Artesunate promoted anti-tumor immunity and overcame EGFR-TKI resistance in non-small-cell lung cancer by enhancing oncogenic TAZ degradation.

Lung cancer is the leading cause of cancer-related death worldwide. The development of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and immune checkpoint inhibitors (ICIs) has brought favorable survival benefits to patients with non-small-cell lung cancer (NSCLC); unfortunately, acquired drug resistance remains a major barrier to the treatment of NSCLC. Recent studies have demonstrated that the transcriptional co-activator with a PDZ-binding motif (TAZ, also called WWTR1) induces tumor immune evasion by directly modulating the expression of programmed death ligand 1 (PD-L1), a key therapeutic target for checkpoint immunotherapy. Moreover, aberrant activation of TAZ is also a major mechanism of acquired resistance to EGFR-TKIs in NSCLC. Therefore, TAZ signaling blockade might be an effective strategy to overcome resistance to ICIs and EGFR-TKIs in NSCLC. In this study, we showed for the first time that artesunate effectively reduced TAZ and PD-L1 expression in NSCLC. We further demonstrated that artesunate suppressed TAZ/PD-L1-induced T-cell growth inhibition in vitro and enhanced anti-tumor immunity by recruiting infiltrating CD8 + T-cells in syngeneic mouse models. Artesunate also inhibited the stem cell-like properties of NSCLC cells and suppressed tumor growth in xenografts bearing gefitinib-resistant tumors. In addition, our results of molecular docking and cellular thermal shift assay analysis suggested that artesunate might directly target the TAZ-TEAD complex and induce proteasome-dependent TAZ degradation in NSCLC cells. These results suggest that artesunate enhanced anti-tumor immunity and overcame EGFR-TKI resistance in NSCLC at least in part by suppressing TAZ/PD-L1 signaling.

1,25-dihvdroxy vitamin D3 ameliorates neutrophilic asthma by regulating NLRP3/caspase-l/GSDMD signal axis / 中国药理学通报

Aim To investigate the effect of 1,25-dihydroxyvitamin D3 on airway inflammation in a mouse model of neutrophilic asthma and its influence on the NLRP3/caspase-1/GSDMD signal axis.Methods Twenty-four female SPF BALB/c mice were selected and randomly(random number table method)divided into three groups:normal control group(A),model group(B),and intervention treatment group(C),with eight mice in each group.An animal model of mouse neutrophilic asthma was made by the method induced by chicken ovalbumin(OVA)combined with lipopolysaccharide(LPS).Group C was given 0.1% 1,25-(OH)2D3 intraperitoneal injection(4 μg·kg-1)before each OVA challenge.A noninvasive pulmonary function test was performed to assess airway responsiveness,and lung tissues and bronchoalveolar lavage fluid(BALF)were collected.HE staining and AB-PAS staining of lung tissues were performed to observe the pathological changes and airway mucus secretion.Total inflammatory cell count and classification were carried out,and the levels of IL-1β,IL-18,and IL-17 in BALF were detected.Immunohistochemistry staining of Ly-6G was done to confirm the presence of neutrophils in lung.The protein expressions of NLRP3,caspase-1,and GSDMD in lung tissues were determined by Western blot.Results The levels of IL-1β,IL-18,IL-17 in BALF in treatment group was lower than that in model group(P<0.05),and the proportion of neutrophils in BALF was lower than that in model group.Lung histology suggested that airway inflammation in treatment group was less than that in model group.In treatment group,AHR was significantly reduced; NLRP3,caspase-1,GSDMD protein expression levels were significantly lower than those in model group(P<0.05).Conclusions 1,25-dihydroxyvitamin D3 reduces airway inflammation and inflammatory cytokine secretion in mice with neutrophil asthma,and inhibits the expression of NLRP3,caspase-1 and GSDMD in lung.1,25-dihydroxyvitamin D3 may improve neutrophilic asthma by regulating the NLRP3/caspase-1/GSDMD signal axis.

