Ras Proteins Research Articles

Salmonella Typhimurium effector SseI regulates host peroxisomal dynamics to acquire lysosomal cholesterol.

Salmonella enterica serotype Typhimurium (Salmonella) resides and multiplies intracellularly in cholesterol-rich compartments called Salmonella-containing vacuoles (SCVs) with actin-rich tubular extensions known as Salmonella-induced filaments (SIFs). SCV maturation depends on host-derived cholesterol, but the transport mechanism of low-density lipoprotein (LDL)-derived cholesterol to SCVs remains unclear. Here we find that peroxisomes are recruited to SCVs and function as pro-bacterial organelle. The Salmonella effector protein SseI is required for the interaction between peroxisomes and the SCV. SseI contains a variant of the PTS1 peroxisome-targeting sequence, GKM, localizes to the peroxisomes and activates the host Ras GTPase, ADP-ribosylation factor-1 (ARF-1). Activation of ARF-1 leads to the recruitment of phosphatidylinsolitol-5-phosphate-4 kinase and the generation of phosphatidylinsolitol-4-5-bisphosphate on peroxisomes. This enhances the interaction of peroxisomes with lysosomes and allows for the transfer of lysosomal cholesterol to SCVs using peroxisomes as a bridge. Salmonella infection of peroxisome-depleted cells leads to the depletion of cholesterol on the SCVs, resulting in reduced SIF formation and bacterial proliferation. Taken together, our work identified peroxisomes as a target of Salmonella secretory effectors, and as conveyance of host cholesterol to enhance SCV stability, SIF integrity, and intracellular bacterial growth.

Endogenous interactomes of MFN1 and MFN2 provide novel insights into interorganelle communication and autophagy

ABSTRACT MFN1 (mitofusin 1) and MFN2 are key players in mitochondrial fusion, endoplasmic reticulum (ER)-mitochondria juxtaposition, and macroautophagy/autophagy. However, the mechanisms by which these proteins participate in these processes are poorly understood. Here, we studied the interactomes of these two proteins by using CRISPR-Cas9 technology to insert an HA-tag at the C terminus of MFN1 and MFN2, and thus generating HeLa cell lines that endogenously expressed MFN1-HA or MFN2-HA. HA-affinity isolation followed by mass spectrometry identified potential interactors of MFN1 and MFN2. A substantial proportion of interactors were common for MFN1 and MFN2 and were regulated by nutrient deprivation. We validated novel ER and endosomal partners of MFN1 and/or MFN2 with a potential role in interorganelle communication. We characterized RAB5C (RAB5C, member RAS oncogene family) as an endosomal modulator of mitochondrial homeostasis, and SLC27A2 (solute carrier family 27 (fatty acid transporter), member 2) as a novel partner of MFN2 relevant in autophagy. We conclude that MFN proteins participate in nutrient-modulated pathways involved in organelle communication and autophagy.

"Undruggable KRAS": druggable after all.

The three RAS genes (HRAS, KRAS, and NRAS) comprise the most frequently mutated oncogene family in cancer. KRAS is the predominant isoform mutated in cancer and is most prevalently mutated in major causes of cancer deaths including lung, colorectal, and pancreatic cancers. Despite extensive academic and industry efforts to target KRAS, it would take nearly four decades before approval of the first clinically effective KRAS inhibitors for the treatment of KRAS mutant lung cancer. We revisit past anti-KRAS strategies and painful lessons learned and then focus on the rapidly evolving landscape of direct RAS inhibitors, resistance mechanisms, and potential combination treatments.

Broussoflavonol F exhibited anti-proliferative and anti-angiogenesis effects in colon cancer via modulation of the HER2-RAS-MEK-ERK pathway

