Association between physical activity and the expression of mediators of inflammation in normal breast tissue among premenopausal and postmenopausal women.

Physical activity is associated with decreased breast cancer risk. The underlying biological mechanisms could include the reduction of the local inflammation in the breast tissue. We conducted a cross-sectional study to assess the association between the physical activity and the protein expression levels of eleven mediators of inflammation in normal breast tissue of 164 women having breast cancer. Information on total physical activity (household, occupational and recreational) performed during a one-year period was collected using a questionnaire. Normal breast tissue was obtained from mastectomy blocks distant from the tumor. The expression of the mediators of inflammation in normal breast tissue was visually evaluated by immunohistochemistry. Multivariate linear regression analyses were used to assess the prevalence ratios (PR) and 95% confidence intervals (CI) for higher protein expression levels of the mediators of inflammation in normal breast tissue across quartiles of physical activity. Higher total physical activity was associated with lower expression levels of the pro-inflammatory mediator TNF-α in normal breast epithelial tissue among all (PR=0.64, 95% CI=0.44-0.93 for the fourth quartile; Ptrend=0.013), premenopausal (PR=0.61, 95% CI=0.41-0.91 for the fourth quartile; Ptrend=0.014) and postmenopausal women (PR=0.45, 95% CI=0.21-0.96 for the fourth quartile; Ptrend=0.022). Conversely, higher total physical activity was associated with higher expression levels of the anti-inflammatory mediator IL-10 in normal breast epithelial tissue among all (PR=1.66, 95% CI=0.97-2.85 for the fourth quartile; Ptrend=0.071) and postmenopausal women (PR=4.69, 95% CI=1.26-17.43 for the fourth quartile; Ptrend=0.010). Our findings suggest a beneficial effect of physical activity on the local inflammatory profile in the breast tissue.

An isoform of AIF1 involved in breast cancer.

BACKGROUND: Inflammation is a major player in breast cancer (BC) progression. Allograft-inflammatory factor-1 (AIF1) is a crucial mediator in the inflammatory response. AIF1 reportedly plays a role in BC, but the mechanism remains to be elucidated. We identified two AIF1 isoforms, AIF1v1 and AIF1v3, which were differentially expressed between affected and unaffected sisters from families with high risk of BC with no deleterious BRCA1/BRCA2 mutations (BRCAX). We investigated potential functions of AIFv1/v3 in BC of varying severity and breast adipose tissue by evaluating their expression, and association with metabolic and clinical parameters of BC patients. METHODS: AIF1v1/v3 expression was determined in BC tissues and cell lines using quantitative real-time PCR. Potential roles and mechanisms were examined in the microenvironment (fibroblasts, adipose tissue, monocytes and macrophages), inflammatory response (cell reaction in BC subgroups), and metabolism [treatment with docosahexaenoic acid (DHA)]. Association of AIF1 transcript expression with clinical factors was determined by Spearman's rank correlation. Bioinformatics analyses were performed to characterize transcripts. RESULTS: AIF1v1/v3 were mostly expressed in the less severe BC samples, and their expression appeared to originate from the tumor microenvironment. AIF1 isoforms had different expression rates and sources in breast adipose tissue; lymphocytes mostly expressed AIF1v1 while activated macrophages mainly expressed AIF1v3. Bioinformatics analysis revealed major structural differences suggesting distinct functions in BC progression. Lymphocytes were the most infiltrating cells in breast tumors and their number correlated with AIF1v1 adipose expression. Furthermore, DHA supplementation significantly lowered the expression of AIF1 isoforms in BRCAX cell lines. Finally, the expression of AIF1 isoforms in BC and breast adipose tissue correlated with clinical parameters of BC patients. CONCLUSIONS: Results strongly suggest that AIF1v1 as much as AIF1v3 play a major role in the crosstalk between BC and infiltrating immune cells mediating tumor progression, implying their high potential as target molecules for BC diagnostic, prognostication and treatment.

Characteristics and long-term survival of patients diagnosed with pure tubular carcinoma of the breast.