Luteolin suppresses epithelial-mesenchymal transition and migration of triple-negative breast cancer cells by inhibiting YAP/TAZ activity.

Triple-negative breast cancer (TNBC) is a highly lethal subtype of breast cancer associated with early relapse and metastasis. Epithelial to mesenchymal transition (EMT) plays pivotal roles in the progression of TNBC, including inducing cancer stem cell (CSC) properties, chemoresistance, tumor metastasis, and recurrence. Abnormally activated YAP/TAZ induces EMT in TNBC, making it a promising target for drug development. Our goal is to identify potential YAP/TAZ inhibitors from naturally derivative molecules and further study its effects on inhibiting EMT and metastasis of TNBC. In the current study, we demonstrate that luteolin significantly inhibits YAP/TAZ activity by promoting YAP/TAZ degradation in TNBC cells. Luteolin treatment leads to a decrease of mesenchymal markers and an increase of epithelial markers in both TNBC cells and TAZ-induced mesenchymal cells. Consistently, luteolin treatment inhibits cell migration in TNBC cells. Additionally, luteolin inhibits tumor growth in mice xenografted with TNBC cells. Collectively, our results support luteolin as a novel YAP/TAZ inhibitor for development as a new agent for the treatment of TNBC.

A rare case of cystadenoma in the small intestine / 北京大学学报(医学版)

In recent years, there have been more and more reports about cystadenoma. Cystadenoma can occur in many parts of the body, and cystadenoma in different parts may show different clinical symptoms, however, some patients with cystadenoma have no symptoms. The vast majority of cystadenomas are benign lesions, but a small number of cystadenomas can be malignant. For example, a small number of ovarian cystadenomas and pancreatic cystadenomas may be malignant. This study reported a patient with small intestinal cystadenoma diagnosed by pathology. The patient's physical examination revealed a lesion in the left upper abdomen. He had only abdominal distension and no other discomfort. His laboratory examination results were basically normal, i.e. blood routine, urine routine, stool routine, liver function, kidney function, myocardial enzyme, tumor marker, etc. The patient underwent sectional small intestine resection and the pathological sample was analyzed. The histological findings of the resected intestinal sample were consistent with cystadenoma. Computed tomography scan of the abdomen was performed 4 months after the surgery. No recurrence of the tumor was found. The patient recovered in good condition. By consulting the literature, I found very few reports of small intestinal cystadenoma before, it was very rare. This article described the clinical manifestation, diagnosis and differential diagnosis, treatment and prognosis of a case of small intestinal cystadenoma, it suggested that cystadenoma can occur in the small intestine, other than the ovary, pancreas, liver, lung, thyroid, prostate, seminal vesicle, skin, etc. The cystadenoma in small intestine is easy to be mistaken with other tumors, such as small intestine stromal tumor, small intestine adenocarcinoma, small intestine lipoma, small intestine hemangiomas, etc., and it is difficult to fully confirm through imaging examinations, such as computed tomography and magnetic resonance imaging. Laparotomy and histopathological examination are necessary before definitive diagnosis. This disease can be treated by small bowel resection at the affected region and good prognosis can be achieved.

Gossypol overcomes EGFR-TKIs resistance in non-small cell lung cancer cells by targeting YAP/TAZ and EGFRL858R/T790M.

EGFR tyrosine kinase inhibitors (EGFR-TKIs) improve the progression-free survival of patients with non-small cell lung cancer (NSCLC). However, most patients inevitably developed drug resistance. EGFR T790 M mutation is the major mechanism for resistance to EGFR-TKIs and becomes an obstacle for the treatment of NSCLC patients with EGFR activating mutations. Besides, YAP/TAZ also confers resistance to EGFR-TKIs. Our previous study identified gossypol as a YAP/TAZ inhibitor. In the current study, we found that gossypol inhibited cell growth and induced apoptosis in H1975 cells harboring EGFRL858R/T790M. Also, gossypol treatment sensitized H1975 cells to EGFR-TKIs. Our mechanism studies showed that gossypol decreased the protein level of YAP/TAZ, which was abrogated by the proteasome inhibition. Moreover, over-expression of YAP/TAZ reversed the effects of gossypol on H1975 cells, and YAP/TAZ knockdown sensitized H1975 cells to gossypol treatment. Furthermore, gossypol reduced the protein level of EGFRL858R/T790M and inhibited the downstream ERK1/2 pathway in H1975 cells. Our findings suggested that gossypol might serve a promise drug candidate for overcoming EGFR-TKIs resistance by targeting both YAP/TAZ and EGFRL858R/T790M.

