Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
Cancer Cell Int ; 24(1): 254, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39030607

RESUMEN

BACKGROUND: Breast cancer is the most common cancer in women. Cancer cells can persist in a prolonged dormant state for years without any clinical evidence of disease creating an urgent need to better understand the molecular mechanisms leading to relapse. This study aimed to identify extracellular matrix (ECM) components associated with hypoxia-induced breast cancer dormancy. The effects of selected ECM proteins on breast cancer cell proliferation were analyzed, along with their correlation with established prognostic markers in human breast cancer tissue. MATERIALS AND METHODS: Screening of extracellular matrix proteins was performed in hypoxia-induced dormant MCF-7 breast cancer cells. Proliferation of MCF-7 cells in vitro was subsequently determined in the presence of recombinant ColVII. Adipose tissue-derived mesenchymal stem cells (AdMSCs) subpopulation overexpressing ColVII were indirectly isolated by ColVII receptor integrin-α6 specific antibodies. AdMSCs- MCF-7 3D spheroid cultures were generated to model solid tumour conditions. In addition, the association between ColVII and various prognostic markers was evaluated in clinical samples of human breast cancer tissue. RESULTS: Dormant MCF-7 cells showed an elevated expression of ColVII while MCF-7 cells cultured on ColVII exhibited reduced proliferation in vitro. In AdMSCs-MCF-7 3D spheroids, a reduced proliferation of MCF-7 cells was observed in Int-α6+/ ColVIIhigh compared with Int-α6-/ ColVIIlow AdMSCs spheroids. In human tissue, high ColVII expression correlated to several positive prognostic markers. Staining for Cytokeratin-5 revealed that ColVIIhigh-expressing cells were predominantly myoepithelial cells. CONCLUSION: ColVII is associated with reduced proliferation of breast cancer cells in vitro. ColVII is strongly expressed in myoepithelial cells and in breast cancer tissue the high ColVII expression correlates with several well-known positive prognostic markers, highlighting its potential as a prognostic marker in breast cancer.

2.
Clin Breast Cancer ; 24(5): e360-e369.e4, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38485557

RESUMEN

INTRODUCTION: Fibrillar collagens accumulate in the breast cancer stroma and appear as poorly defined spiculated masses in mammography imaging. The prognostic value of tissue type I collagen remains elusive in treatment-naïve and chemotherapy-treated breast cancer patients. Here, type I collagen mRNA and protein expression were analysed in 2 large independent breast cancer cohorts. Levels were related to clinicopathological parameters, prognostic biomarkers, and outcome. METHOD: COL1A1 mRNA expression was analysed in 2509 patients with breast cancer obtained from the cBioPortal database. Type I collagen protein expression was studied by immunohistochemistry in 1395 women diagnosed with early invasive breast cancer. RESULTS: Low COL1A1 mRNA and protein levels correlated with poor prognosis features, such as hormone receptor negativity, high histological grade, triple-negative subtype, node positivity, and tumour size. In unadjusted analysis, high stromal type I collagen protein expression was associated with improved overall survival (OS) (HR = 0.78, 95% CI = 0.61-0.99, p = .043) and trended towards improved breast cancer-specific survival (BCSS) (HR = 0.65, 95% CI = 0.42-1.01, P = 0.053), although these findings were lost after adjustment for other clinical variables. In unadjusted analysis, high expression of type I collagen was associated with better OS (HR = 0.70, 95% CI = 0.55-0.90, P = .006) and BCSS (HR = 0.55, 95% CI = 0.34-0.88, P = .014) among patients not receiving chemotherapy. Strikingly, the opposite was observed among patients receiving chemotherapy. There, high expression of type I collagen was instead associated with worse OS (HR = 1.83, 95% CI = 0.65-5.14, P = .25) and BCSS (HR = 1.72, 95% CI = 0.54-5.50, P = .357). CONCLUSION: Low stromal type I collagen mRNA and protein expression are associated with unfavourable tumour characteristics in breast cancer. Stromal type I collagen might predict chemotherapy response.


