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1.
Surgery ; 173(1): 12-18, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36207198

ABSTRACT

BACKGROUND: The mammalian target of rapamycin inhibition has been shown to prolong progression-free survival in patients with pancreatic neuroendocrine tumors. The natural compound baicalein indirectly inhibits the mammalian target of rapamycin, but it is unknown if baicalein exhibits such effects at physiologically achievable concentrations or exhibits synergy. METHODS: Pancreatic neuroendocrine tumor cell lines were cultured with baicalein, everolimus, and/or a synthetic 5' adenosine monophosphate-activated protein kinase activating agent alone and in combination. Cell viability assays and immunoblotting were performed. Female severe combined immunodeficient-beige mice were injected with BON-1 cells and treated with baicalein and COH-SR4 solutions via oral gavage. Tumor volumes were compared at 30 days. RESULTS: Immunoblotting revealed that treatment of baicalein induced 5' adenosine monophosphate-activated protein kinase activation and the mammalian target of rapamycin inhibition. Treatment with baicalein alone led to a significant decrease in the ratio of viable cells compared with controls at 72 hours at concentrations ≥5 µM (P = .021). The addition of COH-SR4 led to significantly greater effect on cell viability than with baicalein alone (P < .001, P < .001). The combination of baicalein with everolimus resulted in significantly lower cell viability than with everolimus alone (P = .005, P < .001). Tumor volume in vivo was significantly decreased with the combination of baicalein and COH-SR4 compared with controls (P = .003). CONCLUSION: Baicalein exhibits antiproliferative effects against pancreatic neuroendocrine tumor cell lines at doses ≥5 µM and demonstrates synergy.


Subject(s)
Neuroendocrine Tumors , Pancreatic Neoplasms , Mice , Animals , Female , Sirolimus/pharmacology , Sirolimus/therapeutic use , Neuroendocrine Tumors/pathology , TOR Serine-Threonine Kinases/metabolism , Everolimus/pharmacology , Everolimus/therapeutic use , Pancreatic Neoplasms/pathology , AMP-Activated Protein Kinases , Adenosine Monophosphate/therapeutic use , Cell Line, Tumor , Mammals/metabolism
2.
Cells ; 8(9)2019 08 30.
Article in English | MEDLINE | ID: mdl-31480338

ABSTRACT

Unlike other breast cancer subtypes, patients with triple negative breast cancer (TNBC) have poor outcomes and no effective targeted therapies, leaving an unmet need for therapeutic targets. Efforts to profile these tumors have revealed the PI3K/AKT/mTOR pathway as a potential target. Activation of this pathway also contributes to resistance to anti-cancer agents, including microtubule-targeting agents. Eribulin is one such microtubule-targeting agent that is beneficial in treating taxane and anthracycline refractory breast cancer. In this study, we compared the effect of eribulin on the PI3K/AKT/mTOR pathway with other microtubule-targeting agents in TNBC. We found that the phosphorylation of AKT was suppressed by eribulin, a microtubule depolymerizing agent, but activated by paclitaxel, a microtubule stabilizing agent. The combination of eribulin and everolimus, an mTOR inhibitor, resulted in an increased reduction of p-S6K1 and p-S6, a synergistic inhibition of cell survival in vitro, and an enhanced suppression of tumor growth in two orthotopic mouse models. These findings provide a preclinical foundation for targeting both the microtubule cytoskeleton and the PI3K/AKT/mTOR pathway in the treatment of refractory TNBC.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Everolimus/pharmacology , Furans/pharmacology , Ketones/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , TOR Serine-Threonine Kinases/antagonists & inhibitors , Triple Negative Breast Neoplasms/drug therapy , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinogenesis/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Everolimus/therapeutic use , Female , Furans/therapeutic use , Humans , Ketones/therapeutic use , Mice , Mice, Inbred BALB C , Mice, Inbred NOD , Mice, SCID , Protein Kinase Inhibitors/therapeutic use
3.
Sci Rep ; 9(1): 7509, 2019 05 17.
Article in English | MEDLINE | ID: mdl-31101835

ABSTRACT

A third of patients with triple negative breast cancer (TNBC) have relapsed disease within 2-5 years from initial diagnosis, leaving an unmet need for therapeutic targets. TNBC frequently harbors alterations of the PI3K/AKT/mTOR pathway, but single agent PI3K/AKT/mTOR inhibitors have not shown marked efficacy. In this study, we investigated a strategy to improve efficacy of PI3K-α inhibitor BYL719 (alpelisib) in TNBC. While BYL719 is effective at inhibiting cell proliferation in T47D, a triple positive cell line, it had limited activity in TNBC. This may be partially due to persistent phosphorylation of RB, and incomplete inhibition of p-S6 in TNBC, since the inhibitory effect of BYL719 on p-RB and p-S6 was significantly reduced in TNBC compared to T47D cells. Addition of the CDK4/6 inhibitor LEE011 to BYL719 caused a simultaneous reduction of p-RB and p-S6, and a more complete inhibition of p-S6, leading to decreased expression of the pro-survival protein MCL-1, an induction of apoptosis, and an enhanced reduction of tumor growth in a PDX model of TNBC. These findings suggest that inhibition of p-RB and p-S6 is important for an effective response to the treatment of TNBC, and provides a strong rationale for clinical development of combination therapy with BYL719 and LEE011 for treatment of metastatic TNBC with intact RB.Presentation: This study was presented in part as an abstract at the 2016 San Antonio Breast Cancer Symposium (P3-03-15) and the 2018 Cancer Research and Targeted Therapy in London.