Clinical Efficacy of Modified Xiaofengsan and Its Effect on Cytokines in Persistent Asthma Patients with Wind-asthma Pattern / 中国实验方剂学杂志

Objective: To observe the clinical efficacy of modified Xiaofengsan and its effect on cytokines in persistent asthma patients with wind-asthma pattern. Method: The 120 eligible patients with chronic and persistent asthma were randomly divided into control group (60 cases) and treatment group (60 cases). Patients in control group received the budesonide/formoterol (160 μg/4.5 μg, 2 inhales/time, bid). Patients in treatment group additionally received the modified Xiaofengsan combined with budesonide/formoterol (160 μg/4.5 μg). The treatment course was 1 month in both groups. The clinical efficacy of the two groups was observed. Before and 3 months after treatment, asthma control test (ACT) and the average times of acute exacerbation in 6 months before and after treatment between two groups were observed; percentage of forced expiratory volume in first second and its predicted value (FEV1%), variety ratio of Peak expiratory flow (PEF), eosinophilic granulocyte (EOS) count in peripheral blood and the levels of interleukin-4(IL-4), interleukin-6(IL-6) and interleukin-13(IL-13) in serum were measured before and after treatment respectively. In addition, the safety of the two groups was evaluated. Result: The total effective rate of the treatment group was higher than that of the control group (P1% in treatment group were higher(PPConclusion: Modified Xiaofengsan combined with budesonide/formoterol could relieve symptoms of asthma, improve pulmonary function and lower the levels of IL-4, IL-6 and IL-13 in serum.

Effect of Modified Jinshui Liujunjian Combined with Salmeterol/Fluticasone on VEGF and TGF-β1 in Serum of Senile Asthma on Persistent Stage / 中国实验方剂学杂志

Objective:To explore the clinical efficacy of modified Jinshui Liujunjian combined with salmeterol/fluticasone on senile asthma on persistent stage and its effect on vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1) in serum. Method:The 100 cases of senile asthma who met inclusion criteria were selected and divided into two equal groups by random number table:the control group and the treatment group. Patients of the two groups were given oxygen therapy,phlegm reduction,infection control and salmeterol/fluticasone 50 μg·(500 μg)-1. Patients in control group were given sustained release capsule of theophylline in addition to the above therapy,while patients in treatment group were given modified Jinshui Liujunjian. The course of treatment was 8 weeks. The therapeutic effectiveness of traditional Chinese medicine (TCM) syndrome between two groups was observed. Asthma control test (ACT) scores at four different time points(before and after treatment,3, 6 months after treatment),pulmonary function,the levels of VEGF and TGF-β1 in serum before and after treatment between two groups were also observed. The pharmic safety during treatment was evaluated. Result:The total effective rate of treatment group was significantly higher than that of control group(PPβ1 in serum in treatment group were significantly lowered after treatment(P1%), and the percentage of forced expiratory volume in the first second and its forced vital capacity (FEV1/FVC) were significantly higher(PPConclusion:Modified Jinshui Liujunjian combined with Salmeterol/Fluticasone was more effective than Sustained release capsule of theophylline combined with Salmeterol/Fluticasone in improving the clinical efficacy and pulmonary function of senile asthma on the persistent stage. Its mechanism of action is probable correlated with the reduction of levels of VEGF and TGF-β1 in serum.

