In the progression from inflammatory bowel disease to associated cancer, the clonal mutational landscape shifts from selection of mutations in inflammatory genes to selection for cancer-driver mutations. How prevalence and expansion of either type of mutant clones could be impacted by the cellular environments in which they arise and how this affects the neoplastic outcome of colitis remains unknown. Here we combine in vivo lineage tracing, in silico modeling, mutational profiling and spatial transcriptomics in a mouse model of colitis-associated tumorigenesis to capture clone fates associated with chronic inflammation. We identify epithelial- and immune-enriched neighborhoods and propose a model in which establishment of a reparative tissue environment facilitates tumor initiation by promoting the selection and expansion of pro-oncogenic clones, reducing the span of inflammation-resistant neighborhoods containing nononcogenic clones.

Chronic lung injury generates metaplasia which occasionally, but ominously, progresses to squamous dysplasia and squamous lung cancer. To identify mechanisms through which disrupted tissue homeostasis contributes to malignant initiation and progression, we used in vivo and in vitro heterotypic recombinant models of human b ronchial e pithelial c ells (hBECs) and fibroblasts. We demonstrate that injury-associated TGF-β signaling creates a fibroblast state dependent upon HSP47 upregulation. These fibroblasts accumulated collagen, thus elevating tissue stiffness and activating mechanosignaling that sustained YAP-dependent embryonic-like, pro-malignant activities in adjacent hBECs. This S tress/ T ension-Instructive F ibroblast (STIF) state, exhibited by stressed fibroblasts in premalignant and malignant lesions across multiple cancer types, was sufficient to reprogram disease-free hBECs to metaplasia and to drive hBECs with compromised tumor suppressor function to dysplasia, yet could be inhibited and reversed. STIFs suffice to activate epithelial phenotypes reminiscent of oncogene-mediated cell transformation and induce (pre)malignancy via increased force transmission, providing novel targets for prevention. Statement of significance:Tissue injury creates a regenerative pro-tumorigenic S tress/ T ension-Instructive F ibroblast (STIF) state which is sufficient to activate a YAP-dependent, pre-malignant program to induce or unmask pre-cancerous phenotypes in epithelial cells through mechanotransduction. Inhibition of STIF activity or mechanosignaling prevents metaplasia and progression to dysplasia. Highlights:Tissue injury creates a pro-tumorigenic Stress/Tension-Instructive Fibroblast (STIF) state in multiple organs that precedes and persists through cancerSTIF signaling alone, working through fibroblasts and not epithelial cells, is sufficient to activate embryonic-like plasticity and induce epithelial pre-cancerous metaplastic lesionsSTIFs program (pre)malignant phenotypes in adjacent epithelial cells through mechanosignaling by activating YAP prior to tumor formationInhibiting STIFs or mechanosignaling prevents/reverts metaplasia and prevents progression to dysplasia.

Breast cancer manifests as multiple subtypes with distinct patient outcomes and treatment strategies. Here, we optimized proteomic analysis of Formalin-Fixed Paraffin-Embedded (FFPE) specimens from patients diagnosed with five breast cancer subtypes, luminal A, luminal B, Her2, triple negative (TNBC) and metaplastic breast cancers (MBC), and from disease-free individuals undergoing reduction mammoplasty (RM). We identified and quantified ∼6,000 protein groups (with >2 peptides per protein) with significant changes in over 26% of proteins comparing each cancer subtype with control RM. Stringent statistical filters allowed us to deeply mine 576 significant conserved protein changes shared by all subtypes and protein changes unique to each subtype. The most aggressive subtype, MBC, revealed exacerbated stromal stress responses, as illustrated by a collagenolytic extracellular matrix (ECM) and immune participation biased towards neutrophils and eosinophils. Immunostaining of breast tissue sections confirmed differences across subtypes, in particular, a strong upregulation of SERPINH1, neutrophil-specific myeloperoxidase and eosinophil cationic protein in MBC. In summary, we present deep proteomic, digitalized protein abundance profiles, generated from FFPE breast cancer tissues, that revealed significant changes in ECM and cellular proteins. Statement of Significance of the Study:This study is significant as it discovered deep proteomic signatures for the highly aggressive and malignant metaplastic breast cancer (MCB) which is now considered a fifth subtype based upon its remarkable intra-tumoral heterogeneity that illustrates its unique cell plasticity. To efficiently analyze formalin-fixed paraffin-embedded (FFPE) breast tissues from patients with different breast cancer subtypes and disease-free individuals, we optimized a novel workflow in which we combined paraffinization and Folch extraction. We identified and confidently quantified ∼6,000 protein groups. We were able to find robust changes in extracellular matrix (ECM) with cancer, even though no ECM enrichments were performed. Interestingly, despite the relatively small human cohort size (42 patients), distinct protein signatures emerged throughout all cancer subtypes - common and unique - with remarkable statistical significance for many cancer-relevant proteins and pathways. This Pilot study indicates the hypothesis that an altered stroma can dictate epithelial tumor cell fate. We also observed that MBC was characterized by an especially immunosuppressed tumor environment. We do note the limitation of the relatively small cohort size of our study, and in the future additional patient cohorts will be needed to further validate our findings.

