BACKGROUND Cancer stem cells(CSCs)are a subpopulation of cancer cells with the potential of self-renewal and differentiation.CSCs play critical roles in tumorigenesis,recurrence,metastasis,radiation tolerance and chem...BACKGROUND Cancer stem cells(CSCs)are a subpopulation of cancer cells with the potential of self-renewal and differentiation.CSCs play critical roles in tumorigenesis,recurrence,metastasis,radiation tolerance and chemoresistance.AIM To assess the expression patterns and clinical potential of doublecortin-like kinase 1(DCLK1)and leucine-rich repeat-containing G-protein-coupled receptor 5(Lgr5),as prognostic CSC markers of colorectal cancer(CRC).METHODS The expression of DCLK1 and Lgr5 in CRC tissue sections from 92 patients was determined by immunohistochemistry.Each case was evaluated using a combined scoring method based on signal intensity staining(scored 0-3)and the proportion of positively stained cancer cells(scored 0-3).The final staining score was calculated as the intensity score multiplied by the proportion score.Low expression of DCLK1 and Lgr5 was defined as a score of 0-3;high expression of DCLK1 and Lgr5 was defined as a score of≥4.Specimens were categorized as either high or low expression,and the correlation between the expression of DCLK1 or Lgr5 and clinicopathological factors was investigated.RESULTS DCLK1 and Lgr5 expression levels were significantly positively correlated.CRC patients with high DCLK1,Lgr5 and DCLK1/Lgr5 expressions had poorer progression-free survival and overall survival.Moreover,high expression of DCLK1 was an independent prognostic factor for recurrence and overall survival in patients with CRC by multivariate analysis(P=0.026 and P=0.049,respectively).CONCLUSION DCLK1 may be a potential CSC marker for the recurrence and survival of CRC patients.展开更多
BACKGROUND Colon cancer cell lines are widely used for research and for the screening of drugs that specifically target the stem cell compartment of colon cancers.It was reported that colon cancer carcinoma specimens ...BACKGROUND Colon cancer cell lines are widely used for research and for the screening of drugs that specifically target the stem cell compartment of colon cancers.It was reported that colon cancer carcinoma specimens contain a subset of leucine-rich repeatcontaining G protein-coupled receptor 5(LGR5)-expressing stem cells,these socalled“tumour-initiating”cells,reminiscent in their properties of the normal intestinal stem cells(ISCs),may explain the apparent heterogeneity of colon cancer cell lines.Also,colon cancer is initiated by aberrant Wnt signaling in ISCs known to express high levels of LGR5.Furthermore,in vivo reports demonstrate the clonal expansion of intestinal adenomas from a single LGR5-expressing cell.AIM To investigate whether colon cancer cell lines contain cancer stem cells and to characterize these putative cancer stem cells.METHODS A portable fluorescent reporter construct based on a conserved fragment of the LGR5 promoter was used to isolate the cell compartments expressing different levels of LGR5 in two widely used colon cancer cell lines(Caco-2 and LoVo).These cells were then characterized according to their proliferation capacity,gene expression signatures of ISC markers,and their tumorigenic properties in vivo and in vitro.RESULTS The data revealed that the LGR5 reporter can be used to identify and isolate a classical intestinal crypt stem cell-like population from the Caco-2,but not from the LoVo,cell lines,in which the cancer stem cell population is more akin to B lymphoma Moloney murine leukemia virus insertion region 1 homolog(+4 crypt)stem cells.This sub-population within Caco-2 cells exhibits an intestinal cancer stem cell gene expression signature and can both self-renew and generate differentiated LGR5 negative progeny.Our data also show that cells expressing high levels of LGR5/enhanced yellow fluorescent protein(EYFP)from this cell line exhibit tumorigenic-like properties in vivo and in vitro.In contrast,cell compartments of LoVo that are expressing high levels of LGR5/EYFP did not show these stem cell-like properties.Thus,cells that exhibit high levels of LGR5/EYFP expression represent the cancer stem cell compartment of Caco-2 colon cancer cells,but not LoVo cells.CONCLUSION Our findings highlight the presence of a spectrum of different ISC-like compartments in different colon cancer cell lines.Their existence is an important consideration for their screening applications and should be taken into account when interpreting drug screening data.We have generated a portable LGR5-reporter that serves as a valuable tool for the identification and isolation of different colon cancer stem cell populations in colon cancer lines.展开更多
