Efficacy of artificial intelligence in reducing miss rates of GI adenomas, polyps, and sessile serrated lesions: a meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: The aim of this study was to determine if utilization of artificial intelligence (AI) in the course of endoscopic procedures can significantly diminish both the adenoma miss rate (AMR) and the polyp miss rate (PMR) compared with standard endoscopy. METHODS: We performed an extensive search of various databases, encompassing PubMed, Embase, Cochrane Library, Web of Science, and Scopus, until June 2023. The search terms used were artificial intelligence, machine learning, deep learning, transfer machine learning, computer-assisted diagnosis, convolutional neural networks, gastrointestinal (GI) endoscopy, endoscopic image analysis, polyp, adenoma, and neoplasms. The main study aim was to explore the impact of AI on the AMR, PMR, and sessile serrated lesion miss rate. RESULTS: A total of 7 randomized controlled trials were included in this meta-analysis. Pooled AMR was markedly lower in the AI group versus the non-AI group (pooled relative risk [RR], .46; 95% confidence interval [CI], .36-.59; P < .001). PMR was also reduced in the AI group in contrast with the non-AI control (pooled RR, .43; 95% CI, .27-.69; P < .001). The results showed that AI decreased the miss rate of sessile serrated lesions (pooled RR, .43; 95% CI, .20 to .92; P < .05) and diminutive adenomas (pooled RR, .49; 95% CI, .26-.93) during endoscopy, but no significant effect was observed for advanced adenomas (pooled RR, .48; 95% CI, .17-1.37; P = .17). The average number of polyps (Hedges' g = -.486; 95% CI, -.697 to -.274; P = .000) and adenomas (Hedges' g = -.312; 95% CI, -.551 to -.074; P = .01) detected during the second procedure also favored AI. However, AI implementation did not lead to a prolonged withdrawal time (P > .05). CONCLUSIONS: This meta-analysis suggests that AI technology leads to significant reduction of miss rates for GI adenomas, polyps, and sessile serrated lesions during endoscopic surveillance. These results underscore the potential of AI to improve the accuracy and efficiency of GI endoscopic procedures.

The associations among Helicobacter pylori infection, white blood cell count and nonalcoholic fatty liver disease in a large Chinese population.

Reported relationships among Helicobacter pylori infection, white blood cell (WBC) count and nonalcoholic fatty liver disease (NAFLD) are inconsistent and controversial. We, therefore, conducted a cross-sectional study to investigate the associations among the presence of NAFLD, WBC count and H pylori infection, as diagnosed using the C-urea breath test (UBT).This study included 20,389 subjects enrolled at the International Health Care Center of the Second Affiliated Hospital of the Zhejiang University School of Medicine from January 2015 to December 2015. All participants underwent a C-UBT for the diagnosis of H pylori infection and ultrasonography for NAFLD as well as a blood test to determine WBC count. Multivariate logistic regression was then performed to evaluate the relationship among H pylori infection, WBC count and NAFLD.H pylori infection was detected in 38.49% (7,848/20,389) of the subjects via the UBT, and NAFLD was present in 37.24% (7,592/20,389) of the subjects. The prevalence of H pylori infection was higher in the NAFLD group than in the control group (41.25% vs 36.85%, P <.001). Significant differences were found between various WBC quartiles and H pylori infection, age, gender, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), high-sensitivity C-reactive protein (HS-CRP), glycosylated hemoglobin (HbA1c), triglyceride (TG), low-density lipoprotein (LDL-C), fasting blood glucose (FPG), homeostasis model assessment of insulin resistance (HOMA-IR), and smoking. Multivariate logistic regression revealed that the combination of H pylori infection and WBC count (odds ratio [OR] = 1.067, 95% confidence interval [CI]: 1.014, 1.093; P = .007; OR = 1.165, 95% CI: 1.023, 1.488; P <.001; OR = 1.183, 95% CI: 1.085, 1.559; P <.001, respectively) was positively associated with NAFLD.H pylori infection and WBC count may contribute to the pathogenesis of NAFLD.

Downregulation of GEP100 Improved the Growth Inhibition Effect of Erlotinib Through Modulating Mesenchymal Epithelial Transition Process in Pancreatic Cancer.

