OASL knockdown inhibits the progression of stomach adenocarcinoma by regulating the mTORC1 signaling pathway.

The present study investigated the effects of 2'-5' oligoadenylate synthetase-like (OASL) on the biological functions of stomach adenocarcinoma (STAD) cells and tumor formation in nude mice. The differential expression levels of OASL in the different cancer types from TCGA dataset were analyzed using gene expression profiling interactive analysis. Overall survival and the receiver operating characteristic were analyzed using the KM plotter and R, respectively. Furthermore, OASL expression and its effects on the biological functions of STAD cells were detected. The possible upstream transcription factors of OASL were predicted using JASPAR. The downstream signaling pathways of OASL were analyzed using GSEA. Tumor formation experiments were performed to evaluate the effect of OASL on tumor formation in nude mice. The results showed that OASL was highly expressed in STAD tissues and cell lines. OASL knockdown markedly inhibited cell viability, proliferation, migration, and invasion and accelerated STAD cell apoptosis. Conversely, OASL overexpression had the opposite effect on STAD cells. JASPAR analysis revealed that STAT1 is an upstream transcription factor of OASL. Furthermore, GSEA showed that OASL activated the mTORC1 signaling pathway in STAD. The protein expression levels of p-mTOR and p-RPS6KB1 were suppressed by OASL knockdown and promoted by OASL overexpression. The mTOR inhibitor, rapamycin, markedly reversed the effect of OASL overexpression on STAD cells. Additionally, OASL promoted tumor formation and increased tumor weight and volume in vivo. In conclusion, OASL knockdown suppressed the proliferation, migration, invasion, and tumor formation of STAD cells by inhibiting the mTOR signaling pathway.

Overexpression of geranylgeranyl diphosphate synthase contributes to tumour metastasis and correlates with poor prognosis of lung adenocarcinoma.

This study aimed to evaluate the biological role of geranylgeranyl diphosphate synthase (GGPPS) in the progression of lung adenocarcinoma. GGPPS expression was detected in lung adenocarcinoma tissues by qRT-PCR, tissue microarray (TMA) and western blotting. The relationships between GGPPS expression and the clinicopathological characteristics and prognosis of lung adenocarcinoma patients were assessed. GGPPS was down-regulated in SPCA-1, PC9 and A549 cells using siRNA and up-regulated in A549 cells using an adenoviral vector. The biological roles of GGPPS in cell proliferation, apoptosis, migration and invasion were determined by MTT and colony formation assays, flow cytometry, and transwell and wound-healing assays, respectively. In addition, the regulatory roles of GGPPS on the expression of several epithelial-mesenchymal transition (EMT) markers were determined. Furthermore, the Rac1/Cdc42 prenylation was detected after knockdown of GGPPS in SPCA-1 and PC9 cells. GGPPS expression was significantly increased in lung adenocarcinoma tissues compared to that in adjacent normal tissues. Overexpression of GGPPS was correlated with large tumours, high TNM stage, lymph node metastasis and poor prognosis in patients. Knockdown of GGPPS inhibited the migration and invasion of lung adenocarcinoma cells, but did not affect cell proliferation and apoptosis. Meanwhile, GGPPS inhibition significantly increased the expression of E-cadherin and reduced the expression of N-cadherin and vimentin in lung adenocarcinoma cells. In addition, the Rac1/Cdc42 geranylgeranylation was reduced by GGPPS knockdown. Overexpression of GGPPS correlates with poor prognosis of lung adenocarcinoma and contributes to metastasis through regulating EMT.

Topotecan alleviates ventilator-induced lung injury via NF-κB pathway inhibition.

