Targeting AKT with Oridonin Inhibits Growth of Esophageal Squamous Cell Carcinoma In Vitro and Patient-Derived Xenografts In Vivo

Therapeutic implications of signaling pathways and tumor microenvironment interactions in esophageal cancer

Esophageal cancer (EC) is significantly influenced by the tumor microenvironment (TME) and altered signaling pathways. Downregulating these pathways in EC is essential for suppressing tumor development, preventing metastasis, and enhancing therapeutic outcomes. This approach can increase tumor sensitivity to treatments, enhance patient outcomes, and inhibit cancer cell proliferation and spread. The TME, comprising cellular and non-cellular elements surrounding the tumor, significantly influences EC's development, course, and treatment responsiveness. Understanding the complex relationships within the TME is crucial for developing successful EC treatments. Immunotherapy is a vital TME treatment for EC. However, the heterogeneity within the TME limits the application of anticancer drugs outside clinical settings. Therefore, identifying reliable microenvironmental biomarkers that can detect therapeutic responses before initiating therapy is crucial. Combining approaches focusing on EC signaling pathways with TME can enhance treatment outcomes. This integrated strategy aims to interfere with essential signaling pathways promoting cancer spread while disrupting factors encouraging tumor development. Unraveling aberrant signaling pathways and TME components can lead to more focused and efficient treatment approaches, identifying specific cellular targets for treatments. Targeting the TME and signaling pathways may reduce metastasis risk by interfering with mechanisms facilitating cancer cell invasion and dissemination. In conclusion, this integrative strategy has significant potential for improving patient outcomes and advancing EC research and therapy. This review discusses the altered signaling pathways and TME in EC, focusing on potential future therapeutics.

Synthesis and Application of a pH-Responsive Functional Metal-Organic Framework: In Vitro Investigation for Delivery of Oridonin in Cancer Therapy

Oridonin (Ori) is a naturally existing diterpenoid substance that mainly exists in the Chinese medicinal plant Rabdosia rubescens. It was previously found to possess intriguing biological properties; however, the quick clearance from plasma and limited solubility in water restricts its use as a drug. Several metal-organic frameworks (MOFs), having big surfaces and large pores, have recently been considered promising drug transporters. The zeolitic imidazolate framework-8 (ZIF-8), a form of MOF consisting of 2-methylimidazole with zinc ions, is structurally stable under physiologically neutral conditions, while it can degrade at low pH values such as in tumor cells. Herein, a nanosized drug delivery system, Ori@ZIF-8, was successfully designed for encapsulating and transporting oridonin to the tumor site. The drug loading of the prepared Ori@ZIF-8 was 26.78%, and the particles' mean size was 240.5 nm. In vitro, the release of Ori@ZIF-8 exhibited acid sensitivity, with a slow release under neutral conditions and rapid release of the drug under weakly acidic conditions. According to the in vitro anti-tumor experiments, Ori@ZIF-8 produced higher cytotoxicity than free Ori and induced apoptosis in A549 cancer cells. In conclusion, Ori@ZIF-8 could be a potential pH-responsive carrier to accurately release more oridonins at the tumor site.

Oridonin from Rabdosia rubescens: An emerging potential in cancer therapy - A comprehensive review

Cancer incidences are rising each year. In 2020, approximately 20 million new cancer cases and 10 million cancer-related deaths were recorded. The World Health Organization (WHO) predicts that by 2024 the incidence of cancer will increase to 30.2 million individuals annually. Considering the invasive characteristics of its diagnostic procedures and therapeutic methods side effects, scientists are searching for different solutions, including using plant-derived bioactive compounds, that could reduce the probability of cancer occurrence and make its treatment more comfortable. In this regard, oridonin (ORI), an ent-kaurane diterpenoid, naturally found in the leaves of Rabdosia rubescens species, has been found to have antitumor, antiangiogenesis, antiasthmatic, antiinflammatory, and apoptosis induction properties. Extensive research has been performed on ORI to find various mechanisms involved in its anticancer activities. This review article provides an overview of ORI's effectiveness on murine and human cancer populations from 1976 to 2022 and provides insight into the future application of ORI in different cancer therapies.

Targeting TAOK1 with resveratrol inhibits esophageal squamous cell carcinoma growth in vitro and in vivo

The worldwide incidence and mortality rates of esophageal squamous cell carcinoma (ESCC) have increased over the last decade. Moreover, molecular targets that may benefit the therapeutics of patients with ESCC have not been fully characterized. Our study discovered that thousand and one amino-acid protein kinase 1 (TAOK1) is highly expressed in ESCC tumor tissues and cell lines. Knock-down of TAOK1 suppresses ESCC cell proliferation in vitro and patient-derived xenograft or cell-derived xenograft tumors growth in vivo. Moreover, TAOK1 overexpression promotes ESCC growth in vitro and in vivo. Additionally, we identified that the natural small molecular compound resveratrol binds to TAOK1 directly and diminishes the kinase activity of TAOK1. Targeting TAOK1 directly with resveratrol significantly inhibits cell proliferation, induces cell cycle arrest and apoptosis, and suppresses tumor growth in ESCC. Furthermore, the silencing of TAOK1 or the application of resveratrol attenuated the activation of TAOK1 downstream signaling effectors. Interestingly, combining resveratrol with paclitaxel, cisplatin, or 5-fluorouracil synergistically enhanced their therapeutic effects against ESCC. In conclusion, this work illustrates the underlying oncogenic function of TAOK1 and provides a theoretical basis for the application of targeting TAOK1 therapy to the clinical treatment of ESCC.

Dexrazoxane inhibits the growth of esophageal squamous cell carcinoma by attenuating SDCBP/MDA-9/syntenin-mediated EGFR-PI3K-Akt pathway activation

Syndecan-binding protein (SDCBP) was reported to stimulate the advancement of esophageal squamous cell carcinoma (ESCC) and could potentially be a target for ESCC treatment. There is a growing corpus of research on the anti-tumor effects of iron chelators; however, very few studies have addressed the involvement of dexrazoxane in cancer. In this study, structure-based virtual screening was employed to select drugs targeting SDCBP from the Food and Drug Administration (FDA)-approved drug databases. The sepharose 4B beads pull-down assay revealed that dexrazoxane targeted SDCBP by interacting with its PDZ1 domain. Additionally, dexrazoxane inhibited ESCC cell proliferation and anchorage-independent colony formation via SDCBP. ESCC cell apoptosis and G2 phase arrest were induced as measured by the flow cytometry assay. Subsequent research revealed that dexrazoxane attenuated the binding ability between SDCBP and EGFR in an immunoprecipitation assay. Furthermore, dexrazoxane impaired EGFR membrane localization and inactivated the EGFR/PI3K/Akt pathway. In vivo, xenograft mouse experiments indicated that dexrazoxane suppressed ESCC tumor growth. These data indicate that dexrazoxane might be established as a potential anti-cancer agent in ESCC by targeting SDCBP.

ThermomiR-377-3p-induced suppression of Cirbp expression is required for effective elimination of cancer cells and cancer stem-like cells by hyperthermia

BACKGROUND

In recent years, the development of adjunctive therapeutic hyperthermia for cancer therapy has received considerable attention. However, the mechanisms underlying hyperthermia resistance are still poorly understood. In this study, we investigated the roles of cold‑inducible RNA binding protein (Cirbp) in regulating hyperthermia resistance and underlying mechanisms in nasopharyngeal carcinoma (NPC).

METHODS

CCK-8 assay, colony formation assay, tumor sphere formation assay, qRT-PCR, Western blot were employed to examine the effects of hyperthermia (HT), HT + oridonin(Ori) or HT + radiotherapy (RT) on the proliferation and stemness of NPC cells. RNA sequencing was applied to gain differentially expressed genes upon hyperthermia. Gain-of-function and loss-of-function experiments were used to evaluate the effects of RNAi-mediated Cirbp silencing or Cirbp overexpression on the sensitivity or resistance of NPC cells and cancer stem-like cells to hyperthermia by CCK-8 assay, colony formation assay, tumorsphere formation assay and apoptosis assay, and in subcutaneous xenograft animal model. miRNA transient transfection and luciferase reporter assay were used to demonstrate that Cirbp is a direct target of miR-377-3p. The phosphorylation levels of key members in ATM-Chk2 and ATR-Chk1 pathways were detected by Western blot.

