Characterization of Full-Length Genomes of Hepatitis B Virus Quasispecies in Sera of Patients at Different Phases of Infection.

Hepatitis B virus (HBV) infection results in different clinical presentation due to different levels of immune response. Our study aimed to characterize HBV full-length genome quasispecies (QS) in patients with different phases of infection to better understand its pathogenesis. Forty treatment-naive HBV-infected patients were enrolled, including 10 cases of acute hepatitis B (AHB), 9 cases of immunotolerant (IT) HBV carriers, 11 cases of chronic hepatitis B (CHB), and 10 cases of acute-on-chronic liver failure (ACLF). The present study was conducted by clone-based sequencing. QS heterogeneity within each open reading frame was calculated. The mutation frequency index (MFI) and amino acid variations within the large HBsAg, HBcAg, and HBxAg regions were analyzed based on the different infection phases. In total, 606 HBV full-length sequences were obtained. HBV QS had higher heterogeneity in ACLF and CHB than that in IT among chronically infected individuals. AHB patients had the lower QS heterogeneity at onset than those with chronic infection. ACLF patients had the highest frequency of mutations in the core promoter and precore region. A triple mutation (A1762T/G1764A/G1896A) was observed more frequently in genotype C than in genotype B. The MFI indicated that specific peptides of the studied regions had more frequent mutations in ACLF. Furthermore, several amino acid variations, known as T- and B-cell epitopes, were potentially associated with the immunoactive phase of infection. More HBV genome mutations and deletions were observed in patients with more severe diseases, particularly in specific regions of the core and preS regions, the clinical significance and mechanism of which need to be further investigated.

FFAS server: novel features and applications.

The Fold and Function Assignment System (FFAS) server [Jaroszewski et al. (2005) FFAS03: a server for profile-profile sequence alignments. Nucleic Acids Research, 33, W284-W288] implements the algorithm for protein profile-profile alignment introduced originally in [Rychlewski et al. (2000) Comparison of sequence profiles. Strategies for structural predictions using sequence information. Protein Science: a Publication of the Protein Society, 9, 232-241]. Here, we present updates, changes and novel functionality added to the server since 2005 and discuss its new applications. The sequence database used to calculate sequence profiles was enriched by adding sets of publicly available metagenomic sequences. The profile of a user's protein can now be compared with ∼20 additional profile databases, including several complete proteomes, human proteins involved in genetic diseases and a database of microbial virulence factors. A newly developed interface uses a system of tabs, allowing the user to navigate multiple results pages, and also includes novel functionality, such as a dotplot graph viewer, modeling tools, an improved 3D alignment viewer and links to the database of structural similarities. The FFAS server was also optimized for speed: running times were reduced by an order of magnitude. The FFAS server, http://ffas.godziklab.org, has no log-in requirement, albeit there is an option to register and store results in individual, password-protected directories. Source code and Linux executables for the FFAS program are available for download from the FFAS server.

Identification and Functional Analysis of ToBPI1/LBP and ToBPI2/LBP in Anti-Bacterial Infection of Trachinotus ovatus.

Bactericidal/permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP) are a group of antibacterial proteins that play an important role in the host's innate immune defense against pathogen infection. In this study, two BPI/LBPs, named ToBPI1/LBP (1434 bp in length, 478 amino acids) and ToBPI2/LBP (1422 bp in length, 474 amino acids), were identified from the golden pompano. ToBPI1/LBP and ToBPI2/LBP were significantly expressed in immune-related tissues after being challenged with Streptococcus agalactiae and Vibrio alginolyticus. The two BPI/LBPs showed significant antibacterial activity against Gram-negative Escherichia coli and Gram-positive S. agalactiae and Streptococcus iniae. In contrast, the antibacterial activity against Staphylococcus aureus, Corynebacterium glutamicum, Vibrio parahaemolyticus, V. alginolyticus and Vibrio harveyi was low and decreased with time. The membrane permeability of bacteria treated with recombinant ToBPI1/LBP and ToBPI2/LBP was significantly enhanced. These results suggest that ToBPI1/LBP and ToBPI2/LBP may play important immunological roles in the immune response of the golden pompano to bacteria. This study will provide basic information and new insights into the immune response mechanism of the golden pompano to bacteria and the function of BPI/LBP.

