RNAi targeting of CCR2 gene expression induces apoptosis and inhibits the proliferation, migration, and invasion of PC-3M cells

Identification of microRNA-21 target genes associated with hair follicle development in sheep

Aim

The target molecule regulatory function of microRNA-21 (miR-21) in multiple signalling pathways has become a main focus of genetic and pharmacological regulatory studies of various diseases. The identification of target genes for miRNA-21 in the development of hair follicles can provide new research pathways for the regulation of cell development.

Methods

In the present study, eight six-month-old ewes from Super Merino (SM) and Small Tailed Han (STH) sheep breeds were selected. Target prediction and dual-luciferase wild-type and mutant vectors were used to identify the target genes of miR-21. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) and bioinformatics analysis were conducted to analyze the effects of miR-21.

Results

The results show that the expressions of CNKSR2, KLF3 and TNPO1 were downregulated by miRNA-21 at rates of 36%, 26% and 48%, respectively. Moreover, there was a significant negative correlation between the expression of miR-21 and the three target genes in sheep with two extreme phenotypes. The expression of microRNA-21in October was significantly lower than that in January and February; while the expression of CNKSR2, KLF3 and TNPO1 in October was higher than that in January and February. Conclusions: These results suggest that CNKSR2, KLF3 and TNPO1 are three newly discovered target genes of miR-21 and might be involved in the effects of miR-21 on hair follicle development.

Exploring new biomarkers in the tumour microenvironment of canine inflammatory mammary tumours

Human inflammatory breast cancer (IBC) and canine inflammatory mammary cancer (CIMC) are the most aggressive forms of mammary cancer. Current research aims to identify new therapeutic targets. Here, we investigated gene expression levels of biomarkers associated with the inflammatory microenvironment. A total of 32 formalin-fixed paraffin-embedded samples of canine mammary carcinoma (CIMC = 26; non-CIMC = 6) were used and their cDNA subjected to quantitative polymerase chain reaction (qPCR) to establish gene expression levels for mediators commonly implicated in linking carcinogenesis with inflammation. Gene expression differences between CIMC and non-CIMC types were obtained for cyclooxygenase 2 (COX-2) (P = 0.004), synuclein gamma (SNCG) (P = 0.006), tribbles 1 (P = 0.025), vascular endothelial growth factor (VEGF) (P = 0.017) and CSF1R (P = 0.045). Among these biomarkers correlations were found, particularly between SNCG and tribbles 1 (r = 0.512, P = 0.001). The efficient metastasis of CIMC is intimately linked to components in the tumour microenvironment. This study suggests that upregulation and correlation of SNCG and tribbles 1 deserves to be further explored.

N-methyl-N-nitro-N'-nitrosoguanidine induces the expression of CCR2 in human gastric epithelial cells promoting CCL2-mediated migration

Chronic inflammation has a decisive role in tumorigenesis, particularly in gastric carcinogenesis. The CC chemokine ligand 2 (CCL2), an important inflammatory cytokine, is involved in the initiation, development and progression of various types of cancer. However, the role of CCL2 in gastric cancer remains to be elucidated. The present study demonstrated that recombinant CCL2 stimulation caused no effect on the morphology, proliferation and migration of human GES-1 gastric mucosa epithelial cells, in which the protein expression of CC-chemokine receptor 2 (CCR2) was markedly low. However, the expression of CCR2 was significantly upregulated in the GES-1 cells following pretreatment with the chemical carcinogen, N-methyl-N-nitro-N′-nitrosoguanidine (MNNG), for 12 h or transformed with MNNG (MC cells). The present study used CCL2 to stimulate MNNG pretreated GES-1 cells and MC cells, and demonstrated that CCL2 clearly promoted their migration and the epithelial-mesenchymal transition (EMT). However, no effect was observed on the proliferative ability of the cells. Taken together, these findings suggested that the CCL2/CCR2 chemokine signaling may regulate the EMT in gastric epithelial cells and resulted in gastric carcinogenesis in response to the intake of the carcinogen, MNNG.

pGlu-serpinin protects the normotensive and hypertensive heart from ischemic injury

Serpinin peptides derive from proteolytic cleavage of Chromogranin-A at C-terminus. Serpinin and the more potent pyroglutaminated-serpinin (pGlu-Serp) are positive cardiac β-adrenergic-like modulators, acting through β1-AR/AC/cAMP/PKA pathway. Because in some conditions this pathway and/or other pro-survival pathways, activated by other Chromogranin-A fragments, may cross-talk and may be protective, here we explored whether pGlu-Serp cardioprotects against ischemia/reperfusion injury under normotensive and hypertensive conditions. In the latter condition, cardioprotection is often blunted because of the limitations on pro-survival Reperfusion Injury Salvage Kinases (RISK) pathway activation. The effects of pGlu-Serp were evaluated on infarct size (IS) and cardiac function by using the isolated and Langendorff perfused heart of normotensive (Wistar Kyoto, WKY) and spontaneously hypertensive (SHR) rats exposed to ischemic pre-conditioning (PreC) and post-conditioning (PostC). In both WKY and SHR rat, pGlu-Serp induced mild cardioprotection in both PreC and PostC. pGlu-Serp administered at the reperfusion (Serp-PostC) significantly reduced IS, being more protective in SHR than in WKY. Conversely, left ventricular developed pressure (LVDevP) post-ischemic recovery was greater in WKY than in SHR. pGlu-Serp-PostC reduced contracture in both strains. Co-infusion with specific RISK inhibitors (PI3K/Akt, MitoKATP channels and PKC) blocked the pGlu-Serp-PostC protective effects. To show direct effect on cardiomyocytes, we pre-treated H9c2 cells with pGlu-Serp, which were thus protected against hypoxia/reoxygenation. These results suggest pGlu-Serp as a potential modulatory agent implicated in the protective processes that can limit infarct size and overcome the hypertension-induced failure of PostC.

The role of chemoattractant receptors in shaping the tumor microenvironment

Chemoattractant receptors are a family of seven transmembrane G protein coupled receptors (GPCRs) initially found to mediate the chemotaxis and activation of immune cells. During the past decades, the functions of these GPCRs have been discovered to not only regulate leukocyte trafficking and promote immune responses, but also play important roles in homeostasis, development, angiogenesis, and tumor progression. Accumulating evidence indicates that chemoattractant GPCRs and their ligands promote the progression of malignant tumors based on their capacity to orchestrate the infiltration of the tumor microenvironment by immune cells, endothelial cells, fibroblasts, and mesenchymal cells. This facilitates the interaction of tumor cells with host cells, tumor cells with tumor cells, and host cells with host cells to provide a basis for the expansion of established tumors and development of distant metastasis. In addition, many malignant tumors of the nonhematopoietic origin express multiple chemoattractant GPCRs that increase the invasiveness and metastasis of tumor cells. Therefore, GPCRs and their ligands constitute targets for the development of novel antitumor therapeutics.