Phosphorylation of islet-1 serine 269 by CDK1 increases its transcriptional activity and promotes cell proliferation in gastric cancer

Abstract Background Despite recent advances in diagnostic and therapeutic approaches for gastric cancer (GC), the survival of patients with advanced GC remains very low. Islet-1 (ISL1) is a LIM-homeodomain transcription factor, which is upregulated and promotes cell proliferation in GC. The exact mechanism by which ISL1 influences GC development is unclear. Methods Co-immunoprecipitation (co-IP) and glutathione S-transferase (GST)-pulldown assays were employed to evaluate the interaction of ISL1 with CDK1. Western blot and immunohistochemistry analyses were performed to evaluate the ability of CDK1 to phosphorylate ISL1 at Ser 269 in GC cell and tissue specimens. Chromatin immunoprecipitation (ChIP), ChIP re-IP, luciferase reporter, and CCK-8 assays were combined with flow cytometry cell cycle analysis to detect the transactivation potency of ISL1-S269-p and its ability to promote cell proliferation. The self-stability and interaction with CDK1 of ISL1-S269-p were also determined. Results ISL1 is phosphorylated by CDK1 at serine 269 (S269) in vivo. Phosphorylation of ISL1 by CDK1 on serine 269 strengthened its binding on the cyclin B1 and cyclin B2 promoters and increased its transcriptional activity in GC. Furthermore, CDK1-dependent phosphorylation of ISL1 correlated positively with ISL1 protein self-stability in NIH3T3 cells. Conclusions ISL1-S269-p increased ISL1 transcriptional activity and self-stability while binding to the cyclinB1 and cyclinB2 promoters promotes cell proliferation. ISL1-S269-p is therefore crucial for tumorigenesis and potentially a direct therapeutic target for GC.

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Deficiency of G9a Inhibits Cell Proliferation and Activates Autophagy via Transcriptionally Regulating c-Myc Expression in Glioblastoma

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2020.593964 ◽

2020 ◽

Vol 8 ◽

Author(s):

Xiao Xue Ke ◽

Rui Zhang ◽

Xi Zhong ◽

Lei Zhang ◽

Hongjuan Cui

Keyword(s):

Cell Proliferation ◽

Cyclin B1 ◽

Luciferase Reporter ◽

Cycle Arrest ◽

Histone Lysine Methyltransferase ◽

Lysine Methyltransferase ◽

A Cell ◽

Cell Proliferation Control

Glioblastoma is an aggressive and difficult to treat cancer. Recent data have emerged implicating that histone modification level may play a crucial role in glioma genesis. The histone lysine methyltransferase G9a is mainly responsible for the mono- and di-methylation of histone H3 lysine 9 (H3K9), whose overexpression is associated with a more aggressive phenotype in cancer. However, the detailed correlations between G9a and glioblastoma genesis remain to be further elucidated. Here, we show that G9a is essential for glioblastoma carcinogenesis and reveal a probable mechanism of it in cell proliferation control. We found that G9a was highly expressed in glioblastoma cells, and knockdown or inhibition of G9a significantly repressed cell proliferation and tumorigenesis ability both in vitro and in vivo. Besides, knockdown or inhibition of G9a led to a cell cycle arrest in G2 phase, as well as decreased the expression of CDK1, CDK2, Cyclin A2, and Cyclin B1, while it induced the activation of autophagy. Further investigation showed that G9a deficiency induced cell proliferation suppression, and activation of autophagy was rescued by overexpression of the full-length c-Myc. Chromatin immunoprecipitation (ChIP) assay showed that G9a was enriched on the −2267 to −1949 region of the c-Myc promoter in LN-229 cells and the −1949 to −1630 region of the c-Myc promoter in U-87 MG cells. Dual-luciferase reporter assay showed that c-Myc promoter activity was significantly reduced after knockdown or inhibition of G9a. Our study shows that G9a controls glioblastoma cell proliferation by transcriptionally modulating oncogene c-Myc and provides insight into the capabilities of G9a working as a potential therapeutic target in glioblastoma.

