ABSTRACT
Introduction. MYC overexpression is a known phenomenon in breast cancer. This study investigates the correlation of MYC gene copy number amplification and MYC protein overexpression with coexisting genetic abnormalities and associated clinicopathologic features in breast cancer patients. Methods. The study analyzed data from 81 patients with localized or metastatic breast cancers using targeted next-generation sequencing and MYC immunohistochemical studies, along with pathological and clinical data. Results. Applying the criteria of MYC/chromosome 8 ratio ≥5, MYC copy number amplified tumors (n = 11, 14%) were associated with invasive ductal carcinoma (91% vs 68%, P = .048), poorly differentiated (grade 3, 64% vs 30%, P = .032), mitotically active (Nottingham mitotic score 3, 71% vs 20%, P = .004), estrogen receptor (ER)-negative (45% vs 12%, P = .008), and triple-negative (56% vs 12%, P = .013) compared to MYC non-amplified tumors. Among MYC-amplified breast cancer patients, those with triple-negative status showed significantly shorter disease-free survival time than non-triple negative MYC-amplified patients (median survival month: 25.5 vs 127.6, P = .049). MYC amplification is significantly associated with TP53 mutation (P = .007). The majority (10 of 11; 91%) of MYC-amplified tumors showed positive c-MYC immunostaining. Conclusion. Breast cancers with MYC copy number amplication display distinct clinicopathologic characteristics indicative of more aggressive behavior.
ABSTRACT
Anogenital mammary-like glands are normal structures of the anogenital region. Tumors originating from these glands often exhibit a striking resemblance to their mammary gland counterparts. Herein, we present a rare case of adenocarcinoma of mammary gland type in the vulva of a 69-year-old female. Histopathologic examination revealed a complex lesion, which included a large encapsulated papillary carcinoma (EPC) with associated invasive carcinoma of mammary gland type and ductal carcinoma in situ (DCIS). The invasive component consisted mostly of invasive ductal carcinoma of no special type, with a notable focus of invasive mucinous carcinoma. p40 immunostain demonstrated a lack of myoepithelial cells in both the EPC and invasive carcinoma, but such cells expressed p40 around the ducts involved by DCIS. The main component of this lesion, EPC, was characterized by a papillary proliferation within a cystic space surrounded by a fibrous capsule without a myoepithelial layer. The histopathologic features of anogenital EPC closely resemble cutaneous hidradenoma papilliferum. Indeed, there have been a few reports in the literature describing cases where in situ and invasive carcinoma arose from a preexisting hidradenoma papilliferum. As tumors of anogenital mammary-like glands bear a closer resemblance to breast lesions than to skin tumors, we recommend that they be aligned with the classification of well-established breast lesions rather than cutaneous adnexal tumors.
Subject(s)
Breast Neoplasms , Vulvar Neoplasms , Humans , Female , Vulvar Neoplasms/pathology , Vulvar Neoplasms/diagnosis , Vulvar Neoplasms/metabolism , Aged , Breast Neoplasms/pathology , Breast Neoplasms/diagnosis , Diagnosis, Differential , Carcinoma, Papillary/pathology , Carcinoma, Papillary/diagnosis , Carcinoma, Intraductal, Noninfiltrating/pathology , Carcinoma, Intraductal, Noninfiltrating/diagnosis , Adenocarcinoma/pathology , Adenocarcinoma/diagnosisABSTRACT
Breast carcinoma with tubulopapillary features is a newly described entity associated with poor prognosis with only 14 tumors reported in the literature. We report 2 additional tumors and identify novel immunohistochemical and molecular features of the tumor. The first tumor was from a 72-year-old woman with nonmetastatic breast carcinoma and the second was from a 32-year-old woman with metastatic breast carcinoma who received neoadjuvant therapy. Both tumors had high-grade nuclear features with a distinctive morphology characterized by infiltrating open glands with intratubular papillary and micropapillary projections in >90% of the invasive carcinoma. In addition to the usual predictors of aggressive behavior, both tumors showed a high expression of p16 and SOX10, which has not been previously described. Targeted tumor sequencing revealed pathogenic variants of TP53 in both tumors, in agreement with previous reports. Prior studies have shown a correlation between p16 and SOX10 expression with high-grade features and worse prognosis; typically seen in triple-negative carcinomas as demonstrated in both of our tumors. However, not all reported tumors of breast carcinoma with tubulopapillary features have demonstrated a triple-negative profile as there are a few reports of tumors with estrogen receptor and/or human epidermal growth factor 2 expression. Due to their distinct morphologic and molecular characteristics, breast carcinoma with tubulopapillary features may represent a new breast cancer histologic subtype.
