Downregulation of miR-16 via URGCP pathway contributes to glioma growth

Overexpression of FRA1 (FOSL1) Leads to Global Transcriptional Perturbations, Reduced Cellular Adhesion and Altered Cell Cycle Progression

FRA1 (FOSL1) is a transcription factor and a member of the activator protein-1 superfamily. FRA1 is expressed in most tissues at low levels, and its expression is robustly induced in response to extracellular signals, leading to downstream cellular processes. However, abnormal FRA1 overexpression has been reported in various pathological states, including tumor progression and inflammation. To date, the molecular effects of FRA1 overexpression are still not understood. Therefore, the aim of this study was to investigate the transcriptional and functional effects of FRA1 overexpression using the CGL1 human hybrid cell line. FRA1-overexpressing CGL1 cells were generated using stably integrated CRISPR-mediated transcriptional activation, resulting in a 2-3 fold increase in FRA1 mRNA and protein levels. RNA-sequencing identified 298 differentially expressed genes with FRA1 overexpression. Gene ontology analysis showed numerous molecular networks enriched with FRA1 overexpression, including transcription-factor binding, regulation of the extracellular matrix and adhesion, and a variety of signaling processes, including protein kinase activity and chemokine signaling. In addition, cell functional assays demonstrated reduced cell adherence to fibronectin and collagen with FRA1 overexpression and altered cell cycle progression. Taken together, this study unravels the transcriptional response mediated by FRA1 overexpression and establishes the role of FRA1 in adhesion and cell cycle progression.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

Mammaglobin 1 mediates progression of trastuzumab-resistant breast cancer cells through regulation of cyclins and NF-κB

Overexpression of human epidermal growth factor receptor 2 (HER2) in various cancers is correlated with poor patient survival. Trastuzumab, a recombinant humanized monoclonal antibody against HER2, has been considered to be a first-line therapy for HER2-positive breast cancer patients, but its usefulness is limited by the development of resistance. In this study, we established resistant cells by long-term treatment with trastuzumab. These cells showed higher proliferation, invasion, and migration abilities than the wild-type cells. Mammaglobin 1 (MGB1), cyclin D1, E1, A2, and phosphorylated NF-κB (p-p65) were upregulated in resistant cells. These proteins regulate cell proliferation, migration, and invasion of resistant cells. Depletion of MGB1 decreased cyclin and p-p65 expression. Cyclin D1 and A2, but not E1 expression, were affected by p-p65 downregulation. In summary, our results indicate that MGB1 expression is increased in breast cancer cells that have gained resistance to trastuzumab, and suggest that MGB1 promotes aggressiveness through cyclin and NF-κB regulation.

miR-16 Inhibits Extracellular Signal-Regulated Kinases (ERK) Mitogen-Activated Protein Kinases (MAPK) Signaling to Affect Epithelial-Mesenchymal Transition (EMT) and Invasion of Glioma Cells

Abnormal MEK1 expression is associated with tumor cell EMT, invasion and metastasis. Decreased miR-16 level is associated with glioma. Bioinformatics analysis showed a relationship between miR-16 and MEK1. This study assessed whether miR-16 regulates MEK1 expression and affects glioma cell EMT and invasion. The tumor tissues and adjacent glioma tissues were collected to measure miR-16 and MEK1 mRNA. The dual luciferase assay validated the relation of miR-16 with MEK1. U251 cells were cultured and assigned into NC group and mimic group, followed by analysis of cell biological behaviors, and MEK1, p-ERK1/2, E-cadherin, N-Cadherin expression. Compared with adjacent tissues, miR-16 expression was significantly decreased and MEK1 was elevated in glioma tissues. Compared with HEB, miR-16 in glioma U251 and SHG44 cells was decreased and MEK1 was increased. Dual luciferase reporter gene experiments confirmed the relation of miR-16 with MEK1. Transfection of miR-16 mimic significantly down-regulated MEK1, p-ERK1/2 and N-cadherin in U251 cells, upregulated E-cadherin, inhibited cell proliferation, promoted apoptosis, and attenuated EMT and invasion of glioma cells. In conclusion, decreased miR-16 expression and increased MEK1 expression is related to glioma pathogenesis. Overexpression of miR-16 can inhibit MEK1 expression, ERK/MAPK signaling, glioma cell proliferation, promote apoptosis, and attenuate EMT and invasion.