OBJECTIVE: The epidermal growth factor receptor is overexpressed in the majority of pancreatic cancer. Epidermal growth factor receptor tyrosine kinase inhibitor erlotinib was approved to treat patients combining with gemcitabine. However, the sensitivity is low. Here, we try to reveal the regulatory role of guanine nucleotide exchange protein 100 (GEP100) in erlotinib sensitivity. METHODS: We investigated the correlation between GEP100 expression and sensitivity to erlotinib in different pancreatic cancer cell lines, followed by examination of the effect of GEP100 on erlotinib sensitivity by establishing the stable knocked-down cell line. The expression level of epithelial mesenchymal transition-related protein was examined by Western blot, and the regulatory mechanism was investigated by short hairpin RNA. Xenograft experiment was also performed in nude mice. RESULTS: We identified a significant correlation between sensitivity to erlotinib and expression of GEP100. GEP100 downregulation increased its sensitivity to erlotinib. E-cadherin short hairpin RNA treatment inhibited this sensitivity. Immunohistochemical staining showed a mutual exclusive expression pattern of GEP100 and E-cadherin in human pancreatic cancer tissues. Xenograft showed that downregulation of GEP100 enhanced the growth inhibition of erlotinib in nude mice. CONCLUSIONS: Our results suggested that GEP100 and E-cadherin have the predictive value for responsiveness to erlotinib in pancreatic cancer.

The virus-induced protein APOBEC3G inhibits anoikis by activation of Akt kinase in pancreatic cancer cells.

Pancreatic cancer is one of the more common cancers with a poor prognosis. Some varieties of cancer are related to virus infection. As a virus-induced protein, APOBEC3G (A3G) presents extensive anti-virus ability, but the role of A3G in pancreatic cancer was previously unknown. The expression of A3G in pancreatic cancer was examined using TaqMan real-time qPCR, immunohistochemical and immunofluorescent staining. Subsequently, the role of A3G in pancreatic cancer was evaluated in vivo using the tumor xenograft model. Anoikis was detected by colony formation assay and flow cytometry in vitro. The Akt kinase activity and target protein PTEN were examined by co-immunoprecipitation and immunoblot. The virus-induced protein A3G was significantly up-regulated in pancreatic cancer, and the up-regulation of A3G promoted xenograft tumor formation. A3G inactivated PTEN by binding to the C2 tensin-type and PDZ domains, thereby inducing anoikis resistance through Akt activation. Our results demonstrate that the up-regulation of A3G in pancreatic cancer cells induces anoikis resistance, and they provide novel insight into the mechanism by which A3G affects the malignant behavior of pancreatic cancer cells.

Down-regulation of GEP100 causes increase in E-cadherin levels and inhibits pancreatic cancer cell invasion.

AIMS: Invasion and metastasis are major reasons for pancreatic cancer death and identifying signaling molecules that are specifically used in tumor invasion is of great significance. The purpose of this study was to elucidate the role of GEP100 in pancreatic cancer cell invasion and metastasis and the corresponding molecular mechanism. METHODS: Stable cell lines with GEP100 knocked-down were established by transfecting GEP100 shRNA vector into PaTu8988 cells and selected by puromycin. qRT-PCR and Western blot were performed to detect gene expression. Matrigel-invasion assay was used to detect cancer cell invasion in vitro. Liver metastasis in vivo was determined by splenic injection of indicated cell lines followed by spleen resection. Immunofluorescence study was used to detect the intracellular localization of E-cadherin. RESULTS: We found that the expression level of GEP100 protein was closely related to the invasive ability of a panel of 6 different human pancreatic cancer cell lines. Down-regulation of GEP100 in PaTu8988 cells significantly decreased invasive activity by Matrigel invasion assay, without affecting migration, invasion and viability. The inhibited invasive activity was rescued by over-expression of GEP100 cDNA. In vivo study showed that liver metastasis was significantly decreased in the PaTu8988 cells with GEP100 stably knocked-down. In addition, an epithelial-like morphological change, mimicking a mesenchymal to epithelial transition (MET) was induced by GEP100 down-regulation. The expression of E-cadherin protein was increased 2-3 folds accompanied by its redistribution to the cell-cell contacts, while no obvious changes were observed for E-cadherin mRNA. Unexpectedly, the mRNA of Slug was increased by GEP100 knock-down. CONCLUSION: These findings provided important evidence that GEP100 plays a significant role in pancreatic cancer invasion through regulating the expression of E-cadherin and the process of MET, indicating the possibility of it becoming a potential therapeutic target against pancreatic cancer.

