Assessments of CYP­inhibition­based drug-drug interaction between vonoprazan and poziotinib in vitro and in vivo.

CONTEXT: Poziotinib and vonoprazan are two drugs mainly metabolized by CYP3A4. However, the drug-drug interaction between them is unknown. OBJECTIVE: To study the interaction mechanism and pharmacokinetics of poziotinib on vonoprazan. MATERIALS AND METHODS: In vitro experiments were performed with rat liver microsomes (RLMs) and the contents of vonoprazan and its metabolite were then determined with UPLC-MS/MS after incubation of RLMs with vonoprazan and gradient concentrations of poziotinib. For the in vivo experiment, rats in the poziotinib treated group were given 5 mg/kg poziotinib by gavage once daily for 7 days, and the control group was only given 0.5% CMC-Na. On Day 8, tail venous blood was collected at different time points after the gavage administration of 10 mg/kg vonoprazan, and used for the quantification of vonoprazan and its metabolite. DAS and SPSS software were used for the pharmacokinetic and statistical analyses. RESULTS: In vitro experimental data indicated that poziotinib inhibited the metabolism of vonoprazan (IC50 = 10.6 µM) in a mixed model of noncompetitive and uncompetitive inhibition. The inhibitory constant Ki was 0.574 µM and the binding constant αKi was 2.77 µM. In vivo experiments revealed that the AUC(0-T) (15.05 vs. 90.95 µg/mL·h) and AUC(0-∞) (15.05 vs. 91.99 µg/mL·h) of vonoprazan increased significantly with poziotinib pretreatment. The MRT(0-∞) of vonoprazan increased from 2.29 to 5.51 h, while the CLz/F value decreased from 162.67 to 25.84 L/kg·h after pretreatment with poziotinib. CONCLUSIONS: Poziotinib could significantly inhibit the metabolism of vonoprazan and more care may be taken when co-administered in the clinic.

Identification and drug metabolic characterization of four new CYP2C9 variants CYP2C9*72-*75 in the Chinese Han population.

Cytochrome 2C9 (CYP2C9), one of the most important drug metabolic enzymes in the human hepatic P450 superfamily, is required for the metabolism of 15% of clinical drugs. Similar to other CYP2C family members, CYP2C9 gene has a high genetic polymorphism which can cause significant racial and inter-individual differences in drug metabolic activity. To better understand the genetic distribution pattern of CYP2C9 in the Chinese Han population, 931 individuals were recruited and used for the genotyping in this study. As a result, seven synonymous and 14 non-synonymous variations were identified, of which 4 missense variants were designated as new alleles CYP2C9*72, *73, *74 and *75, resulting in the amino acid substitutions of A149V, R150C, Q214H and N418T, respectively. When expressed in insect cell microsomes, all four variants exhibited comparable protein expression levels to that of the wild-type CYP2C9 enzyme. However, drug metabolic activity analysis revealed that these variants exhibited significantly decreased catalytic activities toward three CYP2C9 specific probe drugs, as compared with that of the wild-type enzyme. These data indicate that the amino acid substitution in newly designated variants can cause reduced function of the enzyme and its clinical significance still needs further investigation in the future.

Effects of Simvastatin on the Metabolism of Vonoprazan in Rats Both in vitro and in vivo.

