CPBMF65, a synthetic human uridine phosphorylase-1 inhibitor, reduces HepG2 cell proliferation through cell cycle arrest and senescence.

Hepatocellular carcinoma (HCC) is the most prevalent type of tumor among primary liver tumors and is the second highest cause of cancer-related deaths worldwide. Current therapies are controversial, and more research is needed to identify effective treatments. A new synthetic compound, potassium 5-cyano-4-methyl-6-oxo-1,6-dihydropyridine-2-olate (CPBMF65), is a potent inhibitor of the human uridine phosphorylase-1 (hUP1) enzyme, which controls the cell concentration of uridine (Urd). Urd is a natural pyrimidine nucleoside involved in cellular processes, such as RNA synthesis. In addition, it is considered a promising biochemical modulator, as it may reduce the toxicity caused by chemotherapeutics without impairing its anti-tumor activity. Thus, the objective of this study is to evaluate the effects of CPBMF65 on the proliferation of the human hepatocellular carcinoma cell line (HepG2). Cell proliferation, cytotoxicity, apoptosis, senescence, autophagy, intracellular Urd levels, cell cycle arrest, and drug resistance were analyzed. Results demonstrate that, after incubation with CPBMF65, HepG2 cell proliferation decreased, mainly through cell cycle arrest and senescence, increasing the levels of intracellular Urd and maintaining cell proliferation reduced during chronic treatment. In conclusion, results show, for the first time, the ability of a hUP1 inhibitor (CPBMF65) to reduce HepG2 cell proliferation through cell cycle arrest and senescence.

Exenatide induces autophagy and prevents the cell regrowth in HepG2 cells.

The incidence of hepatocellular carcinoma (HCC) keeps rising year by year, and became the second leading cause of cancer-related death. Some studies have found that liraglutide, a GLP-1 analog, may decrease the tumor cells proliferation. Due to this, the aim of this work is to investigate the antiproliferative potential of exenatide, another GLP-1 analog. Cell proliferation was assessed by direct count with Trypan blue dye exclusion. Flow cytometry was used to determinate autophagy and nuclear staining. Morphometric analysis was used to verify senescence and apoptosis. The mechanism that induced cell growth inhibition was analyzed by Western Blot. Treatment with exenatide significantly decreases cell proliferation and increases autophagy, both in relation to control and liraglutide. In addition, mTOR inhibition was greater in cells treated with exenatide. In relation to chronic treatment, exenatide does not allow cellular regrowth by preventing some resistance mechanism that the cells can acquire. These results suggest that exenatide has a potent anti-proliferative activity via mTOR modulation and, among the GLP-1 analogs tested, could be in the future an alternative for HCC treatment.

Therapeutic effect of Baccharis anomala DC. extracts on activated hepatic stellate cells.

The therapeutic potential of Baccharis anomala DC. extracts was evaluated through its cytotoxic and antiproliferative effect and their phenotypic reversion property in activated hepatic stellate cells (HSCs). Baccharis anomala is distributed in Brazil (southeastern and south regions) and used for diuretic effect in folk medicine. Four fractions were obtained from the fractionation of the methanolic extract. Fractions III and IV decreased cell proliferation without increasing cell necrosis markers levels and induced cell cycle arrest in G1 phase. Fraction III induced phenotypic reversion through PPAR-γ activation pathway, while fraction IV did not alter PPAR-α/γ expression levels, suggesting that there is an independent PPAR-α/γ pathway involved. Hydroxybenzoic, chlorogenic and coumaric acids were identified. Fractions III and IV showed antiproliferative effect and ability to induce reversion of activated phenotype of HSCs.

Fructose-1,6-Bisphosphate Prevents Bleomycin-Induced Pulmonary Fibrosis in Mice and Inhibits the Proliferation of Lung Fibroblasts.

Pulmonary fibrosis is a specific form of interstitial pneumonia. In addition to the idiopathic cause, it may be caused by drugs such as bleomycin (BLM)-used in the treatment of tumors. Fructose-1,6-bisphosphate (FBP) is a high-energy endogenous glycolytic compound that has antifibrotic, anti-inflammatory, and immunomodulatory effects. The aim of this study was to investigate the effects of FBP on both BLM-induced pulmonary fibrosis in mice and in a human embryonic lung fibroblast (MRC-5) culture system. C57BL/6 mice were divided into four groups: control, FBP, BLM, and BLM plus FBP. A single dose of bleomycin (7.5 U/kg) was administered intratracheally, and survival, body weight, Ashcroft score, and histological analysis were evaluated. Pulmonary function and bronchoalveolar lavage fluid (BALF) were also evaluated after a single dose of bleomycin (1.2 U/kg-intratracheally). Treatment with FBP (500 mg/kg) was given on day 0 intraperitoneally. Fibroblasts (MRC-5 cells) were used to access the effect of FBP in vitro. In vivo, FBP increased the survival rate and reduced body weight loss (BLM vs. BLM plus FBP-p < 0.05). FBP also prevented BLM-induced loss of pulmonary function and decreased BALF inflammatory cells, level of fibrosis, and superficial collagen density (p < 0.05). In vitro, FBP (0.62 and 1.25 mM) had inhibitory activity on MRC-5 cells and was able to induce senescence in fibroblasts. These results showed that FBP has the potential of reducing the toxic effects of BLM and may provide supportive therapy for conventional methods used for the treatment of cancer.

Octyl gallate reduces ATP levels and Ki67 expression leading HepG2 cells to cell cycle arrest and mitochondria-mediated apoptosis.

Octyl gallate (OG) is an antioxidant that has shown anti-tumor, anti-diabetic and anti-amyloidogenic activities. Mitochondria play an important role in hepatocellular carcinoma, mainly by maintaining accelerated cellular proliferation through the production of ATP. Thus, the mitochondria may be a target for antitumor therapies. Here, we investigated the effects of OG in the hepatocarcinoma cell line (HepG2) and the mechanisms involved. We report, for the first time, that treatment with OG for 24h inhibited HepG2 cell growth by decreasing mitochondrial activity and mass, which led to the reduction of ATP levels. This reduction in the energy supply triggered a decrease in Ki67 protein expression, leading cells to cycle arrest. In addition, treatment with two doses of OG for 48h induced loss of mitochondrial functionality, mitochondrial swelling and apoptosis. Finally, we report that HepG2 cells had no resistance to treatment after multiple doses. Collectively, our findings indicate that metabolic dysregulation and Ki67 protein reduction are key events in the initial anti-proliferative action of OG, whereas mitochondrial swelling and apoptosis induction are involved in the action mechanism of OG after prolonged exposure. This suggests that OG targets mitochondria, thus representing a candidate for further research on therapies for hepatocarcinoma.

Fructose-1,6-bisphosphate reverts iron-induced phenotype of hepatic stellate cells by chelating ferrous ions.

Hepatic fibrosis is an extracellular matrix deposition by hepatic stellate cells (HSC). Fibrosis can be caused by iron, which will lead to hydroxyl radical production and cell damage. Fructose-1,6-bisphosphate (FBP) has been shown to deliver therapeutic effects in many pathological situations. In this work, we aimed to test the effects of FBP in HSC cell line, GRX, exposed to an excess of iron (Fe). The Fe-treatment increased cell proliferation and FBP reversed this effect, which was not due to increased necrosis, apoptosis or changes in cell cycle. Oil Red-O staining showed that FBP successfully increased lipid content and lead GRX cells to present characteristics of quiescent HSC. Fe-treatment decreased PPAR-γ expression and increased Col-1 expression. Both effects were reversed by FBP which also decreased TGF-ß1 levels in comparison to both control and Fe groups. FBP, also, did not present scavenger activity in the DPPH assay. The treatment with FBP resulted in decreased proliferation rate, Col-1 expression and TGF-ß1 release by HSC cells. Furthermore, activated PPAR-γ and increased lipid droplets induce cells to become quiescent, which is a key event to reversion of hepatic fibrosis. FBP also chelates iron showing potential to improve Cell redox state.

Liraglutide, a glucagon-like peptide-1 analog, induce autophagy and senescence in HepG2 cells.

It has been reported that glucagon-like peptide-1 (GLP-1) agents have been associated with both the increased risk of cancer and inhibition of tumor growth and metastases. The aim of this study is to evaluate the effect of liraglutide on hepatocellular carcinoma cells - HepG2. Cytometry was used to evaluate mechanism related to decreased cell proliferation. Nuclear staining and morphometric analysis were also used to verify the process that was taking place after treatment with liraglutide, and in order to better understand the mechanism, TGF-ß1 was performed. HepG2 cells decreased proliferation after liraglutide treatment without altering oxidative stress levels. Liraglutide was able to induce autophagy and senescence through the increase of TGF-ß1 which possibly explains the growth decrease. We have demonstrated that liraglutide has an antiproliferative effect in HepG2 cells inducing autophagy and senescence by the increase of TGF-ß1.

