Macrophage hitchhiking for systematic suppression in postablative multifocal HCC.

BACKGROUND AND AIMS: HCC, particularly the multifocal HCC, features aggressive invasion and dismal prognosis. Locoregional treatments were often refractory to eliminate tumor tissue, resulting in residual tumor cells persisting and subsequent progression. Owing to problematic delivery to the tumor tissue, systemic therapies, such as lenvatinib (LEN) therapy, show limited clinical benefit in preventing residual tumor progression. Therefore, more advanced strategies for postablative multifocal HCC are urgently needed. APPROACH AND RESULTS: Motivated by the chemotaxis in tumor penetration of macrophages, we report a strategy named microinvasive ablation-guided macrophage hitchhiking for the targeted therapy toward HCC. In this study, the strategy leverages the natural inflammatory gradient induced by ablation to guide LEN-loaded macrophages toward tumor targeting, which increased by ~10-fold the delivery efficiency of LEN in postablative HCC in vivo. Microinvasive ablation-guided macrophage hitchhiking has demonstrated significant antitumor activity in various HCC models, including the hydrodynamic tail vein injection multifocal HCC mouse model and the orthotopic xenograft HCC rabbit model, systematically inhibiting residual tumor progression after ablation and prolonging the median survival of tumor-bearing mice. The potential antitumor mechanism was explored using techniques such as flow cytometry, ELISA, and immunohistochemistry. We found that the strategy significantly suppressed tumor cell proliferation and neovascularization, and such enhanced delivery of LEN stimulated systemic immune responses and induced durable immune memory. CONCLUSIONS: The macrophage hitchhiking strategy demonstrates exceptional therapeutic efficacy and biosafety across various species, offering promising prospects for clinical translation in controlling residual tumor progression and improving outcomes following HCC ablation.

Combination of Anti-PD-1 and Electroacupuncture Induces a Potent Antitumor Immune Response in Microsatellite-Stable Colorectal Cancer.

Programmed death receptor-1 (PD-1) inhibitors are ineffective against microsatellite-stable (MSS) colorectal cancer. Electroacupuncture (EA) has oncosuppressive and immunomodulatory properties. Here, we investigated the antitumor effects of EA and explored the feasibility of EA combined with anti-PD-1 in MSS colorectal cancer. Results showed that EA exerted its antitumor effect in an intensity-specific manner, and moderate-intensity EA (1.0 mA) induced maximal tumor inhibition. EA enhanced antitumor immune responses by increasing lymphocytes and granzyme B (GzmB) levels, as well as activating the stimulator of IFN genes (STING) pathway. EA combined with anti-PD-1 showed superior efficacy compared with either monotherapy in multiple MSS colorectal cancer mouse models. Single-cell RNA sequencing revealed that cotreatment reprogrammed the tumor immune microenvironment (TIME), as characterized by enhancement of cytotoxic functions. Mechanically, we found that the potentiated effect of EA was dependent upon the STING pathway. Collectively, EA reshapes the TIME of MSS colorectal cancer and sensitizes tumors to anti-PD-1 in a STING pathway-dependent manner. These results provide a mechanistic rationale for using EA as an immunomodulatory strategy to improve the clinical efficacy of anti-PD-1 in MSS colorectal cancer. EA is safe, well-tolerated, and feasible for clinical translation as a promising strategy for treating MSS colorectal cancer.

Inhibition of autophagy promotes sonodynamic therapy-induced apoptosis of pancreatic cancer cells.