Purpose: To study the potential drug-drug interactions between simvastatin and vonoprazan and to provide the scientific basis for rational use of them in clinical practice. Methods: An incubation system was established with rat liver microsomes, and the main metabolite of vonoprazan M-I was detected by UPLC-MS/MS. The IC50 value of simvastatin was then calculated and its inhibitory mechanism against vonoprazan was also analyzed. Twelve SD rats were randomly divided into 2 groups, then they were given simvastatin or saline for 2 weeks continuously. On the day of the experiment, both groups were intragastrically administered with vonoprazan once, followed by the collection of blood at different time points. Then the plasma concentration of vonoprazan and M-I in rats were detected by UPLC-MS/MS. Results: In vitro experiments revealed that simvastatin could inhibit the metabolism of vonoprazan, and its inhibition type belonged to the mixed non-competitive and competitive inhibition model. In vivo experiments in rats demonstrated that the area under concentration time curve (AUC) of vonoprazan was decreased but the clearance (CLz/F) of it was increased in the simvastatin administrated group, as compared to those of the control group. However, M-I in simvastatin treated group exhibited the higher AUC and lower CLz/F values compared to those in the control group. These data indicated that multiple doses of simvastatin administration could reduce the plasma concentration of vonoprazan and accelerate its metabolic rate in rats. Conclusion: Simvastatin could inhibit the metabolism of vonoprazan in vitro but multiple doses of simvastatin exhibited the opposite effect In vivo. Altogether, our data indicated that an interaction existed between simvastatin and vonoprazan and additional cares might be taken when they were co-administrated in clinic.

Insights regarding novel biomarkers and the pathogenesis of primary colorectal carcinoma based on bioinformatic analysis.

BACKGROUND: Biomarkers are important in the study of tumor processes for early detection and precise treatment. The biomarkers that have been previously detected are not useful for clinical application for primary colorectal carcinoma (PCRC). The aim of this study was to explore clinically valuable biomarkers of PCRC based on integrated bioinformatic analysis. MATERIAL AND METHODS: Gene expression data were acquired from the GSE41258 dataset, and the differentially expressed genes were determined between PCRC and normal colorectal samples. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were implemented via Gene Set Enrichment Analysis. A protein-protein interaction (PPI) network was constructed. The significant modules and hub genes were screened and identified in the PPI network. RESULTS: A total of 202 DEGs were identified, including 58 upregulated and 144 downregulated genes in PCRC samples compared to those in normal colorectal samples. Enrichment analysis demonstrated that the gene sets enriched in PCRC were significantly related to bicarbonate transport, regulation of sodium ion transport, potassium ion homeostasis, regulation of telomere maintenance, and other processes. A total of 10 hub genes was identified by cytoHubba: PYY, CXCL3, CXCL11, CXCL8, CXCL12, CCL20, MMP3, P2RY14, NPY1R, and CXCL1. CONCLUSION: The hub genes, such as NPY1R, P2RY14, and CXCL12, and the electrolyte disequilibrium resulting from the differential expression of genes, especially bicarbonate imbalance, may provide novel insights and evidence for the future diagnosis and targeted therapy of PCRC.

Inhibition of Aurora-B suppresses osteosarcoma cell migration and invasion.

Previous studies have suggested that Aurora-B may be involved in cancer metastasis. However, its role has been poorly evaluated in osteosarcoma (OS). The aim of this study was to investigate the correlation between Aurora-B expression and metastasis in human OS. The human OS cell line, U2-OS, and OS biopsy specimens were used in the study. The expression of Aurora-B protein was examined using immunohistochemistry and western blotting in OS tissues and U2-OS cells, respectively. AZD1152-hydroxyquinazoline-pyrazol-anilide, an inhibitor of Aurora-B, was used to inhibit Aurora-B expression in U2-OS cells. The effect of Aurora-B inhibition on U2-OS cell proliferation, invasion and migration was assessed using MTT, colony formation, wound healing and Transwell assays. The results showed that positive expression of the Aurora-B protein was observed in the nucleus, and that Aurora-B expression levels in the cases with pulmonary metastases were significantly higher than in those without metastasis. In vitro, the proliferation, invasion and migration of U2-OS cells were suppressed by the inhibition of Aurora-B. These results suggest that Aurora-B may be involved in OS metastasis, and may be a promising target in the treatment of OS metastasis.

Lapatinib alters the malignant phenotype of osteosarcoma cells via downregulation of the activity of the HER2-PI3K/AKT-FASN axis in vitro.