Apigenin suppresses the stem cell-like properties of triple-negative breast cancer cells by inhibiting YAP/TAZ activity.

Triple-negative breast cancer (TNBC) remains a clinical challenge because of the absence of effective therapeutic targets. In TNBC, overexpression of YAP and TAZ correlates with bioactivities of cancer stem cells (CSCs), high histological grade, resistance to chemotherapy, and metastasis. Thus, YAP/TAZ may serve as potential therapeutic targets in TNBC. To identify YAP/TAZ inhibitors, in previous experiments, we screened a library of natural compounds by using YAP/TAZ luciferase reporter assay and identified apigenin as a potential inhibitor. In this study, we demonstrated that apigenin significantly suppressed the proliferation and migration of TNBC cells. Furthermore, we demonstrated that apigenin inhibited stemness features of TNBC cells in both in vitro and in vivo assays. Our mechanism study demonstrated that apigenin decreased YAP/TAZ activity and the expression of target genes, such as CTGF and CYR61, in TNBC cells. We also showed that apigenin disrupted the YAP/TAZ-TEADs protein-protein interaction and decreased expression of TAZ sensitized TNBC cells to apigenin treatment. Collectively, our studies suggest that apigenin is a promising therapeutic agent for the treatment of TNBC patients with high YAP/TAZ activity.

A separable surface-enhanced Raman scattering substrate modified with MIL-101 for detection of overlapping and invisible compounds after thin-layer chromatography development.

By coupling surface-enhanced Raman spectroscopy (SERS) with thin-layer chromatography (TLC), a powerful method for detecting complex samples was successfully developed. However, in the TLC-SERS method, metal nanoparticles serving as the SERS-active substrate are likely to disturb the detection of target compounds, particularly in overlapping compounds after TLC development. In addition, the SERS detection of compounds that are invisible under both visible light and UV254/365 after TLC development is still a significant challenge. In this study, we demonstrated a facile strategy to fabricate a TLC plate with metal-organic framework-modified gold nanoparticles as a separable SERS substrate, on which all separated components, including overlapping and invisible compounds, could be detected by a point-by-point SERS scan along the developing direction. Rhodamine 6G (R6G) was used as a probe to evaluate the performance of the substrate. The results indicated that the substrate provided good sensitivity and reproducibility, and optimal SERS signals could be collected in 5 s. Furthermore, this new substrate exhibited a long shelf life. Thus, our method has great potential for the sensitive and rapid detection of overlapping and invisible compounds in complex samples after TLC development.

Two-dimensional code is a digital way to record the palatal rugae properties in Uygur populations / 中国组织工程研究

BACKGROUND: Palatal rugae have unique properties in each individual, which can be applied in the studies on dental forensics. OBJECTIVE: To measure the parameters of palatal rugae in Uygur populations, so as to provide a new idea for its recognition of dental forensics. METHODS: Palate rugae models from 268 Uygur adults aged 19-25 years were collected. The palatal rugae pattern code units (PRPCU) were obtained according to the morphological parameters of palatal rugae such as shape, length and position distribution, and then the PRPCU was converted into a two-dimensional code using online barcode generator to analyze the specificity of palate rugae. RESULTS AND CONCLUSION: The palate rugae in 268 palatal rugae models were different, and the most commonly seen shape was straight (2.76±1.69), followed by curve (1.74±1.35), wavy (1.06±0.90) and circular (0.09±0.351). The most common length classification was the primary rugae (6.17±1.75), followed by secondary rugae (0.70±0.97), and fragmentary rugae (0.33±0.682). The distribution of palatal rugae shape and length was significantly different among Uygur individuals (P < 0.001). Only the straight shape showed significant difference between male and female in Uygur populations (P < 0.05). That is to say, different individuals possess different palate rugae, so a digital record of palatal rugae can be used for personal identification.

Phosphorylation of Tyr188 in the WW domain of YAP1 plays an essential role in YAP1-induced cellular transformation.