Esophageal adenocarcinoma arises from Barrett's esophagus, a metaplastic condition. Multi-omics profiling, integrating single-cell transcriptomics, extracellular matrix proteomics, tissue mechanics and spatial proteomics of the paths of progression from squamous epithelium through metaplasia, dysplasia to adenocarcinoma, in 107 samples from 26 patients in two independent cohorts, defined shared and patient-specific progression characteristics. Metaplastic replacement of epithelial cell composition and architecture was paralleled by changes in stromal cells, extracellular matrix (ECM) and tissue stiffness. This change in pre-cancerous metaplasia was already accompanied by appearance of fibroblasts with the molecular characteristics of carcinoma-associated fibroblasts. These fibroblasts produced the immunosuppressive protein POSTN, whose expression shifted from vascular to stromal cells, consistent with the emergence of an immunosuppressive microenvironment evident in cell neighborhoods enriched for immunoregulatory NK and Treg cells. Thus, Barrett's esophagus progresses as a coordinated multi-component system, supporting treatment paradigms that go beyond targeting cancerous cells to incorporate stromal reprogramming.

The tumor microenvironment (TME) of chronic inflammation-associated cancers (CIACs) is shaped by cycles of injury and maladaptive repair, yet the principles organizing fibrotic stroma in these tumors remain unclear. Here, we applied the concept of hot versus cold fibrosis, originally credentialed in non-cancerous fibrosis of heart and kidney, to lung squamous cell carcinoma (LUSC), a prototypical CIAC. Single-cell transcriptomics of matched tumor and adjacent-normal tissue from 16 treatment-naive LUSC patients identified a cold fibrotic architecture in the LUSC TME: cancer-associated fibroblasts (CAFs) expanded and adopted myofibroblast and stress-response states, while macrophages were depleted. This macrophage-poor, CAF-rich stroma was maintained by CAF autocrine growth factor loops, including TIMP1, INHBA, TGFB1, and GMFB. In parallel, the immune compartment exhibited a hot tumor phenotype with abundant T and B cells, forming spatially distinct but molecularly engaged networks with CAFs. CAF gene programs typifying cold fibrosis in LUSC were conserved in other CIACs, including esophageal and gastric adenocarcinomas. These results redefine desmoplastic regions of tumors through the lens of a non-cancer fibrosis model, demonstrating that conserved stromal circuits constitute therapeutic vulnerabilities in CIACs.

Barrett's esophagus (BE), a metaplastic condition that is the only known precursor for esophageal adenocarcinoma (EAC), is relatively common, but progression to cancer is infrequent. BE is inflamed but the contribution of the immune system to the carcinogenic process is unknown. To this end, we contrasted non-dysplastic metaplasia of BE patients, captured when they did not progress (non-progressors), did subsequently, but had not yet progressed (pre-progressors) or had already progressed to EAC (progressors). Using spatial multiplexed 56-protein analysis, serial laser capture microdissection (LCM) RNAseq and shallow whole genome sequencing, we identified prooncogenic immune neighbourhoods and dysregulated immune cell populations predictive of subsequent progression to EAC. Indeed, spatial analysis revealed that M1 macrophages, regulatory natural killer (NK) cells, neutrophils and altered ratios of intraepithelial CD4+ and CD8+ lymphocytes typify tumor microenvironmental (TME) changes associated with cancer initiation. Spatially derived cell-to-cell interactions revealed progression-specific immune cell interaction signatures predominantly involving M1 macrophages NK cells and plasma cells. Furthermore, LCM RNAseq analysis identified gene expression 'hot' signatures enriched in pre-progression and progression samples. Notably, we also observed a correlation between immune cells and copy number alterations in progressor metaplasia. By exposing coordinated changes in the immune cell landscape in patients at high risk of developing EAC, this multi-omic dataset provides novel diagnostic and therapeutic opportunities.

