Preliminary Study of the in vitro Growth Inhibition of Human Bladder Cancer Cell Line BIU-87 by Arsenic Trioxide

To study the effects of arsenic trioxide (As2O3) on the in vitro growth of human bladder cancer cells and the mechanisms. The growth inhibition rates of human bladder cancer cell line BIU87 by various concentrations of As2O3 were detected by using MTT method. Cell apoptosis was detected by in situ terminally labeled transferase technique and bcl-2 gene expression of BIU-87 cells was observed by SABC immunohistochemical method. The results showed that As2O3 could inhibit the growth of BIU-87 effectively in a dose-dependent manner. After drug's action, the apoptotic bladder cancer cells were obviously increased, which depended on the prolongation of the action time and Bcl-2 expression of BIU-87 cells was decreased significantly. It was suggested that As2O3 could significantly inhibit the growth of bladder human cancer cells. Inducing cell apoptosis by down- regulating the expression of hcl-2 gene might be one of its action mechanisms.

Induction of apoptosis by arsenic trioxide and hydroxycamptothecin in gastric cancer cells in vitro

AIM To study the effects of arsenic trioxide andHCPT on different degrees of differentiated gastriccancer cells（SGC-7901,MKN-45,MKN-28）withrespect to both cytotoxicity and induction ofapoptosis in vitro.METHODS The cytotoxicity of As2O3 and HCPTon gastric cancer cells was determined by MTTassay.Morphologic changes of apoptosis ofgastric cancer cells were observed by lightmicroscopy and transmission electron microscopy.Apoptosis and cell cycle changes of gastric cancercells induced by HCPT and As2O3 were investigatedby TUNEL method and flow cytometry.RESULTS As2O3 and HCPT had remarkablecytotoxic effects on different degrees ofdifferentiated gastric cancer cells.The IC50ofAs2O3 on well differentiated gastric cancer cellMKN-28,moderately differentiated gastric cancercell SGC-7901,and poorly differentiated gastriccancer cell MKN-28 were 8.91 μmol/L,10.57μmol/L,and 11.65 μmol/L,respectively.The IC50of HCPT on MKN-28,SGC-7901,and MKN-45 were9.35 mg/L,10.21 mg/L,and 12.63 mg/Lrespectively after 48 h treatment.After 12 h ofexposure to both drugs,gastric cancer cellsexhibited morphologic features of apoptosis,including cell shrinkage,nuclear condensation, and formation of apoptotic bodies.A typicalsubdiploid peak before G0/G1 phase was observedby flow cytometry.The apoptotic rates of SGC-7901,MKN-45,and MKN-28 were 13.84%,22.52%,and 9.68%,respectively after 48 hexposure to 10 μmol/L As2O3.The apoptotic ratesof SGC-7901,MKN-45,and MKN-28 were 21.88%,12.35%,and 30.26%,respectively after 48 hexposure to 10 mg/L HCPT.The apoptotic indicewere 7%-15% as assessed by TUNEL method.The effect of As2O3 on SGC-7901 showedremarkable cell cycle specificity,which inducedcell death in G1 phase,and blocked G2/M phase.HCPT also showed a remarkable cell cyclespecificity,by inducing cell death and apoptosis inG1 phase and arrest of proliferation at S phase.CONCLUSION As2O3 and HCPT exhibitsignificant cytotoxicity on gastric cancer cells byinduction of apoptosis.As2O3 and HCPT mighthave a promising prospect in the treatment ofgastric cancer,which needs to be further studied.

A study on arsenic trioxide inducing in vitro apoptosis of gastric cancer cell lines

INTRODUCTION Cell apoptosis,which involves the biologic regulation of the numbers and vital activity of cells,is an important metaboloc process in both normal cells and tumor cells.

