Gambogenic acid inhibits fibroblast growth factor receptor signaling pathway in erlotinib-resistant non-small-cell lung cancer and suppresses patient-derived xenograft growth

Unveiling Gambogenic Acid as a Promising Antitumor Compound: A Review

Gambogenic acid is a derivative of gambogic acid, a polyprenylated xanthone isolated from Garcinia hanburyi. Compared with the more widely studied gambogic acid, gambogenic acid has demonstrated advantages such as a more potent antitumor effect and less systemic toxicity than gambogic acid according to early investigations. Therefore, the present review summarizes the effectiveness and mechanisms of gambogenic acid in different cancers and highlights the mechanisms of action. In addition, drug delivery systems to improve the bioavailability of gambogenic acid and its pharmacokinetic profile are included. Gambogenic acid has been applied to treat a wide range of cancers, such as lung, liver, colorectal, breast, gastric, bladder, and prostate cancers. Gambogenic acid exerts its antitumor effects as a novel class of enhancer of zeste homolog 2 inhibitors. It prevents cancer cell proliferation by inducing apoptosis, ferroptosis, and necroptosis and controlling the cell cycle as well as autophagy. Gambogenic acid also hinders tumor cell invasion and metastasis by downregulating metastasis-related proteins. Moreover, gambogenic acid increases the sensitivity of cancer cells to chemotherapy and has shown effects on multidrug resistance in malignancy. This review adds insights for the prevention and treatment of cancers using gambogenic acid.

Design, synthesis, and biological evaluation of gambogenic acid derivatives: Unraveling their anti-cancer effects by inducing pyroptosis

Gambogenic acid (GNA), a caged xanthone derived from Garcinia hanburyi, exhibits a wide range of anti-cancer properties. The caged skeleton of GNA serves as the fundamental pharmacophore responsible for its antitumor effects. However, limited exploration has focused on the structural modifications of GNA. This study endeavors to diversify the structure of GNA and enhance its anti-cancer efficacy. Sulfoximines, recognized as pivotal motifs in medicinal chemistry due to their outstanding properties, have featured in several anti-cancer drugs undergoing clinical trials. Accordingly, a series of 33 GNA derivatives combined with sulfoximines were synthesized and evaluated for their anti-cancer effects against MIAPaCa2, MDA-MB-231, and A549 cells in vitro. The activity screening led to the identification of compound 12k, which exhibited the most potent anti-cancer effect. Mechanistic studies revealed that 12k primarily induced pyroptosis in MIAPaCa2 and MDA-MB-231 cells by activating the caspase-3/gasdermin E (GSDME) pathway. These findings suggested that 12k is a promising drug candidate in cancer therapy and highlighted the potential of sulfoximines as a valuable functional group in drug discovery.

Naturally Occurring Xanthones; Biological Activities, Chemical Profiles and In Silico Drug Discovery

Xanthones are widely distributed polyphenols, present commonly in higher plants; Garcinia, Calophyllum, Hypericum, Platonia, Mangifera, Gentiana and Swertia. Xanthone tricyclic scaffold is able to interact with different biological targets, showing antibacterial and cytotoxic effects, as well as potent effects against osteoarthritis, malaria, and cardiovascular diseases. Thus, in this article we focused on pharmacological effects, applications and preclinical studies with the recent updates of xanthon´s isolated compounds from 2017-2020. We found that only α-mangostin, gambogic acid, and mangiferin, have been subjected to preclinical studies with particular emphasis on the development of anticancer, diabetes, antimicrobial and hepatoprotective therapeutics. Molecular docking calculations were performed to predict the binding affinities of xanthone-derived compounds against SARS-CoV-2 M^pro. According to the results, cratoxanthone E and morellic acid demonstrated promising binding affinities towards SARS-CoV-2 M^pro with docking scores of -11.2 and -11.0 kcal/mol, respectively. Binding features manifested the capability of cratoxanthone E and morellic acid to exhibit nine and five hydrogen bonds, respectively, with the key amino acids of the M^pro active site. In conclusion, cratoxanthone E and morellic acid are promising anti-COVID-19 drug candidates that warrant further detailed in vivo experimental estimation and clinical assessment.

