Nucleoside diphosphate kinase 2 confers acquired 5-fluorouracil resistance in colorectal cancer cells

<p>Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. 5-fluorouracil (5-FU)-based chemotherapeutic regimens are routinely used for the treatment of patients with CRC. However, recurrence and chemotherapeutic drug resistance limit the survival rates of patients with CRC. DNA methylation participates in diverse cellular processes by regulating the transcription of a large number of genes expression, cell division, apoptosis, cell adhesion and differentiation, and metabolism, thus it might mediate chemoresistance. Using an Illumina Infinium HD Assay, DNA methylation levels in a human 5-FU-resistant HCT-8 CRC cell line (HCT-8/FU) and its progenitor cell line HCT-8 were analysed. A total of 16,580 differentially methylated genes were identified, of which 8885 were hypermethylated and 7695 were hypomethylated in resistant cells. Among these genes, <i>NME2</i> (nucleoside diphosphate kinase 2) exhibited a significant difference in methylation between cell lines and has known roles in gastric cancer and breast cancer; accordingly, we hypothesized that it plays a role in acquired resistance in CRC. Knockdown of <i>NME2</i> restored 5-FU sensitivity in 5-FU-resistant CRC cells, reduced cell survival and increased cell apoptosis; and overexpression of <i>NME2</i> in HCT-8 cells results in the acquisition of resistance to 5-FU, this alteration enhanced HCT-8 cells growth abilities and reduced apoptosis. These findings suggest that <i>NME2</i> mediates chemoresistance to 5-FU in CRC and that specific <i>NME2</i> inhibition could optimize 5-FU-based chemotherapy of CRC.</p

Rapid deployment of a mobile biosafety level-3 laboratory in Sierra Leone during the 2014 Ebola virus epidemic

<div><p>Background</p><p>Ebola virus emerged in West Africa in December 2013. The high population mobility and poor public health infrastructure in this region led to the development of the largest Ebola virus disease (EVD) outbreak to date.</p><p>Methodology/Principal findings</p><p>On September 26, 2014, China dispatched a Mobile Biosafety Level-3 Laboratory (MBSL-3 Lab) and a well-trained diagnostic team to Sierra Leone to assist in EVD diagnosis using quantitative real-time PCR, which allowed the diagnosis of suspected EVD cases in less than 4 hours from the time of sample receiving. This laboratory was composed of three container vehicles equipped with advanced ventilation system, communication system, electricity and gas supply system. We strictly applied multiple safety precautions to reduce exposure risks. Personnel, materials, water and air flow management were the key elements of the biosafety measures in the MBSL-3 Lab. Air samples were regularly collected from the MBSL-3 Lab, but no evidence of Ebola virus infectious aerosols was detected. Potentially contaminated objects were also tested by collecting swabs. On one occasion, a pipette tested positive for EVD. A total of 1,635 suspected EVD cases (824 positive [50.4%]) were tested from September 28 to November 11, 2014, and no member of the diagnostic team was infected with Ebola virus or other pathogens, including Lassa fever. The specimens tested included blood (69.2%) and oral swabs (30.8%) with positivity rates of 54.2% and 41.9%, respectively. The China mobile laboratory was thus instrumental in the EVD outbreak response by providing timely and reliable diagnostics.</p><p>Conclusions/Significance</p><p>The MBSL-3 Lab significantly contributed to establishing a suitable laboratory response capacity during the emergence of EVD in Sierra Leone.</p></div

Schematic diagram of the “Four Flows”.

<p>Personnel, materials, water and air flow management were the key elements of biosafety measures in the MBSL-3 Lab.</p

Layout of the mobile biosafety level-3 laboratory.

<p>The main and auxiliary containers were connected by an airtight soft connection and together formed a complete biosafety level-3 (BSL-3) lab. The instruments represented by letters were listed in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0005622#pntd.0005622.s003" target="_blank">S1 Table</a>.</p

Overview of the China mobile laboratory diagnostic team’s composition and their tasks.

<p>Overview of the China mobile laboratory diagnostic team’s composition and their tasks.</p

Diagnostic algorithm for laboratory testing.

<p>Diagnostic algorithm for laboratory testing.</p

Samples and test results from September 28 to November 11, 2014.

<p>Samples and test results from September 28 to November 11, 2014.</p

Worksite layout for the China mobile laboratory diagnostic team.

<p>Worksite layout for the China mobile laboratory diagnostic team.</p

Mobile biosafety level-3 laboratory at its mission in Sierra Leone.

<p>(A) Exterior of the mobile biosafety level-3 laboratory. (B) View to the biosafety level-3 laboratory. Two different perspectives (B1 and B2) were shown. (C) View to the auxiliary container. C1) Pass box (left) and expanded-metal door (middle). C2) Monitoring unit and table for experimental preparation. C3) Shower cubicle. C4) Waste treatment room. (D) View to the command container. D1) Room for meeting or for watching monitoring videos. D2) “King View” industry control software. D3) Real-time surveillance video.</p