Gambogic acid affects ESCC progression through regulation of PI3K/AKT/mTOR signal pathway

Circ_0096710 facilitates tumor growth via controlling ADAM10 expression in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a global cancer related to the sixth largest cause of death. Circular RNAs (circRNAs) have affected the progress of ESCC during recent years, but the mechanism is not completely clear. So here we probed the effects of hsa_circ_0096710 (circ_0096710) in ESCC.

METHODS

Relative levels of circ_0096710, miR-1294, and ADAM10 were quantified by the quantitative real-time reverse transcription-polymerase chain reaction in ESCC tissues. Western blot assessed ADAM10, PCNA, MMP2, VEGFA, and OCT4 protein levels. Cell proliferative capacity was assessed by cell counting and cell colony-forming assays. Transwell assays assessed cell migration and invasion. Angiogenesis was detected by tube formation assays. Stemness of cancer cells was estimated by sphere formation assays. Dual-luciferin reporter and RNA immunoprecipitation assays determined the targeting relationship between miR-1294 and circ_0096710 or ADAM10.

RESULTS

Relative levels of circ_0096710 and ADAM10 mRNA were upregulated in ESCC cells, yet miR-1294 was downregulated. Circ_0096710 silencing repressed ESCC cell proliferation, migration, invasion, angiogenesis, and stem-like properties. Moreover, circ_0096710 was an upstream target of miR-1294, and miR-1294 inhibition reversed the role of circ_0096710 downregulation in ESCC cells. Furthermore, ADAM10 was a downstream target of miR-1294, and miR-1294 overexpression suppressed ESCC cell proliferation, migration, invasion, angiogenesis, and stem-like properties by targeting ADAM10. Meanwhile, circ_0096710 upgraded ADAM10 expression through sponging miR-1294. Also, circ_0096710 downregulation restrained tumor growth in mouse models.

CONCLUSION

Circ_0096710 upregulates ADAM10 via mediating miR-1294 expression so as to accelerate the occurrence of ESCC, suggesting that circ_0096710 may be a potential therapeutic target for ESCC.

The expression and biological role of complement C1s in esophageal squamous cell carcinoma

The present work focused on investigating the role of the altered expression of complement C1s in proliferation and apoptosis of esophageal squamous cell carcinoma (ESCC) cells and explore its biological functions in ESCC, so as to lay a theoretical foundation and provide certain clinical reference for diagnosing and treating ESCC. Complement C1s expression within ESCC was assessed, and its clinical pathological characteristics in ESCC patients were analyzed. Subsequently, in vitro experiments were performed to further explore the mechanisms by which complement C1s affected ESCC. According to the results, complement C1s expression within ESCC markedly increased relative to adjacent non-cancerous samples. High C1s expression showed positive relation to race, residual lesion, and tumor location of ESCC patients. Complement C1s affected ESCC cell proliferation and apoptosis. Notably, C1s knockdown significantly inhibited ESCC cell proliferation and enhanced their apoptosis. C1s suppressed ESCC cell proliferation via Wnt1/β-catenin pathway and promoted their apoptosis through modulating the expression of Bcl2, Bax, and cleaved-caspase3.

KDM6A-SND1 interaction maintains genomic stability by protecting the nascent DNA and contributes to cancer chemoresistance

Genomic instability is one of the hallmarks of cancer. While loss of histone demethylase KDM6A increases the risk of tumorigenesis, its specific role in maintaining genomic stability remains poorly understood. Here, we propose a mechanism in which KDM6A maintains genomic stability independently on its demethylase activity. This occurs through its interaction with SND1, resulting in the establishment of a protective chromatin state that prevents replication fork collapse by recruiting of RPA and Ku70 to nascent DNA strand. Notably, KDM6A-SND1 interaction is up-regulated by KDM6A SUMOylation, while KDM6AK90A mutation almost abolish the interaction. Loss of KDM6A or SND1 leads to increased enrichment of H3K9ac and H4K8ac but attenuates the enrichment of Ku70 and H3K4me3 at nascent DNA strand. This subsequently results in enhanced cellular sensitivity to genotoxins and genomic instability. Consistent with these findings, knockdown of KDM6A and SND1 in esophageal squamous cell carcinoma (ESCC) cells increases genotoxin sensitivity. Intriguingly, KDM6A H101D & P110S, N1156T and D1216N mutations identified in ESCC patients promote genotoxin resistance via increased SND1 association. Our finding provides novel insights into the pivotal role of KDM6A-SND1 in genomic stability and chemoresistance, implying that targeting KDM6A and/or its interaction with SND1 may be a promising strategy to overcome the chemoresistance.

