Nuclear ERK: Mechanism of Translocation, Substrates, and Role in Cancer

Molecular insights into diabetic wound healing: Focus on Wnt/β-catenin and MAPK/ERK signaling pathways

Diabetic wounds manifest significant clinical challenge with approximately 50-70 % reporting non-traumatic lower limb amputations annually. This review examines the intricate relationship between impaired wound healing in diabetes mellitus and two crucial signaling pathways: Wnt/β-catenin and MAPK/ERK. Chronic hyperglycemia in diabetes mellitus leads to peripheral neuropathy, vascular dysfunction, and compromised immune responses, resulting in delayed wound healing. The Wnt/β-catenin pathway, which is essential for cellular proliferation, differentiation, and tissue homeostasis, shows altered activity in diabetic wounds, particularly through decreased R-spondin 3 protein expression. Similarly, the MAPK/ERK pathway, which regulates cellular proliferation and differentiation through hierarchical kinase cascades, exhibits dysregulation under diabetic conditions. This review describes the current understanding of normal wound healing processes, diabetic wound pathophysiology, and the molecular mechanisms of both signaling pathways. Evidence suggests that targeting these pathways, either individually or synergistically offer promising therapeutic approaches for diabetic wound management. Future directions include, developing targeted delivery systems, exploring pathway cross-talk, and investigating dual-pathway modulators to enhance wound healing outcomes in diabetic patients. This comprehensive analysis provides insights into potential therapeutic strategies and emphasizes the necessity of research in this crucial area of diabetes treatment. (Graphical Abstract).

Targeting the MAPK signaling pathway: implications and prospects of flavonoids in 3P medicine as modulators of cancer cell plasticity and therapeutic resistance in breast cancer patients

Cancer drug resistance poses a significant challenge in oncology, primarily driven by cancer cell plasticity, which promotes tumor initiation, progression, metastasis, and therapeutic evasion in many different cancers. Breast cancers (BCs) are a prominent example of that, with an estimated 2.3 million new cases and 670,000 BC-related deaths registered worldwide annually. Triple-negative BC is especially challenging for treatments demonstrating particularly aggressive disease course, an early manifestation of metastatic disease, frequent drug-resistant cancer types, and poor individual outcomes. Although chemosensitizing agents have been developed, their clinical utility in oncology remains unproven. The mitogen-activated protein kinase (MAPK) pathway is considered a critical regulator of intracellular and extracellular signaling highly relevant for both - genetic and epigenetic modifications. Dysregulation of the MAPK signaling pathways plays a significant role in conferring chemoresistance in BC. Contextually, targeting the MAPK pathway represents a promising strategy for overcoming drug resistance and enhancing the therapeutic efficacy of anticancer agents in BC treatment. On the other hand, flavonoids, a prominent class of phytochemicals, are key modulators of MAPK signaling. Flavonoids interact with the ERK, JNK, p38, and ERK5 pathways of the MAPK signaling cascade and present a promising avenue for developing novel anti-cancer therapies and re-sensitizing agents for the treatment of BC. Compounds such as quercetin, kaempferol, genistein, luteolin, myricetin, EGCG, baicalein, baicalin, nobiletin, morin, delphinidin, acacetin, isorhamnetin, apigenin, silymarin, among others, have been identified as specific modulators of MAPK signaling, exerting complex downstream effects in BC cells increasing therewith drug efficacy and suppressing tumor growth and aggressivity. These properties reflect mechanisms of great clinical relevance to overcome therapeutic resistance in overall BC management. This article highlights corresponding mechanisms and provides clinically relevant illustrations in the framework of 3P medicine for primary (protection of individuals at high risk against health-to-disease transition) and secondary care (protection against metastatic BC progression). 3PM novelty makes good use of patient phenotyping and stratification, predictive multi-level diagnostics, and application of Artificial Intelligence (AI) tools to the individualized interpretation of big data - all proposed for cost-effective treatments tailored to individualized patient profiles with clear benefits to patients and advanced BC management.

Integration of network pharmacology, transcriptomics, and experimental verification to investigate the mechanism of action of cepharanthine hydrochloride against prostate cancer

The incidence of prostate cancer (PCa) is high among elderly men. Cepharanthine hydrochloride (CH) is recognized for its important role in the prevention and treatment of various diseases. However, its effects and mechanisms of action in the context of PCa remain unclear. Our study aims to examine the therapeutic role and mechanisms of action of CH in PCa. Targets of CH and PCa-related genes were identified using different databases, and the biological processes through which CH might exert its therapeutic effects were predicted via protein-protein interaction (PPI) network and enrichment analyses. Subsequently, the PCa cell lines PC-3 and DU145 were used to assess the concentration- and time-dependent effects of CH on cell viability, proliferation, and migration. Transcriptomic sequencing and differential expression analysis were used to identify the key target protein of CH and the key signaling pathways involved in its therapeutic effects against PCa. Molecular docking was used to analyze the binding between CH and its target protein. Additionally, quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, gene knockout, pharmacological intervention, and tumor formation experiments were performed to validate the therapeutic effects and mechanisms of action of CH against PCa in vitro and in vivo. Network pharmacology showed that CH, a Chinese herbal medication, might prevent PCa by regulating protein phosphorylation-related biological processes. In vitro experiments showed that CH inhibited the proliferation and migration of PCa cells in a concentration-dependent manner. In addition, integration of transcriptomic sequencing, differential expression analysis, and GO enrichment analysis suggested that the ERK protein played a crucial role in the anti-tumor activity of CH. Molecular docking and molecular dynamics simulations revealed strong binding affinities between CH and ERK1/2. Further experimental verification, involving qRT-PCR, western blotting, gene knockout, pharmacological intervention, and tumor formation experiments, demonstrated that CH upregulated dual-specificity phosphatase (DUSP) 1 and suppressed the phosphorylation of ERK, thereby inhibiting the development and progression of PCa in vivo and in vitro. In conclusion, the findings of this study suggest that CH suppresses the ERK signaling pathway by enhancing the expression of DUSP1, thereby exerting anti-tumor effects against PCa in vitro and in vivo. Therefore, CH may serve as a novel therapeutic agent for PCa, showing remarkable potential for clinical application.

An exploration on the involvement of the methyltransferase like 3-m6A‑zinc finger MYM-type containing 1 axis in the progression of liver hepatocellular carcinoma

An existing study has underlined the involvement of Methyltransferase Like 3 (METTL3) and its mediated N6-methyladenosine (m6A) modification on zinc finger MYM-type containing 1 (ZMYM1) in cancers, and we aimed to explore their implication in liver hepatocellular carcinoma (LIHC). The levels of METTL3 and ZMYM1 in LIHC cells were gauged via qPCR. The involvement of METTL3 in LIHC progression was explored via assays in vitro and in vivo, and the mechanisms underlying the effects of METTL3 on LIHC were explored via m6A methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) and confocal immunofluorescence assays. METTL3, the m6A methyltransferase of interest, expressed relatively higher in LIHC. The promoting effects of METTL3 on LIHC progression were confirmed both in vitro and in vivo, and the relevant mechanisms maybe related to ZMYM1, a target of METTL3. Such effects of METTL3-m6A-ZMYM1 axis on the progression of LIHC were confirmed to be related to the inactivation of RAS/ERK/c-FOS pathway and the reduction in E-cadherin expression yet the elevation in N-cadherin and Vimentin expressions, therefore accelerating the metastasis in LIHC. Our study highlighted the possible involvement of METTL3-mediated m6A modification in LIHC and explored METTL3-m6A-ZMYM1 axis as a possible therapeutic target for the anti-metastatic strategy against LIHC.

ERK Allosteric Activation: The Importance of Two Ordered Phosphorylation Events

ERK, a coveted proliferation drug target, is a pivotal kinase in the Ras/ERK signaling cascade. Despite this, crucial questions about its activation have not been fully explored on the foundational, conformational level. Such questions include (i) Why ERK's activation demands dual phosphorylation; (ii) What is the role of each phosphorylation site in the activation loop; and (iii) Exactly how the (ordered) phosphorylation steps affect the conformational ensembles of the activation loop, their propensities and restriction to a narrower range favoring ERK's catalytic action. Here we used explicit molecular dynamics simulations to study ERK's stability and the conformational changes in different stages along the activation process. The initial monophosphorylation event elongates the activation loop to enable successive phosphorylations, which reintroduce stability/compactness through newly formed salt bridges. The interactions formed by monophosphorylation are site-dependent, with threonine's phosphorylation presenting stronger electrostatic interactions compared to tyrosine's. Dual phosphorylated ERKs revealed a compact kinase structure which allows the HRD catalytic motif to stabilize the ATP. We further observe that the hinge and the homodimerization binding site responded to a tri-state signaling code based solely on the phosphorylation degree (unphosphorylated, monophosphorylated, dual phosphorylated) of the activation loop, confirming that the activation loop can allosterically influence distant regions. Last, our findings indicate that threonine phosphorylation as the second step is necessary for ERK to become effectively activated and that activation depends on the phosphorylation order. Collectively, we offer ERK's dual allosteric phosphorylation code in activation and explain why the phosphorylation site order is crucial.