OBJECTIVE: We investigated the effect of topotecan on injury and inflammation in a model of ventilator-inducedlunginjury (VILI). METHODS: Acute lung injury (ALI) was induced in mice by high-tidal volume ventilation, and the mice were then treated with topotecan or PBS. Lung tissue and bronchoalveolar lavage fluid were collected to assess pulmonary vascular leaks, inflammation, and cell apoptosis. RESULTS: Compared to PBS treatment, topotecan significantly decreased the ALI score, myeloperoxidase (MPO) content, total protein concentration, and presence of inflammatory cells and inflammatory cytokines in bronchoalveolar lavage fluid. Topotecan also reduced caspase-3 activation and type Ⅱ alveolar epithelial cell apoptosis. Moreover, topotecan inhibited NF-κB expression and activation in the VILI model. CONCLUSION: Topotecan alleviates acute lung injury in the model of VILI through the inhibition of the NF-κB pathway.

NCAPG2 promotes tumour proliferation by regulating G2/M phase and associates with poor prognosis in lung adenocarcinoma.

NCAPG2 is a component of the condensin II complex and contributes to chromosome segregation via microtubule-kinetochore attachment during mitosis. It is well known that NCAPG2 plays a critical role in cell mitosis; however, the role of altered NCAPG2 expression and its transcriptional regulatory function in cancer development remains mostly unknown. Here, for the first time we reported that NCAPG2 was evidently increased in non-small cell lung cancer tissues compared to adjacent normal lung tissues. Clinicopathological data analysis showed that NCAPG2 overexpression was significantly correlated with lymph node metastasis and pathologic-Tumour Nodes Metastasen stages, and was an independent prognostic factor in lung adenocarcinoma patients. Moreover, siRNA-mediated knockdown of NCAPG2 could inhibit tumour cell growth of lung adenocarcinoma cells (A549 and H1299) in vitro and could significantly lead to cell cycle arrest in the G2 phase. Furthermore, we found that NCAPG2 silencing significantly decreased the expression levels of G2/M phase cell cycle-related protein expressions (Cyclin B1, Cdc2) and increased the expression levels of p27 and p21 through Western blot analysis. Taken together, we demonstrated that increased NCAPG2 expression could regulate cell proliferation and identified as a poor prognostic biomarker in lung adenocarcinoma.

PRC1 contributes to tumorigenesis of lung adenocarcinoma in association with the Wnt/ß-catenin signaling pathway.

BACKGROUND: Protein regulator of cytokinesis-1 (PRC1) belongs to the microtubule-associated proteins (MAPs) family, and is involved in cytokinesis. Recent investigations suggest PRC1 involvement in human carcinogenesis, including breast carcinoma, hepatocellular carcinoma and etc. However, whether PRC1 contributes to lung adenocarcinoma tumorigenesis remains unknown. METHODS: Quantitative reverse-transcription polymerase chain reaction (qRT-PCR), Western blotting and Immunohistochemical staining (IHC) were used to evaluate and contrast the PRC1 expression profile in lung adenocarcinoma and adjacent normal lung tissues. We examined the clinical use of PRC1 in lung adenocarcinoma prognosis. Additionally, the tumorigenesis impact of PRC1 in lung adenocarcinoma cells was verified via in vitro and in vivo metastasis and tumorigenesis assays. Notably, Next Generation Sequencing (NGS) was performed to investigate the molecular mechanism underlying the oncogenic role of PRC1 in lung adenocarcinoma. RESULTS: PRC1 mRNA and protein expressions were upregulated in lung adenocarcinoma tissues compared to adjacent normal lung tissues. PRC1 protein overexpression correlated with lymph node metastasis and was an independent poor prognostic factor for lung adenocarcinoma patients. Our data implied that PRC1 depletion limited the proliferation and invasion of lung adenocarcinoma cells in vitro and lowered tumor development and lung metastasis in vivo. Remarkably, limiting PRC1 substantially prompted G2/M phase cell cycle arrest and apoptosis. Mechanistically, by conducting NGS on PRC1-depleted A549 cells and control cells, we discovered that PRC1 expression was significantly correlated with the Wnt signaling pathway. CONCLUSIONS: This investigation offers confirmation that PRC1 is a prognostic and promising therapeutic biomarker for people with lung adenocarcinoma and takes on a key part in the activation of the Wnt/ß-catenin pathway in lung adenocarcinoma development.

