BACKGROUND & AIMS:The contribution of common genetic polymorphisms to ulcerative colitis (UC) pathogenesis is modest; however, families with severe colitis may harbor rare variants with large effect sizes that highlight unrecognized pathways. METHODS:A multigenerational family with UC necessitating colectomy was identified. Whole exome sequencing of this kindred was performed, implicating a rare variant in OTUD3. Constitutive knock-out and intestinal specific Otud3 deficient and heterozygous mice were generated. OTUD3 expression in human colonic biopsies and intestinal organoids was assessed using quantitative reverse transcription polymerase chain reaction and immunofluorescence. Prevalence of rare, damaging variants were compared in distinct patient cohorts. Plasmids containing OTUD3 missense variants were introduced into cell lines where OTUD3 was disrupted to determine their effects on cellular response to cytokine stimulation. RESULTS:Constitutive disruption or heterozygosity of Otud3 in mice, or intestinal-specific deletion, resulted in impaired barrier integrity, tight-junction dysregulation, increased endoplasmic reticulum stress, and penetration of luminal bacteria deep into the colonic crypts that preceded a spontaneous progressive colitis. Analysis of distinct UC cohorts demonstrated enrichment of rare, damaging variants in OTUD3. Introduction of OTUD3 variants in intestinal cell lines phenocopied the epithelial immune dysregulation observed in knockout mice. Finally, OTUD3 mRNA and epithelial protein expression were decreased in the quiescent colonic epithelial tissue of genotype-unselected individuals with UC compared with matched non-UC controls. CONCLUSIONS:Our results demonstrate that OTUD3 is required for colonic epithelial barrier function, and plays a role in the pathogenesis of UC.

PURPOSE:Receptor CUB domain-containing protein 1 (CDCP1) was evaluated as a target for detection and treatment of breast cancer. EXPERIMENTAL DESIGN:CDCP1 expression was assessed immunohistochemically in tumors from 423 patients [119 triple-negative breast cancer (TNBC); 75 HER2+; and 229 ER+/HER2-, including 228 primary tumors and 229 lymph node and 47 distant metastases). Cell cytotoxicity induced in vitro by a CDCP1-targeting antibody-drug conjugate (ADC), consisting of the human/mouse chimeric antibody ch10D7 and the microtubule disruptor monomethyl auristatin E (MMAE), was quantified, including in combination with HER-targeting ADC trastuzumab emtansine (T-DM1). Detection of CDCP1-expressing primary and metastatic xenografts in mice was examined by PET-CT imaging using zirconium-89-labeled ch10D7. The impact of ch10D7-MMAE on tumor burden and survival in vivo, including in combination with T-DM1, was quantified in cell line and patient-derived xenograft mouse models. RESULTS:CDCP1 is expressed predominantly on the surface of malignant cells of 70% of TNBC, 80% of HER2+ tumors, and increases in ER+/HER2- tumors from 44.9% in primary tumors to 56.4% in lymph node metastases and 74.3% in distant metastases. PET-CT imaging with zirconium-89-labeled ch10D7 is effective for the detection of primary and metastatic CDCP1-expressing TNBC in mice. ADC ch10D7-MMAE kills CDCP1-expressing cells in vitro and controls primary and metastatic TNBC xenografts in mice, conferring significant survival advantages over chemotherapy. It compares favorably to T-DM1 in vivo, and ch10D7-MMAE combined with T-DM1 showed the most potent efficacy, markedly reducing tumor burden of CDCP1+/HER2+ xenografts and prolonging mouse survival, compared with T-DM1 or ch10D7. CONCLUSIONS:CDCP1-directed molecular imaging has the potential to identify aggressive breast cancers for CDCP1-targeted treatment.