Therapeutic potential of flavonoids in gastrointestinal cancer: Focus on signaling pathways and improvement strategies (Review)

Flavonoids are a group of polyphenolic compounds distributed in vegetables, fruits and other plants, which have considerable antioxidant, anti‑tumor and anti‑inflammatory activities. Several types of gastrointestinal (GI) cancer are the most common malignant tumors in the world. A large number of studies have shown that flavonoids have inhibitory effects on cancer, and they are recognized as a class of potential anti‑tumor drugs. Therefore, the present review investigated the molecular mechanisms of flavonoids in the treatment of different types of GI cancer and summarized the drug delivery systems commonly used to improve their bioavailability. First, the classification of flavonoids and the therapeutic effects of various flavonoids on human diseases were briefly introduced. Then, to clarify the mechanism of action of flavonoids on different types of GI cancer in the human body, the metabolic process of flavonoids in the human body and the associated signaling pathways causing five common types of GI cancer were discussed, as well as the corresponding therapeutic targets of flavonoids. Finally, in clinical settings, flavonoids have poor water solubility, low permeability and inferior stability, which lead to low absorption efficiency in vivo. Therefore, the three most widely used drug delivery systems were summarized. Suggestions for improving the bioavailability of flavonoids and the focus of the next stage of research were also put forward.

ERK1/2 gene expression and hypomethylation of Alu and LINE1 elements in patients with type 2 diabetes with and without cataract: Impact of hyperglycemia-induced oxidative stress

AIMS

This study aimed to delineate the effect of hyperglycemia on the Alu/LINE-1 hypomethylation and in ERK1/2 genes expression in type 2 diabetes with and without cataract.

METHODS

This study included 58 diabetic patients without cataracts, 50 diabetic patients with cataracts, and 36 healthy controls. After DNA extraction and bisulfite treatment, LINE-1 and Alu methylation levels were assessed using Real-time MSP. ERK1/2 gene expression was analyzed through real-time PCR. Total antioxidant capacity (TAC), and fasting plasma glucose (FPG) were measured using colorimetric methods. Statistical analysis was performed with SPSS23, setting the significance level at P < 0.05.

RESULTS

The TAC levels were significantly lower for cataract and diabetic groups than controls (259.31 ± 122.99, 312.43 ± 145.46, 372.58 ± 132.95 nanomole of Trolox equivalent) with a significant correlation between FPG and TAC levels in both the cataract and diabetic groups (P < 0.05). Alu and LINE-1 sequences were found to be statistically hypomethylated in diabetic and cataract patients compared to controls. In these groups, TAC levels were directly correlated with Alu methylation (P < 0.05) but not LINE-1. ERK1/2 gene expression was significantly higher in diabetic and cataract patients, showing increases of 2.41-fold and 1.43-fold for ERK1, and 1.27-fold and 1.5 for ERK2, respectively. ERK1 expression correlated significantly with FPG levels. A reverse correlation was observed between TAC levels and ERK1/2 expression.

CONCLUSIONS

Our findings indicate that hyperglycemia-induced oxidative stress may alter ERK1/2 gene expression patterns and induce aberrant hypomethylation in Alu and LINE-1 sequences. These aberrant changes may play a contributing role in diabetic complications such as cataracts.

Phosphorylation of POU3F3 Mediated Nuclear Translocation Promotes Proliferation in Non-Small Cell Lung Cancer through Accelerating ATP5PF Transcription and ATP Production

Targeting oxidative phosphorylation (OXPHOS) through inhibiting the electron transport chain (ETC) has shown promising pre-clinical efficacy in cancer therapy. Although aerobic glycolysis is a hallmark of cancer, emerging evidence suggest OXPHOS is frequently enhanced, providing metabolic advantages for cell proliferation, metastasis, and drug resistance in a variety of aggressive cancer types including non-small cell lung cancer (NSCLC), yet the underlying molecular mechanisms remain elusive. Here it is reported that POU-domain containing family protein POU3F3 is translocated into the nuclei of NSCLC cell lines harboring mutant RAS, where it activates transcription of ATP5PF, an essential component of mitochondrial ATP synthase and consequent ATP production, leading to enhanced NSCLC proliferation and migration. Moreover, it is further found out that ERK1 phosphorylates POU3F3 at the S393 site in the cytoplasm and promotes the nuclear translocation of POU3F3 via receptor importin β1 in RAS mutant NSCLC cells. Mechanistically, RNA sequencing analysis combined with chromatin immunoprecipitation (ChIP) assay revealed that POU3F3 binds to the promoter of ATP5PF, leading to enhanced ATP5PF transcription and ATP production. Together, this study uncovers a novel RAS-POU3F3-ATP5PF axis in facilitating NSCLC progression, providing a new perspective on the understanding of molecular mechanisms for NSCLC progression.

Unconventional receptor functions and location-biased signaling of the lactate GPCR in the nucleus

G-protein-coupled receptors (GPCRs) are virtually involved in every physiological process. However, mechanisms for their ability to regulate a vast array of different processes remain elusive. An unconventional functional modality could at least in part account for such diverse involvements but has yet to be explored. We found HCAR1, a multifunctional lactate GPCR, to localize at the nucleus and therein capable of initiating location-biased signaling notably nuclear-ERK and AKT. We discovered that nuclear HCAR1 (N-HCAR1) is directly involved in regulating diverse processes. Specifically, N-HCAR1 binds to protein complexes that are involved in promoting protein translation, ribosomal biogenesis, and DNA-damage repair. N-HCAR1 also interacts with chromatin remodelers to directly regulate gene expression. We show that N-HCAR1 displays a broader transcriptomic signature than its plasma membrane counterpart. Interestingly, exclusion of HCAR1 from the nucleus has the same effect as its complete cellular depletion on tumor growth and metastasis in vivo. These results reveal noncanonical functions for a cell nucleus-localized GPCR that are distinct from traditional receptor modalities and through which HCAR1 can participate in regulating various cellular processes.

Disruptions in cellular communication: Molecular interplay between glutamate/NMDA signalling and MAPK pathways in neurological disorders

Neurological disorders significantly impact the central nervous system, contributing to a growing public health crisis globally. The spectrum of these disorders includes neurodevelopmental and neurodegenerative diseases. This manuscript reviews the crucial roles of cellular signalling pathways in the pathophysiology of these conditions, focusing primarily on glutaminase/glutamate/NMDA receptor signalling, alongside the mitogen-activated protein kinase (MAPK) pathways-ERK1/2, C-JNK, and P38 MAPK. Activation of these pathways is often correlated with neuronal excitotoxicity, apoptosis, and inflammation, leading to many other pathological conditions such as traumatic brain injury, stroke, and brain tumor. The interplay between glutamate overstimulation and MAPK signalling exacerbates neurodegenerative processes, underscoring the complexity of cellular communication in maintaining neuronal health. Dysfunctional signalling alters synaptic plasticity and neuronal survival, contributing to cognitive impairments in various neurological diseases. The manuscript emphasizes the potential of targeting these signalling pathways for therapeutic interventions, promoting neuroprotection and reducing neuroinflammation. Incorporating insights from precision medicine and innovative drug delivery systems could enhance treatment efficacy. Overall, understanding the intricate mechanisms of these pathways is essential for developing effective strategies to mitigate the impact of neurological disorders and improve patient outcomes. This review highlights the necessity for further exploration into these signalling cascades to facilitate advancements in therapeutic approaches, ensuring better prognoses for individuals affected by neurological conditions.

Virally mediated expression of a biologically active peptide to restrain the nuclear functions of ERK1/2 attenuates learning extinction but not acquisition

Peptide drug technologies offer powerful approaches to develop potent and selective lead molecules for therapeutic and research applications. However, new and optimized delivery approaches are necessary to overcome current pitfalls including fast degradation in cells and tissue. Extracellular signal-regulated kinases 1/2 (ERK1/2) exemplifies proteins that play crucial and varied roles within distinct cellular compartments. Here, we established an innovative method, based on viral vectors, which utilizes the endogenous biogenesis of neurotrophins to deliver and express a biologically active peptide to attenuate specifically ERK1/2 nuclear functions in specific brain area of the adult forebrain. In contrast to our hypothesis, nuclear functions of ERK1/2 in the forebrain are fundamental for the extinction of associative-aversive memories, but not for acquisition, nor for retrieval of these memories. Our research demonstrates the feasibility and applicability of viral vectors to deliver a peptide of interest to manipulate specific molecular processes and/or protein interactions in specific tissue.