Embelin Enhances the Sensitivity of Renal Cancer Cells to Axitinib by Inhibiting HIF Signaling Pathway.

BACKGROUND: Renal cell carcinoma (RCC) is a common malignant tumor of the urinary system with a high recurrence rate and easy metastasis. Current clinical drugs for renal cell carcinoma include immunotherapies and targeted drugs. Axitinib is a clinically targeted drug for treating renal cell carcinoma, which has shortcomings such as unstable efficacy and easy drug resistance. Therefore, this study aims to determine whether embelin can enhance the sensitivity of renal cancer cells to axitinib and explore its regulatory pathways. METHODS: The enhancing effect of embelin on axitinib was detected using MTT, crystal violet staining, and annexin VFITC staining in two renal cancer cell lines. Western blot was performed to detect the expression of autophagy-related proteins under different conditions. Bioinformatic tools were used to predict the pathways through which embelin may act on renal cancer cells, and pharmacological methods were used to verify the results. RESULTS: Embelin enhanced the sensitivity of renal cancer cells to axitinib in the following aspects: enhancing the inhibition of cell proliferation by axitinib, and the induction of cell apoptosis. HIF was a potential pathway for embelin's action. After IOX2 regulated the HIF-1α pathway, the enhancing effect of embelin on axitinib was weakened. Moreover, after PT2977 regulated the HIF-2α pathway, the enhancing effect of embelin on axitinib was weakened. CONCLUSIONS: Embelin enhanced the sensitivity of A498 and 786-O renal cancer cells to axitinib by inhibiting the HIF pathway.

Knockdown of NEK7 alleviates anterior cruciate ligament transection osteoarthritis (ACLT)-induced knee osteoarthritis in mice via inhibiting NLRP3 activation.

Osteoarthritis is thought to be a NLRP3-related disease. NEK7 is an essential mediator for NLRP3 inflammasome activation. This study aimed to demonstrate whether NEK7 has regulatory roles in the pathogenesis of osteoarthritis. C57BL/6 mice were subjected to anterior cruciate ligament transection osteoarthritis (ACLT) for constructing animal models of osteoarthritis. Injection of adeno-associated virus (AAV) expressing NEK7-specific shRNA into the knee joints of mice, following of which immunohistochemistry, qRT-PCR, western blotting, Safranin-O Fast Green staining, ELISA, and co-immunoprecipitation were performed to determine the effects of NEK7. NEK7 was highly expressed in the joint tissues of ACLT mice. As compared with shScr, AAV delivery of NEK7 shRNA significantly inhibited cartilage degeneration, OARSI score, and serum CTX-II and COMP levels. AAV delivery of NEK7 shRNA downregulated the expression of matrix-degrading enzymes (ADAMTS-4, MMP3, and MMP13) and upregulated the expression of ECM-related molecules (SOX9, collagen II, and aggrecan). In addition, AAV delivery of NEK7 shRNA alleviated ACLT-induced synovial inflammation, as was evidenced by the decreased levels of TNF-α, IL-6, IL-1ß, and IL-18 and increased levels of IL-10. In the joint tissues of ACLT mice, NEK7 interacted with NLRP3 proteins. AAV delivery of NEK7 shRNA inhibited the protein interaction, and thereby inhibited the activation of the NLRP3 inflammasome. AAV delivery of NEK7 shRNA has no significant effects on cartilage degeneration and synovial inflammation in Nlrp3-/- mice. In conclusion, knockdown of NEK7 exerted anti-osteoarthritic effects, possibly via inhibiting the activation of the NLRP3 inflammasome. This study provided a novel mechanism of NEK7-NLRP3 interaction affecting osteoarthritis.

NEK7 is highly expressed in ACLT-induced mouse models of osteoarthritis.Knockdown of NEK7 alleviates ACLT-induced cartilage degeneration and inflammation.NEK7 mediates the activation of NLRP3 inflammasome in ACLT mouse models.Knockdown of NEK7 alleviates ACLT-induced osteoarthritis by inhibition of NLRP3.

