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1.
Breast Cancer Res Treat ; 205(2): 403-411, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38441847

RESUMEN

PURPOSE: The recent findings from the DESTINY-Breast04 trial highlighted the clinical importance of distinguishing between HER2 immunohistochemistry (IHC) scores 0 and 1 + in metastatic breast cancer (BC). However, pathologist interpretation of HER2 IHC scoring is subjective, and standardized methodology is needed. We evaluated the consistency of HER2 IHC scoring among pathologists and the accuracy of digital image analysis (DIA) in interpreting HER2 IHC staining in cases of HER2-low BC. METHODS: Fifty whole-slide biopsies of BC with HER2 IHC staining were evaluated, comprising 25 cases originally reported as IHC score 0 and 25 as 1 +. These slides were digitally scanned. Six pathologists with breast expertise independently reviewed and scored the scanned images, and DIA was applied. Agreement among pathologists and concordance between pathologist scores and DIA results were statistically analyzed using Kendall coefficient of concordance (W) tests. RESULTS: Substantial agreement among at least five of the six pathologists was found for 18 of the score 0 cases (72%) and 15 of the score 1 + cases (60%), indicating excellent interobserver agreement (W = 0.828). DIA scores were highly concordant with pathologist scores in 96% of cases (47/49), indicating excellent concordance (W = 0.959). CONCLUSION: Although breast subspecialty pathologists were relatively consistent in evaluating BC with HER2 IHC scores of 0 and 1 +, DIA may be a reliable supplementary tool to enhance the standardization and quantification of HER2 IHC assessment, especially in challenging cases where results may be ambiguous (i.e., scores 0-1 +). These findings hold promise for improving the accuracy and consistency of HER2 testing.


Asunto(s)
Neoplasias de la Mama , Inmunohistoquímica , Variaciones Dependientes del Observador , Receptor ErbB-2 , Humanos , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Receptor ErbB-2/metabolismo , Femenino , Inmunohistoquímica/métodos , Reproducibilidad de los Resultados , Biomarcadores de Tumor/metabolismo , Biomarcadores de Tumor/análisis , Procesamiento de Imagen Asistido por Computador/métodos
2.
Anal Methods ; 15(47): 6590-6602, 2023 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-38018453

RESUMEN

Algal toxins are important metabolites of toxic harmful algal blooms (HABs), and their qualitative and qualitative detection can serve as early warning indicators for toxic HABs, complementing traditional HAB monitoring and improving the accuracy of early warning. Therefore, this work took the detection of domoic acid (DA) as an example and prepared zeolitic imidazolate framework-8 (ZIF-8) with high enrichment performance and high water stability and its core-shell composite material SiO2@ZIF-8 as an adsorbent filler. Density functional theory (DFT) calculations and interference experiments verified that Zn2+ on SiO2@ZIF-8 played a crucial role in enriching DA on SiO2@ZIF-8. By using it as a solid-phase extraction (SPE) filler, it showed excellent performance compared with other SPE columns (C18/HLB/SAX/ZIF-8). Therefore, the SiO2@ZIF-8 column was coupled to high-performance liquid chromatography-mass spectrometry (SPE-HPLC-MS/MS) to establish a highly sensitive detection method for algal toxins in seawater, which had a wide linear range (12.0-5000.0 ng L-1), good reproducibility (RSD) and low limit of detection (4.0 ng L-1), and realized the monitoring of trace DA in the Pingtan sea area of Fujian Province from 2021 to 2022. By comparing other HAB early warning indicators such as salinity and pH and combining them with the information released by the Fujian Provincial Ocean and Fisheries Bureau, the content of DA in seawater measured by the established SPE-HPLC-MS/MS method can provide reference information for HAB monitoring and early warning.


