Lymph node metastasis is the major concern that causes death in colorectal cancers. However, biomarkers for cancer metastasis are still lacking. In this study, we applied an LC-MS/MS-based label-free quantitative proteomics approach to compare the differential secretome of a primary cell line SW480 and its lymph node metastatic cell line SW620 from the same colorectal cancer patient. We identified a total of 910 proteins from the conditioned media and 145 differential proteins between SW480 and SW620 (>1.5-fold change). The differential expression pattern of 6 candidate proteins was validated by Western blot analysis. Among them, trefoil factor 3 and growth/differentiation factor 15, two up-regulated proteins in SW620, were further analyzed in a large cohort of clinical tissue and serum samples. Sandwich ELISA assay showed that the serum levels of both proteins were significantly higher in lymph node metastatic colorectal cancers. Receiver operating characteristic curve analysis confirmed that serum trefoil factor 3 and growth/differentiation factor 15 could provide a discriminatory diagnostic test for predicting colorectal cancer metastasis. Immunohistochemical analysis also showed that the overexpression of trefoil factor 3 or growth/differentiation factor 15 in colorectal cancer was associated with lymph node metastatic behavior. This study showed an accurate, sensitive, and robust label-free quantitation approach for differential analysis of cancer secretome. The comparison of the cancer secretome in vitro is a feasible strategy to obtain valuable biomarkers for potential clinical application. Both trefoil factor 3 and growth/differentiation factor 15 could serve as potential biomarkers for the prediction of colorectal cancer metastasis.

It has been discovered that Zn metal-organic framework (Zn-MOF) electrodes and ionic liquids are an excellent combination for the efficient and selective reduction of CO2 to CH4.

Highly efficient electrochemical reduction of CO2 into value-added chemicals using cheap and easily prepared electrodes is environmentally and economically compelling. The first work on the electrocatalytic reduction of CO2 in ternary electrolytes containing ionic liquid, organic solvent, and H2 O is described. Addition of a small amount of H2 O to an ionic liquid/acetonitrile electrolyte mixture significantly enhanced the efficiency of the electrochemical reduction of CO2 into formic acid (HCOOH) on a Pb or Sn electrode, and the efficiency was extremely high using an ionic liquid/acetonitrile/H2 O ternary mixture. The partial current density for HCOOH reached 37.6 mA cm(-2) at a Faradaic efficiency of 91.6 %, which is much higher than all values reported to date for this reaction, including those using homogeneous and noble metal electrocatalysts. The reasons for such high efficiency were investigated using controlled experiments.