Role of microglia in mechanical allodynia in the anterior cingulate cortex

Plastic changes that increase nociceptive transmission are observed in several brain regions under conditions of chronic pain. Synaptic plasticity in the anterior cingulate cortex (ACC) is particularly associated with neuropathic pain. Glial cells are considered candidates for the modulation of neural plastic changes in the central nervous system. In this study, we aimed to investigate the role of ACC glial cells in the development of neuropathic pain. First, we examined the expression of glial cells in the ACC of nerve-ligated mice. The expression of astrocytes and microglia was increased in the ACC of nerve-ligated mice, which was reversed by intracerebroventricular (i.c.v) treatment with the microglia inhibitor minocycline. Then, we examined the effect of minocycline on mechanical allodynia in nerve-ligated mice. I.c.v. and intra-ACC treatment with minocycline partially inhibited mechanical allodynia in the nerve-ligated mice. The expression of phosphorylated alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluR1 subunit at Ser831, but not at Ser845, was increased in the ACC of the nerve-ligated mice compared to sham-operated mice, which was attenuated by minocycline administration. These results suggest that the activation of microglia in the ACC is involved in the development of hyperalgesia in mice with neuropathic pain.

Abstract P6-09-25: Circulating tumor cell clusters-associated gene plakoglobin is a novel prognostic predictor in patients with breast cancer

Background: Accumulating evidence shows that circulating tumor cells (CTC) are linked to metastatic relapse and are regarded as a prognostic marker for human cancer. It was reported that CTC clusters (CTCc) have more metastatic potential than single CTC. Lately, studies also show that the high expression of plakoglobin, a cell adhesion protein, within the primary tumor are positively associated with CTCc in breast cancer patients. In addition, it is thought that insufficient expression of plakoglobin could promote epithelial-mesenchymal transition (EMT). In this study, we investigated the correlation between plakoglobin expression and survival of breast cancer.

Materials and Methods:A total of 126 patients with resectable early-stage breast cancer were treated with neoadjuvant chemotherapy (NAC). All patients received a standardized protocol of NAC consisting of four courses of FEC100 (500 mg/m2 fluorouracil, 100 mg/m2 epirubicin, and 500 mg/m2 cyclophosphamide) every 3 weeks, followed by 12 courses of 80 mg/m2 paclitaxel administered weekly. The expression of plakoglobin were identified by immunohistochemical staining properties in cell membrane. Staining with plakoglobin (clone 4C12) was scored according to the percentage of cells that stained positively: low, 0-25%; medium, 26-75%; high, >75%. We investigated the correlation between the plakoglobin expression in primary tumor specimen and clinical outcomes including overall-survival (OS), disease-free-survival (DFS), distant-metastasis-free-survival (DMFS), the efficacy of NAC. And we examined the relation between the expression of plakoglobin and E-cadherin, EMT marker.

Results: The patient with high plakoglobin expression had significantly worse OS (p=0.021, log-rank) and DFS (p=0.015, log-rank), DMFS (p=0.040, log-rank). And the plakoglobin expression had no correlation with pathological complete response (pCR) rate (p=0.596). Also, there was not a statistically significant relationship between the plakoglobin expression and other clinicopathological parameters including tumor size (p=0.708), lymph node status (p=0.479), subtype (p=0.413), nuclear grade (p=0.642), Ki67 (p=0.202), tumor infiltrating lymphocytes (p=0.828). On univariate analysis with respect to distal metastasis, high plakoglobin expression showed worse prognosis than low plakoglobin expression (p=0.013, hazard ratio=4.221). And multivariate analysis found the same result (p=0.015, hazard ratio=4.070). In addition, there was a significant relationship between the expression of plakoglobin and E-cadherin (p=0.023).