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Cyclin D3-CDK6 Complex Facilitates Tumorigenesis by Regulating the C-Myc/miR-15a/16 Axis in a Feedback Loop in Gastric Cancer

10.21203/rs.3.rs-125333/v1 ◽

2020 ◽

Author(s):

Yeting Hong ◽

Wei He ◽

Jianbin Zhang ◽

Lu Shen ◽

Chong Yu ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Cycle ◽

Cell Proliferation ◽

Feedback Loop ◽

Cell Cycle Progression ◽

Molecular Mechanisms ◽

Cyclin D3 ◽

Luciferase Reporter

Abstract Background: Cyclin D3-CDK6 complex is a component of the core cell cycle machinery that regulates cell proliferation. By using Human Protein Atlas database, a higher expression level of this complex was found in gastric cancer. However, the function of this complex in gastric cancer remain poorly understood. This study aims to determine the expression pattern of this complex in gastric cancer and to investigate its biological role during tumorigenesis.Methods: To demonstrate that Cyclin D3-CDK6 regulate the c-Myc/miR-15a/16 axis in a feedback loop in gastric cancer, a series of methods were conducted both in vitro and in vivo experiments, including qRT-PCR, western blot analysis, EdU assay, ﬂow cytometry, luciferase reporter assay and immunohistochemical staining. SPSS and Graphpad prism software were used for data analysis.Results: In this study, we found that Cyclin D3 and CDK6 were significantly upregulated in gastric cancer and correlated with poorer overall survival. Further study proved that this complex significantly promoted cell proliferation and cell cycle progression in vitro and accelerated xenografted tumor growth in vivo. Furthermore, we explored the molecular mechanisms through which the complex mediated Rb phosphorylation and then promoted c-Myc expression in vitro, we also found c-Myc could suppress miR-15a/16 expression in gastric cancer cell. Finally, we found that miR-15a/16 can simultaneously regulate Cyclin D3 and CDK6 expression as direct target genes.Conclusions: Our findings uncover the Cyclin D3-CDK6/c-Myc/miR-15a/16 feedback loop axis as a pivotal role in the regulation of gastric cancer tumorigenesis, and this regulating axis may provide a potential therapeutic target for gastric cancer treatment.

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KLF5 Is Crucial for Androgen-AR Signaling to Transactivate Genes and Promote Cell Proliferation in Prostate Cancer Cells

Cancers ◽

10.3390/cancers12030748 ◽

2020 ◽

Vol 12 (3) ◽

pp. 748 ◽

Cited By ~ 1

Author(s):

Juan Li ◽

Baotong Zhang ◽

Mingcheng Liu ◽

Xing Fu ◽

Xinpei Ci ◽

...

Keyword(s):

Prostate Cancer ◽

Cell Proliferation ◽

Cancer Cells ◽

Transcriptional Activity ◽

Prostate Cancer Cells ◽

Normal Prostate ◽

Promote Cell Proliferation ◽

Therapeutic Opportunity

Androgen/androgen receptor (AR) signaling drives both the normal prostate development and prostatic carcinogenesis, and patients with advanced prostate cancer often develop resistance to androgen deprivation therapy. The transcription factor Krüppel-like factor 5 (KLF5) also regulates both normal and cancerous development of the prostate. In this study, we tested whether and how KLF5 plays a role in the function of AR signaling in prostate cancer cells. We found that KLF5 is upregulated by androgen depending on AR in LNCaP and C4-2B cells. Silencing KLF5, in turn, reduced AR transcriptional activity and inhibited androgen-induced cell proliferation and tumor growth in vitro and in vivo. Mechanistically, KLF5 occupied the promoter of AR, and silencing KLF5 repressed AR transcription. In addition, KLF5 and AR physically interacted with each other to regulate the expression of multiple genes (e.g., MYC, CCND1 and PSA) to promote cell proliferation. These findings indicate that, while transcriptionally upregulated by AR signaling, KLF5 also regulates the expression and transcriptional activity of AR in androgen-sensitive prostate cancer cells. The KLF5-AR interaction could provide a therapeutic opportunity for the treatment of prostate cancer.

