Development of a long term, ex vivo, patient-derived explant model of endometrial cancer.

Incidence of endometrial cancer (EC) is rising in the developed world. The current standard of care, hysterectomy, is often infeasible for younger patients and those with high body mass index. There are limited non-surgical treatment options and a lack of biologically relevant research models to investigate novel alternatives to surgery for EC. The aim of the present study was to develop a long-term, patient-derived explant (PDE) model of early-stage EC and demonstrate its use for investigating predictive biomarkers for a current non-surgical treatment option, the levonorgestrel intra-uterine system (LNG-IUS). Fresh tumour specimens were obtained from patients with early-stage endometrioid EC. Tumours were cut into explants, cultured on media-soaked gelatin sponges for up to 21 days and treated with LNG. Formalin-fixed, paraffin embedded (FFPE) blocks were generated for each explant after 21 days in culture. Tumour architecture and integrity were assessed by haematoxylin and eosin (H&E) and immunohistochemistry (IHC). IHC was additionally performed for the expression of five candidate biomarkers of LNG resistance. The developed ex vivo PDE model is capable of culturing explants from early-stage EC tumours long-term (21 Days). This model can complement existing models and may serve as a tool to validate results obtained in higher-throughput in vitro studies. Our study provides the foundation to validate the extent to which EC PDEs reflect patient response in future research.

A first-in-class pan-lysyl oxidase inhibitor impairs stromal remodeling and enhances gemcitabine response and survival in pancreatic cancer.

The lysyl oxidase family represents a promising target in stromal targeting of solid tumors due to the importance of this family in crosslinking and stabilizing fibrillar collagens and its known role in tumor desmoplasia. Using small-molecule drug-design approaches, we generated and validated PXS-5505, a first-in-class highly selective and potent pan-lysyl oxidase inhibitor. We demonstrate in vitro and in vivo that pan-lysyl oxidase inhibition decreases chemotherapy-induced pancreatic tumor desmoplasia and stiffness, reduces cancer cell invasion and metastasis, improves tumor perfusion and enhances the efficacy of chemotherapy in the autochthonous genetically engineered KPC model, while also demonstrating antifibrotic effects in human patient-derived xenograft models of pancreatic cancer. PXS-5505 is orally bioavailable, safe and effective at inhibiting lysyl oxidase activity in tissues. Our findings present the rationale for progression of a pan-lysyl oxidase inhibitor aimed at eliciting a reduction in stromal matrix to potentiate chemotherapy in pancreatic ductal adenocarcinoma.

Mothers with borderline personality disorders' experiences of mother-infant dialectical behavior therapy.

BACKGROUND: Borderline personality disorder (BPD) is increasingly diagnosed in perinatal and infant settings, and research suggests that as well as an escalation of BPD symptoms in this period, these symptoms may also be detrimental to infant development. Providing tailored treatments during the postnatal period may help women and prevent an intergenerational cycle of emotional and interpersonal symptoms in infants. Mother-infant dialectical behavior therapy (MI-DBT) has produced promising, yet inconsistent, improvements on quantitative scales of maternal mental health and the mother-infant relationship. The qualitative evaluation may provide complementary information. AIMS: This study aimed to explore the subjective experiences of women who had completed MI-DBT. MATERIAL AND METHODS: Thematic analysis of semistructured interviews conducted on 13 women undertaking MI-DBT before, post, and 12 months after MI-DBT were analyzed for themes. RESULTS: Five major themes were identified. Overall, the women expressed that their emotional literacy and regulation improved after MI-DBT, subsequently addressing key risks and challenges such as uncertainty around their child's cues, and low self-esteem, and potentially improving the women's mentalization capability. DISCUSSION AND CONCLUSIONS: This study consolidates previous research on maternal BPD, and provides qualitative evidence of the benefits of MI-DBT for mothers as both individuals and as parents with likely flow-on effects for infants. Lived experience input for future adaptations was a valuable gain.

