Xiaoyan Miao

Glycomic alterations are associated with multidrug resistance in human leukemia.

Correlations of disease phenotypes with glycosylation changes have been analyzed intensively in tumor biology field. In this study we describe glycomic alterations of multidrug resistance in human leukemia cell lines. Using multiple glycan profiling tools: real-time PCR for quantification of glycogenes, FITC-lectin binding for glycan profiling, and mass spectrometry for glycan composition, we compared the glycomics of drug-resistant K562/ADR cells with parental K562 line. The results showed that the expression of glycogenes, glycan profiling and N-glycan composition were different in K562/ADR cells, as compared with those in K562 cells, whereas O-glycans of the two cell lines showed no different mass spectra. Further analysis of the N-glycan regulation by way of tunicamycin application or PNGase F treatment in K562/ADR cells showed partial inhibition of biosynthesis and increased sensitivity to chemotherapeutic drugs in vitro. We targeted glycogene B3GNT8 and ST8SIA4, which were over-expressed in K562/ADR cells, and silenced the expression levels of two glycogenes after using RNA interference approach. The results showed that the silencing of B3GNT8 or ST8SIA4 in K562/ADR cells resulted in increased chemosensitivity to anti-tumor drugs. In conclusion, glycomic alterations are responsible for the overcoming multidrug resistance in human leukemia therapy and the N-linked oligosaccharides are associated with the drug resistance of cancer cells.

CD147 regulates vascular endothelial growth factor-A expression, tumorigenicity, and chemosensitivity to curcumin in hepatocellular carcinoma.

CD147, also named as extracelluar matrix metalloproteinase inducer (EMMPRIN), has been proved to be involved in several aspects of tumor progression. In addition to its ability to induce vascular endothelial growth factor (VEGF) production, it confers resistance to some chemotherapeutic drugs. To investigate the possible role of CD147 in the mouse hepatocarcinoma cell line Hepa1‐6 with no metastatic potential in the lymph nodes, we used RNA interference (RNAi) approach to silence CD147 expression. The results showed that silencing of CD147 in Hepa1‐6 cells significantly impeded the expression of VEGF‐A at both mRNA and protein levels. The siRNA‐treated cells exhibited significantly decreased growth ability when compared with control cells. Colony formation of CD147 deficient cells was dramatically inhibited in soft agar, and tumorigenicity was reduced in nude mice. Furthermore, the downregulation of CD147 expression also sensitized cells to be more sensitive to curcumin. These results suggested that CD147 might be a potential target for therapeutic antitumor drugs.

Functional roles of glycogene and N-glycan in multidrug resistance of human breast cancer cells.

Drug resistance is a major problem in cancer chemotherapy. Aberrant glycosylation has been known to be associated with cancer chemoresistance. Aim of this work is to investigate the alterations of glycogene and N‐glycan involved in multidrug resistance (MDR) in human breast cancer cell lines. Using real‐time polymerase chain reaction (PCR) for quantification of glycogenes, fluorescein isothiocyanate (FITC)‐lectin binding for glycan profiling, and mass spectrometry for N‐glycan composition, the expression of glycogenes, glycan profiling, and N‐glycan composition differed between drug‐resistant MCF/ADR cells and the parental MCF‐7 line. Further analysis of the N‐glycan regulation by tunicamycin (TM) application or PNGase F treatment in MCF/ADR cells showed partial inhibition of the N‐glycan biosynthesis and increased sensitivity to chemotherapeutic drugs dramatically both in vitro and in vivo. Using an RNA interference strategy, we showed that the downregulation of MGAT5 in MCF/ADR cells could enhance the chemosensitivity to antitumor drugs both in vitro and in vivo. Conversely, a stable high expression of MGAT5 in MCF‐7 cells could increase resistance to chemotherapeutic drugs both in vitro and in vivo. In conclusion, the alterations of glycogene and N‐glycan in human breast cancer cells correlate with tumor sensitivity to chemotherapeutic drug and have significant implications for the development of new treatment strategies.

