dactolisib and Disease-Models--Animal

Due to the high relapse rate and toxicity of the common therapies in patients with acute myeloid leukemia (AML), modifications in the treatment strategies are required. The present study was conducted to determine the effects of combinational therapy with a dual PI3K/mTOR inhibitor, BEZ235, and TLR7/8 agonist, R848, on murine AML model.. BEZ235 and R848 were administered to AML leukemic mice in either a single or combination treatment. Frequency of T-CD4. Following combinational therapy with BEZ235 and R848, increasing in the frequency of anti-tumor immune cells including T-CD4. Taken together, we indicated that the combinational therapy with BEZ235 and R848 could be considered as a potential and powerful therapeutic option for AML patients. Further clinical studies are required to expand our current findings.

Topics: Adjuvants, Immunologic; Animals; Body Weight; Disease Models, Animal; Humans; Leukemia, Myeloid, Acute; Mice; Phosphatidylinositol 3-Kinases; Toll-Like Receptor 7

Intrahepatic cholangiocarcinoma (ICC), the second most common primary liver cancer, is a fatal malignancy with a poor prognosis and only very limited therapeutic options. Although molecular targeted therapy is emerged as a promising treatment strategy, resistance to molecular-targeted therapy occurs inevitably, which represents a major clinical challenge. In this study, we confirmed that mammalian target of rapamycin (mTOR) signaling is the most significantly affected pathways in ICC. As a novel phosphoinositide 3-kinase (PI3K)/mTOR dual inhibitor, BEZ235, exerts antitumour activity by effectively and specifically blocking the dysfunctional activation of the PI3K/serine/threonine kinase (AKT)/mTOR pathway. We generate the orthotopic ICC mouse model through hydrodynamic transfection of AKT and yes-associated protein (YAP) plasmids into the mouse liver. Our study confirmed that BEZ235 can suppress the proliferation, invasion and colony conformation abilities of ICC cells in vitro but cannot effectively inhibit ICC progression in vivo. Inhibition of PI3K/mTOR allowed upregulation of c-Myc and YAP through suppressed the phosphorylation of LATS1. It would be a novel mechanism that mediated resistance to PI3K/mTOR dual inhibitor. However, Bromo- and extraterminal domain (BET) inhibition by JQ1 downregulates c-Myc and YAP transcription, which could enhance the efficacy of PI3K/mTOR inhibitors. The efficacy results of combination therapy exhibited effective treatment on ICC in vitro and in vivo. Our data further confirmed that the combination of PI3K/mTOR dual inhibitor and BET inhibition induces M1 polarization and suppresses M2 polarization in macrophages by regulating the expression of HIF-1α. Our study provides a novel and efficient therapeutic strategy in treating primary ICC.

Topics: Animals; Antineoplastic Agents; Azepines; Bile Duct Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cholangiocarcinoma; Disease Models, Animal; Drug Therapy, Combination; Humans; Imidazoles; Mice; MTOR Inhibitors; Nerve Tissue Proteins; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Receptors, Cell Surface; Signal Transduction; TOR Serine-Threonine Kinases; Transcriptome; Treatment Outcome; Triazoles

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Overactivation of the PI3K/mTOR signaling has been identified in non-Hodgkin's lymphoma. BEZ235 is an effective dual PI3K/mTOR inhibitor, but it was withdrawn from early-phase clinical trials owing to poor solubility and on-target/off-tumor toxicity. Here, we developed a nanoparticle (NP)-based pretargeted system for the therapeutic delivery of BEZ235 to CD20- and HLA-DR-expressing lymphoma cells for targeted therapy. The pretargeted system is composed of dibenzocyclooctyne-functionalized anti-CD20 and anti-Lym1 antibodies as the tumor-targeting components and azide-functionalized BEZ235-encapsulated NPs as the effector drug carrier. Using lymphoma cell lines with different CD20 and HLA-DR antigen densities as examples, we demonstrate that the dual antibody pretargeted strategy effectively raises the number of NPs retained on the target tumor cells and improves the in vitro and in vivo antitumor activity of BEZ235 through the inhibition of the PI3K/mTOR pathway. Our data demonstrate that the NP-based pretargeted system improves the therapeutic window of small-molecule kinase inhibitor.

Topics: Animals; Antigens, CD20; Cell Line, Tumor; Disease Models, Animal; Drug Compounding; HLA-DR Antigens; Humans; Imidazoles; Immunophenotyping; Lymphoma, Non-Hodgkin; Nanoparticles; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Quinolines; Tissue Distribution; TOR Serine-Threonine Kinases; Treatment Outcome; Xenograft Model Antitumor Assays

Human papillomavirus (HPV) infection is the major risk factor for anal dysplasia that may progress to squamous cell carcinoma of the anus. We have previously shown that systemic administration of a PI3K/mTOR inhibitor (BEZ235), an autophagic inducer, results in decreased squamous cell carcinoma of the anus in our HPV mouse model. In this study, we investigate the effect of the local, topical application of a BEZ235 on tumor-free survival, histopathology, PI3K/mTOR, and autophagy. The rationale for investigating a topical formulation is the localized nature of anal dysplasia/cancer and the goal for creating a clinically translatable formulation to decrease anal carcinogenesis. In this study, HPV transgenic mice were given no treatment, topical BEZ235, topical 7,12 dimethylbenz[a]anthracene (DMBA) (carcinogen), or both topical DMBA + BEZ235. Mice were assessed for tumor development and treatment-related toxicities. Tissue was evaluated for histology, PI3K/mTOR inhibition (pS6 and pAkt), and autophagy (LC3β and p62). DMBA-alone mice had an average of 16.9 weeks tumor-free survival, whereas mice receiving both DMBA+topical BEZ235 had 19.3 weeks (P < 0.000001). Histopathology revealed a significant decrease in dysplasia/carcinoma with the addition of topical BEZ235 to DMBA (P < 0.000001). Comparing DMBA versus DMBA + BEZ235, topical BEZ235 resulted in a significant decrease in both pS6 and pAkt (P < 0.001). Compared with no-treatment mice, both BEZ235-treated and DMBA + BEZ235-treated mice had significantly higher LC3β expression, signifying autophagic induction (P < 0.01), whereas DMBA-treated, BEZ235-treated, and DMBA+BEZ235-treated mice had a significantly lower p62 expression, signifying active autophagy (P < 0.0005). In conclusion, consistent with systemic delivery, topical application of BEZ235 shows decreased anal carcinogenesis through the activation of autophagy.