K-Ras resides on the Arf6-mediated CIE system and its active type interacted with Arf6T27N.

Ras is known as an oncogene transferring signals from the plasma membrane. Recent studies have demonstrated that plasma membrane was not the unique platform for Ras signaling. Ras could also be endocytosed and transported to different endomembrane compartments, evoking different signal pathways there. It is of great significance to exploit the unique intracellular trafficking features of different Ras isoforms to develop new anti-Ras drugs. ADP-ribosylation factor 6 (Arf6) was known to mediate one of the clathrin-independent endocytosis (CIE) pathways. The role of Arf6 in K-Ras dynamic remains largely unknown. In this study, we showed that K-RasG12V co-localized with Arf6 at the plasma membrane, and entered the tubular endosomes or protrusions induced by cytochalasin D or aluminum fluoride in the same way as H-RasG12V does. A subcellular fractionation experiment demonstrated that Arf6 siRNA treatment reduced the plasma membrane presence of both endogenous Ras isoforms and inhibited the phosphorylation of Erk triggered by EGF. When co-expressed with Arf6Q67L, both isoforms were sequestered into the large phosphatidylinositol 4,5-biphosphate [PI(4,5)P2]-enriched vacuoles. However, when co-expressed with Arf6T27N, K-RasG12V co-localized with Arf6T27N at the tubular endosomes significantly than H-RasG12V. Immunoprecipitation and GST fusion protein pull-down studies found out for the first time that K-RasG12V interacted with Arf6T27N. Swapping mutation study showed that the above difference was due to different C-termini. Our study indicated that Arf6 was involved in the dynamic regulation of both Ras isoforms.

Endoscopic ultrasound features of gastric schwannomas with radiological correlation: a case series report.

Gastric schwannomas are rare mesenchymal tumors of the gastrointestinal tract. They are usually misdiagnosed as other submucosal tumors preoperatively. Experience of the imaging features of gastric schwannomas is extremely limited. In this report, we summarize the features of a series of endoscopic ultrasound (EUS) images of gastric schwannomas in an effort to improve the diagnosis and differential diagnosis rate. We retrospectively reviewed the endosonographic features of four patients with gastric schwannomas and their computed tomography imaging results. Gastric schwannomas had heterogeneous hypoechogenicity or isoechogenicity, and a well-demarcated margin. The tumors originated from the fourth layer. Cystic changes and calcification were uncommon. Marginal hypoechoic haloes were observed in two patients. The results described here were different from those of previous studies. In the EUS evaluation, the internal echogenicity of gastric schwannomas was heterogeneous and low, but slightly higher than that of muscularis propria. These features might help us differentiate gastric schwannomas from other submucosal tumors. Further investigation is needed to differentiate these mesenchymal tumors.

ADP-ribosylation factor like 7 (ARL7) interacts with alpha-tubulin and modulates intracellular vesicular transport.

ADP-ribosylation factor (ARF) like 7 (ARL7, also named ARL4C) is a member of ARL family and recent studies showed that it is involved in the AI-dependent cholesterol secretion process. Yet its biological function remains largely unknown. Using a MALDI-TOF/MS analysis, we identified alpha-tubulin interacted with ARL7. The interaction was confirmed by GST pull-down assay and co-immunoprecipitation in renal carcinoma cell 786-O in which we found the endogenous ARL7 is expressed. This is the second ARL member found interacting with tubulin after ARL8. In addition, ARL7Q72L, a GTP-binding form, promoted the transferrin transport from early endosome to recycling endosome significantly. The above data suggested that ARL7 might modulate the intracellular vesicular transport via interaction with microtubules.

Therapeutic effects of rectal administration of muscovite on experimental colitis in rats.