Imaging Modalities for Early Detection of Pancreatic Cancer: Current State and Future Research Opportunities.

Pancreatic cancer, one of the most lethal malignancies, is increasing in incidence. While survival rates for many cancers have improved dramatically over the last 20 years, people with pancreatic cancer have persistently poor outcomes. Potential cure for pancreatic cancer involves surgical resection and adjuvant therapy. However, approximately 85% of patients diagnosed with pancreatic cancer are not suitable for potentially curative therapy due to locally advanced or metastatic disease stage. Because of this stark survival contrast, any improvement in early detection would likely significantly improve survival of patients with pancreatic cancer through earlier intervention. This comprehensive scoping review describes the current evidence on groups at high risk for developing pancreatic cancer, including individuals with inherited predisposition, pancreatic cystic lesions, diabetes, and pancreatitis. We review the current roles of imaging modalities focusing on early detection of pancreatic cancer. Additionally, we propose the use of advanced imaging modalities to identify early, potentially curable pancreatic cancer in high-risk cohorts. We discuss innovative imaging techniques for early detection of pancreatic cancer, but its widespread application requires further investigation and potentially a combination with other non-invasive biomarkers.

ROR1 and ROR2 expression in pancreatic cancer.

BACKGROUND: The Wnt receptors ROR1 and ROR2 are generating increased interest as cancer therapeutic targets but remain understudied in pancreatic ductal adenocarcinoma (PDAC). Compared to canonical Wnt/ ß-catenin signalling, the role of noncanonical Wnt signalling in PDAC remains largely unknown. Only one study has investigated the prognostic significance of the noncanonical Wnt signalling receptor, ROR2 in PDAC. No studies have investigated the prognostic role of ROR1 in PDAC. METHODS: Here, we performed analysis of ROR1 and ROR2 mRNA expression in three publicly available datasets ICGC-PACA-AU (n = 81), TCGA-PAAD (n = 150) and CPTAC-PDAC (n = 137). ROR1 and ROR2 protein expression from the CPTAC-PDAC discovery cohort were also analysed. Immunohistochemistry (IHC) using the validated anti ROR1 monoclonal antibody (4A5) was performed on the Australian Pancreatic Cancer Genome Initiative (APGI) cohort of PDAC samples (n = 152). Association between ROR1 cytoplasmic staining intensity and clinicopathological parameters including stage, grade and overall survival (OS) was investigated. RESULTS: High ROR1 mRNA expression levels correlated with a favourable OS outcome in all of the ICGC-PACA-AU, TCGA-PAAD and CPTAC-PDAC cohorts. ROR1 protein expression was not associated with stage, grade or OS in the APGI cohort. CONCLUSION: ROR1 and ROR2 have potential as prognostic markers when measured at the mRNA level in PDAC. Our IHC cohort did not support ROR1 protein expression in predicting OS, and highlighted the discrepancy of prognostic biomarkers when measured by MS, IHC and RNAseq.

Does the Microenvironment Hold the Hidden Key for Functional Precision Medicine in Pancreatic Cancer?

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and no significant improvement in patient survival has been seen in the past three decades. Treatment options are limited and selection of chemotherapy in the clinic is usually based on the performance status of a patient rather than the biology of their disease. In recent years, research has attempted to unlock a personalised treatment strategy by identifying actionable molecular targets in tumour cells or using preclinical models to predict the effectiveness of chemotherapy. However, these approaches rely on the biology of PDAC tumour cells only and ignore the importance of the microenvironment and fibrotic stroma. In this review, we highlight the importance of the microenvironment in driving the chemoresistant nature of PDAC and the need for preclinical models to mimic the complex multi-cellular microenvironment of PDAC in the precision medicine pipeline. We discuss the potential for ex vivo whole-tissue culture models to inform precision medicine and their role in developing novel therapeutic strategies that hit both tumour and stromal compartments in PDAC. Thus, we highlight the critical role of the tumour microenvironment that needs to be addressed before a precision medicine program for PDAC can be implemented.

