Study on the Expression and Significance of TGF-β1, p-ERK1/2and K-ras in Colorectal Cancer Using Tissue Microarray Technique

OBJECTIVE This study aimed to explore the expression and significance of transforming growth factor β1（TGF-β1）,extracellular signal-regulated kinases 1/2 （ERK1/2）, and K-ras in colorectal cancer （CRC） using tissue microarray technology.METHODS The expressions of TGF-β1, ERK1/2, and K-ras in colon cancer cells taken from the specimens of 92 CRC patients （stage Ⅰ： 16 cases, stage Ⅱ： 28 cases, stage Ⅲ： 24 cases, and stage Ⅳ：24 cases） were analyzed using tissue microarray technology and immunohistochemistry, and compared with those of 20 normal colon tissue samples.RESULTS High immunoreactive scores （IRS） of TGF-β1,p-ERK1/2, and K-ras protein in CRC were obtained, which were 66.3% （61/92）, 59.8% （55/92）, and 48.9% （45/92）, respectively, and those in normal epithelial cells of colon were 10% （2/20）, 20% （4/20）, and 30% （6/20）, respectively （P 〈 0.05）. The expressions of TGF-β1 and ERK1/2 in CRC at stage Ⅰwere 37.5% and 31.3%,respectively, and those in CRC at stage Ⅳ were 83.3% and79.3%, respectively, with statistically significant differences. No significant relationship was found between K-ras expression and tumor stages （P〉0.05）.CONCLUSION High level expressions of TGF-β1 and ERK1/2 are closely related to the clinical stages of colon cancer and crosstalk may exist between the 2 signal pathways.

Quantitative analysis of tumor mitochondrial RNA using microarray

AIM: To design a novel method to rapidly detect the quantitative alteration of mtRNA in patients with tumors.METHODS: Oligo 6.22 and Primer Premier 5.0 bio-soft were used to design 15 pairs of primers of mtRNA cDNA probes in light of the functional and structural property of mtDNA, and then RT-PCR amplification was used to produce 15 probes of mtRNA from one normal gastric mucosal tissue. Total RNA extracted from 9 gastric cancers and corresponding normal gastric mucosal tissues was reverse transcribed into cDNA labeled with fluorescein. The spotted mtDNA microarrays were made and hybridized. Finally,the microarrays were scanned with a GeneTACTM laser scanner to get the hybridized results. Northern blot was used to confirm the microarray results.RESULTS: The hybridized spots were distinct with clear and consistent backgrounds. After data was standardized according to the housekeeping genes, the results showed that the expression levels of some mitochondrial genes in gastric carcinoma were different from those in the corresponding non-cancerous regions.CONCLUSION: The mtDNA expression microarray can rapidly, massively and exactly detect the quantity of mtRNA in tissues and cells. In addition, the whole expressive information of mtRNA from a tumor patient on just one slide can be obtained using this method, providing an effective method to investigate the relationship between mtDNA expression and tumorigenesis.

Expression Profiling of MicroRNAs in Hippocampus of Rats Following Traumatic Brain Injury

The changes of microRNA expression in rat hippocampus after traumatic brain injury（TBI） were explored. Adult SD rats received a single controlled cortical impact injury, and the ipsilateral hippocampus was harvested for the subsequent microarray assay at three time points after TBI： 1st day, 3rd day and 5th day, respectively. We characterized the microRNA expression profile in rat hippocampus using the microRNA microarray analysis, and further verified microarray results of miR-142-3p and miR-221 using quantitative real-time PCR. Totally 205 microRNAs were identified and up-/down-regu-lated more than 1.5 times. There were significant changes in 17 microRNAs at all three time points post-TBI. The quantitative real-time PCR results of miR-142-3p and miR-221 indicated good consistency with the results of the microarray method. MicroRNAs altered at different time points post-TBI. MiR-142-3p and miR-221 may be used as potentially biological markers for TBI assessment in forensic practice.

Human brain arteriovenous malformation:an analysis of differential expressed genes

Background:Much still remains unknown about the pathogenesis of brain arteriovenous malformations (AVMs).Previous studies have revealed the abnormal expression of various angiogenesis-related genes in AVMs.To further understand this disease,we sought to identify genes differently expressed in AVMs by means of the gene microarray technique.Methods:Nine AVMs specimen and nine samples of normal vessels are collected.Total RNA isolated from these specimen is hybridized with Oligonucleotide array and gene analysis was conducted.Analyzing data with the help of significance analysis of microarrays (SAM) and a free web-based molecular annotation system 3.0 (MAS 3.0).Results:The SAM method identify 37 gene significantly up-regulated and 10 genes down-regulated in AVMs.Conclusions:Among those genes,VACN,SPARK and ARHGAP18 seem to play a facilitating role during the genesis of AVMs.Multiple pathways,as MAPK pathway,may also be involved.