Asunto(s)
Biomarcadores de Tumor , Neoplasias de la Mama , Colágeno Tipo I , Humanos , Femenino , Neoplasias de la Mama/patología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/mortalidad , Biomarcadores de Tumor/metabolismo , Biomarcadores de Tumor/análisis , Colágeno Tipo I/metabolismo , Pronóstico , Persona de Mediana Edad , Cadena alfa 1 del Colágeno Tipo I , Anciano , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Células del Estroma/metabolismo , Células del Estroma/patología
3.
Int J Cancer ; 152(3): 348-362, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36053839

RESUMEN

Experimental evidence suggests that alcohol induces cutaneous carcinogenesis, yet epidemiological studies on the link between alcohol intake and skin cancer have been inconsistent. The European Prospective Investigation into Cancer and Nutrition (EPIC) is a prospective cohort initiated in 1992 in 10 European countries. Alcohol intake at baseline and average lifetime alcohol intake were assessed using validated country-specific dietary and lifestyle questionnaires. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated in Cox models. A total of 14 037 skin cancer cases (melanoma: n = 2457; basal-cell carcinoma (BCC): n = 8711; squamous-cell carcinoma (SCC): n = 1928; unknown: n = 941) were identified among 450 112 participants (average follow-up: 15 years). Baseline alcohol intake was positively associated with SCC (>15 vs 0.1-4.9 g/day: HR = 1.44, 95% CI = 1.17-1.77; Ptrend  = .001), BCC (HR = 1.12, 95% CI = 1.01-1.23; Ptrend  = .04), and melanoma risks in men (HR = 1.17, 95% CI = 0.95-1.44; Ptrend  = .17), while associations were more modest in women (SCC: HR = 1.09, 95% CI = 0.90-1.30; Ptrend  = .13; BCC: HR = 1.08, 95% CI = 1.00-1.17, Ptrend  = .03; melanoma: HR = 0.93, 95% CI = 0.80-1.08, Ptrend  = .13). Associations were similar for lifetime alcohol intake, with an attenuated linear trend. Lifetime liquor/spirit intake was positively associated with melanoma (fourth vs first quartile: HR = 1.47, 95% CI = 1.08-1.99; Ptrend  = .0009) and BCC risks in men (HR = 1.17, 95% CI = 1.04-1.31; Ptrend  = .14). Baseline and lifetime intakes of wine were associated with BCC risk (HR = 1.25 in men; HR = 1.11-1.12; in women). No statistically significant associations were found between beverage types and SCC risk. Intake of beer was not associated with skin cancer risk. Our study suggests positive relationships between alcohol intake and skin cancer risk, which may have important implications for the primary prevention of skin cancer.


Asunto(s)
Carcinoma Basocelular , Carcinoma de Células Escamosas , Melanoma , Neoplasias Cutáneas , Femenino , Humanos , Masculino , Consumo de Bebidas Alcohólicas/efectos adversos , Consumo de Bebidas Alcohólicas/epidemiología , Carcinoma Basocelular/epidemiología , Carcinoma Basocelular/etiología , Estudios Prospectivos , Factores de Riesgo , Neoplasias Cutáneas/epidemiología , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/patología
4.
Breast Cancer Res Treat ; 195(3): 367-377, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35933487

RESUMEN

PURPOSE: To investigate if molecular subtype is associated with outcome in stage 1 breast cancer (BC). METHODS: Tissue samples from 445 women with node-negative BC ≤ 15 mm, treated in 1986-2004, were classified into surrogate molecular subtypes [Luminal A-like, Luminal B-like (HER2-), HER2-positive, and triple negative breast cancer (TNBC)]. Information on treatment, recurrences, and survival were gathered from medical records. RESULTS: Tumour subtype was not associated with overall survival (OS). Luminal B-like (HER2-) and TNBC were associated with higher incidence of distant metastasis at 20 years (Hazard ratio (HR) 2.26; 95% CI 1.08-4.75 and HR 3.24; 95% CI 1.17-9.00, respectively). Luminal B-like (HER2-) and TNBC patients also had worse breast cancer-specific survival (BCSS), although not statistically significant (HR 1.53; 95% CI 0.70-3.33 and HR 1.89; 95% CI 0.60-5.93, respectively). HER2-positive BC was not associated with poor outcome despite no patient receiving HER2-targeted therapy, with most of these tumours being ER+. CONCLUSIONS: Stage 1 TNBC or Luminal B-like (HER2-) tumours behave more aggressively. Women with HER2+/ER+ tumours do not have an increased risk of distant metastasis or death, absent targeted treatment.


