Curcumin inhibits colon cancer malignant progression and promotes T cell killing by regulating miR-206 expression.

Colon cancer is a great threat to human health. Curcumin, as a traditional Chinese medicine extract with anti-tumor and anti-inflammatory effects, can affect the development of diverse human diseases including cancer. The aim of this research was to probe the mechanism by which curcumin regulates colon cancer progression. Colon cancer cells were processed with graded concentrations of curcumin. The proliferation and apoptosis of the treated cells were determined by MTT, colony formation assay and flow cytometry. Expression of signaling pathway-related proteins and programmed death-ligand 1 (PD-L1) was measured by western blotting. The effect of curcumin on tumor cell growth was verified through T cell-mediated killing and ELISA assays. The relationship between target gene expression and the survival rate of colon cancer patients was analyzed by a survival curve. Curcumin treatment restrained proliferation and accelerated apoptosis of colon cancer cells. It elevated miR-206 expression, which in turn affected colon cancer cell function. miR-206 enhanced colon cancer cell apoptosis and inhibited PD-L1 expression; thus, curcumin enhanced the killing effect of T cells on tumor cells by suppressing PD-L1 through inhibiting the JAK/STAT3 pathway. Patients with high expression of miR-206 had better survival rates than those with low expression. Curcumin can regulate miR-206 expression and inhibit the malignant behavior of colon cancer cells and enhance T cell killing through the JAK/STAT3 pathway.

Effects of B-Wave Ultraviolet Supplementation Using Light-Emitting Diodes on Caged Laying Hens during the Later Phase of the Laying Cycle.

Caged laying hens are prone to calcium deficiencies, resulting in osteoporosis and egg quality deterioration during the later phase of the laying cycle. Fluorescent light and light-emitting diodes (LEDs), which are widely used in poultry houses now, are both deficient in ultraviolet (UV) light, the lack of which is detrimental to chickens' welfare and health. This study was conducted to investigate the effects of UVB light supplementation using LEDs on the bone traits, blood parameters, laying performance, and egg quality for caged laying hens at 68-75 weeks. In total, 120 Jingfen laying hens were randomly assigned to four different groups, with three replicates in each group (10 hens in each cage as a replicate). UVB-LED lamps installed under the feed troughs were used to provide UVB light (296-316 nm) for the birds in the three treatment groups (1 h, 2 h, and 3 h UVB supplementation per day, respectively), while the control group was not exposed to UVB-LED light. Bone traits, egg quality, and amounts of calcium (Ca), phosphorus (P), 25-hydroxyvitamin D3 (25(OH)D3), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and 7-dehydrocholesterol (7-DHC) in both the serum and egg yolks were tested during the experiment. The results demonstrated that UVB-LED exposure significantly increased the bone mineral density (BMD), egg production, and yolk 1,25(OH)2D3 concentrations (p < 0.05), and reduced the content of serum 7-DHC (p < 0.05), especially in the 2 h/day group; however, it did not improve egg quality, vitamin D metabolites, or photoproducts in the serum and yolk 25(OH)2D3 concentrations (p > 0.05). This study concluded that UVB supplementation using LEDs had a positive effect on caged laying hens during the later phase of the laying cycle.

Difference and Influence of Inactive and Active States of Cannabinoid Receptor Subtype CB2: From Conformation to Drug Discovery.