Cancer-Associated Fibroblasts in Pancreatic Ductal Adenocarcinoma Determine Response to SLC7A11 Inhibition.

Cancer-associated fibroblasts (CAF) are major contributors to pancreatic ductal adenocarcinoma (PDAC) progression through protumor signaling and the generation of fibrosis, the latter of which creates a physical barrier to drugs. CAF inhibition is thus an ideal component of any therapeutic approach for PDAC. SLC7A11 is a cystine transporter that has been identified as a potential therapeutic target in PDAC cells. However, no prior study has evaluated the role of SLC7A11 in PDAC tumor stroma and its prognostic significance. Here we show that high expression of SLC7A11 in human PDAC tumor stroma, but not tumor cells, is independently prognostic of poorer overall survival. Orthogonal approaches showed that PDAC-derived CAFs are highly dependent on SLC7A11 for cystine uptake and glutathione synthesis and that SLC7A11 inhibition significantly decreases CAF proliferation, reduces their resistance to oxidative stress, and inhibits their ability to remodel collagen and support PDAC cell growth. Importantly, specific ablation of SLC7A11 from the tumor compartment of transgenic mouse PDAC tumors did not affect tumor growth, suggesting the stroma can substantially influence PDAC tumor response to SLC7A11 inhibition. In a mouse orthotopic PDAC model utilizing human PDAC cells and CAFs, stable knockdown of SLC7A11 was required in both cell types to reduce tumor growth, metastatic spread, and intratumoral fibrosis, demonstrating the importance of targeting SLC7A11 in both compartments. Finally, treatment with a nanoparticle gene-silencing drug against SLC7A11, developed by our laboratory, reduced PDAC tumor growth, incidence of metastases, CAF activation, and fibrosis in orthotopic PDAC tumors. Overall, these findings identify an important role of SLC7A11 in PDAC-derived CAFs in supporting tumor growth. SIGNIFICANCE: This study demonstrates that SLC7A11 in PDAC stromal cells is important for the tumor-promoting activity of CAFs and validates a clinically translatable nanomedicine for therapeutic SLC7A11 inhibition in PDAC.

'I know you shouldn't compare to other people, but I can't do anything most people can': Age, family and occupation categorisations in men's reasoning about their anxiety in an online discussion forum.

Despite its prevalence, men's anxiety is arguably under-researched and poorly understood. The present study explores the reasoning provided by male posters to an online discussion forum about the source of their anxiety. Posts were collected from an Australian anxiety online discussion forum. This study utilises discursive psychology, informed by principles of membership categorisation analysis, to describe how age, occupation and family-related identities can be invoked within common sense reasoning about the source of male anxiety. References to various identity categories were routinely employed by male forum posters in their representations of themselves, in order to describe the source of their anxiety in terms of a contrast between how they are, and how they should be. In examining accounts of anxiety and responses to those accounts, we can trace cultural knowledge about issues regarding men, masculinity and anxiety that those accounts make relevant. Findings illustrate how men's descriptions of the source of their anxiety should be understood as culturally bound and related to expectations and obligations associated with their social context and category memberships. By enhancing understandings of how men describe the source of their anxiety, this study offers insight into improving the identification and engagement of men experiencing anxiety in health services.

Communicating with older adults with long-term conditions about self-management goals: A systematic review and thematic synthesis.

OBJECTIVE: To synthesise a body of fine-grained observational research on communication between healthcare professionals (HCPs), older adults, and carers regarding self-management goals and actions. METHODS: We conducted a systematic review, searching nine electronic databases and the grey literature. Two reviewers independently selected for inclusion following a two-stage process and studies and discrepancies were resolved through consultation with the review team. RESULTS: 898 records were retrieved, and eight studies were included in the review. Aggregative thematic analysis resulted in 13 categories of communication practices across three decision-making domains: (1) initiating: actions occurring prior to the commitment point; (2) proposing: putting forward a course of action; and (3) committing and closing: committing (or not) to the course of action. CONCLUSIONS: Despite an increasing emphasis on the importance of personalised care planning and shared decision-making (SDM) to support older people's health and wellbeing, HCPs did not consistently practice this approach and, in some cases, worked in opposition to it. PRACTICE IMPLICATIONS: We encourage HCPs to prepare older adults to engage actively with SDM and the goal setting process by employing patient-centred communication resources. These could assist with identifying different types of goals that are realistic and relevant to patients in daily life.

