Development and therapeutic implications of small molecular inhibitors that target calcium-related channels in tumor treatment

Calcium ion dysregulation exerts profound effects on various physiological activities such as tumor proliferation, migration, and drug resistance. Calcium-related channels play a regulatory role in maintaining calcium ion homeostasis, with most channels being highly expressed in tumor cells. Additionally, these channels serve as potential drug targets for the development of antitumor medications. In this review, we first discuss the current research status of these pathways, examining how they modulate various tumor functions such as epithelial-mesenchymal transition (EMT), metabolism, and drug resistance. Simultaneously, we summarize the recent progress in the study of novel small-molecule drugs over the past 5 years and their current status.

Comprehensive Insights that Targeting PIM for Cancer Therapy: Prospects and Obstacles

Proviral integration sitea for Moloney-murine leukemia virus (PIM) kinases are a family of highly conserved serine/tyrosine kinases consisting of three members, PIM-1, PIM-2, and PIM-3. These kinases regulate a wide range of substrates through phosphorylation and affect key cellular processes such as transcription, translation, proliferation, apoptosis, and energy metabolism. Several PIM inhibitors are currently undergoing clinical trials, such as a phase I clinical trial of Uzanserti (5) for the treatment of relapsed diffuse large B-cell lymphoma that has been completed. The current focus encompasses the structural and biological characterization of PIM, ongoing research progress on small-molecule inhibitors undergoing clinical trials, and evaluation analysis of persisting challenges in this field. Additionally, the design and discovery of small-molecule inhibitors targeting PIM in recent years have been explored, with a particular emphasis on medicinal chemistry, aiming to provide valuable insights for the future development of PIM inhibitors.

Nanomedicine for cancer targeted therapy with autophagy regulation

Nanoparticles have unique physical and chemical properties and are currently widely used in disease diagnosis, drug delivery, and new drug development in biomedicine. In recent years, the role of nanomedical technology in cancer treatment has become increasingly obvious. Autophagy is a multi-step degradation process in cells and an important pathway for material and energy recovery. It is closely related to the occurrence and development of cancer. Because nanomaterials are highly targeted and biosafe, they can be used as carriers to deliver autophagy regulators; in addition to their favorable physicochemical properties, nanomaterials can be employed to carry autophagy inhibitors, reducing the breakdown of chemotherapy drugs by cancer cells and thereby enhancing the drug's efficacy. Furthermore, certain nanomaterials can induce autophagy, triggering oxidative stress-mediated autophagy enhancement and cell apoptosis, thus constraining the progression of cancer cells.There are various types of nanoparticles, including liposomes, micelles, polymers, metal-based materials, and carbon-based materials. The majority of clinically applicable drugs are liposomes, though other materials are currently undergoing continuous optimization. This review begins with the roles of autophagy in tumor treatment, and then focuses on the application of nanomaterials with autophagy-regulating functions in tumor treatment.

Technologies of targeting histone deacetylase in drug discovery: Current progress and emerging prospects

Histone deacetylases (HDACs) catalyze the hydrolysis of acetyl-l-lysine side chains in histones and non-histones, which are key to epigenetic regulation in humans. Targeting HDACs has emerged as a promising strategy for treating various types of cancer, including myeloma and hematologic malignancies. At present, numerous small molecule inhibitors targeting HDACs are actively being investigated in clinical trials. Despite their potential efficacy in cancer treatment, HDAC inhibitors suffer from multi-directional selectivity and preclinical resistance issues. Hence, developing novel inhibitors based on cutting-edge medicinal chemistry techniques is essential to overcome these limitations and improve clinical outcomes. This manuscript presents an extensive overview of the properties and biological functions of HDACs in cancer, provides an overview of the current state of development and limitations of clinical HDAC inhibitors, and analyzes a range of innovative medicinal chemistry techniques that are applied. These techniques include selective inhibitors, dual-target inhibitors, proteolysis targeting chimeras, and protein-protein interaction inhibitors.