BACKGROUND AND AIMS: The aim of this study was to investigate whether rectal administration of muscovite can ameliorate colonic inflammation in a rat model of experimental colitis, and its possible mechanism. METHODS: Female Sprague-Dawley (SD) rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis were treated with rectal administration of muscovite or 5-aminosalicylic acid (5-ASA) daily for 14 days. The changes in body weight, macroscopic damage and histologic scores were subsequently evaluated. Gene expression of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), mucin2 (MUC2) and trefoil factor 3 (TFF3) in the colonic tissues was assessed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR) while protein levels of TNF-alpha and IL-1beta were detected by ELISA. Mucin2 expression in colonic mucosa was detected by immunohistochemistry. The capacity of muscovite to adsorb cytokines in vitro was determined by the changes in the amount of TNF-alpha, IL-1beta secreted by lipopolysaccharide (LPS)-stimulated THP-1 cells and IL-8 secreted by LPS-stimulated HT-29 cells. RESULTS: Rectal administration of muscovite improved the loss of body weight, macroscopic and histologic scores of TNBS-induced colitis in a dose-dependent manner. Trinitrobenzene sulfonic acid-induced expression of TNF-alpha and IL-1beta was reduced by muscovite and 5-ASA treatment. Reduction of MUC2 expression in colitis rats was reversed by muscovite and 5-ASA treatment. However, the expression of TFF3 mRNA in colonic mucosa was not affected. In addition, we found muscovite inhibited the expression of TNF-alpha, IL-1beta secreted by THP-1 and IL-8 secreted by HT-29 cells in a dose-dependent manner. CONCLUSIONS: Our study demonstrated for the first time that rectal administration of muscovite can ameliorate colonic inflammation of TNBS-induced colitis. Further confirmatory studies are needed to prove that muscovite might be a potential therapeutic agent for the treatment of ulcerative colitis.

Reliable experimental model of hepatic veno-occlusive disease caused by monocrotaline.

BACKGROUND: Hepatic veno-occlusive disease (HVOD) is a severe complication of chemotherapy before hematopoietic stem cell transplantation and dietary ingestion of pyrrolizidine alkaloids. Many experimental models were established to study its mechanisms or therapy, but few are ideal. This work aimed at evaluating a rat model of HVOD induced by monocrotaline to help advance research into this disease. METHODS: Thirty-two male rats were randomly classified into 5 groups, and PBS or monocrotaline was administered (100 mg/kg or 160 mg/kg). They were sacrificed on day 7 (groups A, B and D) or day 10 (groups C and E). Blood samples were collected to determine liver enzyme concentrations. The weight of the liver and body and the amount of ascites were measured. Histopathological changes of liver tissue on light microscopy were assessed by a modified Deleve scoring system. The positivity of proliferating cell nuclear antigen (PCNA) was estimated. RESULTS: The rats that were treated with 160 mg/kg monocrotaline presented with severe clinical symptoms (including two deaths) and the histopathological picture of HVOD. On the other hand, the rats that were fed with 100 mg/kg monocrotaline had milder and reversible manifestations. Comparison of the rats sacrificed on day 10 with those sacrificed on day 7 showed that the positivity of PCNA increased, especially that of hepatocytes. CONCLUSIONS: Monocrotaline induces acute, dose-dependent HVOD in rats. The model is potentially reversible with a low dose, but reliable and irreversible with a higher dose. The modified scoring system seems to be more accurate than the traditional one in reflecting the histopathology of HVOD. The enhancement of PCNA positivity may be associated with hepatic tissue undergoing recovery.

Anticancer activity of genistein on implanted tumor of human SG7901 cells in nude mice.

AIM: To investigate genistein-induced apoptosis of implanted tumors of SG7901 cells in nude mice, and the relationship between this apoptosis and expression of Bcl-2 and Bax. METHODS: Establishing a transplanted tumor model by injecting human SG7901 cells into subcutaneous tissue of nude mice. Genistein (0.5, 1 and 1.5 mg/kg) was directly injected adjacent to the tumor, six times at 2-d intervals. Then, changes in tumor volume were measured continuously and tumor inhibition rate of each group was calculated. We observed the morphological alterations by transmission electron microscopy (TEM), measured the apoptotic rate by the TUNEL staining method, and detected the expression of apoptosis-regulated gene Bcl-2 and bax by immunohistochemical staining and RT-PCR. RESULTS: Genistein 0.5, 1 and 1.5 mg/kg significantly inhibited carcinoma growth when it was injected near the tumor by 10.8%, 29.9% and 39.6%, respectively. Genistein induced implanted tumor cells to undergo apoptosis, with apoptotic characteristics seen by TEM. The apoptosis index was increased progressively with increasing genistein dose (28.9%+/-1.2%, 33.8%+/-1.6% and 37.7%+/-1.2%). The positive rate of Bcl-2 protein was decreased progressively (11.9%+/-0.9%, 5.9%+/-0.7% and 4.2%+/-0.6%), and the positive rate of bax protein was increased progressively (0.9%+/-1.7%, 24.9%+/-0.8% and 29.6%+/-1.7%) by immunohistochemical staining, with increasing dose of genistein. The density of Bcl-2 mRNA decreased progressively and the density of bax mRNA increased progressively with elongation of time by RT-PCR. CONCLUSION: Genistein was able to induce apoptosis of transplanted tumor cells. This apoptosis may be mediated by down-regulation of the apoptosis-regulated gene Bcl-2 and up-regulation of apoptosis-regulated gene bax.

