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PDF - 5142K, CD151 clustering at areas of cell-cell contact in vivo (S1); Cell-cell adhesion in response to CD151 clustering (S2); MAB 1A5 binds to CD151 not engaged with α3 integrin in HEp3 cells (S3); MAb 1A5 recognizes the integrin-binding domain of CD151 (S4); Antibodies that recognize the integrin-binding domain of CD151 mediate clustering at areas of cell-cell contact (S5); CD151 expression in normal and prostate cancer tissue (S6); Expression of integrin α3 is not altered in cancers of the bladder or skin (S7); CD151free detectable in benign and normal prostate tissue does not correspond with patient outcome (S8).

MOV - 8452K, CD151 clustering at areas of cell-cell contact in HEp3 tumor cells.

PDf - 92K, Legends for Supplementary Figures S1-S8 as well as Supplementary Movie S1.

PDF - 67K, Demographic information of patients that underwent RRP at the London Regional Cancer Program between 1994 and 1998 (S1); Pathological and clinical outcomes of patients that underwent RRP at the London Regional Cancer Program between 1994 and 1998 (S2); Demographic information of patients that developed metastasis during follow up at the London Regional Cancer Program between 1994 and 1998 (S3).

Chloride is ubiquitous in physiology but understood to provide ionic strength for tissue function. The authors discover a molecular function of chloride whereby the ion signals the assembly of collagen IV, establishing a microenvironment on the outside of cells., Basement membranes are defining features of the cellular microenvironment; however, little is known regarding their assembly outside cells. We report that extracellular Cl− ions signal the assembly of collagen IV networks outside cells by triggering a conformational switch within collagen IV noncollagenous 1 (NC1) domains. Depletion of Cl− in cell culture perturbed collagen IV networks, disrupted matrix architecture, and repositioned basement membrane proteins. Phylogenetic evidence indicates this conformational switch is a fundamental mechanism of collagen IV network assembly throughout Metazoa. Using recombinant triple helical protomers, we prove that NC1 domains direct both protomer and network assembly and show in Drosophila that NC1 architecture is critical for incorporation into basement membranes. These discoveries provide an atomic-level understanding of the dynamic interactions between extracellular Cl− and collagen IV assembly outside cells, a critical step in the assembly and organization of basement membranes that enable tissue architecture and function. Moreover, this provides a mechanistic framework for understanding the molecular pathobiology of NC1 domains.

Malignant pleural effusion (MPE) is a frequent metastatic manifestation of human cancers. While we previously identified KRAS mutations as molecular culprits of MPE formation, the underlying mechanism remained unknown. Here, we determine that non-canonical IKKα-RelB pathway activation of KRAS-mutant tumor cells mediates MPE development and this is fueled by host-provided interleukin IL-1β. Indeed, IKKα is required for the MPE-competence of KRAS-mutant tumor cells by activating non-canonical NF-κB signaling. IL-1β fuels addiction of mutant KRAS to IKKα resulting in increased CXCL1 secretion that fosters MPE-associated inflammation. Importantly, IL-1β-mediated NF-κB induction in KRAS-mutant tumor cells, as well as their resulting MPE-competence, can only be blocked by co-inhibition of both KRAS and IKKα, a strategy that overcomes drug resistance to individual treatments. Hence we show that mutant KRAS facilitates IKKα-mediated responsiveness of tumor cells to host IL-1β, thereby establishing a host-to-tumor signaling circuit that culminates in inflammatory MPE development and drug resistance., Malignant pleural effusion (MPE) is a life-threatening cancer-related disorder. Here, the authors show that KRAS-mutant tumor cells require IKKα, activated via host-provided IL-1β, to promote MPE development and that co-inhibition of both KRAS and IKKα ameliorates the development of MPE in mouse models.

