Design, synthesis, and antitumor activity evaluation of potent fourth-generation EGFR inhibitors for treatment of Osimertinib resistant non-small cell lung cancer (NSCLC).

Epidermal growth factor receptor (EGFR) is one of the most studied drug targets for treating non-small-cell lung cancer (NSCLC). However, there are no approved inhibitors for the C797S resistance mutation caused by the third-generation EGFR inhibitor (Osimertinib). Therefore, the development of fourth-generation EGFR inhibitors is urgent. In this study, we clarified the structure-activity relationship of several synthesized compounds as fourth-generation inhibitors against human triple (Del19/T790M/C797S) mutation. Representative compound 52 showed potent inhibitory activity against EGFRL858R/T790M/C797S with an IC50 of 0.55 nM and significantly inhibited the proliferation of the Ba/F3 cell line harboring EGFRL858R/T790M/C797S with an IC50 of 43.28 nM. Moreover, 52 demonstrated good pharmacokinetic properties and excellent in vivo efficacy. Overall, the compound 52 can be considered a promising candidate for overcoming EGFR C797S-mediated mutations.

Chronological Changes of Viral Shedding in Adult Inpatients With COVID-19 in Wuhan, China.

BACKGROUND: In December 2019, the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out in Wuhan. Epidemiological and clinical characteristics of patients with COVID-19 have been reported, but the relationships between laboratory features and viral load has not been comprehensively described. METHODS: Adult inpatients (≥18 years old) with COVID-19 who underwent multiple (≥5 times) nucleic acid tests with nasal and pharyngeal swabs were recruited from Renmin Hospital of Wuhan University, including general patients (n = 70), severe patients (n = 195), and critical patients (n = 43). Laboratory data, demographic data, and clinical data were extracted from electronic medical records. The fitted polynomial curve was used to explore the association between serial viral loads and illness severity. RESULTS: Viral load of SARS-CoV-2 peaked within the first few days (2-4 days) after admission, then decreased rapidly along with virus rebound under treatment. Critical patients had the highest viral loads, in contrast to the general patients showing the lowest viral loads. The viral loads were higher in sputum compared with nasal and pharyngeal swab (P = .026). The positive rate of respiratory tract samples was significantly higher than that of gastrointestinal tract samples (P < .001). The SARS-CoV-2 viral load was negatively correlated with portion parameters of blood routine and lymphocyte subsets and was positively associated with laboratory features of cardiovascular system. CONCLUSIONS: The serial viral loads of patients revealed whole viral shedding during hospitalization and the resurgence of virus during the treatment, which could be used for early warning of illness severity, thus improve antiviral interventions.

Prominent changes in blood coagulation of patients with SARS-CoV-2 infection.

Background As the number of patients increases, there is a growing understanding of the form of pneumonia sustained by the 2019 novel coronavirus (SARS-CoV-2), which has caused an outbreak in China. Up to now, clinical features and treatment of patients infected with SARS-CoV-2 have been reported in detail. However, the relationship between SARS-CoV-2 and coagulation has been scarcely addressed. Our aim is to investigate the blood coagulation function of patients with SARS-CoV-2 infection. Methods In our study, 94 patients with confirmed SARS-CoV-2 infection were admitted in Renmin Hospital of Wuhan University. We prospectively collect blood coagulation data in these patients and in 40 healthy controls during the same period. Results Antithrombin values in patients were lower than that in the control group (p < 0.001). The values of D-dimer, fibrin/fibrinogen degradation products (FDP), and fibrinogen (FIB) in all SARS-CoV-2 cases were substantially higher than those in healthy controls. Moreover, D-dimer and FDP values in patients with severe SARS-CoV-2 infection were higher than those in patients with milder forms. Compared with healthy controls, prothrombin time activity (PT-act) was lower in SARS-CoV-2 patients. Thrombin time in critical SARS-CoV-2 patients was also shorter than that in controls. Conclusions The coagulation function in patients with SARS-CoV-2 is significantly deranged compared with healthy people, but monitoring D-dimer and FDP values may be helpful for the early identification of severe cases.

Direct Intermolecular Anti-Markovnikov Hydroazidation of Unactivated Olefins.

