Downregulation of transcription factor GATA4 sensitizes human hepatoblastoma cells to doxorubicin-induced apoptosis

Non-dialyzable uremic toxins and renal tubular cell damage in CKD patients: a systems biology approach

BACKGROUND

Chronic kidney disease presents global health challenges, with hemodialysis as a common treatment. However, non-dialyzable uremic toxins demand further investigation for new therapeutic approaches. Renal tubular cells require scrutiny due to their vulnerability to uremic toxins.

METHODS

In this study, a systems biology approach utilized transcriptomics data from healthy renal tubular cells exposed to healthy and post-dialysis uremic plasma.

RESULTS

Differential gene expression analysis identified 983 up-regulated genes, including 70 essential proteins in the protein-protein interaction network. Modularity-based clustering revealed six clusters of essential proteins associated with 11 pathological pathways activated in response to non-dialyzable uremic toxins.

CONCLUSIONS

Notably, WNT1/11, AGT, FGF4/17/22, LMX1B, GATA4, and CXCL12 emerged as promising targets for further exploration in renal tubular pathology related to non-dialyzable uremic toxins. Understanding the molecular players and pathways linked to renal tubular dysfunction opens avenues for novel therapeutic interventions and improved clinical management of chronic kidney disease and its complications.

Nucleic acid immunotherapeutics and vaccines: A promising approach to glioblastoma multiforme treatment

Glioblastoma multiforme (GBM) is a deadly and difficult to treat primary brain tumor for which satisfactory therapeutics have yet to be discovered. While cancer immunotherapeutics, such as immune checkpoint inhibitors, have successfully improved the treatment of some other types of cancer, the poorly immunogenic GBM tumor cells and the immunosuppressive GBM tumor microenvironment have made it difficult to develop GBM immunotherapeutics. Nucleic acids therapeutics and vaccines, particularly those of mRNA, have become a popular field of research in recent years. This review presents the progress of nucleic acid therapeutics and vaccines for GBM and briefly covers some representative delivery methods of nucleic acids to the central nervous system (CNS) for GBM therapy.

Nucleic acid therapy in pediatric cancer

The overall survival, progress free survival, and life quality of cancer patients have improved due to the advance in minimally invasive surgery, precision radiotherapy, and various combined chemotherapy in the last decade. Furthermore, the discovery of new types of therapeutics, such as immune checkpoint inhibitors and immune cell therapies have facilitated both patients and doctors to fight with cancers. Moreover, in the context of the development in biocompatible and cell type targeting nano-carriers as well as nucleic acid-based drugs for initiating and enhancing the anti-tumor response have come to the age. The treatment paradigms utilization of nucleic acids, including short interfering RNA (siRNA), antisense oligonucleotides (ASO), and messenger RNA (mRNA), can target specific protein expression to achieve the therapeutic effects. Over ten nucleic acid therapeutics have been approved by the FDA and EMA in rare diseases and genetic diseases as well as dozens of registered clinical trails for varies cancers. Though generally less dangerous of pediatric cancers than adult cancers was observed during the past decades, yet pediatric cancers accounted for a significant proportion of child deaths which hurt those family very deeply. Therefore, it is necessary to pay more attention for improving the treatment of pediatric cancer and discovering new nucleic acid therapeutics which may help to improve the therapeutic effect and prognoses in turns to ameliorate the survival period and quality of life for children patient. In this review, we focus on the nucleic acid therapy in pediatric cancers.

