Calcipotriol inhibits rectal epithelial cell proliferation in ulcerative proctocolitis.

Vitamin D3 reduces human rectal crypt cell production rate (CCPR) and may thereby protect against colorectal cancer. Cell turnover is increased in ulcerative proctocolitis, which might therefore respond to vitamin D3 metabolites. This study investigated the effect of calcipotriol, a synthetic vitamin D3 analogue that avoids hypercalcaemia, on human rectal CCPR in ulcerative proctocolitis. Paired rectal biopsy specimens from seven patients with severe disease were established in organ culture with or without calcipotriol (1 x 10(-6) M). After 15 hours, vincristine (0.6 microgram/ml) was added to induce metaphase arrest, and CCPR was determined by linear regression analysis of accumulated metaphases. Compared with values in 17 controls with incidental anal conditions, median rectal CCPR was 28% higher in ulcerative proctocolitis: 5.90 (5.00-9.50) v 4.80 (2.85-7.07) cells/crypt/hour (p < 0.01). Calcipotriol reduced CCPR by 62% in patients with ulcerative proctocolitis, from 5.90 (5.00-9.50) to 2.21 (0.81-3.22) cells/crypt/hour (median with range) p < 0.01. Thus calcipotriol can dampen the hyperproliferative state in ulcerative proctocolitis and could have a therapeutic role in the control of this inflammatory condition.     

Prolonged administration of bile salts for gallstone dissolution and its effect on rectal epithelial cell proliferation

Bile acids and cholesterol metabolites may play a role in large bowel carcinogenesis. Currently, the bile acids chenodeoxycholic (CDCA) and ursodeoxycholic acid (UDCA) are being used for dissolution of cholesterol gallstones in surgical high-risk patients. The effect of prolonged exogenous bile acid intake on rectal epithelial cell proliferation, as a marker for preneoplasia, was evaluated in 19 patients selected for treatment. They were divided into two groups: nine patients received CDCA, 15 mg/kg/day for a mean duration of 11.0 months, while 11 patients received UDCA, 10 mg/kg/day for a mean duration of 9.2 months. Rectal biopsies taken before treatment and at one, three, six, and 12 months of treatment were analyzed and evaluated by three proliferative parameters including labeling index (LI), distribution of labeled cells, and total cells per crypt column. No significant alterations in epithelial cell proliferation were observed among patients treated with UDCA or CDCA with the exception of the number of cells per crypt column which, in the latter instance, deviated only slightly from the predicted values. The lack of major persistent alterations in the proliferative behavior of rectal epithelial cells does not justify any change in the selection of patients for gallstone therapy, but cannot exclude the potentially deleterious long-term effects of bile acid treatment.     

Does dietary fibre stimulate intestinal epithelial cell proliferation in germ free rats?

The aim of the present experiment was to investigate the role of hind gut fermentation in the proliferative response of the intestinal epithelium to dietary fibre. We have previously shown that refeeding starved rats with an elemental diet supplemented with fermentable dietary fibre (but not inert bulk) is capable of stimulating intestinal epithelial cell proliferation throughout the gastrointestinal tract. Three groups of 10 germ free (GF) rats and three groups of 10 conventional (CV) rats, were used. All groups were starved for three days and then refed for two days with either an elemental diet (Flexical); Flexical plus 30% kaolin; or Flexical plus 30% of a fibre mixture. Cell production was determined by the accumulation of vincristine arrested metaphases in microdissected crypts. There was no significant difference between refeeding the rats with an elemental diet alone or with kaolin supplementation, however, the addition of fibre in CV rats was associated with a significant increase in intestinal crypt cell production rate in both the small intestine (p less than 0.01) and the colon (p less than 0.001). This marked proliferative effects of fibre was abolished in the GF rats. It can be concluded that it is the products of hind gut fermentation, not fibre per se that stimulate intestinal epithelial cell proliferation in the colon and small intestine.     

