Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with a mortality that is almost identical to incidence. Because early detected PDAC is potentially curable, blood-based ...biomarkers that could detect currently developing neoplasia would improve patient survival and management. PDAC develops from pancreatic intraepithelial neoplasia (PanIN) lesions, graded from low grade (PanIN1) to high grade (PanIN3). We made the hypothesis that specific proteomic signatures from each precancerous stage exist and are detectable in plasma.
We explored the peptide profiles of microdissected PanIN cells and of plasma samples corresponding to the different PanIN grade from genetically engineered mouse models of PDAC using capillary electrophoresis coupled to mass spectrometry (CE-MS) and Chip-MS/MS.
We successfully characterised differential peptides profiles from PanIN microdissected cells. We found that plasma from tumor-bearing mice and age-matched controls exhibit discriminative peptide signatures. We also determined plasma peptide signatures corresponding to low- and high-grade precancerous step present in the mice pancreas using the two mass spectrometry technologies. Importantly, we identified biomarkers specific of PanIN3.
We demonstrate that benign and advanced PanIN lesions display distinct plasma peptide patterns. This strongly supports the perspectives of developing a non-invasive screening test for prediction and early detection of PDAC.
Pancreatic adenocarcinoma (PAC) has a poor prognosis. One treatment approach, investigated here, is to reinforce antitumor immunity. Dendritic cells (DCs) are essential for the development and ...regulation of adaptive host immune responses against tumors. A major role for DCs may be as innate tumoricidal effector cells. We explored the efficacy of vaccination with immature (i)DCs, after selecting optimal conditions for generating immunostimulatory iDCs. We used two models, C57BL/6Jrj mice with ectopic tumors induced by the PAC cell line, Panc02, and genetically engineered (KIC) mice developing PAC. Therapeutic iDC-vaccination resulted in a significant reduction in tumor growth in C57BL/6Jrj mice and prolonged survival in KIC mice. Prophylactic iDC-vaccination prevented subcutaneous tumor development. These protective effects were long-lasting in Panc02-induced tumor development, but not in melanoma. iDC-vaccination impacted the immune status of the hosts by greatly increasing the percentage of CD8
+
T-cells, and natural killer (NK)1.1
+
cells, that express granzyme B associated with Lamp-1 and IFN-γ. Efficacy of iDC-vaccination was CD8
+
T-cell-dependent but NK1.1
+
cell-independent. We demonstrated the ability of DCs to produce peroxynitrites and to kill tumor cells; this killing activity involved peroxynitrites. Altogether, these findings make killer DCs the pivotal actors in the beneficial clinical outcome that accompanies antitumor immune responses.
We asked whether efficacy can be improved by combining DC-vaccination with the FOLFIRINOX regimen. Combined treatment significantly increased the lifespan of KIC mice with PAC. Prolonged treatment with FOLFIRINOX clearly augmented this beneficial effect. Combining iDC-vaccination with FOLFIRINOX may therefore represent a promising therapeutic option for patients with PAC.
Despite clinical advances in diagnosis and treatment, pancreatic ductal adenocarcinoma (PDAC) remains the third leading cause of cancer death, and is still associated with poor prognosis and dismal ...survival rates. Identifying novel PDAC-targeted tools to tackle these unmet clinical needs is thus an urgent requirement. Here we use a peptide conjugate that specifically targets PDAC through low-density lipoprotein receptor (LDLR). We demonstrate by using near-infrared fluorescence imaging the potential of this conjugate to specifically detect and discriminate primary PDAC from healthy organs including pancreas and from benign mass-forming chronic pancreatitis, as well as detect metastatic pancreatic cancer cells in healthy liver. This work paves the way towards clinical applications in which safe LDLR-targeting peptide conjugate promotes tumor-specific delivery of imaging and/or therapeutic agents, thereby leading to substantial improvements of the PDAC patient's outcome.
The TP53INP1 gene encodes two protein isoforms, TP53INP1α and TP53INP1β, located into the nucleus. Their synthesis is increased during cellular stress by p53-mediated activation of transcription. ...Overexpression of these isoforms induces apoptosis, suggesting an involvement of TP53INP1s in p53-mediated cell death. It was recently shown that p53-dependent apoptosis is promoted by homeodomain-interacting protein kinase-2 (HIPK2), which is known to bind p53 and induce its phosphorylation in promyelocytic leukemia protein nuclear bodies (PML-NBs). In this work we show that TP53INP1s localize with p53, PML-IV, and HIPK2 into the PML-NBs. In addition, we show that TP53INP1s interact physically with HIPK2 and p53. In agreement with these results we demonstrate that TP53INP1s, in association with HIPK2, regulate p53 transcriptional activity on p21, mdm2, pig3, and bax promoters. Furthermore, TP53INP1s overexpression induces G1 arrest and increases p53-mediated apoptosis. Although a TP53INP1s and HIPK2 additive effect was observed on apoptosis, G1 arrest was weaker when HIPK2 was transfected together with TP53INP1. These results indicate that TP53INP1s and HIPK2 could be partners in regulating p53 activity.
