No abstract

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy and is highly resistant to standard treatment regimens. Targeted therapies against KRAS, a mutation present in an overwhelming majority of PDAC cases, have been largely ineffective. However, inhibition of downstream components in the KRAS signaling cascade provides promising therapeutic targets in the management of PDAC and warrants further exploration. Here, we investigated Urolithin A (Uro A), a novel natural compound derived from pomegranates, which targets numerous kinases downstream of KRAS, in particular the PI3K/AKT/mTOR signaling pathways. We showed that treatment of PDAC cells with Uro A blocked the phosphorylation of AKT and p70S6K in vitro, successfully inhibited the growth of tumor xenografts, and increased overall survival of Ptf1a Cre/þ ;LSL-Kras G12D/þ ;Tgfbr2 flox/flox (PKT) mice compared with vehicle or gemcitabine therapy alone. Histologic evaluation of these Uro A-treated tumor samples confirmed mechanistic actions of Uro A via decreased phosphorylation of AKT and p70S6K, reduced proliferation, and increased cellular apoptosis in both xenograft and PKT mouse models. In addition, Uro A treatment reprogrammed the tumor microenvironment, as evidenced by reduced levels of infiltrating immunosuppressive cell populations such as myeloid-derived suppressor cells, tumor-associated macrophages, and regulatory T cells. Overall, this work provides convincing preclinical evidence for the utility of Uro A as a therapeutic agent in PDAC through suppression of the PI3K/AKT/mTOR pathway.

Although smoking is a significant risk factor for pancreatic ductal adenocarcinoma (PDAC), the molecular mechanisms underlying PDAC development and progression in smokers are still unclear. Here, we show the role of cyclic AMP response element-binding protein (CREB) in the pathogenesis of smoking-induced PDAC. Smokers had significantly higher levels of activated CREB when compared with nonsmokers. Cell lines derived from normal pancreas and pancreatic intraepithelial neoplasm (PanIN) exhibited low baseline pCREB levels compared with PDAC cell lines. Furthermore, elevated CREB expression correlated with reduced survival in patients with PDAC. Depletion of CREB significantly reduced tumor burden after tobacco-specific nitrosamine 4-(methyl nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) treatment, suggesting a CREB-dependent contribution to PDAC growth and progression in smokers. Conversely, NNK accelerated PanIN lesion and PDAC formation via GM-CSF-mediated activation of CREB in a PDAC mouse model. CREB inhibition (CREBi) in mice more effectively reduced primary tumor burden compared with control or GM-CSF blockade alone following NNK exposure. GM-CSF played a role in the recruitment of tumor-associated macrophages (TAM) and regulatory T cell (Treg) expansion and promotion, whereas CREBi significantly reduced TAM and Treg populations in NNK-exposed mice. Overall, these results suggest that NNK exposure leads to activation of CREB through GM-CSF, promoting inflammatory and Akt pathways. Direct inhibition of CREB, but not GM-CSF, effectively abrogates these effects and inhibits tumor progression, offering a viable therapeutic strategy for patients with PDAC. These findings identify GM-CSF-induced CREB as a driver of pancreatic cancer in smokers and demonstrate the therapeutic potential of targeting CREB to reduce PDAC tumor growth. http://cancerres.aacrjournals.org/content/canres/78/21/6146/F1.large.jpg .

The gold nanoparticle (GNP) as a promising theranostic probe has been increasingly studied. The tumor-targeting efficiency of GNPs is crucial to increase the therapeutic ratio. In this study, we developed PSMA-targeted GNPs to enhance GNP uptake in prostate cancer and developed an x-ray fluorescence imaging system to noninvasively monitor and assess GNP delivery. Methods and Materials: For targeted therapy of prostate cancer, anti−prostate-specific membrane antigen (PSMA) antibodies were conjugated onto PEGylated GNPs through 1-ethyl-3-(-3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) (EDC/NHS) chemistry. In vivo imaging was implemented using an in-house−developed dual-modality computed tomography (CT) and x-ray fluorescence CT (XFCT) system on mice bearing subcutaneous LNCaP prostate tumors. After intravenous administration of GNPs (15 mg/mL, 200 mL), the x-ray fluorescence signals from the tumor were collected at various time points (5 minutes to approximately 30 hours) for GNP pharmacokinetics analysis. At 24 hours after administration, x-ray fluorescence projection (XRFproj) and XFCT imaging were conducted to evaluate the prostate tumor uptake of active-and passive-targeting GNPs. Inductively coupled plasma mass spectrometry analysis was adopted as a benchmark to verify the quantification accuracy of XRFproj/XFCT imaging. Results: Fluorescence microscopic imaging confirmed the enhanced (approximately 4 times) targeting efficiency of PSMAtargeted GNPs in vitro. The pharmacokinetics analysis showed enhanced tumor uptake/retention of PSMA-targeted GNPs

Heavy alcohol consumption is the dominant risk factor for chronic pancreatitis (CP); however, treatment and prevention strategies for alcoholic chronic pancreatitis (ACP) remain limited. The present study demonstrates that ACP induction in C57BL/6 mice causes significant acinar cell injury, pancreatic stellate cell (PSC) activation, exocrine function insufficiency, and an increased fibroinflammatory response when compared to alcohol or CP alone. While the withdrawal of alcohol during ACP recovery led to reversion of pancreatic damage, continued alcohol consumption with established ACP, perpetuated pancreatic injury. Additionally, phosphokinase array and Western blot analysis of ACP-induced mice pancreata revealed activation of the PI3K/AKT/mTOR and CREB pathway, possibly orchestrating the fibroinflammatory program of ACP pathogenesis. Mice treated with Urolithin A (Uro A, a gut-derived microbial metabolite) in the setting of ACP with continued alcohol intake (during the recovery period) showed suppression of AKT and P70S6K activation, and acinar damage was significantly reduced with a parallel reduction in pancreas-infiltrating macrophages and pro-inflammatory cytokine accumulation. These results collectively provide mechanistic insight into the impact of Uro A on attenuation of ACP severity through suppression of PI3K/AKT/mTOR signaling pathways and can be a useful therapeutic approach in ACP patients with continuous alcohol intake.

