Cooperative signaling between Wnt1 and integrin-linked kinase induces accelerated breast tumor development (original) (raw)
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Proceedings of The National Academy of Sciences, 2003
Breast cancer is a genetically and clinically heterogeneous disease, and the contributions of different target cells and different oncogenic mutations to this heterogeneity are not well understood. Here we report that mammary tumors induced by components of the Wnt signaling pathway contain heterogeneous cell types and express early developmental markers, in contrast to tumors induced by other signaling elements. Expression of the Wnt-1 protooncogene in mammary glands of transgenic mice expands a population of epithelial cells expressing progenitor cell markers, keratin 6 and Sca-1; subsequent tumors express these markers and contain luminal epithelial and myoepithelial tumor cells that share a secondary mutation, loss of Pten, implying that they arose from a common progenitor. Mammary tumors arising in transgenic mice expressing -catenin and c-Myc, downstream components of the canonical Wnt signaling pathway, also contain a significant proportion of myoepithelial cells and cells expressing keratin 6. Progenitor cell markers and myoepithelial cells, however, are lacking in mammary tumors from transgenic mice expressing Neu, H-Ras, or polyoma middle T antigen. These results suggest that mammary stem cells and͞or progenitors to mammary luminal epithelial and myoepithelial cells may be the targets for oncogenesis by Wnt-1 signaling elements. Thus, the developmental heterogeneity of different breast cancers is in part a consequence of differential effects of oncogenes on distinct cell types in the breast.
Expression profiling of Wnt pathway genes in breast cancer
2005
There is compelling evidence from transgenic mouse studies and analysis of mutations in human carcinomas indicating that the TGF-β signal transduction pathway is tumor suppressive. We have shown that overexpression of TGF-β1 in mammary epithelial cells suppresses the development of carcinomas and that expression of a dominant negative type II TGF-β receptor (DNIIR) in mammary epithelial cells under control of the MMTV promoter/enhancer increases the incidence of mammary carcinomas. Studies of human tumors have demonstrated inactivating mutations in human tumors of genes encoding proteins involved in TGF-β signal transduction, including DPC4/Smad4, Smad2, and the type II TGF-β receptor (TβRII). There is also evidence that TGF-β can enhance the progression of tumors. This hypothesis is being tested in genetically modified mice. To attain complete loss of TβRII, we have generated mice with loxP sites flanking exon 2 of Tgfbr2 and crossed them with mice expressing Cre recombinase under control of the MMTV promoter/enhancer to obtain Tgfbr2 mgKO mice. These mice show lobuloalveolar hyperplasia. Mice are being followed for mammary tumor development. Tgfbr2 mgKO mice that also express polyoma virus middle T antigen under control of the MMTV promoter (MMTV-PyVmT) develop mammary tumors with a significantly shorter latency than MMTV-PyVmT mice and show a marked increase in pulmonary metastases. Our data do not support the hypothesis that TGF-β signaling in mammary carcinoma cells is important for invasion and metastasis, at least in this model system. The importance of stromal-epithelial interactions in mammary gland development and tumorigenesis is well established. These interactions probably involve autocrine and paracrine action of multiple growth factors, including members of the TGF-β family, which are expressed in both stroma and epithelium. Again, to accomplish complete knockout of the type II TGF-β receptor gene in mammary stromal cells, FSP1-Cre and Tgfbr2 flox/flox mice were crossed to attain Tgfbr2 fspKO mice. The Despite over a decade of scrutiny and over 20 published reports from various countries, the degree to which ATM mutations lead to breast References 1. Gatti RA, Tward A, Concannon P: Cancer risk in ATM heterozygotes: a model of phenotypic and mechanistic differences between missense and truncating mutations. Mol Biol Metab 1999, 68:419-423. 2. Spring K, Ahangari F, Scott SP, Waring P, Purdie DM, Chen PC, Hourigan K, et al.: Mice heterozygous for mutation in Atm, the gene involved in ataxia-telangiectasia, have heightened susceptibility to cancer. Nat Genet 2002, 32:185-190. 3. Scott SP, Bendix R, Chen P, Clark R, Dork T, Lavin MF: Missense mutations but not allelic variants alter the function of ATM by dominant interference in patients with breast cancer. Proc Natl Acad Sci USA 2002, 99:925-930. 4. Concannon P: ATM heterozygosity and cancer risk. Nat Genet 2002, 32:89-90. 5. Chenevix-Trench G, Spurdle AB, Gatei M, Kelly H, Marsh A, Chen X, Donn K, et al.: Dominant negative ATM mutations in breast cancer families.
