BACKGROUND ＆ AIM: We investigated the role of wild type and H179Y_mutated p53 in the regulation of HELF cell cycle and proliferation. MATERIALS AND METHODS: We transfected pcDNA3_wild_type p53 (pcDNA3_wtp53) and pcDNA3_H179Y_mutated p53 (pcDNA3_mtp53) plasmids into human embryonic lung fibroblast (HELF) cells. Then we analyzed cell proliferation by cell growth assays, analyzed cell cycle by flow cytometry, and detected the expression levels of mRNA and proteins by PCR and Western blotting. RESULTS: Over_expression of wild_type p53 caused cell cycle arrest at G1 phase with reduced cell size, decreased expression of cyclin D3, cyclin E, Cdk2 and Cdk4, and increased expression of p21. In contrast, over_expression of H179Y_mutant p53 promoted G1 to S phase transition with enlarged cell size and increased cyclin A and Cdk4 expression. CONCLUSION: These results indicated that mutation at the p53 H179Y residue caused up_regulation in the expression of cyclin A and Cdk4, promoting HELF cell proliferation.

BACKGROUND ＆ AIM: Nitrofen is a herbicide used to establish the pulmonary hypoplasia model. The current study was performed to explore the effects and mechanisms of nitrofen on proliferation and apoptosis of cultured type II pneumocytes. MATERIALS AND METHODS: Type II pneumocytes A549 were treated with 20,40 and 80 μmol/L of nitrofen. Cellular proliferation was measured by MTT colorimetry, colony formation assay. Western blot and real_time RT_PCR were performed to detect the PCNA expression. Apoptosis was assayed by TUNEL labeling and acridine orange_ethidium bromide staining. Expression of apoptosis_related genes was detected by western blot. RESULTS: Compared with controls, administration of 20,40 and 80 μmol/L nitrofen for 12－48 hrs resulted in 12.43％－71.73％ decrease in proliferation (P<0.01), and 79.2％ decrease in colony formation (P<0.01) of A549 cells. The PCNA protein and mRNA within nitrofen_treated cells were reduced in a time_and dose_dependent manner(P<0.01). Partial nitrofen_treated A549 cells presented morphological changes of apoptosis, with apoptotic rates of 8.0％－22.5％ (P<0.01), which could not be abolished by the pan caspase inhibitor zVAD_fmk. The expression of anti_apoptotic Bcl_xL was significantly down_regulated (P<0.01). CONCLUSION: Nitrofen decreased proliferation of cultured type II pneumocytes associated with down_regulation of PCNA, and induced apoptosis associated with suppressed Bcl_xL expression.

BACKGROUND ＆ AIM: To investigate the effects of (－)_epigallocatechin_3_gallate (EGCG, the major phytochemical in green tea) on the expression of connexin43 (Cx43) gene and the intercellular communication of the human bladder cancer cell line BIU_87, and to explore its possible mechanisms of prevention and cure of the bladder tumor. MATERIALS AND METHODS: The methyl thiazolyl tetrazolium and Annexin_V/PI double_labeled flow cytometry methods were used to examine the growth inhibitory rate (IR) and apoptosis rate (AR) of BIU_87 cells treated by EGCG at different concentrations (0,5,10,20 mg/L). The reverse transcription_polymerase chain reaction (RT_PCR) and Western Blot analysis were used to measure the relative expression levels of the Cx43 mRNA and its protein. The scrape_loading fluorescence dye transfer method was used to assess the gap junction intercellular communication (GJIC) through fluorescence microscopy. RESULTS: EGCG at concentrations of 10 mg/L and 20 mg/L could both significantly inhibit the proliferation and induce the apoptosis of BIU_87 cells. The IR and AR were (15.67±1.15)％, (18.33±1.53)％ and (42.00±4.34)％, (27.33±3.21)％, respectively. And EGCG could significantly up_regulate the expression of Cx43 mRNA and its protein,enhance the GJIC of BIU_87 cells compared with groups of 0 and 5 mg/L (P<0.05). The effects showed significant correlation with the dose of EGCG. CONCLUSION: EGCG (10,20 mg/L) could effectively up_regulate Cx43 expression and enhance the GJIC of BIU_87 cells, thereby inducing bladder tumor cells apoptosis and inhibiting its growth. This provides experimental evidence for the mechanism of chemical prevention and cure of the bladder tumor by EGCG.