Objective： To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 （LGR5） expressions in gastric cancer and to evaluate its clinical significance. Methods： LGR5 expression was assessed by immuno...Objective： To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 （LGR5） expressions in gastric cancer and to evaluate its clinical significance. Methods： LGR5 expression was assessed by immunohistochemistry in 257 gastric cancer patients after surgery. The relationships between LGR5 expression and clinicopathological features and patients prognosis were statistically analyzed. Results： The expression of LGR5 was significantly higher in gastric cancers as a cancer stem cell marker than in adjacent normal tissues （P〈0.001）, and more frequently in patients with intestinal type, well-moderate differentiation and stage I and II （P〈0.05）. Although we found gastric cancer patients with LGR5 positive expression had a poorer prognosis, it didn＇t meet statistical significance （P〉0.05）. LGR5 negative expression was significantly related to the favorable overall survival in stage I and II gastric cancer patients （P〈0.05）. Furthermore, patients with high LGR5 expression tended to be more likely to get progression and have poorer progress-free survival （P〈0.05）. Multivariate Cox regression analysis revealed that LGR5 expression was an independent factor of overall survival for the patients with stage I and II gastric cancer （P〈0.05）. Conclusions： Our results show that LGR5 may play an important role in tumorigenesis and progression and would be a powerful marker to predict the prognosis of patients with stage I and II gastric cancer.展开更多
AIM:To investigate the differential expression of leu-cine-rich repeat-containing G protein-coupled receptor5(LGR5)in gastric cancer tissues and its significance related to tumor growth and spread.METHODS:Formalin-fix...AIM:To investigate the differential expression of leu-cine-rich repeat-containing G protein-coupled receptor5(LGR5)in gastric cancer tissues and its significance related to tumor growth and spread.METHODS:Formalin-fixed biopsy specimens of intestinal metaplasia(n=90),dysplasia(n=53),gastric adenocarcinoma(n=180),metastases in lymph nodes and the liver(n=15),and lesion-adjacent normal gastric mucosa(controls;n=145)were obtained for analysis from the Peking University Cancer Hospital’s Department of Pathology and Gastrointestinal Surgery tissue archives(January 2003 to December 2011).The biopsied patients’demographic and clinicopathologic data were retrieved from the hospital’s medical records database.Each specimen was subjected to histopathological typing to classify the tumor node metastasis(TNM)stage and to immunohistochemistry staining to detect the expression of the cancer stem cell marker LGR5.The intergroup differences in LGR5 expression were assessed by Spearman’s rank correlation analysis,and the relationship between LGR5 expression level and the patients’clinicopathological characteristics was evaluated by theχ2test or Fisher’s exact test.RESULTS:Significantly more gastric cancer tissues showed LGR5+staining than normal control tissues(all P<0.01),with immunoreactivity detected in 72.2%(65/90)and 50.9%(27/53)of intestinal metaplasia and dysplasia specimens,respectively,52.8%(95/180)of gastric adenocarcinoma specimens,and 73.3%%(11/15)of metastasis specimens,but 26.9%(39/145)of lesion-adjacent normal gastric mucosa specimens.Comparison of the intensity of LGR5+staining showed an increasing trend that generally followed increasing dedifferentiation and tumor spread(normal tissue<dysplasia,<gastric adenocarcinoma<metastasis;all P<0.001),with the exception of expression level detected in intestinal metaplasia which was higher than that in normal gastric tissues(P<0.001).Moreover,gastric cancer-associated enhanced expression of LGR5 was found to be signifcantly associated with age,tumor differentiation,Lauren type and TNM stage(Ⅰ+ⅡvsⅢ+Ⅳ)(all P<0.05),but not with sex,tumor site,location,size,histology,lymphovascular invasion,depth of invasion,lymph node metastasis or distant metastasis.Patients with LGR5+gastric cancer specimens and without signs of metastasis from the original biopsy experienced more frequent rates of recurrence or metastasis during follow-up than patients with LGR5-specimens(P<0.05).CONCLUSION:Enhanced LGR5 is related to progressive dedifferentiation and metastasis of gastric cancer,indicating the potential of this receptor as an early diagnostic and prognostic biomarker.展开更多