Interfacial Curvature in Confined Coculture Directs Stromal Cell Activity with Spatial Corralling of Pancreatic Cancer Cells.

Interfacial cues in the tumor microenvironment direct the activity and assembly of multiple cell types. Pancreatic cancer, along with breast and prostate cancers, is enriched with cancer-associated fibroblasts (CAFs) that activate to coordinate the deposition of the extracellular matrix, which can comprise over 90% of the tumor mass. While it is clear that matrix underlies the severity of the disease, the relationship between stromal-tumor cell assembly and cell-matrix dynamics remains elusive. Micropatterned hydrogels deconstruct the interplay between matrix stiffness and geometric confinement, guiding heterotypic cell populations and matrix assembly in pancreatic cancer. Interfacial cues at the perimeter of microislands guide CAF migration and direct cancer cell assembly. Computational modeling shows curvature-stress dependent cellular localization for cancer and CAFs in coculture. Regions of convex curvature enhance edge stress that activates a myofibroblast phenotype in the CAFs with migration and increased collagen I deposition, ultimately leading to a central "corralling" of cancer cells. Inhibiting mechanotransduction pathways decreases CAF activation and the associated corralling phenotype. Together, this work reveals how interfacial biophysical cues underpin aspects of stromal desmoplasia, a hallmark of disease severity and chemoresistance in the pancreatic, breast, and prostate cancers, thereby providing a tool to expand stroma-targeting therapeutic strategies.

Ex vivo culture of intact human patient derived pancreatic tumour tissue.

The poor prognosis of pancreatic ductal adenocarcinoma (PDAC) is attributed to the highly fibrotic stroma and complex multi-cellular microenvironment that is difficult to fully recapitulate in pre-clinical models. To fast-track translation of therapies and to inform personalised medicine, we aimed to develop a whole-tissue ex vivo explant model that maintains viability, 3D multicellular architecture, and microenvironmental cues of human pancreatic tumours. Patient-derived surgically-resected PDAC tissue was cut into 1-2 mm explants and cultured on gelatin sponges for 12 days. Immunohistochemistry revealed that human PDAC explants were viable for 12 days and maintained their original tumour, stromal and extracellular matrix architecture. As proof-of-principle, human PDAC explants were treated with Abraxane and we observed different levels of response between patients. PDAC explants were also transfected with polymeric nanoparticles + Cy5-siRNA and we observed abundant cytoplasmic distribution of Cy5-siRNA throughout the PDAC explants. Overall, our novel model retains the 3D architecture of human PDAC and has advantages over standard organoids: presence of functional multi-cellular stroma and fibrosis, and no tissue manipulation, digestion, or artificial propagation of organoids. This provides unprecedented opportunity to study PDAC biology including tumour-stromal interactions and rapidly assess therapeutic response to drive personalised treatment.

How to exploit different endocytosis pathways to allow selective delivery of anticancer drugs to cancer cells over healthy cells.

It was recently shown that it is possible to exploit the nanoparticle shape to selectively target endocytosis pathways found in cancer and not healthy cells. It is important to understand and compare the endocytosis pathways of nanoparticles in both cancer and healthy cells to restrict the healthy cells from taking up anticancer drugs to help reduce the side effects for patients. Here, the clathrin-mediated endocytosis inhibitor, hydroxychloroquine, and the anticancer drug, doxorubicin, are loaded into the same mesoporous silica nanorods. The use of nanorods was found to restrict the uptake by healthy cells but allowed cancer cells to take up the nanorods via the macropinocytosis pathway. Furthermore, it is shown that the nanorods can selectively deliver doxorubicin to the nucleus of breast cancer cells and to the cytoplasm of pancreatic cancer cells. The dual-drug-loaded nanorods were able to selectively kill the breast cancer cells in the presence of healthy breast cells. This study opens exciting possibilities of targeting cancer cells based on the material shape rather than targeting antibodies.

