Optimized screening of DNA methylation sites combined with gene expression analysis to identify diagnostic markers of colorectal cancer.

BACKGROUND: The prognosis of patients with colorectal cancer is related to early detection. However, commonly used screening markers lack sensitivity and specificity. In this study, we identified diagnostic methylation sites for colorectal cancer. METHODS: After screening the colorectal cancer methylation dataset, diagnostic sites were identified via survival analysis, difference analysis, and ridge regression dimensionality reduction. The correlation between the selected methylation sites and the estimation of immune cell infiltration was analyzed. The accuracy of the diagnosis was verified using different datasets and the 10-fold crossover method. RESULTS: According to Gene Ontology, the main enrichment pathways of genes with hypermethylation sites are axon development, axonogenesis, and pattern specification processes. However, the Kyoto Encyclopedia of Genes and Genomes (KEGG) suggests the following main enrichment pathways: neuroactive ligand-receptor interaction, calcium signaling, and cAMP signaling. In The Cancer Genome Atlas (TCGA) and GSE131013 datasets, the area under the curve of cg07628404 was > 0.95. For the NaiveBayes machine model of cg02604524, cg07628404, and cg27364741, the accuracies of 10-fold cross-validation in the GSE131013 and TCGA datasets were 95% and 99.4%, respectively. The survival prognosis of the hypomethylated group (cg02604524, cg07628404, and cg27364741) was better than that of the hypermethylated group. The mutation risk did not differ between the hypermethylated and hypomethylated groups. The correlation coefficient between the three loci and CD4 central memory T cells, hematological stem cells, and other immune cells was not high (p < 0.05). CONCLUSION: In cases of colorectal cancer, the main enrichment pathway of genes with hypermethylated sites was axon and nerve development. In the biopsy tissues, the hypermethylation sites were diagnostic for colorectal cancer, and the NaiveBayes machine model of the three loci showed good diagnostic performance. Site (cg02604524, cg07628404, and cg27364741) hypermethylation predicts poor survival for colorectal cancer. Three methylation sites were weakly correlated with individual immune cell infiltration. Hypermethylation sites may be a useful repository for diagnosing colorectal cancer.

Simple and Commercially Available 6-chloroimidazo[1,2-a]pyridine-2-carboxylic Acid-based Fluorescent Probe for Monitoring pH Changes.

Commercially available compounds that can be directly used as fluorescent probes will greatly promote the development of fluorescent imaging. Based on our previously work related to nitrogen bridgehead heterocycles, herein, a commercially available compound, 6-chloroimidazo[1,2-a]pyridine-2-carboxylic acid, has been detected for monitoring pH value (3.0-7.0). The probe proves to have high selectivity and sensitivity, brilliant reversibility, and extremely short response time. The real-time imaging of pH changes in yeast was also conducted.

Inhibited CD47 gene affects the clearance of acute myelogenous leukemia stem cells.

OBJECTIVE: To investigate the effect of targeted inhibition of CD47 gene expression on stem cell clearance in acute myeloid leukemia. METHODS: After the lentiviral CD47-siRNA was transfected into acute myelogenous leukemia stem cells (LSCs), the proliferative status of acute myelogenous LSCs was detected by cell counting kit-8, and the apoptosis of stem cells of acute myeloid leukemia was detected by annexin/propidium iodide flow assays. The expression of Bcl-2, Bcl-xl, MCL-1, PIK3p110ß, and interleukin (IL)-3 in acute myeloid LSCs was detected by Western blot analysis and the activity of protein phosphatase 2A (PP2A) and the protein content of CD96 and CD90 were measured by enzyme-linked immunosorbent assay kits. RESULTS: After transfection of the lentivirus CD47-siRNA into acute myeloid LSCs, compared with the empty vector transfection group (control group), the cell viability of the CD47-siRNA transfection group was decreased, and the apoptosis rate was increased. Furthermore, the antiapoptotic protein Bcl-2, Bcl-xl, and MCL-1 and the content of IL-3 protein, CD96, and CD90 was decreased, whereas the activity of PIK3p110ß and PP2A protein was increased. CONCLUSION: Targeted inhibition of CD47 could inhibit the proliferation of myeloid LSCs, promote apoptosis, mobilize the cells into the cell cycle, and reduce the high expression of immune proteins on the cell surface, therefore providing a theoretical basis for the elimination and eradication of LSCs.

A FRET-based ratiometric fluorescent probe for detection of intrinsically generated SO2 derivatives in mitochondria.

A mitochondria-targeted ratiometric fluorescent probe based on hemicyanine and pyrido[1,2-a]benzimidazole was presented. It shows high sensitivity and selectivity toward SO2 in pure water. The limit of detection (LOD) was as low as 26.7 nM, which is superior to most reported probes. Most importantly, the probe was successfully used for fluorescence imaging of endogenous bisulfite in mitochondria in Glioma cells.

MicroRNA-331 inhibits development of gastric cancer through targeting musashi1.

BACKGROUND: The molecular mechanisms involved in microRNAs (miRNAs) have been extensively investigated in gastric cancer (GC). However, how miR-331 regulates GC pathogenesis remains unknown. AIM: To illuminate the effect of miR-331 on cell metastasis and tumor growth in GC. METHODS: The qRT-PCR, CCK8, Transwell, cell adhesion, Western blot, luciferase reporter and xenograft tumor formation assays were applied to explore the regulatory mechanism of miR-331 in GC. RESULTS: Downregulation of miR-331 associated with poor prognosis was detected in GC. Functionally, miR-331 suppressed cell proliferation, metastasis and tumor growth in GC. Further, miR-331 was verified to directly target musashi1 (MSI1). In addition, miR-331 inversely regulated MSI1 expression in GC tissues. Furthermore, upregulation of MSI1 weakened the inhibitory effect of miR-331 in GC. CONCLUSION: miR-331 inhibited development of GC through targeting MSI1, which may be used as an indicator for the prediction and prognosis of GC.

[Spatial profile of radiation from the plasma induced by laser-ablated aluminum].

The plasma was acquired with a pulsed Nd:YAG laser beam ablating aluminum. The pulse energy was set up to 145 mJ per pulse. Ar was used as surrounding gas with the pressure of 100 kPa. The radiation of the plasma was recorded with time- and space-resolved technique, so we obtained time-resolved, in 10(-9) s, spectra of the plasma radiation in front of the surface at 0.5 mm, 1.5 mm, 2.5 mm and 3.5 mm, respectively. Based on the spectra, we briefly discussed the characteristics of the plasma radiation in each zone, and studied the behavior of the continuum and aluminum radiation in detail, so the spatial profile of the plasma was obtained. As we found, at the beginning of the plasma coming into being, the radiation of the plasma was dominated by continuum radiation, but aluminum radiation became dominant later. Characteristic and ion radiation was much weaker than continuum radiation. The aluminum radiation lasted much longer than continuum and ion radiation. As a result, it was suggested that the absorption of continuum radiation of plasma by aluminum atoms should be the main mechanism for the formation of the aluminum double lines and the broad absorbtion spectra.