Conclusions: Plakoglobin expression is an independent prognostic factor in the patients with breast cancer; particularly for DMFS, and this mechanism related to EMT.Background: Accumulating evidence shows that circulating tumor cells (CTC) are linked to metastatic relapse and are regarded as a prognostic marker for human cancer. It was reported that CTC clusters (CTCc) have more metastatic potential than single CTC. Lately, studies also show that the high expression of plakoglobin, a cell adhesion protein, within the primary tumor are positively associated with CTCc in breast cancer patients. In addition, it is thought that insufficient expression of plakoglobin could promote epithelial-mesenchymal transition (EMT). In this study, we investigated the correlation between plakoglobin expression and survival of breast cancer.

Materials and Methods:A total of 126 patients with resectable early-stage breast cancer were treated with neoadjuvant chemotherapy (NAC). All patients received a standardized protocol of NAC consisting of four courses of FEC100 (500 mg/m2 fluorouracil, 100 mg/m2 epirubicin, and 500 mg/m2 cyclophosphamide) every 3 weeks, followed by 12 courses of 80 mg/m2 paclitaxel administered weekly. The expression of plakoglobin were identified by immunohistochemical staining properties in cell membrane. Staining with plakoglobin (clone 4C12) was scored according to the percentage of cells that stained positively: low, 0-25%; medium, 26-75%; high, >75%. We investigated the correlation between the plakoglobin expression in primary tumor specimen and clinical outcomes including overall-survival (OS), disease-free-survival (DFS), distant-metastasis-free-survival (DMFS), the efficacy of NAC. And we examined the relation between the expression of plakoglobin and E-cadherin, EMT marker.

Results: The patient with high plakoglobin expression had significantly worse OS (p=0.021, log-rank) and DFS (p=0.015, log-rank), DMFS (p=0.040, log-rank). And the plakoglobin expression had no correlation with pathological complete response (pCR) rate (p=0.596). Also, there was not a statistically significant relationship between the plakoglobin expression and other clinicopathological parameters including tumor size (p=0.708), lymph node status (p=0.479), subtype (p=0.413), nuclear grade (p=0.642), Ki67 (p=0.202), tumor infiltrating lymphocytes (p=0.828). On univariate analysis with respect to distal metastasis, high plakoglobin expression showed worse prognosis than low plakoglobin expression (p=0.013, hazard ratio=4.221). And multivariate analysis found the same result (p=0.015, hazard ratio=4.070). In addition, there was a significant relationship between the expression of plakoglobin and E-cadherin (p=0.023).

Conclusions: Plakoglobin expression is an independent prognostic factor in the patients with breast cancer; particularly for DMFS, and this mechanism related to EMT.

Citation Format: Goto W, Kashiwagi S, Asano Y, Takada K, Takashima T, Morisaki T, Noda S, Onoda N, Ohsawa M, Hirakawa K, Ohira M. Circulating tumor cell clusters-associated gene plakoglobin is a novel prognostic predictor in patients with breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-25.

Abstract P3-04-20: Predicting therapeutic effect by on tumor invasion lymphocytes (TILs) in endocrine therapy for stage IV breast cancer

Background: Breast cancer with distant metastasis at first presentation (stage IV disease) is often encountered in the outpatient department. With recent advances in multimodal therapies for breast cancer, long-term survival can now be expected even in stage IV breast cancer with distant metastasis. However, a goal in treating metastatic disease is prolongation of survival while maintaining good quality of life (QOL). Endocrine therapy is suitable for this purpose.The tumor immune environment not only modulates the effects of immunotherapy, but also the effects of other anticancer drugs and treatment outcomes. These immune responses can be evaluated with tumor-infiltrating lymphocytes (TILs), which has frequently been verified clinically. In the present study, we hypothesized that TILs would be useful as predictive marker of the therapeutic effect in endocrine therapy as well. In this study, the prediction of the therapeutic effect by TILs in endocrine therapy for stage IV breast cancer was clinically verified.

