Discovery of Raf Family Is a Milestone in Deciphering the Ras-Mediated Intracellular Signaling Pathway

Targeting the RAS upstream and downstream signaling pathway for cancer treatment

Cancer often involves the overactivation of RAS/RAF/MEK/ERK (MAPK) and PI3K-Akt-mTOR pathways due to mutations in genes like RAS, RAF, PTEN, and PIK3CA. Various strategies are employed to address the overactivation of these pathways, among which targeted therapy emerges as a promising approach. Directly targeting specific proteins, leads to encouraging results in cancer treatment. For instance, RTK inhibitors such as imatinib and afatinib selectively target these receptors, hindering ligand binding and reducing signaling initiation. These inhibitors have shown potent efficacy against Non-Small Cell Lung Cancer. Other inhibitors, like lonafarnib targeting Farnesyltransferase and GGTI 2418 targeting geranylgeranyl Transferase, disrupt post-translational modifications of proteins. Additionally, inhibition of proteins like SOS, SH2 domain, and Ras demonstrate promising anti-tumor activity both in vivo and in vitro. Targeting downstream components with RAF inhibitors such as vemurafenib, dabrafenib, and sorafenib, along with MEK inhibitors like trametinib and binimetinib, has shown promising outcomes in treating cancers with BRAF-V600E mutations, including myeloma, colorectal, and thyroid cancers. Furthermore, inhibitors of PI3K (e.g., apitolisib, copanlisib), AKT (e.g., ipatasertib, perifosine), and mTOR (e.g., sirolimus, temsirolimus) exhibit promising efficacy against various cancers such as Invasive Breast Cancer, Lymphoma, Neoplasms, and Hematological malignancies. This review offers an overview of small molecule inhibitors targeting specific proteins within the RAS upstream and downstream signaling pathways in cancer.

Biological functions and potential mechanisms of miR‑143‑3p in cancers (Review)

In recent years, microRNAs (miRNAs or miRs) have been increasingly studied for their role in cancer and have shown potential as cancer biomarkers. miR‑143‑3p and miR‑143‑5p are the mature miRNAs derived from pre‑miRNA‑143. At present, there are numerous studies on the function of miR‑143‑3p in cancer progression, but there are no systematic reviews describing the function of miR‑143‑3p in cancer. It is widely considered that miR‑143‑3p is downregulated in most malignant tumors and that upstream regulators can act on this gene, which in turn regulates the corresponding target to act on the tumor. In addition, miRNA‑143‑3p can regulate target genes to affect the biological process of tumors through various signaling pathways, such as the PI3K/Akt, Wnt/β‑catenin, AKT/STAT3 and Ras‑Raf‑MEK‑ERK pathways. The present review comprehensively described the biogenesis of miR‑143‑3p, the biological functions of miR‑143‑3p and the related roles and mechanisms in different cancer types. The potential of miR‑143‑3p as a biomarker for cancer was also highlighted and valuable future research directions were discussed.

Recent advancements in the small-molecule drugs for hepatocellular carcinoma (HCC): Structure-activity relationships, pharmacological activities, and the clinical trials

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world and the sixth leading cause of cancer death worldwide, and it is urgent to find safe and effective drugs for treatment. As an important therapeutic method, small-molecule drugs are continually being updated to achieve improved therapeutic effects. The purpose of this study was to investigate the structural effects of various FDA-listed small-molecule drugs sorafenib, cabozantinib, lenvatinib, and regorafenib on the corresponding HCC targets and possible structural optimization methods, and to explore the mechanism for identifying potential therapeutic drugs that offer better efficacy and fewer side effects.

METHODS

The structure-activity relationship, pharmacological actions, and clinical applications of small-molecule drugs were reviewed by referencing MEDLINE, Web of Science, CNKI, and other databases, summarizing and integrating the relevant content.

RESULTS

The results showed that small-molecule drugs can inhibit HCC primarily by forming hydrogen bonds with Glu885, Asp1046, and Cys919 on the HCC target. HCC can be targeted by inhibiting the activation of multiple pathways, blocking the conduction of downstream signaling, and reducing the formation of tumor blood vessels. In general, small-molecule drugs primarily target four key receptors in HCC: VEGFR, PDGFR, EGFR, and FGFR, to achieve effective treatment.