Nanostructured lipid carriers loaded with morellic acid for enhanced anticancer efficacy: preparation, characterization, pharmacokinetics and anticancer evaluation

Morellic acid (MA), a typical compound found in Garcinia plants, is known for its anticancer properties. In present study, we isolated MA from resin of Garcinia hanburyi Hook. f. using preparative chromatography. We have successfully prepared MA-loaded nanostructured lipid carriers (MA-NLCs) and refined the production process via orthogonal testing. Optimization of the preparation process resulted in an average particle size of 165.50±1.70 nm with a PDI of 0.19±0.01. The EE% and DL% of MA-NLCs were 78.17±0.34% and 7.25±0.38%, respectively. The zeta potential of MA-NLCs was -21.85±0.67 mV. Comparatively, MA-NLCs showed a greater area under the curve (AUC) and an extended half-life (t1/2) than free MA. Pharmacokinetics analysis revealed that the AUC0-t increased from 4.91±0.65 μg/mL∙min (free MA) to 18.91±3.40 μg/mL∙min (MA-NLCs) and the t1/2 value for MA-NLCs was 7.93-fold longer than that of free MA. In vitro cytotoxic assessments indicated that MA formulations curtailed the proliferation of cancer cells. In vivo, MA-NLCs significantly inhibited the tumor growth in tumor-bearing mouse model. Molecular mechanism studies revealed that up-regulation of apaf-1 and activation of caspase-3, caspase-9 and GSDME by MA-NLCs may trigger to apoptosis and pyroptosis in cancer cells. Consequently, our findings support the potential of NLCs as an effective MA delivery system for the clinical management of cancer.

RNF149 confers cisplatin resistance in esophageal squamous cell carcinoma via destabilization of PHLPP2 and activating PI3K/AKT signalling

Chemo-resistance has been identified as a crucial factor contributing to tumor recurrence and a leading cause of worse prognosis in patients with ESCC. Therefore, unravel the critical regulators and effective strategies to overcome drug resistance will have a significant clinical impact on the disease. In our study we found that RNF149 was upregulated in ESCC and high RNF149 expression was associated with poor prognosis with ESCC patients. Functionally, we have demonstrated that overexpression of RNF149 confers CDDP resistance to ESCC; however, inhibition of RNF149 reversed this phenomenon both in vitro and in vivo. Mechanistically, we demonstrated that RNF149 interacts with PH domain and leucine rich repeat protein phosphatase 2 (PHLPP2) and induces E3 ligase-dependent protein degradation of PHLPP2, substantially activating the PI3K/AKT signalling pathway in ESCC. Additionally, we found that inhibition of PI3K/AKT signalling pathway by AKT siRNA or small molecule inhibitor significantly suppressed RNF149-induced CDDP resistance. Importantly, RNF149 locus was also found to be amplified not only in ESCC but also in various human cancer types. Our data suggest that RNF149 might function as an oncogenic gene. Targeting the RNF149/PHLPP2/PI3K/Akt axis may be a promising prognostic factor and valuable therapeutic target for malignant tumours.

