ABSTRACT
Objective:To obtain the conditionally replicative adenovirus with triple-targeting Smac overexpression using gene recombination technology,and to explore its effects on the apoptosis and cell cycle progression of MDA-MB-231 cells.Methods:The triple-targeting Smac overexpression vector pShuttle-Egr1-Smac-HRE-hTERT-E1A-E1Bp-E1B55K was constructed by gene recombination technology,which was recombined with the skeleton vector pAdEasy in the BJ5183 bacteria (AdEasy-1+-) to obtain the conditionally replicative adenovirus CRAd.pE-Smac.After the MDA-MB-231 cells were infected with CRAd.pE-Smac,the cancer cells were mimiced into hypoxic status with chemical reagent CoCl2,then control group,CRAd.pE-Smac group,hypoxia group and CRAd.pE-Smac+-hypoxia group were set up;the cells were irradiated with 4 Gy X-rays,and each group was divided into nonirradiation group and irradiation group.The Smac protein expression was detected by Western blotting assay,the apoptotic rates and the percentages of cells at different phases were detected by flow cytometry.Results:The Western blotting results showed that the Smac protein expressions were increased after infection of CRAd.pE-Smac,hypoxia and 4 Gy irradiation,especially in CRAd.pE-Smac +hypoxia+4 Gy irradiation group.The FCM results showed that the apoptotic rates in CARd.pE-Smac,hypoxia,CARd.pE-Smac + hypoxia group were increased compared with control group (P＜0.05 or P＜0.01),and the apoptotic rates of cells irradiated with 4 Gy were significantly increased compared with the unirradiated cells (P＜0.05 or P＜0.01),especially in CRAd.pE-Smac + hypoxia + 4 Gy irradiation group;the percentages of the cells at S and G2/M phases in irradiation groups were significantly increased (P＜ 0.05 or P＜0.01),which had the similar regularity with the apoptotic change.Conclusion:After the MDA-MB-231 cells are infected with the conditionally replicative adenovirus CRAd.pE-Smac and treated with hypoxia and irradiation,the triple-targeting Smac overexpression can be achieved,and it has the role of promoting the cancer cell apoptosis and inducing the G2/M arrest.
ABSTRACT
Recently,immunologists have payed the attention to the effects of ionizing radiation on tumor immunity,and attempted to induce and improve anti-tumor immune effects with it.More and more evidences showed that exact radiotherapy scheme and irradiation dose,particularly combined with immunotherapy,could induce or regulate systemic immune response and contributed to tumor control and inflammatory occurrence.This paper reviewed the effects and mechanisms of radiotherapy on tumor immune and the results in combination with immunotherapy here for guiding the effective combined application of radiotherapy and immunotherapy.
ABSTRACT
Objective To establish the MCF-7 cell models of Beclin 1 over-and low-expressions,and to detect the autophagic and apoptotic changes after 4 Gy irradiation,and to explore their molecular regulation mechanisms. Methods MCF-7,MCF-7 + 4Gy,MCF-7-Beclin 1 + 4Gy and MCF-7-Belcin 1 RNAi+ 4Gy groups were set up. Molecular biology method was used to construct Beclin 1 over-expression vector pcDNA3.1-Beclin 1,and to estabilish the Beclin 1 over- and low-expression cell models.After the cells were irradiated with 4 Gy, the autopahgic cell percentages were measured by fluorescence microscope with MDC staining, the apoptotic cell percentages were measured by FCM with AnnexinⅤ-FITC and PI staining,and the expressions of Beclin1,P53, Bcl-2 and Bax proteins were measured by Western blotting method.Results Compared with MCF-7 group,the autophagic and apoptotic cell percentages in MCF-7+4 Gy,MCF-7 Beclin 1 +4 Gy and MCF-7-Beclin 1 RNAi+4 Gy groups were significantly increased (P <0.05 or P <0.001 ),especially in MCF-7 Beclin 1+4 Gy group which was significantly higher than those in MCF-7 + 4 Gy (P < 0.05);while there was significant difference in the necrotic cell percentages between various groups. After 4 Gy irradiation, compared with MCF-7 group, the expression levels of Beclin 1,P53 and Bax proteins in MCF-7 + 4 Gy and MCF-7-Beclin 1 + 4 Gy groups were increased,but the expression levels of Bcl-2 protein were decreased,especially in MCF-7-Beclin 1 + 4 Gy group. Conclusion The MCF-7 cell models of Beclin 1 over-and low-expressions are successfully established,and ionizing radiation could induce the autophagy and apoptosis of MCF-7 cells,which is more obvious in Beclin 1 over-expression MCF-7 cells.Beclin 1 can activate P53,inhibit Bcl-2 and activate Bax,which forms the regulation of autophagy and apoptosis by P53 .