CONCLUSIONS

By revealing their structure-activity relationships, pharmacological actions, and clinical trials, small-molecule drugs can offer broad prospects for the development of new medications.

DEPDC1 affects autophagy-dependent glycolysis levels in human osteosarcoma cells by modulating RAS/ERK signaling through TTK

The current treatment for osteosarcoma (OS) is based on surgery combined with systemic chemotherapy, however, gene therapy has been hypothesized to improve patient survival rates. The density-enhanced protein domain 1 protein (DEPDC1) functions as a crucial determinant in the advancement of OS, which is highly expressed in OS cells. The current study was designed to delve into the effect and mechanism of DEPDC1 and phosphotyrosine-picked threonine tyrosine kinase (TTK) in OS. The expression of DEPDC1 and TTK in OS cells was detected by western blotting. Furthermore, the assessment of glycolysis encompassed the quantification of extracellular acidification rate, glucose uptake rate, lactate concentration, and the expression of glucose transporter 1, hexokinase 2, and pyruvate kinase M2. Finally, the functions of DEPDC1 and TTK in autophagy and ras-extracellular signal-regulated kinase signaling were determined by western blotting after interfering with DEPDC1 in SaOS-2 cells. The results revealed that DEPDC1 and TTK were upregulated in OS cell lines and interfering with DEPDC1 inhibited glycolysis and autophagy in OS cells. Furthermore, the STRING database suggested that DEPDC1 and TTK perform targeted binding. Notably, the results of the present study revealed that DEPDC1 upregulated RAS expression through TTK and enhanced ERK activity, thereby affecting glycolysis and autophagy in OS cells. Collectively, the present investigation demonstrated that DEPDC1 affected autophagy-dependent glycolysis levels of OS cells by regulating RAS/ERK signaling through TTK.

BRAF Expression and Copy Number Alterations Predict Unfavorable Tumor Features and Adverse Outcomes in Patients With Breast Cancer

Background: The role of BRAF in breast cancer pathogenesis is still unclear. To address this knowledge gap, this study is aimed at evaluating the impact of BRAF gene expression and copy number alterations (CNAs) on clinicopathologic characteristics and survival in patients with breast cancer. Methods: The Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) dataset was obtained from the cBioPortal public domain. Tumoral BRAF mRNA expression and CNAs along with demographic and tumor data for patients with breast cancer were retrieved. The association of BRAF expression and CNAs with breast cancer clinicopathologic characteristics was analyzed. The impact of BRAF mRNA expression on the overall survival of patients was assessed using Kaplan-Meier survival analysis. Results: BRAF gene mRNA log intensity expression was positively correlated with tumor size and the Nottingham Prognostic Index (NPI) (p < 0.001). Alternatively, BRAF gene expression was negatively correlated with the age at diagnosis (p = 0.003). The average BRAF mRNA expression was significantly higher in premenopausal patients, patients with high tumor grade, hormone receptor-negative status, and non-luminal tumors compared to postmenopausal patients, patients with low-grade, hormone receptor-positive, and luminal disease. BRAF gain and high-level amplification copy numbers were significantly associated with higher NPI scores and larger tumor sizes compared to neutral copy number status. Survival analysis revealed no discernible differences in overall survival for patients with low and high BRAF mRNA expression. Conclusion: High BRAF mRNA expression as well as the gain and high-level amplification copy numbers were associated with advanced tumor characteristics and unfavorable prognostic factors in breast cancer. BRAF could be an appealing target for the treatment of premenopausal patients with hormone receptor-negative breast cancer.

