Novel bile acid derivatives induce apoptosis via a p53-independent pathway in human breast carcinoma cells

Cellular Responses Induced by NCT-503 Treatment on Triple-Negative Breast Cancer Cell Lines: A Proteomics Approach

Breast cancer (BC) remains one of the leading causes of mortality among women, with triple-negative breast cancer (TNBC) standing out for its aggressive nature and limited treatment options. Metabolic reprogramming, one of cancer's hallmarks, underscores the importance of targeting metabolic vulnerabilities for therapeutic intervention. This study aimed to investigate the impact of de novo serine biosynthetic pathway (SSP) inhibition, specifically targeting phosphoglycerate dehydrogenase (PHGDH) with NCT-503, on three TNBC cell lines: MDA-MB-231, MDA-MB-468 and Hs 578T. First, MS-based proteomics was used to confirm the distinct expression of PHGDH and other SSP enzymes using the intracellular proteome profiles of untreated cells. Furthermore, to characterize the response of the TNBC cell lines to the inhibitor, both in vitro assays and label-free, bottom-up proteomics were employed. NCT-503 exhibited significant cytotoxic effects on all three cell lines, with MDA-MB-468 being the most susceptible (IC50 20.2 ± 2.8 µM), while MDA-MB-231 and Hs 578T showed higher, comparable IC50s. Notably, differentially expressed proteins (DEPs) induced by NCT-503 treatment were mostly cell line-specific, both in terms of the intracellular and secreted proteins. Through overrepresentation and Reactome GSEA analysis, modifications of the intracellular proteins associated with cell cycle pathways were observed in the MDA-MBs following treatment. Distinctive dysregulation of signaling pathways were seen in all TNBC cell lines, while modifications of proteins associated with the extracellular matrix organization characterizing both MDA-MB-231 and Hs 578T cell lines were highlighted through the treatment-induced modifications of the secreted proteins. Lastly, an analysis was conducted on the DEPs that exhibited greater abundance in the NCT-503 treatment groups to evaluate the potential chemo-sensitizing properties of NCT-503 and the druggability of these promising targets.

The anticancer activity of bile acids in drug discovery and development

Bile acids (BAs) constitute essential components of cholesterol metabolites that are synthesized in the liver, stored in the gallbladder, and excreted into the intestine through the biliary system. They play a crucial role in nutrient absorption, lipid and glucose regulation, and the maintenance of metabolic homeostasis. In additional, BAs have demonstrated the ability to attenuate disease progression such as diabetes, metabolic disorders, heart disease, and respiratory ailments. Intriguingly, recent research has offered exciting evidence to unveil their potential antitumor properties against various cancer cell types including tamoxifen-resistant breast cancer, oral squamous cell carcinoma, cholangiocarcinoma, gastric cancer, colon cancer, hepatocellular carcinoma, prostate cancer, gallbladder cancer, neuroblastoma, and others. Up to date, multiple laboratories have synthesized novel BA derivatives to develop potential drug candidates. These derivatives have exhibited the capacity to induce cell death in individual cancer cell types and display promising anti-tumor activities. This review extensively elucidates the anticancer activity of natural BAs and synthetic derivatives in cancer cells, their associated signaling pathways, and therapeutic strategies. Understanding of BAs and their derivatives activities and action mechanisms will evidently assist anticancer drug discovery and devise novel treatment.

Synthesis of modified bile acids via palladium-catalyzed C(sp3)-H (hetero)arylation

A Pd(II)-catalyzed strategy for the diastereo- and regioselective (hetero)arylation of unactivated C(sp3)-H bonds in bile acids is accomplished with aryl and heteroaryl iodides under solvent-free conditions using the 8-aminoquinoline auxiliary as a directing group. This methodology demonstrated excellent functional group tolerance with respect to aryl/heteroaryl iodides on O-protected N-(quinolin-8-yl)cholyl/deoxycholyl amides to afford β-C(sp3)-H (hetero)arylated products in good-to-excellent yields. Moreover, the 8-aminoquinoline (AQ) auxiliary can easily be removed to obtain modified bile acids.

Design and synthesis of bile acid derivatives and their activity against colon cancer

Bile acids (BAs) containing both hydrophilic hydroxyl and carboxyl groups and hydrophobic methyl and steroid nuclei can promote the absorption of fat and other substances in the intestine, and they are synthesized by cholesterol in the liver and then returned to the liver through enteric liver circulation. Because there are many BA receptors on the cell membrane of colon tissues, BAs can improve the specific delivery and transport of medicines to colon tissues. Moreover, BAs have a certain anticancer and inflammation activity by themselves. Based on this theory, a series of BA derivatives against colon cancer including cholic acid (CA), chenodeoxycholic acid (CDCA), ursodeoxycholic acid (UDCA) and lithocholic acid (LCA) were designed and synthesized, and their antitumor activity was evaluated. For in vitro anti-tumor tests, all the compounds displayed cell proliferative inhibition to nine human malignant tumor cell lines to some degree, and in particular they showed stronger inhibition to the colon cancer cells than the other cell lines. Among them, four compounds (4, 5, 6, and 7) showed stronger activity than the other compounds as well as the positive control 5-FU against HCT116 cells, and their IC50 was between 21.32 μmol L-1 and 28.90 μmol L-1; cell clone formation and migration tests showed that they not only effectively inhibited the formation of HCT116 cell colonies, but also inhibited the HCT116 cell migration and invasion; moreover, they induced apoptosis, arrested the mitotic process at the G2/M phase of the cell cycle, reduced the mitochondrial membrane potential, increased the intracellular ROS levels, and reduced the expression of Bcl-2 and p-STAT3 in HCT 116 cells. In addition, they also displayed intermediate anti-inflammatory activity by inhibiting inflammatory mediators NO and downregulating TNF-α expression, which also is one of the causes of colon cancer. This suggests that they deserve to be further investigated as candidates for colon cancer treatment drugs.