BACKGROUND Patients with mesenteric ischemia frequently suffer from bowel necrosis even after revascularization.Hydrogen gas has showed promising effects for ischemiareperfusion injury by reducing reactive oxygen spec...BACKGROUND Patients with mesenteric ischemia frequently suffer from bowel necrosis even after revascularization.Hydrogen gas has showed promising effects for ischemiareperfusion injury by reducing reactive oxygen species in various animal and clinical studies.We examined intestinal tissue injury by ischemia and reperfusion under continuous initiation of 3%hydrogen gas.AIM To clarify the treatment effects and target cells of hydrogen gas for mesenteric ischemia.METHODS Three rat groups underwent 60-min mesenteric artery occlusion(ischemia),60-min reperfusion following 60-min occlusion(reperfusion),or ischemiareperfusion with the same duration under continuous 3%hydrogen gas inhalation(hydrogen).The distal ileum was harvested.Immunofluorescence staining with caspase-3 and leucine-rich repeat-containing G-protein-coupled 5(LGR5),a specific marker of intestinal stem cell,was conducted to evaluate the injury location and cell types protected by hydrogen.mRNA expressions of LGR5,olfactomedin 4(OLFM4),hairy and enhancer of split 1,Jagged 2,and Neurogenic locus notch homolog protein 1 were measured by quantitative polymerase chain reaction.Tissue oxidative stress was analyzed with immunostaining for 8-hydroxy-2'-deoxyguanosine(8-OHdG).Systemic oxidative stress was evaluated by plasma 8-OHdG.RESULTS Ischemia damaged the epithelial layer at the tip of the villi,whereas reperfusion induced extensive apoptosis of the cells at the crypt base,which were identified as intestinal stem cells with double immunofluorescence stain.Hydrogen mitigated such apoptosis at the crypt base,and the LGR5 expression of the tissues was higher in the hydrogen group than in the reperfusion group.OLFM4 was also relatively higher in the hydrogen group,whereas other measured RNAs were comparable between the groups.8-OHdG concentration was high in the reperfusion group,which was reduced by hydrogen,particularly at the crypt base.Serum 8-OHdG concentrations were relatively higher in both reperfusion and hydrogen groups without significance.CONCLUSION This study demonstrated that hydrogen gas inhalation preserves intestinal stem cells and mitigates oxidative stress caused by mesenteric ischemia and reperfusion.展开更多
基金Supported by Sanming Project of Shenzhen,No.SZSM201612041Shenzhen Science and Technology Innovation Commission Project,No.GJHZ20180420180754917 and No.ZDSYS20190902092855097Postdoctoral Science Foundation of China,No.2018M633095.
文摘BACKGROUND Cancer stem cells(CSCs)are a subpopulation of cancer cells with the potential of self-renewal and differentiation.CSCs play critical roles in tumorigenesis,recurrence,metastasis,radiation tolerance and chemoresistance.AIM To assess the expression patterns and clinical potential of doublecortin-like kinase 1(DCLK1)and leucine-rich repeat-containing G-protein-coupled receptor 5(Lgr5),as prognostic CSC markers of colorectal cancer(CRC).METHODS The expression of DCLK1 and Lgr5 in CRC tissue sections from 92 patients was determined by immunohistochemistry.Each case was evaluated using a combined scoring method based on signal intensity staining(scored 0-3)and the proportion of positively stained cancer cells(scored 0-3).The final staining score was calculated as the intensity score multiplied by the proportion score.Low expression of DCLK1 and Lgr5 was defined as a score of 0-3;high expression of DCLK1 and Lgr5 was defined as a score of≥4.Specimens were categorized as either high or low expression,and the correlation between the expression of DCLK1 or Lgr5 and clinicopathological factors was investigated.RESULTS DCLK1 and Lgr5 expression levels were significantly positively correlated.CRC patients with high DCLK1,Lgr5 and DCLK1/Lgr5 expressions had poorer progression-free survival and overall survival.Moreover,high expression of DCLK1 was an independent prognostic factor for recurrence and overall survival in patients with CRC by multivariate analysis(P=0.026 and P=0.049,respectively).CONCLUSION DCLK1 may be a potential CSC marker for the recurrence and survival of CRC patients.
基金We thank Professor McGuckin M(MMRI,Brisbane)for providing human colon cancer cell lines(Caco-2,LoVo,and SW480)Dr.Rolfe B(AIBN,Brisbane)for providing mouse NSC-34 cells.
