Sa1918 Effects and Possible Mechanism of Inhibition of PI3K/AKT/mTOR Signaling Pathway on Glycolysis of Gastric Adenocarcinoma Cell Lines

Background: Chondrosarcoma is one of the common malignant histologic tumors, very difficult to treat, but the concrete cause and mechanism have not yet been elucidated. The present study aimed to investigate the functional involvement of BCAR4 in chondrosarcoma and its potentially underlying mechanism. QRT-PCR and western blot were used to determine the expression of BCAR4 and mTOR signaling pathway proteins both in chondrosarcoma tissues and cells. Chondrosarcoma cell proliferation and migration were assessed by MTT assay and transwell migration assay, respectively. The expression vectors were constructed and used to modulate the expression of BCAR4 and mTOR. Chondrosarcoma xenograft mouse model was established by subcutaneous injection with chondrosarcoma cell lines. The tumor volume was monitored to evaluate the effect of BCAR4 on chondrosarcoma cell tumorigenicity. The expressions of BCAR4, p-mTOR and p-P70S6K were up-regulated in chondrosarcoma tissues and cell lines. Moreover, BCAR4 overexpression had significant promoting effect on cell proliferation and migration in chondrosarcoma cells. Furthermore, mTOR signaling pathway was epigenetically activated by BCAR4-induced hyperacetylation of histone H3. We also found that mTOR overexpression abolished the decrease of chondrosarcoma cell proliferation and migration induced by BCAR4 knockdown. In vivo experiments confirmed that BCAR4 overexpression significantly accelerated tumor growth, while the knockdown of BCAR4 significantly inhibited tumor growth. BCAR4 promoted chondrosarcoma cell proliferation and migration through activation of mTOR signaling pathway, and thus contributed to chondrosarcoma progression. Impact statement LncRNA BCAR4 promoted chondrosarcoma cell proliferation and migration through activation of mTOR signaling pathway, and thus contributed to chondrosarcoma progression.

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Inhibition of AKT/mTOR Signaling Pathway Induces Cell Cycle Arrest and Apoptosis in Acute Myelogenous Leukemia.

Blood ◽

10.1182/blood.v106.11.2355.2355 ◽

2005 ◽

Vol 106 (11) ◽

pp. 2355-2355

Author(s):

Weina Chen ◽

Ioannis Grammatikakis ◽

Jiang Li ◽

Vassiliki Leventaki ◽

L. Jeffrey Medeiros ◽

...

Keyword(s):

Cell Cycle ◽

Tumor Cell ◽

Cell Survival ◽

Signaling Pathway ◽

Cell Lines ◽

Mtor Signaling ◽

Mtor Signaling Pathway ◽

Mutational Status ◽

Tumor Cell Survival ◽

Dose Dependent

Abstract Acute myelogeneous leukemia (AML) is a heterogeneous disease and includes a subset of neoplasms that harbor activating mutations of the fms-like tyrosine kinase-3 (FLT3) gene. Mutated FLT3 has recently been shown to activate downstream oncogenic pathways including the PI3K/AKT pathway (Scheijen, et al. Oncogene. 23:3338–3349, 2004; Choudhary, et al. Blood. 106:265–273, 2005). It is known that activated AKT mediates its effects, at least in part, through activation of mammalian target of rapamycin (mTOR). However, the potential role of PI3K/AKT/mTOR signaling pathway in tumor cell survival in AML remains largely unknown. We hypothesized that the PI3K/AKT signaling pathway is activated in AML and contributes to tumor cell survival through activation (phosphorylation) of mTOR and its downstream effectors 4EBP1, p70S6K, ribosomal protein S6 (rpS6), and eIF-4E. We used 3 AML cell lines, including MV4-11 and MOLM-13, that are homozygous and heterozygous for mutated FLT3, respectively, as well as U937 (wild-type FLT3). All 3 cell lines expressed activated (serine 473-phosphorylated) AKT (Ser473pAKT), and phosphorylated 4EBP1, p70S6K and rpS6 shown by Western Blot analysis. Treatment of AML cell lines with LY294002, an inhibitor of PI3K, resulted in a dose-dependent decrease of phosphorylation of AKT, mTOR, 4EBP1, p70S6K, and rpS6. This was associated with decreased cell viability as assessed by trypan-blue exclusion assay. Cell death following inhibition of the PI3K/AKT pathway was predominantly attributed to apoptosis as shown by increased annexin V staining assessed by flow cytometry. These changes were associated with downregulation of the anti-apoptotic proteins cFLIP, Mcl-1, and Bcl-XL that are involved in the extrinsic and intrinsic apoptosis. Cell cycle analysis using flow cytometry also showed that inhibition of PI3K resulted in decreased S-phase and increased G1-phase fraction. These cell cycle changes were associated with increased levels of the cyclin-dependent kinase inhibitor p27 and underphosphorylated Rb in a dose-dependent manner. Similar biologic effects, although to a lesser degree, were found after treatment of AML cells with rapamycin, an inhibitor of mTOR. In addition, expression of activated AKT, mTOR, 4EBP1, p70S6K and rpS6 was assessed in AML tumors (n=19) using tissue microarrays of bone marrow samples and immunohistochemical methods. These included tumors with (n=14) and without (n=5) FLT3 mutations. Using a 10% cutoff to define positivity, 13/19 (68%) expressed Ser473pAKT, 16/18 (89%) mTOR, 15/19 (79%) p4E-BP1, 18/19 (95%) p-p70S6K, and 15/18 (83%) p-rpS6. However, no association between expression of activated AKT, or mTOR signaling proteins and FLT3 mutational status was observed. Our study provides first evidence that the AKT/mTOR signaling pathway is activated in AML cell lines and tumors regardless of FLT3 mutational status. The AKT/mTOR signaling pathway may contribute to cell cycle progression and tumor cell survival in AML. Inhibition of this oncogenic pathway represents a potential target for therapy in patients with AML.

