Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Mol Biol Rep ; 50(10): 8469-8481, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37639153

RESUMEN

BACKGROUND: Oral Squamous Cell Carcinoma (OSCC) is a highly prevalent cancer in the Indian subcontinent. The major cause of mortality in OSCC patients is metastasis. Epithelial-to-mesenchymal transition (EMT) marks an important step in the metastatic process. Additionally, TP53, an important tumor suppressor gene, is also a significant determinant of the treatment outcome, and also plays a role in EMT. Therefore, understanding the interconnections between ultrastructural features, EMT status and TP53 mutational status is of vital importance. METHODS AND RESULTS: The ultrastructure of five OSCC cell lines was visualized by transmission electron microscopy. Trans-well invasion and migration assays as well as scratch-wound assay, and the expression of various EMT-related genes were utilized to assess the EMT status of the cell lines. The TP53 exons were amplified for the ACOSC3, ACOSC4 and ACOSC16 cell lines and sequenced and the mutations in the gene were identified by sequence alignment. The TP53 mutation in the UPCI:SCC029B cell line has been previously reported, while UPCI:SCC040 has been reported to harbor a wild type TP53. The ACOSC4 cell line which showed the shortest intercellular gaps, also had the least invasive and migratory potential. Interestingly, ACOSC4 showed the highest expression of E-cadherin and the lowest expression of Vimentin, TWIST1, ZEB1, and MMPs. Additionally, TP53 gene of ACOSC4 was unmutated, whereas the ACOSC3 and ACOSC16 harbored TP53 mutations. The mutation in ACOSC3 (R196*) was also found in 7 TCGA samples. Similarly, the UPCI:SCC040 cell line that harbors a wild type TP53 showed shorter intracellular gaps. CONCLUSIONS: Cellular migratory properties are associated with cellular ultrastructure, epithelial-to-mesenchymal transition status and the status of TP53 mutation in the genome.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Humanos , Neoplasias de la Boca/genética , Carcinoma de Células Escamosas/genética , Transición Epitelial-Mesenquimal/genética , Carcinoma de Células Escamosas de Cabeza y Cuello , Línea Celular , Proteína p53 Supresora de Tumor/genética
2.
Biochem Biophys Res Commun ; 460(2): 302-7, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25791476

RESUMEN

Poly-N-acetyl-lactosamine (polyLacNAc) on N-glycans facilitate lung specific metastasis of melanoma cells by serving as high affinity ligands for galectin-3, expressed in highest amounts in the lungs, on almost all its tissue compartments including on the surface of vascular endothelium. PolyLacNAc not only aids in initial arrest on the organ endothelium but in all the events of extravasation. Inhibition of polyLacNAc synthesis, or competitive inhibition of its interaction with galectin-3 all inhibited these processes and experimental metastasis. Transgenic galectin-3 mice, viz., gal-3(+/+) (wild type), gal-3(+/-) (hemizygous) and gal-3(-/-) (null) have been used to prove that galectin-3/polyLacNAc interactions are indeed critical for lung specific metastasis. Gal-3(+/-) mice which showed <50% expression of galectin-3 on the lungs also showed proportionate decrease in the number of B16F10 melanoma metastatic colonies affirming that galectin-3 and polyLacNAc interactions are indeed key determinants of lung metastasis. However, surprisingly, the number and size of metastatic colonies in gal-3(-/-) mice was very similar as that seen in gal-3(+/+) mice. The levels of lactose binding lectins on the lungs and the transcripts of other galectins (galectin-1, -8 and -9) which are expressed on lungs and have similar sugar binding specificities as galectins-3, remain unchanged in gal-3(+/+) and gal-3(-/-) mice. Further, inhibition of N-glycosylation with Swainsonine (SW) which drastically reduces metastasis of B16F10 cells in gal-3(+/+) mice, did not affect lung metastasis when assessed in gal-3(-/-) mice. Together, these results rule out the possibility of some other galectin taking over the function of galectin-3 in gal-3(-/-) mice. Chimeric mice generated to assess if absence of any effect on metastasis is due to compromised tumor immunity by replacing bone marrow of gal-3(-/-) mice with that from gal-3(+/+) mice, also failed to impact melanoma metastasis. As galectin-3 regulates several immune functions including maturation of different immune cells, compromised tumor immunity could be the major determinant of melanoma metastasis in gal-3(-/-) mice and warrants thorough investigation.