Peer-to-Peer Health Communication in Older Adults' Online Communities: Protocol for a Qualitative Netnographic Study and Co-Design Approach.

BACKGROUND: Online communities provide an environment in which people with similar health concerns can interact and access content that can support the self-management of long-term conditions (LTCs). Recently, the importance of online social networks as sources of health information and social support has been brought into focus with the emergence and widespread societal impacts of COVID-19. Although online communities exist for older adults, little is known about the specific health and self-care topics that older people discuss in such environments and how these relate to users' support needs and outcomes. A better understanding of users' needs and peer-to-peer communication in these communities is necessary to inform the design of information and communication technology (ICT) interventions that are relevant to older people and their peer supporters. OBJECTIVE: This study aims to use a two-phase, web-based ethnographic (netnography) and co-design approach to explore specific health care and self-care topics that older adults discuss in a UK-based online community and how peer supporters respond to these queries with informational and/or social support and engage with stakeholders to define the needs and requirements for new ICT-based interventions capable of reducing social isolation and facilitating LTC self-management support. METHODS: The first phase of the research will involve a qualitative netnographic analysis of posts in discussion forums in a publicly accessible online community. The second phase will involve co-design workshops with health care consumers (ie, older adults and carers) and service providers to determine the needs and requirements for new ICT-based interventions and digital innovations. Constructivist grounded theory will be used in the first phase; in the second phase, the co-design workshops will be audiorecorded and analyzed thematically. RESULTS: This research project is in progress. Permission was obtained from the website administrator to use materials from the social media forum; data collection for the first phase began in April 2020. The second phase of the study is expected to begin in late 2020. This study is due to be completed by the end of 2021. CONCLUSIONS: This study is the first, to the best of our knowledge, to combine qualitative netnography with an iterative co-design framework to specify the needs and requirements for new ICT-based interventions. The findings from this study will inform the next phase of the multiphase knowledge translation project and will provide insights into the potential of online peer health communities to reduce social isolation and facilitate chronic illness self-management support and self-care. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/19834.

"I Feel Abused by My Own Mind": Themes of Control in Men's Online Accounts of Living With Anxiety.

Men's experiences with anxiety are under-researched and poorly understood. Existing research gives little indication of how men talk about anxiety in situ, and little is known about how men describe their experiences of anxiety. Online discussion forums provide an opportunity to conduct naturalistic observations of how men describe their experiences with anxiety without the influence of a researcher. Thematic analysis, informed by principles of discursive psychology, was used to examine 130 opening posts to an online anxiety discussion forum. One superordinate theme, where anxiety is constructed as a loss of control, was identified. Analysis of this overarching theme generated three themes relating to how posters described a loss of control: (a) anxiety as an immobilizing force, (b) anxiety as an independent entity, and (c) anxiety as a dualist construction of the self. Our analysis has clear implications for developing and improving interventions for men experiencing anxiety.

Fibroblasts from Distinct Pancreatic Pathologies Exhibit Disease-Specific Properties.