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Anti-Leukemia Effect of Rapamycin Alone or Plus Daunorubicin on Acute Lymphoblastic Leukemia Cell Lines

Blood ◽

10.1182/blood.v116.21.3256.3256 ◽

2010 ◽

Vol 116 (21) ◽

pp. 3256-3256

Author(s):

Xi Yang ◽

Yuping Gong ◽

Ting Niu

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Cell Line ◽

Signaling Pathway ◽

Cell Lines ◽

Ribosome Biogenesis ◽

Conflicts Of Interest ◽

Lymphoblastic Leukemia ◽

Leukemia Cell ◽

Mtor Signaling ◽

Mtor Signaling Pathway

Abstract Abstract 3256 Mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine-threonine kinase that integrates signals from multiple inputs, including growth factors, amino acids, and intracellular energy supply, to regulate diverse cellular functions, such as transcription, ribosome biogenesis, translation initiation, and autophagic cell death (autophagy). Aberrant activation of the mTOR signaling pathway has been demonstrated in several tumors, including the majority of acute lymphoblastic leukemia(ALL). The potential anti-leukaemia effect of mTOR inhibitors has received some attention so far in ALL. In this study, we aimed to assess the anti-leukemic activity of Rapamycin (RAPA), an mTOR inhibitor, alone and in combination with daunorubicin (DNR). Here, we demonstrated that RAPA in concentrations of 1–100 nmol/L significantly inhibited the proliferation of Ph+ ALL cell line SUP-B15, whereas exerted poor effect on Ph- ALL cell line CEM. However, RAPA at a dose of 50 nmol/L significantly intensified the inhibition induced by DNR on two ALL cell lines. The synergistic effect was associated with regulation of autophagy and apoptosis, blockage of cell cycle progression in the G1 phase. We also reported that the consequence of DNR-treatment induced the overexpression of the mTOR signaling pathway in two ALL cell lines and primary leukemia cells in vitro, whereas RAPA effectively eliminated this deleterious side effect of the DNR and might enhance DNR ability to kill drug–resistant cancer. Altogether, our results suggested that DNR in combination with RAPA was more effective in the treatment of ALL than DNR alone. Therefore, combination of classical induction chemotherapy with an inhibitor of the mTOR kinase could be a promising strategy in future treatment of ALL. Disclosures: No relevant conflicts of interest to declare.

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MLN4924, An Investigational NAE Inhibitor, Suppresses AKT and mTOR Signaling Pathway Through up Regulating REDD1 in Human Myeloma Cells

Blood ◽

10.1182/blood.v118.21.1870.1870 ◽

2011 ◽

Vol 118 (21) ◽

pp. 1870-1870

Author(s):

Yanyan Gu ◽

Jonathan L. Kaufman ◽

Lawrence H. Boise ◽

Sagar Lonial

Keyword(s):