INTRODUCTION: Sonodynamic therapy (SDT), a promising non-invasive therapeutic modality, has attracted increasing attention in the treatment of pancreatic cancer (PC). At present, the role of autophagy in SDT of PC remains unclear. This study aims to explore the role of autophagy in SDT of PC and its effect on apoptosis of PC cells. MATERIAL AND METHODS: PC cells (Capan-1 and BxPC-3) underwent incubation with 5-aminolevulinic acid (5-ALA) or/and ultrasound (US) exposure (control, 5-ALA, US, and SDT groups), followed by measurement of cell apoptosis and autophagy. Specifically, cell viability, apoptosis, and the expression of apoptosis-related proteins (cleaved Caspase-3, Bax, and Bcl-2) were measured using CCK-8 assay, flow cytometry, and western blot analysis, respectively. The mitochondrial morphology was observed with the transmission electron microscopy, accompanied by the detection of autophagosome marker (LC3) co-located with Mito and the protein expression of LC3II/I. Before SDT treatment, the autophagy inhibitor 3-MA and the apoptosis inhibitor z-VAD were respectively added to PC cell cultures to evaluate the effects of autophagy inhibition on apoptosis and apoptosis inhibition on autophagy in PC cells. RESULTS: Compared with the control group, cell viability was inhibited and cell apoptosis and autophagy were enhanced in the SDT group, while cell viability, autophagy, and apoptosis in the 5-ALA and US groups were not significantly changed. Moreover, 3-MA treatment inhibited autophagy and accelerated apoptosis, whereas z-VAD treatment reduced apoptosis but did not affect autophagy in PC cells. CONCLUSIONS: Autophagy was activated in SDT-treated PC cells, and inhibition of autophagy promoted cell apoptosis in PC cells.

Integrated single-cell and bulk RNA sequencing analyses reveal a prognostic signature of cancer-associated fibroblasts in head and neck squamous cell carcinoma.

Objectives: To identify a prognosis-related subtype of cancer-associated fibroblasts (CAFs) in head and neck squamous cell carcinoma (HNSCC) and comprehend its contributions to molecular characteristics, immune characteristics, and their potential benefits in immunotherapy and chemotherapy for HNSCC. Materials and Methods: We performed single-cell RNA sequencing (scRNA-seq) analysis of CAFs from the samples of HNSCC patients derived from Gene Expression Omnibus (GEO), to identify the prognosis-related subtype of CAFs. CAFs were clustered into five subtypes, and a prognosis-related subtype was identified. Univariate and multivariate cox regression analyses were performed on the cohort selected from The Cancer Genome Atlas (TCGA) to determine signature construction, which was validated in GSE65858 and GSE42743. A prognostic signature based on 4 genes was constructed, which were derived from prognosis-related CAFs. The molecular characteristics, immune characteristics as well as the predicted chemosensitivity and immunotherapeutic response in the signature-defined subgroups were analyzed subsequently. Results: The patients with higher CAF scores correlated with poor survival outcomes. Additionally, a high CAF score correlated with lower infiltration levels of many immune cells including M1 macrophages, CD8+ T cells, follicular T helper cells, monocytes, and naïve B cells. High CAF score also demonstrated different enrichment pathways, mutation genes and copy number variated genes. Furthermore, patients with high CAF scores showed lower sensitivity for chemotherapy and immunotherapy than those with low CAF scores. Conclusion: The results of our study indicate the potential of the CAF signature as a biomarker for the prognosis of HNSCC patients. Furthermore, the signature could be a prospective therapeutic target in HNSCC.

Thermal-Responsive MXene-DNA Hydrogel for Near-Infrared Light Triggered Localized Photothermal-Chemo Synergistic Cancer Therapy.

Stimuli-responsive DNA hydrogels are promising candidates for cancer treatment, as they not only possess biocompatible and biodegradable 3D network structures as highly efficient carriers for therapeutic agents but also are capable of undergoing programmable gel-to-solution transition upon external stimuli to achieve controlled delivery. Herein, a promising platform for highly efficient photothermal-chemo synergistic cancer therapy is established by integrating DNA hydrogels with Ti3 C2 TX -based MXene as a photothermal agent and doxorubicin (DOX) as a loaded chemotherapeutic agent. Upon the irradiation of near-infrared light (NIR), temperature rise caused by photothermal MXene nanosheets triggers the reversible gel-to-solution transition of the DOX-loaded MXene-DNA hydrogel, during which the DNA duplex crosslinking structures unwind to release therapeutic agents for efficient localized cancer therapy. Removal of the NIR irradiation results in the re-formation of DNA duplex structures and the hydrogel matrix, and the recombination of free DOX and adaptive hydrogel transformations can also be achieved. As demonstrated by both in vitro and in vivo models, the MXene-DNA hydrogel system, with excellent biocompatibility and injectability, dynamically NIR-triggered drug delivery, and enhanced drug uptake under mild hyperthermia conditions, exhibits efficient localized cancer treatment with fewer side effects to the organisms.