Plant-derived compounds for treating autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD), the most common monogenic hereditary kidney disease, is the fourth leading cause of end-stage kidney disease worldwide. In recent years, significant progress has been made in delaying ADPKD progression with different kinds of chemical drugs, such as tolvaptan, rapamycin, and somatostatin. Meanwhile, numerous plant-derived compounds have been investigated for their beneficial effects on slowing ADPKD progression. Among them, saikosaponin-d, Ganoderma triterpenes, curcumin, ginkgolide B, steviol, resveratrol, Sparganum stoloniferum Buch.-Ham, Cordyceps sinensis, triptolide, quercitrin, naringin, cardamonin, gambogic acid, and olive leaf extract have been found to retard renal cyst development by inhibiting cell proliferation or promoting cell apoptosis in renal cyst-lining epithelial cells. Metformin, a synthesized compound derived from French lilac or goat's rue (Galega officinalis), has been proven to retard the progression of ADPKD. This review focuses on the roles and mechanisms of plant-derived compounds in treating ADPKD, which may constitute promising new therapeutics in the future.

Determination and tissue distribution comparisons of five xanthones after orally administering crude and processed gamboge

Caged polyprenylated xanthones are the main active ingredients isolated from the resin of Garcinia hanburyi, which has been reported to exhibit potential anticancer and anti-inflammatory activities. This study aimed to develop sensitive and specific ultra-performance liquid chromatography coupled with the triple quadrupole mass spectrometry method for investigating the tissue distribution of five xanthones in rats: β-morellic acid, isogambogenic acid, gambogenic acid, R-gambogic acid and S-gambogic acid. All tissue samples were prepared using the liquid-liquid extraction method and separated on a C₈ column with a gradient system. Detection was performed on a triple quadrupole mass spectrometer in multiple-reaction monitoring using positive ionization. The method established in this assay was successfully applied to the tissue distribution study of the five selected xanthones after orally administering crude and processed gamboge in rat tissues. The results indicated that these five xanthones were distributed to rat tissues rapidly and could be detected in all of the selected tissues after oral administration. After processing, the contents of R-gambogic acid and S-gambogic acid in the gastrointestinal tract were significantly reduced. The findings of this study might be helpful in further understanding the processing mechanism of gamboge and providing references for its reasonable clinical application.

Potential Application of Gambogic Acid for Retarding Renal Cyst Progression in Polycystic Kidney Disease

Abnormal cell proliferation and accumulation of fluid-filled cysts along the nephrons in polycystic kidney disease (PKD) could lead to a decline in renal function and eventual end-stage renal disease (ESRD). Gambogic acid (GA), a xanthone compound extracted from the brownish resin of the Garcinia hanburyi tree, exhibits various pharmacological properties, including anti-inflammation, antioxidant, anti-proliferation, and anti-cancer activity. However, its effect on inhibiting cell proliferation in PKD is still unknown. This study aimed to determine the pharmacological effects and detailed mechanisms of GA in slowing an in vitro cyst growth model of PKD. The results showed that GA (0.25-2.5 μM) significantly retarded MDCK cyst growth and cyst formation in a dose-dependent manner, without cytotoxicity. Using the BrdU cell proliferation assay, it was found that GA (0.5-2.5 μM) suppressed MDCK and Pkd1 mutant cell proliferation. In addition, GA (0.5-2.5 μM) strongly inhibited phosphorylation of ERK1/2 and S6K expression and upregulated the activation of phosphorylation of AMPK, both in MDCK cells and Pkd1 mutant cells. Taken together, these findings suggested that GA could retard MDCK cyst enlargement, at least in part by inhibiting the cell proliferation pathway. GA could be a natural plant-based drug candidate for ADPKD intervention.

Dandelion Seed Extract Affects Tumor Progression and Enhances the Sensitivity of Cisplatin in Esophageal Squamous Cell Carcinoma

