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Gastrointestinal (GI) cancers are the major cause of cancer-related mortality globally. Medical imaging is an important auxiliary means for the diagnosis, assessment and prognostic prediction of GI cancers. Radiomics is an emerging and effective technology to decipher the encoded information within medical images, and traditional machine learning is the most commonly used tool. Recent advances in deep learning technology have further promoted the development of radiomics. In the field of GI cancer, although there are several surveys on radiomics, there is no specific review on the application of deep-learning-based radiomics (DLR). In this review, a search was conducted on Web of Science, PubMed, and Google Scholar with an emphasis on the application of DLR for GI cancers, including esophageal, gastric, liver, pancreatic, and colorectal cancers. Besides, the challenges and recommendations based on the findings of the review are comprehensively analyzed to advance DLR., Competing Interests: Conflict-of-interest statement: All authors declare no conflict of interest., (©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.)

Aim: To evaluate the clinical properties of three subpopulations of circulating tumor cells (CTCs) undergoing epithelial-mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC) patients., Methods: We identified CTCs for expression of the epithelial cell marker cytokeratin or epithelial cell adhesion molecule (EpCAM) (E-CTC), the mesenchymal cell markers vimentin and twist (M-CTC), or both (E/M-CTC) using the CanPatrol system. Between July 2014 and July 2016, 107 patients with PDAC were enrolled for CTC evaluation. CTC enumeration and classification were correlated with patient clinicopathological features and outcomes., Results: CTCs were detected in 78.5% of PDAC patients. The number of total CTCs ranged from 0 to 26 across all 107 patients, with a median value of six. CTC status correlated with lymph node metastasis, TNM stage, distant metastasis, blood lymphocyte counts, and neutrophil-to-lymphocyte ratio (NLR). Kaplan-Meier survival analysis showed that patients with ≥ 6 total CTCs had significantly decreased overall survival and progression-free survival compared with patients with < 6 total CTCs. The presence of M-CTCs was positively correlated with TNM stage ( P < 0.01) and distant metastasis ( P < 0.01). Additionally, lymphocyte counts and NLR in patients without CTCs were significantly different from those in patients testing positive for each CTC subpopulation ( P < 0.01)., Conclusion: Classifying CTCs by EMT markers helps to identify the more aggressive CTC subpopulations and provides useful evidence for determining a suitable clinical approach., Competing Interests: Conflict-of-interest statement: The authors do not have any conflict of interest to disclose.

Aim: To investigate the synergistic effects of 3'-azido-3'-deoxythymidine (AZT) and FA-2-b-beta extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro., Methods: MTT analysis was made to examine the inhibition rate of MKN45 cells treated with AZT (2.5, 5, 10 and 20 mg/L) and FA-2-b-beta (5, 10, 20 and 40 mg/L) singly and combinatively for 24, 48 and 72 h. Apoptotic effects were evaluated by morphological methods, DNA agarose gel electrophoresis and flow cytometry, respectively. Telomerase activity was estimated by TRAP-ELISA. The mRNA expression of caspase-3 and Bcl-2 were detected by RT-PCR., Results: AZT and FA-2-b-beta could significantly inhibit MKN45 cell proliferation and induce its apoptosis. MKN45 cells were inhibited in dose- and time- dependent manner. The inhibition effect of AZT combined with FA-2-b-beta was obviously better than that used singly (0.469 +/- 0.022 vs 1.075 +/- 0.055, P < 0.05, 0.325 +/- 0.029 vs 0.469 +/- 0.022 P < 0.01). AZT used singly and combination of FA-2-b-beta could decrease the activity of tumor cell telomerase, and AZT has synergistic function with FA-2-b-beta. A certain concentration of AZT could up-regulate the expression of caspase-3 mRNA (r = 0.9969, P < 0.01), which was positively related to apoptosis rate, and could down-regulate the expression of Bcl-2 mRNA, which was negatively related to apoptosis rate (r = 0.926, P < 0.01). Furthermore, the effect of AZT combined with FA-2-b-beta was significantly higher than that used singly., Conclusion: Combination of AZT and FA-2-b-beta has an obviously synergetic effect in the gastric cancer cells MKN45, which has provided a new approach to the treatment of gastric cancer clinically.