ABSTRACT
Although mucinous carcinoma (MC) is considered a favorable histologic subtype of invasive breast cancer (BC), a subset of MC is managed with neoadjuvant therapy (NAT). The clinical and pathologic features of MC following NAT are not well characterized. The aim of this study is to characterize pathologic response in patients with MC treated with NAT, including neoadjuvant endocrine therapy (NET), neoadjuvant chemotherapy (NCT), and Herceptin-targeted NCT (H-NCT). We conducted a retrospective cohort study of 28 patients with MC who received preoperative adjuvant therapy followed by resection from three institutions between 2010 and 2020. Demographic and clinical information were retrieved from the medical records. Pathologic review of the post NAT resection specimens was performed including tumor grading, tumor size, staging, residual tumor cellularity, estrogen receptor (ER) and HER2 status. Nine (32 %) patients with ER+/HER2- MC received NET, 8 (29 %) ER+/HER2- MC were treated with NCT only and 11 (39 %) HER2+ MC received HER2-targeted NCT (H-NCT). The HER2+ MC patients were younger (45 vs. 64 years; p = 0.006). The HER2+ MC were of higher grade (p = 0.03) and more likely to be multifocal (p = 0.008). Only 2 of 28 (7 %) MC (both HER2+) showed complete pathologic response with residual acellular mucin pools. Persistent mass-forming mucin pools were present in 26 (93 %) cases. The residual tumor cellularity was markedly reduced (≤5 %) in H-NCT treated MC (11/11, 100 %), followed by NET group (6/9, 67 %) and NCT only group (4/8, 50 %) (p = 0.011). Similarly, a higher rate of pathologic response (pCR/RCB-I) was observed in H-NCT (7/11, 64 %), followed by NET group (5/9, 56 %), and NCT only group (1/7, 13 %) (p = 0.053). Post-therapy, all HER2+ MC were smaller than 2 cm and ypT size was significantly smaller in H-NCT group (11/11, 100 %) versus combined NET (5/9, 55 %) and NCT only groups (4/8, 50 %) (p = 0.029). We conclude that ER-/HER2+ and ER+/HER2-mucinous carcinomas of the breast show robust pathological response to neoadjuvant HER2 targeted and endocrine therapy, respectively. Our findings suggest that MC may show good response to endocrine therapy.
