Proliferating cell nuclear antigen in the cytoplasm interacts with components of glycolysis and cancer

AbstractProliferating cell nuclear antigen (PCNA) is involved in a wide range of functions in the nucleus. However, a substantial amount of PCNA is also present in the cytoplasm, although their function is unknown. Here we show, through Far-Western blotting and mass spectrometry, that PCNA is associated with several cytoplasmic oncoproteins, including elongation factor, malate dehydrogenase, and peptidyl-prolyl isomerase. Surprisingly, PCNA is also associated with six glycolytic enzymes that are involved in the regulation of steps 4–9 in the glycolysis pathway.Structured summaryMINT-7995351: G3P (uniprotkb:P04406) and PCNA (uniprotkb:P12004) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7995334: ENOA (uniprotkb:P06733) and PCNA (uniprotkb:P12004) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7995368: ALDOA (uniprotkb:P04075) and PCNA (uniprotkb:P12004) colocalize (MI:0403) by fluorescence microscopy (MI:0416)MINT-7995141: G3P (uniprotkb:P04406) binds (MI:0407) to PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995182: ENOA (uniprotkb:P06733) binds (MI:0407) to PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995132: G3P (uniprotkb:P04406) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995228: PRDX6 (uniprotkb:P30041) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995220: CAH2 (uniprotkb:P00918) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995114: Triosephosphate isomerase (uniprotkb:P60174) binds (MI:0407) to PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995244: K2C7 (uniprotkb:P08729) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995252: ANXA2 (uniprotkb:P07355) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995122: Triosephosphate isomerase (uniprotkb:P60174) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995093: ALDOA (uniprotkb:P04075) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995148: PGK1 (uniprotkb:P00558) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995158: PGAM1 (uniprotkb:P18669) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995166: PGAM1 (uniprotkb:P18669) binds (MI:0407) to PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995105: ALDOA (uniprotkb:P04075) binds (MI:0407) to PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995260: PPIA (uniprotkb:P62937) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995173: ENOA (uniprotkb:P06733) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995268: EF1A (uniprotkb:P68104) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995236: MDHM (uniprotkb:P40926) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995189: RSSA (uniprotkb:P08865) physically interacts (MI:0915) with PCNA (uniprotkb:P12004) by far western blotting (MI:0047)MINT-7995282: PCNA (uniprotkb:P12004) physically interacts (MI:0915) with ALDOA (uniprotkb:P00883) and G3P (uniprotkb:P46406) by anti bait coimmunoprecipitation (MI:0006)

Analytic study of the urn model for separation of sand

We present an analytic study of the urn model for separation of sand recently introduced by Lipowski and Droz (Phys. Rev. E 65, 031307 (2002)). We solve analytically the master equation and the first-passage problem. The analytic results confirm the numerical results obtained by Lipowski and Droz. We find that the stationary probability distribution and the shortest one among the characteristic times are governed by the same free energy. We also analytically derive the form of the critical probability distribution on the critical line, which supports their results obtained by numerically calculating Binder cumulants (cond-mat/0201472).Comment: 6 pages including 3 figures, RevTe

Analytic study of the three-urn model for separation of sand

We present an analytic study of the three-urn model for separation of sand. We solve analytically the master equation and the first-passage problem. We find that the stationary probability distribution obeys the detailed balance and is governed by the {\it free energy}. We find that the characteristic lifetime of a cluster diverges algebraically with exponent 1/3 at the limit of stability.Comment: 5pages, 4 figures include

Annexin A2 Binds RNA and Reduces the Frameshifting Efficiency of Infectious Bronchitis Virus

Annexin A2 (ANXA2) is a protein implicated in diverse cellular functions, including exocytosis, DNA synthesis and cell proliferation. It was recently proposed to be involved in RNA metabolism because it was shown to associate with some cellular mRNA. Here, we identified ANXA2 as a RNA binding protein (RBP) that binds IBV (Infectious Bronchitis Virus) pseudoknot RNA. We first confirmed the binding of ANXA2 to IBV pseudoknot RNA by ultraviolet crosslinking and showed its binding to RNA pseudoknot with ANXA2 protein in vitro and in the cells. Since the RNA pseudoknot located in the frameshifting region of IBV was used as bait for cellular RBPs, we tested whether ANXA2 could regulate the frameshfting of IBV pseudoknot RNA by dual luciferase assay. Overexpression of ANXA2 significantly reduced the frameshifting efficiency from IBV pseudoknot RNA and knockdown of the protein strikingly increased the frameshifting efficiency. The results suggest that ANXA2 is a cellular RBP that can modulate the frameshifting efficiency of viral RNA, enabling it to act as an anti-viral cellular protein, and hinting at roles in RNA metabolism for other cellular mRNAs

Ablation of Akt2 induces autophagy through cell cycle arrest, the downregulation of p70S6K, and the deregulation of mitochondria in MDA-MB231 cells.