The mechanism and application of traditional Chinese medicine extracts in the treatment of lung cancer and other lung-related diseases

Lung cancer stands as one of the most prevalent malignancies worldwide, bearing the highest morbidity and mortality rates among all malignant tumors. The treatment of lung cancer primarily encompasses surgical procedures, radiotherapy, and chemotherapy, which are fraught with significant side effects, unfavorable prognoses, and a heightened risk of metastasis and relapse. Although targeted therapy and immunotherapy have gradually gained prominence in lung cancer treatment, diversifying the array of available methods, the overall recovery and survival rates for lung cancer patients remain suboptimal. Presently, with a holistic approach and a focus on syndrome differentiation and treatment, Traditional Chinese Medicine (TCM) has emerged as a pivotal player in the prognosis of cancer patients. TCM possesses characteristics such as targeting multiple aspects, addressing a wide range of concerns, and minimizing toxic side effects. Research demonstrates that Traditional Chinese Medicine can significantly contribute to the treatment or serve as an adjunct to chemotherapy for lung cancer and other lung-related diseases. This is achieved through mechanisms like inhibiting tumor cell proliferation, inducing tumor cell apoptosis, suppressing tumor angiogenesis, influencing the cellular microenvironment, regulating immune system function, impacting signal transduction pathways, and reversing multidrug resistance in tumor cells. In this article, we offer an overview of the advancements in research concerning Traditional Chinese Medicine extracts for the treatment or adjunctive chemotherapy of lung cancer and other lung-related conditions. Furthermore, we delve into the challenges that Traditional Chinese Medicine extracts face in lung cancer treatment, laying the foundation for the development of diagnostic, prognostic, and therapeutic targets.

Gambogenic acid induces cell death in human osteosarcoma through altering iron metabolism, disturbing the redox balance, and activating the P53 signaling pathway

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents with extremely poor prognosis. Gambogenic acid (GNA), one of the major bioactive ingredients isolated from Gamboge, has been shown to possess a multipotent antitumor effect, its activity on OS remains unclear yet. In this study, we found that GNA could trigger multiple cell death modalities, including ferroptosis and apoptosis in human OS cells, reduce the cell viability, inhibit the proliferation and invasiveness. Furthermore, GNA provoked oxidative stress leading to GSH depletion-inducing ROS generation and lipid peroxidation, altered iron metabolism represented by the induction of labile iron, mitochondrial membrane potential decreased, mitochondrial morphological changed, decreased the cell viability. In addition, ferroptosis inhibitors (Fer-1) and apoptosis inhibitors (NAC) can partially reversed GNA' s effects on OS cells. Further investigation showed that GNA augmented the expression of P53, bax, caspase 3 and caspase 9 and decreased the expression of Bcl-2, SLC7A11 and glutathione peroxidase-4 (GPX4). In vivo, GNA was showed to delay tumor growth significantly in axenograft osteosarcoma mouse model. In conclusion, this study reveals that GNA simultaneously triggers ferroptosis and apoptosis in human OS cells by inducing oxidative stress via the P53/SLC7A11/GPX4 axis.

EZH1/2 as targets for cancer therapy

The enhancer of zeste homolog 2 (EZH2) and its highly related homolog EZH1 are considered to be epigenetic silencing factors, and they play key roles in the growth and differentiation of cells as the core components of polycomb repressive complex 2 (PRC2). EZH1 and EZH2 are known to have a role in human malignancies, and alterations in these two genes have been implicated in transformation of human malignancies. Inhibition of EZH1/2 has been shown to result in tumor regression in humans and has been studied and evaluated in the preclinical setting and in multiple clinical trials at various levels. Our work thus contributes to the understanding of the relationship between regulatory molecules associated with EZH1/2 proteins and tumor progression, and may provide new insights for mechanism-based EZH1/2-targeted therapy in tumors.

Gambogenic acid induces apoptosis and autophagy through ROS-mediated endoplasmic reticulum stress via JNK pathway in prostate cancer cells

Prostate cancer (PCa) is the most common malignant tumor in males, which frequently develops into castration-resistant prostate cancer (CRPC) with limited therapies. Gambogenic acid (GNA), a flavonoids compound isolated from Gamboge, exhibits anti-tumor capacity in various cancers. Our results showed that GNA revealed not only antiproliferative and pro-apoptotic activities but also the induction of autophagy in PCa cells. In addition, autophagy inhibitor chloroquine enhanced the pro-apoptosis effect of GNA. Moreover, the activation of JNK pathway and the induction of apoptosis and autophagy triggered by GNA were attenuated by JNK inhibitor SP600125. We also found that GNA significantly promoted reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress. Meanwhile, suppressing ER stress with 4-phenylbutyric acid (4-PBA) markedly blocked the activation of JNK pathway induced by GNA. Further research indicated that ROS scavenger N-acetyl-L-cysteine (NAC) effectively abrogated ER stress and JNK pathway activation induced by GNA. Furthermore, NAC and 4-PBA significantly reversed GNA-triggered apoptosis and autophagy. Finally, GNA remarkably suppressed prostate tumor growth with low toxicity in vivo. In conclusion, the present study revealed that GNA induced apoptosis and autophagy through ROS-mediated ER stress via JNK signaling pathway in PCa cells. Thus, GNA might be a promising therapeutic drug against PCa.