Although fibrotic stroma forms an integral component of pancreatic diseases, whether fibroblasts programmed by different types of pancreatic diseases are phenotypically distinct remains unknown. Here, we show that fibroblasts isolated from patients with pancreatic ductal adenocarcinoma (PDAC), chronic pancreatitis (CP), periampullary tumors, and adjacent normal (NA) tissue (N = 34) have distinct mRNA and miRNA profiles. Compared with NA fibroblasts, PDAC-associated fibroblasts were generally less sensitive to an antifibrotic stimulus (NPPB) and more responsive to positive regulators of activation such as TGFß1 and WNT. Of the disease-associated fibroblasts examined, PDAC- and CP-derived fibroblasts shared greatest similarity, yet PDAC-associated fibroblasts expressed higher levels of tenascin C (TNC), a finding attributable to miR-137, a novel regulator of TNC. TNC protein and transcript levels were higher in PDAC tissue versus CP tissue and were associated with greater levels of stromal activation, and conditioned media from TNC-depleted PDAC-associated fibroblasts modestly increased both PDAC cell proliferation and PDAC cell migration, indicating that stromal TNC may have inhibitory effects on PDAC cells. Finally, circulating TNC levels were higher in patients with PDAC compared with CP. Our characterization of pancreatic fibroblast programming as disease-specific has consequences for therapeutic targeting and for the manner in which fibroblasts are used in research. SIGNIFICANCE: Primary fibroblasts derived from various types of pancreatic diseases possess and retain distinct molecular and functional characteristics in culture, providing a series of cellular models for treatment development and disease-specific research.

Are nurses recognised, prepared and supported to teach nursing students: Mixed methods study.

BACKGROUND: The requirement for clinical teaching and supervision of undergraduate nursing students is a continual high volume, high impact essential requirement of registered nursing staff. Nurses are integral in facilitating the learning of nursing students in the practice environment to deliver quality safe care. However nurses engaged in teaching and supervising nursing students have unique challenges. OBJECTIVE: To understand how well recognised, prepared, and supported nurses perceive they are to teach and supervise undergraduate nursing students in the practice environment? METHODS: Nurses from 12 different wards of two hospitals were invited to participate in the study. A sequential mixed methods approach comprising hard-copy questionnaires, completed by 59 nurses, and six focus groups. Four feedback sessions verified findings. RESULTS: A low level of recognition and support for the amount of time available to nurses to teach and supervise was reported from both survey and focus group data. Four themes emerged from focus groups. Nurses recognised their role to teach and supervise students; The role in teaching and supervision was not recognised at a system level; Nurses could be more prepared to teach and supervise students; and Nurses required more support for their role in teaching and supervising students. A major challenge was the low level of support nurses perceived from the education sector in preparing students for placements. The nurses reported a disconnection of components of the student placement system, which was difficult to negotiate when undertaking this teaching and supervision role. CONCLUSION: The complex practice environment, where nursing student numbers are increasing and nurses have to navigate an often disconnected student placement system, requires a rethink of the precentorship or buddy one-to-one model of clinical placement. Addressing these challenges will be an essential step in protecting the interests of the public, nurses and nursing profession.

Targeting the undruggable in pancreatic cancer using nano-based gene silencing drugs.

Pancreatic cancer is predicted to be the second leading cause of cancer-related death by 2025. The best chemotherapy only extends survival by an average of 18 weeks. The extensive fibrotic stroma surrounding the tumor curbs therapeutic options as chemotherapy drugs cannot freely penetrate the tumor. RNA interference (RNAi) has emerged as a promising approach to revolutionize cancer treatment. Small interfering RNA (siRNA) can be designed to inhibit the expression of any gene which is important given the high degree of genetic heterogeneity present in pancreatic tumors. Despite the potential of siRNA therapies, there are hurdles limiting their clinical application such as poor transport across biological barriers, limited cellular uptake, degradation, and rapid clearance. Nanotechnology can address these challenges. In fact, the past few decades have seen the conceptualization, design, pre-clinical testing and recent clinical approval of a RNAi nanodrug to treat disease. In this review, we comment on the current state of play of clinical trials evaluating siRNA nanodrugs and review pre-clinical studies investigating the efficacy of siRNA therapeutics in pancreatic cancer. We assess the physiological barriers unique to pancreatic cancer that need to be considered when designing and testing new nanomedicines for this disease.

Engaging older adults in self-management talk in healthcare encounters: a systematic review protocol.

