RESUMO
@#[Abstract] Objective: To investigate the effect of double oxidase 2 (DUOX2) on the sensitivity of colorectal cancer (CRC) cells to 5-fluorouracil (5-FU). Methods: CRC cell lines DLD-1, SW480, HCT116, SW620 and normal intestinal epithelial cell line NCM460 were selected, and the expression of DUOX2 in these cell lines were detected by qPCR. DUOX2 expression in HT-29 and HCT116 cells was stably knocked down by lentivirus infection technique. The knockdown efficiency was detected by qPCR and WB. Cells in sh-Control and sh-DUOX2 groups were treated with 5-FU at different concentrations (0, 5, 10, 20, 40, 80, 120 μg/ml). The effects of 5-FU on cell proliferation, apoptosis and cell cycle were detected by CCK-8 method and flow cytometry. HT29 cell transplanted xenograft model in nude mice was constructed to observe the effect of DUOX2 gene on the treatment efficacy of 5-FU. Results: the expression level of DUOX2 mRNA in CRC cells was significantly higher than that in NCM460 cells (P<0.05 or P<0.01). Compared with sh-Control group, the mRNA and protein expressions of DUOX2 in sh-DUOX2 group were significantly decreased (all P<0.01); the sensitivity of cells to 5-FU was enhanced, the apoptosis rate and the ratio of cells at G0/G1 phase were significantly increased (all P<0.01), and the ratio of cells at G2 and S phase was significantly decreased (all P<0.01). There was no significant difference in tumor volume and mass between sh-Control group and sh-DUOX2 group without 5-FU treatment (all P>0.05), but the volume and mass of transplanted tumor in sh-DUOX2+5-FU group after 5-FU treatment was significantly lower than that in sh-Control+5-FU group (all P<0.01). Conclusion: The sensitivity of CRC cells to 5-FU can be significantly enhanced by knocking down DUOX2 gene.
RESUMO
Objective:To investigate the effect of oxymatrine (OMT) on the proliferation and migration of human colon cancer cell line HT-29 under Type Ⅱ diabetes environment by co-culturing HT-29 with insulin to simulate hyperinsulinemia. Method:The effect of OMT (2, 4, 8 mmol·L-1) on insulin-induced proliferation of HT-29 was detected by methyl thiazolyl tetrazolium (MTT) assay and cloning assay. The morphology change and cell migration were evaluated under microscope and by wound healing assay. The Annexin V/propidium iodide(PI) assay was used to detect the change of insulin-induced HT-29 cell cycle and apoptosis. Western blot was performed to validate the expression of cell cycle-related protein and cell migration protein. Result:Insulin significantly increased growth of HT-29 (P-1 showed a significant inhibitory effect in this model (P0/G1 phase (P1, CDK4 and the up-regulation of p27 by OMT might involve the growth inhibition mechanism. Furthermore, OMT reduced the migration of insulin-induced HT-29 according to wound healing assay(PPPConclusion:OMT can inhibit the proliferation and migration of insulin-induced HT-29 cells. The changes of cell cycle and migration related proteins may be correlated with the mechanism.
RESUMO
@# Objective: To investigate the effect and mechanism of polysaccharide of atractylodes macrocephala (PAM) on the growth of colon cancer cells in mice bearing in-situ colon cancer transplantation tumor. Methods: 1×107 colon cancer HT-29 cells labeled with luciferase were injected into colon serosa of the mice to establish the in-situ colon cancer transplantation tumor model. When the tumor volume reached 230 mm3, the mice were given 30 mg/kg PAM (PAM group) or equal volume of normal saline (Control group) by gavage for 10 consecutive days. The effect of PAM on the growth of colon cancer cells in mice was tested by in vivo tumor imaging technology. The expressions of MHCII and IL-12 in granulocytes, dendritic cells and macrophages, the activation of lymphocytes, and IFN-γ expression in CD4+ and CD8+ cells of tumor tissues were detected by Flow cytometry. Results: PAM significantly inhibited the growth of colon cancer cells in mice bearing in-situ colon cancer transplantation tumor (P<0.01). PAM activated immune cells though increasing the expression levels of MHCII and IL-12 in dendritic cells and macrophages (both P<0.01). PAM significantly increased the frequency of CD8+ cells, NK cells, CD44+/NK cells and CD44+/CD4+ cells in tumor tissues and the number of CD8+ cells and NK cells per unit volume (all P<0.01). PAM significantly increased the IFN-γ secretion of CD4+ and CD8+ cells (both P<0.01), too. Conclusion: PAM inhibits the growth of colon cancer by activating immune cells in tumor tissues of mice bearing in-situ colon cancer transplantation tumor.