Arsenic trioxide induces apoptosis of human gastrointestinal cancer cells

AIM:To investigate the changes in apoptosis in gastrointestinal cancer cells from patients with gastrointestinal cancers treated with arsenic trioxide(As2O3);and to study the possible molecular mechanisms of such changes by detecting the expression levels of p53and Bcl-2.METHODS:Twenty patients with gastrointestinal adenocarcinoma based on endoscopic and biopsy findings(ten patients with gastric cancer and ten patients with colorectal cancer)who received treatment in our hospital between August 2007 and December 2008were included in this study.None of the patients had received anti-tumour agents prior to As2O3 treatment.As2O3 was administered intravenously at a dose of 0.01g/d diluted with 5%glucose in normal saline for 2-3h for 3 consecutive days before surgery.Morphological changes associated with apoptosis of gastrointestinal cancer cells were observed by light microscopy.Changes in the apoptotic index induced by As2O3 were investigated using the terminal deoxynucleotidyl transferase dUTP nick end labelling method.Expression levels of p53 and Bcl-2 proteins in gastrointestinal cancer tissues were determined by immunohistochemistry.RESULTS:The apoptotic index of human gastrointestinal cancer cells was higher in cells from patients treated with As2O3 than in those not treated(P<0.05).p53 protein expression in gastrointestinal tissues was unchanged by As2O3(P>0.05).However,Bcl-2 protein expression in gastrointestinal tissues was downregulated by As2O3(P<0.01).CONCLUSION:These results demonstrate that As2O3treatment in patients with gastrointestinal cancers can induce apoptosis in gastrointestinal cancer cells and down-regulate Bcl-2 protein expression.

Arsenic Trioxide Induces Apoptosis of Glucocorticoid-Resistant Acute Lymphoblastic Leukemia CEM-C1 Cells

Objective： To explore the effects of arsenic trioxide （ATO） on the apoptosis of glucocorticoid （GC）-resistant T-acute lymphoblastic leukemia （ALL） CEM-C1 cells and its possible mechanisms. Methods： Different concentrations of ATO （0.25 μmol/L-5 μmol/L） were used to induce the apoptosis of CEM-C1 cells. The inhibition rate of cell proliferation and apoptosis were detected by MTT test, Annexin V-FITC/PI flow cytometry and optical microscopy, respectively. RT-PCR was applied to semi-quantitatively analyze the mRNA expression of pro-apoptotic proteins （Bad and PDCD4） and anti-apoptotic proteins （XIAP and MCL-1） induced by different concentrations of ATO at different time points. Results： ATO could inhibit proliferation and induce apoptosis of CEM-C1 cells at a concentration and time dependent manner. Low-dose ATO mildly inhibited the proliferation of CEM-C1 cells while higher concentrations （1 μmol/L and 5 μmol/L） had strong anti-tumor effect with the inhibiting rates of 40.07±7.98% and 88.67±2.88%, respectively. Annexin V-FITC/PI flow cytometry showed that the apoptotic rates of CEM-C1 ceils were significantly increased after 48 hours treatment of different concentrations of ATO. RT-PCR demonstrated up-regulated mRNA expression of pro-apoptotic protein Bad and PDCD4 but down-regulated mRNA expression of anti-apoptotic protein XIAP when CEM-C1 cells were treated with different concentrations of ATO at different time points. The MCL-1 mRNA expression was down-regulated only after the treatment of 5 μmol/L ATO. Conclusion： ATO can inhibit cell proliferation and induce cell apoptosis in GC-resistant CEM-C1 cells. The molecular mechanisms might involve the increased mRNA expression of pro-apoptotic protein Bad and PDCD-4, and rapid down-regulation of XIAP mRNA expression.

STUDY ON EFFECTS OF ARSENIC TRIOXIDE ON GASTRIC CANCER CELL LINES

Objective To evaluate the effects of arsenic trioxide (As-2O-3) on apoptosis and differentiation of gastric cancer cell lines (GCCL). Methods MKN45 and SGC7901 cells were treated with As-2O-3 at different concentrations, then the apoptosis rates and cell cycle were determined by flow cytometry assays, the morphologic changes were observed under fluorescence microscopy and electronic microscopy, and the gene expressions were tested with immunohistologic staining. Results Higher apoptosis rates of GCCL were seen in the As-2O-3-treated group at concentrations of 5μmol and 10μmol, as compared with those in the 5-Fu-treated group. Cell-nuclear pyknosis and chromosomal condensation were observed. The As-2O-3 at a concentration of 0.5 μmol could induce the cell cycle changes of GCCL, revealing an increase in the proportion of G1/G0 phase cells and a decrease in the proportion of S phase cells. From the fifth day after treatment of SGC7901 with As-2O-3 at a low concentration, P53 and bcl-XL genes expression rates were reduced, Bax gene expression rate increased, and bcl-2 gene expression showed little change. Conclusion As-2O-3 could induce GCCL apoptosis at a high concentration and differentiation at a low concentration, but it could not completely reverse the malignant biological behaviours of cancer cells.