Aim: To explore the expression of macrophage inflammatory protein-1alpha (MIP-1alpha) in Kupffer cells (KCs) following liver ischemia/reperfusion injury IRI in rats., Methods: Forty male SD rats were divided randomly into five groups. A model of partial warm ischemia/reperfusion injury in the rat liver was established. KCs were isolated and incubated one hour, six hours, 12 h, and 24 h after the reperfusion. Tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in the supernatants were measured by ELISA. MIP-1alpha in KCs was detected by immunocytochemical and RT-PCR., Results: No or few MIP-1alpha protein and mRNA were expressed in the KCs of the control group. Its expression in the IRI group had a significant increase after the reperfusion (P < 0.05), which was contrary to the control group., Conclusion: The active behavior of the MIP-1alpha gene in KCs following liver ischemia/reperfusion injury is assumed to be one of the major causes for the hepatic ischemia/reperfusion injury.

Aim: To explore the influence of angiostatin up-regulation on the biologic behavior of gallbladder carcinoma cells in vitro and in vitro, and the potential value of angiostatin gene therapy for gallbladder carcinoma., Methods: A eukaryotic expression vector of pcDNA3.1(+) containing murine angiostatin was constructed and identified by restriction endonuclease digestion and sequencing. The recombinant vector pcDNA3.1-angiostatin was transfected into human gallbladder carcinoma cell line GBC-SD with Lipofectamine 2000, and paralleled with the vector and mock control. The resistant clone was screened by G418 filtration. Angiostatin transcription and protein expression were examined by RT-PCR, immunofluorescence and Western-blot. The supernatant was collected to treat endothelial cells. Cell proliferation and growth in vitro were observed under microscope., Results: Murine angiostatin cDNA was successfully cloned into the eukaryotic expression vector pcDNA3.1 (+). After 14 d of transfection and selection with G418, macroscopic resistant cell cloning was formed in the experimental group transfected with pcDNA 3.1(+)-angiostatin and vector control. But untreated cells died in the mock control. Angiostatin was detected by RT-PCR and protein expression was detected in the experimental group by immunofluorescence and Western-blot. Cell proliferation and growth in vitro in the three groups were observed respectively under microscope. No significant difference was observed in the growth speed of GBC-SD cells between groups that were transfected with and without angiostatin. After treatment with supernatant, significant differences were observed in endothelial cell (ECV-304) growth in vitro. The cell proliferation and growth were inhibited., Conclusion: Angiostatin does not directly inhibit human gallbladder carcinoma cell proliferation and growth in vitro, but the secretion of angiostatin inhabits endothelial cell proliferation and growth.

Aim: To observe the biologic behavior of pancreatic cancer cells in vitro and in vivo, and to explore the potential value of angiostatin gene therapy for pancreatic cancer., Methods: The recombinant vector pcDNA3.1(+)-angiostatin was transfected into human pancreatic cancer cells PC-3 with Lipofectamine 2000, and paralleled with the vector and mock control. Angiostatin transcription and protein expression were determined by immunofluorescence and Western blot. The stable cell line was selected by G418. The supernatant was collected to treat endothelial cells. Cell proliferation and growth in vitro were observed under microscope. Cell growth curves were plotted. The troms-fected or untroms-fected cells overexpressing angiostatin vector were implanted subcutaneously into nude mice. The size of tumors was measured, and microvessel density count (MVD) in tumor tissues was assessed by immunohistochemistry with primary anti-CD34 antibody., Results: After transfected into PC-3 with Lipofectamine 2000 and selected by G418, macroscopic resistant cell clones were formed in the experimental group transfected with pcDNA 3.1(+)-angiostatin and vector control. But untreated cells died in the mock control. Angiostatin protein expression was detected in the experimental group by immunofluorescence and Western-blot. Cell proliferation and growth in vitro in the three groups were observed respectively under microscope. After treatment with supernatant, significant differences were observed in endothelial cell (ECV-304) growth in vitro. The cell proliferation and growth were inhibited. In nude mice model, markedly inhibited tumorigenesis and slowed tumor expansion were observed in the experimental group as compared to controls, which was parallel to the decreased microvessel density in and around tumor tissue., Conclusion: Angiostatin does not directly inhibit human pancreatic cancer cell proliferation and growth in vitro, but it inhibits endothelial cell growth in vitro. It exerts the anti-tumor functions through antiangiogenesis in a paracrine way in vivo.