The Hippo signaling pathway regulates cellular proliferation and survival, thus exerting profound effects on normal cell fate and tumorigenesis. The pivotal effector of this pathway is YAP1, a transcriptional co-activator amplified in mouse and human cancers where it promotes epithelial-to-mesenchymal transition (EMT) and malignant transformation. The Hippo tumor suppressor pathway has been suggested to inhibit the YAP1 function through serine phosphorylation-induced cytoplasmic retention and degradation. Here we report that the tyrosine188 (Y188) site of YAP1 isoform with 2 WW domains (known as YAP1-2) plays an important role in YAP1-induced cellular transformation. IP-Mass Spectrometry analysis of YAP1 identified the phosphorylation of Y188 but not other tyrosine residues. In contrast to the aberrant 3D acinus formation observed in YAP1-WT transduced cells, overexpression of YAP1-Y188F (non-phosphorylated mimic) displayed normal 3D structures. In addition, knockdown of the endogenous YAP1 in MDA-MB231 breast cancer cells inhibited cell proliferation and migration, which were then successfully rescued by the exogenous YAP1-WT and YAP1-Y188E but not Y188F. Mechanistically, we also demonstrated that YAP1-Y188F had a higher affinity to the upstream negative regulator PTPN14 and was extensively localized in the cytoplasm. Since the Y188 is located in the conserved aromatic core of the WW domain of YAP1, our finding has a wide implication for WW domain signaling in general, where Y phosphorylation may act as a common positive regulator of the complex formation via WW domains. In summary, our results indicate that tyrosine 188 plays an important role in the YAP1-induced cellular transformation and its phosphorylation may intriguingly serve as a positive indicator of YAP1 activation.

Characterization of TAZ domains important for the induction of breast cancer stem cell properties and tumorigenesis.

The Hippo pathway is an evolutionarily conserved regulator of tissue growth and cell fate during development and regeneration. Conversely, deregulation of the Hippo pathway has been reported in several malignancies. Here, we used integrative functional genomics approaches to identify TAZ, a transcription co-activator and key downstream effector of the Hippo pathway, as an essential driver for the propagation of TNBC malignant phenotype. We further showed in non-transformed human mammary basal epithelial cells that expression of constitutively active TAZ confers cancer stem cell (CSC) traits that are dependent on the TAZ and TEAD interacting domains. In addition, to gain a better understanding of how TAZ functions, we performed genetic-function analysis of TAZ. Significantly, we identified that both the WW and transcriptional activation domains of TAZ are critical for the induced CSC properties as well as tumorigenic potential as manifested in vitro and in human breast cancer xenograft in vivo. Collectively, our data suggest that pharmacological inhibition of TAZ activity may provide a novel means of targeting and eliminating breast CSCs.

Molecular profiling and computational network analysis of TAZ-mediated mammary tumorigenesis identifies actionable therapeutic targets.

Triple-negative breast cancer (TNBC) accounts for approximately 15-20% of all breast cancer (BC) cases and contributes disproportionately to BC mortality. TAZ, a key transducer of the Hippo pathway, has recently been demonstrated to confer breast cancer stem cell (CSC) traits. However, TAZ target genes and the underlying transcriptional regulatory pathways responsible for the CSC phenomenon remain unknown. Here, we demonstrate that the oncogenic activity of TAZ is essential for propagation of the malignant phenotype. We further show that constitutively active TAZ tumor-derived cells exhibit unique tumor-initiating properties, including increased self-renewal and metastatic seeding potential, acquired chemotherapy resistance and the ability to efficiently regenerate tumor formation in vivo. Combined digital RNA expression analysis and computational network approaches identify several signaling pathways that distinguish breast cancer tumor-initiating cells (T-ICs) from bulk tumor cells. We demonstrate the utility of this approach by repositioning the small molecule tyrosine kinase inhibitor, Dasatinib, which selectively targets T-ICs and inhibits TNBC growth in vivo.

PTPN14 forms a complex with Kibra and LATS1 proteins and negatively regulates the YAP oncogenic function.