Targeting MAPK-ERK/JNK pathway: A potential intervention mechanism of myocardial fibrosis in heart failure

Myocardial fibrosis is a significant pathological basis of heart failure. Overactivation of the ERK1/2 and JNK1/2 signaling pathways of MAPK family members synergistically promotes the proliferation of myocardial fibroblasts and accelerates the development of myocardial fibrosis. In addition to some small molecule inhibitors and Western drugs, many Chinese medicines can also inhibit the activity of ERK1/2 and JNK1/2, thus slowing down the development of myocardial fibrosis, and are generally safe and effective. However, the specific biological mechanisms of ERK1/2 and JNK1/2 signaling pathways in myocardial fibrosis still need to be fully understood, and there is no systematic review of existing drugs and methods to inhibit them from improving myocardial fibrosis. This study aims to summarize the roles and cross-linking mechanisms of ERK1/2 and JNK1/2 signaling pathways in myocardial fibrosis and to systematically sort out the small-molecule inhibitors, Western drugs, traditional Chinese medicines, and non-pharmacological therapies that inhibit ERK1/2 and JNK1/2 to alleviate myocardial fibrosis. In the future, we hope to conduct more in-depth research from the perspective of precision-targeted therapy, using this as a basis for developing new drugs that provide new perspectives on the prevention and treatment of heart failure.

Polyphenol-enriched Penthorum chinense Pursh ameliorates alcohol-related liver injury through Ras/Raf/MEK/ERK pathway: Integrating network pharmacology and experiment validation

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense Pursh (PCP) has acknowledged as an edible herbal medicinal plant for the prevention and treatment of alcoholic liver injury (ALI). However, only few of researches focus on the chemical material basis and potential mechanisms of PCP against ALI.

AIM OF THE STUDY

Herein, we explored the therapeutic effects of PCP extract against ALI based on the integration of network pharmacology, molecular docking, and experiment validation.

METHODS

Based on the standard quality control of PCP herbs by UPLC fingerprint and quantitative determination, 80% ethanol extract fraction of PCP containing more polyphenols, compared to aqueous extract fraction of PCP, were chosen for further experiments. After oral administration of PCP ethanol extract, serum pharmacochemistry based on UPLC-Q-Exactive-MS analysis was implemented to evaluate the potential effective compounds. These absorbed prototypes in PCP were used to construct network pharmacology and predict the potential mechanisms of PCP extract against ALI. Then, the predicted targets and biological mechanisms of PCP extract were validated using animal experiments and molecular docking analysis.

RESULTS

Although totally 19 polyphenol compounds were identified in PCP ethanol extract by UPLC-MS analysis, only 18 absorbed prototypes were found in the serum collected from mice at 1 h post-administration with PCP extract. These candidate active compounds were further screened into 13 compounds to construct network pharmacology and 433 targets were identified as PCP targets. GO and KEGG pathway enrichment analyses indicated that the effects of PCP extract would involve in Ras signaling pathway. The animal experiments on chronic ALI model mice shown that the oral administration of PCP can alleviate ALI by attenuating hepatic oxidative stress, inflammation and down-regulating the target proteins in Ras/Raf/MEK/ERK pathway. Molecular docking analysis revealed the good binding ability between the three polyphenols (i.e. quercetin, apigenin, thonningianin B) in PCP with the top contribution in network pharmacology, and these target proteins (Ras, Raf, MEK1/2, and ERK1/2).

CONCLUSION

Our results clarified that PCP ethanol extract could effectively alleviate ALI by down-regulating Ras/Raf/MEK/ERK signaling pathway promisingly. Quercetin, apigenin, and thonningianin B may be the active compounds of PCP, attributing to the intervention benefits of PCP against ALI.

[Progress of BRAF Gene Alteration in Non-small Cell Lung Cancer]

V-Raf murine sarcoma viral oncogene homolog B (BRAF) alteration is one of the most essential driver genes of non-small cell lung cancer (NSCLC). BRAF encodes serine/threonine protein kinases, and its mutations typically lead to protein compositional activation, thereby activating the mitogen-activated protein kinase kinase (MEK) signaling pathway. A promising new approach for the treatment of mutated BRAF and/or downstream MEK may provide customized treatment opportunities for BRAF driven NSCLC patients. However, combination therapy is necessary to overcome the difficulties such as short duration of benefit, poor therapeutic effect of non-V600 BRAF mutations and susceptibility to drug resistance. This article reviewed the progress in structural characteristics, related signaling pathways, mutation types of BRAF gene, and the clinical pathological relationship between BRAF mutations and NSCLC, as well as the therapy, in order to provide more evidences for clinical doctors to make treatment decisions.
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miR-451a suppresses the proliferation and migration of high-grade serous ovarian cancer by targeting RAB5A through the Ras/Raf/MEK/ERK pathway