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Circ_0000144 functions as a miR-623 sponge to enhance gastric cancer progression via up-regulating GPRC5A

Bioscience Reports ◽

10.1042/bsr20201313 ◽

2020 ◽

Vol 40 (8) ◽

Author(s):

Lili Mi ◽

Lianhui Lei ◽

Xiaolei Yin ◽

Ning Li ◽

Jianfei Shi ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Proliferation ◽

Tumor Growth ◽

Cancer Progression ◽

Colony Formation ◽

Human Cancer ◽

Luciferase Reporter ◽

Migration And Invasion ◽

The Impact

Abstract Background: Gastric cancer (GC) remains one of the most common malignancies worldwide. Increasing evidence has demonstrated that circRNAs serve as critical roles in human cancer, including GC. In the present study, we focused on the detailed function and mechanism of circ_0000144 on GC progression. Methods: The levels of circ_0000144, miR-623 and G-protein-coupled receptor, family C, group 5, member A (GPRC5A) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Targeted relationships among circ_0000144, miR-623 and GPRC5A were confirmed using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Cell proliferation, colony formation, apoptosis, migration and invasion were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, flow cytometry and transwell assays. Measurement of glutamine and α-ketoglutarate (α-KG) levels was performed using a corresponding assay kit. GPRC5A protein expression was detected using Western blot. In vivo assays were used to explore the impact of circ_0000144 on tumor growth. Results: Our data indicated that circ_0000144 was up-regulated and miR-623 was down-regulated in GC tissues and cells. Circ_0000144 interacted with miR-623 through directly binding to miR-623. Moreover, the knockdown of circ_0000144 weakened GC cell proliferation, colony formation, migration, invasion and glutaminolysis and accelerated cell apoptosis by up-regulating miR-623. GPRC5A was a direct target of miR-623 and circ_0000144 protected against GPRC5A repression through sponging miR-623. Furthermore, miR-623-mediated regulation on GC cell progression was reversed by the stored expression of GPRC5A. Additionally, circ_0000144 depletion inhibited tumor growth in vivo. Conclusion: Our study indicated that circ-0000144 knockdown repressed GC progression at least partly by regulating GPRC5A expression via sponging miR-623, illumining a novel therapeutic target for GC treatment.

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Compounds from Cynomorium songaricum with Estrogenic and Androgenic Activities Suppress the Oestrogen/Androgen-Induced BPH Process

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2017/6438013 ◽

2017 ◽

Vol 2017 ◽

pp. 1-12 ◽

Cited By ~ 3

Author(s):

Xueni Wang ◽

Rui Tao ◽

Jing Yang ◽

Lin Miao ◽

Yu Wang ◽

...

Keyword(s):

Cell Proliferation ◽

Transcriptional Activity ◽

Nuclear Translocation ◽

Immunofluorescence Assay ◽

Luciferase Reporter ◽

Reporter Assay ◽

Lncap Cells ◽

Mcf 7

Objective. To investigate the phytoestrogenic and phytoandrogenic activities of compounds isolated from CS and uncover the role of CS in prevention of oestrogen/androgen-induced BPH. Methods. Cells were treated with CS compounds, and immunofluorescence assay was performed to detect the nuclear translocation of ERα or AR in MCF-7 or LNCaP cells; luciferase reporter assay was performed to detect ERs or AR transcriptional activity in HeLa or AD293 cells; MTT assay was performed to detect the cell proliferation of MCF-7 or LNCaP cells. Oestrogen/androgen-induced BPH model was established in rat and the anti-BPH, anti-estrogenic, and anti-androgenic activities of CS in vivo were further investigated. Results. The nuclear translocation of ERα was stimulated by nine CS compounds, three of which also stimulated AR translocation. The transcriptional activities of ERα and ERβ were induced by five compounds, within which only ECG induced AR transcriptional activity as well. Besides, ECG stimulated the proliferation of both MCF-7 cells and LNCaP cells. CS extract suppressed oestrogen/androgen-induced BPH progress in vivo by downregulation of E2 and T level in serum and alteration of the expressions of ERα, ERβ, and AR in the prostate. Conclusion. Our data demonstrates that compounds from CS exhibit phytoestrogenic and phytoandrogenic activities, which may contribute to inhibiting the oestrogen/androgen-induced BPH development.