The Hippo signaling pathway regulates cellular proliferation and survival, thus exerting profound effects on normal cell fate and tumorigenesis. Pivotal effectors of this pathway are YAP/TAZ, transcriptional co-activators whose dysfunction contributes to epithelial-to-mesenchymal transition and malignant transformation. Therefore, it is of great importance to decipher the mechanisms underlying the regulations of YAP/TAZ at various levels. Here we report that non-receptor tyrosine phosphatase 14 (PTPN14) interacts with the Kibra protein. The interaction between PTPN14 and Kibra is through the PPXY domain of PTPN14 and WW domain of Kibra. PTPN14 and Kibra can induce the LATS1 activation independently and cooperatively. Interestingly, activation of LATS1 by PTPN14 is dependent on the C terminus of PTPN14 and independent of the upstream mammalian STE20-like kinase (MST) proteins. Furthermore, we demonstrate that PTPN14 increases the LAST1 protein stability. Last, overexpression of Kibra rescues the increased cell migration and aberrant three-dimensional morphogenesis induced by knockdown of PTPN14, and this rescue is mediated through the activation of the upstream LATS1 kinase and subsequent cytoplasmic sequestration of YAP. In summary, our results indicate a potential regulatory role of PTPN14 in the Hippo pathway and demonstrate another layer of regulation in the YAP oncogenic function.

Hit identification of IKKß natural product inhibitor.

BACKGROUND: The nuclear factor-κB (NF-κB) proteins are a small group of heterodimeric transcription factors that play an important role in regulating the inflammatory, immune, and apoptotic responses. NF-κB activity is suppressed by association with the inhibitor IκB. Aberrant NF-κB signaling activity has been associated with the development of cancer, chronic inflammatory diseases and auto-immune diseases. The IKK protein complex is comprised of IKKα, IKKß and NEMO subunits, with IKKß thought to play the dominant role in modulating NF-κB activity. Therefore, the discovery of new IKKß inhibitors may offer new therapeutic options for the treatment of cancer and inflammatory diseases. RESULTS: A structure-based molecular docking approach has been employed to discover novel IKKß inhibitors from a natural product library of over 90,000 compounds. Preliminary screening of the 12 highest-scoring compounds using a luciferase reporter assay identified 4 promising candidates for further biological study. Among these, the benzoic acid derivative (1) showed the most promising activity at inhibiting IKKß phosphorylation and TNF-α-induced NF-κB signaling in vitro. CONCLUSIONS: In this study, we have successfully identified a benzoic acid derivative (1) as a novel IKKß inhibitor via high-throughput molecular docking. Compound 1 was able to inhibit IKKß phosphorylation activity in vitro, and block IκBα protein degradation and subsequent NF-κB activation in human cells. Further in silico optimization of the compound is currently being conducted in order to generate more potent analogues for biological tests.

Epigenetic repression of RARRES1 is mediated by methylation of a proximal promoter and a loss of CTCF binding.

BACKGROUND: The cis-acting promoter element responsible for epigenetic silencing of retinoic acid receptor responder 1 (RARRES1) by methylation is unclear. Likewise, how aberrant methylation interplays effectors and thus affects breast neoplastic features remains largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We first compared methylation occurring at the sequences (-664~+420) flanking the RARRES1 promoter in primary breast carcinomas to that in adjacent benign tissues. Surprisingly, tumor cores displayed significantly elevated methylation occurring solely at the upstream region (-664~-86), while the downstream element (-85~+420) proximal to the transcriptional start site (+1) remained largely unchanged. Yet, hypermethylation at the former did not result in appreciable silencing effect. In contrast, the proximal sequence displayed full promoter activity and methylation of which remarkably silenced RARRES1 transcription. This phenomenon was recapitulated in breast cancer cell lines, in which methylation at the proximal region strikingly coincided with downregulation. We also discovered that CTCF occupancy was enriched at the unmethylayed promoter bound with transcription-active histone markings. Furthermore, knocking-down CTCF expression hampered RARRES1 expression, suggesting CTCF positively regulated RARRES1 transcription presumably by binding to unmethylated promoter poised at transcription-ready state. Moreover, RARRES1 restoration not only impeded cell invasion but also promoted death induced by chemotherapeutic agents, denoting its tumor suppressive effect. Its role of attenuating invasion agreed with data generated from clinical specimens revealing that RARRES1 was generally downregulated in metastatic lymph nodes compared to the tumor cores. CONCLUSION/SIGNIFICANCE: This report delineated silencing of RARRES1 by hypermethylation is occurring at a proximal promoter element and is associated with a loss of binding to CTCF, an activator for RARRES1 expression. We also revealed the tumor suppressive roles exerted by RARRES1 in part by promoting breast epithelial cell death and by impeding cell invasion that is an important property for metastatic spread.