ABSTRACT
Objective To explore the mechanism of radio-resistance of breast cancer stem cells by investigating the effects of ionzing radiation on the reactive oxygen species (ROS),apoptosis and cycle distribution.Methods The breast cancer MCF-7 cells were suspension cultured in serum-free medium containing a variety of growth factors. There were MCF-7 (breast cancer cells),MCF-7-S (breast cancer stem cells),MCF-7+8 Gy and MCF-7-S+8 Gy groups in the experiment. 4-24 h after 8 Gy irradiation, the ROS levels, percentages of apoptotic cells and percentages of the cells at each cycle phage were measured by FCM with 2′, 7′-dichlorodihydrofluorescin diacetate (DCFH-DA ), Annexin Ⅴ-FITC/PI and PI staining, respectively. Results The breast cancer stem cell microsphere accumulated hundreds of cells were obtained successfully at 7 d after suspension culture with serum-free medium containing a variety of growth factors;the FCM results showed that CD44+CD24- phenotype breast stem cells were up to 75.20%.With the time prolongation,the ROS levels and apoptosis in MCF-7 group and MCF-7-S group showed increasing trendency, and reached for the maximum values at 12 and 24 h;the ROS levels in MCF-7-S group were significantly lower than those in MCF-7 group at 4,8,12 and 24 h (P<0.05 or P<0.01), and the percentage of apoptotic cells in MCF-7-S group was significantly higher than that in MCF-7 group only at 8 h(P<0.05);the ROS levels (4,8,12 and 24 h)and percentage of apoptotic cells(12 h)were significantly increased in MCF-7+8 Gy group (P<0.05),and the percentages of apoptotic cells (4,8,12 and 24 h)in MCF-7-S +8 Gy group were significantly decreased (P<0.05 or P<0.01),but the ROS levels had no obvious change in MCF-7-S+8 Gy.At 12 h,as compared with MCF-7 group,the percentages of the cells at G0/G1 phase and G2/M phase in MCF-7-S group were significantly decreased (P<0.05),and the percentage of the cells at S phase was significantly increased (P<0.05 );the percentage of the cells at G2/M phase in MCF-7+8 Gy group was significantly increased (P<0.05 ), but there were no significant changes in MCF-7-S+ 8 Gy group. Conclusion Ionizing irradiation can cause the increasing of ROS level and apoptosis and G2/M phase arrest in breast cancer cells,but has no obvious effects on the breast cancer stem cells;it indicates that radio-resistance might be related to ROS level,apoptosis and G2/M phase arrest.
ABSTRACT
Objective To construct the pshuttle-Egr-1-hSmac plasmid and transfect human breast cancer MDA-MB-435 cells,and to observe its radiotherapy enhancing effect on tumor cells.Methods The empty vector pshuttle and pshuttle-Egr-1-hSmac plasmid were transfected into MDA-MB-435 cells by liposomal.At different time(4,8,12,24 and 48 h)after irradiation with 2.0 Gy X-ray and 24 h after irradiation with 0.5 -5.0 Gy,the total RNA and protein were collected and extracted from these cells to analyze the Smac mRNA and protein expression levels with RT-PCR and Western blotting methods. The cells were divided into control, pshuttle, pshuttle-Egr-1-hSmac,2.0 Gy irradiation group, pshuttle + 2.0 Gy irradiation and pshuttle-Egr-1-hSmac+2.0 Gy irradiation groups.MTT method was used to evaluate cell proliferation,and the cell survival ability was measured with clone formation assay;Annexin Ⅴ/PI double staining and PI single staining were used to examine the apoptosis and cell cycle of MDA-MB-435 cells. Results There was no Smac mRNA expression in MDA-MB-435 cells in control and pshuttle groups,but the Smac mRNA expression levels in MDA-MB-435 cells in pshuttle-Egr-1-hSmac plasmid group were gradually increased with the time prolongation, and reached the maximum at 24 and 48 h;the Smac mRNA expression levels in MDA-MB-435 cells were increased gradually 24 h after irradiation of 0.5 - 5.0 Gy X-ray with the increasing of irradiation doses, and reached the maximum after 2.0 and 5.0 Gy irradiation. The Smac protein expression levels in pshuttle-Egr-1-hSmac plasmid group were increased gradually with the time prolongation,and reached the maximum at 24 h.The Smac protein expression lervels were increased 24 h afer irradiation of 0,0.5,1.0,2.0 and 5.0 Gy X-ray,especially in 5.0 Gy group. The MTT results showed that the A490 values in 2.0 Gy,pshuttle+2.0 