BackgroundThe detection of circulating tumor cells (CTCs) in peripheral blood (PB) of patients with breast cancer predicts poor clinical outcome. Cancer cells with stemness and epithelial-to-mesenchymal transition (EMT) features display enhanced malignant and metastatic potential. A new methodology was developed in order to investigate the co-expression of a stemness and an EMT marker (ALDH1 and TWIST, respectively) on single CTCs of patients with early and metastatic breast cancer.MethodsTriple immunofluorescence using anti-pancytokeratin (A45-B/B3), anti-ALDH1 and anti-TWIST antibodies was performed in cytospins prepared from hepatocellular carcinoma HepG2 cells and SKBR-3, MCF-7 and MDA.MB.231 breast cancer cell lines. Evaluation of ALDH1 expression levels (high, low or absent) and TWIST subcellular localization (nuclear, cytoplasmic or absent) was performed using the ARIOL system. Cytospins prepared from peripheral blood of patients with early (n = 80) and metastatic (n = 50) breast cancer were analyzed for CTC detection (based on pan-cytokeratin expression and cytomorphological criteria) and characterized according to ALDH1 and TWIST.ResultsCTCs were detected in 13 (16%) and 25 (50%) patients with early and metastatic disease, respectively. High ALDH1 expression (ALDH1high) and nuclear TWIST localization (TWISTnuc) on CTCs was confirmed in more patients with metastatic than early breast cancer (80% vs. 30.8%, respectively; p = 0.009). In early disease, ALDH1low/neg CTCs (p = 0.006) and TWISTcyt/neg CTCs (p = 0.040) were mainly observed. Regarding co-expression of these markers, ALDH1high/TWISTnuc CTCs were more frequently evident in the metastatic setting (76% vs. 15.4% of patients, p = 0.001; 61.5% vs. 12.9% of total CTCs), whereas in early disease ALDH1low/neg/TWISTcyt/neg CTCs were mainly detected (61.5% vs. 20% of patients, p = 0.078; 41.9% vs. 7.7% of total CTCs).ConclusionsA new assay is provided for the evaluation of ALDH1 and TWIST co-expression at the single CTC-level in patients with breast cancer. A differential expression pattern for these markers was observed both in early and metastatic disease. CTCs expressing high ALDH1, along with nuclear TWIST were more frequently detected in patients with metastatic breast cancer, suggesting that these cells may prevail during disease progression.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2407-14-651) contains supplementary material, which is available to authorized users.

The striatal protein Regulator of G-protein signaling 9-2 (RGS9-2) plays a key modulatory role in opioid, monoamine, and other G-protein-coupled receptor responses. Here, we use the murine spared-nerve injury model of neuropathic pain to investigate the mechanism by which RGS9-2 in the nucleus accumbens (NAc), a brain region involved in mood, reward, and motivation, modulates the actions of tricyclic antidepressants (TCAs). Prevention of RGS9-2 action in the NAc increases the efficacy of the TCA desipramine and dramatically accelerates its onset of action. By controlling the activation of effector molecules by G protein α and βγ subunits, RGS9-2 affects several protein interactions, phosphoprotein levels, and the function of the epigenetic modifier histone deacetylase 5, which are important for TCA responsiveness. Furthermore, information from RNA-sequencing analysis reveals that RGS9-2 in the NAc affects the expression of many genes known to be involved in nociception, analgesia, and antidepressant drug actions. Our findings provide novel information on NAc-specific cellular mechanisms that mediate the actions of TCAs in neuropathic pain states.desipramine | duloxetine | HDAC5 | spared nerve injury | gene expression R egulator of G-protein signaling 9-2 (RGS9-2) is an intracellular modulator of G-protein-coupled receptor (GPCR) function, which is expressed in medium spiny neurons and cholinergic interneurons of the striatum (1, 2). RGS9-2 influences the magnitude and time course of GPCR signaling by promoting GTPase activity of the Gα subunit and by preventing activation of Gα effectors (3). This modulation can also influence the duration of interactions between the Gβγ subunits and their effector molecules. In addition to Gα subunits, RGS9-2 interacts with several scaffolds and signal transduction proteins that affect its function, expression, and cellular localization. Interactions with the Gβ5 subunit and the adaptor protein R7BP determine the stability and cellular localization of RGS9-2, respectively (3, 4). Several recent studies have provided information on the regulation and function of RGS9-2 complexes in the striatum and how these complexes affect pharmacologic responses (2, 5, 6). In particular, RGS9-2 has been shown to modulate the actions of various psychotropic, antiparkinsonian, neuroleptic, and opiate analgesic drugs (1, 7). The nucleus accumbens (NAc) is a striatal brain region that is a major site of antidepressant drug action (8). Recent studies provided information on signal transduction events triggered by tricyclic antidepressants (TCAs) in NAc neurons and identified several second messengers, transcription factors, and epigenetic molecules involved in their therapeutic actions (9-11). TCAs, such as desipramine (DMI) and nortriptyline (NTL), and selective serotonin/norepinephrine reuptake inhibitors (SNRIs) have also been used to treat neuropathic pain, a complex chronic disorder that is highly comorbid with anxiety and depression (12, 13) and is characterized by thermal hyperalgesia, mech...