Functional, Diagnostic and Therapeutic Aspects of Bile

Bile is a unique body fluid synthesized in our liver. Enterohepatic circulation preserves bile in our body through its efficient synthesis, transport, absorption, and reuptake. Bile is the main excretory route for bile salts, bilirubin, and potentially harmful exogenous lipophilic substances. The primary way of eliminating cholesterol is bile. Although bile has many organic and inorganic contents, bile acid is the most physiologically active component. Bile acids have a multitude of critical physiologic functions in our body. These include emulsification of dietary fat, absorption of fat and fat-soluble vitamins, maintaining glucose, lipid, and energy homeostasis, sustenance of intestinal epithelial integrity and epithelial cell proliferation, reducing inflammation in the intestine, and prevention of enteric infection due to its antimicrobial properties. But bile acids can be harmful in certain altered conditions like cholecystectomy, terminal ileal disease or resection, cholestasis, duodenogastric bile reflux, duodenogastroesophageal bile reflux, and bile acid diarrhea. Bile acids can have malignant potentials as well. There are also important diagnostic and therapeutic roles of bile acid and bile acid modulation.

Design, synthesis, characterization and anticancer activity evaluation of deoxycholic acid-chalcone conjugates

A series of deoxycholic acid-chalcone amides were synthesised and tested against the human lung cancer cell line, A549 and the cervical cancer cell line, SiHa. Among the synthesised deoxycholic acid-chalcone conjugates, some conjugates showed encouraging results as anticancer agents with good in vitro activity. More precisely, deoxycholic acid-chalcone conjugates 4b (IC50: 0.51 μM) and 4e (IC50: 0.84 μM) having 2‑nitrophenyl and 3,4,5‑trimethoxyphenyl groups exhibited a good activity against human cancer cell-line SiHa and while 4d (IC50: 0.25 μM) and 4b (IC50: 1.71 μM) showed better activity against A549 lung cancer cell line with respect to deoxycholic acid and chalcones. The anticancer activity of the bile acid conjugated chalcones was more than the activity of chalcone and deoxycholic acid alone. The results indicate that a bile acid conjugate strategy may be beneficial in improving the biological activity of chalcone derivatives. The enhanced activity of certain compounds may be due to their increased bioavailability.

Mechanism of Bile Acid-Induced Programmed Cell Death and Drug Discovery against Cancer: A Review

Bile acids are major signaling molecules that play a significant role as emulsifiers in the digestion and absorption of dietary lipids. Bile acids are amphiphilic molecules produced by the reaction of enzymes with cholesterol as a substrate, and they are the primary metabolites of cholesterol in the body. Bile acids were initially considered as tumor promoters, but many studies have deemed them to be tumor suppressors. The tumor-suppressive effect of bile acids is associated with programmed cell death. Moreover, based on this fact, several synthetic bile acid derivatives have also been used to induce programmed cell death in several types of human cancers. This review comprehensively summarizes the literature related to bile acid-induced programmed cell death, such as apoptosis, autophagy, and necroptosis, and the status of drug development using synthetic bile acid derivatives against human cancers. We hope that this review will provide a reference for the future research and development of drugs against cancer.

Chenodeoxycholic acid inhibits lung adenocarcinoma progression via the integrin α5β1/FAK/p53 signaling pathway

BACKGROUND

Lung cancer is the leading cause of cancer-associated death worldwide and is classified into non-small cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). NSCLC accounts for approximately 80%-85% of all lung cancer cases. Chenodeoxycholic acid (CDCA), a primary bile acid, has been reported to inhibit carcinoma cell proliferation. Here, we aimed to determine the effects and mechanism of action of CDCA against lung adenocarcinoma (LUAD).

METHODS

Western blotting and quantitative real-time polymerase chain reaction were used to evaluate the protein and mRNA expression levels in LUAD cell lines, respectively. Cell Counting Kit-8 and clone formation assays were performed to evaluate the proliferation ability of different cell types in vitro. Tumor cell motility was evaluated using Transwell assays. The transcriptional profile of A549 cells treated with CDCA was determined through RNA sequencing analysis. A xenograft model was established to evaluate the effects of CDCA on LUAD progression in vivo.

RESULTS

CDCA inhibited LUAD cell proliferation, migration, and invasion. Furthermore, it promoted apoptosis in LUAD cells. Mechanistically, CDCA inhibited the integrin α5β1 signaling pathway in LUAD cells by inhibiting the expression of the α5 and β1 subunits of integrin and phosphorylated FAK. Moreover, CDCA induced an increase in the levels of p53, a downstream gene of the integrin α5β1/FAK pathway. In addition, CDCA significantly decreased tumor volume in mice without inducing significant toxicity.

CONCLUSIONS

Our findings indicate that CDCA attenuates LUAD pathogenesis in vitro and in vivo via the integrin α5β1/FAK/p53 axis.

Synthesis and Anti-Hepatoma Activities of U12 Derivatives Arresting G0/G1 Phase and Inducing Apoptosis by PI3K/AKT/mTOR Pathway

Ursodeoxycholic acid (UDCA) is a first-line clinical drug for the treatment of liver diseases. U12, a derivative of UDCA, showed effective anti-hepatoma activities in previous works. However, the low polarity and large doses limited the druglikeness of U12. In this study, the structural modification and optimization of U12 were further investigated and twelve U12 derivatives were synthesized by substitution, esterification and amidation reactions. The evaluation of the cytotoxicity of synthetic derivatives against hepatoma cell lines (HepG2) indicated that U12-I, U12a-d and U12h showed more effective cytotoxic effects on the growth of HepG2 cells than U12, and the preliminary structure–activity relationship was discussed. Among them, U12a exhibited the most potent anti-hepatocellular carcinoma activity. Mechanism studies indicated that U12a inhibited HepG2 cell proliferation by arresting the G0/G1 phase, and suppressed the activation of the PI3K/AKT/mTOR pathway. Further studies showed that U12a induced HepG2 cells apoptosis through activating the caspase signaling pathway. Furthermore, U12a evidently inhibits the growth of HepG2-derived tumor xenografts in vivo without observable adverse effects. Thus, U12a might be considered as a promising candidate for the treatment of hepatocellular carcinoma.

Ursodeoxycholic acid suppresses the malignant progression of colorectal cancer through TGR5-YAP axis

The Hippo/YAP pathway plays an important role in the development of cancers. Previous studies have reported that bile acids can activate YAP (Yes Associated Protein) to promote tumorigenesis and tumor progression. Ursodeoxycholic acid (UDCA) is a long-established old drug used for cholestasis treatment. So far, the effect of UDCA on YAP signaling in colorectal cancer (CRC) is not well defined. This study means to explore relationship of UDCA and YAP in CRC. UDCA suppressed YAP signaling by activating the membrane G-protein-coupled bile acid receptor (TGR5). TGR5 mainly regulated cAMP/PKA signaling pathway to inhibit RhoA activity, thereby suppressing YAP signaling. Moreover, the restoration of YAP expression alleviated the inhibitory effect of UDCA on CRC cell proliferation. In AOM/DSS-induced CRC model, UDCA inhibited tumor growth in a concentration-dependent manner and decreased expression of YAP and Ki67. UDCA plays a distinguished role in regulating YAP signaling and CRC growth from the primary bile acids and partial secondary bile acids, demonstrating the importance of maintaining normal intestinal bile acid metabolism in cancer patients. It also presents a potential therapeutic intervention for CRC.