miR-155在直肠癌细胞炎性条件下的表达

目的研究在直肠癌细胞炎性条件下的miR-155表达。方法通过研究直肠癌细胞中各种炎性条件下0 h、1 h、4 h、8 h、12 h、24 h的时间段细胞计数,运用统计学绘制细胞生长曲线,利用流式细胞仪检测24 h内的细胞周期变化情况。结果与未加入慢性炎症应激药物比较,H2O2、SPER/NO、HU作用于直肠癌细胞后,直肠癌细胞中miR-155表达量均升高,差异有统计学意义(P0.05),但在不同药物及不同细胞之间miR-155表达差异无统计学意义(P0.05)。不同药物作用后,miR-155表达出现峰值的时间不同。结论 miRNA具有癌基因或抑癌基因的功能,其表达异常后与多种人类癌症发生相关,在肿瘤发生、发展过程中有重要作用。     

幽门螺杆菌感染对胃上皮细胞增殖和凋亡的影响

目的为了探讨幽门螺杆菌感染对胃粘膜上皮细胞动力学的影响。方法应用免疫组织化学和切口末端标记法（ＴＵＮＥＬ），检测了１６例正常胃粘膜者和３１例幽门螺杆菌（Ｈｐ）相关慢性胃炎患者治疗前后胃粘膜上皮细胞增殖细胞核抗原（ＰＣＮＡ）标记指数（ＬＩ％）、细胞凋亡指数（ＡＩ）和表皮生长因子受体（ＥＧＦ－Ｒ）的表达。结果Ｈｐ阳性患者的ＰＣＮＡＬＩ％为１３．９４±１．６４，正常对照组为６．７１±０．９２，差异有非常显著性（Ｐ＜０．０１）；ＥＧＦ－Ｒ表达与ＰＣＮＡＬＩ％呈正相关（ｒ＝０．４４８７，Ｐ＜０．０１）：Ｈｐ阳性患者组的ＡＩ为７．１±１．６，正常对照组为１．３±０．６，差异有非常显著性（Ｐ＜０．０１）；抗Ｈｐ治疗后，２１例Ｈｐ根除者的ＰＣＮＡＬＩ％和细胞ＡＩ分别降至８．２１±１．３２和１．２±０．６，与治疗前相比差异有非常显著性（Ｐ＜０．０１），而１０例Ｈｐ持续阳性者则无明显降低（Ｐ＞０．０５）：ＰＣＮＡＬＩ％、ＥＧＦ－Ｒ表达及细胞ＡＩ与胃粘膜炎症程度无显著相关（Ｐ＞０．０５）。结论上述结果提示，Ｈｐ感Ｈ能引起胃粘膜上皮细胞过度增殖和凋亡。这为Ｈｐ感染胃癌发病中的作用机制提供了一些线索。     

Calcium supplementation decreases rectal epithelial cell proliferation in subjects with sporadic adenoma.

The results of three small clinical trials examining the effect of calcium carbonate supplementation on the proliferation cytokinetics of the rectal epithelium in subjects with a current history of sporadic adenoma are reported. In six subjects, a daily administration of 1500 mg of calcium carbonate for 90 days failed to significantly suppress thymidine labeling in normal-appearing mucosa of the rectum. However, a daily dose of 2000 mg of calcium significantly (P = 0.008) altered mucosal proliferation in a second set of six subjects after a 30-day trial. Finally, a placebo-controlled trial of calcium (2000 mg) was conducted in which 20 subjects were randomized to groups receiving a 4-week intervention with calcium (or placebo), followed by the alternative treatment (placebo or calcium). The results of the study show a marked suppression of rectal proliferation during the calcium phase of the study but not during the placebo phase. This study adds to accumulating evidence showing that calcium supplementation regulates the proliferative behavior of colonic epithelium in the individual at high risk for colon cancer. Longer term trials of calcium supplementation will ascertain whether a continuing benefit from increasing dietary calcium translates into inhibition of adenoma recurrence.     