PEX1 is a mediator of α1-adrenergic signaling attenuating doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is a potent chemotherapeutic agent used for cancer treatment, however, DOX-induced cardiotoxicity is a serious clinical problem because it causes acute and chronic heart dysfunction. Many studies have indicated that the α1-adrenergic receptor protects the heart from pathologic stress through activation survival signaling, however, the mechanism remains largely unknown. Previous studies have detected that the phenylephrine-induced complex-1 (PEX1) transcription factor, also known as zinc-finger protein 260 (Zfp260), is an effector of α1-adrenergic signaling in cardiac hypertrophy. Our present study aimed to investigate the role and underlying mechanism of PEX1 in cardiomyocyte survival during DOX-induced cardiotoxicity. Mice were exposed to a single intraperitoneal injection of DOX (15 mg/kg) to generate DOX-induced cardiotoxicity. We found that PEX1 expression was downregulated in DOX-treated murine hearts. PEX1 deficiency resulted in increased apoptosis, and conversely, PEX1 overexpression alleviated apoptosis induced by DOX in primary cardiomyocytes, as well as upregulated antiapoptotic genes such as BCL-2 and BCL-XL. Mechanistically, we identified that PEX1 might exert its antiapoptosis effect by playing a pivotal role in the action of α1-adrenergic signaling activation, which depends on the presence of GATA-4. Based on these findings, we supposed that PEX1 may be a novel transcription factor involved in cardiac cell survival and a promising candidate target for DOX-induced cardiotoxicity.

Quercetin inhibited the proliferation and invasion of hepatoblastoma cells through facilitating SIRT6-medicated FZD4 silence

Hepatoblastoma (HB) is a malignant liver tumor that occurs during childhood. The histone deacetylase SIRT6 functions as a tumor suppressor in diverse cancers. Quercetin, as activators and antioxidants of sirtuins, exhibits remarkable anticancer activity in many tumors. However, whether quercetin ameliorates HB is still unclear. In our study, we found that SIRT6 was downregulated in HB tissues and cell lines. Overexpression of SIRT6 observably suppressed cell proliferation and invasion, promoted cell apoptosis. Mechanistically, SIRT6 suppressed frizzled 4 (FZD4) transcription by deacetylating histone H3K9. Upregulation of SIRT6 reduced the protein levels of FZD4 and H3K9ac. Additionally, quercetin treatment could enhance the expression of SIRT6, repress FZD4 level, cell viability and invasion, and promote apoptosis. Overexpression of FZD4 signally reversed quercetin-treated the promotion effect on cell apoptosis, and the inhibition effects on FZD4 expression, cell viability, invasion and Wnt/β-catenin pathway related proteins. In addition, LiCl, an agonist of Wnt/β-catenin pathway, could recover the inhibition effects of quercetin on Wnt/β-catenin pathway related proteins, cell viability and invasion, and promotion effect on cell apoptosis. In vivo mouse xenograft tumor growth assay revealed that quercetin markedly suppressed tumor growth. In conclusion, these results demonstrated that the molecular mechanism of quercetin suppressing HB cell proliferation and invasion, promoting apoptosis was to promote the deacetylation of SIRT6 on FZD4 and inhibit the activation of Wnt/β-catenin pathway.

Overexpressed WDR3 induces the activation of Hippo pathway by interacting with GATA4 in pancreatic cancer

BACKGROUND

WD repeat domain 3 (WDR3) is involved in a variety of cellular processes including gene regulation, cell cycle progression, signal transduction and apoptosis. However, the biological role of WDR3 in pancreatic cancer and the associated mechanism remains unclear. We seek to explore the immune-independent functions and relevant mechanism for WDR3 in pancreatic cancer.

METHODS

The GEPIA web tool was searched, and IHC assays were conducted to determine the mRNA and protein expression levels of WDR3 in pancreatic cancer patients. MTS, colony formation, and transwell assays were conducted to determine the biological role of WDR3 in human cancer. Western blot analysis, RT-qPCR, and immunohistochemistry were used to detect the expression of specific genes. An immunoprecipitation assay was used to explore protein-protein interactions.

RESULTS

Our study proved that overexpressed WDR3 was correlated with poor survival in pancreatic cancer and that WDR3 silencing significantly inhibited the proliferation, invasion, and tumor growth of pancreatic cancer. Furthermore, WDR3 activated the Hippo signaling pathway by inducing yes association protein 1 (YAP1) expression, and the combination of WDR3 silencing and administration of the YAP1 inhibitor TED-347 had a synergistic inhibitory effect on the progression of pancreatic cancer. Finally, the upregulation of YAP1 expression induced by WDR3 was dependent on an interaction with GATA binding protein 4 (GATA4), the transcription factor of YAP1, which interaction induced the nuclear translocation of GATA4 in pancreatic cancer cells.