BackgroundA prenylated flavonoid, broussoflavonol F (BFF), was isolated from Macaranga genus with cytotoxicities against various cancer cells, though its underlying mechanisms have not been fully elucidated. HypothesisThis study aimed to investigate the anti-tumor and anti-angiogenesis activities of BFF and its underlying mechanisms in colon cancer. MethodIn the in vitro study, the cytotoxic effects of BFF in human colon cancer HCT-116 and LoVo cells were examined using MTT assay, BrdU assay and colony formation assay. The anti-proliferative effects of BFF in these cells were assessed via cell apoptosis and cell cycle analysis using flow cytometry. The anti-angiogenesis effects of BFF in human endothelial HEMC-1 cells were also detected using scratch wound healing assay and tube formation assay. While the in vivo effects of BFF in colon cancer were further examined in zebrafish embryos and HCT116 tumor-bearing mice. The underlying mechanisms of BFF were predicted using network pharmacology analysis, and Western blotting was performed to validate both in vitro and in vivo results. ResultsBFF exhibited cytotoxicities on 5 colon cancer cell lines, as well as anti-proliferative activities via inducing apoptosis and cell cycle arrest at the G0/G1 phase in HCT116 and LoVo cells. BFF at 1.25-5 µM also suppressed cell proliferation in these two colon cancer cell lines by downregulating HER2, RAS, p-BRAF, p-MEK and p-Erk protein expressions. In addition, BFF at 2.5-5 µM could significantly decrease the length of subintestinal vessels of zebrafish embryos through decreasing mRNA expressions of NRP1a, PDGFba, PDGFRb, KDR, FLT1 and VEGRaa. Besides, BFF exhibited anti-angiogenesis activity via inhibiting cell proliferation, motility and tube formation in HMEC-1 cells. Furthermore, intraperitoneal administration of BFF (10 mg/kg) suppressed tumor growth and decreased the expression of tumor proliferation marker Ki-67 and angiogenesis marker CD31 in the tumor tissues in HCT116 tumor-bearing mice. BFF treatment could also significantly decrease expressions of RAS, p-BRAF, p-MEK and p-Erk in the tumor section, which are consistent with the in vitro results. ConclusionsThis study revealed the anti-tumor and anti-angiogenesis effects of BFF in colon cancer. This is the first report of the in vitro and in vivo anti-proliferative activity of BFF in colon cancer through regulating the HER2-RAS-MEK-ERK pathway. These findings further support the research development of BFF as an anti-cancer agent in colon cancer.

New Therapeutic Approaches for Tumors with RAS Gene Mutations (Clinical Trial NTO-RAS)

Введение. Для онкологических пациентов, исчерпавших возможности стандартной терапии, представляется допустимым использование безопасных лекарственных препаратов, продемонстрировавших признаки противоопухолевой активности в доклинических исследованиях. Например, ингибитор дигидрооротатдегидрогеназы (DHODH) лефлуномид, используемый для противовоспалительной терапии, может обладать определённой активностью по отношению к KRAS-мутированным новообразованиям. Помимо этого, в ходе лабораторных исследований и единичных клинических наблюдений получены сведения о перспективности комбинирования МЕК-ингибиторов с гидроксихлорохином для карцином, характеризующихся активацией генов семейства RAS. Материалы и методы. Нами выполняется многоцентровое, проспективное, когортное исследование фазы II NTO-RAS, которое направлено на изучение потенциальной эффективности упомянутых подходов. Выводы. Данная статья посвящена обоснованию целесообразности и описанию дизайна этого исследования.

Identification of potential key circular RNAs associated with Escherichia coli-infected bovine mastitis using RNA-sequencing: preliminary study results.

Escherichia coli (E. coli) is commonly found in dairy farms and can invade mammary gland tissue, often causing acute clinical mastitis. Mammary infections with E. coli have shown a wide range of clinical signs, causing abnormal appearance of the milk, udder inflammation and systemic signs of illness. Circular RNA is a class of endogenous non-coding RNA that plays an important role in the occurrence and development of various inflammatory diseases. However, there is little information on the circRNA associated with bovine mastitis. In this study investigated the involvement of circRNAs in bovine mastitis through the construction of an E. coli-infected bovine mastitis model by injecting of E. coli into the mammary gland of dairy cows, using healthy gland mammary tissue as a control (M_C). High-throughput RNA-seq was performed on the E. coli-infected mammary gland tissue (M_E) and differentially expressed circRNAs between theM_C and M_E groups, followed by an analysis of their potential functions using bioinformatics methods. A total of 164 differentially expressed circRNAs were identified, including 92 downregulated circRNAs and 72 upregulated circRNAs. As shown by Gene Ontology enrichment analysis these DE circRNAs were mostly enriched in ras protein signal transduction, cytoplasmic vesicle parts, and enzyme binding, and Kyoto Encyclopedia of Genes and genome singal pathway enrichment analysis indicated significant associations with phagosome signal pathway. Additionally, the expression of bovine mastitis-related circRNAs, including novel_circRNA_0000128, novel_circRNA_0011103, novel_circRNA_0012656, novel_circRNA_0015099, novel_circRNA_005648, novel_circRNA_000074, and novel_circRNA_0011796 were verified via quantitative reverse-transcription polymerase chain reaction (RT-qPCR). These results provide a new direction for further investigation of the molecular mechanisms underlying bovine mastitis.