Dioscin induces cancer cell apoptosis through elevated oxidative stress mediated by downregulation of peroxiredoxins.

Dioscin has been shown to promote anticancer activity against several forms of cancers. However, its detailed molecular mechanisms have not been clearly clarified.In this study, we demonstrate that dioscin induces apoptosis in cancer cells through the induction of oxidative stress. Treatment with cancer cells in vitro with dioscin resulted in rapid generation of reactive oxygen species (ROS) and the induction of mitochondrial pathway apoptosis in human esophageal cancer cell line Kyse510. Inhibition of oxidative stress by the antioxidant N-acetylcysteine blocked the induction of apoptosis by dioscin, indicating that ROS generation is the primary mechanism responsible for the proapoptotic activity of dioscin. Proteomic analysis and protein gel blotting further revealed peroxiredoxins 1 and 6 (PRDX 1 and 6), which are implicated in ROS metabolism and apoptosis, were associated with the anticancer effects of dioscin. Meanwhile, overexpression of PRDX 1 and 6 significantly blocked the elevated ROS and apoptosis induced by dioscin. In conclusion, we suggest that PRDX1 and PRDX6 are key targets in the process of dioscin-induced apoptosis that involves intracellular elevated ROS.

Acylated protopanaxadiol-type ginsenosides from the root of Panax ginseng.

Six new protopanaxadiol-type ginsenosides, named ginsenosides Ra(4) -Ra(9) (1-6, resp.), along with 14 known dammarane-type triterpene saponins, were isolated from the root of Panax ginseng, one of the most important Chinese medicinal herbs. The structures of the new compounds were determined by spectroscopic methods, including 1D- and 2D-NMR, HR-MS, and chemical transformation as (20S)- 3-O-{ß-D-6-O-[(E)-but-2-enoyl]glucopyranosyl-(1→2)-ß-D-glucopyranosyl}-20-O-[ß-D-xylopyranosyl-(1→4)-α-L-arabinopyranosyl-(1→6)-ß-D-glucopyranosyl]protopanaxadiol (1), (20S)-3-O-[ß-D-6-O-acetylglucopyranosyl-(1→2)-ß-D-glucopyranosyl]-20-O-[ß-D-xylopyranosyl-(1→4)-α-L-arabinopyranosyl-(1→6)-ß-D-glucopyranosyl]protopanaxadiol (2), (20S)-3-O-{ß-D-6-O-[(E)-but-2-enoyl]glucopyranosyl-(1→2)-ß-D-glucopyranosyl}-20-O-[ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl]protopanaxadiol (3), (20S)-3-O-{ß-D-6-O-[(E)-but-2-enoyl]glucopyranosyl-(1→2)-ß-D-glucopyranosyl}-20-O-[α-L-arabinopyranosyl-(1→6)-ß-D-glucopyranosyl]protopanaxadiol (4), (20S)-3-O-{ß-D-4-O-[(E)-but-2-enoyl]glucopyranosyl-(1→2)-ß-D-glucopyranosyl}-20-O-[α-L-arabinofuranosyl-(1→6)-ß-D-glucopyranosyl]protopanaxadiol (5), (20S)-3-O-{ß-D-6-O-[(E)-but-2-enoyl]glucopyranosyl-(1→2)-ß-D-glucopyranosyl}-20-O-[α-L-arabinofuranosyl-(1→6)-ß-D-glucopyranosyl]protopanaxadiol (6). The sugar moiety at C(3) of the aglycone of each new ginsenoside is butenoylated or acetylated.