Subject(s)
Aminopyridines/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Purines/administration & dosage , Ribosomal Protein S6 Kinases/antagonists & inhibitors , Thiazoles/administration & dosage , Triple Negative Breast Neoplasms/drug therapy , Animals , Apoptosis/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Class I Phosphatidylinositol 3-Kinases/antagonists & inhibitors , Cyclin-Dependent Kinase 4/antagonists & inhibitors , Cyclin-Dependent Kinase 6/antagonists & inhibitors , Drug Synergism , Enzyme Inhibitors/administration & dosage , Female , Humans , Mice , Phosphorylation , Protein Kinase Inhibitors/administration & dosage , Proto-Oncogene Proteins c-akt/metabolism , Retinoblastoma Protein/antagonists & inhibitors , Retinoblastoma Protein/metabolism , Ribosomal Protein S6 Kinases/metabolism , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathology , Xenograft Model Antitumor Assays
4.
Cancer Lett ; 358(2): 170-179, 2015 Mar 28.
Article in English | MEDLINE | ID: mdl-25543165

ABSTRACT

Baicalein is a natural flavone that exhibits anticancer properties. Using microarrays we found that DDIT4 was the highest transcript induced by baicalein in cancer cells. We confirmed in multiple cancer cell lines large, dose-related expression of DDIT4 by quantitative RT-PCR and immunoblot, which correlates with growth inhibition. Time course experiments demonstrate that DDIT4 is rapidly inducible, with high expression maintained for several days in vitro. Induction of DDIT4 expression is p53 independent based on evaluation of p53 knockout cells. Since DDIT4 is known to inhibit mTORC1 activity we confirmed that baicalein suppresses phosphorylation of mTORC1 targets. Using RNA interference we demonstrate that mTORC1 activity and growth inhibition by baicalein is attenuated by knockdown of DDIT4. We furthermore demonstrate suppression of established tumors by baicalein in a mouse model of breast cancer with increased DDIT4 expression in the tumors. Finally, we demonstrate that baicalein upregulates DDIT4 and causes mTORC1 and growth inhibition in platinum resistant cancer cells in marked contrast to platinum chemotherapy treatment. These studies demonstrate that baicalein inhibits mTORC1 through DDIT4 expression, and may be useful in cancer chemotherapy and chemoprevention.


Subject(s)
Flavanones/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Neoplasms/genetics , TOR Serine-Threonine Kinases/antagonists & inhibitors , Transcription Factors/genetics , Animals , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Disease Models, Animal , Female , Flavanones/administration & dosage , Gene Expression Profiling , Humans , Mice , Neoplasms/metabolism , Neoplasms/pathology , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , TOR Serine-Threonine Kinases/metabolism , Time Factors , Transcription Factors/metabolism , Transcription, Genetic , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Up-Regulation
5.
Cancer Lett ; 319(1): 56-65, 2012 Jun 01.
Article in English | MEDLINE | ID: mdl-22200613

ABSTRACT

We have shown that the ectopic expression of Interferon Regulatory Factor 1 (IRF-1) results in human cancer cell death accompanied by the down-regulation of the Inhibitor of Apoptosis Protein (IAP) survivin and the induction of the cyclin-dependent kinase inhibitor p21(WAF1/CIP1). In this report, we investigated the direct role of p21 in the suppression of survivin. We show that IRF-1 down-regulates cyclin B1, cdc-2, cyclin E, E2F1, Cdk2, Cdk4, and results in p21-mediated G1 cell cycle arrest. Interestingly, while p21 directly mediates G1 cell cycle arrest, IRF-1 or other IRF-1 signaling pathways may directly regulate survivin in human cancer cells.


Subject(s)
Cell Cycle Checkpoints/physiology , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Inhibitor of Apoptosis Proteins/metabolism , Interferon Regulatory Factor-1/metabolism , Neoplasm Proteins/metabolism , Cell Line, Tumor , Down-Regulation , Humans , Survivin
6.
Mol Cancer Ther ; 10(10): 1774-83, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21817116