Lapatinib, an inhibitor of human epidermal growth factor receptor 2 (HER2) phosphorylation, has been reported to inhibit several types of tumors such as HER2-overexpressing breast cancer. However, the effect of lapatinib on the malignant phenotype of human osteosarcoma (OS) cells and the potential molecular mechanisms remain unclear. To elucidate the effect of lapatinib on OS, two OS cell lines, U2-OS and MG-63, were utilized in the present study. Various concentrations of lapatinib were used to treat OS cells for different time durations. Cell proliferation was evaluated by MTT and colony formation assays. Flow cytometry (FCM) was used to evaluate cell apoptosis. Wound healing and Transwell invasion assays were performed to examine the migratory and invasive abilities of the cells. To investigate the possible molecular mechanisms involved, the expression of p-HER2, phosphatidylinositol 3-kinase (PI3K), p-AKT, AKT and fatty acid synthase (FASN) protein was detected by western blotting. MTT assays showed that lapatinib inhibited the proliferation of U2-OS and MG-63 cells in a dose- and time-dependent manner, and the rate of colony formation of the lapatinib-treated cells was significantly lower when compared to those cells not treated with lapatinib in both cell lines. FCM assay revealed a significantly higher apoptotic rate in the lapatinib-treated OS cells. Wound healing and Transwell invasion assays revealed that the migratory and invasive abilities of OS cells were significantly inhibited by lapatinib (P<0.05). Western blotting showed that lapatinib suppressed the activity of HER2-PI3K/AKT-FASN in U2-OS and MG-63 cells in vitro. These results suggest that lapatinib may alter the malignant phenotype of OS cells via downregulation of the activity of the HER2-PI3K/AKT-FASN signaling pathway in vitro. Thus, lapatinib may be an effective chemotherapeutic agent for the treatment of osteosarcoma.

Positive feedback regulation between Akt phosphorylation and fatty acid synthase expression in osteosarcoma.

The activation of PI3K/Akt and the overexpression of fatty acid synthase (FASN) are frequently observed in human osteosarcoma (OS). In the present study, in order to investigate the possible association between the phosphorylation of Akt and FASN expression, immunohistochemical staining was conducted on 24 OS specimens from patients with pulmonary metastasis, which revealed a significant positive correlation between phosphorylated Akt (p-Akt) and the expression of FASN (R=0.469, P=0.04). To investigate the association between p-Akt and FASN in vitro, human U2-OS OS cells were treated with FASN-specific RNAi plasmid or LY294002 (an inhibitor of PI3k/Akt). The mRNA levels of Akt and FASN were measured by real-time PCR. Western blot analysis was also performed to detect the protein experession of PI3K, Akt, p-Akt and FASN. The results demonstrated that the PI3K/Akt signaling pathway modulates FASN expression; the inhibition of FASN resulted in the downregulation of p-Akt in the U2-OS cells. Furthermore, the effects induced by the inhibition of the activity of p-Akt or FASN on the malignant phenotype of U2-OS cells were investigated, demonstrating that the malignant phenotype was inhibited by suppressing the activity of PI3K/Akt or FASN in the U2-OS cells. The findings from our study suggest the existence of a positive feedback regulation between Akt phosphorylation and FASN expression and that this loop may play an important role in the malignant phenotype of OS cells.

Expression and significance of Musashi-1 in gastric cancer and precancerous lesions.