Luteolin impacts deoxyribonucleic acid repair by modulating the mitogen-activated protein kinase pathway in colorectal cancer.

This study aimed to investigate the effects of luteolin on colorectal cancer (CRC) and explore its underlying mechanism. HCT-116 and HT-29 cells were treated with luteolin, cisplatin, or selumetinib. The cell survival, cell proliferation, apoptosis and cell cycle distribution, and DNA damage were detected using Cell Counting Kit-8, colony formation, flow cytometry, and immunofluorescence staining analysis, respectively. Western blotting was used to detect the expression of apoptosis-related, cycle-related, DNA-damage-related, and mitogen-activated protein kinase (MAPK) pathway-related proteins. Luteolin showed inhibitory effects on cellular growth by reducing cell survival and proliferation, inducing apoptosis and DNA damage, and arresting the cell cycle in a concentration-dependent manner in HCT-116 and HT-29 cells. Meanwhile, luteolin increased the expression of pro-apoptotic proteins, p-CHK1 (central to the induction of cell cycle arrest), and DNA excision repair protein and decreased anti-apoptotic proteins, G2-M phase-related proteins, and DNA repair proteins. The combination of cisplatin and luteolin significantly decreased cell survival and increased the apoptosis rate of HCT-116 and HT-29 cells compared with cisplatin alone. Bioinformatic analysis using the Comparative Toxicogenomics Database and STITCH and MalaCards databases showed that the MAPK pathway is involved in the pharmacology of luteolin. Furthermore, western blotting demonstrated that luteolin plays an inhibitory role by suppressing the MAPK signaling pathway in CRC, which is enhanced when combined with selumetinib. Luteolin can also prevent tumourigenesis in CRC in vivo. In conclusion, luteolin suppressed cell proliferation, blocked the cell cycle, and induced DNA damage and apoptosis progression in CRC cells by mediating the MAPK pathway.

Bisbibenzyl derivatives sensitize vincristine-resistant KB/VCR cells to chemotherapeutic agents by retarding P-gp activity.

P-glycoprotein (P-gp) is known to mediate multidrug resistance (MDR) by acting as an efflux pump to actively transport chemotherapeutic agents out of carcinoma cells. Inhibition of P-gp function may represent one of the strategies to reverse MDR. We have previously reported that marchantin C (MC), a macrocyclic bisbibenzyl compound from liverworts, exerts anti-tumor activity as an antimitotic agent. This study was designed to evaluate the possible modulatory effect of MC and its three synthetic derivatives (MC1, MC2 and MC3) on P-gp in VCR-resistant KB/VCR cells. Results of the cytotoxicity assay revealed that MC was the most potent inhibitor of cell proliferation in both KB and KB/VCR cells among these four compounds, while the three MC-derived chemicals had little anti-proliferative activity under the same condition. However, in P-gp-expressing MDR cells, analysis of potency of these compounds in enhancing cytotoxicity of VCR led to the identification of MC2 as a more effective chemical on reversal of resistance. Further study showed that MC2 was able to reduce efflux of rhodamine-123, and in turn, increase the accumulation of rhodamine-123 and adriamycin in KB/VCR cells, indicating that MC2 re-sensitized cells to VCR by inhibition of the P-gp transport activity. In addition, the combination of MC2 and VCR at a concentration that does not inhibit cell growth resulted in an induction of apoptosis in KB/VCR cells. These results suggest that MC2, as a novel and effective inhibitor of P-gp, may find potential application as an adjunctive agent with conventional chemotherapeutic drugs to reverse MDR in P-gp overexpressing cancer cells.

Synthesis and multidrug resistance reversal activity of dihydroptychantol A and its novel derivatives.

The macrocyclic bisbibenzyl dihydroptychantol A (DHA), previously isolated from Asterella angusta, was synthesized and showed significant multidrug resistance (MDR) reverting activity in chemoresistant cancer cells. In an attempt to discover more potent MDR reversal agents for efficient cancer chemotherapy, DHA derivatives with thiazole rings (19-22) were synthesized, and their cytotoxicities and MDR reversal activities were evaluated in adriamycin-resistant K562/A02, vincristine-resistant KB/VCR and in their parental cells by MTT assays. In response to treatment with each compound, the K562 cell line was the most sensitive, and the vincristine-resistant KB/VCR cell line was the most resistant. Marked decreases in K562 and K562/A02 cell viability were detectable after treatment with the synthesized derivatives of DHA, while less inhibitory effects on cell growth were observed in chemical-resistant KB/VCR and KB cells. Moreover, among the tested compounds, the intermediate 17 and the analogues 19, 20, and 21 showed potent MDR reversal activities and increased vincristine cytotoxicity in KB/VCR cells, with the reversal fold ranges from 10.54 to 13.81 (10microM), which is 3.2-4.3-fold stronger than the natural product DHA.

GSDMD is required for effector CD8+ T cell responses to lung cancer cells.

GSDMD is a recently discovered pyroptosis executioner in monocytes whose N-terminal domain can insert into the inner leaflet of cell membranes and form extensive pores. However, the function of GSDMD in other biological systems remains unclear. In this study, we showed that the expression of GSDMD was consistently correlated with CD8+ T cell markers in The Cancer Genome Atlas (TCGA) cohorts. GSDMD cleavage increased in OT-1 cytotoxic T lymphocytes (CTLs) and human activated CD8+ T cells. Colocalization of GSDMD with granzyme B was observed in the proximity of immune synapses, and GSDMD deficiency reduced the cytolytic capacity of CD8+ T cells. Overall, our study highlights a function, to our knowledge previously unknown, for GSDMD in CTLs and demonstrated that GSDMD is required for an optimal CTL response to cancer cells.

Downregulation of GSDMD attenuates tumor proliferation via the intrinsic mitochondrial apoptotic pathway and inhibition of EGFR/Akt signaling and predicts a good prognosis in non­small cell lung cancer.

Gasdermin D (GSDMD) is a newly discovered pyroptosis executive protein, which can be cleaved by inflammatory caspases and is essential for secretion of IL­1ß, making it a critical mediator of inflammation. However, the precise role of GSDMD in carcinogenesis remains nearly unknown. Considering the vital role of inflammation in tumorigenesis, we investigated the biological function of GSDMD in non­small cell lung cancer (NSCLC). Our study demonstrated that the GSDMD protein levels were significantly upregulated in NSCLC compared to these levels in matched adjacent tumor specimens. Higher GSDMD expression was associated with aggressive traits including larger tumor size and more advanced tumor-node-metastasis (TNM) stages. In addition, high GSDMD expression indicated a poor prognosis in lung adenocarcinoma (LUAD), but not in squamous cell carcinoma (LUSC). Knockdown of GSDMD restricted tumor growth in vitro and in vivo. Notably, intrinsic and extrinsic activation of pyroptotic (NLRP3/caspase­1) signaling in GSDMD­deficient tumor cells induced another type of programmed cell death (apoptosis), instead of pyroptosis. GSDMD depletion activated the cleavage of caspase­3 and PARP, and promoted cancer cell death via intrinsic mitochondrial apoptotic pathways. In addition, co­expression analyses indicated a correlation between GSDMD and EGFR/Akt signaling. Collectively, our results revealed a crosstalk between pyroptotic signaling and apoptosis in tumor cells. Knockdown of GSDMD attenuated tumor proliferation by promoting apoptosis and inhibiting EGFR/Akt signaling in NSCLC. In conclution, GSDMD is an independent prognostic biomarker for LUAD.

Plasma long noncoding RNA IL-7R as a prognostic biomarker for clinical outcomes in patients with acute respiratory distress syndrome.

BACKGROUND: Long non-coding RNAs (lncRNAs) regulate a variety of genes and biological processes. Lnc-IL7R plays a considerable role in the regulation of inflammation, but its prognostic potential in acute respiratory distress syndrome (ARDS) has not been fully explained. In this study, the role of lnc-IL7R as a potential biomarker in ARDS was examined. OBJECTIVE: Role of lnc-IL7R as potential biomarker in ARDS. METHODS: LncRNA-IL7R was isolated from the plasma of patients with ARDS and healthy controls and clinical indexes were obtained within 24 h after admission. The relative expression of lnc-IL7R was obtained by quantitative real-time PCR. The correlations between lnc-IL7R and continuous variables in ARDS were tested using Spearman's coefficients. RESULTS: A total of 85 ARDS patients and 49 healthy controls were included. Plasma lnc-IL7R was significantly down-regulated in ARDS compared with the levels in healthy control individuals, especially in severe ARDS (P < .01). The area under the curve (AUC) of lnc-IL7R for ARDS diagnosis was 0.87 (sensitivity 75.3%, specificity 93.9%). The lnc-IL7R levels were correlated with the severity of ARDS (ρ = -0.31, P = .0215), oxygenation index (ρ = 0.61, P < .001), APACHE II score (ρ = -0.04, P = .0230), CRP (ρ = -0.26, P = .0148) and WBC (ρ = -0.29, P = .0064). Lnc-IL7R relative value ≥ 0.33 showed the lower 28-day mortality in the patients with ARDS(P < .05).The survivors showed higher lnc-IL7R level and lower APACHE II score, SOFA score and length of mechanical ventilation than in the non-survivors (P = .0109, P < .001, P < .001 and P = .017, respectively). CONCLUSIONS: Lnc-IL7R is a novel biomarker for the diagnosis of ARDS and predicts the severity of ARDS and 28-day mortality in this patients cohort. TRIAL REGISTRATION: The study was registered with the Chinese Clinical Trial Registry (ChiCTR-DOD-16008657).

The protective effect of dopamine on ventilator-induced lung injury via the inhibition of NLRP3 inflammasome.

Dopamine (DA), a neurotransmitter, was previously shown to have anti-inflammatory effects. However, its role in ventilator-induced lung injury (VILI) has not been explicitly demonstrated. This study aimed to investigate the therapeutic efficacy and molecular mechanisms of dopamine in VILI. Rats were treated with dopamine during mechanical ventilation. Afterwards, the influence of dopamine on histological changes, pulmonary edema, the lung wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, polymorphonuclear(PMN)counts, inflammatory cytokine levels, and NLRP3 inflammasome protein expression were examined. Our results showed that dopamine significantly attenuated lung tissue injury, the lung W/D ratio, MPO activity and neutrophil infiltration. Moreover, it inhibited inflammatory cytokine levels in the Bronchoalveolar lavage fluid (BAL). In addition, dopamine significantly inhibited ventilation-induced NLRP3 activation. Our experimental findings demonstrate that dopamine exerted protective effects in VILI by alleviating the inflammatory response through inhibition of NLRP3 signaling pathways. The present study indicated that dopamine could be a potential effective therapeutic strategy for the treatment of VILI.

Protein regulator of cytokinesis-1 expression: prognostic value in lung squamous cell carcinoma patients.

BACKGROUND: Protein regulator of cytokinesis-1 (PRC1) has been shown to participate in the completion of cytokinesis, and it is dysregulated in cancer processes. However, its relevance in lung squamous cell carcinoma (SCC) remained largely unknown. We aimed to study the expression pattern of PRC1 and assess its clinical significance in lung SCC. METHODS: PRC1 protein expression in human lung SCC and adjacent normal lung tissues was detected by immunohistochemistry. PRC1 expression was assessed in association with clinicopathological features and clinical outcomes of lung SCC patients. RESULTS: In lung SCC tissues, PRC1 protein expression was significantly higher than those in paired normal lung tissues. The lung SCC patients with PRC1 overexpression had an advanced pathological stage (TNM stage), positive lymph node metastasis, and a shorter overall survival (OS) time more frequently than patients with low PRC1 expression. Additional, PRC1 expression was also shown to be poor as a prognostic factor for OS in patients with lung SCC. CONCLUSIONS: Our study indicated that aberrant expression of PRC1 may point to biochemical recurrence in lung SCC. This highlights its potential as a valuable prognostic marker for lung SCC.