BACKGROUND ＆ AIM: To examine the inhibitory effects of Phellinus linteus intracellular polysaccharide(PLIP) on proliferation of leukemic cell line K562, and to explore its preliminary mechanisms. MATERIALS AND METHODS: The suppression of cellular growth was detected by MTT assay and trypan blue rejection. Apoptosis was studied by using Hoechst_PI fluorescence staining, DNA agarose gel electrophoresis,and flow cytometry. RESULTS: The PLIP could significantly inhibit the proliferation of K562 cells (P<0.05), and the highest inhibition rate could reach 52.55％ at the dose of 400 μg/ml,IC50 was 262.36 μg/ml. The apoptosis rates for 100 μg/ml,200 μg/ml,400 μg/ml were 5.72％,13.57％,19.39％,respectively, and morphologic and physiologic changes of apoptosis in K562 cells were induced . CONCLUSION: PLIP could significantly inhibit proliferation of K562 cells, and the mechanism responsible for the effect might involve the induction of apoptosis and the effects on cell cycle.

BACKGROUND ＆ AIM： The inhibitory effect of arsenic trioxide (As2O3) on human breast cancer MDA_MB_468 cells and the change of syk expression. MATERIALS AND METHODS: After treatment with various concentrations of As2O3, MDA_MB_468 cells proliferation was assessed by using methyl thiazolyl tetrazolium(MTT) method. The morphologic changes of MDA_MB_468 cells were examined with light microscope. After treated with As2O3 , cell cycle distribution and expression of Syk protein were measured by flow cytometry(FCM). Expression of syk mRNA was eveluated with RT_PCR. RESULTS: As2O3 inhibited the proliferation of MDA_MB_468 cells significantly, and in a time and dose_dependent manner (P<0.05). After treatment with As2O3, MDA_MB_468 cell cycle was arrested in the S＋G2/M phase. MDA_MB_468 cells expressed syk mRNA, As2O3 enhanced syk mRNA and Syk protein expression of MDA_MB_468 cells. CONCLUSIONS: As2O3 may inhibit the proliferation of MDA_MB_468 cells by enhancing the expression of syk.

BACKGROUND ＆ AIM: There are now many reports that telomerase activity can be upregulated in some cells following exposure to low doses radiation, and that the enzyme may be involved in the repair of radiation damage. We studied the effect of telomerase inhibitor Azidothymidine (AZT) on repair of DNA damage induced by irradiation in human HeLa cells. MATERIALS AND METHODS: There were four groups：control group, azidothymidine group(HeLa cells were pretreated by 400 μmol/L Azidothymidine for 24 h),radiation group(HeLa cells were irradiated with 2 Gy 60Co γ rays), azidothymidine/radiation group(HeLa cells were irradiated with 2 Gy 60Co γ rays,with pretreatment by 400 μmol/L Azidothymidine for 24 h). Telomerase activity was measured by a PCR_based telomeric repeat amplification protocol (TRAP) coupled with ELISA and DNA single_stranded breaks was evaluated by single cell gel electrophoresis assay (SCGE). RESULTS: Telomerase activity of HeLa cells began increasing at 10 minutes,more at 60 min,and peaked at 360 min after irradiation with 2 Gy 60Co γ rays,and decreased about 50％ after pretreatment with Azidothymidine. Azidothymidine could inhibit telomerase activity increase after irradiation (P<0.05).In SCGE tests,0－10 min after irradiation with 2 Gy 60Co γ rays, there was no difference in percentage of DNA in the tail between Radiation group and Azidothymidine /Radiation group(P>0.05), but percentage of DNA in the tail of Azidothymidine /Radiation group was more than Radiation group(P<0.05)30－60 min after irradiation. CONCLUSION: Azidothymidine could reduce the repair of single_stranded DNA breaks 30－360 min after irradiation. These results suggested that telomerase could play an important role in irradiation_induced DNA damage repair.