Effect of eradication ofHelicobacter pylori infection on gastric epithelial cell proliferation

Helicobacter pylori infection has been linked with gastric carcinoma. Epithelial cell proliferation is an indicator of cancer risk. The aim of this study was to assess gastric epithelial cell proliferation before and after eradication therapy and to assess the efficacy of treatment ofH. pylori infection using lanzoprazole and clarithromycin. Twenty-three patients withH. pylori-associated gastritis were treated with lanzoprazole 30 mg daily for four weeks and clarithromycin 500 mg three times a day for two weeks. Antral mucosal biopsies were taken for gastric epithelial cell proliferation analysis using thein vitro bromodeoxyuridine (BrdU) immunohistochemical technique before and four weeks after eradication therapy. Labeling index percent (LI%) was calculated as the percent ratio of proliferating cells to the total number of cells in the gastric pit. Efficacy of treatment was assessed in 16 subjects. Eight were negative forH. pylori infection 28 days after therapy and in eight patientsH. pylori infection was not eradicated. The eradication rate for the regimen was 50%. Cell kinetics were assessed in 19 subjects who completed treatment. Patients withH. pylori infection had a significantly higher LI% compared to normal (N=19, LI%: 5.01±0.3 vs 3.2±0.2,N=29). Eradication ofH. pylori infection significantly reduced epithelial cell proliferation (N=9, LI%:5.2±0.4 to 3.2 ±0.8,P<0.001), whereas it was unaltered in those whose infection was not eradicated (N=10, LI%: 4.8±0.4 to 5.5±0.5,P=0.18). Eradication ofH. pylori reduces gastric epithelial cell proliferation to normal levels and may reduce the long-term the risk of gastric carcinoma.We wish to thankLederle for their support with this trial.     

Effect of mesalazine on epithelial cell proliferation in colonic diverticular disease

Background and aimsIncreased epithelial cell proliferation may be detected in diverticular disease, but antibiotics have failed in reducing it. We assess therefore the effect of mesalazine on epithelial cell proliferation in diverticular disease.MethodsA prospective study was conducted on 20 consecutive patients with a new endoscopic diagnosis of symptomatic uncomplicated diverticular disease. The patients were treated with mesalazine 1.6 mg/day for 1 year. The Ki-67 antigen index of the whole crypt and in the upper third was separately evaluated before and after starting the treatment.ResultsCell proliferation index was higher in diverticular disease patients than healthy controls both in the whole crypt (median 6.7%, range 2–9% vs. median 1.6%, range 1–3%, p = 0.001) and in the upper third of the crypt (median 6.8%, range 2–8% vs. median 1.8%, range 1–3%, p = 0.001).Cell proliferation decreased throughout the follow-up. In the whole crypt it was 6.7% at entry and 3.8% at the end of treatment (p < 0.005), whereas it was 6.8% at entry and 2.9% at the end of treatment in the upper third of the crypt (p < 0.005).ConclusionsWe found mesalazine effective in reducing the colonic cell proliferation in long-term treatment for colonic diverticular disease.     