Subject(s)
Breast Neoplasms , Neoadjuvant Therapy , Humans , Female , Neoplasm, Residual , Retrospective Studies , Receptor, ErbB-2 , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Receptors, Estrogen , MucinsABSTRACT
BACKGROUND: Retesting for Human epidermal growth factor receptor-2 (HER2) in post-neoadjuvant therapy resection is variable, and data is conflicting regarding the prognostic significance of changes in HER2 expression pre and post therapy. METHODS: We identified 104 patients with localized HER2 IHC 3+ breast cancer who received neoadjuvant trastuzumab(T)/pertuzumab(P) containing chemotherapy at Yale Cancer Center between 2012 and 2022. Patients were divided into 3 cohorts by response and HER2 IHC in the residual disease: Cohort 1 pathologic complete response (pCR), Cohort 2 pre-treatment IHC 3+/post treatment IHC 1+/2+, and Cohort 3 pre-treatment IHC 3+/post-treatment IHC 3+. Kaplan-Meier survival analysis was performed to assess recurrence free survival at 36 months. RESULTS: The overall pCR rate was 62.5% (65/104), while 37.5% (39/104) of patients had residual disease (RD). Among patients with RD, 58.9% (23/39) remained IHC 3+ and 41.1% (16/39) had reduced HER2 expression IHC1+ or 2+. In patients with HER2 IHC 3+ RD, 26% (6/23) developed local recurrence or distant metastasis while none of patients with post NAT HER2 IHC 1+ or 2+ RD had relapse (p = 0.0309). In patients with pCR, 6.15% (4/65) had recurrence. Kaplan-Meier survival analysis revealed superior disease-free survival in patients with reduced HER2 IHC expression compared to those with remained IHC 3+ (log rank p = 0.004). CONCLUSION: We conclude that reduced HER2 expression by IHC following neoadjuvant treatment was associated with lower recurrence rates in HER2 IHC 3+ breast cancer. If confirmed, RD HER2 IHC expression could be used as a prognostic biomarker to stratify patients in adjuvant trials and identify patients who may benefit from more intensive adjuvant therapy and post therapy surveillance.
Subject(s)
Breast Neoplasms , Humans , Female , Breast Neoplasms/drug therapy , Breast Neoplasms/surgery , Prognosis , Neoadjuvant Therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Neoplasm Recurrence, Local/etiology , Receptor, ErbB-2/metabolism , Trastuzumab/therapeutic useABSTRACT
Genetic aberrations in the Estrogen Receptor 1 (ESR1) gene have been identified as an important mechanism of resistance to endocrine therapy in metastatic breast carcinoma. In this study, we aimed to correlate ESR1 genetic aberrations with the ER and PR status in paired metastatic and primary breast carcinomas. Patients with ER-positive breast cancer were divided into two groups: ESR1 genetic aberration (n = 26) and wild-type control (n = 29) based on genetic profiling of their metastatic tumors. Clinicopathological features and ER/PR status were analyzed in paired primary and metastatic tumors. Although there was no significant difference in ER expression between the ESR1 aberration and control groups in primary tumors, ER positivity rate in metastatic tumors was significantly higher in the ESR1 aberration group than in the control group (100% vs. 86%, P < .05). ESR1 aberrated cases were associated with more liver metastases than control tumors (46% vs. 10%, P < .01). The ER percentage and intensity slightly increased from primary to metastatic tumors in the ESR1 aberration group compared to a decrease in both in the wild-type group (percentage increase 2% vs. decrease 19%, P = .0594; intensity increase 0.04 vs. decrease 0.8, p < .05). Patients with ESR1 aberrated metastases were more likely than those with wild-type ESR1 metastases to have the following characteristics: 1) ER percentage ≥90% and intensity >2, as well as PR percentage ≥30% and intensity >1 in metastatic tumors; 2) ER percentage ≥90% and PR percentage ≥70% in primary tumors; and 3) slightly increase in ER percentage and intensity from primary to metastatic tumors. Based on the ER/PR parameters of paired primary and metastatic breast cancer, ESR1 aberration in metastasis may be predicted.
Subject(s)
Breast Neoplasms , Receptors, Estrogen , Humans , Female , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Breast Neoplasms/pathology , Estrogen Receptor alpha/geneticsABSTRACT
The calcium ion (Ca2+), as a well-known second messenger, plays an important role in multiple processes of growth, development, and stress adaptation in plants. As central Ca2+ sensor proteins and a multifunctional kinase family, calcium-dependent protein kinases (CDPKs) are widely present in plants. In maize, the signal transduction processes involved in ZmCDPKs' responses to abiotic stresses have also been well elucidated. In addition to Ca2+ signaling, maize ZmCDPKs are also regulated by a variety of abiotic stresses, and they transmit signals to downstream target molecules, such as transport proteins, transcription factors, molecular chaperones, and other protein kinases, through protein interaction or phosphorylation, etc., thus changing their activity, triggering a series of cascade reactions, and being involved in hormone and reactive oxygen signaling regulation. As such, ZmCDPKs play an indispensable role in regulating maize growth, development, and stress responses. In this review, we summarize the roles of ZmCDPKs as a convergence point of different signaling pathways in regulating maize response to abiotic stress, which will promote an understanding of the molecular mechanisms of ZmCDPKs in maize tolerance to abiotic stress and open new opportunities for agricultural applications.