BACKGROUND AND OBJECTIVES: Pure tubular carcinomas (TC) of the breast are generally considered to have an excellent prognosis. This study aimed to analyze the characteristics and survival of patients with TC. METHODS: This was a retrospective study conducted at the CHU de Québec-Université Laval. Databases were searched for all cases treated between April 1997 and December 2010. Survival was retrieved from the Province of Quebec Ministry of Health. Follow-up was censored on December 31, 2011. Overall survival (OS) was compared to patients with invasive ductal carcinoma (ICD) matched for age, tumor size, lymph node involvement, year of diagnosis, ER, PgR, and HER2, histological grade, lymphovascular invasion, and chemotherapy. RESULTS: The frequency of TC was 2.9% (n = 223/7563). Tumors size was 7.4 ± 8.8 mm, without lymphovascular invasion (95.1%), ER-positive (98.2%), PgR-positive (69.5%), and HER2-negative (100%). Patients were followed up for 7.1 ± 2.7 years. The actuarial 13-year OS was 89.0% for TC, compared to 85.8% for IDC (P = 0.13). For TC, the 13-year OS was 95.8% in NO patients compared to 90.0% for N1-3 (P = 0.01). CONCLUSION: Despite the general popular belief that patients with TC fare better than patients with IDC, the 13-year OS of TC was similar to that of grade I IDC.

Is there an Upgrading to Malignancy at Surgery of Mucocele-Like Lesions Diagnosed on Percutaneous Breast Biopsy?

Management of pure mucocele-like lesion (MLL) diagnosed on percutaneous breast biopsy (PBB) is controversial. To assess surgical upgrade rate and clinical outcome of pure MLL obtained as sole diagnosis on PBB. Patients diagnosed with a MLL as the most advanced lesion on PBB from April 1997 to December 2010 were reviewed for radiologic presentation, biopsy technique, and pathologic and clinical outcomes. Of the 21,340 image-guided PBB performed during the study period, 50 women with 51 MLL (0.24%) were identified. Mean age was 53.1 ± 7.7 years. Radiologic findings were mostly microcalcifications (n = 47, 92.2%). Stereotactic PBB was performed for 49 lesions (96.1%). Surgery was performed shortly after biopsy in 35 women, with benign final pathology in 33, and upgrade to ductal carcinoma in situ (DCIS) in two patients (2/35, 5.7%). Mean follow-up was 4.2 ± 2.5 years (3.7 ± 2.1 years for surgical patients; 5.9 ± 2.9 years for follow-up only patients); three women were lost to follow-up (3/50). Three invasive cancers (3/47, 6.4%) were diagnosed 1.2, 1.2, and 2.8 years after biopsy: two in surgical patients, and one in a follow-up only patient. No cancer occurred at the same site as the original MLL. Pure MLL lesion of the breast is a rare entity and is mostly associated with a benign outcome. We observed an upgrade to DCIS slightly superior to 5%, but no invasive cancer. It is therefore unclear if these lesions should be excised or clinically and radiologically followed up when such lesions are found at PBB.

Dopamine regulates two classes of primate prefrontal neurons that represent sensory signals.

The lateral prefrontal cortex (PFC), a hub of higher-level cognitive processing, is strongly modulated by midbrain dopamine (DA) neurons. The cellular mechanisms have been comprehensively studied in the context of short-term memory, but little is known about how DA regulates sensory inputs to PFC that precede and give rise to such memory activity. By preparing recipient cortical circuits for incoming signals, DA could be a powerful determinant of downstream cognitive processing. Here, we tested the hypothesis that prefrontal DA regulates the representation of sensory signals that are required for perceptual decisions. In rhesus monkeys trained to report the presence or absence of visual stimuli at varying levels of contrast, we simultaneously recorded extracellular single-unit activity and applied DA to the immediate vicinity of the neurons by micro-iontophoresis. We found that DA modulation of prefrontal neurons is not uniform but tailored to specialized neuronal classes. In one population of neurons, DA suppressed activity with high temporal precision but preserved signal/noise ratio. Neurons in this group had short visual response latencies and comprised all recorded narrow-spiking, putative interneurons. In a distinct population, DA increased excitability and enhanced signal/noise ratio by reducing response variability. These neurons had longer visual response latencies and were composed exclusively of broad-spiking, putative pyramidal neurons. By gating sensory inputs to PFC and subsequently strengthening the representation of sensory signals, DA might play an important role in shaping how the PFC initiates appropriate behavior in response to changes in the sensory environment.

Striatal dopamine signals reflect perceived cue-action-outcome associations in mice.

