Discovery of N-(1,3,4-thiadiazol-2-yl)benzamide derivatives containing a 6,7-methoxyquinoline structure as novel EGFR/HER-2 dual-target inhibitors against cancer growth and angiogenesis.

Targeting EGFR and HER-2 is an essential direction for cancer treatment. Here, a series of N-(1,3,4-thiadiazol-2-yl)benzamide derivatives containing a 6,7-methoxyquinoline structure was designed and synthesized to serve as EGFR/HER-2 dual-target inhibitors. The kinase assays verified that target compounds could inhibit the kinase activity of EGFR and HER-2 selectively. The results of CCK-8 and 3D cell viability assays confirmed that target compounds had excellent anti-proliferation ability against breast cancer cells (MCF-7 and SK-BR-3) and lung cancer cells (A549 and H1975), particularly against SK-BR-3 cells, while the inhibitory effect on healthy breast cells (MCF-10A) and lung cells (Beas-2B) was weak. Among them, the hit compound YH-9 binded to EGFR and HER-2 stably in molecular dynamics studies. Further studies found thatYH-9could induce the release of cytochrome c and inhibit proliferation by promoting ROS expression in SK-BR-3 cells. Moreover,YH-9could diminish the secretion of VEGF and bFGF factors in SK-BR-3 cells, then inhibited tube formation and angiogenesis. Notably,YH-9could effectively inhibit breast cancer growth and angiogenesis with little toxicity in the SK-BR-3 cell xenograft model. Taken together,in vitroandin vivoresults revealed that YH-9 had high drug potential as a dual-target inhibitor of EGFR/HER-2 to inhibit breast cancer growth and angiogenesis.

Design, synthesis and biological evaluation of erythrina derivatives bearing a 1,2,3-triazole moiety as PARP-1 inhibitors.

Inhibitors of poly (ADP-ribose) polymerase-1 (PARP-1) have shown to be promising in clinical trials against cancer, and many researchers are interested in the development of new PARP-1 inhibitors. Herein, we designed and synthesized 44 novel erythrina derivatives bearing a 1,2,3-triazole moiety as PARP-1 inhibitors. MTT assay results indicated that compound 10b had the most potent anti-proliferative activity against A549 cells among five cancer cells. The enzyme inhibitory activity in vitro of compound 10b was also significantly better than rucaparib. Furthermore, the selectivity index of compound 10b was higher than rucaparib for lung cancer cells. Flow cytometry analysis showed that compound 10b induced apoptosis of A549 cells by the mitochondrial pathway. Western blot analysis indicated that compound 10b was able to inhibit the biosynthesis of PAR effectively, and it was more potent than rucaparib. Also, compound 10b was able to up-regulate the ratio of bax/bcl-2, activate caspase-3, and ultimately induced apoptosis of A549 cells. The combined results revealed that the discovery of novel non-amide based PARP-1 inhibitors have great research significance and provide a better choice for the future development of drugs.

Design, synthesis and biological evaluation of novel (E)-N-phenyl-4-(pyridine-acylhydrazone) benzamide derivatives as potential antitumor agents for the treatment of multiple myeloma (MM).

A series of novel (E)-N-phenyl-4-(pyridine-acylhydrazone) benzamide derivatives were designed, synthesized, and evaluated for their anti-proliferative activity against two different human cancer cell lines and one human normal cell line. Compound 8b had the best anti-proliferative activity (IC50 = 0.12 ± 0.09 µM, RPMI8226 cells) than the other compounds. And compound 8b had lower toxicity than imatinib. Flow cytometry analysis showed that compound 8b could arrest the cell cycle at the G0/G1 phase, and induce apoptosis of RPMI8226 cells by promoting mitochondrial ROS release, thereby effectively inhibiting cell proliferation. Our findings provided a promising lead compound 8b for further structural optimization and will be instructive for the discovery of more potent antitumor drugs with high selectivity and low toxicity.

[A comparative analysis of neonatal critical illness score and score for neonatal acute physiology, perinatal extension, version II].

