Germline Testing identifies Pathogenic/Likely Pathogenic Variants in Patients with Pancreatic Neuroendocrine Tumors.

10% of pancreatic neuroendocrine tumors (pNETs) are related to inherited syndromes (MEN1, MEN4, VHL, NF1, TSC). Growing evidence suggests that clinically sporadic pNETs can also harbor germline pathogenic variants. In this study, we report the prevalence of pathological/likely pathological germline variants (P/LP) in a high-risk cohort and an unselected cohort. We collected clinical data of patients with pNETs seen at MD Anderson Cancer Center (MDACC) and Johns Hopkins Hospital (JHH). High-risk cohort included (n=132) patients seen at MDACC who underwent germline testing for high-risk criteria (early onset, personal or family history of cancer and syndromic features) between 2013-2019. Unselected cohort (n=106) patients seen at JHH who underwent germline testing following their diagnosis of pNETs between 2020 to 2022. In the high-risk cohort (n=132), 33% (n=44) had P/LP variants. The majority of the patients had P/LP variants in MEN1 56% (n=25), followed by DNA repair pathways 18% (n=8), and 7 %(n=3) in MSH2 (Lynch Syndrome). Patients with P/LP were younger (45 years vs 50 years; p=0.002). In the unselected cohort (n=106), 21% (n=22) had P/LP. The majority were noted in DNA repair pathways 40% (n=9) and MEN1 36% (n=8). Multifocal tumors correlated with the presence of P/LP (p=0.0035). MEN1 germline P/LP variants correlated with younger age (40 vs 56 years) (p=0.0012). presence of multifocal tumors (p<0.0001), and WHO grade 1 histology (p=0.0078). P/LP variants are prevalent in patients with clinically sporadic pNET irrespective of high-risk features. The findings support upfront universal germline testing in all pNET patients.

Gut epithelial Interleukin-17 receptor A signaling can modulate distant tumors growth through microbial regulation.

Microbes influence cancer initiation, progression and therapy responsiveness. IL-17 signaling contributes to gut barrier immunity by regulating microbes but also drives tumor growth. A knowledge gap remains regarding the influence of enteric IL-17-IL-17RA signaling and their microbial regulation on the behavior of distant tumors. We demonstrate that gut dysbiosis induced by systemic or gut epithelial deletion of IL-17RA induces growth of pancreatic and brain tumors due to excessive development of Th17, primary source of IL-17 in human and mouse pancreatic ductal adenocarcinoma, as well as B cells that circulate to distant tumors. Microbial dependent IL-17 signaling increases DUOX2 signaling in tumor cells. Inefficacy of pharmacological inhibition of IL-17RA is overcome with targeted microbial ablation that blocks the compensatory loop. These findings demonstrate the complexities of IL-17-IL-17RA signaling in different compartments and the relevance for accounting for its homeostatic host defense function during cancer therapy.

Bacterial and fungal characterization of pancreatic adenocarcinoma from Endoscopic Ultrasound-guided biopsies.

Introduction: The tumor microbiome (TM) has been linked to pancreatic cancer prognosis. Specific microbes can confer tumor resistance to therapies. Early knowledge of the TM at time of diagnosis would be clinically relevant for precision therapy based on microbial composition. However, it is difficult to define the TM prior to surgical resection. Methods: In this pilot feasibility study, patients underwent Endoscopic Ultrasound-Fine Needle Aspiration (EUS-FNA) biopsy of pancreatic adenocarcinoma. These samples were analyzed using 16S rRNA and internal transcribed spacer (ITS) sequencing for characterization of the tumor bacteria and fungi. Result: After in silico decontamination and comparison to non-matched tumor, we were able to characterize the TM in biopsies, which was comparable to the TM from surgical specimens. Discussion: EUS-FNA biopsy may represent a feasible modality to characterize the pancreatic TM prior to surgical resection with proper decontamination strategies and improvements in matched controls.

