EphA2 receptors on cell surface with high affinity. In this study, we assessed the ability of YSA-functionalized and non-functionalized poly (dl-lactide-co-glycolide) (PLGA) nanoparticles to enhance delivery to bleomycin treated cultured vascular endothelial cells and, in a bleomycin induced lung injury mouse model. Nanoparticles were loaded with a lipophilic fluorescent dye. Human umbilical vein endothelial cells (HUVEC) with or without 2-day bleomycin pretreatment (25 µg/ml) and adult mice with or without intratracheal instillation of bleomycin (0.1 U) were dosed with nanoparticles. Mice received nanoparticles via tail vein injection 4 days after bleomycin treatment. Three days after nanoparticle injection, tissues (lung, heart, kidney, spleen, liver, brain, eyes and whole blood) were harvested and quantified for fluorescence using IVIS imaging. Mean particle uptake increased with time and concentration for both types of particles in HUVEC, with the uptake being higher for YSA-functionalized nanoparticles. Bleomycin treatment increased the 3-h uptake of both types of nanoparticles in HUVEC by about two-fold, with the YSA-functionalized nanoparticle uptake being 1.66-fold compared to non-functionalized nanoparticles (p < .05). In mice, bleomycin injury resulted in 2.3- and 4.7-fold increase in the lung levels of non-functionalized and YSA-functionalized nanoparticles (p < .05), respectively, although the differences between the two particle types were not significant. In conclusion, PLGA nanoparticle delivery to cultured vascular endothelial cells and mouse lungs in vivo is higher following bleomycin treatment, with the delivery tending to be higher for YSA functionalized nanoparticles.

MicroRNA dysregulation in lung injury: the role of the miR-26a/EphA2 axis in regulation of endothelial permeability.

MicroRNAs (miRNAs) are noncoding RNAs that regulate gene expression in many diseases, although the contribution of miRNAs to the pathophysiology of lung injury remains obscure. We hypothesized that dysregulation of miRNA expression drives the changes in key genes implicated in the development of lung injury. To test our hypothesis, we utilized a model of lung injury induced early after administration of intratracheal bleomycin (0.1 U). Wild-type mice were treated with bleomycin or PBS, and lungs were collected at 4 or 7 days. A profile of lung miRNA was determined by miRNA array and confirmed by quantitative PCR and flow cytometry. Lung miR-26a was significantly decreased 7 days after bleomycin injury, and, on the basis of enrichment of predicted gene targets, it was identified as a putative regulator of cell adhesion, including the gene targets EphA2, KDR, and ROCK1, important in altered barrier function. Lung EphA2 mRNA, and protein increased in the bleomycin-injured lung. We further explored the miR-26a/EphA2 axis in vitro using human lung microvascular endothelial cells (HMVEC-L). Cells were transfected with miR-26a mimic and inhibitor, and expression of gene targets and permeability was measured. miR-26a regulated expression of EphA2 but not KDR or ROCK1. Additionally, miR-26a inhibition increased HMVEC-L permeability, and the disrupted barrier integrity due to miR-26a was blocked by EphA2 knockdown, shown by VE-cadherin staining. Our data suggest that miR-26a is an important epigenetic regulator of EphA2 expression in the pulmonary endothelium. As such, miR-26a may represent a novel therapeutic target in lung injury by mitigating EphA2-mediated changes in permeability.