[Analysis of CSF3R Gene Mutations and Clinical Characteristics in Patients with t(8;21) Acute Myeloid Leukemia].

OBJECTIVE: To investigate the occurrence of CSF3R mutation in patients with t(8;21) acute myeloid leukemia (AML) and its correlation with some clinical parameters. METHODS: The clinical and laboratory data of 167 newly diagnosed AML patients with t(8;21) translocation were analyzed retrospectively. High-throughput DNA sequencing technology combined with Sanger sequencing method was used to detect 112 gene mutations. The occurrence of CSF3R gene mutation and its influence on the remission rate after chemotherapy were analyzed. RESULTS: Among 167 patients with t(8;21) AML, 15 patients (9.0%) carried CSF3R mutations, including 6 cases of membrane proximal region mutations and 9 cases of truncation mutations in the cytoplasmic tail. The most common coexisting mutations of CSF3R were KIT (40.0%), TET2 (33.3%), DNMT3A (26.7%), FLT3 (20.0%), CBL (20.0%), IDH1 (13.3%), etc. Compared with the wild type, the CSF3R mutant group had a higher mutation rate of DNA methylation-related genes（P <0.001）. The median peripheral white blood cell (WBC) count of patients with CSF3R gene mutation was 5.80 (3.20-8.56)×109/L at initial diagnosis, which was significantly lower than 8.80 (5.26-19.92)×109/L of the CSF3R wild-type patients (P =0.017). There was no significant difference between the two groups in sex, median age, FAB classification, hemoglobin level, platelet count, etc. (P >0.05). The CR rate of the CSF3R gene mutation group (100%) was significantly higher than that of the wild-type group (86.8%), but the difference was not statistically significant (P >0.05). The CSF3R gene mutation group had a significantly higher CD19 positive rate and a higher -X rate than the wild group (86.7% vs 47.4%, P =0.004; 33.3% vs 13.2%, P =0.037). CONCLUSION: There is a high incidence of CSF3R mutation in t (8;21) AML patients. The clinical characteristics and coexisting mutation genes of CSF3R mutation-positive patients are different from those of wild-type patients.

Internal organization of large protein families: relationship between the sequence, structure, and function-based clustering.

The protein universe can be organized in families that group proteins sharing common ancestry. Such families display variable levels of structural and functional divergence, from homogenous families, where all members have the same function and very similar structure, to very divergent families, where large variations in function and structure are observed. For practical purposes of structure and function prediction, it would be beneficial to identify sub-groups of proteins with highly similar structures (iso-structural) and/or functions (iso-functional) within divergent protein families. We compared three algorithms in their ability to cluster large protein families and discuss whether any of these methods could reliably identify such iso-structural or iso-functional groups. We show that clustering using profile-sequence and profile-profile comparison methods closely reproduces clusters based on similarities between 3D structures or clusters of proteins with similar biological functions. In contrast, the still commonly used sequence-based methods with fixed thresholds result in vast overestimates of structural and functional diversity in protein families. As a result, these methods also overestimate the number of protein structures that have to be determined to fully characterize structural space of such families. The fact that one can build reliable models based on apparently distantly related templates is crucial for extracting maximal amount of information from new sequencing projects.

[Analysis of the Differential Expression of circRNA in Acute Myeloid Leukemia by GEO Database].

OBJECTIVE: To investigate the difference expression of circular RNA (circRNA) in acute myeloid leukemia (AML) by using bioinformatics method. METHODS: The microarray chip data of AML was searched and downloaded from the Gene Expression Omnibus (GEO) of the National Center for Bioinformatics (NCBI). The differences between AML samples and control samples were analyzed by R software. The interaction between deregulated circRNA, miRNA and mRNA were predicted by miranda software and miRTarBase software. The circRNA-miRNA-mRNA regulatory network was constructed by using the cytoHubba plugin based on the Cytoscape software. RESULTS: A total of 203 differential expression of circRNAs were finally collected, including down-regulated 161 circRNAs and up-regulated 42 circRNAs. CircRNA/miRNA/mRNA interaction network was constructed through software prediction. hsa_circ_0001080, hsa_circ_0004511, hsa_circ_0054211, hsa_circ_0001944 may be positively regulated the gene expression in AML. CONCLUSION: Abnormal expression of circRNA in AML may become a new target for AML treatment.

