Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide, with an increasing prevalence. The 5-year relative survival rate for advanced stages is very low, with only 14% for stage IV. However, that of the early stage of CRC is about 90%. Therefore, it is important to screen CRC in the early stage. Epigenetic alterations linked to the carcinogenesis of CRC have been shown to occur earlier and more frequently than genetic alterations in CRC. Here, our study aims to develop a CRC screening methodology by applying the multiplex methylation specific PCR (MMSP) assay to detect CRC-specific methylation biomarkers, which has been pre-selected from public databases and subsequently validated in CRC samples of the Chinese population. Experimentally, cell free DNA (cfDNA) is extracted from ~4ml peripheral blood plasma. Following bisulfite conversion of the cfDNA, MMSP were applied to amplify and detect CRC-specific methylated CpG sites within the cfDNA. From the results of 28 CRCs and 52 control specimens, a sensitivity of 85.7% and the a specificity of 92.3% was achieved. Current standard and most widely used method of detecting CRC is colonoscopy screening. However, colonoscopy requires bowel preparation, and the sedation for patients is a complex and time-consuming procedure with high cost. Additionally, this invasive method also increases the possibility of infection and complications and patient compliance still largely remains a problem. Our non-invasive MMSP assay therefore provides an alternative non-invasive screening option that is cost-effective, meeting the urgent demand of early CRC detection. In addition, because colonoscopy screening currently has low adherence in Chinese population, our method holds great potential for increasing CRC screening rate in China.Citation Format: Lili Ye, Chunting Zheng, Yuan Jie, Bin Li, Yuan Li, Kunling Hu, Liuhong Zeng, Yuying Wang, Mao Mao, Peirong Ding, Taiping Shi, Mingzhi Ye. Non-invasive detection of aberrant DNA methylation in colorectal cancer by multiplex methylation specific PCR [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3324.
Fruit ripening is a complicated process that is accompanied by the formation of fruit quality. It is not only regulated at the transcriptional level via transcription factors or DNA methylation but also fine-tuned after transcription occurs. Here, we review recent advances in our understanding of key regulatory mechanisms of fleshy fruit ripening after transcription. We mainly highlight the typical mechanisms by which fruit ripening is controlled, namely, alternative splicing, mRNA N6-methyladenosine RNA modification methylation, and noncoding RNAs at the posttranscriptional level; regulation of translation efficiency and upstream open reading frame-mediated translational repression at the translational level; and histone modifications, protein phosphorylation, and protein ubiquitination at the posttranslational level. Taken together, these posttranscriptional regulatory mechanisms, along with transcriptional regulation, constitute the molecular framework of fruit ripening. We also critically discuss the potential usage of some mechanisms to improve fruit traits.
Four compounds that contained the N-benzyl 2-amino-3-methoxypropionamide unit were evaluated for their ability to modulate Na(+) currents in catecholamine A differentiated CAD neuronal cells. The compounds differed by the absence or presence of either a terminal N-acetyl group or a (3-fluoro)benzyloxy moiety positioned at the 4'-benzylamide site. Analysis of whole-cell patch-clamp electrophysiology data showed that the incorporation of the (3-fluoro)benzyloxy unit, to give the (3-fluoro)benzyloxyphenyl pharmacophore, dramatically enhanced the magnitude of Na(+) channel slow inactivation. In addition, N-acetylation markedly increased the stereoselectivity for Na(+) channel slow inactivation. Furthermore, we observed that Na(+) channel frequency (use)-dependent block was maintained upon inclusion of this pharmacophore. Confirmation of the importance of the (3-fluoro)benzyloxyphenyl pharmacophore was shown by examining compounds where the N-benzyl 2-amino-3-methoxypropionamide unit was replaced by a N-benzyl 2-amino-3-methylpropionamide moiety, as well as examining a series of compounds that did not contain an amino acid group but retained the pharmacophore unit. Collectively, the data indicated that the (3-fluoro)benzyloxyphenyl unit is a novel pharmacophore for the modulation of Na(+) currents.
Body axial patterning develops via a rostral-to-caudal sequence and relies on the temporal colinear activation of Hox genes. However, the underlying mechanism of Hox gene temporal colinear activation remains largely elusive. Here, with small-molecule inhibitors and conditional gene knockout mice, we identified Jmjd3, a subunit of TrxG, as an essential regulator of temporal colinear activation of Hox genes with its H3K27me3 demethylase activity. We demonstrated that Jmjd3 not only initiates but also maintains the temporal collinear expression of Hox genes. However, we detected no antagonistic roles between Jmjd3 and Ezh2, a core subunit of PcG repressive complex 2, during the processes of axial skeletal patterning. Our findings provide new insights into the regulation of Hox gene temporal collinear activation for body axial patterning in mice.
Myocardial ischemia-reperfusion (I/R) is a serious and irreversible injury. Bone marrow-derived mesenchymal stem cells (MSCs) is considered to be a potential therapy for I/R injury due to the paracrine effects. High-mobility group box 1 (HMGB1) is a novel mediator in MSC and regulates the response of inflammation injury. Signal Transduction and Transcription Activator 3 (STAT3) is a critical transcription factor and important for release of paracrine factors. However, the relationship between HMGB1 and STAT3 in paracrine effect of MSC remains unknown. In vitro , Hypoxia/Reoxygenation injury model was established by AnaeroPack System and examined by Annexin V flow cytometry, CCK8 assay and morphology observation. Detection of apoptotic proteins and protein expression of HMGB1 and STAT3 by Western blot. The conditioned medium of MSC with or without LPS pretreatment was cocultured with H9c2 cells for 24h before hypoxia treatment and MSC showed obvious cardiomyocytes protect role, as evidence by decreased apoptosis rate and improved cells viability, and LPS pretreated MSC exhibited better protect role than untreated MSC. However, such effect was abolished in HMGB1 deficiency group, silencing HMGB1 decreased the secretion of VEGF, HGF, IGF, cell viability, and the expression of STAT3. Furthermore, STAT3 silence attenuated the protective effect of LPS in MSC. Collectively, these findings suggested that LPS improved MSC-mediated cardiomyocytes protection by HMGB1/STAT3 signaling.