AIM:The effects of vitamin D3 have been investigated on various tumors, including colorectal cancer (CRC). 25-hydroxyvitamin-D3-24-hydroxylase (CYP24A1), the enzyme that inactivates the active vitamin D3 metabolite 1,...AIM:The effects of vitamin D3 have been investigated on various tumors, including colorectal cancer (CRC). 25-hydroxyvitamin-D3-24-hydroxylase (CYP24A1), the enzyme that inactivates the active vitamin D3 metabolite 1,25-dihydroxyvitamin D3 (1,25-D3), is considered to be the main enzyme determining the biological halflife of 1,25-D3. During colorectal carcinogenesis, the expression and concentration of CYP24A1 increases significantly, suggesting that this phenomenon could be responsible for the proposed efficacy of 1,25-D3 in the treatment of CRC. The aim of this study was to investigate the anti-tumor effects of vitamin D3 on the human CRC cell line Caco-2 after inhibition of the cytochrome P450 component of CYP24A1 activity. METHODS:We examined the expression of CYP24A1 mRNA and the effects of 1,25-D3 on the cell line Caco-2 after inhibition of CYP24A1. Cell viability and proliferation were determined by means of sulforhodamine-B staining and bromodeoxyuridine incorporation, respectively, while cytotoxicity was estimated via the lactate dehydrogenase content of the cell culture supernatant. CYP24A1 expression was measured by realtime reverse transcription polymerase chain reaction. A number of tetralone compounds were synthesized to investigate their CP24A1 inhibitory activity. RESULTS:In response to 1,25-D3, CYP24A1 mRNA expression was enhanced significantly, in a time- and dose-dependent manner. Caco-2 cell viability and proliferation were not influenced by the administration of 1,25-D3 alone, but were markedly reduced by coadministration of 1,25-D3 and KD-35, a CYP24A1-inhibiting tetralone. Our data suggest that the mechanism of action of co-administered KD-35 and 1,25-D3 does not involve a direct cytotoxic effect, but rather the inhibition of cell proliferation. CONCLUSION:These findings demonstrate that the selective inhibition of CYP24A1 by compounds such as KD-35 may be a new approach for enhancement of the anti-tumor effect of 1,25-D3 on CRC.展开更多
AIM To determine the pathogenesis and potential single nucleotide polymorphisms(SNPs) as screening sites for colonic polyps,colon cancer and ulcerative colitis,and to analyze the possible association between these gen...AIM To determine the pathogenesis and potential single nucleotide polymorphisms(SNPs) as screening sites for colonic polyps,colon cancer and ulcerative colitis,and to analyze the possible association between these genetic polymorphisms and the three diseases. METHODS We evaluated genetic polymorphisms in 144 newly diagnosed colonic polyp patients,96 colon cancer patients and 44 ulcerative colitis patients. The four SNPs genotyped were rs4809957,rs6068816,rs6091822 and rs8124792. The control group consisted of 504 East Asians enrolled in the 1000 Genomes Project. Correlations between CYP24A1 SNPs and the diseases were analyzed by Fisher's exact probability test.RESULTS CYP24A1 polymorphisms rs4809957 A/G and rs6068816 C/T showed a statistically significant association with risk of the three diseases,when both the genotypes and allele frequencies were considered. With regard to rs6091822 G/T,all three diseases were related to risk allele carriers(GT + TT) vs wild-type(GG),but the associations between the allele frequencies and the diseases were not significant. The risk of colonic polyps and colon cancer was related to the allele frequencies of rs8124792 G/A,and this association remained for genotype frequencies of this SNP. CONCLUSION Four SNPs are related to the risk of colonic polyps and colon cancer. G allele in rs6091822 G/T may play an anti-cancer role only if it is homozygous. The A allele,which is a minor component of rs8124792,may be indicated in the diagnosis of colonic polyps or colon cancer rather than ulcerative colitis.展开更多
Objective While the upregulation of cytochrome P450 family 24 subfamily A member 1(CYP24A1)gene expression has been reported in colon cancer,its role in tumorigenesis remains largely unknown.In this study,we aimed to ...Objective While the upregulation of cytochrome P450 family 24 subfamily A member 1(CYP24A1)gene expression has been reported in colon cancer,its role in tumorigenesis remains largely unknown.In this study,we aimed to investigate the involvement of CYP24A1 in Wnt pathway regulation via the nuclear factor kappa B(NF-κB)pathway.Methods The human colon cancer cell lines HCT-116 and Caco-2 were subjected to stimulation with interleukin-6(IL-6)as well as tumor necrosis factor alpha(TNF-α),with subsequent treatment using the NF-κB pathway-specific