α‐2,8‐sialyltransferase is involved in the development of multidrug resistance via PI3K/Akt pathway in human chronic myeloid leukemia

Cell surface sialylation is emerging as an important feature of cancer cell multidrug resistance (MDR). We have focused on the influence of 2,8‐sialyltransferases in key steps of the development of MDR in chronic myeloid leukemia (CML). The expressional profiles of six α‐2,8‐sialyltransferases were generated in three pairs of CML cell lines and peripheral blood mononuclear cells (PBMC) of CML patients. Cellular MDR phenotype positively correlated with ST8SIA4 and ST8SIA6 levels. Furthermore, ST8SIA4 mediated the activity of phosphoinositide‐3 kinase (PI3K)/Akt signal pathway and the expression of P‐glycoprotein (P‐gp). Targeting the PI3K/Akt pathway by its specific inhibitor LY294002, or by Akt RNA interfering reversed the MDR phenotype of K562/ADR cells. Inhibition of PI3K/Akt pathway also attenuated the effects caused by the overexpression of ST8SIA4 on MDR. Therefore this study indicated that α‐2,8‐sialyltransferases involved in the development of MDR of CML cells probably through ST8SIA4 regulating the activity of PI3K/Akt signaling and the expression of P‐gp.

Silencing CD147 inhibits tumor progression and increases chemosensitivity in murine lymphoid neoplasm P388D1 cells

Overexpression of extracellular matrix metalloproteinase inducer (EMMPRIN or CD147), a member glycoprotein enriched on the surface of many malignant tumor cells, promotes tumor progression and confers resistance to some chemotherapeutic drugs. To investigate the possible role of CD147 in the macrophage-like lymphoid neoplasm P388D1 cells progression, we used RNA interference approach to silence CD147 expression. The results showed that silencing of CD147 in P388D1 cells impeded the expression of MMP11 at both mRNA and protein levels. The reduced CD147 expression also resulted in reductions in tumorigenicity, as well as decreased in regional lymph node metastasis. Furthermore, the down-regulation of CD147 expression sensitized cells to be more sensitive to chemotherapeutic drugs. Treatment of tumor cells with U-0126, an inhibitor of mitogen-activated protein kinase/Erk, also down-regulated the expression of MMP11. Our current results indicate that the expression of CD147 functionally mediates tumor progression and is a potential target for therapeutic anti-cancer drugs.

B4GALT1 gene knockdown inhibits the hedgehog pathway and reverses multidrug resistance in the human leukemia K562/adriamycin-resistant cell line.

B4GALT1 gene encodes type II membrane‐bound glycoprotein, named β‐1, 4‐galactosyltransferase 1 (β1, 4‐Gal‐T1), which can transfer galactose to acceptor sugars. B4GALT1 gene plays important roles in physiological process and disease development. In this study, we investigate the possible role and mechanism of B4GALT1 gene in multidrug resistance of human leukemia cell line. Significantly, higher expression of B4GALT1 was observed in adriamycin‐resistant (ADR) K562 cell line (K562/ADR) than that in K562 cell line by real‐time polymerase chain reaction and Western blotting. The activity of β1, 4‐Gal‐T1 enzyme, and Galβ‐1,4GlcNAc structures on cell membrane glycoproteins was found at higher levels in K562/ADR cells than those in K562 cells. Further analysis of the B4GALT1 deregulation after using RNA interference approach showed that the silencing of B4GALT1 in K562/ADR cells resulted in increased sensitivity to chemotherapeutic drugs both in vitro and in vivo. The activity of the hedgehog signaling pathway affected the chemosensitivity of K562/ADR cells and was downregulated in K562/ADR cells with suppression of B4GALT1 gene. We hypothesize that B4GALT1 is responsible for the overcoming multidrug resistance in human leukemia therapy via regulating the activity of the hedgehog signaling pathway.