Effects of invigorating-spleen and anticancer prescription on extracellular signal-regulated kinase/mitogen-activated protein kinase signaling pathway in colon cancer mice model.

Colon cancer (CC) is one of the most common malignant tumors in the gastrointestinal system. Overall, CC had the third highest incidence but the second highest mortality rate globally in 2020. Nowadays, CC is mainly treated with capecitabine chemotherapy regimen, supplemented by radiotherapy, immunotherapy and targeted therapy, but there are still limitations, so Chinese medicine plays an important role. To investigate the effects of invigorating-spleen and anticancer prescription (ISAP) on body weight, tumor inhibition rate and expression levels of proteins in extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signaling pathway in CC mice model. The CC mice model were established and the mice were randomly divided into 5 groups, including the control group, capecitabine group, the low-dose, medium-dose and high-dose groups of ISAP, with 8 mice in each group, respectively. After 2 weeks of intervention, the body weight and tumor inhibition rate of mice were observed, and the expression of RAS, ERK, phosphorylated ERK (p-ERK), C-MYC and matrix metalloproteinase 2 (MMP2) proteins in the tissues of tumors were detected. Compared with the control group, the differences of body weight before and after treatment was much smaller in the groups of ISAP, with the smallest difference in the high-dose group of ISAP, while the capecitabine group had the greatest difference, indicating ISAP had a significant inhibiting effect on the growth of transplanted tumor in mice. The expression of RAS protein was decreased in the low- and medium-dose groups of ISAP, and the change of p-ERK was significant in the medium- and high- dose groups of ISAP. MMP2 protein expression was significantly decreased in both the low-dose and medium-dose groups of ISAP. There were no significant changes in ERK in the ISAP group compared to the capecitabine group, while RAS, MMP2, and C-MYC protein expression were reduced in the ISAP group. The expression level of C-MYC protein decreased after treated with ISAP, and the decrease was the most significant in the medium-dose group of ISAP. ISAP has a potential inhibiting effect on transplanted tumor in mice, and could maintain the general conditions, physical strength and body weight of mice. The expression levels of RAS, p-ERK, MMP2 and c-myc were also decreased to a certain extent. By inhibiting the expression of upstream proteins, the expression levels of downstream proteins in ERK/MAPK signaling pathway were significantly decreased. Therefore, it can be concluded that ISAP may exert an anti-tumor effect by blocking the ERK/MAPK signaling pathway and inhibiting the expression of MMP2 and c-myc proteins.

Comparison of efficacy and safety of regorafenib and anti-EGFR targeted therapy in metastatic colorectal cancer: A retrospective study