Aim: To investigate the role of cyclin D1, p16 and retinoblastoma in cancerous process of gallbladder carcinomas and to assess the relation between cyclin D1, p16, Rb and the biological characteristics of gallbladder carcinoma., Methods: Forty-one gallbladder carcinoma, 7 gallbladder adenoma and 14 chronic cholecystitis specimens were immunohistochemically and histopathologically investigated for the relation of cyclin D1, p16 and Rb with Nevin staging and pathologic grading., Results: The expression rates of abnormal cyclin D1 in gallbladder carcinoma (68.3%) and gallbladder adenoma (57.1%) were significantly higher than those in chronic cholecystitis (7.1%) (P<0.05). No significant difference was found both among the pathological grades G(1), G(2) and G(3) and among Nevin stagings S(1)-S(2), S(3) and S(4)-S(5) of gallbladder carcinoma. The positive rates of p16 (48.8%) and Rb (58.5%) in gallbladder carcinoma were significantly lower compared to those in adenoma (100.0%) and cholecystitis (100.0%) (P<0.05). The positive rates of p16 and Rb in Nevin stagings S(1)-S(2) (80.0% and 90.0%) and S(3) (46.2% and 61.5%) gallbladder carcinomas were significantly higher than those in S(4)-S(5) (33.3% and 38.8%) (P<0.05), and those in pathologic grades G(1) (54.5% and 81.8%) and G(2) (50.0% and 62.5%) gallbladder carcinoma were significantly higher than those in G(3) (28.6% and 35.7%) (P<0.05). The protein expression of p16 and Rb had a negative-correlation in gallbladder carcinoma (r = -0.2993, P<0.05), and this negative-correlation was correlated with Nevin staging (P<0.05). Moreover, the protein expression of p16 and cyclin D1 had a negative-correlation in gallbladder carcinoma (r = -0.9417, P<0.05)., Conclusion: Cyclin D1 may play a role in the early stage of gallbladder carcinoma. Mutation of p16 and Rb genes might be correlated with progression of gallbladder carcinoma. Analysis of p16 and Rb can estimate the prognosis of gallbladder carcinoma. Expression of p16 and Rb may be correlated with Nevin staging and pathologic grading in gallbladder carcinoma.

