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Lai Wei

Publications and source records attributed to Lai Wei.

At least 19 recordsLinked to original sources
PubMed2025

Genome-wide CRISPR Screening Identifies NFκB and c-MET as Druggable Targets to Sensitize Lenvatinib Treatment in Hepatocellular Carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC), the dominant form of liver cancer, is a leading cause of cancer death worldwide. Sorafenib and lenvatinib have long been the 2 limited options of first-line treatments for patients with unresectable advanced HCC. However, the single-drug treatment strategy only shows modest survival benefit, mostly because of the survival ability of cancer cells to activate alternative pathways for compensation. In this study, we aim to identify druggable targets contributing to lenvatinib resistance and evaluate the efficacy of combining respective inhibitors and lenvatinib on HCC. METHODS: Genome-scale clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 knockout library screening was applied on the vehicle group and lenvatinib treatment group. Identified druggable candidates were validated individually on HCC cell models. Therapeutic effects of the combined treatment of inhibitors of candidate genes and lenvatinib were evaluated in vitro and in vivo. RESULTS: We successfully identified NFKB1 and MET as critical drivers for the development of lenvatinib resistance in HCC cells. By perturbing the 2 genes with either CRISPR knockout or RNA interference approaches, lenvatinib treatments were significantly sensitized. Moreover, using small molecules QNZ and cabozantinib to target NFKB1 and MET, respectively, this together with lenvatinib could synergistically induce apoptosis and suppress HCC growth in vitro and in vivo. CONCLUSION: Our results demonstrated that genome-wide CRISPR/Cas9 screening is a powerful tool for the design of rational combinational cancer therapy and provided candidate genes possible for combined treatments with lenvatinib to improve therapy efficacy.

Carcinoma, Hepatocellular↗
PubMed2007

Identification of CXCL11 as a STAT3-dependent gene induced by IFN.

IFNs selectively regulate gene expression through several signaling pathways. The present study explored the involvement of STAT3 in the IFN-induced expression of the gene encoding the CXCL11 chemokine. The CXCL11 gene was induced in IFN-sensitive Daudi cells, but not in an IFN-resistant DRST3 subline with a defective STAT3 signaling pathway. Although the IFN-stimulated gene ISG15 was induced to a similar extent in Daudi and DRST3 cells, expression of wild-type STAT3 in DRST3 cells restored the IFN inducibility of CXCL11. Reconstitution of STAT3 knockout mouse embryonic fibroblasts with wild-type STAT3, or STAT3 with the canonical STAT3 dimerization site at Y705 mutated, restored IFN inducibility of the CXCL11 gene. These data indicate that CXCL11 gene induction by IFN is STAT3 dependent, but that phosphorylation of Y705 of STAT3 is not required. Chromatin immunoprecipitation assays demonstrated that IFN treatment of Daudi and DRST3 cells induced STAT3 binding to the CXCL11 promoter. Chromatin immunoprecipitation assays also revealed that NF-kappaB family member p65 and IFN regulatory factor (IRF)1 were bound to CXCL11 promoter upon IFN treatment of Daudi cells. In contrast, IFN induced the binding of p50 and IRF2 to the CXCL11 promoter in DRST3 cells. The profile of promoter binding was indistinguishable in IFN-sensitive Daudi cells and DRST3 cells reconstituted with wild-type STAT3. Thus, STAT3 also plays a role in the recruitment of the transcriptional activators p65 and IRF1, and the displacement of the transcriptional repressors p50 and IRF2 from the CXCL11 promoter also appears to regulate the induction of CXCL11 gene transcription.

Animals↗
PubMed2007

Impact of polysol, a newly developed preservation solution, on cold storage of steatotic rat livers.