We herein report a direct intermolecular anti-Markovnikov hydroazidation method for unactivated olefins, which is promoted by a catalytic amount of bench-stable benziodoxole at ambient temperature. This method facilitates previously difficult, direct addition of hydrazoic acid across a wide variety of unactivated olefins in both complex molecules and unfunctionalized commodity chemicals. It conveniently fills a synthetic chemistry gap of existing olefin hydroazidation procedures, and thereby provides a valuable tool for azido-group labeling in organic synthesis and chemical biology studies.

Influenza A virus inhibits influenza virus replication by inducing IL-37.

BACKGROUNDS: The influenza virus is one of the major pathogens that seriously affect human health. It can cause a strong immune response and trigger a series of complications. Interleukin 37 (IL-37) is a newly discovered cytokine that plays an important regulatory role in infection and immunity. To date, there have been few studies on the correlation between influenza virus infection and IL-37. METHODS: Serum levels of IL-37 in 115 patients with influenza A virus (IAV) infection and 102 healthy subjects were measured by an enzyme-linked immunosorbent assay (ELISA). Real-time quantitative PCR (RT-qPCR) was used to detect differences in IL-37 expression in peripheral blood mononuclear cells (PBMCs) between IAV patients and healthy subjects. IL-37 expression was measured in A549 cells and PBMCs infected with IAV H3N2 using ELISA and RT-qPCR. After the H3N2-infected A549 cells were treated with human IL-37, the concentration of viral RNA was determined using RT-qPCR, and the titer of influenza virus was determined by a hemagglutination test. RESULTS: The IL-37 levels in the sera and PBMCs of patients infected with IAV were higher than those of healthy subjects. The expression of IL-37 mRNA and protein in IAV-infected A549 cells and PBMCs was upregulated, and IL-37 protein was able to inhibit the replication of IAV RNA. CONCLUSION: IAV-induced IL-37 expression inhibits IAV replication.

Enantioselective Synthesis of Oseltamivir Phosphate (Tamiflu) via the Iron-Catalyzed Stereoselective Olefin Diazidation.

We herein report a gram-scale, enantioselective synthesis of Tamiflu, in which the key trans-diamino moiety has been efficiently installed via an iron-catalyzed stereoselective olefin diazidation. This significantly improved, iron-catalyzed method is uniquely effective for highly functionalized yet electronically deactivated substrates that have been previously problematic. Preliminary catalyst structure-reactivity-stereoselectivity relationship studies revealed that both the iron catalyst and the complex substrate cooperatively modulate the stereoselectivity for diazidation. Safety assessment using both differential scanning calorimetry (DSC) and the drop weight test (DWT) has also demonstrated the feasibility of carrying out this iron-catalyzed olefin diazidation for large-scale Tamiflu synthesis.

Iron(II)-Catalyzed Intermolecular Aminofluorination of Unfunctionalized Olefins Using Fluoride Ion.

We herein report a new catalytic method for intermolecular olefin aminofluorination using earth-abundant iron catalysts and nucleophilic fluoride ion. This method tolerates a broad range of unfunctionalized olefins, especially nonstyrenyl olefins that are incompatible with existing olefin aminofluorination methods. This new iron-catalyzed process directly converts readily available olefins to internal vicinal fluoro carbamates with high regioselectivity (N vs F), many of which are difficult to prepare using known methods. Preliminary mechanistic studies demonstrate that it is possible to exert asymmetric induction using chiral iron catalysts and that both an iron-nitrenoid and carbocation species may be reactive intermediates.

Iron(II)-catalyzed intermolecular amino-oxygenation of olefins through the N-O bond cleavage of functionalized hydroxylamines.

An iron-catalyzed diastereoselective intermolecular olefin amino-oxygenation reaction is reported, which proceeds via an iron-nitrenoid generated by the N-O bond cleavage of a functionalized hydroxylamine. In this reaction, a bench-stable hydroxylamine derivative is used as the amination reagent and oxidant. This method tolerates a range of synthetically valuable substrates that have been all incompatible with existing amino-oxygenation methods. It can also provide amino alcohol derivatives with regio- and stereochemical arrays complementary to known amino-oxygenation methods.

HBV promotes its replication by up-regulating RAD51C gene expression.