Multiple Myeloma ◽

Western Blot ◽

Signaling Pathway ◽

Cell Lines ◽

Research Funding ◽

Myeloma Cell ◽

Mtor Pathway ◽

Mtor Signaling ◽

Mtor Signaling Pathway ◽

Myeloma Cells

Abstract Abstract 1870 Introduction: The development and survival of normal plasma cells as well as multiple myeloma cells depend on an elaborately regulated ubiquitin proteasome system (UPS). Proteasome inhibitors such as bortezomib have proved to be highly active in the treatment of multiple myeloma. MLN4924, a newly developed investigational NEDD8 activating enzyme (NAE) inhibitor, exhibits promising anti-tumor effect through both clinical and laboratory observation. We sought to evaluate the individual signaling effects of MLN4924 in multiple myeloma, with the intent of further understanding the mechanism of action and identifying potential combinations. Methods: Human myeloma cell lines (MM.1S, MM.1R and U266) were treated with increasing concentrations of MLN4924 for 24, 48 and 72 hrs respectively or concurrently with bortezomib. Cell viability (MTT), apoptosis, western blot, RT-qPCR and siRNA assays were used to identify the cellular and molecular sequelae of MLN4924 treatment. Results: Single agent studies demonstrate that MLN4924 induces cytotoxicity in all three MM cell lines. Cytotoxicity is associated with increased apoptosis and suppression of AKT and mTOR signaling pathway, as detected by FACS and western blot. MLN4924 suppresses protein turnover of Cullin-ring ligases substrates leading to stabilization of specific proteins, such as p27, CDT1, NRF2. We find that REDD1, a substrate of CUL4 A–DDB 1–ROC1–β-TRCP ubiquitin ligase and negative regulator of mTOR pathway, increases in as early as 2 hours when treated with MLN4924. Knock-down of REDD1 using siRNA alleviates MLN4924 induced AKT, mTOR signaling suppression as well as the growth inhibition, which suggests that MLN4924 inhibits AKT, mTOR signaling through upregulating REDD1 protein leading to cytotoxicity. Combining MLN4924 with bortezomib synergistically enhances the antitumor effect of MLN4924. Western blot confirms the development of significantly increased procaspase and PARP cleavage, as well as substantial down regulation of AKT and mTOR signaling. Neither IL-6 nor IGF-1 is able to abrogate these combination effects. When we silence REDD1 in the combination assay in MM.1R, we find less cell apoptosis and suppression of AKT, mTOR pathway, which further support that REDD1 is an important regulator for MLN4924 induced cytotoxicity in MMs. Conclusion: MLN4924 is a potent investigational antitumor compound suppressing mTOR signaling pathways in myeloma cell lines. Down-regulation of the mTOR signaling pathway is associated with increased expression of REDD1. Combination of MLN4924 with the proteasome inhibitor bortezomib induces synergistic apoptosis in MMs cell lines which can overcome the prosurvival effects of growth factor (IL-6 and IGF-1). These findings could positively impact clinical combination strategies. Disclosures: Kaufman: Millenium: Consultancy; Onyx Pharmaceuticals: Consultancy; Novartis: Consultancy; Keryx: Consultancy; Merck: Research Funding; Celgene: Research Funding. Lonial:Millennium Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Bristol-Myers Squibb: Consultancy; Onyx: Consultancy; Merck: Consultancy.

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A steroidal saponin isolated from Allium chinense simultaneously induces apoptosis and autophagy by modulating the PI3K/Akt/mTOR signaling pathway in human gastric adenocarcinoma

Steroids ◽

10.1016/j.steroids.2020.108672 ◽

2020 ◽

Vol 161 ◽

pp. 108672

Author(s):

Jingwen Xu ◽

Mingmei Zhang ◽

Xiaoying Lin ◽

Yihai Wang ◽

Xiangjiu He

Keyword(s):

Signaling Pathway ◽

Gastric Adenocarcinoma ◽

Mtor Signaling ◽

Steroidal Saponin ◽

Mtor Signaling Pathway ◽

Human Gastric Adenocarcinoma ◽

Allium Chinense

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Cezanne enhances epithelial mesenchymal transition and prevents anthracycline-induced apoptosis via AKT/mTOR signaling in hepatocellular carcinoma

10.21203/rs.3.rs-676858/v1 ◽

2021 ◽

Author(s):

Xiao-Ping Zhong ◽

Jiahong Wang ◽

Jie Mei ◽

Lianghe Lu ◽

Yihong Ling ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Signaling Pathway ◽

Cell Lines ◽

Mtor Inhibitor ◽

Epithelial Mesenchymal Transition ◽

Mtor Signaling ◽

Mtor Signaling Pathway ◽

Mesenchymal Transition

Abstract Background Anthracycline resistance have hindered the efficacy of transcatheter arterial chemoembolization (TACE). Translational research is therefore in need to find potential combinations by studying the resistance mechanism of anthracycline. In our published work, we found Cezanne could predict the efficacy of adjuvant TACE (ad-TACE) and induce epithelium mesenchymal transition (EMT) in hepatocellular carcinoma (HCC). We hereby conduct a sequential investigation to reveal the role of Cezanne on EMT and its potential to retard resistance. Methods The response of Cezanne in patients treated with adjuvant TACE after hepatectomy was evaluated. Functional assays were used to examine the resistance function of Cezanne to anthracyclin. In-situ tumorigenesis models and intraperitoneal perfusion chemotherapy experiment were used for in vivo verification. Results High expression of Cezanne correlated to a better outcome. Multivariate analysis showed low expression of Cezanne and the application of postoperative ad-TACE therapy were independent prognostic risk factors. However, patient outcome was significantly shorter in high Cezanne group of ad-TACE patients. In vitro assays revealed that HCC functions were inhibited after overexpressing Cezanne (OE-Cezanne). After treated with epirubicin, however, OE-Cezanne cell lines did not respond to treatment. In vivo experiment was consistent with in vitro assays. Besides, high Cezanne transforms cell morphology and is correlated to the activation of EMT related genes. Gene set analysis showed that Cezanne can regulate PI3K/AKT/mTOR signaling pathway. Therefore, mTOR inhibitor Rapamycin can reverse the resisting effect of Cezanne on HCC cell lines. Conclusions Adjuvant anthracycline-based TACE treatment after curative surgery can reduce the recurrence rate in HCC patients. However, in patients with high Cezanne expression, the efficacy of TACE may be undermined by EMT inducement. We discovered Cezanne modulates EMT by activating the AKT/mTOR signaling pathway and provided evidence for the rationale of combining mTOR inhibitor with TACE to prevent recurrence in HCC patients.

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Long Non-Coding RNA XLOC_006753 Promotes the Development of Multidrug Resistance in Gastric Cancer Cells Through the PI3K/AKT/mTOR Signaling Pathway

Cellular Physiology and Biochemistry ◽

10.1159/000495499 ◽

2018 ◽

Vol 51 (3) ◽

pp. 1221-1236 ◽

Cited By ~ 18

Author(s):

Lisi Zeng ◽

Quanxing Liao ◽

Zhaowei Zou ◽

Yuefeng Wen ◽

Jingshu Wang ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Cycle ◽

Cell Proliferation ◽

Overall Survival ◽

Signaling Pathway ◽

Cell Lines ◽

Progression Free Survival ◽

Mtor Signaling ◽

Mtor Signaling Pathway ◽

Free Survival

Background/Aims: The development of multidrug resistance (MDR), which results in disease recurrence and metastasis, is a crucial obstacle to successful chemotherapy for patients with gastric cancer (GC). Long non-coding RNAs (lncRNAs) have been found to play various roles in cancer. This study aimed to investigate the effect of XLOC_006753 on the development of MDR in GC cells. Methods: The expression levels of XLOC_006753 in GC patients and MDR GC cell lines (SGC-7901/5-FU and SGC-7901/DDP cell line) were assessed by qRT-PCR. Statistical analyses were conducted to determine the relationship between XLOC_006753 expression and clinical features and to assess the prognostic value of XLOC_006753 for overall survival and progression-free survival. Then, a CCK-8 assay was used to detect cell proliferation ability and chemosensitivity. Flow cytometry was used to detect cell cycle and cell apoptosis. A wound-healing assay and transwell assay were used to detect cell migration. The expression of markers for MDR, G1/S transition, epithelial–mesenchymal transition (EMT) and PI3K/ AKT/mTOR signaling pathway were examined by western blot. Results: XLOC_006753 was highly expressed in GC patients and MDR GC cell lines (SGC-7901/5-FU and SGC-7901/DDP cell lines), and its high expression was positively associated with metastasis, TNM stage, tumor size, and poor survival in GC patients. Moreover, XLOC_006753 was an independent prognostic biomarker of overall survival and progression-free survival for gastric cancer patients. Knocking down XLOC_006753 in the two MDR GC cell lines significantly inhibited cell proliferation, cell viability, cell cycle G1/S transition, and migration. XLOC_006753 knockdown also promoted apoptosis. Furthermore, western blots showed that XLOC_006753 knockdown decreased some markers of MDR, G1/S transition, and EMT expression, while increasing caspase9 expression and inhibiting the PI3K/AKT/mTOR signaling pathway in SGC-7901/5-FU and SGC-7901/DDP cells. Conclusion: High expression of XLOC_006753 promoted the development of MDR, which was activated by the PI3K/AKT/mTOR pathway in GC cells.

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