Purpose : To construct differentially expressed cDNA libraries from different malignant transformed human bronchial epithelial cells induced by alpha-particle radiation. Methods : Suppression subtractive hybridization (SSH) . Results : Three differentially expressed cDNA libraries were constructed from different malignant transformed human bronchial epithelial cells. The number of clones is 416 in A subtraction library (The cDNAs of BEP2D cells as tester and R15Hp35 cells as driver) , 301 in B subtraction library ( The cDNAs of R15Hp20 cells as tester and R15Hp35 and BEP2D cells mixed together as driver. ) and 568 in C subtraction library (The cDNAs of R15Hp35 cells as tester and BEP2D cells as driver) . After 70 cDNAs were sequenced and analyzed , 61 cDNAs were found to be known genes , and 9 cDNAs were found to be novel ones. Conclusion : The cDNAs of three subtraction libraries may represent differentially expressed cDNA of different malignant transformed human bronchial epithelial cells induced by alpha-particle radiation.The data provide a basis for further investigation of the molecular mechanism of lung cancer induced by alpha-particle radiation.

Purpose : To subclone the malignant transformants of human bronchial epithelial cell line (BEP2D) induced byα-particles and to analyse their karyotypes and capacity of rejoining DNA double-strand breaks (DSB) . Methods :Tumor cells were isolated from nude mice bearing malignant transformed cells(passage 35 cells of 1. 5 Gy ofα-articles- irradiated BEP2D and were subcloned in vitro. Trypsin/ Giemsa banding of chromosomes and pulsed field gel electrophoresis were used to analyse karyotypes and DNA repair respectively. Results : Five individual malignant transformed cell lines (RP35T21 ,22 ,24 ,25 ,26) were subcloned. Multi-locus chromosome deletions were shown in these malignant transformed cell lines as well as the parental line BEP2D. The ratio of polyploids of RP35T22 and RP35T24 cells was about 40 % and was higher than that of PEB2D cells(5 %) , The other three lines showed the same polyploid levels as the parental cell line. The capacity of rejoining DSB in RP35T21 and RP35T24 cell lines was obviously deficient. Conclusion : Five malignant transformed cell lines were subcloned. The deficiency of DNA DSB repair could be an important characteristic ofα-particle-induced carcinogenesis.

Purpose and Methods : To detect related genes mutation in human bronchial epithelial (BEP2D) cells transformed by α-particles and by using PCR amplification and single2strand conformation polymorphism ( SSCP) . Results : The point mutation of double-strand break repair gene XRCC5 occurred at the early stage of transformation , but no mutation was found in the exon-of p16 gene and exon12 of hMSH2 gene. Conclusion :Mutated XRCC5 gene can't repair DNA lesions induced byα-particles , and plays as one initiator in the process of transformation induced byα-particles.

Purpose : To study the protective effects ofβ-carotene (βC) and vitamin E(V-E) on DNA damages of mice induced by mitomycin C (MMC) . Methods : Forty eight male Kunming mice were divided into 4 groups at random , the mice then were fed with basal diets in normal (A) and positive control (B) groups , basal diet + V-E (200 mg/ kg·bw ,C) , and basal diet + βC (200 mg/ kg·bw , D) for 4 weeks respectively. The mice were injected with MMC (1 mg/ kg·bw) intraperitoneously except for group A which was injected with normal saline before and after 24 h. 12 h later after administration , the mice were killed. The spleen and sternum were excised sterily. The double-stranded DNA remained rate of spleen cells and micronucleus frequency in bone marrow cells were studied. Results : For each group the double- stranded DNA remained rate ( %) was 66. 44 ±5. 97 (A) , 43. 06 ±5. 95 (B) , 58. 69 ±8. 28 (C) , 63. 26 ±7. 95 (D) respectively. The value of group B was significantly lower than those of the others ( P < 0. 01) . Micronuclei ( ‰) in bone marrow cells were 1. 87 ±0. 83 (A) , 31. 00 ±6. 32 (B) , 17. 37 ±2. 88 (C) , 15. 25 ±4. 68 (D) respectively. Group B was significantly higher than those of the others ( P < 0. 01) . Conclusion :βC and V-E can obviously inhibit the DNA breakages of spleen cells and reduce the formation of micronuclei of bone marrow cells in mice induced by MMC.