BACKGROUND

Ovarian cancer is one of the most common cancers in women. Profiles changes of microRNAs (miRNAs) are closely linked to malignant tumors. In the present study, we investigated expression of miR-451a in high-grade serous ovarian cancer (HGSOC). We also investigated the potential pathological roles and the likely mechanism of miR-451a in the development of HGSOC using animal models and cell lines.

METHODS

Using bioinformatics techniques and a real-time PCR, we analyzed differently expressed miRNAs in HGSOC compared to normal tissue. MTT (i.e. 3-[4, 5-dimethyl thiazol-2-yl]-2,5-diphenyl tetrazolium bromide), EDU (i.e. 5-ethynyl-2'-deoxyuridine) and transwell assays were performed to investigate the effect of miR-451a on the proliferation and migration of HGSOC SKOV-3 cells. A dual luciferase reporter assay was performed to verify the targeting relationship of miR-451 and RAB5A (one of the Rab GTPase proteins that regulates endocytosis and vesicle transport). Also, we analyzed levels of the RAB5A mRNA and protein by real-time PCR, western blotting and immunohistochemistry assays in HGSOC cells and tissues. Finally, we performed in vivo experiments using HGSOC mice.

RESULTS

miR-451a was substantially upregulated in HGSOC and associated with favorable clinical characteristics. miR-451a knockdown significantly increased growth and metastasis of HGSOC cell line SKOV-3 through Ras/Raf/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling. In addition, RAB5A, an early endosome marker, was shown to be a direct target of miR-451a. Moreover, RAB5A is correlated with unfavorable clinical features and shows independent prognostic significance in HGSOC.

CONCLUSIONS

We found that the miR-451a/RAB5A axis is associated with tumorigenesis and progression through the Ras/Raf/MEK/ERK pathway, providing prognostic indicators and therapeutic targets for patients with HGSOC.

Neurodevelopmental disorders and cancer networks share pathways, but differ in mechanisms, signaling strength, and outcome

Epidemiological studies suggest that individuals with neurodevelopmental disorders (NDDs) are more prone to develop certain types of cancer. Notably, however, the case statistics can be impacted by late discovery of cancer in individuals afflicted with NDDs, such as intellectual disorders, autism, and schizophrenia, which may bias the numbers. As to NDD-associated mutations, in most cases, they are germline while cancer mutations are sporadic, emerging during life. However, somatic mosaicism can spur NDDs, and cancer-related mutations can be germline. NDDs and cancer share proteins, pathways, and mutations. Here we ask (i) exactly which features they share, and (ii) how, despite their commonalities, they differ in clinical outcomes. To tackle these questions, we employed a statistical framework followed by network analysis. Our thorough exploration of the mutations, reconstructed disease-specific networks, pathways, and transcriptome levels and profiles of autism spectrum disorder (ASD) and cancers, point to signaling strength as the key factor: strong signaling promotes cell proliferation in cancer, and weaker (moderate) signaling impacts differentiation in ASD. Thus, we suggest that signaling strength, not activating mutations, can decide clinical outcome.

Navigating the ERK1/2 MAPK Cascade

The RAS-ERK pathway is a fundamental signaling cascade crucial for many biological processes including proliferation, cell cycle control, growth, and survival; common across all cell types. Notably, ERK1/2 are implicated in specific processes in a context-dependent manner as in stem cells and pancreatic β-cells. Alterations in the different components of this cascade result in dysregulation of the effector kinases ERK1/2 which communicate with hundreds of substrates. Aberrant activation of the pathway contributes to a range of disorders, including cancer. This review provides an overview of the structure, activation, regulation, and mutational frequency of the different tiers of the cascade; with a particular focus on ERK1/2. We highlight the importance of scaffold proteins that contribute to kinase localization and coordinate interaction dynamics of the kinases with substrates, activators, and inhibitors. Additionally, we explore innovative therapeutic approaches emphasizing promising avenues in this field.