Aneuploidy is a characteristic of most solid tumors, often associated with negative prognosis. It can arise from two principal mechanisms: from a tetraploid intermediate state, or directly from ...errors at cell division. The control of cell division, crucial to maintain genomic stability, is still poorly understood in its relationship to aneuploidy. Here we show that the TAp73α isoform induces polyploidy when over-expressed. This is possibly due to the interaction of TAp73α with kinetochore-related proteins leading to the alteration of mitotic checkpoint abilities. TAp73α but not p53 or any of the other p73 isoforms binds Bub1 and Bub3. Since TAp73α is frequently over-expressed in cancer, this interaction may contribute to the aneuploidy observed in cancer progression. Our results suggest a novel molecular mechanism leading to aneuploidy involving interference of TAp73α with Bub1 and Bub3 resulting in an altered mitotic checkpoint.
Initiation, progression and evasion are sequential steps in cancer formation, with autonomous cell proliferation as a final outcome. Genetic or epigenetic alterations of key regulatory genes of the ...cell cycle are frequently associated with these phenomena. Recently, chromosomal instability, a long-supposed driving force of tumorigenesis, was associated with dysregulation of mitotic genes, providing advantages to tumor cells. Numerous molecules thus provide a key link in the chain of relationships between chromosomal instability and cancer. Here, we discuss emerging evidence revealing that two p53 family members, p53 and p73 , might be key regulatory genes at the heart of the relationship between chromosomal instability and cancer. We argue that the role of members of the p53 family as tumor suppressor proteins, their impact on the control of cellular ploidy, and their newly emerging connection with mitotic checkpoint regulatory genes support the suggestion that p73 and p53 could be two of the missing links among chromosomal instability, the mitotic checkpoint and cancer.
Pancreatic cancer is associated with an abundant stromal reaction leading to immune escape and tumour growth. This massive stroma drives the immune escape in the tumour. We aimed to study the impact ...of βig-h3 stromal protein in the modulation of the antitumoural immune response in pancreatic cancer.
We performed studies with
Cre;
,
-Cre;
/
,
-Cre;
mice and tumour tissues from patients with pancreatic ductal adenocarcinoma (PDA). Some transgenic mice were given injections of anti-βig-h3, anti-CD8, anti-PD1 depleting antibodies. Tumour growth as well as modifications in the activation of local immune cells were analysed by flow cytometry, immunohistochemistry and immunofluorescence. Tissue stiffness was measured by atomic force microscopy.
We identified βig-h3 stromal-derived protein as a key actor of the immune paracrine interaction mechanism that drives pancreatic cancer. We found that βig-h3 is highly produced by cancer-associated fibroblasts in the stroma of human and mouse. This protein acts directly on tumour-specific CD8
T cells and F4/80 macrophages. Depleting βig-h3
reduced tumour growth by enhancing the number of activated CD8
T cell within the tumour and subsequent apoptotic tumour cells. Furthermore, we found that targeting βig-h3 in established lesions released the tissue tension and functionally reprogrammed F4/80 macrophages in the tumour microenvironment.
Our data indicate that targeting stromal extracellular matrix protein βig-h3 improves the antitumoural response and consequently reduces tumour weight. Our findings present βig-h3 as a novel immunological target in pancreatic cancer.
Drug delivery systems (DDSs) that can overcome tumor heterogeneity and achieve deep tumor penetration are challenging to develop yet in high demand for cancer treatment. We report here a DDS based on ...self-assembling dendrimer nanomicelles for effective and deep tumor penetration via in situ tumor-secreted extracellular vesicles (EVs), an endogenous transport system that evolves with tumor microenvironment. Upon arrival at a tumor, these dendrimer nanomicelles had their payload repackaged by the cells into EVs, which were further transported and internalized by other cells for delivery "in relay." Using pancreatic and colorectal cancer-derived 2D, 3D, and xenograft models, we demonstrated that the in situ-generated EVs mediated intercellular delivery, propagating cargo from cell to cell and deep within the tumor. Our study provides a new perspective on exploiting the intrinsic features of tumors alongside dendrimer supramolecular chemistry to develop smart and effective DDSs to overcome tumor heterogeneity and their evolutive nature thereby improving cancer therapy.
In pancreatic ductal adenocarcinoma (PDAC), signaling from stromal cells is implicated in metastatic progression. Tumor-stroma cross-talk is often mediated through extracellular vesicles (EVs). We ...previously reported that EVs derived from cancer-associated stromal fibroblasts (CAFs) that are abundant in annexin A6 (ANXA6
EVs) support tumor cell aggressiveness in PDAC. Here, we found that the cell surface glycoprotein and tetraspanin CD9 is a key component of CAF-derived ANXA6
EVs for mediating this cross-talk. CD9 was abundant on the surface of ANXA6
CAFs isolated from patient PDAC samples and from various mouse models of PDAC. CD9 colocalized with CAF markers in the tumor stroma, and CD9 abundance correlated with tumor stage. Blocking CD9 impaired the uptake of ANXA6
EVs into cultured PDAC cells. Signaling pathway arrays and further analyses revealed that the uptake of CD9
ANXA6
EVs induced mitogen-activated protein kinase (MAPK) pathway activity, cell migration, and epithelial-to-mesenchymal transition (EMT). Blocking either CD9 or p38 MAPK signaling impaired CD9
ANXA6
EV-induced cell migration and EMT in PDAC cells. Analysis of bioinformatic datasets indicated that CD9 abundance was an independent marker of poor prognosis in patients with PDAC. Our findings suggest that CD9-mediated stromal cell signaling promotes PDAC progression.
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