In this article for the "Highlights of 2024" series, we discuss antibody-drug conjugates (ADCs), which are an emerging class of targeted cancer therapies that harness the specificity of monoclonal antibodies to deliver cytotoxic agents directly to tumor cells. ADCs bind to tumor-associated antigens, undergo internalization via receptor-mediated endocytosis, and release their cytotoxic payload intracellularly, reducing systemic toxicity. This highly selective mechanism has led to significant advancements in oncology, improving treatment efficacy while minimizing adverse effects.

BACKGROUND:There is uncertainty when determining the optimal treatment for malignant polyps. Clinicians must balance the oncological risk of a malignant polyp with the risk of morbidity and mortality from surgery. This study developed an online risk-calculator using machine-learning techniques to predict the risk of an adverse outcome from a malignant colorectal polyp following polypectomy. METHODS:Retrospective data collection of a population-wide database of all malignant polyps from 2011 to 2020 was performed. Utilizing an artificial intelligence-based machine learning approach a generalized linear mixed (GLM) model was developed to predict the risk of an adverse outcome after polypectomy. The presence of an adverse outcome was determined by assessing for the presence of residual disease or lymphatic disease if colorectal resection was undertaken. Delayed disease recurrence was also assessed as an additional adverse outcome. Patient and pathological details from the Queensland Cancer Registry were collected and included in the calculator development. RESULTS:The following variables were included in the final model: age, gender, polyp location (right colon, left colon, rectum), depth of tumour invasion, lymphovascular space invasion, tumour grade, associated polyp type, mismatch repair immunohistochemistry status and margin status. Based on ROC analysis, the AUC for the final GLM model was 0.76. The mean accuracy of the GLM model was 0.76 (95% CI: 0.72-0.80). CONCLUSION:This web-based nomogram will facilitate the discussion of whether individual patients with malignant colorectal polyps can be safely managed with polypectomy or whether the patient should undergo colorectal resection. This nomogram is now available at https://malignantpolyp.com/risk-calculator.

High grade serous ovarian carcinoma (HGSC) is a fatal gynaecological malignancy with limited therapeutic options. Immunotherapies targeting MHC-I-dependent antigen presentation offer potential. Currently, the antigen presentation machinery (APM) of widely used syngeneic murine HGSC models remains poorly characterised, limiting translational relevance. Here, we systematically evaluate APM gene expression in syngeneic murine and patient samples. Tap1 and Psmb8 were identified as critical APM markers, deficient in murine models and strongly correlating with MHC-I expression. Hierarchical clustering correlation analysis using these markers revealed that ID8-p53⁻/⁻BRCA1⁻/⁻ was the most strongly correlated model and aligned with the largest patient subset. Moreover, ID8-ip1 correlated to the smaller second patient subset strongly. The low MHC-I expressing IG10 model was unique clustering alongside patient derived LP28 tumour and not fitting either patient subset. In vivo test of a novel combination immune therapy consisting of Flt3L, Poly(I:C), and paclitaxel therapy demonstrated significantly reduced tumour burden in high APM models (p53⁻/⁻BRCA1⁻/⁻, ID8-ip1; p < 0.01), but not IG10. Furthermore, high expressing MHC-I models were linked to enhanced DC expansion, CD8⁺ T-cell infiltration, and effector differentiation (131 % increase in ID8-ip1), alongside improved CD8⁺ T-cell activation and CD86⁺ B-cell co-stimulation. These findings establish MHC-I as a predictive biomarker for immunotherapy response and underscore the need for APM-enhancing strategies in antigen-poor tumours. By bridging murine models to human APM heterogeneity, this work provides a framework for optimising preclinical immunotherapy evaluation and patient stratification, advancing tailored therapeutic approaches for HGSC.

