Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0008370 (cholestasis)
 9,378 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transport across hepatocyte plasma membranes is a key parameter in hepatic clearance and usually occurs through different carrier-mediated systems. Sinusoidal uptake of compounds is thus mediated by distinct transporters, such as Na(+)-dependent or Na(+)-independent anionic transporters and by some cationic transporters. Similarly, several membrane proteins located at the apical pole of hepatocytes have been incriminated in the excretion of compounds into the bile. Indeed, biliary elimination of anionic compounds, including glutathione S-conjugates, is mediated by MRP2, whereas bile salts are excreted by a bile salt export pump (BSEP) and Class I-P-glycoprotein (P-gp) is involved in the secretion of amphiphilic cationic drugs, whereas class II-P-gp is a phospholipid transporter. The expression of hepatic transporters and their activity are regulated in various situations, such as ontogenesis, carcinogenesis, cholestasis, cellular stress and after treatment by hormones and xenobiotics. Moreover, a direct correlation between a defect and the absence of transporter with hepatic disease has been demonstrated for BSEP, MDR3-P-gp and MRP2.
 ...
PMID:Expression and regulation of hepatic drug and bile acid transporters. 1109 Sep 58

Glucuronide conjugates represent one of the major types of naturally occurring phase 2 metabolites of xenobiotics and endobiotics. The process underlying their formation, glucuronidation, is normally considered detoxifying, because glucuronides usually possess less intrinsic biological or chemical activity than their parent aglycones and they are rapid excreted. However, a number of glucuronide conjugates are known that are active and may contribute to pharmacological activities or toxicities associated with their parent compounds. These include two classes of glucuronides with electrophilic chemical reactivity (N-O-glucuronides of hydroxamic acids and acyl glucuronides of carboxylic acids) and several types of glucuronides that impart biological effects through non-covalent interactions (morphine 6-O-glucuronide, retinoid glucuronides, and D-ring glucuronides of estrogens). Glucuronides may thus contribute to clinically significant effects, including environmental arylamine-induced carcinogenesis, drug hypersensitivity and other toxicities associated with carboxylic acid drugs, morphine analgesia, and cholestasis from estrogens. This review summarizes the rat and human UDP-glucuronosyltransferases that may be involved in the formation of bioactive glucuronides, including their substrate- and tissue-specificity and genetic and environmental influences on their activity. This knowledge may be useful for enhancing the therapeutic efficacy and minimizing the risk of adverse effects associated with xenobiotics that undergo bioactivating glucuronidation reactions.
 ...
PMID:Roles of glucuronidation and UDP-glucuronosyltransferases in xenobiotic bioactivation reactions. 1115 40

It is very difficult to predict new developments in hepatology so we have decided to analyse the most important issues related to three clinical conditions in hepatology. The first is chronic hepatitis. Here, we discuss the relevance of occult forms of hepatitis B virus infection in the development of cryptogenic liver disease and hepatocellular carcinoma. In addition, the role of genotyping in hepatitis B is analysed, indicating that patients with genotype A have a better prognosis than those with genotype D. The treatment of hepatitis B virus infection is also reviewed, and it has been suggested that research should be directed towards the development of new anti-viral agents to suppress virus replication. The natural history of hepatitis C virus infection is considered, emphasizing the need to know the progression of fibrosis in these patients. The chapter also suggests that treatment of hepatitis C virus infection with pegilated interferon and ribavirin is currently relatively effective. New therapeutic strategies will be required in the future, the most important challenge being the development of a hepatitis C virus vaccine. The second section is on chronic cholestasis. The role of anti-mitochondrial antibodies in primary biliary cirrhosis is considered. The possible infectious agents implicated as potential triggers of primary biliary cirrhosis are also discussed, suggesting that several infections may play a role in the pathogenesis of this condition. Other aetiopathogenic factors, for example organic compounds, drugs and chemicals, are indicated. It is possible that, in the near future, the precise sequence and molecular basis by which infectious agents or xenobiotics may initiate the cascade of the autoimmune response will be defined. One of the most important challenges in primary sclerosing cholangitis concerns the mechanisms that may induce the development of this disease. Up until now, genetic factors have been suggested, recent data reporting a clear-cut association between primary sclerosing cholangitis and the tumour necrosis factor-alpha(2) allele. The third part of this chapter includes recent progress achieved in hepatocellular carcinoma, discussing developments in the knowledge of hepatocellular carcinogenesis. Hepatocellular carcinomas appear so far to be genetically heterogeneous neoplasms, and this heterogeneity may correlate with the variety of aetiological factors involved. The risk factors and primary, secondary and tertiary prevention of the condition are also analysed. Finally, the development of new therapeutic strategies for hepatocellular carcinoma is evaluated by evidence-based studies.