BACKGROUND ＆ AIM: To study the effect of cholesterin on apoptosis and inhibition of proliferation in human umbilical vein endothelial cells (HUVECs)and evaluate the role of CuSO4 in the process. MATERIALS AND METHODS: HUVECs were treated with different culture media:control(with equal volume of solvent),lower_dose group (LD,25 mg/L of cholesterin),medium_dose group (MD，50 mg/L of cholesterin),high_dose group (HD，100 mg/L of cholesterin),control＋10 μmol/L CuSO4 ,LD＋10 μmol/L CuSO4 ,MD＋10 μmol/L CuSO4 and HD＋10 μmol/L CuS04.Apoptosis in HUVECs were analyzed by flow cytometry and proliferation rate of HUVECs were determined by MTT test. RESULTS: Different doses of cholesterin caused different degrees of apoptosis and inhibition of proliferation in HUVECS. With increasing concentration of cholesterin , the effects on HUVECs were enhanced. At the same time, when CuSO4 was added, apoptosis and inhibition of proliferation in HUVECs became more severe. CONCLUSION: Cholesterin could induce apoptosis of HUVECs and inhibit proliferation of HUVECs. CuSO4 could accelerate the effect of cholesterin on HUVECs.

BACKGROUND ＆ AIM: To study the mutagenicity of 2,2＇,4,4＇_tetrabromodiphenyl ethers (PBDE_47) in human neuroblastoma SH_SY5Y cells in vitro. MATERIALS AND METHODS: The frequencies of micronuclei(MNi) and nucleoplasmic bridges (NPBs) were measured after SH_SY5Y cells were exposed to different doses of PBDE_47 for 24 h in vitro. RESULTS: PBDE_47 caused a significant concentration_dependent decrease in nuclear division index(NDI), and a concentration_dependent increase in MNi frequency in terms of total MNi/1000 binucleated cells (BNCs), BNCs with MNi/1000 BNCs, and NPBs/1000 BNCs. The NDI was obviously decreased, while the frequencies of BNCs with MNi/1000 BNCs and NPBs/1000 BNCs were increased significantly at 2 μg/ml and above PBDE_47 _treated groups (P<0.05). There was statistically difference in frequcency of MNi/1000 BNCs only in 4 μg/ml PBDE_47_treated group (P<0.05). CONCLUSION: PBDE_47 may induce the MNi and NPB formation, causing mutagenicity.

BACKGROUND ＆ AIM:To investigate the effects and mechanisms of resveratrol on human colon cell line HT_29. MATERIALS AND METHODS: HT_29 cells were incubated with 0,12,5,25,50,100 μmol/L resveratrol. The proliferation of HT_29 cells was measured by MTT,the COX_2 were analyzed by Western blot,the Bcl_2 and Bax were detected by immunohistochemistrical method. RESULTS:MTT results revealed that resveratrol could inhibit the proliferation of HT_29 cells in a dose and time_dependent manner.And after HT_29 cells were treated with different concentrations of resveratrol for 48 h, resveratrol at concentrations of 50 and 100 μmol/L could inhibit the expression of COX_2,and resveratrol at concentrations of 100 μmol/L could induce the expression of Bax. CONCLUSION: Resveratrol could inhibit the proliferation of HT_29 cells in a dose and time_dependent manner. The inhibition of COX_2 protein expression and the induction of Bax protein expression may be the underlying mechanisms.

