Clinicopathologic Significance of BRAF Mutation and Extracellular Signal Regulated Kinase 1/2 Expression in Patients With a Colorectal Adenocarcinoma

BRAF protein immunoprecipitation, elution, and digestion from cell extract using a microfluidic mixer for mutant BRAF protein quantification by mass spectrometry

This study utilized a microfluidic mixer for the sample pretreatment of cell extracts for target protein quantification by mass spectrometers, including protein immunoprecipitation and protein enzymatic digestion. The time of sample pretreatment was reduced and thus the throughput of quantitative mutant proteins was increased by using the proposed method. Whole cell lysates of the cancer cell line HT-29 with gene mutations were used as the sample. The target protein BRAF was immunoprecipitated using magnetic beads in a pneumatic micromixer. Purified protein was then eluted and digested by trypsin in another two micromixers to yield peptide fragments in the solution. Using stable isotope-labeled standard as the internal control, wild-type and mutant BRAF proteins were quantified using mass spectrometry, which could be used for cancer screening. Compared with conventional methods in which protein immunoprecipitation lasts overnight, the micromixer procedure takes only 1 h, likely improving the throughput of mutant BRAF protein quantification by mass spectrometry. Graphical abstract Three micromixers were used to reduce the sample pretreatment time of cell extracts for target protein quantification by mass spectrometers, including protein immunoprecipitation, protein elution, and protein enzymatic digestion.

Progression inference for somatic mutations in cancer

Computational methods were employed to determine progression inference of genomic alterations in commonly occurring cancers. Using cross-sectional TCGA data, we computed evolutionary trajectories involving selectivity relationships among pairs of gene-specific genomic alterations such as somatic mutations, deletions, amplifications, downregulation, and upregulation among the top 20 driver genes associated with each cancer. Results indicate that the majority of hierarchies involved TP53, PIK3CA, ERBB2, APC, KRAS, EGFR, IDH1, VHL, etc. Research into the order and accumulation of genomic alterations among cancer driver genes will ever-increase as the costs of nextgen sequencing subside, and personalized/precision medicine incorporates whole-genome scans into the diagnosis and treatment of cancer.

Combined detection of the expression of Nm23-H1 and p53 is correlated with survival rates of patients with stage II and III colorectal cancer

Molecular tumor markers hold considerable promise for accurately predicting the recurrence and progression of colorectal cancer (CRC) in patients. However, in the majority of cases, single marker analysis has been found to have low accuracy, and is of little practical use in clinical practice. The present study investigated the prognostic value of the combined detection of the protein expression of metastasis suppressor 23-H1 (Nm23-H1) and p53 using immunohistochemical analysis, and the mRNA expression levels were analyzed using reverse transcription-quantitative polymerase chain reaction in 110 cases of stage II and III CRC. The results revealed that the expression levels of Nm23-H1 in CRC tissues were lower, compared with those in normal tissues (χ²=18.249; P<0.001), and the protein expression levels of p53 were higher in the CRC tissues (χ²=23.940; P<0.001); although the mRNA expression levels of Nm23-H1 and p53 presented with the same trend. The protein expression of Nm23-H1 was correlated with lymph node metastases (χ²=11.847; P=0.001) and pathological patterns (χ²=6.911; P=0.032). However, it did not correlate with patient gender or age, or with tumor World Health Organization classification or invasive depth (P>0.05). No significant correlation was observed between the expression of p53 and clinicopathological features (P>0.05). Patients with CRC with Nm23-H1(+)/p53(−) tumors had increased survival rates, with a five-year overall survival rate of 83.8% and a five-year disease-free survival rate of 70.2%. The five-year overall survival rates in other study cohorts were lower, compared with the Nm23-H1(+)/p53(−) group (P<0.0125), and this was the same for the five-year disease-free survival rate (P<0.0125). In conclusion, the present study demonstrated that the combined detection of the protein expression of Nm23-H1 and p53 was associated with the long term survival rates of patients with stage II and III CRC; and this may offer potential for use as a predictor of survival rates in patients with CRC.