The Principle of Cortical Development and Evolution

Human's robust cognitive abilities, including creativity and language, are made possible, at least in large part, by evolutionary changes made to the cerebral cortex. This paper reviews the biology and evolution of mammalian cortical radial glial cells (primary neural stem cells) and introduces the concept that a genetically step wise process, based on a core molecular pathway already in use, is the evolutionary process that has molded cortical neurogenesis. The core mechanism, which has been identified in our recent studies, is the extracellular signal-regulated kinase (ERK)-bone morphogenic protein 7 (BMP7)-GLI3 repressor form (GLI3R)-sonic hedgehog (SHH) positive feedback loop. Additionally, I propose that the molecular basis for cortical evolutionary dwarfism, exemplified by the lissencephalic mouse which originated from a larger gyrencephalic ancestor, is an increase in SHH signaling in radial glia, that antagonizes ERK-BMP7 signaling. Finally, I propose that: (1) SHH signaling is not a key regulator of primate cortical expansion and folding; (2) human cortical radial glial cells do not generate neocortical interneurons; (3) human-specific genes may not be essential for most cortical expansion. I hope this review assists colleagues in the field, guiding research to address gaps in our understanding of cortical development and evolution.

Shared molecular, cellular, and environmental hallmarks in cardiovascular disease and cancer: Any place for drug repurposing?

Cancer and cardiovascular disease (CVD) are the 2 biggest killers worldwide. Specific treatments have been developed for the 2 diseases. However, mutual therapeutic targets should be considered because of the overlap of cellular and molecular mechanisms. Cancer research has grown at a fast pace, leading to an increasing number of new mechanistic treatments. Some of these drugs could prove useful for treating CVD, which realizes the concept of cancer drug repurposing. This review provides a comprehensive outline of the shared hallmarks of cancer and CVD, primarily ischemic heart disease and heart failure. We focus on chronic inflammation, altered immune response, stromal and vascular cell activation, and underlying signaling pathways causing pathological tissue remodeling. There is an obvious scope for targeting those shared mechanisms, thereby achieving reciprocal preventive and therapeutic benefits. Major attention is devoted to illustrating the logic, advantages, challenges, and viable examples of drug repurposing and discussing the potential influence of sex, gender, age, and ethnicity in realizing this approach. Artificial intelligence will help to refine the personalized application of drug repurposing for patients with CVD. SIGNIFICANCE STATEMENT: Cancer and cardiovascular disease (CVD), the 2 biggest killers worldwide, share several underlying cellular and molecular mechanisms. So far, specific therapies have been developed to tackle the 2 diseases. However, the development of new cardiovascular drugs has been slow compared with cancer drugs. Understanding the intersection between pathological mechanisms of the 2 diseases provides the basis for repurposing cancer therapeutics for CVD treatment. This approach could allow the rapid development of new drugs for patients with CVDs.

Evaluation of CacyBP/SIP expression and its relationship with ERK1/2 and p38 kinase in testicular seminoma

Testicular cancer accounts for approximately 5 % of all urologic cancers. The most common histopathological diagnosis of testicular neoplastic lesions are germ cell tumors (90-95 % of cases), among which the majority of cases are seminomas, the most common malignant tumors among men aged 15-44. For better clinical diagnosis and treatment, it is important to understand the molecular mechanisms of tumor formation. In this study, the expression of the CacyBP/SIP protein and ERK1/2 and p38 kinases was analyzed for the first time in seminomas and normal testicular tissues. The research was carried out using archival tissue material from 30 patients undergoing surgery due to testicular seminoma, whereas the comparative material consisted of the adjacent normal tissues. Immunohistochemistry and qRT-PCR were used to identify the expression of CacyBP/SIP, ERK1/2, and p38. A marked weakening of the immunohistochemical reaction was observed in the cancerous tissue compared to the control tissue. PCR testing of the marked proteins confirmed their lower expression in seminoma. Our findings suggest the involvement of the CacyBP/SIP protein in the ERK1/2 and p38 signalling pathways, which may be involved in the processes of testicular seminoma carcinogenesis. The results of our research provide the basis for further research in this area.

Exploration of rutin derivatives as potential inhibitors of prostate cancer signaling pathways: A comprehensive in-silico study

Prostate cancer is a widespread health issue that affects men worldwide. It is one of the most common forms of cancer, and its development is influenced by a combination of hereditary, epigenetic, environmental, age, and lifestyle factors. Given that it is the second most common cause of cancer-related deaths in men, it is crucial to comprehend its complex facets. Present research especially targets the 3-kinase/protein kinase B, Epidermal Growth Factor Receptor, and extracellular signal-related kinase pathways, which are known to be significantly involved in prostate cancer progression. Here, Rutin derivatives were screened against selected prostate cancer targets. Molecular docking was performed to identify favorable interactions and the most promising compound. Further, Density functional theory, pharmacokinetics, Molecular dynamics simulation, principal component analysis, free energy landscape analysis, and Molecular Mechanics Poisson-Boltzmann Surface Area provided additional insights into selecting the best drug candidate. Among all the selected rutin derivatives, RU4b1 has potent inhibitory action. We also performed predictive analysis to identify the distinct metabolic sites within the structure of RU4b1. RU4b1 also exhibits drug-like properties and potent antioxidant activity. The findings were also compared with standard drugs and reference molecules of the respective proteins, and it is noteworthy that RU4b1 exhibited superior action compared to the standard drugs and reference molecules. This study aims to contribute valuable insights into developing targeted therapies for prostate cancer, emphasizing the potential of rutin derivatives as effective anti-cancer agents.

Study of the role of transmembrane emp24 domain-containing protein 2 in oral squamous cell carcinoma

OBJECTIVE

This study aimed to investigate the role of transmembrane emp24 domain-containing protein 2 (TMED2) in oral squamous cell carcinoma (OSCC).

METHODOLOGY

A bioinformatics analysis was first conducted to explore TMED2 expression in OSCC and its relation with overall survival. The analysis results were further verified by assessing TMED2 expression levels in human normal oral keratinocyte cells and human OSCC cell lines using quantitative real-time polymerase chain reaction and the Western blot. Finally, the effects of TMED2 knockdown and overexpression on the expression levels of TMED2, ADP-ribosylation factor 1, extracellular signal-regulated kinase ½, and phospho-extracellular signal-regulated kinase ½ proteins were examined in cells using the Western blot.

RESULTS

The GEPIA2 database showed that OSCC tissues expressed more TMED2 than normal tissues. At the cellular level, TMED2 expression significantly increased in SCC-4, HSC-3, and CAL-27 cells than in human normal oral keratinocyte cells. TMED2 knockdown reduced cell proliferation, increased the apoptosis rate in SCC-4 cells, and led to a higher proportion of cells in the G0/G1 phase and a lower proportion in the S phase.

CONCLUSION

TMED2 may promote OSCC cell proliferation and inhibit apoptosis, potentially by activation of the ADP-ribosylation factor 1/ extracellular signal-regulated kinase ½ signaling pathway.

Postoperative Tongqi Formula ameliorates postoperative ileus via p38 MAPK signaling pathway and metabolic disorder

Aim of the study

This study investigated the mechanism by which the Postoperative Tongqi Formula (PTQF) treats postoperative ileus (POI) through regulation of the p38 MAPK signaling pathway, Zona occludens 1 (ZO-1) protein, and metabolism.

Methods

The primary components of PTQF were characterized using UHPLC-Q-TOF-MS/MS. The identified compounds subsequently employed network pharmacology to predict the signaling pathways associated with the inflammatory phase of POI. The anti-inflammatory effects of PTQF were evaluated in vitro using RAW264.7 cells. A rat model of POI was used to assess efficacy based on the spleen index and charcoal powder propulsion rat in the small intestine. Furthermore, pathological damage to the small intestine was analyzed using hematoxylin and eosin (HE) staining as well as immunofluorescence to evaluate ZO-1 protein expression. Inflammatory cytokine levels were quantified using enzyme-linked immunosorbent assay (ELISA). Subsequently, Western blot analysis was performed to examine the p38 MAPK signaling pathway. Finally, a metabolomics approach was employed to analyze serum samples to identify potential metabolic pathways.

Results

A total of 130 chemical constituents were identified in PTQF. Following the network pharmacology analysis of these compounds, the p38 MAPK signaling pathway was chosen for further investigation. In vitro, PTQF effectively inhibited inflammatory responses in RAW264.7 cells. Results from the spleen index and charcoal powder propulsion rate indicated that PTQF alleviated the inflammatory phase of POI in rats by mitigating systemic and intestinal inflammation. This was supported by reduced levels of inflammatory factors, modulation of ZO-1 protein expression, and a decrease in p38 MAPK phosphorylation levels. Furthermore, serum metabolomics revealed nine differential metabolites linked to intestinal inflammation.