RESULTS

Our results firstly revealed that hyperthermia significantly attenuated the stemness of NPC cells, while combination treatment of hyperthermia and oridonin dramatically increased the killing effect on NPC cells and cancer stem cell (CSC)‑like population. Moreover, hyperthermia substantially improved the sensitivity of radiation‑resistant NPC cells and CSC‑like cells to radiotherapy. Hyperthermia noticeably suppressed Cirbp expression in NPC cells and xenograft tumor tissues. Furthermore, Cirbp inhibition remarkably boosted anti‑tumor‑killing activity of hyperthermia against NPC cells and CSC‑like cells, whereas ectopic expression of Cirbp compromised tumor‑killing effect of hyperthermia on these cells, indicating that Cirbp overexpression induces hyperthermia resistance. ThermomiR-377-3p improved the sensitivity of NPC cells and CSC‑like cells to hyperthermia in vitro by directly suppressing Cirbp expression. More importantly, our results displayed the significantly boosted sensitization of tumor xenografts to hyperthermia by Cirbp silencing in vivo, but ectopic expression of Cirbp almost completely counteracted hyperthermia-mediated tumor cell-killing effect against tumor xenografts in vivo. Mechanistically, Cirbp silencing-induced inhibition of DNA damage repair by inactivating ATM-Chk2 and ATR-Chk1 pathways, decrease in stemness and increase in cell death contributed to hyperthermic sensitization; conversely, Cirbp overexpression-induced promotion of DNA damage repair, increase in stemness and decrease in cell apoptosis contributed to hyperthermia resistance.

CONCLUSION

Taken together, these findings reveal a previously unrecognized role for Cirbp in positively regulating hyperthermia resistance and suggest that thermomiR-377-3p and its target gene Cirbp represent promising targets for therapeutic hyperthermia.

The bioavailability enhancement and insight into the action mechanism of poorly soluble natural compounds from co-crystals preparation: Oridonin as an example

BACKGROUND

Natural bioactive molecules are important sources for the development of new drugs. However, most of them were limited in clinical applications due to their low aqueous solubility and bioavailability. Oridonin (ORI) is a powerful anticancer compound with above characteristics.

OBJECTIVE

This study aimed to find an effective method to improve the bioavailability of poorly soluble natural compounds, and explore the action mechanisms of them to promote their application.

RESULTS

In this study, ORI-nicotinamide (NCT) cocrystal was successfully prepared for the first time to overcome the defects of ORI. The solubility and oral bioavailability of cocrystal (COC) increased 1.34 and 1.18 times compared with ORI. Moreover, MTT assay was applied to compare the cytotoxicity of positive control drug sorafenib with ORI and COC. The IC50 values of sorafenib, ORI and COC on HepG2 cells were 7.61, 8.79 and 7.36 nmol·mL-1, which indicated that the cytotoxicity of ORI could be enhanced by cocrystal preparation. The cellular metabolomics was innovatively introduced to gain insight into the difference of cytotoxicity mechanism between ORI and COC. The results showed that there were 78 metabolites with significant differences in content between the two groups, while these differential metabolites were related to 11 metabolic pathways. Among these, glycerophospholipid metabolism and cysteine and methionine metabolism were the significant differential pathways, and the downregulation of PC(14:0/16:1(9z)) and upregulation of homocysteine were the likely main reasons for higher cytotoxicity of COC.

CONCLUSIONS

This study has presented novel approaches for enhancing the bioavailability and drug efficacy of natural compounds, while also offering fresh insights into the underlying action mechanisms of pharmaceutical cocrystals.

Research Progress on the Synergistic Anti-Tumor Effect of Natural Anti-Tumor Components of Chinese Herbal Medicine Combined with Chemotherapy Drugs

The application of chemotherapy drugs in tumor treatment has a long history, but the lack of selectivity of drugs often leads to serious side effects during chemotherapy. The natural anti-tumor ingredients derived from Chinese herbal medicine are attracting increased attention due to their diverse anti-tumor effects, abundant resources, and minimal side effects. An effective anti-tumor strategy may lie in the combination of these naturally derived anti-tumor ingredients with conventional chemotherapy drugs. This approach could potentially inhibit tumor growth and the development of drug resistance in tumor cells while reducing the adverse effects of chemotherapy drugs. This review provides a comprehensive overview of the combined therapy strategies integrating natural anti-tumor components from Chinese herbal medicine with chemotherapy drugs in current research. We primarily summarize various compounds in Chinese herbal medicine exhibiting natural anti-tumor activities and the relevant mechanisms in synergistic anti-tumor combination therapy. The focus of this paper is on underlining that this integrative approach, combining natural anti-tumor components of Chinese herbal medicine with chemotherapy drugs, presents a novel cancer treatment methodology, thereby providing new insights for future oncological research.

Target discovery of bioactive natural products with native-compound-coupled CNBr-activated Sepharose 4B beads (NCCB): Applications, mechanisms and outlooks

Natural products (NPs) represent a treasure trove for drug discovery and development due to their chemical structural diversity and a broad spectrum of biological activities. Uncovering the biological targets and understanding their molecular mechanism of actions are crucial steps in the development of clinical therapeutics. However, the structural complexity of NPs and intricate nature of biological system present formidable challenges in target identification of NPs. Although significant advances have been made in the development of new chemical tools, these methods often require high levels of synthetic skills for preparing chemical probes. This can be costly and time-consuming relaying on operationally complicated procedures and instruments. In recent efforts, we and others have successfully developed an operationally simple and practical chemical tool known as native-compound-coupled CNBr-activated Sepharose 4B beads (NCCB) for NP target identification. In this approach, a native compound readily reacts with commercial CNBr-activated Sepharose 4B beads with a process that is easily performed in any biology laboratory. Based on NCCB, our group has identified the direct targets of more than 60 NPs. In this review, we will elucidate the application scopes, including flavonoids, quinones, terpenoids and others, characteristics, chemical mechanisms, procedures, advantages, disadvantages, and future directions of NCCB in specific target discovery.

Molecular insights into the behavior of the allosteric and ATP-competitive inhibitors in interaction with AKT1 protein: A molecular dynamics study

AKT1 is a family of serine/threonine kinases that play a key role in regulating cell growth, proliferation, metabolism, and survival. Two significant classes of AKT1 inhibitors (allosteric and ATP-competitive) are used in clinical development, and both of them could be effective in specific conditions. In this study, we investigated the effect of several different inhibitors on two conformations of the AKT1 by computational approach. We studied the effects of four inhibitors, including MK-2206, Miransertib, Herbacetin, and Shogaol, on the inactive conformation of AKT1 protein and the effects of four inhibitors, Capivasertib, AT7867, Quercetin, and Oridonin molecules on the active conformation of AKT1 protein. The results of simulations showed that each inhibitor creates a stable complex with AKT1 protein, although AKT1/Shogaol and AKT1/AT7867 complexes showed less stability than other complexes. Based on RMSF calculations, the fluctuation of residues in the mentioned complexes is higher than in other complexes. As compared to other complexes in either of its two conformations, MK-2206 has a stronger binding free energy affinity in the inactive conformation, -203.446 kJ/mol. MM-PBSA calculations showed that the van der Waals interactions contribute more than the electrostatic interactions to the binding energy of inhibitors to AKT1 protein.

Ferroptosis-modulating small molecules for targeting drug-resistant cancer: Challenges and opportunities in manipulating redox signaling

Ferroptosis is an iron-dependent cell death program that is characterized by excessive lipid peroxidation. Triggering ferroptosis has been proposed as a promising strategy to fight cancer and overcome drug resistance in antitumor therapy. Understanding the molecular interactions and structural features of ferroptosis-inducing compounds might therefore open the door to efficient pharmacological strategies against aggressive, metastatic, and therapy-resistant cancer. We here summarize the molecular mechanisms and structural requirements of ferroptosis-inducing small molecules that target central players in ferroptosis. Focus is placed on (i) glutathione peroxidase (GPX) 4, the only GPX isoenzyme that detoxifies complex membrane-bound lipid hydroperoxides, (ii) the cystine/glutamate antiporter system Xc - that is central for glutathione regeneration, (iii) the redox-protective transcription factor nuclear factor erythroid 2-related factor (NRF2), and (iv) GPX4 repression in combination with induced heme degradation via heme oxygenase-1. We deduce common features for efficient ferroptotic activity and highlight challenges in drug development. Moreover, we critically discuss the potential of natural products as ferroptosis-inducing lead structures and provide a comprehensive overview of structurally diverse biogenic and bioinspired small molecules that trigger ferroptosis via iron oxidation, inhibition of the thioredoxin/thioredoxin reductase system or less defined modes of action.