Oncogene, 2001
Development of strategies for prevention of breast cancer development requires an understanding of the eects of mammary oncogenes on mammary cells at early stages in neoplastic transformation. As mammary oncogenes wnt-1 and int-2 aect dierent signal transduction pathways, we investigated their eects on established mouse mammary epithelial cell lines (MMECLs) re¯ecting early stages in tumorigenesis. Normal interactions between b-catenin and E-cadherin were abrogated in all three immortalized MMECLs and the cells lacked b-catenin-mediated transactivation activity, detectable using a reporter assay, suggesting that alterations in cell adhesion may be very early events in mammary tumorigenesis. Immortalized FSK4 and EL12 cells and hyperplastic TM3 cells were stably transfected with expression vectors encoding wnt-1 or int-2 or the control vector, and drug-selected pooled cells from each line were con®rmed by reverse transcription-polymerase chain reaction to express the transfected oncogene; this expression persisted in the cells analysed in vitro and in vivo. Resultant phenotypic changes depended both on the oncogene and the target mammary cell line. In FSK4 cells, expression of wnt-1 or int-2 resulted in proliferative changes in vitro, including reduced contact inhibition, increased b-catenin expression, and decreased p53 transcriptional activity, but neither oncogene conferred upon those cells the ability to produce tumors in vivo. EL12 cells were highly refractory to the eects of both oncogenes, with the only measurable changes being increased E-cadherin levels induced by both oncogenes and increased proliferation of the int-2-transfected cells in the absence of serum. Parental TM3 cells were phenotypically similar to wnt-1-or int-2-transfected FSK4 cells and displayed an increased rate of proliferation in vitro and markedly increased tumorigenicity in vivo following transfection with int-2 but not with wnt-1. These results suggest that wnt-1 signaling is redundant in the hyperplastic TM3 cells and indicate that wnt-1-induced eects in the immortalized FSK4 and EL12 cells were not sucient to mediate a tumorigenic phenotype. This study showed that the wnt-1 and int-2 oncogenes have similar but distinguishable eects on immortalized MMECLs and that the genetic background of the mammary cells greatly in¯uences the consequences of oncogene expression at early stages of cell transformation. Oncogene (2001) 20, 7645 ± 7657.
WNT-1 inducible signaling pathway protein-1 enhances growth and tumorigenesis in human breast cancer
Scientific Reports, 2015
WNT1 inducible signaling pathway protein 1 (WISP1) plays a key role in many cellular functions in a highly tissue-specific manner; however the role of WISP1 in breast cancer is still poorly understood. Here, we demonstrate that WISP1 acts as an oncogene in human breast cancer. We demonstrated that human breast cancer tissues had higher WISP1 mRNA expression than normal breast tissues and that treatment of recombinant WISP1 enhanced breast cancer cell proliferation. Further, ectopic expression of WISP1 increased the growth of breast cancer cells in vitro and in vivo. WISP1 transfection also induced epithelial-mesenchymal-transition (EMT) in MCF-7 cells, leading to higher migration and invasion. During this EMT-inducing process, E-cadherin was repressed and N-cadherin, snail, and b-catenin were upregulated. Filamentous actin (F-actin) remodeling and polarization were also observed after WISP1 transfection into MCF-7 cells. Moreover, forced overexpression of WISP1 blocked the expression of NDRG1, a breast cancer tumor suppressor gene. Our study provides novel evidence that WISP1-modulated NDRG1 gene expression is dependent on a DNA fragment (2128 to 146) located within the human NDRG1 promoter. Thus, we concluded that WISP1 is a human breast cancer oncogene and is a potential therapeutic target. B reast cancer is the most commonly diagnosed cancer and ranks first on the list of cancer-related death in females 1 . Even with recent improvements in understanding the underlying mechanisms of breast cancer and development of new therapeutic approaches, 226,870 American women are diagnosed with breast cancer and 39,510 women die from this disease annually 2 . Of all cancer patients, breast cancer accounts for 23% of the cases and 14%of cancer-related deaths. Metastasis attributes to almost all breast cancer-related deaths, with approximately 25 to 50% of all breast cancer cases eventually developing metastasis. Once metastasis is diagnosed, the 5 year survival rate is generally less than 25%, even with aggressive treatment 3,4 . Thus, to develop new therapeutic strategies to treat metastatic breast cancer, or even to prevent metastasis, should be top priority.