Asunto(s)
Dióxido de Silicio , Zeolitas , Espectrometría de Masas en Tándem/métodos , Adsorción , Zeolitas/química , Reproducibilidad de los Resultados , Teoría Funcional de la Densidad , Agua de Mar/química , Toxinas Marinas/análisis , Extracción en Fase Sólida/métodos
3.
Breast Cancer Res Treat ; 199(3): 457-469, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37061619

RESUMEN

PURPOSE: Neoadjuvant anti-PD-(L)1 therapy improves the pathological complete response (pCR) rate in unselected triple-negative breast cancer (TNBC). Given the potential for long-term morbidity from immune-related adverse events (irAEs), optimizing the risk-benefit ratio for these agents in the curative neoadjuvant setting is important. Suboptimal clinical response to initial neoadjuvant therapy (NAT) is associated with low rates of pCR (2-5%) and may define a patient selection strategy for neoadjuvant immune checkpoint blockade. We conducted a single-arm phase II study of atezolizumab and nab-paclitaxel as the second phase of NAT in patients with doxorubicin and cyclophosphamide (AC)-resistant TNBC (NCT02530489). METHODS: Patients with stage I-III, AC-resistant TNBC, defined as disease progression or a < 80% reduction in tumor volume after 4 cycles of AC, were eligible. Patients received atezolizumab (1200 mg IV, Q3weeks × 4) and nab-paclitaxel (100 mg/m2 IV,Q1 week × 12) as the second phase of NAT before undergoing surgery followed by adjuvant atezolizumab (1200 mg IV, Q3 weeks, × 4). A two-stage Gehan-type design was employed to detect an improvement in pCR/residual cancer burden class I (RCB-I) rate from 5 to 20%. RESULTS: From 2/15/2016 through 1/29/2021, 37 patients with AC-resistant TNBC were enrolled. The pCR/RCB-I rate was 46%. No new safety signals were observed. Seven patients (19%) discontinued atezolizumab due to irAEs. CONCLUSION: This study met its primary endpoint, demonstrating a promising signal of activity in this high-risk population (pCR/RCB-I = 46% vs 5% in historical controls), suggesting that a response-adapted approach to the utilization of neoadjuvant immunotherapy should be considered for further evaluation in a randomized clinical trial.


Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama Triple Negativas , Humanos , Femenino , Antraciclinas/uso terapéutico , Neoplasias de la Mama Triple Negativas/patología , Terapia Neoadyuvante , Neoplasias de la Mama/tratamiento farmacológico , Paclitaxel/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos
4.
Front Oncol ; 13: 860711, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36910668

RESUMEN

Purpose: We evaluated he effects of molecular guided-targeted therapy for intractable cancer. Also, the epidemiology of druggable gene alterations in Chinese population was investigated. Materials and methods: The Long March Pathway (ClinicalTrials.gov identifier: NCT03239015) is a non-randomized, open-label, phase II trial consisting of several basket studies examining the molecular profiles of intractable cancers in the Chinese population. The trial aimed to 1) evaluate the efficacy of targeted therapy for intractable cancer and 2) identify the molecular epidemiology of the tier II gene alterations among Chinese pan-cancer patients. Results: In the first stage, molecular profiles of 520 intractable pan-cancer patients were identified, and 115 patients were identified to have tier II gene alterations. Then, 27 of these 115 patients received targeted therapy based on molecular profiles. The overall response rate (ORR) was 29.6% (8/27), and the disease control rate (DCR) was 44.4% (12/27). The median duration of response (DOR) was 4.80 months (95% CI, 3.33-27.2), and median progression-free survival (PFS) was 4.67 months (95% CI, 2.33-9.50). In the second stage, molecular epidemiology of 17,841 Chinese pan-cancer patients demonstrated that the frequency of tier II gene alterations across cancer types is 17.7%. Bladder cancer had the most tier-II alterations (26.1%), followed by breast cancer (22.4%), and non-small cell lung cancer (NSCLC; 20.2%). Conclusion: The Long March Pathway trial demonstrated a significant clinical benefit for intractable cancer from molecular-guided targeted therapy in the Chinese population. The frequency of tier II gene alterations across cancer types supports the feasibility of molecular-guided targeted therapy under basket trials.