Normal physiology relies on the organization of transmembrane proteins by molecular scaffolds, such as tetraspanins. Oncogenesis frequently involves changes in their organization or expression. The tetraspanin CD151 is thought to contribute to cancer progression through direct interaction with the laminin-binding integrins α3β1 and α6β1. However, this interaction cannot explain the ability of CD151 to control migration in the absence of these integrins or on non-laminin substrates. We demonstrate that CD151 can regulate tumor cell migration without direct integrin binding and that integrin-free CD151 (CD151free) correlates clinically with tumor progression and metastasis. Clustering CD151free through its integrin-binding domain promotes accumulation in areas of cell–cell contact, leading to enhanced adhesion and inhibition of tumor cell motility in vitro and in vivo. CD151free clustering is a strong regulator of motility even in the absence of α3 expression but requires PKCα, suggesting that CD151 can control migration independent of its integrin associations. The histologic detection of CD151free in prostate cancer correlates with poor patient outcome. When CD151free is present, patients are more likely to recur after radical prostatectomy and progression to metastatic disease is accelerated. Multivariable analysis identifies CD151free as an independent predictor of survival. Moreover, the detection of CD151free can stratify survival among patients with elevated prostate-specific antigen levels. Cumulatively, these studies demonstrate that a subpopulation of CD151 exists on the surface of tumor cells that can regulate migration independent of its integrin partner. The clinical correlation of CD151free with prostate cancer progression suggests that it may contribute to the disease and predict cancer progression. Cancer Res; 74(1); 173–87. ©2013 AACR.

A long and productive history in biomedical research defines the chick as a model for human biology. Fundamental discoveries, including the description of directional circulation propelled by the heart and the link between oncogenes and the formation of cancer, indicate its utility in cardiac biology and cancer. Despite the more recent arrival of several vertebrate and invertebrate animal models during the last century, the chick embryo remains a commonly used model for vertebrate biology and provides a tractable biological template. With new molecular and genetic tools applied to the avian genome, the chick embryo is accelerating the discovery of normal development and elusive disease processes. Moreover, progress in imaging and chick culture technologies is advancing real-time visualization of dynamic biological events, such as tissue morphogenesis, angiogenesis, and cancer metastasis. A rich background of information, coupled with new technologies and relative ease of maintenance, suggest an expanding utility for the chick embryo in cardiac biology and cancer research.

Basement membranes (BMs) are specialized extracellular scaffolds that influence behaviors of cells in epithelial, endothelial, muscle, nervous, and fat tissues. Throughout development and in response to injury or disease, BMs are fine-tuned with specific protein compositions, ultrastructure, and localization. These features are modulated through implements of the BM toolkit that is comprised of collagen IV, laminin, perlecan, and nidogen. Two additional proteins, peroxidasin and Goodpasture antigen-binding protein (GPBP), have recently emerged as potential members of the toolkit. In the present study, we sought to determine whether peroxidasin and GPBP undergo dynamic regulation in the assembly of uterine tissue BMs in early pregnancy as a tractable model for dynamic adult BMs. We explored these proteins in the context of collagen IV and laminin that are known to extensively change for decidualization. Electron microscopic analyses revealed: 1) a smooth continuous layer of BM in between the epithelial and stromal layers of the preimplantation endometrium; and 2) interrupted, uneven, and progressively thickened BM within the pericellular space of the postimplantation decidua. Quantification of mRNA levels by qPCR showed changes in expression levels that were complemented by immunofluorescence localization of peroxidasin, GPBP, collagen IV, and laminin. Novel BM-associated and subcellular spatiotemporal localization patterns of the four components suggest both collective pericellular functions and distinct functions in the uterus during reprogramming for embryo implantation.

Molecular biomarkers of cancer are needed to assist histologic staging in the selection of treatment, outcome risk stratification, and patient prognosis. This is particularly important for patients with early-stage disease. We show that shedding of the extracellular domain of activated leukocyte cell adhesion molecule (ALCAM) is prognostic for outcome in patients with colorectal cancer (CRC). Previous reports on the prognostic value of ALCAM expression in CRC have been contradictory and inconclusive. This study clarifies the prognostic value of ALCAM by visualizing ectodomain shedding using a dual stain that detects both the extracellular and the intracellular domains in formalin-fixed tissue. Using this novel assay, 105 patients with primary CRCs and 12 normal mucosa samples were evaluated. ALCAM shedding, defined as detection of the intracellular domain in the absence of the corresponding extracellular domain, was significantly elevated in patients with CRC and correlated with reduced survival. Conversely, retention of intact ALCAM was associated with improved survival, thereby confirming that ALCAM shedding is associated with poor patient outcome. Importantly, analysis of patients with stage II CRC showed that disease-specific survival is significantly reduced for patients with elevated ALCAM shedding (P = 0.01; HR, 3.0), suggesting that ALCAM shedding can identify patients with early-stage disease at risk of rapid progression. Cancer Res; 73(10); 2955–64. ©2013 AACR.