Green walnut husk extracts Proliferation and Migration in Gastric Cancer.

Background: In the past few decades, natural products have become an increasingly important source of potential anti-cancer agents. The green walnut husk(GWH) extracts have been reported to inhibit multiple tumor cells and might be a promising chemopreventive agent in human neoplasia. However, it is not clear whether GWH extracts inhibit gastric cancer. Methods: Proliferation, invasion, and migration of gastric cancer cells were assessed by the CCK-8, wound-healing, and Transwell assay. The apoptotic rate was detected by flow cytometry(FCM). The expressions of Bcl-2, Bax, and Caspase-3 proteins were examined by Western blot. Moreover, the growth of gastric cancer cells was assessed using orthotopic xenograft models, and related proteins expressions were evaluated using immunohistochemistry. Finally, the Gene expression profile of gastric cancer treated with GWH extracts was evaluated by using High-throughput RNA sequencing(RNA-seq). Results: GWH extracts effectively inhibited gastric cancer cell growth in vitro and in vivo. In vivo, GWH extracts inhibited the survival of gastric cancer cells in a dose and time-dependent manner, inhibited the migration and invasion of gastric cancer cells, regulated the expressions of apoptosis-related proteins, and induced apoptosis of gastric cancer cells. In vitro, GWH extracts inhibited the growth of mouse xenografted tumors. A total of differentially expressed genes, of which 41 genes were up-regulated, and 610 genes were down-regulated, were identified by RNA-seq. GO, and KEGG analysis showed that these differentially expressed genes might be related to the mechanism of the anti-gastric cancer effect of GWH extracts. Conclusion: GWH extracts played an anti-gastric cancer effect by inducing apoptosis and inhibiting invasion. Secondly, the differential expression of many genes, multiple signal pathways, and metabolic pathways in gastric cancer play an essential role in the anti-gastric cancer effect of GWH extracts. The results suggested that GWH extracts are expected to be a low toxic drug for the treatment of gastric cancer in the future.

LncRNA UCA1 mediates Cetuximab resistance in Colorectal Cancer via the MiR-495 and HGF/c-MET Pathways.

Background: Cetuximab is one of the most widely used monoclonal antibodies to treat patients with RAS/BRAF wild-type metastatic colorectal cancer (mCRC). Unfortunately, cetuximab resistance often occurs during targeted therapy. However, the underlying epigenetic mechanisms remain unclear. Our previous study demonstrated that the exosomal transfer of urothelial carcinoma-associated 1 (UCA1) confers cetuximab resistance to CRC cells. The goal of this study was to elucidate the detailed role of UCA1 in cetuximab resistance in CRC and the underlying molecular mechanism. Methods: In vitro and in vivo functional studies were performed to assess the role of UCA1 in cetuximab resistance in CRC cell lines and xenograft models. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to examine UCA1 localization and expression. Bioinformatics analysis was performed to predict the potential mechanism of UCA1, which was further validated by the dual-luciferase reporter assay and the RNA immunoprecipitation (RIP) assay. Cells treated with indicators were subjected to Cell Counting Kit-8 (CCK-8) and western blotting to investigate the role of hepatocyte growth factor (HGF)/c-mesenchymal-epithelial transition (c-MET) signalling in UCA1-mediated cetuximab resistance. Results: We showed that UCA1 decreased CRC cell sensitivity to cetuximab by suppressing apoptosis. Mechanistic studies revealed that UCA1 promoted cetuximab resistance by competitively binding miR-495 to facilitate HGF and c-MET expression in CRC cells. Moreover, HGF was shown to attenuate the cetuximab-induced inhibition of cell proliferation by activating the HGF/c-MET pathway in CRC cells. Conclusion: We provide the first evidence of a UCA1-miR-495-HGF/c-MET regulatory network involved in cetuximab resistance in CRC. Therefore, UCA1 has potential as a predictor and therapeutic target for cetuximab resistance.

Suppression of CHOP Reduces Neuronal Apoptosis and Rescues Cognitive Impairment Induced by Intermittent Hypoxia by Inhibiting Bax and Bak Activation.