5.
Clin Cancer Res ; 28(13): 2878-2889, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35507014

RESUMEN

PURPOSE: Metaplastic breast cancer (MpBC) is a rare subtype of breast cancer that is commonly triple-negative and poorly responsive to neoadjuvant therapy in retrospective studies. EXPERIMENTAL DESIGN: To better define clinical outcomes and correlates of response, we analyzed the rate of pathologic complete response (pCR) to neoadjuvant therapy, survival outcomes, and genomic and transcriptomic profiles of the pretreatment tumors in a prospective clinical trial (NCT02276443). A total of 211 patients with triple-negative breast cancer (TNBC), including 39 with MpBC, received doxorubicin-cyclophosphamide-based neoadjuvant therapy. RESULTS: Although not meeting the threshold for statistical significance, patients with MpBCs were less likely to experience a pCR (23% vs. 40%; P = 0.07), had shorter event-free survival (29.4 vs. 32.2 months, P = 0.15), metastasis-free survival (30.3 vs. 32.4 months, P = 0.22); and overall survival (32.6 vs. 34.3 months, P = 0.21). This heterogeneity is mirrored in the molecular profiling. Mutations in PI3KCA (23% vs. 9%, P = 0.07) and its pathway (41% vs. 18%, P = 0.02) were frequently observed and enriched in MpBCs. The gene expression profiles of each histologically defined subtype were distinguishable and characterized by distinctive gene signatures. Among nonmetaplastic (non-Mp) TNBCs, 10% possessed a metaplastic-like gene expression signature and had pCR rates and survival outcomes similar to MpBC. CONCLUSIONS: Further investigations will determine if metaplastic-like tumors should be treated more similarly to MpBC in the clinic. The 23% pCR rate in this study suggests that patients with MpBC should be considered for NAT. To improve this rate, a pathway analysis predicted enrichment of histone deacetylase (HDAC) and RTK/MAPK pathways in MpBC, which may serve as new targetable vulnerabilities.


Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama Triple Negativas , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/patología , Femenino , Humanos , Metaplasia , Terapia Neoadyuvante , Estudios Retrospectivos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología
6.
Clin Breast Cancer ; 22(2): e158-e166, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34187752

RESUMEN

INTRODUCTION: Breast conservation surgery (BCS) is the treatment of choice for unifocal, early-stage breast cancer. The ability to offer BCS to a wider subset of patients, including those with multifocal/multicentric cancer as well as extensive ductal carcinoma in situ, has emerged over time, especially in those undergoing joint oncoplastic reconstruction and those treated with neoadjuvant therapy. However, localization techniques using multiple radioactive seeds for bracketing in this patient subset have not been validated. MATERIALS AND METHODS: A single-institution retrospective review was conducted of all patients with breast cancer who underwent BCS, guided by multiple bracketed iodine I 125 radioactive seeds between January 2014 and April 2017. RESULTS: Bracketing of breast cancer using 2 or more radioactive seeds was performed in 157 breasts in 156 patients. Negative margins were achieved in 124 of 157 (79%) breasts, including 33 cases (21%) that underwent targeted margin reexcision at the time of surgery after intraoperative, multidisciplinary margin assessment. Thirty-three cases (21%) resulted in close or positive margins, of which 11 (7%) and 10 (6.4%) underwent completion mastectomy or repeat lumpectomy, respectively. Twelve patients (7.6%) did not undergo reexcision. En bloc resection was successful in 134 of 157 (85.4%) lumpectomies. Eighty-nine percent of the procedures were coupled with oncoplastic reconstruction. CONCLUSION: Bracketing techniques using multiple radioactive seeds expands the indications for breast conservation therapy in patients who would have traditionally required mastectomy. Intraoperative margin assessment improves surgical and pathologic success. Larger defects created by multifocal resection are optimally managed in concert with oncoplastic reconstruction to minimize asymmetries and aesthetic defects.


Asunto(s)
Neoplasias de la Mama/cirugía , Estética , Márgenes de Escisión , Mastectomía Segmentaria/métodos , Adulto , Neoplasias de la Mama/patología , Femenino , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
7.
Clin Cancer Res ; 27(19): 5365-5375, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34253579