Abstract Chronic exposure to tobacco smoke triggers chronic inflammation, fostering a fibrotic microenvironment and promoting the focal replacement of columnar human bronchial epithelial cells (hBECs) with cells exhibiting squamous morphology, termed metaplasia. How squamous metaplasia progresses to squamous dysplasia and, ultimately, squamous lung carcinoma is under intense investigation. Using human bronchial tissues, we demonstrate that, both in vitro and in vivo, cellular stress associated with chronic inflammation (e.g., oxidative stress, DNA damage) enhances TGF-β signaling and creates a fibroblast state exhibiting upregulated HSP47 expression, driving increased collagen fiber alignment, elevated tissue stiffness, and subsequent activation of YAP-dependent mechanotransduction in adjacent hBECs. These Stress/Tension-producing Instructive Fibroblasts (STIFs) alone were sufficient to induce hBECs to squamous metaplasia, precursors to tumor formation. Furthermore, when tumor suppressor function was compromised in hBECs, STIFs induced dysplastic phenotypes. Mechanistically, STIFs act in a dominant manner modulating epithelial cell identity and malignant phenotypes via extracellular matrix (ECM)-dependent mechanotransduction. Inhibition of HSP47-dependent collagen processing effectively prevented fibroblast-induced squamous metaplasia and dysplasia and was capable of reversing fibroblast-induced metaplasia, restoring bronchial epithelial cell identity. Citation Format: Thea D. Tisty, Deng Pan, Philippe Gascard, Joseph Caruso, Lorenzo Ferri, Chira Chen-Tanyolac. Inflammation-induced mechanotransduction is necessary and sufficient to create pre-cancerous squamous lung metaplasias and necessary to drive progression to dysplasia [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr PR018.

The term 'precancer' typically refers to an early stage of neoplastic development that is distinguishable from normal tissue owing to molecular and phenotypic alterations, resulting in abnormal cells that are at least partially self-sustaining and function outside of normal cellular cues that constrain cell proliferation and survival. Although such cells are often histologically distinct from both the corresponding normal and invasive cancer cells of the same tissue origin, defining precancer remains a challenge for both the research and clinical communities. Once sufficient molecular and phenotypic changes have occurred in the precancer, the tissue is identified as a 'cancer' by a histopathologist. While even diagnosing cancer can at times be challenging, the determination of invasive cancer is generally less ambiguous and suggests a high likelihood of and potential for metastatic disease. The 'hallmarks of cancer' set out the fundamental organizing principles of malignant transformation but exactly how many of these hallmarks and in what configuration they define precancer has not been clearly and consistently determined. In this Expert Recommendation, we provide a starting point for a conceptual framework for defining precancer, which is based on molecular, pathological, clinical and epidemiological criteria, with the goal of advancing our understanding of the initial changes that occur and opportunities to intervene at the earliest possible time point.

Cancer research seeks to understand the biology underlying the progression to malignant transformation. Recently, the incidence of esophageal adenocarcinoma (EAC) has increased dramatically, and if we understand why and how, we will be better equipped for diagnosis, prognosis, detection, prevention, and intervention. The earliest steps in progression for most malignancies are the most difficult to study. The initiation of cancer is believed to be a relatively rare and sporadic event, the locations and timings of which are most often unknown. Of the trillions of somatic cells in our bodies, only a few ever find themselves on a path to malignancy. However, chronic inflammation generates a metaplastic lesion that is directly linked to increased incidence of EAC and thus alerts us to the time and place that progression is initiated and allows us to study the biology. We describe recent studies that identify coordinated actions between stromal and epithelial cells that progress to EAC.