Impact of cereal fibre on glucose-regulating factors

Aims/hypothesis Insoluble dietary fibre intake is associated, by unknown mechanisms, with a reduced risk of type 2 diabetes. We investigated whether a short-term dietary intervention with purified insoluble fibres influences acute and delayed responses of glucose, insulin, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1.Methods Fourteen healthy women with NGT were studied for 300 min on six to eight occasions. Subjects consumed three matched portions of control (C) or fibre-enriched bread (10.4–10.6 g/portion; wheat fibre [WF], oat fibre [OF], and, in a substudy [n=9], resistant starch [RS]) followed by control (C-C, C-WF, C-OF, C-RS) on subsequent days.Results Fibre enrichment accelerated the early insulin response (fibre×time interaction p=0.026 for WF, p<0.001 for OF, p=0.126 for RS; time of maximal concentration [T_max], C 57.9±5.9, WF 49.3±2.5 [p=0.086], OF 46.1±2.9 [p=0.026], RS 46.7±5.8 min [p=0.029]). It was also associated with an earlier postprandial GIP response after OF (T_max, C 83.6±7.2, WF 70.7±6.0 [p=0.054], OF 64.3±6.9 [p=0.022], RS 60.0±5.0 [p>0.15]). Increased fibre intake for 24 h was further associated with a reduced postprandial glucose response on the following day subsequent to ingestion of a control meal (AUC_C-C 4,140±401, AUC_C-WF 2,850±331 [p=0.007], AUC_C-OF 2,830±277 [p=0.011]), with no difference in maximal concentration and T_max of glucose responses. No differences in insulin responses were observed 24 h after the fibre-enriched diets compared with control (p>0.15). Colonic fermentation was increased only on study days C-OF (p=0.017) and C-RS (p=0.016).Conclusions/interpretation The consumption of highly purified insoluble dietary fibres accelerated the acute GIP and insulin response and was further associated with enhanced postprandial carbohydrate handling the following day upon ingestion of a control meal.     

Increased rectal cell proliferation following alcohol abuse

BACKGROUND: Epidemiological data indicate an increased risk for rectal cancer following chronic alcohol consumption. As chronic ethanol ingestion leads to rectal hyperregeneration in experimental animals, indicating a state of increased susceptibility to carcinogens, we studied cell proliferation in alcohol abusers. METHODS: Rectal biopsies were taken from 44 heavy drinkers and 26 controls. Cell proliferation, including proliferative compartment size, was measured by immunohistological staining for proliferative cell nuclear antigen (PCNA) and Ki67, and by in situ hybridisation for histone H3. Quantification of cell proliferation using PCNA staining was evaluated in 27 alcohol abusers and 12 controls. In addition, immunohistology was performed for cytokeratins and gene products of Rb1, bcl-2, and p53. RESULTS: Heavy drinking resulted in increased cell proliferation of the rectal mucosa, as shown by increased detection of different proliferation markers. However, cell differentiation regarding cytokeratin expression patterns was unchanged as well as regulatory factors involved in carcinogenesis and/or apoptosis. CONCLUSION: Chronic alcohol abuse leads to rectal mucosal hyperproliferation in humans, a condition associated with an increased cancer risk.     

Gastric or rectal instillation of short-chain fatty acids stimulates epithelial cell proliferation of small and large intestine in rats

Short-chain fatty acids stimulate gut epithelial cell proliferation in vivo, although the difference between oral and rectal routes is unknown. Accordingly, we examined the effect of oral or rectal administration of these acids. We instilled a mixture of acetic acid, propionic acid, and n-butyric acid (150, 60, and 60 mmol/liter, respectively; pH 6.5) or saline (270 mM, pH 6.5) into the stomach (2 ml) or rectum (1 ml) three times daily for five days in rats fed an elemental diet. We measured crypt cell production rate of the jejunum, ileum, and distal colon of these rats. The crypt cell production rate of these segments was higher in rats with gastric or rectal instillation of short-chain fatty acids than in saline controls. The rectal route was slightly more effective than the gastric route. The above results indicated that the instillation of short-chain fatty acids orally or rectally stimulated gut epithelial cell proliferation.     