Striatal dopamine drives associative learning by acting as a teaching signal. Much work has focused on simple learning paradigms, including Pavlovian and instrumental learning. However, higher cognition requires that animals generate internal concepts of their environment, where sensory stimuli, actions and outcomes become flexibly associated. Here, we performed fiber photometry dopamine measurements across the striatum of male mice as they learned cue-action-outcome associations based on implicit and changing task rules. Reinforcement learning models of the behavioral and dopamine data showed that rule changes lead to adjustments of learned cue-action-outcome associations. After rule changes, mice discarded learned associations and reset outcome expectations. Cue- and outcome-triggered dopamine signals became uncoupled and dependent on the adopted behavioral strategy. As mice learned the new association, coupling between cue- and outcome-triggered dopamine signals and task performance re-emerged. Our results suggest that dopaminergic reward prediction errors reflect an agent's perceived locus of control.

The neuronal implementation of representational geometry in primate prefrontal cortex.

Modern neuroscience has seen the rise of a population-doctrine that represents cognitive variables using geometrical structures in activity space. Representational geometry does not, however, account for how individual neurons implement these representations. Leveraging the principle of sparse coding, we present a framework to dissect representational geometry into biologically interpretable components that retain links to single neurons. Applied to extracellular recordings from the primate prefrontal cortex in a working memory task with interference, the identified components revealed disentangled and sequential memory representations including the recovery of memory content after distraction, signals hidden to conventional analyses. Each component was contributed by small subpopulations of neurons with distinct spiking properties and response dynamics. Modeling showed that such sparse implementations are supported by recurrently connected circuits as in prefrontal cortex. The perspective of neuronal implementation links representational geometries to their cellular constituents, providing mechanistic insights into how neural systems encode and process information.

Human acute microelectrode array recordings with broad cortical access, single-unit resolution, and parallel behavioral monitoring.

There are vast gaps in our understanding of the organization and operation of the human nervous system at the level of individual neurons and their networks. Here, we report reliable and robust acute multichannel recordings using planar microelectrode arrays (MEAs) implanted intracortically in awake brain surgery with open craniotomies that grant access to large parts of the cortical hemisphere. We obtained high-quality extracellular neuronal activity at the microcircuit, local field potential level and at the cellular, single-unit level. Recording from the parietal association cortex, a region rarely explored in human single-unit studies, we demonstrate applications on these complementary spatial scales and describe traveling waves of oscillatory activity as well as single-neuron and neuronal population responses during numerical cognition, including operations with uniquely human number symbols. Intraoperative MEA recordings are practicable and can be scaled up to explore cellular and microcircuit mechanisms of a wide range of human brain functions.

Resolving the prefrontal mechanisms of adaptive cognitive behaviors: A cross-species perspective.

The prefrontal cortex (PFC) enables a staggering variety of complex behaviors, such as planning actions, solving problems, and adapting to new situations according to external information and internal states. These higher-order abilities, collectively defined as adaptive cognitive behavior, require cellular ensembles that coordinate the tradeoff between the stability and flexibility of neural representations. While the mechanisms underlying the function of cellular ensembles are still unclear, recent experimental and theoretical studies suggest that temporal coordination dynamically binds prefrontal neurons into functional ensembles. A so far largely separate stream of research has investigated the prefrontal efferent and afferent connectivity. These two research streams have recently converged on the hypothesis that prefrontal connectivity patterns influence ensemble formation and the function of neurons within ensembles. Here, we propose a unitary concept that, leveraging a cross-species definition of prefrontal regions, explains how prefrontal ensembles adaptively regulate and efficiently coordinate multiple processes in distinct cognitive behaviors.

Low frequency of cancer occurrence in same breast quadrant diagnosed with lobular neoplasia at percutaneous needle biopsy.