Conclusion

PTQF mitigates inflammation and intestinal damage in POI rats by modulating inflammatory factors, ZO-1 protein expression, the p38 MAPK signaling pathway, and metabolic disturbances.

Emerging targets in amyotrophic lateral sclerosis (ALS): The promise of ATP-binding cassette (ABC) transporter modulation

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative primarily affecting motor neurons, leading to disability and neuronal death, and ATP-Binding Cassette (ABC) transporter due to their role in drug efflux and modulation of various cellular pathways contributes to the pathogenesis of ALS. In this article, we extensively investigated various molecular and mechanistic pathways linking ALS transporter to the pathogenesis of ALS; this involves inflammatory pathways such as Mitogen-Activated Protein Kinase (MAPK), Phosphatidylinositol-3-Kinase/Protein Kinase B (PI3K/Akt), Toll-Like Receptor (TLR), Glycogen Synthase Kinase 3β (GSK-3β), Nuclear Factor Kappa-B (NF-κB), and Cyclooxygenase (COX). Oxidative pathways such as Astrocytes, Glutamate, Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), Sirtuin 1 (SIRT-1), Forkhead box protein O (FOXO), Extracellular signal-regulated kinase (ERK). Additionally, we delve into the role of autophagic pathways like TAR DNA-binding protein 43 (TDP-43), AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and lastly, the apoptotic pathways. Furthermore, by understanding these intricate interactions, we aim to develop novel therapeutic strategies targeting ABC transporters, improving drug delivery, and ultimately offering a promising avenue for treating ALS.

Research advances on CaMKs-mediated neurodevelopmental injury

Calcium/calmodulin-dependent protein kinases (CaMKs) are important proteins in the calcium signaling cascade response pathway, which can broadly regulate biological functions in vivo. Multifunctional CaMKs play key roles in neural development, including neuronal circuit building, synaptic plasticity establishment, and neurotrophic factor secretion. Currently, four familial proteins, calcium/calmodulin-dependent protein kinase I (CaMKI), calcium/calmodulin-dependent protein kinase II (CaMKII), eukaryotic elongation factor 2 kinase (eEF2K, popularly known as CaMKIII) and calcium/calmodulin-dependent protein kinase IV (CaMKIV), are thought to have been the most extensively studied during neurodevelopment. Although their spatial structures are extremely similar, as well as the initial starting point of activation, both require the activation of calcium and calmodulin (CaM) complexes to be involved in the process, and the phosphorylation sites and modes of each member are different. Furthermore, due to the high structural similarity of CaMKs, their members may play synergistic roles in the regulation of neural development, but different CaMKs also have their own means of regulating neural development. In this review, we first describe the visualized protein structural forms of CaMKI, CaMKII, eEF2K and CaMKIV, and then describe the functions of each kinase in neurodevelopment. After that, we focus on four main mechanisms of neurodevelopmental damage caused by CaMKs: CaMKI/ERK/CREB pathway inhibition leading to dendritic spine structural damage; Ca2+/CaM/CaMKII through induction of mitochondrial kinetic disorders leading to neurodevelopmental damage; CaMKIII/eEF2 hyperphosphorylation affects the establishment of synaptic plasticity; and CaMKIV/JNK/NF-κB through induction of an inflammatory response leading to neurodevelopmental damage. In conclusion, we briefly discuss the pathophysiological significance of aberrant CaMK family expression in neurodevelopmental disorders, as well as the protective effects of conventional CaMKII and CaMKIII antagonists against neurodevelopmental injury.

Roles of deubiquitinases in urologic cancers (Review)

Human health is endangered by the occurrence and progression of urological cancers, including renal cell carcinoma, prostate cancer and bladder cancer, which are usually associated with the activation of oncogenic factors and inhibition of cancer suppressors. The primary mechanism for protein breakdown in cells is the ubiquitin-proteasome system, whilst deubiquitinases contribute to the reversal of this process. However, both are important for protein homeostasis. Deubiquitination may also be involved in the control of the cell cycle, proliferation and apoptosis, and dysregulated deubiquitination is associated with the malignant transformation, invasion and metastasis of urologic malignancies. Therefore, a comprehensive summary of the mechanisms underlying deubiquitination in urological cancers may provide novel strategies and insights for diagnosis and treatment. The present review aimed to methodically clarify the role of deubiquitinating enzymes in urinary system cancers as well as their prospective application prospects for clinical treatment.

GCC2 promotes non-small cell lung cancer progression by maintaining Golgi apparatus integrity and stimulating EGFR signaling pathways

Fundamental changes in intracellular processes, such as overactive growth signaling pathways, are common in carcinomas and are targets of many cancer therapeutics. GRIP and coiled-coil containing 2 (GCC2) is a trans-Golgi network (TGN) golgin maintaining Golgi apparatus structure and regulating vesicle transport. Here, we found an aberrant overexpression of GCC2 in non-small cell lung cancer (NSCLC) and conducted shRNA-mediated gene knockdown to investigate the role of GCC2 in NSCLC progression. shRNA-mediated GCC2 knockdown suppressed NSCLC cell growth, migration, stemness, and epithelial-mesenchymal transition (EMT) in vitro and tumor growth in vivo. In addition, GCC2 knockdown suppressed cancer cell exosome secretion and the oncogenic capacity of cancer cell-derived exosomes. Mechanistically, GCC2 inhibition decreased epidermal growth factor receptor (EGFR) expression and downstream growth and proliferation signaling. Furthermore, GCC2 inhibition compromised Golgi structural integrity in cancer cells, indicating a functional role of GCC2 in regulating intracellular trafficking and signaling to promote lung cancer progression. Together, these findings suggest GCC2 as a potential therapeutic target for the treatment of NSCLC.

Oxidative Stress and Cancer Therapy: Controlling Cancer Cells Using Reactive Oxygen Species

Cancer is a multifaceted disease influenced by various mechanisms, including the generation of reactive oxygen species (ROS), which have a paradoxical role in both promoting cancer progression and serving as targets for therapeutic interventions. At low concentrations, ROS serve as signaling agents that enhance cancer cell proliferation, migration, and resistance to drugs. However, at elevated levels, ROS induce oxidative stress, causing damage to biomolecules and leading to cell death. Cancer cells have developed mechanisms to manage ROS levels, including activating pathways such as NRF2, NF-κB, and PI3K/Akt. This review explores the relationship between ROS and cancer, focusing on cell death mechanisms like apoptosis, ferroptosis, and autophagy, highlighting the potential therapeutic strategies that exploit ROS to target cancer cells.

Special Issue: MAPK Signaling Cascades in Human Health and Diseases

In order to survive and fulfil their functions, cells of any organism need to be able to respond to a large number of extracellular factors, also termed extracellular stimuli [...].

Melatonin receptor 1A variants as genetic cause of idiopathic osteoporosis

Idiopathic osteoporosis (IOP) is a rare form of early-onset osteoporosis diagnosed in patients with no known metabolic or hormonal cause of bone loss and unknown pathogenesis. Patients with IOP commonly report both childhood fractures and family history of osteoporosis, raising the possibility of genetic etiologies of IOP. Whole-exome sequencing analyses of different IOP cohorts identified multiple variants in melatonin receptor 1A (MTNR1A) with a potential pathogenic outcome. A rare MTNR1A variant (rs374152717) was found in members of an Ashkenazi Jewish family with IOP, and an MTNR1A variant (rs28383653) was found in a nonrelated female IOP cohort (4%). Both variants occur at a substantially higher frequency in Ashkenazi Jewish individuals than in the general population. We investigated consequences of the heterozygous (rs374152717) variant [MTNR1Ac.184+1G>T (MTNR1Ac.184+1G>T)] on bone physiology. A mouse model of the human rs374152717 variant reproduced the low bone mass (BM) phenotype of young-adult patients with IOP. Low BM occurred because of induction of senescence in mutant osteoblasts followed by compromised differentiation and function. In human cells, introduction of rs374152717 led to translation of a nonfunctional protein and subsequent dysregulation of melatonin signaling. These studies provide evidence that MTNR1A mutations entail a genetic etiology of IOP and establish the rs374152717 variant as a loss-of-function allele that impairs bone turnover by inducing senescence in osteoblasts. The higher prevalence of the MTNR1A variants identified in IOP cohorts versus the general population indicates a greater risk of IOP in those carrying these variants, especially Ashkenazi Jewish individuals bearing the rs374152717 variant.

