Biology subjects

Palermo, C. F.

Publications and source records attributed to Palermo, C. F..

7 recordsLinked to original sources

bioRxiv2025

Netrin-1 promotes pancreatic tumorigenesis and innervation through NEO1.

Nerves have been shown to regulate cancer progression. However, a clear demonstration of a role for axon guidance molecules in pancreatic tumorigenesis, innervation, and metastasis has been lacking. Using murine KrasG12D-mutant pancreatic organoids, we screened axon guidance molecules by qRT-PCR, identified Ntn1 upregulation, and then verified its in vivo upregulation during pancreatic tumorigenesis in humans and mice. NTN1 and its receptor NEO1 were upregulated in epithelial cells by the Kras mutation and {beta}-adrenergic signaling, in part, through the MAPK pathway. Ex-vivo culture of celiac ganglia showed that NTN1 promoted the axonogenesis of sympathetic neurons through the nerve NEO1 receptor. In the Pdx1-Cre;LSL-KrasG12D/+ model, Ntn1 knockout decreased sympathetic innervation and the development of pancreatic intraepithelial neoplasia. Treatment of pancreatic tumor organoids with recombinant NTN1 enhanced cell growth, epithelial-mesenchymal transition (EMT), and cancer stemness with the upregulation of ZEB1 and SOX9 through NEO1-mediated activation of focal adhesion kinase (FAK). In Pdx1-Cre;LSL-KrasG12D/+;LSL-Trp53R172H/+mice, Ntn1 knockout reduced innervation, FAK phosphorylation, and the features of EMT and stemness to extend mouse survival. In a liver metastasis model of PDAC (pancreatic ductal adenocarcinoma), treatment with a NTN1-neutralizing antibody or tumoral knockdown of Neo1 reduced ZEB1 and SOX9 and decreased tumor progression. In contrast, Ntn1 overexpression promoted innervation and the progression of PDAC liver metastasis. These data suggest that the NTN1/NEO1 axis is a key regulator of PDAC progression, directly influencing cancer cell stemness and EMT, while indirectly promoting tumor growth through nerves. Inhibiting the NTN1/NEO1 axis could represent a potential therapeutic approach for PDAC. Statement of SignificanceNTN1 promotes pancreatic tumorigenesis and metastasis directly and indirectly through nerves, highlighting the importance of tumor cell-nerve crosstalk in cancer. NTN1 blockade could represent a promising strategy for treating PDAC liver metastasis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/666009v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@ca611corg.highwire.dtl.DTLVardef@ad9264org.highwire.dtl.DTLVardef@1661c00org.highwire.dtl.DTLVardef@b86798_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

Tumor-selective treatment of metastatic pancreatic cancer with an engineered, probiotic living drug

Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges for effective treatment, with systemic chemotherapy often proving inadequate due to poor drug delivery and the tumors immunosuppressive microenvironment. Engineered bacteria present a novel approach to target PDAC, leveraging their ability to colonize tumors and deliver therapeutic payloads. Here, we engineered probiotic Escherichia coli Nissle 1917 (EcN) to produce the pore-forming Theta toxin (Nis-Theta) and evaluated its efficacy in a preclinical model of PDAC. Probiotic administration resulted in selective colonization of tumor tissue, leading to improved overall survival compared to standard chemotherapy. Moreover, this strain exhibited cytotoxic effects on both primary and distant tumor lesions while sparing normal tissues. Importantly, treatment also modulated the tumor microenvironment by increasing anti-tumor immune cell populations and reducing immunosuppressive markers. These findings demonstrate the potential of engineered probiotic bacteria as a safe and effective therapeutic approach for PDAC, offering promise for improved patient outcomes.

cancer biology↗

bioRxiv2023

Tumor-selective effects of active RAS inhibition in pancreatic ductal adenocarcinoma

Broad-spectrum RAS inhibition holds the potential to benefit roughly a quarter of human cancer patients whose tumors are driven by RAS mutations. However, the impact of inhibiting RAS functions in normal tissues is not known. RMC-7977 is a highly selective inhibitor of the active (GTP-bound) forms of KRAS, HRAS, and NRAS, with affinity for both mutant and wild type (WT) variants. As >90% of human pancreatic ductal adenocarcinoma (PDAC) cases are driven by activating mutations in KRAS, we assessed the therapeutic potential of RMC-7977 in a comprehensive range of PDAC models, including human and murine cell lines, human patient-derived organoids, human PDAC explants, subcutaneous and orthotopic cell-line or patient derived xenografts, syngeneic allografts, and genetically engineered mouse models. We observed broad and pronounced anti-tumor activity across these models following direct RAS inhibition at doses and concentrations that were well-tolerated in vivo. Pharmacological analyses revealed divergent responses to RMC-7977 in tumor versus normal tissues. Treated tumors exhibited waves of apoptosis along with sustained proliferative arrest whereas normal tissues underwent only transient decreases in proliferation, with no evidence of apoptosis. Together, these data establish a strong preclinical rationale for the use of broad-spectrum RAS inhibition in the setting of PDAC.

cancer biology↗

bioRxiv2023

Ras-dependent activation of BMAL2 regulates hypoxic metabolism in pancreatic cancer