Chronic shortage of donor organs has led to acceptance of steatotic livers as grafts, although there is a higher risk of primary graft dysfunction. We herein report the beneficial impact of Polysol, a newly developed preservation solution, on cold storage of steatotic rat livers. Dietary hepatic steatosis was induced in Wistar rats by 2-day fasting and subsequent 3-day re-feeding with a fat-free, carbohydrate-rich diet. Fatty livers were retrieved, flushed and then stored at 4 degrees C for 24 hours with either HTK or Polysol. Functional integrity of the grafts was evaluated by isolated reperfusion with oxygenated Krebs-Henseleit buffer at 37 degrees C for 45 minutes in both groups. Polysol preservation resulted in significant reductions of not only parenchymal (AST (IU/L); 6728+/-824 in HTK vs. 3107+/-718 in Polysol; P < 0.001) but also mitochondrial (GLDH (IU/L); 3189+/-773 vs. 1282+/-365; P < 0.01) enzyme release throughout reperfusion. Moreover, PVP (16.9+/-2.7 vs. 7.8+/-1.5 mmHg; P < 0.05), hepatic O2 consumption (0.291+/-0.047 vs. 1.056+/-0.053 micromol/g liver/min; P < 0.001), tissue ATP content (0.695+/-0.086 vs. 1.340+/-0.157 micromol/g dry-liver; P < 0.005), bile production (0.79+/-0.11 vs. 4.08+/-0.66 microL/g liver/45-min; P < 0.001), malondialdehyde into the perfusate (1.922+/-0.198 vs. 0.573+/-0.094 nmol/L; P < 0.0001) and wet/dry-weight ratio of the liver tissues (5.20+/-0.31 vs. 3.85+/-0.15; P < 0.005) were all better preserved by Polysol. In line with these benefits, electron microscopy revealed that Polysol preservation substantially suppressed deleterious mitochondrial alterations in steatotic livers. In conclusion, cold storage using Polysol resulted in significantly better integrity and function of steatotic livers. Polysol, therefore, may be a new alternative especially for "marginal" organs.

Animals↗
PubMed2006

[Analysis and state of HCV genotype 6a infection].

OBJECTIVE: To investigate the infection state of hepatitis C virus genotype 6a in China. METHODS: Three (95, 126, 150)HCV genotype 6a serum samples were identified by digesting 5'NCR with compound enzyme method. Then, HCV 5'NCR and NS5B fragments were amplified from these samples by RT-PCR assay and sequenced. The phylogenetic trees of the samples were analyzed and compared with 24 HCV complete gene sequences from GenBank. RESULTS: The sequencing reports on 5'NCR showed "CA" bases in 3 serum samples (95,126,150) were inserted into -145 site, and the sequences of 3 serum samples had the highest homology with sequence Y12083( 0.934, 0.930, and 0.926, respectively). The results of the phylogenetic trees suggested these 3 serum samples belonged to HCV genotype 6a. The sequencing reports on NS5B showed the 3 serum samples also had the highest homology with HC-J4(0.934, 0.930, and 0.926, respectively), and the results of the phylogenetic trees suggested these 3 serum samples belonged to HCV genotype 1b. To exclude the influence of amplification efficiency of primers, NS5B fragments were amplified by HCV genotype 6a specific primers and no amplification products appeared. CONCLUSION: There are different results of HCV genotype by analyzing 5'NCR and NS5B in 3 samples infected with HCV genotype 6a. It may be related with gene recombination. It suggests HCV genotype should be analyzed on more than two regions.

Base Sequence↗
PubMed2006

Mechanisms of co-modified liver-targeting liposomes as gene delivery carriers based on cellular uptake and antigens inhibition effect.

In order to deliver antisense oligonucleotides (asODN) into hepatocytes orientedly in the treatment of hepatitis B virus (HBV) infection, the liver-targeting cationic liposomes was developed as a gene carrier, which was co-modified with the ligand of the asialoglycoprotein receptor (ASGPR), beta-sitosterol-beta-d-glucoside (sito-G) and the nonionic surfactant, Brij 35. Flow cytometry (FCM) analysis and enzyme-linked immunosorbent assay (ELISA) showed that the asODN-encapsulating cationic liposomes exhibited high transfection efficiency and strong antigens inhibition effect in primary rat hepatocytes and HepG2.2.15 cells, respectively. With the help of several inhibitors acting on different steps during the targeting lipofection, the cellular uptake mechanisms of the co-modified liver-targeting cationic liposomes were investigated through antigens inhibition effect assay and confocal laser scanning microscopy (CLSM) analysis. The cellular uptake with high transfection efficiency seemed to involve both endocytosis and membrane fusion. The ligand sito-G was confirmed to be able to enhance ASGPR-mediated endocytosis, the nonionic surfactant Brij 35 seemed to be able to facilitate membrane fusion, and the co-modification resulted in the most efficient transfection but no enhanced cytotoxicity. These results suggested that the co-modified liver-targeting cationic liposomes would be a specific and effective carrier to transfer asODN into hepatocytes infected with HBV orientedly.