RESUMEN

PURPOSE: Increasing tumor-infiltrating lymphocytes (TIL) is associated with higher rates of pathologic complete response (pCR) to neoadjuvant therapy (NAT) in patients with triple-negative breast cancer (TNBC). However, the presence of TILs does not consistently predict pCR, therefore, the current study was undertaken to more fully characterize the immune cell response and its association with pCR. EXPERIMENTAL DESIGN: We obtained pretreatment core-needle biopsies from 105 patients with stage I-III TNBC enrolled in ARTEMIS (NCT02276443) who received NAT from Oct 22, 2015 through July 24, 2018. The tumor-immune microenvironment was comprehensively profiled by performing T-cell receptor (TCR) sequencing, programmed death-ligand 1 (PD-L1) IHC, multiplex immunofluorescence, and RNA sequencing on pretreatment tumor samples. The primary endpoint was pathologic response to NAT. RESULTS: The pCR rate was 40% (42/105). Higher TCR clonality (median = 0.2 vs. 0.1, P = 0.03), PD-L1 positivity (OR: 2.91, P = 0.020), higher CD3+:CD68+ ratio (median = 14.70 vs. 8.20, P = 0.0128), and closer spatial proximity of T cells to tumor cells (median = 19.26 vs. 21.94 µm, P = 0.0169) were associated with pCR. In a multivariable model, closer spatial proximity of T cells to tumor cells and PD-L1 expression enhanced prediction of pCR when considered in conjunction with clinical stage. CONCLUSIONS: In patients receiving NAT for TNBC, deep immune profiling through detailed phenotypic characterization and spatial analysis can improve prediction of pCR in patients receiving NAT for TNBC when considered with traditional clinical parameters.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Humanos , Linfocitos Infiltrantes de Tumor , Terapia Neoadyuvante , Fenotipo , Pronóstico , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/genética , Microambiente Tumoral/genética
8.
PLoS One ; 15(11): e0241775, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33180796

RESUMEN

PURPOSE: The 2018 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guideline on HER2 testing in breast cancer permits reclassification of cases with HER2-equivocal results by FISH. The impact of such reclassification is unclear. We sought to determine the proportion of HER2-equivocal cases that are reclassified as HER2-negative and the impact of anti-HER2 therapy on survival in HER2-equivocal cases. METHODS: We reviewed medical records of breast cancer patients who had HER2 testing by fluorescence in stitu hybridization (FISH) and immunohistochemistry (IHC) performed or verified at The University of Texas MD Anderson Cancer Center during April 2014 through March 2018 and had equivocal results according to the 2013 ASCO/CAP guideline. The population was divided into 2 cohorts according to whether the biopsy specimen analyzed came from primary or from recurrent or metastatic disease. HER2 status was reclassified according to the 2018 ASCO/CAP guideline. Overall survival (OS) and event-free survival (EFS) were calculated using the Kaplan-Meier method, and the relationship between anti-HER2 therapy and clinical outcomes was assessed. RESULTS: We identified 139 cases with HER2-equivocal results according to the 2013 ASCO/CAP guideline: 90 cases of primary disease and 49 cases of recurrent/metastatic disease. Per the 2018 ASCO/CAP guideline, these cases were classified as follows: overall, HER2-negative 112 cases (80%), HER2-positive 1 (1%), and unknown 26 (19%); primary cohort, HER2-negative 85 (94%), HER2-positive 1 (1%), unknown 4 (4%); and recurrent/metastatic, HER2-negative 27 (55%) and unknown 22 (45%). Five patients in the primary-disease cohort and 1 patient in the recurrent/metastatic-disease cohort received anti-HER2 therapy. There was no significant association between anti-HER2 therapy and OS or EFS in either cohort (primary disease: OS, p = 0.67; EFS, p = 0.49; recurrent/metastatic-disease, OS, p = 0.61; EFS, p = 0.78. CONCLUSIONS: The majority of HER2-equivocal breast cancer cases were reclassified as HER2-negative per the 2018 ASCO/CAP guideline. No association between anti-HER2 therapy and OS or EFS was observed. HER2-equivocal cases seem to have clinical behavior similar to that of HER2-negative breast cancers.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Receptor ErbB-2/metabolismo , Adulto , Anciano , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/genética , Neoplasias de la Mama/mortalidad , Bases de Datos Genéticas , Femenino , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Supervivencia sin Progresión , Receptor ErbB-2/genética
9.
Appl Biochem Biotechnol ; 192(3): 881-894, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32607896

RESUMEN

A stable culture environment is the key for optimal growth and metabolic activity of microorganisms, especially in marine species, and intermittent feeding during DHA production using Schizochytrium sp. generates an unstable culture environment. To investigate the effect of unstable culture environment on the cells' physiological status and DHA synthesis, fermentations with different feeding strategies were performed on the lab scale. The intermittent feeding strategy caused fluctuations of substrate concentration and osmotic pressure, which had a negative effect on cell division and product synthesis. The physiological status and metabolic level of Schizochytrium sp. were relatively stable under a continuous feeding strategy with a relatively stable substrate concentration of 20-25 g/L, which was beneficial for the efficient transformation of substrate, leading to an improvement of DHA productivity. This strategy was further applied to pilot scale, whereby the DHA content, DHA productivity, convert ratio of glucose to lipid and DHA reached 55.02%, 320.17 mg/(L·h), 24.35%, and 13.40%, respectively. This study therefore provides an efficient strategy for ensuring a stable culture environment for the production of DHA and similar metabolites. Graphical Abstract.