Aim. To compare the efficacy of regorafenib and the combination of chemotherapy (CT) with anti-EGFR (cetuximab/panitumumab) in the third-line treatment of metastatic colorectal cancer (mCRC). Materials and methods. A retrospective analysis of a prospective database of patients with mCRC from two clinics in the Russian Federation was conducted. Overall survival was considered the primary efficacy criterion. Additional criteria were progression-free survival (PFS), objective effect (OE), and incidence of toxicity. No statistical hypothesis was assumed. Statistical analysis was performed using SPSS (IBM SPPS Statistics v. 20). Results. The database identified 51 patients with morphologically confirmed left-sided mCRC with wild-type RAS and BRAF genes who received more than two lines of antitumor drug therapy from 2010 to 2021, one of which included anti-EGFR antibodies in the third and subsequent lines of treatment. Thirty patients who received regorafenib in the third line and 21 patients who received CT in combination with anti-EGFR in the third line were selected, of which 7 patients had a history of anti-EGFR use, and 14 patients received anti-EGFR for the first time. The median overall survival from the third line initiation date in the CT group in combination with anti-EGFR was numerically higher (21 months, CI 9.0–32.9 months) than in the regorafenib group (10 months, CI 2.4–17.5 months); p=0.1 by log-rank test (Mantel–Cox test); p=0.2 by Breslow–Wilcoxon test; p=0.3 (Tarone–Ware test). PFS was also higher in the anti-EGFR CT group (6 months, CI 3.8–8.2 months) than in the regorafenib group (3 months, CI 1.2–4.7 months); p=0.05 according to Breslow–Wilcoxon test. OE of third-line therapy was reported in 57.1% (n=12) of patients in the CT with anti-EGFR group and significantly less often in the regorafenib group – 10.3% (n=3) of patients (p=0.001). The toxicity of drug therapy of all grades in the regorafenib group was reported in 86.2% (n=25) of patients, while in the CT anti-EGFR group, it was significantly less common – in 52.4% (n=11) of patients (p=0.01). Conclusion. Compared with regorafenib, combining CT with anti-EGFR agents in the third-line treatment of patients with left-sided mCRC with wild-type RAS and BRAF genes is associated with better PFS and the frequency of OE with significantly less toxicity.

A Novel NRAS Variant Near the Splice Junction in Moroccan Childhood Acute Lymphoblastic Leukemia: A Molecular Dynamics Study.

The RAS genes are importantly implicated in oncogenesis and are frequently mutated in childhood acute lymphoblastic leukemia. This study is the first to our knowledge, to determine the mutational status of NRAS and KRAS genes in Moroccan pediatric acute lymphoblastic leukemia (ALL). Polymerase chain reaction and Sanger sequencing were performed for 45 ALL samples to explore the coding exons. The functional effect of the mutation was evaluated using in silico prediction tools and molecular modeling. We identified a novel variant c.290 G > C p.Arg97Thr within NRAS gene in a patient with T-ALL, which is a rare missense point mutation affecting the last base of exon 3. Analyses revealed that p.Arg97Thr impairs the adjacent splice site efficiency. Moreover, it leads to structural modifications at local and global levels of the protein through the loss of hydrogen bonds. Additionally, the molecular dynamics (MD) simulation showed that it slightly increases the stability of NRAS protein by locally decreasing the flexibility of the mutated region. No variant was detected within KRAS gene. R97 at NRAS gene is an overlapping splice site residue. Our findings suggest that the NRAS p.Arg97Thr variant may disrupt the splicing machinery and functions of the protein, thus playing a vital role in leukemogenesis. In addition, the highly druggable pocket may possibly be studied for its therapeutic implications.

Advances and challenges in RAS signaling targeted therapy in leukemia.

RAS mutations are prevalent in leukemia, including mutations at G12, G13, T58, Q61, K117, and A146. These mutations are often crucial for tumor initiation, maintenance, and recurrence. While much is known about RAS function in the last 40 years, there is a substantial knowledge gap concerning the mutation-specific biological activities of RAS in cancer and the approaches needed to target specific RAS mutants effectively. The recent approval of KRASG12C inhibitors, adagrasib and sotorasib, has validated KRAS as a direct therapeutic target and demonstrated the feasibility of selectively targeting specific RAS mutants. Nevertheless, KRASG12C remains the only RAS mutant successfully targeted with FDA approved inhibitors for cancer treatment in patients, limiting its applicability for other oncogenic RAS mutants, such as G12D in leukemia. Despite these challenges, new approaches have generated optimism about targeting specific RAS mutations in an allele-dependent manner for cancer therapy, supporting by compelling biochemical and structural evidence, which inspires further exploration of RAS allele-specific vulnerabilities. This review will discuss recent advances and challenges in the development of therapies targeting RAS signaling, highlight emerging therapeutic strategies, and emphasize the importance of allele-specific approaches for leukemia treatment.