Aim: To detect the micrometastasis of gastric carcinoma in peripheral blood circulation using immunomagnetic beads sorting technique and RT-PCR technique, and to discuss its significance and the difference between the two methods., Methods: Density gradient centrifugation was used to isolate mononuclear cells from peripheral blood, immunomagnetic beads sorting technique and RT-PCR technique were used to detect the disseminated carcinoma cells. HE, immunocytochemical and immunofluorescence staining were also used to identify the characteristics of the cells separated with immunomagnetic beads sorting technique., Results: Cells expressing cytokeratin were separated and enriched from the peripheral blood specimens of patients suffering from gastric carcinoma or chronic gastritis. After HE staining, two kinds of cells with little cytoplasm were found. Majority of these cells had small and round nuclei, even chromatins and the thickness of nuclear membrane was normal. Immunohistochemical staining indicated that there were CD34 and CD45 expression on the cell membrane of this kind of cells and these cells also showed expressed human telomerase reverse transcriptase by immunofluorescence staining, but the expression of carcinoembryonic antigen was absent. So, these cells might hematopoiesis precursors. Another kind of cells had larger and abnormal nuclei with thicker nuclear membranes. Massed chromatins and poly-nucleoli were found in the nuclei. These cells expressed human telomerase reverse transcriptase and carcinoembryonic antigen, but CD34 and CD45 were not found on the cell membrane. So, these cells were considered as gastric carcinoma cells escaping from the original focuses and existing in the peripheral blood circulation. Carcinoma cells were found in 25 of 60(41.7%) specimens of peripheral blood from patients with gastric carcinoma, while there were no such cells separated from the blood specimens of chronic gastritis patients. The difference of positive rates of disseminated carcinoma cells between two groups was markedly significant (P<0.005). The expressions of CK20 mRNA in peripheral blood specimens were examinated with RT-PCR. CK20 mRNA was detected from 32 of 60(53.3%) peripheral blood specimens in the group of gastric carcinoma patients, while none of the specimens from patients suffering from chronic gastritis had CK20 mRNA. Significant difference was also found between two groups (P<0.005). Statistic analyses also showed that there was a significant difference between the positive rates of two methods in detecting the disseminated carcinoma cells from the peripheral blood circulation of gastric carcinoma patients (P<0.05)., Conclusion: The results demonstrated that there were disseminated carcinoma cells in the peripheral blood circulation of some patients with gastric carcinoma. Disseminated carcinoma cells can be detected from the peripheral blood samples with immunomagnetic beads sorting technique and RT-PCR technique. The positive rate of RT-PCR technique is higher than that of immunomagnetic beads sorting technique in detecting micrometastasis.

Aim: To explore the relationship between angiogenesis and biological behaviors of primary gallbladder carcinoma (PGBC), the relationship between the expression of inducible nitric oxide synthase (iNOS) and biological behaviors of PGBC and its relationship with the expression of iNOS and angiogenesis of PGBC., Methods: The expression of iNOS and micro-vessel density (MVD) were assessed by immunohistochemical method and image analysis system in 40 specimens of PGBC and in 8 specimens of normal gallbladder. The immunostaining results and related clinicopathologic materials were analyzed by statistical methods., Results: MVD in PGBC was significantly higher than that in normal gallbladder tissue (46+/-14 vs 14+/-6, P<0.05), and was not related with age, gender, tumor size and histological type. MVD of poorly and undifferentiated tumor tissues was higher than that of moderately-differentiated and well-differentiated tumor tissues (52+/-9 vs 43+/-9 vs 33+/-6, P<0.01). MVD of Nevin IV and V stages was higher than that of Nevin I, II and III stages (52+/-8 vs 37+/-13, P<0.01). MVD of cases with lymphatic or liver metastasis was significantly higher than that without liver metastasis (55+/-6 vs 42+/-10, P<0.05)or lymphatic metastasis (53+/-8 vs 38+/-8, P<0.01). The positive level index (PLI) of iNOS in PGBC was 0.435+/-0.134, and was not related with age, gender, tumor size, histological type, differentiation and clinical stage of PGBC. The PLI of iNOS in cases with lymphatic metastasis was higher than that without lymphatic metastasis (0.573+/-0.078 vs 0.367+/-0.064, P<0.01). The PLI of iNOS in cases with liver metastasis was higher than that without liver metastasis (0.533+/-0.067 vs 0.424+/-0.084, P<0.05). There was a significant correlation between PLI of iNOS and MVD in PGBC (P<0.05)., Conclusion: Angiogenesis of PGBC is significantly related to the biological behaviors of PGBC. The expression of iNOS is related to the biological behaviors of PGBC. The detection of MVD and the expression of iNOS in PGBC can be used as parameters to determine the degree of malignancy and prognosis.