[Mechanism of Anti Apoptosis and Immune Evasion in Drug-Resistant Leukemia Cells Mediated by STAT3].

OBJECTIVE: To investigate the mechanisms of anti-apoptosis and immune evasion in drug-resistant leukemia cells mediated by STAT3, further to explore the possible mechanism of leukemia relapse caused by minimal residual. METHODS: Drug-resistance leukemia cell line was established by transfecting pcDNA3.1-STAT3 into K562 cells (K562/STAT3). The expression of STAT3, BAX and NKG2D ligands (MICA and ULBP1) in K562/-cells, K562/STAT3 were detected by Western blot and/or RQ-PCR. Cells apoptosis and the killing effect of NK cells on leukemia cells were detected by flow cytometry. RESULTS: The expression of the total STAT3, STAT3 phosphorylation in K562/STAT3 was significantly increased, and P-gp mRNA expression was increased also significantly (P<0.005). In K562/STAT3 cells, the expression of pro-apoptotic BAX (P=0.005) was significantly lower, and the number of apoptotic cells (P=0.002) induced by adriamycin was significantly decreased as compared with those in K562/- cells. After K562/STAT3 cells were treated by STAT3 inhibitor (SH-4-54), the expression of BAX mRNA (P=0.017) was significantly higher and the number of apoptotic cells (P=0.005) was significantly increased. The MICA and ULBP1 mRNA expression in K562/STAT3 cells was significantly lower than that in K562/- cells, and also for MICA and ULBP1 protein (MICA and ULPB1 mRNA: P<0.0001, MICA protein: P=0.001, ULPB1 protein: P=0.022). After K562/STAT3 cells were treated with STAT3 inhibitor (SH-4-54), the expression of MICA mRNA and protein was increased (mRNA: P=0.001, protein: P=0.002), but ULBP1 mRNA and protein showed no significantly change (mRNA: P=0.137, protein: P=0.1905). The cytotoxicity of NK cells to K562/STAT3 cells was susceptible as compared with K562/- (P=0.002), but the cytotoxicity of K562/STAT3 cells to NK cell could be recovered by STAT3 inhibitor (P=0.006). CONCLUSION: STAT3 phosphorylation can inhibits cell apoptosis and promotes cell immune escape. STAT3 inhibitors can promote the apoptosis of leukemia cells and increase their sensitivity to NK cells.

[Analysis of RUNX1 Gene Mutation in Patients with Myelodysplastic Syndrome].

OBJECTIVE: To investigate the mutation of RUNX1 gene in patients with myelodysplastic syndrome (MDS) and its correlation with other gene mutations and some clinical parameters. METHODS: The mutations of RUNX1, DNMT3A, TET2, IDH1/2, NPM1, FLT3-ITD and C-KIT in 170 patients with MDS were detected by direct and indirect sequencing of genomic DNA-PCR amplification products. RESULTS: The RUNX1 mutation was found in 23 patients (13.5 %, 23/170). Among the 170 patients, other most frequent mutation was TET2 (11.2%, 19/170), followed by mutations in DNMT3A (9.4%, 16/170), NPM1 (8.2%, 14/170), IDH2 (4.1%, 7/170)、FLT3-ITD (2.9%, 5/170), IDH1 (1.7%, 3/170) and c-KIT (0.58%, 1/170). The most common coexisting mutations were TET2 (5/23). The RUNX1-mutated group showed significantly higher leukocyte levels, higher percentages of blast cells, higher incidences of leukemia transformation and lower platelet counts in comparison with RUNX1 non-mutation group (P＜0.05). whereas there were no statistically significant difference in age, MDS subtype, karyotype and hemoglobin level between 2 groups (P＞0.05). Seventeen patients harboring RUNX1 mutations were followed up and almost 47.05% (8/17) of the patients progressed into acute myeloid leukemia (AML). The rates of transformation into AML in ASXL1-mutation group was significantly higher than that in ASXLL- non-mutation group (47.05% vs 11.7%) (P=0.001). CONCLUSION: The incidence of RUNX1 mutation is high in MDS patients. The RUNX1-mutated patients have higher leukocyte level, higher percentages of blast cells, higher incidences of leukemia transformation and lower platelet count.

