Lung cancer remains the leading cause of cancer-related deaths in men and women worldwide, and 85% of these patients have non-small cell lung cancer. In recent years, the clinical use of targeted drug therapy and immune checkpoint inhibitors has dramatically changed the treatment landscape for advanced NSCLC. The mechanism and the value of targeted therapies have been a hot topic of research, as KRAS is one of the earliest discovered and most frequently mutated oncogenes, which is activated by binding to GTP and triggers a series of cascade reactions in cell proliferation and mitosis. The KRAS protein acts as a molecular switch and is activated by binding to GTP, triggering a series of cascade responses in cell proliferation and mitosis. Clinically, patients with KRAS mutated NSCLC have poor response to systemic medical therapy and poor prognosis. Since the first report of KRAS gene in 1982, research on KRAS targeted therapeutics has been slow, and previous studies such as farnesyltransferase inhibitors and downstream protein inhibitors of KRAS signaling pathway have not achieved the expected results, making KRAS long defined as a "non-druggable target". The deeper understanding of the crystal structure of KRAS has led to the discovery of potential therapeutic sites for KRAS and the development of several drugs directly targeting KRAS, especially KRAS G12C inhibitors such as AMG510 (sotorasib) and MRTX849 (adagrasib), which have shown encouraging results in clinical trials. In recent years, studies on the therapeutic efficacy of immune checkpoint inhibitors for KRAS-mutated NSCLC have made some progress. In this review, we systematically introduce the basic understanding of RAS gene and clinical characteristics of KRAS mutated NSCLC patients, summarize the medical treatments for KRAS mutated NSCLC, including chemotherapy, anti-vascular drug therapy and tumor immunotherapy, and focus on the review and outlook of the research progress of KRAS targeted therapy.
Male ; Humans ; Female ; Carcinoma, Non-Small-Cell Lung/pathology* ; Lung Neoplasms/genetics* ; Proto-Oncogene Proteins p21(ras)/therapeutic use* ; Genes, ras ; Immune Checkpoint Inhibitors/therapeutic use* ; Guanosine Triphosphate/therapeutic use* ; Mutation

Objective To investigate the effect of Echinococcus granulosus cyst fluid(EgCF) on the cytoskeletal rearrangement and phagocytosis and the migration of macrophages induced by lipopolysaccharide(LPS). Methods Peritoneal macrophages of C57BL/6 mice were isolated and cultured in vitro, and divided into control group and LPS group and LPS combined with EgCF group. After 48 hours of treatment, filamentous actin (F-actin) changes were observed with rhodamine-labelled phalloidin staining and fluorescence microscopy; Transwell^TM chamber was used to test cell migration ability and flow cytometry to test cell phagocytosis. After 1 hour of treatment, PI3K and AKT, phosphorylated AKT (p-AKT), Rac1, guanosine triphospho-Rac1 (GTP-Rac1), WASP and Arp2 protein expressions were detected with Western blot analysis. Results Compared with the control group, after LPS stimulation, macrophages were deformed significantly; pseudopodia increased; actin cytoskeleton increased and was more distributed in pseudopodia; the ability of migration and phagocytosis were significantly improved, and the expression of PI3K, p-AKT, GTP-Rac1, WASP and Arp2 proteins significantly increased. EgCF treatment caused cell shrinkage and disappearance of pseudopodia protrusions of LPS-activated cells, and led to the reduced phagocytic and migratory of cells; the protein expression of PI3K, p-AKT, GTP-Rac1, WASP and Arp2 decreased significantly compared with the LPS group. Conclusion LPS induces the migration and enhances phagocytosis of macrophages while EgCF inhibits these effects, which is related to actin cytoskeleton rearrangement.
Mice ; Animals ; Lipopolysaccharides/pharmacology* ; Echinococcus granulosus/metabolism* ; Proto-Oncogene Proteins c-akt ; Cyst Fluid/metabolism* ; Mice, Inbred C57BL ; Macrophages/metabolism* ; Phagocytosis ; Actins/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Guanosine Triphosphate/pharmacology*