BACKGROUND: Clinical practice guidelines for the management of complex chronic conditions in older adults encourage healthcare providers to engage patients in shared decision-making about self-management goals and actions. Yet, healthcare decision-making and communication for this population can pose significant challenges. As a result, healthcare professionals may struggle to help patients define and prioritise their values, goals, and preferences in ways that are clinically and personally meaningful, incorporating physical functioning and quality of life, when faced with numerous diagnostic and treatment alternatives. The aim of this systematic review is to locate and synthesise a body of fine-grained observational research on communication between professionals, older adults, and carers regarding self-management in audio/audio-visually recorded naturalistic interactions. METHODS/DESIGN: The paper describes a systematic review of the published conversation analytic and discourse analytic research, using an aggregative thematic approach and following the PRISMA-P guidelines. This review will include studies reporting on adult patients (female or male) aged ≥ 60 years whose consultations are conducted in English in any healthcare setting and stakeholders involved in their care, e.g. general practitioners, nurses, allied health professionals, and family carers. We will search nine electronic databases and the grey literature and two independent reviewers will screen titles and abstracts to identify potential studies. Discrepancies will be resolved via consultation with the review team. The methodological quality of the final set of included studies will be appraised using the Joanna Briggs Institute Critical Appraisal Checklist for Qualitative Research and a detailed description of the characteristics of the included studies using a customised template. DISCUSSION: This is the first systematic review to date to locate and synthesise the conversation analytic research on how healthcare professionals raise and pursue talk about self-management with older adults in routine clinical interactions. Amalgamating these findings will enable the identification of effective and potentially trainable communication practices for engaging older adults in healthcare decision-making about the self-management goals and actions that enable the greatest possible health and quality of life in older adulthood. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019139376.

Identification of Novel Medulloblastoma Cell-Targeting Peptides for Use in Selective Chemotherapy Drug Delivery.

Medulloblastoma is a malignant brain tumor diagnosed in children. Chemotherapy has improved survival rates to approximately 70%; however, children are often left with long-term treatment side effects. New therapies that maintain a high cure rate while reducing off-target toxicity are required. We describe for the first time the use of a bacteriophage-peptide display library to identify heptapeptides that bind to medulloblastoma cells. Two heptapeptides that demonstrated high [E1-3 (1)] or low [E1-7 (2)] medulloblastoma cell binding affinity were synthesized. The potential of the peptides to deliver a therapeutic drug to medulloblastoma cells with specificity was investigated by conjugating E1-3 (1) or E1-7 (2) to doxorubicin (5). Both peptide-drug conjugates were cytotoxic to medulloblastoma cells. E1-3 doxorubicin (3) could permeabilize an in vitro blood-brain barrier and showed a marked reduction in cytotoxicity compared to free doxorubicin (5) in nontumor cells. This study provides proof-of-concept for developing peptide-drug conjugates to inhibit medulloblastoma cell growth while minimizing off-target toxicity.

CAF hierarchy driven by pancreatic cancer cell p53-status creates a pro-metastatic and chemoresistant environment via perlecan.

Heterogeneous subtypes of cancer-associated fibroblasts (CAFs) coexist within pancreatic cancer tissues and can both promote and restrain disease progression. Here, we interrogate how cancer cells harboring distinct alterations in p53 manipulate CAFs. We reveal the existence of a p53-driven hierarchy, where cancer cells with a gain-of-function (GOF) mutant p53 educate a dominant population of CAFs that establish a pro-metastatic environment for GOF and null p53 cancer cells alike. We also demonstrate that CAFs educated by null p53 cancer cells may be reprogrammed by either GOF mutant p53 cells or their CAFs. We identify perlecan as a key component of this pro-metastatic environment. Using intravital imaging, we observe that these dominant CAFs delay cancer cell response to chemotherapy. Lastly, we reveal that depleting perlecan in the stroma combined with chemotherapy prolongs mouse survival, supporting it as a potential target for anti-stromal therapies in pancreatic cancer.