dactolisib and Neoplasm-Metastasis

Colon cancer is one of the most common cancers worldwide with high mortality. A major issue in colon cancer treatment is drug-resistance and metastasis that have been ascribed to the cancer stem cells. In this study, colon cancer stem cells were isolated through sphere culture and verified with the cancer stem cell markers CD133, CD44, and CD24. It was demonstrated that the PI3K/Akt/mTOR signalling pathway was highly activated in the colon cancer stem cells and that inhibition of the PI3K/Akt/mTOR pathway by the inhibitor BEZ235 suppressed the colon cancer stem cell proliferation with reduced stemness indicated by CD133 and Lgr5 expressions. Treatment with insulin as a known activator of the PI3K/Akt pathway increased CD133 expression and decreased the effects of BEZ235 on colon cancer proliferation and survival. The data presented here collectively suggest that the PI3K/Akt/mTOR pathway underpins the stemness of colon cancer stem cells and BEZ235 is potentially a good drug candidate for treatment of colon cancer drug resistance and metastasis.

Topics: Antineoplastic Agents; Cell Survival; Colonic Neoplasms; Drug Resistance, Neoplasm; HCT116 Cells; Humans; Imidazoles; Insulin; Neoplasm Metastasis; Neoplastic Stem Cells; Phosphatidylinositol 3-Kinase; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases

Phosphatidylinositol 3-kinase (PI3K) signaling plays a critical role in cholangiocarcinoma (CCA), as well as anti-cancer drug resistance and autophagy, the type II program cell death regulation. In this work, we aimed to: (1) determine the expression levels of several key components of PI3K signaling and (2) evaluate whether NVP-BEZ235, a novel dual PI3K/mTOR inhibitor, could inhibit CCA cell growth. Immunohistochemistry for p85α, p110α, AKT, p-AKT (T308), mTOR, p-mTOR (S2448), GSK-3β, p-GSK-3β (S9), PTEN, and p-PTEN (S380, T382/383) was performed in 30 CCA patients. Western blotting was used to analyze PTEN and p-PTEN expression in the cell lines (KKU-OCA17, KKU-100, KKU-M055, KKU-M139, KKU-M156, KKU-M213, and KKU-M214). The effects of NVP-BEZ235 on CCA cells were evaluated using a growth inhibition assay, flow cytometer and migration assay. Increased activation of PI3K/AKT signaling was reproducibly observed in the CCA tissues. The expression of p85α, mTOR, and GSK-3β was significantly correlated with metastasis. Interestingly, PTEN suppression by loss of expression or inactivation by phosphorylation was observed in the majority of patients. Furthermore, NVP-BEZ235 effectively inhibited CCA cell growth and migration through reduced AKT and mTOR phosphorylation and significantly induced G1 arrest without apoptosis induction, although increase autophagy response was observed. In conclusion, the constitutive activation of PI3K/AKT pathway in CCA is mainly due to PTEN inactivation by either loss of expression or phosphorylation along with an increased expression in its pathway components heralding a poor prognosis for CCA patients. This work also indicates that inhibition of PI3K and mTOR activity by the inhibitor NVP-BEZ235 has anti-cancer activity against CCA cells which might be further tested for CCA treatment.

Topics: Adult; Aged; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Blotting, Western; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cholangiocarcinoma; Dose-Response Relationship, Drug; Enzyme Activation; Female; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Imidazoles; Immunohistochemistry; Male; Middle Aged; Neoplasm Metastasis; Phosphatidylinositol 3-Kinase; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Quinolines; Signal Transduction; TOR Serine-Threonine Kinases

Aberrant activation and mutation status of proteins in the phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and the mitogen activated protein kinase (MAPK) signaling pathways have been linked to tumorigenesis in various tumors including urothelial carcinoma (UC). However, anti-tumor therapy with small molecule inhibitors against mTOR turned out to be less successful than expected. We characterized the molecular mechanism of this pathway in urothelial carcinoma by interfering with different molecular components using small chemical inhibitors and siRNA technology and analyzed effects on the molecular activation status, cell growth, proliferation and apoptosis. In a majority of tested cell lines constitutive activation of the PI3K was observed. Manipulation of mTOR or Akt expression or activity only regulated phosphorylation of S6K1 but not 4E-BP1. Instead, we provide evidence for an alternative mTOR independent but PI3K dependent regulation of 4E-BP1. Only the simultaneous inhibition of both S6K1 and 4E-BP1 suppressed cell growth efficiently. Crosstalk between PI3K and the MAPK signaling pathway is mediated via PI3K and indirect by S6K1 activity. Inhibition of MEK1/2 results in activation of Akt but not mTOR/S6K1 or 4E-BP1. Our data suggest that 4E-BP1 is a potential new target molecule and stratification marker for anti cancer therapy in UC and support the consideration of a multi-targeting approach against PI3K, mTORC1/2 and MAPK.

Topics: Adaptor Proteins, Signal Transducing; Apoptosis; Carcinoma, Transitional Cell; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Enzyme Activation; Everolimus; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Neoplasm Metastasis; Phosphatidylinositol 3-Kinases; Phosphoproteins; Proto-Oncogene Proteins c-akt; Quinolines; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; Time Factors; TOR Serine-Threonine Kinases; Urinary Bladder Neoplasms

To evaluate the in vitro and in vivo effects of NVP-BEZ235, a dual pan-phosphoinositide 3-kinase-mammalian target of rapamycin inhibitor in the three most common musculoskeletal tumors (osteosarcoma, Ewing's sarcoma, and rhabdomyosarcoma).. Antiproliferative activity as well as the effects on migration and metastasis were evaluated in a panel of osteosarcoma, Ewing's sarcoma, as well as rhabdomyosarcoma cell lines. Moreover, simultaneous and sequential treatments were done in association with two of the most important conventional drugs in the treatment of sarcoma, doxorubicin and vincristine.. NVPBEZ235 effectively blocked the pathway in in vitro and in vivo settings. Under the experimental conditions tested, the compound induced disease stasis, by arresting cells in G(1) phase of cell cycle, without remarkable effects on apoptosis. As a consequence, to obtain the maximum exploitation of its therapeutic potential, NVP-BEZ235 has been evaluated in combination with conventional cytotoxic agents, thus showing promising efficacy with either doxorubicin and vincristine. Inhibition of the phosphoinositide 3-kinase/mammalian target of rapamycin pathway increased activation of extracellular signal-regulated kinase 1/2, likely due to the presence of autocrine circuits shifting growth factor signaling toward the mitogen-activated protein kinase pathway. This supports the combined use of NVP-BEZ235 with other small signaling inhibitors. Here, we showed synergistic effects when the compound was associated with a anti-insulin-like growth factor-I receptor tyrosine kinase inhibitor. NVP-BEZ235 also inhibited cell migration and metastasis. Combination with vincristine further potentiated the antimetastatic effects.. NVP-BEZ235 displays the features to be considered for sarcoma therapy to potentiate the activity of other anticancer agents. The drug is currently undergoing phase I/II clinical trials in advanced cancer patients.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cell Proliferation; Dose-Response Relationship, Drug; Female; Humans; Imidazoles; Mice; Mice, Inbred BALB C; Mice, Knockout; Mice, Nude; Muscle Neoplasms; Neoplasm Metastasis; Quinolines; Sarcoma; Xenograft Model Antitumor Assays