[Coexisting Mutations in IDH1/2-Mutated Acute Myeloid Leukemia].

OBJECTIVE: To explore the coexisting mutations in IDH-mutated acute myeloid leukemia(AML) and its relation with partial clinical parametrs. METHODS: The exon 4 mutation of IDH1/2 gene was screened by using genome DNA-PCR combined with sanger sequencing, 51 targeted gene mutations in the patients with IDH1/2 mutation were detected by using high throughput DNA sequencing combined with sanger sequencing. RESULTS: Among 358 patients, the IDH1/2 mutation was found in 46 cases including IDH1 mutation in 35 cases and IDH2 mutation in 11 cases, 97.87%(45/46) patients with IDH1/2 mutation simultaneously carried other gene mutations including 8(17.8%) cases with mutation of double gene, 17(37.8%) cases with mutation of 3 genes and 20(44.4%) cases with mutation of ≥ 4 genes. The mutation frequency of each patient averaged 3.52 times. In mutation of accompanied genes, the common genes were NPM1(n=29, 63.0%), next DNMT3A(n=25, 54.3%), FLT3-ITD(n=7, 15.2%), TET2(n=5, 10.9%) and NRAS(n=5, 10.9%). The average WBC level of patients with NPM1 mutation in IDH1 mutation group was higher than that of patients in wild type group(P<0.05). The complete remission (CR) rate of patients with DNMT3A mutation was significant lower than that of patients with wild type (30% vs 80%, P<0.01). The presence of ≥ 4 mutations was found to be significantly associated with higher white blood level than that in the patients with double mutations(P<0.05). CONCLUSION: More than 95% AML patients with IDH1/2 mutation commonly show additional mutations. The number and the type of IDH coexisting mutations have certain effect on the clinical features and CR rate.

Clinical characteristics and phenotype distribution in 10 Chinese patients with X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (X-ALD) is the most frequent type of inherited demyelinating peroxisomal disease caused by mutations in the ATP binding cassette subfamily D member 1 (ABCD1) gene. The rate of early recognition and genetic diagnosis of X-ALD remains low due to its variable clinical manifestations. The present study summarized the clinical features Chinese X-ALD patients and performed a follow-up study to further precisely characterize this disease. A total of 10 patients diagnosed with X-ALD between 1994 and 2016 at Shandong Provincial Hospital Affiliated to Shandong University (Jinan, China) were included in the present study. Through reviewing their medical records and performing telephone follow-ups, the clinical features, biochemical laboratory data, brain images, treatments and long-term outcomes were retrospectively summarized. Mutation analysis of the ABCD1 gene was performed in certain patients. Most of the patients (8/10) had the childhood cerebral form of X-ALD. One patient presented with the olivo-ponto-cerebellar form, the rarest form of X-ALD. In all patients, brain magnetic resonance images revealed abnormalities with typical T2-weighted hyperintensity. Analysis of very long chain fatty acid revealed high plasma levels of hexacosanoic acid in all patients. Increased adrenocorticotropic hormone, decreased cortisol and neurophysiological manifestations were also observed. Three different mutations of the ABCD1 gene were identified in the 3 patients subjected to genotyping. During the follow-ups, most patients took neurotrophic drugs and received hydrocortisone replacement when required. One patient received a hematopoietic stem cell transplantation, but died 1 year following the transplantation. Chronic myelopathy and peripheral neuropathy progressed with time, gradually leading to a vegetative state or paralysis within several years of clinical symptom onset. In conclusion, male patients with adrenocortical insufficiency should be further investigated for X-ALD. Early detection is critical to prevent the progression of X-ALD with mutation analysis of ABCD1 the most accurate method to confirm diagnosis.

[Influence of Fe3O4Magnetic Nanoparticles Combined with As2O3 and Adriamycin on Raji Cell Apoptosis and Autophagy].