The dysregulation of cell migration enables tumor cells to escape their tissue of origin and disseminate. Since cancer-related deaths are primarily caused by the dissemination of tumor cells, mechanisms of migration are both a target for therapy and an indicator of disease progression. The regulation of cell adhesion is widely recognized as a rate-limiting step in metastasis but how tumor cells achieve dynamic control over their adhesion receptors is poorly understood. During an analysis of prostate cancer progression we discovered that α3β1 expression is reduced and that its tetraspanin partner, CD151, is not “integrin-free”. We were able to detect integrin-free CD151 using antibodies specific to the integrin-binding domain of CD151. Dual staining of tumor tissue and normal tissue from prostate cancer patients for total CD151 and integrin-free CD151 revealed that the appearance of integrin-free CD151 corresponds with poor-patient outcome. In fact, the detection of integrin-free CD151 is an independent predictor of prostate cancer progression. Surprisingly, the clustering of integrin-free CD151 immobilizes tumor cells in vivo and prevents metastasis suggesting that the ability of CD151 to control migration does not depend on its α3β1 integrin partner. Indeed, integrin-free CD151 is now associated with non-integrin partners through which it can regulate tumor cell motility. These observations demonstrate that the appearance of integrin-free CD151 reflects the disruption of the CD151/ α3β1/laminin axis and thereby reveals an altered migratory ability in tumor cells. This has clinical as well molecular implications. Integrin-free CD151 can be used as a molecular indicator of disease progression and assist in the distinction between indolent (benign) and advanced disease (Palmer et al. 2013). In addition, the identification of new CD151 partners can provide new therapeutic targets to inhibit the motility of tumor cells that have undergone this change in migratory status. A preliminary evaluation identified a similar appearance of integrin-free CD151 in cancers derived from other tissues, suggesting that this change in molecular status is broadly applicable to most solid tumors. Palmer, et al. (2013). Integrin-free tetraspanin CD151 can inhibit tumor cell motility upon clustering and is a clinical indicator of prostate cancer progression. Cancer Research. Citation Format: Trenis Palmer, Carlos Martinez, Catalina Vasquez, Katie Hebron, Shanna Arnold, Celestial Jones-Paris, Susanne Chan, Venu Chalasani, Jose Gomez-Lemus, Andrew Williams, Joseph Chin, Giovanna Giannico, Tatiana Ketova, John Lewis, Andries Zijlstra. Separation of tetraspanin CD151 from its integrin partner α3β1 reflects an alter migratory state and predicts prostate cancer progression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 55. doi:10.1158/1538-7445.AM2014-55

50 Background: ALCAM (Activated Leukocyte Cell Adhesion Molecule) is thought to be involved in tumor cell adhesion, migration and metastasis. The ectodomain responsible for adhesion is proteolytically shed. Elevated shedding of ALCAM ectodomain is associated with malignant progression. Considering the proximity of urogentical cancer to both urinary secretions and hematogenous circulation we investigated if ALCAM shed into urine and/or blood could act as a prognostic or diagnostic marker of disease and patient outcome. Methods: Shed ALCAM in serum and urine was measured by ELISA while ALCAM shedding in tissues was detected with a unique immunohistochemical approach. ALCAM shedding was correlated with patient parameters including tumor stage, metastasis, recurrence, overall and disease-specific survival. Results: ALCAM shedding was compared across tissue and fluids from normal age-matched healthy adults, non-urological neoplasia, and non-cancer patients. Elevated ALCAM shedding was readily detected in fluids and tissue from patients with urogenital cancers. However, only the detection of shedding in tissue and urine correlated significantly with disease progression and patient outcome. Specifically, shed ALCAM detected in urine collected from bladder cancer patients undergoing cystectomy (Vanderbilt 2000-2010) correlated strongly with patient outcome. Urine ALCAM correlates positively with invasiveness (80%), and is predictive of recurrence as well as survival (HR=10.2 and 2.9). Urinary ALCAM ROC curves show the optimal sensitivity and specificity of predicting recurrence (90 and 68%) and survival (62 and 83%). Conclusions: We show for the first time that cleaved ALCAM is detectable in the urine and that urinary ALCAM is a novel biomarker in urogenital cancers. ALCAM shedding is marker of cancer progression and patient outcome with high specificity and accuracy. Evaluating levels of shed ALCAM in urine offers a unique and effective method to diagnose, assess, and stratify patients with urogenital cancers. We find this correlation particularly exciting because ALCAM is functionally involved in cancer progression and therefore reports on cellular behavior rather than mere presence of neoplastic disease.