Polyploidy is a common outcome of chemotherapies, but there is conflicting evidence as to whether polyploidy is an adverse, benign or even favourable outcome. We show Aurora B kinase inhibitors efficiently promote polyploidy in many cell types, resulting in the cell cycle exit in RB and p53 functional cells, but hyper-polyploidy in cells with loss of RB and p53 function. These hyper-polyploid cells (>8n DNA content) are viable but have lost long-term proliferative potential in vitro and fail to form tumours in vivo. Investigation of mitosis in these cells revealed high numbers of centrosomes that were capable of supporting functional mitotic spindle poles, but these failed to progress to anaphase/telophase structures even when AURKB inhibitor was removed after 2–3 days. However, when AURKB inhibitor was removed after 1 day and cells had failed a single cytokinesis to become tetraploid, they retained colony forming ability and long-term proliferative potential. Mathematical modelling of the potential for polyploid cells to produce viable daughter cells demonstrated that cells with >8n DNA and >4 functional spindle poles approach zero probability of a viable daughter, supporting our experimental observations. These findings demonstrate that tetraploidy is tolerated by tumour cells, but higher ploidy states are incompatible with long-term proliferative potential.

Polyploidy is a common outcome of chemotherapies, but there is conflicting evidence as to whether this is a source of increased chemotherapy resistance and aggressive disease, or a benign or even favorable outcome. We have used Aurora B kinase (AURKB) inhibitors that efficiently promote polyploidy in many cell types to investigate the fate of polyploid cells. We demonstrate AURKB inhibitor treatment of cells that have loss of RB and p53 function causes them to become hyper-polyploid, undergoing continuous rounds of growth, replication and failed mitosis/cytokinesis (endomitosis), whereas RB and p53 functional cells will eventually exit the cell cycle. These hyper-polyploid cells (>4n DNA content) are viable and undergo continuous endomitotic cycles, but have lost the ability to form viable colonies in vitro or form tumours in vivo. Investigation of mitosis in these cells revealed that centrosome duplication remained coupled to DNA replication, with the hyper-polyploid cells containing high numbers of centrosome that were capable of supporting functional mitotic spindle poles, but these failed to progress to anaphase/telophase structures even when AURKB inhibitor was removed after 2-3 days. However, when AURKB inhibitor was removed after 1 day and cells had failed a single cytokinesis to become tetraploid, they retained long term colony forming ability. Collectively, these findings demonstrate that tetraploidy is well tolerated by tumour cells but higher ploidy states are incompatible with long term proliferative potential. ### Competing Interest Statement JU is an employee and shareholder of AstraZeneca. JS and JT were employees of AstraZeneca.

Background 5-Fluorouracil (5-FU) remains a core component of systemic therapy for colorectal cancer (CRC). However, response rates remain low, and development of therapy resistance is a primary issue. Combinatorial strategies employing a second agent to augment the therapeutic effect of chemotherapy is predicted to reduce the incidence of treatment resistance and increase the durability of response to therapy. Methods Here, we employed quantitative proteomics approaches to identify novel druggable proteins and molecular pathways that are deregulated in response to 5-FU, which might serve as targets to improve sensitivity to chemotherapy. Drug combinations were evaluated using 2D and 3D CRC cell line models and an ex vivo culture model of a patient-derived tumour. Results Quantitative proteomics identified upregulation of the mitosis-associated protein Aurora B (AURKB), within a network of upregulated proteins, in response to a 24 h 5-FU treatment. In CRC cell lines, AURKB inhibition with the dihydrogen phosphate prodrug AZD1152, markedly improved the potency of 5-FU in 2D and 3D in vitro CRC models. Sequential treatment with 5-FU then AZD1152 also enhanced the response of a patient-derived CRC cells to 5-FU in ex vivo cultures. Conclusions AURKB inhibition may be a rational approach to augment the effectiveness of 5-FU chemotherapy in CRC.