CONCLUSIONS

We identified a novel mechanism by which WDR3 plays a critical role in promoting pancreatic cancer progression by activating the Hippo signaling pathway through the interaction with GATA4. Therefore, WDR3 is potentially a therapeutic target for pancreatic cancer treatment.

Neuropilin-2 Is Associated With Increased Hepatoblastoma Cell Viability and Motility

The neuropilins NRP1 and NRP2 are multifunctional glycoproteins that have been implicated in several cancer-related processes including cell survival, migration, and invasion in various tumor types. Here, we examine the role of neuropilins in hepatoblastoma (HB), the most common pediatric liver malignancy. Using a combination of immunohistochemistry, RNA analysis and western blotting, we observed high level expression of NRP1 and NRP2 in 19 of 20 HB specimens and in a majority of human HB cell lines (HUH6 and five cell lines established from patient-derived xenografts) studied but not in normal hepatocytes. Silencing of NRP2 expression in HUH6 and HB-282 HB cells resulted in decreased cell viability, impaired cytoskeleton remodeling, and reduced cell motility, suggesting that NRP2 contributes to the malignant phenotype. We propose that neuropilins warrant further investigation as biomarkers of HB and potential therapeutic targets.

Inhibition of microRNA-429 attenuates oxygen-glucose deprivation/reoxygenation-induced neuronal injury by promoting expression of GATA-binding protein 4

MicroRNAs (miRNAs) have been documented as critical regulators in ischemia/reperfusion-induced neuronal death. A better understanding of miRNA-mediated molecular mechanisms in ischemia/reperfusion-induced neuronal death may provide therapeutic targets for cerebral ischemia/reperfusion injury. A growing body of evidence suggests that miR-429 is a apoptosis-related miRNA that is also induced by hypoxia. However, whether miR-429 is involved in regulating neuronal apoptosis during cerebral ischemia/reperfusion injury remains unclear. In this study, the effect of miR-429 on oxygen-glucose deprivation and reoxygenation (OGD/R)-induced neuronal injury was investigated in vitro. The results showed that miR-429 expression levels were upregulated in cultured neurons with OGD/R treatment. The downregulation of miR-429 significantly alleviated OGD/R-induced neuronal injury, whereas upregulation of miR-429 aggravated it. Bioinformatic analysis showed that miR-429 could directly target the 3'-untranslated region of GATA-binding protein 4 (GATA4), which was verified by dual-luciferase reporter assay. Moreover, we found that miR-429 negatively regulated GATA4 expression. Overexpression of GATA4 also significantly alleviated OGD/R-induced neuronal injury. However, knockdown of GATA4 partially reversed the protective effect induced by miR-429 downregulation. Overall, our data showed that downregulation of miR-429 protected neurons against OGD/R-induced injury by promoting GATA4 and suggested a potential therapeutic target for the treatment of cerebral ischemia/reperfusion injury.

Mechanisms of Anticancer Drug Resistance in Hepatoblastoma

The most frequent liver tumor in children is hepatoblastoma (HB), which derives from embryonic parenchymal liver cells or hepatoblasts. Hepatocellular carcinoma (HCC), which rarely affects young people, causes one fourth of deaths due to cancer in adults. In contrast, HB usually has better prognosis, but this is still poor in 20% of cases. Although more responsive to chemotherapy than HCC, the failure of pharmacological treatment used before and/or after surgical resection is an important limitation in the management of patients with HB. To advance in the implementation of personalized medicine it is important to select the best combination among available anti-HB drugs, such as platinum derivatives, anthracyclines, etoposide, tyrosine-kinase inhibitors, Vinca alkaloids, 5-fluorouracil, monoclonal antibodies, irinotecan and nitrogen mustards. This requires predicting the sensitivity to these drugs of each tumor at each time because, it should be kept in mind, that cancer chemoresistance is a dynamic process of Darwinian nature. For this goal it is necessary to improve our understanding of the mechanisms of chemoresistance involved in the refractoriness of HB against the pharmacological challenge and how they evolve during treatment. In this review we have summarized the current knowledge on the multifactorial and complex factors responsible for the lack of response of HB to chemotherapy.

