Mutations of p53, E-cadherin, alpha- and beta-catenin genes and tyrosine phosphorylation of beta-catenin in human gastric carcinomas

Author(s):  
T Mazaki ◽  
Y Ishii ◽  
M Fujii ◽  
S Iwai ◽  
K Ishikawa
2007 ◽  
Vol 22 (5) ◽  
pp. 855 ◽  
Author(s):  
In Mok Jung ◽  
Jung Kee Chung ◽  
Young A Kim ◽  
Je Eun Kim ◽  
Seung Chul Heo ◽  
...  

1995 ◽  
Vol 130 (2) ◽  
pp. 461-471 ◽  
Author(s):  
M S Kinch ◽  
G J Clark ◽  
C J Der ◽  
K Burridge

Transformed epithelial cells often are characterized by a fibroblastic or mesenchymal morphology. These cells exhibit altered cell-cell and cell-substrate interactions. Here we have identified changes in the adhesions and cytoskeletal interactions of transformed epithelial cells that contribute to their altered morphology. Using MCF-10A human breast epithelial cells as a model system, we have found that transformation by an activated form of ras is characterized by less developed adherens-type junctions between cells but increased focal adhesions. Contributing to the modified adherens junctions of the transformed cells are decreased interactions among beta-catenin, E-cadherin, and the actin cytoskeleton. The ras-transformed cells reveal elevated phosphotyrosine in many proteins, including beta-catenin and p120 Cas. Whereas in the normal cells beta-catenin is found in association with E-cadherin, p120 Cas is not. In the ras-transformed cells, the situation is reversed; tyrosine-phosphorylated p120 Cas, but not tyrosine-phosphorylated beta-catenin, now is detected in E-cadherin complexes. The tyrosine-phosphorylated beta-catenin also shows increased detergent solubility, suggesting a decreased association with the actin cytoskeleton. p120 Cas, whether tyrosine phosphorylated or not, partitions into the detergent soluble fraction, suggesting that it is not tightly bound to the actin cytoskeleton in either the normal or ras-transformed cells. Inhibitors of tyrosine kinases decrease the level of tyrosine phosphorylation and restore a normal epithelial morphology to the ras-transformed cells. In particular, decreased tyrosine phosphorylation of beta-catenin is accompanied by increased interaction with both E-cadherin and the detergent insoluble cytoskeletal fraction. These results suggest that elevated tyrosine phosphorylation of proteins such as beta-catenin and p120 Cas contribute to the altered adherens junctions of ras-transformed epithelia.


1993 ◽  
Vol 120 (3) ◽  
pp. 757-766 ◽  
Author(s):  
J Behrens ◽  
L Vakaet ◽  
R Friis ◽  
E Winterhager ◽  
F Van Roy ◽  
...  

Loss of histotypic organization of epithelial cells is a common feature in normal development as well as in the invasion of carcinomas. Here we show that the v-src oncogene is a potent effector of epithelial differentiation and invasiveness. MDCK epithelial cells transformed with a temperature-sensitive mutant of v-src exhibit a strictly epithelial phenotype at the nonpermissive temperature for pp60v-src activity (40.5 degrees C) but rapidly loose cell-to-cell contacts and acquire a fibroblast-like morphology after culture at the permissive temperature (35 degrees C). Furthermore, the invasiveness of the cells into collagen gels or into chick heart fragments was increased at the permissive temperature. The profound effects of v-src on intercellular adhesion were not linked to changes in the levels of expression of the epithelial cell adhesion molecule E-cadherin. Rather, we observed an increase in tyrosine phosphorylation of E-cadherin and, in particular, of the associated protein beta-catenin. These results suggest a mechanism by which v-src counteracts junctional assembly and thereby promotes invasiveness and dedifferentiation of epithelial cells through phosphorylation of the E-cadherin/catenin complex.


2004 ◽  
Vol 171 (4S) ◽  
pp. 194-195
Author(s):  
Kyoichi Tomita ◽  
Haruki Kume ◽  
Keishi Kashibuchi ◽  
Satoru Muto ◽  
Shigeo Horie ◽  
...  

Reproduction ◽  
2000 ◽  
pp. 375-385 ◽  
Author(s):  
K Sundfeldt ◽  
Y Piontkewitz ◽  
H Billig ◽  
L Hedin

The cadherins and their cytoplasmic counterparts, the catenins, form the adherens junctions, which are of importance for tissue integrity and barrier functions. The development and maturation of the ovarian follicle is characterized by structural changes, which require altered expression or function of the components involved in cell-cell contacts. The present study examined the cell-specific localization and temporal expression of epithelial cadherin (E-cadherin) and alpha- and beta-catenin during follicular development, ovulation and corpus luteum formation in the immature gonadotrophin- and oestrogen-stimulated rat ovary. Immunohistochemistry and immunoblotting demonstrated the expression of E-cadherin in theca and interstitial cells of immature ovaries before and after injection of equine chorionic gonadotrophin (eCG). E-cadherin was not detected in granulosa cells, except in the preantral follicles located to the inner region of the ovary. The content of E-cadherin in theca and interstitial cells decreased after an ovulatory dose of hCG. Granulosa cells of apoptotic follicles did not express E-cadherin. Oestrogen treatment (diethylstilboestrol) of immature rats for up to 3 days did not result in a measurable expression of E-cadherin in granulosa cells. alpha- and beta-catenin were expressed in all ovarian compartments. The concentration of beta-catenin was constant during the follicular phase, whereas the content of alpha-catenin decreased in granulosa cells after treatment with diethylstilboestrol or hCG. The expression of alpha-catenin was also reduced in theca and interstitial cells after hCG. alpha- and beta-catenin were present in most ovarian cells at all stages of folliculogenesis. Therefore, the catenins have the potential to associate with different members of the cadherin family and to participate in the regulation of cytoskeletal structures and intracellular signalling. The restricted expression of E-cadherin in granulosa cells of preantral follicles indicates a role in the recruitment of these follicles to subsequent cycles. The specific decrease of alpha-catenin in granulosa cells and the reduction of both alpha-catenin and E-cadherin in theca cells of ovulatory follicles might reflect some of the molecular changes in cell-cell adhesion associated with ovulation and luteinization.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A970-A970
Author(s):  
Danielle Fails ◽  
Michael Spencer

