Project description:TIMP-2 is an endogenous angiogenesis inhibitor, i.e. inhibits endothelial cell proliferation and tumor angiogenesis. As a result, TIMP-2 inhibits tumor growth and progression to metastasis. Understanding, therefore, the mechanisms of TIMP-2-mediated tumor growth inhibition would provide further support on the use of TIMP-2 as a novel biological agent for cancer therapy. We used microarray analysis to determine the TIMP-2 and Ala+TIMP-2 transcriptional profiles of A549 cancer cells in order to understand how TIMP-2 inhibits tumor growth and angiogenesis.
Project description:TIMP-2 is an endogenous angiogenesis inhibitor, i.e. inhibits endothelial cell proliferation and tumor angiogenesis. As a result, TIMP-2 inhibits tumor growth and progression to metastasis. Understanding, therefore, the mechanisms of TIMP-2-mediated tumor growth inhibition would provide further support on the use of TIMP-2 as a novel biological agent for cancer therapy. We used microarray analysis to determine the TIMP-2 and Ala+TIMP-2 transcriptional profiles of A549 cancer cells in order to understand how TIMP-2 inhibits tumor growth and angiogenesis. We overexpressed TIMP-2 and its mutant (does not inhibit MMP) in A549 human lung cancer cells and determined TIMP-2 and Ala+TIMP-2 transcriptional profiles, groups of genes and associated biological functions. We then injected the cells in NOD-SCID mice and RNA from tumors were isolated for further analysis to identify genes that are associated with tumor growth inhibition.
Project description:KSHV is a principal causative agent of primary effusion lymphoma (PEL). Despite this knowledge about the close relationship between HGF/c-MET network and solid tumors development, the role of HGF/c-MET in KSHV-related malignancies remains mostly unclear. We report that HGF/c-MET pathway is highly active within KSHV+ PEL cells and plays important role in tumor cell survival/growth. Targeting HGF/c-MET by a selective inhibitor, PF-2341066, significantly induces PEL apoptosis through a complex of underlying mechanisms, including cell-cycle arrest and DNA damage. By using microarray analysis, we have identified the global gene profile controlled by HGF/c-MET pathway within KSHV+ PEL cell-lines and several novel âdruggableâ candidates closely related to cancer cell survival/growth. Finally, we found that targeting HGF/c-MET pathway by PF-2341066 effectively prevents PEL tumor expansion and/or reduce established lymphoma progression in vivo. PEL cells were treated with vehicle control or c-MET inhibitor PF-2341066 (0.8 µM) for 24 h, and the gene expression signature was compared to respective vehicle controls
Project description:Tumors maintain an alkaline intracellular environment to enable rapid growth. The proton exporter NHE1 participates in maintenance of this pH gradient. However, whether targeting NHE1 could inhibit the growth of tumor cells remains unknown. Here, we report that the NHE1 inhibitor Hexamethylene amiloride (HA) efficiently suppresses the growth of AML cell lines. Moreover, HA combined with venetoclax synergized to efficiently inhibit the growth of AML cells. Interestingly, lysosomes are the main contributors to the synergism of HA and venetoclax in inhibiting AML cells. Most importantly, the combination of HA and venetoclax also had prominent anti-leukemia effects in both xenograft models and bone marrow samples from AML patients. In summary, our results provide evidence that the NHE1 inhibitor HA or its combination with venetoclax efficiently inhibits the growth of AML in vitro and in vivo.