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.

Gambogenic acid alleviates kidney fibrosis via epigenetic inhibition of EZH2 to regulate Smad7-dependent mechanism

BACKGROUND

Epigenetics regulating gene expression plays important role in kidney fibrosis. Natural products originating from diverse sources including plants and microorganisms are capable to influence epigenetic modifications. Gambogenic acid (GNA) is a caged xanthone extracted from gamboge resin, exudation of Garcinia hanburyi Hook.f., and the effect of GNA on kidney fibrosis with its underlying mechanism on epigenetics remains unknown.

PURPOSE

This study aimed to explore the role of GNA against kidney fibrogenesis by histone methylation mediating gene expression.

METHODS

Two experimental mice of unilateral ureteral obstruction (UUO) and folic acid (FA) were given two dosages of GNA (3 and 6 mg/kg/d). TGF-β1 was used to stimulate mouse tubular epithelial (TCMK-1) cells and siRNAs were transfected to verify the underlying mechanisms of GNA. Histological changes were evaluated by HE, MASSON stainings, immunohistochemistry and immunofluorescence. Western blot and qPCR were used to measure protein/gene transcription levels.

RESULTS

GNA dose-dependently alleviated UUO-induced kidney fibrosis and FA-induced kidney early fibrosis, indicated by the pathology and fibrotic factor changes (α-SMA, collagen I, collagen VI, and fibronectin). Mechanically, GNA reduced enhancer of zeste homolog 2 (EZH2) and H3K27me3, promoted Smad7 transcription, and inhibited TGF-β/Smad3 fibrotic signaling in injured kidneys. Moreover, with TGF-β1-induced EZH2 increasing, GNA suppressed α-SMA, fibronectin and collagen levels in tubular epithelial TCMK-1 cells. Although partially decreasing EZH2, GNA did not influence fibrotic signaling in Smad7 siRNA-transfected TCMK-1 cells.

CONCLUSION

Epigenetic inhibition of EZH2 by GNA ameliorated kidney fibrogenesis via regulating Smad7-meidated TGF-β/Smad3 signaling.

Meta analysis of bioactive compounds, miRNA, siRNA and cell death regulators as sensitizers to doxorubicin induced chemoresistance

Cancer has presented to be the most challenging disease, contributing to one in six mortalities worldwide. The current treatment regimen involves multiple rounds of chemotherapy administration, alone or in combination. The treatment has adverse effects including cardiomyopathy, hepatotoxicity, and nephrotoxicity. In addition, the development of resistance to chemo has been attributed to cancer relapse and low patient overall survivability. Multiple drug resistance development may be through numerous factors such as up-regulation of drug transporters, drug inactivation, alteration of drug targets and drug degradation. Doxorubicin is a widely used first line chemotherapeutic drug for a myriad of cancers. It has multiple intracellular targets, DNA intercalation, adduct formation, topoisomerase inhibition, iron chelation, reactive oxygen species generation and promotes immune mediated clearance of the tumor. Agents that can sensitize the resistant cancer cells to the chemotherapeutic drug are currently the focus to improve the clinical efficiency of cancer therapy. This review summarizes the recent 10-year research on the use of natural phytochemicals, inhibitors of apoptosis and autophagy, miRNAs, siRNAs and nanoformulations being investigated for doxorubicin chemosensitization.

Signaling Pathway and Small-Molecule Drug Discovery of FGFR: A Comprehensive Review

Targeted therapy is a groundbreaking innovation for cancer treatment. Among the receptor tyrosine kinases, the fibroblast growth factor receptors (FGFRs) garnered substantial attention as promising therapeutic targets due to their fundamental biological functions and frequently observed abnormality in tumors. In the past 2 decades, several generations of FGFR kinase inhibitors have been developed. This review starts by introducing the biological basis of FGF/FGFR signaling. It then gives a detailed description of different types of small-molecule FGFR inhibitors according to modes of action, followed by a systematic overview of small-molecule-based therapies of different modalities. It ends with our perspectives for the development of novel FGFR inhibitors.