Dopa-responsive dystonia (DRD) is characterized by lower limb-onset, diurnally fluctuating dystonia and dramatic and sustained response to levodopa treatment. Segawa disease, an autosomal dominant deficiency of guanosine triphosphate cyclohydrolase 1 (encoded by GCH1) is the most common and well-known condition manifesting as DRD. However, similar clinical manifestations can be seen in individuals with deficiencies of other enzymes that are involved in the biosynthesis of dopamine. We describe the case of an 11-year-old girl who presented with abnormal gait, which had initially begun 2 years back. The patient showed diurnally fluctuating dystonia in both legs. She was able to walk without support in the morning, but was unable to stand without support in the evening. She had been diagnosed as having spastic cerebral palsy and had been managed with physical therapy at a local rehabilitation clinic. The patient had been healthy until the development of dystonia, and did not have a history of perinatal problems or developmental delay. Routine hematologic and biochemical test results were normal. Brain magnetic resonance imaging and electroencephalography showed no abnormalities. When levodopa was administered, the patient's abnormal gait dramatically improved 1 hour after receiving the medication. Genetic testing for the GCH1 gene revealed a missense mutation (c.293C>T [p.A98V]) that has previously been reported in patients with DRD. This case demonstrated that a levodopa trial is vital for accurate and early diagnosis of DRD in patients with dystonia resulting from an unknown cause.
Brain ; Cerebral Palsy* ; Child ; Diagnostic Errors ; Dopamine ; Dystonia* ; Early Diagnosis ; Electroencephalography ; Female ; Gait ; Genetic Testing ; Guanosine Triphosphate ; Humans ; Leg ; Levodopa ; Magnetic Resonance Imaging ; Mutation, Missense ; Rehabilitation

Guanylyl cyclase C (GC-C) is a member of a family of enzymes that metabolize GTP to cGMP and was first identified as a receptor for heat-stable enterotoxin. Guanylin (GNY) has since been identified as an endogenous ligand for GC-C in the intestine of several mammalian species. The GNY/GC-C system regulates ion transportation and pH in the mucosa. Recently, it was reported that GC-C and GNY are involved in lipid metabolism in rat mesenteric adipose tissue macrophages. To examine the role of GC-C and GNY in lipid metabolism in cattle, we used a bovine mesenteric adipocyte primary culture system and a coculture system for bovine adipocytes and GNY-/GC-C-expressing macrophages. Fat droplets were observed to accumulate in bovine mesenteric adipocytes cultured alone, whereas few fat droplets accumulated in adipocytes indirectly cocultured with macrophages. We also observed that GC-C was present in bovine mesenteric adipose tissue, and that fat droplet accumulation decreased after in vitro GNY administration. Expressions of mRNAs encoding lipogenic factors decreased significantly in adipocytes after either coculture or GNY administration. These results suggest that the GNY/GC-C system is part of the control system for lipid accumulation in bovine mesenteric adipose tissue.
Adipocytes ; Adipose Tissue* ; Animals ; Cattle* ; Coculture Techniques ; Enterotoxins ; Guanosine Triphosphate ; Guanylate Cyclase* ; Humans ; Hydrogen-Ion Concentration ; In Vitro Techniques ; Intestines ; Ion Transport ; Lipid Metabolism ; Macrophages ; Mucous Membrane ; Rats ; RNA, Messenger

Tomato extract has been shown to exert antiplatelet activity in vitro and to change platelet function ex vivo, but with limitations. In this study, antiplatelet activity of water soluble tomato concentrate (Fruitflow I) and dry water soluble tomato concentrate (Fruitflow II) was investigated using rat platelets. Aggregation was induced by collagen and adenosine diphosphate and granule-secretion, [Ca2+]i, thromboxane B2, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) levels were examined. The activation of integrin αIIbβ3 and phosphorylation of signaling molecules, including mitogen-activated protein kinase (MAPK) and PI3K/Akt, were investigated by flow cytometry and immunoblotting, respectively. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) were examined. Moreover, in vivo thrombus weight was tested by an arteriovenous shunt model. Fruitflow I and Fruitflow II significantly inhibited agonist induced platelet aggregation, adenosine triphosphate and serotonin release, [Ca2+]i, and thromboxane B2 concentration, while having no effect on cAMP and cGMP levels. Integrin αIIbβ3 activation was also significantly decreased. Moreover, both concentrates reduced phosphorylation of MAPK pathway factors such as ERK, JNK, P38, and PI3K/Akt. In vivo thrombus formation was also inhibited. Taken together, these concentrates have the potential for ethnomedicinal applications to prevent cardiovascular ailments and can be used as functional foods.
Adenosine Diphosphate ; Adenosine Monophosphate ; Adenosine Triphosphate ; Animals ; Blood Platelets* ; Cardiovascular Diseases ; Collagen ; Flow Cytometry ; Functional Food ; Guanosine Monophosphate ; Immunoblotting ; In Vitro Techniques ; Lycopersicon esculentum* ; Partial Thromboplastin Time ; Phosphorylation ; Platelet Aggregation ; Protein Kinases* ; Prothrombin Time ; Rats ; Serotonin ; Thrombosis ; Thromboxane B2 ; Water*

