Conservation, commercialisation and confusion: Harvesting of Ischyrolepis in a coastal forest, South Africa

Harvesting of non-timber forest products is an integral component of rural livelihoods throughout the developing world. At times this is at odds with conservation objectives. Reconciliation of the two requires examination of local level contexts and needs. This paper reports on the harvesting needs for Ischyrolepis by a rural community in South Africa, against the setting that they had recently been prohibited from harvesting by the local conservation officials. Interviews were conducted with conservation officials to understand the reasoning for the prohibition. Local demand for Ischyrolepis was assessed by household surveys, as well as in-depth interviews with traders. The density and size class distribution of Ischyrolepis was determined using transects. The total annual demand for Ischyrolepis was determined to be approximately only 2.7% of the standing crop. The bulk of the annual demand was for small-scale trade, the income from which was a primary source of income for the few harvesters. Very little evidence could be found indicating that harvesting was damaging the resource or its habitat, and local knowledge suggested that the abundance of the species was stimulated by harvesting. Even if market demand were to increase, the size of the shoots required means that less than 20% of the standing crop could be harvested annually. Current regulations around harvesting are in a state of revision, and hence confusion prevails regarding if harvesting is permissible, and if so, under what conditions, which is detrimental to both conservation and livelihoods

Intravital imaging technology guides FAK-mediated priming in pancreatic cancer precision medicine according to Merlin status

Pancreatic ductal adenocarcinoma (PDAC) is a highly metastatic, chemoresistant malignancy and is characterized by a dense, desmoplastic stroma that modulates PDAC progression. Here, we visualized transient manipulation of focal adhesion kinase (FAK), which integrates bidirectional cell-environment signaling, using intravital fluorescence lifetime imaging microscopy of the FAK-based Förster resonance energy transfer biosensor in mouse and patient-derived PDAC models. Parallel real-time quantification of the FUCCI cell cycle reporter guided us to improve PDAC response to standard-of-care chemotherapy at primary and secondary sites. Critically, micropatterned pillar plates and stiffness-tunable matrices were used to pinpoint the contribution of environmental cues to chemosensitization, while fluid flow–induced shear stress assessment, patient-derived matrices, and personalized in vivo models allowed us to deconstruct how FAK inhibition can reduce PDAC spread. Last, stratification of PDAC patient samples via Merlin status revealed a patient subset with poor prognosis that are likely to respond to FAK priming before chemotherapy

Intravital imaging technology guides FAK-mediated priming in pancreatic cancer precision medicine according to Merlin status

Pancreatic ductal adenocarcinoma (PDAC) is a highly metastatic, chemoresistant malignancy and is characterized by a dense, desmoplastic stroma that modulates PDAC progression. Here, we visualized transient manipulation of focal adhesion kinase (FAK), which integrates bidirectional cell-environment signaling, using intravital fluorescence lifetime imaging microscopy of the FAK-based Forster resonance energy transfer biosensor in mouse and patient-derived PDAC models. Parallel real-time quantification of the FUCCI cell cycle reporter guided us to improve PDAC response to standard-of-care chemotherapy at primary and secondary sites. Critically, micro-patterned pillar plates and stiffness-tunable matrices were used to pinpoint the contribution of environmental cues to chemosensitization, while fluid flow-induced shear stress assessment, patient-derived matrices, and personalized in vivo models allowed us to deconstruct how FAK inhibition can reduce PDAC spread. Last, stratification of PDAC patient samples via Merlin status revealed a patient subset with poor prognosis that are likely to respond to FAK priming before chemotherapy

Targeting the SRC/JAK/STAT3 signalling pathway: A novel and promising therapeutic strategy for pancreatic cancer

Pancreatic cancer has a 5-year survival of only 8%, and persists as the 4th most common cause of cancer-related death in Western societies. A more tailored treatment approach may be beneficial as the current standard-of-care therapies offer only a modest increase in overall patient survival. Recent large-scale genomic studies have revealed that the SRC/JAK/STAT3 signalling pathway is deregulated in up to 35% of pancreatic cancers, and is yet to be systematically examined in this disease. Consequently, we hypothesised that targeting pancreatic tumours with alterations in the SRC/JAK/STAT3 signalling pathway with JAK and SRC inhibitors represents a promising novel therapeutic strategy for this disease. In this thesis, we use well-annotated patient-derived cell-line models (ICGC), along with cell-lines generated from the aggressive KPC mouse model, to show that the combination of selected JAK and SRC inhibitors is synergistic in cell lines characterised by high phospho-STAT3 expression and P53 mutations. Using 3D in vitro models, including organotypic and organoid models, we show that this therapeutic strategy inhibits the invasive and proliferative capacity of tumour cells, disrupts collagen remodelling and extracellular matrix integrity, interferes with paracrine signalling and has strong immunomodulatory effects. Lastly, we examine the in vivo efficacy of dasatinib and ruxolitinib using a syngeneic KPC mouse model, as well as patient-derived pancreatic tumour models, characterised by high phospho-STAT3 expression and P53 mutations. From these studies we demonstrate that the combination of dasatinib and ruxolitinib significantly inhibited tumour progression, improved survival, delayed the development of metastasis and significantly improved response to standard of care chemotherapy. Furthermore, tumours treated with dasatinib and ruxolitinib displayed decreased collagen deposition and remodelling, and altered immune cell infiltration in the syngeneic setting. Our findings demonstrate the potential for tailored therapeutic strategies involving SRC/JAK/STAT3 inhibition in pancreatic cancer, and suggest that therapeutic efficacy may be the result of targeting both tumour cells and the tumour microenvironment, by decreasing fibrosis and overcoming tumour-induced immunosuppression

The Evolving Understanding of the Molecular and Therapeutic Landscape of Pancreatic Ductal Adenocarcinoma

Pancreatic cancer is the third leading cause of cancer-related deaths, characterised by poor survival, marked molecular heterogeneity and high intrinsic and acquired chemoresistance. Only 10⁻20% of pancreatic cancer patients present with surgically resectable disease and even then, 80% die within 5 years. Our increasing understanding of the genomic heterogeneity of cancer suggests that the failure of definitive clinical trials to demonstrate efficacy in the majority of cases is likely due to the low proportion of responsive molecular subtypes. As a consequence, novel treatment strategies to approach this disease are urgently needed. Significant developments in the field of precision oncology have led to increasing molecular stratification of cancers into subtypes, where individual cancers are selected for optimal therapy depending on their molecular or genomic fingerprint. This review provides an overview of the current status of clinically used and emerging treatment strategies, and discusses the advances in and the potential for the implementation of precision medicine in this highly lethal malignancy, for which there are currently no curative systemic therapies

MCL-1 antagonism enhances the anti-invasive effects of dasatinib in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies. It is phenotypically heterogeneous with a highly unstable genome and provides few common therapeutic targets. We found that MCL1, Cofilin1 (CFL1) and SRC mRNA were highly expressed by a wide range of these cancers, suggesting that a strategy of dual MCL-1 and SRC inhibition might be efficacious for many patients. Immunohistochemistry revealed that MCL-1 protein was present at high levels in 94.7% of patients in a cohort of PDACs from Australian Pancreatic Genome Initiative (APGI). High MCL1 and Cofilin1 mRNA expression was also strongly predictive of poor outcome in the TCGA dataset and in the APGI cohort. In culture, MCL-1 antagonism reduced the level of the cytoskeletal remodeling protein Cofilin1 and phosphorylated SRC on the active Y416 residue, suggestive of reduced invasive capacity. The MCL-1 antagonist S63845 synergized with the SRC kinase inhibitor dasatinib to reduce cell viability and invasiveness through 3D-organotypic matrices. In preclinical murine models, this combination reduced primary tumor growth and liver metastasis of pancreatic cancer xenografts. These data suggest that MCL-1 antagonism, while reducing cell viability, may have an additional benefit in increasing the antimetastatic efficacy of dasatinib for the treatment of PDAC

?133p53 isoform promotes tumour invasion and metastasis via interleukin-6 activation of JAK-STAT and RhoA-ROCK signalling

International audienc

Inhibition of HCK in myeloid cells restricts pancreatic tumor growth and metastasis

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a low 5-year survival rate and is associated with poor response to therapy. Elevated expression of the myeloid-specific hematopoietic cell kinase (HCK) is observed in PDAC and correlates with reduced patient survival. To determine whether aberrant HCK signaling in myeloid cells is involved in PDAC growth and metastasis, we established orthotopic and intrasplenic PDAC tumors in wild-type and HCK knockout mice. Genetic ablation of HCK impaired PDAC growth and metastasis by inducing an immune-stimulatory endotype in myeloid cells, which in turn reduced the desmoplastic microenvironment and enhanced cytotoxic effector cell infiltration. Consequently, genetic ablation or therapeutic inhibition of HCK minimized metastatic spread, enhanced the efficacy of chemotherapy, and overcame resistance to anti-PD1, anti-CTLA4, or stimulatory anti-CD40 immunotherapy. Our results provide strong rationale for HCK to be developed as a therapeutic target to improve the response of PDAC to chemo- and immunotherapy

Effective targeting of intact and proteolysed CDCP1 for imaging and treatment of pancreatic ductal adenocarcinoma

Background: CUB domain-containing protein 1 (CDCP1) is a cell surface receptor regulating key signalling pathways in malignant cells. CDCP1 has been proposed as a molecular target to abrogate oncogenic signalling pathways and specifically deliver anti-cancer agents to tumors. However, the development of CDCP1-targeting agents has been questioned by its frequent proteolytic processing which was thought to result in shedding of the CDCP1 extracellular domain limiting its targetability. In this study, we investigated the relevance of targeting CDCP1 in the context of pancreatic ductal adenocarcinoma (PDAC) and assess the impact of CDCP1 proteolysis on the effectiveness of CDCP1 targeting agents. Methods: The involvement of CDCP1 in PDAC progression was assessed by association analysis in several PDAC cohorts and the proteolytic processing of CDCP1 was evaluated in PDAC cell lines and patient-derived cells. The consequences of CDCP1 proteolysis on its targetability in PDAC cells was assessed using immunoprecipitation, immunostaining and biochemical assays. The involvement of CDCP1 in PDAC progression was examined by loss-of-function in vitro and in vivo experiments employing PDAC cells expressing intact or cleaved CDCP1. Finally, we generated antibody-based imaging and therapeutic agents targeting CDCP1 to demonstrate the feasibility of targeting this receptor for detection and treatment of PDAC tumors. Results: High CDCP1 expression in PDAC is significantly associated with poorer patient survival. In PDAC cells proteolysis of CDCP1 does not always result in the shedding of CDCP1-extracellular domain which can interact with membrane-bound CDCP1 allowing signal transduction between the different CDCP1-fragments. Targeting CDCP1 impairs PDAC cell functions and PDAC tumor growth independently of CDCP1 cleavage status. A CDCP1-targeting antibody is highly effective at delivering imaging radionuclides and cytotoxins to PDAC cells allowing specific detection of tumors by PET/CT imaging and superior anti-tumor effects compared to gemcitabine in in vivo models. Conclusion: Independent of its cleavage status, CDCP1 exerts oncogenic functions in PDAC and has significant potential to be targeted for improved radiological staging and treatment of this cancer. Its elevated expression by most PDAC tumors and lack of expression by normal pancreas and other major organs, suggest that targeting CDCP1 could benefit a significant proportion of PDAC patients. These data support the further development of CDCP1-targeting agents as personalizable tools for effective imaging and treatment of PDAC