Subject(s)
Calcium , Zea mays , Zea mays/genetics , Zea mays/metabolism , Calcium/metabolism , Protein Kinases/genetics , Protein Kinases/metabolism , Plants/metabolism , Signal Transduction , Stress, Physiological , Gene Expression Regulation, PlantABSTRACT
OBJECTIVES: Standard chemotherapy agents, including carboplatin, have known immunogenic properties. We sought to determine how carboplatin may influence lymphocyte trafficking to tumor sites. METHODS: Murine models of ovarian cancer were utilized to examine lymphocyte trafficking with common clinically used agents including carboplatin, anti-PD-1 antibody, or anti-VEGFR-2 antibody. Adhesion interactions of lymphocytes with tumor vasculature were measured using intravital microscopy, lymphocyte homing with immunohistochemistry, and treatment groups followed for overall survival. RESULTS: Carboplatin chemotherapy profoundly alters the tumor microenvironment to promote lymphocyte adhesive interactions with tumor vasculature and resultant improvement in lymphocyte trafficking. The measured results seen with carboplatin in the tumor microenvironment were superior to anti-PD-1 treatment or anti-VEGFR-2 which may have contributed to increased overall survival in carboplatin treated groups. CONCLUSIONS: These novel findings suggest a role for chemotherapeutic agents to broadly influence anti-tumor immune responses beyond the induction of immunogenic tumor cell death.
Subject(s)
Antineoplastic Agents , Ovarian Neoplasms , Female , Mice , Humans , Animals , Carboplatin , Tumor Microenvironment , Antineoplastic Agents/therapeutic use , CD8-Positive T-Lymphocytes , Ovarian Neoplasms/pathology , Lymphocytes, Tumor-InfiltratingABSTRACT
OBJECTIVES: Clinical and demographic features of cystic neutrophilic granulomatous mastitis (CNGM) have not been fully explored due to the rarity of the disease. Herein we studied clinicopathologic characteristics of CNGM in a sizable hospital-based cohort. METHODS: A case-control study was performed to compare clinicopathologic characteristics between patients with CNGM and granulomatous mastitis other than CNGM and between CNGM with and without Corynebacterium identification. RESULTS: Cases of CNGM (n = 31) and non-CNGM (n = 30) were included. Compared with the non-CNGM group, patients with CNGM were statistically significantly younger (median age: 38 vs 43 years), were less likely to be smokers (9% vs 40%), were more likely to have a painful lesion (97% vs 77%) or a larger mass-like lesion (median size: 4.6 vs 1.9 cm), and tended to have a higher Breast Imaging Reporting and Data System score in radiologic studies (score ≥4: 81% vs 53%), positive Corynebacterium identification results (36% vs 0%), and a longer resolving time (12 vs 6 months; all P values for above comparisons <.05). Among CNGM cases, patients with and without Corynebacterium identification shared a similar clinicopathologic profile. CONCLUSIONS: Our study further demonstrated that CNGM is a unique infectious disease with distinct clinicopathologic features.