The signal transduction modulator Rgs9-2 (Regulator of G protein signaling 9-2) plays a key role in dopaminergic and opioidergic transmission in the striatum. Rgs9-2 is a potent modulator of opiate reward and analgesia, but its role in chronic pain remains unknown. Here, we use the spared nerve injury model (SNI), to evaluate the influence of Rgs9-2 in sensory symptoms, as well as in anxiety and depression-like behaviors observed under neuropathic pain conditions. Our data demonstrate that knockout of the Rgs9 gene reduces the intensity of thermal hyperalgesia and mechanical allodynia the first few days after nerve injury. This small, but significant effect is only observed at early time points after nerve injury, whereas after the first week of SNI, Rgs9 knockout (Rgs9KO) and Rgs9 wildtype (Rgs9WT) mice show similar levels of mechanical allodynia and thermal hyperalgesia. Furthermore, Rgs9-2 deletion exacerbates anxiety and depression like behaviors several weeks after the emergence of the neuropathic pain symptoms. Our findings also reveal a temporal and regional regulation of Rgs9-2 protein expression by neuropathic pain, as Rgs9-2 levels are reduced in the spinal cord a few days after nerve injury, whereas decreased Rgs9-2 levels in the Nucleus Accumbens (NAc) are only observed several weeks after nerve injury. Thus, adaptations in Rgs9-2 activity in the spinal cord and in the NAc may contribute to sensory and affective components of neuropathic pain.

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Regulator of G-protein signaling 9-2 (RGS9-2) is a striatal-enriched signal-transduction modulator known to have a critical role in the development of addiction-related behaviors following exposure to psychostimulants or opioids. RGS9-2 controls the function of several G-protein-coupled receptors, including dopamine receptor and mu opioid receptor (MOR). We previously showed that RGS9-2 complexes negatively control morphine analgesia, and promote the development of morphine tolerance. In contrast, RGS9-2 positively modulates the actions of other opioid analgesics, such as fentanyl and methadone. Here we investigate the role of RGS9-2 in regulating responses to oxycodone, an MOR agonist prescribed for the treatment of severe pain conditions that has addictive properties. Using mice lacking the Rgs9 gene (RGS9KO), we demonstrate that RGS9-2 positively regulates the rewarding effects of oxycodone in pain-free states, and in a model of neuropathic pain. Furthermore, although RGS9-2 does not affect the analgesic efficacy of oxycodone or the expression of physical withdrawal, it opposes the development of oxycodone tolerance, in both acute pain and chronic neuropathic pain models. Taken together, these data provide new information on the signal-transduction mechanisms that modulate the rewarding and analgesic actions of oxycodone.

Total hip arthroplasty (THA) for end-stage osteoarthritis is one of the most effective surgical treatments in medicine. Impressive outcomes have been well documented in the literature with patients gaining ambulation and recovery of hip joint function. Nevertheless, there are still debatable issues and controversies that the orthopedic community has not been able to provide a definitive answer for. This review is focused on the current three most debatable issues surrounding the THA procedure: (1) new cutting-edge technology, (2) spinopelvic mobility, and (3) fast-track protocols. The scope of the herein narrative review is to analyze the debatable issues surrounding the three aforementioned topics and conclude the best contemporary clinical approaches regarding each issue.

Background: The detection of circulating tumor cells (CTCs) in peripheral blood (PB) of patients with breast cancer (BC) has been associated with poor disease outcome. Cancer cells with stemness and epithelial-to-mesenchymal transition (EMT) properties are considered to display enhanced metastatic potential. The presence of these features in CTCs could be an important determinant of increased metastatic behaviour. A new methodology was developed to investigate the co-expression of the stemness marker ALDH1 and the EMT marker TWIST on CTCs from patients with early and metastatic breast cancer, at the single-cell level. Patients and Methods : PBMC’ cytospins were prepared from PB obtained from 80 patients with early and 50 with metastatic breast cancer. Triple immunofluorescence staining was performed using anti-pancytokeratin (A45-B/B3), anti-ALDH1 and anti-TWIST antibodies. Classification of ALDH1 expression levels (high or low) and TWIST subcellular localization (nuclear or cytoplasmic) was performed in HepG2 control cells and three representative BC cell lines, using the ARIOL system. A total of 500.000 PBMCs per patient were subsequently analyzed. Results : CTCs were detected in 13 out of 80 (16%) and in 25 out of 50 (50%) patients with early and metastatic BC, respectively. Although co-expression of ALDH1 and TWIST was observed on almost all CTCs in both patient groups, CTCs expressing the phenotype ALDH1high/TWISTnuclear were more frequently detected among patients with metastatic compared to early disease (76% vs. 15% of patients, p = 0.0004). Moreover, a higher proportion of ALDH1high/TWISTnuclear CTCs was confirmed in the metastatic setting (62% vs. 13% of CTCs, p<0.0001). On the contrary, the phenotype ALDH1low/TWISTcytoplasmic was more prevalent among CTCs detected in early disease (32% vs. 8% of CTCs, p = 0.0006). Conclusions : A new assay is provided for the evaluation of ALDH1 and TWIST co-expression at the single-CTC level. CTCs bearing the ALDH1high/TWISTnuclear phenotype were more commonly detected in metastatic compared to early BC, suggesting that this phenotype prevails during disease progression. The characterization of CTCs according to these markers could be used to improve risk stratification in BC. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-04-08.