RESUMO
@# Objective: To investigate the therapeutic effect of dendritic cell-induced killer cells (DC-CIK) combined with 5-fluorouracil (5-FU) and loaded with CD133+ HT-29 cell lysate or RNA on mice bearing colon cancer HT-29 cell transplanted tumor, and to explore the underlying mechanism. Methods: Colon cancer xenograft model was established in BALB /c nude mice by using human colon cancer HT-29 cells at logarithmic growth phase; Antigen-free DC-CIK, 5-FU+DC-CIK, R+DC-CIK (loaded with total RNA of CD133+ cells), L+DC-CIK (loaded with CD133+ cell lysate), 5-FU and normal saline were respectively injected into transplanted mice, and the treatment efficacies on the growth of transplanted tumor in each group after three treatment cycles were observed, and the tumor growth curve was drawn. The nude mice were sacrificed by cervical dislocation and the tumor volume and body weight were measured. qPCR was used to detect the expression of AKT mRNA in transplanted tumor tissue, and WB was used to detect the expression of phosphorylated AKT protein. Results: After treatment, the body mass of nude mice in R+DC-CIK group, L+DC-CIK group and 5-FU+DC-CIK group increased steadily, while the body mass of nude mice in DC-CIK group and 5-FU group decreased gradually; the tumor growth speed of nude mice in R+DC-CIK group, 5-FU+DC-CIK group and L+DC-CIK group was significantly slower than that of the control group (P<0.05). Compared with 5-FU and DC-CIK alone, the combined treatment with loaded lysate/RNA had more sig nificant effect on mRNA and protein expressions of AKT(P<0.05). Conclusion: The effect of DC-CIKwithdifferentloadingoritscombinationwith5-FUisbetterthanthatofchemotherapy alone. One of the mechanisms is related to the down-regulation ofAKT level.
RESUMO
@# Objective: To investigate the effect of astragalus polysaccharides (APS) on proliferation, invasion, apoptosis and drugresistance of cisplatin-resistant colorectal cancer (CRC) HT-29/DDP cells through regulating miR-20a/TGFBR2 axis, and to explore the possible mechanism. Methods: Human CRC HT-29 cells and HT-29/DDP cells were used as non-drug resistant and resistant cell models, respectively; HT-29/DDP cells were randomly divided into four groups, including untreated (HT-29/DDP) group, APS treatment group, miR-20a mimics + APS group, and si-TGFBR2 + APS group. qPCR and Western blotting were applied to detect the expressions of miR-20a and TGFBR2 in HT-29/DDP cells treated with different concentrations ofAPS (0, 0.5, 1.0, 1.5 and 2.0 mg/ml). Subsequently, dual luciferase reporter gene assay was used to verify whether TGFBR2 was a target gene of miR-20a. In addition, CCK-8, Transwell andAnnexin V-FITC/PI double staining were applied to examine the effect ofAPS on proliferation, invasion and apoptosis of HT29/DDP cells. Furthermore, subcutaneous HT-29/DDP cell xenograft model was established on nude mice, and the effect ofAPS on the growth of transplanted tumor was observed. Results: APS significantly inhibited the proliferation of HT-29/DDP cells in a dose-dependent manner (P<0.01). Meanwhile, the expression of miR-20a was down-regulated in HT-29/DDP cells treated with APS, while the expression of TGFBR2 was significantly up-regulated (all P<0.01). Additionally, dual luciferase reporter gene assay result showed that TGFBR2 was a direct target of miR-20a in HT-29/DDP cells and its expression was suppressed. Furthermore, APS could enhance the drug sensitivity of HT-29/DDP cells through downregulating the inhibitory effect of miR-20a on TGFBR2 expression, thereby suppressed proliferation and invasion, and induced apoptosis of HT-29/DDP cells in vitro and in vivo. It was also found that this effect was related with the suppression of PCNA and Bcl-2 proteins and promotion of Bax and Caspase-3 proteins. Conclusion: APS reverses the resistance of HT-29/DDPcells to cisplatin by down-regulating the inhibitory effect of miR-20a on TGFBR2 expression.