 ...
PMID:Expected developments in hepatology. 1247 1

Oxazepam is one of a number of benzodiazepines used therapeutically as a sedative-hypnotic and antianxiety agent. Toxicology and carcinogenesis studies were performed by administering oxazepam (greater than 99% pure) in feed to male and female Swiss-Webster and B6C3F1 mice for 14 weeks, 57 weeks (Swiss-Webster), or 2 years (B6C3F1). Neurobehavioral assessments were performed during the studies. Genetic toxicology studies were conducted in Salmonella typhimurium and cultured Chinese hamster ovary cells, and peripheral blood samples were analyzed for frequency of micronucleated normochromatic erythrocytes. Supplemental studies were performed to compare the metabolism and toxicokinetics of oxazepam in the two mouse strains, to evaluate the effect on liver cell replication rates, to perform clinical pathology assessments, and to examine the mutation spectrum and frequency of activated H-ras oncogenes in liver neoplasms from the 2-year study with B6C3F1 mice. 14-WEEK STUDY IN SWISS-WEBSTER MICE: Groups of 10 male and 10 female Swiss-Webster mice received oxazepam in feed at concentrations of 0, 625, 1,250, 5,000, 10,000 ppm for 14 weeks. One 625 ppm male and one 10,000 female were killed moribund before the end of the study, and the condition of the female mouse was attributed to oxazepam exposure. Mean body weight gains of exposed groups were similar to those of the controls. Exposed mice displayed chemical-related sedation and lethargy during the first study week, but appeared normal thereafter. In the neurobehavioral studies, reductions in grip strength were evident in both male and female mice at week 2 and persisted in males through week 11. An antianxiety effect was detected in exposed mice in measures of motor activity, startle response, and reactions to thermal stimulus. At necropsy, absolute and relative liver weights were increased in an exposure-related manner and were approximately two-fold greater in 10,000 ppm mice than in controls. Centrilobular hepatocellular hypertrophy was present only in exposed mice, and the severity increased with dose. 14-WEEK STUDY IN B6C3F1 MICE: Groups of 10 male and 10 female B6C3F1 mice received oxazepam in feed at concentrations of 0, Groups of 10 male and 10 female Swiss-Webster mice 625, 1,250, 2,500, 5,000, or 10,000 ppm for 14 weeks. received oxazepam in feed at concentrations of 0, There were no deaths that were clearly related to 625,1,250, 2,500, 5,000, or 10,000 ppm for 14 weeks. oxazepam exposure. Mean body weight gains of One 625 ppm male and one 10,000 ppm female were exposed groups were similar to those of the controls. Exposed mice displayed chemical-related sedation and lethargy during only the first study week. In neurobehavioral studies, reductions in grip strength were evident in males at week 2 but were no longer observed at week 12. An antianxiety effect was noted in exposed mice in measures of motor activity, startle response, and reactions to a thermal stimulus (females). At necropsy, absolute and relative liver weights were increased in an exposure-related manner and were approximately two-fold greater in 10,000 ppm mice than in controls. Centrilobular hepatocellular hypertrophy was present only in exposed mice, and the severity increased with dose. CHRONIC STUDIES: Groups of 60 male and 60 female Swiss-Webster and B6C3F1 mice received oxazepam in feed at concentrations of 0, 2,500, or 5,000 ppm. Additional groups of 60 male and 60 female B6C3F1 mice received 125 ppm in feed to allow for study of a group with projected serum concentrations of oxazepam similar to those achieved in humans taking a therapeutic dose. Ten male and 10 female B6C3F1 mice per group were evaluated at 15 months. Average daily oxazepam consumption varied throughout the studies, and the overall daily average ranged from 10 to 29 mg/kg body weight for the 125 ppm groups, 234 to 512 mg/kg for the 2,500 ppm groups, and 444 to 1,085 mg/kg for the 5,000 ppm groups. Serum oxazepam concentrations determined at 57 weeks in Swiss-Webster mice and at the 15-month interim evaluation of B6C3F1 mice 1 mice were approximately 1 ug/mL in the 125 ppm groups, 4 to 7 μg/mL in the 2,500 ppm groups, and 7 to 10 μg/mL in the 5,000 ppm groups. Neurobehavioral assessments during the chronic studies of each strain of mice were confounded by the poor survival and deteriorating condition of mice with hepatic neoplasia. However, within the limitations of the studies, there were no notable changes in the types of behaviors observed compared to those observed in the 14-week studies, nor was there an enhancement in the degree to which they were exhibited. 