阿司匹林、氯吡格雷联用对人胃黏膜上皮细胞株GES-1增殖的影响

目的探讨阿司匹林、氯吡格雷及二者联用对人胃黏膜上皮细胞株GES-1增殖的影响。方法体外培养人胃黏膜上皮细胞株GES-1,分别将不同浓度阿司匹林(2.5、5、10和20mmol/L)及氯吡格雷(0.01、0.1、0.5和1mmol/L)与GES-1细胞共同培养24、48、72h,采用MTT比色法计算细胞生长抑制率。分别以药物的不同浓度对GES-1细胞生长抑制率作图,得到剂量反应曲线。根据Bliss法,分别求出阿司匹林和氯吡格雷的半数抑制浓度(IC50),倒置相差显微镜下观察IC50剂量阿司匹林和IC50剂量氯吡格雷单独和联合与GES-1细胞共同培养24h后,细胞形态学变化。MTT比色法检测药物联合作用对GES-1细胞增殖率的影响。结果阿司匹林对GES-1细胞的损害呈剂量和时间依赖性。阿司匹林作用24h的IC50为18.32mmol/L(95%CI=2.66～26.98)。氯吡格雷对GES-1细胞的损害呈剂量依赖性,但无时间依赖性。氯吡格雷作用24h的IC50为0.36mmol/L(95%CI=0.26～0.46)。光镜下可见药物作用后贴壁细胞数量减少,细胞变圆,悬浮,部分细胞核浓缩;药物联合作用组悬浮细胞数明显增多,细胞损害明显增大。氯吡格雷和阿司匹林联合使用对GES-1细胞的生长抑制率明显高于单独使用阿司匹林或氯吡格雷(P0.01)。结论阿司匹林和氯吡格雷均可抑制人胃黏膜上皮细胞的增殖,二者联合使用对细胞的损害具有协同作用。     

Effect of cholecystokinin-octapeptide, caerulein, and pentagastrin on epithelial cell proliferation in the murine gallbladder

The growth-promoting effect of cholecystokinin-octapeptide, caerulein, and pentagastrin on gallbladder mucosa was investigated in mice. The acute effects on deoxyribonucleic acid synthesis activity was explored with a [3H]thymidine pulse and autoradiography after subcutaneous injection of the polypeptides. The administration of a supramaximal dose of caerulein or of cholecystokinin-octapeptide induced a significant increase (p less than 0.01) in the nuclear uptake of [3H]thymidine by the gallbladder epithelial cells. The injection of pentagastrin had no effect. Implantation of osmotic minipumps was used for the chronic administration of submaximal doses of caerulein or pentagastrin. Using successive [3H]thymidine pulses and autoradiography, increases in labeling (p less than 0.01) and mitotic indices (p less than 0.05) were observed in the caerulein group, whereas pentagastrin had no effect. In addition, a morphometric method was used to determine the total epithelial cell number in the entire gallbladder after chronic administration of the peptides. A significant (p less than 0.01) epithelial cell hyperplasia was observed to occur after caerulein administration whereas pentagastrin given by the same route had no effect on the epithelial cell population. These data indicate that cholecystokininlike peptides promote epithelial growth in the gallbladder of mice.     

Effect of ethanol and vitamin A deficiency on epithelial cell proliferation and structure in the rat esophagus

An increased risk of cancer of the esophagus has been reported in alcoholics and in populations with low dietary vitamin A consumption. As cancer is a disorder of cell proliferation and differentiation, we have assessed the combined effects of ethanol and vitamin A deficiency on cell proliferation and structure of the esophagus. Weanling male rats were fed liquid diets with either a standard amount of vitamin A or lacking vitamin A for 8 wk. Littermates were pair-fed the same diets with carbohydrate (36% of calories) replaced by ethanol. Rats were given [3H]thymidine 1 h before death, and the labeling index of the proliferative basal cells was determined on radioautographs. In rats fed the normal vitamin A diet with or without ethanol, plasma vitamin A was normal. Hepatic vitamin A was markedly decreased, whereas esophageal vitamin A was increased after ethanol feeding. Ethanol feeding resulted in a twofold increase in basal cell labeling index (14.6 +/- 0.7 vs. 6.8 +/- 0.8; p less than 0.001). The thickness of the epithelium and the morphology of basal cells were not altered by ethanol feeding. In rats fed the vitamin A-deficient diet with or without ethanol, plasma vitamin A was extremely low, and hepatic and esophageal vitamin A were unmeasurable. The epithelium was thin (with a 50% reduction in thickness) and showed abnormalities of basal cells and increased production of keratohyalin granules, changes suggesting a disorder in the epithelial differentiation. This altered differentiation caused by vitamin A deficiency was not affected by ethanol consumption. Ethanol feeding again resulted in an increase in the basal cell labeling index (13.2 +/- 1.6 vs. 4.8 +/- 0.7; p less than 0.001). Vitamin A deficiency had no effect on basal cell proliferation. Therefore, the stimulatory effect of ethanol on cell proliferation is independent of vitamin A deficiency. Nevertheless, the combined actions of ethanol and vitamin A deficiency may have a synergistic effect on the susceptibility of the esophagus to carcinogens.     