Abstract Ovarian Cancer (OC) is the most common gynaecological malignancy and the eighth most diagnosed cancer in females worldwide. Currently, it is the fifth leading cause of cancer-related mortality among patients globally, largely due to delayed diagnosis, chemotherapy resistance, high metastasis rates, and subtype heterogeneity. Recent OC research highlights extracellular vesicles (EVs) as pivotal contributors to intercellular communication and disease progression, elucidating the intricacies of OC pathology. EVs, diverse membrane-derived vesicles released by most cells, carry molecular cargoes containing proteins and nucleic acids. Studies indicate that the biogenesis, packaging, and release of EVs are highly dependent and sensitive to the cellular microenvironment and depend on the in-vitro and in-vivo modelling systems. Labs use varied model systems—2D monolayers, animal models, and innovative 3D models—to investigate EVs' ovarian cancer roles. Therefore, in this study we aimed to compare the miRNA profiles associated with EVs in 3D ovarian cancer cell models, and to identify the pathophysiological relevance of the EVs isolated from these models to the patient derived EVs.In this study, two OC epithelial cell lines, SKOV-3 and OVCAR-, were initially cultured as 2D monolayers and embedded within Gelatin Methacryloyl hydrogels. Over nine days, multiple assays observed spheroid formation within the cell-laden hydrogels. EVs isolated from the cell-conditioned media were characterized per MISEV 2018 guidelines. Small RNA sequencing identified statistically significant miRNAs, subject to gene ontology and gene rank analyses. EVs from a cohort of 60 OC patients were used to identify survival-associated miRNA profiles.Our findings in the cell-laden hydrogels demonstrated OC cell growth, proliferation, and aggregation into spheroidal structures, establishing an ideal 3D model. The isolated EVs were characterized for size, concentration, morphology, and surface markers. Small RNA sequencing revealed 18 significantly different EV-associated miRNA species across 3D vs 2D models, influencing apoptosis, angiogenesis, migration, and proliferation in ovarian cancer. Notably, 3D model-derived EV-associated miRNAs mirrored patient-derived EV-associated miRNA profiles, indicating their pathophysiological relevance.This study establishes a robust 3D OC model in hydrogels, showcasing growth, proliferation, and aggregation capabilities. Differential miRNA profiles between 3D and 2D model EVs highlight the critical roles of these miRNAs in essential ovarian cancer processes. Moreover, similarities between 3D model and patient-derived EV-associated miRNA profiles emphasize the clinical relevance of our model. Citation Format: Nihar Godbole, Akhilandeshwari Ravichandran, Dominic Guanzon, Andrew Lai, Flavio Carrion, Priyakshi Kalita de Croft, Lewis Perrin, John Hooper, Laura Bray, Carlos Salomon. Changes in extracellular vesicle miRNAs from three-dimensional ovarian cancer cell models reflect physiological changes and cancer survival [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 3386.

Aurora B kinase (AURKB) inhibitors have been trialled in a range of different tumour types but are not approved for any indication. Expression of the human papilloma virus (HPV) oncogenes and loss of retinoblastoma (RB) protein function has been reported to increase sensitivity to AURKB inhibitors but the mechanism of their contribution to sensitivity is poorly understood. Two commonly reported outcomes of AURKB inhibition are polyploidy and senescence, although their relationship is unclear. Here we have investigated the major cellular targets of the HPV E6 and E7, p53 and RB, to determine their contribution to AURKB inhibitor induced polyploidy and senescence. We demonstrate that polyploidy is a universal feature of AURKB inhibitor treatment in all cell types including normal primary cells, but the subsequent outcomes are controlled by RB and p53. We demonstrate that p53 by regulating p21 expression is required for an initial cell cycle arrest by inhibiting both CDK2 and CDK4 activity, but this arrest is only triggered after cells have undergone two failed mitosis and cytokinesis. However, cells can enter senescence in the absence of p53. RB is essential for AURKB inhibitor-induced senescence. AURKB inhibitor induces rapid hypophosphorylation of RB independent of inhibition of CDK2 or CDK4 kinases and p53. This work demonstrates that p53 activation determines the timing of senescence onset, but RB is indispensable for senescence.