Asunto(s)
Neoplasias de la Mama , Carcinoma , Neoplasias de la Mama Triple Negativas , Biomarcadores de Tumor , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/terapia , Estudios de Cohortes , Femenino , Humanos , Pronóstico , Receptor ErbB-2 , Receptores de Progesterona , Estudios Retrospectivos , Suecia/epidemiología , Neoplasias de la Mama Triple Negativas/epidemiología , Neoplasias de la Mama Triple Negativas/terapia
5.
Front Mol Biosci ; 9: 904526, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35693557

RESUMEN

Breast cancer is the most common cause of cancer death among women worldwide. Localized breast cancer can be cured by surgery and adjuvant therapy, but mortality remains high for tumors that metastasize early. Type IV collagen is a basement membrane protein, and breach of this extracellular matrix structure is the first step of cancer invasion. Type IV collagen is found in the stroma of many cancers, but its role in tumor biology is unclear. Here, expression of type IV collagen in the stroma of small breast cancers was analyzed, correlated to clinically used prognostic biomarkers and patient survival. The findings were further validated in an independent gene expression data cohort. Tissue samples from 1,379 women with in situ and small invasive breast cancers (≤15 mm) diagnosed in 1986-2004 were included. Primary tumor tissue was collected into tissue microarrays. Type IV collagen expression in tissues was visualized using immunohistochemistry. Gene expression data was extracted from the Cancer Genome Atlas database. Out of 1,379 women, 856 had an invasive breast cancer and type IV collagen staining was available for 714 patients. In Kaplan-Meier analysis high type IV collagen expression was significantly associated (p = 0.026) with poorer breast cancer specific survival. There was no correlation of type IV collagen expression to clinically used prognostic biomarkers. High type IV collagen expression was clearly associated to distant metastasis (p = 0.002). In an external validation cohort (n = 1,104), high type IV collagen mRNA expression was significantly (p = 0.041) associated with poorer overall survival, with overexpression of type IV collagen mRNA in metastatic tissue. Stromal type IV collagen expression in the primary tumor correlates to poor breast cancer specific survival most likely due to a higher risk of developing distant metastasis. This ECM protein may function as biomarker to predict the risk of future metastatic disease in patients with breast cancers.

6.
Clin Exp Metastasis ; 38(2): 175-185, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33655422

RESUMEN

No reliable, non-invasive biomarker of metastatic breast cancer (mBC) exists: circulating CA15-3 (cCA15-3) is the marker mostly used to monitor mBC. Circulating collagen IV (cCOLIV) has been evaluated in other metastatic cancers and has been found to be a promising biomarker. The overarching aim of this study was to evaluate cCOLIV as a potential biomarker in patients with mBC. The first aim was to determine the levels of cCOL IV and cCA15-3 in patients with healthy controls, primary breast cancer (pBC) and mBC. The second aim was to compare levels of cCOLIV and cCA15-3 in patients with different metastatic sites of BC. The third aim was to investigate the prognostic value of cCOLIV and cCA15-3 for mBC patients. The fourth aim was to analyse whether a combination of the two biomarkers was more accurate in detecting mBC than a single marker. Lastly, we investigated the tissue expression levels of COLIV in BC bone metastases (BM) and liver metastases (LM). Plasma levels of cCOLIV and cCA15-3 from healthy controls and patients with pBC and mBC were measured. COLIV expression in tissue from patients with LM and BM was analysed using immunohistochemistry. Clinical and survival data were collected from medical charts. The levels of cCOLIV and cCA15-3 were significantly elevated in mBC patients compared with healthy controls and pBC patients. No differences in cCOLIV and cCA15-3 levels were found based on the metastatic site. High levels of cCOLIV, but not cCA15-3, correlated with poorer survival. cCOLIV alone and the combination of cCA15-3 and cCOLIV were superior to cCA15-3 at detecting mBC. COL IV was highly expressed in the tissue of LM and BM. Our study suggests that cCOLIV is a potential marker to monitor patients with BC.