57-Week Study in Swiss-Webster Mice: Survival, Body Weights, Feed and Compound Consumption, and Clinical Findings: At 57 weeks, survival of exposed mice was significantly lower than that of controls (males: O ppm, 45/60; 2,500 ppm, 19/60; 5,000 ppm, 10/60; females: 47/60, 28/59, 17/59), causing the study to be terminated. Mean body weights of exposed males were similar to controls until week 17; afterwards, mean body weights of exposed male groups were lower than those of controls. Final mean body weights of exposed males were 9% lower than that of the controls. The mean body weight of 2,500 ppm females was greater than that of the controls throughout the study. Females receiving 5,000 ppm had a mean body weight greater than that of the controls early in the study; after week 29, the mean body weight of this group was similar to that of the controls. Feed consumption by exposed males and females was slightly lower than that by the controls, and females in all groups, including controls, consumed slightly more feed than males throughout the study. Dietary levels of 2,500 and 5,000 ppm oxazepam resulted in average daily compound consumption levels of 270 and 570 mg/kg for males and 320 and 670 mg/kg for females. Hypoactivity and sedation were observed in exposed mice during the first week of the study. There were no other clinical findings associated with oxazepam exposure. Pathology Findings: Systemic amyloidosis was the principal cause of death in mice dying before the study was terminated. The lower survival of mice receiving oxazepam was attributed to an increase in the extent and severity of amyloid deposits in many organs, including the heart and kidney. Atrial thrombosis and pulmonary lesions consistent with chronic heart failure occurred at higher incidences and with greater severity in exposed mice. The incidence of hepatocellular adenomas (males: 1/60, 35/60, 50/60; females: 0/60, 22/59, 47/59) and carcinomas (males: 0/60, 5/60,19/60; females: 1/60, 1/59, 11/59) were increased in exposed mice. The incidences of eosinophilic foci were also increased in exposed mice (males: 0/60, 22/60, 22/60; females: 0/60, 20/59, 14/59), and there was evidence of increased centrilobular hepatocyte hypertrophy (males: 12/60, 46/60, 47/60; females: 3/60, 51/59, 53/59). 2-Year Study in B6C3F1 Mice: Survival, Body Weights, Feed and Compound Consumption, and Clinical Findings: Survival of mice receiving 2,500 and 5,000 ppm was significantly lower than that of controls (males: O ppm, 45/50; 125 ppm, 44/50; 2,500 ppm, 15/50; 5,000 ppm, 0/50; females: 39/50, 41/50, 2/50, 0/50). Mean body weight gains of exposed male and female mice were similar to controls until about week 15 when weight gains for mice exposed to 2,500 or 5,000 ppm slowed in relation to controls, resulting in weight gains approximately 30% to 40% lower than those of the controls throughout the remainder of the study. Mean body weight gain of male mice exposed to 125 ppm was similar to that of the controls, while that of female mice receiving 125 ppm was 10% to 15% lower than that of the controls after about week 45. Feed consumption by exposed males and females was similar to that by controls. Dietary levels of 125, 2,500, and 5,000 ppm resulted in average daily oxazepam consumption levels of 12, 310, and 690 mg/kg body weight for males and 15, 350, and 780 mg/kg for females. In the 5,000 ppm groups, lethargy and sedation were observed in a few mice during the first week of study. Pathology Findings: The early deaths of many of the B6C3F1 mice exposed to oxazepam were attributed to a marked increase in the incidences of hepatoblastoma (males: 0/49, 2/50, 21/50, 13/50; females: 0/50, 1/50, 8/50, 8/50), hepatocellular adenoma (males: 17/49,18/50, 34/50, 32/50; females: 25/50, 35/50, 35/50, 36/50), and hepatocellular carcinoma (males: 9/49, 5/50, 45/50, 50/50; females: 9/50, 5/50, 49/50, 44/50). Moderate hypertrophy of centrilobular hepatocytes occurred in mice receiving 2,500 and 5,000 ppm (males: 0/49, 2/50, 26/50, 43/50; females: 0/50, 2/50,11/50, 29/50). An increase in the incidence of follicular cell hyperplasia of the thyroid gland occurred in all exposed groups of mice (males: 4/49, 22/50, 49/50, 47/50; females: 16/50, 34/50, 49/50, 44/50), and thyroid gland follicular cell adenoma was increased in exposed females (0/50, 4/50, 5/50, 6/50). Testicular atrophy occurred in the 2,500 and 5,000 ppm groups (1/50, 0/50, 25/50, 38/50), and the incidence of epididymal Iymphocyte infiltration was increased in all exposed groups (2/50,14/50, 33/50, 21/50). The frequency of hepatocellular neoplasms with an activated H-ras oncogene in the B6C3F1 mice and the mutation spectrum of the H-ras gene were determined. The mutation spectrum of the H-ras genes in the relatively few neoplasms from exposed mice that did have an activated H-ras did not differ from the spectrum of mutations observed in neoplasms from controls, but the proportion of neoplasms with an activated H-ras gene decreased with increasing oxazepam dose. While 11 of 19 (58%) neoplasms from control mice had an activated H-ras gene, only 1 of 40 neoplasms from mice receiving 2,500 or 5,000 ppm oxazepam exhibited a similar molecular lesion. Thirteen of 37 (35%) neoplasms from mice in the 125 ppm group had an activated H-ras oncogene, suggesting that, although the incidence of all liver neoplasms was not statistically increased compared to controls, there was an increase in a similar subset of neoplasms (lacking an activated H-ras) that occurred with increased incidence at higher doses. SUPPLEMENTAL STUDIES: Because exposure to oxazepam caused increased incidences of liver neoplasms, supplemental short-term studies were performed. Oxazepam given in feed to male B6C3F1 mice at 25, 125, 2,500, or 5,000 ppm for up to 13 weeks was found to cause a dose-related increase in nuclear labeling index in studies measuring the incorporation of bromodeoxyuridine into replicating liver cells. This increase was statistically significant at all but the 25 ppm exposure level and was limited to mice evaluated at 15 days. Cell replication rates in most groups evaluated at 30 days and after were similar to control rates. There was minimal evidence suggestive of hepatocyte necrosis either by light microscopy or in clinical chemistry measures. There was, however, evidence of cholestasis, likely due to physical obstruction of bile canaliculi by swollen hepatocytes. The metabolic fate and toxicokinetics of oxazepam were evaluated in each strain of mice and were compared to published data from human studies. Both mice and humans form glucuronides of oxazepam and form 3- and 4-hydroxy and methoxy derivatives of the phenyl group. Oxidative metabolism of the phenyl group appears to be more prevalent in mice than is reported for humans. Elimination half-lives of parent compound do not differ between Swiss-Webster and B6C3F1 mice and are similar to values reported for humans. GENETIC TOXICOLOGY: Oxazepam was not mutagenic in any of several strains of Salmonella typhimurium, nor did it induce sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells. These in vitro tests were performed with and without S9 metabolic activation. Results from an in vivo mouse peripheral blood micronucleus test performed on the B6C3F1 mice used in the 14-week study were also negative. CONCLUSIONS: Under the conditions of these feed studies, there was clear evidence of carcinogenic activity of oxazepam in male and female Swiss-Webster mice based on increased incidences of hepatocellular adenoma and carcinoma. There was clear evidence of carcinogenic activity of oxazepam in male and female B6C3F1 mice based on increased incidences of hepatoblastoma and hepatocellular adenoma and carcinoma. Increased incidences of hyperplasia of thyroid gland follicular cells in male and female B6C3F1 mice and of follicular cell adenomas in female B6C3F1 mice were also related to oxazepam exposure. Administration of oxazepam to Swiss-Webster mice resulted in centrilobular hepatocellular hypertrophy and increased incidences and severity of systemic amyloidosis. Administration of oxazepam to B6C3F1 mice also resulted in centrilobular hepatocellular hypertrophy. Synonyms: 7-Chloro-1,3-dihydro-3-hydroxy-5-phenyl-2 H - 1,4-benzodiazepin-2-one Trade Names: Tazepam, Wy-3498, Serax
 ...
PMID:NTP Toxicology and Carcinogenesis Studies of Oxazepam (CAS No. 604-75-1) in Swiss-Webster and B6C3F1 Mice (Feed Studies). 1259 20

Primary sclerosing cholangitis (PSC) is an idiopathic inflammatory disorder of the biliary tract characterized by diffuse biliary tract stricture formation, progressive chronic cholestasis and the development of secondary biliary cirrhosis. Biliary tract ischemia can produce morphological changes identical to PSC. We propose the existence of a localized renin-angiotensin system within the liver and extend the hypothesis that aberrant production of angiotensin II within the portal tract is the critical event contributing to the pathogenesis of PSC. A chronic reparative and proliferative state caused by chronic ischemia may promote carcinogenesis. Proof of this hypothesis will have implications for future therapeutic approaches given that current treatments for PSC aimed at reducing inflammation or the effects of cholestasis have proven ineffective.
 ...
PMID:Aberrant local renin-angiotensin II responses in the pathogenesis of primary sclerosing cholangitis. 1278 43

Prolonged administration of peroxisome proliferators to rodents typically leads to hepatocarcinogenesis. Peroxisome proliferator-activated receptor-alpha (PPARalpha) is required to mediate alterations in PPARalpha target gene expression, repress apoptosis, enhance replicative DNA synthesis, oxidative stress to DNA and hepatocarcinogenesis induced by the relatively specific PPARalpha agonist, Wy-14,643. Interestingly, administration of the less specific PPARalpha agonist, bezafibrate, leads to a modest induction of PPARalpha target genes in the absence of PPARalpha expression. In these studies, the role of PPARalpha in modulating hepatocarcinogenesis induced by long-term feeding of 0.5% bezafibrate was examined in wild-type (+/+) and PPARalpha-null (-/-) mice. The average liver weight was significantly higher in (+/+) and (-/-) mice fed bezafibrate than controls, but this effect was considerably less in (-/-) mice as compared with similarly treated (+/+) mice. Increased levels of mRNA encoding cell cycle regulatory proteins and DNA repair enzymes were found in (+/+) mice fed bezafibrate, and this effect was not found in (-/-) mice. In mice fed bezafibrate for 1 year, preneoplastic foci, adenomas and a hepatocellular carcinoma were found in (+/+) mice, while only a single microscopic adenoma was found in one (-/-) mouse. This effect was observed in both Sv/129 and C57BL/6N strains of mice, although only preneoplastic foci were observed in the latter strain. Interestingly, hepatic cholestasis was observed in 100% of the bezafibrate-fed (-/-) mice, and this was accompanied by significantly elevated hepatic expression of mRNA encoding bile salt export pump and lower expression of mRNA encoding cytochrome P450 7A1, consistent with enhanced activation of the bile acid receptor, farnesoid X receptor. Results from these studies demonstrate that the PPARalpha is required to mediate hepatocarcinogenesis induced by bezafibrate, and that PPARalpha protects against potential cholestasis.
Carcinogenesis 2005 Jan
PMID:Role of peroxisome proliferator-activated receptor-alpha (PPARalpha) in bezafibrate-induced hepatocarcinogenesis and cholestasis. 1544 78

The etiology of biliary tract cancer is obscure, but there are evidences that bile acid plays a role in carcinogenesis. To find the association between biliary tract cancer and bile acid, this study compared the bile acid concentration and composition among patients with biliary cancer, biliary tract stones, and no biliary disease. Bile was compared among patients with biliary tract cancer (n = 26), biliary tract stones (n = 29), and disease free controls (n = 9). Samples were obtained by percutaneous transhepatic biliary drainage, endoscopic nasobiliary drainage, or gallbladder puncture, and analyzed for cholic, deoxycholic, chenodeoxycholic, lithocholic, and ursodeoxycholic acid composition. Total bile acid concentration was lower in the cancer group than the biliary stone and control groups; the proportions of deoxycholic (2.2% vs. 10.2% and 23.6%, p < 0.001 and p < 0.001, respectively) and lithocholic acid (0.3% vs. 0.6% and 1.0%, p = 0.065 and p < 0.001, respectively) were also lower. This result was similar when disease site was limited to bile duct or gallbladder. Analysis of cases with bilirubin <or= 2.0 mg/dL also showed lower total bile acid concentration and deoxycholic acid composition in the cancer group compared to controls (5.7% vs. 23.6%, p = 0.003). Although the presence of bile duct obstruction explains some of the difference in total concentration and composition of bile acid, there are other contributing mechanisms. We suspect the alteration of bile acid transport might decrease bile acid excretion and cause the accumulation of carcinogenic bile acid in bile duct epithelium.
 ...
PMID:Bile acid analysis in biliary tract cancer. 1719 11

Liver fibrosis and cirrhosis are predisposing factors for the development of hepatocellular carcinoma (HCC). Hemosiderosis has also been described to trigger carcinogenesis. A significant iron overload, as found in hereditary hemochromatosis (HHC), is a risk factor for HCC and may also promote the symptoms of porphyria cutanea tarda (PCT). A 68-year old male patient presented to our clinic with a suspected HCC, elevated alpha-fetoprotein but normal liver function tests. He reported a 25 year-old history of vitiligo upon exposure to sunlight. The patient underwent an extended left hemihepatectomy, and the recovery was uneventful, with the exception of a persistent hyperbilirubinemia. Perfusion problems and extrahepatic cholestasis were ruled out by CT-scan with angiography and MR-cholangiopancreatography. However, MRI showed an iron overload. Histology confirmed the HCC (pT3, pN0, G3, R0) and revealed a portal fibrosis and hemosiderosis. Based on the skin lesions we suspected a PCT that was confirmed by laboratory tests showing elevated porphyrin, uroporphyrin, coproporphyrin and porphobilinogen. Concurrently, molecular diagnostics revealed homozygosity for the C282Y mutation within the hemochromatosis HFE gene. After phlebotomy and normalization of liver function tests the patient was discharged. This is the first case ever showing the unusual combination of HCC in a fibrotic liver with HHC and PCT. This diagnosis not only warrants oncological follow-up but also symptomatic therapy to normalize iron metabolism and thereby improve liver function and alleviate the symptoms of HHC and PCT. Thus progression of fibrosis may be prevented and liver regeneration supported.
 ...
PMID:An unhappy triad: hemochromatosis, porphyria cutanea tarda and hepatocellular carcinoma-a case report. 1746 5

Cholestatic liver diseases encompass a wide spectrum of disorders with different causes, resulting in impaired bile flow and accumulation of bile acids and other potentially hepatotoxic cholephils. The understanding of the molecular mechanisms of bile formation and cholestasis has recently improved significantly through new insights into nuclear receptor (patho)biology. Nuclear receptors are ligand-activated transcription factors, which act as central players in the regulation of genes responsible for elimination and detoxification of biliary constituents accumulating in cholestasis. They also control other pathophysiologic processes such as inflammation, fibrogenesis, and carcinogenesis involved in the pathogenesis and disease progression of cholestasis liver diseases.
 ...
PMID:Nuclear receptors as drug targets in cholestatic liver diseases. 2354 Apr 96

Cholangiocarcinoma (CCA) is one of the most frequent malignant epithelial liver tumors after hepatocellular carcinoma (HCC). Its incidence seems to be increasing worldwide, although risk factors are heterogeneous and differ globally. Although diagnostic and therapeutic medicine have advanced in several countries, tackling this tumor remains a challenge. The causes of CCA's increasing incidence are likely a differential increment of some factors according to the geographical area, which will be considered in this review. Environment-linked risk factors may play a critical role in the carcinogenesis. Liver flukes may play a major role in East Asia, while exposure to chemical compounds, such as naphthenic acids, has been postulated as a source of the rate increase in Western countries. Carcinogenesis is variable and confounding factors also need to be taken into account. Carcinogenesis depends on a sequential process and most probably involves both cholestasis and chronic inflammation as promoting steps after induction. The release and interaction of interleukin-6 (IL-6), transforming growth factor beta (TGF-beta), tumor necrosis factor alpha (TNF-alpha), and platelet-derived growth factor (PDGF) are at the basis of the proliferation of biliary epithelial cells or cholangiocytes. Additional steps for the final development of CCA may also involve an increase of the mutation rate of tumor suppressor genes, such as TP53, and the evasion of apoptosis.
 ...
PMID:Cholangiocarcinoma: risk factors, environmental influences and oncogenesis. 2369 97


<< Previous 1 2 3 4 Next >>