Tumor self-seeding is a process whereby circulating tumor cells (CTCs) recolonize the primary tumor, which promotes tumor growth, angiogenesis, and invasion. However, the detailed nature and functions of tumor self-seeded cells (TSCs) have not been well defined due to challenges in tracking and isolating TSCs. Here, we report an accurate animal model using photoconvertible tagging to recapitulate the spontaneous process of tumor self-seeding and identify TSCs as a subpopulation of primary tumor cells with enhanced invasiveness and survival. We demonstrate transmembrane-4-L-six-family-1 (TM4SF1) as a marker of TSCs, which promotes migration, invasion, and anchorage-independent survival in cancer cells. By analyzing single-cell RNA sequencing datasets, we identify a potential TSC population with a metastatic profile in patients with cancer, which is detectable in early-stage disease and expands during cancer progression. In summary, we establish a framework to study TSCs and identify emerging cell targets with diagnostic, prognostic, or therapeutic potential in cancers.

ABSTRACT Background Clear cell carcinomas (CCCs) are a distinct histopathological subtype defined by a clear cytoplasm comprised of glycogen and lipids and characterised by poor prognosis and widespread chemoresistance. In the present work we investigate glycogen metabolism as a targetable modality for these cancers. Methods and Results Adopting the indole carboxamide site pan-glycogen phosphorylase inhibitor CP91149 against clear cell ovarian and renal cancer cell line models, we note antiproliferative and antimigratory effects, as well as energetic stress reflected by reduced ATP pools and increased superoxide-derived reactive oxygen species. Following this, using the agent alongside standard of care chemotherapies for clear cell ovarian (ccOC) and renal cell carcinoma (ccRCC), we note specific synergy with microtubule disrupting chemotherapy paclitaxel, a phenomenon retained in ccOC lines made stably resistant to paclitaxel. Rescue experiments, as well as phenotypic assays suggest that combination-treated cells undergo ferroptotic cell death. We postulate this synergistic efficacy to arise from subjecting the already hypersensitive clear cell cancers to the mitochondrial stress elicited by taxol chemotherapy alongside the oxidative stress augured by glycogen phosphorylase inhibition. Conclusions Given that CCCs are widely chemoresistant, the present work potentially presents a novel therapeutic avenue for this shared histotype.

AimsAccurate assessment of human epidermal growth factor receptor 2 (HER2) expression by HER2 immunohistochemistry and in‐situ hybridisation (ISH) is critical for the management of patients with breast cancer. The revised 2018 ASCO/CAP guidelines define 5 groups based on HER2 expression and copy number. Manual pathologist quantification by light microscopy of equivocal and less common HER2 ISH groups (groups 2–4) can be challenging, and there are no data on interobserver variability in reporting of these cases. We sought to determine whether a digital algorithm could improve interobserver variability in the assessment of difficult HER2 ISH cases.Methods and resultsHER2 ISH was evaluated in a cohort enriched for less common HER2 patterns using standard light microscopy versus analysis of whole slide images using the Roche uPath HER2 dual ISH image analysis algorithm. Standard microscopy demonstrated significant interobserver variability with a Fleiss's kappa value of 0.471 (fair–moderate agreement) improving to 0.666 (moderate–good) with the use of the algorithm. For HER2 group designation (groups 1–5), there was poor–moderate reliability between pathologists by microscopy [intraclass correlation coefficient (ICC) = 0.526], improving to moderate–good agreement (ICC = 0.763) with the use of the algorithm. In subgroup analysis, the algorithm improved concordance particularly in groups 2, 4 and 5. Time to enumerate cases was also significantly reduced.ConclusionThis work demonstrates the potential of a digital image analysis algorithm to improve the concordance of pathologist HER2 amplification status reporting in less common HER2 groups. This has the potential to improve therapy selection and outcomes for patients with HER2‐low and borderline HER2‐amplified breast cancers.

