Curcumin Induces p53-Null Hepatoma Cell Line Hep3B Apoptosis through the AKT-PTEN-FOXO4 Pathway

Defining the mechanisms behind the hepatoprotective properties of curcumin

As a critical cause of human dysfunctionality, hepatic failure leads to approximately two million deaths per year and is on the rise. Considering multiple inflammatory, oxidative, and apoptotic mechanisms behind hepatotoxicity, it urges the need for finding novel multi-targeting agents. Curcumin is a phenolic compound with anti-inflammatory, antioxidant, and anti-apoptotic roles. Curcumin possesses auspicious health benefits and protects against several diseases with exceptional safety and tolerability. This review focused on the hepatoprotective mechanisms of curcumin. The need to develop novel delivery systems of curcumin (e.g., nanoparticles, self-micro emulsifying, lipid-based colloids, solid lipid nanoparticles, cyclodextrin inclusion, phospholipid complexes, and nanoemulsions) is also considered.

Anticancer Potential of Indole Phytoalexins and Their Analogues

Indole phytoalexins, found in economically significant Cruciferae family plants, are synthesized in response to pathogen attacks or stress, serving as crucial components of plant defense mechanisms against bacterial and fungal infections. Furthermore, recent research indicates that these compounds hold promise for improving human health, particularly in terms of potential anticancer effects that have been observed in various studies. Since our last comprehensive overview in 2016 focusing on the antiproliferative effects of these substances, brassinin and camalexin have been the most extensively studied. This review analyses the multifaceted pharmacological effects of brassinin and camalexin, highlighting their anticancer potential. In this article, we also provide an overview of the antiproliferative activity of new synthetic analogs of indole phytoalexins, which were synthesized and tested at our university with the aim of enhancing efficacy compared to the parent compound.

The Role of HSP90 and TRAP1 Targets on Treatment in Hepatocellular Carcinoma

Hepatocellular Carcinoma (HCC) is the predominant form of liver cancer and arises due to dysregulation of the cell cycle control machinery. Heat Shock Protein 90 (HSP90) and mitochondrial HSP90, also referred to as TRAP1 are important critical chaperone target receptors for early diagnosis and targeting HCC. Both HSP90 and TRAP1 expression was found to be higher in HCC patients. Hence, the importance of HSP90 and TRAP1 inhibitors mechanism and mitochondrial targeted delivery of those inhibitors function is widely studied. This review also focuses on importance of protein-protein interactions of HSP90 and TRAP1 targets and association of its interacting proteins in various pathways of HCC. To further elucidate the mechanism, systems biology approaches and computational biology approach studies are well explored in the association of inhibition of herbal plant molecules with HSP90 and its mitochondrial type in HCC.

Counteracting Action of Curcumin on High Glucose-Induced Chemoresistance in Hepatic Carcinoma Cells

Along with direct anticancer activity, curcumin hinders the onset of chemoresistance. Among many, high glucose condition is a key driving factor for chemoresistance. However, the ability of curcumin remains unexplored against high glucose-induced chemoresistance. Moreover, chemoresistance is major hindrance in effective clinical management of liver cancer. Using hepatic carcinoma HepG2 cells, the present investigation demonstrates that high glucose induces chemoresistance, which is averted by the simultaneous presence of curcumin. Curcumin obviated the hyperglycemia-induced modulations like elevated glucose consumption, lactate production, and extracellular acidification, and diminished nitric oxide and reactive oxygen species (ROS) production. Modulated molecular regulators are suggested to play a crucial role as curcumin pretreatment also prevented the onset of chemoresistance by high glucose. High glucose instigated suppression in the intracellular accumulation of anticancer drug doxorubicin and drug-induced chromatin compactness along with declined expression of drug efflux pump MDR-1 and transcription factors and signal transducers governing the survival, aggressiveness, and apoptotic cell death (p53, HIF-1α, mTOR, MYC, STAT3). Curcumin alleviated the suppression of drug retention and nuclear condensation along with hindering the high glucose-induced alterations in transcription factors and signal transducers. High glucose-driven resistance in cancer cells was associated with elevated expression of metabolic enzymes HKII, PFK1, GAPDH, PKM2, LDH-A, IDH3A, and FASN. Metabolite transporters and receptors (GLUT-1, MCT-1, MCT-4, and HCAR-1) were also found upregulated in high glucose exposed HepG2 cells. Curcumin inhibited the elevated expression of these enzymes, transporters, and receptors in cancer cells. Curcumin also uplifted the SDH expression, which was inhibited in high glucose condition. Taken together, the findings of the present investigation first time demonstrate the ability of curcumin against high glucose-induced chemoresistance, along with its molecular mechanism. This will have implication in therapeutic management of malignancies in diabetic conditions.

Targeting of cancer cell death mechanisms by curcumin: Implications to cancer therapy

Cancer is known as a second major cause of death globally. Nowadays, several modalities have been developed for the treatment of cancer. Radiotherapy and chemotherapy are the most common modalities in most countries. However, newer modalities such as immunotherapy and targeted therapy drugs can kill cancer cells with minimal side effects. All anticancer agents work based on the killing of cancer cells. Numerous studies are ongoing to kill cancer cells more effectively without increasing side effects to normal tissues. The combination modalities with low toxic agents are interesting for this aim. Curcumin is one of the most common herbal agents that has shown several anticancer properties. It can regulate immune system responses against cancer. Furthermore, curcumin has been shown to potentiate cell death signalling pathways and attenuate survival signalling pathways in cancer cells. The knowledge of how curcumin induces cell death in cancers can improve therapeutic efficiency. In this review, the regulatory effects of curcumin on different cell death mechanisms and their signalling pathways will be discussed. Furthermore, we explain how curcumin may potentiate the anticancer effects of other drugs or radiotherapy through modulation of apoptosis, mitotic catastrophe, senescence, autophagy and ferroptosis.

Role of Forkhead Box O Proteins in Hepatocellular Carcinoma Biology and Progression (Review)

Hepatocellular carcinoma (HCC), the most common type of malignant tumor of the digestive system, is associated with high morbidity and mortality. The main treatment for HCC is surgical resection. Advanced disease, recurrence, and metastasis are the main factors affecting prognosis. Chemotherapy and radiotherapy are not sufficiently efficacious for the treatment of primary and metastatic HCC; therefore, optimizing targeted therapy is essential for improving outcomes. Forkhead box O (FOXO) proteins are widely expressed in cells and function to integrate a variety of growth factors, oxidative stress signals, and other stimulatory signals, thereby inducing the specific expression of downstream signal factors and regulation of the cell cycle, senescence, apoptosis, oxidative stress, HCC development, and chemotherapy sensitivity. Accordingly, FOXO proteins are considered multifunctional targets of cancer treatment. The current review discusses the roles of FOXO proteins, particularly FOXO1, FOXO3, FOXO4, and FOXO6, in HCC and establishes a theoretical basis for the potential targeted therapy of HCC.

Brassinin Inhibits Proliferation in Human Liver Cancer Cells via Mitochondrial Dysfunction

Brassinin is a phytochemical derived from Chinese cabbage, a cruciferous vegetable. Brassinin has shown anticancer effects on prostate and colon cancer cells, among others. However, its mechanisms and effects on hepatocellular carcinoma (HCC) have not been elucidated yet. Our results confirmed that brassinin exerted antiproliferative effects by reducing proliferating cell nuclear antigen (PCNA) activity, a proliferation indicator and inducing cell cycle arrest in human HCC (Huh7 and Hep3B) cells. Brassinin also increased mitochondrial Ca²⁺ levels and depolarized the mitochondrial membrane in both Huh7 and Hep3B cells. Moreover, brassinin generated high amounts of reactive oxygen species (ROS) in both cell lines. The ROS scavenger N-acetyl-L-cysteine (NAC) inhibited this brassinin-induced ROS production. Brassinin also regulated the AKT and mitogen-activated protein kinases (MAPK) signaling pathways in Huh7 and Hep3B cells. Furthermore, co-administering brassinin and pharmacological inhibitors for JNK, ERK1/2 and P38 decreased cell proliferation in both HCC cell lines more than the pharmacological inhibitors alone. Collectively, our results demonstrated that brassinin exerts antiproliferative effects via mitochondrial dysfunction and MAPK pathway regulation on HCC cells.

Long noncoding RNA MEG3 blocks telomerase activity in human liver cancer stem cells epigenetically

BACKGROUND

MEG3 downregulated the expression in several tumors and inhibits human tumorigenesis. But so far, the mechanism of MEG3 in tumorigenesis is still unclear.

METHODS

In gene infection, cellular and molecular technologies and tumorigenesis test in vitro and in vivo were performed, respectively.

RESULTS

Our results indicate that MEG3 enhances the P53 expression by triggering the loading of P300 and RNA polymerase II onto its promoter regions dependent on HP1α. Moreover, MEG3 increases the methylation modification of histone H3 at the 27th lysine via P53. Furthermore, MEG3 inhibits the expression of TERT by increasing the H3K27me3 in TERT promoter regions, thereby inhibiting the activity of telomerase by reducing the binding of TERT to TERC. Furthermore, MEG3 also increases the expression of TERRA; therefore, the interaction between TERC and TERT was competitively attenuated by increasing the interaction between TERRA and TERT, which inhibits the activity of telomerase in hLCSCs. Strikingly, MEG3 reduces the length of telomere by blocking the formation of complex maintaining telomere length (POT1-Exo1-TRF2-SNM1B) and decreasing the binding of the complex to telomere by increasing the interplay between P53 and HULC. Ultimately, MEG3 inhibits the growth of hLCSCs by reducing the activity of telomerase and attenuating telomeric repeat binding factor 2(TRF2).

CONCLUSIONS

Our results demonstrates MEG3 inhibits the occurrence of human liver cancer by blocking telomere, and these findings provide an important insight into the prevention and treatment of human liver cancer.

Herbal and Natural Dietary Products: Upcoming Therapeutic Approach for Prevention and Treatment of Hepatocellular Carcinoma

The most common tumor linked with elevated death rates is considered the hepatocellular carcinoma (HCC), sometimes called the malignant hepatoma. The initiation and progression of HCC are triggered by multiple factors like long term alcohol consumption, metabolic disorders, fatty liver disease, hepatitis B and C infection, age, and oxidative stress. Sorafenib is the merely US Food and Drug Administration (FDA)-approved drug used to treat HCC. Several treatment methods are available for HCC therapy such as chemotherapy, immunotherapy and adjuvant therapy but they often lead to several side effects. Yet these treatment methods are not entirely adequate due to the increasing resistance to the drug and their toxicity. Many natural products help to prevent and treat HCC. A variety of pathways are associated with the prevention and treatment of HCC with herbal products and their active components. Accumulating research shows that certain natural dietary compounds are possible source of hepatic cancer prevention and treatments, such as black currant, strawberries, plum, grapes, pomegranate, cruciferous crops, tomatoes, French beans, turmeric, garlic, ginger, asparagus, and many more. Such a dietary natural products and their active constituents may prevent the production and advancement of liver cancer in many ways such as guarding against liver carcinogens, improving the effectiveness of chemotherapeutic medications, inhibiting the growth, metastasis of tumor cells, reducing oxidative stress, and chronic inflammation. The present review article represents hepatic carcinoma etiology, role of herbal products, their active constituents, and dietary natural products for the prevention and treatment of HCC along with their possible mechanisms of action.

Current perspective on the regulation of FOXO4 and its role in disease progression

Forkhead box O4 (FOXO4) is a member of the FOXO family that regulates a number of genes involved in metabolism, cell cycle, apoptosis, and cellular homeostasis via transcriptional activity. It also mediates cell responses to oxidative stress and treatment with antitumor agents. The expression of FOXO4 is repressed by microRNAs in multiple cancer cells, while FOXO4 function is regulated by post-translational modifications and interaction with other proteins. The deregulation of FOXO4 is closely linked to the progression of several types of cancer, senescence, and other diseases. In this review, we present recent findings on the regulation of FOXO4 in physiological and pathological conditions and provide an overview of the complex role of FOXO4 in disease development and response to therapy.

