scholarly journals S1P Lyase Regulates Intestinal Stem Cell Quiescence via Ki-67 and FOXO3

2021 ◽  
Vol 22 (11) ◽  
pp. 5682
Author(s):  
Anja Schwiebs ◽  
Farha Faqar-Uz-Zaman ◽  
Martina Herrero San Juan ◽  
Heinfried H. Radeke
Keyword(s):  
Colorectal Cancer ◽  
Cell Cycle ◽  
Stem Cell ◽  
Signaling Pathway ◽  
Stem Cell Niche ◽  
Akt Signaling ◽  
Akt Signaling Pathway ◽  
Ki 67 ◽  
Cell Niche ◽  
S1p Lyase

Background: Reduction of the Sphingosine-1-phosphate (S1P) degrading enzyme S1P lyase 1 (SGPL1) initiates colorectal cancer progression with parallel loss of colon function in mice. We aimed to investigate the effect of SGPL1 knockout on the stem cell niche in these mice. Methods: We performed immunohistochemical and multi-fluorescence imaging on tissue sections of wildtype and SGPL1 knockout colons under disease conditions. Furthermore, we generated SGPL1 knockout DLD-1 cells (SGPL1−/−M.Ex1) using CRISPR/Cas9 and characterized cell cycle and AKT signaling pathway via Western blot, immunofluorescence, and FACS analysis. Results: SGPL1 knockout mice were absent of anti-Ki-67 staining in the stem cell niche under disease conditions. This was accompanied by an increase of the negative cell cycle regulator FOXO3 and attenuation of CDK2 activity. SGPL1−/−M.Ex1 cells show a similar FOXO3 increase but no arrest of proliferation, although we found a suppression of the PDK1/AKT signaling pathway, a prolonged G1-phase, and reduced stem cell markers. Conclusions: While already established colon cancer cells find escape mechanisms from cell cycle arrest, in vivo SGPL1 knockout in the colon stem cell niche during progression of colorectal cancer can contribute to cell cycle quiescence. Thus, we propose a new function of the S1P lyase 1 in stemness.

scholarly journals The tRNA-derived fragment 5026a inhibits the proliferation of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Linwen Zhu ◽  
Zhe Li ◽  
Xiuchong Yu ◽  
Yao Ruan ◽  
Yijing Shen ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Cancer Cells ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Akt Signaling ◽  
Akt Signaling Pathway ◽  
Gastric Cancer Cells ◽  
Qrt Pcr

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.

scholarly journals Silencing of lncRNA UCA1 inhibited the pathological progression in PCOS mice through the regulation of PI3K/AKT signaling pathway

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dongyong Yang ◽  
Yanqing Wang ◽  
Yajing Zheng ◽  
Fangfang Dai ◽  
Shiyi Liu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Structural Damage ◽  
Polycystic Ovary ◽  
Serum Insulin ◽  
Tumor Cell Line ◽  
Akt Signaling ◽  
Akt Signaling Pathway

Abstract Background Polycystic ovary syndrome (PCOS) is the most common hormonal disorder among reproductive-aged women worldwide, however, the mechanisms and progression of PCOS still unclear due to its heterogeneous nature. Using the human granulosa-like tumor cell line (KGN) and PCOS mice model, we explored the function of lncRNA UCA1 in the pathological progression of PCOS. Results CCK8 assay and Flow cytometry were used to do the cell cycle, apoptosis and proliferation analysis, the results showed that UCA1 knockdown in KGN cells inhibited cell proliferation by blocking cell cycle progression and promoted cell apoptosis. In the in vivo experiment, the ovary of PCOS mice was injected with lentivirus carrying sh-UCA1, the results showed that knockdown of lncRNA UCA1 attenuated the ovary structural damage, increased the number of granular cells, inhibited serum insulin and testosterone release, and reduced the pro-inflammatory cytokine production. Western blot also revealed that UCA1 knockdown in PCOS mice repressed AKT activation, inhibitor experiment demonstrated that suppression of AKT signaling pathway, inhibited the cell proliferation and promoted apoptosis. Conclusions Our study revealed that, in vitro, UCA1 knockdown influenced the apoptosis and proliferation of KGN cells, in vivo, silencing of UCA1 regulated the ovary structural damage, serum insulin release, pro-inflammatory production, and AKT signaling pathway activation, suggesting lncRNA UCA1 plays an important role in the pathological progression of PCOS.

scholarly journals MicroRNA-561 Affects Proliferation and Cell Cycle Transition Through PTEN/AKT Signaling Pathway by Targeting P-REX2a in NSCLC

2020 ◽  
Vol 28 (2) ◽  
pp. 147-159 ◽  
Author(s):  
ZiJun Liao ◽  
Qi Zheng ◽  
Ting Wei ◽  
YanBing Zhang ◽  
JieQun Ma ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Akt Signaling ◽  
Nsclc Cell ◽  
Luciferase Reporter ◽  
Akt Signaling Pathway ◽  
Proliferation And Metastasis ◽  
Exogenous Expression ◽  
Induced Apoptosis