ARSENIC TRIOXIDE DOWNREGULATES TELOMERASE ACTIVITY IN HL-60 CELLS

Objective: To evaluate whether arsenic trioxide (AS2O3) could downregulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity during induction of apoptosis of HL-60 cells. Methods: Apoptosis was detected by morphological observation and flow cytomertric cell cycle analysis. The expression of hTERT at mRNA and protein levels was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence using fluoresce isothiocyanate (FITC) label, respectively. Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Results: Treatment of 2 μmol/L at As2O3 could induce apoptosis of HL-60 cells. hTERT was decreased at both mRNA and protein levels during apoptosis of HL-60 cells. Telomerase activity of HL-60 cells was significantly inhibited. Conclusion: It is suggested that telomerase activity of HL-60 cells might be specifically inhibited by AS2O3 through the downregulation of hTERT gene expression.

Autophagy plays a pro-apoptotic role in arsenic trioxide-induced cell death of liver cancer

Objective: The effects of arsenic trioxide(As2O3) on hepatocellular carcinoma have been documented widely. Autophagy plays dual roles in the survival and death of cancer cells. Therefore, we investigated the exact role of autophagy in As2O3-induced apoptosis in liver cancer cells.Methods: The viability of hepatoma cells was determined using the MTT assay with or without fetal bovine serum. The rate of apoptosis in liver cancer cells treated with As2O3was evaluated using flow cytometry, Hoechst 33258 staining, and TUNEL assays. The rate of autophagy among liver cancer cells treated with As2O3was detected using immunofluorescence, Western blot assay and transmission electron microscopy.Results: Upon treatment with As2O3, the viability of HepG2 and SMMC-7721 cells was decreased in a time-and dose-dependent manner. The apoptosis rates of both liver cancer cell lines increased with the concentration of As2O3, as shown by flow cytometry. Apoptosis in liver cancer cells treated with As2O3was also shown by the activation of the caspase cascade and the regulation of Bcl-2/Bax expression.Furthermore, As2O3treatment induced autophagy in liver cancer cells;this finding was supported by Western blot, immunofluorescence of LC3-II and beclin 1, and transmission electron microscopy. In liver cancer cells, As2O3inhibited the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR) signal pathway that plays a vital role in both apoptosis and autophagy. The PI3K activator SC-79 partially reversed As2O3-induced autophagy and apoptosis. Furthermore, inhibiting autophagy with 3-methyladenine partially reversed the negative effects of As2O3on cell viability.Serum starvation increased autophagy and amplified the effect of As2O3on cell death.Conclusion: As2O3induces apoptosis and autophagy in liver cancer cells. Autophagy induced by As2O3may have a proapoptotic effect that helps to reduce the viability of liver cancer cells. This study provides novel insights into the effects of As2O3against liver cancer.

Proteomic analysis of nuclear matrix proteins during arsenic trioxide induced apoptosis in leukemia K562 cells

Background Arsenic trioxide (As2O3) has been identified as a very potent antiacute leukemic agent However its role in apoptosis needs to be elucidated As2O3 interferes with the proliferation and survival of tumor cells via a variety of mechanisms Drugtarget interactions at the level of nuclear matrix (NM) may be critical events in the induction of cell death by As2O3 This study dealt with As2O3-target interactions at the level of NM in chronic myelogenous leukemia cell line K562 by proteomics Methods K562 cells were cultured in MEM and treated with different concentrations of As2O3 The nuclear matrix proteins were analyzed by highresolution twodimensional gel electrophoresis and computerassisted image analysis Results As2O3 significantly inhibited the growth of chronic myelogenous leukemia cell line K562 at low concentrations While more than 200 protein spots were shared among the nuclear matrices, about 18 distinct spots in the nuclear matrices were found characteristic for As2O3 treated cells Conclusions: As2O3 induces apoptosis in K562 cells in a dose and timedependent manner Our results demonstrated that for the detection of the onset of apoptosis, the alteration in the composition of nuclear matrix proteins was a more sensitive indicator than nucleosomal DNA fragmentation test These results indicated that As2O3 might be clinically useful in the treatment of chronic myelogenous leukemia. The changes of nuclear matrix proteins in the treated cells can be used as a useful indicator for this treatment