Enhanced compound-protein binding affinity prediction by representing protein multimodal information via a coevolutionary strategy

Due to the lack of a method to efficiently represent the multimodal information of a protein, including its structure and sequence information, predicting compound-protein binding affinity (CPA) still suffers from low accuracy when applying machine-learning methods. To overcome this limitation, in a novel end-to-end architecture (named FeatNN), we develop a coevolutionary strategy to jointly represent the structure and sequence features of proteins and ultimately optimize the mathematical models for predicting CPA. Furthermore, from the perspective of data-driven approach, we proposed a rational method that can utilize both high- and low-quality databases to optimize the accuracy and generalization ability of FeatNN in CPA prediction tasks. Notably, we visually interpret the feature interaction process between sequence and structure in the rationally designed architecture. As a result, FeatNN considerably outperforms the state-of-the-art (SOTA) baseline in virtual drug evaluation tasks, indicating the feasibility of this approach for practical use. FeatNN provides an outstanding method for higher CPA prediction accuracy and better generalization ability by efficiently representing multimodal information of proteins via a coevolutionary strategy.

Case report: First case of early adenoid cystic carcinoma and squamous cell carcinoma collision cancer treated by endoscopic submucosal dissection

Background

Collision cancer, a rare tumor, rarely occurs in the esophagus. Most reported cases of esophageal collision cancers are advanced cancers that can only be treated with surgery or palliative chemoradiotherapy. Here, we report a rare case of collisional squamous cell carcinoma (SqCC) and adenoid cystic carcinoma (AdCC) that was detected in the early stages by endoscopy.

Case summary

A 66-year-old man presented with retrosternal pain after swallowing and underwent endoscopy. Pathological biopsy showed high-grade squamous intraepithelial neoplasia. The lesion was removed by endoscopic submucosal dissection (ESD) after magnification and endoscopic ultrasonography. Postoperative pathology proved that the lesion was collision cancer comprising SqCC and AdCC. After six months of postoperative follow-up, there was no recurrence of esophageal cancer.

Conclusions

We provided a case report related to the diagnosis and treatment of esophageal collision cancer, especially early collision cancer. More research is needed to provide insights into the management of collision cancers.

Discovery of Polyphenolic Natural Products as SARS-CoV-2 Mpro Inhibitors for COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has forced the development of direct-acting antiviral drugs due to the coronavirus disease 2019 (COVID-19) pandemic. The main protease of SARS-CoV-2 is a crucial enzyme that breaks down polyproteins synthesized from the viral RNA, making it a validated target for the development of SARS-CoV-2 therapeutics. New chemical phenotypes are frequently discovered in natural goods. In the current study, we used a fluorogenic assay to test a variety of natural products for their ability to inhibit SARS-CoV-2 Mpro. Several compounds were discovered to inhibit Mpro at low micromolar concentrations. It was possible to crystallize robinetin together with SARS-CoV-2 Mpro, and the X-ray structure revealed covalent interaction with the protease's catalytic Cys145 site. Selected potent molecules also exhibited antiviral properties without cytotoxicity. Some of these powerful inhibitors might be utilized as lead compounds for future COVID-19 research.

Construction of a phos-tag-directed self-assembled fluorescent magnetobiosensor for the simultaneous detection of multiple protein kinases

Protein kinases play important roles in regulating various cellular processes and may function as potential diagnostic and therapeutic targets for various diseases including cancers. Herein, we construct a phos-tag-directed self-assembled fluorescent magnetobiosensor to simultaneously detect multiple protein kinases with good selectivity and high sensitivity. In the presence of protein kinases (i.e., PKA and Akt1), their substrate peptides (i.e., a FITC-labeled substrate peptide and a Cy5-labeled substrate peptide) are phosphorylated, and are then specifically recognized and captured by a biotinylated phos-tag to generate biotinylated substrate peptides for the assembly of magnetic bead (MB)-peptides-FITC/Cy5 nanostructures. After magnetic separation, the phosphorylated substrate peptides are disassembled from the MB-peptides-FITC/Cy5 nanostructures using deionized water at 80 °C, releasing FITC and Cy5 molecules. The released FITC and Cy5 molecules are detected by steady-state fluorescence measurements, with FITC indicating PKA and Cy5 indicating Akt1. This magnetobiosensor only involves one phos-tag without the requirement of radiolabeling, antibody screening, carboxypeptidase Y (CPY) cleavage, and cumbersome chemical/enzyme reactions. The introduction of magnetic separation can effectively eliminate the interference from complex real samples, generating an extremely low background signal. Moreover, this magnetobiosensor can accurately measure cellular protein kinase activities and screen inhibitors, with great potential for kinase-related biomedical research and therapeutic applications.

Natural Products for Esophageal Cancer Therapy: From Traditional Medicine to Modern Drug Discovery

Esophageal cancer (EC) is one of the most malignant types of cancer worldwide and has a high incidence and mortality rate in Asian countries. When it comes to treating EC, although primary methods such as chemotherapy and surgery exist, the prognosis remains poor. The purpose of this current research is to review the range of effects that natural products have on cancer by analyzing studies conducted on EC. Fifty-seven studies were categorized into four anti-cancer mechanisms, as well as clinical trials. The studies that were scrutinized in this research were all reported within five years. The majority of the substances reviewed induced apoptosis in EC, acting on a variety of mechanisms. Taken together, this study supports the fact that natural products have the potential to act as a candidate for treating EC.

Oridonin Delays Aging Through the AKT Signaling Pathway

Aging is a major risk factor for chronic diseases and disability in humans. Nowadays, no effective anti-aging treatment is available clinically. In this study, oridonin was selected based on the drug screening strategy similar to Connectivity MAP (CMAP) but upon transcriptomes of 102 traditional Chinese medicines treated cell lines. Oridonin is a diterpenoid isolated from Rabdosia rubescens. As reported, Oridonin exhibits a variety of pharmacological activities, including antitumor, antibacterial and anti-inflammatory activities. Here, we found that oridonin inhibited cellular senescence in human diploid fibroblasts (2BS and WI-38), manifested by decreased senescence-associated β-galactosidase (SA-β-gal) staining. Compared with the elderly control group, the positive cell rate in the oridonin intervention group was reduced to 48.5%. Notably, oridonin prolonged the lifespan of yeast by 48.9%, and extended the average life span of naturally aged mice by 21.6%. Our mice behavior experiments exhibited that oridonin significantly improved the health status of naturally aged mice. In addition, oridonin also delayed doxorubicin-induced cellular senescence and mouse senescence. Compared with the model group, the percentage of SA-β-gal positive cells in the oridonin treatment group was reduced to 59.8%. It extended the average lifespan of mice by 53.8% and improved healthspan. Mechanistically, we showed that oridonin delayed aging through the AKT signaling pathway and reversed the genetic changes caused by doxorubicin-induced cell senescence. Therefore, oridonin is a potential candidate for the development of anti-aging drugs.

Role of Plant-Derived Active Constituents in Cancer Treatment and Their Mechanisms of Action

Despite significant technological advancements in conventional therapies, cancer remains one of the main causes of death worldwide. Although substantial progress has been made in the control and treatment of cancer, several limitations still exist, and there is scope for further advancements. Several adverse effects are associated with modern chemotherapy that hinder cancer treatment and lead to other critical disorders. Since ancient times, plant-based medicines have been employed in clinical practice and have yielded good results with few side effects. The modern research system and advanced screening techniques for plants’ bioactive constituents have enabled phytochemical discovery for the prevention and treatment of challenging diseases such as cancer. Phytochemicals such as vincristine, vinblastine, paclitaxel, curcumin, colchicine, and lycopene have shown promising anticancer effects. Discovery of more plant-derived bioactive compounds should be encouraged via the exploitation of advanced and innovative research techniques, to prevent and treat advanced-stage cancers without causing significant adverse effects. This review highlights numerous plant-derived bioactive molecules that have shown potential as anticancer agents and their probable mechanisms of action and provides an overview of in vitro, in vivo and clinical trial studies on anticancer phytochemicals.

PI3K/Akt/mTOR Signaling Pathway: Role in Esophageal Squamous Cell Carcinoma, Regulatory Mechanisms and Opportunities for Targeted Therapy

Esophageal squamous cell carcinoma (ESCC), is the most common type of esophageal cancer worldwide, mainly occurring in the Asian esophageal cancer belt, including northern China, Iran, and parts of Africa. Phosphatidlinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway is one of the most important cellular signaling pathways, which plays a crucial role in the regulation of cell growth, differentiation, migration, metabolism and proliferation. In addition, mutations in some molecules of PI3K/Akt/mTOR pathway are closely associated with survival and prognosis in ESCC patients. A large number of studies have found that there are many molecules in ESCC that can regulate the PI3K/Akt/mTOR pathway. Overexpression of these molecules often causes aberrant activation of PI3K/Akt/mTOR pathway. Currently, several effective PI3K/Akt/mTOR pathway inhibitors have been developed, which can play anticancer roles either alone or in combination with other inhibitors. This review mainly introduces the general situation of ESCC, the composition and function of PI3K/Akt/mTOR pathway, and regulatory factors that interact with PI3K/Akt/mTOR signaling pathway. Meanwhile, mutations and inhibitors of PI3K/Akt/mTOR pathway in ESCC are also elucidated.