Asunto(s)
Biomarcadores de Tumor/análisis , Neoplasias de la Mama/diagnóstico , Colágeno Tipo IV/análisis , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Óseas/secundario , Neoplasias de la Mama/química , Neoplasias de la Mama/mortalidad , Femenino , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Mucina-1/análisis
8.
BMC Cancer ; 20(1): 1197, 2020 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-33287744

RESUMEN

BACKGROUND: The incidence of cutaneous malignant melanoma (CMM) is increasing worldwide. In Sweden, over 4600 cases were diagnosed in 2018. The prognosis after radical surgery varies considerably with tumor stage. In recent years, new treatment options have become available for metastatic CMM. Early onset of treatment seems to improve outcome, which suggests that early detection of recurrent disease should be beneficial. Consequently, in several countries imaging is a part of the routine follow-up program after surgery of high risk CMM. However, imaging has drawbacks, including resources required (costs, personnel, equipment) and the radiation exposure. Furthermore, many patients experience anxiety in waiting for the imaging results and investigations of irrelevant findings is another factor that also could cause worry and lead to decreased quality of life. Hence, the impact of imaging in this setting is important to address and no randomized study has previously been conducted. The Swedish national guidelines stipulate follow-up for 3 years by clinical examinations only. METHODS: The TRIM study is a prospective randomized multicenter trial evaluating the potential benefit of imaging and blood tests during follow-up after radical surgery for high-risk CMM, compared to clinical examinations only. Primary endpoint is overall survival (OS) at 5 years. Secondary endpoints are survival from diagnosis of relapse and health-related quality of life (HRQoL). Eligible for inclusion are patients radically operated for CMM stage IIB-C or III with sufficient renal function for iv contrast-enhanced CT and who are expected to be fit for treatment in case of recurrence. The planned number of patients is > 1300. Patients are randomized to clinical examinations for 3 years +/- whole-body imaging with CT or FDG-PET/CT and laboratory tests including S100B protein and LDH. This academic study is supported by the Swedish Melanoma Study Group. DISCUSSION: This is the first randomized prospective trial on the potential benefit of imaging as a part of the follow-up scheme after radical surgery for high-risk CMM. RESULTS: The first patient was recruited in June 2017 and as of April 2020, almost 500 patients had been included at 19 centers in Sweden. TRIAL REGISTRATION: ClinicalTrials.gov , NCT03116412 . Registered 17 April 2017, https://clinicaltrials.gov/ct2/show/study/NCT03116412.


Asunto(s)
Melanoma/diagnóstico por imagen , Neoplasias Cutáneas/diagnóstico por imagen , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Melanoma/cirugía , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Neoplasias Cutáneas/cirugía , Melanoma Cutáneo Maligno
9.
J Mammary Gland Biol Neoplasia ; 25(1): 69-77, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32124140

RESUMEN

Localised breast cancer can be cured by surgery and adjuvant treatments, but mortality remains high as some tumours metastasize early. Perlecan is a basement membrane (BM) protein involved in tumour development and progression. Here, mRNA and protein expression of perlecan, and mRNA expression of matrix degrading enzymes were studied in normal breast and invasive breast cancer, and correlated to prognostic risk factors, in particular oestrogen status. Moreover, plasma levels of perlecan were measured in patients with breast cancer and compared with controls. mRNA data was extracted from the Cancer Genome Atlas database. Perlecan protein expression was visualized using immunofluorescence and plasma levels measured by ELISA assay. Perlecan mRNA levels were twice as high in normal breast compared with breast cancer tissue. A strong correlation was found between mRNA expression of perlecan and several matrix-degrading enzymes in oestrogen receptor positive (ER+) tumours. Perlecan protein was localized to both epithelial and vascular BMs, but absent in the stroma in normal breast. In breast cancer, the expression of perlecan in epithelial BM was fragmented or completely lost, with a marked upregulation of perlecan expression in the stroma. Significantly higher levels of perlecan were found in plasma of ER+ patients when compared with ER- patients. This study shows that perlecan expression and degradation in breast cancer may be linked to the ER status of the tumour.