Materials and Methods:Data from 40 patients who underwent endocrine therapy as the initial drug therapy for stage IV breast cancer were used. The correlation between TILs evaluated according to the standard method, and prognosis, including the efficacy of endocrine therapy, was investigated retrospectively. Patients with 350% lymphocytic infiltration were considered to have lymphocyte-predominant breast cancer (LPBC).

Results:Among all 40 patients, TIL levels were high in 13 (32.5%) and low in 27 (67.5%) patients. Nine patients (22.5%) had LPBC, and 31 patients (77.5%) had non-LPBC. Investigation of the clinical pathological features of patients showed no significant differences between the high TIL and low TIL groups. There were also no significant differences between LPBC and non-LPBC patients. An analysis of outcomes comparing the high TIL and low TIL groups showed no prolongation in progression-free survival (PFS) (p=0.171, log-rank), time to treatment failure (TTF)(p=0.054), or overall survival (OS) (p=0.641). LPBC patients had significant prolongations of PFS (p=0.005), TTF (p=0.001), and OS (p=0.027) compared to non-LPBC patients. On receiver operating characteristic (ROC) curve analyses, results were better with LPBC (AUC: 0.700) than with TILs (AUC: 0.606).

Conclusion: The present findings suggest that a high level of lymphocytic infiltration in the tumor stroma may serve as a predictor of the therapeutic effect of endocrine therapy for patients with stage IV ER-positive breast cancer.

Citation Format: Kashiwagi S, Asano Y, Goto W, Takada K, Takashima T, Morisaki T, Noda S, Onoda N, Ohsawa M, Hirakawa K, Ohira M. Predicting therapeutic effect by on tumor invasion lymphocytes (TILs) in endocrine therapy for stage IV breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-04-20.

Abstract P2-05-05: Prediction of survival after neoadjuvant chemotherapy for breast cancer by evaluation of tumor-infiltrating lymphocytes (TILs) and residual cancer burden (RCB)

Background: The tumor immune environment not only modulates the effects of immunotherapy, but also the effects of other anticancer drugs and treatment outcomes. Thus, the importance of inhibiting and improving the tumor immune microenvironment is now recognized. These immune responses can be evaluated with tumor-infiltrating lymphocytes (TILs), which has frequently been verified clinically. On the other hand, residual cancer burden (RCB) evaluation has been shown to be a useful predictor of survival after neoadjuvant chemotherapy (NAC). In this study, RCB and TILs evaluations were combined to produce an indicator that we have termed “RCB-TILs”, and its clinical application to NAC for breast cancer was verified by subtype-stratified analysis.

Materials and Methods:A total of 177 patients with resectable early-stage breast cancer were treated with NAC.The correlation between TILs evaluated according to the standard method, and prognosis, including the efficacy of NAC, was investigated retrospectively. The RCB was calculated using the Residual Cancer Burden Calculator on the website of the MD Anderson Cancer Center. The RCB and TILs evaluations were combined to create the “RCB-TILs”. Patients who were RCB-positive and had high TILs were considered RCB-TILs-positive, and all other combinations were RCB-TILs-negative.

Results: Univariable analysis of patients with high TILs found that this contributed significantly to prolonging DFS in all patients (p = 0.022, hazard ratio = 0.420), TNBC patients (p = 0.004, hazard ratio = 0.177), and HER2BC patients (p = 0.026, hazard ratio = 0.123). For HRBC patients, however, high TILs did not contribute to survival (p = 0.990, hazard ratio = 0.992). Being RCB-TILs-positive, however, contributed significantly to prolonging DFS in all patients (p < 0.001, hazard ratio = 0.181), TNBC patients (p < 0.001, hazard ratio = 0.099), HER2BC patients (p = 0.026, hazard ratio = 0.123), and HRBC patients (p = 0.039, hazard ratio = 0.258). On multivariable analysis, being RCB-TILs-positive was an independent factor for recurrence after NAC in all patients (p < 0.001, hazard ratio = 0.048), TNBC patients (p = 0.018, hazard ratio = 0.041), HER2BC patients (p = 0.036, hazard ratio = 0.134), and HRBC patients (p = 0.002, hazard ratio = 0.081).

