Combination of laser microdissection, 2D-DIGE and MALDI-TOF MS to identify protein biomarkers to predict colorectal cancer spread
CLINICAL PROTEOMICS
Authors: Kirana, Chandra; Peng, Lifeng; Miller, Rose; Keating, John P.; Glenn, Corinne; Shi, Hongjun; Jordan, T. William; Maddern, Guy J.; Stubbs, Richard S.
Abstract
Biomarkers are urgently required to support current histological staging to provide additional accuracy in stratifying colorectal cancer (CRC) patients according to risk of spread to properly assign adjuvant chemotherapy after surgery. Chemotherapy is given to patients with stage III to reduce the risk of recurrence but is controversial in stage II patients. Up to 25% of stage II patients will relapse within 5 years after tumor removal and when this occurs cure is seldom possible. The aim of this study was to identify protein biomarkers to stratify risk of spread of CRC patients. Laser micro-dissection was used to isolate cancer cells from primary colorectal tumors of stage II patients which did or did not metastasize within 5 years after surgical resection. Protein expression differences between two groups of tumors were profiled by 2D-DIGE with saturation CyDye labeling and identified using MALDI-TOF mass spectrometry. Evaluation of protein candidates was conducted using tissue micro array (TMA) immunohistochemistry on 125 colorectal tumor tissue samples of different stages. A total of 55 differentially expressed proteins were identified. Ten protein biomarkers were chosen based on p value and ratio between non metastasized and metastazised groups and evaluated on 125 tissues using TMA immunohistochemistry. Expression of HLAB, protein 14-3-3 beta, LTBP3, ADAMTS2, JAG2 and NME2 on tumour cells was significantly associated with clinical parameters related to tumour progression, invasion and metastasis. Kaplan-Meier survival curve showed strong expression of six proteins was associated with good CRC specific survival. Expression of HLAB, ADAMTS2, LTBP3, JAG2 and NME2 on tumour cells, was associated with tumour progression and invasion, metastasis and CRC specific survival may serve as potential biomarkers to stratify CRC patients into low and high risk of tumour metastasis. Combined methods of laser microdissection, 2D DIGE with saturation labelling and MALDI-TOF MS proved to be resourceful techniques capable of identifying protein biomarkers to predict risk of spread of CRC to liver.
Genetic prediction of the effectiveness of biologics for psoriasis treatment
JOURNAL OF DERMATOLOGY
Authors: Nishikawa, Rika; Nagai, Hiroshi; Bito, Toshinori; Ikeda, Tetsuya; Horikawa, Tatsuya; Adachi, Atsuko; Matsubara, Tsukasa; Nishigori, Chikako
Abstract
Anti-tumor necrosis factor (TNF)-alpha therapy is used for the treatment of psoriasis, with varying outcomes. However, the specific cause of inadequate response or treatment failure remains unknown. The aim of the present study was to identify useful clinical biomarkers for predicting therapeutic responses or to serve as new drug targets for refractory psoriasis cases. We performed a genome-wide association study (GWAS) of 65 psoriasis patients who were prospectively followed after beginning anti-TNF-alpha therapy using Human Omni Express-8 v1.2 Beadchips. Patients were enrolled at the dermatology departments of Kobe University Hospital and six collaborative hospitals. Associations between single nucleotide polymorphisms (SNP) and changes in the Psoriasis Area and Severity Index (PASI) after 12 weeks of treatment were evaluated. After genome data collection and quality control, a total of 731 442 SNPs were identified in 65 Asian psoriasis patients who were treated with adalimumab or infliximab. Here, we present 10 SNPs, such as those in JAG2 and ADRA2A, that were associated with treatment responses to anti-TNF-alpha agents (strongest effect, P < 7.11E-06). This is the first GWAS to examine SNP associated with treatment responses in psoriasis patients. In addition, we identified other SNP that exhibited potential associations with anti-TNF-alpha treatment response, which merit further study. Of these, rs11096957 on TLR10, which is associated with increased TNF-alpha production, was previously reported to be associated with treatment responses to TNF-alpha inhibitors.