Subject(s)
Corynebacterium Infections , Granulomatous Mastitis , Adult , Case-Control Studies , Corynebacterium , Corynebacterium Infections/microbiology , Female , Granulomatous Mastitis/microbiology , HumansABSTRACT
AIMS: To examine our hypothesis that a higher number of touching tumour-infiltrating lymphocytes (TILs) in low-risk ductal carcinoma in situ (DCIS) detected in a setting such as an active surveillance clinical trial correlates with upgrading to high-grade DCIS (HG-DCIS) in the subsequent excisional biopsy. METHODS AND RESULTS: The clinical inclusion criteria of the Comparison of Operative versus Monitoring and Endocrine Therapy (COMET) trial were applied to women who were mammographically screened between 2007 and 2017. In the core needle biopsy, touching TILs were assessed by counting the number of TILs touching the ductal basement membrane or away from it by one lymphocyte thickness. The highest number of TILs around a single involved duct and the average number among involved ducts were recorded. DCIS was graded as low or intermediate. Twenty-six of 129 (20.2%) cases had upgrading [14 (10.9%) to pure HG-DCIS, and 12 (9.3%) to invasive carcinoma, two of them with concurrent HG-DCIS]. An increased average number of touching TILs and intermediate-grade DCIS correlated with upgrading to HG-DCIS in 11 of 16 (68.8%) cases, and a decreased average number of touching TILs and low-grade DCIS correlated with no upgrading in 89 of 113 (78.8%) cases [accuracy of 0.775; area under the curve (AUC) of 0.746]. An increased highest number of touching TILs and intermediate-grade DCIS correlated with upgrading to HG-DCIS in 12 of 16 (75%) cases, and a decreased highest number of touching TILs and low-grade DCIS correlated with no upgrading in 82 of 113 (72.6%) cases (accuracy of 0.7287; AUC of 0.734). A highest number of touching TILs of ≥10 correlated with upgrading to invasive carcinoma and/or HG-DCIS (P = 0.018). CONCLUSIONS: Intermediate-grade and touching TILs may be good variables to examine in the COMET trial and to correlate with the risk of upgrading.
Subject(s)
Breast Neoplasms/pathology , Carcinoma, Intraductal, Noninfiltrating/pathology , Lymphocytes, Tumor-Infiltrating/pathology , Neoplasm Recurrence, Local/pathology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , PrognosisABSTRACT
An efficient and straightforward metal-free regioselective C-H dithiocarbamation of indolizines with tetraalkylthiuram disulfide has been described. A series of indolizine-dithiocarbamate derivatives were easily accessed in moderate to good yields with a broad scope. In addition, imidazo[1,2-a]pyridines were also well tolerated to afford diverse imidazoheterocycle-dithiocarbamate products, which are expected to be utilized for drug discovery. Of note, the reaction could be readily scaled up, and shows its practical value in organic synthesis.
ABSTRACT
OBJECTIVES: This study aims to investigate the consequences of comedonecrosis omission as an exclusion criterion of the Comparison of Operative vs Monitoring and Endocrine Therapy (COMET) trial. METHODS: The clinical inclusion criteria of the COMET trial were applied on women who were mammographically screened between 2007 and 2017 and had a diagnosis of low- or intermediate-grade ductal carcinoma in situ (DCIS). The percentage of ductal diameter occupied by necrosis was calculated. RESULTS: Twenty-six of 129 (20.2%) cases were upgraded. Larger calcification span correlated with upgrade (P = .02), with the best cutoff of 1.1 cm, and negative predictive value of 86%. When solely analyzing cases with no comedonecrosis (n = 76), none of the variables correlated with upgrade. Comedonecrosis was significantly correlated with upgrade to invasive carcinoma (P = .041), with the best cutoff of 53% of ductal diameter occupied by necrosis. CONCLUSIONS: Results indicate that comedonecrosis and span of mammographic calcifications could be risk factors in women managed with active surveillance.