Asunto(s)
Biomarcadores de Tumor/sangre , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Carcinoma Lobular/patología , Proteoglicanos de Heparán Sulfato/sangre , Receptores de Estrógenos/metabolismo , Células del Estroma/metabolismo , Biomarcadores de Tumor/genética , Neoplasias de la Mama/sangre , Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/sangre , Carcinoma Ductal de Mama/genética , Carcinoma Lobular/sangre , Carcinoma Lobular/genética , Estudios de Casos y Controles , Estudios de Cohortes , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Femenino , Estudios de Seguimiento , Proteoglicanos de Heparán Sulfato/genética , Humanos , Persona de Mediana Edad , Pronóstico , Receptor ErbB-2/metabolismo , Receptores de Progesterona/metabolismo , Células del Estroma/patología
10.
Int J Cancer ; 146(12): 3267-3280, 2020 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-31506954

RESUMEN

Evidence suggests an influence of sex hormones on cutaneous melanoma risk, but epidemiologic findings are conflicting. We examined the associations between use of oral contraceptives (OCs) and menopausal hormone therapy (MHT) and melanoma risk in women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC is a prospective cohort study initiated in 1992 in 10 European countries. Information on exogenous hormone use at baseline was derived from country-specific self-administered questionnaires. We used Cox proportional hazards regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Over 1992-2015, 1,696 melanoma cases were identified among 334,483 women, whereof 770 cases among 134,758 postmenopausal women. There was a positive, borderline-significant association between OC use and melanoma risk (HR = 1.12, 95% CI = 1.00-1.26), with no detected heterogeneity across countries (phomogeneity = 0.42). This risk increased linearly with duration of use (ptrend = 0.01). Among postmenopausal women, ever use of MHT was associated with a nonsignificant increase in melanoma risk overall (HR = 1.14, 95% CI = 0.97-1.43), which was heterogeneous across countries (phomogeneity = 0.05). Our findings do not support a strong and direct association between exogenous hormone use and melanoma risk. In order to better understand these relations, further research should be performed using prospectively collected data including detailed information on types of hormone, and on sun exposure, which may act as an important confounder or effect modifier on these relations.


Asunto(s)
Anticonceptivos Hormonales Orales/efectos adversos , Terapia de Reemplazo de Estrógeno/efectos adversos , Melanoma/epidemiología , Neoplasias Cutáneas/epidemiología , Adulto , Anciano , Factores de Confusión Epidemiológicos , Terapia de Reemplazo de Estrógeno/estadística & datos numéricos , Europa (Continente)/epidemiología , Femenino , Humanos , Incidencia , Melanoma/etiología , Persona de Mediana Edad , Posmenopausia , Premenopausia , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Neoplasias Cutáneas/etiología , Encuestas y Cuestionarios/estadística & datos numéricos , Factores de Tiempo
11.
Sci Rep ; 7(1): 17254, 2017 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-29222502

RESUMEN

Monoclonal antibodies (mAbs) have not been used as positron emission tomography (PET) ligands for in vivo imaging of the brain because of their limited passage across the blood-brain barrier (BBB). However, due to their high affinity and specificity, mAbs may be an attractive option for brain PET if their brain distribution can be facilitated. In the present study, a F(ab')2 fragment of the amyloid-beta (Aß) protofibril selective mAb158 was chemically conjugated to the transferrin receptor (TfR) antibody 8D3 to enable TfR mediated transcytosis across the BBB. The generated bispecific protein, 8D3-F(ab')2-h158, was subsequently radiolabeled and used for microPET imaging of Aß pathology in two mouse models of AD. [124I]8D3-F(ab')2-h158 was distributed across the BBB several fold more than unmodified mAbs in general and its accumulation in the brain reflected disease progression, while its concentration in blood and other organs remained stable across all age groups studied. Cerebellum was largely devoid of 8D3-F(ab')2-h158 in young and middle aged mice, while mice older than 18 months also showed some accumulation in cerebellum. In a longer perspective, the use of bispecific antibodies as PET ligands may enable in vivo 'immunohistochemistry' also of other proteins in the brain for which PET radioligands are lacking.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Anticuerpos Biespecíficos/farmacocinética , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Tomografía de Emisión de Positrones , Animales , Anticuerpos Biespecíficos/inmunología , Anticuerpos Biespecíficos/metabolismo , Barrera Hematoencefálica/metabolismo , Fragmentos Fab de Inmunoglobulinas/inmunología , Ligandos , Ratones , Ratones Endogámicos C57BL , Receptores de Transferrina/inmunología , Receptores de Transferrina/metabolismo , Distribución Tisular , Transcitosis
13.
Psychol Res Behav Manag ; 5: 97-103, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22915948