Project description:Endoplasmic reticulum (ER) stress triggers an adaptive response which fosters tumor cell survival and resilience to stress conditions. Activation of the endoplasmic reticulum stress response, through its PERK branch, promotes the phosphorylation of the α-subunit of translation initiation factor eIF2alpha, thereby repressing general protein translation and selectively augmenting the translation of ATF4 with the downstream CHOP transcription factor and the protein disulfide oxidase ERO1. Here, we show that ISRIB, a small molecule, which inhibits the action of the phosphorylated α-subunit of eIF2, thereby activating protein translation, synergistically interacts with the genetic deficiency of protein disulfide oxidase ERO1 enfeebling tumor growth and spreading. ISRIB represses CHOP signal but surprisingly does not inhibit ERO1. Mechanistically, ISRIB increases the ER protein load with a prominent perturbing effect on ERO1 deficient Triple-Negative breast cells, which have adapted to live with low client protein load, while ERO1 deficiency selectively impairs VEGF-dependent angiogenesis. Strikingly, ERO1-deficient Triple Negative Breast Cancer xenografts have augmented ER stress response and PERK branch. In vivo, ISRIB synergistically with ERO1 deficiency inhibits the growth of Triple-Negative Breast cancer xenografts by impairing proliferation and angiogenesis, while it is not effective on the xenograft counterparts with ERO1. In summary, these results demonstrate that ISRIB together with ERO1 deficiency synergistically shatters a feature of the adaptive ER stress response while ERO1 deficiency selectively impairs angiogenesis in tumors, thereby together promoting tumor cytotoxicity. Therefore, our findings suggest two surprising findings in breast tumors: ERO1 is not regulated via CHOP and ISRIB represents a therapeutic option to efficiently inhibit tumor progression in those tumors with limited ERO1 and high PERK.
Project description:Tumor hypoxia is relevant for tumor growth, metabolism and epithelial-to-mesenchymal transition (EMT). We report that hyperbaric oxygen (HBO) treatment induced mesenchymal-to-epithelial transition (MET) in a dimetyl-α-benzantracene induced mammary rat adenocarcinoma model, and the MET was associated with extensive coordinated gene expression changes and less aggressive tumors. One group of tumor bearing rats was exposed to HBO (2 bar, pO2 = 2 bar, 4 exposures à 90 minutes), whereas the control group was housed under normal atmosphere (1 bar, pO2 = 0.2 bar). Treatment effects were determined by assessment of tumor growth, tumor vascularisation, tumor cell proliferation, cell death, collagen fibrils and gene expression profile. Tumor growth was significantly reduced (~16%) after HBO treatment compared to day 1 levels, whereas control tumors increased almost 100 % in volume. Significant decreases in tumor cell proliferation, tumor blood vessels and collagen fibrils, together with an increase in cell death, are consistent with tumor growth reduction and tumor stroma influence after hyperoxic treatment. Gene expression profiling showed that HBO induced MET with coordinated expression of gene modules involved in cell junctions and attachments together with a shift towards non-tumorigenic metabolism. This leads to more differentiated and less aggressive tumors, and indicates that oxygen per se might be an important factor in the â??switchesâ?? of EMT and MET in vivo. HBO treatment also attenuated tumor growth and changed tumor stroma, by targeting the vascular system, having anti-proliferative and pro-apoptotic effects.
Project description:KSHV is a principal causative agent of primary effusion lymphoma (PEL). Despite this knowledge about the close relationship between HGF/c-MET network and solid tumors development, the role of HGF/c-MET in KSHV-related malignancies remains mostly unclear. We report that HGF/c-MET pathway is highly active within KSHV+ PEL cells and plays important role in tumor cell survival/growth. Targeting HGF/c-MET by a selective inhibitor, PF-2341066, significantly induces PEL apoptosis through a complex of underlying mechanisms, including cell-cycle arrest and DNA damage. By using microarray analysis, we have identified the global gene profile controlled by HGF/c-MET pathway within KSHV+ PEL cell-lines and several novel “druggable” candidates closely related to cancer cell survival/growth. Finally, we found that targeting HGF/c-MET pathway by PF-2341066 effectively prevents PEL tumor expansion and/or reduce established lymphoma progression in vivo.
