Cadherin 11 Promotes Immunosuppression and Extracellular Matrix Deposition to Support Growth of Pancreatic Tumors and Resistance to Gemcitabine in Mice

BACKGROUND & AIMS

Pancreatic ductal adenocarcinomas (PDACs) are characterized by fibrosis and an abundance of cancer-associated fibroblasts (CAFs). We investigated strategies to disrupt interactions among CAFs, the immune system, and cancer cells, focusing on adhesion molecule CDH11, which has been associated with other fibrotic disorders and is expressed by activated fibroblasts.

METHODS

We compared levels of CDH11 messenger RNA in human pancreatitis and pancreatic cancer tissues and cells with normal pancreas, and measured levels of CDH11 protein in human and mouse pancreatic lesions and normal tissues. We crossed p48-Cre;LSL-Kras^G12D/+;LSL-Trp53^R172H/+ (KPC) mice with CDH11-knockout mice and measured survival times of offspring. Pancreata were collected and analyzed by histology, immunohistochemistry, and (single-cell) RNA sequencing; RNA and proteins were identified by imaging mass cytometry. Some mice were given injections of PD1 antibody or gemcitabine and survival was monitored. Pancreatic cancer cells from KPC mice were subcutaneously injected into Cdh11^+/+ and Cdh11^-/- mice and tumor growth was monitored. Pancreatic cancer cells (mT3) from KPC mice (C57BL/6), were subcutaneously injected into Cdh11^+/+ (C57BL/6J) mice and mice were given injections of antibody against CDH11, gemcitabine, or small molecule inhibitor of CDH11 (SD133) and tumor growth was monitored.

RESULTS

Levels of CDH11 messenger RNA and protein were significantly higher in CAFs than in pancreatic cancer epithelial cells, human or mouse pancreatic cancer cell lines, or immune cells. KPC/Cdh11^+/- and KPC/Cdh11^-/- mice survived significantly longer than KPC/Cdh11^+/+ mice. Markers of stromal activation entirely surrounded pancreatic intraepithelial neoplasias in KPC/Cdh11^+/+ mice and incompletely in KPC/Cdh11^+/- and KPC/Cdh11^-/- mice, whose lesions also contained fewer FOXP3⁺ cells in the tumor center. Compared with pancreatic tumors in KPC/Cdh11^+/+ mice, tumors of KPC/Cdh11^+/- mice had increased markers of antigen processing and presentation; more lymphocytes and associated cytokines; decreased extracellular matrix components; and reductions in markers and cytokines associated with immunosuppression. Administration of the PD1 antibody did not prolong survival of KPC mice with 0, 1, or 2 alleles of Cdh11. Gemcitabine extended survival of KPC/Cdh11^+/- and KPC/Cdh11^-/- mice only or reduced subcutaneous tumor growth in mT3 engrafted Cdh11^+/+ mice when given in combination with the CDH11 antibody. A small molecule inhibitor of CDH11 reduced growth of pre-established mT3 subcutaneous tumors only if T and B cells were present in mice.

CONCLUSIONS

Knockout or inhibition of CDH11, which is expressed by CAFs in the pancreatic tumor stroma, reduces growth of pancreatic tumors, increases their response to gemcitabine, and significantly extends survival of mice. CDH11 promotes immunosuppression and extracellular matrix deposition, and might be developed as a therapeutic target for pancreatic cancer.

A role for the vitamin D pathway in non-intestinal lesions in genetic and carcinogen models of colorectal cancer and in familial adenomatous polyposis

Vitamin D is implicated in the etiology of cancers of the gastrointestinal tract, usually characterized by alteration in the APC/β-catenin/TCF tumor suppressor pathway. The vitamin D receptor (VDR) is also implicated in cardiovascular and skin diseases as well as in immunity. Activated VDR can indirectly alter β-catenin nuclear localization and directly suppress β-catenin/TCF mediated transcriptional activity. We treated VDR null mice with the carcinogen azoxymethane (AOM) and generated mice bearing a mutated APC (hypomorph) on a VDR null background (Apc^1638N/+Vdr^−/−). VDR null mice do not develop GI or extra-colonic tumors but loss of VDR decreased intestinal tumor latency and increased progression to adenocarcinoma in both models. AOM treatment of VDR null mice also caused squamous cell carcinoma of the anus. Although levels and distribution of total or activated β-catenin in the epithelial component of tumors were unaffected by loss of VDR, β-catenin dependent cyclin D1 expression was affected suggesting a direct VDR effect on β-catenin co-activator activity. Extra-colonic mucosa manifestations in Apc^1638N/+Vdr^−/− animals included increased nuclear β-catenin in submucosal stromal cells, spleno- and cardiomegaly and large epidermoid cysts characteristic of the FAP variant, Gardner's syndrome. Consistent with this, SNPs in the VDR, vitamin D binding protein and CYP24 as well as mutations in APC distal to codon 850 were strongly associated with Gardners syndrome in a cohort of 457 FAP patients, This work suggests that alterations in the vitamin D/VDR axis are important in Gardner's syndrome, as well as in the etiology of anal cancer.