Conclusion: The results of the present study suggest that RCB-TILs is a significant predictor for breast cancer recurrence after NAC and may be a more sensitive indicator than TILs alone.

Citation Format: Asano Y, Kashiwagi S, Goto W, Takada K, Takashima T, Morisaki T, Noda S, Onoda N, Ohsawa M, Hirakawa K, Ohira M. Prediction of survival after neoadjuvant chemotherapy for breast cancer by evaluation of tumor-infiltrating lymphocytes (TILs) and residual cancer burden (RCB) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-05.

Processed aconite root and its active ingredient neoline may alleviate oxaliplatin-induced peripheral neuropathic pain

ETHNOPHARMACOLOGICAL RELEVANCE

Processed aconite root (PA, the root of Aconitum carmichaeli, Ranunculaceae) is a crude drug used in traditional Chinese or Japanese kampo medicine to generate heat in the body and to treat pain associated with coldness. Oxaliplatin (L-OHP) is a platinum-based anticancer drug that frequently causes acute and chronic peripheral neuropathies, including cold and mechanical hyperalgesia.

AIM OF THE STUDY

We investigated the effects of PA on L-OHP-induced peripheral neuropathies and identified the active ingredient within PA extract.

MATERIALS AND METHODS

L-OHP was intraperitoneally injected into mice, and PA boiled water extract was orally administered. Cold and mechanical hyperalgesia were evaluated using the acetone test and the von Frey filament method, respectively. Dorsal root ganglion (DRG) neurons were isolated from normal mice and cultured with L-OHP with or without PA extract. Cell viability and neurite elongation were evaluated.

RESULTS

PA extract significantly attenuated cold and mechanical hyperalgesia induced by L-OHP in mice. In cultured DRG neurons, L-OHP reduced cell viability and neurite elongation in a dose-dependent manner. Treatment with PA extract significantly alleviated the L-OHP-induced reduction of neurite elongation, while the cytotoxicity of L-OHP was not affected. Using activity-guided fractionation, we isolated neoline from PA extract as the active ingredient. Neoline significantly alleviated L-OHP-induced reduction of neurite elongation in cultured DRG neurons in a concentration-dependent manner. Moreover, subcutaneous injection of neoline attenuated cold and mechanical hyperalgesia in L-OHP-treated mice. PA extract and neoline did not show sedation and motor impairment.

CONCLUSIONS

The present study indicates that PA and its active ingredient neoline are promising agents to alleviate L-OHP-induced neuropathic pain.

Tumour-infiltrating CD8 to FOXP3 lymphocyte ratio in predicting treatment responses to neoadjuvant chemotherapy of aggressive breast cancer

BACKGROUND

Tumour-infiltrating lymphocytes (TILs) can be used to monitor the immune response, and are important in predicting treatment responses and outcomes for various types of cancer. Recently, specific TIL subsets have been reported to be clinically useful in predicting treatment responses. The CD8+/FOXP3+ TIL ratio (CFR) may be a more sensitive indicator for monitoring immune function. This study investigated the clinical significance and value of CFR as a biomarker to predict treatment responses to neoadjuvant chemotherapy for breast cancer.

METHODS

Patients with resectable early-stage breast cancer treated with neoadjuvant chemotherapy at Osaka City University Hospital, Japan, between 2007 and 2013 were included. Oestrogen receptor, progesterone receptor, human epidermal growth factor receptor (HER) 2, Ki-67, CD8 and FOXP3 status were assessed by immunohistochemistry, and correlated with pathological complete response (pCR).

