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Aerobic glycolysis is critical for tumor growth and metastasis. Previously, we have found that the overexpression of the inhibitor of growth 5 (ING5) inhibits lung cancer aggressiveness and epithelial–mesenchymal transition (EMT). However, whether ING5 regulates lung cancer metabolism reprogramming remains unknown. Here, by quantitative proteomics, we showed that ING5 differentially regulates protein phosphorylation and identified a new site (Y163) of the key glycolytic enzyme PDK1 whose phosphorylation was upregulated 13.847-fold. By clinical study, decreased p-PDK1Y163 was observed in lung cancer tissues and correlated with poor survival. p-PDK1Y163 represents the negative regulatory mechanism of PDK1 by causing PDHA1 dephosphorylation and activation, leading to switching from glycolysis to oxidative phosphorylation, with increasing oxygen consumption and decreasing lactate production. These effects could be impaired by PDK1Y163F mutation, which also impaired the inhibitory effects of ING5 on cancer cell EMT and invasiveness. Mouse xenograft models confirmed the indispensable role of p-PDK1Y163 in ING5-inhibited tumor growth and metastasis. By siRNA screening, ING5-upregulated TIE1 was identified as the upstream tyrosine protein kinase targeting PDK1Y163. TIE1 knockdown induced the dephosphorylation of PDK1Y163 and increased the migration and invasion of lung cancer cells. Collectively, ING5 overexpression—upregulated TIE1 phosphorylates PDK1Y163, which is critical for the inhibition of aerobic glycolysis and invasiveness of lung cancer cells. [ABSTRACT FROM AUTHOR]

Background: Non-small cell lung cancer (NSCLC) is one of most threatening malignancies with a high morbidity and mortality that threaten human health and life. Objective: This study aimed to investigate the role of circBLNK in NSCLC and reveal the regulation mechanism of circBLNK in NSCLC. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine the levels of circBLNK, miR-578 and inhibitor of growth 5 (ING5) mRNA. Cell proliferation activity was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU) staining and colony formation assays. Flow cytometry was carried out to examine cell cycle and cell apoptosis. The dual-luciferase reporter assay was used to validate the interaction between miR-578 and circBLNK or ING5. Xenograft tumor experiment was performed to uncover the function of circBLNK in vivo. Results: CircBLNK was notably down-regulated in NSCLC tissues and cells. Overexpression of circBLNK suppressed the proliferation and accelerated the apoptosis of NSCLC cells in vitro. CircBLNK targeted miR-578, and circBLNK exerted its biological function in NSCLC cells through sponging miR-578. ING5 was verified as a target of miR-578, and circBLNK increased the abundance of ING5 through targeting miR-578 in NSCLC cells. ING5 interference could partly reverse the biological effects of NSCLC cells mediated by circBLNK overexpression. CircBLNK overexpression repressed NSCLC tumor growth in vivo. Conclusion: CircBLNK functioned as a tumor suppressor in NSCLC to suppress the proliferation and cell cycle and promote cell apoptosis of NSCLC cells through miR-578/ING5 axis. [ABSTRACT FROM AUTHOR]

Ischemic stroke is a disease with high mortality. Circular RNA_0010729 (hsa_circ_0010729) has been reported to be involved in ischemic heart disease. However, it is not clear whether hsa_circ_0010729 is involved in the regulation of ischemic stroke. In this study, we used oxygen–glucose deprivation/reoxygenation (OGD/R) to stimulate human brain microvascular endothelial cells (HBMECs) model to investigate the potential role of hsa_circ_0010729 in stroke in vitro. The expression levels of hsa_circ_0010729, miR-665, and ING5 in ischemic stroke were detected by quantitative real-time polymerase chain reaction (qRT-PCR). HBMECs proliferation was detected by CCK-8. Cell apoptosis was detected by flow cytometry. The levels of inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA). Western blot was used to detect the related protein expression. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) were used to examine the target relationship between miR-665 and hsa_circ_0010729 or ING5. Compared with the control group, hsa_circ_0010729 and ING5 were highly expressed in OGD/R-induced HBMECs, while miR-665 was lowly expressed. Hsa_circ_0010729 silencing promoted OGD/R-induced cell proliferation and inhibited apoptosis. However, the effect of hsa_circ_0010729 down-regulation on OGD/R-induced cell was partially restored after co-transfection with miR-665 inhibitor. Overexpression of miR-665 can promote the proliferation and inhibit apoptosis of OGD/R-induced HBMECs by inhibiting ING5 expression. In OGD/R-induced HBMECs, hsa_circ_0010729 silencing decreased ING5 expression by upregulating miR-665. Hsa_circ_0010729 regulated miR-665/ING5 axis in OGD/R-induced HBMECs. Therefore, hsa_circ_0010729 may be a new therapeutic target for ischemic stroke. [ABSTRACT FROM AUTHOR]