Aim: The diagnosis of cholangiocarcinoma is often difficult, making management approaches problematic. A reliable serum marker for cholangiocarcinoma would be a useful diagnostic test. The aims of our study were to evaluate the usefulness of a serum CA19-9 determination in the diagnosis of cholangiocarcinoma., Methods: We prospectively measured serum CA19-9 and CEA concentrations in patients with cholangiocarcinoma (n=35), benign biliary diseases (n=92), and healthy individuals (n=15). Serum CA19-9 and CEA concentrations were measured by an immunoradiometric assay without knowledge of the clinical diagnosis., Results: The sensitivity of a CA19-9 value >37 KU/L(-1) and a CEA value >22 microg/L(-1) in diagnosing cholangiocarcinoma were 77.14% and 68.57%, respectively. When compared with the benign biliary diseases group, the true negative rates of serum CA19-9 and CEA were 84.78% and 81.52%, respectively. The false positive rates of serum CA19-9 and CEA were 15.22% and 18.48%, whereas the accuracy of serum CA19-9 and CEA were 82.68% and 77.95%, respectively. Serum CA19-9 and CEA concentrations were significantly elevated (P<0.001 and P<0.05) in patients with cholangiocarcinoma (290.31+/-5.34 KU/L(-1) and 36.46+/-18.03 microg/L(-1)) compared with patients with benign biliary diseases (13.38+/-2.59 KU/L(-1) and 13.84+/-3.85 microg/L(-1)) and healthy individuals (12.78+/-3.69 KU/L(-1) and 11.48+/-3.37 microg/L(-1)). In 15 patients undergoing curative resection of cholangiocarcinoma, the mean serum CA19-9 concentration was decreased from a preoperative level of 286.41+/-4.36 KU/L(-1) to a postoperative level of 62.01+/-17.43 KU/L(-1) (P<0.001), and the mean serum CEA concentration from 39.41+/-24.35 microg/L(-1) to 28.69+/-11.03 microg/L(-1) (P<0.05). In patients with cholangiocarcinoma, however, no correlation was found between serum CEA and CA19-9 concentrations (r=0.036)., Conclusion: These data suggest that the serum CA19-9 determination is a useful addition to the available tests for the differential diagnosis of cholangiocarcinoma. Serum CA19-9 is an effective tumor marker in diagnosing cholangiocarcinoma, deciding whether the tumor has been radically resected and monitoring effect of treatment.

Aim: Pancreatic cancer in the head is frequently accompanied by jaundice and high bile acid level in serum. This study focused on the direct effects of bile acids on proliferation and ultrastructural alteration of pancreatic cancer., Methods: Pancreatic cancer cell lines PANC-1, MIA PaCa-2 and PGHAM-1 were explored in this study. The cell lines were cultured in media supplemented with certain bile acids, CA, DCA, LCA, TCDC, TDCA and GCA. Their influence on cell growth was measured with MTT assay after 72 h of incubation. Cell cycles of PANC-1 cells in 40 microM of bile acids media were analyzed by flow cytometry. Ultrastructural alteration of PANC-1 cells induced by DCA was observed using scanning and transmission electron microscope (SEM and TEM)., Results: At various concentrations of bile acids and incubation time, no enhanced effects of bile acids on cell proliferation were observed. Significant inhibitory effects were obtained in almost all media with bile acids. DCA and CA increased the percentage of G0+G1 phase cells, while GCA and TDCA elevated the S phase cell number. After 48 h of incubation in DCA medium, PANC-1 cells showed some structural damages such as loss of their microvilli and vacuolization of organelles in cytoplasm., Conclusion: Bile acids can reduce proliferation of pancreatic cancer cells due to their direct cytotoxicity. This result implies that elevation of bile acids in jaundiced serum may inhibit pancreatic cancer progression.