Nuclear Targeted Peptide Combined With Gambogic Acid for Synergistic Treatment of Breast Cancer

As a natural compound, gambogic acid (GA) emerged a shining multi-target antitumor activity in a variety of tumors. Whereas its poor solubility and non-specific effect to tumor blocked the clinical application of this drug. Herein, we reported a simple and effective strategy to construct liposome modified with nuclear targeted peptide CB5005N (VQRKRQKLMPC) via polyethylene glycol (PEG) linker to decrease the inherent limitations of GA and promote its anti-tumor activity. In this study, liposomes were prepared by thin film hydration method. The characterization of formulations contained particle size, Zeta potential, morphology and encapsulation efficiency. Further, in vitro cytotoxicity and uptake tests were investigated by 4T1 and MDA-MB-231 cells, and nuclear targeting capability was performed on MDA-MB-231 cells. In addition, the in vivo antitumor effect and biological distribution of formulations were tested in BALB/c female mice. The GA-loaded liposome modified by CB5005N showed small size, good uniformity, better targeting, higher anti-tumor efficiency, better tumor inhibition rate and lower toxicity to normal tissues than other groups. In vitro and in vivo research proved that CB5005N-GA-liposome exhibited excellent anti-tumor activity and significantly reduced toxicities. As a result, CB5005N-GA-liposome nano drug delivery system enhanced the tumor targeting and antitumor effects of GA, which provided a basis for its clinical application.

Gambogenic Acid Induces Endoplasmic Reticulum Stress in Colorectal Cancer via the Aurora A Pathway

Colorectal cancer (CRC) is one of the most common malignancies in the world and has a poor prognosis. In the present research, gambogenic acid (GNA), isolated from the traditional Chinese medicine gamboge, markedly induced apoptosis and inhibited the proliferation of CRC in vitro and in vivo. Furthermore, GNA triggered endoplasmic reticulum (ER) stress, which subsequently activated inositol-requiring enzyme (IRE) 1α and the eukaryotic translation initiation factor (eIF) 2α pathway. Pretreatment with salubrinal (an eIF2α inhibitor) rescued GNA-induced cell death. Furthermore, GNA downregulated the expression of Aurora A. The Aurora A inhibitor alisertib decreased ER stress. In human colorectal adenocarcinoma tissue, Aurora A was upregulated compared to normal colorectal epithelial nuclei. Furthermore, GNA ameliorated mouse colitis-associated cancer models. Our findings demonstrated that GNA significantly inhibited the proliferation of CRC through activation of ER stress by regulating Aurora A, which indicates the potential of GNA for preventing the progression of CRC.

Traditional Chinese medicine reverses cancer multidrug resistance and its mechanism

Chemotherapy is one of the most commonly used clinical treatments among the currently available cancer therapies. However, the phenomenon of Multidrug resistance (MDR) has become a challenge in the treatment process, weakening the impact of chemotherapy. Extensive research on elucidating the development of cancer MDR has identified the following mechanisms that play a critical role in the development of several MDR reversal agents: abnormal expression of cell membrane transporters, adaptation of cancer cells to the microenvironment, regulation of hypoxia, repair of DNA damage and reduction of apoptosis, the enhancement of the EMT process, the existence of cancer stem cells (CSCs), and the abnormal activation of key signaling pathways. However, they failed to demonstrate significant efficacy due to severe side effects during their clinical trials. Traditional Chinese medicines (TCMs) are known to play an important anti-cancer role since they have low toxicity, high efficacy, and safety and can reverse MDR. TCMs reversal agents can be divided into Chinese medicine monomers, synthetic monomers, analogs, or derivatives. Several studies have shown that TCMs can effectively overcome cancer MDR and can be effectively used for treating cancer patients.

Medicinal herbs and bioactive compounds overcome the drug resistance to epidermal growth factor receptor inhibitors in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related mortality worldwide. Non-small cell lung cancer (NSCLC) accounts for ~85% of all lung cancer cases. Patients harboring epidermal growth factor receptor (EGFR) mutations usually develop resistance to treatment with frontline EGFR-tyrosine kinase inhibitors (EGFR-TKIs). The present review summarizes the current findings and delineates the molecular mechanism of action for the therapeutic effects of herbal extracts and phytochemicals in overcoming EGFR-TKI resistance in NSCLC. Novel molecular targets underlying EGFR-TKI resistance in NSCLC are also discussed. This review provides valuable information for the development of herbal bioactive compounds as alternative treatments for EGFR-TKI-resistant NSCLC.

EGFR mutation mediates resistance to EGFR tyrosine kinase inhibitors in NSCLC: From molecular mechanisms to clinical research

With the development of precision medicine, molecular targeted therapy has been widely used in the field of cancer, especially in non-small-cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) is a well-recognized and effective target for NSCLC therapies, targeted EGFR therapy with EGFR-tyrosine kinase inhibitors (EGFR-TKIs) has achieved ideal clinical efficacy in recent years. Unfortunately, resistance to EGFR-TKIs inevitably occurs due to various mechanisms after a period of therapy. EGFR mutations, such as T790M and C797S, are the most common mechanism of EGFR-TKI resistance. Here, we discuss the mechanisms of EGFR-TKIs resistance induced by secondary EGFR mutations, highlight the development of targeted drugs to overcome EGFR mutation-mediated resistance, and predict the promising directions for development of novel candidates.

