Prognostic Factors and Survival Outcomes of Patients With Early HER2+ Breast Cancer Treated With Trastuzumab in a Brazilian Public Reference Center: A Real-World Study.

PURPOSE: Trastuzumab was introduced into the Brazilian public health care service for early breast cancer (BC) in 2012. This study describes the survival outcomes and prognostic factors related to early HER2+ BC treatment in a Brazilian reference cancer center. PATIENTS AND METHODS: This were a retrospective, single-center, observational study of early HER2+ BC patients treated with trastuzumab in the (neo)adjuvant setting between 2012 and 2018 at Hospital Pérola Byington. Demographic, clinical, disease-free survival (DFS) and overall survival (OS) data were evaluated. Multivariate analysis was performed to assess independent prognostic factors. RESULTS: One hundred seventy-six and 353 patients treated in the neoadjuvant and adjuvant setting were included, respectively. The 3- and 5-year OS rates were 79% and 56% for the neoadjuvant group and 97% and 92% for the adjuvant group, respectively. Node positivity at diagnosis predicted poor OS for both groups. In the neoadjuvant group, stage III disease at diagnosis, delayed surgery, and lack of pathological complete response (pCR) predicted poor prognosis. The 3- and 5-year DFS rates were 67% and 46% in the neoadjuvant group and 91% and 86% in the adjuvant group, respectively. Histological grade 2, stage III disease at diagnosis, and lack of pCR predicted poor DFS for the neoadjuvant group. For the adjuvant group, node positivity at diagnosis predicted poor DFS. CONCLUSION: Our results reveal multiple clinical parameters affecting survival outcomes according to the treatment setting. Patients treated with neoadjuvant therapy have a poor prognosis since they present with more advanced disease, indicating the importance of early diagnosis and optimized treatment.

2-AG promotes the expression of conditioned fear via cannabinoid receptor type 1 on GABAergic neurons.

RATIONALE: The contribution of two major endocannabinoids, 2-arachidonoylglycerol (2-AG) and anandamide (AEA), in the regulation of fear expression is still unknown. OBJECTIVES: We analyzed the role of different players of the endocannabinoid system on the expression of a strong auditory-cued fear memory in male mice by pharmacological means. RESULTS: The cannabinoid receptor type 1 (CB1) antagonist SR141716 (3 mg/kg) caused an increase in conditioned freezing upon repeated tone presentation on three consecutive days. The cannabinoid receptor type 2 (CB2) antagonist AM630 (3 mg/kg), in contrast, had opposite effects during the first tone presentation, with no effects of the transient receptor potential vanilloid receptor type 1 (TRPV1) antagonist SB366791 (1 and 3 mg/kg). Administration of the CB2 agonist JWH133 (3 mg/kg) failed to affect the acute freezing response, whereas the CB1 agonist CP55,940 (50 µg/kg) augmented it. The endocannabinoid uptake inhibitor AM404 (3 mg/kg), but not VDM11 (3 mg/kg), reduced the acute freezing response. Its co-administration with SR141716 or SB366791 confirmed an involvement of CB1 and TRPV1. AEA degradation inhibition by URB597 (1 mg/kg) decreased, while 2-AG degradation inhibition by JZL184 (4 and 8 mg/kg) increased freezing response. As revealed in conditional CB1-deficient mutants, CB1 on cortical glutamatergic neurons alleviates whereas CB1 on GABAergic neurons slightly enhances fear expression. Moreover, 2-AG fear-promoting effects depended on CB1 signaling in GABAergic neurons, while an involvement of glutamatergic neurons remained inconclusive due to the high freezing shown by vehicle-treated Glu-CB1-KO. CONCLUSIONS: Our findings suggest that increased AEA levels mediate acute fear relief, whereas increased 2-AG levels promote the expression of conditioned fear primarily via CB1 on GABAergic neurons.

Cannabinoid receptor type 1 receptors on GABAergic vs. glutamatergic neurons differentially gate sex-dependent social interest in mice.

Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, depression, autism, and schizophrenia. Thus, comprehension of the neurobiological basis of social interaction is important for a better understanding of numerous pathologies and improved treatments. Several findings have suggested that an alteration of cannabinoid receptor type 1 (CB1) receptor function could be involved in the pathophysiology of such disorders. However, the role of CB1 receptors is still unclear, and their localisation on different neuronal subpopulations may produce distinct outcomes. To dissect the role of CB1 receptors in different neuronal populations, we used male knockout mice and their respective control littermates [total deletion (CB1(-/-) ); specific deletion on cortical glutamatergic neurons (Glu-CB1(-/-) ) or on GABAergic interneurons (GABA-CB1(-/-) ), and wild-type (WT) mice treated with the CB1 antagonist/inverse agonist SR141716A (3 mg/kg). Mice were required to perform different social tasks - direct social interaction and social investigation. Direct interaction of two male mice was not modified in any group; however, when they were paired with females, Glu-CB1(-/-) mice showed reduced interaction. Also, exploration of the male stimulus subject in the three-chamber social investigation test was almost unaffected. The situation was completely different when a female was used as the stimulus subject. In this case, Glu-CB1(-/-) mice showed reduced interest in the social stimulus, mimicking the phenotype of CB1(-/-) or WT mice treated with SR141716A. GABA-CB1(-/-) mice showed the opposite phenotype, by spending more time investigating the social stimulus. In conclusion, we provide evidence that CB1 receptors specifically modulate the social investigation of female mice in a neuronal subtype-specific manner.

Medial prefrontal cortex Transient Receptor Potential Vanilloid Type 1 (TRPV1) in the expression of contextual fear conditioning in Wistar rats.

RATIONALE: Contextual fear is evoked by re-exposing an animal to an environment that has been previously paired with an aversive or unpleasant stimulus. It can be assessed by freezing and cardiovascular changes such as increase in mean arterial pressure and heart rate. A marked increase in neuronal activity is associated with contextual fear conditioning, especially in limbic structures involved with defense reactions, such as the ventral portion of medial prefrontal cortex. OBJECTIVE: Given the fact that transient receptor potential vanilloid type 1 (TRPV1) receptors could be involved in the expression of defensive behavior, the present work tested the hypothesis that TRPV1 manipulation in the ventromedial prefrontal cortex (vMPFC) modulates the expression of contextual conditioned fear. METHODS: Male Wistar rats received bilateral microinjections into the vMPFC of the TRPV1 receptor antagonists capsazepine (1, 10, and 60 nmol/200 nL) or 6-iodonordihydrocapsaicin (3 nmol/200 nL), and the TRPV1 agonist capsaicin (1 nmol/200 nL) preceded by vehicle or 6-iodonordihydrocapsaicin before re-exposure to the experimental chamber for 10 min, 48 h after conditioning in two different protocols distinct by their aversiveness. RESULTS: Both antagonists reduced the freezing and cardiovascular responses in the high aversive protocol. Capsaicin caused an increase in fear-associated responses that could be blocked by 6-iodonordihydrocapsaicin. CONCLUSIONS: Our results indicate that TRPV1 receptors located in the vMPFC have a tonic involvement in the modulation of the expression of contextual fear conditioning.

Opposing roles for cannabinoid receptor type-1 (CB1) and transient receptor potential vanilloid type-1 channel (TRPV1) on the modulation of panic-like responses in rats.