OBJECTIVE: To explore the effect of magnetic iron nanoparticles ( Fe3O4- MNP) in combination with arsenic trioxide and adriamycin on apoptosis and autophagy of Raji cells, a non-Hodgkin's lymphoma (NHL) cell line. METHODS: The growth inhibition rate of Raji cells was analyzed by MTT assay, the cells apoptosis and intracellular concentration of ADM were determined by flow cytometry (FCM), the expression levels of apoptosis-related proteins such as BCL-2, NFκB, Survivin, BAX, P53, and Caspase-3, and related to autophagy-proteins, such as LC3, Beclin-1, and P62/SQSTM1 were detected by Western blot. RESULTS: The growth inhibition of Raji cells in the group of ADM + As2O3were higher than that in the group of ADM or As2O3alone, however, lower than that in the group of Fe3O4- MNP combined with ADM and As2O3(ADM+As2O3+ MNP) (P < 0.05). The apoptotic rate and accumulation of intracellular ADM in the group of Fe3O4- MNP combined with ADM and As2O3were significantly higher than those in control, ADM, As2O3, and ADM plus As2O3groups (P < 0.05). The upregulation of BAX, P53 and Caspase-3 expression and the down regulation of BCL-2, NFκB, and Survivin expression at protein level were more remarkable in the group of ADM+As2O3 + MNP, compared with the other groups (P < 0.05). Moreover, the expressions of LC3 and Beclin-1 proteins in the group of ADM+As2O3+ MNP were higher, while the expression of P62/SQSTM1 was lower than that in other groups (P < 0.05). CONCLUSION: The Fe3O4 - MNP combined with ADM and As2O3can increase the antitumor efficacy on Raji cells by promoting apoptosis and inducing autophagy. It would be a promising strategy for malignant lymphoma therapy.

[Effects of Garcinia Acid Combined with Daunorubicin on Expression of Pregnane X Receptor in Leukemia Cell Line K562/A02].

OBJECTIVE: To explore the expression of PXR (Pregnane X receptor) in several malignant hematological cell lines, and to investigate the reversal effect of Gambogic acid (GA) on multi-drug resistance (MDR) of K562/A02 cell line and its reversal mechanism. METHODS: Transcription of PXR was detected by real-time PCR in several malignant hematological cell lines. The growth inhibition rate of K562/A02 in different experimental groups was assayed by MTT method, and the expression of PXR protein was measured by Western blot. RESULTS: PXR gene transcription could be detected in several hematological malignancy cell lines, and it was significantly higher in K562/A02 cell line, compared with the other cell lines used in this experiment. Low-dose GA could enhance cell growth inhibition rate, increasing the effect of chemotherapy, which may be associated with down-regulation of PXR expression. PXR gene transcription and protein expression in GA and DNR+GA groups decreased as compared with control group and the DNR group, suggesting that low-dose GA can down-regulate PXR gene transcription and protein expression. CONCLUSION: PXR gene transcription can be detected in several hematological malignancy cell line, which is significantly higher in K562/A02 cell line, as compared with the other cell lines used in this experiment. Low-dose GA can enhance cell growth inhibition rate, increasing the effect of chemotherapy, which may be associated with down-regulation of PXR expression.

[Determination of guanfu base A hydrochloride in plasma by LC-MS method and its pharmacokinetics in dogs].

AIM: To establish an analytical method for determination of guanfu base A (GFA) concentration in plasma and to study its pharmacokinetic profile in dogs. METHODS: Six dogs were given a 7.56 mg.kg-1 dose intravenously. Blood samples were collected at various time-points after drug administration. Analytical method based on liquid chromatography-mass spectrometry (LC-MS) was established to determine the plasma concentration of GFA. Pharmacokinetic evaluation was carried out using the 3P87 program. RESULTS: The calibration curves were linear over the concentration range from 0.42 microgram.mL-1 to 21.2 micrograms.mL-1 (gamma = 0.9994). The intra-day and inter-day precisions were generally good (< 15%) at low, medium and high concentrations. The overall recovery of the analytes was more than 80%. Six dogs were given an i.v. dose of 7.56 mg.kg-1 of GFA hydrochloride, an open three compartment model best described the concentration-time profiles for GFA. The half-lives for the rapid and slow distribution phase and terminal elimination phase (T1/2 pi, T1/2 alpha and T1/2 beta) were 0.07 h, 1.5 h, and 13.5 h, respectively. The total area under the plasma concentration-time curve (AUC), the volume of the central compartment (Vc), and plasma clearance (CLs) were 61.43 micrograms.h.mL-1, 0.37 L.kg-1 and 0.14 L.kg-1.h-1, respectively. CONCLUSION: The analytical method was shown to be sensitive, specific, rapid and reproducible, and was suitable for pharmacokinetic studies of GFA.