Aim: To study changes in characteristics of colorectal carcinoma during the metastatic process and to investigate the correlation between cell proliferation activity and metastatic ability of patients with Dukes' stage C or D., Methods: Formalin fixed and paraffin embedded materials of primary tumors and corresponding lymph node metastases resected from 56 patients with Dukes' stage C or D of colorectal carcinoma were stained immunohistochemically with proliferating cell nuclear antigen (PCNA) and CD44 variant exon 6 (CD44v6)., Results: Thirty-one of 56 patients (55.4 %) expressed PCNA in the primary sites and 36 of 56 patients (64.3 %) expressed PCNA in the metastatic lymph nodes. A significant relation in PCNA expression was observed between the primary site and the metastatic lymph node (0.010

Aim: To evaluate the influence of various clinicopathologic factors on survival of patients with bile duct carcinoma after curative resection., Methods: A retrospective analysis was made for 86 cases of bile duct carcinoma treated from January 1981 to September 1995. Fifteen clinicopathologic factors possibly influencing survival were selected. Independent variables were first analyzed by univariate methods. Survival for variable was estimated by the method of Kaplan and Meier. The variables that were statistically significant by univariate analysis were included in a multivariate analysis, which were confirmed using the Cox stepwise proportion hazard model with the help of SPSS 10.0 for Windows software., Results: The overall cumulative survival rate was 72.6 % at 1 year, 32.4 % at 3 years, and 18.7 % at 5 years. The results of univariate analysis showed that the major significant prognostic factors influencing survival of these patients were histological type of lesion, lymph node metastasis, pancreatic invasion, duodenal invasion, perineural invasion, macroscopic vessel involvement, resected surgical margin and depth of cancer invasion (P=0.02, 0.02, 0.004, 0.005, 0.01, 0.43, 0.03 and 0.04). Age, sex, location of tumor, size of tumor, macroscopic type of lesions, hepatic metastasis, and hepatic invasion were not significantly associated with prognosis (P>0.05). Pancreatic invasion, perineural invasion and lymph node metastases were the three most important prognostic factors by multivariate analysis using the Cox proportional hazards model., Conclusion: Pancreatic invasion, perineural invasion and lymph node metastases are the most important prognostic factors for bile duct carcinoma after curative resection.

Aim: To examine the expression of activin A, a member of the transforming growth factor (TGFbeta) superfamily, recently has been reported to be overexpressed in liver cirrhosis, in the course of carbon tetrachloride-induced rat hepatic fibrosis., Methods: Hepatic fibrosis was induced in rats by subcutaneous injections of 40% carbon tetrachloride oily solution for a period of 1 to 7 weeks. At the end of 1, 2, 3, 4, 5, 6 and 7 weeks after carbon tetrachloride injections, the rats were killed in group (6-10 rats each time) for study. The activin A messenger RNA expression and its protein localization were assessed by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry., Results: The normal rat liver expressed activin A mRNA and protein, and its expression was transiently decreased and became undetectable after carbon tetrachloride injections for 2 or 3 weeks and then increased gradually. After injection of carbon tetrachloride for 6 and 7 weeks, activin A mRNA and protein expressions were significantly enhanced in rat liver. Compared with that of the normal rat liver. Activin A mRNA expression levels in rats receiving carbon tetrachloride injections for 6 and 7 weeks were 1.6 and 2.2 times that of those in normal rat liver respectively (0.456 +/- 0.094 vs 0.2860.0670, P< 0.01; 0.620 +/- 0.134 vs 0.286 +/- 0670, P< 0.01). Immunohistochemistry showed that activin A expressed in hepatocytes of normal liver, and its expression was decreased in rats receiving carbon tetrachloride for 2 or 3 weeks. Compared with normal liver, activin A expression distribution mode changed in fibrotic liver, being increased significantly in hepatocytes around fibrotic areas., Conclusion: Activin A expression was increased in late stage of hepatic fibrosis, and this may be involved in hepatic fibrosis formation in this period.

