scholarly journals Positive Effects of PI3K/Akt Signaling Inhibition on PTEN and P53 in Prevention of Acute Lymphoblastic Leukemia Tumor Cells

2019 ◽  
Vol 9 (3) ◽  
pp. 470-480 ◽  
Author(s):  
Elahe Naderali ◽  
Behnaz Valipour ◽  
Amir Afshin Khaki ◽  
Jafar Soleymani Rad ◽  
Alireza Alihemmati ◽  
...  

Purpose: The PI3K/Akt signaling pathway regulates cell growth, proliferation and viability in hematopoietic cells. This pathway always dysregulates in acute lymphoblastic leukemia (ALL). PTEN and P53 are tumor suppressor genes correlated with PI3K/Akt signaling pathway, and both have a tight link in regulation of cell proliferation and cell death. In this study, we investigated the effects of dual targeting of PI3K/Akt pathway by combined inhibition with nvp-BKM-120 (PI3K inhibitor) and MK-2206 (Akt inhibitor) in relation with PTEN and P53 on apoptosis and proliferation of leukemia cells. Methods: Both T and B ALL cell lines were treated with both inhibitors alone or in combination with each other, and induction of apoptosis and inhibition of proliferation were evaluated by flow cytometry. Expression levels of PTEN as well as p53 mRNA and protein were measured by real-time qRT-PCR and western blot, respectively. Results: We indicated that both inhibitors (BKM-120 and MK-2206) decreased cell viability and increased cytotoxicity in leukemia cells. Reduction in Akt phosphorylation increased PTEN and p53 mRNA and p53 protein level (in PTEN positive versus PTEN negative cell lines). Additionally, both inhibitors, particularly in combination with each other, increased apoptosis (evaluated with Annexin V and caspase 3) and reduced proliferation (Ki67 expression) in leukemia cells. However, administration of IL7 downregulated PTEN and P53 mRNA expression and rescued cancer cells following inhibition of BKM-120 and MK-2206. Conclusion: This investigation suggested that inhibition of Akt and PI3K could be helpful in leukemia treatment.

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
Yi-Fen Shi ◽  
Zi-Yang Huang ◽  
Yi-Sha Huang ◽  
Ru-Jiao Dong ◽  
Chong-Yun Xing ◽  
...  

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4886-4886 ◽  
Author(s):  
Tina-Susann Langhammer ◽  
Catrin Roolf ◽  
Saskia Krohn ◽  
Christin Kretzschmar ◽  
Rayk Huebner ◽  
...  

Abstract Signaling pathways play essential roles in biological processes as development, cell proliferation and homeostasis. The accurate modulation of signaling pathways, their adapted interaction and their time- and tissue-specific adjusted regulation are required for normal cell development. PI3K/Akt and Wnt/β-Catenin signaling pathways act as key regulators in cell proliferation, differentiation and growth. Both signaling pathways include GSK3β as a common protein, which may mediate an interaction and cross-talk between the pathways. Aberrant activation of PI3K/Akt signaling has been linked to different types of leukemia while Wnt/β-Catenin signaling is known to be deregulated in some solid tumors. However, a potential role of Wnt/β-Catenin signaling for pathogenesis of acute lymphoblastic leukemia (ALL) has not yet been analyzed. In our study we analyzed both signaling pathways in different B- and T-ALL cell lines (RS4;11, SEM, REH, CEM, Jurkat, MOLT-4), thereby focusing mainly on their potential interaction via the protein GSK3β. Western Blot experiments were performed to evaluate the expression of specific PI3K/Akt and Wnt/β-Catenin key proteins. To evaluate the activation status of Wnt signaling immunofluorescence and protein fractionation experiments were performed, analyzing the activation linked nucleic localization of β-Catenin. The effect of pathway activation and inhibition on cell proliferation via chemical compounds was analyzed by WST-1 test. High pAkt levels were detected in B-ALL cell line SEM and T-ALL cell line CEM, indicating a hyperactive PI3K/Akt signaling, whereas other analyzed cell lines diplayed lower pAkt status. Among all cell lines analyzed SEM and CEM also showed the highest cytoplasmic β-Catenin levels, indicating a direct interaction of both signaling pathways. However, immunofluorescence and fractionation experiments revealed that a translocation of β-Catenin into the nucleus did not occur. To further investigate the role and interaction of PI3K/Akt and Wnt/β-Catenin signaling, pathway inhibiting and stimulating experiments were performed. Treatment of cells with Wnt3a led to activation of the Wnt/β-Catenin signaling cascade, characterized by nuclear β-Catenin accumulation. Inhibition of cell proliferation was detected after treatment with high concentrations Wnt3a (≥ 500 ng/ml). PI3K inhibition by LY294002 led to decreased phosphorylation of GSK3β at Ser9 and an increased decay of β-Catenin. Stimulation of PI3K/Akt signaling using activating ligand FLT3L induced GSK3β phosphorylation at Ser9 and accumulation of cytoplasmic β-Catenin. However a translocation of β-Catenin into the nucleus seems not to occur. In summary our results indicate that PI3K/Akt and Wnt/β-Catenin signaling can interact through their common protein GSK3β, but stimulation of the PI3K/Akt signaling pathway by addition of PI3K/Akt specific activators does not fully activate Wnt/β-Catenin signaling in ALL cells. Complete activation of the Wnt cascade characterized by translocation of β-Catenin into the nucleus can only be induced by use of specific Wnt effectors. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Linwen Zhu ◽  
Zhe Li ◽  
Xiuchong Yu ◽  
Yao Ruan ◽  
Yijing Shen ◽  
...  