Anticancer and multidrug-resistance reversing potential of traditional medicinal plants and their bioactive compounds in leukemia cell lines.

Multidrug resistance remains a serious clinical problem in the successful therapy of malignant diseases. It occurs in cultured tumor cell lines, as well as in human cancers. Therefore, it is critical to develop novel anticancer drugs with multidrug-resistance modulating potential to increase the survival rate of leukemia patients. Plant-derived natural products have been used for the treatment of various diseases for thousands of years. This review summarizes the anticancer and multidrug-resistance reversing properties of the extracts and bioactive compounds from traditional medicinal plants in different leukemia cell lines. Further mechanistic studies will pave the road to establish the anticancer potential of plant-derived natural compounds.

Cytotoxic effects of mono-(2-ethylhexyl) phthalate on human embryonic stem cells.

BACKGROUND: Mono-(2-ethylhexyl) phthalate (MEHP), the metabolite of di-(2-ethylhexyl) phthalate (DEHP), was suspected to be toxic to human embryos. This study contributes to investigating its toxic effects by an embryonic stem cell test (EST) based on two human embryonic stem cell (hESCs) lines. METHODS: CH1 established in our own lab and H1, a federally registered cell line were two human embryonic stem cell lines used in this test. Four endpoint measurements were performed consisting of cell viability, proliferation ability, apoptosis as well as changes of gene expression patterns after spontaneous differentiation were determined. For measuring effects on the first three endpoints, the cells were treated with various concentrations of MEHP dissolved in dimethyl sulfoxide (DMSO) and only with DMSO which served as control and harvested after 5 days. For measuring effects during spontaneous differentiation, the RNA of embryoid bodies (EBs) formed after 8 days' MEHP exposure was collected and changes in differentiation specific gene expression patterns were analyzed by quantitative real time RT-PCR. RESULTS: As a result the viability and proliferation ability of both cell lines decreased significantly at 1000 µmol/L MEHP, while there was no effect on apoptosis or cell morphology. In addition MEHP also changed the gene expression pattern in the EBs of both cell lines. CONCLUSION: MEHP in a high dose was cytotoxic and affected the development of hESCs, which indicates its embryo toxicity in human embryos.

[Roles of NKG2D in cytokine-induced killer (CIK) against hematological malignant cells lines].

This study was purposed to investigate the CIK cell cytotoxicity to hematological malignant cell lines by interaction NKG2D receptors and corresponding ligands. The CIK cells was expanded from healthy individual with interferon (IFN)γ, CD3 monoclonal antibodies (mAb) and interleukin-2 (IL-2). The subset of lymphocyte and the expression of NK cell receptors on CIK cells was detected by flow cytometry; NKG2D ligand expression on hematological malignant cell lines was also analyzed by flow cytometry, the calcein acetoxymethyl ester (CAM) was used for labeling target cells, then the cytotoxicity of CIK cells to hematological malignant cell lines was detected by flow cytometry. The results showed that most of CIK cells expressed CD3 (97.85 ± 1.95%) , CD3(+)CD8(+) cells and CD3(+)CD56(+) cells increased significantly as compared with un-cultured cells (P < 0.001;P = 0.033). About 86% CIK cells expressed NKG2D receptor but no other NK receptors such as CD158a, CD158b and NCR. Different levels of NKG2D ligands were detected in hematological malignant cell lines U266, K562 and Daudi. CIK cells showed high cytotoxicity to these three different cell lines, and this cytotoxicity was partially blocked by treating CIK cells with anti-NKG2D antibody (U266 52.67 ± 4.63% vs 32.67 ± 4.81%, P = 0.008;K562 71.67 ± 4.91% vs 50.33 ± 4.91%, P = 0.007;Daudi 68.67 ± 5.04 vs 52.67 ± 2.60%, P = 0.024) . It is concluded that most of CIK cells express NKG2D receptor, interaction of NKG2D-NKG2D ligands may be one of the mechanisms, by which CIK cells kill hematological malignant cells.