Chronic hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC), pegylated-interferon-α(PEG-IFNα) and long-term nucleos(t)ide analogs (NUCs) are mainly drugs used to treat HBV infection, but the effectiveness is unsatisfactory in different populations, the exploration of novel therapeutic approaches is necessary. RAD51C is associated with DNA damage repair and plays an important role in the development and progression of tumors. Early cDNA microarray results showed that RAD51C expression was significantly increased in HBV-infected HCC cells, however, the relationship between HBV infection and abnormal expression of RAD51C has not been reported. Therefore, we conducted RT-PCR, western blot, Co-immunoprecipitation(Co-IP), and immunofluorescence(IF) to detect HBV-RAD51C interaction in RAD51C overexpression or interfering HCC cells. Our results showed that RAD51C and HBV X protein(HBX) produced a direct interaction in the nucleus, the HBV infection of HCC cells promoted RAD51C expression, and the increased expression of RAD51C promoted HBV replication. This indicated that RAD51C is closely related to the occurrence and development of HCC caused by HBV infection, and may bring a breakthrough in the the prevention and treatment study of HCC.

Tacolimus postconditioning alleviates apoptotic cell death in rats after spinal cord ischemia-reperfusion injury via up-regulating protein-serine-threonine kinases phosphorylation.

The effects of tacrolimus postconditioning on protein-serine-threonine kinases (Akt) phosphorylation and apoptotic cell death in rats after spinal cord ischemia-reperfusion injury were investigated. Ninety male SD rats were randomly divided into sham operation group, ischemia-reperfusion group and tacrolimus postconditioning group. The model of spinal cord ischemia was established by means of catheterization through femoral artery and balloon dilatation. The spinal cord was reperfused 20 min after ischemia via removing saline out of balloon. The corresponding spinal cord segments were excised and determined for Akt activity in spinal cord tissue by using Western blotting at 5, 15, and 60 min after reperfusion respectively. Spinal cord tissue sections were stained immunohistochemically for detection of the phosphorylated Akt expression at 15 min after reperfusion. Flow cytometry was applied to assess apoptosis of neural cells, and dry-wet weights method was employed to measure water content in spinal cord tissue at 24 h after reperfusion. The results showed that the activities of Akt in tarcolimus postconditioning group were significantly higher than those in ischemia-reperfusion group at 5, 15, and 60 min after reperfusion (P<0.05, P<0.01). The Akt activities reached the peak at 15 min after reperfusion in ischemia-reperfusion group and tacrolimus postconditioning group. The percentage of apoptotic cells and water content in spinal cord tissue were significantly reduced (P<0.01) in tacrolimus postconditioning group as compared with those in ischemia-reperfusion group at 24 h after reperfusion. It is concluded that tacrolimus post-conditioning can increase Akt activity in spinal cord tissue of rats, inhibit apoptosis of neural cells as well as tissue edema, and thereby alleviate spinal cord ischemia-reperfusion injury.

[Protective effect of tacrolimus postconditioning on oxidative stress injury provoked by spinal cord ischemia-reperfusion in rats].

OBJECTIVE: To investigate whether protective effect of tacrolimus postconditioning on rats' spinal cord ischemia-reperfusion injury is mediated by up-regulation of activity of endogenous antioxidant enzymes and down-regulation of production of oxygen free radicals. METHODS: Ninety male Sprague-Dawley rats were randomly divided into ischemia-reperfusion (IR) group, tacrolimus postconditioning (TP) group and sham operation (SO) group. The model of spinal cord ischemia was prepared by means of catheterization through femoral artery and balloon dilatation. IR group underwent reperfusion 20 min after spinal cord ischemia. TP group experienced a single injection of tacrolimus (0.5 mg/kg) through the left common carotid artery at the onset of reperfusion. SO group received femoral artery catheterization only. Fluoro spectro photometry was employed to detect the level of reactive oxygen species (ROS) in injured spinal cord segment at 15 minutes after reperfusion. The content of malondialdehyde (MDA) and activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX) were determined at 15 minutes, 1, 6, and 24 hours after reperfusion respectively. BBB scale was conducted to evaluate hindlimb motor function at 14 days after reperfusion. RESULTS: The level of ROS in TP group was significantly lower than that in IR group at 15 minutes after reperfusion. The activity of SOD was significantly higher in TP group than in IR group at all observational time points, while the activities of CAT and GSH-PX were significantly higher in TP group than in IR group at 1 and 6 hours after reperfusion. The content of MDA in TP group was significantly less than that in IR group at all observational time points. The motor function score of TP group was significantly superior to that of IR group at 14 days after reperfusion. CONCLUSION: Tacrolimus post conditioning can improve activity of endogenous antioxidant enzymes, decrease production of oxygen free radicals, suppress lipid peroxidation, and thereby promote functional recovery after spinal cord ischemia-reperfusion injury in rats.