Oral Delivery of Gambogenic Acid by Functional Polydopamine Nanoparticles for Targeted Tumor Therapy

To enhance the water solubility, oral bioavailability, and tumor targeting of gambogenic acid (GNA), polydopamine nanoparticles (PDA NPs) were prepared to encapsulate and stabilize GNA surface modified by folic acid (FA) and then coated with sodium alginate (GNA@PDA-FA SA NPs) to achieve an antitumor effect by oral administration. GNA@PDA-FA SA NPs exhibited in vitro pH-sensitive release behavior. In vitro cell studies manifested that GNA@PDA-FA NPs had higher cytotoxicity to 4T1 cells compared with raw GNA (IC₅₀ = 2.58 μM vs 7.57 μM). After being modified with FA, GNA@PDA-FA NPs were taken up easily by 4T1 cells. In vivo studies demonstrated that the area under the curve (AUC_0→∞) of the plasma drug concentration-time of GNA@PDA-FA SA NPs was 2.97-fold higher than that of raw GNA, along with improving drug distribution in the liver, lung, and kidney tissues. In vivo anti-tumor experiments, GNA@PDA-FA SA NPs significantly inhibited the growth of breast tumors in the 4T1 xenograft breast cancer model via oral administration without obvious toxicity on major organs. Our studies indicated that the GNA@PDA-FA SA NPs modified with FA and coated with SA were a promising drug delivery system for targeting tumor therapy via oral administration.

Gambogenic acid induces Noxa-mediated apoptosis in colorectal cancer through ROS-dependent activation of IRE1α/JNK

BACKGROUND

Gambogenic acid (GNA), an active component of Garcinia hanburyi Hook.f. (Clusiaceae) (common name gamboge), exerts anti-inflammatory and antitumor properties. However, the underlying mechanism of GNA in colorectal cancer (CRC) is still not well understood.

PURPOSE

This study aimed to investigate the antitumor effects and mechanisms of GNA on CRC in vitro and in vivo.

METHODS

Cell viability, colony formation and cell apoptosis assays were performed to determine the antitumor effects of GNA. qRT-PCR and Western blotting were performed to evaluate the expression of genes or proteins affected by GNA in vitro and in vivo. HCT116 colon cancer xenografts and the APC^min/+ mice model were used to confirm the antitumor effects of GNA on CRC in vivo.

RESULTS

GNA induced Noxa-mediated apoptosis by inducing reactive oxygen species (ROS) generation and c-Jun N-terminal kinase (JNK) activation. Moreover, GNA triggered endoplasmic reticulum (ER) stress, which subsequently activated inositol-requiring enzyme-1α (IRE1α) leading to JNK phosphorylation. ROS scavenger attenuated GNA-induced IRE1α activation and JNK phosphorylation. Knockdown of IRE1α also prevented GNA-induced JNK phosphorylation. In vivo, GNA suppressed tumor growth and progression in HCT116 colon cancer xenografts and the APC^min/+ mices model.

CONCLUSION

These findings revealed that GNA induced Noxa-mediated apoptosis by activating the ROS/IRE1α/JNK signaling pathway in CRC both in vitro and in vivo. GNA is therefore a promising antitumor agent for CRC treatment.

In vitro/in vivo evaluation of pH-sensitive Gambogenic acid loaded Zein nanoparticles with polydopamine coating

As one of the active pharmaceutical ingredients in Gamboge, Gambogenic acid (GNA) has shown diverse anti-tumor activities. To reduce the vascular irritation of GNA and improve its water solubility, tumor targeting, and bioavailability, GNA loaded Zein nanoparticles (GNA@Zein NPs) was further coated by polydopamine (PDA) to develop GNA@Zein-PDA NPs by anti-solvent precipitation and surface modification. The results showed that particle size and Zeta potential of GNA@Zein-PDA NPs were about 310 nm and -40.8 mV with core-shell morphology confirmed by TEM. GNA@Zein-PDA NPs increased the water solubility of GNA by more than 700 times and showed pH-sensitive release behavior in PBS with pH 6.86. In vitro cytotoxicity tests showed that GNA@Zein-PDA NPs had higher inhibitory activity on HepG2 cells than free GNA, and their IC₅₀ were 1.59 μg/mL and 9.89 μg/mL, respectively. Additionally, the hemolysis and vascular irritation assay showed that GNA@Zein-PDA NPs had good cytocompatibility and reduced the irritation of GNA to blood vessels. Moreover, the in vivo pharmacokinetic experiments exhibited that the C_max and AUC_0-t of GNA@Zein-PDA NPs were significantly improved approximately by 2.09-fold and 3.48-fold over that of GNA, respectively. In conclusion, GNA@Zein-PDA NPs solve many defects of GNA and provide a tumor-targeting drug delivery for GNA.