The adipokine vaspin reduces apoptosis in human hepatocellular carcinoma (Hep-3B) cells, associated with lower levels of NO and superoxide anion

BACKGROUND

Among adipose-derived factors, adipocytokines play roles as hormones and signaling mediators for apoptotic pathway. Among of them, vaspin, regulates the metabolism of adipose tissue itself as an endocrine organ, and stimulates adipocytes to maturation, differentiation, etc. Damaged adipocytes, present in obesity and hepatocellular carcinoma (HCC) respond with over-production of inflammatory cytokines. Such pro-inflammatory stimulation remains under adipokine control. Pro-inflammatory pathways are connected to oxidative stress and apoptosis, reported as co-existing with an elevated level of some adipokines in cancer cell lines. However, some hormones, such as vaspin, reduce apoptosis, have anti-inflammatory and anti-oxidative roles in cancer cell lines.

METHODS

Hep-3B cells were cytometrically evaluated under vaspin treatment for reactive oxygen species (ROS) and apoptosiss induction. The statistical significant changes to the untreated controls was calculated by T-tests (indicated at value p < 0.05).

RESULTS

Here we studied the production of reactive oxygen and nitrogen species in cells of HCC line Hep-3B after vaspin treatment. A decreased level of nitric oxide and superoxide anion 24 h after vaspin addition at 5 ng/ml was correlated with restricted, to the physiological level, apoptosis. A protective role of vaspin was displayed as enhanced cell viability and proliferation, which could be a poor prognostic in liver cancer.

CONCLUSIONS

Apoptosis was suppressed after vaspin treatment, together with low levels of nitric oxide and superoxide anions.

Characterization and Inception of a Triterpenoid Astrakurkurol, as a Cytotoxic Molecule on Human Hepatocellular Carcinoma Cells, Hep3B

Mushrooms are customary influential sources of pharmaceutically active metabolites. Usually lanostane-type triterpenoids from mushrooms had prospective for cancer disease treatments. Recently, a triterpenoid, astrakurkurol obtained from the fresh basidiocarps of the edible mushroom Astraeus hygrometricus, drew attention as a new cytotoxic therapeutic. The structural stability of this triterpenoid had been established with the amalgamation of density functional theory (DFT) calculations and study of single-crystal X-ray diffraction. To successfully manifest astrakurkurol as a potent cytotoxic therapeutics, a wide apprehension on the molecular and cellular mechanisms underlying their action is prerequisite. On this account, our study was directed to scrutinize the influence of this triterpenoid on human hepatocellular cancer cell model Hep3B. Encapsulating all experimental facts revealed that astrakurkurol had significantly decreased cell viability in a concentration-dependent manner. This effect was unveiled to be apoptosis, documented by DNA fragmentation, chromatin condensation, nuclear shrinkage, membrane blebing, and imbalance of cell cycle distribution. Astrakurkurol persuaded the expression of death receptor associated proteins (Fas), which triggered caspase-8 activation following tBid cleavage. Moreover, tBid mediated ROS generation, which triggered mitochondrial dysfunction and activated the mitochondrial apoptotic events. Astrakurkurol cytotoxicity was based on caspase-8-mediated intrinsic apoptotic pathway and was associated with inhibition at Akt and NF-κB pathway. Astrakurkurol had also inhibited the migration of Hep3B cells, indicating its antimigratory potential. These findings led us to introduce astrakurkurol as a feasible and natural source for a safer cytotoxic drug against hepatocellular carcinoma.

Inhibition of Brd4 alleviates renal ischemia/reperfusion injury-induced apoptosis and endoplasmic reticulum stress by blocking FoxO4-mediated oxidative stress

Ischemia/reperfusion injury (I/R) is one of the leading causes of acute kidney injury (AKI) that typically occurs in renal surgeries. However, renal I/R still currently lacks effective therapeutic targets. In this study, we proved that inhibition of Brd4 with its selective inhibitor, JQ1, could exert a protective role in renal I/R injury in mice. Inhibiting Brd4 with either JQ1 or genetic knockdown resulted in reduction of endoplasmic reticulum stress (ERS)-associated protein and proapoptotic protein expression both in I/R-induced injury and hypoxia/reoxygenation (H/R) stimulation in HK-2 cells. H/R-induced apoptosis and ERS depended on oxidative stress in vitro. Moreover, FoxO4, which is involved in the generation of hydrogen peroxide, was up-regulated during H/R stimulation-mediated apoptosis and ERS, and this upregulation could be abolished by Brd4 inhibition. Consistently, FoxO4-mediated ROS generation was attenuated upon inhibition of Brd4 with JQ1 or siRNA against Brd4. Further, the transcriptional activity of FoxO4 was suppressed by PI3K and AKT phosphorylation, which are upstream signals of FoxO4 expression, and were enhanced by Brd4 both in vivo and in vitro. In conclusion, our results proved that Brd4 inhibition blocked renal apoptotic and ERS protein expression by preventing FoxO4-dependent ROS generation through the PI3K/AKT pathway, indicating that Brd4 could be a potential therapeutic target for renal I/R injury.

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Brd4 was up-regulated in renal I/R injury.

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Brd4 inhibitor JQ1 alleviated renal I/R injury.

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Brd4 inhibition blocked H/R-induced oxidative stress, apoptosis and ERS through FoxO4.

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Brd4 regulated FoxO4 through the PI3K/AKT pathway.

Forkhead box O4 transcription factor in human neoplasms: Cannot afford to lose the novel suppressor

Forkhead box O4 (FOXO4), a member of FOXO family, has been highlighted as an essential transcriptional regulator in many diverse carcinomas. Accumulated studies have demonstrated that FOXO4 is downregulated and associated with tumorigenesis, invasiveness, and metastasis of most human cancer. FOXO4 alteration is also closely linked to the prognosis of various types of cancer. The aim of this review is to comprehensively present the clinical and pathological significance of FOXO4 in human cancer. Additionally, the potential clinical applications of future FOXO4 research are discussed. Collectively, the information reviewed here should increase the potential of FOXO4 as a therapeutic target for cancer.

High expression of Ras-related protein 1A promotes an aggressive phenotype in colorectal cancer via PTEN/FOXO3/CCND1 pathway

Background

Colorectal cancer (CRC) is a commonly diagnosed digestive malignancy worldwide. Ras-related protein 1A (RAP1A) is a member of the Ras superfamily of small GTPases and has been recently identified as a novel oncoprotein in several human malignancies. However, its specific role in CRC remains unclear.

Method

In this study, we firstly analyzed its expression and clinical significance in a retrospective cohort of 144 CRC patients. Then, cellular assays in vitro and in vivo were performed to clarify its biological role in CRC cells. Finally, microarray analysis was utilized to investigate the molecular mechanisms regulated by RAP1A in CRC progression.

Results

Firstly, RAP1A expression was abnormally higher in CRC tissues as compared with adjacent normal tissues, and significantly correlated tumor invasion. High RAP1A expression was an independent unfavourable prognostic factor for CRC patients. Combining RAP1A expression and preoperative CEA level contributed to a more accurate prognostic stratification in CRC patients. Secondly, knockdown of RAP1A dramatically inhibited the growth of CRC cells, while it was opposite for RAP1A overexpression. Finally, the microarray analysis revealed RAP1A promoted CRC growth partly through phosphatase and tensin homolog (PTEN)/forkhead box O3(FOXO3)/cyclin D1(CCND1) signaling pathway. FOXO3 overexpression could partly mimic the inhibitory effect of RAP1A knockdown in CRC growth. Moreover, FOXO3 overexpression inhibited CCND1 expression, but had no impact on RAP1A and PTEN expression.

Conclusion

RAP1A promotes CRC development partly through PTEN/FOXO3 /CCND1 signaling pathway. It has a great potential to be an effective clinical biomarker and therapeutic target for CRC patients.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0827-y) contains supplementary material, which is available to authorized users.