RESUMO
OBJECTIVE:To study the effect and its mechanism of Fuzheng Jiedu Quyu formula(short forFuzheng formula) combined with oxaliplatin (L-OHP) on human colon cancer HT-29 cell proliferation and apoptosis. METHODS:HT-29 cells were divided into blank control group(without drugs),Fuzheng formula group(1000 mg/L),L-OHP group(31.25 mg/L)and combi-nation group (1000 mg/L Fuzheng formula+31.25 mg/L L-OHP). After cultured with corresponding drug for 48 h,MTT method was used to detect the cell proliferation;the changes of cellular morphology were observed by invert microscope;flow cytometry was used to detect the cell cycle and apoptosis rate. Proapoptotic gene Bax,apoptotic gene Bcl-2 mRNA expressions were deter-mined by real-time fluorescence quantitative polymerase chain reaction method;Bax,Bcl-2 protein expressions were assayed by Western blot. RESULTS:Compared with blank control group,cell proliferation was inhibited in L-OHP group and combination group;cell proportion was increased in S stage,G2/M stage and decreased in G0/G1 stage(P<0.05). Cell apoptosis rate in L-OHP group,Fuzheng formula group and combination group was increased;Bax mRNA and protein expression were up-regulated,Bcl-2 mRNA expression was downregulated(P<0.05);and combination group changed more obviously than the single drug groups(P<0.05). CONCLUSIONS:Fuzheng formula combined with L-OHP can inhibit HT-29 cell proliferation and promote its apoptosis, showing better effects than either of the two drugs alone. The mechanism may be associated with up-regulation of Bax gene and pro-tein expressions and down-regulation of Bcl-2 gene expressions in cells.
RESUMO
Background:Ulcerative colitis-associated colorectal cancer(UcCRC)is the most serious complication of ulcerative colitis(UC). 5-Aminosalicylic acid(5-ASA)could reduce the risk of UC progressing to UcCRC. Aims:To investigate the effect of 5-ASA on cell proliferation,apoptosis and cell cycle in human colon cancer cell line HT-29 for verifying the inhibitory effect of 5-ASA on UcCRC. Methods:HT-29 cells were treated with different concentrations(0,10,20,30, 40 mmol/ L)of 5-ASA. Cell proliferation was measured by CCK-8 assay. Cell apoptosis was determined by TUNEL method. Cell cycle was analyzed by flow cytometry. Expressions of cell mitotic regulators AuroraB and BubR1 were determined by immunohistochemistry. Results:Proliferation inhibition rates and apoptosis rates of HT-29 cells in 5-ASA 10,20,30,40 mmol/ L groups were increased with increase in concentration of 5-ASA(P ﹤ 0. 05). Proportions of cells in phase G0 / G1 in 5-ASA 30,40 mmol/ L groups were significantly lower than those in 5-ASA 0,10,20 mmol/ L groups (P ﹤ 0. 05);proportions of cells in phase S in 5-ASA 0,10,20,30 mmol/ L groups were significantly lower than that in 5-ASA 40 mmol/ L group(P ﹤ 0. 05);while proportions of cells in phase G2 / M in 5-ASA 30,40 mmol/ L groups were significantly higher than those in 5-ASA 0,10,20 mmol/ L groups(P ﹤ 0. 05). Mean optical density(MOD)values of AuroraB and BubR1 were decreased with increase in concentration of 5-ASA(P ﹤ 0. 05). Concentration of 5-ASA was positively correlated with proliferation inhibition rate and apoptosis rate of HT-29 cells(P ﹤ 0. 05),but was negatively correlated with MOD values of AuroraB and BubR1( P ﹤ 0. 05). MOD values of AuroraB and BubR1 were negatively correlated with proliferation inhibition rate and apoptosis rate of HT-29 cells as well as proportion of cells in phase G2/ M (P ﹤0. 05),but were positively correlated with proportion of cells in phase G0/ G1(P ﹤0. 05). MOD value of AuroraB was positively correlated with MOD value of BubR1(P ﹤ 0. 05). Conclusions:5-ASA can inhibit proliferation and induce apoptosis in HT-29 cells,the mechanism may be related to inhibiting expressions of AuroraB and BubR1 and the resulted effect on cell cycle.