Drug Discovery of Plausible Lead Natural Compounds That Target the Insulin Signaling Pathway: Bioinformatics Approaches

The growing smooth talk in the field of natural compounds is due to the ancient and current interest in herbal medicine and their potentially positive effects on health. Dozens of antidiabetic natural compounds were reported and tested in vivo, in silico, and in vitro. The role of these natural compounds, their actions on the insulin signaling pathway, and the stimulation of the glucose transporter-4 (GLUT4) insulin-responsive translocation to the plasma membrane (PM) are all crucial in the treatment of diabetes and insulin resistance. In this review, we collected and summarized a group of available in vivo and in vitro studies which targeted isolated phytochemicals with possible antidiabetic activity. Moreover, the in silico docking of natural compounds with some of the insulin signaling cascade key proteins is also summarized based on the current literature. In this review, hundreds of recent studies on pure natural compounds that alleviate type II diabetes mellitus (type II DM) were revised. We focused on natural compounds that could potentially regulate blood glucose and stimulate GLUT4 translocation through the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway. On attempt to point out potential new natural antidiabetic compounds, this review also focuses on natural ingredients that were shown to interact with proteins in the insulin signaling pathway in silico, regardless of their in vitro/in vivo antidiabetic activity. We invite interested researchers to test these compounds as potential novel type II DM drugs and explore their therapeutic mechanisms.

Toward Targeted Therapies in Oesophageal Cancers: An Overview

Oesophageal cancer is one of the leading causes of cancer-related death worldwide. Oesophageal cancer occurs as squamous cell carcinoma (ESCC) or adenocarcinoma (EAC). Prognosis for patients with either ESCC or EAC is poor, with less than 20% of patients surviving more than 5 years after diagnosis. A major progress has been made in the development of biomarker-driven targeted therapies against breast and lung cancers, as well as melanoma. However, precision oncology for patients with oesophageal cancer is still virtually non-existent. In this review, we outline the recent advances in oesophageal cancer profiling and clinical trials based on targeted therapies in this disease.

Oxethazaine inhibits esophageal squamous cell carcinoma proliferation and metastasis by targeting aurora kinase A

Esophageal squamous cell carcinoma (ESCC), a malignant neoplasm with high incidence, is a severe global public health threat. The current modalities used for treating ESCC include surgery, chemotherapy, and radiotherapy. Although ESCC management and treatment strategies have improved over the last decade, the overall 5-year survival rate remains <20%. Therefore, the identification of novel therapeutic strategies that can increase ESCC patient survival rates is urgently needed. Oxethazaine, an amino-amide anesthetic agent, is mainly prescribed in combination with antacids to relieve esophagitis, dyspepsia, and other gastric disorders. In the present study, we found that oxethazaine inhibited the proliferation and migration of esophageal cancer cells. According to the results of in vitro screening and binding assays, oxethazaine binds directly to AURKA, suppresses AURKA activity, and inhibits the downstream effectors of AURKA. Notably, we found that oxethazaine suppressed tumor growth in three patient-derived esophageal xenograft mouse models and tumor metastasis in vivo. Our findings suggest that oxethazaine can inhibit ESCC proliferation and metastasis in vitro and in vivo by targeting AURKA.

The unique Akt inhibitor SC66 suppressed AMPK activity and abolished autophagy through the EGFR-p62 pathway

Akt is usually considered to be a negative regulator of both autophagy and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling. In the present study, we found that SC66, a pyridine-based allosteric Akt inhibitor, suppressed basal and H₂ O₂ -induced autophagy concurrent with decreased phosphorylation and activity of AMPK. SC66 treatment led to the formation of a high molecular weight (HMW) form of SQSTM1/p62 (p62), which is an autophagic substrate and is essential for selective autophagy. Moreover, we observed that SC66 inhibited the binding of p62 and microtubule-associated protein light chain 3 (LC3). The immunoprecipitation results revealed the interaction between p62 and epidermal growth factor receptor (EGFR), and knockdown of EGFR reversed SC66-mediated autophagy inhibition without affecting the phosphorylation of acetyl-CoA carboxylase (ACC), a well-known substrate of AMPK. SC66 increased the interaction between EGFR and Beclin 1 and markedly decreased the association of EGFR with VPS34, a critical protein for autophagy induction. Collectively, the data presented here indicate that EGFR-p62 pathway plays a critical role in Akt-mediated positive regulation of autophagy.

WISP3 suppresses ESCC progression by inhibiting the IGF-2-IGF1R-AKT signaling cascade

Esophageal squamous cell carcinoma (ESCC) is a major health problem worldwide, especially in the Chinese population. However, the intrinsic molecular mechanisms of ESCC progression are largely unclear, thus there is an unmet need to identify essential genes governing this disease. Here, we discovered WISP3, an important member of the CCN family, is markedly downregulated in ESCC tissues compared to the normal esophageal epithelium. Downregulation of WISP3 in cancer tissue correlates with worse overall survival of ESCC patients. Using ESCC cell lines as models, we found that forced expression of WISP3 not only suppressed proliferation and migration of cancer cells in vitro, but also inhibited ESCC tumor growth and metastasis in vivo. On the contrary, WISP3 depletion strongly promoted the tumorigenicity of ESCC cells. Mechanistically, we found that WISP3 negates the activity of AKT via inhibiting the IGF-2-IGF1R signaling cascade, which mediates the tumor-suppressive function of WISP3 in esophageal cancers. Together, we identified a novel factor driving the development of ESCC, and revealed a potential therapeutic target for ESCC treatment.

Potential Mechanisms of Plant-Derived Natural Products in the Treatment of Cervical Cancer

Cervical cancer is the second most common gynecological malignancy globally; it seriously endangers women’s health because of its high morbidity and mortality. Conventional treatments are prone to drug resistance, recurrence and metastasis. Therefore, there is an urgent need to develop new drugs with high efficacy and low side effects to prevent and treat cervical cancer. In recent years, plant-derived natural products have been evaluated as potential anticancer drugs that preferentially kill tumor cells without severe adverse effects. A growing number of studies have shown that natural products can achieve practical anti-cervical-cancer effects through multiple mechanisms, including inhibition of tumor-cell proliferation, induction of apoptosis, suppression of angiogenesis and telomerase activity, enhancement of immunity and reversal of multidrug resistance. This paper reviews the therapeutic effects and mechanisms of plant-derived natural products on cervical cancer and provides references for developing anti-cervical-cancer drugs with high efficacy and low side effects.

Anticancer effects of 6-shogaol via the AKT signaling pathway in oral squamous cell carcinoma

Objective

Oral squamous cell carcinoma (OSCC) is one of the common type of cancer that leads to death; and is becoming a global concern. Due to the lack of efficient chemotherapeutic agents for patients with oral cancer, the prognosis remains poor. 6-shogaol, a bioactive compound of ginger, has a broad spectrum of bioactivities and has been widely used to relieve many diseases. However, its effects on human oral cancer have not yet been fully evaluated. In our study, we investigated the anticancer effects of 6-shogaol on the proliferation, migration, invasion, apoptosis, and underlying mechanisms within human OSCC cell lines.

Methodology

We investigated the effect of 6-shogaol on the growth of OSCC cells by cell viability and soft agar colony formation assay. Migration and invasion assays were conducted to confirm the effect 6-shogaol on OSCC cell metastasis. Apoptosis was detected by flow cytometry and the underlying mechanism on the antigrowth effect of 6-shogaol in OSCC cells was assessed using western blotting.

Results

In our results, 6-shogaol not only suppressed proliferation and anchorage-independent cell growth in OSCC cells, but also induced apoptosis by regulating the apoptosis-associated factors such as p53, Bax, Bcl-2, and cleaved caspase-3. Migration and invasion of OSCC cells were inhibited following the regulation of E-cadherin and N-cadherin by 6-shogaol. Additionally, 6-shogaol treatment significantly inhibited the PI3K/AKT signaling pathway.

Conclusion

Therefore, our results may provide critical evidence that 6-shogaol can be a potential new therapeutic candidate for oral cancer.