Our previous study showed that growth arrest- and DNA damage-inducible gene 153 (GAD153/CHOP) plays an important role in intermittent hypoxia- (IH-) induced apoptosis and impaired synaptic plasticity. This study is aimed at determining which signaling pathway is activated to induce CHOP and the role of this protein in mitochondria-dependent apoptosis induced by IH. In the in vivo study, mice were placed in IH chambers for 8 h daily over a period of 2 weeks; the IH chambers had oxygen (O2) concentrations that oscillated between 10% and 21%, cycling every 90 s. In the in vitro study, PC12 cells were exposed to 21% O2 (normoxia) or 8 IH cycles (25 min at 21% O2 and 35 min at 0.1% O2 for each cycle). After 2 weeks of IH treatment, we observed that the expression levels of phosphorylated protein kinase-like endoplasmic reticulum kinase (p-PERK), activating transcription factor 4 (ATF-4) and phosphorylated eukaryotic initiation factor 2 alpha (p-elf2α), were increased, but the levels of activating transcription factor 6 (ATF-6) and inositol-requiring enzyme 1 (IRE-1) were not increased. GSK2606414, a specific chemical inhibitor of the PERK pathway, reduced the expression of p-PERK, ATF-4, p-elf2α, and CHOP and rescued ER structure. In addition, Bax and Bak accumulated in the mitochondria after IH treatment, which induced cytochrome c release and initiated apoptosis. These effects were prevented by GSK2606414 and CHOP shRNA. Finally, the impaired long-term potentiation and long-term spatial memory in the IH group were rescued by GSK2606414. Together, the data from the in vitro and in vivo experiments indicate that IH-induced apoptosis and impaired synaptic plasticity were mediated by the PERK-ATF-4-CHOP pathway. Suppressing PERK-ATF-4-CHOP signaling pathway attenuated mitochondria-dependent apoptosis by reducing the expression of Bax and Bak in mitochondria, which may serve as novel adjunct therapeutic strategy for ameliorating obstructive sleep apnea- (OSA-) induced neurocognitive impairment.

Therapeutic impact of thymoquninone to alleviate ischemic brain injury via Nrf2/HO-1 pathway.

Introduction: Reactive oxygen species (ROS)-mediated inflammation plays a crucial role in ischemic brain injury. Therefore, the activation of the nuclear erythroid 2 related protein and heme-oxygenase-1 (Nrf2/HO-1) pathway by thymoquinone (TQ) could ameliorate ischemic brain damage.Areas covered: The photo-thrombotic method was employed to assess the impact of TQ in attenuating ischemic brain damage in C57BL/6 J mice and thy1-YFP-16 transgenic mice. In vitro study of TQ efficiency to attenuate the oxygen-glucose deprivation/reoxygenation (OGD/R) induced cell death by fluorescence-activated cell sorting (FACs) analysis was also analyzed. The protein expression levels of Nrf2/HO-1, inflammatory, and apoptotic were evaluated by immunofluorescence and western blot techniques. Besides, mRNA expression level of inducible nitric oxide synthase (iNOS), proto-oncogene (c-MYC), proto-oncogene (c-FOS), 5-hydroxytryptamine receptors (5-HT), and autophagy-related 5 (Atg5) were evaluated by RT-qPCR. The dendritic spine density of YFP slices was determined by confocal microscope.Results: Our in vivo and in vitro results indicated that TQ significantly mitigates brain damage and motor dysfunction after ischemic stroke. These observations coincided with curtailed cell death, inflammation, oxidative stress, apoptosis, and autophagy. Most importantly, Nrf2/HO-1 signaling pathway activation by TQ was vital in the modulation of the above processes. Lastly, we found TQ to have minimal toxicity in liver tissue.Conclusion: Our study gives credence to TQ as a promising intervention therapy for cerebral ischemia that decreases inflammation, oxidative stress, and neuronal cell death via the Nrf2/HO-1 pathway, along with modulation of apoptotic and autophagic processes.

Hypoxia Inducible Factor-1α Attenuates Ischemic Brain Damage by Modulating Inflammatory Response and Glial Activity.