PURPOSE: To determine the type of mammographic abnormality leading to needle biopsy of lobular neoplasia (LN) and define the clinical evolution of low-risk LN lesions diagnosed at needle biopsy but not surgically removed. MATERIALS AND METHODS: This study was approved by the institutional review board, and the requirement to obtain informed consent was waived. Among 16 945 needle biopsies performed between April 1998 and August 2008, LN was determined to be the most suspicious lesion in 352 samples (2.1%) (pleomorphic and necrotic forms were excluded). Among 299 pure LN lesions that were not surgically removed, follow-up was available for 276 lesions in 275 women. RESULTS: Needle biopsy was performed because of mammographic calcifications in 215 of the 276 lesions (77.9%) and because of mammographic masses in 35 (12.7%). The mean follow-up was 5.0 years ± 2.4 (range, 0.6-12.2 years). All 275 women underwent one mammographic follow-up, 205 (74.5%) underwent a second mammographic follow-up, and 147 (53.5%) underwent a third mammographic follow-up. Cancer was diagnosed in 27 of the 275 cases (9.8%) after a mean of 3.9 years ± 2.6 (range, 1.2-10.8 years). Only three cancers (1.1%) occurred in the same breast quadrant as the one originally diagnosed with LN at needle biopsy. CONCLUSION: Lumpectomy of pure LN lesions may not prevent malignancy in most cases. Consequently, women with pure LN of a low-risk type diagnosed at needle biopsy are strongly encouraged to undergo a yearly breast clinical examination and yearly mammographic follow-up to detect an eventual cancer in its early stages.

Association between genome-wide epigenetic and genetic alterations in breast cancer tissue and response to HER2-targeted therapies in HER2-positive breast cancer patients: new findings and a systematic review.

Recent evidence suggests that genetic and epigenetic mechanisms might be associated with acquired resistance to cancer therapies. The aim of this study was to assess the association of genome-wide genetic and epigenetic alterations with the response to anti-HER2 agents in HER2-positive breast cancer patients. PubMed was screened for articles published until March 2021 on observational studies investigating the association of genome-wide genetic and epigenetic alterations, measured in breast cancer tissues or blood, with the response to targeted treatment in HER2-positive breast cancer patients. Sixteen studies were included in the review along with ours, in which we compared the genome-wide DNA methylation pattern in breast tumor tissues of patients who acquired resistance to treatment (case group, n = 6) to that of patients who did not develop resistance (control group, n = 6). Among genes identified as differentially methylated between the breast cancer tissue of cases and controls, one of them, PRKACA, was also reported as differentially expressed in two studies included in the review. Although included studies were heterogeneous in terms of methodology and study population, our review suggests that genes of the PI3K pathway may play an important role in developing resistance to anti-HER2 agents in breast cancer patients. Genome-wide genetic and epigenetic alterations measured in breast cancer tissue or blood might be promising markers of resistance to anti-HER2 agents in HER2-positive breast cancer patients. Further studies are needed to confirm these data.

Notation-independent representation of fractions in the human parietal cortex.

Although the concept of whole numbers is intuitive and well suited for counting and ordering, it is with the invention of fractions that the number system gained precision and flexibility. Absolute magnitude is encoded by single neurons that discharge maximally to specific numbers. However, it is unknown how the ratio of two numbers is represented, whether by processing numerator and denominator in separation, or by extending the analog magnitude code to relative quantity. Using functional MRI adaptation, we now show that populations of neurons in human fronto-parietal cortex are tuned to preferred fractions, generalizing across the format of presentation. After blood oxygen level-dependent signal adaptation to constant fractions, signal recovery to deviant fractions was modulated parametrically as a function of numerical distance between the deviant and adaptation fraction. The distance effect was invariant to changes in notation from number to word fractions and strongest in the anterior intraparietal sulcus, a key region for the processing of whole numbers. These findings demonstrate that the human brain uses the same analog magnitude code to represent both absolute and relative quantity. Our results have implications for mathematical education, which may be tailored to better harness our ability to access automatically a composite quantitative measure.

Involuntary eyelid closure after STN-DBS: evidence for different pathophysiological entities.