Inhibition of the Immunoproteasome Subunit LMP7 with ONX 0914 Ameliorates Graft-versus-Host Disease in an MHC-Matched Minor Histocompatibility Antigen-Disparate Murine Model

In the current study we evaluated the effects of immunoproteasome inhibition using ONX 0914 (formerly PR-957) to ameliorate graft-versus-host disease (GVHD). ONX 0914, an LMP7-selective epoxyketone inhibitor of the immunoproteasome, has been shown to reduce cytokine production in activated monocytes and T cells and attenuate disease progression in mouse models of rheumatoid arthritis, colitis, systemic lupus erythematosus, and, more recently, encephalomyelitis. Inhibition of LMP7 with ONX 0914 in the B10.BR→CBA MHC-matched/minor histocompatibility antigen (miHA)-disparate murine blood and marrow transplant (BMT) model caused a modest but significant improvement in the survival of mice experiencing GVHD. Concomitant with these results, in vitro mixed lymphocyte cultures revealed that stimulator splenocytes, but not responder T cells, treated with ONX 0914 resulted in decreased IFN-γ production by allogeneic T cells in both MHC-disparate (B10.BR anti-B6) and miHA-mismatched (B10.BR anti-CBA) settings. In addition, a reduction in the expression of the MHC class I-restricted SIINFEKL peptide was observed in splenocytes from transgenic C57BL/6-Tg(CAG-OVA)916Jen/J mice exposed to ONX 0914. Taken together, these data support that LMP7 inhibition in the context of BMT modulates allogeneic responses by decreasing endogenous miHA presentation and that the consequential reduction in allogeneic stimulation and cytokine production reduces GVHD development.

Cadherin-11 in poor prognosis malignancies and rheumatoid arthritis: common target, common therapies

Cadherin-11 (CDH11), associated with epithelial to mesenchymal transformation in development, poor prognosis malignancies and cancer stem cells, is also a major therapeutic target in rheumatoid arthritis (RA). CDH11 expressing basal-like breast carcinomas and other CDH11 expressing malignancies exhibit poor prognosis. We show that CDH11 is increased early in breast cancer and ductal carcinoma in-situ. CDH11 knockdown and antibodies effective in RA slowed the growth of basal-like breast tumors and decreased proliferation and colony formation of breast, glioblastoma and prostate cancer cells. The repurposed arthritis drug celecoxib, which binds to CDH11, and other small molecules designed to bind CDH11 without inhibiting COX-2 preferentially affect the growth of CDH11 positive cancer cells in vitro and in animals. These data suggest that CDH11 is important for malignant progression, and is a therapeutic target in arthritis and cancer with the potential for rapid clinical translation

Trp63 is regulated by STAT5 in mammary tissue and subject to differentiation in cancer

Transformation-related protein 63 (Trp63), the predominant member of the Trp53 family, contributes to epithelial differentiation and is expressed in breast neoplasia. Trp63 features two distinct promoters yielding specific mRNAs encoding two major TRP63 isoforms, a transactivating transcription factor and a dominant negative isoform. Specific TRP63 isoforms are linked to cell cycle arrest, apoptosis, survival, and epithelial mesenchymal transition (EMT). Although TRP63 overexpression in cultured cells is used to elucidate functions, little is known about Trp63 regulation in normal and cancerous mammary tissues. This study used ChIP-seq to interrogate transcription factor binding and histone modifications of the Trp63 locus in mammary tissue and RNA-seq and immunohistochemistry to gauge gene expression. H3K4me2 and H3K4me3 marks coincided only with the proximal promoter, supporting RNA-seq data showing the predominance of the dominant negative isoform. STAT5 bound specifically to the Trp63 proximal promoter and Trp63 mRNA levels were elevated upon deleting Stat5 from mammary tissue, suggesting its role as a negative regulator. The dominant negative TRP63 isoform was localized to nuclei of basal mammary epithelial cells throughout reproductive cycles and retained in a majority of the triple-negative cancers generated from loss of full-length Brca1. Increased expression of dominant negative isoforms was correlated with developmental windows of increased progesterone receptor binding to the proximal Trp63 promoter and decreased expression during lactation was correlated with STAT5 binding to the same region. TRP63 is present in the majority of triple-negative cancers resulting from loss of Brca1 but diminished in less differentiated cancer subtypes and in cancer cells undergoing EMT.