Distinct association of HRAS and KRAS with Mn(II) ion illustrated by paramagnetic NMR

Rat sarcoma virus oncogene (RAS) proteins are among crucial oncogenic proteins and are involved in several essential intracellular processes. The RAS protein has an intrinsic metal binding site for Mg2+, which is important for the conformational stability of the active site. Recently, it was reported that a second metal ion binding site, located further from the active site in HRAS (Harvey RAS homolog), binds Ca2+ with millimolar affinity. As one of the most abundant metal ions in cells, Mn2+ is a potential candidate for the second metal ion binding site in RAS proteins. Here, we examined the interaction of Mn2+ with HRAS and KRAS (Kirsten RAS homolog) using high resolution NMR spectroscopy. The NMR data showed that both the second metal ion binding site and the switch I and II regions bind Mn2+ in the RAS proteins. Furthermore, our paramagnetic NMR results disclosed the conformational differences in helix α3 and the following loop between HRAS and KRAS, accompanied by the association with metal ion binding. These results provide new insights into the interaction of RAS proteins and Mn2+ in the respective biological processes in cells.

Long-term effects of IVF on offspring kidneys: observations from adolescence to adulthood

Research questionWhat is the effect of in-vitro fertilization (IVF) on long-term health of offspring kidney? DesignWe established an IVF mouse model and subsequently observed renal structure, function, and cortical oxidative stress from the age of 2 months to ascertain any disparities compared to natural conceived (NC) offspring. And this kind of process continued until the mice reached 5 months old. ResultsWe found no significant difference in the body weight of mice aged 2 to 5 months between IVF and NC offspring. However, the renal/weight ratio of IVF offspring was higher than that of NC offspring at 2 months and 3 months, but this difference disappeared in offspring aged 4 to 5 months. IVF offspring at 5 months of age had lower urine creatinine (Ucr) levels compared to NC offspring. Moreover, The expression of ACE2 was observed to decrease in the kidneys of 4 to 5-month-old IVF mice, and the expression of AGTR1A was higher in 5-month-old IVF mice compared to NC mice. The malondialdehyde (MDA) level in 5-month-old IVF offspring was higher than in NC offspring. ConclusionOur study indicated that microvascular thickness in the kidneys of IVF offspring remains unchanged, but minor alterations in kidney function, RAS gene expression, and renal cortical oxidative stress were evident by 5 months of age.

The Role of the Swollen State in Cell Proliferation.

Cell swelling is known to be involved in various stages of the growth of plant cells and microorganisms but in mammalian cells how crucial a swollen state is for determining the fate of the cellular proliferation remains unclear. Recent evidence has increased our understanding of how the loss of the cell surface interactions with the extracellular matrix at early mitosis decreases the membrane tension triggering curvature changes in the plasma membrane and the activation of the sodium/hydrogen (Na +/H +) exchanger (NHE1) that drives osmotic swelling. Such a swollen state is temporary, but it is critical to alter essential membrane biophysical parameters that are required to activate Ca2 + channels and modulate the opening of K + channels involved in setting the membrane potential. A decreased membrane potential across the mitotic cell membrane enhances the clustering of Ras proteins involved in the Ca2 + and cytoskeleton-driven events that lead to cell rounding. Changes in the external mechanical and osmotic forces also have an impact on the lipid composition of the plasma membrane during mitosis.

The prominent pervasive oncogenic role and tissue specific permissiveness of RAS gene mutations

In cancer research, RAS biology has been focused on only a handful of tumor types. While RAS genes have long been suspected as common contributors to a wide spectrum of cancer types, robust evidence is required to firmly establish their critical oncogenic significance. We present a data mining study using DepMap genome-wide CRISPR screening data, which provide substantial evidence to support the prominent pervasive oncogenic role and tissue-specific permissiveness of RAS gene mutations. Differential analysis of CRISPR effect scores identifies K- or N-RAS genes as the most differential gene in contrasts of (K-, N-, combined) RAS mutant versus wild-type cell lines across multiple tissue types. The distinguished tissue-specific pattern of KRAS vs. NRAS as top differential genes in subsets of tissue types and evidence from genome data supported the idea of KRAS- and NRAS-engaged tissue types. To our knowledge, this is the first report of prominent pervasive oncogenic role of RAS mutations revealed by gene dependency data that is beyond the current understanding of the oncogenic role of RAS genes and their well-known involved tissue types. Our findings strongly support RAS mutations as primary oncogenic drivers beyond traditionally recognized cancer types and offer insights into their tissue-specific permissiveness.

Rac1 GTPase Regulates the βTrCP-Mediated Proteolysis of YAP Independently of the LATS1/2 Kinases.