Abstract Esophageal adenocarcinoma (EAC) is a deadly cancer with an increasing incidence which arises out of it's precancerous precursor, termed Barrett’s esophagus (BE). A better understanding of the factors that influence BE progression is essential for early detection and novel therapeutics. 3D Air Liquid Interface (ALI) cultures provide an edge over traditional 2D cultures as they better mimic the in vivo conditions of the esophagus. The aim of the study was to establish conditions for a BE ALI model and to evaluate the phenotypic and molecular changes in primary human BE cells upon interaction with different types of esophageal fibroblasts (EF) and exposure to bile acids(BA) (a major component of gastroesophageal reflux). ALI conditions that allowed growth of both primary BE and fibroblast for at least 30 days were optimized. Non dysplastic BE cells from two patients were utilized with one having EAC (P) and the other with no history of progression (NP). The BE cells were cultured in our ALI model with 3 types of EFs: normal esophageal fibroblasts(NFs), BE associated fibroblasts(BFs) and EAC associated fibroblasts(CFs). To determine the effect of BA exposure, ALI cultures underwent daily 1 hour exposure to bile salts. To determine if BE cells that lacked p53 responded differently to BA exposure, CRISPR Cas9 was utilized to knockout TP53. ALI cultures were conducted for 28 days. Phenotypic differences were determined by H&E staining and immunofluorescence (IF). Changes in cell proliferation was evaluated by Ki67 IF. Successful ALI cultures were validated by positive expression of laminin, pan-cytokeratin, Muc2 and Muc5ac by IF. Upon co-culture, we observed opposing histologic changes in the BE cells from the P and NP patients. The NP BE cells had a less complex structure upon culture with the BFs and CFs compared to NFs. The P BE cells showed the development of a complex morphology upon culture with the CFs compared to the BFs and the NFs. In both patients, we observed an increase in Ki67 positivity with fibroblast co culture; NFs (NP: 6.91%, p=0.070, P: 10.6%, p=0.001), BFs (NP: 12.49%, p=0.0001, P: 11.196%, p=0.003) and CFs (NP: 19.88%, p<0.0001, P:14.63 %, p=0.0001) compared to no fibroblasts (NP = 5.32%, P= 7.25% Ki67+). Co-culture with CFs increased Ki67 staining compared to either NFs or BFs (p=0.007,0.014). Exposure to BA showed a thinning but intact BE epithelial surface in both patients with and without TP53 knockout. Overall, primary BE cells and fibroblasts can be maintained long term in an ALI culture and co-culture with fibroblasts drive increased proliferation in BE cells. The histology changes observed in NP and P cell could be an indication of possible activation and interaction of differential signaling pathways. Ongoing studies aim to identify these pathways and determine transcriptional changes due to co-culture and BA exposure. Citation Format: Annesha Chatterjee, Jordana Maria Azevedo-Martins, Chira Chen Tanyolac, Qurat-Ul Ain, Hui Yu, Sophie Camilleri-Broet, Lorenzo Ferri, Philippe Gascard, Thea D. Tlsty, Matthew D. Stachler. Establishment and optimization of an air liquid interface co-culture system to evaluate phenotypic changes in primary human Barrett's esophagus cells upon different environmental exposures [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6774.

Abstract The stroma that surrounds the tumor in many solid cancers exhibits potent immunosuppressive activity to promote tumor progression and confer resistance to immune-based therapies. Cancer associated fibroblasts (CAFs) encompassing functionally distinct populations are key components of the stroma that are emerging as a key cell type in regulating an immune response. However, the mechanisms by which CAFs can directly suppress the immune activity to promote tumor growth is not clear. Here, we identify that a subset of CAF in both rodent and human stromagenic cancers that displays characteristics of senescent fibroblasts and referred to as sCAFs. We show that sCAFs secrete a decoy protein that interferes with cytotoxic activity of activated T effector (Teff) cells. In mouse models for stroma-rich pancreatic cancer, administration of an antibody that blocked the decoy protein resulted in recalibration of the stromal fibroblast by promoted the formation of interferon-licensed-fibroblast cells at the expense of sCAFs. This switch not only enhanced infiltration of tumor-infiltrating T cells but also alleviated their direct suppression resulting in enhanced effector function and tumor regression. Collectively, these results point to the potent immunosuppressive activity of sCAFs mediated by decoy protein as a mechanism by which stroma can promote tumor progression. As stromagenic-cancers are resistance to current therapies, the development of treatments involving blocking of decoy protein may inhibit tumor growth and improve patient survival. Citation Format: Yao Wang, Hara Apostolopoulou, Arjun Sanyal, Hong Sun, Cynthia Sieland, Kavya Gupta, Jiayu Ye, David Gibbs, Paul Wong, Ntranos Vasilis, Sui Huang, James Gardner, Ajay Maker, Thea Tlsty, Anil Bhushan, Tamara Alliston. Restoration of T effector cells function by targeting senescent cancer-associated fibroblast in tumor microenvironment of stroma-rich cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C036.