Hypoxia-inducible factor 1 can sufficiently control the progress of neurological symptoms after ischemic stroke owing to their actions associated with its downstream genes. In this study, we evaluated the role of HIF-1α in attenuating brain damage after endothelin-1 injection. Focal cerebral ischemia in mice were induced by endothelin-1 microinjection. Hypoxia-inducible factor 1 activator, dimethyloxalylglycine (DMOG), and HIF-1α inhibitor, acriflavine (ACF), were used to evaluate the hypoxia-inducible factor 1 activity during cerebral ischemia. The expression levels of HIF-1α, glial fibrillary acidic protein (GFAP), interleukin-10 (IL-10), inducible nitric oxide synthase (iNOS), phosphorylated I-kappa-B-alpha/total I-kappa-B-alpha (p-IκBα/IκBα) and nuclear factor kappa B (NF-kB) were assessed. Besides, mRNA levels of IL-10, tumor necrosis factor- alpha (TNF-α), and NF-kB were also analyzed. Results showed a noticeable increase in hypoxia-inducible factor 1 and IL-10 levels in the DMOG group with a decline in iNOS, TNF-α, and NF-kB levels, implying the anti-inflammatory role of hypoxia-inducible factor 1 activator following stroke. These findings were further corroborated by GFAP immunostaining that showed astrocytic activation to be inhibited 12 days post-ischemia, as well as histological and TEM analyses that demonstrated hypoxia-inducible factor 1 induction to alleviate neuronal soma damage and cell death. Based on our study, HIF-1α could be a potential therapeutic target for ischemic stroke.

Combinational Pretreatment of Colony-Stimulating Factor 1 Receptor Inhibitor and Triptolide Upregulates BDNF-Akt and Autophagic Pathways to Improve Cerebral Ischemia.

Ki20227, a selective inhibitor of colony-stimulating factor 1 receptor (CSF1R), has been suggested to regulate microglia inflammatory function and neuronal synaptic plasticity. Triptolide (TP) pretreatment has neuroprotective effects through its anti-inflammatory and antiapoptotic features in ischemic stroke mice. However, the underlying mechanism and pathway are presently unclear. We thus investigated the association between neuroprotective effects of combined TP and Ki20227 and BDNF-Akt and autophagy pathways. Ki20227 was administrated for 7 days, and TP was administered once 24 hours prior to building the ischemic stroke model in C57BL/6 mice. Behavioral tests, Golgi staining, immunofluorescence, and western blot analyses were employed to examine neuroprotective effects of TP and Ki20227. TP and Ki20227 pretreatments improved the neurobehavioral function in stroke mice. Synaptic protein expressions and density of dendritic spine density were upregulated in Ki20227 and TP pretreated stroke mice. Further, optimized integration of TP and Ki20227 pretreatments upregulated the NeuN expression and downregulated Iba1 expression after stroke. In addition, both TP and Ki20227 pretreatments significantly upregulated BDNF, p-Akt/Akt, and Erk1/2 protein expressions and autophagy related proteins (LC3II/I, Atg5, and p62), indicating the activation of BDNF and autophagic pathways. Optimized integration of TP and Ki20227 can improve cerebral ischemia by inhibiting CSF1R signal and trigger autophagy and BDNF-Akt signaling pathways to increase dendritic spine density and synaptic protein expressions, which in turn enhances neurobehavioral function.

Smart Bilayer Polyacrylamide/DNA Hybrid Hydrogel Film Actuators Exhibiting Programmable Responsive and Reversible Macroscopic Shape Deformations.

As a crucial instinct for the survival of organisms, adaptive smart deformation has been well shown via profusely astounding examples within biological morphogenesis in nature, which inspired the construction of biomimetic shape-morphing materials with controlled actuating behaviors. Herein, the construction of nature-inspired bilayer hydrogel film actuators, composed of a polyacrylamide hydrogel passive layer and a polyacrylamide-DNA hybrid hydrogel active layer, which exhibited programmable stimuli-responsive and reversible macroscopic shape deformations directed by the sequence of DNA crosslinking units in the active layer, is reported. As a proof-of-concept, the introduction of DNA i-motif based crosslinking structures into the active layer, which can undergo pH-stimulated formation and dissociation of crosslinking between polymers and therefore change the crosslinking density of the active layer, lead to the redistribution of the internal stresses within the bilayer structure, and result in the pH-stimulated shape deformations. By programming the sequence of DNA units in the active layer, a Ag+ /Cysteamine-stimulated bilayer DNA hybrid hydrogel film actuator is further constructed and exhibits excellent actuation behaviors. Thanks to the micrometer-scale thickness of the films, these actuators exhibit a high degree of macroscopic and reversible shape deformations at high speed, which may find use in future smart biosensing and biomedical applications.