BACKGROUND ＆ AIM: To detect and evaluate the antimutagenicity of puerarin by TK gene mutation test. MATERIALS AND METHODS: The TK6 human lymphoid cells were exposed to puerarin at concentrations of 25,50, 100 μg/ml with 5 μg/ml MMS, 0.1％ DMSO, 5 μg/ml MMS and 5 μg/ml MMS＋100 μg/ml VitC using simultaneous treatment to determine PE0, PE3, RSG and TMF. RESULTS:Puerarin at concentration 100 μg/ml significantly decreased the TMF induced by MMS. CONCLUSION: Under this experimental condition，puerarin inhibited TK gene mutation on TK6 cell induced by MMS at higher concentration, and has good potential for further development and application.

BACKGROUND ＆ AIM: To analyze the expression of RAP2B in lung cancer and adjacent tissue . MATERIALS AND METHODS: mRNA and protein expression level of RAP2B in 30 lung cancer and adjacent tissues were assessed by RT_PCR and Western_blot. RESULTS: ①The expression rate of RAP2B mRNA in lung cancer tissues was 73.3％(22/30)and 30.0％(9/30)in adjacent tissues. The difference between the two was statistically significant(P<0.05). Semi_quantitative results revealed that the relative expression of RAP2B mRNA was 0.155(0.000－0.530) in cancer tissues and 0.000(0.000－0.160) in adjacent tissues. The difference between the two was statistically significant(P<0.05). ②The detection rate of RAP2B protein in lung cancer tissues was 80％(24/30)and 60.0％(18/30)in adjacent tissues. The difference between the two was not statistically significant (P>0.05). Semi_quantitative results of Western blot demonstrated that the relative expression of RAP2B protein was 0.195(0.050－0.580) in cancer tissues and 0.030(0.000－0.180) in adjacent tissues. The difference between the two was statistically significant(P<0.05). CONCLUSION: Over_expression of RAP2B may play an important role in cancer development.

BACKGROUND ＆ AIM: To study the correlation between the level of Cap43 expression and histological pattern in hunman lung cancer. MATERIALS AND METHODS: The method of immunohistochemistry was used to detect Cap43 expression in 79 lung cancer specimens and western blot was used to detect its expression in 28 fresh lung cancer specimens and their surrounding normal controls.The results were semiquantitatively analyzed by image analysis systems. RESULTS: Immunohistochemistry staining revealed the distribution of Cap43 was mainly in cell cytoplasm.However,parts of the proteins were in the nucleus. Cap43 expression in lung cancer was obviously higher than normal controls (P<0.05). It was also found that Cap43 expression in patient with adenocarcinoma was higher than those with squamous cell carcinoma(P<0.01). Western blot also showed high expression of cap43 in lung cancer. Cap43 expression in mucoid adenocarcinoma was significantly higher than the other pathological types of lung cancer. (P<0.01).It was shown that the less the lung cancer differentiated, the higher the Cap43 expression was(P<0.05). Two detection methods together demonstrated Cap43 expression in normal controls and small cell lung cancers was very low. The positive rate of western blot(82.14％) was higer than immunohistochemistry(69.62％),but the two detection methods were not significantly different(P>0.05). CONCLUSION: Cap43 was highly expressed in non_small cell lung cancer and the level of expression was closely correlated with the histological pattern of tumor.

