Project description:RNA-seq performed in triplicates in MCF10A and MEF cells. Wildtype/parental vs PIK3CA H1047R mutant. MEFs were treated with DMSO or GDC0032 (500nM) PI3Ka inhibitor treatment while MCF10A cells were treated with DMSO or alpelisib (BYL719) at 1uM.
Project description:While growth factor-independent signaling and proliferation are well-established hallmarks of cancer, little is known regarding growth factor-independent changes in gene expression which occur downstream from oncogenes. The PI3K pathway is one of the most commonly misregulated signaling pathways in human cancers. Here, MCF10A cells expressing the two most common PI3K mutations, PIK3CA E545K and H1047R, were used to identify the repertoire of genes altered by oncogenic PI3K mutations following growth factor deprivation. This gene set most closely correlated with gene signatures from claudin-low and basal-like breast tumors, and categorical enrichment analyses suggested that NF-kB target genes were dramatically upregulated by these mutations. An IKKb inhibitor was used to identify the subset of PI3K-driven genes that is NF-kB dependent. Interestingly, virtually all of these NF-kB dependent genes were secreted proteins, suggesting a paracrine role for this gene set. Among these genes was IL-6, a cytokine frequently expressed in tumors which plays a critical role in generating a tumor-promoting microenvironment. Consistent with this, conditioned media from cells expressing the E545K or H1047R mutations led to increased STAT3 activation in recipient THP-1 monocytes or normal epithelial cells in a NF-kB and IL-6-dependent manner. Together, these data describe a PI3K-driven, NF-kB-dependent gene expression profile which may play a critical role in promoting a microenvironment amenable to tumor progression. 39 normal cell lines vs treated cell lines for micorarray analysis
Project description:Cancer is a genetic disease with frequent somatic alterations in DNA. Study of recurrent copy number aberrations (CNAs) in human cancers would enable the elucidation of disease mechanisms and the identification of key oncogenic drivers with causal roles in oncogenesis. We have comprehensively and systematically characterized CNAs and accompanied gene expression changes in the tumors and their matched non-tumor liver tissues from 286 hepatocellular carcinoma (HCC) patients. Our analysis identified 29 recurrently amplified regions and 22 deleted regions with a high level of copy number changes, harboring established oncogenes and tumor suppressors, including CCND1, MET, CDKN2A and CDKN2B, as well as many other genes not previously reported to be involved in liver carcinogenesis. Cis-acting genes in the amplification and deletion peaks were enriched in core cancer pathways, including cell cycle, p53, PI3K, MAPK, Wnt and TGFβ signaling in large proportions of HCCs. We further validated two candidate driver genes, BCL9 and MTDH, from the recurrent focal amplification peaks and showed that they play a significant role in HCC growth and survival. In summary, we have demonstrated that characterizing the CNA landscape in HCC will facilitate the understanding of disease mechanisms and the identification of oncogenic drivers that may serve as potential therapeutic targets for the treatment of this devastating disease. Two hundred and eighty-six hepatocellular carcinoma tumors and their matched non-tumor adjacent liver tissue samples were genotyped using Illumina HumanOmni1-Quad BeadChip to estimate their somatic copy number profiles.
Project description:Cancer is a genetic disease with frequent somatic alterations in DNA. Study of recurrent copy number aberrations (CNAs) in human cancers would enable the elucidation of disease mechanisms and the identification of key oncogenic drivers with causal roles in oncogenesis. We have comprehensively and systematically characterized CNAs and accompanied gene expression changes in the tumors and their matched non-tumor liver tissues from 286 hepatocellular carcinoma (HCC) patients. Our analysis identified 29 recurrently amplified regions and 22 deleted regions with a high level of copy number changes, harboring established oncogenes and tumor suppressors, including CCND1, MET, CDKN2A and CDKN2B, as well as many other genes not previously reported to be involved in liver carcinogenesis. Cis-acting genes in the amplification and deletion peaks were enriched in core cancer pathways, including cell cycle, p53, PI3K, MAPK, Wnt and TGFβ signaling in large proportions of HCCs. We further validated two candidate driver genes, BCL9 and MTDH, from the recurrent focal amplification peaks and showed that they play a significant role in HCC growth and survival. In summary, we have demonstrated that characterizing the CNA landscape in HCC will facilitate the understanding of disease mechanisms and the identification of oncogenic drivers that may serve as potential therapeutic targets for the treatment of this devastating disease. Thirty hepatocellular carcinoma cell lines were genotyped using Illumina HumanOmni1-Quad BeadChip to estimate their copy number profiles relative to pooled Hapmap samples.