AIM: To investigate expression of stem cell marker Musashi-1 (Msi-1) in relationship to tumorigenesis and progression of intestinal-type gastric cancer (GC). METHODS: Endoscopic biopsy specimens and surgical specimens were obtained, including 54 cases of intestinal-type GC, 41 high-grade intraepithelial neoplasia, 57 low-grade intraepithelial neoplasia, 31 intestinal metaplasia, and 36 normal gastric mucosa. Specimens were fixed in 10% paraformaldehyde, conventionally dehydrated, embedded in paraffin, and sliced in 4-µm-thick serial sections. Two-step immunohistochemical staining was used to detect Msi-1 and proliferating cell nuclear antigen (PCNA) expression. Correlation analysis was conducted between Msi-1 and PCNA expression. The relationship between Msi-1 expression and clinicopathological parameters of GC was analyzed statistically. RESULTS: There were significant differences in Msi-1 and PCNA expression in different pathological tissues (χ² = 15.37, P < 0.01; χ² = 115.36, P < 0.01). Msi-1 and PCNA-positive cells were restricted to the isthmus of normal gastric glands. Expression levels of Msi-1 and PCNA in intestinal metaplasia were significantly higher than in normal mucosa (U = 392.0, P < 0.05; U = 40.50, P < 0.01), whereas there was no significant difference compared to low or high-grade intraepithelial neoplasia. Msi-1 and PCNA expression in intestinal-type GC was higher than in high-grade intraepithelial neoplasia (U = 798.0, P < 0.05; U = 688.0, P < 0.01). There was a significantly positive correlation between Msi-1 and PCNA expression (r(s) = 0.20, P < 0.01). Msi-1 expression in GC tissues was correlated with their lymph node metastasis and tumor node metastasis stage (χ² = 12.62, P < 0.01; χ² = 11.24, P < 0.05), but not with depth of invasion and the presence of distant metastasis. CONCLUSION: Msi-1-positive cells may play a key role in the early events of gastric carcinogenesis and may be involved in invasion and metastasis of GC.

Inhibiting valosin-containing protein suppresses osteosarcoma cell metastasis via AKT/nuclear factor of kappa B signaling pathway in vitro.

BACKGROUND AND AIM: The strategies of targeting valosin-containing protein (VCP) may have therapeutic potential for treating cancer metastasis. In this study, we aim to investigate the correlation of VCP protein expression in osteosarcoma (OS) tissues with pulmonary metastasis and its possible molecular mechanism. MATERIALS AND METHODS: Expression of VCP in 60 OS specimens was detected by immunohistochemistry (IHC) and the relationship with metastasis was analyzed. An artificial micro ribonucleic acid, targeting VCP, was performed to silence the expression of VCP in U2-OS cells. Cell mobility was detected by wound healing and Transwell assays. Western blot and real-time polymerase chain reaction were performed to investigate the expression of VCP in U2-OS cells. Furthermore, the protein of pAKT (phosphorylated serine/threonine protein kinase) and nuclear factor of kappa B protein 65 were measured by western blot to evaluate the effect of silencing VCP on AKT/nuclear factor of kappa B (NF-kB) signaling pathway. RESULTS: The results showed that the expression level of VCP protein in cases with pulmonary metastases was significantly higher than that in those without metastasis (P = 0.004). The invasion and migration of U2-OS cells were suppressed by silencing VCP. Furthermore, silencing VCP could down-regulate the phosphorylation of AKT and nuclear transfer of NF-kB. CONCLUSIONS: Our findings suggested that inhibition of VCP could suppress OS cells invasion and migration through down-regulating AKT/NF-kB signaling pathway.

Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro.

FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the "HER2/PI3K/AKT" axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.

Fatty acid synthase expression in osteosarcoma and its correlation with pulmonary metastasis.

Previous experimental evidence has suggested that fatty acid synthase (FASN) may be involved in cancer metastasis. However, its role has been poorly evaluated in osteosarcoma. The aim of this study was to investigate the correlation of FASN expression with pulmonary metastasis and the correlation of FASN expression with the Ki-67 antigen, a proliferation marker, in patients with osteosarcoma of the extremities. The expression of FASN protein and Ki-67 was detected by immunohistochemistry of biopsy tissues from 136 patients with osteosarcoma of the extremities and 21 cases of osteoenchondroma. Positive expression of the FASN protein was observed and located in the cytoplasm. The positive expression rate of FASN was 63.2% in osteosarcoma and 28.6% in osteoenchondroma (p<0.05). The expression levels of the FASN protein were higher in the cases with lung metastasis compared to those without metastasis (p<0.01). The percentage of Ki-67 stained nuclei in osteosarcoma with pulmonary metastasis and in those without was 43.43±10.05 and 25.41±6.68%, respectively (p<0.01). There was a positive correlation between FASN and Ki-67 protein expression in osteosarcoma (Spearman's rho, F=43.05, R=0.734). Therefore, FASN may be a promising target in the treatment of osteosarcoma metastasis.