BackgroundEpithelial-mesenchymal transition (EMT) is instrumental during embryonic development—assisting in extensive movement and differentiation of cells. However, during metastasis and tumorigenesis, this process is hijacked. The disruption of this developmental process, and subsequent acquisition of a mesenchymal phenotype, has been shown to increase therapeutic resistance and often leads to poor prognosis in breast cancer.1 Using bioinformatic resources and current clinical data, we designed a panel of biomarkers of value to specifically observe this epithelial/mesenchymal transition.MethodsHuman breast cancer FFPE tissue samples were stained with Bethyl Laboratories IHC-validated primary antibodies, followed by Bethyl HRP-conjugated secondary antibodies, and detected using Akoya Opal™ Polaris 7-color IHC kit fluorophores (Akoya Biosciences [NEL861001KT]). The panel consisted of beta-Catenin, E-Cadherin, Ki67, CD3e, PD-L1, and FOXP3. Antibody staining order was optimized using tissue microarray serial sections, three slides per target, and stained in either the first, third, or sixth position via heat-induced epitope retrieval (HIER) methods. Exposure time was maintained for all three slides/target and cell counts, signal intensity, background, and autofluorescence were analyzed. The final optimized order was then tested on the breast cancer microarray in seven-color mIF. Whole slide scans were generated using the Vectra Polaris® and analyses performed using InForm® and R® Studio.ResultsTwo integral EMT targets, E-Cadherin and beta-Catenin, were used to observe a key occurrence in this transition. Under tumorigenic circumstances, when released from the complex they form together (E-cadherin-B-catenin complex), Beta-catenin can induce EMT. This disjunction/activation of EMT can be seen in the invasive ductal carcinoma below (figure 1).The disorganized E-cadherin cells are in direct contrast to normal, non-cancerous cells in similar tissue. Total CD3e cell counts were down (2%), with 35% cells restricted to the stroma vs. the 1% seen intra-tumorally. Coupled with the elevated presence of Ki67 (10%), a level of rapid cancer growth and potential metastasis (Invasive Ductal Carcinoma Grade II) can be observed.Abstract 925 Figure 1Invasive ductal carcinoma, grade II stained with a 6-plex mIF panel designed to show the epithelial-mesenchymal transitionConclusionsThe presence of EMT in breast cancers is often indicative of a poor prognosis, so the need for reliable markers is imperative. E-Cadherin and beta-Catenin are both up-and-coming clinical targets that can serve to outline this transition within the tumor microenvironment. By utilizing these markers in mIF, closer spatial examination of proteins of interest can be achieved. The application of this mIF panel has the potential to provide invaluable insights into how tumor infiltrating lymphocytes behave in cancers exhibiting the hallmarks of EMT.AcknowledgementsWe would like to acknowledge Clemens Deurrschmid, PhD, Technical Applications Scientist Southeast/South Central, Akoya Biosciences for his assistance with image analysis.ReferencesHorne HN, Oh H, Sherman ME, et al. E-cadherin breast tumor expression, risk factors and survival: pooled analysis of 5,933 cases from 12 studies in the breast cancer association consortium. Sci Rep 2018;8:6574.


2021 ◽  
Vol 118 (5) ◽  
pp. e2020478118
Author(s):  
Tobias Wijshake ◽  
Zhongju Zou ◽  
Beibei Chen ◽  
Lin Zhong ◽  
Guanghua Xiao ◽  
...  

Beclin 1, an autophagy and haploinsufficient tumor-suppressor protein, is frequently monoallelically deleted in breast and ovarian cancers. However, the precise mechanisms by which Beclin 1 inhibits tumor growth remain largely unknown. To address this question, we performed a genome-wide CRISPR/Cas9 screen in MCF7 breast cancer cells to identify genes whose loss of function reverse Beclin 1-dependent inhibition of cellular proliferation. Small guide RNAs targeting CDH1 and CTNNA1, tumor-suppressor genes that encode cadherin/catenin complex members E-cadherin and alpha-catenin, respectively, were highly enriched in the screen. CRISPR/Cas9-mediated knockout of CDH1 or CTNNA1 reversed Beclin 1-dependent suppression of breast cancer cell proliferation and anchorage-independent growth. Moreover, deletion of CDH1 or CTNNA1 inhibited the tumor-suppressor effects of Beclin 1 in breast cancer xenografts. Enforced Beclin 1 expression in MCF7 cells and tumor xenografts increased cell surface localization of E-cadherin and decreased expression of mesenchymal markers and beta-catenin/Wnt target genes. Furthermore, CRISPR/Cas9-mediated knockout of BECN1 and the autophagy class III phosphatidylinositol kinase complex 2 (PI3KC3-C2) gene, UVRAG, but not PI3KC3-C1–specific ATG14 or other autophagy genes ATG13, ATG5, or ATG7, resulted in decreased E-cadherin plasma membrane and increased cytoplasmic E-cadherin localization. Taken together, these data reveal previously unrecognized cooperation between Beclin 1 and E-cadherin–mediated tumor suppression in breast cancer cells.


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