RESULTS

A total of 177 patients were included, of whom 90 had a high CFR and 87 a low CFR. Triple-negative breast cancer (TNBC) was more common in the high-CFR group than in the low-CFR group (46 versus 23 per cent; P = 0·002), as was HER2-enriched breast cancer (HER2BC) (27 versus 14 per cent; P = 0·033). Among these patients, the pCR rate was significantly higher in the high-CFR group than in the low-CFR group (TNBC: P = 0·022; HER2BC: P < 0·001). In multivariable analysis high-CFR status was an independent predictor of a favourable prognosis: hazard ratio 0·24 (95 per cent c.i. 0·05 to 0·72; P = 0·015) for TNBC and 0·10 (0·10 to 0·90; P = 0·041) for HER2BC.

CONCLUSION

The CFR may be a useful biomarker to predict treatment response to neoadjuvant therapy in aggressive breast cancer subtypes, such as TNBC and HER2BC.

Oseltamivir produces hypothermic and neuromuscular effects by inhibition of nicotinic acetylcholine receptor functions: comparison to procaine and bupropion

Oseltamivir, an anti-influenza virus drug, induces marked hypothermia in normal mice. We have proposed that the hypothermic effect arises from inhibition of the nicotinic acetylcholine receptor function of sympathetic ganglion neurons which innervate the brown adipose tissue (a heat generator). It has been reported that local anesthetics inhibit nicotinic acetylcholine receptor function by acting on its ionic channels, and that bupropion, a nicotinic antagonist, induces hypothermia. In this study, we compared the effects of oseltamivir, procaine and bupropion on body temperature, cardiovascular function and neuromuscular transmission. Intraperitoneal administration of oseltamivir (100mg/kg), procaine (86.6mg/kg) and bupropion (86.7mg/kg) lowered the core body temperature of normal mice. At lower doses (10-30mg/kg oseltamivir, 8.7-26mg/kg procaine and bupropion), when administered subcutaneously, the three drugs antagonized the hypothermia induced by intraperitoneal injection of nicotine (1mg/kg). In anesthetized rats, intravenous oseltamivir (30-100mg/kg), procaine (10mg/kg) and bupropion (10mg/kg) induced hypotension and bradycardia. Oseltamivir alone (100mg/kg) did not inhibit neuromuscular twitch contraction of rats, but at 3-30mg/kg it augmented the muscle-relaxing effect of d-tubocurarine. Similar effects were observed when lower doses of procaine (10-30mg/kg) and bupropion (3-10mg/kg) were administered, suggesting that systemic administration of oseltamivir inhibits muscular nicotinic acetylcholine receptors. These results support the idea that the hypothermic effect of oseltamivir is due to its effects on sympathetic ganglia which innervate the brown adipose tissue, and suggest that oseltamivir may exert non-selective ion channel blocking effects like those of ester-type local anesthetics.

[Contribution of the sensitization of supraspinal nociceptive transmission in chronic pain]

Central sensitization in the spinal cord is well known to be involved in chronic pain. Recent investigations indicated that the protein expressions involving the synaptic plasticity are changed in several brain areas under a chronic pain condition. These changes in supraspinal neural function might cause the emotional and memory dysfunction. It is also possible that these changes are involved in the chronic pain. Indeed, since the improvement of spinal and peripheral sensitization showed limited relief in the neuropathic pain, the sensitization of supraspinal nociceptive transmission might be involved in the expression of chronic pain. We recently found that intra-thalamic treatment with excitatory neurotransmitter glutamate caused hyperalgesia, which is mediated by the stimulation of glutamate N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. Moreover, intracerebroventricular treatment with gabapentin, a calcium channel alpha2delta-1 subunit blocker, attenuated the hyperalgesia in the nerve-injury model of mice. These results suggest that the sensitization of supraspinal nociceptive transmission is involved in neuropathic pain. It is also indicated that neuropathic pain is resulted from the activations of spinal glial cells. Likewise, the supraspinal glial activation was observed in the neuropathic pain. Therefore, the sensitization of supraspinal nociceptive transmission might be important for a chronic pain. In this review, we would like to discuss the possible involvement of the supraspinal sensitization in neuropathic pain and in its application for the curative treatment in chronic pain.