An updated literature on BRAF inhibitors (2018-2023)

BRAF is the most common serine-threonine protein kinase and regulates signal transduction from RAS to MEK inside the cell. The BRAF is a highly active isoform of RAF kinase. BRAF has two domains such as regulatory and kinase domains. The BRAF inhibitors bind in the c-terminus of the kinase domain and inhibit the downstream pathways. The mutation occurs mainly in the A-loop of the kinase domain. The mutation occurs due to a conversion of valine to glutamate/lysine/arginine/aspartic acid at 600th position. Among the diverse mutations, BRAF^V600E is the most common and responsible for numerous cancer such as melanoma, colorectal, ovarian, and thyroid cancer. Due to mutations in RAC1, loss of PTEN, NF1, CCND1, USP28-FBW7 complex, COT overexpression, and CCND1 amplification, the BRAF kinase enzyme developed resistance over the commercially available BRAF inhibitors. There is still unmute urgence for the development of BRAF inhibitors to overcome the persistent limitation such as resistance, mutation, and adverse effects of drugs. In the current study, we described the structure, activation, downstream signaling pathway, and mutation of BRAF. Our group also provided a detailed review of BRAF inhibitors from the last five years (2018-2023) highlighting the structure-activity relationship, mechanistic study, and molecular docking studies. We hope that the current analysis will be a useful resource for researchers and provide chemists a glimpse into the future as design and development of more effective and secure BRAF kinase inhibitors. The development of BRAF inhibitors to overcome the persistent limitation such as resistance, mutation, and adverse effects of drugs. In depth description about different heterocyclic scaffolds (quinoline, imidazole, pyridine, triazole, pyrrole etc.) as BRAF inhibitors from the last five years (2018-2023) highlighting the structure-activity relationship, mechanistic study, and molecular docking studies.

A Study Based on Network Pharmacology Decoding the Multi-Target Mechanism of Duhuo Jisheng Decoction for the Treatment of Intervertebral Disc Degeneration

Intervertebral disc degeneration (IDD) poses a grim public health impact. Duhuo Jisheng Decoction (DJD), a traditional Chinese medicine formula, has recently received significant attention for its efficacy and safety in treating IDD. However, the pathological processes of IDD in which DJD interferes and molecular mechanism involved are poorly understood, which brings difficulties to the clinical practice of DJD for the treatment of IDD. This study systematically investigated the underlying mechanism of DJD treatment of IDD. Network pharmacology approaches were employed, integrating molecular docking and random walk with restart (RWR) algorithm, to identify key compounds and targets for DJD in the treatment of IDD. Bioinformatics approaches were used to further explore the biological insights in DJD treatment of IDD. The analysis identifies AKT1, PIK3R1, CHUK, ALB, TP53, MYC, NR3C1, IL1B, ERBB2, CAV1, CTNNB1, AR, IGF2, and ESR1 as key targets. Responses to mechanical stress, oxidative stress, cellular inflammatory responses, autophagy, and apoptosis are identified as the critical biological processes involved in DJD treatment of IDD. The regulation of DJD targets in extracellular matrix components, ion channel regulation, transcriptional regulation, synthesis and metabolic regulation of reactive oxygen products in the respiratory chain and mitochondria, fatty acid oxidation, the metabolism of Arachidonic acid, and regulation of Rho and Ras protein activation are found to be potential mechanisms in disc tissue response to mechanical stress and oxidative stress. MAPK, PI3K/AKT, and NF-κB signaling pathways are identified as vital signaling pathways for DJD to treat IDD. Quercetin and Kaempferol are assigned a central position in the treatment of IDD. This study contributes to a more comprehensive understanding of the mechanism of DJD in treating IDD. It provides a reference for applying natural products to delay the pathological process of IDD.