Purpose : To study the malignant transforming activity of crystalline nickel sulfide (NiS) in human bronchial epithelial cell line (16HBE) immortalized by SV40 Large T antigen. Methods : 16HBE cells were treated several times with NiS at different concentrations in vitro , and the malignant degree of transformed cells were identified by the assay for anchorage2independent growth and tumorigenicity. Results : The 35th passage cells exhibited overlapping growth. As compared with that of negative control cells , colony formation efficiency of the transformed cells in soft agar showed significant increases ( P < 0. 01) , and a dose-dependent effect . The transformed cells could grow into tumor in nude mice , a squamous cell carcinoma confirmed by histopathological examination. Conclusion : Crystalline nickel sulfide can induce malignant transformation of 16HBE cells. This transformed model provides a potential tool for the study on molecular mechanism of nickel carcinogenesis.

Purpose : To establish a new modal system to evaluate the genetic toxicity of aneugens and to investigate the effects of colchicine (COL) on preimplantation embryo cells. Methods : Kunming mice were divided into 5 groups including solvent control , and COL-treatments (0. 00 mg/ kg , 0. 25 mg/ kg , 0. 50 mg/ kg and 0. 75 mg/ kg) . The mitotic index (MI) and micronucleus frequency(MNF) of cells from preimplantation embryos of mice were observed. Results :①The MI of the 0. 75 mg/ kg group was highly significant as compared to that of the control ( P < 0. 01) . ②MNF of 0.25 mg/ kg , 0. 50 mg/ kg and 0. 75 mg/ kg groups were 2. 99 ‰, 7. 35 ‰, 10. 13 ‰ respectively and presented a dose responsive relationship with COL. All of MNF of COL treated groups were highly significant as compared to that of control ( P < 0. 01) . Conclusion : ①A new reliable animal model for evaluating the genetic toxicity of aneuploidogen was established by a series of pre2test procedures. ②COL could arrest nuclear division of preimplantation embryo cells only when the dose reaches a certain level . COL may induce the aneuploidy of preimplantation embryos with dose response.

Purpose : To compare the genetic polymorphism of glutathione S-transferase M1 (GSTM1) locus between the populations in Xuanwei and Fuyuan counties in Qujing city and between Qujing and non-Qujing residents in Yunnan province. Methods : Polymerase chain reaction ( PCR) was employed to justify the genotype of the aim population. Results : No significant difference was found in the GSTM1 genotype frequencies among those three groups ( P > 0. 05) , i . e. , the frequencies of GSTM1 null genotype (0/ 0) were 63. 6 % in Xuanwei residents , 64. 5 % in Fuyuan group and 68. 5 % in non-Qujing group , respectively. Conclusion : Among the normal populations studied , the genetic polymorphism distribution of GSTM1 genes was proved to be homogenous. The result is helpful for further research on the association on lung cancer and xenobiotics detoxification genes.

Purpose : To explore cigarette end immersion-induced mutagenesis in bone marrow PCE and primary spermatocyte. Methods : Micronucleus test in bone marrow PCE and chromosome aberration assay in primary spermatocyte were undertaken in mice exposed to the immersion. Results : In the low , middle and high dose groups , the mean frequencies of micronuclei (3. 0 ‰, 5. 6 ‰, 11. 3 ‰) , the mean frequencies of sex chromosome univalent (4. 6 % ,5. 0 % , 6. 6 %) , and the mean frequencies of autosome univalent (4. 4 % , 8. 0 % , 10. 4 %) were higher than those in the control groups (2. 0 ‰ in micronucleus frequency , 2. 4 % in sex chromosome univalent and 2. 6 % in antosome univalent) . No significant difference in the frequencies of structural aberration was observed between the treated and the control groups. Conclusion : Cigarette end immersion increases the frequencies of micronucleus in bone marrow PCE and induces numeral aberration of chromosomes in primary spermatocyte.