[Liver histopathological features influencing HBeAg seroconversion in patients with HBeAg-positive chronic hepatitis B responding to Peg-IFN treatment].

OBJECTIVE: To investigate the therapeutic efficiency of antiviral treatment with pegylated-interferon (Peg-IFN) for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) and to explore whether liver histopathological features or other factors influence the HBeAg seroconversion treatment response. METHODS: Eighty HBeAg-positive CHB patients with diagnosis confirmed by liver puncture were treated with Peg-IFN(2a or 2b)body weight dose, once weekly). At treatment week 48, the rate of HBeAg seroconversion was determined and used to analyze the influence of liver histopathological features (liver biopsy assessment of: inflammation, graded G0 to G4; fibrosis stage, graded S0 to S4), sex, age, differential levels (pre-treatment baseline vs. week 48 post-treatment) of serum alanine transferase (ALT), and HBV DNA, by binary logistic analysis. RESULTS: At week 48, the overall rate of HBeAg seroconversion was 30.0%. The rate of HBeAg seroconversion gradually advanced with increased liver inflammation (X2 = 8.435, P = 0.015): 9.09% of the 22 patients with G1; 31.58% of the 38 patients with G2; 47.30% of the 19 patients with G3; the one patient with G4. In contrast, the rate of HBeAg seroconversion showed a much weaker association with liver fibrosis (X2 = 5.917, P = 0.116). Only baseline HBeAg level, and no other baseline index, was significantly different between the patients who achieved HBeAg seroconversion and those who did not. Liver inflammation and baseline HBeAg level were identified as influencing factors of HbeAg seroconversion in response to Peg-IFN treatment. CONCLUSION: Peg-IFN therapy induces a higher rate of HBeAg seroconversion in HBeAg-positive CHB patients with severe liver inflammation; histological analysis of pre-treatment liver biopsies may help to identify patients most likely to benefit from the antiviral regimen.

Upregulation of RasGRF1 ameliorates spatial cognitive dysfunction in mice after chronic cerebral hypoperfusion.

Chronic cerebral hypoperfusion (CCH)-mediated cognitive impairment is a serious problem worldwide. However, given its complexity, the underlying mechanisms by which CCH induces cognitive dysfunction remain unclear, resulting in a lack of effective treatments. In this study, we aimed to determine whether changes in the expression of RasGRF1, an important protein associated with cognition and synaptic plasticity, underlie the associated impairments in cognition after CCH. We found that RasGRF1 levels markedly decreased following CCH. Through prediction and validation studies, we observed that miRNA-323-3p was upregulated after CCH and could bind to the 3'-untranslated region of Rasgrf1 mRNA and regulate its expression in vitro. Moreover, the inhibition of miRNA-323-3p upregulated Rasgrf1 expression in the hippocampus after CCH, which was reversed by Rasgrf1 siRNA. This suggests that miRNA-323-3p is an important regulator of Rasgrf1. The Morris water maze and Y maze tests showed that miRNA-323-3p inhibition and Rasgrf1 upregulation improved spatial learning and memory, and electrophysiological measurements revealed deficits in long-term potentiation after CCH that were reversed by Rasgrf1 upregulation. Dendritic spine density and mature mushroom spine density were also improved after miRNA-323-3p inhibition and Rasgrf1 upregulation. Furthermore, Rasgrf1 upregulation by miRNA-323-3p inhibition improved dendritic spine density and mature mushroom spine density and ameliorated the deterioration of synapses and postsynaptic density. Overall, RasGRF1 regulation attenuated cognitive impairment, helped maintain structural and functional synaptic plasticity, and prevented synapse deterioration after CCH. These results suggest that Rasgrf1 downregulation by miRNA-323-3p plays an important role in cognitive impairment after CCH. Thus, RasGRF1 and miRNA-323-3p may represent potential therapeutic targets for cognitive impairment after CCH.

A practical "preTACs-cytoblot" platform accelerates the streamlined development of PROTAC-based protein degraders.