OBJECTIVE: To investigate the accuracy and clinical utility of neonatal critical illness score (NCIS) and score for neonatal acute physiology, perinatal extension, version II (SNAPPE-II) in predicting the "dead and abandoned" risk in critically ill neonates. METHODS: A total of 269 critically ill neonates were divided into two groups according to their prognosis: dead/abandoned and improved/cured. The accuracy of these two scoring systems, NCIS and SNAPPE-II, in predicting the "dead and abandoned" risk was compared. RESULTS: The dead/abandoned group had a significantly higher SNAPPE-II score than the improved/cured group (P<0.001), while there was no significant difference in the NCIS score between the two groups (P=0.091). The children who were in line with the individual indicator in the NCIS results had a significantly higher "dead and abandoned" risk than those who were not (P=0.005). CONCLUSIONS: SNAPPE-II is more accurate in early prediction of the "dead and abandoned" risk in critically ill neonates compared with NCIS. NCIS has the ability to predict the "dead and abandoned" risk in children in line with the individual indicator.

Astragalus polysaccharide upregulates hepcidin and reduces iron overload in mice via activation of p38 mitogen-activated protein kinase.

Thalassemia is a genetic disease characterized by iron overload which is a major detrimental factor contributing to mortality and organ damage. The hepcidin secreted by liver plays an essential role in orchestrating iron metabolism. Lowering iron load in thalassemia patients by means of increasing hepcidin might be a therapeutic strategy. In this study, we first found that astragalus polysaccharide (APS) significantly increased hepcidin expression in HepG2 and L-02 cell lines originating from hepatocytes and mice liver, respectively. Following treatment with APS, the iron concentrations in serum, liver, spleen, and heart were significantly reduced in comparison to saline treated control mice. In further experiments, upregulation of interleukin-6 (IL-6) and enhanced p38 MAPK phosphorylation were detected in APS treated cells and mice, and as documented in previous studies, IL-6 and P38 MAPK phosphorylation are involved in the regulation of hepcidin expression. We also found that the effects of APS on upregulating hepcidin and IL-6 expressions could be antagonized by pretreatment with SB203580, an inhibitor of p38 MAPK signaling. These findings suggest that activation of p38 MAPK and release of IL-6 might mediate induction of hepcidin by APS. It is concluded that APS might have therapeutic implications in patients with iron overload, especially for thalassemia patients.

Yinzhihuang attenuates ANIT-induced intrahepatic cholestasis in rats through upregulation of Mrp2 and Bsep expressions.

BACKGROUND: The treatment of intrahepatic cholestasis has been limited, and development of an effective drug is needed. Clinical studies have shown that Yinzhihuang (YZH), a traditional Chinese decoction, enhances bilirubin clearance. The goal of this study was to determine the protective effect of YZH on experimental intrahepatic cholestasis in young rats and to explore its underlying molecular mechanisms. METHODS: Intrahepatic cholestasis in rats was induced by α-naphthylisothiocyanate (ANIT) on days 1 and 8. The rats received YZH, ursodeoxycholic acid (UDCA), or vehicle for 9 d and were killed on either day 3 or day 10. Serum biomarkers, liver histology, and the distribution of protein and mRNA expression of Mrp2 and Bsep were analyzed. RESULTS: YZH treatment resulted in decreased levels of serum biomarkers except γ-glutamyl transpeptidase, attenuated liver histological injuries, increased protein expressions of Mrp2 and Bsep, and upregulated expressions of Mrp2 and Bsep mRNAs. The effects of YZH on serum biomarkers (aminotransferase, alanine aminotransferase, and direct bilirubin), liver histology, and Mrp2 mRNA expressions were significantly greater and earlier than those of UDCA. CONCLUSION: Our results suggest that YZH has protective effect against ANIT-induced intrahepatic cholestasis in rats, through upregulation of Mrp2 and Bsep expressions.

[Prospective clinical study of radix astragali and its compound prescription for treatment of ß-thalassemia in children].

OBJECTIVE: To evaluate the efficacy and safety of radix astragali and its compound prescription for treatment of ß-thalassemia in children. METHODS: This study was a randomized, controlled, double-blind clinical trial. Fifty-seven children with ß-thalassemia were randomly assigned to radix astragali, compound prescription (radix astragali+ codonopsis pilosula + tortoise plastron) and placebo control groups after stratifying the patients according to disease type (intermedia and major). The parameters of hematology and safety were assessed after 12 weeks of treatment. RESULTS: After 12 weeks of treatment, the mean Hb elevation levels in children with ß-thalassemia intermedia from the compound prescription and the radix astragali groups were 1.21±1.12 and 1.05±0.80 g/dL respectively compared with -(0.28±0.51) g/dL in the placebo control group (P<0.01). Mean Hb levels in the compound prescription and radix astragali groups were significantly higher than in the placebo control group (P<0.05). Therapy with both radix astragali and its compound prescription increased fetal hemoglobin, red blood cell, mean corpuscular hemoglobin and reticulocyte levels in children with ß-thalassemia intermedia. The total effective rates were 64% and 62% in children with ß-thalassemia intermedia from the compound prescription and radix astragali groups respectively, which was significantly higher than in the placebo control group (9%; P<0.01). Therapy with radix astragali or its compound prescription in children with ß-thalassemia major had similar but less favourable effects than the same therapy in children with ß-thalassemia intermedia. White blood cell, neutrophil, platelet and hepatic and renal functions were not adversely affected by the medicines. CONCLUSIONS: Therapy with radix astragali or its compound prescription is effective and safe in children with ß-thalassemia.

Synthesis and evaluation of novel HER-2 inhibitors to exert anti-breast cancer ability through epithelial-mesenchymal transition (EMT) pathway.

Human epidermal growth factor receptor 2 (HER-2) is an essential member of the receptor tyrosine kinase (RTK) superfamily and has been reported as a critical method for treating HER-2 positive breast cancer. Here, we retained (E)-4-methyl-2-(4-(trifluoromethyl)styryl)oxazole, a fragment of HER-2 inhibitor Mubritinib, and synthesized 32 novel compounds from it. We screened out the most potential compound Q7j with HER-2 positive breast cancer cells through MTT assays, which possessed low toxicity on normal cells (MCF7-10A). Subsequently, wound healing, transwell, western blotting, and immunofluorescence experiments were performed, and it was found that compound Q7j could suppress cell migration by inhibiting the phosphorylation of HER-2 and affecting the expression of EMT-related proteins. Moreover, the SKBR3 orthotopic xenograft model confirmed that compound Q7j was more effective than Mubritinib in inhibiting the proliferation of cancer cells. In general, compound Q7j was a potential HER-2 inhibitor in treating breast cancer, which may be of great significance for developing and improving HER-2 small molecule inhibitors.

[Preparation of polyclonal antibody of recombinant human thioredoxin-1 and its protective effects on neonatal rats with endotoxemia].

OBJECTIVE: To clone the gene human thioredoxin 1 (hTrx-1) expressing its protein in the E.coli expression system and to obtain its polyclonal antibody, and to study the protective effects of hTrx-1 on neonatal rats with endotoxemia. METHODS: DNA encoding hTrx-1 from fetal liver cells was isolated by RT-PCR. The hTrx-1 was cloned to the prokaryotic expression plasmid PET-28a to induce its protein expression in the E.coli expression system. The purified hTrx-1 was injected into rats to prepare polyclonal antibody. Newborn Sprague-Dawley rats were randomly assigned to three groups: control, lipopolysaccharide (LPS) and hTrx-1 (n=12 each). The control and the LPS groups were intraperitoneally injected with normal saline and LPS (5 mg/kg), respectively. The hTrx-1 group received an intraperitoneal injection of hTrx-1 (10 mg/kg) 30 minutes before LPS injection. The mortality rate 24 hrs after injection was compared between the three groups. RESULTS: The prokaryotic expression plasmid PET-28a-hTrx-1 was constructed. The hTrx-1 protein was expressed and purified. The polyclonal antibody of hTrx-1 with the titer of 1∶51200 was prepared. The mortality rate of the control, LPS and hTrx-1 groups was 0, 67% and 17%, respectively (χ2=14.400, P<0.01). CONCLUSIONS: The polyclonal antibody of hTrx-1 is prepared successfully. The hTrx-1 protein has protective effects on neonatal rats with endotoxiamia.

Design, synthesis, and in vitro and in vivo anti-angiogenesis study of a novel vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor based on 1,2,3-triazole scaffold.

In the past five years, our team had been committed to click chemistry research, exploring the biological activity of 1,2,3-triazole by synthesizing different target inhibitors. In this study, a series of novel indole-2-one derivatives based on 1,2,3-triazole scaffolds were synthesized for the first time, and their inhibitory activity on vascular endothelial growth factor receptor-2 (VEGFR-2) was tested. Most of the compounds had shown promising activity in the VEGFR-2 kinase assay and had low toxicity to human umbilical vein endothelial cells (HUVECs). The compound 13d (IC50 = 26.38 nM) had better kinase activity inhibition ability than sunitinib (IC50 = 83.20 nM) and was less toxic to HUVECs. Moreover, it had an excellent inhibitory effect on HT-29 and MKN-45 cells. On the one hand, by tube formation assay, transwell, and Western blot analysis, compound 13d could inhibit VEGFR-2 protein phosphorylate on HUVECs, thereby inhibiting HUVECs migration and tube formation. In vivo study, the zebrafish model with VEGFR-2 labeling also verified that compound 13d had more anti-angiogenesis ability than sunitinib. On the other hand, molecular docking and molecular dynamics (MD) simulation results showed that compound 13d could stably bind to the active site of VEGFR-2. Based on the above findings, compound 13d could be considered an effective anti-angiogenesis drug and has more development value than sunitinib.

Novel Allosteric Inhibitors of Deoxyhypusine Synthase against Malignant Melanoma: Design, Synthesis, and Biological Evaluation.

Based on the novel allosteric site of deoxyhypusine synthase (DHPS), two series of 30 novel 5-(2-methoxyphenoxy)-2-phenylpyrimidin-4-amine derivatives as DHPS inhibitors were designed and synthesized. Among them, compound 8m, with the best DHPS inhibitory potency (IC50 = 0.014 µM), exhibited excellent inhibition against melanoma cells, which was superior to that of GC7. Besides, molecular docking and molecular dynamics (MD) simulations further proved that compound 8m was tightly bound to the allosteric site of DHPS. Flow cytometric analysis and enzyme-linked immunosorbent assay (ELISA) showed that compound 8m could inhibit the intracellular reactive oxygen species (ROS) level. Furthermore, by western blot analysis, compound 8m effectively activated caspase 3 and decreased the expressions of GP-100, tyrosinase, eIF5A2, MMP2, and MMP9. Moreover, both Transwell analysis and wound healing analysis showed that compound 8m could inhibit the invasion and migration of melanoma cells. In the in vivo study, the tumor xenograft model showed that compound 8m effectively inhibited melanoma development with low toxicity.

2-((1-Phenyl-1H-1,2,3-triazol-4-yl)methyl)-2-azabicyclo[3.2.1]octan-3-one derivatives: Simplification and modification of aconitine scaffold for the discovery of novel anticancer agents.

The molecular chaperone heat shock protein 90 (Hsp90) is a promising target for cancer therapy. Natural product aconitine is a potential Hsp90 inhibitor reported in our previous work. In this study, we designed and synthesized a series of 2-((1-phenyl-1H-1,2,3-triazol-4-yl)methyl)-2-azabicyclo[3.2.1]octan-3-one derivatives as potent Hsp90 inhibitors by simplifying and modifying aconitine scaffold. Among these compounds, 14t exhibited an excellent antiproliferative activity against LoVo cells with an IC50 value of 0.02 µM and a significant Hsp90α inhibitory activity with an IC50 value of 0.71 nM. Molecular docking studies provided a rational binding model of 14t in complex with Hsp90α. The following cell cycle and apoptosis assays revealed that compound 14t could arrest cell cycle at G1/S phase and induce cell apoptosis via up-regulation of bax and cleaved-caspase 3 protein expressions while inhibiting the expressions of bcl-2. Moreover, 14t could inhibit cell migration in LoVo and SW620 cell lines. Consistent with in vitro results, 14t significantly repressed tumor growth in the SW620 xenograft mouse model.

[Risk factors for adverse neonatal outcomes in 254 twins].

OBJECTIVE: The aim of this study was to identify the risk factors for adverse neonatal outcome in twins in order to provide a basis for the improvement of the survival and neonatal outcomes of twins. METHODS: Data from 254 twins admitted to Nanfang Hospital of Southern Medical University From January 2005 to December 2009 were retrospectively studied. Risk factors for adverse neonatal outcomes were assessed by logistic regression analysis. RESULTS: Of the 254 twins, 84 (33.1%) had an adverse outcome, including 10 (3.9%) neonatal deaths. Logistic regression analysis demonstrated that gestational age (≤34 weeks), cord abnormalities, meconium-stained amniotic fluid and 5-min Apgar scores (≤7) were independent risk factors for adverse neonatal outcomes (OR=4.434, 4.731, 3.424, 18.958, respectively; P=0.021, 0.001, 0.037, 0.011, respectively). Conception by assisted reproductive technology was shown as a protective factor for adverse neonatal outcomes (OR=0.389, P=0.037). CONCLUSIONS: The twins with gestational age ≤34 weeks, cord abnormalities, meconium-stained amniotic fluid or 5-min Apgar scores (≤7) are subject to adverse neonatal outcome.

Development of a novel thymidylate synthase (TS) inhibitor capable of up-regulating P53 expression and inhibiting angiogenesis in NSCLC.

INTRODUCTION: The development of a new type of Thymidylate synthase (TS) inhibitor that could inhibit cancer cells' proliferation and anti-angiogenesis is of great significance for cancer's clinical treatment. OBJECTIVES: Our research hopes to develop a TS inhibitor that is more effective than the current first-line clinical treatment of pemetrexed (PTX) and provide a new reference for the clinical treatment of non-small cell lung cancer (NSCLC). METHODS: We obtained a series of novel TS inhibitors by chemical synthesis. Moreover, TS assay and molecular docking to verify the target compound's inhibitory mode. Use MTT assay, colony-forming assay, flow cytometry, and western blot to verify the compound's inhibitory effect on cancer cell proliferation and its mechanism; and explore the compound's effect on angiogenesis in vitro and in vivo. Further, explore the hit compound's anti-cancer ability through the xenograft tumor model and the orthotopic cancer murine model. RESULTS: A series of N-(3-(5-phenyl-1,3,4-oxadiazole-2-yl) phenyl)-2,4-dihydroxypyrimidine-5-sulfamide derivatives were synthesized as TS inhibitors for the first time. All target compounds significantly inhibited hTS enzyme activity and demonstrated significant antitumor activity against five cancer cell lines. Notably, 7f had a high selectivity index (SI) and unique inhibitory effects on eight NSCLC cells. In-depth research indicated that 7f could induce apoptosis by the mitochondrial pathway in A549 and PC-9 cells through the upregulation of wild-type P53 protein expression. Additionally, 7f was shown to inhibit angiogenesis in vitro and in vivo. In vivo studies, compared to PTX, 7f significantly inhibited tumor growth in A549 cell xenografts and had a higher therapeutic index (TGI). Moreover, 7f could prolong the survival of the orthotopic lung cancer murine model more effectively than PTX. CONCLUSION: The anti-angiogenic effect of 7f provides a new reference for the development of TS inhibitors and the clinical treatment of NSCLC.

p38 MAP kinase activation mediates gamma-globin gene induction in erythroid progenitors.

OBJECTIVE: Our goal was to determine the role of p38 mitogen-activated protein kinase (MAPK) signaling in fetal hemoglobin (HbF) induction. Two histone deacetylase inhibitors (HDAIs), sodium butyrate (NB), and trichostatin (TSA) and hemin were analyzed. In addition, the effect of direct activation of p38 MAPK on gamma-globin gene activity was studied. METHOD: Primary erythroid progenitors derived from peripheral blood mononuclear cell and K562 erythroleukemia cells were analyzed. Cells were grown in NB, TSA, hemin, or anisomycin either alone or in the presence of the p38 MAPK inhibitor SB203580. The effects of the various treatments on gamma-globin RNA, HbF, and phosphorylated p38 MAPK levels were measured by RNase protection assay, alkaline denaturation, and Western blot analysis, respectively. A K562 stable line overexpressing constitutively active p38 MAPK was established using MAPK kinase kinase 3 (MKK3) and MKK6, the immediate upstream activators of p38. The direct effect of p38 MAPK overexpression on gamma-globin mRNA synthesis was analyzed. RESULTS: NB and TSA activated p38 MAPK and increased gamma-globin mRNA levels in K562 cells and primary erythroid progenitors. Pretreatment with SB203580 blocked p38 MAPK and gamma-globin gene activation. In contrast, no change in p38 activity was observed with hemin inductions. Direct activation of p38 by anisomycin or constitutive overexpression also increased gamma-globin mRNA in the absence of HbF inducers in wild-type K562 cells and in the MKK stable lines. CONCLUSION: This study supports a novel role for p38 MAPK in gamma-globin regulation in human erythroid progenitors.

[Preliminary study of sodium butyrate-induced expression of lung resistance-related protein in K562 cells].

OBJECTIVE: To investigate the effect of sodium butyrate (NaB) on the expression level of lung resistance-related protein (LRP) in K562 cells. METHODS: K562 cells, used as an in vitro model system, were treated with NaB to induce differentiation of the cells. LRP mRNA expression and protein levels in the cells were detected by reverse transcriptase-PCR (RT-PCR) and flow cytometry, respectively. RESULTS: A 1-day treatment with 2 mmol/L NaB induced the gene expression of LRP to increase to the maximum in the cells, and a 3-day treatment caused the corresponding protein level to increase to the maximum. CONCLUSION: Both the mRNA level and the protein expression of LRP can be induced by NaB in K562 cells.

[DNA, RNA and hemoglobin extraction from one sample of peripheral blood].

Nucleated cells were isolated from peripheral blood of healthy normal adults, dissolved and centrifuged to acquire the supernatant for RNA and the deposit for DNA extraction. Hemoglobin was extracted from the deposit formed by the red blood cells. Property assessment of the extracts indicated high quality products, demonstrating that this method is highly efficient and operable in DNA, RNA and hemoglobin extraction from the same blood sample of limited volume.

[Comparison of several silver staining methods for DNA polyacrylamide gel electrophoresis].

OBJECTIVE: To compare 4 silver staining methods for DNA detection in polyacrylamide gel electrophoresis. METHODS: After the electrophoresis was completed, the gels were stained separately by four different methods, namely using ammonia-silver-citric acid, low-concentration silver nitrate, 0.1% and 0.2% silver nitrate. RESULTS: DNA was detected only by staining with 0.1% and 0.2% silver nitrate. CONCLUSION: 0.2% silver nitrate used along with sodium hydroxide shows the highest sensitivity in DNA detection, while its use with sodium carbonate produces the best quality of the image.

Induction of erythroid differentiadon in K562 cells by different butyrate regimens.

OBJECTIVE: To investigate the hemoglobinization induced by butyrate and observe the effects of different butyrate regimens on erythroid differentiation of K562 cells. METHODS: K562 cells, used as an in vitro model system, were stained with benzidine to assess hemoglobin (Hb) production in response to different treatment regimens of butyrate at varied concentrations. Comparison of the percentage of benzidine-positive cells (BZ%)in untreated and butyrate-treated K562 cells was performed. Protein absorption at 414 nm using a spectrophotometer and cellulose acetate gel electrophoresis were employed to determine the changes of Hb production in K562 cells. RESULT: The BZ% increased by 4 to 6 fold and Hb production by 9 to 14 fold 3 d after the cells were incubated with butyrate which selectively promoted fetal hemoglobin(HbF) production in K562 cells. The BZ% increased gradually and reached the peak of l9% to 28% on day 3 or 4 in cells receiving pulse treatment with butyrate for only once, followed by a subsequent rapid fall and on day 7 to 9, it decreased to the level of untreated K562 cells. The length of time for incubation with butyrate was not related to in the increment or the maintenance of the increased level of BZ%. Continuous treatment with butyrate yielded a similar result to that of a single administration of pulse treatment. In contrast, in cells with intermittent pulse treatment the BZ% reached a peak after 72 h and was maintained between 20% and 30% till 3 cycles of treatment was completed. CONCLUSION: Butyrate can induce the expression of globin genes and augment Hb producfion especially that of HbF. A sustained erythroid differentiation of K562 cells can be achieved by intermittent pulse treatment with butyrate which can be an ideal regimen for children with beta globin diseases.

Effects of Astragalus polysaccharide on the erythroid lineage and microarray analysis in K562 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Astragalus polysaccharide (APS), obtained from Astragalus membranaceus, displays a range of activities in many systems, including the promotion of immune responses, anti-inflammation, and the protection of vessels. It possesses potent pharmacological activity on differentiation to the erythroid lineage. AIM OF THE STUDY: To investigate the effects of APS on the erythroid differentiation and the mechanism of action by microarray analysis in K562 cells. MATERIALS AND METHODS: Benzidine staining, semi-quantitative RT-PCR, Western blot and microarray methods were used to survey the effects of APS on inducing erythroid differentiation and the changes of gene expression profile in K562 cells. RESULTS: Of the 13.2% positive cells detected by benzidine staining, the induction was the highest with 200 microg/ml APS on 72h. Ggamma-mRNA expression and fetal hemoglobin synthesis were significantly up-regulated. Microarray analysis showed that 31 genes were up-regulated and 108 genes were down-regulated. These differential expression genes generally regulate protein binding, cellular metabolic process, the cell proliferation, and transcriptional activator activity. The gamma-globin gene was up-regulated, the genes related with erythroid differentiation such as LMO2, Runx1 and GTF2I were up-regulated, while Bklf, Eklf, EPHB4 and Sp1 were down-regulated. CONCLUSIONS: Our studies indicate that APS indicate potent activities on the erythroid differentiation by modulating genes of LMO2, Klf1, Klf3, Runx1, EphB4 and Sp1, increasing gamma-globin mRNA expression and fetal hemoglobin synthesis in K562 cells.