Asunto(s)
Galectina 3/fisiología , Metástasis de la Neoplasia , Polisacáridos/fisiología , Animales , Secuencia de Bases , Línea Celular Tumoral , Cartilla de ADN , Galectina 3/genética , Neoplasias Pulmonares/secundario , Melanoma Experimental/patología , Ratones , Ratones Transgénicos , Reacción en Cadena de la Polimerasa
3.
Exp Cell Res ; 322(2): 249-64, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24530578

RESUMEN

Invasion is the key requirement for cancer metastasis. Expression of ß1,6 branched N-oligosaccharides associated with invasiveness, has been shown to promote adhesion to most Extra Cellular Matrix (ECM) and basement membrane (BM) components and haptotactic motility on ECM (fibronectin) but attenuate it on BM (laminin/matrigel) components. To explore the mechanism and to evaluate the significance of these observations in terms of invasion, highly invasive B16BL6 cells were compared with the parent (B16F10) cells or B16BL6 cells in which glycosylation was inhibited. We demonstrate that increased adhesion to matrix components induced secretion of MMP-9, important for invasion. Further, both the subunits of integrin receptors for fibronectin (α5ß1) and laminin (α3ß1) on B16BL6 cells were shown to carry these oligosaccharides. Although, glycosylation of receptors had no effect on their surface expression, it had same differential effect on cell spreading as haptotactic motility. Absence of correlation between invasiveness and expression of most tetraspanins (major regulators of integrin function) hints at an alternate mechanism. Here we show that glycosylation on α3ß1 impedes its association with CD151 and modulates spreading and motility of cells apparently to reach an optimum required for invasion of BM. These studies demonstrate the complex mechanisms used by cancer cells to be invasive.


Asunto(s)
Membrana Basal/patología , Movimiento Celular , Colágeno/metabolismo , Integrina alfa3beta1/metabolismo , Laminina/metabolismo , Melanoma Experimental/patología , Proteoglicanos/metabolismo , Receptores de Laminina/metabolismo , Tetraspanina 24/metabolismo , Animales , Membrana Basal/metabolismo , Western Blotting , Adhesión Celular , Colágeno/genética , Combinación de Medicamentos , Fibronectinas/genética , Fibronectinas/metabolismo , Citometría de Flujo , Regulación Neoplásica de la Expresión Génica , Glicosilación , Integrina alfa3beta1/genética , Integrina alfa5beta1/genética , Integrina alfa5beta1/metabolismo , Laminina/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Melanoma Experimental/metabolismo , Ratones , Invasividad Neoplásica , Proteoglicanos/genética , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Laminina/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tetraspanina 24/genética , Células Tumorales Cultivadas
4.
Glycoconj J ; 26(4): 445-56, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-18949555

RESUMEN

Galectin-3 on vascular endothelium has been shown to facilitate lung specific metastasis. Metastatic variants of B16 melanoma were chosen to identify specific ligands that mediate lung colonization via galectin-3. Flow cytometry showed that, galectin-3 binding to cells correlates with surface expression of poly N-acetyllactosamine (polylacNAc) but not with other reported ligands, e.g. Thomsen-Friedenreich (T/Tn) antigen. Immobilized galectin-3 promoted adhesion of melanoma cells in a metastasis dependent manner. Moreover, adhesion and galectin-3 binding to cells were specifically inhibited with lactose. These properties together with lung metastasis were inhibited with N-glycosylation inhibitor Swainsonine (SW), whereas, O-glycosylation inhibitor Benzyl-alpha-N-acetylgalactosamine (BG) had no effect. BG treatment significantly increased expression of T/Tn antigen on low metastatic cells; however, had no effect on their metastatic potential. The studies very comprehensively demonstrate the importance of polylacNAc substitutions on N-oligosaccharides in galectin-3 mediated lung metastasis.


Asunto(s)
Antígenos de Carbohidratos Asociados a Tumores/metabolismo , Galectina 3/metabolismo , Neoplasias Pulmonares/secundario , Melanoma/metabolismo , Melanoma/patología , Oligosacáridos/metabolismo , Polisacáridos/metabolismo , Acetilgalactosamina/análogos & derivados , Acetilgalactosamina/farmacología , Animales , Compuestos de Bencilo/farmacología , Biotinilación/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Citometría de Flujo , Humanos , Proteínas Inmovilizadas , Ratones , Oligosacáridos/química , Especificidad de Órganos/efectos de los fármacos , Unión Proteica/efectos de los fármacos
5.
Mol Biosyst ; 13(11): 2303-2309, 2017 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-28875213

RESUMEN

Adhesive interactions between molecules on tumor cells and those on target organs play a key role in organ specific metastasis. Poly-N-acetyl-lactosamine (polyLacNAc) substituted N-oligosaccharides on melanoma cell surface glycoproteins promote lung specific metastasis via galectin-3 by facilitating their arrest and extravasation. This study reports the identification and characterization of galectin-3 interacting proteins using a combination of galectin-3 sepharose affinity and leucoagglutinating phytohemagglutinin (L-PHA) columns. A total of 83 proteins were identified as galectin-3 interacting glycoproteins, of which 35 were constituents of the L-PHA bound fraction, suggesting that these proteins carry polyLacNAc substituted ß1,6 branched N-glycans. The identities of some of these proteins, like LAMP-1, LAMP-3, basigin, embigin, and α5 and ß1 Integrin, have been confirmed by western blotting, and functional relevance with respect to metastatic properties has been established.