STL1, a New AKT Inhibitor, Synergizes with Flavonoid Quercetin in Enhancing Cell Death in A Chronic Lymphocytic Leukemia Cell Line

Using a pharmacophore model based on the experimental structure of AKT-1, we recently identified the compound STL1 (ZINC2429155) as an allosteric inhibitor of AKT-1. STL1, was able to reduce Ser473 phosphorylation, thus inhibiting the PI₃K/AKT pathway. Moreover, we demonstrated that the flavonoid quercetin downregulated the phosphorylated and active form of AKT. However, in this case, quercetin inhibited the PI₃K/AKT pathway by directly binding the kinases CK2 and PI₃K. In the present work, we investigated the antiproliferative effects of the co-treatment quercetin plus STL1 in HG-3 cells, derived from a patient affected by chronic lymphocytic leukemia. Quercetin and STL1 in the mono-treatment maintained the capacity to inhibit AKT phosphorylation on Ser473, but did not significantly reduce cell viability. On the contrary, they activated a protective form of autophagy. When the HG-3 cells were co-treated with quercetin and STL1, their association synergistically (combination index < 1) inhibited cell growth and induced apoptosis. The combined treatment caused the switch from protective to non-protective autophagy. This work demonstrated that cytotoxicity could be enhanced in a drug-resistant cell line by combining the effects of different inhibitors acting in concert on PI₃K and AKT kinases.

NSUN2-mediated RNA 5-methylcytosine promotes esophageal squamous cell carcinoma progression via LIN28B-dependent GRB2 mRNA stabilization

5-Methylcytosine (m5C) is a posttranscriptional RNA modification participating in many critical bioprocesses, but its functions in human cancer remain unclear. Here, by detecting the transcriptome-wide m5C profiling in esophageal squamous cell carcinoma (ESCC), we showed increased m5C methylation in ESCC tumors due to the overexpressed m5C methyltransferase NSUN2. Aberrant expression of NSUN2 was positively regulated by E2F Transcription Factor 1 (E2F1). High NSUN2 levels predicted poor survival of ESCC patients. Moreover, silencing NSUN2 suppressed ESCC tumorigenesis and progression in Nsun2 knockout mouse models. Mechanistically, NSUN2 induced m5C modification of growth factor receptor-bound protein 2 (GRB2) and stabilized its mRNA, which was mediated by a novel m5C mediator, protein lin-28 homolog B (LIN28B). Elevated GRB2 levels increased the activation of PI3K/AKT and ERK/MAPK signalling. These results demonstrate that NSUN2 enhances the initiation and progression of ESCC via m5C-LIN28B dependent stabilization of GRB2 transcript, providing a promising epitranscriptomic-targeted therapeutic strategy for ESCC.

Costunolide Induces Apoptosis via the Reactive Oxygen Species and Protein Kinase B Pathway in Oral Cancer Cells

Oral cancer (OC) has been attracted research attention in recent years as result of its high morbidity and mortality. Costunolide (CTD) possesses potential anticancer and bioactive abilities that have been confirmed in several types of cancers. However, its effects on oral cancer remain unclear. This study investigated the potential anticancer ability and underlying mechanisms of CTD in OC in vivo and in vitro. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of CTD on OC cells; assessments for migration and invasion of OC cells were conducted by transwell; Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. The results revealed that CTD suppressed the proliferation, migration and invasion of oral cancer cells effectively and induced cell cycle arrest and apoptosis; regarding the mechanism, CTD bound to AKT directly by binding assay and repressed AKT activities through kinase assay, which thereby downregulating the downstream of AKT. Furthermore, CTD remarkably promotes the generation of reactive oxygen species by flow cytometry assay, leading to cell apoptosis. Notably, CTD strongly suppresses cell-derived xenograft OC tumor growth in an in vivo mouse model. In conclusion, our results suggested that costunolide might prevent progression of OC and promise to be a novel AKT inhibitor.

Downregulation of ATXN3 Enhances the Sensitivity to AKT Inhibitors (Perifosine or MK-2206), but Decreases the Sensitivity to Chemotherapeutic Drugs (Etoposide or Cisplatin) in Neuroblastoma Cells

Background

Chemotherapy resistance is the major cause of failure in neuroblastoma (NB) treatment. ATXN3 has been linked to various types of cancer and neurodegenerative diseases; however, its roles in NB have not been established. The aim of our study was to explore the role of ATXN3 in the cell death induced by AKT inhibitor (perifosine or MK-2206) or chemotherapy drugs (etoposide or cisplatin) in NB cells.

Methods

The expressions of ATXN3 and BCL-2 family members were detected by Western blot. Cell survival was evaluated by CCK8, cell confluence was measured by IncuCyte, and apoptosis was detected by flow cytometry. AS and BE2 were treated with AKT inhibitors or chemotherapeutics, respectively.

Results

Downregulation of ATXN3 did not block, but significantly increased the perifosine/MK-2206-induced cell death. Among the BCL-2 family members, the expression of pro-apoptotic protein BIM and anti-proapoptotic protein Bcl-xl expression increased significantly when ATXN3 was down-regulated. Downregulation of BIM protected NB cells from the combination of perifosine/MK-2206 and ATXN3 downregulation. Downregulation of ATXN3 did not increase, but decrease the sensitivity of NB cells to etoposide/cisplatin, and knockdown of Bcl-xl attenuated this decrease in sensitivity.

Conclusion

Downregulation of ATXN3 enhanced AKT inhibitors (perifosine or MK-2206) induced cell death by BIM, but decreased the cell death induced by chemotherapeutic drugs (etoposide or cisplatin) via Bcl-xl. The expression of ATXN3 may be an indicator in selecting different treatment regimen.

Integrative cBioPortal Analysis Revealed Molecular Mechanisms That Regulate EGFR-PI3K-AKT-mTOR Pathway in Diffuse Gliomas of the Brain

Simple Summary

The current classification of central nervous system tumors has incorporated molecular changes that have clarified biological behavior and categorized gliomas into different types and malignancy grades. The most malignant type—glioblastoma, represents one of the most therapeutically challenging tumors, with a median survival of only 12–14 months despite trimodal therapy. In our integrative large-scale study, we used genomics, transcriptomics, epigenomics, and proteomics to investigate and make sense of the molecular changes that activate or inhibit the EGFR-PI3K-AKT-mTOR signaling pathway. Different pathohistological types of diffuse brain gliomas harbored distinct changes. A better understanding of signaling pathway regulation helps to the discovery of new targets for glioma therapies. Our results have potential for diagnostics improvement and tailored therapies.

Abstract

Diffuse gliomas are a heterogeneous group of tumors with aggressive biological behavior and a lack of effective treatment methods. Despite new molecular findings, the differences between pathohistological types still require better understanding. In this in silico analysis, we investigated AKT1, AKT2, AKT3, CHUK, GSK3β, EGFR, PTEN, and PIK3AP1 as participants of EGFR-PI3K-AKT-mTOR signaling using data from the publicly available cBioPortal platform. Integrative large-scale analyses investigated changes in copy number aberrations (CNA), methylation, mRNA transcription and protein expression within 751 samples of diffuse astrocytomas, anaplastic astrocytomas and glioblastomas. The study showed a significant percentage of CNA in PTEN (76%), PIK3AP1 and CHUK (75% each), EGFR (74%), AKT2 (39%), AKT1 (32%), AKT3 (19%) and GSK3β (18%) in the total sample. Comprehensive statistical analyses show how genomics and epigenomics affect the expression of examined genes differently across various pathohistological types and grades, suggesting that genes AKT3, CHUK and PTEN behave like tumor suppressors, while AKT1, AKT2, EGFR, and PIK3AP1 show oncogenic behavior and are involved in enhanced activity of the EGFR-PI3K-AKT-mTOR signaling pathway. Our findings contribute to the knowledge of the molecular differences between pathohistological types and ultimately offer the possibility of new treatment targets and personalized therapies in patients with diffuse gliomas.

Biological Role of AKT and Regulation of AKT Signaling Pathway by Thymoquinone: Perspectives in Cancer Therapeutics

BACKGROUND

AKT/PKB is an important enzyme with numerous biological functions, and its overexpression is related to carcinogenesis. AKT stimulates different signaling pathways that are downstream of activated tyrosine kinases and phosphatidylinositol 3-kinase, hence functions as an important target for anti-cancer drugs.

OBJECTIVE

In this review article, we have interpreted the role of AKT signaling pathway in cancer and the natural inhibitory effect of Thymoquinone (TQ) in AKT and its possible mechanisms.

METHOD

We have collected the updated information and data on AKT, its role in cancer and the inhibitory effect of TQ in AKT signaling pathway from Google Scholar, PubMed, Web of Science, Elsevier, Scopus, and many more.

RESULTS

Many drugs are already developed, which can target AKT, but very few among them have passed clinical trials. TQ is a natural compound, mainly found in black cumin, which has been found to have potential anti-cancer activities. TQ targets numerous signaling pathways, including AKT, in different cancers. In fact, many studies revealed that AKT is one of the major targets of TQ. The preclinical success of TQ suggests its clinical studies on cancer.