Tanshinone IIA Suppresses Glioma Cell Proliferation, Migration and Invasion Both in vitro and in vivo Partially Through miR-16-5p/Talin-1 (TLN1) Axis

Background

Tanshinone IIA (TIIA) is one of the active constituents derived from the rhizome of Danshen, a traditional Chinese herbal. Recently, microRNAs (miRNAs) have been suggested to be associated with the anticancer role of TIIA. However, it remains vague of the interaction between miRNAs and TIIA in glioma, a common aggressive brain tumor in humans.

Methods

Expression of miRNA (miR)-16-5p and talin-1 (TLN1) was detected using reverse transcription-quantitative polymerase chain reaction and Western blotting. Cell proliferation, migration and invasion were assessed with cell viability assay, transwell assay, Western blotting, and xenograft tumor experiment. The target binding between miR-16-5p and TLN1 was confirmed by dual-luciferase reporter assay and RNA pull-down assay.

Results

TIIA treatment inhibited cell viability, migration and invasion, and decreased Cyclin D1, matrix metalloproteinase (MMP)-9 and Vimentin expression in glioma T98G and A172 cells both in vitro and in vivo. Thus, TIIA induced anti-glioma role, wherein miR-16-5p was upregulated and TLN1 was downregulated. Moreover, silencing miR-16-5p could abate TIIA-mediated suppression on glioma cell proliferation, migration and invasion in vitro and in vivo. TLN1 overexpression also exerted tumor-promoting effect in TIIA-treated T98G and A172 cells. Mechanically, miR-16-5p could regulate TLN1 expression via target binding, and depleting TLN1 could counteract the inhibitory effect of miR-16-5p knockdown on the curative effect of TIIA in T98G and A172 cells.

Conclusion

TIIA exerted the anti-proliferation, anti-migration and anti-invasion role in glioma cells both in vitro and in vivo partially through regulating miR-16-5p/TLN1 axis.

URG4 mediates cell proliferation and cell cycle in osteosarcoma via GSK3β/β-catenin/cyclin D1 signaling pathway

BACKGROUND

Osteosarcoma is one of the most common malignant bone tumors with the annual global incidence of approximately four per million. Upregulated gene 4 (URG4) expression in the osteosarcoma tissue is closely associated with recurrence, metastasis, and poor prognosis of osteosarcoma. However, the biological function and underlying mechanisms of URG4 in osteosarcoma have not been elucidated. This study aimed to explore the expression and underlying mechanism of URG4 in osteosarcoma.

METHODS

The expression level of URG4 in osteosarcoma and normal tissues was compared using immunohistochemistry (IHC). PCR and western blotting (WB) techniques are used to detect URG4 mRNA and protein levels. Wound healing and Transwell analysis to assess the effect of URG4 on osteosarcoma cell migration and invasion. Cell Counting Kit-8 assay and colony proliferation assay were performed to evaluate the effects of silencing URG4 on the inhibition of cell proliferation. The cell cycle distribution was detected by flow cytometry, and a xenograft mouse model was used to verify the function of URG4 in vivo.

RESULTS

URG4 was found to be highly expressed in osteosarcoma tissues and cells, and its high expression was correlated with advanced Enneking stage, large tumor size, and tumor metastasis in osteosarcoma patients. The proliferation in osteosarcoma cell lines and cell cycle in the S phase was suppressed when siRNA was used to downregulate URG4. URG4 promoted cell proliferation and tumorigenesis in vitro and in vivo. WB verified that URG4 promotes cell proliferation in osteosarcoma via pGSK3β/β-catenin/cyclinD1 signaling.

CONCLUSION

URG4, which is high-expressed in osteosarcoma, promotes cell cycle progression via GSK3β/β-catenin/cyclin D1 signaling pathway and may be a novel biomarker and potential target for the treatment of osteosarcoma.