Androstadienes↗
PubMed2006

Differentiation of rat bone marrow stem cells in liver after partial hepatectomy.

AIM: To investigate the differentiation of rat bone marrow stem cells in liver after partial hepatectomy. METHODS: Bone marrow cells were collected from the tibia of rat with partial hepatectomy, the medial and left hepatic lobes were excised. The bone marrow stem cells (Thy(+)CD3(-)CD45RA(-) cells) were enriched from the bone marrow cells by depleting red cells and fluorescence-activated cell sorting. The sorted bone marrow stem cells were labeled by PKH26-GL in vitro and autotransplanted by portal vein injection. After 2 wk, the transplanted bone marrow stem cells in liver were examined by the immunohistochemistry of albumin (hepatocyte-specific marker). RESULTS: The bone marrow stem cells (Thy(+)CD3(-)CD45RA(-) cells) accounted for 2.8% of bone marrow cells without red cells. The labeling rate of 10 microM PKH26-GL on sorted bone marrow stem cells was about 95%. There were sporadic PKH26-GL-labeled cells among hepatocytes in liver tissue section, and some of the cells expressed albumin. CONCLUSION: Rat bone marrow stem cells can differentiate into hepatocytes in regenerative environment and may participate in liver regeneration after partial hepatectomy.

Animals↗
PubMed2006

Combining gene expression QTL mapping and phenotypic spectrum analysis to uncover gene regulatory relationships.

Gene expression QTL (eQTL) mapping can suggest candidate regulatory relationships between genes. Recent advances in mammalian phenotype annotation such as mammalian phenotype ontology (MPO) enable systematic analysis of the phenotypic spectrum subserved by many genes. In this study we combined eQTL mapping and phenotypic spectrum analysis to predict gene regulatory relationships. Five pairs of genes with similar phenotypic effects and potential regulatory relationships suggested by eQTL mapping were identified. Lines of evidence supporting some of the predicted regulatory relationships were obtained from biological literature. A particularly notable example is that promoter sequence analysis and real-time PCR assays support the predicted regulation of protein kinase C epsilon (Prkce) by cAMP responsive element binding protein 1 (Creb1). Our results show that the combination of gene eQTL mapping and phenotypic spectrum analysis may provide a valuable approach to uncovering gene regulatory relations underlying mammalian phenotypes.

Animals↗
PubMed2006

NFkappaB negatively regulates interferon-induced gene expression and anti-influenza activity.

Interferons (IFNs) are antiviral cytokines that selectively regulate gene expression through several signaling pathways including nuclear factor kappaB(NFkappaB). To investigate the specific role of NFkappaB in IFN signaling, we performed gene expression profiling after IFN treatment of embryonic fibroblasts derived from normal mice or mice with targeted deletion of NFkappaB p50 and p65 genes. Interestingly, several antiviral and immunomodulatory genes were induced higher by IFN in NFkappaB knock-out cells. Chromatin immunoprecipitation experiments demonstrated that NFkappaB was basally bound to the promoters of these genes, while IFN treatment resulted in the recruitment of STAT1 and STAT2 to these promoters. However, in NFkappaB knock-out cells IFN induced STAT binding as well as the binding of the IFN regulatory factor-1 (IRF1) to the IFN-stimulated gene (ISG) promoters. IRF1 binding closely correlated with enhanced gene induction. Moreover, NFkappaB suppressed both antiviral and immunomodulatory actions of IFN against influenza virus. Our results identify a novel negative regulatory role of NFkappaB in IFN-induced gene expression and biological activities and suggest that modulating NFkappaB activity may provide a new avenue for enhancing the therapeutic effectiveness of IFN.

Animals↗
PubMed2006

Synthesis and evaluation of febrifugine analogues as potential antimalarial agents.

Febrifugine is an alkaloid isolated from Dichroa febrifuga Lour as the active component against Plasmodium falciparum. Strong liver toxicity has precluded febrifugine as a potential clinical drug. In this study novel febrifugine analogues were designed and synthesized. Lower toxicity was achieved by reducing or eliminating the tendency of forming chemically reactive and toxic intermediates and metabolites. Synthesized compounds were evaluated in vitro against chloroquine sensitive (D6) and chloroquine resistant (W2) P. falciparum strains for efficacy and in freshly isolated rat hepatocytes for potential cytotoxicity. The IC(50)'s of the best compounds were superior to their parent compound febrifugine. Noticeably, these compounds were also over 100 times less toxic than febrifugine. These compounds, as well as the underlying design rationale, may find usefulness in the discovery and development of new antimalarial drugs.