Background: Oncogenic mutations in the KRAS gene are detected in >90% of pancreatic cancers (PC). In genetically engineered mouse models of PC, oncogenic KRAS drives the formation of precursor lesions and their progression to invasive PC. The Yes-associated Protein (YAP) is a transcriptional coactivator required for transformation by the RAS oncogenes and the development of PC. In Ras-driven tumors, YAP can also substitute for oncogenic KRAS to drive tumor survival after the repression of the oncogene. Ras oncoproteins exert their transforming properties through their downstream effectors, including the PI3K kinase, Rac1 GTPase, and MAPK pathways. Methods: To identify Ras effectors that regulate YAP, YAP levels were measured in PC cells exposed to inhibitors of oncogenic K-Ras and its effectors. Results: In PC cells, the inhibition of Rac1 leads to a time-dependent decline in YAP protein, which could be blocked by proteosome inhibitor MG132. This YAP degradation after Rac1 inhibition was observed in a range of cell lines using different Rac1 inhibitors, Rac1 siRNA, or expression of dominant negative Rac1T17N mutant. Several E3 ubiquitin ligases, including SCFβTrCP, regulate YAP protein stability. To be recognized by this ligase, the βTrCP degron of YAP (amino acid 383-388) requires its phosphorylation by casein kinase 1 at Ser384 and Ser387, but these events must first be primed by the phosphorylation of Ser381 by LATS1/2. Using Flag-tagged mutants of YAP, we show that YAP degradation after Rac1 inhibition requires the integrity of this degron and is blocked by the silencing of βTrCP1/2 and by the inhibition of casein kinase 1. Unexpectedly, YAP degradation after Rac1 inhibition was still observed after the silencing of LATS1/2 or in cells carrying a LATS1/2 double knockout. Conclusions: These results reveal Rac1 as an oncogenic KRAS effector that contributes to YAP stabilization in PC cells. They also show that this regulation of YAP by Rac1 requires the SCFβTrCP ligase but occurs independently of the LATS1/2 kinases.

Deciphering the role of lipid metabolism-related genes in Alzheimer's disease: a machine learning approach integrating Traditional Chinese Medicine.

Alzheimer's disease (AD) represents a progressive neurodegenerative disorder characterized by the accumulation of misfolded amyloid beta protein, leading to the formation of amyloid plaques and the aggregation of tau protein into neurofibrillary tangles within the cerebral cortex. The role of carbohydrates, particularly apolipoprotein E (ApoE), is pivotal in AD pathogenesis due to its involvement in lipid and cholesterol metabolism, and its status as a genetic predisposition factor for the disease. Despite its significance, the mechanistic contributions of Lipid Metabolism-related Genes (LMGs) to AD remain inadequately elucidated. This research endeavor seeks to bridge this gap by pinpointing biomarkers indicative of early-stage AD, with an emphasis on those linked to immune cell infiltration. To this end, advanced machine-learning algorithms and data derived from the Gene Expression Omnibus (GEO) database have been employed to facilitate the identification of these biomarkers. Differentially expressed genes (DEGs) were identified by comparing gene expression profiles between healthy individuals and Alzheimer's disease (AD) patients, using data from two Gene Expression Omnibus (GEO) datasets: GSE5281 and GSE138260. Functional enrichment analysis was conducted to elucidate the biological relevance of the DEGs. To ensure the reliability of the results, samples were randomly divided into training and validation sets. The analysis focused on lipid metabolism-related DEGs (LMDEGs) to explore potential biomarkers for AD. Machine learning algorithms, including Support Vector Machine-Recursive Feature Elimination (SVM-RFE) and the Least Absolute Shrinkage and Selection Operator (LASSO) regression model, were applied to identify a key gene biomarker. Additionally, immune cell infiltration and its relationship with the gene biomarker were assessed using the CIBERSORT algorithm. The Integrated Traditional Chinese Medicine (ITCM) database was also referenced to identify Chinese medicines related to lipid metabolism and their possible connection to AD. This comprehensive strategy aims to integrate modern computational methods with traditional medicine to deepen our understanding of AD and its underlying mechanisms. The study identified 137 genes from a pool of 751 lipid metabolism-related genes (LMGs) significantly associated with autophagy and immune response mechanisms. Through the application of LASSO and SVM-RFE machine-learning techniques, four genes-choline acetyl transferase (CHAT), member RAS oncogene family (RAB4A), acyl-CoA binding domain-containing protein 6 (ACBD6), and alpha-galactosidase A (GLA)-emerged as potential biomarkers for Alzheimer's disease (AD). These genes demonstrated strong therapeutic potential due to their involvement in critical biological pathways. Notably, nine Chinese medicine compounds were identified to target these marker genes, offering a novel treatment approach for AD. Further, ceRNA network analysis revealed complex regulatory interactions involving these genes, underscoring their importance in AD pathology. CIBERSORT analysis highlighted a potential link between changes in the immune microenvironment and CHAT expression levels in AD patients, providing new insights into the immunological dimensions of the disease. The discovery of these gene markers offers substantial promise for the diagnosis and understanding of Alzheimer's disease (AD). However, further investigation is necessary to validate their clinical utility. This study illuminates the role of Lipid Metabolism-related Genes (LMGs) in AD pathogenesis, offering potential targets for therapeutic intervention. It enhances our grasp of AD's complex mechanisms and paves the way for future research aimed at refining diagnostic and treatment strategies.