CONCLUSION

This review article summarizes the role of AKT in carcinogenesis, its potent inhibitors in clinical trials, and how TQ acts as an inhibitor of AKT and TQ's future as a cancer therapeutic drug.

Synergistic combination therapy of lung cancer using lipid-layered cisplatin and oridonin co-encapsulated nanoparticles

Lung cancer treatment using cisplatin (DDP) in combination with other drugs are effective for the treatment of non-small cell lung cancer (NSCLC). The aim of this study was to prepare a layer-by-layer nanoparticles (NPs) for the co-loading of DDP and oridonin (ORI) and to evaluate the antitumor activity of the system in vitro and in vivo. Novel DDP and ORI co-loaded layer-by-layer NPs (D/O-NPs) were constructed. The mean diameter, surface change stability and drug release behavior of NPs were evaluated. In vitro cytotoxicity of D/O-NPs was investigated against DDP resistant human lung cancer cell line (A549/DDP cells), and in vivo anti-tumor efficiency of D/O-NPs was tested on mice bearing A549/DDP cells xenografts. D/O-NPs have a diameter of 139.6 ± 4.4 nm, a zeta potential value of +13.8 ± 1.6 mV. D/O-NPs could significantly enhance in vitro cell toxicity and in vivo antitumor effect against A549/DDP cells and lung cancer animal model compared to the single drug loaded NPs and free drugs. The results demonstrated that the D/O-NPs could be used as a promising lung cancer treatment system.

Identification of ferroptosis as a novel mechanism for antitumor activity of natural product derivative a2 in gastric cancer

Ferroptosis is a type of cell death accompanied by iron-dependent lipid peroxidation, thus stimulating ferroptosis may be a potential strategy for treating gastric cancer, therapeutic agents against which are urgently required. Jiyuan oridonin A (JDA) is a natural compound isolated from Jiyuan Rabdosia rubescens with anti-tumor activity, unclear anti-tumor mechanisms and limited water solubility hamper its clinical application. Here, we showed a2, a new JDA derivative, inhibited the growth of gastric cancer cells. Subsequently, we discovered for the first time that a2 induced ferroptosis. Importantly, compound a2 decreased GPX4 expression and overexpressing GPX4 antagonized the anti-proliferative activity of a2. Furthermore, we demonstrated that a2 caused ferrous iron accumulation through the autophagy pathway, prevention of which rescued a2 induced ferrous iron elevation and cell growth inhibition. Moreover, a2 exhibited more potent anti-cancer activity than 5-fluorouracil in gastric cancer cell line-derived xenograft mice models. Patient-derived tumor xenograft models from different patients displayed varied sensitivity to a2, and GPX4 downregulation indicated the sensitivity of tumors to a2. Finally, a2 exhibited well pharmacokinetic characteristics. Overall, our data suggest that inducing ferroptosis is the major mechanism mediating anti-tumor activity of a2, and a2 will hopefully serve as a promising compound for gastric cancer treatment.

Novel Mechanistic Observations and NES-Binding Groove Features Revealed by the CRM1 Inhibitors Plumbagin and Oridonin

The protein chromosome region maintenance 1 (CRM1) is an important nuclear export factor and drug target in diseases such as cancer and viral infections. Several plant-derived CRM1 inhibitors including plumbagin and oridonin possess potent antitumor activities. However, their modes of CRM1 inhibition remain unclear. Here, a multimutant CRM1 was engineered to enable crystallization of these two small molecules in its NES groove. Plumbagin and oridonin share the same three conjugation sites in CRM1. In solution, these two inhibitors targeted more CRM1 sites and inhibited its activity through promoting its aggregation, in addition to directly targeting the NES groove. While the plumbagin-bound NES groove resembles the NES-bound groove state, the oridonin complex reveals for the first time a more open NES groove. The observed greater NES groove dynamics may improve cargo loading through a "capture-and-tighten" mechanism. This work thus provides new insights on the mechanism of CRM1 inhibition by two natural products and a structural basis for further development of these or other CRM1 inhibitors.

Targeting the NLRP3 Inflammasome as a New Therapeutic Option for Overcoming Cancer

Inflammasomes are multiprotein complexes that regulate the maturation and secretion of the proinflammatory cytokines interleukin-1beta (IL-1β and interleukin-18 (IL-18) in response to various intracellular stimuli. As a member of the inflammasomes family, NLRP3 is the most studied and best characterized inflammasome and has been shown to be involved in several pathologies. Recent findings have made it increasingly apparent that the NLRP3 inflammasome may also play a central role in tumorigenesis, and it has attracted attention as a potential anticancer therapy target. In this review, we discuss the role of NLRP3 in the development and progression of cancer, offering a detailed summary of NLRP3 inflammasome activation (and inhibition) in the pathogenesis of various forms of cancer. Moreover, we focus on the therapeutic potential of targeting NLRP3 for cancer therapy, emphasizing how understanding NLRP3 inflammasome-dependent cancer mechanisms might guide the development of new drugs that target the inflammatory response of tumor-associated cells.

Knockdown of NOLC1 Inhibits PI3K-AKT Pathway to Improve the Poor Prognosis of Esophageal Carcinoma

Objective

Esophageal carcinoma (ESCA) is a common malignant gastrointestinal tumor. The abnormal expression of NOLC1 is involved in the tumorigenesis of various human tumors, whereas the function and mechanism of NOLC1 in ESCA remain unclear. In this study, we explored the relationship between NOLC1 and poor prognosis of ESCA, and its role and mechanism in the occurrence of ESCA.

Methods

The NOLC1 expression in ESCA tissues and cell lines was determined by qRT-PCR, immunohistochemistry, or western blot. The Kaplan–Meier method was conducted to estimate the overall survival. Cox regression analysis was carried out to examine the association between patient characteristics and prognosis. A recombined lentiviral vector containing NOLC1 was applied for transfecting ESCA cells (Eca109 and TE-13) and established a stable cell line with low NOLC1 expression or high NOLC1 expression, in the absence or presence of PI3K inhibitor (LY294002) treatment. Cell proliferation, apoptosis rate, invasion ability, migration ability, and PI3K/AKT pathway were detected by CCK8 assay, flow cytometry, Transwell assay, wound-healing assay, and western blot.

Results

NOLC1 overexpression was observed in ESCA tissues and ESCA cell lines (EC9706, Eca109, TE-13, Kyse170, T.TN) compared with adjacent normal tissues and normal esophageal cell line HEEC. NOLC1 overexpression was markedly associated with bigger tumor size, lymph node metastasis, and advanced TNM stage. Patients with NOLC1 overexpression have shorter overall survival than that of those with low NOLC1 expression. NOLC1 overexpression was considered to be an independent poor prognostic factor affecting overall survival. NOLC1 knockdown inhibited proliferation, migration, invasion, and cyclin B1 expression and promoted the apoptosis and cleaved-caspase-3 expression of Eca109 and TE-13 cells. NOLC1 overexpression accelerated proliferation, migration, invasion, and cyclin B1 expression and inhibited the apoptosis and cleaved-caspase-3 expression of ESCA cells via activating PI3K/AKT pathway. Rescue experiments showed that PI3K inhibitor (LY294002) could reverse the phenomenon caused by NOLC1 overexpression.

Conclusion

NOLC1 may be a marker for poor prognosis. It can participate in the occurrence and development of ESCA via the PI3K/AKT pathway.

Patient-derived xenograft: a developing tool for screening biomarkers and potential therapeutic targets for human esophageal cancers

Esophageal cancer (EC) represents a human malignancy, diagnosed often at the advanced stage of cancer and resulting in high morbidity and mortality. The development of precision medicine allows for the identification of more personalized therapeutic strategies to improve cancer treatment. By implanting primary cancer tissues into immunodeficient mice for expansion, patient-derived xenograft (PDX) models largely maintain similar histological and genetic representations naturally found in patients' tumor cells. PDX models of EC (EC-PDX) provide fine platforms to investigate the tumor microenvironment, tumor genomic heterogeneity, and tumor response to chemoradiotherapy, which are necessary for new drug discovery to combat EC in addition to optimization of current therapeutic strategies for EC. In this review, we summarize the methods used for establishing EC-PDX models and investigate the utilities of EC-PDX in screening predictive biomarkers and potential therapeutic targets. The challenge of this promising research tool is also discussed.