inhibitor ammonium pyrrolidinedithiocarbamate(PDTC).Furthermore,CYP24A1 expression was subjected to knockdown via the use of small interfering RNA(siRNA).Subsequently,NF-κB pathway activation was determined by an electrophoretic mobility shift assay,and the transcriptional activity ofβ-catenin was determined by a dual-luciferase reporter assay.A mouse ulcerative colitis(UC)-associated carcinogenesis model was established,wherein TNF-αand the NF-κB pathway were blocked by anti-TNF-αmonoclonal antibody and NF-κB antisense oligonucleotides,respectively.Then the tumor size and protein level of CYP24A1 were determined.Results IL-6 and TNF-αupregulated CYP24A1 expression and activated the NF-κB pathway in colon cancer cells.PDTC significantly inhibited this increase in CYP24A1 expression.Additionally,knockdown of CYP24A1 expression by siRNA could partially antagonize Wnt pathway activation.Upregulated CYP24A1 expression was observed in the colonic epithelial cells of UC-associated carcinoma mouse models.Anti-TNF-αmonoclonal antibody and NF-κB antisense oligonucleotides decreased the tumor size and suppressed CYP24A1 expression.Conclusion Taken together,this study suggests that inflammatory factors may increase CYP24A1 expression via NF-κB pathway activation,which in turn stimulates Wnt signaling.展开更多
Vitamin D has found to have a critical regula-tory role in genes expression by modifying cell proliferation,differentiation,and apoptosis.In this study,by using real-time polymerase chain reaction(PCR),the expression ...Vitamin D has found to have a critical regula-tory role in genes expression by modifying cell proliferation,differentiation,and apoptosis.In this study,by using real-time polymerase chain reaction(PCR),the expression levels of SIRT1 and CYP24A1 genes and their correlation with clinical feature were evaluated before and after the vitamin D treatment in breast cancer(BC)cell lines(MCF-7 and MDA-MB-231)and in tissues.Our results indicated that the transcription of CYP24A1 and SIRT1 were affected by vitamin D treatment and,CYP24A1expression showed a significant correlation with tumor stages(P=0.02).Moreover,CYP24A1,SIRT1 showed a high diagnostic values based on the large area under the receiver operating char-acteristic(ROC)curve,(0.85,0.77)respectively,in conclusion,CYP24A1and SIRT1 can be used as potential biomarkers in the assessment of BC,and vitamin D treatment showed a regulatory role on the expression of CYP24A1 and SIRT1in BC cell lines.展开更多
基金Supported by Research Grants ETT022/2006 and ETT151/2009 from the Ministry of Health,HungaryTáMOP-4.2.1/B-09/1/KONV-2010-0005 from Creating the Center of Excellence at the University of Szegedsupported by the European Union and cofinanced by the European Regional Fund
文摘AIM:The effects of vitamin D3 have been investigated on various tumors, including colorectal cancer (CRC). 25-hydroxyvitamin-D3-24-hydroxylase (CYP24A1), the enzyme that inactivates the active vitamin D3 metabolite 1,25-dihydroxyvitamin D3 (1,25-D3), is considered to be the main enzyme determining the biological halflife of 1,25-D3. During colorectal carcinogenesis, the expression and concentration of CYP24A1 increases significantly, suggesting that this phenomenon could be responsible for the proposed efficacy of 1,25-D3 in the treatment of CRC. The aim of this study was to investigate the anti-tumor effects of vitamin D3 on the human CRC cell line Caco-2 after inhibition of the cytochrome P450 component of CYP24A1 activity. METHODS:We examined the expression of CYP24A1 mRNA and the effects of 1,25-D3 on the cell line Caco-2 after inhibition of CYP24A1. Cell viability and proliferation were determined by means of sulforhodamine-B staining and bromodeoxyuridine incorporation, respectively, while cytotoxicity was estimated via the lactate dehydrogenase content of the cell culture supernatant. CYP24A1 expression was measured by realtime reverse transcription polymerase chain reaction. A number of tetralone compounds were synthesized to investigate their CP24A1 inhibitory activity. RESULTS:In response to 1,25-D3, CYP24A1 mRNA expression was enhanced significantly, in a time- and dose-dependent manner. Caco-2 cell viability and proliferation were not influenced by the administration of 1,25-D3 alone, but were markedly reduced by coadministration of 1,25-D3 and KD-35, a CYP24A1-inhibiting tetralone. Our data suggest that the mechanism of action of co-administered KD-35 and 1,25-D3 does not involve a direct cytotoxic effect, but rather the inhibition of cell proliferation. CONCLUSION:These findings demonstrate that the selective inhibition of CYP24A1 by compounds such as KD-35 may be a new approach for enhancement of the anti-tumor effect of 1,25-D3 on CRC.
