Cullin 4A (CUL4A) encodes a core subunit of an E3 ubiquitin ligase that targets proteins for ubiquitin-mediated degradation, and aberrant expression of the CUL4A is found in many tumor types. However, its roles and clinicopathologic significance in pituitary adenomas are not clear. The aim of this study was to investigate the possible role of CUL4A in pituitary tumorigenesis. Immunohistochemistry was used to examine CUL4A expression in human normal pituitaries and pituitary tumors with respect to various clinicopathologic factors in pituitary adenomas. Cell proliferation was assessed by MTT and colony formation, and migration and invasion were analyzed by Transwell and Matrigel assays after CUL4A overexpression or knockdown in pituitary tumor cells. Overexpression of CUL4A was frequently observed in pituitary adenomas compared with normal adenohypophysial tissue and significantly associated with tumor progressiveness and invasion. CUL4A overexpression in GH3 adenoma cells increased colony numbers, cell viability and cell invasion and silencing CUL4A in AtT20 adenoma cells decreased cell proliferation, migration and invasion. Mechanistically, CUL4A could modulate the expression of p53, p21, and p27 in pituitary tumor cells. In addition, high levels of CUL4A expression also significantly inversely correlated with the p53 protein level in human pituitary adenomas. Our results indicate that CUL4A enhances pituitary cell proliferation, migration and invasion and may thus contribute to pituitary tumor development and progression.
CUL4A encodes a core component of a cullin-based E3 ubiquitin ligase complex that regulates many critical processes such as cell cycle progression, DNA replication, DNA repair and chromatin remodeling by targeting a variety of proteins for ubiquitination and degradation. In the research described in this report we aimed to clarify whether CUL4A participates in multiple drug resistance (MDR) in breast cancer cells. We first transfected vectors carrying CUL4A and specific shCUL4A into breast cancer cells and corresponding Adr cells respectively. Using reverse transcription polymerase chain OPEN ACCESSMolecules 2014, 19 160 reactions and western blots, we found that overexpression of CUL4A in MCF7 and MDA-MB-468 cells up-regulated MDR1/P-gp expression on both the transcription and protein levels, which conferred multidrug resistance to P-gp substrate drugs, as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. On the other hand, silencing CUL4A in MCF7/Adr and MDA-MB-468/Adr cells led to the opposite effect. Moreover, ERK1/2 in CUL4A-overexpressing cells was highly activated and after treatment with PD98059, an ERK1/2-specific inhibitor, CUL4A-induced expression of MDR1/P-gp was decreased significantly. Lastly, immunohistochemistry in breast cancer tissues showed that P-gp expression had a positive correlation with the expression of CUL4A and ERK1/2. Thus, these results implied that CUL4A and ERK1/2 participated in multi-drug resistance in breast cancer through regulation of MDR1/P-gp expression.
Mass transfer plays a key role in the diffusion‐controlled heterogeneous reactions. Varied efforts have been made to design the structure of catalysts and reactors to optimize the diffusion process. Herein, a facile strategy is reported to construct highly reactive agitating impeller (denoted as AI) by employing 3D printing and a facile surface activation treatment. On the one hand, experimental results and numerical simulation analysis reveal that the 3D printing AI with appropriate structure can not only effectively eliminate external diffusion but also conveniently be separated from heterogeneous reaction systems. On the other hand, surface activation helps to significantly promote the chemical reactivity of AI for Fenton and galvanic replacement reaction, which are used to treat organic and inorganic pollutants in water, respectively. Benefiting from these cooperative merits, the integrated catalytic AI delivers a catalytic performance toward Fenton reactions as high as a homogeneous catalyst, and the removal rate for heavy metal ions is nearly 100% through galvanic replacement. This 3D printing with surface engineering strategy should also be extended to other applications, and provide new field for preparing efficient and durable heterogeneous catalysts in a more economical way.
How single nucleotide polymorphisms in long non-coding RNAs are involved in cancer susceptibility remains poorly understood. We hypothesized that polymerase II polypeptide E (POLR2E) rs3787016 polymorphism, identified in a genome-wide association study of prostate cancer, might be a common genetic risk factor for cancer risk. To address this issue, we here conducted a case–control study to investigate the association of POLR2E rs3787016 polymorphism with risk of liver and lung cancer (including 800 normal controls, 480 liver cancer patients, and 550 lung cancer patients), followed by a meta-analysis. The genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism and confirmed by sequencing. Although no significant association was found for rs3787016 with risk of liver or lung cancer, the further stratified analysis identified that rs3787016 contributed to liver cancer risk particularly for over than 60 years individuals who drink. Moreover, the meta-analysis demonstrated that rs3787016 was associated with overall cancer risk and prostate cancer risk. Collectively, the POLR2E rs3787016 polymorphism may be a valuable biomarker for cancer predisposition.
Hypereosinophilia (HE) is caused by a variety of disorders, ranging from parasite infections to autoimmune diseases and cancer. Only a small proportion of HE cases are clonal malignancies, and one of these, the group of eosinophilia-associated tyrosine kinase fusion-driven neoplasms, is sensitive to tyrosine kinase inhibitors, while most subtypes lack specific treatment. Eosinophil functions are highly dependent on actin polymerization, promoting priming, shape change, and infiltration of inflamed tissues. Therefore, we investigated the role of the actin-binding protein lymphocyte cytosolic protein 1 (LCP1) in malignant and nonmalignant eosinophil differentiation. We use the protein kinase C-β (PKCβ) selective inhibitor enzastaurin (Enza) to dephosphorylate and inactivate LCP1 in FIP1L1-platelet-derived growth factor receptor α (PDGFRA)-positive Eol-1 cells, and this was associated with reduced proliferation, metabolic activity, and colony formation as well as enhanced apoptosis and impaired migration. While Enza did not alter FIP1L1-PDGFRA-induced signal transducer and activator of transcription 3 (STAT3), STAT5, and ERK1/2 phosphorylation, it inhibited STAT1 Tyr701 and AKT Ser473 (but not AKT Thr308 ) phosphorylation, and short hairpin RNA knockdown experiments confirmed that this process was mediated by LCP1 and associated mammalian target of rapamycin complex 2 (mTORC2) activity loss. Homeobox protein HoxB8 immortalized murine bone marrow cells showed impaired eosinophilic differentiation upon Enza treatment or LCP1 knockdown. Furthermore, Enza treatment of primary HE samples reduced eosinophil differentiation and survival. In conclusion, our data show that HE involves active LCP1, which interacts with mTOR and triggers mTORC2 activity, and that ---
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