Cross-talk between the RAS-ERK and mTOR signalings-associated autophagy contributes to tripterygium glycosides tablet-induced liver injury

BACKGROUND AND AIMS

Drug-induced liver injury (DILI) remains a critical issue and a hindrance to clinical application of Tripterygium Glycosides Tablet (TGT) despite its favorable therapeutic efficacy in rheumatoid arthritis. Herein, we aimed to elucidate the molecular mechanisms underlying TGT-induced hepatotoxicity.

METHODS

Chemical profiling of TGT was identified by UPLC-Q/TOF-MS/MS and its putative targets were predicted based on chemical structure similarity calculation. Following "DILI-related gene-TGT putative target" interaction network construction, a list of key network targets was screened according to nodes' topological importance and functional relevance. Both in vivo and in vitro experiments were performed to determine drug hepatotoxicity and the underlying mechanisms.

RESULT

A total of 49 chemical components and 914 putative targets of TGTs were identified. Network calculation and functional modularization screened RAS-ERK and mTOR signalings-associated autophagy to be one of the candidate targets of TGT-induced hepatotoxicity. Experimentally, TGT significantly activated RAS-ERK axis, elevated the number of autophagosomes and the expression of LC3II protein, but reduced the expression of p62 protein and suppressed mTOR phosphorylation in the liver tissues of TGT-induced acute liver injury mice and chronic liver injury mice in vivo and AML12 cells in vitro. Moreover, TGT and mL-098 (an activator of RAS) co-treatment reduced AML12 cell viability via regulating autophagy and TGT-induced liver injury-related indicators more dramatically than TGT treatment alone, whereas Salirasib (an inhibitor of RAS) had an opposite effect.

CONCLUSION

RAS-ERK-mTOR cross-talk may play a crucial role in TGT-induced hepatocyte autophagy, offering a promising target for developing novel therapeutics to combat TGT-induced hepatotoxicity.

Inhibition Ras/MEK/ERK pathway: An important mechanism of Baihu Jia Guizhi Decoction ameliorated rheumatoid arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Alleviating rheumatism by inhibiting synovitis is a routine treatment for rheumatoid arthritis (RA). Baihu Jia Guizhi Decoction (BHJGZ) is a classic prescription and has a long history of application for treating RA with a good anti-inflammatory action. However, the underlying molecular mechanisms have not been fully elucidated.

AIM OF THE STUDY

This work aimed to decipher the potential mechanism of BHJGZ against RA focusing on Ras/MEK/ERK pathway.

MATERIALS AND METHODS

Based on the prediction of network pharmacology, the inhibition action of BHJGZ on Ras/MEK/ERK pathway was firstly validated in vivo and in vitro. Moreover, the affinity with the ingredients of BHJGZ in serum and the targets of Ras/MEK/ERK pathway were evaluated. Finally, the efficacy of BHJGZ for relieving RA was assessed in AA rats.

RESULTS

The Ras/MEK/ERK pathway was predicted by network pharmacology as one of important mechanisms of BHJGZ to treat RA. The high expression of Ras protein in synovitis of AA rats was significantly reduced by the treatment with BHJGZ, and the activation of Ras/MEK/ERK pathway in vivo and in vitro was also markedly inhibited (p < 0.05 or p < 0.01). Moreover, the level of p-ERK/ERK, IL-6 and TNF-α in vitro were further suppressed after Ras or MEK was inhibited by mirdametinib or lonafarnib respectively (p < 0.01). Furthermore, the results of molecular docking showed a good affinity and stable binding with the ingredients of BHJGZ in serum and multiple key proteins of the Ras/MEK/ERK pathway. Finally, paw swelling, paw circumference and pathological changes of joint synovitis were significantly reduced by BHJGZ in AA rats (p < 0.05).

CONCLUSION

The inhibition of Ras/MEK/ERK pathway is one of crucial mechanisms of BHJGZ for ameliorating synovitis of RA.

Immunotherapy or targeted therapy: What will be the future treatment for anaplastic thyroid carcinoma?