AIM:To assess the effect of ACE inhibitor and Ang II type 1 (AT1) receptor antagonist in preventing hepatic fibrosis caused by CCl(4) administration in rats;to investigate whether or not there are expression of AT 1 receptors on hepatic stellate cells; and to observe the effect of Ang II on proliferation and ECM synthesis of cultured HSCs.METHODS:Studies were conducted in male Sprague-Dawley rats. Except for the hepatofibrotic model group and the control group, in three treated groups, either enalapril (5mg/kg), or losartan (10mg/kg), or enalapril + losartan were given to the fibrotic rats by daily gavage, and saline vehicle was given to model and normal control rats. After 6 weeks, liver fibrosis was assessed directly by hepatic morphometric analysis, which has been considered the gold standard for the quantification of fibrosis. The expressions of AT 1 receptors and (alpha-mooth muscle actin,alpha-SMA) in liver tissue or isolated hepatic stellate cells (HSCs) were detected by immunohistochemical techniques. The effect of Ang II on HSC proliferation was determined by MTT method. Effect of Ang II on collagen synthesis of HSCs was determined by (3)H-proline incorporation.RESULTS:Contrasted to the fibrosis in rats of the model group, groups of rats treated with either enalapril or losartan, or a combination of two drugs showed a limited expansion of the interstitium (4.23 plus minus 3.70 vs 11.22 plus minus 4.79, P<0.05), but no difference was observed among three treated groups (5.38 plus minus3.43, 4.96 plus minus 2.96, 4.23 plus minus 2.70, P>0.05). Expression of AT 1 receptors was found in fibrotic interstitium of fibrotic rats, whereas in normal control rats they were limited to vasculature only to a very slight degree. AT 1 receptors were also expressed on activated HSCs in the culture. At concentrations from 10(-9) to 10(-5)mol/L, Ang II stimulated HSC proliferation in culture in a dose dependent manner. Increasing Ang II concentrations produced corresponding increases in (3)H-proline incorporation. Differences among groups were significant.CONCLUSION:Angiotensin converting enzyme inhibitors and AT 1 blocker may slow the progression of hepatic fibrosis;activated HSCs express AT 1 receptors, and Ang II can stimulate the proliferation and collagen synthesis of HSCs in a dose-dependent manner; and activation of RAS may be related to hepatic fibrogenesis induced by CCl(4).

AIM:To investigate effect of losartan, an AT1 receptor antagonist, on hepatic fibrosis induced by CCl(4); and to determine whether or not AT1 receptors are expressed on hepatic stellate cells. METHODS AND RESULTS:Fifty male Sprague-Dawley rats, weighing (180 plus minus20)g, were randomized into five groups (control group, model group, and three losartan treated groups), in which all rats were given the subcutaneous injection of 40% CCl(4)(every 3 days for 6 weeks) except for rats of control group. Rats of losartan-treated groups were treated with losartan (20 mg/kg, 10 mg/kg, 5 mg/kg, daily gavage). After 6 weeks liver tissue and serum samples of all rats were examined. Serum hyaluronic acid (HA), procollagen type III (PC III) were detected by radioimmunoassays. van Giesion collagen staining was used to evaluate the extracellular matrix of rats with liver fibrosis. The expression of AT1 receptors, transforming growth factor-beta (TGF-beta), and alpha-smooth muscle actinalpha-SMA) in liver tissue were determined by immunohistochemical techniques. Compared with model group, serum ALT and AST of losartan-treated groups were significantly reduced (italic>t = 4.20,P < 0.01 and italic>t = 4.57,P < 0.01). Serum HA and PC III also had significant differences (italic>t = 3.53,P<0.01 and t=2.20, P<0.05). The degree of fibrosis was improved by losartan and correlated with the expressions of AT1 receptors, TGF-beta, and alpha-SMA in liver tissue.CONCLUSION:AT1 receptor antagonist, losartan, could limit the progression of the hepatic fibrosis induced by CCl(4). The mechanism may be related to the decrease in the expression of AT1 receptors and TGF-beta, ameliorating the injury of hepatocytes; activation of local renin-angiotensin system might relate to hepatic fibrosis; and during progression of fibrosis, activated hepatic stellate cells might express AT1 receptors.