Comprehensive analysis of CXCL10 and MIP-3a reveals their potential clinical application in hepatocellular carcinoma

Chemokines play a crucial role in the pathogenesis of patients with hepatocellular carcinoma (HCC). The expression levels of interferon-γ-induced protein-10 (CXCL10) and macrophage inflammatory protein-3α (MIP-3a) were investigated to clarify their clinical significance in HCC. The protein levels of CXCL10 and MIP-3a in the serum of 105 HBV-associated HCC patients, 50 patients with liver cirrhosis (LC), 50 patients with chronic hepatitis B (CHB) and 50 healthy donors (HC) were detected by liquid chip technology (Luminex) or ELISA. In addition, their mRNA levels were also determined in liver cancer and adjacent cancer tissue (paracancer; ParaCa) from 65 HCC patients. The online database UALCAN was used to analyze the association between CXCL10 and pathological manifestations of liver cancer. In addition, the diagnostic value of CXCL10/MIP-3a and AFP in HCC patients was determined by analyzing the Receiver Operating Characteristic Curve (ROC). The protein concentrations of CXCL10 and MIP-3a were significantly higher in the HCC group than in the LC, CHB and HC groups. CXCL10 in sera and liver cancer tissues is significantly positively correlated with ALT, but no significance between CXCL10 in ParaCa tissues and sera-ALT. Their mRNA is significantly higher in cancer tissues than in ParaCa tissues. The areas under the ROC curve of CXCL10, MIP-3a, CXCL10 and MIP-3a combined and AFP were 0.9169, 0.9261, 0.9299 and 0.7880, respectively. Elevated chemokines CXCL10 and MIP-3a in HCC patients may be associated with the clinical manifestation of HCC and could be a potential molecular marker for prognostic evaluation or a therapeutic target for HCC.

Targeting the p90RSK/MDM2/p53 Pathway Is Effective in Blocking Tumors with Oncogenic Up-Regulation of the MAPK Pathway Such as Melanoma and Lung Cancer

In most human tumors, the MAPK pathway is constitutively activated. Since p90RSK is downstream of MAPK, it is often hyperactive and capable of phosphorylating oncogenic substrates. We have previously shown that p90RSK phosphorylates MDM2 at S166, promoting p53 degradation in follicular thyroid carcinomas. Thus, the inhibition of p90RSK restores p53 expression, which in turn inhibits cell proliferation and promotes apoptosis. In the present study, we demonstrated that the p90RSK/MDM2/p53 pathway proved to be an excellent target in the therapy of tumors with MAPK hyperactivation. For this purpose, we selected p53wt melanoma, lung and medullary thyroid carcinoma cell lines with high activation of p90RSK. In these cell lines, we demonstrated that the p90RSK/MDM2/p53 pathway is implicated in the regulation of the cell cycle and apoptosis through p53-dependent transcriptional control of p21 and Bcl-2. Furthermore, with an immunohistochemical evaluation of primary melanomas and lung tumors, which exhibit highly activated p90RSK compared to corresponding normal tissue, we demonstrated that MDM2 stabilization was associated with p90RSK phosphorylation. The results indicate that p90RSK is able to control the proliferative rate and induction of apoptosis through the regulation of p53wt levels by stabilizing MDM2 in selected tumors with constitutively activated MAPKs, making p90RSK a new attractive target for anticancer therapy.

Potential Application of Plant-Derived Compounds in Multiple Sclerosis Management

Multiple sclerosis (MS) is a chronic autoimmune disorder characterized by inflammation, demyelination, and neurodegeneration, resulting in significant disability and reduced quality of life. Current therapeutic strategies primarily target immune dysregulation, but limitations in efficacy and tolerability highlight the need for alternative treatments. Plant-derived compounds, including alkaloids, phenylpropanoids, and terpenoids, have demonstrated anti-inflammatory effects in both preclinical and clinical studies. By modulating immune responses and promoting neuroregeneration, these compounds offer potential as novel adjunctive therapies for MS. This review provides insights into the molecular and cellular basis of MS pathogenesis, emphasizing the role of inflammation in disease progression. It critically evaluates emerging evidence supporting the use of plant-derived compounds to attenuate inflammation and MS symptomology. In addition, we provide a comprehensive source of information detailing the known mechanisms of action and assessing the clinical potential of plant-derived compounds in the context of MS pathogenesis, with a focus on their anti-inflammatory and neuroprotective properties.

Specific 3-O-sulfated heparan sulfate domains regulate salivary gland basement membrane metabolism and epithelial differentiation

Heparan sulfate (HS) regulation of FGFR function, which is essential for salivary gland (SG) development, is determined by the immense structural diversity of sulfated HS domains. 3-O-sulfotransferases generate highly 3-O-sulfated HS domains (3-O-HS), and Hs3st3a1 and Hs3st3b1 are enriched in myoepithelial cells (MECs) that produce basement membrane (BM) and are a growth factor signaling hub. Hs3st3a1;Hs3st3b1 double-knockout (DKO) mice generated to investigate 3-O-HS regulation of MEC function and growth factor signaling show loss of specific highly 3-O-HS and increased FGF/FGFR complex binding to HS. During development, this increases FGFR-, BM- and MEC-related gene expression, while in adult, it reduces MECs, increases BM and disrupts acinar polarity, resulting in salivary hypofunction. Defined 3-O-HS added to FGFR pulldown assays and primary organ cultures modulates FGFR signaling to regulate MEC BM synthesis, which is critical for secretory unit homeostasis and acinar function. Understanding how sulfated HS regulates development will inform the use of HS mimetics in organ regeneration.

Decoding the Role of Insulin-like Growth Factor 1 and Its Isoforms in Breast Cancer

Insulin-like Growth Factor-1 (IGF-1) is a crucial mitogenic factor with important functions in the mammary gland, mainly through its interaction with the IGF-1 receptor (IGF-1R). This interaction activates a complex signaling network that promotes cell proliferation, epithelial to mesenchymal transition (EMT) and inhibits apoptosis. Despite extensive research, the precise molecular pathways and intracellular mechanisms activated by IGF-1, in cancer, remain poorly understood. Recent evidence highlights the essential roles of IGF-1 and its isoforms in breast cancer (BC) development, progression, and metastasis. The peptides that define the IGF-1 isoforms-IGF-1Ea, IGF-1Eb, and IGF-1Ec-act as key points of convergence for various signaling pathways that influence the growth, metastasis and survival of BC cells. The aim of this review is to provide a detailed exami-nation of the role of the mature IGF-1 and its isoforms in BC biology and their potential use as possible therapeutical targets.

M2-like tumor-associated macrophage-secreted CCL2 facilitates gallbladder cancer stemness and metastasis

BACKGROUND

The predominant immune cells in solid tumors are M2-like tumor-associated macrophages (M2-like TAMs), which significantly impact the promotion of epithelial-mesenchymal transition (EMT) in tumors, enhancing stemness and facilitating tumor invasion and metastasis. However, the contribution of M2-like TAMs to tumor progression in gallbladder cancer (GBC) is partially known.

METHODS

Immunohistochemistry was used to evaluate the expression of M2-like TAMs and cancer stem cell (CSC) markers in 24 pairs of GBC and adjacent noncancerous tissues from patients with GBC. Subsequently, GBC cells and M2-like TAMs were co-cultured to examine the expression of CSC markers, EMT markers, and migratory behavior. Proteomics was performed on the culture supernatant of M2-like TAMs. The mechanisms underlying the induction of EMT, stemness, and metastasis in GBC by M2-like TAMs were elucidated using proteomics and transcriptomics. GBC cells were co-cultured with undifferentiated macrophages (M0) and analyzed. The therapeutic effect of gemcitabine combined with a chemokine (C-C motif) receptor 2 (CCR2) antagonist on GBC was observed in vivo.

RESULTS

The expression levels of CD68 and CD163 in M2-like TAMs and CD44 and CD133 in gallbladder cancer stem cells (GBCSCs) were increased and positively correlated in GBC tissues compared with those in neighboring noncancerous tissues. M2-like TAMs secreted a significant amount of chemotactic cytokine ligand 2 (CCL2), which activated the MEK/extracellular regulated protein kinase (ERK) pathway and enhanced SNAIL expression after binding to the receptor CCR2 on GBC cells. Activation of the ERK pathway caused nuclear translocation of ELK1, which subsequently led to increased SNAIL expression. GBCSCs mediated the recruitment and polarization of M0 into M2-like TAMs within the GBC microenvironment via CCL2 secretion. In the murine models, the combination of a CCR2 antagonist and gemcitabine efficiently inhibited the growth of subcutaneous tumors in GBC.

CONCLUSIONS

The interaction between M2-like TAMs and GBC cells is mediated by the chemokine CCL2, which activates the MEK/ERK/ELK1/SNAIL pathway in GBC cells, promoting EMT, stemness, and metastasis. A combination of a CCR2 inhibitor and gemcitabine effectively suppressed the growth of subcutaneous tumors. Consequently, our study identified promising therapeutic targets and strategies for treating GBC.