Targeting autophagy augments the activity of DHA-E3 to overcome p-gp mediated multi-drug resistance.

Multidrug resistance (MDR) is a major obstacle for successful chemotherapy treatment. Searching for effective MDR modulators and combining them with anticancer drug therapies has been a promising strategy against clinical MDR. In our previous study, we have found that DHA-E3, a synthetic derivative of DHA, has the ability to modulate the function of P-glycoprotein (P-gp) and reverse MDR in cancer cells. In this study, we further evaluated the reversal effect of DHA-E3 on MDR and explored its mechanism of action in vitro. Our findings showed that DHA-E3 significantly potentiated the cytotoxicity of vincristine(VCR) and adriamycin(ADR) in the P-gp over-expressing KB/VCR and A02 cells. The mechanistic study found that DHA-E3 increased the intracellular accumulation of ADR and rhodamine-123 by directly inhibiting the drug-transport activity of P-gp. In the present study, we found that DHA-E3 not only reversed MDR, but also induced autophagy in MDR cancer cells. To determine whether DHA-E3-induced autophagy is an adaptive survival response or contributes to cell death, we manipulated autophagic activity using autophagy inhibitor 3-MA or siRNA targeting Beclin1. We found that the reversal activity of DHA-E3 was significantly exacerbated in the presence of 3-MA or blocking the expression of Beclin1. These results suggest that DHA-E3 is capable of reversing MDR, induction of autophagy represents a defense mechanism and inhibiting this process may be an effective strategy to augment the reversal activity of reversal agents.

Autophagy inhibition promotes paclitaxel-induced apoptosis in cancer cells.

Paclitaxel has been demonstrated to be an effective mitotic inhibitor and apoptosis inducer to treat aggressive malignancies. In this paper, we have provided a line of evidence that promotion of apoptotic cell death by paclitaxel was accompanied with induction of autophagy in A549 cells. Paclitaxel treatment could lead to the formation of acidic vesicular organelles (AVOs), the induction of Atg5, Beclin 1 and microtubule-associated protein 1 light chain 3 (LC3) expressions, and the increase of punctate fluorescent signals in A549 cells pre-transfected with green fluorescent protein (GFP)-tagged LC3. Interestingly, paclitaxel-mediated apoptotic cell death was further potentiated by pretreatment with autophagy inhibitor 3-methyladenine (3-MA) or small interfering RNA against the autophagic gene beclin1. These findings suggest that paclitaxel-elicited autophagic response plays a protective role that impedes the eventual cell death, and inhibition of autophagy could be an adjunctive strategy for enhancing chemotherapeutic effect of paclitaxel as an antitumor agent.

Labdane diterpenoids and highly methoxylated bibenzyls from the liverwort Frullania inouei.

Four undescribed labdane diterpenoids, 1,2-dehydro-3,7-dioxo-manoyl oxide (1), 1,2-dehydro-7 beta-hydroxy-3-oxo-manoyl oxide (2), 3,7-dioxo-manoyl oxide (3), and 3beta-hydroxy-7-oxo-manoyl oxide (4) together with three known diterpenoids (5-7) and four highly methoxylated bibenzyls (8-11) were isolated from the liverwort Frullania inouei. The absolute structures of 1-4 were established by combined analysis of NMR data, CD data coupled with TDDFT CD calculations, and single-crystal X-ray diffraction measurement. Cytotoxicity tests to human tumor KB, KB/VCR, K562 or K562/A02 cells showed bibenzyls 8-11 inhibited cell proliferation with ID(50) values ranging from 11.3 to 49.6 microM and overcame the multidrug resistance (MDR) with the reversal fold (RF) values ranging from 3.19 to 10.91 (5 microM) for vincristine-resistant KB/VCR and RF values from 4.40 to 8.26 (5 microM) for adriamycin-resistant K562/A02 cells, respectively. However, none of the diterpenoids were found to be active (ID(50)>50 microM).