Survival In Pancreatic Ductal Adenocarcinoma Research Articles

Aberrant accumulation of Kras-dependent pervasive transcripts during tumor progression renders cancer cells dependent on PAF1 expression

KRAS is the most commonly mutated oncogene in human cancer, and mutant KRAS is responsible for over 90% of pancreatic ductal adenocarcinoma (PDAC), the most lethal cancer. Here, we show that RNA polymerase II-associated factor 1 complex (PAF1C) is specifically required for survival of PDAC but not normal adult pancreatic cells. We show that PAF1C maintains cancer cell genomic stability by restraining overaccumulation of enhancer RNAs (eRNAs) and promoter upstream transcripts (PROMPTs) driven by mutant Kras. Loss of PAF1C leads to cancer-specific lengthening and accumulation of pervasive transcripts on chromatin and concomitant aberrant R-loop formation and DNA damage, which, in turn, trigger cell death. We go on to demonstrate that the global transcriptional hyperactivation driven by Kras signaling during tumorigenesis underlies the specific demand for PAF1C by cancer cells. Our work provides insights into how enhancer transcription hyperactivation causes general transcription factor addiction during tumorigenesis.

A comprehensive analysis of tumor-stromal collagen in relation to pathological, molecular, and immune characteristics and patient survival in pancreatic ductal adenocarcinoma

BackgroundAbundant collagen deposition is a hallmark of pancreatic ductal adenocarcinomas (PDACs). This study clarified the interactive relationship between tumor-stromal collagen, molecular and immune characteristics, and tumor pr ogression in human PDAC.MethodsWe performed a comprehensive examination using an integrative molecular pathological epidemiology database on 169 cases with resected PDAC . The amount of tumor-stromal collagen was quantified through digital imaging analysis for Elastica van Gieson-stained whole-section tumor slides. We analyzed the association of tumor-stromal collagen with gene alterations (KRAS, TP53, CDKN2A/p16, and SMAD4), immune parameters (CD4+ tumor-infiltrating lymphocytes [TILs], CD8+ TILs, FOXP3+ TILs, and tertiary lymphoid structures), and patient prognosis.ResultsLow amounts of tumor-stromal collagen were associated with poor differentiation (multivariable OR = 3.82, 95%CI = 1.41–12.2, P = 0.008) and CDKN2A/p16 alteration (OR [95%CI] = 2.06 [1.08–4.02], P = 0.03). Tumors with low collagen levels had shorter overall survival (HR [95%CI] = 2.38 [1.59–3.56], P < 0.0001). In the S-1 and gemcitabine (GEM) treatment groups, low tumor-stromal collagen was linked to poor prognosis of patients with PDAC (S-1 group: multivariable HR [95%CI] = 2.76 [1.36–5.79], P = 0.005; GEM group: multivariate HR [95%CI] = 2.91 [1.34–6.71], P = 0.007). Additionally, low amounts of tumor-stromal collagen were also linked to low levels of CD4+ TILs (P = 0.046), CD8+ TILs (P = 0.09), and tertiary lymphoid structures (P = 0.001).ConclusionsTumor-stromal collagen deposition may play a crucial role in modulating tumor-immune microenvironment and determining response to adjuvant chemotherapy and patient survival outcomes.

Tomatidine targets ATF4-dependent signaling and induces ferroptosis to limit pancreatic cancer progression

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with high metastasis and therapeutic resistance. Activating transcription factor 4 (ATF4), a master regulator of cellular stress, is exploited by cancer cells to survive. Prior research and data reported provide evidence that high ATF4 expression correlates with worse overall survival in PDAC. Tomatidine, a natural steroidal alkaloid, is associated with inhibition of ATF4 signaling in multiple diseases. Here, we discovered that invitro and invivo tomatidine treatment of PDAC cells inhibits tumor growth. Tomatidine inhibited nuclear translocation of ATF4 and reduced the transcriptional binding of ATF4 with downstream promoters. Tomatidine enhanced gemcitabine chemosensitivity in 3D ECM-hydrogels and invivo. Tomatidine treatment was associated with induction of ferroptosis signaling validated by increased lipid peroxidation, mitochondrial biogenesis, and decreased GPX4 expression in PDAC cells. This study highlights a possible therapeutic approach utilizing a plant-derived metabolite, tomatidine, to target ATF4 activity in PDAC.