CMBD: a manually curated cancer metabolic biomarker knowledge database

The pathogenesis of cancer is influenced by interactions among genes, proteins, metabolites and other small molecules. Understanding cancer progression at the metabolic level is propitious to the visual decoding of changes in living organisms. To date, a large number of metabolic biomarkers in cancer have been measured and reported, which provide an alternative method for cancer precision diagnosis, treatment and prognosis. To systematically understand the heterogeneity of cancers, we developed the database CMBD to integrate the cancer metabolic biomarkers scattered over literatures in PubMed. At present, CMBD contains 438 manually curated relationships between 282 biomarkers and 76 cancer subtypes of 18 tissues reported in 248 literatures. Users can access the comprehensive metabolic biomarker information about cancers, references, clinical samples and their relationships from our online database. As case studies, pathway analysis was performed on the metabolic biomarkers of breast and prostate cancers, respectively. 'Phenylalanine, tyrosine and tryptophan biosynthesis', 'phenylalanine metabolism' and 'primary bile acid biosynthesis' were identified as playing key roles in breast cancer. 'Glyoxylate and dicarboxylate metabolism', 'citrate cycle (TCA cycle)', and 'alanine, aspartate and glutamate metabolism' have important functions in prostate cancer. These findings provide us with an understanding of the metabolic pathway of cancer initiation and progression. Database URL: http://www.sysbio.org.cn/CMBD/.

Physiology and Physical Chemistry of Bile Acids

Bile acids (BAs) are facial amphiphiles synthesized in the body of all vertebrates. They undergo the enterohepatic circulation: they are produced in the liver, stored in the gallbladder, released in the intestine, taken into the bloodstream and lastly re-absorbed in the liver. During this pathway, BAs are modified in their molecular structure by the action of enzymes and bacteria. Such transformations allow them to acquire the chemical-physical properties needed for fulling several activities including metabolic regulation, antimicrobial functions and solubilization of lipids in digestion. The versatility of BAs in the physiological functions has inspired their use in many bio-applications, making them important tools for active molecule delivery, metabolic disease treatments and emulsification processes in food and drug industries. Moreover, moving over the borders of the biological field, BAs have been largely investigated as building blocks for the construction of supramolecular aggregates having peculiar structural, mechanical, chemical and optical properties. The review starts with a biological analysis of the BAs functions before progressively switching to a general overview of BAs in pharmacology and medicine applications. Lastly the focus moves to the BAs use in material science.

Updates in bile acid-bioactive molecule conjugates and their applications

Bile acid conjugates are emerging as important chemical resources due to their low cost and wide availability of bile acids, making them privileged molecules in drug carrier systems and building blocks for derivatization and chiral template introduction into bioactive molecules. In recent years, bile acids as scaffolds in supramolecular, medicinal, and material chemistry attracted prime focus of researchers as an area of research to be followed with passion. Due to peculiar physicochemical and biological properties, bile acid exhibited various applications in biomedical and pharmaceutical fields. In this review, the bile acid conjugations with different bioactive compounds have been discussed to understand their influence on the bioavailability of bioactive compounds.

Metabolite profiling of traditional Chinese medicine XIAOPI formula: An integrated strategy based on UPLC-Q-Orbitrap MS combined with network pharmacology analysis

XIAOPI formula has been approved for mammary hyperplasia treatment by National Medical Products Administration in China. However, the absorbed substances of XIAOPI formula and their influences on metabolic pathways are largely remained unknown. Liquid chromatography coupled with mass spectrometry was used to identify the substances existing in the serum. Network pharmacology was utilized to explore the underlying metabolic targets and pathways involved in. Western blotting and immunofluorescence assays were carried out for target validation. The exogenous results demonstrated 196 compounds were filtered as absorbed substances, among which 63 constituents or metabolites were tentatively identified in rat serum, and the metabolites of tanshinone II and tanshinone I were found to act as the major metabolic pathways. Subsequently, the endogenous results revealed that XIAOPI formula could significantly regulate serum biochemical indices and the bile acid secretion signaling ranks as top1 among all the involved pathways. The levels of intermediates including cholic acid, glycocholic acid, taurochenodeoxycholic acid and taurocholic acid were significantly upregulated following XIAOPI treatment, accompanied by increased expression of key enzyme CYP7A1, indicating that XIAOPI formula could accelerate the bile acid metabolism pathway. Our study presented a comprehensive metabolic profile of XIAOPI formula in vivo for the first time, and bile acid synthesis pathway might be one of the key mechanisms contributing to the pharmacological function of the formula.

Clickable conjugates of bile acids and nucleosides: Synthesis, characterization, in vitro anticancer and antituberculosis studies

A series of clickable bile acid-nucleosides conjugates linked directly or via amino acid linker were synthesized, and characterized by spectroscopic techniques such as ¹H NMR, ¹³C NMR, FT-IR, HRMS and HPLC. The synthesized compounds 6a-p were screened for their in vitro anticancer property against a panel of three cancer cell lines (PC-3, MCF-7, IMR-32). In addition, the synthesized derivatives were also tested for their antimycobacterial activity against Mycobacterium tuberculosis H₃₇Rv (ATCC 27294 strain). Among the screened compounds, cholic acid-uridine clicked conjugate (6c), and cholic acid-uridine clicked conjugate liked via phenylalanine moiety (6m) were found to be most active against MCF-7 and IMR-32 exhibiting an IC₅₀ value of 8.084 and 8.71 µM, respectively. The antimycobacterial study of the synthesized conjugates revealed all the conjugates to be active with MIC values in the range of 4.09-15.41 µM. Deoxycholic acid-adenosine clicked conjugate (6b) showed most promising antituberculosis property with MIC value of 4.09 µM. Most of the synthesized conjugates were found to be safe at 50 µM against normal human embryonic kidney (HEK 293 T) cell line.

Prospective serum metabolomic profile of prostate cancer by size and extent of primary tumor

Two recent investigations found serum lipid and energy metabolites related to aggressive prostate cancer up to 20 years prior to diagnosis. To elucidate whether those metabolomic profiles represent etiologic or tumor biomarker signals, we prospectively examined serum metabolites of prostate cancer cases by size and extent of primary tumors in a nested case-control analysis in the ATBC Study cohort that compared cases diagnosed with T2 (n = 71), T3 (n = 51), or T4 (n = 15) disease to controls (n = 200). Time from fasting serum collection to diagnosis averaged 10 years (range 1-20). LC/MS-GC/MS identified 625 known compounds, and logistic regression estimated odds ratios (ORs) associated with one-standard deviation differences in log-metabolites. N-acetyl-3-methylhistidine, 3-methylhistidine and 2'-deoxyuridine were elevated in men with T2 cancers compared to controls (ORs = 1.38-1.79; 0.0002 ≤ p ≤ 0.01). By contrast, four lipid metabolites were inversely associated with T3 tumors: oleoyl-linoleoyl-glycerophosphoinositol (GPI), palmitoyl-linoleoyl-GPI, cholate, and inositol 1-phosphate (ORs = 0.49-0.60; 0.000017 ≤ p ≤ 0.003). Secondary bile acid lipids, sex steroids and caffeine-related xanthine metabolites were elevated, while two Krebs cycle metabolites were decreased, in men diagnosed with T4 cancers. Men with T2, T3, and T4 prostate cancer primaries exhibit qualitatively different metabolite profiles years in advance of diagnosis that may represent etiologic factors, molecular patterns reflective of distinct primary tumors, or a combination of both.

Bile Acids Increase Doxorubicin Sensitivity in ABCC1-expressing Tumour Cells

Tumour cells possess or acquire various mechanisms to circumvent the cytotoxic effects of chemotherapy drugs. One such mechanism involves the overexpression of ABC transporters that facilitate the extrusion of a variety of structurally distinct chemotherapy drugs from the cytoplasm into the extracellular space. While specific ABC transporter inhibitors have been developed, many affect other ABC transporters, particularly at elevated concentrations. It is also unclear whether they show clear efficacy for combatting drug resistance in cancer patients with minimal host toxicity. In this study, we demonstrate the ability of two bile acids [β-cholanic acid (urso-cholanic acid) and deoxycholic acid] to specifically inhibit ABCC1-mediated drug transport, augmenting doxorubicin accumulation in breast and lung tumour cells selected for doxorubicin resistance through overexpression of the ABCC1 (but not ABCB1) drug transporter. The bile acids could also restore uptake and sensitivity to doxorubicin in human endothelial kidney cells genetically engineered to overexpress the ABCC1 drug transporter. These observations suggest a previously unreported role for bile acids as ABCC1 inhibitors or regulators. Given its additional properties of minimal clinical toxicity in humans and its ability to inhibit aldo-keto reductases involved in anthracycline resistance and anthracycline-induced cardiotoxicity, β-cholanic acid merits further in vivo and clinical investigation.

Chenodeoxycholic Acid Derivative HS-1200 Inhibits Hepatocarcinogenesis and Improves Liver Function in Diethylnitrosamine-Exposed Rats by Downregulating MTH1

Aim. To investigate the effects of HS-1200 on liver tumorigenesis and liver function in a diethylnitrosamine- (DEN-) induced hepatocellular carcinoma (HCC) rat model. Methods. Rats were randomly assigned into five groups: control, HS-1200, HCC, HCC + low dose HS-1200, and HCC + high dose HS-1200 groups. Rat HCC model was established by intraperitoneal injection of DEN. And rats were given HS-1200 by daily oral gavage. After 20 weeks, we examined animal body weight, liver weight, liver pathological changes, serum levels of AST, ALT, and AFP, and mutT homologue gene 1 (MTH1) in liver tissue. Results. Oral gavage of HS-1200 significantly increased animal body weight and decreased liver weight as well as liver coefficient in HCC rats (P < 0.05 versus HCC group). Moreover, oral administration of HS-1200 suppressed tumorigenesis, attenuated pathological changes in liver tissues, and decreased serum levels of AST, ALT, and AFP in HCC rats (P < 0.05 versus HCC group). In addition, the mRNA level of MTH1 was upregulated in the liver tissues of HCC rats (P < 0.05 versus control group), which was reversed by HS-1200 treatment in a dose-dependent manner (P < 0.05 versus HCC group). Conclusions. HS-1200 inhibits hepatocarcinogenesis and improves liver function maybe by inducing downregulation of MTH1.

Biocompatible hydrogelators based on bile acid ethyl amides

Four novel bile acid ethyl amides were synthetized using a well-known method. All the four compounds were characterized by IR, SEM, and X-ray crystal analyses. In addition, the cytotoxicity of the compounds was tested. Two of the prepared compounds formed organogels. Lithocholic acid derivative 1 formed hydrogels as 1% and 2% (w/v) in four different aqueous solutions. This is very intriguing regarding possible uses in biomedicine.

Synthesis, characterization and biological evaluation of bile acid-aromatic/heteroaromatic amides linked via amino acids as anti-cancer agents

A series of bile acid (Cholic acid and Deoxycholic acid) aryl/heteroaryl amides linked via α-amino acid were synthesized and tested against 3 human cancer cell-lines (HT29, MDAMB231, U87MG) and 1 human normal cell line (HEK293T). Some of the conjugates showed promising results to be new anticancer agents with good in vitro results. More specifically, Cholic acid derivatives 6a (1.35 μM), 6c (1.41 μM) and 6m (4.52 μM) possessing phenyl, benzothiazole and 4-methylphenyl groups showed fairly good activity against the breast cancer cell line with respect to Cisplatin (7.21 μM) and comparable with respect to Doxorubicin (1 μM), while 6e (2.49μM), 6i (2.46 μM) and 6m (1.62 μM) showed better activity against glioblastoma cancer cell line with respect to both Cisplatin (2.60 μM) and Doxorubicin (3.78 μM) drugs used as standards. Greater than 65% of the compounds were found to be safer on human normal cell line.

Ursodeoxycholic acid induces apoptosis in hepatocellular carcinoma xenografts in mice

AIM: To evaluate the efficacy of ursodeoxycholic acid (UDCA) as a chemotherapeutic agent for the treatment of hepatocellular carcinoma (HCC).

METHODS: BALB/c nude mice were randomized into four groups 24 h before subcutaneous injection of hepatocarcinoma BEL7402 cells suspended in phosphate buffered saline (PBS) into the right flank. The control group (n = 10) was fed a standard diet while treatment groups (n = 10 each) were fed a standard daily diet supplemented with different concentrations of UDCA (30, 50 and 70 mg/kg per day) for 21 d. Tumor growth was measured once each week, and tumor volume (V) was calculated with the following equation: V = (L × W²) × 0.52, where L is the length and W is the width of the xenograft. After 21 d, mice were killed under ether anesthesia, and tumors were excised and weighed. Apoptosis was evaluated through detection of DNA fragmentation with gel electrophoresis and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Western blot analysis was performed to determine the expression of apoptosis-related proteins BAX, BCL2, APAF1, cleaved caspase-9, and cleaved caspase-3.

RESULTS: UDCA suppressed tumor growth relative to controls. The mean tumor volumes were the following: control, 1090 ± 89 mm³; 30 mg/kg per day, 612 ± 46 mm³; 50 mg/kg per day, 563 ± 38 mm³; and 70 mg/kg per day, 221 ± 26 mm³. Decreased tumor volumes reached statistical significance relative to control xenografts (30 mg/kg per day, P < 0.05; 50 mg/kg per day, P < 0.05; 70 mg/kg per day, P < 0.01). Increasing concentrations of UDCA led to increased DNA fragmentation observed on gel electrophoresis and in the TUNEL assay (control, 1.6% ± 0.3%; 30 mg/kg per day, 2.9% ± 0.5%; 50 mg/kg per day, 3.15% ± 0.7%, and 70 mg/kg per day, 4.86% ± 0.9%). Western blot analysis revealed increased expression of BAX, APAF1, cleaved-caspase-9 and cleaved-caspase-3 proteins, which induce apoptosis, but decreased expression of BCL2 protein, which is an inhibitor of apoptosis, following administration of UDCA.

CONCLUSION: UDCA suppresses growth of BEL7402 hepatocellular carcinoma cells in vivo, in part through apoptosis induction, and is thus a candidate for therapeutic treatment of HCC.

Cross-talk between bile acids and gastrointestinal tract for progression and development of cancer and its therapeutic implications

Increasing incidences of gastrointestinal (GI) cancer are linked to changes in lifestyle with excess of red meat/fat consumption, and elevated secretion of bile acids. Bile acids are strong signaling molecules that control various physiological processes. Failure in bile acid regulation has detrimental effects, often linked with development and promotion of cancer of digestive tract including esophagus, stomach, liver, and intestine. Excessive concentration of bile acids especially lipophillic secondary bile acids are cytotoxic causing apoptosis and reactive oxygen species-mediated damage to the cells. Resistance to this apoptosis and accumulation of mutations leads to progression of cancer. Cytotoxicity of bile acids is contingent on their chemical structure. In this review, we discuss the chemistry of bile acids, bile acid mediated cellular signaling processes, their role in GI cancer progression, and therapeutic potential of synthetic bile acid derivatives for cancer therapy.

U12, a UDCA derivative, acts as an anti-hepatoma drug lead and inhibits the mTOR/S6K1 and cyclin/CDK complex pathways

U12, one of 20 derivatives synthesized from ursodeoxycholic acid (UDCA), has been found to have anticancer effects in liver cancer cell lines (SMMC-7721 and HepG2) and to protect normal liver cells from deoxycholic acid (DCA) damage (QSG-7701). Its anticancer mechanism was investigated using computer-aided network pharmacology and comparative proteomics. Results showed that its anti-malignancy activities were activated by mTOR/S6K1, cyclinD1/CDK2/4 and caspase-dependent apoptotic signaling pathways in hepatocellular carcinoma cells (HCC). The action of U12 may be similar to that of rapamycin. Animal testing confirmed that U12 exerted better anti-tumor activity than UDCA and had less severe side effects than fluorouracil (5-Fu). These observations indicate that U12 differs from UDCA and other derivatives and may be a suitable lead for the development of compounds useful in the treatment of HCC.

Ursodeoxycholic acid induces apoptosis of hepatocellular carcinoma cells in vitro

OBJECTIVE

Ursodeoxycholic acid (UDCA) is widely used to treat chronic liver diseases, and its cytoprotective effect on normal hepatocytes has been shown. This study aimed to investigate the apoptotic effects of UDCA on hepatocellular carcinoma (HCC) cells and the underlying molecular events in vitro.

METHODS

HCC cells were treated by UDCA at different doses and periods of time to assess cell morphology, viability, apoptosis and gene expression using methyl thiazolyl tetrazolium (MTT), Annexin V/propidium iodide (PI) stain, transferase dUTP nick end labeling (TUNEL), enzyme-linked immunosorbent assay (ELISA), immunocytochemistry and quantitative reverse transcription polymerase chain reaction, respectively.

RESULTS

UDCA treatment reduced cell viability but induced HCC cell apoptosis in dose-dependent and time-dependent manners. UDCA arrested HepG2 cells at phase S of the cell cycle. At the gene levels, UDCA downregulated Bcl-2 and second mitochondria-derived activator of caspase (Smac) protein expressions, but upregulated Bax and Livin proteins in HCC cells. At the highest concentration, UDCA inhibited Livin mRNA expression but increased Smac and caspase-3 mRNA expressions as well as the activity of caspase-3 in HCC cells.

CONCLUSIONS

The induction of HCC cell apoptosis by UDCA was dose-dependent and time-dependent and was mediated by the regulation of Bax to Bcl-2 ratio, the expressions of Smac and Livin, and caspase-3 expression and activity.

Synthesis and biological evaluation of bile carboxamide derivatives with pro-apoptotic effect on human colon adenocarcinoma cell lines

We previously reported that the cinnamylpiperazinyl group in the side chain of the chenodeoxycholic acid showed apoptosis-inducing activity on multiple myeloma cancer cell line KMS-11. In the present study, we synthesized and tested the pro-apoptotic potency of fifteen new piperazinyl bile carboxamide derived from cholic, ursodeoxycholic, chenodeoxycholic, deoxycholic and lithocholic acids on human colon adenocarcinoma cell lines DLD-1, HCT-116, and HT-29. Cell viability was first measured using XTT assay. The most of the synthetic bile carboxamide derivatives decreased significantly cell viability in a dose-dependent manner. HCT-116 and DLD-1 cell lines were more sensitive than HT-29 to tested compounds. 9c, 9d showed the best in vitro results in term of solubility and dose-response effect on the three colon adenocarcinoma cell lines. Additionally, flow cytometric and Western-blotting analysis showed that 9c induced pro-apoptosis in DLD-1 and HCT-116 whereas 9d did not. We conclude that the benzyl group improved anti-proliferative activity and that the α-hydroxyl group was found to be more beneficial at the 7-position in steroid skeleton.

Apoptosis of human gastric carcinoma SGC-7901 induced by deoxycholic acid via the mitochondrial-dependent pathway

The study aimed to evaluate the effects of deoxycholic acid (DCA) on human gastric carcinoma cell lines and to explore its mechanisms. In the present study, effects of DCA on SGC-7901 cell growth, cell cycle, and apoptosis were investigated by MTT assay, inverted microscopy, fluorescence microscopy, PI single- and FITC/PI double-staining flow cytometry, and western blotting. The study have revealed that DCA significantly inhibited the growth of SGC-7901 cells in a dose- and time-dependent manner and arrested cell cycle at G0/G1 phase. SGC-7901 cells showed typical apoptotic morphological changes after treated with DCA for 48 h. The intensity of typical apoptosis pattern- "ladders" formed by DNA in fragments of multiples of 200 base pairs was also observed. Apoptosis of SGC-7901 cells induced by DCA were associated with collapse of the mitochondrial membrane potential. DCA treatment could also increase the ratio of Bax to Bcl-2 in SGC-7901 cells. Meanwhile, the expression of p53, cyclinD1, and c-Myc were changed after DCA treatment. These results suggest that DCA induces apoptosis of gastric carcinoma cells through an intrinsic mitochondrial-dependent pathway, and the increase in the Bax/Bcl-2 ratio and collapse of the mitochondrial membrane potential may play important roles in DCA-induced apoptosis of gastric carcinoma cells.

Anticancer steroids: linking natural and semi-synthetic compounds

Steroids, a widespread class of natural organic compounds occurring in animals, plants and fungi, have shown great therapeutic value for a broad array of pathologies. The present overview is focused on the anticancer activity of steroids, which is very representative of a rich structural molecular diversity and ability to interact with various biological targets and pathways. This review encompasses the most relevant discoveries on steroid anticancer drugs and leads through the last decade and comprises 668 references.

Deciphering the role of charge, hydration, and hydrophobicity for cytotoxic activities and membrane interactions of bile acid based facial amphiphiles

We synthesized four cationic bile acid based facial amphiphiles featuring trimethyl ammonium head groups. We evaluated the role of these amphiphiles for cytotoxic activities against colon cancer cells and their membrane interactions by varying charge, hydration and hydrophobicity. The singly charged cationic Lithocholic acid based amphiphile (LCA-TMA1) is most cytotoxic, whereas the triply charged cationic Cholic acid based amphiphile (CA-TMA3) is least cytotoxic. Light microscopy and Annexin-FITC assay revealed that these facial amphiphiles caused late apoptosis. In addition, we studied the interactions of these amphiphiles with model membrane systems by Prodan-based hydration, DPH-based anisotropy, and differential scanning calorimetry. LCA-TMA1 is most hydrophobic with a hard charge causing efficient dehydration and maximum perturbations of membranes thereby facilitating translocation and high cytotoxicity against colon cancer cells. In contrast, the highly hydrated and multiple charged CA-TMA3 caused least membrane perturbations leading to low translocation and less cytotoxicity. As expected, Chenodeoxycholic acid and Deoxycholic acid based amphiphiles (CDCA-TMA2, DCA-TMA2) featuring two charged head groups showed intermediate behavior. Thus, we deciphered that charge, hydration, and hydrophobicity of these amphiphiles govern membrane interactions, translocation, and resulting cytoxicity against colon cancer cells.

Plasma membrane transporters in modern liver pharmacology

The liver plays a crucial role in the detoxification of drugs used in the treatment of many diseases. The liver itself is the target for drugs aimed to modify its function or to treat infections and tumours affecting this organ. Both detoxification and pharmacological processes occurring in the liver require the uptake of the drug by hepatic cells and, in some cases, the elimination into bile. These steps have been classified as detoxification phase 0 and phase III, respectively. Since most drugs cannot cross the plasma membrane by simple diffusion, the involvement of transporters is mandatory. Several members of the superfamilies of solute carriers (SLC) and ATP-binding cassette (ABC) proteins, with a minor participation of other families of transporters, account for the uptake and efflux, respectively, of endobiotic and xenobiotic compounds across the basolateral and apical membranes of hepatocytes and cholangiocytes. These transporters are also involved in the sensitivity and refractoriness to the pharmacological treatment of liver tumours. An additional interesting aspect of the role of plasma membrane transporters in liver pharmacology regards the promiscuity of many of these carriers, which accounts for a variety of drug-drug, endogenous substances-drug and food components-drug interactions with clinical relevance.

Molecular mechanisms of ursodeoxycholic acid toxicity & side effects: ursodeoxycholic acid freezes regeneration & induces hibernation mode

Ursodeoxycholic acid (UDCA) is a steroid bile acid approved for primary biliary cirrhosis (PBC). UDCA is reported to have “hepato-protective properties”. Yet, UDCA has “unanticipated” toxicity, pronounced by more than double number of deaths, and eligibility for liver transplantation compared to the control group in 28 mg/kg/day in primary sclerosing cholangitis, necessitating trial halt in North America. UDCA is associated with increase in hepatocellular carcinoma in PBC especially when it fails to achieve biochemical response (10 and 15 years incidence of 9% and 20% respectively). “Unanticipated” UDCA toxicity includes hepatitis, pruritus, cholangitis, ascites, vanishing bile duct syndrome, liver cell failure, death, severe watery diarrhea, pneumonia, dysuria, immune-suppression, mutagenic effects and withdrawal syndrome upon sudden halt. UDCA inhibits DNA repair, co-enzyme A, cyclic AMP, p53, phagocytosis, and inhibits induction of nitric oxide synthatase. It is genotoxic, exerts aneugenic activity, and arrests apoptosis even after cellular phosphatidylserine externalization. UDCA toxicity is related to its interference with drug detoxification, being hydrophilic and anti-apoptotic, has a long half-life, has transcriptional mutational abilities, down-regulates cellular functions, has a very narrow difference between the recommended (13 mg/kg/day) and toxic dose (28 mg/kg/day), and it typically transforms into lithocholic acid that induces DNA strand breakage, it is uniquely co-mutagenic, and promotes cell transformation. UDCA beyond PBC is unjustified.

Effects of DCA on Cell Cycle Proteins in Colonocytes

Purpose

Evidence that indicates bile acid is a promoter of colon cancer exists. Deoxycholic acid (DCA) modifies apoptosis or proliferation by affecting intracellular signaling and gene expression. However, because previous studies have been based on studies on colon cancer cell lines, the effect of DCA on normal colonocytes is unknown.

Methods

Normal colonocytes and Caco-2 and HCT116 cells were treated with 20 µM and 250 µM of DCA, and the effect of different concentrations of DCA was measured based on the expression of cell-cycle-related proteins by using Western blots.

Results

The expressions of CDK2 and cyclin D1 for different concentrations of DCA in normal colonocytes and colon cancer cells were similar, but the expressions of cyclin E and A were significantly different. In HCT116 colon cancer cells, the expression of cyclin E increased regardless of the DCA concentration, but in normal colonocytes and Caco-2 cells, the expression of cyclin E was not changed or decreased. In HCT116 colon cancer cells, the expression of cyclin A was not changed or decreased regardless of the DCA concentration, but in normal colonocytes and Caco-2 cells, the expression of cyclin A was increased at a DCA concentration of 20 µM.

Conclusion

The effect of DCA on stimulating cell proliferation suggests that DNA synthesis is stimulated by an increased expression of cyclin E in colon cancer cells. Our results suggest that a low dose of DCA induces cellular proliferation through increased expression of cyclin A and that a high dose of DCA induces decreased expression of cyclin E and CDK2 in normal colonocytes.

First report of a haemagglutinin-induced apoptotic pathway in breast cancer cells

A dimeric 64 kDa HA (haemagglutinin) was isolated with a high yield from dried Phaseolus vulgaris cultivar 'French bean number 35' seeds. It inhibited the proliferation of hepatoma HepG2 cells and breast cancer MCF-7 cells with an IC50 of 100 and 2 microM respectively. After exposure of MCF-7 cells to the HA for 24 h, a number of changes were detected in the cells. Growth arrest in the G0/G1 and G2/M phases was observed. The number of cells undergoing early apoptosis and late apoptosis increased. Disruption of the mitochondrial transmembrane potential and disorganization of the inner mitochondrial membrane were induced. Western-blot analysis disclosed that the HA induced apoptosis through the death receptor-mediated pathway.

Apoptosis-inducing effect of synthetic chenodeoxycholic acid derivative, HS-1200, in human hepatoma cell line BEL-7402 and the mechanisms involved

Chenodeoxycholic acid (CDCA) derivative HS-1200 can inhibit the proliferation and induce the apoptosis of human hepatoma BEL7402 cells in a dose- and time-dependent manner. In contrast, HS-1200 shows no apoptosis-inducing effect in normal human hepatic cell lines. HS-1200 induces the apoptosis of BEL7402 cells perhaps by up-regulating the expression of Bax protein and down-regulating the expression of Bcl-2 protein. The increased ratio of Bax to Bcl-2 might contribute to the permeabilization of the outer mitochondrial membrane (OMM) and make it permeable to intermembrane space proteins such as cytochrome C. Once released, cytochrome C promotes the activation of caspase-9 and thereby results in the activation of caspase-3, which functions as the downstream effector of the cell death program. Furthermore, as caspase-8-specific inhibitor z-IETDfmk shows no impact on HS-1200-mediated apoptosis of BEL7402 cells, HS-1200 induces apoptosis perhaps via the activation of mitochondrial pathway.

Apoptosis and modulation of cell cycle control by bile acids in human leukemia T cells

Depending on the nature of chemical structures, different bile acids exhibit distinct biological effects. Their therapeutic efficacy has been widely demonstrated in various liver diseases, suggesting that they might protect hepatocytes against common mechanisms of liver damage. Although it has been shown to prevent apoptotic cell death in certain cell lines, bile acids significantly inhibited cell growth and induced apoptosis in cancer cells. To better understand the pharmacological potential of bile acids in cancer cells, we investigated and compared the effects of deoxycholic acid (DCA), ursodeoxycholic acid (UDCA), and their taurine-derivatives [taurodeoxycholic acid (TDCA) and tauroursodeoxycholic acid (TUDCA), respectively] on the induction of apoptosis and inhibition of cell proliferation of a human T leukemia cell line (Jurkat cells). All the bile acids tested induced a delay in cell cycle progression. Moreover, DCA markedly increased the fraction of apoptotic cells. The effects of TDCA, UDCA, and TUDCA were different from those observed for DCA. Their primary effect was the induction of necrosis. These distinctive features suggest that the hydrophobic properties of DCA play a role in its cytotoxic potential and indicate that it is possible to create new drugs useful for cancer therapy from bile acid derivatives as lead compounds.

Synthesis and cytotoxic activity of a series of bile acid derivatives

The new conjugates of selected bile acids (hyocholic (2), deoxycholic (3), hyodeoxycholic (4) and 12-ketocholic (5) acids) with ethyl 11-aminoundecanoate 7, 8, 11, and 13 were synthesized. The conjugation reaction was carried out in ethyl acetate in the presence of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) and triethylamine. Under the same experimental conditions, the conjugation reaction involving ethyl 6-aminohexanoate resulted in formation of a conjugate 9 only in the case of deoxycholic acid (3) in addition to the unexpected ethyl ester 10. In the case of the other bile acids (cholic (1), hyodeoxycholic (4) and 12-ketocholic (5) acids) only an unexpected ester formation took place giving esters 6, 12, and 14. Cytotoxic activity against four tumor cell lines (human breast adenocarcinoma ER-, MDA-MB-231; breast adenocarcinoma ER+, MCF-7; cervix epiteloid carcinoma, HeLa S-3; and prostate cancer, PC-3) was evaluated. Conjugate 8 showed strong activity against HeLa S-3 and conjugate 11 for PC-3. Ethyl ester of 12-ketocholic acid 14 showed very strong antiproliferative activity against MCF-7 and HeLa S-3.

Synthetic chenodeoxycholic acid derivative, HS-1200, induces apoptosis of human hepatoma cells via a mitochondrial pathway

We investigated whether HS-1200 has anti-proliferation effects on human hepatoma cells in vitro. Here, chromatin condensation, DNA ladder formation and proteolytic cleavage of poly (ADP-ribose) polymerase (PARP) were observed after treatment of HS-1200, indicating the occurrence of apoptotic cell death, which was associated with up-regulation of Bax, cleaved-caspase-3 and cleaved-caspase-9. Inhibition of caspase-9 rescued HS-1200-induced apoptosis. Furthermore, cells treated with HS-1200 showed a reduction in mitochondrial membrane potential (Deltapsi(m)) and caused cytochrome c release into the cytosol. The results indicated that synthetic chenodeoxycholic acid HS-1200 could induce cell apoptosis in BEL7402 human hepatoma cell line, via a Bax/cytochrome c/caspase-9 independent pathway. This study suggested that HS-1200 is potentially useful as an apoptosis inducer for the treatment of hepatocellular carcinoma.

A chenodeoxycholic derivative, HS-1200, induces apoptosis and cell cycle modulation via Egr-1 gene expression control on human hepatoma cells

We previously reported that HS-1200, a synthetic chenodeoxycholic acid derivative, has apoptosis-inducing activity in various human cancer cells. The present study was undertaken to examine whether HS-1200 had an anticancer effect on HepG2 (wild-type p53) and Hep3B (p53 deleted) human hepatoma cells. Treatment of both cells with HS-1200 resulted in growth inhibition and induction of apoptosis as measured by MTT assay, nuclear staining, DNA fragmentation and flow cytometry analysis. The increase in apoptosis was associated with the alteration in the ratio of Bcl-2/Bax protein expression. In addition, flow cytometry analysis indicated that HS-1200 induced G1 phase arrest in both cells. When analyzing the expression of cell cycle-related proteins, we found that HS-1200 reduced the expression levels of cyclin D1, cyclin A, and Cdk2. HS-1200 treatment also caused an increase in the expression levels of p21 WAF1/CIP1 in HepG2 cells in a p53-dependent manner and in Hep3B cells in a p53-independent manner. Moreover, the expression level of p27 KIP1 was increased in both cell lines. We also observed that HS-1200 decreased the levels of cyclooxygenase (COX)-2 mRNA and protein expression. Furthermore, HS-1200 treatment markedly induced the Egr-1 expression at an early time point, and the increased expression levels of p53, p21 WAF1/CIP1, p27 KIP1, and COX-2 after treatment with HS-1200 were completely inhibited in HepG2 cells and partially inhibited in Hep3B cells by silencing of Egr-1, respectively. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anticancer activity of the synthetic bile acid derivative, HS-1200, through Egr-1 regulation.

Dietary fat-gene interactions in cancer

Epidemiologic studies have suggested for decades an association between dietary fat and cancer risk. A large body of work performed in tissue culture and xenograft models of cancer supports an important role of various types of fat in modulating the cancer phenotype. Yet, the molecular mechanisms underlining the effects of fat on cancer initiation and progression are largely unknown. The relationships between saturated fat, polyunsaturated fat, cholesterol or phytanic acid with cancer have been reviewed respectively. However, few have considered the relationship between all of these fats and cancer. The purpose of this review is to present a more cohesive view of dietary fat-gene interactions, and outline a working hypothesis of the intricate connection between fat, genes and cancer.

Taurolidine induces apoptosis of murine melanoma cells in vitro and in vivo by modulation of the Bcl-2 family proteins

BACKGROUND

This study evaluates whether taurolidine, a novel antibiotic agent, induces murine melanoma cell apoptosis in vitro and in vivo.

METHODS

Murine melanoma cells (B16 4A5 and B16 F10) were treated with taurolidine (0-100 microM) for 12 and 24 hr. Cell viability and apoptosis were assessed by MTT assay and FACScan analysis. Expression of the Bcl-2 family proteins was detected by Western blot analysis. In vivo, taurolidine-induced anti-tumor cytotoxicity was assessed in C57BL/6 mice. Therapeutic effectiveness, by intraperitoneal injection of taurolidine (15 mg/mouse) on alternate days for 2 weeks, was evaluated in mice bearing B16 4A5 tumor xenografts. Primary and metastatic tumor growth and intra-tumor apoptotic index were measured.

RESULTS

Taurolidine induced cell apoptosis and reduced cell viability in murine melanoma cells. The pro-apoptotic protein Bax was enhanced, whereas the anti-apoptotic protein Bcl-2 was inhibited by taurolidine treatment. In vivo, systemic injection of 15-mg taurolidine was identified as the maximally tolerated dose. Administration of taurolidine at 15 mg/mouse significantly inhibited primary and metastatic tumor growth, which was mirrored by a significantly increased intra-tumor apoptotic index.

CONCLUSIONS

These results demonstrate that taurolidine significantly attenuated melanoma tumor growth, which may result from taurolidine-induced apoptosis by modulation of the Bcl-2 family proteins.

Mechanism of apoptotic effects induced selectively by ursodeoxycholic acid on human hepatoma cell lines

AIM: To investigate the effects of ursodeoxycholic acid (UDCA) on apoptosis and proliferation of hepatoma cell lines.

METHODS: Human hepatoma cell lines HepG2 and BEL 7402 were cultured in medium supplemented with different concentrations of UDCA, normal human hepatic line L-02 was used as control. Cell proliferation, apoptosis and gene expression were detected using methyl thiazolyl tetrazolium (MTT) assay, flow cytometry, Western blot, DNA ladder assay, electron microscopy, and immunocytochemistry.

RESULTS: Ursodeoxycholic acid inhibited the proli-feration of HepG2 and BEL7402 cell lines in a dose-dependent manner. Ursodeoxycholic acid can change cell cycle distribution of HepG2 and BEL7402, the proportion of cells in G₀-G₁ phase increased whereas the proportion of S phase cells and G₂-M phase cells decreased. Ursodeoxycholic acid arrested the cell cycle in G₀-G₁ phase by down-regulating the cell cycle related proteins cyclin D₁, D₃ and retinoblastoma protein (p^Rb). The apoptotic rates of HepG2 and BEL7402 treated with UDCA (1.0 mmol/L) were significantly higher than those of control. In the HepG2 and BEL7402 treated with UDCA, expression of bcl-2 decreased whereas expression of Bax increased, the nuclear fragmentation and chromosomal condensed, cells shrank and lost attachment, apoptotic bodies and DNA ladders appeared. UDCA had no effect in inducing apoptosis on L-02 cell lines.

CONCLUSION: UDCA can selectively inhibit proliferation and induce apoptosis of HepG2 and BEL7402 cell lines by blocking cell cycle and regulating the expression of Bax/bcl-2 genes.