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The POU2F1/miR-4490/USP22 axis regulates cell proliferation and metastasis in gastric cancer

Cellular Oncology ◽

10.1007/s13402-020-00553-1 ◽

2020 ◽

Vol 43 (6) ◽

pp. 1017-1033 ◽

Cited By ~ 1

Author(s):

Yizhi Xiao ◽

Side Liu ◽

Jiaying Li ◽

Weiyu Dai ◽

Weimei Tang ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Proliferation ◽

Cell Cycle Progression ◽

Epithelial Mesenchymal Transition ◽

Luciferase Reporter ◽

Migration And Invasion ◽

Aberrant Expression ◽

Mesenchymal Transition

Abstract Purpose Growing evidence indicates that aberrant expression of microRNAs contributes to tumor development. However, the biological role of microRNA-4490 (miR-4490) in gastric cancer (GC) remains to be clarified. Methods To explore the function of miR-4490 in GC, we performed colony formation, EdU incorporation, qRT-PCR, Western blotting, in situ hybridization (ISH), immunohistochemistry (IHC), flow cytometry, ChIP and dual-luciferase reporter assays. In addition, the growth, migration and invasion capacities of GC cells were evaluated. Results We found that miR-4490 was significantly downregulated in primary GC samples and in GC-derived cell lines compared with normal controls, and that this expression level was negatively correlated with GC malignancy. Exogenous miR-4490 expression not only reduced cell cycle progression and proliferation, but also significantly inhibited GC cell migration, invasion and epithelial-mesenchymal transition (EMT) in vitro. Mechanistically, we found that miR-4490 directly targets USP22, which mediates inhibition of GC cell proliferation and EMT-induced metastasis in vitro and in vivo. Moreover, we found through luciferase and ChIP assays that transcription factor POU2F1 can directly bind to POU2F1 binding sites within the miR-4490 and USP22 promoters and, by doing so, modulate their transcription. Spearman’s correlation analysis revealed a positive correlation between USP22 and POU2F1 expression and negative correlations between miR-4490 and USP22 as well as miR-4490 and POU2F1 expression in primary GC tissues. Conclusion Based on our results we conclude that miR-4490 acts as a tumor suppressor, and that the POU2F1/miR-4490/USP22 axis plays an important role in the regulation of growth, invasion and EMT of GC cells.

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Tumor Suppressor Gene XEDAR Promotes Differentiation and Suppresses Proliferation and Migration of Gastric Cancer Cells Through Upregulating the RELA/LXRα Axis and Deactivating the Wnt/β-Catenin Pathway

Cell Transplantation ◽

10.1177/0963689721996346 ◽

2021 ◽

Vol 30 ◽

pp. 096368972199634

Author(s):