PDE4 inhibitors for disease therapy: advances and future perspective

The PDE4 enzyme family is specifically responsible for hydrolyzing cAMP and plays a vital role in regulating the balance of second messengers. As a crucial regulator in signal transduction, PDE4 has displayed promising pharmacological targets in a variety of diseases, for which its inhibitors have been used as a therapeutic strategy. This review provides a comprehensive summary of the development of PDE4 inhibitors in the past few years, along with the structure, clinical and research progress of multiple inhibitors of PDE4, focusing on the research and development strategies of PDE4 inhibitors. We hope our analysis will provide a significant reference for the future development of new PDE4 inhibitors.

Montelukast prevents mice against carbon tetrachloride- and methionine-choline deficient diet-induced liver fibrosis: Reducing hepatic stellate cell activation and inflammation

AIMS

Montelukast is an antagonist of cysteinyl leukotriene receptor 1 (CysLTR1) that protects against inflammation and oxidative stress. However, the function of montelukast in liver fibrosis remains unknown. In this study, we examined whether the pharmacological inhibition of CysLTR1 could protect mice against hepatic fibrosis.

MATERIALS AND METHODS

Carbon tetrachloride (CCl₄) and methionine-choline deficient (MCD) diet models were used in this study. The expression of CysLTR1 in liver were detected by RT-qPCR and Western blot analysis. Liver hydroxyproline levels, fibrotic genes expression, serum biochemical indexes and inflammatory factors were used to evaluate the effect of montelukast on liver fibrosis, injury, and inflammation. In vitro, we used the RT-qPCR and Western blot analysis to assess CysLTR1 in mouse primary hepatic stellate cell (HSC) and human LX-2 cell line. The role of montelukast on HSC activation and the underlying mechaisms were determined using RT-qPCR analysis, Western blot and immunostaining assays.

KEY FINDINGS

Chronic stimulation from CCl₄ and MCD diet upregulated the mRNA and protein levels of CysLTR1 in the liver. Pharmacological inhibition of CysLTR1 by montelukast ameliorated liver inflammation and fibrosis in both models. Mechanistically, montelukast suppressed HSC activation by targeting the TGFβ/Smad pathway in vitro. The hepatoprotective effect of montelukast was also associated with reduced liver injury and inflammation.

SIGNIFICANCE

Montelukast suppressed CCl₄- and MCD-induced chronic hepatic inflammation and liver fibrosis. CysLTR1 might be a therapeutic target for treating liver fibrosis.

Small-molecule LRRK2 inhibitors for PD therapy: Current achievements and future perspectives

Leucine-rich repeat kinase 2 (LRRK2) is a multifunctional protein that orchestrates a diverse array of cellular processes, including vesicle transport, autophagy, lysosome degradation, neurotransmission, and mitochondrial activity. Hyperactivation of LRRK2 triggers vesicle transport dysfunction, neuroinflammation, accumulation of α-synuclein, mitochondrial dysfunction, and the loss of cilia, ultimately leading to Parkinson's disease (PD). Therefore, targeting LRRK2 protein is a promising therapeutic strategy for PD. The clinical translation of LRRK2 inhibitors was historically impeded by issues surrounding tissue specificity. Recent studies have identified LRRK2 inhibitors that have no effect on peripheral tissues. Currently, there are four small-molecule LRRK2 inhibitors undergoing clinical trials. This review provides a summary of the structure and biological functions of LRRK2, along with an overview of the binding modes and structure-activity relationships (SARs) of small-molecule inhibitors targeting LRRK2. It offers valuable references for developing novel drugs targeting LRRK2.