基金Supported by the Special Fund for Health Research and Development,Beijing Municipal Government,China,No.2011-4001-01
文摘AIM To determine the pathogenesis and potential single nucleotide polymorphisms(SNPs) as screening sites for colonic polyps,colon cancer and ulcerative colitis,and to analyze the possible association between these genetic polymorphisms and the three diseases. METHODS We evaluated genetic polymorphisms in 144 newly diagnosed colonic polyp patients,96 colon cancer patients and 44 ulcerative colitis patients. The four SNPs genotyped were rs4809957,rs6068816,rs6091822 and rs8124792. The control group consisted of 504 East Asians enrolled in the 1000 Genomes Project. Correlations between CYP24A1 SNPs and the diseases were analyzed by Fisher's exact probability test.RESULTS CYP24A1 polymorphisms rs4809957 A/G and rs6068816 C/T showed a statistically significant association with risk of the three diseases,when both the genotypes and allele frequencies were considered. With regard to rs6091822 G/T,all three diseases were related to risk allele carriers(GT + TT) vs wild-type(GG),but the associations between the allele frequencies and the diseases were not significant. The risk of colonic polyps and colon cancer was related to the allele frequencies of rs8124792 G/A,and this association remained for genotype frequencies of this SNP. CONCLUSION Four SNPs are related to the risk of colonic polyps and colon cancer. G allele in rs6091822 G/T may play an anti-cancer role only if it is homozygous. The A allele,which is a minor component of rs8124792,may be indicated in the diagnosis of colonic polyps or colon cancer rather than ulcerative colitis.
基金supported by grants from the National Natural Science Foundation of China(No.81370500 and No.81770559)CAMS Innovation Fund for Medical Sciences(No.CIFMS2021-I2M-C&T-A-001 and No.2016-I2M-3-005)the CAMS Initiative for Innovative Medicine(No.CAMS-a12M 2016-I2M-1-007).
文摘Objective While the upregulation of cytochrome P450 family 24 subfamily A member 1(CYP24A1)gene expression has been reported in colon cancer,its role in tumorigenesis remains largely unknown.In this study,we aimed to investigate the involvement of CYP24A1 in Wnt pathway regulation via the nuclear factor kappa B(NF-κB)pathway.Methods The human colon cancer cell lines HCT-116 and Caco-2 were subjected to stimulation with interleukin-6(IL-6)as well as tumor necrosis factor alpha(TNF-α),with subsequent treatment using the NF-κB pathway-specific inhibitor ammonium pyrrolidinedithiocarbamate(PDTC).Furthermore,CYP24A1 expression was subjected to knockdown via the use of small interfering RNA(siRNA).Subsequently,NF-κB pathway activation was determined by an electrophoretic mobility shift assay,and the transcriptional activity ofβ-catenin was determined by a dual-luciferase reporter assay.A mouse ulcerative colitis(UC)-associated carcinogenesis model was established,wherein TNF-αand the NF-κB pathway were blocked by anti-TNF-αmonoclonal antibody and NF-κB antisense oligonucleotides,respectively.Then the tumor size and protein level of CYP24A1 were determined.Results IL-6 and TNF-αupregulated CYP24A1 expression and activated the NF-κB pathway in colon cancer cells.PDTC significantly inhibited this increase in CYP24A1 expression.Additionally,knockdown of CYP24A1 expression by siRNA could partially antagonize Wnt pathway activation.Upregulated CYP24A1 expression was observed in the colonic epithelial cells of UC-associated carcinoma mouse models.Anti-TNF-αmonoclonal antibody and NF-κB antisense oligonucleotides decreased the tumor size and suppressed CYP24A1 expression.Conclusion Taken together,this study suggests that inflammatory factors may increase CYP24A1 expression via NF-κB pathway activation,which in turn stimulates Wnt signaling.
基金a research grant from the Tehran University of Medical Sciences(Nos:TUM81224517)。
文摘Vitamin D has found to have a critical regula-tory role in genes expression by modifying cell proliferation,differentiation,and apoptosis.In this study,by using real-time polymerase chain reaction(PCR),the expression levels of SIRT1 and CYP24A1 genes and their correlation with clinical feature were evaluated before and after the vitamin D treatment in breast cancer(BC)cell lines(MCF-7 and MDA-MB-231)and in tissues.Our results indicated that the transcription of CYP24A1 and SIRT1 were affected by vitamin D treatment and,CYP24A1expression showed a significant correlation with tumor stages(P=0.02).Moreover,CYP24A1,SIRT1 showed a high diagnostic values based on the large area under the receiver operating char-acteristic(ROC)curve,(0.85,0.77)respectively,in conclusion,CYP24A1and SIRT1 can be used as potential biomarkers in the assessment of BC,and vitamin D treatment showed a regulatory role on the expression of CYP24A1 and SIRT1in BC cell lines.
