Genome-wide identification and analysis of high-affinity nitrate transporter 2 (NRT2) family genes in rapeseed (Brassica napus L.) and their responses to various stresses.

BACKGROUND: High-affinity nitrate transporter 2 (NRT2) genes have been implicated in nitrate absorption and remobilization under nitrogen (N) starvation stress in many plant species, yet little is known about this gene family respond to various stresses often occurs in the production of rapeseed (Brassica napus L.). RESULTS: This report details identification of 17 NRT2 gene family members in rapeseed, as well as, assessment of their expression profiles using RNA-seq analysis and qRT-PCR assays. In this study, all BnNRT2.1 members, BnNRT2.2a and BnNRT2.4a were specifically expressed in root tissues, while BnNRT2.7a and BnNRT2.7b were mainly expressed in aerial parts, including as the predominantly expressed NRT2 genes detected in seeds. This pattern of shoot NRT expression, along with homology to an Arabidopsis NRT expressed in seeds, strongly suggests that both BnNRT2.7 genes play roles in seed nitrate accumulation. Another rapeseed NRT, BnNRT2.5 s, exhibited intermediate expression, with transcripts detected in both shoot and root tissues. Functionality of BnNRT2s genes was further outlined by testing for adaptive responses in expression to exposure to a series of environmental stresses, including N, phosphorus (P) or potassium (K) deficiency, waterlogging and drought. In these tests, most NRT2 gene members were up-regulated by N starvation and restricted by the other stresses tested herein. In contrast to this overall trend, transcription of BnNRT2.1a was up-regulated under waterlogging and K deficiency stress, and BnNRT2.5 s was up-regulated in roots subjected to waterlogging. Furthermore, the mRNA levels of BnNRT2.7 s were enhanced under both waterlogging stress and P or K deficiency conditions. These results suggest that these three BnNRT2 genes might participate in crosstalk among different stress response pathways. CONCLUSIONS: The results presented here outline a diverse set of NRT2 genes present in the rapeseed genome that collectively carry out specific functions throughout rapeseed development, while also responding not just to N deficiency, but also to several other stresses. Targeting of individual BnNRT2 members that coordinate rapeseed nitrate uptake and transport in response to cues from multiple stress response pathways could significantly expand the genetic resources available for improving rapeseed resistance to environmental stresses.

Apigenin inhibits epithelial-mesenchymal transition of human colon cancer cells through NF-κB/Snail signaling pathway.

Colon cancer is a leading cause of cancer-related deaths worldwide. The epithelial-mesenchymal transition (EMT) plays an important role in tumor metastasis of colon cancer. We first evaluated the effects of EMT-related transcription factors on the prognosis of colon cancer through analysis the data obtained from The Cancer Genome Atlas (TCGA). And then we screened a series of Chinese medicine monomers to find effect EMT inhibitors. First, Snail is a more important EMT transcription factors for colon cancer prognosis, compared with Twist and Slug. Then, we found that apigenin effectively inhibits the activity of Snail. Apigenin could inhibit the EMT, migration, and invasion of human colon cancer cells in vitro and in vivo through the NF-κB/Snail pathway. Snail is a key regulator of EMT in colon cancer and Snail inhibitor apigenin may be a therapeutic application for patients with colon cancer.

FKBP3 mediates oxaliplatin resistance in colorectal cancer cells by regulating HDAC2 expression.

Colorectal cancer (CRC), a commonly occurring malignant tumor in the gastrointestinal tract, is the third leading cause of cancer­related deaths worldwide. FK506­binding proteins (FKBPs) comprise an immunophilin family that are involved in the carcinogenesis, progression and chemoresistance of cancers, including CRC. FKBP3 (also known as FKBP25) is a nuclear protein that is a member of the FKBP family and is correlated with the activity of histone deacetylase 2 (HDAC2). However, the role of FKBP3 and HDAC2 in oxaliplatin resistance in CRC and the potential molecular mechanisms are still poorly understood. In the present study, the expression of FKBP3, HDAC2 and related­genes was detected by real­time PCR and western blot analysis. Furthermore, cell apoptosis was detected by flow cytometry (FCM). We found high expression of FKBP3 and HDAC2 in CRC tissues. In vitro, primary CRC cells with high expression of FKBP3 and HDAC2 were insensitive to oxaliplatin. Downregulation of FKBP3 significantly increased the sensitivity of primary CRC cells to oxaliplatin, reduced expression of HDAC2, permeability glycoprotein (P­gp) and phosphorylated AKT (p­AKT), and increased expression of phosphatase and tensin homolog (PTEN) and cleaved caspase­3. Accordingly, upregulation of FKBP3 had the opposite effect. Furthermore, downregulation of HDAC2 significantly counteracted FKBP3­induced oxaliplatin resistance in CRC cells. Our data revealed that oxaliplatin resistance in CRC cells is positively associated with FKBP3 and HDAC2 expression, and FKBP3 downregulation could attenuate oxaliplatin resistance in CRC cells by reducing HDAC2 expression and possibly through regulation of the PTEN/AKT pathway.

Molecular Role of EGFR-MAPK Pathway in Patchouli Alcohol-Induced Apoptosis and Cell Cycle Arrest on A549 Cells In Vitro and In Vivo.

Nowadays, chemotherapy is still the main effective treatment for cancer. Herb prescriptions containing Pogostemon cablin Benth (also known as "Guang-Huo-Xiang") have been widely used in Chinese medicine today. In our research, we found that patchouli alcohol, a compound isolated from the oil of Pogostemon cablin Benth, exerted antitumor ability against human lung cancer A549 cells ability both in vitro and in vivo. MTT assay was used to assess cell viability. Hoechst 33342 staining and TUNEL cover glass staining provided the visual evidence of apoptosis. Caspase activity measurement showed that patchouli alcohol activated caspase 9 and caspase 3 of mitochondria-mediated apoptosis. Consistently, patchouli alcohol inhibited the xenograft tumor in vivo. Further investigation of the underlying molecular mechanism showed that MAPK and EGFR pathway might contribute to the antitumor effect of patchouli alcohol. Our study proved that patchouli alcohol might be able to serve as a novel antitumor compound in the clinical treatment of lung cancer.