Oncogene, 2002
The Wnt/b-catenin signaling pathway controls cell fate and neoplastic transformation. Expression of an endogenous stabilized b-catenin (DE3 b-catenin) in mammary epithelium leads to the transdifferentiation into epidermis-and pilar-like structures. Signaling molecules in the canonical Wnt pathway upstream from b-catenin induce glandular tumors but it is not clear whether they also cause squamous transdifferentiation. To address this question we have now investigated mammary epithelium from transgenic mice that express activating molecules of the Wnt pathway: Wnt10b, Int2/Fgf3, CK2a, DE3 b-catenin, Cyclin D1, and dominant negative (dn) GSK3b. Cytokeratin 5 (CK5), which is expressed in both mammary myoepithelium and epidermis, and the epidermis-specific CK1 and CK6 were used as differentiation markers. Extensive squamous metaplasias and widespread expression of CK1 and CK6 were observed in DE3 b-catenin transgenic mammary tissue. Wnt10b and Int2 transgenes also induced squamous metaplasias, but expression of CK1 and CK6 was sporadic. While CK5 expression in Wnt10b transgenic tissue was still confined to the lining cell layer, its expression in Int2 transgenic tissue was completely disorganized. In contrast, cytokeratin expression in CK2a, dnGSK3b and Cyclin D1 transgenic mammary tissues was similar to that in DE3 bcatenin tissue. In support of transdifferentiation, expression of hard keratins specific for hair and nails was observed in pilar tumors. These results demonstrate that the activation of Wnt signaling components in mammary epithelium induces not only glandular tumors but also squamous differentiation, possibly by activating LEF-1, which is expressed in normal mammary epithelium.
Breast Cancer …, 2007
Background De-regulation of the wingless and integration site growth factor (WNT) signaling pathway via mutations in APC and Axin, proteins that target β-catenin for destruction, have been linked to various types of human cancer. These genetic alterations rarely, if ever, are observed in breast tumors. However, various lines of evidence suggest that WNT signaling may also be de-regulated in breast cancer. Most breast tumors show hypermethylation of the promoter region of secreted Frizzled-related protein 1 (sFRP1), a negative WNT pathway regulator, leading to downregulation of its expression. As a consequence, WNT signaling is enhanced and may contribute to proliferation of human breast tumor cells. We previously demonstrated that, in addition to the canonical WNT/β-catenin pathway, WNT signaling activates the extracellular signalregulated kinase 1/2 (ERK1/2) pathway in mouse mammary epithelial cells via epidermal growth factor receptor (EGFR) transactivation.
Disease Models & Mechanisms, 2019
The Wnt gene family is an evolutionarily conserved group of proteins that regulate cell growth, differentiation, and stem cell self-renewal. Aberrant Wnt signaling in human breast tumors has been proposed to be a driver of tumorigenesis, especially in the basal-like subtype where canonical Wnt signaling is both enriched and predictive of poor clinical outcomes. The development of effective Wnt based therapeutics, however, has been slowed in part by a limited understanding of the context dependent nature with which these aberrations influence breast tumorigenesis. We previously reported that MMTV-Wnt1 mice, which are an established model for studying Wnt signaling in breast tumors, develop two subtypes of tumors by gene expression classification: Wnt1-EarlyEx and Wnt1-LateEx. Here, we extend this initial observation significantly and show that Wnt1-EarlyEx tumors have high expression of canonical Wnt, non-canonical Wnt, and EGFR signaling pathway signatures. Therapeutically, Wnt1-Ear...