Abstract Background Recently, tRNA-derived fragments (tRFs) have been shown to serve important biological functions. However, the role of tRFs in gastric cancer has not been fully elucidated. This study aimed to identify the tumor suppressor role of tRF-5026a (tRF-18-79MP9P04) in gastric cancer. Methods Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was first used to detect tRF-5026a expression levels in gastric cancer tissues and patient plasma. Next, the relationship between tRF-5026a levels and clinicopathological features in gastric cancer patients was assessed. Cell lines with varying tRF-5026a levels were assessed by measuring tRF-5026a using qRT-PCR. After transfecting cell lines with a tRF-5026a mimic or inhibitor, cell proliferation, colony formation, migration, apoptosis, and cell cycle were evaluated. The expression levels of related proteins in the PTEN/PI3K/AKT pathway were also analyzed by Western blotting. Finally, the effect of tRF-5026a on tumor growth was tested using subcutaneous tumor models in nude mice. Results tRF-5026a was downregulated in gastric cancer patient tissues and plasma samples. tRF-5026a levels were closely related to tumor size, had a certain diagnostic value, and could be used to predict overall survival. tRF-5026a was also downregulated in gastric cancer cell lines. tRF-5026a inhibited the proliferation, migration, and cell cycle progression of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway. Animal experiments showed that upregulation of tRF-5026a effectively inhibited tumor growth. Conclusions tRF-5026a (tRF-18-79MP9P04) is a promising biomarker for gastric cancer diagnostics and has tumor suppressor effects mediated through the PTEN/PI3K/AKT signaling pathway.


Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1377
Author(s):  
Yasser Perera ◽  
Alice Melão ◽  
Ailyn C. Ramón ◽  
Dania Vázquez ◽  
Daniel Ribeiro ◽  
...  

Despite remarkable advances in the treatment of T-cell acute lymphoblastic leukemia (T-ALL), relapsed cases are still a major challenge. Moreover, even successful cases often face long-term treatment-associated toxicities. Targeted therapeutics may overcome these limitations. We have previously demonstrated that casein kinase 2 (CK2)-mediated phosphatase and tensin homologue (PTEN) posttranslational inactivation, and consequent phosphatidylinositol 3-kinase (PI3K)/Akt signaling hyperactivation, leads to increased T-ALL cell survival and proliferation. We also revealed the existence of a crosstalk between CK2 activity and the signaling mediated by interleukin 7 (IL-7), a critical leukemia-supportive cytokine. Here, we evaluated the impact of CIGB-300, a the clinical-grade peptide-based CK2 inhibitor CIGB-300 on T-ALL biology. We demonstrate that CIGB-300 decreases the viability and proliferation of T-ALL cell lines and diagnostic patient samples. Moreover, CIGB-300 overcomes IL-7-mediated T-ALL cell growth and viability, while preventing the positive effects of OP9-delta-like 1 (DL1) stromal support on leukemia cells. Signaling and pull-down experiments indicate that the CK2 substrate nucleophosmin 1 (B23/NPM1) and CK2 itself are the molecular targets for CIGB-300 in T-ALL cells. However, B23/NPM1 silencing only partially recapitulates the anti-leukemia effects of the peptide, suggesting that CIGB-300-mediated direct binding to CK2, and consequent CK2 inactivation, is the mechanism by which CIGB-300 downregulates PTEN S380 phosphorylation and inhibits PI3K/Akt signaling pathway. In the context of IL-7 stimulation, CIGB-300 blocks janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway in T-ALL cells. Altogether, our results strengthen the case for anti-CK2 therapeutic intervention in T-ALL, demonstrating that CIGB-300 (given its ability to circumvent the effects of pro-leukemic microenvironmental cues) may be a valid tool for clinical intervention in this aggressive malignancy.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3241-3241
Author(s):  
Noriko Satake ◽  
Astra Chang ◽  
Bridget McLaughlin ◽  
Sara Bauman ◽  
James Chan ◽  
...  