Topics: Administration, Topical; Animals; Anthracenes; Antineoplastic Agents; Anus Neoplasms; Apoptosis; Carcinogens; Cell Proliferation; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Mice; Papillomaviridae; Papillomavirus Infections; Phosphatidylinositol 3-Kinases; Piperidines; Quinolines; TOR Serine-Threonine Kinases

To compare the anti-peritoneal fibrotic effects between a mammalian target of rapamycin complex 1-specific blocker and a phosphatidyl-inositol 3-kinase/mammalian target of rapamycin dual-blocker.. A total of 40 male Sprague-Dawley rats were randomly divided into five groups with eight animals per group. The normal group (N group) did not receive any intervention. The normal saline group (NS group) received an intraperitoneal injection of normal saline at 1 ml/100 g daily. The model group (3 W group), rapamycin (RAPA) group and BEZ235 (PI3K/mTOR dual-blocker) group all received an intraperitoneal injection of 0.1% chlorhexidine gluconate at 1 ml/100g daily. And the RAPA and BEZ235 groups also received a 0.5 mg/d RAPA or 2.5 mg/d BEZ235 gavage every day, respectively. Rats in each group were sacrificed after 3 weeks.. Immunohistochemistry, real-time PCR and western blotting analysis of fibrosis-related indicators (FN, Col 1, and α-SMA) confirmed that RAPA and BEZ235 significantly inhibited peritoneal fibrosis and that these two drugs had similar effects. The p-Akt, p-mTOR, p-p70S6K expression levels were significantly up-regulated in the 3 W group compared to the NS group, confirming that the mTOR pathway was significantly activated during peritoneal fibrosis. RAPA significantly inhibited the phosphorylation of mTOR and p70S6K but did not have significant effects on p-Akt upstream of mTOR. BEZ235 had significant inhibitory effects on all signaling molecules (p-Akt, p-mTOR, and p-p70S6K) in the mTOR pathway.. RAPA did not up-regulate p-Akt in a negative feedback fashion. Both drugs effectively inhibited peritoneal fibrosis.

Topics: Animals; Chlorhexidine; Disease Models, Animal; Drug Evaluation, Preclinical; Humans; Imidazoles; Injections, Intraperitoneal; Kidney Failure, Chronic; Male; Mechanistic Target of Rapamycin Complex 1; Peritoneal Dialysis; Peritoneal Fibrosis; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-akt; Quinolines; Rats; Rats, Sprague-Dawley; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Use of drug combinations that target different pathways involved in the development and progression of prostate cancer (PCa) has emerged as an alternative to overcome the resistance caused by drug monotherapies. The antiandrogen abiraterone acetate and the PI3K/Akt inhibitor NVP-BEZ235 (BEZ235) may be suitable options for the prevention of drug resistance and the inhibition of PCa progression. The aim of the present study was to evaluate whether abiraterone acetate and BEZ235 achieve superior therapeutic effects to either drug administered as monotherapy, in the early stages of PCa in an androgen-dependent system. Our study showed that each drug might impair tumor growth by reducing proliferation and increasing cell death when administered as monotherapy. However, tumor growth continued to progress with each drug monotherapy and some important side effects were related to BEZ. Conversely, when used in combination, the drugs impaired the inflammatory response, decreased hyperplastic lesions, and blocked tumor progression from premalignant to a malignant stage. Our data showed that the strategy to block the androgenic and PI3K/AKT/mTOR pathway is an effective therapeutic option and should be investigated including distinct PI3K pathway inhibitors.

Topics: Abiraterone Acetate; Androgen Antagonists; Androgens; Animals; Antineoplastic Combined Chemotherapy Protocols; Carcinogenesis; Disease Models, Animal; Drug Synergism; Humans; Imidazoles; Male; Phosphoinositide-3 Kinase Inhibitors; Prostatic Neoplasms; Protein Kinase Inhibitors; Quinolines; Rats; Rats, Inbred F344; Signal Transduction; Tumor Cells, Cultured

A significant fraction of patients with advanced prostate cancer treated with androgen deprivation therapy experience relapse with relentless progression to lethal metastatic castration-resistant prostate cancer (mCRPC). Immune checkpoint blockade using antibodies against cytotoxic-T-lymphocyte-associated protein 4 (CTLA4) or programmed cell death 1/programmed cell death 1 ligand 1 (PD1/PD-L1) generates durable therapeutic responses in a significant subset of patients across a variety of cancer types. However, mCRPC showed overwhelming de novo resistance to immune checkpoint blockade, motivating a search for targeted therapies that overcome this resistance. Myeloid-derived suppressor cells (MDSCs) are known to play important roles in tumour immune evasion. The abundance of circulating MDSCs correlates with prostate-specific antigen levels and metastasis in patients with prostate cancer. Mouse models of prostate cancer show that MDSCs (CD11b

Topics: Anilides; Animals; CD8-Positive T-Lymphocytes; Chimera; Cytokines; Disease Models, Animal; Drug Synergism; Female; Humans; Imidazoles; Immunotherapy; Lymphocytes, Tumor-Infiltrating; Male; Mice; Molecular Targeted Therapy; Myeloid-Derived Suppressor Cells; Phosphoinositide-3 Kinase Inhibitors; Prostatic Neoplasms, Castration-Resistant; Pyridines; Quinolines; Signal Transduction; Tumor Microenvironment

The aim of our study is to evaluate the preclinical therapeutic activity and mechanism of action of BEZ235, a dual PI3K/mTOR inhibitor, in combination with dexamethasone in acute lymphoblastic leukemia (ALL).. The cytotoxic effects of BEZ235 and dexamethasone as single agents and in combination were assessed in a panel of ALL cell lines and xenograft models. The underlying mechanism of BEZ235 and dexamethasone was evaluated using immunoblotting, TaqMan RT-PCR, siRNA, immunohistochemistry, and immunoprecipitation.. Inhibition of the PI3K/AKT/mTOR pathway with the dual PI3K/mTOR inhibitor BEZ235 enhanced dexamethasone-induced anti-leukemic activity in in vitro (continuous cell lines and primary ALL cultures) and systemic in vivo models of T-ALL (including a patient-derived xenograft). Through inhibition of AKT1, BEZ235 was able to alleviate AKT1-mediated suppression of dexamethasone-induced apoptotic pathways leading to increased expression of the proapoptotic BCL-2 protein BIM. Downregulation of MCL-1 by BEZ235 further contributed to the modulation of dexamethasone resistance by increasing the amount of BIM available to induce apoptosis, especially in PTEN-null T-ALL where inhibition of AKT only partially overcame AKT-induced BIM suppression.. Our data support the further investigation of agents targeting the PI3K/mTOR pathway to modulate glucocorticoid resistance in T-ALL.