Dihydroartemisinin represses esophageal cancer glycolysis by down-regulating pyruvate kinase M2.

Esophageal cancer, especially esophageal squamous cell carcinoma (ESCC) threatens so many lives in China every year. Traditional treatment of ESCC has usually been disappointing. The development of novel therapy is worth investigation. We have previously demonstrated that dihydroartemisinin (DHA) has anticancer effect on esophageal cancer. However, the mechanism has not been completely known. In this present study, we explored the effect of DHA on cancer cell glycolysis, also known as Warburg effect. Pyruvate kinase M2 (PKM2) is a key regulatory factor of glycolysis, and our results showed that it is significantly overexpressed in patients with ESCC and ESCC cell lines. In DHA treatment cells, PKM2 was down-regulated and lactate product and glucose uptake were inhibited. Overexpression of PKM2 by lentiviral transfection abrogated the inhibition effect of DHA. These results suggested that DHA might repress esophageal cancer glycolysis partly by down-regulating PKM2 expression. We believe that DHA might be a prospective agent against esophageal cancer.

Progesterone and fluoxetine treatments of postpartum depressive-like behavior in rat model.

Research studies have indicated that alterations in plasma progesterone levels might be associated with the hippocampal synaptic plasticity of postpartum depressive-like behavior. Herein, we assess both progesterone and fluoxetine effects in adult female Sprague-Dawley rats with postpartum depressive-like behavior. Depressive-like behavior of postpartum rats was established using chronic ultra-mild stress (CUMS) method for 1 week from gestation day 15. Postpartum rats that showed depressive-like behavior were treated with either progesterone (subcutaneously, 0.5 mg/kg) from gestation day 17 to gestation day 22 or fluoxetine (by gavage, 10 mg/kg/day) for 4 weeks after birth. Open field and sucrose preference tests were conducted at the start, week 2 and week 4 postpartum. Golgi staining, immunofluorescence and Western blot analyses of rats' hippocampi were conducted on week 4 postpartum. Results showed CUMS increases depressive-like behavior, however, treatment with progesterone and fluoxetine improves this behavior. Both progesterone and fluoxetine treatments increase the numbers of dendritic spines pyramidal neurons in the CA3 region of the hippocampus as well as protein expression levels of microtubule-associated protein 2 (MAP-2) and synaptophysin (SYP). CUMS-induced decrement of MAP-2 and SYP protein expressions can be prevented by treatment with progesterone in advanced pregnant stage and fluoxetine in the postpartum period.

Predictive role of UCA1-containing exosomes in cetuximab-resistant colorectal cancer.

BACKGROUND: Primary or acquired resistance to cetuximab often occurs during targeted therapy in metastatic colorectal cancer (mCRC) patients. In many cancers, the key role of the long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) in anticancer drug resistance has been confirmed. Emerging evidence has shown that specific exosomal lncRNAs may serve as meaningful biomarkers. In this study, we hypothesize that exosomal UCA1 might predict the response to cetuximab in CRC patients. METHODS: First, acquired cetuximab-resistant cell lines were generated, and UCA1 expressions in these cells and their exosomes were compared. We also systematically evaluate the stability of exosomal UCA1. Thereafter, the predictive value of exosomal UCA1 in CRC patients treated with cetuximab was evaluated. Finally, through cell apoptosis assays and immunofluorescence staining, we analyzed the role of UCA1-containing exosomes in conferring cetuximab resistance. RESULTS: UCA1 expression was markedly higher in cetuximab-resistant cancer cells and their exosomes. Exosomal UCA1 was shown to be detectable and stable in serum from CRC patients. In addition, circulating UCA1-containing exosomes could predict the clinical outcome of cetuximab therapy in CRC patients, and UCA1 expression was considerably higher in the progressive disease/stable disease patients than in the partial response/complete response patients. Furthermore, exosomes derived from cetuximab-resistant cells could alter UCA1 expression and transmit cetuximab resistance to sensitive cells. CONCLUSIONS: We discovered a novel role of UCA1-containing exosomes, showed their capability to transmit drug resistance and investigated their potential clinical use in predicting cetuximab resistance.