First Report of Tomato mottle mosaic virus infecting Chinese snake gourd (Trichosanthes kirilowii) in China

Tomato mottled mosaic virus (ToMMV) was first identified in tomato in Mexico (Li et al. 2013). It belongs to the genus Tobamovirus and family Virgaviridae, and is a positive-sense single-stranded RNA virus. The viral genome contains about 6400 nucleotides, encoding four proteins, including the 126 K protein, 183 K protein, movement protein (MP) and coat protein (CP) (Tu et al. 2021). ToMMV mainly poses a serious risk to solanaceous crops. The virus-infected plants appear stunted growth and top necrosis, and the disease leaves show mottled, shrinkage and necrosis symptoms, resulting in a significant decline in tomato fruit yield and quality (Li et al. 2017; Tu et al. 2021). Chinese snake gourd (Trichosanthes kirilowii Maxim) is a perennial climbing herb in the family Cucurbitaceae, and the fruit, seed, peel and root can all be used as traditional Chinese medicine. In May of 2021, twenty-seven symptomless seedlings (developed from tissue culture plantlets) were randomly collected from nursery in Fengyang, Anhui Province. Total RNA of each sample was extracted, and RT-PCR was performed using degenerate tobamovirus primers Tob-Uni1 (5'-ATTTAAGTGGASGGAAAAVCACT-3') and Tob-Uni2 (5'-GTYGTT GATGAGTTCRTGGA-3') (Letschert et al. 2002). Amplicons with expected size were obtained from 6 of 27 samples and sequenced. Alignment results showed that the nucleotide sequence identities ranged from 98.7 to 100% with all ToMMV isolates deposited in NCBI GenBank. Then, ToMMV coat protein (CP) gene was amplified using specific primers CP-F (5'-ATGTCTTACGCTATTACTT CTCCG-3') and CP-R (5'-TTAGGACGCTGGCGCAGAAG-3'). The CP fragment was obtained and sequenced. Sequence alignment indicated that CP sequence of isolate FY (GenBank accession no. ON924176) exhibited a 100% identity with ToMMV isolate LN (MN853592.1). The anti-ToMMV polyclonal antibody (PAb) was prepared by the author (S.L.) by immunizing rabbit with purified virus from Nicotiana benthamiana, and serological tests (dot-enzyme linked immunosorbent assay, Dot-ELISA) of RNA-positive T. kirilowii leaf samples using anti-ToMMV PAb were also positive. To fulfill a Koch's postulate, a pure culture of ToMMV was obtained from N. benthamiana using infectious cDNA clone of ToMMV (Tu et al. 2021), and then healthy T. kirilowii plants were mechanically inoculated with a prepared inoculum from ToMMV-infected N. benthamiana, as described previously (Sui et al. 2017). T. kirilowii seedlings showed chlorosis and leaf tip necrosis symptoms at 10 and 20 day post-inoculation respectively, and ToMMV infection on symptomatic plants was also verified by RT-PCR detection using primers CP-F and CP-R. These results demonstrated that T. kirilowii is a host of ToMMV under natural conditions, which might threaten the production of this medicinal plant. The seedlings from nursery appeared to be asymptomatic, but the plants showed chlorosis and necrosis symptoms after indoor inoculation. In qRT-PCR analysis, viral accumulation level in greenhouse-inoculated plants was a 25.6-fold of that in field-collected samples, which may be the reason of different symptom expression between field samples and inoculated samples. ToMMV has now been detected from the solanaceous (tomato, pepper and eggplant) and leguminous (pea) crops in the field (Li et al. 2014; Ambrós et al. 2017; Zhang et al. 2022). To our knowledge, this is the first report of natural infection of ToMMV in T. kirilowii as well as its natural infection on Cucurbitaceae plants.

Genome-wide identification and expression analysis of SlRR genes in response to abiotic stress in tomato