Gabapentin prevents oxaliplatin-induced mechanical hyperalgesia in mice

Oxaliplatin, a platinum-based chemotherapy drug, frequently causes acute and chronic peripheral neuropathies including mechanical hyperalgesia. These adverse effects hinder anticancer therapy with the drug. In this study, we examined several drugs that might prevent oxaliplatin-induced peripheral neuropathy. Single intraperitoneal (i.p.) injection of oxaliplatin (10 mg/kg) induced cold allodynia (acetone test) and mechanical hyperalgesia (von Frey test). Gabapentin, but not simvastatin and atorvastatin, prevented oxaliplatin-induced mechanical hyperalgesia without affecting cold allodynia. Moreover, oxaliplatin caused phosphorylation of cofilin protein in the spinal cord, which has been shown to be involved in the neuropathic hyperalgesia. This increased phosphorylation of cofilin was also attenuated by gabapentin treatment. These results suggest that gabapentin is useful for relieving oxaliplatin-induced mechanical hyperalgesia and that the pathogenic mechanisms of cold allodynia and mechanical hyperalgesia differ.

Involvement of protein isoprenylation in neuropathic pain induced by sciatic nerve injury in mice

Isoprenylation is crucial step for activating many intracellular signaling. The present study examined whether inhibition of the protein isoprenylation could affect neuropathic pain in partial sciatic nerve-ligated mice. Intrathecal treatment with a geranylgeranyl transferase I inhibitor GGTI-2133, but not with a farnesyl transferase inhibitor FTI-277, dose-dependently blocked the thermal hyperalgesia in partial sciatic nerve-ligated mice. Intrathecal treatment with GGTI-2133 also attenuated the mechanical allodynia in partial sciatic nerve-ligated mice. Phosphorylated MARCKS expression was increased in the ipsilateral side of the spinal cord dorsal horn in partial sciatic nerve-ligated mice, and this increase was attenuated by GGTI-2133 but not by FTI-277. These results suggest that protein isoprenylation by geranylgeranyl transferase I is involved in the neuropathic pain.

Olanzapine increases hepatic glucose production through the activation of hypothalamic adenosine 5'-monophosphate-activated protein kinase

AIMS

To investigate the mechanism of the metabolic disturbance induced by the atypical antipsychotic olanzapine, we examined whether adenosine 5'-monophosphate-activated protein kinase (AMPK) in the hypothalamus and hepatic glucose production are involved in the effect of olanzapine.

METHODS

Male 6-week-old ICR mice were used. Blood glucose levels were determined by the glucose oxidase method. The mRNA levels of gluconeogenic or glycolytic enzymes were measured by reverse transcription polymerase chain reaction (RT-PCR). AMPK expression was measured by Western blotting.

RESULTS

Systemic injection of olanzapine increased blood glucose levels in both unfasted and fasted mice. However, the increase in fasted mice was less than that in unfasted mice. Central administration of olanzapine also increased the blood glucose levels in unfasted mice, but not in fasted mice. In a pyruvate tolerance test, olanzapine significantly increased blood glucose levels. In addition, olanzapine increased the mRNA levels of glucose-6-phosphatase (G6Pase), a gluconeogenic enzyme, in the liver. Furthermore, olanzapine increased phosphorylated AMPK in the hypothalamus of unfasted mice, and olanzapine-induced hyperglycaemia was inhibited by the AMPK inhibitor compound C. Central administration of the AMPK activator AICAR significantly increased G6Pase mRNA levels in the liver and blood glucose levels. Moreover, both olanzapine- and AICAR-induced hyperglycaemia were attenuated by the β-adrenergic receptor antagonist propranolol, suggesting that olanzapine and AICAR induce hepatic glucose production through the sympathetic nervous system.

CONCLUSIONS

Our results indicate that olanzapine activates AMPK in the hypothalamus, which increases hepatic glucose production via the sympathetic nervous system.