PURPOSE:This study aimed to identify serum glycoprotein biomarkers for early detection of high-grade serous ovarian cancer (HGSOC), the most common and aggressive histotype of ovarian cancer. EXPERIMENTAL DESIGN:The glycoproteomics pipeline lectin magnetic bead array (LeMBA)-mass spectrometry (MS) was used in age-matched case-control serum samples. Clinical samples collected at diagnosis were divided into discovery (n = 30) and validation (n = 98) sets. We also analysed a set of preclinical sera (n = 30) collected prior to HGSOC diagnosis in the UK Collaborative Trial of Ovarian Cancer Screening. RESULTS:A 7-lectin LeMBA-MS/MS discovery screen shortlisted 59 candidate proteins and three lectins. Validation analysis using 3-lectin LeMBA-multiple reaction monitoring (MRM) confirmed elevated A1AT, AACT, CO9, HPT and ITIH3 and reduced A2MG, ALS, IBP3 and PON1 glycoforms in HGSOC. The best performing multimarker signature had 87.7% area under the receiver operating curve, 90.7% specificity and 70.4% sensitivity for distinguishing HGSOC from benign and healthy groups. In the preclinical set, CO9, ITIH3 and A2MG glycoforms were altered in samples collected 11.1 ± 5.1 months prior to HGSOC diagnosis, suggesting potential for early detection. CONCLUSIONS AND CLINICAL RELEVANCE:Our findings provide evidence of candidate early HGSOC serum glycoprotein biomarkers, laying the foundation for further study in larger cohorts.

Background Epithelial ovarian cancer (EOC) is a global health burden, with the poorest five-year survival rate of the gynecological malignancies due to diagnosis at advanced stage and high recurrence rate. Recurrence in EOC is driven by the survival of chemoresistant, stem-like tumor-initiating cells (TICs) that are supported by a complex extracellular matrix and immunosuppressive microenvironment. To target TICs to prevent recurrence, we identified genes critical for TIC viability from a whole genome siRNA screen. A top hit was the cancer-associated, proteoglycan subunit synthesis enzyme UDP-glucose dehydrogenase (UGDH). Methods Immunohistochemistry was used to characterize UGDH expression in histological and molecular subtypes of EOC. EOC cell lines were subtyped according to the molecular subtypes and the functional effects of modulating UGDH expression in vitro and in vivo in C1/Mesenchymal and C4/Differentiated subtype cell lines was examined. Results High UGDH expression was observed in high-grade serous ovarian cancers and a distinctive survival prognostic for UGDH expression was revealed when serous cancers were stratified by molecular subtype. High UGDH was associated with a poor prognosis in the C1/Mesenchymal subtype and low UGDH was associated with poor prognosis in the C4/Differentiated subtype. Knockdown of UGDH in the C1/mesenchymal molecular subtype reduced spheroid formation and viability and reduced the CD133 + /ALDH high TIC population. Conversely, overexpression of UGDH in the C4/Differentiated subtype reduced the TIC population. In co-culture models, UGDH expression in spheroids affected the gene expression of mesothelial cells causing changes to matrix remodeling proteins, and fibroblast collagen production. Inflammatory cytokine expression of spheroids was altered by UGDH expression. The effect of UGDH knockdown or overexpression in the C1/ Mesenchymal and C4/Differentiated subtypes respectively was tested on mouse intrabursal xenografts and showed dynamic changes to the tumor stroma. Knockdown of UGDH improved survival and reduced tumor burden in C1/Mesenchymal compared to controls. Conclusions These data show that modulation of UGDH expression in ovarian cancer reveals distinct roles for UGDH in the C1/Mesenchymal and C4/Differentiated molecular subtypes of EOC, influencing the tumor microenvironmental composition. UGDH is a strong potential therapeutic target in TICs, for the treatment of EOC, particularly in patients with the mesenchymal molecular subtype.