Dihydroartemisinin Increases the Sensitivity of Photodynamic Therapy Via NF-κB/HIF-1α/VEGF Pathway in Esophageal Cancer Cell in vitro and in vivo.

BACKGROUND/AIMS: Although photodynamic therapy (PDT) can relieve esophageal obstruction and prolong survival time of patients with esophageal cancer, it can induce nuclear factor-kappa B (NF-κB) activation in many cancers, which plays a negative role in PDT. Dihydroartemisinin (DHA), the most potent artemisinin derivative, can enhance the effect of PDT on esophageal cancer cells. However, the mechanism is still unclear. METHODS: We generated stable cell lines expressing the super-repressor form of the NF-κB inhibitor IκBα and cell lines with lentivirus vector-mediated silencing of the HIF-1α gene. Esophageal xenograft tumors were created by subcutaneous injection of Eca109 cells into BALB/c nude mice. Four treatment groups were analyzed: a control group, photosensitizer alone group, light alone group, and PDT group. NF-κB expression was detected by an electrophoretic mobility shift assay, hypoxia-inducible factor α (HIF-1α) and vascular endothelial growth factor (VEGF) by real-time PCR, NF-κB, HIF-1α, and VEGF protein by western blot, and Ki-67, HIF-1α, VEGF, and NF-κB protein by immunohistochemistry. RESULTS: PDT increased NF-κB activity and the gene expression of HIF-1α and VEGF in vitro and in vivo. In contrast, the DHA groups, particularly the combined DHA and PDT treatment group, abolished the effect. The combined treatment significantly inhibited tumor growth in vitro and in vivo. NF-κB activity and HIF-1α expression were also reduced in the stable IκBα expression group, whereas the former showed no change in HIF-1α-silenced cells. CONCLUSION: DHA might increase the sensitivity of esophageal cancer cells to PDT by inhibiting the NF-κB/HIF-1α/VEGF pathway.

siRNA-mediated inactivation of HER3 improves the antitumour activity and sensitivity of gefitinib in gastric cancer cells.

The human EGFR family consists of four type-1 transmembrane tyrosine kinase receptors: HER1 (EGFR, ErbB1), HER2 (Neu, ErbB2), HER3 (ErbB3), and HER4 (ErbB4). HER3 can dimerize with EGFR, HER2 and even c-Met and likely plays a central role in the response to EGFR-targeted therapy. Because HER3 lacks significant kinase activity and cannot be inhibited by tyrosine kinase inhibitors, neutralizing antibodies and alternative inhibitors of HER3 have been sought as cancer therapeutics. Here, we describe the stable suppression of HER3 mRNA and protein using siRNA. The inhibition of HER3 expression decreased cell proliferation, suppressed cell cycle progression, induced apoptosis and inhibited cell motility, migration, invasiveness, and soft agar growth. In addition, we found that gefitinib treatment increased the HER3 and HER2 mRNA levels. The administration of various concentrations of gefitinib to HER3-knockdown cells enhanced antitumour activity and sensitivity due to the downregulation of protein phosphorylation via PI3K/AKT and ERK signalling. Our results support the use of combined treatments targeting multiple EGFR receptors, particularly the use of HER3 inhibitors combined with EGFR inhibitors, such as gefitinib.

Initiation of apoptosis, cell cycle arrest and autophagy of esophageal cancer cells by dihydroartemisinin.

Dihydroartemisinin (DHA) has recently been shown anti-tumor activity in various cancer cells. However, its effect on esophageal cancer remains unclear. In this study, for the first time, we demonstrated that DHA reduced viability of esophageal cancer cells in a dose-dependent manner. The mechanism was at least partially due to DHA induced apoptosis by upregulating the expression of Bax, downregulating Bcl-2, Bcl-xL and Procaspase-3, and increasing caspase-9 activation, induced cell cycle arrest by downregulating cyclin E, CDK2 and CDK4. Furthermore, we firstly found that DHA induced autophagy in cancer cells. We concluded DHA might be a novel agent against esophageal cancer.