Costunolide suppresses melanoma growth via the AKT/mTOR pathway in vitro and in vivo

Melanoma is the most common type of skin cancer and its incidence is rapidly increasing. AKT, and its related signaling pathways, are highly activated in many cancers including lung, colon, and esophageal cancers. Costunolide (CTD) is a sesquiterpene lactone that has been reported to possess neuroprotective, anti-inflammatory, and anti-cancer properties. However, the target and mechanism underlying its efficacy in melanoma have not been identified. In this study, we elucidated the mechanism behind the anti-cancer effect of CTD in melanoma in vitro and in vivo by identifying CTD as an AKT inhibitor. We first verified that p-AKT and AKT are highly expressed in melanoma patient tissues and cell lines. CTD significantly inhibited the proliferation, migration, and invasion of melanoma cells including SK-MEL-5, SK-MEL-28, and A375 that are overexpressed p-AKT and AKT proteins. We investigated the mechanism of CTD using a computational docking modeling, pull-down, and site directed mutagenesis assay. CTD directly bound to AKT thereby arresting cell cycle at the G1 phase, and inducing the apoptosis of melanoma cells. In addition, CTD regulated the G1 phase and apoptosis biomarkers, and inhibited the expression of AKT/mTOR/GSK3b/p70S6K/4EBP cascade proteins. After reducing AKT expression in melanoma cells, cell growth was significantly decreased and CTD did not showed further inhibitory effects. Furthermore, CTD administration suppressed tumor growth and weight in cell-derived xenograft mice models in vivo without body weight loss and inhibited the expression of Ki-67, p-AKT, and p70S6K in tumor tissues. In summary, our study implied that CTD inhibited melanoma progression in vitro and in vivo. In this study, we reported that CTD could affect melanoma growth by targeting AKT. Therefore, CTD has considerable potential as a drug for melanoma therapy.

Oridonin interferes with simple steatosis of liver cells by regulating autophagy

Oridonin has significant liver-protective effects, but its effect on liver steatosis has not been reported. We investigated the effects of oridonin on liver steatosis by cell cultures. The optimal experimental concentration of oridonin was determined through cytotoxicity experiments. A simple steatosis liver cell model was induced using free fatty acids (FFA). After adding oridonin to the FFA-induced cell model for 24 h, the lipid droplets and triglyceride (TG) content in the cells were measured by Oil Red O staining and TG kits. The expressions of autophagy-related markers (cyclin dependent kinases inhibitor 1a (p21), Beclin-1, microtubule-associated protein light chain 3 (LC3)-I and LC3-II, protein kinase B (AKT), phosphorylated-AKT (p-AKT), AMP-activated protein kinase (AMPK), and phosphorylated-AMPK (p-AMPK)) were detected by Western blot. Based on the results, the cell model was further treated by autophagy inhibitor 3-methyladenine (3-MA) to determine the degree of steatosis and the expressions of autophagy-related factors. Oridonin at a concentration higher than 10 μmol/L caused cytotoxicity to the cells. Adding 10 μmol/L oridonin to the FFA-induced cell model effectively reduced lipid droplets and TG content in the cells. Oridonin up-regulated p21, Beclin-1 and LC3-II expressions, but down-regulated those of p62 and LC3-I. Also, oridonin increased the ratios of LC3-II/LC3-I and p-AMPK/AMPK, but reduced that of p-AKT/AKT. With the addition of 3-MA, the effect of oridonin on reducing steatosis was partially reversed, and the autophagy was inhibited. This study found that oridonin can activate autophagy, thereby preventing simple steatosis of liver cells.

Virtual Screening of Natural Compounds as Potential PI3K-AKT1 Signaling Pathway Inhibitors and Experimental Validation

A computational screening for natural compounds suitable to bind the AKT protein has been performed after the generation of a pharmacophore model based on the experimental structure of AKT1 complexed with IQO, a well-known inhibitor. The compounds resulted as being most suitable from the screening have been further investigated by molecular docking, ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) analysis and toxicity profiles. Two compounds selected at the end of the computational analysis, i.e., ZINC2429155 (also named STL1) and ZINC1447881 (also named AC1), have been tested in an experimental assay, together with IQO as a positive control and quercetin as a negative control. Only STL1 clearly inhibited AKT activation negatively modulating the PI₃K/AKT pathway.

Role of Phytochemicals in Perturbation of Redox Homeostasis in Cancer

Over the past few decades, research on reactive oxygen species (ROS) has revealed their critical role in the initiation and progression of cancer by virtue of various transcription factors. At certain threshold values, ROS act as signaling molecules leading to activation of oncogenic pathways. However, if perturbated beyond the threshold values, ROS act in an anti-tumor manner leading to cellular death. ROS mediate cellular death through various programmed cell death (PCD) approaches such as apoptosis, autophagy, ferroptosis, etc. Thus, external stimulation of ROS beyond a threshold is considered a promising therapeutic strategy. Phytochemicals have been widely regarded as favorable therapeutic options in many diseased conditions. Over the past few decades, mechanistic studies on phytochemicals have revealed their effect on ROS homeostasis in cancer. Considering their favorable side effect profile, phytochemicals remain attractive treatment options in cancer. Herein, we review some of the most recent studies performed using phytochemicals and, we further delve into the mechanism of action enacted by individual phytochemicals for PCD in cancer.

2,6-DMBQ suppresses cell proliferation and migration via inhibiting mTOR/AKT and p38 MAPK signaling pathways in NSCLC cells

2,6-Dimethoxy-1,4-benzoquinone (2,6-DMBQ) is the major bioactive compound found in fermented wheat germ extract. Although fermented wheat germ extract has been reported to show anti-proliferative and anti-metabolic effects in various cancers, the anticancer potential and molecular mechanisms exerted by 2,6-DMBQ have not been investigated in non-small cell lung cancer (NSCLC) cells. Here, we report that 2,6-DMBQ suppresses NSCLC cell growth and migration through inhibiting activation of AKT and p38 MAPK. 2,6-DMBQ significantly suppressed anchorage-dependent and independent cell growth. Additionally, 2,6-DMBQ induced G2 phase cell cycle arrest through inhibiting the expression and phosphorylation of cyclin B1 and CDC2, respectively. Furthermore, 2,6-DMBQ strongly suppressed NSCLC cell migration through induction of E-cadherin expression. To determine the molecular mechanism(s) exerted by 2,6-DMBQ upon NSCLC cell lines, various signaling kinases were screened; the results indicate that 2,6-DMBQ strongly inhibits the phosphorylation of AKT and p38 MAPK. Additionally, the growth kinetics of cells treated with an AKT or p38 MAPK inhibitor in combination with 2,6-DMBQ indicate that 2,6-DMBQ suppresses NSCLC cell growth and migration through inhibition of AKT and p38 MAPK. Taken together, our results suggest that 2,6-DMBQ is a potential anticancer reagent against NSCLC cells and could be useful for treating lung cancer patients.

Integrating Network Pharmacology and Experimental Validation to Investigate the Mechanisms of Huazhuojiedu Decoction to Treat Chronic Atrophic Gastritis

Background

Chronic atrophic gastritis (CAG) is an important stage in the normal gastric mucosa's transformation into gastric cancer. Huazhuojiedu decoction (HZJD), a Chinese herbal preparation, has proven clinically effective to treat CAG. However, few studies have explored the mechanism of HZJD in CAG treatment.

Purpose

This study aimed to shed light on the mechanisms underlying HZJD decoction CAG treatment using a network pharmacology approach and experimental validation.

Methods

The active components of HZJD decoction were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. Their targets were predicted through the SwissTargetPrediction database. Disease targets were screened using the GeneCards database. The disease and drug prediction targets were intersected to select the common potential therapeutic targets, which then were input into the Search Tool for the Retrieval of Interacting Genes to build a protein-protein interaction network. The “herb-compound-target-disease” and the “herb-target-pathway” network diagrams were constructed in Cytoscape 3.3.0. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of effective targets were performed using the Database for Annotation, Visualization, and Integrated Discovery. Finally, the core targets were preliminarily verified by CAG rat model. The gastric mucosa's histopathological changes were observed via hematoxylin-eosin staining. The expressions of MAPK1, AKT1, TNF, VEGFA, and EGFR were detected by western blot and quantitative real-time reverse transcription-polymerase chain reaction.

Results

A total of 155 nodes, including 20 putative targets of HZJD decoction, were selected as core hubs based on topological importance and were closely associated with the regulation of cell proliferation, apoptotic process, and cancer-related pathways (AKT1, TNF, VEGFA, and EGFR) in CAG. Further animal experiments showed that the expression of AKT1 in CAG rats was significantly increased, which was suppressed by HZJD decoction. TNF and VEGFA expression increased in the model group, but did not change in the HZJD group. MAPK1 and EGFR expression showed no significant differences among control, model, and HZJD groups.

Conclusion

Taken together, the results suggest that the components of HZJD decoction can alleviate and prevent the severity of gastric precancerous lesions via AKT1 inhibition in CAG.