Exercise-induced engagement of the IL-15/IL-15Rα axis promotes anti-tumor immunity in pancreatic cancer.

Aerobic exercise is associated with decreased cancer incidence and cancer-associated mortality. However, little is known about the effects of exercise on pancreatic ductal adenocarcinoma (PDA), a disease for which current therapeutic options are limited. Herein, we show that aerobic exercise reduces PDA tumor growth, by modulating systemic and intra-tumoral immunity. Mechanistically, exercise promotes immune mobilization and accumulation of tumor-infiltrating IL15Rα+ CD8 T cells, which are responsible for the tumor-protective effects. In clinical samples, an exercise-dependent increase of intra-tumoral CD8 T cells is also observed. Underscoring the translational potential of the interleukin (IL)-15/IL-15Rα axis, IL-15 super-agonist (NIZ985) treatment attenuates tumor growth, prolongs survival, and enhances sensitivity to chemotherapy. Finally, exercise or NIZ985 both sensitize pancreatic tumors to αPD-1, with improved anti-tumor and survival benefits. Collectively, our findings highlight the therapeutic potential of an exercise-oncology axis and identify IL-15 activation as a promising treatment strategy for this deadly disease.

Antibiotic use influences outcomes in advanced pancreatic adenocarcinoma patients.

Recent studies defined a potentially important role of the microbiome in modulating pancreatic ductal adenocarcinoma (PDAC) and responses to therapies. We hypothesized that antibiotic usage may predict outcomes in patients with PDAC. We retrospectively analyzed clinical data of patients with resectable or metastatic PDAC seen at MD Anderson Cancer from 2003 to 2017. Demographic, chemotherapy regimen and antibiotic use, duration, type, and reason for indication were recorded. A total of 580 patients with PDAC were studied, 342 resected and 238 metastatic patients, selected retrospectively from our database. Antibiotic use, for longer than 48 hrs, was detected in 209 resected patients (61%) and 195 metastatic ones (62%). On resectable patients, we did not find differences in overall survival (OS) or progression-free survival (PFS), based on antibiotic intake. However, in the metastatic cohort, antibiotic consumption was associated with a significantly longer OS (13.3 months vs. 9.0 months, HR 0.48, 95% CI 0.34-0.7, p = 0.0001) and PFS (4.4 months vs. 2 months, HR 0.48, 95% CI 0.34-0.68, p = <0.0001). In multivariate analysis, the impact of ATB remained significant for PFS (HR 0.59, p = 0.005) and borderline statistically significant for OS (HR 0.69, p = 0.06). When we analyzed by chemotherapy regimen, we found that patients who received gemcitabine-based chemotherapy as first-line therapy (n = 118) had significantly prolonged OS (HR 0.4, p 0.0013) and PFS (HR 0.55, p 0.02) if they received antibiotics, while those receiving 5FU-based chemotherapy (n = 98) had only prolonged PFS (HR 0.54, p = 0.03). Antibiotics-associated modulation of the microbiome is associated with better outcomes in patients with metastatic PDAC.

Interleukin-17-induced neutrophil extracellular traps mediate resistance to checkpoint blockade in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) remains a lethal malignancy with an immunosuppressive microenvironment that is resistant to most therapies. IL17 is involved in pancreatic tumorigenesis, but its role in invasive PDAC is undetermined. We hypothesized that IL17 triggers and sustains PDAC immunosuppression. We inhibited IL17/IL17RA signaling using pharmacological and genetic strategies alongside mass cytometry and multiplex immunofluorescence techniques. We uncovered that IL17 recruits neutrophils, triggers neutrophil extracellular traps (NETs), and excludes cytotoxic CD8 T cells from tumors. Additionally, IL17 blockade increases immune checkpoint blockade (PD-1, CTLA4) sensitivity. Inhibition of neutrophils or Padi4-dependent NETosis phenocopies IL17 neutralization. NMR spectroscopy revealed changes in tumor lactate as a potential early biomarker for IL17/PD-1 combination efficacy. Higher expression of IL17 and PADI4 in human PDAC corresponds with poorer prognosis, and the serum of patients with PDAC has higher potential for NETosis. Clinical studies with IL17 and checkpoint blockade represent a novel combinatorial therapy with potential efficacy for this lethal disease.