Animals↗
PubMed2006

Hematopoietic stem cells mobilized by granulocyte colony-stimulating factor partly contribute to liver graft regeneration after partial orthotopic liver transplantation.

On the basis of the recently recognized potential of hematopoietic stem cells (HSCs) to give rise to hepatocytes, we investigated whether HSCs mobilized by granulocyte colony-stimulating factor (G-CSF) or G-CSF per se could contribute to faster recovery and promote tissue reparation after rats' (cross-sex) partial orthotopic liver transplantation (PLTx). Sex-mismatched (female to male) syngeneic rat PLTx was established. The recipients were repeatedly administrated recombinant G-CSF for 5 consecutive days before (G-CSF + PLTx group) and after PLTx (PLTx + G-CSF group). Compared with those in PLTx group, CD34+ cells in peripheral blood and portal tract region increased from day 1 to 7 after transplantation in G-CSF + PLTx group and from day 3 to 14 after transplantation in PLTx + G-CSF group, respectively, which suggested that CD34+ HSCs were mobilized and migrated into liver graft. Compared with that in G-CSF + PLTx and PLTx groups, there was a higher survival rate in the PLTx + G-CSF group. On day 3 after surgery, the level of aspartate aminotransferase and alanine aminotransferase were lower, whereas the mitosis index, proliferating cell nuclear antigen-positive nuclei, bromodeoxyuridine (BrdU) incorporation, and graft-to-recipient weight ratio were higher in the PLTx + G-CSF group. In contrast, these parameters had no significant difference between G-CSF + PLTx and PLTx groups. To define the origin of proliferating cells reconstituting liver after injury, sry+ (sex-determining region for Y chromosome) and sry+/cytokeratin 19+ (CK19) cells were quantitated. Higher percentage of sry+ and sry+/CK19+ cells in PLTx + G-CSF was detected than in G-CSF + PLTx groups on day 14 after surgery, although the liver engraftment rate still remained rather low. Some of the sry+/CK19+ cells in the portal tract areas were similar to hepatic oval cells/cholangiocytes. In conclusion, G-CSF administration after PLTx greatly improved survival rate and liver regeneration of partial graft, partly by its mobilizing HSCs into the injured liver to differentiate into hepatocytes through hepatic oval cells'/cholangiocytes' engraftment.

Alanine Transaminase↗
PubMed2006

[The direct antiviral effect of interferon-gamma on hepatitis C virus replicon].

OBJECTIVE: To study the effects of interferon-gamma and interferon-gamma combined with interferon-alpha on HCV RNA replication and the possible mediators of interferon-gamma anti-HCV in vitro. METHODS: An HCV replicon cell culture system was established and the cells were treated with interferon-gamma or interferon-gamma combined with interferon-alpha. HCV RNA levels in the cells were evaluated by semi-quantitative RT-PCR and real-time PCR, and the levels of NS5A protein were examined by Western blot. RESULTS: Interferon-gamma could inhibit HCV RNA replication and NS5A protein expression effectively; The anti-HCV effects of interferon-gamma were both in time-dependent and does-dependent manners; Pretreating the cells with interferon-gamma could significantly enhance the antiviral effects of interferon-alpha; The expressions of IRF-1, 2'5'-OAS1(p46), 2'5'-OAS2(p69), ISGF3gamma and STAT1 were significantly increased after interferon-gamma treatment. CONCLUSION: Interferon-gamma has a direct inhibitory effect on HCV replicon RNA replication and NS5A expression, and both are in a dose and time dependent manner; Interferon-gamma has a synergistic anti-HCV effect with interferon-alpha. IRF-1, 2'5'-OAS1(p46), 2'5'-OAS2(p69) and ISGF3gamma may mediate the anti-HCV effects of interferon-gamma.

Antiviral Agents↗
PubMed2006

[Liver targeting of cationic liposomes modified with soybean-derived sterylglucoside in vitro].