文摘BACKGROUND Colon cancer cell lines are widely used for research and for the screening of drugs that specifically target the stem cell compartment of colon cancers.It was reported that colon cancer carcinoma specimens contain a subset of leucine-rich repeatcontaining G protein-coupled receptor 5(LGR5)-expressing stem cells,these socalled“tumour-initiating”cells,reminiscent in their properties of the normal intestinal stem cells(ISCs),may explain the apparent heterogeneity of colon cancer cell lines.Also,colon cancer is initiated by aberrant Wnt signaling in ISCs known to express high levels of LGR5.Furthermore,in vivo reports demonstrate the clonal expansion of intestinal adenomas from a single LGR5-expressing cell.AIM To investigate whether colon cancer cell lines contain cancer stem cells and to characterize these putative cancer stem cells.METHODS A portable fluorescent reporter construct based on a conserved fragment of the LGR5 promoter was used to isolate the cell compartments expressing different levels of LGR5 in two widely used colon cancer cell lines(Caco-2 and LoVo).These cells were then characterized according to their proliferation capacity,gene expression signatures of ISC markers,and their tumorigenic properties in vivo and in vitro.RESULTS The data revealed that the LGR5 reporter can be used to identify and isolate a classical intestinal crypt stem cell-like population from the Caco-2,but not from the LoVo,cell lines,in which the cancer stem cell population is more akin to B lymphoma Moloney murine leukemia virus insertion region 1 homolog(+4 crypt)stem cells.This sub-population within Caco-2 cells exhibits an intestinal cancer stem cell gene expression signature and can both self-renew and generate differentiated LGR5 negative progeny.Our data also show that cells expressing high levels of LGR5/enhanced yellow fluorescent protein(EYFP)from this cell line exhibit tumorigenic-like properties in vivo and in vitro.In contrast,cell compartments of LoVo that are expressing high levels of LGR5/EYFP did not show these stem cell-like properties.Thus,cells that exhibit high levels of LGR5/EYFP expression represent the cancer stem cell compartment of Caco-2 colon cancer cells,but not LoVo cells.CONCLUSION Our findings highlight the presence of a spectrum of different ISC-like compartments in different colon cancer cell lines.Their existence is an important consideration for their screening applications and should be taken into account when interpreting drug screening data.We have generated a portable LGR5-reporter that serves as a valuable tool for the identification and isolation of different colon cancer stem cell populations in colon cancer lines.
文摘Objective： To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 （LGR5） expressions in gastric cancer and to evaluate its clinical significance. Methods： LGR5 expression was assessed by immunohistochemistry in 257 gastric cancer patients after surgery. The relationships between LGR5 expression and clinicopathological features and patients prognosis were statistically analyzed. Results： The expression of LGR5 was significantly higher in gastric cancers as a cancer stem cell marker than in adjacent normal tissues （P〈0.001）, and more frequently in patients with intestinal type, well-moderate differentiation and stage I and II （P〈0.05）. Although we found gastric cancer patients with LGR5 positive expression had a poorer prognosis, it didn＇t meet statistical significance （P〉0.05）. LGR5 negative expression was significantly related to the favorable overall survival in stage I and II gastric cancer patients （P〈0.05）. Furthermore, patients with high LGR5 expression tended to be more likely to get progression and have poorer progress-free survival （P〈0.05）. Multivariate Cox regression analysis revealed that LGR5 expression was an independent factor of overall survival for the patients with stage I and II gastric cancer （P〈0.05）. Conclusions： Our results show that LGR5 may play an important role in tumorigenesis and progression and would be a powerful marker to predict the prognosis of patients with stage I and II gastric cancer.