[NKG2D-mediated natural killer cell cytotoxicity against myeloid leukemia cells OUN-1].

OBJECTIVE: To investigate NK cell cytotoxicity to leukemic cell by NKG2D receptors and NKG2D ligands interaction upregulated by hydroxyurea (HU). METHODS: Leukemic cell lines OUN-1 and primary leukemic cells were cultured for 24 hours in the presence of HU, then the NKG2D ligands expressions were analyzed by flow cytometry (FCM). Isolated NK cells from healthy individual cultured for 72 hours in presence of IL-2 were used as effect cell, and leukemic cell line OUN-1 treated with HU was used as target cell, NK cell cytotoxicity against leukemic cell line was assessed using chromium-51 release assay. RESULTS: Leukemic cell lines showed upregulation of MIC A/B (MFI: 8.9 ± 0.9 vs 23.5 ± 3.4, P = 0.01) and ULBP2 (MFI: 14.5 ± 0.6 vs 33.5 ± 4.8, P = 0.03) following incubation with HU. HU also upregulated the NKG2DLs on primary leukemia cells from patients with acute myeloid leukemia. Treatment of OUN-1 with HU significantly increased the cytotoxicity of NK cells isolated from healthy individual \[(62.0 ± 5.6)% vs (76.0 ± 5.3)%, P = 0.02\], and the enhancing effect of HU was partly blocked by anti-NKG2D Abs \[(76.0 ± 5.3)% vs (46.0 ± 4.5)%, P = 0.00\]. CONCLUSION: HU selectively upregulated NKG2D ligand expression on leukemic cell lines, and enhanced NK cell cytotoxicity against leukemic cells through NKG2D receptors and NKG2D ligands interaction.

Mechanisms of tetrandrine and 5-bromotetrandrine in reversing multidrug resistance may relate to down-regulation of multidrug resistance associated protein 7 expression.

Both tetrandrine (Tet) and 5-bromotetrandrine (BrTet) can effectively reverse P-glycoprotein (P-gp)-mediated multidrug resistance (MDR). The structure of multidrug resistance associated protein 7 (MRP7) has its own specificity and difference compared with other members of the MRP family. This study was aimed to investigate whether Tet and BrTet can inhibit the expression level of MRP7 so as to further look into the mechanisms of the reversal effects of Tet and BrTet on MDR. The inhibitory effects of daunorubicin (DNR) used alone on the proliferation of K562 and K562/A02 cells were evaluated by MTT assay, the IC(50) of DNR and drug resistant folds were calculated. The mRNA level of MRP7 was tested by real-time PCR, and the protein levels of MRP7 and P-gp were tested by Western blot. The DNR accumulation was analyzed by flow cytometry (FCM). The results showed that the resistance of K562/A02 cells to DNR was 23.65-folds of that of K562 cells. After administration of 1 µmol/L Tet or 2 µmol/L BrTet, the mRNA level of MRP7 in the K562/A02 cells decreased to 2% and 12% respectively, and the protein level of MRP7 decreased by 53.2% and 83.7% respectively. The protein level of P-gp decreased by 58.47% and 52.20% in the 1 µmol/L Tet and 2 µmol/L BrTet groups. FCM detection showed that 1 µmol/L Tet and 2 µmol/L BrTet significantly increased the accumulation of DNR in K562/A02 cells by 94.32% and 271% respectively. It is concluded that Tet and BrTet both can reverse MDR in vitro. The mechanisms may be related to the inhibition of MRP7 overexpression and the increase of anticancer drug concentration in cells. At the same molar concentration, the effects of Tet and BrTet in inhibiting the protein level of MRP7 expression do not show significant difference.

Effectiveness of 5-flurouracil-based neoadjuvant chemotherapy in locally-advanced gastric/gastroesophageal cancer: a meta-analysis.

