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ABSTRACT: It was reported that chemokine receptor CXCR4 and its ligand stromal cell-derived factor 1(SDF-1) were involved in the proliferation, differentiation, and metastasis of tumor. This study was designed to observe the expression of CXCR4 in NPC cells with different differentiation grade and proliferative ability to primitively clarify the relationship between CXCR4 and the malignity of NPC cells.
After treated with all-trans-retinoic acid(RA) and telomerase antisense oligodeoxynucleotide (ASODN) respectively, the expression of CXCR4 mRNA and CXCR4 protein in NPC CNE1 and CNE2Z cells were determined by in situ hybridization and immunohistochemistry, respectively; the distribution of cell cycle was examined with flow cytometry and the proliferation of cells was identified by MTT method.
CXCR4 mRNA and CXCR4 protein were strongly expressed in both CNE1 and CNE2Z cells, and their expression in CNE2Z cells was stronger than that in CNE1 cells. After treated with 1x10(-5) mol/L and 1x10(-4) mol/L RA, CNE1 cells were arrested in G1 phase and CNE2Z cells in S phase, while the CXCR4 mRNA expression was significantly decreased in both CNE1 and CNE2Z cells compared with control group cells (P< 0.01). The effect of 1x10(-4) mol/L RA was more powerful than that of 1x10(-5) mol/L RA. After treated with ASODN, the proliferation of CNE1 and CNE2Z cells was inhibited, and the expression of CXCR4 protein was decreased compared with the control (P< 0.01).
CXCR4 is highly expressed in NPC cells,and its expression was associated with differentiation grade and proliferation ability of NPC cells.
Ai zheng = Aizheng = Chinese journal of cancer 03/2004; 23(2):136-40.
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ABSTRACT: We had proved that different latent membrane protein 1 (LMP1) variants of Epstein-Barr virus (EBV) had different effects upon growth characteristics of a human well-differentiated nasopharyngeal carcinoma (NPC) cell strain CNE1. This study was designed to investigate the possible effects of different LMP1 variants on resistance of CNE1 to TGFbeta1 and the related mechanism(s) so as to further elucidate the intrinsic mechanisms of their growth-promoting effects upon CNE1.
The plasmids including J124 (served as a control plasmid),124-B95-8 (carried LMP1 gene cloned from B95-8 lymphocytes,B95-8-LMP1), and J124- CAO-5 (carried LMP1 gene cloned from NPC tissues,CAO-LMP1) were introduced into CNE1 by liposomal transfection. The transfected cell strains were named CNE1-V,CNE1-B,and CNE1-C,respectively. Gene and protein expression of LMP1 in CNE1 were identified by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis,respectively. Then growth inhibition assay using MTT colorimetric method and flow cytometry were conducted to investigate different effects of the two LMP1 variants on resistance of CNE1 to TGFbeta1. Meanwhile,TGFbetaRI,TGFbetaRII, and cyclin D1 were detected by Western blot analysis and p15 mRNA was examined by semi-quantitative RT-PCR.
Two transfected cell strains (CNE1-B and CNE1-C) stably expressing different LMP1 variants were established successfully. When the treating concentration of TGFbeta1 was 5 ng/ml, the growth inhibitory rates of CNE1, CNE1-V,CNE1-B,and CNE1-C were 31.8%, 27.9%, 10.94%, and -4.26%, respectively, and the proliferation index (PI) were (24.55+/-2.55)%, (25.43+/-2.18)%, (46.78+/-2.56)%, and (54.70+/-3.84)%, respectively. CAO-LMP1 induced complete TGFbeta1 resistance in CNE1, whereas B95-8-LMP1 induced partial resistance. Neither of the two LMP1 variants had effects on TGFbetaRI and TGFbetaRII protein expression in CEN1,whereas both of them induced cyclin D1 expression significantly. CAO-LMP1 induced higher level of cyclin D1 than B95-8-LMP1 did (P< 0.05). B95-8-LMP1 had no significant effect on p15 mRNA expression (P >0.05), whereas CAO-LMP1 down-regulated p15 mRNA level obviously (P< 0.05).
B95-8-LMP1 could induce partial resistance of CNE1 to TGFbeta1 and the main mechanism was correlated with up-regulation of cyclin D1 protein, whereas CAO-LMP1 could induce complete resistance to TGFbeta1 and the mechanisms were correlated with up-regulation of cyclin D1 protein as well as down-regulation of p15 mRNA.
Ai zheng = Aizheng = Chinese journal of cancer 01/2004; 22(12):1254-9.
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ABSTRACT: It was reported that telomere and telomerase were associated with the development of cancers. Telomerase antisense oligodeoxynucleotides(ASODN) directly act on telomerase, or induce tumor cells to differentiate, result in telomerase activity decreases, and cells growth inhibited. However, whether the inhibition of telomerase activity by ASODN could induce tumor cells to differentiate is still unknown. Telomerase RNA acts as a template for synthesis of telomere, so telomerase sense oligodeoxynucleotides(SODN) can be hybridized to the telomere DNA. Whether this reaction could affect the growth of tumor cells is worth being studied. This research was just to investigate the effects of telomerase SODN and ASODN on the growth and differentiation of nasopharyngeal carcinoma(NPC) cells.
After transfecting telomerase SODN and ASODN into NPC CNE1 and CNE2Z cells by lipofectin, the proliferation of the cells was identified by MTT method, and the expression of keratin was detected by immunohistochemistry. Meanwhile, the morphological changes of the cells were observed.
SODN inhibited the growth of CNE1 and CNE2Z cells as well as ASODN in dose- and time-dependent manner. After being treated with 1.5 mumol/L, 3.0 mumol/L, 4.5 mumol/L, and 6.0 mumol/L SODN, the inhibition rates in CNE1 cells for 6 h were 16.28%, 19.38%, 22.48%, and 23.26%, respectively; for 48 h were 26.26%, 38.89%, 39.90%, and 38.89%, respectively; the inhibition rates in CNE2Z cells for 6 h were 7.69%, 8.24%, 18.13%, and 20.32%, respectively, and for 48 h were 28.84%, 28.88%, 32.89%, and 31.54%, respectively. The keratin expressions in cells of SODN and ASODN groups were significantly increased and the cells tended to be mature.
The telomerase SODN and ASODN could both inhibit the growth of NPC cells and induce cells to differentiate.
Ai zheng = Aizheng = Chinese journal of cancer 06/2002; 21(5):493-7.