Project description:c-Jun N-terminal kinase (JNK) plays a pivotal role in the regulation of cancer cell apoptosis. Previous studies have revealed that forkhead transcription factor (Foxo3a) is a critical effector of JNK-mediated tumor suppression. However, it is not clear whether caveolin-1 (CAV1) mediated JNK/Foxo3a pathway is involved in cancer cell apoptosis. We found that cordycepin upregulates CAV1 expression, which was accompanied by JNK phosphorylation (p-JNK), which induced Foxo3a translocation into the nucleus, resulting in the upregulation of levels of Bax protein. Furthermore, we found that CAV1 overexpression upregulated p-JNK, whereas siRNA mediated inhibition of CAV1 downregulated p-JNK, and that JNK inhibition by SP600125, a specific JNK inhibitor, significantly increased Foxo3a phosphorylation (p-Foxo3a), which attenuated Foxo3a translocation into the nucleus, indicating caveolin-1 mediated JNK’s regulation of Foxo3a. siRNA mediated inhibition of Foxo3a downregulated levels of Bax protein, attenuated A549 cell apoptosis, indicating that CAV1 mediated JNK/Foxo3a pathway induce the apoptosis of A549 lung cancer cells. Taken, together, these results indicate that cordycepin promotes CAV1 upregulation to enhance JNK/Foxo3a signaling pathway activation to induce apoptosis in lung cancer cells and support the potential of cordycepin as a therapeutic agent for lung cancer.
Project description:Embelin (15 uM) induced alterations in the gene expression profile was studied in A549 lung cancer cells during the initial stages of apoptosis (4h following treatment) As embelin (15 uM) induces apoptosis as early as 4h time period, we performed microarray analysis to study embelin-induced differential gene expression as early as 4h to identify the responsible pathways.
Project description:BRD4 assembles transcriptional machinery at gene super-enhancer regions and governs the expression of genes that are critical for cancer progression. However, it remains unclear whether BRD4-mediated gene transcription is required for tumor cells to develop drug resistance. Our data show that prolonged treatment of luminal breast cancer cells with AKT inhibitors induces FOXO3a de-phosphorylation, nuclear translocation, and disrupts its association with SIRT6, eventually leading to FOXO3a acetylation as well as BRD4 recognition. Acetylated FOXO3a recognizes the BD2 domain of BRD4, recruits the BRD4/RNAPII complex to the CDK6 gene promoter and induces its transcription. Pharmacological inhibition of either BRD4/FOXO3a association or CDK6 significantly overcomes the resistance of luminal breast cancer cells to AKT inhibitors in vitro and in vivo. Our study reports the involvement of BRD4/FOXO3a/CDK6 axis in AKTi resistance and provides potential therapeutic strategies for treating resistant breast cancer.
Project description:The molecular events that are involved in the establishment and the maintenance of CD4+ Central Memory (TCM) and Effector Memory (TEM) T cells are poorly understood. Using global gene expression profiling, single cell proteomics, and functional assays, we show that the survival of TCM CD4+ T cells involves the activation and phosphorylation of STAT5a and FOXO3a. STAT5a phosphorylation induces the transcriptional up-regulation of anti-apoptotic genes specifically in TCM. The phosphorylation of FOXO3a at S315, following TCR engagement, prevents the transcription of pro-apoptotic gene like FasL and BIM. Experiments aimed at blocking FOXO3a phosphorylation confirmed the role of FOXO3a in protecting TCM from apoptosis. Our results define the underlying molecular mechanisms responsible for the longevity and persistence of CD4+ TCM. Keywords: comparative gene profile, cell-type comparison, central memory to Effector memory
Project description:Minichromosome maintenance protein 2 (MCM2) is a licensing factor for DNA replication. It interacts with other MCM proteins to comprise MCM2-7 complex, which acts as a helicase for DNA unwinding and limits DNA replication to one round per cell cycle. MCM2 has been widely used as a biomarker for proliferation in many types of cancer. However, the molecular regulation underlying MCM2 in lung cancer cells is poorly understood. In this study, we investigated the role of MCM2 in lung adenocarcinoma A549 (wild-type p53) and H1299 (null p53) cells. MCM2 overexpression increased cell proliferation in A549 cells while silencing MCM2 decreased cell proliferation in H1299 cells. We performed global quantitative phosphoproteomic analysis to uncover the important downstream networks regulated by MCM2 in lung cancer cells. We identified 1484 phosphorylation sites in 593 phosphoproteins of MCM2-overexpressed A549 cells. Of these phosphosites, 110 phosphoproteins were significantly changed in response to MCM2 overexpression. In addition, we identified 1599 phosphorylation sites in 592 phosphoproteins of MCM2-silenced H1299 cells. Of these phosphosites, 57 phosphoproteins were significantly changed in response to MCM2 silencing. The differentially regulated phosphoproteins are involved in biological functions such as RNA splicing, cell cycle and cytoskeleton regulation. Functional study demonstrated that MCM2 overexpression promoted cell migration in A549 cells. Moreover, silencing MCM2 inhibits cell migration and induces cell cycle arrest in H1299 cells. Furthermore, we observed a common phosphorylation change at Ser-99 of high mobility group protein HMG-I/HMG-Y (HMGA1) in both MCM2 overexpression and silencing, indicating an important regulatory effect of Ser-99 HMGA1 on lung cancer cells. The phosphoproteomic profiling of MCM2 in lung cancer cells provides new insight about phosphorylation networks regulated by MCM2 and reveals novel targets for lung cancer therapy.