Effect of Ad-p16 Combined with CDDP or As_2O_3 on Human Bladder Cancer Cells

To evaluate the therapeutic efficiency of combined use of p16-expressing adenovirus and chemotherapeutic agents CDDP or As2O3 on human bladder cancer cell line EJ, the human bladder cancer cell line EJ were transfected with adenovirus-mediated p16 gene (Ad-pl6), with administration of cisplatin (CDDP) or arsenic trioxide (As2O3). The cell growth, morphological changes, cell cycle, apoptosis and molecular changes were measured using cell counting, reverse microscopy, flow cytometry, cloning formation, immunocytochemical assays and in vivo therapy experiments to evaluate the therapeutic efficacy of such combined regimen. Ad-pl6 transfer and CDDP or As2O3 administration to EJ cells could exert substantially stronger therapeutic effects than the single agent treatment. Especially in in vivo experiments, combined administration of p16 and CDDP or As2O3 induced almost tumor diminish compared to the partial tumor diminish induced by single agent. Moreover, delivery of Ad-p16, or administration of minimal-dose CDDP or As2O3or combined regimen could induce massive apoptosis of EJ cell. Cell cycle analysis demonstrated that administration of CDDP or As2O3 remarkably arrested EJ cell in G1 prior to apoptotic cell death. When treated with combined regimen, cells were arrested in G1 to a greater extent prior to apoptotic cell death. It is concluded that after introduction into EJ cell, Ad-pl6 shows enhanced therapeutic efficacy for EJ cell when used in combination with CDDP or As2O3.

Effects of Arsenic Trioxide on Human Renal Cell Carcinoma Lines in Vitro

Objective: To observe the effects of arsenic trioxide (As2O3) on human renal cell carcinoma (RCC) lines in vitro and to explore its possible molecular mechanisms. Methods: The microculture tetrazoli-um (MTT) assay was used to determine the anti-proliferative effects of As2O3 on human RCC lines. Flow cy-tometry was performed to investigate the effects of As2O3 on cell cycle and cell apoptosis. The reverse tran-scription-polymerase chain reaction (RT-PCR) was conducted to detect mRNA expression of Bcl-2, Bax, p53 and c-myc. Results: As2O3 inhibited the growth of RCC lines in vitro in a concentration-dependent manner. At the concentrations of 0.5, 1.0, 2.0 and 4.0μmol/L, the inhibition rates of As2O3 on RCC-WCS cells were 27.60%, 30.09%, 41.03% and 50.77%, respectively. Compared with untreated RCC-WCS, there was significant difference at each concentration (P<0.01). As2O3 induced a G1 phase arrest in RCC-LSL cells, but a G2/M phase arrest in RCC-WCS and RCC-SHK. As2O3 induced cell apoptosis in these cell lines. The mRNA level of p53 and c-myc decreased, but no detectable changes of Bcl-2 and Bax were observed after As2O3 treatmen. Conclusion: As2O3 in therapeutic concentrations inhibited the in vitro growth of RCC lines via cell cycle arrest and apoptosis. One of its possible mechanisms was down-regulation of p53 and c-myc. Our results suggest that As2O3 is probably a new candidate agent for the treatment of human renal carcinoma.

Mechanisms of arsenic trioxide induced apoptosis of human cervical cancer HeLa cells and protection by Bcl-2

It was recently reported that arsenic trioxide （As2O3） can induce complete remission in patients with acute promyelocytic leukemia （APL）. In this present article, the biological effect of As2O3 on human cervical cancer HeLa cells and HeLa cells overexpressing Bcl-2 is studied. By MTT and colony forming ability assays, morphology alteration, flow cytometric analysis, DNA gel electrephoresis and in situ cell death detection （TUNEL）, it was found that As2O3 inhibited the growth of HeLa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR, Northern blot, Western blot analysis revealed that As2O3 induced HeLa cell apoptosis possibly via decreasing the expression of c-myc and viral genes. HeLa cells overexpressing Bcl-2 partly resist As2O3 induced apoptosis, which might be relative to preventing the cells from As2O3 caused G2/M block, downregulation of c-myc gene expression and inhibition of viral gene expression was also noted, However, it was found that As2O3 at a high

Cell cycle arrest and apoptotic cell death in cultured human gastric carcinoma cells mediated by arsenic trioxide