Gambogenic acid suppresses bladder cancer cells growth and metastasis by regulating NF-κB signaling

BACKGROUND

Gambogenic acid (GNA) is one of the main active components of Gamboge, and its anticancer role has been reported in some cancers. The study was to investigate the inhibitory effects of GNA on the proliferation and metastasis of bladder cancer (BC) cells and its potential regulatory mechanisms.

MATERIALS AND METHODS

BC cell lines (BIU-87 cells, T24 cells, and J82 cells) were treated with different doses of GNA for different time, and then the effects of GNA on BC cell were examined in vitro using CCK-8 assay, apoptosis assays, and Transwell tests. NF-κB signaling activity was detected by the NF-κB p65 luciferase reporter assay. Western blot was used to detect the expressions of cIAP2, XIAP, Survivin, and p65.

RESULTS

GNA inhibited the viability of BC cells in vitro in a dose- and time-dependent manner and facilitated apoptosis of BC cells. Moreover, GNA could remarkably impede the migration and invasion abilities of BC cells. In terms of mechanism, GNA administration reduced the activity of NF-κB signaling and down-regulated the expressions of p65, survivin, XIAP, and cIAP2.

CONCLUSION

GNA blocks the growth and metastasis of BC cells via inhibiting the NF-κB signal transduction pathway.

A novel drug delivery system of mixed micelles based on poly(ethylene glycol)-poly(lactide) and poly(ethylene glycol)-poly(ɛ-caprolactone) for gambogenic acid

In this study, a novel mixed polymeric micelles formed from biocompatible polymers, poly(ethylene glycol)-poly(lactide) (mPEG-PLA) and poly(ethylene glycol)-poly(ɛ-caprolactone) (mPEG-PCL), used as a novel nanocarrier to encapsulate gambogenic acid (GNA). GNA-loaded mixed polymeric micelles (GNA-MMs) was prepared by cosolvent evaporation method. The mean average size of GNA-MMs was (83.23 ± 1.06) nm (n = 3) and entrapment efficiency (EE%) of GNA-MMs was (90.18 ± 2.59) % (n = 3) as well as (12.36 ± 0.64) % (n = 3) for drug loading (DL%). Transmission electron microscopy revealed that the GNA-MMs were spherical with "core-shell" structures. Compared with free GNA solution, in vitro release of GNA from GNA-MMs showed a two-phase sustained release profile: an initial relatively fast phase and followed by a slower release phase. Pharmacokinetic results also indicated that the GNA-MMs have longer systemic circulation time and slower plasma elimination rate than free GNA solution. Moreover, the in vitro cytotoxicity assay showed that the IC₅₀ values on HepG2 cells for GNA-MMs and free GNA were (5.67 ± 0.02) μM and (9.02 ± 0.03) μM, respectively. In addition, GNA-MMs significantly increased the HepG2 cellular apoptosis in a concentration-dependent manner. In conclusion, the results showed that mPEG-PLA/mPEG-PCL mixed micelles may serve as an ideal drug delivery system for GNA to prolong drug circulation time in body, enhance bioavailability and retained its potent antitumor effect.

MicroRNA-6077 enhances the sensitivity of patients-derived lung adenocarcinoma cells to anlotinib by repressing the activation of glucose transporter 1 pathway

Anlotinib is a novel molecular targeted agent targeting the vascular endothelial growth factor receptor, which differs from the other currently available non-small cell lung cancer (NSCLC) molecular targeted drugs targeting this receptor. Although the application of anlotinib may bring new hope for patients with advanced NSCLC, the cost of treatment is high. The results of this study showed that microRNA-6077 (miR-6077) represses the expression of GLUT1 (glucose transporter 1) and enhances the sensitivity of patient-derived lung adenocarcinoma (AC) cells to anlotinib. The miR-6077, which potentially binds to the 3'untranslated region of GLUT1, was identified and screened by miRDB, an online tool; sequences of miR-6077 were prepared as lentivirus particles. A549 cells (a lung adenocarcinoma cell line) and five patient-derived AC cell lines were infected with control miRNA or miR-6077, and subsequently treated with the indicated concentration of anlotinib. The expression of proteins, such as GLUT1, was determined by western blotting. The antitumor effect of anlotinib was identified through in-vitro (e.g., MTT) or in-vivo methods (e.g., subcutaneous tumor model). Overexpression of miR-6077 repressed the expression of GLUT1 and decreased the glucose uptake, lactate production, or ATP generation in AC cells. In addition, MiR-6077 may enhance the antitumor effect of anlotinib on A549 or patient-derived AC cell lines. Therefore, our results indicated that miR-6077 represses the expression of GLUT1 and enhances the sensitivity of patients-derived lung AC cells to anlotinib.