Identification of Nedd4 as a novel regulator in Hedgehog signaling.

BACKGROUND: Hedgehog (Hh) signaling plays an important role in both embryonic development and postnatal tissue homeostasis. Aberrant Hh activation results in a large variety of cancers. This study was designed to discover novel modulators in Hh signaling pathway. METHODS: We performed yeast-two-hybrid screening and immunoprecipitation to identify the interaction of Nedd4 and Smo. To verify whether Nedd4 is involved in the regulation of Hh signaling, we monitored the activation of Gli-luciferase reporter by overexpressing Nedd4 together with Gli-luciferase reporter. In order to examine the role of endogenous Nedd4 in regulating Hh signaling, we used a short hairpin RNA (shRNA) interference strategy to silence the Nedd4 expression, and then perform dual-luciferase reporter assay. Statistical comparisons were performed by Student's t tests. RESULTS: We showed that Nedd4 binds to Smo in the transfected HEK293 cells. Overexpression of Nedd4 alone did not significantly activate the Gli reporter compared to pcDNA3 control (Nedd4 group: dimethyl sulfoxide (DMSO), relative luciferase unit (RLU) 1.87 ± 0.41). However, Smo agonist (SAG)-stimulated activation of Gli-luciferase reporter was markedly potentiated in Nedd4 transfected cells (Nedd4 group: SAG, RLU 13.49 ± 1.04, P < 0.05), indicating that overexpression of Nedd4 increases Gli luciferase reporter activity and Nedd4-induced activation of Hh signaling is activity dependent. In Nedd4 knockdown NIH 3T3 cells, the luciferase reporter activity was measured basally and after SAG treatment. In scrambled cells, compared to DMSO, SAG could activate reporter activity by (4.16 ± 0.84)-fold. In Nedd4 knockdown cells, the luciferase reporter activation by SAG was significantly inhibited (SAG, RLU 1.72 ± 0.24, P < 0.05); knockdown of Nedd4 did not change the basal activity of luciferase activity (DMSO, RLU 0.86 ± 0.11), suggesting that the loss of Nedd4 expression diminishes Gli-dependent activity in the Hh pathway and the regulation of Nedd4 in the Hh signaling pathway is activity-dependent. CONCLUSION: Nedd4 positively regulates the Hh pathway and provides a potential target for inhibiting Hh signaling in cancer therapy.

Inhibition of fatty acid synthase supresses osteosarcoma cell invasion and migration.

BACKGROUND: Fatty acid synthase (FASN) is overexpressed in a variety of human cancers, and may be involved in cancer metastasis. Hence, the strategies targeted on FASN may have therapeutic potential for treating cancer metastasis. OBJECTIVES: The aim of this study is to investigate the correlation of FASN expression with metastasis in human osteosarcoma. MATERIALS AND METHODS: Human osteosarcoma cell lines U2-OS and osteosarcoma biopsy specimens were employed in this study. The expression of FASN protein in osteosarcoma specimens was detected by IHC (immunohistochemistry) and the relationship with metastasis was analyzed. We performed the cerulenin, an inhibitor of FASN, to inhibit FASN expression in U2-OS cells. Western blot and RT-PCR were performed to investigate the expression of FASN in U2-OS cells. Cells mobility was detected by wound healing and Transwell assays. RESULTS: Results showed that the FASN expression level in the cases with pulmonary metastases was significantly higher than in those without metastasis. In vitro, the invasion and migration of U2-OS cells were suppressed by inhibiting FASN. Our findings suggested that FASN may be involved in osteosarcoma metastasis.