KRAS is the archetypal oncogenic driver of pancreatic cancer. To identify new modulators of KRAS activity in human pancreatic ductal adenocarcinoma (PDAC), we performed regulatory network analysis on a large collection of expression profiles from laser capture microdissected samples of PDAC and benign controls. We discovered that BMAL2, a member of the PAS family of transcription factors, promotes tumor initiation, progression, and post-resection survival, and is highly correlated with KRAS activity. Functional analysis of BMAL2 target genes suggested a role in regulating the hypoxia response, a hallmark of PDAC. Knockout of BMAL2 in multiple human PDAC cell lines reduced cancer cell viability, invasion, and glycolysis, leading to broad dysregulation of cellular metabolism, particularly under hypoxic conditions. We find that BMAL2 directly regulates hypoxia-responsive target genes and is necessary for the stabilization of HIF1A under low oxygen conditions, while simultaneously destabilizing HIF2A. Notably, in vivo xenograft studies demonstrated that BMAL2 loss significantly impairs tumor growth and reduces tumor volume, underscoring its functional importance in tumor progression. We conclude that BMAL2 is a master transcriptional regulator of hypoxia responses in PDAC that works downstream of KRAS signaling, possibly serving as a long-sought molecular switch that distinguishes HIF1A- and HIF2A-dependent modes of hypoxic metabolism. Statement of SignificanceWe annotate the landscape of KRAS-associated transcriptional drivers of pancreatic cancer initiation, progression, and overall survival, leading to the identification of BMAL2 as a novel regulator of hypoxic metabolism. BMAL2 helps execute the oncogenic transcriptional programs of KRAS and serves as a long-sought switch between HIF1A- and HIF2A-dependent modes of hypoxic metabolism.

cancer biology↗

bioRxiv2023

Tumor Explants Elucidate a Cascade of Paracrine SHH, WNT, and VEGF Signals Driving Pancreatic Cancer Angiosuppression

The sparse vascularity of Pancreatic Ductal Adenocarcinoma (PDAC) presents a mystery: what prevents this aggressive malignancy from undergoing neoangiogenesis to counteract hypoxia and better support growth? An incidental finding from prior work on paracrine communication between malignant PDAC cells and fibroblasts revealed that inhibition of the Hedgehog (HH) pathway partially relieved angiosuppression, increasing tumor vascularity through unknown mechanisms. Initial efforts to study this phenotype were hindered by difficulties replicating the complex interactions of multiple cell types in vitro. Here we identify a cascade of paracrine signals between multiple cell types that act sequentially to suppress angiogenesis in PDAC. Malignant epithelial cells promote HH signaling in fibroblasts, leading to inhibition of WNT signaling in fibroblasts and epithelial cells, thereby limiting VEGFR2-dependent activation of endothelial hypersprouting. This cascade was elucidated using human and murine PDAC explant models, which effectively retain the complex cellular interactions of native tumor tissues.

cancer biology↗

bioRxiv2020

GOT1 Inhibition Primes Pancreatic Cancer for Ferroptosis through the Autophagic Release of Labile Iron

Pancreatic ductal adenocarcinoma (PDA) is one of the deadliest solid malignancies, with a 5-year survival rate at ten percent. PDA have unique metabolic adaptations in response to cell-intrinsic and environmental stressors, and identifying new strategies to target these adaptions is an area of active research. We previously described a dependency on a cytosolic aspartate aminotransaminase (GOT1)-dependent pathway for NADPH generation. Here, we sought to identify metabolic dependencies induced by GOT1 inhibition that could be exploited to selectively kill PDA. Using pharmacological methods, we identified cysteine, glutathione, and lipid antioxidant function as metabolic vulnerabilities following GOT1 withdrawal. Targeting any of these pathways was synthetic lethal in GOT1 knockdown cells and triggered ferroptosis, an oxidative, non-apoptotic, iron-dependent form of cell death. Mechanistically, GOT1 inhibition promoted the activation of autophagy in response to metabolic stress. This enhanced the availability of labile iron through ferritinophagy, the autolysosome-mediated degradation of ferritin. In sum, our study identifies a novel biochemical connection between GOT1, iron regulation, and ferroptosis, and suggests the rewired malate-aspartate shuttle plays a role in protecting PDA from severe oxidative challenge. HighlightsO_LIPDA exhibit varying dependence on GOT1 for in vitro and in vivo growth. C_LIO_LIExogenous cystine, glutathione synthesis, and lipid antioxidant fidelity are essential under GOT1 suppression. C_LIO_LIGOT1 inhibition sensitizes pancreatic cancer cell lines to ferroptosis. C_LIO_LIGOT1 inhibition represses anabolic metabolism and promotes the release of iron through autophagy. C_LI

cancer biology↗

bioRxiv2019

Induction of pancreatic tumor-selective ferroptosis through modulation of cystine import

Pancreatic ductal adenocarcinoma (PDA) is the third-leading cause of cancer mortality in the US and is highly resistant to classical, targeted, and immune therapies. We show that human PDA cells are dependent on the provision of exogenous cystine to avert a catastrophic accumulation of lipid reactive oxygen species (ROS) that, left unchecked, leads to ferroptotic cell death, both in vitro and in vivo. Using a dual-recombinase genetically engineered model, we found that acute deletion of Slc7a11 led to tumor-selective ferroptosis, tumor stabilizations/regressions, and extended overall survival. The mechanism of ferroptosis induction in PDA cells required the concerted depletion of both glutathione and coenzyme A, highlighting a novel branch of ferroptosis-relevant metabolism. Finally, we found that cystine depletion in vivo using the pre-IND agent cyst(e)inase phenocopied Slc7a11 deletion, inducing tumor-selective ferroptosis and disease stabilizations/regressions in the well-validated KPC model of PDA.\n\nOne Sentence SummaryGenetic and pharmacological targeting of cystine import induces pancreatic cancer-selective ferroptosis in vivo.

cancer biology↗