Anaplastic thyroid carcinoma (ATC) is a rare and aggressive form of thyroid carcinoma (TC). Currently, there are no effective treatments for this condition. In the past few years, targeted therapy and immunotherapy have made significant progress in ATC treatment. Several common genetic mutations have been found in ATC cells, involving different molecular pathways related to tumor progression, and new therapies that act on these molecular pathways have been studied to improve the quality of life of these patients. In 2018, the FDA approved dabrafenib combined with trametinib to treat BRAF-positive ATC, confirming its therapeutic potential. At the same time, the recent emergence of immunotherapy has also attracted wide attention from researchers. While immunotherapy for ATC is still in the experimental stage, numerous studies have shown that immunotherapy is a potential therapy for ATC. In addition, it has also been found that the combination of immunotherapy and targeted therapy may enhance the anti-tumor effect of targeted therapy. In recent years, there has been some progress in the study of targeted therapy or immunotherapy combined with radiotherapy or chemotherapy, showing the prospect of combined therapy in ATC. In this review, we analyze the response mechanism and potential effects of targeted therapy, immunotherapy, and combination therapy in ATC treatment and explore the future of treatment for ATC.

Insight into Oncogenic Viral Pathways as Drivers of Viral Cancers: Implication for Effective Therapy

As per a recent study conducted by the WHO, 15.4% of all cancers are caused by infectious agents of various categories, and more than 10% of them are attributed to viruses. The emergence of COVID-19 has once again diverted the scientific community's attention toward viral diseases. Some researchers have postulated that SARS-CoV-2 will add its name to the growing list of oncogenic viruses in the long run. However, owing to the complexities in carcinogenesis of viral origin, researchers across the world are struggling to identify the common thread that runs across different oncogenic viruses. Classical pathways of viral oncogenesis have identified oncogenic mediators in oncogenic viruses, but these mediators have been reported to act on diverse cellular and multiple omics pathways. In addition to viral mediators of carcinogenesis, researchers have identified various host factors responsible for viral carcinogenesis. Henceforth owing to viral and host complexities in viral carcinogenesis, a singular mechanistic pathway remains yet to be established; hence there is an urgent need to integrate concepts from system biology, cancer microenvironment, evolutionary perspective, and thermodynamics to understand the role of viruses as drivers of cancer. In the present manuscript, we provide a holistic view of the pathogenic pathways involved in viral oncogenesis with special emphasis on alteration in the tumor microenvironment, genomic alteration, biological entropy, evolutionary selection, and host determinants involved in the pathogenesis of viral tumor genesis. These concepts can provide important insight into viral cancers, which can have an important implication for developing novel, effective, and personalized therapeutic options for treating viral cancers.

Central role for BRAF in cardiac hypertrophy: rethinking the pathological-physiological divide

The RAF/MEK/ERK1/2 signaling cascade has been implicated in pathological cardiac hypertrophy downstream of some Gq-coupled receptors. The RAF family of kinases consists of three isoforms (ARAF, BRAF, and CRAF) and until recently most studies on this signaling pathway in the heart have focused on RAF1 (CRAF). In a recent issue of Clinical Science, Alharbi et al. utilized an inducible cardiac myocyte targeted knockout mouse model to define the role of BRAF in pathological versus physiological hypertrophy using angiotensin II and phenylephrine (PE) infusion, respectively. They reported that loss of BRAF attenuated both pathological cardiac hypertrophy and interstitial fibrosis. BRAF knockout decreased cardiac function with PE in male mice and enhanced both interstitial and perivascular cardiac fibrosis but had no effect on hypertrophy. In contrast, loss of BRAF attenuated physiological hypertrophy in female mice but had no effect on fibrosis or contractility. These observations extend those previously made by this group assessing the consequences of expressing an inducible activating mutant of BRAF in the heart and the benefit of enhancing RAF/MEK/ERK1/2 signaling by exploiting the 'RAF paradox'. Additional studies are needed to better define the role of BRAF under conditions reflective of chronic stress on the heart due to the biomechanical stimulation exerted by hypertension. In addition, the role of BRAF and its activation in overt heart failure remains to be established. Nevertheless, the new findings highlight the potential importance of additional signaling events, perhaps related to RAF1 or ERK1/2 activation, in shaping BRAF signaling in a sex- and context-dependent manner.