Subject(s)
Breast Neoplasms/pathology , Carcinoma, Intraductal, Noninfiltrating/pathology , Adult , Aged , Aged, 80 and over , Breast/diagnostic imaging , Breast/pathology , Breast Neoplasms/diagnostic imaging , Carcinoma, Intraductal, Noninfiltrating/diagnostic imaging , Female , Humans , Mammography , Middle Aged , Risk Factors , Watchful WaitingABSTRACT
Rectifying electrical synapses (RESs) exist across animal species, but their rectification mechanism is largely unknown. We investigated why RESs between AVA premotor interneurons and A-type cholinergic motoneurons (A-MNs) in Caenorhabditis elegans escape circuit conduct junctional currents (I j) only in the antidromic direction. These RESs consist of UNC-7 innexin in AVA and UNC-9 innexin in A-MNs. UNC-7 has multiple isoforms differing in the length and sequence of the amino terminus. In a heterologous expression system, only one UNC-7 isoform, UNC-7b, can form heterotypic gap junctions (GJs) with UNC-9 that strongly favor I j in the UNC-9 to UNC-7 direction. Knockout of unc-7b alone almost eliminated the I j, whereas AVA-specific expression of UNC-7b substantially rescued the coupling defect of unc-7 mutant. Neutralizing charged residues in UNC-7b amino terminus abolished the rectification property of UNC-7b/UNC-9 GJs. Our results suggest that the rectification property results from electrostatic interactions between charged residues in UNC-7b amino terminus.
ABSTRACT
New bis-2(5H)-furanone derivatives containing a benzidine core were synthesized via a one-step transition-metal-free reaction of benzidine with 5-substituted 3,4-dihalo-2(5H)-furanones. Their antitumor activities against various tumor cells have been evaluated by MTT assay. Among them, compound 4e exhibits significant inhibitory activity against C6 glioma cells with an IC50 value of 12.1 µm and low toxicity toward HaCaT human normal cells. Studies on the antitumor mechanism reveal that cell cycle arrest at S-phase in C6 cells is induced by compound 4e. Furthermore, investigations with electronic, fluorescence emission and circular dichroism spectra show that compound 4e can significantly interact with C6-DNA. These data indicate that DNA may be one of the potential targets for bis-2(5H)-furanone derivatives as anticancer drugs.
Subject(s)
Antineoplastic Agents/chemical synthesis , Drug Design , Furans/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Circular Dichroism , DNA/chemistry , DNA/metabolism , Drug Screening Assays, Antitumor , Furans/metabolism , Furans/pharmacology , Humans , Nucleic Acid Conformation , Octanols/chemistry , Static Electricity , Structure-Activity Relationship , Water/chemistryABSTRACT
An efficient Ag-catalyzed three-component reaction of amidines, ynals, and alcohols, phenols, or water has been developed. This strategy provides a wide range of substrates and represents a simple process for the preparation of different imidazole derivatives in good yields with high regioselectivities.
ABSTRACT
Impaired sonic hedgehog (Shh) signaling is involved in the pathology of cortical formation found in neuropsychiatric disorders. However, its role in the specification of human cortical progenitors is not known. Here, we report that Shh is expressed in the human developing cortex at mid-gestation by radial glia cells (RGCs) and cortical neurons. We used RGC cultures, established from the dorsal (cortical) telencephalon of human brain at mid-gestation to study the effect of Shh signaling. Cortical RGCs in vitro maintained their regional characteristics, expressed components of Shh signaling, and differentiated into Nkx2.1, Lhx6, and calretinin-positive (CalR(+)) cells, potential cortical interneuron progenitors. Treatment with exogenous Shh increased the pool of Nkx2.1(+) progenitors, decreased Lhx6 expression, and suppressed the generation of CalR(+) cells. The blockade of endogenous Shh signaling increased the number of CalR(+) cells, but did not affect Nkx2.1 expression, implying the existence of parallel Shh-independent pathways for cortical Nkx2.1 regulation. These results support the idea that, during human brain development, Shh plays an important role in the specification of cortical progenitors. Since direct functional studies in humans are limited, the in vitro system that we established here could be of great interest for modeling the development of human cortical progenitors.
Subject(s)
Calcium/metabolism , Cell Differentiation/physiology , Cell Lineage/physiology , Hedgehog Proteins/metabolism , Interneurons/cytology , Telencephalon/cytology , Adolescent , Adult , Cerebral Cortex/cytology , Humans , Nerve Tissue Proteins/metabolism , Young AdultABSTRACT
A convenient one-pot Cu(I)-catalyzed strategy for regioselective synthesis of trisubstituted furan derivatives has been developed via (2-furyl) carbene complexes. This process has opened a new synthetic route to a variety of α-carbonyl furans using air as the oxidant affording furans in good yields.
