Modulation of miR-139-5p on chronic morphine-induced, naloxone-precipitated cAMP overshoot in vitro

β-Elemene Improves Morphine Tolerance in Bone Cancer Pain via N-Methyl-D-Aspartate Receptor 2B Subunit-Mediated μ-Opioid Receptor

Background

Improving morphine tolerance (MT) is an urgent problem in the clinical treatment of bone cancer pain. Considering that β-Elemene is widely used in the treatment of cancer pain, we explored the effects and mechanism of β-Elemene in preventing MT of bone cancer pain.

Method

Bone cancer pain and chronic MT rat model was established by injecting MADB106 cells and morphine (10 mg/kg). SH-SY5Y cells were treated with morphine (10 μg/mL) for 48 h to establish a cell model. The mechanical withdrawal threshold and thermal withdrawal latency of rats were detected by mechanical allodynia and thermal hyperalgesia tests, respectively. The protein expressions of μ-opioid receptor (MOPR), cyclic adenosine monophosphate (cAMP), N-methyl-D-aspartate receptor subunit 2B (NR2B), phosphorylated-calmodulin-dependent protein kinase II (p-CaMKII), and CaMKII were detected by western blot. The viability of SH-SY5Y cells was determined by the cell counting kit-8 assay. cAMP content in SH-SY5Y cells was measured by a LANCE cAMP kit.

Result

Animal experiments showed that MT strengthened over time, while increased β-Elemene dosage alleviated MT. The viability of SH-SY5Y cells was down-regulated by high-dose β-Elemene. In the rat and cell models, long-term morphine treatment decreased the expression of MOPR and increased the cAMP and NR2B expressions and p-CaMKII/CaMKII, while β-Elemene and siNR2B counteracted the effects of morphine treatment. In addition, siNR2B reversed the effects of β-Elemene on related protein expressions and cAMP content in the cell model.

Conclusion

β-Elemene improved MT in bone cancer pain through the regulation of NR2B-mediated MOPR.

LncRNA RP11‑805J14.5 functions as a ceRNA to regulate CCND2 by sponging miR‑34b‑3p and miR‑139‑5p in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common lung cancer with high incidence. The prognosis of LUAD is poor due to its aggressive behavior. Long non‑coding RNAs (lncRNAs) have been reported as a key modulator on LUAD progression. Therefore, the present study aimed to clarify the molecular mechanism of lncRNAs in LUAD development. The expression of lncRNA RP11‑805J14.5 (RP11‑805J14.5) in LUAD tissues and cells was quantified based on the data in The Cancer Genome Atlas (TCGA). Cell viability was determined using Cell Counting Kit‑8 method. Apoptotic cells were sorted and determined by flow cytometry. Cell migration and invasion abilities were detected by the Transwell assay. Luciferase reporter experiment and RNA pull‑down assay were utilized to determine the interactions between RP11‑805J14.5, microRNA (miR)‑34b‑3p, miR‑139‑5p, and cyclin D2 (CCND2). A xenograft tumor was established to determine tumor growth in vivo. RP11‑805J14.5 was highly expressed in LUAD and associated with poor survival of LUAD patients. Knockdown of RP11‑805J14.5 suppressed LUAD cell growth, invasion, migration and tumor growth, indicating that RP11‑805J14.5 is an important regulator of LUAD. Our study demonstrated that the regulation of RP11‑805J14.5 on LUAD was mediated by CCND2 whose expression was regulated by sponging miR‑34b‑3p and miR‑139‑5p. The expression of RP11‑805J14.5 was increased in LUAD, and the knockdown of RP11‑805J14.5 expression suppressed LUAD cell growth, invasion and migration by downregulating CCND2 by sponging miR‑34b‑3p and miR‑139‑5p, indicating that RP11‑805J14.5 could be a prospective target for LUAD therapy.