Vesicular stomatitis virus (VSV) expressing IFNb induces apoptosis in multiple tumor models while maintaining an excellent safety profile. VSV-IFNb is oncoselective due to permissive replication in cells with an altered IFN pathway. The human VSV-IFNb (hIFNb) vector is currently used in clinical trials as a standalone therapy; however, we hypothesized that oncolytic virotherapy might be more effective when used in combination with radiotherapy (RT). We investigated the synergistic effects of RT and VSV-hIFNb in the subcutaneous PC3 and orthotopic LNCaP prostate xenograft models and a syngeneic RM9 prostate tumor model. VSV-IFNb combined with RT amplified tumor killing for PC3 and LNCaP xenografts, and RM9 tumors. This was attributed to the induction of proapoptotic genes leading to increased VSV-IFNb infection and replication, VSV expression, and oncolysis. In the RM9 tumors, combination therapy resulted in a robust antitumor immune response. Treated RM9 tumor-bearing mice demonstrated an increase in CD8 þ and CD4 þ T-cell numbers, 100% resistance to tumor rechallenge, and reduced resistance to reimplantation challenge with CD8 þ knockdown. RT enhanced the activity of VSVmediated oncolysis via attenuation of the innate antiviral response, resulting in increased VSV replication and the generation of an adaptive immune response earmarked by an increase in CD8 þ lymphocyte numbers and antitumor activity. Local tumor irradiation combined with VSV-IFNb affects tumor cell death through direct and systemic activity in conjunction with pronounced antitumor immunity.Implications: Radiotherapy enhances VSV-mediated oncolysis and anti-tumor immunity, indicating that the ombination has promise for very high risk prostate cancer.

Purpose Immunotherapy (IT) and radiotherapy (RT) can act synergistically, enhancing antitumor response beyond what either treatment can achieve separately. Anecdotal reports suggest that these results are in part due to the induction of an abscopal effect on non-irradiated lesions. Systematic data on incidence of the abscopal effect are scarce, while the existence and the identification of predictive signatures or this phenomenon are lacking. The purpose of this pre-clinical investigational work is to shed more light on the subject by identifying several imaging features and blood counts, which can be utilized to build a predictive binary logistic model. Materials and methods This proof-of-principle study was performed on Lewis Lung Carcinoma in a syngeneic, subcutaneous murine model. Nineteen mice were used: four as control and the rest were subjected to combined RT plus IT regimen. Tumors were implanted on both flanks and after reaching volume of ~200 mm3 the animals were CT and MRI imaged and blood was collected. Quantitative imaging features (radiomics) were extracted for both flanks. Subsequently, the treated animals received radiation (only to the right flank) in three 8 Gy fractions followed by PD-1 inhibitor administrations. Tumor volumes were followed and animals exhibiting identical of better tumor growth delay on the non-irradiated (left) flank as compared to the irradiated flank were identified as experiencing an abscopal effect. Binary logistic regression analysis was performed to create models for CT and MRI radiomics and blood counts, which are predictive of the abscopal effect. Results Four of the treated animals experienced an abscopal effect. Three CT and two MRI radiomics features together with the pre-treatment neutrophil-to-lymphocyte (NLR) ratio correlated with the abscopal effect. Predictive models were created by combining the radiomics with NLR. ROC analyses indicated that the CT model had AUC of 0.846, while the MRI model had AUC of 0.946. Conclusions The combination of CT and MRI radiomics with blood counts resulted in models with AUCs of 1 on the modeling dataset. Application of the models to the validation dataset exhibited AUCs above 0.84, indicating very good predictive power of the combination between quantitative imaging and blood counts.

The aim of the present study was to investigate the effect of lyophilized A. indica leaf extract (125, 250 and 375 mg in suspension of 1 mL Propylene Glycol, respectively / kg body weight) on androgen-dependent biochemical parameters such as cholesterol and glycogen in the testis, total protein, total free sugar, enzymes like acid phosphatase (ACP), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in the testis and epididymis of both control and treated groups. Results indicated no significant difference in their body weight. However, testis and epididymis showed a significant decrease in their weights. The biochemical analysis showed a general decrease in the total protein content and the activity of ACP and, an increase in the total free sugar, glycogen, cholesterol contents and the activities of ALP and LDH in the dose-dependent treated rats. Since it is known that the accumulation of cholesterol and glycogen in the testis and epididymis are indicators of androgen deprivation. In this study such effects may have resulted from the deficiency in the level of circulating androgen, probably due to androgen deficiency resulting to the anti-androgenic property of the carbohydrate-rich nature of lyophilized A. indica leaf extract.