Gy and pshuttle-Egr-1-hSmac groups 24, 48,and 72 h after irradiation were lower than those in control group(P<0.01);the A490 values of MDA-MB-435 cells in pshuttle-Egr-1-hSmac group after 1.0-5.0 Gy X-ray irradiation were lower than those in 0 Gy group (P<0.05 or P<0.01);the survival fraction(SF)in pshuttle-Egr-1-hSmac group was lower than those in control group (P<0.01).The percentages of the cells at G0/G1 and S phase in pshuttle-Egr-1-hSmac group were lower than those in 2.0 Gy group(P<0.01),the percentage of the cells at G2/M phase was higher than that in 2.0 Gy group (P<0.01);the apoptotic rate of the cells in pshuttle-Egr-1-hSmac group was higher than that in 2.0 Gy group (P<0.01).Conclusion X-ray irradiation can significantly increase the Smac mRNA and protein expression levels in MDA-MB-435 cells transfected with pshuttle-Egr-1-hSmac plasmid,inhibit the cell survival rate,and induce G2/M arrest and apoptotic increasing;Smac gene combined with radiotherapy could significantly increase the radiosensitivity of breast cancer cells.
ABSTRACT
Objective To construct the conditionally replicative adenovirus vector pAd-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K carrying early growth response gene-1 (Egr1)promoter and tumor necrosis factor related apoptosis inducing ligand (TRAIL)gene, and to observe the effects of the vector combined with 2 Gy irradiation on the TRAIL expression in MDA-MB-231 cells.Methods Egr-1 promotor sequence was cloned from pMD18 T-Egr1, TRAIL was constructed the downstream of Egr1 promoter, pShuttle-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K (CRAd.pEgr1-TRAIL)was constructed,after the adenovirus vector was packaged successfully,MDA-MB-231 cells were infected with them and irradiated with X-rays.Real time PCR method and ELISA were used to detect the expression levels of TRAIL mRNA and protein, respectively. Six groups in the experiment were set up:control, 2 Gy,CRAd.p,CRAd.pEgr1-TRAIL,CRAd.p + 2 Gy and CRAd.pEgr1-TRAIL + 2 Gy. Results The recombinant adenovirus vector pAd-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K was constructed and packaged successfully.The expression level of TRAIL mRNA in MDA-MB-231 cells transfected with the vector of 5 MOI for 24 h following 2.0 Gy X-rays irradiation began to increase and arrived to the top 8 h later in various groups,then declined.The expression level of TRAIL protein in MDA-MB-231 cells began to increase 6 h after irradiation and reached to the peak 24 h later,then declined 48 h later.There were significant differences in the expression levels of TRAIL protein between CRAd.pEgr1-TRAIL + 2.0 Gy and other groups at the same time point (P<0.01). Conclusion The recombinant adenovirus vector is obtained successfully, and the TRAIL mRNA and protein expression levels in MDA-MB-231 cells can be increased significantly by the vector combined with 2.0 Gy X-rays irradiation.
ABSTRACT
This study examined the effects of TRAIL-endostatin-based gene-radiotherapy on cellular growth, apoptosis and cell cycle progression in human vascular endothelial cells ECV304 in vitro. The expression of TRAIL and endostatin protein in ECV304 cells was detected by ELISA after the transfection of recombinant plasmid pshuttle-Egr1-shTRAIL-shES and X-ray irradiation. Then MTT assay was used for determining the cellular proliferation, and flow cytometry (FCM) plus Annexin V and propidium iodide (PI) double-staining or PI single-staining were employed for the detection of apoptosis and cell cycle progression. The results showed that expression of TRAIL and endostatin protein exhibited a time- and dose-dependent change in ECV304 cells after pshuttle-Egr1-shTRAIL-shES transfection in conjunction with irradiation. In the TRAIL-endostatin-based single- or double-gene-radiotherapy, the cell viability declined in a time- and dose-dependent manner, the percentage of cells at G(2)/M phase and apoptotic rate was increased, and the percentage of cells at G(0)/G(1) phase was lowered as compared with those receiving radiotherapy alone. Moreover, TRAIL-endostatin-based double-gene-radiotherapy demonstrated better effects on growth inhibition, promotion of apoptosis and induction of cell cycle arrest in ECV304 cells than single-gene-radiotherapy.