OBJECTIVE: This study is to compare the effects of green tea polyphenol (GTP) pre-treatment with those of GTP post-treatment on cisplatin (CP)-induced nephrotoxicity in rat. METHODS: Male Sprague-Dawley rats were randomly divided into six groups. Animals in the control group received 0.9% saline (intraperitoneal); animals in the GTP group received 0.9% saline and GTP (0.2% GTP as their sole source of drinking water); the CP group received only CP (7 mg/kg, intraperitoneal); the CP+preGTP group received GTP from two days before CP to four days after CP and the CP+postGTP group received GTP for four days after CP. CP-induced renal toxicity was evaluated by plasma creatinine and blood urea nitrogen (BUN) concentrations; kidney tissue gamma-glutamyl transpeptidase (GGT) and alkaline phosphatase (AP) activities and histopathological examinations. RESULTS: High serume creatinine and BUN concentrations were observed in CP treated rats. The GGT and AP activites were lower in kidney of CP treated rats compared to control rats. In addition, treatment with CP resulted in development of a marked tubular necrosis, and tubular dilation in kidney of rats. Pretreatment with GTP resulted in markedly reduced elevation of serum creatinine and BUN amounts and changes of GGT and AP activity in kidney induced by CP. CP-induced histopathological changes, including tubular necrosis and dilation, were ameliorated in GTP pre-treated rats, compared to CP alone or GTP post-treated rats. CONCLUSION: These results demonstrate that GTP might have some protective effect against CP-induced nephrotoxicity in rat, and GTP pre-treatment was more effective than GTP post-treatment on reduction of CP-induced renal dysfunction.
Alkaline Phosphatase ; Animals ; Blood Urea Nitrogen ; Cisplatin ; Creatinine ; Drinking ; gamma-Glutamyltransferase ; Guanosine Triphosphate ; Humans ; Kidney ; Male ; Necrosis ; Plasma ; Rats* ; Rats, Sprague-Dawley ; Tea*

Nucleoside diphosphate kinase (Ndk) is ubiquitous and highly conserved multifunctional key enzyme in nucleotide metabolism. It generates nucleoside triphosphates (NTPs) by transfer of gamma-phosphates from nucleoside triphosphates such as ATP or GTP to nucleoside diphosphate. The formation of an autophosphorylated enzyme intermediate is involved in that mechanism. The phosphate is usually supplied by ATP and Ndk activity in different subcellular compartments. Ndk may regulate the crucial balance between ATP and GTP or other nucleoside triphosphates. Ndk is playing an important role in bacterial pathogenesis and emerging evidences recognize multiple roles of Ndk in host-microbe interaction. Here, I review some examples of the role of Ndk in intra- and extracellular microorganism.
Adenosine Triphosphate ; Guanosine Triphosphate ; Nucleoside-Diphosphate Kinase