Xinwu Zhang ◽

Di Zhang ◽

Xiaoli Sun ◽

Shunle Li ◽

Yun Sun ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Proliferation ◽

Opposite Effect ◽

Tumor Necrosis Factor Receptor ◽

Suppressor Gene ◽

Gastric Cancer Cells ◽

Promote Cell Proliferation ◽

And Migration ◽

Proliferation And Migration

X-linked ectodermal dysplasia receptor (XEDAR) is a new member of the tumor necrosis factor receptor (TNFR) family that induces cell death. The purpose of this study is to determine the tumor-suppressive potential of XEDAR in the development and differentiation of gastric cancer (GC). XEDAR levels were analyzed in human GC tissues and adjacent normal tissues by immunohistochemistry (IHC), quantitative real-time reverse transcription PCR (RT-qPCR), and Western blot analysis. We found that XEDAR expression was significantly downregulated in GC tissues and further decreased in low differentiated GC tissues. Overexpression of XEDAR in MKN45 and MGC803 cells suppressed the ability of cell proliferation and migration, whereas silencing XEDAR showed the opposite effect. Additionally, XEDAR silencing resulted in the upregulation of the differentiation molecular markers β-catenin, CD44 and Cyclin D1 at the protein levels, whereas XEDAR overexpression showed the opposite effect. Notably, XEDAR positively regulated the expression of liver X receptor alpha (LXRα) through upregulating the RELA gene that was characterized as a transcription factor of LXRα in this study. Inhibition of LXRα by GSK2033 or activation of the Wnt/β-catenin pathway by Wnt agonist 1 impaired the effect of XEDAR overexpression on differentiation of MKN45 cells. Moreover, inhibition of RELA mediated by siRNA could promote cell proliferation/migration and rescue the effect of XEDAR overexpression on cell behaviors and expression of genes. Subsequently, overexpression of XEDAR suppressed the growth of GC cells in vivo. Taken together, our findings showed that XEDAR could promote differentiation and suppress proliferation and invasion of GC cells.

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Assessing the Regulatory Functions of LncRNA SNHG11 in Gastric Cancer Cell Proliferation and Migration

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.620476 ◽

2021 ◽

Vol 9 ◽

Author(s):

Danyi Zhao ◽

Huawei Chen ◽

Bing Wang

Keyword(s):

Gastric Cancer ◽

Cell Proliferation ◽

Luciferase Reporter ◽

Cell Proliferation And Migration ◽

Gastric Cancer Cell Proliferation ◽

And Migration ◽

Migration Capacity ◽

Regulatory Functions ◽

Proliferation And Migration

The aim of this study was to assess the regulatory functions of SNHG11 in gastric cancer (GC) cell proliferation and migration. Dual-luciferase reporter assay and bioinformatics prediction [starBase (http://starbase.sysu.edu.cn/) and TargetScan (http://www.targetscan.org)] indicated that SNHG11 functions as a miR-184 sponge that can directly act on CDC25A. Compared with normal healthy gastric tissue and mucosal epithelial cell GES-1, SNHG11 and CDC25A expressions were dramatically increased in GC samples and cell lines, whereas microRNA-184 (miR-184) levels were reduced. SNHG11 silencing led to increased miR-184 and reduced CDC25A, whereas miR-184 downregulation recovered the expression of CDC25A. Additionally, miR-184 upregulation also played a role in regulating CDC25A ablation. Then, SNHG11 was silenced or miR-184 was upregulated in two GC cells (SGC-7901 and MKN-28). SNHG11 silencing and miR-184 upregulation caused a notable decrease in GC cell growth and proliferation and increased the apoptotic level of GC cells. Furthermore, SNHG11 silencing and miR-184 upregulation contributed to a decreased migration capacity of GC cells. Downregulated miR-184 expression in SNHG11 silenced GC cells showed that miR-184 inhibition reversed the effect of SNHG11 silencing on the growth, proliferation, apoptosis, and migration of GC cells. Moreover, in vivo xenograft experiments demonstrated that SNHG11 knockdown can inhibit tumor growth. These observations confirmed that SNHG11 acts as an oncogene, whereas miR-194 served as a tumor suppressor in GC development. SNHG11 may provide a new biomarker for GC diagnosis, treatment, and prognosis.

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miR-122 Inhibits Hepatocarcinoma Cell Progression by Targeting LMNB2

Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics ◽

10.3727/096504019x15615433287579 ◽

2020 ◽

Vol 28 (1) ◽

pp. 41-49 ◽

Cited By ~ 1

Author(s):

Xiao-Na Li ◽

Hong Yang ◽

Tao Yang

Keyword(s):