BACKGROUND ＆ AIM: To evaluate the chronic toxic effects of trivalent and hexavalent chromium to rats. MATERIALS AND METHODS: Groups were set up on the basis of 10％ LD50,6％ LD50,2％ LD50 ,and the negative control group simultaneously.After ninety_days feeding test, the serum and histopathological indexes and the ratio of viscera and body were assessed. RESULTS: The CHO,HDL,TG,Glu were significantly decreased in high_dose group of CrCl3 and control group(P<0.05).The body weight gradual decreased with increasing doses of K2Cr2O7,and the difference were significant compared with control group(P<0.05).The erythrocyte count were significantly higher than that of control group(P<0.05)，and lymphocyte were significantly lower.Serum ALT,BUN,Cr were raised but HDL,TG,Glu were decreased in the high_dose group of K2Cr2O7 and were significantly higher than that of control group.Pathological the changes in the high_dose group of K2Cr2O7 showed hepatic sinus dilation and congestion, mild exudative hemorrhage,and focal necrosis was found. CONCLUSION: K2Cr2O7 could damage the immunologic system,liver and kidney．The chronic toxicity of K2Cr2O7 was obviously higher than CrCl3.

BACKGROUND ＆ AIM: To investigate the pathological features, immunochistochemistry and prognosis of carcinoma with micropapillary pattern (MPP) in different extramammary sites. MATERIALS AND METHODS: 33 cases with MPP were evaluated for pathologic features and examined for the immunohistochemical expression of EMA, E_cadherin (E_cd), CD44v6 and Ki67. Follow_up was undertaken. RESULTS: 33 cases of carcinoma with MPP occurred in different anatomic sites, including lung, urinary bladder, kidney and large intestine. Microscopically, the tumor was characterized by small papillae of malignant cells floating within irregular interstitial spaces.There were lymphatic invasion in all cases and nodular metastases in 25 cases. The foci of expression of EMA, E_cd, CD44v6 were different from those of ordinary carcinoma in the same sites. Follow up showed 23 cases died and 3 cases recurred or metastasized in short time. CONCLUSION: Extramammary carcinoma with MPP occur at various anatomic sites, including lung, urinary bladder, pancreas and large intestine. These tumors share a high propensity for lymphatic invasion and lymph node metastases. Presence of this histological pattern should alert clinicians for more active treatment and closer follow up.

BACKGROUND ＆ AIM:To study the mutagenicity of Fructus Aristolochiae (FA) alone and compounded with Long Dan Xie Gan Wan (LDXGW) using Ames test and mouse lymphoma assay. MATERIALS AND METHODS: Ames test was conducted to determine whether FA and LDXGW ,which contained AA at the concentration of 20 μg/ml, would cause mutagenic changes in the average number of revertants for TA97,TA98,TA100 and TA102. L5178Y/tk(＋/－) －3.7.2C_cells were treated with FA and LDXGE at a concentration of 5 μg/ml by the 96_well microwell method. The plating efficiency (PE), relative total growth (RTG) and the mutant frequency (MF) were determined by the microtiter procedure. RESELTS: FA and LDXGE were considered to be nonmutagenic to Salmonella typhimurium tester strains TA97, TA98, TA100 and TA102 in Ames test. FA was characterized by marked cytotoxicity and mutagenic activity. However LDXGW showed that cytotoxicity and mutagenic activity were largely reduced when made into a compound. CONCLUSION: FA had certain cytotoxicity and mutagenicity while LDXGE could reduce the mutation of tk gene.

BACKGROUND ＆ AIM: Establish the tumor animal model of the H22 liver cancer in mice,and study the inhibition effects of chitosan oligosaccharide and bifidobacteria on the tumor. MATERIALS AND METHODS: Chitosan oligosaccharide and bifidobacteria were injected into tumor-bearing mice,the growth and pathological changes of the tumor were examined;and the immunological functions were measured. RESULTS: Growth of tumor were inhibited by chitosan oligosaccharide and bifidobacteria. They could increase the content of IL-2 and IFN-γ and the weights of spleen and thymus of the mice.Necrosis was observed in the tumor tissue. CONCLUSION: Chitosan oligosaccharide and bifidobacteria could inhibit the growth of tumor,improve immunity and induce tumor necrosis.