We recently demonstrated that actively promoting the formation of cell surface complexes by engaging the tetraspanin CD151 with a monoclonal antibody (mAb 1A5) inhibits metastasis by immobilizing the tumor cells. Tetraspanins influence cellular behavior via the regulation of associated partner molecules such as integrins, cell adhesion molecules, and members of the immunoglobulin superfamily. Although CD151 is able to associate with and regulate the activity of laminin-binding integrins we demonstrate that CD151 does not associate with α3α1 in the presence of mAb 1A5. Using a 2-color flow cytometric approach we mapped the domains of CD151 required for antigen recognition by mAb 1A5 and determined that 1A5 maps to the integrin 194QRD196 motif of CD151, using this information we further performed CD151 co-immunoprecipitations and demonstrated that 1A5 recognizes CD151 not associated with α3α1.To determine the identity of the protein(s) associated with the antibody-engaged CD151 and also possibly responsible for the anti-migratory, anti-metastatic phenotype we used a proteomic approach. Using tandem mass spectrometry on CD151-associated proteins co-immunoprecipitated by mAb 1A5, we detected in excess of 200 proteins. This strategy identified several putative partners of CD151. Further analysis of the CD151 associated proteins led to our discovery of the novel CD151-associated protein ALCAM/CD166, a member of the immunoglobulin superfamily. Using an RNAi-mediated knockdown approach we demonstrate that ALCAM/CD166 is required for the CD151 complex to regulate tumor cell mobility in vitro. Conversely, CD151 is required for ALCAM to control motility. Spontaneous metastasis assays using the avian chorioallantoic membrane and subcutaneous murine xenografts demonstrate thatALCAM/CD166 is indeed required for the engaged tetraspanin to inhibit tumor cell dissemination in vivo. Further mechanistic analysis of this complex revealed that the CD151/ALCAM protein complex promotes activation of the small GTPase Rap1 via activated protein kinase C. Collectively, we present data, which demonstrate that, the ALCAM-containing CD151 complex can control metastasis. This novel complex reveals how cell-cell interactions can control migration through the regulation of cell-matrix adhesions. These results also demonstrate mechanistically that tetraspanins can integrate signaling between physically distinct molecular functions and therefore behave as a molecular clutch that controls matrix adhesion in response to cell-cell interactions. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4217. doi:1538-7445.AM2012-4217

Basement membranes (BMs) are specialized extracellular scaffolds that provide architecture and modulate cell behaviors in tissues, such as fat, muscle, endothelium, endometrium, and decidua. Properties of BMs are maintained in homeostasis for most adult tissues. However, BM ultrastructure, composition, and localization are rapidly altered in select uterine tissues that are reprogrammed during pregnancy to enable early maternal-embryo interactions. Here, our data exhibit both static and dynamic BMs that were tracked in mouse uterine tissues during pre-, peri-, and postimplantation periods of pregnancy. The data exhibit spatial-temporal patterns of BM property regulation that coincide with the progression of adapted physiology. Further interpretation and discussion of these data in this article are described in the associated research article titled, “Embryo implantation triggers dynamic spatiotemporal expression of the basement membrane toolkit during uterine reprogramming” (C.R. Jones-Paris, S. Paria, T. Berg, J. Saus, G. Bhave, B.C. Paria, B.G. Hudson, 2016) [1] .