MicroRNA profiles in cisplatin-induced apoptosis of hepatocellular carcinoma cells

Cell cycle-specific phosphorylation of p53 protein in A549 cells exposed to cisplatin and standardized air pollutants

Exposure to particulate matter is associated with DNA damage and the risk of lung cancer. Protein p53 is activated by multi-site phosphorylation in the early stages of DNA damage and affects cell outcome. Our study aimed to assess the effect of (100 µg/mL-1/24 h) standardized air pollutants: carbon black (CB), urban dust (UD), and nanoparticle carbon black (NPCB) on cell cycle, DNA damage and 53 phosphorylation at Ser 9, Ser 20, Ser 46, and Ser 392 in proliferating and quiescent A549 cells and in cells that survived cisplatin (CisPT) exposure. Phosphorylated p53 was quantified in cell subpopulations by flow cytometry using specific fluorochrome-tagged monoclonal antibodies and analysis of bivariate fluorescence distribution scatterplots. CisPT, UD and NPCB increased site-specific p53 phosphorylation producing unique patterns. NPCB activated all sites irrespectively on the cell cycle, while the UD was more selective. p53 Ser 9-P and p53 Ser 20-P positively correlated with the numbers of CisPT-treated cells at G0/G1, and NPCB and NPCB + CisPT produced a similar effect. A positive correlation and integrated response were also found between Ser 20-P and Ser 392-P in resting A549 cells treated with NPCB and CisPT but not UD. Interdependence between the expression of p53 phosphorylated at Ser 20, and Ser 392 and cell cycle arrest show that posttranslational alterations are related to functional activation. Our data suggest that p53 protein phosphorylation in response to specific DNA damage is driven by multiple independent and integrated pathways to produce functional activation critical in cancer prevention and treatment.

Pharmacodynamic Modeling to Evaluate the Impact of Cimetidine, an OCT2 Inhibitor, on the Anticancer Effects of Cisplatin

Despite potent anticancer activity, the clinical utilization of cisplatin is limited due to nephrotoxicity. As Organic Cation Transporter 2 (OCT2) has been shown to be one of the key transporters involved in the uptake of cisplatin into renal proximal tubules, OCT2 inhibitors such as cimetidine have been explored to suppress cisplatin-induced nephrotoxicity. Nonetheless, the impact of OCT2 inhibition or cimetidine on the anti-cancer effects of cisplatin has not been extensively examined. The main objective of the present study was to quantitatively characterize the anticancer effects of cisplatin and cimetidine and determine their nature of interactions in two cancer cell lines, OCT2-negative hepatocellular carcinoma (HCC) cell line, Huh7, and OCT2-positive breast cancer cell line, MDA-MB-468. First, we determined the static concentration-response curves of cisplatin and cimetidine as single agents. Next, with the help of three-dimensional (3D) response surface analyses and a competitive interaction model, we determined their nature of interactions at static concentrations to be modestly synergistic or additive in Huh7 and antagonistic in MDA-MB-468. These results were consistent with the cell-level pharmacodynamic (PD) modeling analysis which leveraged the time-course effects of drugs as single agents and drug combinations. Our developed PD model can be further used to design future preclinical studies to further investigate the cisplatin and cimetidine combinations in different in vitro and in vivo cancer models.

Systems Pharmacology-Based Strategy to Investigate the Mechanism of Ruangan Lidan Decoction for Treatment of Hepatocellular Carcinoma

epatocellular carcinoma (HCC) is one of the leading contributors to cancer mortality worldwide. Currently, the prevention and treatment of HCC remains a major challenge. As a traditional Chinese medicine (TCM) formula, Ruangan Lidan decoction (RGLD) has been proved to own the effect of relieving HCC symptoms. However, due to its biological effects and complex compositions, its underlying mechanism of actions (MOAs) have not been fully clarified yet. In this study, we proposed a pharmacological framework to systematically explore the MOAs of RGLD against HCC. We firstly integrated the active ingredients and potential targets of RGLD. We next highlighted 25 key targets that played vital roles in both RGLD and HCC disease via a protein-protein interaction (PPI) network and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Furthermore, an ingredient-target network of RGLD consisting of 216 ingredients with 306 targets was constructed, and multilevel systems pharmacology analyses indicated that RGLD could act on multiple biological processes related to the pathogenesis of HCC, such as cellular response to hypoxia and cell proliferation. Additionally, integrated pathway analysis of RGLD uncovered that RGLD might treat HCC through regulating various pathways, including MAPK signaling pathway, PI3K/Akt signaling pathway, TNF signaling pathway, and ERBB signaling pathway. Survival analysis results showed that HCC patients with low expression of VEGFA, HIF1A, CASP8, and TOP2A were related with a higher survival rate than those with high expression, indicating the potential clinical significance for HCC. Finally, molecular docking results of core ingredients and targets further proved the feasibility of RGLD in the treatment of HCC. Overall, this study indicates that RGLD may treat HCC through multiple mechanisms, which also provides a potential paradigm to investigate the MOAs of TCM prescription.