ABSTRACT
Objective To detect the inhibiting effects of ionizing radiation combined with inhibitors or inducer of autophagy and apoptosis on MCF7 cell line,and to provide the evidence for human breast cancer therapy radiation.Methods MCF7 cells were exposed to X-rays and randomly divided into 4 groups,including 0 Gy,4 Gy,4 Gy+rapamycin,4 Gy+3-MA,and 4 Gy+z-VAD-fmk groups,including 0 Gy,4 Gy,4 Gy+rapamycin,4 Gy+3-MA,and 4 Gy+z-VAD-fmk groups,respectively.The growth doubling time was calculated by MTT method.The specific protein expressions of LC3 autophagy and beclinl were detected by using Western blot and the difference of Drotein contents wasLC3 autophagy and beclinl were detected by using Western blot and the difference of Drotein contents was compared.The percentage of apoptosis of MCF7 cells was measured by flow cytometry (FCM).Resuits The growth doubling time of MCF7 cells in 4 Gy group wag longer than that in O Gy group(t=4.41,P<O.05),but shorter than that in 4 Gy+rapamycin group(t=4.35,P<0.05).Compared to 4 Gy+rapamycin group,both of the growth doubling time in 4 Gy+3-MA and 4 Gy+z-VAD-fmk groups were shorter(t=4.32,P<O.05).The expressions of beclinl and LC3-Ⅱ proteins in 4 Gy+rapamycin group were the highest,while those in 4 Gy+3-MA group the lowest.Except for 4 Gy+3-MA and 4 Gv+z-VAD-fmk groups,there were significant differences among the other groups in two protein expressions(t=3.9 1-4.78,P<0.05).Conclusions Ionizing radiation could induce MCF7 cell autophagy,ptomote the apoptosis of tumor ceils in combination with autophagy inducer.Ionizing radiation combined with autophagy inhibitor might inhibit the development of autophagy,and delay the apoptosis of tumor cells.
ABSTRACT
Objective To explore the effect of multiple low dose radiation(LDR)on the apoptosis of splenocytes and immune factors in diabetes mellitus(DM)rats.Methods The rats were randomly divided into control,DM and DM + LDR groups.The irradiation doses were 25,50 and 75 mGy,and the irradiated times were 15.At the fourth weekend after the DM rats irradiated,the apoptotie rate and TCRαβ percentage of splenoeytes were detected by flow cytometry,and the content of IL-2 in both serum and supernatant of cultured splenocytes were detected by ELISA.Results Compared with that in the control,the body weight(BW)decreased in the DM and DM + LDR groups,particularly in DM group.The blood glucose(BG)level in the DM + LDR groups was higher than that in the control,but decreased significantly as compared with that in the DM group(P < 0.01).As compared with those in the control,the apoptotic rate in DM + 50 mGy(P < 0.05)and the content of serum IL-2 in DM + 75 mGy group(P < 0.01)all increased significantly,while the content of IL-2 in supernatant of cultured splenocytes decreased significantly in the DM + LDR groups.Compared with those in the DM group,the apoptotic rate and the percentage of TCRαβ in splenocytes in the DM + LDR groups(P < 0.01-P < 0.001)and the content of IL-2 in serum in DM + 50 mGy group(P < 0.01)decreased significantly.Conclusions The multiple LDR could weaken the loss of BW and increase of BG caused by DM,decrease the splenocyte apoptosis induced by DM,and regulate the immune factors.