We investigated dietary effects of green tea powder (GTP) on plasma lipids, platelet aggregation, hemolysis, plasma TBARS, and liver enzymes. Thirty one volunteer diving women living on Jeju island consumed 4 g green tea powder daily for a period of four weeks and data for the study subjects were analyzed on the basis of diagnostic criteria for blood pressure (BP)(> or = 140/90 mmHg), plasma total cholesterol (TC)(> or = 200 mg/dL), and triglyceride (TG)(> or = 150mg/dL). Subjects with high BP had significantly higher TC and TG than those with normal BP. Subjects with higher TC had higher TG, and those with higher TG had lower HDL cholesterol. Platelet aggregation in the initial slope was significantly higher in subjects with normal BP, normal TC, or normal TG than their counterparts in high BP, TC, and TG. HDL cholesterol after GTP intake increased only in subject groups with normal BP, normal TC, or normal TG, and plasma TG after GTP intake decreased only in groups with higher BP, higher TG, or higher TC. Plasma TC and TG in subjects with normal BP increased after GTP intake. GTP intake caused a decrease in the initial slope of platelet aggregation in all subject groups with little effect on maximum aggregation. Total bilirubin showed a significant increase and GOT increased in all subject groups after GTP intake. Beneficial effects of short term intake of green tea powder might differ depending on the subject conditions in terms of blood pressure, plasma lipids, and other cardiovascular conditions. However, with the hypolipidemic, antithrombotic, and antioxidant actions of its bioactive flavonoids, long term usage of GTP or brewed green tea may provide preventive effects against cardiovascular disease.
Bilirubin ; Blood Platelets ; Blood Pressure ; Cardiovascular Diseases ; Cholesterol ; Cholesterol, HDL ; Diving ; Female ; Flavonoids ; Guanosine Triphosphate ; Hemolysis ; Humans ; Liver ; Plasma ; Platelet Aggregation ; Tea ; Thiobarbituric Acid Reactive Substances

As a large family of hydrolases, GTPases are widespread in cells and play the very important biological function of hydrolyzing GTP into GDP and inorganic phosphate through binding with it. GTPases are involved in cell cycle regulation, protein synthesis, and protein transportation. Chaperones can facilitate the folding or refolding of nascent peptides and denatured proteins to their native states. However, chaperones do not occur in the native structures in which they can perform their normal biological functions. In the current study, the chaperone activity of the conserved GTPases of Escherichia coli is tested by the chemical denaturation and chaperone-assisted renaturation of citrate synthase and α-glucosidase. The effects of ribosomes and nucleotides on the chaperone activity are also examined. Our data indicate that these conserved GTPases have chaperone properties, and may be ancestral protein folding factors that have appeared before dedicated chaperones.
Citrate (si)-Synthase ; chemistry ; Cloning, Molecular ; Conserved Sequence ; Escherichia coli ; cytology ; enzymology ; GTP Phosphohydrolases ; chemistry ; genetics ; isolation & purification ; metabolism ; Guanosine Diphosphate ; pharmacology ; Guanosine Triphosphate ; analogs & derivatives ; pharmacology ; Molecular Chaperones ; chemistry ; genetics ; isolation & purification ; metabolism ; Protein Denaturation ; drug effects ; Protein Renaturation ; drug effects ; Ribosomes ; metabolism ; alpha-Glucosidases ; chemistry

The guanine-nucleotide exchange factor (GEF) RalGPS1a activates small GTPase Ral proteins such as RalA and RalB by stimulating the exchange of Ral bound GDP to GTP, thus regulating various downstream cellular processes. RalGPS1a is composed of an Nterminal Cdc25-like catalytic domain, followed by a PXXP motif and a C-terminal pleckstrin homology (PH) domain. The Cdc25 domain of RalGPS1a, which shares about 30% sequence identity with other Cdc25-domain proteins, is thought to be directly engaged in binding and activating the substrate Ral protein. Here we report the crystal structure of the Cdc25 domain of RalGPS1a. The bowl shaped structure is homologous to the Cdc25 domains of SOS and RasGRF1. The most remarkable difference between these three Cdc25 domains lies in their active sites, referred to as the helical hairpin region. Consistent with previous enzymological studies, the helical hairpin of RalGPS1a adopts a conformation favorable for substrate binding. A modeled RalGPS1a-RalA complex structure reveals an extensive binding surface similar to that of the SOS-Ras complex. However, analysis of the electrostatic surface potential suggests an interaction mode between the RalGPS1a active site helical hairpin and the switch 1 region of substrate RalA distinct from that of the SOS-Ras complex.
Amino Acid Sequence ; Binding Sites ; Catalytic Domain ; Cloning, Molecular ; Crystallography, X-Ray ; Escherichia coli ; Guanosine Diphosphate ; metabolism ; Guanosine Triphosphate ; metabolism ; Humans ; Models, Molecular ; Molecular Conformation ; Molecular Sequence Data ; Plasmids ; metabolism ; Protein Binding ; Protein Structure, Tertiary ; genetics ; Recombinant Proteins ; chemistry ; genetics ; metabolism ; ral GTP-Binding Proteins ; chemistry ; genetics ; metabolism ; ral Guanine Nucleotide Exchange Factor ; chemistry ; genetics ; metabolism