Induction of experimental acute ulcerative colitis in rats by administration of dextran sulfate sodium at low concentration followed by intracolonic administration of 30% ethanol.

Several models of experimental ulcerative colitis have been reported previously. However, none of these models showed the optimum characteristics. Although dextran sulfate sodium-induced colitis results in inflammation resembling ulcerative colitis, an obvious obstacle is that dextran sulfate sodium is very expensive. The aim of this study was to develop an inexpensive model of colitis in rats. Sprague-Dawley rats were treated with 2% dextran sulfate sodium in drinking water for 3 d followed by an intracolonic administration of 30% ethanol. The administration of 2% dextran sulfate sodium followed by 30% ethanol induced significant weight loss, diarrhea and hematochezia in rats. Severe ulceration and inflammation of the distal part of rat colon were developed rapidly. Histological examination showed increased infiltration of polymorphonuclear leukocytes, lymphocytes and existence of cryptic abscesses and dysplasia. The model induced by dextran sulfate sodium at lower concentration followed by 30% ethanol is characterized by a clinical course, localization of the lesions and histopathological features similar to human ulcerative colitis and fulfills the criteria set out at the beginning of this study.

Morphological and pathologic changes of experimental chronic atrophic gastritis (CAG) and the regulating mechanism of protein expression in rats.

OBJECTIVE: To study the pathologic change and molecular regulation in cell proliferation and apoptosis of gastric mucosa in rats with chronic atrophic gastritis (CAG), and evaluate the possible mechanisms. METHODS: Rats were administered with 60% alcohol or 2% salicylate sodium, 20 mmol/L deoxycholate sodium and 0.1% ammonia water to establish chronic atrophic gastritis (CAG) models. The gastric specimens were prepared for microscopic view with hematoxylin and eosin (H-E) and alcian blue (A-B) stain. The number of infiltrated inflammatory cells, the thickness of the mucosa gland layer (microm) and the number of gastric glands were calculated. The damage of barrier in mucosa with erosion or ulceration, and the thickness of mucin were examined by scanned electron microscope (SEM). The levels of PGE(2), EGF (epiderminal growth factor) and gastrin in the serum were measured with radioimmunoassay or ELISA method. The immunohistochemistry method was used to observe the number of G cells, the expression of protein of EGFR (EGF receptor), C-erbB-2, p53, p16 and bcl-2 in gastric tissue. RESULTS: Under SEM observation, the gastric mucosa was diffused erosion or ulceration and the thickness of mucin was decreased. Compared with normal rats, the grade of inflammatory cell infiltration in CAG rats was elevated, whereas the thickness and number of gastric gland were significantly lower (P<0.05). Compared with normal level of (0.61+/-0.28) microg/L, EGF in CAG (2.24+/-0.83) microg/L was significantly higher (P<0.05). The levels of PGE(2) and gastrin in serum were significantly lower in CAG rats than that in normal rats (P<0.05). Immunohistochemistry detection showed that the number of G cell in antrum was lower in CAG group (P<0.05). Immuno-stain showed EGFR protein expression in the basal and bilateral membrane, and the cytoplasma in atrophic gastric gland, while negative expression was observed in normal gastric epithelial cells. Positive staining of p53 and p16 protein was localized in the nucleus of epithelial cells. The former was higher positively expressed in atrophic gland, while the later was higher positively stained in normal gastric tissue. bcl-2 protein was positively stained in the cytoplasma in atrophic gastric gland, while very weakly stained in normal gastric tissue. CONCLUSION: The pathological findings in gastric gland accorded with the Houston diagnostic criteria of antrum-predominant CAG. CAG in rats was related with the damage of barrier in gastric mucosa and the misbalance of cell proliferation and apoptosis. There was high protein expression of oncogene, while inhibitor of suppressor gene in CAG rats indicated high trend of carcinogenesis.