20(S)-Protopanaxadiol, a metabolite of ginsenosides, induced cell apoptosis through endoplasmic reticulum stress in human hepatocarcinoma HepG2 cells.

20(S)-Protopanaxadiol (PPD), a metabolite of ginsenosides, has been demonstrated to possess cytotoxic effects on several cancer cell lines. The molecular mechanism is, however, not well understood. In this study, we have shown that PPD inhibits cell growth and induces apoptosis in human hepatocarcinoma HepG2 cells. PPD-treated cells showed a massive cytoplasmic vacuolization and a dramatic change of endoplasmic reticulum (ER) morphology. The induction of ER stress is associated with the upregulation of ER stress-associated genes and proteins. PPD activates the unfolded protein response (UPR) through the phosphorylation of PERK and eIF2α, the splicing of XBP1 mRNA, and the cleavage of AFT6. PPD also induces the intrinsic and extrinsic apoptotic pathways. It activates DR5, caspase-8, -9, -3, and promotes the cleavage of PARP while it downregulates Bcl-2, Bcl-x(L) and mitochondrial membrane potential. Knockdown of one of the three UPR limbs by specific siRNAs did not affect PPD-induced apoptosis, which was however, significantly suppressed by the downregulation of CHOP. Western blot analysis showed that PPD-stimulated downregulation of Bcl-2 protein, increase of DR5 protein, activation of caspase-8 and cleavage of PARP were significantly inhibited in CHOP siRNA-transfected cells. Taken together, we have identified ER as a molecular target of PPD and our data support the hypothesis that PPD induces HepG2 cell apoptosis through the ER stress pathway.

Furanodienone induces cell cycle arrest and apoptosis by suppressing EGFR/HER2 signaling in HER2-overexpressing human breast cancer cells.

PURPOSE: Overexpression of EGFR and HER2 is seen in breast cancers and results in poor prognosis and decreased patient survival. Clinically, EGFR and HER2 are effective therapeutic targets. The objective of this study is to investigate the in vitro effects of furanodienone, an active chemical component isolated from Rhizoma Curcumae, on the activation of EGFR/HER2 signaling, cell cycle, and apoptosis in HER2-overexpressing BT474 and SKBR3 cells. METHODS: Cell growth was assessed by SRB protein assay. Cell cycle analysis was carried out by flow cytometry, and apoptosis was observed by Annexin V and DAPI staining. Effects of furanodienone on the activation of EGFR/HER2 signaling-related proteins were analyzed by western blotting. RESULTS: Furanodienone inhibited cell growth in BT474 and SKBR3 cells. Furanodienone caused G1 arrest in BT474 cells and induced apoptosis in SKBR3 cells. Furanodienone interfered with EGFR/HER2 signaling in treated cells as shown by decreases in phosphorylated EGFR, HER2, Akt, Gsk3ß and an increase in p27(kip1) protein. Accordingly, furanodienone inhibited EGF-induced phosphorylation of EGFR, HER2, Akt, and Gsk3ß. EGFR-specific siRNA knockdown did not affect the cell growth inhibitory effect of furanodienone. On the contrary, specific siRNA knockdown of HER2 increased cellular resistance to furanodienone toxicity. In HER-2-deficient MDA-MB-231 cells, the transfection and expression of HER2 increased the sensitivity of cells to furanodienone toxicity. CONCLUSION: Furanodienone inhibited EGFR/HER2 signaling pathway in BT474 and SKBR3 cells. More importantly, the effect of furanodienone was specifically dependent on HER2, but not EGFR, expression.