SRC and MEK Co-inhibition Synergistically Enhances the Anti-tumor Effect in Both Non-small-cell Lung Cancer (NSCLC) and Erlotinib-Resistant NSCLC

Non-small-cell lung cancer (NSCLC) is the predominant form of lung cancer, and it is regulated by a complex signal transduction network. Single-agent targeted therapy often results in acquired resistance, which leads to treatment failure. In this study, we demonstrated that a combination of the kinase inhibitors trametinib and bosutinib can synergistically suppress the growth of NSCLC by inhibiting both the mitogen-activated protein kinase (MAPK) and proto-oncogene tyrosine-protein kinase (SRC) pathways. The combination was profiled against a panel of 22 NSCLC cell lines, including one erlotinib-resistant cell line, and this combination was found to show synergistic effects against 16 cell lines. NSCLC cell lines (HCC827, HCC827-erlotinib-resistant, and H1650) were treated with trametinib, bosutinib, or a combination of these drugs. The drug combination inhibited colony formation and induced cell apoptosis. A mechanism study showed that the phosphorylation of multiple kinases in the epidermal growth factor receptor (EGFR) signaling pathway in NSCLC was down-regulated. In addition, the combination significantly attenuated tumor growth of HCC827 xenografts with low toxicity. Our findings provide a theoretical basis for further study of the combination of MAPK and SRC pathway inhibitors in NSCLC, especially in the treatment of erlotinib-resistant NSCLC.

Chinese Herbal Medicine Combined With EGFR-TKI in EGFR Mutation-Positive Advanced Pulmonary Adenocarcinoma (CATLA): A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

Background: To determine the clinical activity and safety of Chinese herbal medicine (CHM) combined with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) in patients with advanced pulmonary adenocarcinoma (ADC) and the ability of CHM combined with EGFR-TKI to activate EGFR mutations.

Methods: Three hundred and fifty-four patients were randomly assigned to EGFR-TKI (erlotinib 150 mg/d, gefitinib 250 mg/d, or icotinib 125 mg tid/d) plus CHM (TKI+CHM, N = 185) or EGFR-TKI plus placebo (TKI+placebo, N = 169). Progression-free survival (PFS) was the primary end point; the secondary end points were overall survival (OS), objective response rate (ORR), disease control rate (DCR), quality of life [Functional Assessment of Cancer Therapy-Lung (FACT-L) and Lung Cancer Symptom Scale (LCSS)], and safety.

Results: The median PFS was significantly longer for the TKI+CHM group (13.50 months; 95% CI, 11.20–16.46 months) than with the EGFR-TKI group (10.94 months; 95% CI, 8.97–12.45 months; hazard ratio, 0.68; 95% CI, 0.51–0.90; P = 0.0064). The subgroup analyses favored TKI+CHM as a first-line treatment (15.97 vs. 10.97 months, P = 0.0447) rather than as a second-line treatment (11.43 vs. 9.23 months, P = 0.0530). Patients with exon 19 deletion had a significantly longer PFS than with 21 L858R. The addition of CHM to TKI significantly improved the ORR (64.32% vs. 52.66%, P = 0.026) and QoL. Drug-related grade 1–2 adverse events were less common with TKI+CHM.

Conclusions: TKI+CHM improved PFS when compared with TKI alone in patients with EGFR mutation-positive advanced non-small-cell lung cancer (NSCLC).

Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT01745302.

TEEG Induced A549 Cell Autophagy by Regulating the PI3K/AKT/mTOR Signaling Pathway

TEEG (3β,16β,23-trihydroxy-13,28-epoxyurs-11-ene-3-O-β-D-glucopyranoside) is derived from the chloroform extract of the Chinese medicine formula Shenqi San (CE-SS). In the present study, we aimed to elucidate the anticancer effect and possible molecular mechanism underlying the action of TEEG against the human non-small cell lung cancer (NSCLC) cell line A549 in vitro. A549 cells were incubated with different concentrations of TEEG. Cell proliferation was assessed by MTT assay. Autophagy was evaluated by immunofluorescence staining. Autophagy-associated proteins were examined by Western blot analysis. TEEG markedly inhibited A549 cell proliferation in a concentration-dependent manner. Immunofluorescence staining showed that TEEG induced autophagy in A549 cells. The LC3-II : LC3-I conversion ratio and the expression of Beclin-1, Atg5, Atg7, and Atg12 increased with the concentration of TEEG. In addition, increased TEEG concentration enhanced the expression of Class III p-PI3K and reduced the expression of Class I p-PI3K, p-AKT, p-mTOR, and p-P70S6K. These results indicate that TEEG induces autophagy of A549 cells through regulation of the PI3K/AKT/mTOR signaling pathway.