Nutritional support in the treatment of aplastic anemia.

OBJECTIVE Whether a specific nutritional support promotes healing of aplastic anemia (AA) patients is still unclear. Therefore, we explored the potential of a high-nucleotide, arginine, and micronutrient nutritional supplement on the nutritional rehabilitation of AA mice. METHODS The BALB/c AA mice model was treated with hypodermic injections of acetylphenylhydrazine (100 mg/kg), x-ray (2.0 Gy), and intraperitoneal injections of a cyclophosphamide (80 mg/kg) combination. Then AA mice were fed with nutritional supplements in a dose-dependent manner (1445.55, 963.7, 674.59 mg/kg/d) for 7 wk. At the end of the experimental period, mice were autopsied. A full blood count was performed, and femoral marrow cell suspensions were prepared to assess the total femoral nucleated cell count and the number of committed hemopoietic progenitor cells (colony-forming units). The pathologic changes of liver and spleen were analyzed. RESULTS The significant increases of nutrient mixture groups were evident in many peripheral blood parameters. The femoral nucleated cell count and colony-forming units of nutritional supplements groups were markedly increased, compared with the AA group. Transmission electron microscopy showed that the number of mitochondria in similar bone marrow cells was increased in nutritional supplements groups. The nutritional supplements also affected the recovery of livers and spleens of AA mice. CONCLUSION Specific nutritional supplements accelerated rehabilitation of AA mice and can be used as nutritional support in the treatment of AA.

Retraction notice to:“Effect of ST3GAL 4 and FUT 7 on sialyl Lewis X synthesis and multidrug resistance in human acute myeloid leukemia” [1842 (9) 1681–1692]

Retraction notice to:“Effect of ST3GAL 4 and FUT 7 on sialyl Lewis X synthesis and multidrug resistance in human acute myeloid leukemia” [1842 (9) 1681–1692] Hongye Ma , Huimin Zhou , Peng Li , Xiaobo Li , Xiaoyan Miao , Yanping Li , Li Jia a a College of Laboratory Medicine, Dalian Medical University, Dalian, Liaoning Province, China b Department of Microbiology, Dalian Medical University, Dalian, Liaoning Province, China c Department of Bone Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province, China d Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway

MiR-193a-3p and miR-224 mediate renal cell carcinoma progression by targeting alpha-2,3-sialyltransferase IV and the phosphatidylinositol 3 kinase/Akt pathway

Tumor metastasis is a major cause of cancer‐related death in renal cell carcinoma (RCC). MicroRNAs (miRNAs) have been widely known to modulate proliferation invasion, metastasis, and apoptosis of cancer cells. In this study, we aimed to investigate the function and novel target of miR‐193a‐3p and miR‐224 in RCC. The levels of miR‐193a‐3p and miR‐224 were significantly increased in RCC tissues and RCC cell lines. Alpha‐2,3‐Sialyltransferase IV (ST3GalIV) was highly expressed in adjacent nontumor tissues and human normal proximal tubular cell line HK‐2 compared to RCC tissues and cell lines. ST3GalIV expression was negatively correlated with miR‐193a‐3p and miR‐224. Further analysis indicated that miR‐193a‐3p and miR‐224 directly targeted ST3GalIV. MiR‐193a‐3p and miR‐224 increased cell proliferation and migration by directly inhibiting ST3GalIV, and this effect was reversed by co‐transfection with ST3GalIV in vitro. Overexpression of miR‐193a‐3p and miR‐224 increased RCC cell proliferation in vivo. Furthermore, the phosphatidylinositol 3 kinase (PI3K)/Akt pathway was mediated by miR‐193a‐3p and miR‐224 in RCC cell lines. Collectively, these results suggested that miR‐193a‐3p and miR‐224 played an important role in regulation of RCC by targeting ST3GalIV via PI3K/Akt pathway.