The midbrain dorsal periaqueductal gray (dPAG) has an important role in orchestrating anxiety- and panic-related responses. Given the cellular and behavioral evidence suggesting opposite functions for cannabinoid type 1 receptor (CB1) and transient receptor potential vanilloid type-1 channel (TRPV1), we hypothesized that they could differentially influence panic-like reactions induced by electrical stimulation of the dPAG. Drugs were injected locally and the expression of CB1 and TRPV1 in this structure was assessed by immunofluorescence and confocal microscopy. The CB1-selective agonist, ACEA (0.01, 0.05 and 0.5 pmol) increased the threshold for the induction of panic-like responses solely at the intermediary dose, an effect prevented by the CB1-selective antagonist, AM251 (75 pmol). Panicolytic-like effects of ACEA at the higher dose were unmasked by pre-treatment with the TRPV1 antagonist capsazepine (0.1 nmol). Similarly to ACEA, capsazepine (1 and 10 nmol) raised the threshold for triggering panic-like reactions, an effect mimicked by another TRPV1 antagonist, SB366791 (1 nmol). Remarkably, the effects of both capsazepine and SB366791 were prevented by AM251 (75 pmol). These pharmacological data suggest that a common endogenous agonist may have opposite functions at a given synapse. Supporting this view, we observed that several neurons in the dPAG co-expressed CB1 and TRPV1. Thus, the present work provides evidence that an endogenous substance, possibly anandamide, may exert both panicolytic and panicogenic effects via its actions at CB1 receptors and TRPV1 channels, respectively. This tripartite set-point system might be exploited for the pharmacotherapy of panic attacks and anxiety-related disorders.

Anxiolytic-like effects induced by blockade of transient receptor potential vanilloid type 1 (TRPV1) channels in the medial prefrontal cortex of rats.

RATIONALE: The endocannabinoid anandamide, in addition to activating cannabinoid type 1 receptors (CB1), may act as an agonist at transient receptor potential vanilloid type 1 (TRPV1) channels. In the periaqueductal gray, CB1 activation inhibits, whereas TRPV1 increases, anxiety-like behavior. In the medial prefrontal cortex (mPFC), another brain region related to defensive responses, CB1 activation induces anxiolytic-like effects. However, a possible involvement of TRPV1 is still unclear. OBJECTIVES: In the present study, we tested the hypothesis that TRPV1 channel contributes to the modulation of anxiety-like behavior in the mPFC. MATERIALS AND METHODS: Male Wistar rats (n = 5-7 per group) received microinjections of the TRPV1 antagonist capsazepine (1-60 nmol) in the ventral portion of the mPFC and were exposed to the elevated plus maze (EPM) or to the Vogel conflict test. RESULTS: Capsazepine increased exploration of open arms in the EPM as well as the number of punished licks in the Vogel conflict test, suggesting anxiolytic-like effects. No changes in the number of entries into the enclosed arms were observed in the EPM, indicating that there were no changes in motor activity. Moreover, capsazepine did not interfere with water consumption or nociceptive threshold, discarding potential confounding factors for the Vogel conflict test. CONCLUSIONS: These data suggest that TRPV1 in the ventral mPFC tonically inhibits anxiety-like behavior. TRPV1 could facilitate defensive responses opposing, therefore, the anxiolytic-like effects reported after local activation of CB1 receptors.

Modulation of anxiety-like behaviour by Transient Receptor Potential Vanilloid Type 1 (TRPV1) channels located in the dorsolateral periaqueductal gray.

The endocannabinoid anandamide is a possible agonist at the Transient Receptor Potential Vanilloid Type 1 (TRPV1) channel, in addition to its agonist activity at cannabinoid type 1 (CB1) receptor. In the midbrain dorsolateral periaqueductal gray (dlPAG) our previous data showed that CB1 activation induces anxiolytic-like effects. However, the role of TRPV1 has remained unclear. Thus, in the present study we tested the hypothesis that this channel would contribute to the modulation of anxiety-like behaviour in the dlPAG. Male Wistar rats received local injections of the TRPV1 antagonist capsazepine (10-60 nmol) and were submitted to the elevated plus-maze (EPM) and to the Vogel test. In addition, animals received local injections of capsaicin (0.01-1 nmol), a TRPV1 agonist, and were tested in the same models. In accordance with our hypothesis, capsazepine produced anxiolytic-like effects both in the EPM and in the Vogel test. Capsaicin mimicked these results, which might be attributed to its ability to quickly desensitize the channel. Altogether, our data suggest that, while CB1 receptors seem to inhibit aversive responses in the dlPAG, TRPV1 could facilitate them. Thus, CB1 and TRPV1 may have opposite functions in modulating anxiety-like behaviour in this region.