Cannabinoid receptor 2 (CB2), a G protein-coupled receptor (GPCR), is a promising target for the treatment of neuropathic pain, osteoporosis, immune system, cancer, and drug abuse. The lack of an experimental three-dimensional CB2 structure has hindered not only the development of studies of conformational differences between the inactive and active CB2 but also the rational discovery of novel functional compounds targeting CB2. In this work, we constructed models of both inactive and active CB2 by homology modeling. Then we conducted two comparative 100 ns molecular dynamics (MD) simulations on the two systems-the active CB2 bound with both the agonist and G protein and the inactive CB2 bound with inverse agonist-to analyze the conformational difference of CB2 proteins and the key residues involved in molecular recognition. Our results showed that the inactive CB2 and the inverse agonist remained stable during the MD simulation. However, during the MD simulations, we observed dynamical details about the breakdown of the "ionic lock" between R131(3.50) and D240(6.30) as well as the outward/inward movements of transmembrane domains of the active CB2 that bind with G proteins and agonist (TM5, TM6, and TM7). All of these results are congruent with the experimental data and recent reports. Moreover, our results indicate that W258(6.48) in TM6 and residues in TM4 (V164(4.56)-L169(4.61)) contribute greatly to the binding of the agonist on the basis of the binding energy decomposition, while residues S180-F183 in extracellular loop 2 (ECL2) may be of importance in recognition of the inverse agonist. Furthermore, pharmacophore modeling and virtual screening were carried out for the inactive and active CB2 models in parallel. Among all 10 hits, two compounds exhibited novel scaffolds and can be used as novel chemical probes for future studies of CB2. Importantly, our studies show that the hits obtained from the inactive CB2 model mainly act as inverse agonist(s) or neutral antagonist(s) at low concentration. Moreover, the hit from the active CB2 model also behaves as a neutral antagonist at low concentration. Our studies provide new insight leading to a better understanding of the structural and conformational differences between two states of CB2 and illuminate the effects of structure on virtual screening and drug design.

Target-selective phototherapy using a ligand-based photosensitizer for type 2 cannabinoid receptor.

Phototherapy is a powerful, noninvasive approach for cancer treatment, with several agents currently in clinical use. Despite the progress and promise, most current phototherapy agents have serious side effects as they can lead to damage to healthy tissue, even when the photosensitizers are fused to targeting molecules due to nonspecific light activation of the unbound photosensitizer. To overcome these limitations, we developed a phototherapy agent that combines a functional ligand and a near infrared phthalocyanine dye. Our target is type 2 cannabinoid receptor (CB2R), considered an attractive therapeutic target for phototherapy given it is overexpressed by many types of cancers that are located at a surface or can be reached by an endoscope. We show that our CB2R-targeted phototherapy agent, IR700DX-mbc94, is specific for CB2R and effective only when bound to the target receptor. Overall, this opens up the opportunity for development of an alternative treatment option for CB2R-positive cancers.

Interaction of TRPC2 and TRPC6 in erythropoietin modulation of calcium influx.

Erythropoietin (Epo) modulates calcium influx through voltage-independent calcium-permeable channel(s). Here, we characterized the expression of transient receptor potential channels (TRPCs) in primary erythroid cells and examined their regulation. Erythroblasts were isolated from the spleens of phenylhydrazine-treated mice, and Epo stimulation resulted in a significant and dose-dependent increase in [Ca](i). Among the classical TRPC channels, expression of three N-terminal splice variants of TRPC2 (clones 14, 17, and alpha) and of TRPC6 were demonstrated in these erythroblasts by both reverse transcriptase-PCR and Western blotting. Confocal microscopy confirmed localization to the plasma membrane. To determine the function of individual TRPC channels in erythropoietin modulation of calcium influx, digital video imaging was used to measure calcium influx through these TRPCs in a Chinese hamster ovary (CHO) cell model. Single CHO-S cells, expressing transfected Epo-R, were identified by detection of green fluorescent protein. Cells that express transfected TRPCs were identified by detection of blue fluorescent protein. [Ca](i) was monitored with Fura Red. Epo stimulation of CHO-S cells transfected with single TRPC2 isoforms (clone 14, 17, or alpha) and Epo-R resulted in a significant increase in [Ca](i). This was not observed in cells transfected with Epo-R and TRPC6. In addition, coexpression of TRPC6 with TRPC2 and Epo-R inhibited the increase in [Ca](i) observed after Epo stimulation. Immunoprecipitation experiments demonstrated that TRPC2 associates with TRPC6, indicating that these TRPCs can form multimeric channels. These data demonstrate that specific TRPCs are expressed in primary erythroid cells and that two of these channels, TRPC2 and TRPC6, can interact to modulate calcium influx stimulated by erythropoietin.