Diagnosis and Therapeutic Management of Liver Fibrosis by MicroRNA

Remarkable progress has been made in the treatment and control of hepatitis B and C viral infections. However, fundamental treatments for diseases in which liver fibrosis is a key factor, such as cirrhosis, alcoholic/nonalcoholic steatohepatitis, autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis, are still under development and remain an unmet medical need. To solve this problem, it is essential to elucidate the pathogenesis of liver fibrosis in detail from a molecular and cellular perspective and to develop targeted therapeutic agents based on this information. Recently, microRNAs (miRNAs), functional RNAs of 22 nucleotides, have been shown to be involved in the pathogenesis of liver fibrosis. In addition, extracellular vesicles called “exosomes” have been attracting attention, and research is being conducted to establish noninvasive and extremely sensitive biomarkers using miRNAs in exosomes. In this review, we summarize miRNAs directly involved in liver fibrosis, miRNAs associated with diseases leading to liver fibrosis, and miRNAs related to complications of cirrhosis. We will also discuss the efficacy of each miRNA as a biomarker of liver fibrosis and pathology, and its potential application as a therapeutic agent.

Ameliorative effect of betanin on experimental cisplatin-induced liver injury; the novel impact of miRNA-34a on the SIRT1/PGC-1α signaling pathway

The anticancer agent, cisplatin (CIS), is associated with hepatotoxic effects related to activation of oxidative stress and inflammation pathways. CIS-induced oxidative DNA damage reduces sirtuin 1 (SIRT1) activity, which in turn, modulates the activity of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α). Moreover, microRNA-34a (miRNA-34a) was shown to hinder both SIRT1 and nuclear factor erythroid 2-related factor 2 (Nrf2) activity. Thus, targeting such a pathway can alleviate CIS-induced hepatotoxicity. Betanin (BET) is a natural red glycoside food dye obtained from beets, which is reported to exhibit antioxidant function. However, its role in CIS-induced liver injury and the molecular mechanism has not been fully elucidated. Thus, the aim of this study was to investigate the ameliorative effect of BET on CIS-induced acute hepatotoxicity through the SIRT1/PGC-1α signaling pathway and illustrate the impact of miRNA-34a. Seventy-two rats were divided into six equal groups: (1) Control, (2) BET, (3) CIS, (4) CIS/BET, (5) CIS/EX527, and (6) CIS/BET/EX527. CIS-induced liver injury was evidenced by deregulated BAX and BCL2 levels, decreased levels of AMP-activated protein kinase and PGC-1α expression, and decreased SIRT1 activity. Consequently, reduced levels of Nrf2 and the expression of associated heme oxygenase-1 and glutamate-cysteine ligase modifier subunit were observed. Intriguingly, BET succeeded in reducing the CIS-induced liver injury through reducing miRNA-34a expression and enhancing the SIRT1/PGC-1α pathway. These findings coincide with the molecular docking results and the histopathological picture. In conclusion, the current research provided novel findings of the BET ameliorative effect on CIS-induced liver injury through modulating miRNA-34a expression and the SIRT1/PGC-1α signaling cascade.

The Effect of Gemcitabine on Cell Cycle Arrest and microRNA Signatures in Pancreatic Cancer Cells

BACKGROUND/AIM

Gemcitabine, an inhibitor of DNA synthesis, is the gold standard chemotherapeutic agent for pancreatic ductal adenocarcinoma (PDAC). MicroRNAs (miRNAs) play critical roles in cancers, including PDAC. However, less is known about the effect of gemcitabine on PDAC cells and miRNA expression in PDAC. We evaluated the effect of gemcitabine on the cell cycle of PDAC cells in vitro and in vivo and on the miRNA expression profile.

MATERIALS AND METHODS

Effects of gemcitabine on PK-1 and PK-9 cell growth were evaluated using a cell counting kit-8 assay. Xenografted mouse models were used to assess gemcitabine effects in vivo.

RESULTS

Gemcitabine inhibited the proliferation and tumour growth of PK-1 cells, and induced S phase cell cycle arrest. Numerous miRNAs were altered upon gemcitabine treatment of PK-1 cells and xenograft models.

CONCLUSION

Altered miRNAs may serve as potential therapeutic targets for improving the efficacy of gemcitabine in PDAC.

MiR-124 sensitizes cisplatin-induced cytotoxicity against CD133+ hepatocellular carcinoma cells by targeting SIRT1/ROS/JNK pathway

Drug resistance is still a major obstacle for efficient treatment of hepatocellular carcinoma (HCC) during the cisplatin-based chemotherapy. Recent studies have demonstrated that CD133 positive population of cancer cells are responsible for multiple drug resistance. We are supposed to take strategies to sensitize CD133⁺ HCC cells to cisplatin treatment. In the present study, CD133⁺ HCC cells showed significant cisplatin-resistance compared to the CD133^- HCC cells. Downregulation of miR-124 was observed in CD133⁺ HCC cells. However, enforced expression of miR-124 can increase the sensitivity of CD133⁺ HCC cells to cisplatin treatment in vitro and in vivo. Mechanically, overexpression of miR-124 was found to inhibit the expression of SIRT1 and thus promoted the generation of ROS and phosphorylation of JNK. As the results, overexpression of miR-124 expanded the apoptosis in cisplatin-treated CD133⁺ HCC cells. We then demonstrated that overexpression of miR-124 sensitized cisplatin-induced cytotoxicity against CD133⁺ hepatocellular carcinoma cells by targeting SIRT1/ROS/JNK pathway.

Interactions between anticancer active platinum complexes and non-coding RNAs/microRNAs

Platinum(II) complexes such as cisplatin, carboplatin and oxaliplatin are clinically approved for the therapy of various solid tumors. Challenging pathogenic properties of cancer cells and the response of cancers towards platinum-based drugs are strongly influenced by non-coding small RNA molecules, the microRNAs (miRNAs). Both increased platinum activity and formation of tumor resistance towards platinum drugs are controlled by miRNAs. This review gives an overview of the interactions between platinum-based drugs and miRNAs, and their influence on platinum activity in various cancer types is discussed.