BACKGROUND ＆ AIM： To establish a convenient acute aging model by γ-ray irradiation． MATERIALS AND METHODS： 45 mice were divided into 3 groups：the control group，the model 1 group irradiated by 3 Gy×8 times and the model 2 group irradiated by 6 Gy×4 times. Complete blood count, thymus weight index，spleen weight index， activity of SOD，the contents of MDA and lipofuscin were determined.The expression of β-galactosidase was evaluated by staining at the end of 50 days experiment． RESULTS： Compared with control group, the complete blood count，thymus weight index and spleen weight index all decreased(P<0.05),the activity of SOD also decreased(P<0.05),but the contents of MDA and lipofuscin were increased(P<0.05).The β-galactosidase activity of hepatic cells was enhanced in the aging mice model．CONCLUSION：The acute aging model by γ-ray irradiation was successfully established, and it was a feasible method.

BACKGROUND ＆ AIM： To explore the effects of different intensities of low power microwave on the male reproductive system in mice. MATERIALS AND METHODS： 48 adult male mice were randomized into 3 microwave groups and 1 control group,each with 12 animals: microwave groups was exposed to 900 MHz microwave (250 μW/cm2, 150 μW/cm2, 50 μW/cm2,24 h/d for 34.5 d) and control group was not exposed to microwave. The sexual function： capture incubation period (CIP), the pathomorphological changes of the testes ,testis-weight ratio, comparative sperm count, malformed sperm ratio and serum testosterone were used to assess the effects of the low power microwave. RESULTS:In microwave group exposure(150 μW/cm2)testis showed slight pathological changes,comparative sperm count,serum testosterone level were significantly decreased compared with the normal control(P<0.05, respectively). CIP ，sperm malformed ratio in microwave group were significantly increased compared with the normal control group (P<0.05, respectively) .But testis-weight ratio showed no significant difference compared with the control(P>0.05, respectively). CONCLUSION: Low power microwave exposure (150 μW/cm2)could weaken sexual function(CIP) and induce pathological changes of testis, obvious increase of sperm malformed ratio , significant decrease of comparative sperm count and serum testosterone in mice.

BACKGROUND ＆ AIM: To investigate suitable methods for detecting mutagenicity of hair restorers. MATERIALS AND METHODS: Using Ames test and mouse lymphoma assay (MLA) to evaluate the mutagenic effects of three kinds of hair restorers. RESULTS: Three hair restorers had strong bacteriostatic and bacteriocidal effects on Salmonella typhimurium, and no mutagenicity was observed. In MLA test, sample No.1 and sample No.3 had no mutagenic effects at concentrations tested, However, in No.2 hair restorer, TK locus mutation frequency was significantly higher than that of control group (P<0.05)at high dose. CONCLUSION: MLA test may be a complementary method used to detect the mutagenic effect of hair restorer.

ACKGROUND ＆ AIM:Assessed the expression of ZAP_70 in T_NHL, and analyzed the correlation between ZAP_70 and P53,Ki67,to explore the significance of ZAP_70 protein expression in T_NHL. MATERIALS AND METHODS:Evaluated the expression of ZAP_70, P53 and Ki67 in 48 T_NHL by SP immunohistochemistry techniques. The results were analyzed by χ2，t test and Spearman's rank correlation. RESULTS: Expression of ZAP_70 was detected in 58.3％T_cell lymphomas, and the expression of this protein was correlated negatively with tumor grade. Expression of ZAP_70 in high_grade T_NHL was significantly lower than that in low_grade T_NHL(P=0.001).Of 48 T_NHL,expression of P53 was not only correlated positively with tumor grade, but also had a positive relationship with infection of EBV (P<0.05).The expression of ki67 was also increased in high_grade T_NHL. Statistical analysis demonstrated that there was a positive correlation between P53 and Ki67 (P<0.01). CONCLUSION:Absence of ZAP_70 may be diagnostically useful in paraffin sections suggesting T_NHL. Simultaneous measurement of P53 and Ki67 may have great importance in evaluating prognosis and directing therapy after operation in T_NHL.