MicroRNAs (miRNAs) play crucial roles in tumorigenesis and tumor progression. miR-561 has been reported to be downregulated in gastric cancer and affects cancer cell proliferation and metastasis. However, the role and underlying molecular mechanism of miR-561 in human non-small cell lung cancer (NSCLC) remain unknown and need to be further elucidated. In this study, we discovered that miR-561 expression was downregulated in human NSCLC tissues and cell lines. The overexpression of miR-561 inhibited NSCLC cell proliferation and cell cycle G1/S transition and induced apoptosis. The inhibition of miR-561 facilitated cell proliferation and G1/S transition and suppressed apoptosis. miR-561 expression was inversely correlated with P-REX2a expression in NSCLC tissues. P-REX2a was confirmed to be a direct target of miR-561 using a luciferase reporter assay. The overexpression of miR-561 decreased P-REX2a expression, and the suppression of miR-561 increased P-REX2a expression. Particularly, P-REX2a silencing recapitulated the cellular and molecular effects observed upon miR-561 overexpression, and P-REX2a overexpression counteracted the effects of miR-561 overexpression on NSCLC cells. Moreover, both exogenous expression of miR-561 and silencing of P-REX2a resulted in suppression of the PTEN/AKT signaling pathway. Our study demonstrates that miR-561 inhibits NSCLC cell proliferation and G1/S transition and induces apoptosis through suppression of the PTEN/AKT signaling pathway by targeting P-REX2a. These findings indicate that miR-561 plays a significant role in NSCLC progression and serves as a potential therapeutic target for NSCLC.

scholarly journals Grape seed procyanidin B2 promotes the autophagy and apoptosis in colorectal cancer cells via regulating PI3K/Akt signaling pathway [Corrigendum]

2019 ◽  
Vol Volume 12 ◽  
pp. 4665-4666
Author(s):  
Ruijuan Zhang ◽  
Qianyun Yu ◽  
Wenqiang Lu ◽  
Jun Shen ◽  
Dongqing Zhou ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Signaling Pathway ◽  
Grape Seed ◽  
Akt Signaling ◽  
Akt Signaling Pathway ◽  
Colorectal Cancer Cells

Akt-Mediated Phosphorylation of Bmi1 Regulates Its Chromatin Association and Growth Promoting Properties.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3605-3605
Author(s):  
Yan Liu ◽  
Fan Liu ◽  
Xinyang Zhao ◽  
Goro Sashida ◽  
Anthony Deblasio ◽  
...  
Keyword(s):  
Stem Cell ◽  
Signaling Pathway ◽  
Conflicts Of Interest ◽  
Bone Marrow Failure ◽  
Akt Signaling ◽  
Polycomb Group ◽  
Akt Pathway ◽  
Akt Signaling Pathway ◽  
Self Renewal ◽  
Hematopoietic Stem

Abstract Abstract 3605 Poster Board III-541 The Polycomb group (PcG) protein Bmi1 maintains silencing of the Ink4a-Arf locus and plays a key role in stem cell self-renewal and oncogenesis. The phosphoinositide 3-kinase-Akt (PI3K-Akt) signaling pathway regulates cell survival, growth, metabolism, migration and angiogenesis. In response to acute Pten loss (which results in Akt activation), mouse embryonic fibroblasts (mefs) accumulate p16Ink4a and p19Arf and undergo senescence. Similarly, Bmi1 −/− mefs undergo premature senescence and accumulate p16Ink4a and p19Arf. PTEN and Bmi1 have similar effects on hematopoiesis; Pten deletion promotes hematopoietic stem cell (HSC) proliferation, resulting in HSC depletion, whereas loss of Bmi1 impairs HSC self-renewal capability, also leading to bone marrow failure. These similarities led us to examine whether the PI3K/Akt pathway functions upstream of Bmi1 to negatively regulate its function and indeed we found that PKB/Akt phosphorylates Bmi1 in vivo, which results in its dissociation from chromatin and in de-repression of the Ink4a-Arf locus. Furthermore, activation of the PI3K/Akt pathway suppresses the ability of Bmi1 to promote cell growth and tumourigenesis and decreases the global level of histone H2A ubiquitination. PI3K/Akt signaling is not active in hematopoietic stem cells, but it is active in more committed progenitor cells. Thus, phosphorylation and inactivation of Bmi1 by Akt may limit HSC self-renewal. Our study also provides a mechanism for the upregulation of p16Ink4a and p19Arf seen in cancer cells that have activation of the PI3K/Akt signaling pathway, and identifies important crosstalk between phosphorylation and chromatin structure. Disclosures: No relevant conflicts of interest to declare.

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