Effect of acute and chronic glucocorticoid treatments on epithelial cell proliferation in the esophagus and small intestine of rats

Data about glucocorticoid influence on proliferation in the esophagus and small intestine are very contradictory and need to be reexamined. Moreover, only the effects of acute or short-term treatments with glucocorticoids have been demonstrated, whereas nothing is known about their effects under chronic exposure. This work was therefore carried out to examine proliferative activity in the esophagus and small intestine under conditions of acute and chronic glucocorticoid exposure. Rats were treated with either glucocorticoid triamcinolone acetonide or vehicle for 3, 33, or 63 days. Proliferation was assessed in the basal layer of esophageal epithelium and in the epithelium of jejunal crypts, using three criteria, as the number of mitotic, bromodeoxyuridine-labelled, and proliferating cell nuclear antigen-labelled cells. Treatment with glucocorticoid for 3 days led to a slight decrease in all parameters in the esophageal epithelium and had almost no effect on proliferation in the epithelium of jejunal crypts. Long-term treatment with glucocorticoid for either 33 or 63 days resulted in an increase in all parameters tested in both esophageal and jejunal crypt epithelia. Sixty-three-day treatment had a more prominent and significant (P < 0.05) effect. These results suggest that acute glucocorticoid treatment nonsignificantly reduces the number of cells in the cell cycle in the esophageal epithelium, whereas chronic treatment increases the number of proliferating cells in both esophageal and jejunal crypt epithelia. Received: February 22, 1999 / Accepted: June 25, 1999     

Divergent effects of epidermal growth factor and calcipotriol on human rectal cell proliferation.

Vitamin D may protect against colorectal cancer by reducing cell proliferation and inducing differentiation. By contrast, epidermal growth factor (EGF) stimulates cell proliferation and may encourage gastrointestinal mucosal healing. This study investigated the effect of a synthetic vitamin D analogue, calcipotriol, and EGF on human rectal epithelial cell proliferation in patients with familial adenomatous polyposis (FAP). In addition, a new technique to measure the cell cycle time is described. Sigmoidoscopic biopsy specimens were obtained from 14 patients with FAP. Tissue was established in organ culture, with or without the addition of EGF (n = 8), or calcipotriol (n = 6). Proliferation was determined using (a) metaphase arrest to measure the crypt cell production rate, (b) native mitotic index, and (c) the growth fraction using PC10 antibody. EGF receptor expression was shown using a polyclonal antibody AP12E. Calcipotriol reduced crypt cell production rate by 52% from mean (SEM) 5.29 (1.18) to 2.56 (0.80) cells/crypt/hour (p < 0.01) and EGF increased crypt cell production rate by 102% from 3.62 (0.59) to 7.33 (0.90) cells/crypt/hour (p < 0.05), and this tissue expressed the EGF receptor. The growth fraction was 48.40 (4.0)%, and the native mitotic index 1.08 (0.14)%. The cell cycle time was estimated as 94.5 hours and the time for mitosis as one hour. Thus, calcipotriol and EGF have divergent effects on human rectal mucosal proliferation.