AIM: To investigate the effect of arsenic trioxide on human gastric cancer cell line MKN45 with respect to both cytotoxicity and induction of apoptosis in vitro. METHODS: MKN45 cells were treated with arsenic trioxide(As2O3) at the concentration of 1, 5, and 10 μmol/L,respectively, for three successive days. Cell growth and proliferation were observed by cell counting and trypanblue exclusion. Cytotoxicity of As2O3 was determined by MTT assay. Morphologic changes were studied with light microscopy. Flow cytometry was used to assay cell DNA distribution and apoptotic cells were confirmed with terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL) and DNA electrophoresis.RESULTS: The growth of MKN45 cells was significantlyinhibited by As2O3 which was confirmed by colony-forming assay. After 7 d of culture with various concentrations of As2O3, colony-forming capacity of MKN45 cells decreased with As2O3 increment in comparison with that of control group. The inhibitory rate of colony-formation was 38.5%, 99.1%, and 99.5% when the concentration of As2O3 was1, 5, and 10 iμmol/L in culture medium, respectively. The cell number of a single colony in drug treatment groups was less than that of control group. The cell-killing rate of As2O3 to MKN45 cells was both dose- and timedependent with an IC50 of (11.05±0.25) μmol/L. After incubation in 10 μmol/L As2O3 for 24 h, the cell-killing rate was 27.1%, and it was close to 50% after 48 h. The results showed that As2O3 induced time- and dosedependent apoptosis in MKN45 cells, blocked at G2/M phase. The apoptotic peak (sub-G1 phase) appeared and cell apoptotic rate in MKN45 cells was 18.3-32.5% aftertreatment by 10 μmol/L As2O3 for 48 h. The percentage of G2/M cell of the experimental groups was 2.0-5.0 times than that of the control group. Gel electrophoresis of DNA from cells treated with each concentration of As2O3 for 48 h revealed a 'ladder' pattern, indicating preferential DNA degradation at the internucleosomal, linker DNA sections. TUNEL also demonstrated strand breaks in DNA of MKN45 cells treated with As2O3, while control cellsshowed negative labeling.CONCLUSION: As2O3 can induce apoptosis of human gastric carcinoma cells MKN45, which is the basis of its effectiveness. It shows great potential in the treatment of gastric carcinoma.

Anti-hepatoma effect of arsenic trioxide on experimental liver cancer induced by 2-acetamidofluorene in rats

瞄准：学习三氧化二砷的 anti-hepatoma 效率(作为(2 ) O (3 )) 在试验性的老鼠肝细胞的治疗，癌(HCC ) 由 2-acetamidofluorene (2-FAA ) 导致了并且阐明可能的机制。方法：SD 老鼠(2 瞬间旧) 用 2-FAA 被喂了让 8 wk 导致 HCC，然后他们被对待与作为(2 ) O (3 ) 或妈三倍。在 d 上 29，老鼠被打死，肝被称，肝肿瘤被数。肝织物的组织学的变化在显微镜下面被观察，并且细胞的动态参数被流动血细胞计数学习。Immunohistochemistry (二拍子的圆舞方法) 被用来在连续的节上观察脉管的内皮生长因素(VEGF ) 和微容器的密度(MVD ) 的表示。病理学的参数也被分析，浆液 aspartate aminotransferase (著名计算机生产厂商) 的层次，丙氨酸 aminotransferase (中高音) ，全部的胆红素(TBi ) ，和直接胆红素(DBi ) 。结果：肝肿瘤的数字在对待与的组显著地减少了作为(2 ) O (3 ) ，在特别中等剂量(1 mg/kg ) 组织(t = 2.80， P【0.01 ) 。当(2 ) O (3 ) 经由 apoptosis 引起了 HCC 细胞死亡；坏死被看见，当剂量是 1 mg/kg 时， apoptosis 是普通的。增长索引严厉地减少了在中等剂量(1 mg/kg ) 组织(7.87+/-4.11 对 24.46+/-6.49， t = 2087， P【0.01 ) ，然而并非在 0.2 mg/kg 组。然而，S阶段部分在两个组戏剧性地减少了，仅仅当剂量与控制相比是 1 mg/kg 时，它到达了底部水平( 0.40+/-0.13 对 3.01+/-0.51 ， t = 2.97 ， P【0.01 )，并且它显然在 G ( 0 ) /G ( 1 )( G ( 0 ) /G ( 1 )限制)伴有房间的累积。VEGF 和 MVD 在的表情中等剂量(1 mg/kg ) 组比生理盐水组显著地低(0.63+/-0.74 对 2.44+/-0.88， P【0.05；15.75+/-3.99 对 47.44+/-13.41， t = 2.80， P【0.01 ) 。与生理盐水组相比，是的中等剂量、低剂量的组( 2 ) O ( 3 )和妈三倍在浆液降低了中高音的层次( 61.46+/-9.46 ， 63.75+/-20.40 ， 61.18+/-13.00 对 108.98+/-29.86 ， t = 2.14 ， P【0.05 )，但是没有浆液著名计算机生产厂商诚实的效果， TBi ，和 DBi 。结论：当(2 ) O (3 ) 穿上禁止的效果，在老鼠的试验性的 HCC 的生长由 2-FAA 导致了，但是没在正常肝细胞上有明显的效果。机制可以通过堵住 VEGF 在血管生成上包含两极分裂，在 /G (1 ) 分阶段执行的 G (0 ) 的房间的累积，肿瘤房间的 apoptosis，和禁止的效果的减少。