Background:Human mammary epithelial cell (HMEC) cultures encounter a stress-associated barrier termed stasis, during which most cells adopt a senescence-like phenotype. From these cultures, rare variants emerge from the basal epithelial population, re-initiating growth. Variants exhibit pre-malignant properties, including an aberrant epigenetic program that enables continued proliferation and acquisition of genetic changes. Following oncogenic transformation, variants produce tumors that recapitulate the histopathological characteristics of metaplastic breast cancer (MBC), a rare subtype characterized by squamous and mesenchymal differentiation. Methods:Using the conventional serum-free HMEC culture system, we probed the capacity for phenotypic plasticity inherent to basal epithelial cell populations from human breast tissue as they navigated stasis and emerged as variant populations. Results:We observed robust activation of a TGF-β-dependent epithelial-mesenchymal transition (EMT) program in basal epithelial cells during stasis, followed by subsequent attenuation of this program in emerging variants. Inhibiting the TGF-β pathway or depleting the EMT regulators Snail or Slug allowed basal epithelial cells to collectively bypass stasis, demonstrating that cellular dysfunction and arrest resulting from TGF-β and EMT activation are central to this in vitro barrier. The spontaneous emergence of variants from stasis cultures was associated with a restricted EMT trajectory, which diverted cells away from a complete mesenchymal state characterized by irreversible growth arrest, and instead limited variants to epithelial and intermediate EMT states associated with greater proliferative capacity and stemness. Epigenetic mechanisms, which contributed to the dysregulated growth control characteristic of the variant phenotype, also contributed to the constrained EMT program in variants. By overcoming the cellular dysfunction and growth arrest resulting from TGF-β and EMT activation, variants exhibited increased oncogenic transformation efficiency compared to pre-stasis basal epithelial cells. Inhibiting the TGF-β pathway prior to stasis significantly reduced EMT in the basal epithelial population, alleviated selective pressure driving variant emergence, and enhanced oncogenic transformation efficiency, resulting in tumors with markedly diminished metaplastic differentiation. Conclusions:This study reveals how adaptive EMT reprogramming governs basal epithelial cell fate decisions and contributes to the development of MBC progenitors by restricting access to terminal mesenchymal states that induce growth arrest and, instead, favoring intermediate states with enhanced tumorigenic potential.

BACKGROUND & AIMS: Chronic inflammatory illnesses are debilitating and recurrent conditions associated with signifi- cant comorbidities, including an increased risk of developing cancer. Extensive tissue remodeling is a hallmark of such illnesses, and is both a consequence and a mediator of disease progression. Despite previous characterization of epithelial and stromal remodeling during inflammatory bowel disease, a complete understanding of its impact on disease progression is lacking. METHODS: A comprehensive proteomic pipeline using dataindependent acquisition was applied to decellularized colon samples from the Muc2 knockout (Muc2KO) mouse model of colitis for an in-depth characterization of extracellular matrix remodeling. Unique proteomic profiles of the matrisomal landscape were extracted from prepathologic and overt colitis. Integration of proteomics and transcriptomics data sets extracted from the same murine model produced network maps describing the orchestrating role of matrisomal proteins in tissue remodeling during the progression of colitis. RESULTS: The in-depth proteomic workflow used here allowed the addition of 34 proteins to the known colon matrisomal signature. Protein signatures of prepathologic and pathologic colitic states were extracted, differentiating the 2 states by expression of small leucine-rich proteoglycans. We outlined the role of this class and other matrisomal proteins in tissue remodeling during colitis, as well as the potential for coordinated regulation of cell types by matrisomal ligands.

Advanced melanoma is considered the most aggressive and deadly form of skin cancer whose incidence has been rising over the past three decades. In the absence of treatment, the median overall survival for advanced-stage metastatic disease is less than 6 months. Although most melanomas detected at an early stage can be cured with surgery, a subset of these eventually metastasize. Therefore, a critical need exists to identify unique molecular features that would be predictive of long-term outcome and response to specific therapies. Recent promising therapeutic regimens have included the use of immune checkpoint inhibitors, such as anti-PD1 antibodies. However, the ability to identify responders and non-responders to this therapy remains elusive. To address this challenge at the molecular level, previously our laboratory identified the emergence of a stem cell phenotype associated with advanced melanoma and other aggressive forms of cancer. Underlying this phenotype is the aberrant re-expression of the embryonic morphogen “Nodal”. Particularly noteworthy, we have observed Nodal to remain in advanced tumors of non-responders to standard-of-care therapies (i.e., BRAFi). This pilot study is the first proof-of-principle attempt to predict treatment response survival outcome in a small cohort of melanoma patients receiving anti-PD1 immune checkpoint inhibitor therapy – based on their Nodal expression profile. Using advanced multiplex immunohistochemistry-based digital pathology, the major finding of this preliminary study indicates that higher Nodal expression is often associated with poorer overall survival after anti-PD1 therapy, reaching nearly statistical relevance.

Supplementary Figure Legends 1-4 from DNA Damage Drives an Activin A–Dependent Induction of Cyclooxygenase-2 in Premalignant Cells and Lesions

PDF file - 392K, Tables S1, S2, S5, S6, S7 and S8: Patient information Table S3: LDAFs vs HDAFs microarray analysis Table S4: CD36 expression in published microarrays Table S9: Association of CD36 levels with tumor characteristics