Exportin 1 governs the immunosuppressive functions of myeloid-derived suppressor cells in tumors through ERK1/2 nuclear export

Myeloid-derived suppressor cells (MDSCs) are a main driver of immunosuppression in tumors. Understanding the mechanisms that determine the development and immunosuppressive function of these cells could provide new therapeutic targets to improve antitumor immunity. Here, using preclinical murine models, we discovered that exportin 1 (XPO1) expression is upregulated in tumor MDSCs and that this upregulation is induced by IL-6-induced STAT3 activation during MDSC differentiation. XPO1 blockade transforms MDSCs into T-cell-activating neutrophil-like cells, enhancing the antitumor immune response and restraining tumor growth. Mechanistically, XPO1 inhibition leads to the nuclear entrapment of ERK1/2, resulting in the prevention of ERK1/2 phosphorylation following the IL-6-mediated activation of the MAPK signaling pathway. Similarly, XPO1 blockade in human MDSCs induces the formation of neutrophil-like cells with immunostimulatory functions. Therefore, our findings revealed a critical role for XPO1 in MDSC differentiation and suppressive functions; exploiting these new discoveries revealed new targets for reprogramming immunosuppressive MDSCs to improve cancer therapeutic responses.

Overcoming Vemurafenib Resistance in Metastatic Melanoma: Targeting Integrins to Improve Treatment Efficacy

Metastatic melanoma, a deadly form of skin cancer, often develops resistance to the BRAF inhibitor drug vemurafenib, highlighting the need for understanding the underlying mechanisms of resistance and exploring potential therapeutic strategies targeting integrins and TGF-β signalling. In this study, the role of integrins and TGF-β signalling in vemurafenib resistance in melanoma was investigated, and the potential of combining vemurafenib with cilengitide as a therapeutic strategy was investigated. In this study, it was found that the transcription of PAI1 and p21 was induced by acquired vemurafenib resistance, and ITGA5 levels were increased as a result of this resistance. The transcription of ITGA5 was mediated by the TGF-β pathway in the development of vemurafenib resistance. A synergistic effect on the proliferation of vemurafenib-resistant melanoma cells was observed with the combination therapy of vemurafenib and cilengitide. Additionally, this combination therapy significantly decreased invasion and colony formation in these resistant cells. In conclusion, it is suggested that targeting integrins and TGF-β signalling, specifically ITGA5, ITGB3, PAI1, and p21, may offer promising approaches to overcoming vemurafenib resistance, thereby improving outcomes for metastatic melanoma patients.

The role of periodontitis in cancer development, with a focus on oral cancers

Periodontitis is a severe gum infection that begins as gingivitis and can lead to gum recession, bone loss, and tooth loss if left untreated. It is primarily caused by bacterial infection, which triggers inflammation and the formation of periodontal pockets. Notably, periodontitis is associated with systemic health issues and has been linked to heart disease, diabetes, respiratory diseases, adverse pregnancy outcomes, and cancers. Accordingly, the presence of chronic inflammation and immune system dysregulation in individuals with periodontitis significantly contributes to the initiation and progression of various cancers, particularly oral cancers. These processes promote genetic mutations, impair DNA repair mechanisms, and create a tumor-supportive environment. Moreover, the bacteria associated with periodontitis produce harmful byproducts and toxins that directly damage the DNA within oral cells, exacerbating cancer development. In addition, chronic inflammation not only stimulates cell proliferation but also inhibits apoptosis, causes DNA damage, and triggers the release of pro-inflammatory cytokines. Collectively, these factors play a crucial role in the progression of cancer in individuals affected by periodontitis. Further, specific viral and bacterial agents, such as hepatitis B and C viruses, human papillomavirus (HPV), Helicobacter pylori (H. pylori), and Porphyromonas gingivalis, contribute to cancer development through distinct mechanisms. Bacterial infections have systemic implications for cancer development, while viral infections provoke immune and inflammatory responses that can lead to genetic mutations. This review will elucidate the link between periodontitis and cancers, particularly oral cancers, exploring their underlying mechanisms to provide insights for future research and treatment advancements.

Personalizing Therapy Outcomes through Mitogen-Activated Protein Kinase Pathway Inhibition in Non-Small Cell Lung Cancer

Lung cancer (LC) is a highly invasive malignancy and the leading cause of cancer-related deaths, with non-small cell lung cancer (NSCLC) as its most prevalent histological subtype. Despite all breakthroughs achieved in drug development, the prognosis of NSCLC remains poor. The mitogen-activated protein kinase signaling cascade (MAPKC) is a complex network of interacting molecules that can drive oncogenesis, cancer progression, and drug resistance when dysregulated. Over the past decades, MAPKC components have been used to design MAPKC inhibitors (MAPKCIs), which have shown varying efficacy in treating NSCLC. Thus, recent studies support the potential clinical use of MAPKCIs, especially in combination with other therapeutic approaches. This article provides an overview of the MAPKC and its inhibitors in the clinical management of NSCLC. It addresses the gaps in the current literature on different combinations of selective inhibitors while suggesting two particular therapy approaches to be researched in NSCLC: parallel and aggregate targeting of the MAPKC. This work also provides suggestions that could serve as a potential guideline to aid future research in MAPKCIs to optimize clinical outcomes in NSCLC.

GPR168 functions as a tumor suppressor in mouse melanoma by restraining Akt signaling pathway

Malignant melanoma (MM) is a malignant tumor associated with high mortality rates and propensity for metastasis. Despite advancement in treatment, the incidence of MM continue to rise globally. GPR168, also known as MrgprF, is a MAS related GPR family member. The low expression of GPR168 has also been reported in many malignant tumors including MM. In the study, the statistical analysis from The Cancer Genome Atlas (TCGA) revealed a significant down regulation of GPR168 in melanoma compared to normal melanocytes, underscoring its importance in MM. The aim of the present study is to investigate the affect of GPR168 overexpression and elucidate its molecular mechanisms in MM cells. In addition, we used mouse melanoma B16-F10 cell line and xenograph tumor model to explore the function of GPR168 in melanoma. Our findings demonstrate that GPR168 overexpression could inhibit B16-F10 cell proliferation, migration, and xenografts tumor growth. Further, mechanistic studies revealed that GPR168 affected B16-F10 progress through Akt signal pathway with the decreased expression of p-Akt, p-GSK-3β, β-catenin, Myc, CyclinD1 and CDK4. In order to validate these findings, a rescue experiment was formulated employing GPR168 polyclonal antibody (Anti-GPR168 pAbs) to block GPR168 functionality. The addition of Anti-GPR168 pAbs into the culture medium restored both cell proliferation and migration. In conclusion, the overexpression of GPR168 in mouse melanoma B16-F10 cells suppressed proliferation and migration through the Akt signaling pathway. These findings collectively propose GPR168 as a promising novel tumor suppressor in MM, suggesting its potential as a therapeutic target in future interventions.

PLCβ1 by-passes early growth response -1 to induce the differentiation of neuronal cells

The Gαq/phospholipase C-β (PLCβ) signaling system mediates calcium responses to a variety of hormones and neurotransmitters. Recent studies suggest that PLCβ1 expression plays a role in the differentiation of two types of cultured neuronal cells (PC12 and SK-N-SH) through a mechanism independent of Gαq. Here, we show that, similar to that observed in PC12 and SK-N-SH cells, PLCβ1 expression increases when human NT2 cells are induced to differentiate either through cytosine-β-D-arabinofuranoside or retinoic acid. Preventing this increase, abolishes differentiation, and down-regulating PLCβ1 in rat primary astrocytes causes cells to adapt an undifferentiated morphology. Surprisingly, transfecting PLCβ1 into undifferentiated PC12 or NT2 cells induces differentiation without the need for differentiating agents. Studies to uncover the underlying mechanism focused on the transcription factor early growth response 1 (Egr-1) which mediates PLCβ1 expression early in differentiation. Over-expressing PLCβ1 in HEK293 cells enhances Egr-1 expression and induces morphological changes. We show that increased levels of cytosolic PLCβ1 in undifferentiated PC12 cells disrupts the association between Egr-1 and its cytosolic binding partner (Tar RNA binding protein), promoting relocalization of Egr-1 to the nucleus, which promotes transcription of proteins needed for differentiation. These studies show a novel mechanism through which differentiation can be modulated.