BACKGROUND: Akt/PKB is a promising anticancer therapeutic target, since abnormally elevated Akt activity is directly correlated to tumor development, progression, poor prognosis and resistance to cancer therapies. Currently, the unique role of each Akt isoform and their relevance to human breast cancer are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We previously found that Akt1, 2 and 3 are localized at specific subcellular compartments (the cytoplasm, mitochondria and nucleus, respectively), raising the possibility that each isoform may have unique functions and employ different regulation mechanisms. By systematically studying Akt-ablated MDA-MB231 breast cancer cells with isoform-specific siRNA, we here show that Akt2 is the most relevant isoform to cell proliferation and survival in our cancer model. Prolonged ablation of Akt2 with siRNA resulted in cell-cycle arrest in G0/G1 by downregulating Cdk2 and cyclin D, and upregulating p27. The analysis of the Akt downstream signaling pathways suggested that Akt2 specifically targets and activates the p70S6K signaling pathway. We also found that Akt2 ablation initially resulted in an increase in the mitochondrial volume concomitantly with the upregulation of PGC-1α, a regulator of mitochondrial biogenesis. Prolonged ablation of Akt2, but not Akt1 or Akt3, eventually led to cell death by autophagy of the mitochondria (i.e., mitophagy). CONCLUSIONS/SIGNIFICANCE: Collectively, our data demonstrates that Akt2 augments cell proliferation by facilitating cell cycle progression through the upregulation of the cell cycle engine, and protects a cell from pathological autophagy by modulating mitochondrial homeostasis. Our data, thus, raises the possibility that Akt2 can be an effective anticancer target for the control of (breast) cancer

Prognostic Impact of Longitudinal Monitoring of Radiomic Features in Patients with Advanced Non-Small Cell Lung Cancer

Tumor growth dynamics vary substantially in non-small cell lung cancer (NSCLC). We aimed to develop biomarkers reflecting longitudinal change of radiomic features in NSCLC and evaluate their prognostic power. Fifty-three patients with advanced NSCLC were included. Three primary variables reflecting patterns of longitudinal change were extracted: area under the curve of longitudinal change (AUC1), beta value reflecting slope over time, and AUC2, a value obtained by considering the slope and area over the longitudinal change of features. We constructed models for predicting survival with multivariate cox regression, and identified the performance of these models. AUC2 exhibited an excellent correlation between patterns of longitudinal volume change and a significant difference in overall survival time. Multivariate regression analysis based on cut-off values of radiomic features extracted from baseline CT and AUC2 showed that kurtosis of positive pixel values and surface area from baseline CT, AUC2 of density, skewness of positive pixel values, and entropy at inner portion were associated with overall survival. For the prediction model, the areas under the receiver operating characteristic curve (AUROC) were 0.948 and 0.862 at 1 and 3 years of follow-up, respectively. Longitudinal change of radiomic tumor features may serve as prognostic biomarkers in patients with advanced NSCLC. © The Author(s) 201

The Potential of Combining Tubulin-Targeting Anticancer Therapeutics and Immune Therapy

Cancer immune therapy has recently shown tremendous promise to combat many different cancers. The microtubule is a well-defined and very effective cancer therapeutic target. Interestingly, several lines of evidence now suggest that microtubules are intimately connected to the body’s immune responses. This raises the possibility that the combination of microtubule inhibitors and immune therapy can be a highly effective option for cancer treatments. However, our understanding on this potentially important aspect is still very limited, due in part to the multifaceted nature of microtubule functions. Microtubules are not only involved in maintaining cell morphology, but also a variety of cellular processes, including the movement of secretory vesicles and organelles, intracellular macromolecular assembly, signaling pathways, and cell division. Microtubule inhibitors may be subdivided into two classes: Anti-depolymerization agents such as the taxane family, and anti-polymerization agents such as colchicine and vinka alkaloids. These two different classes may have different effects on immune cell subtypes. Anti-depolymerization agents can not only induce NK cells, but also appear to inhibit T regulatory (Treg) cells. However, different inhibitors may have different functions even among the same class. For example, the doxetaxel anti-depolymerization agent up-regulates cytotoxic T cells, while paclitaxel down-regulates them. Certain anti-polymerization agents such as colchicine appear to down-regulate most immune cell types, while inducing dendritic cell maturation and increasing M1 macrophage population. In contrast, the vinblastine anti-polymerization agent activates many of these cell types, albeit down-regulating Treg cells. In this review, we focus on the various effects of tubulin inhibitors on the activities of the body’s immune system, in the hope of paving the way to develop an effective cancer therapy by combining tubulin-targeting anticancer agents and immune therapy