Like dandelion, dandelion seed also have anti-inflammatory activity. Therefore, in this article, we intend to explore the anti-cancer availability of aqueous dandelion seed extract (DSE) in esophageal squamous cell carcinoma (ESCC). Firstly, the effects of DSE on cell proliferation, apoptosis, migration, invasion and angiogenesis were investigated. Then to explore the mechanism of DSE against ESCC, the levels of proliferation-associated proteins (PI3K, Akt and pAkt), apoptosis-associated proteins (survivin, Bcl-2, Bax, caspase3 and caspase9), metastasis-associated proteins (MMP2, MMP9, VEGF) and EMT progression-associated proteins (Snail, E-cadherin and Vimentin) were analyzed. Next, we further explored the effect of DSE on the sensitivity of cisplatin (DDP) in ESCC cells and investigated the effect of DSE combined with DDP on DNA damage repair-associated proteins (MSH2, MLH1 and ERCC1) and drug resistant target protein STAT3. The results indicated that DSE selectively inhibited cell growth, proliferation, migration, invasion, angiogenesis and induced cell apoptosis in ESCC cells. It was observed the decreased PI3K, Akt and pAkt proteins levels in KYSE450 and Eca109 cells administrated with DSE. The data also showed that the application of DSE decreased the level of survivin and the ratio of Bcl-2/Bax, while increased the levels of caspase3 and caspase9. We also observed that DSE significantly decreased the levels of MMP2, MMP9 and VEGF proteins and inhibited the EMT progression in KYSE450 and Eca109 cells. In addition, survivin plays a critical role in DSE against ESCC followed with the application of survivin inhibitor YM155 impairing the inhibitory abilities of DSE in ESCC cells. Meanwhile, it was observed that DSE enhances the sensitivity of DDP to human ESCC cells via promoting DNA damage and inhibiting phosphorylation of STAT3. Therefore, DSE may affect ESCC progression and enhance the sensitivity of cisplatin, and consequently become an effective anti-cancer option for human ESCC treatment.

A Review: PI3K/AKT/mTOR Signaling Pathway and Its Regulated Eukaryotic Translation Initiation Factors May Be a Potential Therapeutic Target in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor developing from the esophageal squamous epithelium, and is the most common histological subtype of esophageal cancer (EC). EC ranks 10th in morbidity and sixth in mortality worldwide. The morbidity and mortality rates in China are both higher than the world average. Current treatments of ESCC are surgical treatment, radiotherapy, and chemotherapy. Neoadjuvant chemoradiotherapy plus surgical resection is recommended for advanced patients. However, it does not work in the significant promotion of overall survival (OS) after such therapy. Research on targeted therapy in ESCC mainly focus on EGFR and PD-1, but neither of the targeted drugs can significantly improve the 3-year and 5-year survival rates of disease. Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is an important survival pathway in tumor cells, associated with its aggressive growth and malignant progression. Specifically, proliferation, apoptosis, autophagy, and so on. Related genetic alterations of this pathway have been investigated in ESCC, such as PI3K, AKT and mTOR-rpS6K. Therefore, the PI3K/AKT/mTOR pathway seems to have the capability to serve as research hotspot in the future. Currently, various inhibitors are being tested in cells, animals, and clinical trials, which targeting at different parts of this pathway. In this work, we reviewed the research progress on the PI3K/AKT/mTOR pathway how to influence biological behaviors in ESCC, and discussed the interaction between signals downstream of this pathway, especially eukaryotic translation initiation factors (eIFs) and the development and progression of ESCC, to provide reference for the identification of new therapeutic targets in ESCC.

Anticancer Properties and Mechanism of Action of Oblongifolin C, Guttiferone K and Related Polyprenylated Acylphloroglucinols

Polyprenylated acylphloroglucinols represent an important class of natural products found in many plants. Among them, the two related products oblongifolin C (Ob-C) and guttiferone K (Gt-K) isolated from Garcinia species (notably from edible fruits), have attracted attention due to their marked anticancer properties. The two compounds only differ by the nature of the C-6 side chain, prenyl (Gt-K) or geranyl (Ob-C) on the phloroglucinol core. Their origin, method of extraction and biological properties are presented here, with a focus on the targets and pathways implicated in their anticancer activities. Both compounds markedly reduce cancer cell proliferation in vitro, as well as tumor growth and metastasis in vivo. They are both potent inducer of tumor cell apoptosis, and regulation of autophagy flux is a hallmark of their mode of action. The distinct mechanism leading to autophagosome accumulation in cells and the implicated molecular targets are discussed. The specific role of the chaperone protein HSPA8, known to interact with Ob-C, is addressed. Molecular models of Gt-K and Ob-C bound to HSPA8 provide a structural basis to their common HSPA8-binding recognition capacity. The review shed light on the mechanism of action of these compounds, to encourage their studies and potential development.