Abstract Abstract 3241 Leukemia cells are believed to arise from leukemia stem cells (LSC). It is also known that LSC are responsible for relapse in certain types of leukemia, such as acute myeloid leukemia (AML). However, the existence and role of LSC in acute lymphoblastic leukemia (ALL) is unclear. CD9 was reported to be a marker for LSC in B-ALL using cell lines (Nishida H. et al., 2009). CD9 is a tetraspanin and is believed to be involved in cell adhesion, motility, and signaling events. It is also involved in metastasis; however, the mechanisms are unknown. Since childhood ALL is a heterogeneous group of diseases and cell lines can be different from primary leukemia cells, we tested the role of CD9 as a candidate LSC marker using primary precursor B (preB) ALL cells from pediatric patients. Two methods, Raman spectroscopy and serial transplantation of sorted leukemia cells in NOD/SCID/IL2R g null (NSG) mice, were used to confirm LSC. Raman spectroscopy is a laser-based technique for the single cell analysis of intrinsic molecular vibrations reflecting cellular biochemical information. It can provide a quantitative assessment of the levels of DNA, RNA, proteins, lipids, and carbohydrates in the cell, as well as molecular-level conformational changes. Previous studies by our group showed that unique Raman fingerprints were identified in normal blood cells, ALL cells, and stem cells, including hematopoietic stem cells and embryonic stem cells. Four preB ALL samples were stained for CD9 and sorted by flow cytometry. ALL samples were obtained from patients at diagnosis or freshly harvested from NSG mice engrafted with primary leukemia samples. All samples showed heterogeneous expression of CD9. CD9 high-positive cells and negative cells were flow sorted. Raman spectra of freshly sorted CD9 high-positive and negative cells were obtained. 10 to 20 cells were analyzed in each sample. CD34 positive cells, which were isolated from normal donors, were also analyzed by Raman spectroscopy as a control. No unique Raman fingerprints were identified to separate CD9 high-positive cells from negative cells using Principal Component Analysis (PCA). Furthermore, CD9 high-positive and negative cells from three preB ALL samples were transplanted into NSG mice via intra-bone marrow injection. Equal cell numbers (5×105 to 1.5×106 cells) were used for positive and negative samples in each injection. The majority of the mice from both groups (transplanted with CD9 high-positive or negative cells) developed leukemia 3 to 4 months after injection. Leukemia phenotype was confirmed to be the same as the original leukemia. In conclusion, although CD9 was shown to be a marker for LSC in B-ALL cell lines, it does not appear to be an LSC marker in primary preB ALL. Since childhood preB ALL is a heterogeneous group of diseases, larger cohorts are necessary to confirm our findings. Raman spectroscopy may be a useful screening tool for analysis of cellular intrinsic markers. Disclosures: No relevant conflicts of interest to declare.


2020 ◽  
Author(s):  
LU GE ◽  
Chang-long Hu ◽  
Zheng-hui Ge ◽  
Chun-rong Wang ◽  
Li Qian ◽  
...  

Abstract Purpose Capicua homolog protein (CIC) played a broad role in the development of cancer in humans, however, its role in the progression of gastric cancer (GC) specifically has been unclear. This study aimed to explore the expression of CIC and its potential clinical value in patients with GC. Methods The CIC levels in GC tissues and cell lines were examined by quantitative real-time polymerase chain reaction (qRT-PCR). And the in-vitro effects of CIC expression in MGC-803 cells on their proliferation, invasion, and the progression of epithelial-mesenchymal transition were assessed by CCK-8 assays, Matrigel-invasion analysis, qRT-PCR and Western blot assays, separately. In addition, the effects of downregulation of CIC on the activation of PI3K/AKT signaling pathway were measured using Western-blot analysis. Results The results showed CIC levels were lower in GC tissues and GC cell lines, and these lower CIC levels were correlated with tumor differentiation, Helicobacter pylori infection, TNM stage, and patient survival. In addition, CIC overexpression could promote cell proliferation, invasion, and progression of epithelial-mesenchymal transition in MGC-803 cells. Notably, exotic expression of CIC inactivated the phosphoinositide 3-kinase/protein kinase B signaling pathway. Conclusions In conclusion, our finding suggested CIC could serve as a potential diagnostic and prognostic biomarker and a probable therapy target for GC.


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