C-reactive protein is a prognostic biomarker in pancreatic ductal adenocarcinoma patients.

The 5-year survival rate of pancreatic ductal adenocarcinoma (PDAC) is approximately 11% and has only improved marginally over the last three decades. For operable PDAC, resection and adjuvant FOLFIRINOX chemotherapy is standard of care. There is growing interest in perioperative regimens to improve outcomes. The non-randomized Phase II study "Gemcitabine and Abraxane for resectable Pancreatic cancer" (GAP) demonstrated the feasibility of perioperative gemcitabine/abraxane. Long-term survival in PDAC requires an effective immune response; hence, we undertook this translational study of the GAP trial cohort to identify immune-oncology biomarkers for clinical use. We combined Nanostring nCounter technology with immunohistochemistry to investigate the correlation between gene expression and overall patient survival. Findings were investigated in samples from the International Cancer Genome Consortium (ICGC, n=88) and the Australian Pancreatic Genome Initiative (APGI, n=227). We confirmed that human equilibrative nucleoside transporter 1 (hENT1) expression was not a prognostic marker in PDAC but patients with high levels of hENT1 were more likely to live longer than 24 months post-surgery. Additionally, CD274 (PD-L1) and two novel biomarkers of survival, cathepsin W (CTSW) and C-reactive protein (CRP), were identified in the GAP cohort (n=19). CRP expression was confirmed in data from the ICGC. Although PD-L1 and CTSW proteins were not significant across all three cohorts, results show that low CRP mRNA and protein expression are associated with longer overall survival in all three patient groups. PDAC patients with long survival have higher hENT1 expression levels. Furthermore, CRP expression is a biomarker of poor prognosis following perioperative chemotherapy and resection in PDAC patients and thus may be useful for identifying patients who could benefit from more aggressive adjuvant strategies.

Recent onset diabetes is associated with better survival in pancreatic ductal adenocarcinoma—An analysis of preoperative symptoms within the DGAV StuDoQ|Pancreas Registry

BackgroundThis multicenter study analyzed the relationship between preoperative symptoms and postsurgical outcomes utilizing the German national DGAV StuDoQ|Pancreas database. MethodsThis retrospective study included 2,643 pancreatic ductal adenocarcinoma patients undergoing pancreatic head resection from 2013–2017 within the German pancreatic surgery registry (DGAV StuDoQ|Pancreas). The association of preoperative symptoms with overall survival was analyzed using Kaplan-Meier and Cox regression analysis. ResultsPreoperative symptoms were common, with 2,380 of 2,643 (90%) patients presenting with any one or more of the following symptoms: jaundice (40%), biliary obstruction treated with biliary stent (41%), pain (37%), weight loss (29%), nausea (18%), diabetes (31%), emesis (6%), and recent onset diabetes (5%). Patients were separated into 3 groups: no symptoms (n = 293), symptoms (n = 2,229), and recent onset diabetes (n = 121). The 3 groups differed in body mass index and nodal staging, where patients with recent onset diabetes had the highest values (body mass index: no symptoms: 24.5 kg/m2, symptoms: 25.1 kg/m2; recent-onset diabetes: 26.3 kg/m2, P = .007), (no symptoms: N1: 55%, N2: 10%; symptoms: N1: 53%, N2: 17%; recent-onset diabetes: N1: 56%, N2: 16%, P = .023). Other pathological characteristics, carbohydrate antigen 19-9 levels, and adjuvant chemotherapy receival did not differ between the groups. Interestingly, recent-onset diabetes was associated with better survival compared with the other groups (Median overall survival: 28 months [no symptoms at all], 22 months [symptoms] versus not reached [recent onset diabetes group], and 5-year overall survival rates of 28%, 11%, and 57%, respectively [log rank, P = .013]). Multivariable analysis revealed that recent-onset diabetes and preoperative symptoms were independently associated with overall survival (recent-onset diabetes, relative risk 0.052 P = .027, >5 symptoms relative risk 3.66, P < .001). ConclusionPancreatic ductal adenocarcinoma symptoms occured in up to 90% of patients with resectable pancreatic ductal adenocarcinoma. In addition, PDAC symptoms were associated with overall survival and might identify unique pancreatic ductal adenocarcinoma subtypes.

