CR3 and Dectin-1 Collaborate in Macrophage Cytokine Response through Association on Lipid Rafts and Activation of Syk-JNK-AP-1 Pathway

Copyright: © 2015 Huang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited Acknowledgments We are grateful to the Second Core Laboratory of Research Core Facility at the National Taiwan University Hospital for confocal microscopy service and providing ultracentrifuge. We thank Dr. William E. Goldman (University of North Carolina, Chapel Hill, NC) for kindly providing WT and ags1-null mutant of H. capsulatum G186A. Funding: This work is supported by research grants 101-2320-B-002-030-MY3 from the Ministry of Science and Technology (http://www.most.gov.tw) and AS-101-TP-B06-3 from Academia Sinica (http://www.sinica.edu.tw) to BAWH. GDB is funded by research grant 102705 from Welcome Trust (http://www.wellcome.ac.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Androgens as therapy for androgen receptor-positive castration-resistant prostate cancer

Prostate cancer is the most frequently diagnosed non-cutaneous tumor of men in Western countries. While surgery is often successful for organ-confined prostate cancer, androgen ablation therapy is the primary treatment for metastatic prostate cancer. However, this therapy is associated with several undesired side-effects, including increased risk of cardiovascular diseases. Shortening the period of androgen ablation therapy may benefit prostate cancer patients. Intermittent Androgen Deprivation therapy improves quality of life, reduces toxicity and medical costs, and delays disease progression in some patients. Cell culture and xenograft studies using androgen receptor (AR)-positive castration-resistant human prostate cancers cells (LNCaP, ARCaP, and PC-3 cells over-expressing AR) suggest that androgens may suppress the growth of AR-rich prostate cancer cells. Androgens cause growth inhibition and G1 cell cycle arrest in these cells by regulating c-Myc, Skp2, and p27Kip via AR. Higher dosages of testosterone cause greater growth inhibition of relapsed tumors. Manipulating androgen/AR signaling may therefore be a potential therapy for AR-positive advanced prostate cancer

Caffeic Acid Phenethyl Ester Causes p21Cip1 Induction, Akt Signaling Reduction, and Growth Inhibition in PC-3 Human Prostate Cancer Cells

Caffeic acid phenethyl ester (CAPE) treatment suppressed proliferation, colony formation, and cell cycle progression in PC-3 human prostate cancer cells. CAPE decreased protein expression of cyclin D1, cyclin E, SKP2, c-Myc, Akt1, Akt2, Akt3, total Akt, mTOR, Bcl-2, Rb, as well as phosphorylation of Rb, ERK1/2, Akt, mTOR, GSK3α, GSK3β, PDK1; but increased protein expression of KLF6 and p21Cip1. Microarray analysis indicated that pathways involved in cellular movement, cell death, proliferation, and cell cycle were affected by CAPE. Co-treatment of CAPE with chemotherapeutic drugs vinblastine, paclitaxol, and estramustine indicated synergistic suppression effect. CAPE administration may serve as a potential adjuvant therapy for prostate cancer

Putative model of anticancer effect of CAPE in PC-3 human prostate cancer cells.

<p>Protein abundance or activity being stimulated by CAPE treatment are labeled with red upward arrows, while those being suppressed by CAPE treatment are labeled with blue downward arrows.</p

CAPE suppresses proliferation and colony formation of PC-3 cells.

<p>Proliferation of PC-3 cell treated with increasing concentration of CAPE was determined by Trypan blue staining after 72 h treatment (A) or measuring total DNA content per well using Hoechst 33258 fluorescence by 96-well proliferation assay after 24, 48, and 72 h treatment (B). Relative cell numbers were normalized to the average cell number of the control (no CAPE treatment) of each cell line in each individual experiment. Columns represent mean for 18 replicates; bars represent standard deviation. Asterisk (*) represents cell number is statistically significantly different (<i>p</i><0.05) compared to the control. Columns represent mean for 5 biological replicates; bars represent standard deviation. (C) Anticancer effect of CAPE was determined by colony formation assay of PC-3 cells treated with 0, 10, 20 µM for 14 days. Image is a representative result of three biological replicates.</p

Combined treatment of CAPE with chemotherapy drugs shows synergistic and antagonistic inhibition on proliferation of PC-3 cells.

<p>Proliferation of PC-3 cells treated with increasing dosage (0, 5, 10, 20 µM) of CAPE in combination with increasing concentration of etoposide (A), paclitaxol (B), vinblastine (C), mitoxantrone (D), and estramustine (E) for 72 h was determined by 96-well proliferation assay. The right part of the figure show the ratio of expected cell number/observed cell number. For example, treatment of 5 µM of CAPE or 1 nM vinblastine decreases cell number of PC-3 to 80.9% and 88.7%, respectively, compared to the control (no treatment). The expected cell number of treatment combining 5 µM of CAPE and 1 nM vinblastine is 0.809*0.887 = 71.8%. The observed cell number is 48.8% compared to the control. So the ratio is 0.718/0.488 = 1.5. Ratio larger than one represents synergy of growth inhibition, while ratio smaller than one represents antagonistic effect.</p

Growth response to CAPE treatment of PC-3 and PC-3 p21^Cip1 siRNA cells.

<p>Protein levels of wild type PC-3, PC-3 cells transfect with scramble control (20 nM), and PC-3 cells transfected with p21^Cip1 siRNA (20 nM) were determined by Western blotting assay. Proliferation of these PC-3 cells treated with 20 µM CAPE for 24 h was determined by 96-well plate proliferation assay as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0031286#s4" target="_blank">Material and Methods</a>.</p

CAPE inhibits Akt signaling-related proteins in PC-3 cells.

<p>Protein expression of Akt, Akt1, Akt2, Akt3, total Akt, phospho-Akt S473, phospho-Akt T308, mTOR, phospho-mTOR Ser2448 and Ser2481, GSK3α, GSK3β, phopho-GSK3α S21, phospho-GSK3β S9, PDK1, phospho-PDK1 Ser241, Bcl-2, KLF6, β-tubulin, and β-actin in PC-3 cells treated with 20 µM CAPE for 24, 48, and 5, 10, 20 µM CAPE for 72 h were assayed by Western blotting.</p