Abstract A045: Cadherin-11, a common therapeutic target in poor prognosis malignancies and rheumatoid arthritis

Rational: Poor prognosis epithelial-derived cancers often exhibit morphologic and molecular changes characteristic of an epithelial to mesenchymal transition (EMT). EMT markers are predominantly found in tumors with a basal-like phenotype. Increased expression of the mesenchymal cadherins N-cadherin and/or Cadherin-11 (CDH11) and decreased E-cadherin, have been associated with both EMT and tumor progression. Importantly, CDH11 is a therapeutic target in rheumatoid arthritis (RA), an inflammatory disease with properties often compared with cancer. As CDH11 antibody based therapeutics are in clinical trials for RA and we recently showed that the arthritis drug celecoxib has the structural potential to bind CDH11, there is a strong possibility that, if CDH11can be shown to drive malignant progression rather than simply be associated with it, therapeutic options may be rapidly developed.

Results: We show that CDH11 is increased early in breast cancer and ductal carcinoma in-situ. CDH11 knockdown and antibodies effective in RA slowed the growth of basal-like breast tumors. CDH11 attenuation decreased proliferation and colony formation of breast, glioblastoma and prostate cancer cells. The arthritis drug celecoxib, which has characteristics consistent with CDH11 binding, an analogue without COX-2 inhibitory activity and other molecules that target CDH11, preferentially affect CDH11 positive cancer cells.

Conclusion: Our work demonstrates that cadherin-11 is important for malignant progression, is a therapeutic target in several aggressive tumors and introduces an antibody, novel small molecules and an approved arthritis drug that inhibit its function with potential for rapid clinical translation.

Citation Format: Shahin Assefnia, Sivanesan Dakshanamurthy, Jaime M. Guidry Auvil, Constanze Hampel, Panos Anastasiadis, Bhaskar Kallakury, Aykut Uren, David W. Foley, Milton Brown, Lawrence Shapiro, Michael Brenner, David Haigh, Stephen W. Byers. Cadherin-11, a common therapeutic target in poor prognosis malignancies and rheumatoid arthritis. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr A045.

Predicting new indications for approved drugs using a proteochemometric method

The most effective way to move from target identification to the clinic is to identify already approved drugs with the potential for activating or inhibiting unintended targets (repurposing or repositioning). This is usually achieved by high throughput chemical screening, transcriptome matching, or simple in silico ligand docking. We now describe a novel rapid computational proteochemometric method called "train, match, fit, streamline" (TMFS) to map new drug-target interaction space and predict new uses. The TMFS method combines shape, topology, and chemical signatures, including docking score and functional contact points of the ligand, to predict potential drug-target interactions with remarkable accuracy. Using the TMFS method, we performed extensive molecular fit computations on 3671 FDA approved drugs across 2335 human protein crystal structures. The TMFS method predicts drug-target associations with 91% accuracy for the majority of drugs. Over 58% of the known best ligands for each target were correctly predicted as top ranked, followed by 66%, 76%, 84%, and 91% for agents ranked in the top 10, 20, 30, and 40, respectively, out of all 3671 drugs. Drugs ranked in the top 1-40 that have not been experimentally validated for a particular target now become candidates for repositioning. Furthermore, we used the TMFS method to discover that mebendazole, an antiparasitic with recently discovered and unexpected anticancer properties, has the structural potential to inhibit VEGFR2. We confirmed experimentally that mebendazole inhibits VEGFR2 kinase activity and angiogenesis at doses comparable with its known effects on hookworm. TMFS also predicted, and was confirmed with surface plasmon resonance, that dimethyl celecoxib and the anti-inflammatory agent celecoxib can bind cadherin-11, an adhesion molecule important in rheumatoid arthritis and poor prognosis malignancies for which no targeted therapies exist. We anticipate that expanding our TMFS method to the >27 000 clinically active agents available worldwide across all targets will be most useful in the repositioning of existing drugs for new therapeutic targets.