Antibiotics &amp; Improved Survival in Pancreatic Ductal Adenocarcinoma

Antibiotics &amp; Improved Survival in Pancreatic Ductal Adenocarcinoma

Real-world impact of time-to-treatment initiation and initial treatment modality on survival in pancreatic and colorectal cancers.

e15646 Background: Overall survival for patients with pancreatic ductal adenocarcinoma (PDAC) and colorectal cancers (CRC) has increased significantly over the past decade; however, the optimal time-to-treatment initiation (TTI) and initial treatment modality (ITM) have not been defined. These variables have likely been affected by increased adoption and changes in types of neoadjuvant treatment strategies for these cancer types. Thus, we performed a retrospective observational study of TTI and ITM in patients with CRC and PDAC within the MHealth/Fairview medical system. Methods: We identified 424 patients with stage I-III RC and 316 patients with stage I-III PDAC within the MHealth/Fairview system (Minneapolis, MN) from 2011-2021 with North American Association of Central Cancer Registries data enriched by the electronic health record. Patients were stratified by TTI from diagnoses as: 0-7 days, 8-14 days, 15-28 days, 29-42 days, and over 43 days. ITM, defined as initial chemotherapy/chemoradiation, surgery, or radiation, was analyzed independently for patients with rectal cancer (N = 267) and PDAC. Effect of TTI and ITM on overall survival was calculated using a Cox proportional Hazard (CPH) model controlling for clinical stage. Results: TTI was significantly associated with survival in CRC, with patients treated in 8-14 days and 15-28 days showing increased survival over patients treated in over 43 days (HR 0.397, p = 0.007 and HR 0.276 p &lt; 0.001, respectively). There was no significant hazard for TTI and survival in PDAC. We also found that neoadjuvant chemotherapy/chemoradiation had a lower hazard for death in rectal cancer relative to upfront surgery (HR 0.323, p = 0.002), when controlling for stage. Surgery was significantly more likely to be correlated with stage I or II disease than chemotherapy/chemoradiation (68.5% vs 24.7%, p &lt; 0.0001 by Spearman method). There was no significant association between ITM and survival in patients with PDAC. Conclusions: Early treatment for CRC is associated with improved survival in this population, implying that treatment delays decrease the efficacy of curative-intent therapy. Evaluation of treatment modality in the rectal sub-group showed improved outcomes with neoadjuvant chemotherapy and chemoradiation, despite upfront surgery being associated with lower stage. The lack of association between TTI and survival in PDAC is likely related to the relatively poor outcomes observed with this disease and highlights the need for better screening and treatment for resectable disease. These results are notable because they suggest that a thorough workup and appropriate therapy may be more important than rapid treatment.

Risk stratification of pancreatic ductal adenocarcinoma patients undergoing curative-intent surgery after neoadjuvant therapy.

e16312 Background: To identify preoperative factors associated with survival in pancreatic ductal adenocarcinoma (PDAC) patients who underwent curative-intent surgery after neoadjuvant therapy (NAT) and develop risk stratification criteria. Methods: Consecutive PDAC patients who underwent post-NAT curative-intent surgeries between 2007 and 2020 at a high-volume center were retrospectively analyzed. Demographic, laboratory, surgical, and histopathologic variables were collected. Baseline, preoperative, and interval changes of CT findings proposed by the Society of Abdominal Radiology and the American Pancreatic Association were analyzed. Cox proportional hazard analyses were used to identify preoperative variables associated with survival since the time of diagnosis. We developed risk stratification criteria using the variables independently associated with survival, i.e., "post-NAT response criteria." We compared the discrimination performance of "post-NAT response criteria" with that of post-NAT pathological (yp) AJCC TNM staging system. Results: A total 145 PDAC patients who completed chemo- (n=47) or chemoradiation therapy (n=98) were included. Stable or increased tumor size on CT (hazard ratio, 2.58 [1.58, 4.21]; P &lt; 0.001) and elevated preop. CA 19-9 level (1.98 [1.11, 3.55]; P = 0.021) were independent poor prognostic factors. The survival of the patient groups stratified by "post-NAT response criteria" which combined changes in tumor size and CA 19-9 showed significant difference (P &lt; 0.001). Such stratification was comparable to ypTNM staging in discrimination performance (difference of C-index, 0.068 [-0.012, 0.142]). Conclusions: Decrease in tumor size and CA 19-9 normalization or staying normal until the time of surgery were independent favorable factors of survival. The combination of the two factors discriminated survival comparably to ypTNM staging.[Table: see text]

KRAS-Dependency in Pancreatic Ductal Adenocarcinoma: Mechanisms of Escaping in Resistance to KRAS Inhibitors and Perspectives of Therapy.