Subject(s)
Copper/chemistry , Furans/chemical synthesis , Methane/analogs & derivatives , Alkynes/chemistry , Catalysis , Cyclization , Furans/chemistry , Methane/chemistry , Molecular Structure , Oxidation-Reduction , StereoisomerismABSTRACT
5-Ethyl-5-phenylpyrimidine-2,4,6(1H, 3H, 5H)-trione is an anti-convulsant used to treat disorders of movement, e.g. tremors. This work deals with the transformation of phenobarbital by UV/TiO(2) heterogeneous photocatalysis, to assess the decomposition of the pharmaceutical compound, to identify intermediates, as well as to elucidate some mechanistic details of the degradation. The photocatalytic removal efficiency of 100 µm phenobarbital is about 80% within 60 min, while the degradation efficiency of phenobarbital was better in alkaline solution. The study on contribution of reactive oxidative species (ROSs) has shown that ()OH is responsible for the major degradation of phenobarbital, while the photohole, photoelectrons and the other ROSs have the minor contribution to the degradation. Finally, based on the identification of degradation intermediates, two main photocatalytic degradation pathways have been tentatively proposed, including the hydroxylation and cleavage of pyrimidine ring in the phenobarbital molecule respectively. Certainly, the phenobarbital can be mineralized when the photocatalytic reaction time prolongs.
Subject(s)
Anticonvulsants/chemistry , Phenobarbital/chemistry , Titanium/chemistry , Water Pollutants, Chemical/chemistry , Anticonvulsants/analysis , Kinetics , Models, Chemical , Oxidation-Reduction , Phenobarbital/analysis , Photochemical Processes , Water Pollutants, Chemical/analysisABSTRACT
The pannexin-1 (Panx1) channel (often referred to as the Panx1 hemichannel) is a large-conductance channel in the plasma membrane of many mammalian cells. While opening of the channel is potentially detrimental to the cell, little is known about how it is regulated under physiological conditions. Here we show that stomatin inhibited Panx1 channel activity. In transfected HEK-293 cells, stomatin reduced Panx1-mediated whole-cell currents without altering either the total or membrane surface Panx1 protein expression. Stomatin coimmunoprecipitated with full-length Panx1 as well as a Panx1 fragment containing the fourth membrane-spanning domain and the cytosolic carboxyl terminal. The inhibitory effect of stomatin on Panx1-mediated whole-cell currents was abolished by truncating Panx1 at a site in the cytosolic carboxyl terminal. In primary culture of mouse astrocytes, inhibition of endogenous stomatin expression by small interfering RNA enhanced Panx1-mediated outward whole-cell currents. These observations suggest that stomatin may play important roles in astrocytes and other cells by interacting with Panx1 carboxyl terminal to limit channel opening.
Subject(s)
Blood Proteins/metabolism , Connexins/chemistry , Connexins/metabolism , Ion Channel Gating , Membrane Proteins/metabolism , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/metabolism , Animals , Astrocytes/metabolism , Blood Proteins/antagonists & inhibitors , Cell Membrane/metabolism , Ethidium/metabolism , HEK293 Cells , Humans , Immunoprecipitation , Membrane Proteins/antagonists & inhibitors , Mice , Mice, Inbred C57BL , Protein Binding , Structure-Activity Relationship , TransfectionABSTRACT
A convenient method for the copper(I)-catalyzed arylation of substituted imidazo[1,2-a]pyridine has been developed. This method is applicable to a variety of aryl electrophiles, including bromides, iodides, and triflates. It represents the first general process for C-3 arylation of substituted imidazo[1,2-a]pyridine by Cu(I) catalysis to construct various functionalized imidazo[1,2-a]pyridine core π-systems.