Asunto(s)
Proteínas Portadoras/metabolismo , Galectina 3/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundario , Espectrometría de Masas , Melanoma/patología , Mapeo de Interacción de Proteínas/métodos , Animales , Cromatografía de Afinidad , Cromatografía Liquida , Espectrometría de Masas/métodos , Melanoma Experimental , Ratones , Unión Proteica , Reproducibilidad de los Resultados , Flujo de Trabajo
6.
Clin Exp Metastasis ; 22(1): 11-24, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16132574

RESUMEN

Adhesive interactions between the molecules on cancer cells and the target organ are one of the key determinants of the organ specific metastasis. In this communication we show that b1,6 branched N-oligosaccharides which are expressed in a metastasis-dependent manner on B16-melanoma metastatic cell lines, participate in the adhesion process. We demonstrate that high metastatic cells show significantly increased translocation of one of the major carriers of these oligosaccharides, lysosome associated membrane protein (LAMP1), to the cell surface. LAMP1 on high metastatic cells, carry very high levels of these oligosaccharides, which are further substituted with poly N-acetyl lactosamine (polylacNAc), resulting in the expression of high density of very high affinity ligands for galectin-3 on the cell surface. We show that galectin-3 is expressed in highest amount in the lungs as compared to other representative organs. Blocking galectin-3 by pre-incubating the frozen sections of the lungs with 100 mM lactose, substantially inhibited the adhesion of high metastatic cells, while pre-incubation with sucrose had no effect. Finally, by in situ labeling and immunoprecipitation experiment, we demonstrated that the lung vascular endothelial cells express galectin-3 constitutively on their surface. Galectin-3 on the organ endothelium could thus serve as the first anchor for the circulating cancer cells, expressing high density of very high affinity ligands on their surface, and facilitate organ specific metastasis.


Asunto(s)
Antígenos CD/metabolismo , Endotelio Vascular/metabolismo , Galectina 3/metabolismo , Neoplasias Pulmonares/secundario , Pulmón/irrigación sanguínea , Melanoma Experimental/patología , Oligosacáridos de Cadena Ramificada/metabolismo , Animales , Antígenos CD/análisis , Bioensayo , Adhesión Celular/efectos de los fármacos , Membrana Celular/química , Membrana Celular/metabolismo , Membrana Celular/patología , Glicosilación , Lactosa/farmacología , Pulmón/metabolismo , Neoplasias Pulmonares/metabolismo , Proteína 1 de la Membrana Asociada a los Lisosomas , Proteínas de Membrana de los Lisosomas , Melanoma Experimental/metabolismo , Ratones , Ratones Endogámicos C57BL , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patología , Oligosacáridos de Cadena Ramificada/análisis , Polisacáridos/metabolismo , Transporte de Proteínas , Receptores Mitogénicos/metabolismo , Sacarosa/farmacología , Adherencias Tisulares , Regulación hacia Arriba
7.
Clin Exp Metastasis ; 31(6): 661-73, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24952269

RESUMEN

Interactions between molecules on the surface of tumor cells and those on the target organ endothelium play an important role in their arrest in an organ. Galectin-3 on the lung endothelium and high affinity ligands poly-N-acetyllactosamine (polyLacNAc) on N-oligosaccharides on melanoma cells facilitate such interactions. However, to extravasate and colonize an organ the cells must stabilize these interactions by spreading to retract endothelium, degrade exposed basement membrane (BM) and move into parenchyma and proliferate. Here, we show that galectin-3 is expressed on all the major compartments of the lungs and participates in not just promoting adhesion but also in spreading. We for the first time demonstrate that both soluble and immobilized galectin-3 induce secretion of MMP-9 required to breach vascular BM. Further, we show that immobilized galectin-3 is used as traction for the movement of cells. Downregulation of galactosyltransferases-I and -V resulted in significant loss in expression of polyLacNAc and thus reduced binding of galectin-3. This was accompanied with a loss in adhesion, spreading, MMP-9 secretion and motility of the cells on galectin-3 and thus their metastasis to lungs. Metastasis could also be inhibited by blocking surface polyLacNAc by pre-incubating cells with truncated galectin-3 (which lacked oligomerization domain) or by feeding mice with modified citrus pectin in drinking water. Overall, these results unequivocally show that polyLacNAc on melanoma cells and galectin-3 on the lungs play a critical role in arrest and extravasation of cells in the lungs and strategies that target these interactions inhibit lung metastasis.


Asunto(s)
Galectina 3/metabolismo , Pulmón/metabolismo , Melanoma Experimental/patología , Animales , Secuencia de Bases , Western Blotting , Adhesión Celular , Línea Celular Tumoral , Cartilla de ADN , Citometría de Flujo , Ligandos , Pulmón/patología , Ratones , Reacción en Cadena en Tiempo Real de la Polimerasa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA