Faculty Bibliography
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254
Synergistic targeting and resistance to PARP inhibition in DNA damage repair-deficient pancreatic cancer
OBJECTIVE:(ATM) is the most frequently mutated DNA damage response gene, involved in homologous recombination (HR), in pancreatic ductal adenocarcinoma (PDAC). DESIGN/METHODS:Combinational synergy screening was performed to endeavour a genotype-tailored targeted therapy. RESULTS:Synergy was found on inhibition of PARP, ATR and DNA-PKcs (PAD) leading to synthetic lethality in ATM-deficient murine and human PDAC. Mechanistically, PAD-induced PARP trapping, replication fork stalling and mitosis defects leading to P53-mediated apoptosis. Most importantly, chemical inhibition of ATM sensitises human PDAC cells toward PAD with long-term tumour control in vivo. Finally, we anticipated and elucidated PARP inhibitor resistance within the ATM-null background via whole exome sequencing. Arising cells were aneuploid, underwent epithelial-mesenchymal-transition and acquired multidrug resistance (MDR) due to upregulation of drug transporters and a bypass within the DNA repair machinery. These functional observations were mirrored in copy number variations affecting a region on chromosome 5 comprising several of the upregulated MDR genes. Using these findings, we ultimately propose alternative strategies to overcome the resistance. CONCLUSION/CONCLUSIONS:Analysis of the molecular susceptibilities triggered by ATM deficiency in PDAC allow elaboration of an efficient mutation-specific combinational therapeutic approach that can be also implemented in a genotype-independent manner by ATM inhibition.
PMCID:7948173
PMID: 32873698
ISSN: 1468-3288
CID: 4835152
Cancer surveillance awareness and practice among families at increased risk for pancreatic adenocarcinoma
BACKGROUND:Early detection of pancreatic ductal adenocarcinoma (PDAC) is an important goal for improving survival. Individuals who meet published guidelines for surveillance may be underidentified, and family communication about risk represents a pathway to increasing participation in surveillance. We investigated the uptake of and barriers to surveillance in at-risk relatives of clinic patients. METHODS:We conducted a retrospective record review of patients with personal or family history of PDAC evaluated over 12 months. The first relative presenting to clinic (proband) reported surveillance status and reasons for nonparticipation for at-risk relatives. Descriptive analyses and Fisher's exact tests were conducted to evaluate differences in surveillance participation. RESULTS:Among 193 at-risk relatives, 21% were in surveillance. The primary reasons for nonparticipation were lack of awareness (36%) and lack of interest (24%). Neither the sex nor the cancer status of probands impacted surveillance. At-risk relatives with familial pancreatic cancer (FPC) who also carried relevant pathogenic germline variants (PGVs) were more likely to undergo surveillance than those with FPC or PGVs alone (P = .003). Among families with PGVs, 59% of relatives potentially eligible for surveillance had not completed genetic testing. CONCLUSION/CONCLUSIONS:PDAC surveillance is underutilized in high-risk families. Communication interventions to address informational needs and decisional support could improve outcomes.
PMID: 33721345
ISSN: 1097-0142
CID: 4823462
A novel target for combination immunotherapy in pancreatic cancer: IL-1β mediates immunosuppression in the tumour microenvironment
Immune checkpoint blockade (ICB) has demonstrated efficacy in multiple cancers, offering the potential of long-term disease control not achievable with cytotoxic or targeted therapies. However, the field has not yet achieved the crucial next steps - the expansion of the response rate and achievement of clinical efficacy in so-called "cold tumours". Mechanistic studies of tumour-type specific immunosuppressive pathways can reveal underlying biological hurdles to immunotherapy and offer new therapeutic insights. Our finding that tumour-derived IL-1β mediates immunosuppression in pancreatic cancer has precipitated a new clinical trial.
PMID: 33758330
ISSN: 1532-1827
CID: 4822682
ATDC binds to KEAP1 to drive NRF2-mediated tumorigenesis and chemoresistance in pancreatic cancer
Pancreatic ductal adenocarcinoma is a lethal disease characterized by late diagnosis, propensity for early metastasis and resistance to chemotherapy. Little is known about the mechanisms that drive innate therapeutic resistance in pancreatic cancer. The ataxia-telangiectasia group D-associated gene (ATDC) is overexpressed in pancreatic cancer and promotes tumor growth and metastasis. Our study reveals that increased ATDC levels protect cancer cells from reactive oxygen species (ROS) via stabilization of nuclear factor erythroid 2-related factor 2 (NRF2). Mechanistically, ATDC binds to Kelch-like ECH-associated protein 1 (KEAP1), the principal regulator of NRF2 degradation, and thereby prevents degradation of NRF2 resulting in activation of a NRF2-dependent transcriptional program, reduced intracellular ROS and enhanced chemoresistance. Our findings define a novel role of ATDC in regulating redox balance and chemotherapeutic resistance by modulating NRF2 activity.
PMID: 33446568
ISSN: 1549-5477
CID: 4747272
Targeting DNA Damage Response and Replication Stress in Pancreatic Cancer
BACKGROUND & AIMS/OBJECTIVE:Continuing recalcitrance to therapy cements pancreatic cancer (PC) as the most lethal malignancy, which is set to become the second leading cause of cancer death in our society. The study aim was to investigate the association between DNA damage response (DDR), replication stress, and novel therapeutic response in PC to develop a biomarker-driven therapeutic strategy targeting DDR and replication stress in PC. METHODS:We interrogated the transcriptome, genome, proteome, and functional characteristics of 61 novel PC patient-derived cell lines to define novel therapeutic strategies targeting DDR and replication stress. Validation was done in patient-derived xenografts and human PC organoids. RESULTS:Patient-derived cell lines faithfully recapitulate the epithelial component of pancreatic tumors, including previously described molecular subtypes. Biomarkers of DDR deficiency, including a novel signature of homologous recombination deficiency, cosegregates with response to platinum (P < .001) and PARP inhibitor therapy (P < .001) in vitro and in vivo. We generated a novel signature of replication stress that predicts response to ATR (P < .018) and WEE1 inhibitor (P < .029) treatment in both cell lines and human PC organoids. Replication stress was enriched in the squamous subtype of PC (P < .001) but was not associated with DDR deficiency. CONCLUSIONS:Replication stress and DDR deficiency are independent of each other, creating opportunities for therapy in DDR-proficient PC and after platinum therapy.
PMID: 33039466
ISSN: 1528-0012
CID: 4722552
Multidisciplinary standards of care and recent progress in pancreatic ductal adenocarcinoma
Despite tremendous gains in the molecular understanding of exocrine pancreatic cancer, the prognosis for this disease remains very poor, largely because of delayed disease detection and limited effectiveness of systemic therapies. Both incidence rates and mortality rates for pancreatic cancer have increased during the past decade, in contrast to most other solid tumor types. Recent improvements in multimodality care have substantially improved overall survival, local control, and metastasis-free survival for patients who have localized tumors that are amenable to surgical resection. The widening gap in prognosis between patients with resectable and unresectable or metastatic disease reinforces the importance of detecting pancreatic cancer sooner to improve outcomes. Furthermore, the developing use of therapies that target tumor-specific molecular vulnerabilities may offer improved disease control for patients with advanced disease. Finally, the substantial morbidity associated with pancreatic cancer, including wasting, fatigue, and pain, remains an under-addressed component of this disease, which powerfully affects quality of life and limits tolerance to aggressive therapies. In this article, the authors review the current multidisciplinary standards of care in pancreatic cancer with a focus on emerging concepts in pancreatic cancer detection, precision therapy, and survivorship.
PMCID:7722002
PMID: 32683683
ISSN: 1542-4863
CID: 5080712
Needle-compatible miniaturized optoelectronic sensor for pancreatic cancer detection
Pancreatic cancer is one of the deadliest cancers, with a 5-year survival rate of <10%. The current approach to confirming a tissue diagnosis, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), requires a time-consuming, qualitative cytology analysis and may be limited because of sampling error. We designed and engineered a miniaturized optoelectronic sensor to assist in situ, real-time, and objective evaluation of human pancreatic tissues during EUS-FNA. A proof-of-concept prototype sensor, compatible with a 19-gauge hollow-needle commercially available for EUS-FNA, was constructed using microsized optoelectronic chips and microfabrication techniques to perform multisite tissue optical sensing. In our bench-top verification and pilot validation during surgery on freshly excised human pancreatic tissues (four patients), the fabricated sensors showed a comparable performance to our previous fiber-based system. The flexibility in source-detector configuration using microsized chips potentially allows for various light-based sensing techniques inside a confined channel such as a hollow needle or endoscopy.
PMCID:7679167
PMID: 33219025
ISSN: 2375-2548
CID: 5080722
Author Correction: Integrating microarray-based spatial transcriptomics and single-cell RNA-seq reveals tissue architecture in pancreatic ductal adenocarcinomas
A Correction to this paper has been published: https://doi.org/10.1038/s41587-019-0392-8.
PMID: 33230294
ISSN: 1546-1696
CID: 4680492
Extracellular Vesicle and Particle Biomarkers Define Multiple Human Cancers
There is an unmet clinical need for improved tissue and liquid biopsy tools for cancer detection. We investigated the proteomic profile of extracellular vesicles and particles (EVPs) in 426 human samples from tissue explants (TEs), plasma, and other bodily fluids. Among traditional exosome markers, CD9, HSPA8, ALIX, and HSP90AB1 represent pan-EVP markers, while ACTB, MSN, and RAP1B are novel pan-EVP markers. To confirm that EVPs are ideal diagnostic tools, we analyzed proteomes of TE- (n = 151) and plasma-derived (n = 120) EVPs. Comparison of TE EVPs identified proteins (e.g., VCAN, TNC, and THBS2) that distinguish tumors from normal tissues with 90% sensitivity/94% specificity. Machine-learning classification of plasma-derived EVP cargo, including immunoglobulins, revealed 95% sensitivity/90% specificity in detecting cancer. Finally, we defined a panel of tumor-type-specific EVP proteins in TEs and plasma, which can classify tumors of unknown primary origin. Thus, EVP proteins can serve as reliable biomarkers for cancer detection and determining cancer type.
PMID: 32795414
ISSN: 1097-4172
CID: 4565512
HNF4A and GATA6 Loss Reveals Therapeutically Actionable Subtypes in Pancreatic Cancer
Pancreatic ductal adenocarcinoma (PDAC) can be divided into transcriptomic subtypes with two broad lineages referred to as classical (pancreatic) and squamous. We find that these two subtypes are driven by distinct metabolic phenotypes. Loss of genes that drive endodermal lineage specification, HNF4A and GATA6, switch metabolic profiles from classical (pancreatic) to predominantly squamous, with glycogen synthase kinase 3 beta (GSK3β) a key regulator of glycolysis. Pharmacological inhibition of GSK3β results in selective sensitivity in the squamous subtype; however, a subset of these squamous patient-derived cell lines (PDCLs) acquires rapid drug tolerance. Using chromatin accessibility maps, we demonstrate that the squamous subtype can be further classified using chromatin accessibility to predict responsiveness and tolerance to GSK3β inhibitors. Our findings demonstrate that distinct patterns of chromatin accessibility can be used to identify patient subgroups that are indistinguishable by gene expression profiles, highlighting the utility of chromatin-based biomarkers for patient selection in the treatment of PDAC.
PMID: 32402285
ISSN: 2211-1247
CID: 4438132