Expression of trefoil factors 1 and 2 in precancerous condition and gastric cancer.

AIM: To study the expression of trefoil factor 1 (TFF1) and TFF2 in precancerous condition and gastric cancer and to explore the relationship between TFFs and tumorigenesis, precancerous condition and gastric cancer. METHODS: The expression of TFF1 and TFF2 was immunohistochemically analyzed in paraffin-embedded samples from 140 patients including 35 cases of chronic superficial gastritis (CSG), 35 cases of gastric ulcer (GU), 35 cases of chronic atrophic gastritis (CAG) and 35 cases of gastric cancer (GC). RESULTS: TFF1 and TFF2 were located in cytoplasm of gastric mucous cells. In CSG, GU, CAG and GC, the level of TFF1 expression had a decreased tendency (P < 0.05). The expression of TFF2 was higher in GU than in CSG, but the difference was not significant. The expression of TFF2 also had a decreased tendency in GU, CAG, and GC (P < 0.05). CONCLUSION: The reduced expression of TFF1 and TFF2 in precancerous conditions and gastric cancer may be associated with the proliferation and malignant transformation of gastric mucosa. More investigations are needed to explore the mechanism of TFFs and the relationship between TFFs and gastric cancer.

Anticancer activity of resveratrol on implanted human primary gastric carcinoma cells in nude mice.

AIM: To investigate the apoptosis of implanted primary gastric cancer cells in nude mice induced by resveratrol and the relation between this apoptosis and expression of bcl-2 and bax. METHODS: A transplanted tumor model was established by injecting human primary gastric cancer cells into subcutaneous tissue of nude mice. Resveratrol (500 mg/kg, 1,000 mg/kg and 1,500 mg/kg) was directly injected beside tumor body 6 times at an interval of 2 d. Then changes of tumor volume were measured continuously and tumor inhibition rate of each group was calculated. We observed the morphologic alterations by electron microscope, measured the apoptotic rate by TUNEL staining method, detected the expression of apoptosis-regulated genes bcl-2 and bax by immunohistochemical staining and PT-PCR. RESULTS: Resveratrol could significantly inhibit carcinoma growth when it was injected near the carcinoma. An inhibitory effect was observed in all therapeutic groups and the inhibition rate of resveratrol at the dose of 500 mg/kg, 1,000 mg/kg and 1,500 mg/kg was 10.58%, 29.68% and 39.14%, respectively. Resveratrol induced implanted tumor cells to undergo apoptosis with apoptotic characteristics, including morphological changes of chromatin condensation, chromatin crescent formation, nucleus fragmentation. The inhibition rate of 0.2 mL of normal saline solution, 1,500 mg/kg DMSO, 500 mg/kg resveratrol, 1 000 mg/kg resveratrol, and 1 500 mg/kg resveratrol was 13.68+/-0.37%, 13.8+/-0.43%, 48.7+/-1.07%, 56.44+/-1.39% and 67+/-0.96%, respectively. The positive rate of bcl-2 protein of each group was 29.48+/-0.51%, 27.56+/-1.40%, 11.86+/-0.97%, 5.7+/-0.84% and 3.92+/-0.85%, respectively by immunohistochemical staining. The positive rate of bax protein of each group was 19.34+/-0.35%, 20.88+/-0.91%, 40.02+/-1.20%, 45.72+/-0.88% and 52.3+/-1.54%, respectively by immunohistochemical staining. The density of bcl-2 mRNA in 0.2 mL normal saline solution, 1,500 mg/kg DMSO, 500 mg/kg resveratrol, 1,000 mg/kg resveratrol, and 1,500 mg/kg resveratrol decreased progressively and the density of bax mRNA in 0.2 mL normal saline solution, 1,500 mg/kg DMSO, 500 mg/kg resveratrol, 1,000 mg/kg resveratrol, and 1,500 mg/kg increased progressively with elongation of time by RT-PCR. CONCLUSION: Resveratrol is able to induce apoptosis of transplanted tumor cells. This apoptosis may be mediated by down-regulating apoptosis-regulated gene bcl-2 and up-regulating the expression of apoptosis-regulated gene bax.

Apoptosis of human primary gastric carcinoma cells induced by genistein.