RESUMO
Aim To investigate the anti-angiogenesis and anti-xenograftes of UA in zebrafish larvaes. Meth-ods 24 hour post-fertilization ( hpf ) TG zebrafish was treated with different concentration of UA for 24h, and the number of intersegmental vessels( IVS) were detec-ted under fluorescent microscope respectively;then the models of AB/TG zebrafish xenografts were established by be micro-injected with SMMC-7721 or HT-29 cell at 48hpf respectively, and after cocultured with UA for 48h, optical density (OD) of the SMMC-7721 cell and subintestinal veins ( SIVs) induced by HT-29 were e-valuated under confocal microscope. Results ISV as-say showed that UA could cause IVS missing or disap-perance, inhibition ratio reaching 20. 25% and 26. 65%. UA blocked the spread of SMMC-7721 cells in zebrafish and OD value,and inhibition ratios at three concentrations were 38. 01%, 54. 69%, 61. 88%, re-spectively; in another SIVs assay induced by xeno-grafts, UA at concentration 10 and 15mg·L-1 showed that SIVs were inhibited (P<0. 01) obviously. Con-clusion UA could inhibit the angiogenesis and the growth of SMMC-7721/HT-29 xenografts,and the anti-tumor mechanism may be related with VEGFR2 expres-sion.
RESUMO
Objective To establish chicken embryo transplantation model of human colon cancer and to research the effect of so‐lanine on angiogenesis .Methods Cases with chicken embryos were divided into the low‐,mid‐and high dose solanine group and con‐trol group ,with 10 cases in each groups ,and then the cultured human colon cancer cell line HT‐29 cell lines were inoculated to the chicken embryo villus allantois membrane (CAM ) .We observed the characteristics of the transplanted tumor in CAM angiogenesis by the stereo microscope .Image analysis software of Image‐pro plus 6 .0 and immunohistochemical method were used to observe the effect of different dose of solanine on angiogenesis .Results HT‐29 cell lines were inoculated to CAM 3-5 days ,a large number of blood vessels concentrated in tumors ,growing into or acrossing the surface of tumors .While tumors also rapidly growed .We took photo on the 5th day after receiving medicine and did imaging analysis .Then we calculated the area of angiogenesis in experimental group ,which was significantly lower than that of the control group ,quantitatively in a dose‐dependent manner .There were signifi‐cant differences among the groups(P<0 .01) .Microvascular density of 3 different dose of solanine was significantly lower than that of the control group by immunohistochemical method ;the expression of Ki‐67 antigen index decreased gradually ,which was highest in the control group ,and there were significant differences among the groups (P<0 .01) .Conclusion Solanine could inhibit angio‐genesis induced by human colon cancer HT‐29 cell lines obviously ,thus inhibiting the growth of tumor and providing an important basis for the treatment of anti‐tumor angiogenesis .
RESUMO
Objective To explore the effects of silencing Livin gene by RNA interference mediated by lentiviral vector on colorectal cancer HT-29 cell xenograft growth and sensitivity to radiotherapy in nude mice.Methods BALB/c nude mice models were established by subcutaneously inoculating differently treated HT-29 cells into nude mice and the tumor growth situation of tumors was observed by measuring the volume of tumors and the weight of the nude mice at different time points after cell seeding.Livin expression was detected by RT-PCR and immunohistochemistry,respetively.Apoptosis rate was detected by TUNEL.Normal saline,lentivirus carring unrelated sequences,lentivirus caning Livin shRNA were injected intratumorally.All the nude mice were given 10 Gy of 6 MV X-ray irradiation.The changes of mice weight and the tumor volume were measured at different time points and the weight and tumor growth curves were drawn.Results The inhibition rate of tumor volume was(50.04 ± 0.07)％ and the tumor weight of the RNA interfering group was significantly less than that in experimental group compared to the blank and negative groups(F=4.85,P＜0.05),and the inhibition rate of tumor weight was(50.27 ±0.17)％.Relative Livin mRNA expression level in the RNA interfering experimental group was(17.75 ±0.08)％,and was significantly lower than that of the blank group(67.60 ± 0.05)％ and the negative group(68.54 ± 0.03)％(F=89.97,P＜0.01).Livin protein expression level in the RNA inferring group was also significantly lower[(36.00 ± 3.40)％ versus(85.00 ± 3.15)％,(80.33 ± 3.08)％,F=107.32,P＜0.01].The apoptosis rate in the RNA interfering experimental group was significantly higher than that in the blank and the negative groups[(23.67 ± 2.25)％ versus(5.00 ± 1.50)％,(8.33 ± 1.82)％,F=56.94,P＜0.01].Combined with radiotherapy,the tumor volume at different groups had significant difference(F=10.70,P＜0.01),and RNA interfering group was significantly less than negative group and blank group(F=7.01-9.32,P＜0.01).Conclusions Silencing of Livin gene expression by lentiviral vector-mediated RNA interference could inhibit the growth of colorectal HT-29 cell xenograft and increase the sensitivity of the transplanted tumors to radiotherapy.