Treatment of a mutant KRAS lung cancer cell line with polyisoprenylated cysteinyl amide inhibitors activates the MAPK pathway, inhibits cell migration and induces apoptosis.

KRAS mutations are the most common oncogenic mutations in lung adenocarcinoma in Black Americans. Polyisoprenylated Cysteinyl amide Inhibitors (PCAIs) constitute a group of potential cancer therapy agents that we designed to specifically disrupt and suppress hyperactive G-protein signaling, such as that caused by mutated RAS proteins. Here we determine the effects of PCAIs on the viability, G-protein levels, downstream mediators, and apoptosis-related proteins on the KRAS-mutated, Black American-derived lung adenocarcinoma cell line, NCI-H23. Of the 17 PCAIs tested, compounds NSL-YHJ-2-27 and NSL-YHJ-2-46 showed the most potency with EC50 values of 2.7 and 3.3 μM, respectively. Western blotting was used to determine the effect of the PCAIs on the phosphorylation levels of MAPK pathway enzymes. After 48 h exposure to 5 μM of the PCAIs, NSL-YHJ-2-46, the MAPK proteins BRAF, MEK1/2, ERK1/2, and p90RSK were activated through phosphorylation by 90, 190, 150 and 120%, respectively. However, CRAF/RAF1 phosphorylation decreased by 40%, suggesting significant changes in the KRAS/MAPK signaling patterns. Furthermore, 5 μM of NSL-YHJ-2-27 depleted the singly polyisoprenylated monomeric G-proteins RAC 1/2/3 and CDC42 by 77 and 76%, respectively. The depletion of these key cytoskeletal proteins may account for the observed inhibition of cell migration and invasion, and spheroid invasion observed on exposure to NSL-YHJ-2-27 and NSL-YHJ-2-46. Treatment with 5 μM of NSL-YHJ-2-27 suppressed full-length inactive caspase 3 and 7 levels by 72 and 91%, respectively. An analysis of cells treated with the fluorescently labeled active caspase 3/7 irreversible inhibitor, CaspaTagTM Caspase-3/7 in situ reagent revealed a 124% increase in active caspase at 3 μM over controls. These findings clearly show the direct effects of the PCAIs on the RAS signaling pathway. Given the profound increases observed in RPS6KA1/p90RSK phosphorylation, future work will involve a determination whether the proapoptotic isoforms of RPS6KA1/p90RSK are phosphorylated due to the PCAIs treatments. These results support the potential use of the PCAIs as targeted therapies against cancers with KRAS mutations.