Simulating BRAFV600E-MEK-ERK signalling dynamics in response to vertical inhibition treatment strategies

In vertical inhibition treatment strategies, multiple components of an intracellular pathway are simultaneously inhibited. Vertical inhibition of the BRAFV600E-MEK-ERK signalling pathway is a standard of care for treating BRAFV600E-mutated melanoma where two targeted cancer drugs, a BRAFV600E-inhibitor, and a MEK inhibitor, are administered in combination. Targeted therapies have been linked to early onsets of drug resistance, and thus treatment strategies of higher complexities and lower doses have been proposed as alternatives to current clinical strategies. However, finding optimal complex, low-dose treatment strategies is a challenge, as it is possible to design more treatment strategies than are feasibly testable in experimental settings. To quantitatively address this challenge, we develop a mathematical model of BRAFV600E-MEK-ERK signalling dynamics in response to combinations of the BRAFV600E-inhibitor dabrafenib (DBF), the MEK inhibitor trametinib (TMT), and the ERK-inhibitor SCH772984 (SCH). From a model of the BRAFV600E-MEK-ERK pathway, and a set of molecular-level drug-protein interactions, we extract a system of chemical reactions that is parameterised by in vitro data and converted to a system of ordinary differential equations (ODEs) using the law of mass action. The ODEs are solved numerically to produce simulations of how pathway-component concentrations change over time in response to different treatment strategies, i.e., inhibitor combinations and doses. The model can thus be used to limit the search space for effective treatment strategies that target the BRAFV600E-MEK-ERK pathway and warrant further experimental investigation. The results demonstrate that DBF and DBF-TMT-SCH therapies show marked sensitivity to BRAFV600E concentrations in silico, whilst TMT and SCH monotherapies do not.

Targeted therapy, immunotherapy, and small molecules and peptidomimetics as emerging immunoregulatory agents for melanoma

Primary cutaneous melanoma is the most lethal of all skin neoplasms and its incidence is increasing. Clinical management of advanced melanoma in the last decade has been revolutionised by the availability of immunotherapies and targeted therapies, used alone and in combination. This article summarizes advances in the treatment of late-stage melanoma including use of protein kinase inhibitors, antibody-based immune checkpoint inhibitors, adoptive immunotherapy, vaccines and more recently, small molecules and peptidomimetics as emerging immunoregulatory agents.

Inhibition of MEK Signaling Attenuates Cancer Stem Cell Activity in Anaplastic Thyroid Cancer

Background: Anaplastic thyroid cancer (ATC) is highly aggressive and has very limited treatment options. Recent studies suggest that cancer stem cell (CSC) activity in ATC could underlie this recurrence and resistance to treatment. The recent approval by the U.S. Food and Drug Administration of the combined treatment of BRAF and MEK inhibitors for ATC patients has shown some efficacy in patients harboring the BRAFV600E mutation. However, it was unknown whether the combined treatment could affect the CSC activity. This study explores the effects of the BRAF and MEK inhibitors on CSC activity in human ATC cells. Methods: Using three human ATC cells, THJ-11T, THJ-16T, and 8505C cells, we evaluated the effects of dabrafenib (a BRAF kinase inhibitor), trametinib (an MEK inhibitor), or a combined treatment of the two drugs on the CSC activity by tumorsphere formation, Aldefluor assays, expression profiles of key CSC markers, immunohistochemistry, and in vivo xenograft mouse models. Furthermore, we also used confocal imaging to directly visualize the effects on drugs on CSCs by the SORE6-mCherry reporter in cultured cells and xenograft tumor cells. Results: The BRAF inhibitor, dabrafenib, had weak efficacy, while the MEK inhibitor, trametinib, showed strong efficacy in attenuating the CSC activity, as evidenced by suppression of CSC marker expression, tumorsphere formation, and Aldefluor assays. Using ATC cells expressing a fluorescent CSC SORE6 reporter, we showed reduction of CSC activity in the rank order of combined > trametinib > dabrafenib through in vitro and in vivo xenograft models. Molecular analyses showed that suppression of CSC activity by these drugs was, in part, mediated by attenuation of the transcription by dampening the RNA polymerase II activity. Conclusions: Our analyses demonstrated the presence of CSCs in ATC cells. The inhibition of CSC activity by the MEK signaling could partially account for the efficacy of the combined treatment shown in ATC patients. However, our studies also showed that not all CSC activity was totally abolished, which may account for the recurrence observed in ATC patients. Our findings have provided new insights into the molecular basis of efficacy and limitations of these drugs in ATC patients.

A chemical magnet: Approaches to guide precise protein localization

Small molecules that chemically induce proximity between two proteins have been widely used to precisely modulate protein levels, stability, and activity. Recently, several studies developed novel strategies that employ heterobifunctional molecules that co-opt shuttling proteins to control the spatial localization of a target protein, unlocking new potential within this domain. Together, these studies lay the groundwork for novel targeted protein relocalization modalities that can rewire the protein circuitry and interactome to influence biological outcomes.

DOCK1 regulates the malignant biological behavior of endometrial cancer through c-Raf/ERK pathway

BACKGROUND

The effect of DOCK1 gene on the biological behavior of endometrial carcinoma cells and its related pathway has not been reported.

METHODS

The immunohistochemical method and western blot were utilized to analyze DOCK1 protein expression in endometrial tissues and cells, respectively. CCK-8, BrdU, transwell and flow cytometry were performed to analyze the effect of DOCK1 expression changes on the viability, proliferation, invasion, migration and apoptosis of endometrial cancer cells, respectively. The effects of DOCK1 gene on Bcl-2, MMP9, Ezrin, E-cadherin and c-RAF/ERK1/2 signaling pathway were evaluated by western blot. The xenograft models were constructed to analyze the effect of DOCK1 in vivo.

RESULTS

DOCK1 expression was increased in endometrial cancer tissues and cells compared with those in normal adjacent tissues and cells. DOCK1 knockout could inhibit the malignant biological behavior of endometrial cancer cells, while DOCK1 overexpression played the opposite effect. The expression of E-cadherin was upregulated and those of MMP9, Ezrin, Bcl-2, p-c-RAF (S338) and p-ERK1/2 (T202/Y204) were downregulated after DOCK1 knockout, while DOCK1 overexpression played the opposite effect. Additionally, Raf inhibitor LY3009120 reversed the function of DOCK1 on malignant biological behavior. In vivo experiment results showed that the growth and weight of transplanted tumors in nude mice were inhibited after DOCK1 knockout. The changes of E-cadherin, MMP9, Ezrin and Bcl-2 expressions in the transplanted tumors were consistent with those in vitro.

CONCLUSION

DOCK1 could enhance the malignant biological behavior of endometrial cancer cells, which might be through c-RAF/ERK1/2 signaling pathways in vitro and in vivo.

Sacubitril/valsartan inhibits the proliferation of vascular smooth muscle cells through notch signaling and ERK1/2 pathway

AIMS

To explore the role and mechanism of Notch signaling and ERK1/2 pathway in the inhibitory effect of sacubitril/valsartan on the proliferation of vascular smooth muscle cells (VSMCs).

MAIN METHODS

Human aortic vascular smooth muscle cells (HA-VSMCs) were cultured in vitro. The proliferating VSMCs were divided into three groups as control group, Ang II group and Ang II + sacubitril/valsartan group. Cell proliferation and migration were detected by CCK8 and scratch test respectively. The mRNA and protein expression of PCNA, MMP-9, Notch1 and Jagged-1 were detected by qRT-PCR and Western blot respectively. The p-ERK1/2 expression was detected by Western blot.

KEY FINDINGS

Compared with the control group, proliferation and migration of VSMCs and the expression of PCNA, MMP-9, Notch1, Jagged-1 and p-ERK1/2 was increased in Ang II group. Sacubitril/valsartan significantly reduced the proliferation and migration. Additionally, pretreatment with sacubitril/valsartan reduced the PCNA, MMP-9, Notch1, Jagged-1 and p-ERK1/2 expression.

Two Main Cancer Biomarkers as Molecular Targets of Binase Antitumor Activity

Cancer is frequently coupled with the disturbance of key signaling pathways. Aberrant activation of the mitogen-activated protein kinase (MAPK) signaling cascade, occurring in over 85% of cancers, is mainly caused by the genetic alterations of its main components-oncogenes EGFR and RAS, and plays a crucial role in cell fate. The importance of EGFR and RAS proteins in a variety of tumors suggests that they would be good therapeutic targets, but at present, no effective targeted therapy against these two oncogenes has been proven. Here, we show that ribonuclease from Bacillus pumilus (binase) inhibits MAPK signaling through direct interaction with EGFR and RAS proteins. This effect contributes to the antitumor potential of binase along with its enzymatic activity. Multitargeticity of binase prevents the development of drug resistance, which is considered a major obstacle to effective anticancer treatment.