The cytokinin two-component signal transduction system (TCS) is involved in many biological processes, including hormone signal transduction and plant growth regulation. Although cytokinin TCS has been well characterized in Arabidopsis thaliana, its role in tomato remains elusive. In this study, we characterized the diversity and function of response regulator (RR) genes, a critical component of TCS, in tomato. In total, we identified 31 RR genes in the tomato genome. These SlRR genes were classified into three subgroups (type-A, type-B and type-C). Various stress-responsive cis-elements were present in the tomato RR gene promoters. Their expression responses under pesticide treatment were evaluated by transcriptome analysis. Their expression under heat, cold, ABA, salinity and NaHCO₃ treatments was further investigated by qRT-PCR and complemented with the available transcription data under these treatments. Specifically, SlRR13 expression was significantly upregulated under salinity, drought, cold and pesticide stress and was downregulated under ABA treatment. SlRR23 expression was induced under salt treatment, while the transcription level of SlRR1 was increased under cold and decreased under salt stress. We also found that GATA transcription factors played a significant role in the regulation of SlRR genes. Based on our results, tomato SlRR genes are involved in responses to abiotic stress in tomato and could be implemented in molecular breeding approaches to increase resistance of tomato to environmental stresses.

Predicting hot electron generation in inertial confinement fusion with particle-in-cell simulations

A series of two-dimensional particle-in-cell simulations with speckled laser drivers was carried out to study hot electron generation in direct-drive inertial confinement fusion on OMEGA. Scaling laws were obtained for hot electron fraction and temperature as functions of laser/plasma conditions in the quarter-critical region. Using these scalings and conditions from hydro simulations, the temporal history of hot electron generation can be predicted. The scalings can be further improved to predict hard x-rays for a collection of OMEGA warm target implosions within experimental error bars. These scalings can be readily implemented into inertial confinement fusion design codes.

Small molecule angiotensin converting enzyme inhibitors: A medicinal chemistry perspective

Angiotensin-converting enzyme (ACE), a zinc metalloprotein, is a central component of the renin-angiotensin system (RAS). It degrades bradykinin and other vasoactive peptides. Angiotensin-converting-enzyme inhibitors (ACE inhibitors, ACEIs) decrease the formation of angiotensin II and increase the level of bradykinin, thus relaxing blood vessels as well as reducing blood volume, lowering blood pressure and reducing oxygen consumption by the heart, which can be used to prevent and treat cardiovascular diseases and kidney diseases. Nevertheless, ACEIs are associated with a range of adverse effects such as renal insufficiency, which limits their use. In recent years, researchers have attempted to reduce the adverse effects of ACEIs by improving the selectivity of ACEIs for structural domains based on conformational relationships, and have developed a series of novel ACEIs. In this review, we have summarized the research advances of ACE inhibitors, focusing on the development sources, design strategies and analysis of structure-activity relationships and the biological activities of ACE inhibitors.

[Correlation analysis of clock genes and MEN2 medullary thyroid carcinoma]

Objective: To investigate the correlation between CLOCK and BMAL1 genes and MEN2 medullary thyroid carcinoma (MTC). Methods: Thirteen cases with MEN2 MTC and thirteen cases with non-MEN2 MTC were selected who were treated in the Yantai Yuhuangding Hospital between January 2013 and September 2021. Clinical indicators such as blood calcitonin level, tumor diameter and metastatic lymph node of patients were collected. The expression differences of CLOCK and BMAL1 between MEN2 MTC and para-carcinoma tissue as well as between MEN2 MTC and non-MEN2 MTC were detected by immunohistochemistry and qPCR. The correlation between lymph node metastasis and CLOCK or BMAL1 expression was analyzed. Protein-protein interaction (PPI) network analysis combined with qPCR and correlation analysis was used to explore the expression regulation relationship between RET and circadian clock genes. The rhythm disorder of MEN2 cells was verified by lipopolysaccharide cell stimulation experiment after dexamethasone rhythm synchronization. Results: MEN2 MTC exhibited typical RET gene mutation. The mean blood calcitonin level, the tumor diameter and the number of metastatic lymph nodes of patients with MEN2 MTC were higher than those of patients with non-MEN2 MTC (t value was 2.76, 2.53, 2.26, all P<0.05). Immunohistochemical results showed that the expression levels of CLOCK and BMAL1 in MEN2 MTC were higher than those in non-MEN2 MTC, while negatively expressed in para-cancerous thyroid follicle. qPCR displayed that the expression of CLOCK gene in cancer tissues was higher than that in non-MEN2 MTC and para-cancerous tissues (t value was 2.68 and 2.86, all P<0.05); the expression of BMAL1 gene in MEN2 MTC was higher than that in non-MEN2 MTC and para-cancerous tissues (t value was 2.21 and 2.35, all P<0.05). Correlation analysis showed that the expression levels of CLOCK and BMAL1 genes were positively correlated with the number of lymph node metastases in patients with MEN2 MTC (r=0.65, P<0.001; r=0.52, P=0.005). PPI network analysis indicated that the expression of CLOCK gene was positively correlated with the abnormal expression of RET gene (r=0.96, P<0.001). With lipopolysaccharide to stimulate cultured cells in vitro after dexamethasone rhythm synchronization, the expressions of CLOCK and BMAL1 in MEN2 MTC cells (0.47±0.22 and 2.60±1.48) at 12 hours of synchronization were significantly lower than those in para-cancerous tissues (1.70±1.62 and 8.23±2.52), the difference was statistically significant(t=5.04, P=0.007; t=3.34, P=0.029). Conclusion: CLOCK and BMAL1 are correlated with the occurrence and development of MEN2 MTC, and may be potential targets for the development of new therapeutic strategies for MEN2 MTC.

