Ubiquitin-specific protease 21 promotes tumorigenicity and stemness of colorectal cancer by deubiquitinating and stabilizing ZEB1.

BACKGROUND: Colorectal cancer (CRC) is one very usual tumor together with higher death rate. Ubiquitin-specific protease 21 (USP21) has been confirmed to take part into the regulation of CRC progression through serving as a facilitator. Interestingly, the promotive function of USP21 has also discovered in the progression of CRC. ZEB1 has illustrated to be modulated by USP7, USP22 and USP51 in cancers. However, the regulatory functions of USP21 on ZEB1 in CRC progression need more investigations. AIM: To investigate the relationship between USP21 and ZEB1 in CRC progression. METHODS: The mRNA and protein expressions were assessed through RT-qPCR, western blot and IHC assay. The interaction between USP21 and ZEB1 was evaluated through Co-IP and GST pull down assays. The cell proliferation was detected through colony formation assay. The cell migration and invasion abilities were determined through Transwell assay. The stemness was tested through sphere formation assay. The tumor growth was evaluated through in vivo mice assay. RESULTS: In this work, USP21 and ZEB1 exhibited higher expression in CRC, and resulted into poor prognosis. Moreover, the interaction between USP21 and ZEB1 was further investigated. It was demonstrated that USP21 contributed to the stability of ZEB1 through modulating ubiquitination level. In addition, USP21 strengthened cell proliferation, migration and stemness through regulating ZEB1. At last, through in vivo assays, it was illustrated that USP21/ZEB1 axis aggravated tumor growth. CONCLUSION: For the first time, these above findings manifested that USP21 promoted tumorigenicity and stemness of CRC by deubiquitinating and stabilizing ZEB1. This discovery suggested that USP21/ZEB1 axis may provide novel sights for the treatment of CRC.

Expression and clinical role of PRDX6 in lung adenocarcinoma.

OBJECTIVE: To explore the levels of expression and clinical role of peroxiredoxin 6 (PRDX6) in lung adenocarcinoma. METHODS: This retrospective study used a series of bioinformatics methods to detect the levels of expression of and mutations in the PRDX6 gene in a range of cancers and lung adenocarcinoma. Immunohistochemistry was used to verify the levels of expression of PRDX6 protein in samples of lung adenocarcinoma compared with normal adjacent tissue. The effect of PRDX6 gene knockdown on the in vitro proliferation of a lung adenocarcinoma cell line was measured. Bioinformatics methods were used to determine the diagnostic value and impact on survival of the PRDX6 gene in patients with lung adenocarcinoma. RESULTS: The results showed that the PRDX6 gene was highly expressed in lung adenocarcinoma and there were five mutations at different sites on the gene. PRDX6 promoted the proliferation of the lung adenocarcinoma cell line. The survival duration of lung adenocarcinoma patients with high levels of PRDX6 gene expression was significantly shorter than that of patients with low PRDX6 gene expression. CONCLUSION: PRDX6 is highly expressed in lung adenocarcinoma and higher levels of expression of the PRDX6 gene were associated with a poorer prognosis.

Ca2+- and Zn2+-dependent nucleases co-participate in nuclear DNA degradation during programmed cell death in secretory cavity development in Citrus fruits.

Calcium (Ca2+)- and zinc Zn2+-dependent nucleases play pivotal roles in plant nuclear DNA degradation in programmed cell death (PCD). However, the mechanisms by which these two nucleases co-participate in PCD-associated nuclear DNA degradation remain unclear. Here, the spatiotemporal expression patterns of two nucleases (CrCAN and CrENDO1) were analyzed qualitatively and quantitatively during PCD in secretory cavity formation in Citrus reticulata 'Chachi' fruits. Results show that the middle and late initial cell stages and lumen-forming stages are key stages for nuclear degradation during the secretory cavity development. CAN and ENDO1 exhibited potent in vitro DNA degradation activity at pH 8.0 and pH 5.5, respectively. Quantitative real-time reverse-transcription polymerase chain reaction, in situ hybridization assays, the subcellular localization of Ca2+ and Zn2+, and immunocytochemical localization showed that CrCAN was activated at the middle and late initial cell stages, while CrENDO1 was activated at the late initial cell and lumen-forming stages. Furthermore, we used immunocytochemical double-labelling to simultaneously locate CrCAN and CrENDO1. The DNA degradation activity of the two nucleases was verified by simulating the change of intracellular pH in vitro. Our results also showed that CrCAN and CrENDO1 worked respectively and co-participated in nuclear DNA degradation during PCD of secretory cavity cells. In conclusion, we propose the model for the synergistic effect of Ca2+- and Zn2+-dependent nucleases (CrCAN and CrENDO1) in co-participating in nuclear DNA degradation during secretory cavity cell PCD in Citrus fruits. Our findings provide direct experimental evidence for exploring different ion-dependent nucleases involved in nuclear degradation during plant PCD.

Involvement of Vacuolar Processing Enzyme CgVPE1 in Vacuole Rupture in the Programmed Cell Death during the Development of the Secretory Cavity in Citrus grandis 'Tomentosa' Fruits.