[Hypocholesterolemic effect of stilbene extract from Cajanus cajan L. on serum and hepatic lipid in diet-induced hyperlipidemic mice].

Cajanus cajan L. is a natural plant, which contains a lot of potential active components. In the present study, we identified the effects of the stilbene extract from Cajanus cajan L. (sECC) on hepatic cholesterol metabolism in diet-induced (for 4 weeks) hyperlipidemic Kunming mice. All experimental mice were divided into 5 groups: control group, high lipid model group, sECC-treated with 200 or 100 mg kg(-1), and simvastatin (Sim, 12 mg kg(-1)) treated group. The mice were fed with fat and cholesterol-enriched chow except control mice that were fed with standard diet. The effects of sECC were investigated by monitoring serum and liver lipid profile (i. e. cholesterol homeostasis) in mice. To further explore the mechanism of sECC, hepatic cholesterol 7alpha-hydroxylase (CYP7A1) and low density lipoprotein (LDL) receptor expressions in cholesterol homeostasis were analyzed by reverse transcription PCR. After 4 weeks pretreatment, the mice in the high lipid model group showed markedly higher serum and hepatic lipid contents than control group (P< 0.01). Compared with high lipid model group, the increased serum and hepatic lipid contents were markedly attenuated by sECC (200 mg kg(-1)), the serum and hepatic total cholesterol were reduced by 31.5% and 22.7% (P<0.05), respectively. The triglyceride contents of serum and liver were also lowered by 23.0% and 14.4%, respectively. At the same times, serum LDL cholesterol decreased by 53.0% (P<0.01). The mRNA expressions of hepatic CYP7A1 and LDL-receptor were significantly enhanced in the mice administered with sECC (200 mg kg(-1)), whereas those expressions were suppressed by the fat and cholesterol-enriched diet. These data indicate that sECC reduces the atherogenic properties of dietary cholesterol in mice. It is indicated that expression enhancement of hepatic LDL-receptor and cholesterol 7alpha-hydroxylase may be responsible for the hypercholesterolemic effect.

Hypocholesterolemic effect of stilbenes containing extract-fraction from Cajanus cajan L. on diet-induced hypercholesterolemia in mice.

Cajanus cajan (L) is a natural plant which contains a lot of potential active components. In the present study, we identified the effects of the stilbenes containing extract-fraction from Cajanus cajan L (sECC) on diet-induced (for 4 weeks) hypercholesterolemia in Kunming mice. All experimental mice were divided into 5 groups: control group, model group, sECC-treated with 200 or 100 mg/kg/day, and simvastatin group. The effects of sECC were investigated by monitoring serum and liver lipid profile (cholesterol homeostasis and triglyceride) as well as serum superoxide dismutase activity in those mice. To further explore the mechanism of sECC, hepatic 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase), cholesterol 7α-hydroxylase (CYP7A1), and low density lipoprotein receptor (LDL receptor) expressions in cholesterol homeostasis were analyzed by reverse transcription PCR. After 4 weeks pretreatment, compared with model group, the increased serum and hepatic total cholesterol were markedly attenuated by sECC (200 mg/kg) by 31.4% and 22.7% (p<0.01), respectively, the triglyceride levels of serum and liver were also lowered by 22.98% and 14.39%, respectively. At the same time, serum LDL cholesterol decreased by 52.8% (p<0.01) accompanied with the activities of serum superoxide dismutase increased by 20.98%. Atherogenic index and body weight were also reduced markedly. The mRNA expressions of HMG-CoA reductase, CYP7A1, and LDL-receptor were significantly enhanced in the mice administered with sECC (200 mg/kg/day), whereas those expressions were suppressed by the hypercholesterolemic diet. These data indicate that sECC reduces the atherogenic properties of dietary cholesterol in mice. Its hypocholesterolemic effect may involve enhancement of the hepatic LDL-receptor and cholesterol 7alpha-hydroxylase expression levels and bile acid synthesis.