Progress and Challenges in Targeted Protein Degradation for Neurodegenerative Disease Therapy

Neurodegenerative diseases (NDs) are currently incurable diseases that cause progressive degeneration of nerve cells. Many of the disease-causing proteins of NDs are "undruggable" for traditional small-molecule inhibitors (SMIs). None of the compounds that attenuated the amyloid-β (Aβ) accumulation process have entered clinical practice, and many phase III clinical trials of SMIs for Alzheimer's disease (AD) have failed. In recent years, emerging targeted protein degradation (TPD) technologies such as proteolysis-targeting chimeras (PROTACs), lysosome-targeting chimaeras (LYTACs), and autophagy-targeting chimeras (AUTACs) with TPD-assistive technologies such as click-formed proteolysis-targeting chimeras (CLIPTACs) and deubiquitinase-targeting chimera (DUBTAC) have developed rapidly. In vitro and in vivo experiments have also confirmed that TPD technology can target the degradation of ND pathogenic proteins, bringing hope for the treatment of NDs. Herein, we review the latest TPD technologies, introduce their targets and technical characteristics, and discuss the emerging TPD technologies with potential in ND research, with the hope of providing a new perspective for the development of TPD technology in the NDs field.

Current progress and novel strategies that target CDK12 for drug discovery

CDK12 is a cyclin-dependent kinase that plays critical roles in DNA replication, transcription, mRNA splicing, and DNA damage repair. CDK12 genomic changes, including mutation, amplification, deletion, and fusion, lead to various cancers, such as colorectal cancer, gastric cancer, and ovarian cancer. An increasing number of CDK12 inhibitors have been reported since CDK12 was identified as a biomarker and cancer therapeutic target. A major challenge lies in that CDK12 and CDK13 share highly similar sequences, which leads to great difficulties in the development of highly selective CDK12 inhibitors. In recent years, great efforts were made in developing selective CDK12 blockers. Techniques including PROTAC and molecular glue degraders were also applied to facilitate their development. Also, the drug combination strategy of CDK12 small molecule inhibitors were studied. This review discusses the latest studies on CDK12 inhibitors and analyzes their structure-activity relationships, shedding light on their further development.

Small molecule NS5B RdRp non-nucleoside inhibitors for the treatment of HCV infection: A medicinal chemistry perspective

Hepatitis C virus (HCV) infection has become a global health problem with enormous risks. Nonstructural protein 5B (NS5B) RNA-dependent RNA polymerase (RdRp) is a component of HCV, which can promote the formation of the viral RNA replication complex and is also an essential part of the replication complex itself. It plays a vital role in the synthesis of the positive and negative strands of HCV RNA. Therefore, the development of small-molecule inhibitors targeting NS5B RdRp is of great value for treating HCV infection-related diseases. Compared with NS5B RdRp nucleoside inhibitors, non-nucleoside inhibitors have more flexible structures, simpler mechanisms of action, and more predictable efficacy and safety of drugs in humans. Technological advances over the past decade have led to remarkable achievements in developing NS5B RdRp inhibitors. This review will summarize the non-nucleoside inhibitors targeting NS5B RdRp developed in the past decade and describe their structure optimization process and structure-activity relationship.