Our study explored the effects of lncRNA UCA1 on the proliferation and apoptosis in hypoxic human pulmonary artery smooth muscle cells (HPASMCs) and highlighted the endogenous relationship between UCA1, ING5, and hnRNP I in cell proliferation. Hypoxia-induced HPASMCs were used to simulate pulmonary arterial hypertension in vitro. Microarray assay was adopted to screen the dysregulated expressed lncRNAs in HPASMCs to find out the target gene of our study. And RT-qPCR was performed to detect the expression of lncRNA UCA1 under hypoxia and normoxia. After transfection, the relationship between UCA1 and cell proliferation in HPASMCs under hypoxia were determined by cell proliferation assay and relative expression of PCNA. Next, ELISA assays were conducted to measure the protein levels of PCNA and ING5. What's more, flow cytometry was employed to measure the apoptosis rate in differentially UCA1-expressed HPASMCs. RIP assays were conducted to further clarify the endogenous relationship between UCA1 and ING5 in hypoxic HPASMCs. Finally, the effects of ING5 to HPASMCs were detected after transfection of ING5 and UCA1 to figure out the role of ING5 in HPASMCs. Hypoxia was revealed to induce proliferation and inhibited apoptosis in HPASMCs. Besides, UCA1 was confirmed to be highly expressed under hypoxia compared with normoxia. UCA1 boosted cell proliferation under hypoxia in HPASMCs. However, the apoptosis was suppressed in the hypoxic HPASMCs transfected with pcDNA3.1-UCA1. Further, mechanism studies found that UCA1 competed with ING5 for hnRNP I, so that upregulating UCA1 inhibited the protein levels of ING5. And finally we found that ING5 restrained cell viability, but promoted cell apoptosis in hypoxic HPASMCs, which was reversed by UCA1 over-expression. In summary, our findings manifested that UCA1 promoted proliferation and restrained apoptosis by competing with ING5 for hnRNP I in HPASMCs induced by hypoxia, indicating their potential roles for the cure of hypoxic pulmonary hypertension. [ABSTRACT FROM AUTHOR]

In these studies, inhibitor of growth protein 5 (ING5) and various fragments of it were overexpressed in the human tongue squamous cell carcinoma cell line, HSC-3. The roles of ING5 in HSC-3 cells were then identified in vitro. Our results indicate that intact ING5 can inhibit proliferation and induce apoptosis in HSC-3 cells. Moreover, two truncated fragments of ING5 (aa 1-184 and aa 107-226) can induce cellular senescence. To analyze the signaling pathway involved, western blotting was performed. In these assays, two truncated fragments of ING5 were found to inhibit the cyclin E and CDK2 expression. These results are consistent with the S phase arrest observed with the overexpression of truncated ING5. However, the mechanisms of ING5-induced cellular senescence remain unclear, and extensive investigations are required in future studies. [ABSTRACT FROM AUTHOR]

This study aimed to assess the protein level of inhibitor of growth gene 5 ( ING5) in head and neck squamous cell carcinoma (HNSCC) and to explore its roles in tumorigenesis and cancer progression. ING5 expression was assessed in 172 cases of HNSCC by immunohistochemistry using tissue microarray, and in 3 oral SCC cell lines by immunohistochemistry and Western blot. Expression of ING5 was compared with clinicopathological variables, TUNEL assay staining, and the expression of several tumorigenic markers. In addition, double immunofluorescence labeling was performed in order to analyze the colocalization of ING5 with p300 and p21. ING5 expression was primarily observed in the nuclei, but was also occasionally found in the cytoplasm of both SCC cell lines and tissue samples of HNSCC. Nuclear expression of ING5 in HNSCC was significantly lower than that of non-cancerous epithelium, and was positively correlated with a well-differentiated status. In contrast, cytoplasmic expression of ING5 was significantly increased in HNSCC, and was inversely correlated with a well-differentiated status and nuclear ING5 expression. In addition, nuclear expression of ING5 was positively correlated with p21 and p300 expression, and with the apoptotic index. In contrast, cytoplasmic expression of ING5 was negatively correlated with the expression of p300, p21, and PCNA. Although no statistical association was found between the expression of nuclear ING5 and mutant p53 in HNSCC, patients with high expression of nuclear ING5 tended to have converse prognoses when grouped according to mutant p53 expression. Our results suggest that a decrease in nuclear ING5 localization and cytoplasmic translocation are involved in tumorigenesis and tumor differentiation in HNSCC. Nuclear ING5 may modulate the transactivation of target genes, and may promote apoptosis and cell cycle arrest by interacting with the p300 and p21 proteins. ING5 may function as a tumor suppressor gene or oncogene tightly linked with p53 status, and may play an important role in the prognosis of HNSCC patients. Therefore, we propose that ING5 represents a novel potential molecular therapeutic target for HNSCC. [ABSTRACT FROM AUTHOR]

Genes of the human monocytic leukemia zinc-finger protein MOZ (HUGO symbol, MYST3) and its paralog MORF (MYST4) are rearranged in chromosome translocations associated with acute myeloid leukemia and/or benign uterine leiomyomata. Both proteins have intrinsic histone acetyltransferase activity and are components of quartet complexes with noncatalytic subunits containing the bromodomain, plant homeodomain-linked (PHD) finger and proline-tryptophan-tryptophan-proline (PWWP)-containing domain, three types of structural modules characteristic of chromatin regulators. Although leukemia-derived fusion proteins such as MOZ-TIF2 promote self-renewal of leukemic stem cells, recent studies indicate that murine MOZ and MORF are important for proper development of hematopoietic and neurogenic progenitors, respectively, thereby highlighting the importance of epigenetic integrity in safeguarding stem cell identity.Oncogene (2007) 26, 5408–5419; doi:10.1038/sj.onc.1210609 [ABSTRACT FROM AUTHOR]