Topics: Animals; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; Cell Line, Tumor; Cell Survival; Dexamethasone; Disease Models, Animal; Drug Resistance, Neoplasm; Drug Synergism; Female; Gene Expression Regulation, Neoplastic; Glucocorticoids; Humans; Imidazoles; Membrane Proteins; Myeloid Cell Leukemia Sequence 1 Protein; Phosphoinositide-3 Kinase Inhibitors; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Quinolines; TOR Serine-Threonine Kinases; Tumor Burden; Xenograft Model Antitumor Assays

The volatile anesthetic isoflurane (ISO) has been widely used in ischemia reperfusion (IR) injury because its abilities to induce and trigger recovery are faster and smoother than other agents. However, the underlying molecular mechanisms for preconditioning the ISO in protecting the brain against IR injury are still largely unclear. In this paper, we investigated the neuroprotective effect of the ISO in the in vivo and in vitro models of IR injury and evaluated the possible correlation with Akt/mTOR/s6K signaling pathway. From the in vivo studies, we demonstrated that ISO preconditioning alleviated the IR-induced neurological deficits, infarct volume, brain edema and cell apoptosis, which were mainly due to the up-regulation of the p-Akt, p-mTOR and p-s6K proteins by the histopathological detections and Western blotting assay. The in vitro studies, demonstrated that ISO preconditioning reduced the release of OGD-induced lactate dehydrogenase (LDH) and enhanced the OGD-inhibited cell viability. It has also been observed that the hypoxia inducible factor-1α (HIF-1α) was increased under ISO preconditioning. Utilization of the BEZ235, a PI3K/mTOR dual inhibitor, halted the ISO-induced up-regulation of the HIF-1α, and inhibited the phosphorylation of the Akt, mTOR and s6K proteins. Besides, the ISO reduced the OGD-induced cell apoptosis, which was blocked by the BEZ235. In fact, these results thus suggest that the ISO preconditioning may provide potential neuroprotection against IR injury via up-regulating the HIF-1α expression through the Akt/mTOR/s6K activation.

Topics: Animals; Apoptosis; Blotting, Western; Brain; Cell Line; Cell Survival; Disease Models, Animal; Hypoxia-Inducible Factor 1, alpha Subunit; Imidazoles; Ischemic Preconditioning; Isoflurane; Male; Mice; Phosphorylation; Protective Agents; Proto-Oncogene Proteins c-akt; Quinolines; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Ribosomal Protein S6 Kinases; Signal Transduction; TOR Serine-Threonine Kinases; Up-Regulation

Imaging studies in animals and in humans have indicated that the oxygenation and nutritional status of solid tumors is dynamic. Furthermore, the extremely low level of glucose within tumors, while reflecting its rapid uptake and metabolism, also suggests that cancer cells must rely on other energy sources in some circumstances. Here, we find that some breast cancer cells can switch to utilizing lactate as a primary source of energy, allowing them to survive glucose deprivation for extended periods, and that this activity confers resistance to PI3K/mTOR inhibitors. The nuclear receptor, estrogen-related receptor alpha (ERRα), was shown to regulate the expression of genes required for lactate utilization, and isotopomer analysis revealed that genetic or pharmacological inhibition of ERRα activity compromised lactate oxidation. Importantly, ERRα antagonists increased the in vitro and in vivo efficacy of PI3K/mTOR inhibitors, highlighting the potential clinical utility of this drug combination.

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Cell Line, Tumor; Cell Respiration; Cytoprotection; Disease Models, Animal; Drug Resistance, Neoplasm; ERRalpha Estrogen-Related Receptor; Female; Glucose; Glutamine; Humans; Imidazoles; Lactates; Mice, Inbred NOD; Mice, SCID; Mitochondria; Models, Biological; Oxidation-Reduction; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Quinolines; Reactive Oxygen Species; Receptors, Estrogen; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

The plasma cell malignancy multiple myeloma (MM) is unique among haematological malignancies in its capacity to cause osteoclast-mediated skeletal destruction. The PI3K/Akt/mTOR pathway mediates proliferation, survival and drug resistance in MM plasma cells and is also involved in regulating the formation and activity of bone-forming osteoblasts and bone-resorbing osteoclasts. NVP-BEZ235 is a dual pan class I PI3K and mTOR inhibitor that is currently undergoing clinical evaluation in several tumour settings. In this study, we examined the anti-tumorigenic effects of BEZ235 in an immunocompetent mouse model of MM and assessed the effects of BEZ235 on osteoblast and osteoclast formation and function. BEZ235 treatment (50 mg/kg) resulted in a significant decrease in serum paraprotein and tumour burden, and μCT analysis of the proximal tibia revealed a significant reduction in the number of osteolytic bone lesions in BEZ235-treated animals. Levels of the serum osteoblast marker P1NP were significantly higher in BEZ235-treated animals, while levels of the osteoclast marker TRAcP5 were reduced. In vitro, BEZ235 decreased MM plasma cell proliferation, osteoclast formation and function and promoted osteoblast formation and function. These findings suggest that, in addition to its anti-tumour properties, BEZ235 could be useful in treating osteolytic bone disease in MM patients.

Topics: Animals; Bone Diseases; Cell Line; Cell Proliferation; Disease Models, Animal; Imidazoles; Mesenchymal Stem Cells; Mice; Multiple Myeloma; Osteoclasts; Osteogenesis; Osteolysis; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases; Tumor Burden

Novel therapeutic approaches are needed to improve the postoperative management of residual nonfunctioning pituitary adenomas (NFPA), given their high relapse rate. Here, we evaluated the antitumor efficacy of the dual PI3K/mTOR inhibitor NVP-BEZ235 in the only available model of spontaneous NFPAs (MENX rats).. Organotypic cultures of rat primary NFPAs were incubated with NVP-BEZ235 and assessed for cell viability, proliferation, apoptosis, and PI3K/mTOR inhibition. NVP-BEZ235, or placebo, was administered to MENX rats and tumor response was monitored noninvasively by diffusion weighted-magnetic resonance imaging (DW-MRI). Following treatment, tumor tissues were investigated for cell proliferation, apoptosis, and PI3K/mTOR inhibition. Genes mediating the cytotoxic activity of NVP-BEZ235 were identified by gene-expression profiling. Among them, Defb1, encoding beta-defensin 1, was further studied for its role in pituitary cells and in human pancreatic neuroendocrine tumor (NET) cells.. NVP-BEZ235 showed antiproliferative and pro-cell death activities against NFPAs both in vitro and in vivo, and the response to the drug correlated with inhibition of the PI3K pathway. DW-MRI identified early functional changes (decreased cellularity) in the adenomas before their size was affected and emerged as a useful modality to assess therapy response. The cytotoxic effect of PI3K/mTOR blockade in NFPA was mediated by several genes, including Defb1. NVP-BEZ235 treatment induced Defb1 expression in NFPAs in vitro and in vivo, and in pancreatic NET cells. High Defb1 levels sensitized NET cells to PI3K/mTOR inhibition.. Our findings provide rationale for clinical investigation of PI3K/mTOR inhibition in NFPAs and identify novel effectors of PI3K-mediated neuroendocrine cell survival.

Topics: Animals; Antineoplastic Agents; beta-Defensins; Defensins; Disease Models, Animal; Fluorescent Antibody Technique; Gene Expression Regulation; Humans; Imidazoles; Phosphoinositide-3 Kinase Inhibitors; Pituitary Neoplasms; Quinolines; Rats; Rats, Mutant Strains; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; TOR Serine-Threonine Kinases

A prominent role in the pathogenesis of squamous cell carcinoma of the lung (SQCLC) has been attributed to the aberrant activation of the PI3K signaling pathway, due to amplification or mutations of the p110α subunit of class I phosphatidylinositol 3-kinase (PIK3CA) gene. The aim of our study was to determine whether different genetic alterations of PIK3CA affect the biologic properties of SQCLC and to evaluate the response to specific targeting agents in vitro and in vivo. The effects of NVP-BEZ235, NVP-BKM120, and NVP-BYL719 on two-dimensional/three-dimensional (2D/3D) cellular growth, epithelial-to-mesenchymal transition, and invasiveness were evaluated in E545K or H1047R PIK3CA-mutated SQCLC cells and in newly generated clones carrying PIK3CA alterations, as well as in a xenograft model. PIK3CA mutated/amplified cells showed increased growth rate and enhanced migration and invasiveness, associated with an increased activity of RhoA family proteins and the acquisition of a mesenchymal phenotype. PI3K inhibitors reverted this aggressive phenotype by reducing metalloproteinase production, RhoA activity, and the expression of mesenchymal markers, with the specific PI3K inhibitors NVP-BKM120 and NVP-BYL719 being more effective than the dual PI3K/mTOR inhibitor NVP-BEZ235. A xenograft model of SQCLC confirmed that PIK3CA mutation promotes the acquisition of a mesenchymal phenotype in vivo and proved the efficacy of its specific targeting drug NVP-BYL719 in reducing the growth and the expression of mesenchymal markers in xenotransplanted tumors. These data indicate that PIK3CA mutation/amplification may represent a good predictive feature for the clinical application of specific PI3K inhibitors in SQCLC patients.

Topics: Aminopyridines; Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Class I Phosphatidylinositol 3-Kinases; Disease Models, Animal; Epithelial-Mesenchymal Transition; Humans; Imidazoles; Lung Neoplasms; Morpholines; Mutation; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Signal Transduction; Thiazoles; Xenograft Model Antitumor Assays

The mammalian target of rapamycin (mTOR) is a key signaling kinase associated with a variety of cellular functions including the regulation of immunological and inflammatory responses. Classic mTOR inhibitors such as rapamycin or everolimus are commonly used in transplant as well as cancer patients to prevent transplant rejection or cancer progression, respectively. Noninfectious drug-induced pneumonitis is a frequent side effect in mTOR-inhibitor-treated patients. Therefore, we tested the effects of the mTOR inhibitor everolimus and the novel dual PI3K/mTOR inhibitor NVP-BEZ235 in a murine lipopolysaccharide (LPS)-induced acute lung injury model. C57BL/6 mice were treated with either everolimus or NVP-BEZ235 on two consecutive days prior to intratracheal administration of LPS. LPS administration induced a significant increase in total cell, neutrophil and erythrocyte numbers in the bronchoalveolar lavage fluid. Histological examination revealed a serious lung injury as shown by interstitial edema, vascular congestion and mononuclear cell infiltration in these mice after 24h. Everolimus as well as NVP-BEZ235 did not noticeably affect overall histopathology of the lungs in the lung injury model. However, NVP-BEZ235 enhanced IL-6 and TNF-α expression after 24h. In contrast, everolimus did not affect IL-6 and TNF-α levels. Interestingly, both inhibitors reduced inflammatory cytokines in an LPS/oleic acid-induced lung injury model. In conclusion, the mTOR inhibitors did not worsen the overall histopathological severity, but they exerted distinct effects on proinflammatory cytokine expression in the lung depending on the lung injury model applied.

Topics: Acute Lung Injury; Animals; Disease Models, Animal; Everolimus; Female; Humans; Imidazoles; Interleukin-6; Lipopolysaccharides; Mice; Oleic Acid; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Quinolines; TOR Serine-Threonine Kinases; Tumor Necrosis Factor-alpha

The objective of tailoring medicines for cancer patients according to the molecular profile of their disease holds great promise for the improvement of cancer therapy. Nevertheless, this approach has been limited, in part, due to the lack of predictive and informative preclinical studies. Herein, we describe an assessment of the therapeutic potential of targeting PI3K/mTOR and MAPK signaling in genetically defined mouse models of colorectal cancer mirroring disease subtypes targeted for novel therapy in the FOCUS4 trial. Our studies demonstrate that dual PI3K/mTOR inhibition is highly effective in invasive adenocarcinoma models characterized by combinatorial mutations in Apc and Pten; Apc and Kras; and Apc, Pten and Kras. MEK inhibition was effective in the combinatorial Apc and Kras setting, but had no impact in either Apc Pten mutants or in Apc Pten Kras triple mutants. Furthermore, we describe the importance of scheduling for combination studies and show that although no additional benefit is gained in Apc Pten mice, combination of PI3K/mTOR and MAPK inhibition leads to an additive benefit in survival in Apc Kras mice and a synergistic increase in survival in Apc Pten Kras mice. This is the first study using robust colorectal cancer genetically engineered mouse models to support the validity of PI3K/mTOR and MEK inhibitors as tailored therapies for colorectal cancer and highlight the potential importance of drug scheduling in the clinic.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Benzimidazoles; Colorectal Neoplasms; Disease Models, Animal; Drug Screening Assays, Antitumor; Genes, APC; Imidazoles; MAP Kinase Kinase Kinases; Mice, Transgenic; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Proto-Oncogene Proteins p21(ras); PTEN Phosphohydrolase; Quinolines; Tumor Burden

To investigate the in vitro and in vivo antitumor activity of dual PI3K/mTOR inhibitor BEZ235 (NVP-BEZ235) in HER2-positive gastric cancer.. HER2-positive breast cancer cell line (BT474), HER2-positive (NCI-N87 and SNU216), and HER2-negative (MKN45) gastric cancer cell lines were used in this study. Cell viability, cell cycle, and HER2 downstream signaling pathways were analyzed using the MTS assay, flow cytometry, and western blotting, respectively. For the in vivo experiments, HER2-positive gastric cancer patient-derived xenografts were treated with BEZ235 to assess its antitumor activity.. The sensitivity of trastuzumab in BT474 cells was higher than that for NCI-N87 and SNU216 cells, which may be partially attributed to continuously active HER2 downstream signaling pathway. BEZ235 inhibited the proliferation of NCI-N87 and SNU216 cells in vitro in a dose-dependent manner by inducing the cell cycle arrest at the G1 phase. BEZ235 demonstrated greater inhibitory effects than trastuzumab, a unique targeted drug, in both the in vitro and in vivo set of experiments. Additionally, our results indicate that BEZ235 displayed some synergism with trastuzumab. BEZ235 exhibited its antitumor activity in gastric cancer by inhibiting important HER2 downstream signaling pathways, as indicated by the inhibition of phosphorylated AKT and S6.. The present study has demonstrated, for the first time, the antitumor activity of BEZ235 against HER2-positive gastric cancer in patient-derived xenografts, as well its synergistic interaction with trastuzumab. These important findings can be utilized to facilitate the design of future clinical trials.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; G1 Phase Cell Cycle Checkpoints; Humans; Imidazoles; Mice; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Receptor, ErbB-2; Signal Transduction; Stomach Neoplasms; TOR Serine-Threonine Kinases; Trastuzumab; Tumor Burden; Xenograft Model Antitumor Assays

Effective therapeutic strategies that can achieve long-term improvement in patients with castration resistant prostate cancer are urgently needed. We recently reported that the activated PI3K/Akt/mTOR signaling pathway induced by docetaxel explains resistance to docetaxel in castration resistant prostate cancer. In this study we explored the efficacy of NVP-BEZ235, a dual PI3K and mTORC1/2 inhibitor, for docetaxel resistant castration resistant prostate cancer.. We used the 2 human castration resistant prostate cancer cell lines C4-2 and C4-2AT6. At our laboratory C4-2AT6 cells were established from C4-2 under androgen ablated treatment for 6 months. We investigated the efficacy of NVP-BEZ235 monotherapy and NVP-BEZ235 combined with docetaxel in vitro and in vivo.. Increased phosphorylated Akt in C4-2AT6 cells was significantly inhibited by NVP-BEZ235 in a dose and time dependent manner. WST cell proliferation assay results in C4-2AT6 cells revealed that combined administration of NVP-BEZ235 and docetaxel had significant, synergistically greater cytotoxicity than NVP-BEZ235 or docetaxel monotherapy. Combined NVP-BEZ235 (40 mg/kg) and docetaxel (4 mg/kg) in vivo in a castrated mouse xenograft model inhibited C4-2AT6 tumor growth to a greater degree than in the monotherapy groups. Also, NVP-BEZ235 showed significant efficacy with docetaxel at a low concentration in vivo, suggesting that NVP-BEZ235 effectively decreased resistance to docetaxel.. Results suggest that inhibition of the PI3K/Akt/mTOR signaling pathway by NVP-BEZ235 can overcome docetaxel resistance in human castration resistant prostate cancer. Our findings provide a molecular basis for the clinical use of combined administration of NVP-BEZ235 and docetaxel in patients with castration resistant prostate cancer.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Disease Models, Animal; Docetaxel; Humans; Imidazoles; Male; Mice; Mice, Inbred BALB C; Orchiectomy; Phosphoinositide-3 Kinase Inhibitors; Prostatic Neoplasms, Castration-Resistant; Quinolines; Taxoids; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

Inhibitors of the DNA damage response (DDR) have great potential for radiosensitization of numerous cancers, including glioblastomas, which are extremely radio- and chemoresistant brain tumors. Currently, there are no DNA double-strand break (DSB) repair inhibitors that have been successful in treating glioblastoma. Our laboratory previously demonstrated that the dual phosphoinositide 3-kinase/mTOR inhibitor NVP-BEZ235 can potently inhibit the two central DDR kinases, DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and ataxia-telangiectasia mutated (ATM), in vitro. Here, we tested whether NVP-BEZ235 could also inhibit ATM and DNA-PKcs in tumors in vivo and assessed its potential as a radio- and chemosensitizer in preclinical mouse glioblastoma models.. The radiosensitizing effect of NVP-BEZ235 was tested by following tumor growth in subcutaneous and orthotopic glioblastoma models. Tumors were generated using the radioresistant U87-vIII glioma cell line and GBM9 neurospheres in nude mice. These tumors were then treated with ionizing radiation and/or NVP-BEZ235 and analyzed for DNA-PKcs and ATM activation, DSB repair inhibition, and attenuation of growth.. NVP-BEZ235 potently inhibited both DNA-PKcs and ATM kinases and attenuated the repair of ionizing radiation-induced DNA damage in tumors. This resulted in striking tumor radiosensitization, which extended the survival of brain tumor-bearing mice. Notably, tumors displayed a higher DSB-load when compared with normal brain tissue. NVP-BEZ235 also sensitized a subset of subcutaneous tumors to temozolomide, a drug routinely used concurrently with ionizing radiation for the treatment of glioblastoma.. These results demonstrate that it may be possible to significantly improve glioblastoma therapy by combining ionizing radiation with potent and bioavailable DNA repair inhibitors such as NVP-BEZ235.

Topics: Animals; Ataxia Telangiectasia Mutated Proteins; Blood-Brain Barrier; Catalytic Domain; Cell Line, Tumor; Dacarbazine; Disease Models, Animal; DNA Breaks, Double-Stranded; DNA Repair; DNA-Activated Protein Kinase; Glioblastoma; Humans; Imidazoles; Mice; Mice, Transgenic; Phosphoinositide-3 Kinase Inhibitors; Protein Interaction Domains and Motifs; Quinolines; Radiation-Sensitizing Agents; Temozolomide; TOR Serine-Threonine Kinases

Cancer therapies that simultaneously target activated mammalian target of rapamycin (mTOR) and cell metabolism are urgently needed. The goal of our study was to identify therapies that effectively inhibited both mTOR activity and cancer cell metabolism in primary tumors in vivo. Using our mouse model of spontaneous breast cancer promoted by loss of LKB1 expression in an ErbB2 activated model; referred to as LKB1-/-NIC mice, we evaluated the effect of novel therapies in vivo on primary tumors. Treatment of LKB1-/-NIC mice with AZD8055 and 2-DG mono-therapies significantly reduced mammary gland tumorigenesis by inhibiting mTOR pathways and glycolytic metabolism; however simultaneous inhibition of these pathways with AZD8055/2-DG combination was significantly more effective at reducing tumor volume and burden. At the molecular level, combination treatment inhibited mTORC1/mTORC2 activity, selectively inhibited mitochondria function and blocked MAPK pro-survival signaling responsible for the ERK-p90RSK feedback loop. Our findings suggest that loss of LKB1 expression be considered a marker for metabolic dysfunction given its role in regulating AMPK and mTOR function. Finally, the outcome of our pre-clinical study confirms therapies that simultaneously target mTORC1/mTORC2 and glycolytic metabolism in cancer produce the best therapeutic outcome for the treatment of patients harboring metabolically active HER2 positive breast cancers.

Topics: AMP-Activated Protein Kinases; Animals; Antineoplastic Combined Chemotherapy Protocols; Deoxyglucose; Disease Models, Animal; Female; Glycolysis; Imidazoles; Mammary Neoplasms, Experimental; Mice; Mice, Transgenic; Molecular Targeted Therapy; Morpholines; Protein Serine-Threonine Kinases; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases

A series of [1,2,4]triazolo[1,5-a]pyridinylpyridines were synthesized and characterized. Their antiproliferative activities in vitro were evaluated by MTT against three human cancer cell lines including HCT-116, U-87 MG and MCF-7 cell lines. The SAR of target compounds was preliminarily discussed. The compounds 1c and 2d with potent antiproliferative activities were tested for their effects on the AKT and p-AKT(473). The anticancer effect of 1c was evaluated in mice bearing sarcoma S-180 model. The results suggest that the title compounds are potent anticancer agents.

Topics: Animals; Antineoplastic Agents; Cell Proliferation; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; HCT116 Cells; Humans; MCF-7 Cells; Mice; Models, Molecular; Molecular Structure; Neoplasms, Experimental; Pyridines; Structure-Activity Relationship; Triazoles; Tumor Cells, Cultured

The PI3K/AKT/mTOR pathway has frequently been found activated in human tumors. We show that in addition to Wnt signaling dysfunction, the PI3K/AKT/mTOR pathway is often upregulated in mouse Msh2(-/-) initiated intestinal tumors. NVP-BEZ235 is a dual PI3K/mTOR inhibitor toxic to many cancer cell lines and currently involved in clinical trials. We have treated two mouse models involving Msh2 that develop small intestinal and/or colonic tumors with NVP-BEZ235, and a subset of animals with NVP-BEZ235 and MEK inhibitor ADZ4266. The disease phenotype has been followed with pathology, (18)F FDG PET imaging, and endoscopy. Intestinal adenocarcinomas are significantly decreased in multiplicity by both drug regimens. The majority of tumors treated with combined therapy regress significantly, while a small number of highly progressed tumors persist. We have examined PTEN, AKT, MEK 1&2, MAPK, S6K, mTOR, PDPK1, and Cyclin D1 and find variable alterations that include downregulation of PTEN, upregulation of AKT and changes in its phosphorylated forms, upregulation of pMEK 1&2, p42p44MAPK, pS6K, and Cyclin D1. Apoptosis has been found intact in some tumors and not in others. Our data indicate that NVP-BEZ235 alone and in combination with ADZ4266 are effective in treating a proportion of colorectal cancers, but that highly progressed resistant tumors grow in the presence of the drugs. Pathways upregulated in some resistant tumors also include PDPK1, suggesting that metabolic inhibitors may also be useful in treating these tumors.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Disease Models, Animal; Disease Progression; DNA Mismatch Repair; Gene Rearrangement; Genotype; Humans; Imidazoles; Integrases; Intestinal Neoplasms; MAP Kinase Signaling System; Mice; MutS Homolog 2 Protein; Neoplasm Proteins; Neoplasms; Phosphatidylinositol 3-Kinases; Positron-Emission Tomography; Quinolines; TOR Serine-Threonine Kinases; Up-Regulation; Wnt Proteins

Gastric cancer is the second most common cause of cancer-related deaths worldwide. Taxanes have shown therapeutic effects against gastric cancer while also activating the PI3K/mTOR signaling pathway. We investigated the effects of NVP-BEZ235 (BEZ235), a novel dual PI3K/mTOR inhibitor, alone and in combination with nanoparticle albumin-bound (nab)-paclitaxel in experimental gastric cancer. Cell proliferation and protein expression were measured by WST-1 assay and immunoblotting. Tumor growth and survival studies were performed in murine xenografts. Phosphorylated mTOR and 4E-BP1 levels were elevated in gastric cancer cells and tumor tissues by nab-paclitaxel. BEZ235 effectively inhibited cell proliferation in vitro and provided additive effects in combination with nab-paclitaxel. Furthermore, BEZ235 blocked the activated PI3K/mTOR pathway either alone or in combination with nab-paclitaxel in gastric cancer cells. BEZ235 and nab-paclitaxel caused an increase in PARP-1 and caspase-3 cleavage. Net local tumor growth inhibition for the BEZ235, nab-paclitaxel and BEZ235+nab-paclitaxel groups was 45.1, 77.9 and 97% compared to controls. The effects of therapy on intratumoral proliferation and apoptosis corresponded with tumor growth inhibition data. BEZ235 also caused a decrease in phospho-mTOR and phospho-Akt in tumor tissue lysates. Median animal survival (controls, 23 days) was 26.5 days after BEZ235 (p=0.227), 90.5 days after nab-paclitaxel (p=0.001) and 97 days in the BEZ235+nab-paclitaxel combination treatment group (p=0.001). Our findings suggest that BEZ235 exerts some antitumor effects against gastric cancer and enhances effects of nab-paclitaxel through inhibition of cell proliferation and modulation of the PI3K/mTOR pathway. This approach may represent a promising combination targeted therapy for gastric cancer.

Topics: Albumins; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blotting, Western; Cell Cycle; Cell Proliferation; Disease Models, Animal; Drug Synergism; Female; Humans; Imidazoles; Mice; Mice, Inbred NOD; Mice, SCID; Nanoparticles; Paclitaxel; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-akt; Quinolines; Stomach Neoplasms; Tumor Cells, Cultured

Phosphoinositide 3-kinase (PI3K) plays an important role in tissue inflammatory reactions and fibrotic processes. The objective of this study was to evaluate the potential mechanism and therapeutic effects of PI3K inhibitor on pancreatic elastase (PE)-induced acute and chronic lung inflammation, edema, and injury.. Rats were terminated at 7 or 28 days after an intratracheal challenge with PE and intranasal instillation with a PI3K inhibitor, SHBM1009. Alterations of airway epithelial cells and myofibroblasts were studied in vitro.. Lung inflammation, edema, and injury; emphysema; and tissue remodeling were measured after PE instillation with or without treatment with PI3K inhibitor and budesonide. Cellular biologic functions were monitored.. SHBM1009 could prevent PE-induced acute lung inflammation, edema, and injury, and chronic lung inflammation, remodeling, and emphysema. Different patterns of inhibitory effects of SHBM1009 and BEZ235, a dual PI3K/mechanistic target of rapamycin inhibitor, on PE-challenged epithelial cells were observed. PE per se reduced epithelial cell proliferation and stability through the inhibition of cell division rather than promoting cell death, in dose- and time-dependent patterns. Effects of PI3K inhibitors on cells were associated with the severity of PE challenges.. PI3K plays a critical role in the development of acute and chronic lung injury, including the process of tissue remodeling and emphysema. PI3K inhibitors could be new therapeutic alternatives for chronic lung diseases.

Topics: Acute Disease; Airway Remodeling; Animals; Anti-Inflammatory Agents; Budesonide; Cell Proliferation; Chronic Disease; Disease Models, Animal; Dose-Response Relationship, Drug; Emphysema; Enzyme Inhibitors; Imidazoles; Male; Pancreatic Elastase; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Pneumonia; Quinolines; Rats; Rats, Wistar; Time Factors

Peritoneal dissemination of gastric cancer is a common reason for unresectability, a frequent recurrence mechanism, and a common cause for death. The present study was performed to test peritoneal dissemination gastric cancer xenografts mouse models that would support survival outcome analyses.. Human gastric cancer cell lines AGS, NCI-N87, and SNU-16 were intraperitoneally injected into nude mice and severe combined immunodeficiency (SCID) mice. The peritoneal tumor formation and mouse survival were compared among different groups. Mice were treated with oxaliplatin (5 mg/kg) and NVP-BEZ235 (10 mg/kg).. The formation rate of peritoneal cancer after intraperitoneal injection of 5 × 10(6) SNU16, NCI-N87, and AGS cells was 2/8, 6/8, and 0/8 in nude mice, and 6/6, 6/6, and 0/6 in SCID mice, respectively. Median animal survival with peritoneal dissemination was 74 d for NCI-N87 cells (10 × 10(6)), 95 d for SNU16 cells (10 × 10(6)), 78 d for SNU16 cells (20 × 10(6)), and 44 d for SNU16 cells (40 × 10(6)). In a therapeutic experiment with 40 × 10(6) SNU16 cells, animal survival was significantly improved by oxaliplatin treatment compared with the control group (58.5 d versus 45 d, P < 0.001), but not by NVP-BEZ235 (48 d versus 45 d, P = 0.249) treatment. In the accompanying subcutaneous SNU16 mouse model, relative tumor volume compared with controls was not significantly decreased by oxaliplatin treatment (P = 0.151) but by NVP-BEZ235 therapy (P = 0.008).. Peritoneal gastric cancer xenografts were successfully established after intraperitoneal injection NCI-N87 and SNU16 cells. These findings provide a useful survival outcome assessment model for experimental gastric cancer research.

Topics: Animals; Cell Line, Tumor; Disease Models, Animal; Female; Humans; Imidazoles; Mice; Mice, SCID; Organoplatinum Compounds; Oxaliplatin; Peritoneal Neoplasms; Quinolines; Stomach Neoplasms

Medulloblastoma (MB) is the most common malignant brain tumor in children. Patients whose tumors exhibit overexpression or amplification of the MYC oncogene (c-MYC) usually have an extremely poor prognosis, but there are no animal models of this subtype of the disease. Here, we show that cerebellar stem cells expressing Myc and mutant Trp53 (p53) generate aggressive tumors following orthotopic transplantation. These tumors consist of large, pleiomorphic cells and resemble human MYC-driven MB at a molecular level. Notably, antagonists of PI3K/mTOR signaling, but not Hedgehog signaling, inhibit growth of tumor cells. These findings suggest that cerebellar stem cells can give rise to MYC-driven MB and identify a novel model that can be used to test therapies for this devastating disease.

Topics: Aminopyridines; Animals; Cell Proliferation; Cell Transformation, Neoplastic; Cerebellar Neoplasms; Cerebellum; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Genes, p53; Imidazoles; Medulloblastoma; Mice; Morpholines; Neural Stem Cells; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-myc; Quinolines; TOR Serine-Threonine Kinases

This study evaluates the effect of dual PI3K and mTOR inhibition using NVP-BEZ235 in preclinical models of ovarian cancer as a potential novel therapeutic strategy.. Inhibition of PI3K/Akt/mTOR signaling by NVP-BEZ235 was demonstrated by immunoblotting. The effect on cell proliferation was assessed in 18 ovarian cancer cell lines, including four pairs of syngeneic cisplatin-sensitive and cisplatin-resistant cell lines. The in vivo effects of NVP-BEZ235 on established tumor growth were evaluated using an immunocompetent, transgenic murine ovarian cancer model (LSL-K-ras(G12D/+)Pten(loxP/loxP)).. NVP-BEZ235 decreased cell proliferation in all ovarian cancer cell lines assayed and sensitized cisplatin-resistant cells to the cytotoxic effects of cisplatin. Cell lines with PI3K-activating mutations or Pten deletions were significantly more sensitive to the effect of NVP-BEZ235 than cell lines without these mutations (P < 0.05). A statistically significant correlation was found between relative levels of p4E-BP1 and the IC(50) for NVP-BEZ235. In LSL-K-ras(G12D/+)Pten(loxP/loxP) mice with established intraperitoneal tumor disease, oral administration of NVP-BEZ235 decreased pAkt, p4E-BP1 and Ki67 in tumor tissue, and resulted in significantly longer survival compared to control animals (P < 0.05). NVP-BEZ235 also induced cell cycle arrest, caspase 3 activity, and reduced cell migration.. Targeting PI3K and mTOR simultaneously using NVP-BEZ235 effectively inhibits ovarian cancer cell growth even in the presence of platinum resistance and prolongs survival of mice with intra-abdominal ovarian tumor disease. We propose that dual PI3K and mTOR inhibition using NVP-BEZ235 may be an effective novel therapeutic approach in patients with ovarian cancer.

Topics: Animals; Antineoplastic Agents; Caspase 3; Cell Cycle; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cisplatin; Disease Models, Animal; Drug Resistance, Neoplasm; Enzyme Activation; Female; Humans; Imidazoles; Immunoblotting; Mice; Mice, Transgenic; Mutation; Ovarian Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases

Immunodeficient animal models are invaluable tools to investigate the metastatic propensity of human tumours. However residual immune responses, in particular natural killer (NK) cells, severely hamper the traffic and growth of human tumour cells. We studied whether a genetically modified mouse host lacking T, B and NK immunity allowed an improved expression of the metastatic phenotype of malignant human tumours. Metastatic spread of a panel of human sarcoma cell lines was studied in double knockout Rag2(-/-);gammac(-/-) mice in comparison with NK-depleted nude mice. Rag2(-/-);gammac(-/-) mice receiving intravenous (i.v.) or subcutaneous (s.c.) human sarcoma cell lines developed extensive multiorgan metastases. Metastatic efficiency in Rag2(-/-);gammac(-/-) was superior than in nude mice in terms of both metastatic sites and metastasis number. Metastatic growth in Rag2(-/-);gammac(-/-) mice was faster than that in nude mice, thus allowing an earlier metastasis evaluation. Most human sarcomas metastasised in the liver of Rag2(-/-);gammac(-/-) mice, a kind of organ preference undetectable in nude mice and specific of sarcomas, as several carcinoma cell lines failed to colonise the liver of Rag2(-/-);gammac(-/-) mice, independently of their metastatic spread to other sites. In vitro analysis of the molecular mechanisms of liver metastasis of sarcomas implicated liver-produced growth and motility factors, in particular the insulin-like growth factor (IGF) axis. NVP-BEZ235, a specific inhibitor of downstream signal transduction targeting PI3K and mTOR, strongly inhibited liver metastasis of human sarcoma cells. In conclusion, the Rag2(-/-);gammac(-/-) mouse model allowed the expression of human metastatic phenotypes inapparent in conventional immunodeficient mice and the preclinical testing of appropriate targeted therapies.

Topics: Animals; Antineoplastic Agents; Chemotaxis; Culture Media, Conditioned; Disease Models, Animal; DNA-Binding Proteins; Enzyme Inhibitors; Female; Humans; Imidazoles; Immune Tolerance; Liver Neoplasms; Lung Neoplasms; Mice; Mice, Knockout; Neoplasm Transplantation; Phosphoinositide-3 Kinase Inhibitors; Quinolines; Sarcoma; Transplantation, Heterologous; Treatment Outcome; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Inhibitors of TORC1 have been shown to be active in patients with metastatic renal cell carcinoma (RCC). As the phosphatidylinositol 3-kinase (PI3K) pathway activates numerous other kinases, transcription factors, and proteins associated with cell growth and survival besides mammalian target of rapamycin (mTOR), disruption of this pathway upstream of mTOR may be more effective than inhibition of TORC1 alone.. To investigate this possibility, the dual PI3K/mTOR inhibitor NVP-BEZ235 was compared with rapamycin in RCC cell lines and xenografts generated from 786-O and A498 cells.. Treatment of RCC cell lines with NVP-BEZ235 in vitro resulted in the nuclear translocation of p27, greater reduction in tumor cell proliferation, and more complete suppression of Akt, Mnk-1, eIF4E, and 4EBP-1 phosphorylation and cyclin D1 and hypoxia-inducible factor 2alpha (HIF2alpha) expression than that achieved with rapamycin. The reduction of HIF2alpha levels correlated with reduced HIF activity as determined by luciferase assay. NVP-BEZ235 induced growth arrest in both the 786-O and A498 xenografts that was associated with inhibition of Akt and S6 phosphorylation as well as the induction of apoptosis and reduction in markers of tumor cell proliferation. In contrast, rapamycin induced only minimal growth retardation.. Dual inhibition of PI3K/mTOR with NVP-BEZ235 induced growth arrest in RCC cell lines both in vitro and in vivo more effectively than inhibition of TORC1 alone. These results provide the rationale for the clinical assessment of agents such as NVP-BEZ235 in patients with advanced RCC.

Topics: Animals; Carcinoma, Renal Cell; Cell Death; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Enzyme Inhibitors; Female; Humans; Imidazoles; Kidney Neoplasms; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Nude; Multiprotein Complexes; Neoplasm Transplantation; Phosphoinositide-3 Kinase Inhibitors; Proteins; Quinolines; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors; Xenograft Model Antitumor Assays

Tuberous sclerosis (TSC) is a hamartoma syndrome in which renal and lung tumors cause the greatest morbidity. Loss of either TSC1 or TSC2 in TSC hamartomas leads to activation of mTORC1 and suppression of AKT. Recent studies indicate that inhibition of mTORC1 with RAD001 (everolimus) leads to rebound activation of AKT, which could protect tumors from drug-induced cell death. Here we examine the potential benefit of inhibition of both mTOR and AKT signaling in a mouse model of TSC, using a dual pan class I PI3K/mTOR catalytic small molecule inhibitor NVP-BEZ235.. Using ENU to enhance Tsc2+- kidney tumor development, both RAD001 (10 mg/kg PO 5 d/week) and NVP-BEZ235 (45 mg/kg PO QD) had equivalent effects in suppressing tumor development during a 4 week treatment period, with a 99% reduction in tumor cell mass. Marked reduction in activation of mTORC1, induction of cell cycle arrest, and absence of apoptotic cell death was seen in mice treated with either drug. However, when either was discontinued, there was prompt recovery of tumor growth, with extensive proliferation.. Both mTORC1 blockade alone and combined PI3K-mTOR blockade lead to suppression of tumor development but not tumor elimination in this TSC model.

Topics: Animals; Antineoplastic Agents; Carrier Proteins; Disease Models, Animal; Ethylnitrosourea; Everolimus; Imidazoles; Kidney Neoplasms; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Inbred C57BL; Mice, Transgenic; Multiprotein Complexes; Neoplasm Recurrence, Local; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphotransferases (Alcohol Group Acceptor); Proteins; Quinolines; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors; Tuberous Sclerosis