AIM: To investigate the effectiveness of 5-flurouracil-based neoadjuvant chemotherapy (NAC) for gastroesophageal and gastric cancer by meta-analysis. METHODS: MEDLINE and manual searches were performed to identify all published randomized controlled trials (RCTs) investigating the efficacy of the flurouracil-based NAC for gastroesophageal and gastric cancer, and RCTs of NAC for advanced gastroesophageal and gastric cancer vs no therapy before surgery. Studies that included patients with metastases at enrollment were excluded. Primary endpoint was the odds ratio (OR) for improving overall survival rate of patients with gastroesophageal and gastric cancer. Secondary endpoints were the OR of efficiency for down-staging tumor and increasing R0 resection in patients with gastroesophageal and gastric cancer. Safety analyses were also performed. The OR was the principal measurement of effect, which was calculated as the treatment group (NAC plus surgery) vs control group (surgery alone) and was presented as a point estimate with 95% confidence intervals (CI). All calculations and statistical tests were performed using RevMan 5.1 software. RESULTS: Seven RCTs were included for the analysis. A total of 1249 patients with advanced gastroesophageal and gastric cancer enrolled in the seven trials were divided into treatment group (n = 620) and control group (n = 629). The quality scores of the RCTs were assessed according to the method of Jadad. The RCT quality scores ranged from 2 to 7 (5-point scale), with a mean of 3.75. The median follow-up time in these studies was over 3 years. The meta-analysis showed that NAC improved the overall survival rate (OR 1.40, 95%CI 1.11-1.76; P = 0.005), which was statistically significant. The 3-year progression-free survival rate was significantly higher in treatment group than in control group (37.7% vs 27.3%) (OR 1.62, 95%CI 1.21-2.15; P = 0.001). The tumor down-stage rate was higher in treatment group than in control group (55.76% vs 41.38%) (OR 1.77, 95%CI 1.27-2.49; P = 0.0009) and the R0 resection rate of the gastroesophageal and gastric cancer was higher in treatment group than in control group (75.11% vs 68.56%) (OR 1.38, 95%CI 1.03-1.85; P = 0.03), with significant differences. No obvious safety concerns about mortality and complications were raised in these trials. There were no statistically significant differences in perioperative mortality (5.08% vs 4.86%) (OR 1.05, 95%CI 0.57-1.94; P = 0.87 fixed-effect model) and in the complication rate between the two groups (13.25% vs 9.66%) (OR 1.40, 95%CI 0.91-2.14; P = 0.12 fixed-effect model). Trials showed that patients from Western countries favored NAC compared with those from Asian countries (OR 1.40, 95%CI 1.07-1.83). Monotherapy was inferior to multiple chemotherapy (OR 1.40, 95%CI 1.07-1.83). Intravenous administration of NAC was more advantageous than oral route (OR 1.41, 95%CI 1.09-1.81). CONCLUSION: Flurouracil-based NAC can safely improve overall survival rate of patients with gastroesophageal/gastric cancer. Additionally, NAC can down the tumor stage and improve R0 resection.

[Reversal effect of gambogic acid on multidrug resistance of K562/A02 cell line].

This study was purposed to investigate the reversal effect of gambogic acid (GA) on multidrug resistance of K562/A02 cells and its mechanism. The IC(50) (half maximal inhibitory concentration) of adriamycin (ADM) was evaluated by MTT. Cell apoptosis was detected by flow cytometry. Morphological changes of K562/A02 cells were observed by fluorescent microscopy with DAPI staining. The expressions of Survivin and P-gp were determined by Western blot. The results showed that the IC(50) of ADM on K562 and K562/A02 cell proliferation were (1.42 ± 0.07) µg/ml and (28.42 ± 1.40) µg/ml respectively. GA ≤ 0.0625 µmol/L had no inhibitory effect on proliferation of K562 and K562/A02. 0.0625 µmol/L GA could enhance the sensitivity of K562/A02 cells to ADM (P < 0.05) and the reversal multiples was 1.53. The apoptotic rate was raised after treating with ADM combined with 0.0625 µmol/L GA for 48 h (P < 0.05). Morphological differences were typical and obvious between cells of control and treated groups under fluorescence microscopy using DAPI staining. After treating K562/A02 cells with ADM combined with 0.0625 µmol/L GA for 48 h, the expressions of Survivin and P-gp were down-regulated at protein levels. It is concluded that GA can enhance the sensitivity of K562/A02 cells to ADM, which may be related to increasing cell apoptosis and down-regulating expressions of Survivin and P-gp.