Fructose-1,6-bisphosphate decreases IL-8 levels and increases the activity of pro-apoptotic proteins in HepG2 cells.

Hepatocellular carcinoma (HCC) is the most prevalent primary liver tumor that affects the world population. Liver cancer inevitably causes great harms and its treatment is extremely difficult. Its development is related to the existence of chronic liver injury, such as in cirrhosis. Cancer is a disease related to the process of inflammation so, research with anti-inflammatory agents has been performed for the development of anti-tumor drugs. Fructose-1,6-bisphosphate (FBP), a metabolite of the glycolytic route, has shown anti-inflammatory actions. The purpose of this study is to investigate the effect of FBP on HepG2 cells growth and inflammatory parameters. Results showed that FBP decreased the proliferation of HepG2 cells through trypan blue assay, without causing necrosis, shown by the intracellular release of LDH. By flow cytometry, we observed a significant IL-8 decrease which is closely related to the tumoral progression and chemotherapeutic resistance, especially in HCC. Then, we found, by RT-PCR, a high expression level of pro-apoptotic protein, such as Bax and p53, and decreased the expression levels of anti-apoptotic proteins, like Bcl-2 suggesting apoptosis. Finally, our results showed that FBP can be a potential therapeutic agent to slow the progress of HCC.

Gallic acid reduces cell growth by induction of apoptosis and reduction of IL-8 in HepG2 cells.

Hepatocellular carcinoma is the most prevalent primary liver tumor and is among the top ten cancer that affect the world population. Its development is related, in most cases, to the existence of chronic liver injury, such as in cirrhosis. The knowledge about the correlation between chronic inflammation and cancer has driven new researches with anti-inflammatory agents that have potential for the development of antitumor drugs. Gallic acid is a phenolic acid found in many natural products and have shown anti-inflammatory, anti-tumor, anti-mutagenic and antioxidant actions. The purpose of this study was to investigate the effect of gallic acid on acute and chronic cell proliferation and inflammatory parameters of hepatocellular carcinoma cells (HepG2), as well as to investigate the mechanisms involved. Results showed that the gallic acid decreased the proliferation of HepG2 cells in a dose-dependent manner (Trypan blue exclusion assay), without causing necrosis (LDH assay). We observed a significant increase in the percentage of small and regular nuclei (Nuclear Morphometric Analysis assay), a significant induction of apoptosis by Annexin V-FITC and PI assay and no interference with the cell cycle using the FITC BrdU Flow Kit. We observed a significant reduction in the levels of IL-8 and increased levels of IL-10 and IL-12 (Cytometric Bead Array Human Inflammation Assay). Furthermore, gallic acid caused no cancer cells regrowth at a long term (Cumulative Population Doubling assay). According to these results, gallic acid showed a strong potential as an anti-tumor agent in hepatocellular carcinoma cells.

Rapamycin and fructose-1,6-bisphosphate reduce the HEPG2 cell proliferation via increase of free radicals and apoptosis.

Hepatocellular carcinoma is the most prevalent type of tumor among primary tumors affecting the liver. Rapamycin is currently used as a basis for chemotherapy in the treatment of cancers, including the liver. Because it shows several adverse effects, minimizing these effects without compromising efficacy is important. In this sense other drugs may be used concomitantly. One of these drugs is fructose-1,6-bisphosphate (FBP), which has shown therapeutic effect in various pathological situations, having antioxidant and anti-inflammatory proprieties. The objective of the present study was to evaluate the activity of rapamycin in combination with the FBP in HepG2 cell proliferation and the mechanisms involved. HepG2 cells were analyzed after 72 h of treatment with both drugs. Cell proliferation, cytotoxicity, cytokines, apoptosis, senescence, autophagy and oxidative stress were accessed. Ιt was demonstrated that the combination is more efficient than the single use of substances, because subtherapeutic doses of rapamycin, when associated to FBP become effective, reducing cell proliferation, through a significant increase in the production of tiobarbituric acid reactive substances (TBARS), suggesting that this might be the cause of death by apoptosis. According to these results, we believe that the association of both drugs may be a promising choice for the treatment of hepatocarcinoma.