[Establishment of A Patient-derived Xenotransplantation Animal Model for Small Cell Lung Cancer and Drug Resistance Model]

背景与目的

小细胞肺癌（small cell lung cancer, SCLC）是细胞分化程度低，恶性程度高，生长速度快，早期容易发生转移的恶性肿瘤。目前SCLC患者的临床治疗以化疗为主，但是在治疗6个月-9个月后极易发生获得性耐药而复发。因此，构建有效的临床前SCLC动物模型具有重要的临床价值。人源性肿瘤异种移植动物模型（patient-derived xenotransplantation, PDX）能够较好地保留原发肿瘤的特性，是比较理想的临床前动物模型。本研究旨在构建中国人来源的SCLC PDX动物模型，并诱导构建化疗耐药的PDX模型，为研究SCLC耐药机制及个体化治疗提供实验模型。

方法

取临床SCLC患者的新鲜手术切除标本或穿刺标本，移植至重度免疫缺陷小鼠NOD-PrkdcscidIL2rgtm1/Bcgen（B-NSGTM）皮下，HE染色及免疫组化对比移植肿瘤组织与患者肿瘤组织的病理学一致性。给予可稳定传代的每一代PDX模型小鼠腹腔注射8个周期的化疗药物（顺铂8 mg/kg+依托泊苷5mg/kg），定期监测荷瘤小鼠体质量和肿瘤体积，对长至1, 000 mm³大小的肿瘤进行传代移植。

结果

本研究收集并移植9例SCLC肿瘤标本，成功构建可多次传代SCLC PDX模型3例并成功诱导其耐药模型，模型较好地保留了原发肿瘤的特征。

结论

成功构建了SCLC PDX模型及其耐药模型，建模成功率为33%。为后续研究人的SCLC耐药机制、临床药物筛选以及个体化治疗提供了实验平台。

Methylseleninic Acid Suppresses Breast Cancer Growth via the JAK2/STAT3 Pathway

Previous studies show that methylseleninic acid (MSA), which is the most common selenium derivative used as a drug in humans, exerts specific cytotoxic effects in several cancer cell types. However, the complex mechanism of these effects has not been fully elucidated. Here, we demonstrate by Cell Counting Kit-8 in mouse breast cancer cell line 4T1 that MSA inhibits cell viability in a concentration-dependent (5, 10, 20 μmol/L) and time-dependent (6, 12, 24 hours) manner. Flow cytometry, Western blot, and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) analyses indicated that MSA inhibits cancer cell invasion and induces apoptosis by the activation of caspase-3, poly ADP ribose polymerase 1 (PARP1), and BCL2-associated X. Furthermore, MSA demonstrated anticancer activity by inhibiting the Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) pathway. The MSA treatment for 24 hours decreased the phosphorylation of JAK2 and STAT3 in 4T1 cells by Western blot. We also confirmed this with the use of a JAK2 chemical inhibitor, AG490, as a positive control. In a 4T1 orthotopic allograft model, morphological and TdT-mediated dUTP nick-end labeling analyses showed that MSA treatment (1.5 mg/kg/weight) for 28 days inhibits tumor growth consistent with the clinical anticancer drug cyclophosphamide. Our observations demonstrate that MSA is a potent anticancer drug in breast cancer and uncovered a key role of the JAK2/STAT3 pathway in modulating tumor growth.

Total Synthesis of Norsampsones A and B, Garcinielliptones N and O, and Hyperscabrin A

The asymmetric total synthesis of five decarbonyl polycyclic polyprenylated acylphloroglucinols norsampsnes A (3) and B (4), garcinielliptones O (5) and N (6), and hyperscabrin A (7) is described. The synthesis to construct the core substituted cyclohexanone ring of these natural products was achieved by a key Dieckmann condensation. The chirality of the molecules was introduced by the stereoselective alkylation with Evans' oxazolidinones. The synthesis could be run on grams scale, and the Dieckmann condensation was investigated through the DFT calculations to help improve the yield of garcinielliptone O (5). Determination of the absolute configuration of garcinielliptones O (5) and N (6) was also achieved.