Oridonin Sensitizes Hepatocellular Carcinoma to the Anticancer Effect of Sorafenib by Targeting the Akt Pathway

Background

Oridonin is the core bioactive component of Rabdosia rubescens, a traditional Chinese herbal medicine used in the treatment of hepatoma. Sorafenib, a targeted therapeutic agent for advanced hepatocellular carcinoma (HCC), has recently been shown to exert limited clinical effects. However, few studies have focused on the synergistic effect of these two drugs on hepatocellular carcinoma.

Methods

We treated different HCC cell lines with different concentrations of oridonin and sorafenib and assessed the viability by using MTT assays and examined proliferation, migration, invasion and apoptosis after cotreatment of HepG2 cells with 20 μM oridonin and 5 μM sorafenib via colony formation assays, Transwell assays and flow cytometry. Regulatory effects were measured by Western blotting. The in vivo synergistic effect was confirmed through xenograft tumor models, and tumor tissues were analyzed by immunohistochemistry.

Results

The inhibitory effects of oridonin and sorafenib cotreatment on HCC cells were stronger than those of either drug alone. In addition, combined treatment with the two drugs synergistically inhibited epithelial–mesenchymal transition and the Akt pathway but not NF-κB or MAPK signaling. Akt phosphorylation by SC79 reversed the inhibitory effects of the combined treatment. Synergistic inhibition was equally observed in vivo.

Conclusion

Oridonin combined with sorafenib synergistically inhibited proliferation, migration, invasion, and epithelial–mesenchymal transition and induced apoptosis by targeting the Akt pathway but not NF-κB or MAPK signaling.

Proteomics Reveal the Inhibitory Mechanism of Levodopa Against Esophageal Squamous Cell Carcinoma

High recurrence rates and poor survival of patients with esophageal squamous cell carcinoma (ESCC) after treatment make ongoing research on chemoprevention drugs for ESCC particularly important. In this study, we screened a large number of FDA-approved drugs and found levodopa, a drug used to treat Parkinson's disease, had an inhibitory effect on the growth of ESCC cells. To elucidate the molecular mechanisms involved, we applied quantitative proteomics to investigate the anti-tumor activity of levodopa on ESCC. The results suggest that levodopa could down-regulate oxidative phosphorylation, non-alcoholic fatty liver disease, and Parkinson's disease pathways. Major mitochondrial respiratory compounds were involved in the pathways, including succinate dehydrogenase subunit D, NADH-ubiquinone oxidoreductase Fe-S protein 4, and mitochondrial cytochrome c oxidase subunit 3. Down-regulation of these proteins was associated with mitochondrial dysfunction. Western blotting and immunofluorescence results confirmed the proteomics findings. Cell viability assays indicated mitochondrial activity was suppressed after levodopa treatment. Reduced mitochondrial membrane potential was detected using JC-1 staining and TMRE assays. Transmission electron microscopy revealed changes in the morphology of mitochondria. Taken together, these results indicate that levodopa inhibited the growth of ESCC through restraining mitochondria function.

Alternative Options for Skin Cancer Therapy via Regulation of AKT and Related Signaling Pathways

Global environmental pollution has led to human exposure to ultraviolet (UV) radiation due to the damaged ozone layer, thereby increasing the incidence and death rate of skin cancer including both melanoma and non-melanoma. Overexpression and activation of V-akt murine thymoma viral oncogene homolog (AKT, also known as protein kinase B) and related signaling pathways are major factors contributing to many cancers including lung cancer, esophageal squamous cell carcinoma and skin cancer. Although BRAF inhibitors are used to treat melanoma, further options are needed due to treatment resistance and poor efficacy. Depletion of AKT expression and activation, and related signaling cascades by its inhibitors, decreases the growth of skin cancer and metastasis. Here we have focused the effects of AKT and related signaling (PI3K/AKT/mTOR) pathways by regulators derived from plants and suggest the need for efficient treatment in skin cancer therapy.

Oridonin inhibits hypoxia-induced epithelial-mesenchymal transition and cell migration by the hypoxia-inducible factor-1α/matrix metallopeptidase-9 signal pathway in gallbladder cancer

Hypoxia has crucial roles in cancer development and progression. Our previous study indicated that cell migration was increased in a hypoxic microenvironment in GBC-SD gallbladder cancer (GBC) cells. Oridonin, a bioactive diterpenoid compound that is isolated from the plant Rabdosia rubescens, has been identified as an anticancer agent in various types of cancer. However, its roles in cell proliferation, apoptosis, and migration in a hypoxic microenvironment and the associated regulatory mechanisms have not yet to be fully elucidated in GBC. The present study investigated the effect of oridonin on cell proliferation, apoptosis, the cell cycle and cell migration in GBC in vitro and in vivo. Furthermore, the role of oridonin in hypoxia-induced cell migration and its underlying mechanisms were explored in GBC. The results indicated that treatment with oridonin significantly suppressed cell proliferation and the metastatic ability of GBC-SD cells in a dose-dependent manner, increased the level of cell apoptosis and induced cell cycle arrest at the G0/G1 phase. Further experiments demonstrated that oridonin could inhibit hypoxia-induced epithelial-mesenchymal transition and cell migration by downregulating the expression levels of hypoxia-inducible factor (HIF)-1α/matrix metallopeptidase (MMP)-9. In addition, oridonin suppressed GBC cell growth and downregulated the expression levels of HIF-1α and MMP-9 in a GBC-SD cell xenograft model. Taken together, these results suggest that oridonin possesses anticancer properties in GBC. Notably, oridonin can suppress tumor epithelial-mesenchymal transition and cell migration by targeting the HIF-1α/MMP-9 signaling pathway.

OP16 induces deadly autophagy and apoptosis of cells by inhibiting Akt in esophageal squamous cell carcinoma

BACKGROUND

OP16, a derivative of the novel ent-kaurene diterpenoid compound separated from Rabdosia rubescens, has been confirmed for its efficacy and safety in the treatment of esophageal squamous cell carcinoma (ESCC) in our previous study. However, the precise mechanisms of tumor lethality mediated by OP16 have not yet been fully characterized.

AIMS

To investigate the effects and molecular mechanism of OP16 on autophagy and apoptosis of ESCC cells.

METHODS

Effects and mechanism of OP16 on autophagy of ESCC cells were first detected by Western blot, immunofluorescence, mRFP-GFP-LC3 adenovirus infection and transmission electron microscope. Next, function of autophagy and apoptosis induced by OP16 on cell death was investigated by flow cytometry and CCK-8 assay. Finally, molecular mechanism of OP16 affecting autophagy and apoptosis of ESCC cells was explored by Western blot.

RESULTS

We demonstrated that OP16 could induce autophagy by promoting the formation of autophagosome and autolysosome, and promote autophagic cell death in ESCC. Furthermore, we also found that OP16 could promote cell apoptosis by activating mitochondria apoptosis pathway in ESCC. Finally, we demonstrated that OP16 affecting autophagy and mitochondria apoptosis pathway was mediated by phosphorylation of Akt.

CONCLUSION

Our data show that OP16 could promote cell death through affecting autophagy and mitochondria apoptosis pathway mediated by Akt in ESCC, which enriches the theoretical mechanism of anti-tumor effects of OP16 and provides a basis for treatment of OP16 on ESCC.

Oridonin induces ferroptosis by inhibiting gamma-glutamyl cycle in TE1 cells

Oridonin (Ori) is a natural tetracyclic diterpenoid active compound with excellent antitumor activity, but the mechanism of Ori on esophageal cancer cell, TE1, remains unclear. In this study, we examined the levels of intracellular iron, malondialdehyde, and reactive oxygen species after Ori treatment, while interfering with the effects of Ori with ferroptosis inhibitor, demonstrating that Ori's inhibition of TE1 cell proliferation is associated with ferroptosis. To understand the molecular mechanism of Ori, we performed UPLC-MS/MS metabolomics profiling on TE1 cells, which show that gamma-glutamyl amino acids (gamma-glutamylleucine, gamma-glutamylvaline), 5-oxoproline, glutamate, GSH, and GSSG are changed significantly after Ori treatment. Meanwhile, the activity of gamma-glutamyl transpeptidase 1 (GGT1) decreased. This revealed that Ori inhibited the gamma-glutamyl cycle in TE1 cells. Furthermore, we found that Ori can covalently bind to cysteine to form the conjugate oridonin-cysteine (Ori-Cys), resulting in the inhibition of glutathione synthesis, which is consistent with the decrease in the enzymatic activity of glutamate cysteine ligase catalytic subunit (GCLC). Eventually, the value of intracellular GSH/GSSG was reduced, and the enzymatic activity of the glutathione peroxidase 4 (GPX4) was significantly decreased. In conclusion, our experiments indicated that Ori can inhibit the gamma-glutamyl cycle, thereby inducing ferroptosis to exert anti-cancer activity.