基金Supported by A grant from the Beijing Municipal Science and Technology Commission’s NOVA Program,No.2009BG-02Beijing Municipal Health System Special funds of High-Level Medical Personnel Construction,No.2013-3-082
文摘AIM:To investigate the differential expression of leu-cine-rich repeat-containing G protein-coupled receptor5(LGR5)in gastric cancer tissues and its significance related to tumor growth and spread.METHODS:Formalin-fixed biopsy specimens of intestinal metaplasia(n=90),dysplasia(n=53),gastric adenocarcinoma(n=180),metastases in lymph nodes and the liver(n=15),and lesion-adjacent normal gastric mucosa(controls;n=145)were obtained for analysis from the Peking University Cancer Hospital’s Department of Pathology and Gastrointestinal Surgery tissue archives(January 2003 to December 2011).The biopsied patients’demographic and clinicopathologic data were retrieved from the hospital’s medical records database.Each specimen was subjected to histopathological typing to classify the tumor node metastasis(TNM)stage and to immunohistochemistry staining to detect the expression of the cancer stem cell marker LGR5.The intergroup differences in LGR5 expression were assessed by Spearman’s rank correlation analysis,and the relationship between LGR5 expression level and the patients’clinicopathological characteristics was evaluated by theχ2test or Fisher’s exact test.RESULTS:Significantly more gastric cancer tissues showed LGR5+staining than normal control tissues(all P<0.01),with immunoreactivity detected in 72.2%(65/90)and 50.9%(27/53)of intestinal metaplasia and dysplasia specimens,respectively,52.8%(95/180)of gastric adenocarcinoma specimens,and 73.3%%(11/15)of metastasis specimens,but 26.9%(39/145)of lesion-adjacent normal gastric mucosa specimens.Comparison of the intensity of LGR5+staining showed an increasing trend that generally followed increasing dedifferentiation and tumor spread(normal tissue<dysplasia,<gastric adenocarcinoma<metastasis;all P<0.001),with the exception of expression level detected in intestinal metaplasia which was higher than that in normal gastric tissues(P<0.001).Moreover,gastric cancer-associated enhanced expression of LGR5 was found to be signifcantly associated with age,tumor differentiation,Lauren type and TNM stage(Ⅰ+ⅡvsⅢ+Ⅳ)(all P<0.05),but not with sex,tumor site,location,size,histology,lymphovascular invasion,depth of invasion,lymph node metastasis or distant metastasis.Patients with LGR5+gastric cancer specimens and without signs of metastasis from the original biopsy experienced more frequent rates of recurrence or metastasis during follow-up than patients with LGR5-specimens(P<0.05).CONCLUSION:Enhanced LGR5 is related to progressive dedifferentiation and metastasis of gastric cancer,indicating the potential of this receptor as an early diagnostic and prognostic biomarker.
文摘BACKGROUND Patients with mesenteric ischemia frequently suffer from bowel necrosis even after revascularization.Hydrogen gas has showed promising effects for ischemiareperfusion injury by reducing reactive oxygen species in various animal and clinical studies.We examined intestinal tissue injury by ischemia and reperfusion under continuous initiation of 3%hydrogen gas.AIM To clarify the treatment effects and target cells of hydrogen gas for mesenteric ischemia.METHODS Three rat groups underwent 60-min mesenteric artery occlusion(ischemia),60-min reperfusion following 60-min occlusion(reperfusion),or ischemiareperfusion with the same duration under continuous 3%hydrogen gas inhalation(hydrogen).The distal ileum was harvested.Immunofluorescence staining with caspase-3 and leucine-rich repeat-containing G-protein-coupled 5(LGR5),a specific marker of intestinal stem cell,was conducted to evaluate the injury location and cell types protected by hydrogen.mRNA expressions of LGR5,olfactomedin 4(OLFM4),hairy and enhancer of split 1,Jagged 2,and Neurogenic locus notch homolog protein 1 were measured by quantitative polymerase chain reaction.Tissue oxidative stress was analyzed with immunostaining for 8-hydroxy-2'-deoxyguanosine(8-OHdG).Systemic oxidative stress was evaluated by plasma 8-OHdG.RESULTS Ischemia damaged the epithelial layer at the tip of the villi,whereas reperfusion induced extensive apoptosis of the cells at the crypt base,which were identified as intestinal stem cells with double immunofluorescence stain.Hydrogen mitigated such apoptosis at the crypt base,and the LGR5 expression of the tissues was higher in the hydrogen group than in the reperfusion group.OLFM4 was also relatively higher in the hydrogen group,whereas other measured RNAs were comparable between the groups.8-OHdG concentration was high in the reperfusion group,which was reduced by hydrogen,particularly at the crypt base.Serum 8-OHdG concentrations were relatively higher in both reperfusion and hydrogen groups without significance.CONCLUSION This study demonstrated that hydrogen gas inhalation preserves intestinal stem cells and mitigates oxidative stress caused by mesenteric ischemia and reperfusion.