Multi-gene mutations in ultrasound-guided fine-needle aspiration specimens of thyroid micronodules and diagnostic value in thyroid microcarcinomas using next-generation sequencing

Objective: To explore the detection of BRAF, RAS, TERT promoter, and TP53 gene mutations in solitary thyroid micronodule (TMN) specimens obtained by ultrasound-guided fine-needle aspiration (US-FNA) using next-generation sequencing (NGS) technology and assess its diagnostic value in thyroid microcarcinomas (TMC). Methods: On-site recruitment of 428 patients with single suspicious TMC who underwent thyroid ultrasound examination, US-FNA, and NGS from September 2018 to July 2021 at Beijing Tongren Hospital affiliated to Capital Medical University. A total of 147 patients were finally included. NGS was used to detect mutations in the BRAF, RAS, TERT promoter, and TP53 genes in the US-FNA specimens. Comparisons were made between patients with and without gene mutations in terms of age, gender, and the maximum diameter of nodules. The diagnostic efficiency of BRAF mutation for TMC was calculated using the receiver operating characteristic (ROC) curve, with postoperative pathology as the gold standard. Results: The age [M (Q1, Q3)] of the 147 patients was 43.0 (32.0, 51.0) years, and 37 were male (25.2%). Among the 147 US-FNA specimens, 97 (66.0%) were detected with BRAF gene mutations, all of which were p.V600E point mutation; 6 (4.1%) were detected with RAS gene mutation, and no TERT promoter or TP53 gene mutations were detected. Postoperative pathology confirmed that 136 cases were TMC, all of which were papillary thyroid microcarcinomas (PTMC); 11 cases (7.5%)were benign. Among 136 TMC samples, BRAF gene mutations were detected in 97 cases (71.3%). There were no statistically significant differences in age, gender, and maximum nodule diameter between patients with and without BRAF gene mutations (all P>0.05). The sensitivity and specificity of BRAF gene mutation in diagnosing TMC were 71.3% and 100.0%, respectively, with an area under the ROC curve (AUC) (95%CI) of 0.857 (0.789-0.925). For nodules classified as Bethesda Ⅲ-Ⅴ, the sensitivity and specificity were 63.0% and 100.0%, respectively, with an AUC (95%CI) of 0.815 (0.680-0.950). Conclusions: NGS technology can successfully detect multiple gene mutations in US-FNA specimens from TMN patients, especially BRAF gene mutation, and BRAF gene mutation has certain value in diagnosing TMC.

Myosin-5a facilitates stress granule formation by interacting with G3BP1

Stress granules (SGs) are non-membranous organelles composed of mRNA and proteins that assemble in the cytosol when the cell is under stress. Although the composition of mammalian SGs is both cell-type and stress-dependent, they consistently contain core components, such as Ras GTPase activating protein SH3 domain binding protein 1 (G3BP1). Upon stress, living cells rapidly assemble micrometric SGs, sometimes within a few minutes, suggesting that SG components may be actively transported by the microtubule and/or actin cytoskeleton. Indeed, SG assembly has been shown to depend on the microtubule cytoskeleton and the associated motor proteins. However, the role of the actin cytoskeleton and associated myosin motor proteins remains controversial. Here, we identified G3BP1 as a novel binding protein of unconventional myosin-5a (Myo5a). G3BP1 uses its C-terminal RNA-binding domain to interact with the middle portion of Myo5a tail domain (Myo5a-MTD). Suppressing Myo5a function in mammalian cells, either by overexpressing Myo5a-MTD, eliminating Myo5a gene expression, or treatment with myosin-5 inhibitor, inhibits the arsenite-induced formation of both small and large SGs. This is different from the effect of microtubule disruption, which abolishes the formation of large SGs but enhances the formation of small SGs under stress conditions. We therefore propose that, under stress conditions, Myo5a facilitates the formation of SGs at an earlier stage than the microtubule-dependent process.

Development and safety of investigational and approved drugs targeting the RAS function regulation in RAS mutant cancers.

The RAS gene family holds a central position in controlling key cellular activities such as migration, survival, metabolism, and other vital biological processes. The activation of RAS signaling cascades is instrumental in the development of various cancers. Although several RAS inhibitors have gained approval from the United States Food and Drug Administration (FDA) for their substantial antitumor effects, their widespread and severe adverse reactions significantly curtail their practical usage in the clinic. Thus, there exists a pressing need for a comprehensive understanding of these adverse events, ensuring the clinical safety of RAS inhibitors through the establishment of precise management guidelines, suitable intermittent dosing schedules, and innovative combination regimens. This review centers on the evolution of RAS inhibitors in cancer therapy, delving into the common adverse effects associated with these inhibitors, their underlying mechanisms, and the potential strategies for mitigation.