Asunto(s)
Técnicas de Cultivo/métodos , Ácidos Docosahexaenoicos/biosíntesis , Fermentación , Estramenopilos/crecimiento & desarrollo , Estramenopilos/metabolismo , Reactores Biológicos , Biotecnología , Biotransformación
10.
BMC Chem ; 13(1): 92, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31384839

RESUMEN

BACKGROUND: Atractylodis rhizoma, is the dried rhizomes of Atractylodes lancea (Thunb.) DC. or A. chinensis (DC.) Koidz. Both of two are pharmacologically and economically important, while with differences in efficacy. Therefore, an authentication system is vital for evaluation the quality and discrimination adulteration of Atractylodis rhizoma. Fructooligosaccharides (FOS), which are regarded as functional ingredients in Atractylodis rhizoma, have not been used for quality control of Atractylodis rhizoma for shortage of reference compounds. RESULTS: A HPLC-ELSD method was developed for the quantification of FOS in Atractylodis rhizoma. And chemometrics analysis showed that 2 markers including content of degree of polymerization (DP) 12 and total content of DP 3-15 could be used as the main distinctive elements for quality evaluation of Atractylodis rhizome. Actually, the separation and purification of high DP FOS, such as DP 12, is still a challenge because of high polarity. Then DP 5-based qualification evaluation was investigated for quality control of Atractylodis rhizoma. The results showed that A. lancea and A. chinensis could be clearly separated. CONCLUSIONS: DP 5-based quantification method was credible and effectively adopted for solving the shortage of reference compounds and improving the quality control of Atractylodis rhizoma.

11.
Huan Jing Ke Xue ; 36(7): 2389-94, 2015 Jul.
Artículo en Chino | MEDLINE | ID: mdl-26489303

RESUMEN

The emission factor method was used to estimate major air pollutant emissions of coal-fired power plant in the Yangtze River Delta (YRD) region of the year 2012. Results showed that emissions of SO2, NOx, dust, PM10, PM2.5 were respectively 473 238, 1 566 195, 587 713, 348 773 and 179 820 t. For SO2 and NOx, 300 MW and above class units made contributions of 85% and 82% in emission; while in the respect of dust, PM10 and PM2.5 contribution rates of 100 MW and below class units were respectively 81%, 53% and 40%. Considering the regional distribution, Jiangsu discharged the most, followed by Zhejiang, Shanghai. According to discharge data of several local power plants, we also calculated and made a comparative analysis of emission factors in different unit levels in Shanghai, which indicated a lower emission level. Assuming an equal level was reached in whole YRD, SO2 emission would cut down 55. 8% - 65. 3%; for NOx and dust emissions were 50. 5% - 64. 1% and 3. 4% - 11. 3%, respectively. If technologies and pollution control of lower class units were improved, the emission cuts would improve. However, according to the pollution realities of YRD, we suggested to make a multiple-cuts plan, which could effectively improve the reaional atmospheric environment.


Asunto(s)
Contaminantes Atmosféricos/análisis , Carbón Mineral , Polvo/análisis , Monitoreo del Ambiente , China , Centrales Eléctricas
12.
Yi Chuan ; 37(7): 711-9, 2015 07.
Artículo en Chino | MEDLINE | ID: mdl-26351171

RESUMEN

4-coumaric acid: coenzyme A ligase (4CL) gene is one of the key genes involved in the regulation of lignin metabolism and the synthesis of flavonoid and other secondary metabolites in plant, while the synthesized and polymerized lignin is deposited in cell walls and leads to thickening of secondary walls in some parenchyma cells and formation of stone cells. To better understand the variety and quantity of 4CL genes in Pyrus bretschneideri Rehd., we used the amino acid and cDNA databases of Pyrus bretschneideri Rehd. genome to screen 4CL gene family, and analyzed their classification, evolutionary relationships, physical location, gene structure and conserved motif. Our results showed that 29 4CL genes were identified and preliminarily characterized, and these 4CL genes were distributed in all chromosomes except chromosomes 4, 8, 11, 12 and clustered on chromosomes 9 and 17 through gene location analysis. The relationship between 4CL gene structure and evolution was further determined by comparing gene structure and phylogenetic tree. These findings provide a basis for further analysis of 4CL gene function in Pyrus bretschneideri Rehd.