Transcription factor GATA4 associates with mesenchymal-like gene expression in human hepatoblastoma cells

GATA4, a transcription factor crucial for early liver development, has been implicated in the pathophysiology of hepatoblastoma, an embryonal tumor of childhood. However, the molecular and phenotypic consequences of GATA4 expression in hepatoblastoma are not fully understood. We surveyed GATA4 expression in 24 hepatoblastomas using RNA in situ hybridization and immunohistochemistry. RNA interference was used to inhibit GATA4 in human HUH6 hepatoblastoma cells, and changes in cell migration were measured with wound healing and transwell assays. RNA microarray hybridization was performed on control and GATA4 knockdown HUH6 cells, and differentially expressed genes were validated by quantitative polymerase chain reaction or immunostaining. Plasmid transfection was used to overexpress GATA4 in primary human hepatocytes and ensuring changes in gene expression were measured by quantitative polymerase chain reaction. We found that GATA4 expression was high in most hepatoblastomas but weak or negligible in normal hepatocytes. GATA4 gene silencing impaired HUH6 cell migration. We identified 106 differentially expressed genes (72 downregulated, 34 upregulated) in knockdown versus control HUH6 cells. GATA4 silencing altered the expression of genes associated with cytoskeleton organization, cell-to-cell adhesion, and extracellular matrix dynamics (e.g. ADD3, AHNAK, DOCK8, RHOU, MSF, IGFBP1, COL4A2). These changes in gene expression reflected a more epithelial (less malignant) phenotype. Consistent with this notion, there was reduced F-actin stress fiber formation in knockdown HUH6 cells. Forced expression of GATA4 in primary human hepatocytes triggered opposite changes in the expression of genes identified by GATA4 silencing in HUH6 cells. In conclusion, GATA4 is highly expressed in most hepatoblastomas and correlates with a mesenchymal, migratory phenotype of hepatoblastoma cells.

Use of HuH6 and other human-derived hepatoma lines for the detection of genotoxins: a new hope for laboratory animals?

Cell lines which are currently used in genotoxicity tests lack enzymes which activate/detoxify mutagens. Therefore, rodent-derived liver preparations are used which reflect their metabolism in humans only partly; as a consequence misleading results are often obtained. Previous findings suggest that certain liver cell lines express phase I/II enzymes and detect promutagens without activation; however, their use is hampered by different shortcomings. The aim of this study was the identification of a suitable cell line. The sensitivity of twelve hepatic cell lines was investigated in single cell gel electrophoresis assays. Furthermore, characteristics of these lines were studied which are relevant for their use in genotoxicity assays (mitotic activity, p53 status, chromosome number, and stability). Three lines (HuH6, HCC1.2, and HepG2) detected representatives of five classes of promutagens, namely, IQ and PhIP (HAAs), B(a)P (PAH), NDMA (nitrosamine), and AFB₁ (aflatoxin), and were sensitive towards reactive oxygen species (ROS). In contrast, the commercially available line HepaRG, postulated to be a surrogate for hepatocytes and an ideal tool for mutagenicity tests, did not detect IQ and was relatively insensitive towards ROS. All other lines failed to detect two or more compounds. HCC1.2 cells have a high and unstable chromosome number and mutated p53, these features distract from its use in routine screening. HepG2 was frequently employed in earlier studies, but pronounced inter-laboratory variations were observed. HuH6 was never used in genotoxicity experiments and is highly promising, it has a stable karyotype and we demonstrated that the results of genotoxicity experiments are reproducible.