Function of selected natural antidiabetic compounds with potential against cancer via modulation of the PI3K/AKT/mTOR cascade

Diabetes mellitus (DM) is a metabolic disorder with growing global incidence, as 387 million people were diagnosed in 2014 with an expected projection of 642 million in 2040. Several complications are associated with DM including heart attack, stroke, kidney failure, blindness, and cancer. The latter is the second leading cause of death worldwide accounting for one in every six deaths, with liver, pancreas, and endometrium cancers are the most abundant among patients with diabetes. Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway plays a vital role in developing a wide array of pathological disorders, among them diabetes and cancer. Natural secondary metabolites that counteract the deleterious effects of reactive oxygen species (ROS) and modulate PI3K/Akt/mTOR pathway could be a promising approach in cancer therapy. Here, 717 medicinal plants with antidiabetic activities were highlighted along with 357 bioactive compounds responsible for the antidiabetic activity. Also, 43 individual plant compounds with potential antidiabetic activities against cancer via the modulation of PI3K/Akt/mTOR cascade were identified. Taken together, the available data give an insight of the potential of repurposing medicinal plants and/or the individual secondary metabolites with antidiabetic activities for cancer therapy.

Dandelion root extract affects ESCC progression via regulating multiple signal pathways

Dandelion, a medicinal and edible plant, exhibits anti-inflammatory activity. The purpose of the present study was to investigate the inhibitory effectiveness of the aqueous dandelion root extract (DRE) on esophageal squamous cell carcinoma (ESCC). The in vitro cell proliferation, migration, invasion and apoptosis and the in vivo tumor growth were evaluated. The effects of DRE on PI3K/Akt and Ras/Raf/ERK pathways, which are important signaling pathways related to the development and progression of esophageal squamous cell carcinoma, were studied. The effects of DRE on the expression of apoptosis-related proteins BCL2 and BAX were also investigated. Meanwhile, the role of a cystathionine-β-synthase (CBS)/H₂S system in ESCC cells and the effects of DRE on the CBS/H₂S system were assessed. The results showed that DRE selectively inhibited cell growth, proliferation, migration and invasion and induced cell apoptosis in ESCC cells. Moreover, the oral administration of DRE retarded the growth of tumors in human ESCC xenograft models. The DRE treatment led to a dose-dependent reduction in the levels of PI3K, p-Akt, Ras, Raf and pERK1/2 proteins in ESCC cells. DRE also caused a decrease in the anti-apoptotic protein BCL2 and an increase in the pro-apoptotic protein BAX. The data also showed that the CBS/H₂S system implicated in the process of ESCC and DRE inhibited the CBS/H₂S system. Moreover, the CBS knockdown weakened the cancer cell-inhibiting effectiveness of DRE. Therefore, DRE may affect ESCC progression through the regulation of PI3K/Akt and Ras/Raf/ERK signal pathways as well as the endogenous CBS/H₂S system, and consequently, serve as an effective anti-cancer alternative for human ESCC treatment.

Anti-Cancer Activity of Phytochemicals Targeting Hypoxia-Inducible Factor-1 Alpha

Hypoxia-inducible factor-1 alpha (HIF-1α) is overexpressed in cancer, leading to a poor prognosis in patients. Diverse cellular factors are able to regulate HIF-1α expression in hypoxia and even in non-hypoxic conditions, affecting its progression and malignant characteristics by regulating the expression of the HIF-1α target genes that are involved in cell survival, angiogenesis, metabolism, therapeutic resistance, et cetera. Numerous studies have exhibited the anti-cancer effect of HIF-1α inhibition itself and the augmentation of anti-cancer treatment efficacy by interfering with HIF-1α-mediated signaling. The anti-cancer effect of plant-derived phytochemicals has been evaluated, and they have been found to possess significant therapeutic potentials against numerous cancer types. A better understanding of phytochemicals is indispensable for establishing advanced strategies for cancer therapy. This article reviews the anti-cancer effect of phytochemicals in connection with HIF-1α regulation.