α4-α5 Helices on Surface of KRAS Can Accommodate Small Compounds That Increase KRAS Signaling While Inducing CRC Cell Death

KRAS is the most frequently mutated oncogene associated with the genesis and progress of pancreatic, lung and colorectal (CRC) tumors. KRAS has always been considered as a therapeutic target in cancer but until now only two compounds that inhibit one specific KRAS mutation have been approved for clinical use. In this work, by molecular dynamics and a docking process, we describe a new compound (P14B) that stably binds to a druggable pocket near the α4-α5 helices of the allosteric domain of KRAS. This region had previously been identified as the binding site for calmodulin (CaM). Using surface plasmon resonance and pulldown analyses, we prove that P14B binds directly to oncogenic KRAS thus competing with CaM. Interestingly, P14B favors oncogenic KRAS interaction with BRAF and phosphorylated C-RAF, and increases downstream Ras signaling in CRC cells expressing oncogenic KRAS. The viability of these cells, but not that of the normal cells, is impaired by P14B treatment. These data support the significance of the α4-α5 helices region of KRAS in the regulation of oncogenic KRAS signaling, and demonstrate that drugs interacting with this site may destine CRC cells to death by increasing oncogenic KRAS downstream signaling.

Wenshen-Jianpi prescription, a Chinese herbal medicine, improves visceral hypersensitivity in a rat model of IBS-D by regulating the MEK/ERK signal pathway

The goal of the study was to analyze whether WJP can alleviate visceral hypersensitivity in IBS-D model rats. In this study, 36 Sprague–Dawley (SD) rats aged 4 weeks old were randomly divided into two groups: the model group (n = 27) and the control group (n = 9). The rat model of IBS-D was established by modified compound methods for 4 weeks. After the modification, IBS-D rats were randomly divided into three groups, namely, the IBS-D model group (n = 9), the positive drug group (n = 9), and the WJP group (n = 9), with different interventions, respectively. The control group was fed and allowed to drink water routinely. The Bristol stool scale scores were used to assess the severity of diarrhea. Abdominal withdrawal reflex (AWR) scores were used to assess visceral sensitivity. Expression of TNF-α was measured, and histopathological examinations were performed to assess colon inflammation in IBS-D model rats. Key factors of the MEK/ERK signal pathway in the tissue of the colon and hippocampus were measured to analyze the mechanism of WJP. Compared with the control group, the Bristol stool scale scores in the model group were significantly increased (p < 0.0001). The scores of the WJP group were significantly decreased compared with the model group (p = 0.0001). Compared with the control group, AWR scores in the model group at each pressure level were significantly increased (p = 0.0003, p < 0.0001, p = 0.0007, and p = 0.0009). AWR scores of the WJP group were significantly decreased compared with the model group (p = 0.0003, p = 0.0007, p = 0.0007, and p = 0.0009). Compared with the control group, the model group had significantly higher expression of TNF-α in the colon tissue (p < 0.0001). However, the WJP group had significantly lower level of TNF-α compared with the model group (p < 0.0001). Meanwhile, compared with the control group, the relative expression of the proteins of p-MEK1/2, p-ERK1, and p-ERK2 in the colon tissue was significantly increased in the model group (p < 0.0001). Compared with the model group, the relative expression of the proteins in the colon tissue were significantly decreased in the WJP group (p < 0.0001, p = 0.0019, and p = 0.0013). Compared with the control group, the relative expression of the proteins of p-MEK1/2, p-ERK1, and p-ERK2 in the hippocampus tissue were significantly increased in the model group (p < 0.0001). Compared with the model group, the relative expression of the proteins in the hippocampus tissue were significantly decreased in the WJP group (p = 0.0126, p = 0.0291, and p = 0.0145). The results indicated that WJP can alleviate visceral hypersensitivity in IBS-D model rats, possibly mediated by downregulating the expression of TNF-α, p-MEK1/2, p-ERK1, and p-ERK2 in the colon tissue. At the same time, WJP also affects downregulating the expression of p-MEK1/2, p-ERK1, and p-ERK2 in the hippocampus tissue.