Qiang Ma

Nanfang Hospital, Shengcheng, Guangdong, China

Are you Qiang Ma?

Claim your profile

Publications (5)0 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the expression of pro-inflammation cytokines and activation of nuclear factor kappaB (NF-kappaB) in mouse models of ulcerative colitis. Mouse models of ulcerative colitis were established by oral administration of 5% dextran sulfate sodium for 7 d, and the expression of tumor necrosis factor (TNF)- alpha and interleukin (IL)-1beta in the intestinal mucosa were detected by semi-quantitative reverse transcriptional (RT) PCR. The activation of NF-kappaB in the intestinal mucosa was evaluated by electrophoretic mobility shift assay (EMSA). The expressions of TNF-alpha and IL-1beta were increased in the intestinal mucosa (P=0.009), and the nuclear binding activity of NF-kappaB was also up-regulated after the onset of colitis. Pro-inflammatory cytokines play important roles in the pathogenesis of UC, and may exacerbate the inflammation of the intestinal mocosa and cause apoptosis of the epithelial cells, possibly under the regulation of NF-kappaB activation.
    Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA 12/2003; 23(11):1202-5.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the angiogenesis in human colorectal carcinoma and its modulation by p53 and K-ras gene. The positive rate of p53 and K-ras gene mutation, the expression of vascular endothelial growth factor (VEGF) and microvessel density in 68 cancer tissue, peritumoral tissue samples and 20 normal controls were studied by PCR-SSCP and immunohistochemical methods. The positive rate of p53 and K-ras gene mutation and the expression of VEGF in cancer tissue (47.1%, 32/68; 44.1%, 30/68; 55.9%, 38/68) were significantly higher than in peritumoral tissue (13.2%, 9/68; 7.4%, 5/68; 11.8%, 8/68). p53, K-ras gene mutation and the expression of VEGF were not detected in 20 normal tissue. The expression of VEGF was closely related with the angiogenesis and metastasis of colorectal carcinoma (r = 0.820, P < 0.01). VEGF expression correlated with both p53 and K-ras gene mutation (P < 0.01). p53 and K-ras gene upregulated the expression of VEGF. p53 and K-ras gene might play an important role in modulating tumor angiogenesis.
    Zhonghua nei ke za zhi [Chinese journal of internal medicine] 02/2003; 42(2):77-80.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Based on the findings that calcium content increased in multidrug resistant (MDR) cells and that the resistance could be reversed by the calcium channel blocker verapamil, it has been speculated that Ca2+ may have role in drug resistance. This study was designed to investigate the relationship between multidrug resistance in human colon carcinoma LoVo/Adr cells and the level of cytoplasmic Ca2+. Fluo-3/AM was used to label Ca2+ in the cytoplasm and confocal microscope was used to observe the changes of Ca2+ concentration. The reverse effect of verapamil was determined by MTT method. The content of intracellular adriamycin(ADR) was determined by flow cytometry. Fluo-3/AM fluorescent intensities of LoVo and LoVo/Adr cells were 850.45 and 1,495.88, respectively. After treatment with verapamil, Fluo-3/AM fluorescent intensities of LoVo and LoVo/Adr cells were 813.25 and 1,284.14, respectively. The level of Ca2+ in the cytoplasm of LoVo/Adr cells was significantly higher than that in LoVo cells, and was not significantly changed by verapamil. The concentration of ADR was increased by verapamil in LoVo/Adr cells. The potentiation folds of adriamycin and vincristine by verapamil in LoVo/Adr cells were 8.85 and 5.31, respectively. The increasement of cytoplasmic calcium content might be a characteristic phenotype of MDR LoVo/Adr cells. However, there was no direct relationship between multidrug resistance and cytoplasmic Ca2+ concentration.
    Ai zheng = Aizheng = Chinese journal of cancer 08/2002; 21(8):846-9.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To observe the effect of protein kinase C (PKC) on the multidrug resistance of multidrug-resistant colorectal cancer LoVo/Adr cells and explore the mechanism. The changes of PKC activity in LoVo/Adr cells in response to treatment with staurosporine (SP) and phorbol-12-myristate-13-acetate (PMA) were detected by way of 32P incorporation. The effect of PKC on adriamycin uptake in LoVo/Adr cells was detected by flow cytometry. Reverse transcriptase-PCR was utilized to observe the effect of PKC on mdr1 gene expression. PMA evinced bi-directional regulation of PKC activity in LoVo/Adr cells, and SP significantly inhibited membrane and cytosol fraction of PKC activity. Preincubation with PMA for 30 min caused the uptake of adriamycin to decrease significantly, but when the preincubation was prolonged to 24 h, significant increase occurred in adriamycin uptake. Neither PMA nor SP, however, could affect the expression of mdr1 gene. PKC regulates multidrug resistance of the cells through mechanisms other than regulation of mRNA level of mdr1 gene.
    Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA 08/2002; 22(7):626-8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate adriamycin (Adr) uptake and distribution features in multidrug-resistant LoVo/Adr cells and explore the drug-resistance mechanism of the cells. Adr uptake in LoVo/Adr cells was observed by flow cytometry and the distribution of the drug examined by fluorescence microscope. Immunohistochemical method was employed to detect the expression of P-glycoprotein (P-gp) by the cells. In comparison with that in LoVo/Adr cells, Adr level in LoVo cells was significantly higher, but after treatment with verapamil, the former cells showed an increased Adr level. Adr distributed mainly in the nucleus in the drug-sensitive LoVo cells, with only a small quantity in the cytoplasm, while in multidrug-resistant LoVo/Adr cells, significantly reduction of Adr quantity in the nucleus and relative increase in the cytoplasm were observed. In response to verapamil treatment, the Adr uptake in LoVo/Adr cells increased and the distribution of the drug was similar to that in sensitive cells. P-gp expression was positive in LoVo/Adr cells, while negative in LoVo cells. Abnormal Adr uptake and distribution in drug-resistant cells is related to P-gp expression which is one of the mechanisms for multidrug resistance.
    Di 1 jun yi da xue xue bao = Academic journal of the first medical college of PLA 04/2002; 22(3):264-6.