Scoparone attenuates PD-L1 expression in human breast cancer cells by MKP-3 upregulation

Breast cancer is a frequently occurring malignant tumor that is one of the leading causes of cancer-related deaths in women worldwide. Monoclonal antibodies that block programed cell death 1 (PD-1)/programed cell death ligand 1 (PD-L1) - a typical immune checkpoint - are currently the recommended standard therapies for many advanced and metastatic tumors such as triple-negative breast cancer. However, some patients develop drug resistance, leading to unfavorable treatment outcomes. Therefore, other approaches are required for anticancer treatments, such as downregulation of PD-L1 expression and promotion of degradation of PD-L1. Scoparone (SCO) is a bioactive compound isolated from Artemisia capillaris that exhibits antitumor activity. However, the effect of SCO on PD-L1 expression in cancer has not been confirmed yet. This study aimed to evaluate the role of SCO in PD-L1 expression in breast cancer cells in vitro. Our results show that SCO downregulated PD-L1 expression in a dose-dependent manner, via AKT inhibition. Interestingly, SCO treatment did not alter PTEN expression, but increased the expression of mitogen-activated protein kinase phosphatase-3 (MKP-3). In addition, the SCO-induced decrease in PD-L1 expression was reversed by siRNA-mediated MKP-3 knockdown. Collectively, these findings suggest that SCO inhibited the expression of PD-L1 in breast cancer cells by upregulating MKP-3 expression. Therefore, SCO may serve as an innovative combinatorial agent for cancer immunotherapy.

Calothrixin B derivatives induce apoptosis and cell cycle arrest on HEL cells through the ERK/Ras/Raf/MEK pathway

BACKGROUND

Acute erythroleukemia (AEL) is acute myeloid leukemia characterized by malignant erythroid proliferation. AEL has a low survival rate, which has seriously threatened the health of older adults. Calothrixin B is a carbazole alkaloid isolated from the cyanobacteria Calothrix and exhibits anti-cancer activity. To discover more potential anti-erythroleukemia compounds, we used calothrixin B as the structural skeleton to synthesize a series of new compounds.

METHODS

In the cell culture model, we evaluated apoptosis and cell cycle arrest using MTT assay, flow cytometry analysis, JC-1 staining, Hoechst 33258 staining, and Western blot. Additionally, assessing the curative effect in the animal model included observation of the spleen, HE staining, flow cytometry analysis, and detection of serum biochemical indexes.

RESULTS

Among the Calothrixin B derivatives, H-107 had the best activity against leukemic cell lines. H-107 significantly inhibited the proliferation of HEL cells with an IC50 value of 3.63 ± 0.33 μM. H-107 induced apoptosis of HEL cells by damaging mitochondria and activating the caspase cascade and arrested HEL cells in the G0/G1 phase. Furthermore, H-107 downregulated the protein levels Ras, p-Raf, p-MEK, p-ERK and c-Myc. Pretreatment with ERK inhibitor (U0126) increased H-107-induced apoptosis. Thus, H-107 inhibited the proliferation of HEL cells by the ERK /Ras/Raf/MEK signal pathways. Interestingly, H-107 promoted erythroid differentiation into the maturation of erythrocytes and effectively activated the immune cells in erythroleukemia mice.

CONCLUSION

Overall, our findings suggest that H-107 can potentially be a novel chemotherapy for erythroleukemia.

ADAMTS Proteases: Their Multifaceted Role in the Regulation of Cancer Metastasis

Cancer leads to nearly 10 million deaths worldwide per year. The tumour microenvironment (TME) is fundamental for tumour growth and progression. A key component of the TME, the extracellular matrix (ECM) has recently become a focus of interest in cancer research. Dysregulation of ECM synthesis and proteolysis leads to uncontrolled tumour growth and metastasis. Matrix remodelling enzymes, secreted by cancer cells and stromal cells, modify the overall structure and organisation of ECM proteins, therefore influencing biochemical interactions, tissue integrity and tissue turnover. While A Disintegrin and Metalloproteinases (ADAMs)' and matrix metalloproteinases' role in cancer has been deeply investigated, other proteolytic enzymes, like ADAMs with thrombospondin(-like) motifs (ADAMTSs) have been gaining interest due to their roles in modulating cancer cell-ECM interactions and oncogenic signalling pathways. In this review, we will discuss the dysregulation of ADAMTSs in cancer and their roles in regulating cancer development and progression, via ECM remodelling and cell signalling modulation.

Alternative Splicing Landscape of Head and Neck Squamous Cell Carcinoma

Head and neck malignancies are a significant global health concern, with head and neck squamous cell carcinoma (HNSCC) being the sixth most common cancer worldwide accounting for > 90% of cases. In recent years, there has been growing recognition of the potential role of alternative splicing (AS) in the etiology of cancer. Increasing evidence suggests that AS is associated with various aspects of cancer progression, including tumor occurrence, invasion, metastasis, and drug resistance. Additionally, AS is involved in shaping the tumor microenvironment, which plays a crucial role in tumor development and response to therapy. AS can influence the expression of factors involved in angiogenesis, immune response, and extracellular matrix remodeling, all of which contribute to the formation of a supportive microenvironment for tumor growth. Exploring the mechanism of AS events in HNSCC could provide insights into the development and progression of this cancer, as well as its interaction with the tumor microenvironment. Understanding how AS contributes to the molecular changes in HNSCC cells and influences the tumor microenvironment could lead to the identification of new therapeutic targets. Targeted chemotherapy and immunotherapy strategies tailored to the specific AS patterns in HNSCC could potentially improve treatment outcomes and reduce side effects. This review explores the concept, types, processes, and technological advancements of AS, focusing on its role in the initiation, progression, treatment, and prognosis of HNSCC.

Biased Dopamine D2 Receptors Exhibit Distinct Intracellular Trafficking Properties and ERK Activation in Different Subcellular Domains

Biased signaling or functional selectivity refers to the ability of an agonist or receptor to selectively activate a subset of transducers such as G protein and arrestin in the case of G protein-coupled receptors (GPCRs). Although signaling through arrestin has been reported from various GPCRs, only a few studies have examined side-by-side how it differs from signaling via G protein. In this study, two signaling pathways were compared using dopamine D2 receptor (D2R) mutants engineered via the evolutionary tracer method to selectively transduce signals through G protein or arrestin (D2G and D2Arr, respectively). D2G mediated the inhibition of cAMP production and ERK activation in the cytoplasm. D2Arr, in contrast, mediated receptor endocytosis accompanied by arrestin ubiquitination and ERK activation in the nucleus as well as in the cytoplasm. D2Arr-mediated ERK activation occurred in a manner dependent on arrestin3 but not arrestin2, accompanied by the nuclear translocation of arrestin3 via importin1. D2R-mediated ERK activation, which occurred in both the cytosol and nucleus, was limited to the cytosol when cellular arrestin3 was depleted. This finding supports the results obtained with D2Arr and D2G. Taken together, these observations indicate that biased signal transduction pathways activate distinct downstream mechanisms and that the subcellular regions in which they occur could be different when the same effectors are involved. These findings broaden our understanding on the relation between biased receptors and the corresponding downstream signaling, which is critical for elucidating the functional roles of biased pathways.

A guide to ERK dynamics, part 2: downstream decoding

Signaling by the extracellular signal-regulated kinase (ERK) pathway controls many cellular processes, including cell division, death, and differentiation. In this second installment of a two-part review, we address the question of how the ERK pathway exerts distinct and context-specific effects on multiple processes. We discuss how the dynamics of ERK activity induce selective changes in gene expression programs, with insights from both experiments and computational models. With a focus on single-cell biosensor-based studies, we summarize four major functional modes for ERK signaling in tissues: adjusting the size of cell populations, gradient-based patterning, wave propagation of morphological changes, and diversification of cellular gene expression states. These modes of operation are disrupted in cancer and other related diseases and represent potential targets for therapeutic intervention. By understanding the dynamic mechanisms involved in ERK signaling, there is potential for pharmacological strategies that not only simply inhibit ERK, but also restore functional activity patterns and improve disease outcomes.

Nuclear ERK1/2 signaling potentiation enhances neuroprotection and cognition via Importinα1/KPNA2

Cell signaling is central to neuronal activity and its dysregulation may lead to neurodegeneration and cognitive decline. Here, we show that selective genetic potentiation of neuronal ERK signaling prevents cell death in vitro and in vivo in the mouse brain, while attenuation of ERK signaling does the opposite. This neuroprotective effect mediated by an enhanced nuclear ERK activity can also be induced by the novel cell penetrating peptide RB5. In vitro administration of RB5 disrupts the preferential interaction of ERK1 MAP kinase with importinα1/KPNA2 over ERK2, facilitates ERK1/2 nuclear translocation, and enhances global ERK activity. Importantly, RB5 treatment in vivo promotes neuroprotection in mouse models of Huntington's (HD), Alzheimer's (AD), and Parkinson's (PD) disease, and enhances ERK signaling in a human cellular model of HD. Additionally, RB5-mediated potentiation of ERK nuclear signaling facilitates synaptic plasticity, enhances cognition in healthy rodents, and rescues cognitive impairments in AD and HD models. The reported molecular mechanism shared across multiple neurodegenerative disorders reveals a potential new therapeutic target approach based on the modulation of KPNA2-ERK1/2 interactions.