OBJECTIVE: Involuntary eyelid closure (IEC) may occur after deep brain stimulation of the subthalamic nucleus (STN-DBS) in Parkinson's disease (PD) and is often categorised as apraxia of lid opening (ALO), albeit the appropriateness of this term is under debate. To gain insight into the hitherto undefined pathophysiology of IEC after STN-DBS, we performed a comprehensive clinical and electrophysiological characterisation of lid function in a total of six PD patients. METHODS: The study was carried out in six PD patients who developed IEC after STN-DBS. They underwent neurological examination and electromyography recording of activity in the orbicularis oculi muscle (OO) upon varying stimulation patterns. Intraoperative studies were performed in one patient. RESULTS: Increasing STN-DBS intensity induced IEC in four patients, whereas it improved the condition in two. Needle EMG showed tonic hyperactivity of the OO in STN-DBS induced IEC, while variable patterns of OO activity (irregular and tonic) were seen in patients with STN-DBS-relieved IEC. Intraoperative analysis in one patient showed evidence for IEC being induced by activation of corticobulbar fibres. CONCLUSIONS: We identified two groups of IEC after STN-DBS based on clinical and EMG patterns: (1) STN-DBS induced IEC associated with tonic OO overactivity and (2) STN-DBS relieved IEC presenting with variable EMG patterns. Our findings provide relevant information on pathophysiology of STN-DBS related IEC and implications for its therapeutic management.

Quantitative DNA methylation analysis of laser capture microdissected formalin-fixed and paraffin-embedded tissues.

We developed an assay to quantify DNA methylation in breast cancer cells isolated by laser capture microdissection (LCM). The assay uses methylation sensitive restriction enzyme (MSRE) digestion and quantitative polymerase chain reaction (qPCR). To assess the validity and precision of the assay, we prepared standard samples with expected methylation percentage (MP) for two gene promoters (PLAU (plasminogen inhibitor, urokinase) and TIMP3 (TIMP metallopeptidase inhibitor 3)) that we compared with measured MPs. We found good linearity of MSRE digestion and qPCR procedures for both promoters (beta=0.90-1.19+/-0.05-0.10 and r=0.95-0.98; all P<0.0001). Moreover, results remained similar after addition of a purification step between MSRE digestion and qPCR procedures. The validity of this technique was also confirmed by successfully replicating previously published MPs of four cell lines for PLAU and TIMP3 promoters. We assessed the consistency of our approach by comparing MPs of PLAU and TIMP3 promoters from nine breast cancer patients and two cell lines using LCM frozen tissues and their corresponding formalin-fixed paraffin-embedded tissues. We found good consistency (intraclass correlation coefficient=0.93) of MPs between frozen tissues and formalin-fixed paraffin-embedded tissues. Our data demonstrate that this assay based on digestion with MSRE and qPCR procedures is a good technique to quantify MP on limited amounts of DNA and may find clinical applications.

Trastuzumab effects depend on HER2 phosphorylation in HER2-negative breast cancer cell lines.

The breast cancer (BC) biomarker HER2 (Human Epidermal Receptor 2) is overexpressed in 25% of BC. Only patients with HER2-positive tumors receive HER2-targeting therapies, like trastuzumab (Herceptin). However, some women with a HER2-negative BC could benefit from trastuzumab. This could be explained by the activation/phosphorylation of HER2 that can be recognized by trastuzumab. The aim of this study is to examine trastuzumab effects on HER2 phosphorylation at tyrosine Y877 (pHER2Y877). HER2 and pHER2Y877 status were evaluated in a cohort of BC patients representative of molecular subtypes distribution (n = 497) and in a series of BC cell lines (n = 7). Immunohistochemistry against pHER2Y877 was performed on tissue micro arrays. Cellular proliferation assays were performed on BC cell lines presenting different combinations of HER2 and pHER2Y877 status and treated with increasing doses of trastuzumab (0-150 µg/ml). The prevalence of pHER2Y877 in this cohort was 6%. Nearly 5% of patients with HER2-negative tumors (n = 406, 82%) overexpressed pHER2Y877. Among triple negative BC patients (n = 39, 8%), 7.7% expressed pHER2Y877. Trastuzumab treatment decreased cell proliferation in HER2-/pHER2Y877+ BC cell lines, to an extent comparable to what occurs in HER2+ cell lines, but did not affect HER2-/pHER2Y877- cell lines. Trastuzumab sensitivity in HER2-/pHER2Y877+ cell line is specific to HER2 tyrosine 877 phosphorylation. Hence, with further confirmation in a bigger cohort, trastuzumab treatment could be envisaged as a treatment option to women presenting with HER2-/pHER2+ tumors, representing more than 1000 BC women in Canada in 2019.

Tuning to non-symbolic proportions in the human frontoparietal cortex.