AIM: To construct a liposomal liver targeting delivery system by adding soybean-derived sterylglucoside (SG) to the cationic liposomes. METHODS: The physico-chemical properties of SG modified cationic lipsomes were investigated using fluorescein sodium (FS) as a model drug, as well as the interaction of SG modified liposomes with HepG2 2. 2. 15 cells in the point of involvement of asialoglycoprotein receptor (ASGP-R) mediated transfection. Liver targeting of modified cationic liposomes were also investigated using liver perfusing technique, and hepatocytes and non-hepatocytes were separated and examined after perfusing. RESULTS: All the formula yielded high incorporation efficiency (83.12% - 91.74%), small particle size (93.0 - 124.4 nm). The zeta potential of blank liposomes all showed positive values. The transfection efficiency of FS entrapped in SG-liposomes with HepG2 2.2. 15 was significantly higher than that of liposomes without modification. The transfection of SG-liposomes were reduced significantly by the 20/30 mmol galactose as a competitor of ASGP-R. All the cationic liposomes showed high level of liver uptake of FS. Compared with the uptake of non-hepatocytes of each respectively, only SG/Brij-35 liposomes showed difference in FS uptake by hepatocytes (P < 0.05). CONCLUSION: It showed that SG/Brij-35 modified cationic liposomes are potentially useful drug carrier to liver but may be affected by different modification.

Animals↗
PubMed2006

[A multicenter, randomized, open-label study of the safety and effectiveness of pegylated interferon alpha 2b and interferon alpha 2b in treating HBeAg positive chronic hepatitis B patients].

OBJECTIVE: To compare the efficacy and safety of PEG-IFNalpha-2b (Peg-Intron) with IFNalpha-2b (Intron A) in treating HBeAg positive chronic hepatitis B patients. METHODS: Two hundred thirty chronic hepatitis B (CHB) patients eligible to the following criteria were enrolled into this study: HBsAg and HBeAg(Abbott kit) positive for at least 6 months, serum HBV DNA > or =10(5) copies/ml (real time PCR, LLQ <10(3) copies/ml) and ALT > or =2 x ULN. After 1:1 randomization, the patients received PegIntron (group A: 1.0 microg/kg body weight, SC, once a week) or Intron A (group B: 3 MIU SC, three times a week) for 24 weeks, and followed up for 24 weeks. RESULTS: (1) In groups A and B, respectively, 80.87% and 83.48% were males; their median ages were 31.0 and 32.0 years old; their median body weights were 65.6 and 65.5 kg; mean serum HBV DNA loads were 8.06 log10 and 7.99 log10; their mean ALT values were 4.17 x ULN and 3.77 x ULN. All of the above parameters between the two groups had no statistically significance differences. (2) At the end of treatment and after follow-up, compared to the Intron A group, the PegIntron group showed better response (including complete and partial response rate, HBV DNA undetectable rate, HBeAg seroconversion rate), but the differences of all of them had no statistical significance. The rate of HBeAg loss was higher in patients receiving PegIntron after follow-up (P = 0.0424). (Table 2) (3) PegIntron and Intron A reduced serum HBV DAN persistently during the therapy. Mean reduction at the end of the treatment was much higher in the PegIntron group than in the Intron group (2.22 log10 copies/ml vs 1.66 log10 copies/ml, P = 0.0283). (4) The overall incidence of adverse events (AEs) in the PegIntron group was similar to that of the Intron A group (94.78% vs 95.65%). The AEs associated with PegIntron administration were similar in nature to those with Interon A, such as influenza-like symptoms, fever, fatigue, headache, nausea, etc and the differences of their incidences had no statistical significance. CONCLUSIONS: The efficacy and safety of PEG-IFNalpha-2b treatment for CHB patients seems to be better than that of IFNalpha-2b; however, further studies are needed to confirm it.

Adolescent↗
PubMed2006

[Dynamic variations of hepatitis B virus polymerase gene in lamivudine-treated hepatitis B patients].

OBJECTIVE: To study variation features of the hepatitis B virus polymerase gene in chronic hepatitis B patients before and after lamivudine treatment. METHODS: From the serum samples of five CHB patients both before and after 12 months' lamivudine treatment, HBV polymerase gene was amplified and positive DNA fragments were cloned into JM105. Twenty positive clones of every sample were checked with mismatched polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and YMDD variants were sequenced. RESULTS: Among five patients after 12 months lamivudine treatment, M552I mutations in two patients with HBV DNA rebounding and D553G mutation in one non-responder were detected except in two patients with negative HBV DNA. CONCLUSIONS: D553G mutation is probably one of the reasons which caused non-responsiveness to the lamivudine treatment. The mutations of YMDD motif that occurred after lamivudine treatment are caused by the induction of the drug.

Amino Acid Sequence↗