Project description:With the advent of potent second-line anti-androgen therapy, we and others have observed an increased incidence of androgen receptor (AR)-null small cell or neuroendocrine prostate cancer (SCNPC) in metastatic castration-resistant prostate cancer (mCRPC). Additionally, we have detected upregulated expression of MET and RET transcripts in SCNPC metastases relative to adenocarcinoma. Our study was designed to determine the effect of cabozantinib, a multi-targeted tyrosine kinase inhibitor that inhibits MET, RET and VEGFR2, on SCNPC patient-derived xenografts (PDX) in vivo. Surveillance of SU2C and University of Washington rapid autopsy mCRPC cohorts through RNA-Seq revealed that increased MET expression significantly correlated with loss of AR expression and activity. In vitro treatment of SCNPC PDX cells with AMG 337 had no impact on cell viability in LuCaP 93 (MET+/RET+) and LuCaP 173.1 (MET-/RET-), whereas cabozantinib decreased cell viability in LuCaP 93, but not in LuCaP 173.1. Notably, tumor volume was significantly decreased (p<0.001) with cabozantinib treatment in SCID mice bearing LuCaP 93 and LuCaP 173.1 tumors. Tissue analysis indicated that tumor cell proliferation was not inhibited by cabozantinib, but that cabozantinib decreased microvessel density (CD31) in LuCaP 93 (p<0.001) and LuCaP 173.1 (p<0.01) tumors. RNA-Seq and gene set enrichment analysis determined that hypoxia and glycolysis pathways were increased in cabozantinib treated tumors relative to control tumors. Thus, cabozantinib inhibited tumor growth in MET+/RET+ LuCaP 93 and MET-/RET- LuCaP 173.1 tumors in vivo and this activity was independent of MET or RET expression in LuCaP 173.1. Our data suggest that the most likely mechanism of tumor growth suppression is through disruption of the stromal architecture and cabozantinib may represent a potential therapy for patients with metastatic disease in tumor phenotypes that have a significant dependence on the tumor vasculature for survival and proliferation.
Project description:The platelet-derived growth factor (PDGF) signaling system contributes to tumor angiogenesis and vascular remodeling. Here, we show PDGF-BB markedly induces erythropoietin (EPO) mRNA and protein expression by targeting the PDGFR-beta+ stromal and perivascular compartments. In mouse tumor models, PDGF-BB-induced EPO promotes tumor growth via two mechanisms: 1) paracrine stimulation of tumor angiogenesis by directly inducing endothelial cell proliferation, migration, sprouting and tube formation; and 2) endocrine stimulation of extramedullary hematopoiesis leading to increased oxygen perfusion and protection against tumor-associated anemia. Similarly, delivery of an adenovirus-PDGF-BB to tumor-free mice markedly increases EPO production and hematopoietic parameters. An EPO blockade specifically attenuates PDGF-BB-induced tumor growth, angiogenesis and hematopoiesis. At the molecular level, we show that the PDGF-BB-PDGFR-beta signaling system activates EPO promoter via in part transcriptional regulation of ATF3 by possible association with c-Jun and SP1. These findings uncover a novel mechanism of PDGF-BB-induced tumor growth, angiogenesis and hematopoiesis. Comparison of S17 stromal cells treated with PDGF-BB for 72h to control
Project description:Despite advances in molecular pathogenesis, pancreatic cancer remains a major unsolved health problem. It is a rapidly invasive, metastatic tumor that is resistant to standard therapies. The phosphatidylinositol-3-kinase (PI3K)/Akt and mammalian target of rapamycin (mTOR) signaling pathways are frequently dysregulated in pancreatic cancer. Gemcitabine (Gem) is the mainstay treatment for metastatic pancreatic cancer. P276 is a novel CDK inhibitor that induces G2/M arrest and inhibits tumor growth in vivo models. Here, we determined that P276 sensitizes pancreatic cancer cells to Gem induced apoptosis, a mechanism mediated through inhibition of Akt-mTOR signaling. In vitro, the combination of P276 and Gem resulted in a dose- and time-dependent inhibition of proliferation and colony formation of pancreatic cancer cells but not with normal pancreatic ductal cells. This combination also induced apoptosis, as seen by activated caspase 3 and increased Bax/Bcl2 ratio. Gene profiling studies demonstrated that this combination down regulated Akt-mTOR signaling pathway, which was confirmed by western blot analyses. There was also a down regulation of vascular endothelial growth factor (VEGF) and interleukin-8 expression suggesting effects on angiogenesis pathway. In vivo, intraperitoneal administration of the P276-Gem combination significantly suppressed the growth of pancreatic cancer tumor xenografts. There was a reduction in CD31 positive blood vessels, and reduced VEGF expression, again suggesting an effect on angiogenesis. Taken together, these data suggest that P276-Gem combination is a novel potent therapeutic agent that can target the Akt-mTOR signaling pathway to inhibit both tumor growth and angiogenesis. Case control dual channel design