We have developed a highly sensitive microarray protein chip, ProteoChip, coated with ProLinker, novel calixcrown derivatives with a bifunctional coupling property that permits efficient immobilization of capture proteins on solid matrixes and makes high-throughput analysis of protein-protein interactions possible. The analysis of quartz crystal microbalance showed that both monoclonal antibody (mAb) and antigen (Ag) bound to the gold film of the sensor surface coated with ProLinker B and that it is useful for studies of Ab-Ag interactions. ProteoChip, aminated glass slide coated with ProLinker A, was also demonstrated to be useful for preparation of high-density array spots by using a microarrayer and for analysis of analyte Ags either by direct or sandwich methods of fluorescence immunoassay. The detection sensitivity of ProteoChip was as low as 1-10 femtogram/mL of analyte protein, useful for detection of tumor markers. ProteoChip was also useful for studies of direct protein-protein interactions as demonstrated by analysis of integrin-extracellular matrix protein interaction. These experimental results suggest that ProteoChip is a powerful tool for development of chip-based lead screening microarrays to monitor protein-protein interactions (i.e. drug target) as well as for biomarker assays which require high detection sensitivity.

Multidimensional analysis considering various surgical outcomes is necessary to evaluate the learning curve for laparoscopic rectal cancer surgery. The effective surgical learning curve was approximately 60-80 procedures in this series.

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PurposeThe optimal treatment for synchronous liver metastasis (LM) from colorectal cancer (CRC) depends on various factors. The present study was intended to investigate the oncologic outcome according to the time of resection of metastatic lesions.MethodsData from patients who underwent treatment with curative intent for primary CRC and synchronous LM between 2004 and 2009 from 9 university hospitals in Korea were collected retrospectively. One hundred forty-three patients underwent simultaneous resection for primary CRC and synchronous LM (simultaneous surgery group), and 65 patients were treated by 2-stage operation (staged surgery group).ResultsThe mean follow-up length was 41.2 ± 24.6 months. In the extent of resection for hepatic metastasis, major hepatectomy was more frequently performed in staged surgery group (33.8% vs. 8.4%, P < 0.001). The rate of severe complications of Clavien-Dindo classification grade III or more was not significantly different between the 2 groups. The 3-year overall survival (OS) rate was 85.0% in staged surgery group and 69.4% in simultaneous surgery group (P = 0.013), and the 3-year recurrence-free survival (RFS) rate was 46.4% in staged surgery group and 30.2% in simultaneous surgery group (P = 0.143). In subgroup analysis based on the location of primary CRC, the benefit of staged surgery for OS and RFS was clearly shown in rectal cancer (P = 0.021 and P = 0.015).ConclusionBased on our results, staged surgery with or without neoadjuvant chemotherapy should be considered for resectable synchronous LM from CRC, especially in rectal cancer, as a safe and fairly promising option.

A functional proteomic technology using protein chip and molecular simulation was used to demonstrate a novel biomolecular interaction between P11, a peptide containing the Ser-Asp-Val (SDV) sequence and integrin alpha v beta 3. P11 (HSDVHK) is a novel antagonistic peptide of integrin alpha v beta 3 screened from hexapeptide library through protein chip system. An in silico docking study and competitive protein chip assay revealed that the SDV sequence of P11 is able to create a stable inhibitory complex onto the vitronectin-binding site of integrin alpha v beta 3. The Arg-Gly-Asp (RGD)-binding site recognition by P11 was site specific because the P11 was inactive for the complex formation of a denatured form of integrin-vitronectin. P11 showed a strong antagonism against alpha v beta 3-GRGDSP interaction with an IC(50) value of 25.72+/-3.34 nM, whereas the value of GRGDSP peptide was 1968.73+/-444.32 nM. The binding-free energies calculated from the docking simulations for each P11 and RGD peptide were -3.99 and -3.10 kcal/mol, respectively. The free energy difference between P11 and RGD corresponds to approximately a 4.5-fold lower K(i) value for the P11 than the RGD peptide. The binding orientation of the docked P11 was similar to the crystal structure of the RGD in alpha v beta 3. The analyzed docked poses suggest that a divalent metal-ion coordination was a common driving force for the formation of both SDV/alpha v beta 3 and RGD/alpha v beta 3 complexes. This is the first report on the specific recognition of the RGD-binding site of alpha v beta 3 by a non-RGD containing peptide using a computer-assisted proteomic approach.