Abstract B71: Decreased expression of Tgfβ family members appears to be an acquired phenotype of progression to malignancy in the context of loss of Brca1 in mammary epithelial cells

B71

Rational

Loss of full length Brca1 in mammary epithelial cells of conditional knockout mice is associated with an aberrant proliferative response to estrogen treatment promoting cancer progression. We had previously found that loss of full-length Brca1 in mammary epithelial cells was associated with decreased expression of Tgfβ family members at early stage of malignancy. Initial time course study was conducted to find if decreased expression of growth inhibitory Tgfβ family members is directly related to loss of Brca1 in mammary epithelial cells.

Methods

Mammary gland tissue of Brca1f/f;MMTV-Cre and control wild-type mice from different time points: prior to puberty (age 2½ weeks), mid-puberty (age 6 weeks), end of puberty (age 10 weeks) and maturity (4 and 6 months) was isolated at the time of necropsy(N=3 per cohort). RNA expression levels of TGF-β 1,2,3 and TGF-βRI, II were measured by real time RT-PCR.

Results

No significant differences in the expression levels of Tgfβ family members between Brca1f/f;MMTV-Cre and wild-type mice were found at these time-points using current number of samples.

Conclusions

Decreased expression of Tgfβ family members in these mice does not seem to be directly associated with loss of Brca1 in mammary epithelial cells and appears to be an acquired phenotype as part of the malignancy progression, which would suggest that it is due to modulation of other signaling pathways.

Funding: This study was supported by U.S. Army Medical Research and Material Command WX81XWH-07-1-0588(S. A. and P. A. F.) and Bridges to the Doctorate NIGMS 1R25GM075360-01(S. K. M.).

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B71.

Identification of conserved gene expression features between murine mammary carcinoma models and human breast tumors

BACKGROUND

Although numerous mouse models of breast carcinomas have been developed, we do not know the extent to which any faithfully represent clinically significant human phenotypes. To address this need, we characterized mammary tumor gene expression profiles from 13 different murine models using DNA microarrays and compared the resulting data to those from human breast tumors.

RESULTS

Unsupervised hierarchical clustering analysis showed that six models (TgWAP-Myc, TgMMTV-Neu, TgMMTV-PyMT, TgWAP-Int3, TgWAP-Tag, and TgC3(1)-Tag) yielded tumors with distinctive and homogeneous expression patterns within each strain. However, in each of four other models (TgWAP-T121, TgMMTV-Wnt1, Brca1Co/Co;TgMMTV-Cre;p53+/- and DMBA-induced), tumors with a variety of histologies and expression profiles developed. In many models, similarities to human breast tumors were recognized, including proliferation and human breast tumor subtype signatures. Significantly, tumors of several models displayed characteristics of human basal-like breast tumors, including two models with induced Brca1 deficiencies. Tumors of other murine models shared features and trended towards significance of gene enrichment with human luminal tumors; however, these murine tumors lacked expression of estrogen receptor (ER) and ER-regulated genes. TgMMTV-Neu tumors did not have a significant gene overlap with the human HER2+/ER- subtype and were more similar to human luminal tumors.

CONCLUSION

Many of the defining characteristics of human subtypes were conserved among the mouse models. Although no single mouse model recapitulated all the expression features of a given human subtype, these shared expression features provide a common framework for an improved integration of murine mammary tumor models with human breast tumors.

Activation of estrogen signaling pathways collaborates with loss of Brca1 to promote development of ERalpha-negative and ERalpha-positive mammary preneoplasia and cancer

BRCA1 can regulate estrogen receptor-alpha (ERalpha) activity. This study tested the hypotheses that Brca1 loss in mammary epithelium alters the estrogenic growth response and that exposure to increased estrogen or ERalpha collaborates with Brca1 deficiency to accelerate preneoplasia and cancer development. Longer ductal extension was found in mammary glands of Brca1(f/f;MMTV-Cre) mice during puberty as compared to wild-type mice. Terminal end bud differentiation was impaired in Brca1 mutant mice with preservation of prolactin-induced alveolar differentiation. Exogenous estrogen stimulated an abnormal sustained increase in mammary epithelial cell proliferation and the appearance of ERalpha-negative preneoplasia in postpubertal Brca1 mutant mice. Carcinogenesis was investigated using Brca1(f/f;MMTV-Cre) mice hemizygous for p53. Exogenous estrogen increased the percentage of mice with multiple hyperplastic alveolar nodules. Targeted conditional ERalpha overexpression in mammary epithelial cells of mice that were Brca1 mutant and hemizygous for p53 increased the percentage of mice exhibiting multiple hyperplastic nodules, invasive mammary cancers and cancer multiplicity. Significantly more than half of the preneoplasia and cancers were ERalpha negative even as their initiation was promoted by ERalpha overexpression.