Cell Proliferation ◽

Scratch Test ◽

Luciferase Reporter ◽

Migration And Invasion ◽

Luciferase Reporter Gene ◽

Promote Cell Proliferation ◽

Hepatocarcinoma Cell ◽

Gene Assay ◽

Cell Progression

In the present study, we investigated the role of miR-122 in hepatocarcinoma progression and explored the mechanism. In hepatocarcinoma tissues and cells, we used qRT-PCR to validate the miR-122 expression level. Next, we used colony formation by crystal violet staining assay to compare cell proliferation ability, and we used scratch test or Transwell assay to compare cell migration or invasion ability. We then conducted bioinformatics or luciferase reporter gene assay to prove the regulation effect of miR-122 on lamin B2 (LMNB2), and the biological function of LMNB2 was analyzed. We used nude mouse tumorigenicity assay to test the inhibition effect of miR-122 ASO therapy against hepatocarcinoma. miR-122 was reduced in hepatocarcinoma tissues compared to the paracarcinoma tissues, which was relatively low or high in hepatocarcinoma cell line SMMC7721 or Hep3B, and overexpressed miR-122 inhibited proliferation, migration, and invasion in hepatocarcinoma cells. Additionally, some reports showed that LMNB2 was regulated by miR-122, which inhibited the expression of LMNB2. Moreover, LMNB2 functioned to promote cell proliferation, migration, and invasion. We could achieve the inhibition of hepatocarcinoma using miR-122 therapy through decreasing LMNB2 expression in vivo. Our data indicated that miR-122 could inhibit hepatocellular carcinoma cell progression by targeting LMNB2 and as a therapeutic target for hepatocarcinoma treatment.

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LncRNA MT1JP Suppresses Gastric Cancer Cell Proliferation and Migration Through MT1JP/MiR-214-3p/RUNX3 Axis

Cellular Physiology and Biochemistry ◽

10.1159/000489651 ◽

2018 ◽

Vol 46 (6) ◽

pp. 2445-2459 ◽

Cited By ~ 27

Author(s):

Ying Xu ◽

Guohua Zhang ◽

Chen Zou ◽

Heng Zhang ◽

Zhigang Gong ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Proliferation ◽

Luciferase Reporter ◽

Loss Of Function ◽

Ki 67 ◽

Invasion And Migration ◽

Tumorigenesis And Progression ◽

Gastric Cancer Cell Proliferation ◽

And Migration

Background/Aims: Emerging evidence points towards an important role of long noncoding RNAs (lncRNAs) in the tumorigenesis and progression of gastric cancer (GC). MT1JP has recently been reported to be differentially expressed and act as a tumor suppressor in different tumors, with its mechanisms not fully understood in GC. Methods: RT-qPCR was used to detect the expression of MT1JP, miR-214-3p and RUNX3 in tumor tissues and cell lines of GC. The CCK-8 assay, colony formation, Transwell assay and wound healing assay were used to evaluate the proliferation, invasion and migration of GC cells, respectively. Bioinformatics analysis and luciferase reporter assay were performed to disclose the interaction between MT1JP, miR-214-3p and RUNX3. Western blot and immunofluorescence were applied to assess the downstream signaling of RUNX3. Results: MT1JP was found downregulated in GC tissues and cells. Low expression of MT1JP was significantly correlated with advanced TNM stage and lymphatic metastasis. The expression of plasma MT1JP was also found decreased in GC patients compared to healthy controls, with an area under the ROC curve (AUC) of 0.649 for diagnosis of GC. Gain- and loss-of-function of MT1JP revealed that MT1JP functioned as a ceRNA for miR-214-3p to facilitate RUNX3 expression and then upregulated p21 and Bim levels suppressing GC cell proliferation, invasion and migration, and promoting apoptosis. Furthermore, MT1JP overexpression suppressed tumor growth and inhibited the expression of miR-214-3p and proliferation antigen Ki-67, but increased the expression of RUNX3, p21 and Bim in vivo. Conclusions: Our results suggest a potential ceRNA regulatory network involving MT1JP regulates RUNX3 expression by competitively binding endogenous miR-214-3p in tumorigenesis and progression of GC. This mechanism may contribute to a better understanding of GC pathogenesis and provide potential therapeutic strategy for GC.

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