Mammary Tumor Regression Elicited by Wnt Signaling Inhibitor Requires IGFBP5
Cancer Research, 2012
Wnt ligand-driven tumor growth is inhibited by the soluble Wnt inhibitor Fzd8CRD, but the mechanism through which this effect is mediated is unknown. In the MMTV-Wnt1 mouse model, regression of mammary tumors by Fzd8CRD treatment coincides with an acute and strong induction of insulin-like growth factor (IGF)binding protein IGFBP5, an antagonist of IGF signaling that mediates involution of mammary gland in females after offspring are weaned. In this study, we show that repression of this IGF inhibitory pathway is crucial for Wntdriven growth of mammary tumors. We found that IGFBP5 regulation was mediated by the b-catenin-dependent Wnt pathway. Wnt, in addition to IGF ligands, facilitated tumor growth by paracrine communication among tumor cells. In addition, Fzd8CRD caused precocious induction of IGFBP5 in normal mammary glands undergoing involution, implying an acceleration of the involution process by inhibition of Wnt signaling. The molecular and phenotypic parallel between tumor regression and mammary gland involution suggests that Wntdriven mammary tumors use the same growth mechanism as proliferating normal mammary glands. Cancer Res; 72(6); 1568-78. Ó2012 AACR.
Oncogene, 2001
Secreted Frizzled-related protein 1 (SFRP1) encodes a member of a protein family that contains a cysteine-rich domain similar to the WNT-binding site of Frizzled receptors and regulates the WNT pathway. The WNT pathway is frequently altered in human cancers. We have de®ned the pattern of SFRP1 mRNA expression in the progression of breast cancer. We show that SFRP1 is expressed in the epithelial component of normal breast, in the in situ component of ductal carcinomas and is lost in more than 80% of invasive breast carcinomas except the medullary type. Loss of SFRP1 expression is correlated with the presence of hormonal receptors. Conversely, the maintenance of SFRP1 in carcinomas is correlated with the presence of lymphoplasmocytic stroma. No signi®cant association was observed between SFRP1 status and the level of apoptosis in tumoral cells.
Neoplasia, 2019
Tetraspanin CD151 is increasingly implicated as a multifaceted mediator of cancer development and progression. Here we investigated the role of CD151 in breast cancer in the context of the Wnt oncogenic activation. Our data showed that removal of one or both of CD151 alleles in the MMTV-Wnt1 model significantly decreased the tumor-free survival of mice from 34 weeks on average to 22 weeks and 18 weeks, respectively. This effect coincided with an accelerated tumor growth and an increased number of Ki-67 + proliferative cells. Mechanistically, the CD151-deficient tumors were largely ER + , and exhibited hyperactivation of the Wnt pathway as reflected by a marked upregulation in b-catenin and Cyclin D1, and their target genes. In addition, E-cadherin displayed a cytosolic distribution and transcription factor Snail was markedly upregulated. Collectively, this data implies that CD151 suppresses the Wnt1-driven tumorigenesis, at least in part, via counteracting the epithelial-mesenchymal transition (EMT)-like program in luminal epithelial cells. Meanwhile, the proportion of tumor cells expressing CK5 or p63, the biomarkers of myoepithelial/basal cells, markedly decreased in the absence of CD151. This change was accompanied by a decreased invasiveness of tumors and their incompetence to form a long-term cell culture. Consistent with this basal cell-linked role, the CD151 downregulation impairs mammosphere formation in MCF-10A cells and the defect was rescued by re-expression of intact CD151 ORF, but not its integrin binding-defective mutant. Overall, our study suggests that CD151 is a key player in the Wnt oncogene-driven tumorigenesis and impacts breast cancer malignancy in a cell type-dependent manner.