Project description:While growth factor-independent signaling and proliferation are well-established hallmarks of cancer, little is known regarding growth factor-independent changes in gene expression which occur downstream from oncogenes. The PI3K pathway is one of the most commonly misregulated signaling pathways in human cancers. Here, MCF10A cells expressing the two most common PI3K mutations, PIK3CA E545K and H1047R, were used to identify the repertoire of genes altered by oncogenic PI3K mutations following growth factor deprivation. This gene set most closely correlated with gene signatures from claudin-low and basal-like breast tumors, and categorical enrichment analyses suggested that NF-kB target genes were dramatically upregulated by these mutations. An IKKb inhibitor was used to identify the subset of PI3K-driven genes that is NF-kB dependent. Interestingly, virtually all of these NF-kB dependent genes were secreted proteins, suggesting a paracrine role for this gene set. Among these genes was IL-6, a cytokine frequently expressed in tumors which plays a critical role in generating a tumor-promoting microenvironment. Consistent with this, conditioned media from cells expressing the E545K or H1047R mutations led to increased STAT3 activation in recipient THP-1 monocytes or normal epithelial cells in a NF-kB and IL-6-dependent manner. Together, these data describe a PI3K-driven, NF-kB-dependent gene expression profile which may play a critical role in promoting a microenvironment amenable to tumor progression.
Project description:Hyperactivation of the phosphatydil-inositol-3' phosphate kinase (PI3K)/AKT pathway is observed in most NSCLCs, promoting proliferation, migration, invasion and resistance to therapy. AKT can be activated through several mechanisms that include loss of the negative regulator PTEN, activating mutations of the catalytic subunit of PI3K (PIK3CA) and/or mutations of AKT1 itself. However, number and identity of downstream targets of activated PI3K/AKT pathway are poorly defined. To identify the genes that are targets of constitutive PI3K/AKT signalling in lung cancer cells, we performed a comparative transcriptomic analysis of human lung epithelial cells (BEAS-2B) expressing active mutant AKT1 (AKT1-E17K), active mutant PIK3CA (PIK3CA-E545K) or that are silenced for PTEN. For each sample, 500 ng of total RNA were used to synthesize biotinylated cRNA with Illumina RNA Amplification Kit (Ambion, Austin, TX). Synthesis was carried out according to the manufacturersâ instructions. From each sample, technical triplicates were produced and 750 ng cRNA were hybridized for 18h to Human HT-12_V3_0_R1 Expression BeadChips (Illumina, San Diego, CA). Hybridized chips were washed and stained with streptavidin-conjugated Cy3 (GE Healthcare, Milan, Italy). BeadChips were dried and scanned with an Illumina Bead Array Reader (Illumina).
Project description:The PTEN/PI3K pathway is commonly mutated in cancer and therefore represents a rational target for therapeutic intervention. In order to investigate the primary phenotype(s) mediated by mutant PIK3CA in a clean and highly patient-relevant context, we utilized a non-tumorigenic MCF10A parental and isogenic knock-in cell line that harbors a common activating PIK3CA kinase domain mutation (H1047R). We found that introduction of an endogenously mutated PIK3CA primarily results in a marked epithelial-mesenchymal transition (EMT) and invasive phenotype compared to isogenic wild-type cells. Moreover, a potent and selective inhibitor of PIK3CA (GDC-0941) was highly effective and selective on reversing this phenotype compared to cell-proliferation, highlighting a potential new paradigm for studying PI3K-pathway targeted agents. Keywords: Expression Array Gene expression profiles from a parental MCF10A breast line and an MCF10A clone that has a PI3K activating mutation (H1047R) knocked-in. We plated the cells in 10cm dishes overnight in media with serum, but lacking EGF or insulin. DMSO or GDC-0941 (PI3K inhibitor) at an EC50 concentration were added to triplicate plates of cells in the morning. After 4 hours the RNA was harvested using the Qiagen RNeasy kit. There are 12 samples total.
Project description:Dysregulation of PI3K/Akt signaling is a dominant feature in basal-like or triple-negative breast cancers (TNBC). However, the mechanisms regulating this pathway are largely unknown in this subset of aggressive tumors. Here we demonstrate that the transcription factor SOX4 is a key regulator of PI3K signaling in TNBC. Genomic and proteomic analyses coupled with mechanistic studies identified TGFBR2 as a direct transcriptional target of SOX4 and demonstrated that TGFBR2 is required to mediate SOX4-dependent PI3K signaling. We further report that SOX4 and the SWI/SNF ATPase SMARCA4, which are uniformly overexpressed in basal-like tumors, form a previously unreported complex that is required to maintain an open chromatin conformation at the TGFBR2 regulatory regions in order to mediate TGFBR2 expression and PI3K signaling. Collectively, our findings delineate the mechanism by which SOX4 and SMARCA4 cooperatively regulate PI3K/Akt signaling and suggest that this complex may play an essential role in TNBC genesis and/or progression.