RESUMO
Objective To study the effects of Irinotecan (CPT-11) on human colorectal cancer HCT-116 and HT-29 cells and investigate the potential mechanisms.Methods The effect of Irinotecan on the proliferation of HCT-116 and HT-29 cells was determined by MTT assays.The invasive capacity was measured by transwell assays,and the apoptosis of the tumor cells was detected by flow cytometry after stained with Annexin-V and PI.The difference between the current of ATP-sensitive potassium ion of HCT-116 and HT-29 was examined by patch clamp.Results It was found that 1.0-64.0 μg/ml CPT-11 could inhibit the proliferation and the invasive capacity of HCT-116 and HT-29 cells at both dose-and time-dependent manner.The IC_(50) of HCT-116 and HT-29 were 39.3 and 19.5 μg/ml respectively.Cytometry showed that the apoptotic rates were increased from 14.8% and 9.3% to 36.9% and 27.9% after the treatment of 32.0 μg/ml and 16.0 μg/ ml CPT-11,which were close to their IC_(50).The proportion of G_0/G_1 and S of HCT-116 and HT-29 was enhanced from 27.4% and 17.4% to 95.9% and 98.2%.Transwell assay indicated that the invasiveness of HCT-116 and HT-29 was reduced by 40.8% and 47.5%.The patch clamp showed that CPT-11 reduced the I_(KATP) of cell membrane at a negative dose-dependent manner.Conclusion CPT-11 could have a significant impact on the proliferation,invasiveness,cell cycle,and the apoptosis of human colorectal cancer cell HCT-116 and HT-29.HT-29 was more sensitive to CPT-11 than HCT-116.The inhibitory effect of CPT-11 on cell proliferation might be linked to its inhibition of ATPsensitive potassium channel.
RESUMO
Aim To explore the effects of DADS in the cell cycle of HT-29 cells. Methods HT-29 cells growth inhibition were measured by MTT assay and cell counting. Phase distribution of cell cycle was analyzed by flow cytometry. Expression of p21~(Waf1),C-myc,Cyclin E was determined by immunohisto- chemistry analysis. Results MTT assay showed that DADS significantly inhibited HT-29 cells and exhibited a time, dose- dependent model. Adding 60 ?mol?L~(-1) and 120 ?mol?L~(-1) DADS for 24 h suppressed HT-29 growth by 23.1%,45.6% respectively. Cell counting showed that average doubling time retarded from 22.58 h in normal cultured HT-29 cells to 31.2 h in 60umol?L~(-1) DADS experimented HT-29 cells(P
RESUMO
Aim To study the effect of emodin on IL-8 secretion and NF-?B activation of HT-29 cells,and explore the molecular mechanism of emodin.Methods The cytotoxicity of emodin was assessed by WST;NF-?B activation was detected with co-focal microscopy by immunofluorescence;the production of IL-8 was investigated by ELISA.Results Emodin with the concentration of 10~80 ?mol?L-1 could decrease the mass production of IL-8 Secretion of HT-29 cells stimulated by IFN-?+LPS in a dose-dependent manner.Emodin with various concentrations could inhibit NF-?B activation dose-dependently.Conclusions Emodin inhibited IL-8 secretion and NF-?B activation of HT-29 cells stimulated by IFN-?+LPS.
RESUMO
Objective To study the effect of a selective COX-2 inhibitor Celecoxib on cell proliferation and apoptosis of human coloretal cancer cell line HT-29 to seek an effective and safe drug for colon cancer chemoprevention. Methods Using MTT assay, flow cytometry(FCM), acridine orange and ethidium bromide staining, the effect of celecoxib on the proliferation and apoptosis of HT-29 cells were investigated. Results The growth of HT-29 cells was inhibited by celecoxib in a dose- and time- dependent manners. FCM analysis showed that the treated HT-29 cells had typical Sub-G 1 peak, the apoptotic rate of which was (7 31?2 37)%～(48 3?2 86)%. The cell ratio of G 0/G 1 phase increased, whereas the cell ratio of S and G 2/M phases decreased after treatment, which was in a dose-dependent manner as well. The treated HT-29 cells exhibited some morphological features of apoptosis, including cell shrinkage, nuclear condensation, DNA fragmentation, and the formation of apoptosis bodies, the apoptotic index of which was in a dose- and time- dependent manners. Conclusions Celecoxib inhibited proliferation and induced apoptosis of human colorectal cancer cell line HT-29, which may be related to blocking the cell cycle progress of HT-29 cells.
RESUMO
PURPOSE: In normal tissue, MUC2 mucin gene is expressed predominantly in goblet cells, while MUC3 is expressed in both goblet cells and columnar absorptive cells of small intestine and colon. MUC5 mucin genes are expressed predominantly in the surface epithelial cells, while MUC6 is expressed mainly in the mucus neck cells of gastric glands and pyloric glands of stomach. In this paper, we determined any changes of mucin in drug-resistant cell lines from those parental cells, and we evaluated the altered regulation of mucin production in drug-resistant cells. MATERIALS AND METHODS: In the study of 17 day postconfluent parental HT29 (HT29) and methotrexate-resistant HT29 (HT29-MTX) colon cancer cell lines were examined for the expression of MUC2, 3, 5 and 6 mucin polypeptide (apomucin) by Northern blot and slot blot analysis, and also by immunoblot analysis. RESULTS: The level of MUC2 expression was unchanged, while there was increase in MUC3 expression in HT29-MTX compared to HT29. Interestingly there was a marked increase in the expression of MUC5 mRNA in HT29-MTX. The densitometric readings expressed as HT29-MTX/HT29 at 17th day after the cells were confluent are MUC2 (1.1), MUC3 (1.3), MUC5 (>70), MUC6 (1.0) with RNA slot blot. Immunoblot analysis was consistent with these data. CONCLUSION: Marked induction in MUC5 but not MUC6 gastric mucin gene was found in MTX resistance in HT29 colon cancer cells. The possible biological consequences of altered regulation of mucin genes in drug resistant colon cancer cells require further investigation.
Assuntos
Humanos , Adenocarcinoma , Northern Blotting , Linhagem Celular , Colo , Neoplasias do Colo , Resistência a Medicamentos , Células Epiteliais , Mucinas Gástricas , Mucosa Gástrica , Expressão Gênica , Células Caliciformes , Células HT29 , Intestino Delgado , Metotrexato , Mucinas , Muco , Pescoço , Pais , Leitura , RNA , RNA Mensageiro , EstômagoRESUMO
Objective To investigate the effects and mechanisms of inositol hexaphosphate on diffe-rentiation of HT-29 human colon carcinoma cell line. Method Cells were exposed to various concentrations (control,1.8 mmol/L,3.3 mmol/L) of IP6 for different time (1d,3d,5d). Its effects on the cells were evaluated by detecting follow indices:(1) Observing ultrastructure of HT-29 cells by transmission electron microscopy. (2) Detecting alkaline phosphate (ALP) activity to evaluate cell differentiation. (3) Expression of c-Myc mRNA was determined by reverse transcription polymerase chain reaction (RT-PCR). (4) Immunocytochemical stain was used to detect expression of Rb protein. Results (1) After having been treated at 3.3mmol/L concentration,the cell structure changed,and appeared tendency of differentiation,such as karyopyknosis,abundant cellular organs and microvillus increase. (2) The activity of alkaline phosphate increased along with the concentration and time. (3) RT-PCR showed that different concentrations of IP6 decreased the expression of c-Myc mRNA. (4) The immunocytochemical stain showed that different concentrations of IP6 increased expression of Rb protein. Conclusion IP6 can induce differentiation of HT-29 cell by augmenting expression of Rb,decreasing expression of c-Myc and blocking cell cycle.
RESUMO
Objective: To investigate the effects and mechanisms of inositol hexaphosphate(IP6)on cell cycle of HT-29 human colon carcinoma cell line. Method: HT-29 cells were exposed to various concentrations of IP6 for certain time. The effect of IP6 on cells proliferation was evaluated by MTT assay. Flow cytometric analysis was performed for cell cycle progression. Immunocytochemical stain was used to detect the expression of p53 and p21 protein. Results: A significant dose-dependent as well as time-dependent growth inhibition was observed in IP6-treated HT-29 cells, and associated with an increase in G1 arrest; Different concentrations of IP6 decreased the abnormal expressions of p53 gene and strongly increased the expression of p21. Conclusions: IP6 had an inhibitory effect on proliferation of HT-29 cells .and its mechanisms might be related to many factors, such as inhibiting the abnormal expression of p53 gene, inducing the expression of cell cycle inhibitor p21 which block the cell cycle.