Retracted Article: Overexpression of circ_0034642 contributes to hypoxia-induced glycolysis, cell proliferation, migration and invasion in gliomas by facilitating TAGLN2 expression via sponging miR-625-5p

Glioma is an aggressive brain cancer with poor prognosis and high invasiveness. Dysregulation of circular RNAs (circRNAs) has been widely discovered in various cancers, including glioma. However, the molecular mechanism of circ_0034642 in glioma is still unclear. The expression of circ_0034642, microRNA (miR)-625-5p and transgelin-2 (TAGLN2) in glioma tumors and cells was detected by performing a quantitative real-time polymerase chain reaction (qRT-PCR). The stability of circ_0034642 was determined by carrying out RNase R treatment. Cell proliferation was evaluated by performing the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Glycolysis was analyzed by measuring the extracellular acidification rate (ECAR) using glucose detection and lactic acid detection kits. Cell migration and invasion were determined by performing the transwell assay. Protein expression levels of the proteins hexokinase 2 (HK2), matrix metalloproteinase-2 (MMP2), matrix metalloproteinase-9 (MMP9) and TAGLN2 were analyzed using western blots. The interaction between miR-625-5p and circ_0034642 or TAGLN2 was proved using a dual-luciferase reporter system. Animal models were established by subcutaneously injecting glioma cells stably transfected with sh-NC or sh-circ_0034642. Circ_0034642 and TAGLN2 were overexpressed whereas miR-625-5p was expressed at low levels in glioma tumors and cells. Moreover, circ_0034642 and TAGLN2 were upregulated while miR-625-5p was downregulated under hypoxic conditions in a time-dependent manner. Next, elimination of circ_0034642 was shown to inhibit cell glycolysis, proliferation, migration and invasion under hypoxic conditions in gliomas. Then, we found that circ_0034642 acted as a “sponge” of miR-625-5p while TAGLN2 acted as a target of miR-625-5p. In addition, recovery of circ_0034642 attenuated the repression mediated by miR-625-5p on glioma cell glycolysis and progression under hypoxic conditions. Meanwhile, an inhibitor of miR-625-5p alleviated TAGLN2 deficiency-induced inhibition of glioma cell development under hypoxic conditions. We also discovered that circ_0034642 could interact with miR-625-5p and further alter the expression of TAGLN2. Lastly, a circ_0034642 knockdown hindered tumor growth in vivo by regulating the miR-625-5p/TAGLN2 axis. Enhanced expression of circ_0034642 was found to promote cell glycolysis, proliferation, migration and invasion under hypoxic conditions in gliomas by sponging miR-625-5p to improve TAGLN2 expression, providing prospective biomarkers for the diagnosis of glioma.

Circ_0034642 was upregulated under hypoxic conditions in gliomas.

URG4 expression in invasive breast carcinoma and its relation to clinicopathological characteristics

BACKGROUND

Upregulated gene 4 (URG4) is a recently described oncogene that upregulates cell proliferation. Its overexpression has been identified in many malignancies, and it is thought to be related to tumour progression, angiogenesis, metastasis and the recurrence of many cancers. This is the first study to show its expression in breast cancer patients and its association with clinicopathological characteristics in these patients.

METHODS

Fifty invasive ductal breast carcinoma cases and 25 control cases were included in the study. Tumourous tissues and control tissues were assessed molecularly for quantification of mRNA expression of URG4 and immunohistochemically for protein expression of URG4.

RESULTS

The mean ages of the patients and controls were 54.3 ± 11.3 and 38.9 ± 9.7 years, respectively. The expression levels of URG4 mRNA in tumour tissues were higher compared to control breast tissues (p = 0.023). An immunohistochemical assessment suggested that URG4 is strongly expressed in normal breast tissues and lower-grade (grades I and II) ductal carcinomas of the breast, but it is weakly expressed in high-grade (grade III) ductal breast carcinomas. Additionally, the immunohistochemical and molecular expression results of URG4 were relevant to most prognostic parameters (tumour size, oestrogen and progesterone receptor status, HER2 status and Ki67 proliferative index) for breast cancer. However, unlike the immunohistochemical studies, the molecular studies revealed that there was no significant difference in URG4 expression for different grades of tumour tissues.

CONCLUSION

The literature data suggest that URG4 overexpression is associated with poor prognosis in many types of cancer. Conversely, our results in breast cancer specimens indicate that URG4 overexpression in breast ductal carcinomas is significantly associated with good prognostic parameters. Nevertheless, these preliminary findings should be confirmed by further studies.