ABSTRACT
Objective To explore the effects of 75 mGy irradiation on the apoptosis of spermatogenic cells and antioxidant capacity of serum and testis and hormone levels in male rats with diabetes mellitus(DM).Methods Rats were injected intraperitoneally with streptozotocin(STZ)to develop diabetes.The diabetic rats were irradiated with 75 mGy X-rays every other day for 4 weeks.Their survival rate and body weight were recorded 12 weeks after development of diabetes.The apeptosis percentage of germ cells was measured with flow cytometry and TUNEL method.The changes of anti-oxidation and gonadal hormone levels in serum and testis were measured with kits.Results After the rats suffered from diabetes for 12 weeks,the survival rate in DM group was 25%(6/24),100% in normal control group(16116).The survival rate in 75 mGy + DM group(9/16,56.25%)was obviously higher than that in the DM group(X2= 4.00,P < 0.05).Meanwhile,the percentage of apaptotic spermatogenic cells in the diabetic rats was significantly larger than those in the normal control and irradiation groups(F = 5.496,P < 0.05).MDA and NO levels in serum and testis of diabetic rats were higher in varying degrees than that in the normal control,while the serum and testis MDA content in the 75 mGy + DM group were lower than those in the DM group especially in the testis(F = 10.644,P < 0.01).75 mGy X-ray irradiation decreased NO content in the diabetic rats serum significantly(F = 14.379,P < 0.05)and increased NOS activity and TS,FSH level(F = 9.676,43.194 and 5.282,respectively,P < 0.05 and P < 0.01).Conclusions LDR could decrease the MDA level and NO content,and increase the antioxidant enzyme activity and TS and FSH levels in testis and serum of diabetic rats.
ABSTRACT
Objective To observe the effects of 3,4,5-trihydroxybenzoic acid dimmer (TAD) in different doses on apoptosis and cell cycle progression of liver cancer SMMC-7721 cells in vitro and explore its possible mechanism of inhibiting tumor growth.Methods The experiment was divided into 0,3.125,6.250,12.500 and 25.000 ?g TAD groups. Apoptosis was observed with JEM-1200EX transmission electron microscope (TEM).The changes of apoptosis and cell cycle progression were measured with flow cytometry.Results The typical features of apoptosis were found in tumor cells,the nuclei were broken to pieces,mitochondrion cristae were disrupted and vacuoles were showed in nucleus and cytoplasm in 25.000 ?g TAD group observed under TEM.Meantime,the apoptotic percentages of the cells treated with 3.125—25.000 ?g TAD were increased significantly as compared with control group (P
ABSTRACT
Objective To study the changes of apoptosis and cell cycle progression of Hela cells after the poly(ADP-ribose) polymerase(PARP) was inhibited by its inhibitor 3-aminobenzamid(3-AB) and the mechanisms of PARP interaction with Hela cells damaged by irradiation.Methods Hela cell line was used.Flow cytometry(FCM) was used to examine the PARP expression of control and 3-AB groups at 0,2,4,8,12 h after administration with 5 mmol?L-1 3-AB.The percentage of apoptotic cells and cell cycle progression of control,irradiation,3-AB plus irradiation groups were measured with FCM at 2,8,12,24 h after exposure to 2 Gy irradiation following administration with 5 mmol?L-1 3-AB.Results The percentage of Hela cells with positive expression of PARP protein decreased after administration with 3-AB and there was significant difference between 3-AB plus irradiation group and control group(P
ABSTRACT
Objective To observe the effects of purified product trihydroxybenzoic acid dimmer in different doses from Trapa manshurica Fler on apoptosis and cell cycle progression of liver cancer SMMC-7721 cells in vitro and explore its possible mechanism of inhibiting tumor growth. Methods The changes of apoptosis and cell cycle progression were measured with flow cytometry. Results The apoptotic percentages of the cells treated with the purified products with doses of 3.125, 6.250, 12.500 and 25.000 mg?L~ -1 increased significantly as compared with that in the control (P
ABSTRACT
BACKGROUND: Stem cells, cells with special function in animals and humans, exist in various tissues. Most of stem cells differentiate into special tissue organs and some of them remain in the status of stem cells for tissue repair. Mesenchymal stem cells were transplanted to burn wounds in some researches for inducing the proliferation and activation of skin stem cells so as to cure burn.OBJECTIVE: To observe the effect of stem cell culture medium cultured in vitro instilled locally into the severely traumatic skin in guinea pigs on healing time and healing degree of the wound.DESIGN: Random grouping and blank control trial.SETTING: Department of Toxicology, School of Public Health, Jilin University.MATERIALS: Totally 14 adult healthy guinea pigs of either gender weighing 300 to 350 g were recruited.METHODS: The experiment was conducted in the Laboratory of Toxicology Department, School of Public Health, Jilin University, from March to September 2003. Ten guinea pigs were put to death by bloodletting on the neck. The bone marrow was extracted and cultured in unicellular supematant fluid for use. The 14 guinea pigs were made into models of bilateral severe skin trauma.Ten of the guinea pigs were chosen randomly, stem cell culture was instilled into one side of the animals (stem cell group), while the culture medium was instilled into the other side of the animals (culture medium group). The remaining 4 guinea pigs that received no treatment were blank control group.Three days later, transparent lucite was put on the wound every other day for drawing the shape and observing the wound. After the shape was copied onto the transparent lucite, the wound area was worked out on the rectangular coordinate paper and the speed of wound healing was calculated.MAIN OUTCOME MEASURES: Gross observation was performed on the healing status of the wound and average healing time and speed of the guinea pigs in each group.wound healing status of the guinea pigs in each group: At day 3, the wound in stem cell group was dry without obvious exudation. There was a layer of membrane at the bottom of the wound and it stuck to the pledget closely so that the dressing could not easily be removed. The wound status in the culture medium was practically the same as that of the stem cells, but no membrane-ike material was formed and the dressing was easily removed. Inflammation appeared obviously in blank control group.nificantly less in stem cell group than in culture medium group and blank control group [(12.45±2.18) days vs (26.29±1.38) days and ＞ 30It was obviously faster in stem cell group than in culture medium group and blank control group [(40.42±2.14) mm2 per day vs (15.53±5.22) mm2 per day and(10.27±4.57) mm2 per day,P ＜ 0.05].CONCLUSION: The stem cells of homologous animals were instilled on the skin surface to repair injury wound. Stem cells can grow on the wound and transform into skin cells, which promotes the recovery of wounded skin. Therefore, it is feasible to treat severe skin defect with stem cells.
ABSTRACT
Diabetes is a metabolic disease caused by complicated factors, and its damage to the male reproductive system is threatening men's health. This article reviews the pathophysiological changes in the diabetes-damaged male reproductive system and the mechanism of these changes. Oxidative stress induced by hyperglycemia plays an important role in working damage to the reproductive system of diabetic males, for which some anti-oxidative substances may prove to be an effective cure.
Subject(s)
Animals , Humans , Male , Rats , Androgen-Binding Protein , Diabetes Mellitus , Pathology , Free Radicals , Leydig Cells , Metabolism , Oxidative Stress , Sertoli Cells , Bodily Secretions , Testis , Pathology , TestosteroneABSTRACT
Objective: In the present study we observed the general pattern of the adaptive response of thymocyte apoptosis and cell cycle progression induced by low dose radiation (LDR). Methods: Kunming male mice were irradiated with the inductive dose (D1, 75 mGy) and the challenging dose (D2, 1.5 Gy). The intervals between D1 and D2 were 3, 6, 12, 24 and 60 hours. The changes of thymocyte apoptotic bodies (TAB) and cell cycle progression were measured with flow cytometry with the thymocytes cultured for 4, 20 and 44 hours, respectively, 18 hours after irradiation with D2. Results: When the intervals between D1 and D2 were 3, 6 and 12 hours, the percentages of TAB in the D1 + D2 groups in the thymocytes cultured for 4 and 20 hours were significantly lower than those in the D2 groups (P<0.05) and the percentages of G0/G1 and G2 + M phase cells decreased in varying degrees, while the percentages of S phase cells increased significantly (P<0.05 or P<0.01). Conclusion: The results mentioned above indicate that when the mice were irradiated with 75 mGy (D1, 12.5 mGy/min) 3～12 hours before 1.5 Gy (D2, 0.285 Gy/min) exposure, the adaptive response of apoptosis and cell cycle progression may be induced with the thymocytes cultured for 4 and 20 hours after whole-body irradiation with D2.
ABSTRACT
Objective:To study effects of large dose thymopeptides on T cell subpopulations of patients with malignant tumor under radiotherapy.Methods:Fifty one patients with malignant tumor under radiotherapy were divided into 2 groups with 100 mg and 200 mg thymopeptides respectively.The patients we re given thymopeptides,100 mg/d or 200 mg/d,iv, for 10 days.The positive percent ages of CD4,CD8,CD25 and CD56 in T cells of peripheral blood before and after thymopeptide treatment were determined by flow cytometry.Results:The positive percentages of CD4 and CD25 in T cells of peripheral bl ood after 100 mg/d thymopeptide treatment were significantly higher than those befor e thymopeptide treatment (P<0.05),while those of CD4，CD8，CD25 and CD56 in T cells of peripheral blood after 200 mg/d thymopeptide treatment all increased significantly (P<0.05 or P<0.01). Conclusion:These results suggest that large dose of thymopeptides can increase i mmune function of patients with malignant tumor under radiotherapy,and the curat ive effect of 200 mg/d thymopeptides is better.
ABSTRACT
AIM: The effect of low dose radiation (LDR) with different doses of X-rays on apoptosis and its related gene P53 expression were studied in spermatogenic cells of male Kunming mouse testis. METHODS: The different kinds of spermatogenic cells were separated using density gradient centrifugation and their apoptosis was measured by flow cytometry. At meantime, P53 protein and P53 mRNA was measured with immunohistochemical SABC and in situ hybridization, respectively. RESULTS: The apoptosis in all kinds of spermatogenic cells induced by LDR had a remarkable regularity. When the doses were 0 025 and 0 05 Gy, spermatogone apoptosis was domaint. With the increase in irradiation dose (0 075-0 2 Gy), spermatocytes also showed an apoptotic change, but the apoptotic percentage of spermatogonia was significantly higher than that of spermatocytes. Moreover, the apoptosis of spermatids and spermatozoa scarely occurred after LDR. P53 protein expressed in spermatogonia and spermatocytes in varying degrees, and the former was significantly higher than that of the latter after LDR. With the increase in irradiation dose, P53 protein expression showed a upregulated tendency, but that of spermatids and spermatozoa scarcely occurred. P53 mRNA primarily expressed in spermatids and spermatocytes when the dose was 0 025 Gy. With the increase in irradiation doses (0 05-0 2 Gy), that of spermatogonia also showed an enhancement. P53 mRNA expression in spermatogonia and spermatocytes showed a remarkable dose-effect relationship. CONCLUSION: The apoptosis of spermatogenic cells was selectively induced by LDR of X-rays, which had remarkable the dose-effect and time-effect relationships. The mechanism of the selective apoptosis in spermatogenic cells by LDR is closely related to the upregulation of P53 .
ABSTRACT
Objective:In present study we observed the effect of whole body irradiation (WBI) with 75 mGy X-rays on the immune function of tumor-bearing mice.Methods:Lewis lung carcinoma cells were implanted into the right thigh muscle of C57BL/6J mice.Ten days after tumor implantation,the tumor-bearing mice were administrated with 75 mGy X-rays WBI,then the mice were sacrificed 18 h after irradiation to detect the immune parameters including the spontaneous proliferation of thymocytes,the proliferative response of splenocytes to ConA and LPS,the cytotoxic activities of specific cytotoxic lymphocytes (CTL) and natural killer cells (NK),as well as lymphokine activated killer cells (LAK) in spleen.The methods we used were 3H-TdR incorporation or release assay.Results:The immune parameters of exposed tumor-bearing mice were much higher than those of sham-irradiated tumor-bearing mice (P<0.01).Conclusion:These results suggested that low dose radiation (LDR) could enhance the immune function of tumor-bearing mice,which might be of practical significance in the prevention and therapy of cancer.
ABSTRACT
AIM: To explore the effect of melatonin (MLT) on the apoptosis of thymocytes and splenocytes in mice induced by ionizing radiation and its mechanism. METHODS: The percentages of apoptotic bodies and the DNA lytic rates of thymocytes and splenocytes in mice in vitro and in vivo were detected with flow cytometry and fluorospectrophotometry, respectively. RESULTS: The apoptosis of mouse thymocytes and splenocytes in vitro increased with significant dose-dependence in 0 5-6 0 Gy X-irradiation. When MLT of 2 mmol?L -1 was added into thymocytes or splenocytes in vitro before irradiation with 0 5-6 0 Gy X-rays, the percentages of apoptotic bodies and the DNA lytic rates all decreased significantly as compared with those in the irradiation group. The percentages of apoptotic bodies in these two kinds of cells were 86 25% and 89 22% of those in the irradiation group, respectively, and the DNA lytic rates were 87 23% and 89 16%, respectively. When MLT was injected into intraperitonium in mice 60 min before whole-body irradiation with 2 Gy X-rays, the percentages of apoptotic bodies and the DNA lytic rates were significantly lower than those in the irradiation group, and near or lower than those in the sham-irradiation group. MLT of 0 1-2 5 mg/kg decreased the lymphocyte apoptosis, but without significant dose-dependence. CONCLUSION: The protective effects of MLT on mouse lymphocytes damaged by irradiation in vivo are obvious than those in vitro. [