ABSTRACT

The transcription factor interferon regulatory factor-1 (IRF-1) is induced by many tumor-suppressive stimuli and can mediate antiproliferative and proapoptotic effects in cancer cells. Thus, identifying agents that enhance IRF-1 activity may be an effective approach to cancer therapy. A cell-based screening assay was developed to identify extracts and compounds that could enhance IRF-1 activity, using an IRF-1-dependent luciferase reporter cell line. Through this approach, we identified a natural product extract and a known active component of this extract, baicalein, which causes a marked increase in IRF-1-dependent reporter gene expression and IRF-1 protein, with modulation of known IRF-1 targets PUMA and cyclin D1. Baicalein causes suppression of growth in vitro in multiple cancer cell lines in the low micromolar range. IRF-1 plays a role in this growth suppression as shown by significant resistance to growth suppression in a breast cancer cell line stably transfected with short hairpin RNA against IRF-1. Finally, intraperitoneal administration of baicalein by repeated injection causes inhibition of growth in both xenogeneic and syngeneic mouse models of cancer without toxicity to the animals. These findings indicate that identifying enhancers of IRF-1 activity may have utility in anticancer therapies and that cell-based screening for activation of transcription factors can be a useful approach for drug discovery.


Subject(s)
Flavanones/pharmacology , Interferon Regulatory Factor-1/biosynthesis , Interferon Regulatory Factor-1/genetics , Neoplasms/drug therapy , Neoplasms/genetics , Animals , Cell Growth Processes/drug effects , Cell Line, Tumor , Disease Models, Animal , Female , Humans , Interferon Regulatory Factor-1/metabolism , Mice , Mice, SCID , Neoplasms/metabolism , Neoplasms/pathology , Random Allocation , Transcription Factors/genetics , Transcription Factors/metabolism , Transfection , Up-Regulation/drug effects , Xenograft Model Antitumor Assays
7.
Yi Chuan Xue Bao ; 30(8): 717-22, 2003 Aug.
Article in Chinese | MEDLINE | ID: mdl-14682239

ABSTRACT

beta-1,3-glucanase(BG2) is one of the pathogensis-related-proteins(PR). Study of these proteins and their related genes is one of the hot points in plant genetic engineering of disease resistance for a long time. In this research, specific primers were designed with the enzyme cleavage site of Spe I in its forward one and Not I site in the backward according to the BG2 gene sequence. Using this pair of primers, BG2 gene, which was contained in the plasmid of pRTL2, was amplified and confirmed by sequencing the amplified fragment inserted into T-easy vector. The positive clone containing BG2 gene was digested with the enzymes of Spe I/Not I and then BG2 gene was inserted into the Xba I/Not I sites of super expression binary vector pATC940. The reconstructed expression vector named as pATCBG2 was introduced into the wheat of Longfumai10 and Longfumai3 (Triticum aestivum L. em. Thell) through the particle gun transformation method. The Kanamysin resistant (Km') transformants were obtained. PCR, Dot-blotting and PCR-Southern hybridization analysis showed that the BG2 gene was integrated into the genome of wheat. Result of pathogen inoculation assay on the transgenic plants showed that the transgenic plants had a higher resistant disease score of 1-2 grade than the control.


Subject(s)
Genetic Vectors/genetics , Glucan 1,3-beta-Glucosidase/genetics , Triticum/genetics , Ascomycota/growth & development , Blotting, Southern , Cloning, Molecular/methods , DNA, Plant/genetics , DNA, Plant/metabolism , Deoxyribonuclease EcoRI/metabolism , Deoxyribonuclease HindIII/metabolism , Immunity, Innate/genetics , Plant Diseases/genetics , Plant Diseases/microbiology , Plants, Genetically Modified , Transformation, Genetic , Triticum/microbiology
8.
Yi Chuan Xue Bao ; 30(4): 341-4, 2003 Apr.
Article in Chinese | MEDLINE | ID: mdl-12812059

ABSTRACT

Southern corn rust (SCR) is a destructive disease in maize. The inbred line Qi319 is highly resistant to southern corn rust. SSR technique was employed to preliminary mapping of the resistance gene. Bulked segregant analysis revealed that two primers, phi 118 and phi 041, amplified polymorphic bands. SSR analysis on populations indicated the two primers were linked to the rust resistance gene, which was mapped on the short arm of chromosome 10. In addition, comparative analysis of the amplification bands among different populations revealed that the amplification products with the same primer in different populations were dissimilar. This result indicates that the genetic background may affect results of gene mapping and tagging. So, it is important to select suitable population to performing molecular marker analysis and gene mapping.


Subject(s)
Basidiomycota/growth & development , Chromosome Mapping/methods , Zea mays/genetics , Chromosomes, Plant/genetics , DNA, Plant/genetics , Immunity, Innate/genetics , Microsatellite Repeats/genetics , Plant Diseases/genetics , Plant Diseases/microbiology , Polymorphism, Restriction Fragment Length , Zea mays/microbiology
9.
Yi Chuan ; 24(6): 715-20, 2002 Nov.
Article in Chinese | MEDLINE | ID: mdl-15979977

ABSTRACT

Study of beta-1,3-glucanase is one of the hot points in plant genetic engineering of disease resistance,big progress has been made in the past few years. This paper briefly reviewed the main biological characters and mechanism involved in the disease resistance,the classification,structure,function and the transformation of beta-1,3-glucanase genes.

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