Humans share with many species a non-verbal system to estimate absolute quantity. This sense of number has been linked to the activity of quantity-selective neurons that respond maximally to preferred numerosities. With functional magnetic resonance imaging adaptation, we now show that populations of neurons in the human parietal and frontal cortex are also capable of encoding quantity ratios, or proportions, using the same non-verbal analog code as for absolute number. Following adaptation to visually presented constant proportions (specified by the ratio of line lengths or numerosities), we introduced novel relative magnitudes to examine the tuning characteristics of the population of stimulated neurons. In bilateral parietal and frontal cortex we found that blood oxygenation level-dependent signal recovery from adaptation was a function of numerical distance between the deviant proportion and the adaptation stimulus. The strongest effects were observed in the cortex surrounding the anterior intraparietal sulcus, a region considered pivotal for the processing of absolute magnitudes. Overall, there was substantial overlap of frontoparietal structures representing whole numbers and proportions. The identification of tuning to non-symbolic ratio stimuli, irrespective of notation, adds to the magnitude system a remarkable level of sophistication by demonstrating automatic access to a composite, derived quantitative measure. Our results argue that abstract concepts of both absolute and relative number are deeply rooted in the primate brain as fundamental determinants of higher-level numerical cognition.

The ABC of cardinal and ordinal number representations.

Numerical cognition encompasses the concepts of quantity ('how many?') and serial order ('which position?'). Yet, although numbers can convey different meanings, a recent imaging study by Fias and coworkers showed that ranking letters in the alphabet is subserved by a cortical network highly similar to that involved in judging magnitudes. In terms of neural processing, quantity and rank might just be two sides of the same coin.

Characterization of common UGT1A8, UGT1A9, and UGT2B7 variants with different capacities to inactivate mutagenic 4-hydroxylated metabolites of estradiol and estrone.

The oxidative metabolism of estrone (E1) and estradiol (E2) to form carcinogenic 4-hydroxy-catecholestrogens (4-OHCE) is associated with uterine and breast carcinogenesis. In this study, we conducted functional analyses of genetic variants in the UDP-glucuronosyltransferase UGT1A8, UGT1A9, and UGT2B7 enzymes primarily involved in the inactivation of 4-OHCEs. Compared with UGT2B7*2 (H268Y), UGT2B7*1 exhibited a 2-fold lower efficiency (intrinsic clearance) at conjugating 4-hydroxyestrone and 4-hydroxyestradiol at positions 3 and 4 caused by altered capacities (Vmax) and affinities (Km). The -79 G>A promoter variation, characterizing the UGT2B7*2g haplotype, leads to a 50% reduction of transcription (P < 0.001) in human endometrial carcinoma-1B cells. Furthermore, a >12-fold decreased intrinsic clearance of the *1 proteins was induced by selected amino acid substitutions in UGT1A8 (*3 C277Y) and UGT1A9 (*3 M33T). Frequencies of the low-activity alleles in Caucasians were 45% for UGT2B7*1, 5% for the -79A promoter variant, 1.2% for UGT1A8*3, and 2.2% for UGT1A9*3. Supporting a protective role in two organs sensitive to 4-OHCE-induced damages, the expression of UGT enzymes was shown by immunohistochemistry in normal breast and endometrial tissues and confirmed by Western blotting in a subset of samples. Altogether, findings suggest that specific polymorphisms in UGT genes may modulate the exposure to carcinogenic metabolites of E2 and potentially lead to an altered risk of breast and endometrial cancers in women carrying the variant alleles.

Structuring of Abstract Working Memory Content by Fronto-parietal Synchrony in Primate Cortex.

How is neuronal activity across distant brain regions orchestrated to allow multiple stimuli to be stored together in working memory, yet maintained separate for individual readout and protection from distractors? Using paired recordings in the prefrontal and parietal cortex of monkeys discriminating numbers of items (numerosities), we found that working memory content is structured by frequency-specific oscillatory synchrony. Parieto-frontal signaling in the beta band carried information about the most recent numerical input. Fronto-parietal coupling in the theta band differentiated between multiple memorized numerosities. Task-relevant and distracting stimuli were nested in spiking activity of single prefrontal neurons, but could be separated by reading out spikes at distinct phases of parietal theta oscillations. The strength of phase-locked, cross-regional memory coding predicted task performance. Frequency-specific communication channels in the fronto-parietal network could enable serial bottom-up and parallel top-down information transmission, providing an important mechanism to protect working memory from interference.