DYRK1A inhibitors for disease therapy: Current status and perspectives

Dual-specificity tyrosine phosphorylation-regulated kinase 1 A (DYRK1A) is a conserved protein kinase that plays essential roles in various biological processes. It is located in the region q22.2 of chromosome 21, which is involved in the pathogenesis of Down syndrome (DS). Moreover, DYRK1A has been shown to promote the accumulation of amyloid beta (Aβ) peptides leading to gradual Tau hyperphosphorylation, which contributes to neurodegeneration. Additionally, alterations in the DRK1A expression are also associated with cancer and diabetes. Recent years have witnessed an explosive increase in the development of DYRK1A inhibitors. A variety of novel DYRK1A inhibitors have been reported as potential treatments for human diseases. In this review, the latest therapeutic potential of DYRK1A for different diseases and the novel DYRK1A inhibitors discoveries are summarized, guiding future inhibitor development and structural optimization.

Variability of right ventricular linear measurements of size and function using a standardized echocardiographic protocol

Funding Acknowledgements

Type of funding sources: None.

Background

Right ventricular size and function have a prognostic value not only in right heart conditions (pulmonary hypertension, congenital heart disease), but also in left ventricular (LV) disease states. The right ventricle (RV) has a unique shape, for which a simple geometrical model is not achievable as is the case for the LV. In clinical practice simple measurements are used for the RV, since these are considered to be most reliable  and reproducible: linear cavity dimensions, tricuspid annular plane systolic excursion (TAPSE) and tissue Doppler systolic velocity s’ at the tricuspid annulus. The latest RV quantitation guidelines made important modifications to RV measurements, in particular, by shifting from the apical 4-chamber view to the RV focused apical view. Very scarce data exist on the variability of these measurements.

Purpose

In this study we aim to analyze the intra and inter-observer variability of the linear measurements of RV size and function using a standardized methodology.

Methods

A mixed cohort, randomly selected from the echocardiographic database, comprising 50 patients, was retrospectively analyzed. We measured linear diameters (basal = 1, longitudinal = 2, mid = 3) in apical RV-focused view, TAPSE and s’. Based on computer simulations, we propose a step-by-step approach: tracing the longitudinal diameter as perpendicular to the mid of the basal and generally parallel with the interventricular septum, and the mid as perpendicular to the middle of the longitudinal (Figure). Two observers measured independently the same images at baseline, three (inter-observer) and six months (intra-observer).

Results

The longitudinal diameter had the lowest relative bias (3% inter and 4% intra-observer), followed by the basal (7% and 2%), and mid (6% and 6%). The limits of agreement (LOA) were small for s’ (-3 to 1 intra and -1 to 1mm inter-observer), TAPSE (-6 to 5 and -3 to 3mm), and larger for diameters (1=-5 to 10 and -8 to 6; 2=-13 to 17 and -11 to 6; 3=-11 to 7 and -9 to 4mm). ICCs for individual measurements were very good (1= 0.94 intra and 0.94 inter; 2 = 0.78 and 0.94; 3: 0.72 and 0.56; TAPSE: 0.86 and 0.94; s’=0.94 and 0.98), p &lt; 0.001 for all (Table).

Conclusion

A systematic approach to linear RV-focused apical view measurements may lead to reproducible results. It is essential that size measurements be performed in the RV focused view. Our study shows best consistency and reproducibility for the basal diameter and the linear functional parameters.  Echocardiographic laboratories may benefit from implementing a consistent analysis protocol and assessing its reproducibility. Abstract Figure: linear RV measurements  Abstract Table: variability results