Exosomal miRNA confers chemo resistance via targeting Cav1/p-gp/M2-type macrophage axis in ovarian cancer.

BACKGROUND: Circulating miRNAs are known to play important roles in intercellular communication. However, the effects of exosomal miRNAs on cells are not fully understood. METHODS: To investigate the role of exosomal miR-1246 in ovarian cancer (OC) microenvironment, we performed RPPA as well as many other in vitro functional assays in ovarian cancer cells (sensitive; HeyA8, Skov3ip1, A2780 and chemoresistant; HeyA8-MDR, Skov3-TR, A2780-CP20). Therapeutic effect of miR-1246 inhibitor treatment was tested in OC animal model. We showed the effect of OC exosomal miR-1246 uptake on macrophages by co-culture experiments. FINDINGS: Substantial expression of oncogenic miR-1246 OC exosomes was found. We showed that Cav1 gene, which is the direct target of miR-1246, is involved in the process of exosomal transfer. A significantly worse overall prognosis were found for OC patients with high miR-1246 and low Cav1 expression based on TCGA data. miR-1246 expression were significantly higher in paclitaxel-resistant OC exosomes than in their sensitive counterparts. Overexpression of Cav1 and anti-miR-1246 treatment significantly sensitized OC cells to paclitaxel. We showed that Cav1 and multi drug resistance (MDR) gene is involved in the process of exosomal transfer. Our proteomic approach also revealed that miR-1246 inhibits Cav1 and acts through PDGFß receptor at the recipient cells to inhibit cell proliferation. miR-1246 inhibitor treatment in combination with chemotherapy led to reduced tumor burden in vivo. Finally, we demonstrated that when OC cells are co-cultured with macrophages, they are capable of transferring their oncogenic miR-1246 to M2-type macrophages, but not M0-type macrophages. INTERPRETATION: Our results suggest that cancer exosomes may contribute to oncogenesis by manipulating neighboring infiltrating immune cells. This study provide a new mechanistic therapeutic approach to overcome chemoresistance and tumor progression through exosomal miR-1246 in OC patients.

Comparison of two different antibiotic regimens for the prophylaxisis of cases with preterm premature rupture of membranes: a randomized clinical trial.

OBJECTIVES: The aim of the study was to assess the effect of 1 g ampicillin prophylactic dosage whether it is as effective as the dosage of 2 g to prevent maternal and neonatal morbidity in a randomized manner. MATERIALS AND METHODS: One hundred and fourty eight singleton pregnant women with preterm premature rupture of membranes between 21 and 33 weeks of gestation were followed-up during the study period in our institution. We com-pared the efficacy of two different different dosages of ampicillin. The study population was randomized into 2 groups. In the group 1, 1 g of intravenous ampicillin was given every 6 hours. In the group 2, 2 g of intravenous ampicillin was given every 6 hours. RESULTS: There was no significant difference between groups interms of fetal complications (RDS, icterus, mortality, sepsis, transient tachypnea of newborn and the pneumonia), rate of intensive care unit admission, fetal gender, fever, rate of clinical chorioamnionitis, high white blood cell count and the CRP, rate of cases < 30 weeks (p > 0.05). There was a significant differ-ence between the groups for the rate of previous preterm premature rupture of membranes history, steroid administration and the need for tocolysis (p < 0.05). CONCLUSIONS: Although antibiotics seems to be innocent, several side effects have been introduced. It is reasonable to use the lowest dosages in shortest period in order to minimize these unwanted effects.