Introduction: CUB-domain containing- protein 1 (CDCP1) is a transmembrane receptor involved in the progression of several cancers. Recent studies demonstrate that CDCP1 is a rational target for the development of innovative targeted therapies for cancer including theranostics agents and antibody-drug conjugates. Objective/Methods: To determine the therapeutic potential of CDCP1 in breast cancer, we investigated its expression in multiple cohorts of breast cancer tissues by immunohistochemistry, as well as in various preclinical models including cell lines, primary cells and patient-derived xenografts using flow cytometry, western blot and immunofluorescence staining. Then, we evaluated the capacity of the CDCP1-targeting chimeric antibody ch10D7 to specifically accumulate in breast cancer lesions in in vivo preclinical models including patient-derived xenografts and breast cancer metastasis models. Finally, we determined the efficacy of the ch10D7-MMAE antibody-drug conjugate to kill breast cancer cells in vitro and breast tumours ex-vivo and in vivo. Results: The CDCP1 receptor is expressed at targetable level in a significant proportion of breast cancer cases with high/intermediate expression detected in ~30% of localized ER-positive cases, ~50% of metastatic ER-positive cases and >70% of Triple negative or HER2-positive cases. Similar proportion of expression was detected in cellular models. We demonstrated that ch10D7 antibody labelled with the radionucleotide Zircodium-89 specifically accumulates in breast cancer lesions in vivo allowing the detection of mammary-fat pad implanted patient-derived xenografts and of breast cancer metastasis by PET/CT imaging. Finally, we confirmed that the ch10D7-MMAE antibody-drug conjugate is very efficient at inducing cell death in vitro as well as controlling primary tumour and metastatic tumour burden in pre-clinical models, conferring a significant survival advantage compared to classical therapy. Conclusion: Our work demonstrates that CDCP1 is a potential target to detect and limit the progression of breast tumours and that biomolecules specifically recognising this receptor are promising agents which could improve survival of patients. Citation Format: Madeline Gough, Tashbib Khan, Kayden Kwah, Yaowu He, Gishan Ratnayake, Christopher Pyke, Cameron Snell, John Hooper, Thomas Kryza. Development of CDCP1-targeting antibody-drug conjugate for Triple negative and metastatic breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-26.

e15012 Background: CUB-domain containing- protein 1 (CDCP1) is a transmembrane receptor involved in the progression of several cancers. Recent studies demonstrate that CDCP1 is a rational target for the development of innovative targeted therapies for cancer including theranostics agents and antibody-drug conjugates. Methods: To determine the therapeutic potential of CDCP1 in breast cancer, we investigated its expression in multiple cohorts of breast cancer tissues by immunohistochemistry, as well as in various preclinical models including cell lines, primary cells and patient-derived xenografts using flow cytometry, western blot and immunofluorescence staining. Then, we evaluated the capacity of the CDCP1-targeting chimeric antibody ch10D7 to specifically accumulate in breast cancer lesions in in vivo preclinical models including patient-derived xenografts and breast cancer metastasis models. Finally, we determined the efficacy of the ch10D7-MMAE antibody-drug conjugate to kill breast cancer cells in vitro and breast tumours ex-vivo and in vivo. Results: The CDCP1 receptor is expressed at targetable level in a significant proportion of breast cancer cases with high/intermediate expression detected in ~30% of localized ER-positive cases, ~50% of metastatic ER-positive cases and > 70% of Triple-negative or HER2-positive cases. Similar proportion of expression was detected in cellular models. We demonstrated that ch10D7 antibody labelled with the radionucleotide Zircodium-89 specifically accumulates in breast cancer lesions in vivo allowing the detection of mammary-fat pad implanted patient-derived xenografts and of breast cancer metastasis by PET/CT imaging. Finally, we confirmed that the ch10D7-MMAE antibody-drug conjugate is very efficient at inducing cell death in vitro as well as controlling primary tumour and metastatic tumour burden in pre-clinical models, conferring a significant survival advantage compared to classical therapy. Conclusions: Our work demonstrates that CDCP1 is a potential target to detect and limit the progression of breast tumours in both the primary and metastatic disease setting, particularly in triple-negative and HER2-positive breast cancer subtypes. Furthermore, we show that biomolecules specifically recognising this receptor are promising therapeutic agents which could improve survival of patients.