The cell cycle related apoptotic susceptibility to arsenic trioxide is associated with the level of reactive oxygen species

Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate,to detect the level fluctuation of reactive oxygen species (ROS) during the cell cycle of normal NB4 cells. Our results showed that NB4 cells possessed higher level of ROS in G2/M phase than in G1 and S phases. Double staining flow cytometry,with TdT mediated dUTP nick end labeling (Tunel) and propidium iodide (PI),indicated that As2O3 (2 μM) could induce apoptosis in NB4 cells prevailingly from G2/M phase,and this efficacy was enhanced upon co-administration of 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) (2.5 μM) which could produce the endogenous ROS. These results suggested that different ROS level in different cell cycle phases of NB4 cells might determin the selective induction of G2/M apoptosis and the cells' susceptibility to apoptosis by As2O3.

Nuclear matrix associated protein PML: an arsenic trioxide apoptosis therapeutic target protein in HepG2 cells

Objective To investigate arsenic trioxide (As 2O 3)-induced apoptosis and the effects on cell nuclear matrix related protein promyelocytic leukaemia (PML). Methods HepG2 cells were cultured in MEM medium and treated with 0.5, 2, 5 and 10 μmol/L As 2O 3 for either 24 h or 96 h at each concentration. In situ terminal deoxynucleotidyl transferase (TdT) labeling (TUNEL) and DNA ladders were used to detect apoptosis. Confocal microscopy and Western blotting were used to observe the expression of PML. Results The growth rates of HepG2 cells were slower in the As 2O 3 treated than the untreated control group. DNA ladder and TUNEL positive apoptotic cells could be detected in As 2O 3 treated groups. The expression of PML decreased in HepG2 cells with 2 μmol/L As 2O 3 treatment. Confocal images demonstrated that the expression of PML protein in HepG2 cell nuclei decreased after treatment with 2 μmol/L As 2O 3, and micropunctates characteristic of PML protein in HepG2 cell nuclei disappeared after treatment with 5 μmol/L As 2O 3.Conclusions Our results show that arsenic trioxide can significantly inhibit the growth of HepG2 cells in vitro. As 2O 3 induces apoptosis in HepG2 tumor cells in a time and concentration dependent manner. As 2O 3 may degrade the PML protein in HepG2 cell nuclei. The decreased expression of PML in As 2O 3 treated tumor cells is most likely to be caused by apoptosis. Nuclear matrix associated protein PML could be the target of As 2O 3 therapy.

Over-expression of LRIG3 Suppresses Growth and Invasion of Bladder Cancer Cells

The purpose of this study was to investigate the impact of leucine-rich repeats and immu- noglobulin-like domains 3 （LRIG3） on the biological features of bladder cancer cell lines. The plasmids of over-expressed LRIG3 and the blank plasmid serving as control were transfected into the bladder cancer cell lines, T24, EJ and BIU-87, and the expression levels of LRIG3 mRNA and protein were de- tected by using real-time PCR and Western blotting. The changes in the cell cycle and apoptosis were examined by using flow cytometry. The invasive ability was measured by Transwell assay, and CCK-8 assays were used to measure the proliferation of cells. As compared with the control group, the LRIG3 mRNA and protein expression levels in LRIG3 cDNA-transfected group were raised significantly （P〈0.05）. The average number of cells with up-regulated LRIG3 passing through the inserted filter was decreased significantly as compared with the control group （P〈0.05）. Up-regulation of LRIG3 also could inhibit proliferation and induce apoptosis of T24, EJ and BIU-87 cells. Except BIU-87, the T24 and EJ cells transfected with LIRG3 eDNA were arrested in G0/G1 phase compared to the control group （P〈0.05）. In conclusion, the over-expression of LRIG3 could influence the cell cycle and invasion, in- hibit proliferation and induce apoptosis in the three bladder cancer cell lines.