Project description:Lung cancer is the leading cause of cancer mortality worldwide, yet the therapeutic strategy for advanced non-small cell lung cancer (NSCLC) is limitedly effective. In addition, validated histone deacetylase (HDAC) inhibitors for the treatment of solid tumors remain to be developed. Here, we propose a novel HDAC inhibitor, OSU-HDAC-44, as a chemotherapeutic drug for NSCLC. OSU-HDAC-44 was a pan-HDAC inhibitor and exhibits 3-4 times more effectiveness than suberoylanilide hydroxamic acid (SAHA) in suppressing cell viability in various NSCLC cell lines. Upon OSU-HDAC-44 treatment, mitosis and cytokinesis were inhibited and subsequently led to mitochondria-mediated apoptosis. The cytokinesis inhibition resulted from OSU-HDAC-44-mediated degradation of mitosis and cytokinesis regulators Auroroa B and survivin. The deregulation of F-actin dynamics induced by OSU-HDAC-44 was associated with reduction in RhoA activity resulting from srGAP1 induction. Chromatin-immunoprecipitation-on-chip analysis revealed that OSU-HDAC-44 induced chromatin loosening and facilitated transcription of genes involved in crucial signaling pathways such as apoptosis, axon guidance and protein ubiquitination. Finally, OSU-HDAC-44 efficiently inhibited A549 xenograft tumor growth and induced acetylation of histone and non-histone proteins and apoptosis in vivo. Collectively, our data provide compelling evidence that OSU-HDAC-44 is a potent HDAC targeted inhibitor and can be tested for NSCLC chemotherapy. ChIP-chip analysis for H3K9K14ac in A549, H1299 and CL1-1 lung cancer cells treated with 2.5 uM histone deacetylase inhibitor, OSU-HDAC-44, for 2 hours.
Project description:Application of cisplatin (DDP) for treating lung cancer is restricted due to its toxicity and drug resistance. In this study, we aimed to examine whether Jinfukang (JFK), an effective herbal medicine against lung cancer, enhances DDP-induced cytotoxicity in lung cancer cells. Morphologically, we observed JFK increases DDP-induced pro-apoptosis in A549 cells in a synergistic manner. Transcriptome profiling analysis indicated that combination of JFK and DDP regulates genes involved in apoptosis-related signaling pathways. Moreover, we found the combination of JFK and DDP produces synergistic pro-apoptosis effect in other lung cancer cell lines NCI-H1975, NCI-H1650 and NCI-H2228. Particularly, we demonstrated AIFM2 is activated by the combined treatment of JFK and DDP, and partially mediate the synergistic pro-apoptosis effect. Collectively, this study gives the first evidence that activation of AIFM2 contributes to induction of pro-apoptosis by combined treatment with JFK and DDP in human lung cancer cells and provides an insight for its potential clinical application in lung cancer treatment.
Project description:Background: Lung cancer is the leading cause of cancer related death worldwide. Over the past 15 years no major improvement of survival rates could be accomplished. The recently discovered histone methyltransferase KMT9 as epigenetic regulator of prostate tumor growth has now raised hopes of enabling new cancer therapies. In this study we aimed to identify the function of KMT9 in lung cancer which has remained elusive so far. Methods: We linked full transcriptome and proteome analyses of A549 lung adenocarcinoma cells using RNA-Seq and mass spectrometry with functional cell culture, real-time proliferation and flow cytometry assays. Results: KMT9 is expressed in lung cancer tissue and cell lineswith high levels of KMT9 correlating with poor patient survival. We identified 460 overlapping genes and proteins that are deregulated upon knock-down of KMT9alpha in A549 cells. These genes cluster with proliferation, cell cycle and cell death gene sets as well as with subcellular organelles in gene ontology analysis. Knock-down of KMT9alpha inhibits lung cancer cell proliferation and induces non-apoptotic cell death in A549 cells. Conclusions: The novel histone methyltransferase KMT9 is crucial for proliferation and survival of lung cancer cells harboring various mutations. Small molecule inhibitors targeting KMT9 therefore should be further examined as potential milestones in modern epigenetic lung cancer therapy.
Project description:Embelin (15 uM) induced alterations in the gene expression profile was studied in A549 lung cancer cells during the initial stages of apoptosis (4h following treatment)
Project description:Aldehyde dehydrogenase isozymes ALDH1A1 and ALDH3A1 are highly expressed in non small cell cell lung cancer. Neither the mechanism nor the biological significance for such over expression have been studied. We used microarrays to analyze changes in A549 lung cancer cell line in which ALDH activity was reduced using lentiviral mediated expression of siRNA against both isozymes (Lenti 1+3) Experiment Overall Design: A549 lung cancer cell lines were transduced with lentiviral vectors containing specific siRNA sequences against ALDH1A1, ALDH3A1, both vectors (Lenti 1+3 cells), and against the green flourescent protein (GFP) gene (GFP cells, used as control).