Comprehensive Signaling Profiles Reveal Unsuspected Functional Selectivity of δ-Opioid Receptor Agonists and Allow the Identification of Ligands with the Greatest Potential for Inducing Cyclase Superactivation

Prolonged exposure to opioid receptor agonists triggers adaptations in the adenylyl cyclase (AC) pathway that lead to enhanced production of cyclic adenosine monophosphate (cAMP) upon withdrawal. This cellular phenomenon contributes to withdrawal symptoms, hyperalgesia and analgesic tolerance that interfere with clinical management of chronic pain syndromes. Since δ-opioid receptors (DOPrs) are a promising target for chronic pain management, we were interested in finding out if cell-based signaling profiles as generated for drug discovery purposes could inform us of the ligand potential to induce sensitization of the cyclase path. For this purpose, signaling of DOPr agonists was monitored at multiple effectors. The resulting signaling profiles revealed marked functional selectivity, particularly for Met-enkephalin (Met-ENK) whose signaling bias profile differed from those of synthetic ligands like SNC-80 and ARM390. Signaling diversity among ligands was systematized by clustering agonists according to similarities in E_max and Log(τ) values for the different responses. The classification process revealed that the similarity in Gα/Gβγ, but not in β-arrestin (βarr), responses was correlated with the potential of Met-ENK, deltorphin II, (d-penicillamine2,5)-enkephalin (DPDPE), ARM390, and SNC-80 to enhance cAMP production, all of which required Ca²⁺ mobilization to produce this response. Moreover, superactivation by Met-ENK, which was the most-effective Ca²⁺ mobilizing agonist, required Gαi/o activation, availability of Gβγ subunits at the membrane, and activation of Ca²⁺ effectors such as calmodulin and protein kinase C (PKC). In contrast, superactivation by (N-(l-tyrosyl)-(3S)-1,2,3,4-tetrahydroisoquinoline-3-carbonyl)-l-phenylalanyl-l-phenylalanine (TIPP), which was set in a distinct category through clustering, required activation of Gαi/o subunits but was independent of the Gβγ dimer and Ca²⁺ mobilization, relying instead on Src and Raf-1 to induce this cellular adaptation.

Endogenous Opiates and Behavior: 2018

This paper is the forty-first consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2018 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (2), the roles of these opioid peptides and receptors in pain and analgesia in animals (3) and humans (4), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (5), opioid peptide and receptor involvement in tolerance and dependence (6), stress and social status (7), learning and memory (8), eating and drinking (9), drug abuse and alcohol (10), sexual activity and hormones, pregnancy, development and endocrinology (11), mental illness and mood (12), seizures and neurologic disorders (13), electrical-related activity and neurophysiology (14), general activity and locomotion (15), gastrointestinal, renal and hepatic functions (16), cardiovascular responses (17), respiration and thermoregulation (18), and immunological responses (19).

Morphine contributed to the deterioration of cancer via miR-543/MARCKS/FcγR-mediated phagocytosis pathway

OBJECTIVES

It has been confirmed that morphine was detrimental to patients with cancers. Hence, we aimed to reveal a certain mechanism of morphine in cancer development.

METHODS

Microarray and GSEA analysis were utilized to seek for differently expressed genes and pathway.

KEY FINDINGS

Bioinformatics analysis identified that downregulation of MARCKS and upregulation of miR-543 in samples treated with morphine. FcγR-mediated phagocytosis pathway was illustrated to be upregulated in the control. PANC-1 and DU145 cell viability was increased but apoptosis was declined as morphine concentration went up from 10^-8 to 10^-6  mol/l. On the other curve, the viability was reduced and apoptosis was elevated from 10^-6 to 10^-5  mol/l. The expression of miR-543 ran the same trend as cell viability. Assays in vivo and in vitro validated that miR-543 facilitated cell viability, tumour growth, levels of CA199 and PSA, whereas inhibited apoptosis. MARCKS could target and inhibit miR-543 expression, which exhibited an opposite effect on cancer progression. MiR-543 blocked but MARCKS activated FcγR-mediated phagocytosis pathway.

CONCLUSIONS

Morphine at 10^-6  mol/l could benefit miR-543 expression to inhibit MARCKS expression, consequently, blocking FcγR-mediated phagocytosis pathway, which contributed to the cancer progression in vitro and in vivo.