With the growing importance of PROTAC-mediated protein degradation in drug discovery, robust synthetic methodologies and rapid screening assays are urgently needed. By harnessing the improved alkene hydroazidation reaction, we developed a novel strategy to introduce azido groups into the linker-E3 ligand conjugates and effectively created a range of prepacked terminal azide-labeled "preTACs" as PROTAC toolkit building blocks. Moreover, we demonstrated that preTACs are ready to conjugate to ligands targeting a protein of interest to generate libraries of chimeric degraders, which are subsequently screened for effective protein degradation directly from cultured cells with a cytoblot assay. Our study exemplifies that this practical "preTACs-cytoblot" platform allows efficient PROTAC assembly and rapid activity assessments. It may help industrial and academic investigators to accelerate their streamlined development of PROTAC-based protein degraders.

Noncovalent CDK12/13 dual inhibitors-based PROTACs degrade CDK12-Cyclin K complex and induce synthetic lethality with PARP inhibitor.

Cyclin-dependent kinase 12 (CDK12) plays a crucial role in DNA-damage response gene transcription and has recently been validated as a promising target in cancer therapy. However, existing CDK12 inhibitors potently inhibit its closest isoform CDK13, which could cause potential toxicity. Therefore, the development of CDK12 inhibitors with isoform-selectivity against CDK13 continues to be a challenge. By taking advantage of the emerging PROteolysis-TArgeting Chimeras (PROTACs) approach, we have synthesized a potent PROTAC degrader PP-C8 based on the noncovalent dual inhibitors of CDK12/13 and demonstrated its specificity for CDK12 over CDK13. Notably, PP-C8 induces profound degradation of cyclin K simultaneously and downregulates the mRNA level of DNA-damage response genes. Global proteomics profiling revealed PP-C8 is highly selective toward CDK12-cyclin K complex. Importantly, PP-C8 demonstrates profound synergistic antiproliferative effects with PARP inhibitor in triple-negative breast cancer (TNBC). The potent and selective CDK12 PROTAC degrader developed in this study could potentially be used to treat CDK12-dependent cancers as combination therapy.

Structure-based rational design enables efficient discovery of a new selective and potent AKT PROTAC degrader.

AKT and associated signaling pathways have been recognized as promising therapeutic targets for decades, and growing evidence indicates that inhibition or degradation of cellular AKT are viable strategies to treat cancer. Guided by an in silico modeling approach for rational linker design and based on our previous work in this field, we herein efficiently synthesized a small group of cereblon-recruiting AKT PROTAC molecules and identified a highly potent AKT degrader B4. Compared to the existing AKT degraders, B4 has a structurally unique AKT targeting warhead derived from the pyrazole-furan conjugated piperidine derivatives. It induces selective degradation of all three isoforms of AKT and exhibits efficacious anti-proliferation against several human hematological cancers. Notably, B4 demonstrates potent inhibition of AKT downstream signaling superior to its parental inhibitor. Together with its active analogs, B4 expands the arsenal of AKT chemical degraders as a valuable probe to uncover AKTs new functions and as a potential drug candidate to treat cancer.

Analysis of Common Respiratory Infected Pathogens in 3100 Children after the Coronavirus Disease 2019 Pandemic.

OBJECTIVE: To investigate the epidemiological features in children after the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This study collected throat swabs and serum samples from hospitalized pediatric patients of Renmin Hospital of Wuhan University, Wuhan, Hubei province, China before and after the COVID-19 pandemic. Respiratory infected pathogens [adenovirus (ADV), influenza virus A/B (Flu A/B), parainfluenza virus 1/2/3 (PIV1/2/3), respiratory syncytial virus (RSV), Mycoplasma pneumoniae (MP), and Chlamydia pneumoniae (CP)] were detected. The pathogens, age, and gender were used to analyze the epidemiological features in children after the COVID-19 pandemic. RESULTS: The pathogen detection rate was significantly higher in females than in males (P<0.05), and the infection of PIV1 and MP was mainly manifested. After the COVID-19 pandemic, PIV1, PIV3, RSV, and MP had statistically different detection rates among the age groups (P<0.05), and was mainly detected in patients aged 0-6 years, 0-3 years, 0-3 years, and 1-6 years, respectively. When comparing before the COVID-19 pandemic, the total detection rate of common respiratory pathogens was lower (P<0.05). Except for the increase in the detection rate of PIV1 and CP, the infection rate of other pathogens had almost decreased. CONCLUSION: The prevention and control measures for the COVID-19 pandemic effectively changed the epidemiological features of common respiratory tract infectious diseases in pediatric children.