AIM: To investigate the apoptosis in primary gastric cancer cells induced by genistein, and the relationship between this apoptosis and expression of bcl-2 and bax. METHODS: MTT assay was used to determine the cell growth inhibitory rate in vitro. Transmission electron microscope and TUNEL staining were used to quantitatively and qualitatively detect the apoptosis of primary gastric cancer cells before and after genistein treatment. Immunohistochemical staining and RT-PCR were used to detect the expression of apoptosis-associated genes bcl-2 and bax. RESULTS: Genistein inhibited the growth of primary gastric cancer cells in dose-and time-dependent manner. Genistein induced primary gastric cancer cells to undergo apoptosis with typically apoptotic characteristics. TUNEL assay showed that after the treatment of primary gastric cancer cells with genistein for 24 to 96 h, the apoptotic rates of primary gastric cancer cells increased time-dependently. Immunohistochemical staining showed that after the treatment of primary gastric cancer cells with genistein for 24 to 96 h, the positivity rates of Bcl-2 proteins were apparently reduced with time and the positivity rates of Bax proteins were apparently increased with time. After exposed to genistein at 20 micromol/L for 24, 48, 72 and 96 respectively, the density of bcl-2 mRNA decreased progressively and the density of bax mRNA increased progressively with elongation of time. CONCLUSION: Genistein is able to induce the apoptosis in primary gastric cancer cells. This apoptosis may be mediated by down-regulating the apoptosis- associated bcl-2 gene and up-regulating the expression of apoptosis-associated bax gene.

[The expression of trefoil factor 1 and trefoil factor 2 in gastric cancer and precancer].

OBJECTIVE: Trefoil factor 1 (TFF1) and trefoil factor 2 (TFF2) are members of the trefoil peptide family. To investigate the relationship between TFF1, TFF2 and tumorigenesis of precancerous conditions and gastric cancer. METHODS: The expression of TFF1, TFF2 was determined by immunohistochemical method in 140 gastric specimens including 35 chronic superficial gastritis (CSG), 35 gastric ulcer (GU), 35 chronic atrophic gastritis (CAG) and 35 gastric cancer (GC). RESULTS: In the CSG, GU, CAG and GC, the level of TFF1 expression had a decreasing tendency (P < 0.05). The expression of TFF2 also had a decreased tendency in GU, CAG, and GC (P < 0.05). CONCLUSIONS: The reducing expression of TFF1, TFF2 in the precancerous conditions and gastric cancer was confirmed, and the decrease of TFF1, TFF2 expression may be related to tumorigenesis, progression and the degree of tumor differentiation. Further studies will be necessary to determine the mechanisms of TFF1, TFF2 in the tumor and prospects of clinical implication.

[Effect of selective cyclooxygenase-2 inhibitor celebrex on expression of vascular endothelial growth factor (VEGF) in pancreatic carcinoma].

BACKGROUND & OBJECTIVE: The previous study has identified that cyclooxygenase-2 (COX-2) may have a close relation with tumor genesis, particularly with digestive tract tumors, and its inhibitor can exert the chemoprevention role on carcinogenesis. This study was designed to investigate the effect of celebrex, a selective cyclooxygenase-2 inhibitor, on the expression of vascular endothelial growth factor (VEGF) in pancreatic carcinoma of xenografted nude mice induced by pancreatic carcinoma PC-3 cell lines. METHODS: The effect of celebrex on tumor growth was observed.The expression of VEGF in the tumors was determined by reverse transcription polymerase chain reaction (RT-PCR), Western blot analysis, and enzyme-linked immunosorbent assay (ELISA). RESULTS: Average tumor volume and tumor weight from control mice were 0.438+/-0.052 cm(3) and 0.552+/-0.064 g as compared with 0.215+/-0.038 cm(3) and 0.244+/-0.042 g from treated mice (inhibition rate:51.6%,P< 0.05). VEGF expression was significantly down-regulated in the celebrex-treated tumors. ELISA revealed that the expression levels of VEGF were 1.11+/-0.11(microg/g) in control mice and the 0.66+/-0.11(microg/g) in the treated mice. The inhibition rate of VEGF was 40.6% (P< 0.05). CONCLUSION: COX-2 may play an important role in the angiogenesis of pancreatic carcinoma. The selective COX-2 inhibitor, celebrex, can result in the inhibition of angiogenesis and tumor growth.