RESUMEN

BACKGROUND: The aim of this study was to pilot test a prototype website called MODIAB-web designed to support pregnant women and mothers with type 1 diabetes. METHOD: A focus group was undertaken and the results were analyzed using qualitative content analysis. RESULTS: Eight subthemes were identified, comprising "blood glucose versus insulin," "application for smart phones," "the time aspect," "interface and technology," "forum," "direct link to the diabetes midwife," "ask the expert," and "lack of contact information." These subthemes were condensed into two main themes. The first theme was "easily understood interface, but in need of a more blood-glucose focused orientation" and the second theme was "forum for interaction with both equals and experts." CONCLUSION: The women in this study had positive impressions of several of the MODIAB-web functions, including a forum for pregnant mothers with type 1 diabetes and the possibility of being able to put their blood glucose levels into a diagram which could be sent directly to the diabetes midwife. Access to articles and information via the "fact" tab and the ability to ask questions of experts were also significantly helpful to women in the focus group. Pregnant women and mothers with type 1 diabetes can gain support from such a Web-based self-help system.

14.
Genetics ; 180(1): 191-206, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18723884

RESUMEN

Sordaria macrospora, a self-fertile filamentous ascomycete, carries genes encoding three different alpha-subunits of heterotrimeric G proteins (gsa, G protein Sordaria alpha subunit). We generated knockout strains for all three gsa genes (Deltagsa1, Deltagsa2, and Deltagsa3) as well as all combinations of double mutants. Phenotypic analysis of single and double mutants showed that the genes for Galpha-subunits have distinct roles in the sexual life cycle. While single mutants show some reduction of fertility, double mutants Deltagsa1Deltagsa2 and Deltagsa1Deltagsa3 are completely sterile. To test whether the pheromone receptors PRE1 and PRE2 mediate signaling via distinct Galpha-subunits, two recently generated Deltapre strains were crossed with all Deltagsa strains. Analyses of the corresponding double mutants revealed that compared to GSA2, GSA1 is a more predominant regulator of a signal transduction cascade downstream of the pheromone receptors and that GSA3 is involved in another signaling pathway that also contributes to fruiting body development and fertility. We further isolated the gene encoding adenylyl cyclase (AC) (sac1) for construction of a knockout strain. Analyses of the three DeltagsaDeltasac1 double mutants and one Deltagsa2Deltagsa3Deltasac1 triple mutant indicate that SAC1 acts downstream of GSA3, parallel to a GSA1-GSA2-mediated signaling pathway. In addition, the function of STE12 and PRO41, two presumptive signaling components, was investigated in diverse double mutants lacking those developmental genes in combination with the gsa genes. This analysis was further completed by expression studies of the ste12 and pro41 transcripts in wild-type and mutant strains. From the sum of all our data, we propose a model for how different Galpha-subunits interact with pheromone receptors, adenylyl cyclase, and STE12 and thus cooperatively regulate sexual development in S. macrospora.


Asunto(s)
Adenilil Ciclasas/genética , Adenilil Ciclasas/fisiología , Regulación Fúngica de la Expresión Génica , Sordariales/genética , Sordariales/fisiología , Secuencia de Aminoácidos , Cuerpos Fructíferos de los Hongos/genética , Proteínas Fúngicas , Eliminación de Gen , Técnicas Genéticas , Modelos Genéticos , Datos de Secuencia Molecular , Mutación , Feromonas/metabolismo , Estructura Terciaria de Proteína , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA