Guangkai Bian

Publications (2)3.16 Total impact

• Article: Methylated actinomycin D, a novel actinomycin D analog induces apoptosis in HepG2 cells through fas- and mitochondria-mediated pathways.

  Yongqiang Chen, Jinjuan Liu, Bo Yuan, Chengliang Cao, Sheng Qin, Xiaoying Cao, Guangkai Bian, Zhe Wang, Jihong Jiang
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  ABSTRACT: Actinomycin D (Act D), a well known of clinical antitumor drug, has been used for the treatment of some highly malignant tumors, however, the clinical application was limited by its extreme cytotoxicity. In the present study, we reported that methylated actinomycin D (mAct D), a novel actinomycin D analog isolated from Streptomyces sp. KLBMP 2541 in our previous study, could not only exert stronger inhibitory effects on several human cancer cells than Act D in dose- and time-dependent manner at ng concentrations, especially on HepG2 cells, but also lower cytotoxicity in normal cells (HL-7702). Base on these results, HepG2 cells were treated for further study to illustrate the potential mechanism of mAct D. The results of nuclei morphology examination, DNA fragmentation detection, sub-G(1) analysis, annexin V-FITC/PI staining and activation of caspase-3 indicated mAct D significantly induced HepG2 cells apoptosis. Semiquantitative RT-PCR and Western blot analysis revealed that mAct D induced apoptosis in HepG2 cells through mitochondria-dependent pathway by increasing levels of caspase-9, Bax, Bak while decreasing levels of Bcl-2, Bid, and Fas-dependent pathway by increasing levels of Fas, FasL, FADD, and caspase-8. Subsequently, pretreatment with specific inhibitor of caspase-8 Z-LEHD-FMK and caspase-9 Z-LEHD-FMK significantly attenuated caspase-3 activity, the cleavage of caspase-3 and PARP, meanwhile increased the cell viability. In addition, p53 and mitochondrial transcription factor A (mtTFA) were also upregulated. Taken together, ng concentrations mAct D induces the apoptosis of HepG2 through Fas- and mitochondria-mediated pathway and presents a potential novel alternative agent for the treatment of human hepatic carcinoma. © 2012 Wiley Periodicals, Inc.
  Molecular Carcinogenesis 07/2012; · 3.16 Impact Factor
• Article: [Isolation and biodiversity of heavy metal tolerant endophytic bacteria from halotolerant plant species located in coastal shoal of Nantong].

  Guangkai Bian, Yueji Zhang, Sheng Qin, Ke Xing, Huansong Xie, Jihong Jiang
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  ABSTRACT: We isolated and identified endophytic bacteria from halotolerant plants collected from coastal shoal of Nantong and investigated their heavy-metal tolerance and plant growth promoting potential. In total 45 strains were obtained from 4 halotolerant plants and 23 representative isolates were selected to detect their tolerance against NaCl and heavy metals of Cu2+, Pb2+, Cd2+, Zn2+, Hg2+; plant growth promoting index of nitrogen fixation, phosphate solubilization, indoleacetic acid (IAA) production and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase. Most of the isolates could grow under high consistency of Cu2+ and Pb2+. Of the bacteria 26.1% had the ability of nitrogen fixation, 21.7% of phosphate solubilization, 60.9% of IAA production and 39.1% of ACC deaminase activity. The results of 16S rRNA sequencing show that they belonged to the genera of Bacillus, Halobacillus, Oceanobacillus, Exiguobacterium, Serratia, Brevundimonas, Vibrio and Staphylococcus. Among them, strains KLBMP 2432 and KLBMP 2447 were potential novel species. The halotolerant plants located in the area of coastal shoal contain a variety of endophytic bacteria as well as the source of novel taxa. Some of them had the ability of plant growth promoting and high resistance against heavy-metal Cu2+ and Pb2+.
  ACTA MICROBIOLOGICA SINICA 11/2011; 51(11):1538-47.