Vacuolar processing enzymes (VPEs) with caspase-1-like activity are closely associated with vacuole rupture. The destruction of vacuoles is one of the characteristics of programmed cell death (PCD) in plants. However, whether VPE is involved in the vacuole destruction of cells during secretory cavity formation in Citrus plants remains unclear. This research identified a CgVPE1 gene that encoded the VPE and utilized cytology and molecular biology techniques to explore its temporal and spatial expression characteristics during the PCD process of secretory cavity cells in the Citrus grandis 'Tomentosa' fruit. The results showed that CgVPE1 is an enzyme with VPE and caspase-1-like activity that can self-cleave into a mature enzyme in an acidic environment. CgVPE1 is specifically expressed in the epithelial cells of secretory cavities. In addition, it mainly accumulates in vacuoles before it is ruptured in the secretory cavity cells. The spatial and temporal immunolocalization of CgVPE1 showed a strong relationship with the change in vacuole structure during PCD in secretory cavity cells. In addition, the change in the two types of VPE proteins from proenzymes to mature enzymes was closely related to the change in CgVPE1 localization. Our results indicate that CgVPE1 plays a vital role in PCD, causing vacuole rupture in cells during the development of the secretory cavity in C. grandis 'Tomentosa' fruits.

Purification of menthone and menthol from Mentha haplocalyx by suspension particle assisted solvent sublation, neuroprotective effect in vitro and molecular docking of menthol on amyloid-ß.

Suspension particle assisted solvent sublation was designed for the first time. The volatile monoterpenes in Mentha haplocalyx Briq were extracted using this method from a solution containing plant solid particles as the lower phase of solvent sublation. Under the optimum conditions of the solvent sublation (n-hexane/plant solid particles 20% ethanol-water solution system, pH 4, flotation time 30 min and air flow rate 30 mL/min), the extraction yields were 2.0 × 102 mg/kg, 9.5 × 101 mg/kg and 1.2 × 103 mg/kg for menthone, isomenthone and menthol, respectively. Compared with the traditional methods, the established suspension particle assisted solvent sublation might be an economical and efficient extraction method in some aspects. Through a cellular antioxidant activity experiment, menthol could alleviate H2O2-induced oxidative stress. Molecular docking was applied to simulate the molecular recognition process between amyloid-ß and menthol. The affinity energy of menthol was -12.59 kJ/mol, indicating that menthol might have neuroprotective activity and the potential to be an amyloid-ß inhibitor.

PDK2-mediated alternative splicing switches Bnip3 from cell death to cell survival.

Herein we describe a novel survival pathway that operationally links alternative pre-mRNA splicing of the hypoxia-inducible death protein Bcl-2 19-kD interacting protein 3 (Bnip3) to the unique glycolytic phenotype in cancer cells. While a full-length Bnip3 protein (Bnip3FL) encoded by exons 1-6 was expressed as an isoform in normal cells and promoted cell death, a truncated spliced variant of Bnip3 mRNA deleted for exon 3 (Bnip3Δex3) was preferentially expressed in several human adenocarcinomas and promoted survival. Reciprocal inhibition of the Bnip3Δex3/Bnip3FL isoform ratio by inhibiting pyruvate dehydrogenase kinase isoform 2 (PDK2) in Panc-1 cells rapidly induced mitochondrial perturbations and cell death. The findings of the present study reveal a novel survival pathway that functionally couples the unique glycolytic phenotype in cancer cells to hypoxia resistance via a PDK2-dependent mechanism that switches Bnip3 from cell death to survival. Discovery of the survival Bnip3Δex3 isoform may fundamentally explain how certain cells resist Bnip3 and avert death during hypoxia.

MicroRNA-24 is a novel regulator of aldosterone and cortisol production in the human adrenal cortex.

Dysregulation of aldosterone or cortisol production can predispose to hypertension, as seen in aldosterone-producing adenoma, a form of primary aldosteronism. We investigated the role of microRNA (miRNA) in their production, with particular emphasis on the CYP11B1 (11ß-hydroxylase) and CYP11B2 (aldosterone synthase) genes, which produce the enzymes responsible for the final stages of cortisol and aldosterone biosynthesis, respectively. Knockdown of Dicer1, a key enzyme in miRNA maturation, significantly altered CYP11B1 and CYP11B2 expression in a human adrenocortical cell line. Screening of nondiseased human adrenal and aldosterone-producing adenoma samples yielded reproducible but distinctive miRNA expression signatures for each tissue type, with levels of certain miRNA, including microRNA-24 (miR-24), differing significantly between the 2. Bioinformatic analysis identified putative binding sites for several miRNA, including miR-24, in the 3' untranslated region of CYP11B1 and CYP11B2 mRNAs. In vitro manipulation of miR-24 confirmed its ability to modulate CYP11B1 and CYP11B2 expression, as well as cortisol and aldosterone production. This study demonstrates that Dicer-dependent miRNA, including miR-24, can post-transcriptionally regulate expression of the CYP11B1 and CYP11B2 genes. Normal adrenal tissue and aldosterone-producing adenoma differ significantly and reproducibly in their miRNA expression profiles, with miR-24 significantly downregulated in the latter. Adrenal miRNA may, therefore, be a novel and valid target for the therapeutic manipulation of corticosteroid biosynthesis.

[Results after laser epithelial keratectomileusis for myopia].

PURPOSE: To study the results of laser epithelial keratectomileusis (LASEK) for myopia. METHODS: LASEK was performed with the Nidek EC-5000 excimer laser. 39 patients (78 eyes) with a refraction of -1.50 to -12.00 diopters were treated and followed for 3-12 months. Postoperrative pain, uncorrected visual acuity (UCVA), refraction, corneal haze, and surgical preference were examined. RESULTS: During 3-12 months follow-up, 96.2% UCVA were above 0.5, 92.3% eyes were at least 1.0 in UCVA. The last refraction were whthin +1.00 D and -1.00 D in 18 eyes except 4 eyes. The II grade haze was found in four eye. CONCLUSIONS: LASEK was one of methods to treat eyes with myopia safely and effectively, but also studied in operation, experiment, and further effect.