Asunto(s)
Coenzima A Ligasas/genética , Genoma de Planta , Pyrus/genética , Secuencia de Aminoácidos , Datos de Secuencia Molecular , Mapeo Físico de Cromosoma
13.
Case Rep Neurol Med ; 2013: 263718, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24151568

RESUMEN

Multiple observations suggest that certain parasitic infections can be oncogenic. Among these, neurocysticercosis is associated with increased risk for gliomas and hematologic malignancies. We report the case of a 71-year-old woman with colocalization of a metazoan parasite, possibly cysticercosis, and a WHO grade IV neuroepithelial tumor with exclusively neuronal differentiation by immunohistochemical stains (immunopositive for synaptophysin, neurofilament protein, and Neu-N and not for GFAP, vimentin, or S100). The colocalization and temporal relationship of these two entities suggest a causal relationship.

14.
Cancer Res ; 69(4): 1343-9, 2009 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-19190323

RESUMEN

Wnt/beta-catenin signaling plays an essential role in colon carcinogenesis. Galectin-3, a beta-galactoside-binding protein, has been implicated in Wnt signaling, but the precise mechanisms by which galectin-3 modulates the Wnt pathway are unknown. In the present study, we determined the effects of galectin-3 on the Wnt/beta-catenin pathway in colon cancer cells, as well as the mechanisms involved. Galectin-3 levels were manipulated in human colon cancer cells by stable transfection of galectin-3 antisense, short hairpin RNA, or full-length galectin-3 cDNA, and effects on beta-catenin levels, subcellular distribution, and Wnt signaling were determined. Galectin-3 levels correlated with beta-catenin levels in a variety of colon cancer cell lines. Down-regulation of galectin-3 resulted in decreased beta-catenin protein levels but no change in beta-catenin mRNA levels, suggesting that galectin-3 modulates beta-catenin by another mechanism. Reduction of galectin-3 led to reduced nuclear beta-catenin with a concomitant decrease in TCF4 transcriptional activity and expression of its target genes. Conversely, transfection of galectin-3 cDNA into colon cancer cells increased beta-catenin expression and TCF4 transcriptional activity. Down-regulation of galectin-3 resulted in AKT and glycogen synthase kinase-3beta (GSK-3beta) dephosphorylation and increased GSK activity, increasing beta-catenin phosphorylation and degradation. Ly294002, an inhibitor of phosphatidylinositol 3-kinase, and dominant-negative AKT, suppressed TCF4 transcriptional activity induced by galectin-3 whereas LiCl, a GSK-3beta inhibitor, increased TCF4 activity, mimicking the effects of galectin-3. These results suggest that galectin-3 mediates Wnt signaling, at least in part, by regulating GSK-3beta phosphorylation and activity via the phosphatidylinositol 3-kinase/AKT pathway, and, thus, the degradation of beta-catenin in colon cancer cells.


Asunto(s)
Neoplasias del Colon/fisiopatología , Galectina 3/genética , Glucógeno Sintasa Quinasa 3/metabolismo , Proteínas Wnt/fisiología , beta Catenina/metabolismo , Adenocarcinoma/enzimología , Adenocarcinoma/fisiopatología , Línea Celular Tumoral , Neoplasias del Colon/enzimología , Neoplasias Colorrectales/enzimología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/fisiopatología , Regulación hacia Abajo , Galectina 3/metabolismo , Regulación Neoplásica de la Expresión Génica , Genes Reporteros , Glucógeno Sintasa Quinasa 3 beta , Humanos , Inmunohistoquímica , Luciferasas/genética , Plásmidos , Reacción en Cadena de la Polimerasa , ARN Mensajero/genética , Transducción de Señal , Transfección , Regulación hacia Arriba , beta Catenina/genética
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