Purpose : To investigate the mutagenic effects of anticancer drug Jinke. Methods : micronucleus test in mice and bone marrow PCE cells were used respectively to determine micronucleul cell frequencies (MNCF) . Results : The MNCF of Jinke-treated groups were much significantly higher than that of control group , and to some extent , were dose-responsive. Conclusion : Jinke has strong mutagenic effect , and the result of micronucleus test on spleen PCE cells is closely similar to that on bone marrow cells.

Purpose : To investigate the effects of CYP1A1 and GSTM1 allelotypes on the in vivo micronucleus formation in human peripheral lymphocytes induced by smoking and drinking. Methods : The allelotypes of CYP1A1 and GSTM1 were detected by allele-specific (AS)- and multiplex differential (MD)-PCR respectively. Micronuclei were detected by the in vivo micronucleus test in human capillary blood lymphocytes. Results : It showed that cigarette smoking increased significantly MNF in lymphocvtes (0. 65 ‰, P < 0. 05) as compared with those of healthy non-smokers (0. 24 ‰) , heavy alcohol-drinking enhanced this effect (0. 89 ‰, P < 0. 01) ; smoking increased significantly MNF in lymphocytes from individuals with the genotype GSTM1 0/ 0 (0. 75 ‰, P < 0. 05) and induced the statistically marginal increase of MNF in lymphocytes of individuals with the genotype CYP1A1 Val/ Val and the susceptible combined genotypes CYP1A1 Val/ Val ·GSTM1 0/ 0 , CYP1A1Val/ Val·GSTM1 + ( + / + and + / 0) and CYP1A1 Val/ Ile·GSTM1 0/ 0 as compared wich those of individuals with the non-susceptible combined genotypes CYP1A1 Ile/ Ile·GSTM1 + , CYP1A1 Ile/ Ile·GSTM1 0/0 and CYP1A1 Ile/ Val ·GSTM1 + . Conclusion : Cigarette smoking induced the significant increase of MNF in lymphocytes of human peripheral blood , heavy alcohol drinking enhanced obviously the effect . The in vivo micronucleus formation induced by smoking and drinking had the close association wich CYP1A1 and GSTM1 allelotypes.

Purpose : To study the mutagenicity for a hair dye as a part of toxicological evaluation. Methods : The Ames test and chromosome aberration test in vitro in CHL cells were used. Results : At the dose of 2 500μg/ plate to 5 000 μg/ plate with the S9mix , the sample can induce the mutation of the strain TA98 , the number of reverse mutation bacteria clone was 2～3 times higher than the number of spontaneous mutation bacteria clone. CHL cell chromosome aberration test showed that at the concentration of 300μg/ ml without the S9mix , and at concentration of 600μg / ml and 1 000μg/ml with or without the S9mix , the sample can induce the chromosome aberration. The rate of chromosome aberration in treated group was significantly higher than that in the negative control group. Conclusion : The oxidative hair dye tested has certain genetic toxicity.

Purpose : to evaluate the changes af the serum levels of immunosuppressive acidic protein ( IAP) in patients with large bowel carcinoma (LBC) and their familial members ( FM) . Methods : the serum changes of IAP in the 20 cases with LBC and 20 FM were determined using single immunodiffusion method. Results : the serum levels of IAP in patients with LBC , compared with normal subjects (NS) , were significantly increased ( P < 0. 01) . there also were statistical differences in serum levels between FM and the NS ( P < 0. 01) . conclusion : It is suggested that IAP may probably be associated with carcinogenesis of LBC. The changes of IAP may be served as an indicator of diagnosis for susceptible individuals of LBC.

Purpose : The teratogenic potential of cigarette smoke was evaluated by using the short term biological assay. Methods : The adults and regenerators of Hydra were exposed respectively to water-soluble and fat-soluble extracts of cigarette smoke. According to Wilby’s score method , median toxic concentration (T50) in adults and median inhibition concentration ( I50) in regenerators of the extracts were calculated. On the basis of T50 to I50 ratios , the teratogenicity was judged. Results : T50 and I50 of the water-soluble and fat-soluble extracts 159. 1 mg/ L , 29. 8 mg/ L and 14. 5 mg/ L , 3.8 mg/ L , and T50 to I50 ratios were 10. 97 and 7. 84 , respectively. Conclusion : The water-soluble and fat-soluble extracts of cigarette smoke showed teratogenesis in the Hydra regeneration assay.