HBV inhibits apoB production via the suppression of MTP expression.

BACKGROUND: Liver dominates the production and secretion of apolipoprotein B (apoB) and evidence shows that liver malfunction induced by hepatitis B virus (HBV) infection could lead to apolipoprotein metabolism disorders. The present study was undertaken to assess the effects of HBV on apoB expression. METHODS: Clinical examination: serum apoB levels in patients with chronic HBV infection and in healthy individuals were measured by immunoturbidimetry using biochemical analyzer Olympus 5400. Cell study: mRNA and protein expression levels of apoB in HepG2 and HepG2.2.15 cells were measured by RT-PCR and Western blot. Alternatively, HBV infectious clone pHBV1.3 or control plasmid pBlue-ks were tranfected into HepG2 cells, and mRNA and protein expression levels of apoB, as well as the microsomal triglyceride transfer protein (MTP) in tranfected HepG2 cells were also measured by RT-PCR and western blot. RESULTS: Serum apoB level was much lower in chronic HBV patients as compared to healthy individuals (P < 0.05). Expression of apoB mRNA and protein was lower in HepG2.2.15 cells than in HepG2 cells. Similarly, expression of apoB mRNA and protein was lower in pHBV1.3 transfected HepG2 cells than in pBlue-ks transfected HepG2 cells. Expression of MTP mRNA and protein in pHBV1.3 transfected HepG2 cells was reduced in a dose-dependent fashion. CONCLUSION: HBV infection plays an inhibitory effect on apoB expression.

Enchanced levels of apolipoprotein M during HBV infection feedback suppresses HBV replication.

BACKGROUND: Chronic liver diseases can interfere with hepatic metabolism of lipoproteins, apolipoproteins. Hepatitis B virus (HBV) is a major etiological agent causing acute and chronic liver diseases. Apolipoprotein M (ApoM) is a high-density lipoprotein (HDL) apolipoprotein and exclusively expressed in the liver parenchyma cells and in the tubular cells of the kidney. This study was to determine the correlation between HBV infection and ApoM expression. MATERIALS AND METHODS: Serum ApoM levels in patients with HBV infection and in healthy individuals were measured by ELISA, ApoM mRNA expression were determined by RT-PCR, and the expression of S and E proteins of HBV, as well as the synthesis of viral DNA were measured by ELISA and real-time PCR. RESULTS: The levels of serum ApoM was significantly elevated in patients as compared to healthy individuals (P < 0.001), ApoM promoter activity, mRNA and protein expression were all stimulated in cells transfected with infectious HBV clone. In addition, ApoM decreases the expression of S and E proteins of HBV and the synthesis of viral DNA. CONCLUSION: Raised ApoM levels in HBV infection may in turn suppress HBV replication, one of the protective mechanisms of nature.

[Effects of HCV core protein on the expression of hypoxia-inducible factor 1 alpha and vascular endothelial growth factor].

OBJECTIVE: To investigate the effect of core protein of hepatitis C virus (HCV) on the expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF). METHODS: Huh7.5.1 cells were transfected with plasmid flag2B-core carrying HCV core gene, expression of HIF-1alpha and VEGF were measured by reverse transcription-polymorphism chain reaction (RT-PCR) and western blot. Enzyme link immunoabsorbent assay (ELISA) were used to detect the level of VEGF in the supernatants. RESULTS: The expression of HIF-1alpha and VEGF mRNA and protein were upregulated after flag2B-core was transfected into Huh7.5.1 cells, and VEGF level in the supernatant was significant elevated as compared to controls [(654.5+/-43.7) pg/ml vs (365.9+/-26.8) pg/ml, t = 653.1%, P less than 0.01]. The expression of HIF-1alpha and VEGF mRNA and protein were downregulated after flag2B-core and HIF-1alpha siRNA were co-transfected into Huh7.5.1 cells, and VEGF level in the supernatant was significantly reduced as compared to controls [(389.2+/-29.6) pg/ml vs (768.8+/-47.3)pg/ml, t = 1330.22, P less than 0.01]. CONCLUSIONS: HCV core protein enhances the expression of HIF-1alpha and VEGF. HCV may regulate the expression of HIF-1alpha and VEGF via the core protein.