Significance: Reactive oxygen species (ROS) are critical to normal cellular function with redox homeostasis achieved by balancing ROS production with removal through detoxification mechanisms. Many of the conventional chemotherapies used to treat colorectal cancer (CRC) derive a proportion of their cytotoxicity from ROS generation, and resistance to chemotherapy is associated with elevated detoxification mechanisms. Furthermore, cancer stem cells demonstrate elevated detoxification mechanisms making definitive treatment with existing chemotherapy challenging. In this article, we review the roles of ROS in normal and malignant colonic cell biology and how existing and emerging therapies might harness ROS for therapeutic benefit.Recent Advances: Recent publications have elucidated the contribution of ROS to the cytotoxicity of conventional chemotherapy alongside the emerging approaches of photodynamic therapy (PDT), sonodynamic therapy (SDT), and radiodynamic therapy (RDT), in which ROS are generated in response to excitatory light, sound, or X-ray stimuli to promote cancer cell apoptosis.Critical Issues: The majority of patients with metastatic CRC have a very poor prognosis with a 5-year survival of similar to 13% making the need for new or more effective treatments an imperative.Future Directions: Modulation of ROS through a combination of new and emerging therapies may improve the efficacy of current chemotherapy providing novel approaches to treat the otherwise resistant disease.

Since the 1800s, there have been live load surveys and analyses carried out, particularly of area-dependent loads in office buildings. While some occupancies have received careful examination, there has been no systematic review and consideration of reliability-based scenarios for office gathering space live loads. The results of the research reported here indicates (supports) a more consistent, reliable, and economic design load for office gathering spaces in buildings. These results provide the theoretical and practical basis for design live loads for gathering spaces within offices, a step toward possible enactment in the current standard, and subsequently by adoption into the International Building Code and materials standards. Following a review of historical load surveys and theoretical models, the paper presents models and observations of crowding, serving as a basis for a different approach for such areas, including a Delphi among leading design firms in the United States. The paper concludes with recommendations for a new live load use category for gathering spaces for offices. Modern office usage often contains work spaces for meeting, gathering, and collaboration. The current standard for minimum design loads and associated criteria for buildings and other structures does not directly address this situation. Interpretation has led to conflicting requirements for the design loads of such spaces, including the possibility of assigning them as assembly areas. This can lead to overdesign and uneconomical structures. This research reviews historical office surveys with an emphasis on assembly spaces, presents the results of a Delphi of design firms throughout the United States, and contains a stochastic maximum load analysis. These various assessments lead to a consistent evaluation of plausible loads for such spaces, and a recommendation for a new subcategory in the standard live load table. The study recommends treating these spaces similar to general offices, with a basic live load of 2.39 kN/m2 (50 psf), and permissible live load reduction as is currently in the standard for offices. Exception is made for such work spaces that are directly accessible from outside and intended for use by the general public.

Since the proposition of the pro-invasive activity of proteolytic enzymes over 70 years ago, several roles for proteases in cancer progression have been established. About half of the 473 active human proteases are expressed in the prostate and many of the most well-characterized members of this enzyme family are regulated by androgens, hormones essential for development of prostate cancer. Most notably, several kallikrein-related peptidases, including KLK3 (prostate-specific antigen, PSA), the most well-known prostate cancer marker, and type II transmembrane serine proteases, such as TMPRSS2 and matriptase, have been extensively studied and found to promote prostate cancer progression. Recent findings also suggest a critical role for proteases in the development of advanced and aggressive castration-resistant prostate cancer (CRPC). Perhaps the most intriguing evidence for this role comes from studies showing that the protease-activated transmembrane proteins, Notch and CDCP1, are associated with the development of CRPC. Here, we review the roles of proteases in prostate cancer, with a special focus on their regulation by androgens.