Pancreatic ductal adenocarcinoma (PDAC) is still one of the deadliest cancers in oncology because of its increasing incidence and poor survival rate. More than 90% of PDAC patients are KRAS mutated (KRASmu), with KRASG12D and KRASG12V being the most common mutations. Despite this critical role, its characteristics have made direct targeting of the RAS protein extremely difficult. KRAS regulates development, cell growth, epigenetically dysregulated differentiation, and survival in PDAC through activation of key downstream pathways, such as MAPK-ERK and PI3K-AKT-mammalian target of rapamycin (mTOR) signaling, in a KRAS-dependent manner. KRASmu induces the occurrence of acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) and leads to an immunosuppressive tumor microenvironment (TME). In this context, the oncogenic mutation of KRAS induces an epigenetic program that leads to the initiation of PDAC. Several studies have identified multiple direct and indirect inhibitors of KRAS signaling. Therefore, KRAS dependency is so essential in KRASmu PDAC that cancer cells have secured several compensatory escape mechanisms to counteract the efficacy of KRAS inhibitors, such as activation of MEK/ERK signaling or YAP1 upregulation. This review will provide insights into KRAS dependency in PDAC and analyze recent data on inhibitors of KRAS signaling, focusing on how cancer cells establish compensatory escape mechanisms.

Beta-blocker exposure and survival outcomes in patients with advanced pancreatic ductal adenocarcinoma: a retrospective cohort study (BETAPANC).

Introduction: Preclinical studies have demonstrated the possible role of beta-adrenergic receptors in pancreatic ductal adenocarcinoma (PDAC) tumor invasion and migration. The current study aimed to explore the possible association between survival outcomes and beta-blocker (BB) exposure in patients with advanced PDAC. Methods: This retrospective single-center study included 182 patients with advanced PDAC. Clinical [age, sex, BMI, cardiovascular condition, presence (SBB) or absence (NSBB) of beta-1 selectivity of BB, exposure duration, and multimorbidity], oncological (stage and anticancer treatment regimen), and biological (renal and liver function) data were collected. The endpoints were overall survival (OS) and progression-free survival (PFS). Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for survival outcomes associated with BB exposure were estimated using Cox regression model and propensity score (PS) methods. Results: Forty-one patients (22.5%) were exposed to BB. A total of 104 patients progressed (57.1%) to PDAC and 139 (76.4%) patients died at the end of follow-up (median, 320days; IQR, 438.75days). When compared to the non-exposed group, there was no increase in survival outcomes associated with BB use (OS: HR = 1.38, 95% CI = 0.80-2.39, p = 0.25; PFS: adjusted HR = 0.95, 95% CI = 0.48-1.88, p = 0.88). Similar results were obtained using the PS method. Compared to no BB usage, SBB use was associated with a significant decrease in OS (HR = 1.80, 95% CI = 1.16-2.80, p < 10-2). Conclusion: BB exposure was not associated with improved PDAC survival outcomes. Beta-1-selectivity was not independently associated with any differences.

Brg1 controls stemness and metastasis of pancreatic cancer through regulating hypoxia pathway.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. We previously reported that chromatin remodeler Brg1 is essential for acinar cell-derived PDAC formation in mice. However, the functional role of Brg1 in established PDAC and its metastasis remains unknown. Here, we investigated the importance of Brg1 for established PDAC by using a mouse model with a dual recombinase system. We discovered that Brg1 was a critical player for the cell survival and growth of spontaneously developed PDAC in mice. In addition, Brg1 was essential for metastasis of PDAC cells by inhibiting apoptosis in splenic injection and peritoneal dissemination models. Moreover, cancer stem-like property was compromised in PDAC cells by Brg1 ablation. Mechanistically, the hypoxia pathway was downregulated in Brg1-deleted mouse PDAC and BRG1-low human PDAC. Brg1 was essential for HIF-1α to bind to its target genes to augment the hypoxia pathway, which was important for PDAC cells to maintain their stem-like properties and to metastasize to the liver. Human PDAC cells with high BRG1 expression were more susceptible to BRG1 suppression. In conclusion, Brg1 plays a critical role for cell survival, stem-like property and metastasis of PDAC through the regulation of hypoxia pathway, and thus could be a novel therapeutic target for PDAC.

ASO Visual Abstract: Predictors of Long-Term Survival in Pancreatic Ductal Adenocarcinoma After Pancreatectomy-TP53 and SMAD4 Mutation Scoring in Combination with CA19-9.

ASO Visual Abstract: Predictors of Long-Term Survival in Pancreatic Ductal Adenocarcinoma After Pancreatectomy-TP53 and SMAD4 Mutation Scoring in Combination with CA19-9.

Autophagy supports mitochondrial metabolism through the regulation of iron homeostasis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) cells maintain a high level of autophagy, allowing them to thrive in an austere microenvironment. However, the processes through which autophagy promotes PDAC growth and survival are still not fully understood. Here, we show that autophagy inhibition in PDAC alters mitochondrial function by losing succinate dehydrogenase complex iron sulfur subunit B expression by limiting the availability of the labile iron pool. PDAC uses autophagy to maintain iron homeostasis, while other tumor types assessed require macropinocytosis, with autophagy being dispensable. We observed that cancer-associated fibroblasts can provide bioavailable iron to PDAC cells, promoting resistance to autophagy ablation. To overcome this cross-talk, we used a low-iron diet and demonstrated that this augmented the response to autophagy inhibition therapy in PDAC-bearing mice. Our work highlights a critical link between autophagy, iron metabolism, and mitochondrial function that may have implications for PDAC progression.

The Revised R Status is an Independent Predictor of Postresection Survival in Pancreatic Cancer After Neoadjuvant Treatment.

To investigate the oncological outcomes of patients with pancreatic ductal adenocarcinoma (PDAC) who had an R 0 or R 1 resection based on the revised R status (1mm) after neoadjuvant therapy (NAT). The revised R status is an independent prognostic factor in upfront-resected PDAC; however, the significance of 1mm margin clearance after NAT remains controversial. Patients undergoing pancreatectomy after NAT for PDAC were identified from 2 prospectively maintained databases. Clinicopathological and survival data were analyzed. The primary outcomes were overall survival (OS), recurrence-free survival (RFS), and pattern of recurrence in association with R 0 >1mm and R 1 ≤1mm resections. Three hundred fifty-seven patients with PDAC were included after NAT and subsequent pancreatic resection. Two hundred eight patients (58.3%) received FOLFIRINOX, 41 patients (11.5%) received gemcitabine-based regimens, and 299 individuals (83.8%) received additional radiotherapy. R 0 resections were achieved in 272 patients (76.2%) and 85 patients (23.8%) had R 1 resections. Median OS after R 0 was 41.0 months, compared with 20.6 months after R 1 resection ( P = 0.002), and even longer after additional adjuvant chemotherapy ( R 0 44.8 vs R1 20.1 months; P = 0.0032). Median RFS in the R 0 subgroup was 17.5 months versus 9.4 months in the R 1 subgroup ( P < 0.0001). R status was confirmed as an independent predictor for OS ( R 1 hazard ratio: 1.56, 95% CI: 1.07-2.26) and RFS ( R 1 hazard ratio: 1.52; 95% CI: 1.14-2.0). In addition, R 1 resections were significantly associated with local but not distant recurrence ( P < 0.0005). The revised R status is an independent predictor of postresection survival and local recurrence in PDAC after NAT. Achieving R 0 resection with a margin of at least 1mm should be a primary goal in the surgical treatment of PDAC after NAT.

Abstract 369: Gemcitabine nab-paclitaxel combination with DMAPT in PDAC cachexia

Abstract Background: Cachexia is the progressive, unintentional wasting of muscle and adipose tissue caused by tumors. Cancer cachexia affects &amp;gt;80% of patients with pancreatic ductal adenocarcinoma (PDAC). Certain chemotherapy regimens cause debilitation in patients and muscle and fat wasting in mouse models. Gemcitabine with nab-paclitaxel (GemNP) is a first line treatment for PDAC. Whether GemNP promotes cachexia is unknown. Muscle wasting in cancer cachexia has been functionally linked to NF-κB, which can be induced by chemotherapies and is active in PDAC tumors. Among other functions, NF-κB induces expression of Interleukin-6 (IL-6), a major mediator of cancer cachexia. DMAPT is a small molecule NF-κB inhibitor. In prior work, DMAPT plus Gem reduced tumor burden in a genetic model of pancreatic cancer and separately, prevented muscle wasting in a genetic model of mammary cancer. Therefore, the purpose of our study was to determine whether GemNP promotes cachexia and whether DMAPT could reduce tumor burden and/or cachexia in PDAC, potentially through reducing IL-6 expression. Methods: In our in vitro model, conditioned media (CM) from KPC pancreatic cancer cells derived from the KrasG12D;Trp53R172H;Pdx1-Cre mouse, induces wasting of C2C12 myotubes. Thus, myotubes were treated with 50% KPC-CM or control CM and supplemented with 0, 5, or 10uM DMAPT for 48hrs. For in vivo modeling of PDAC cachexia, 12-week-old male C57BL/6J mice were orthotopically implanted with 5x104 KPC cells or KPC cells deleted for IL6 (KPC-IL6KO) cells; controls underwent sham surgery. Starting on day 4, every 6 days tumor-bearing mice were given 120 mg/kg gemcitabine and 10 mg/kg nab-paclitaxel (GemNP) for four rounds, then gemcitabine only for subsequent rounds, with or without 100mg/kg DMAPT (by gavage 5 days/week). Controls received vehicle only. Results: DMAPT prevented atrophy in KPC-CM treated myotubes. In vivo, GemNP increased median survival, to 23.5d in KPC + GemNP mice versus 17d in untreated KPC mice (P&amp;lt;0.001). GemNP + DMAPT increased survival (25d) compared to untreated KPC (P&amp;lt;0.001), but was similar to KPC + GemNP alone (P=0.693). There were no differences in tumor mass at euthanasia. All KPC groups lost significant body weight and fat mass compared to sham controls. In mice with KPC IL-6KO tumors, GemNP increased survival, with median survival of 39d in KPC-IL6KO + GemNP mice compared with 30d in untreated KPC-IL6KO (P&amp;lt;0.001). GemNP + DMAPT increased survival (35 d in KPC IL-6KO) compared to untreated KPC-IL6KO (P&amp;lt;0.001), but was similar to KPC IL-6KO + GemNP (P=0.276). There was a trend for GemNP + DMAPT to have smaller KPC-IL6KO tumors compared to GemNP (p=0.055). Conclusion: Regardless of IL-6 expression from tumor cells, treatment with GemNP improved survival in orthotopic PDAC without exacerbating cachexia. DMAPT did not extend survival above GemNP alone. Despite promising in vitro data and prior published work, DMAPT was not efficacious in reducing tumor growth or treating PDAC cachexia in this model. Citation Format: Brittany Counts, Sephora Jean, Reggie Wang, Teresa Zimmers. Gemcitabine nab-paclitaxel combination with DMAPT in PDAC cachexia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 369.

NUAK1 governs centrosome replication in pancreatic cancer via MYPT1/PP1β and GSK3β-dependent regulation of PLK4.

The AMP-activated protein kinase (AMPK)-related kinase NUAK1 (NUAK family SNF1-like kinase 1) has emerged as a potential vulnerability in MYC-dependent cancer but the biological roles of NUAK1 in different settings are poorly characterised, and the spectrum of cancer types that exhibit a requirement for NUAK1 is unknown. Unlike canonical oncogenes, NUAK1 is rarely mutated in cancer and appears to function as an obligate facilitator rather than a cancer driver per se. Although numerous groups have developed small-molecule NUAK inhibitors, the circumstances that would trigger their use and the unwanted toxicities that may arise as a consequence of on-target activity are thus undetermined. Reasoning that MYC is a key effector of RAS pathway signalling and the GTPase KRAS is almost uniformly mutated in pancreatic ductal adenocarcinoma (PDAC), we investigated whether this cancer type exhibits a functional requirement for NUAK1. Here, we show that high NUAK1 expression is associated with reduced overall survival in PDAC and that inhibition or depletion of NUAK1 suppresses growth of PDAC cells in culture. We identify a previously unknown role for NUAK1 in regulating accurate centrosome duplication and show that loss of NUAK1 triggers genomic instability. The latter activity is conserved in primary fibroblasts, raising the possibility of undesirable genotoxic effects of NUAK1 inhibition.

The Expressions of NF−κB, COX−2, Sp1, and c−Jun in Pancreatic Ductal Adenocarcinoma and Their Associations with Patient Survival

Chronic inflammation is a crucial driver of carcinogenesis in pancreatic ductal adenocarcinoma (PDAC). Several studies have investigated the prognostic significance of cyclooxygenase-2 (COX-2) expression in PDAC patients, obtaining conflicting results. Nuclear factor kappa-B (NF-κB), specificity protein 1 (Sp1), and c-Jun are known as the transcription factors of the COX2 gene. This exploratory observational study investigated the association of the NF-κB, COX-2, Sp1, and c-Jun expressions with patient survival in PDAC. We used the immunohistochemical method to detect the PDAC tissue expressions of NF-κB (RelA/p65), COX-2, Sp1, and c-Jun. The expressions of these proteins were correlated with the overall survival (OS) and other clinicopathological characteristics of PDAC patients. We obtained 53 PDAC specimens from resections and biopsies. There were significant correlations between the four proteins' expressions in the PDAC tissues. The expression of the cytoplasmic (aHR = 0.31; 95% CI 0.11-0.90; p = 0.032) or nuclear NF-κB (aHR = 0.22; 95% CI 0.07-0.66; p = 0.007) was independently associated with a better prognosis in the PDAC patients. COX-2, Sp1, and c-Jun showed no significant association with a prognosis in the PDAC patients. The PDAC patients who expressed NF-κB had a better prognosis than the other patients, which suggests that the role of inflammation in PDAC is more complex than previously thought.

Urokinase-Type Plasminogen Activator Receptor (uPAR) Cooperates with Mutated KRAS in Regulating Cellular Plasticity and Gemcitabine Response in Pancreatic Adenocarcinomas.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers. Given the currently limited therapeutic options, the definition of molecular subgroups with the development of tailored therapies remains the most promising strategy. Patients with high-level gene amplification of urokinase plasminogen activator receptor (uPAR/PLAUR) have an inferior prognosis. We analyzed the uPAR function in PDAC to understand this understudied PDAC subgroup's biology better. A total of 67 PDAC samples with clinical follow-up and TCGA gene expression data from 316 patients were used for prognostic correlations. Gene silencing by CRISPR/Cas9, as well as transfection of uPAR and mutated KRAS, were used in PDAC cell lines (AsPC-1, PANC-1, BxPC3) treated with gemcitabine to study the impact of these two molecules on cellular function and chemoresponse. HNF1A and KRT81 were surrogate markers for the exocrine-like and quasi-mesenchymal subgroup of PDAC, respectively. High levels of uPAR were correlated with significantly shorter survival in PDAC, especially in the subgroup of HNF1A-positive exocrine-like tumors. uPAR knockout by CRISPR/Cas9 resulted in activation of FAK, CDC42, and p38, upregulation of epithelial makers, decreased cell growth and motility, and resistance against gemcitabine that could be reversed by re-expression of uPAR. Silencing of KRAS in AsPC1 using siRNAs reduced uPAR levels significantly, and transfection of mutated KRAS in BxPC-3 cells rendered the cell more mesenchymal and increased sensitivity towards gemcitabine. Activation of uPAR is a potent negative prognostic factor in PDAC. uPAR and KRAS cooperate in switching the tumor from a dormant epithelial to an active mesenchymal state, which likely explains the poor prognosis of PDAC with high uPAR. At the same time, the active mesenchymal state is more vulnerable to gemcitabine. Strategies targeting either KRAS or uPAR should consider this potential tumor-escape mechanism.

A small Rho GTPase RAB25 with a potential role in chemotherapy resistance in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDA) is one of the major human health challenges with minimal therapeutic benefits due to its late detection, and de novo - and acquired chemotherapy resistance. In this work we unravel the potential pro-survival role of RAB25 in pancreatic cancer chemotherapy resistance and aim to identify if RAB25is a prognostic marker of patients' survival in PDA. We used RNA sequencing, shRNA mediated gene knockdown, BioGRID open repository of CRISPR screens (ORCS), GEPIA, kmplot.com, and cBioPortal.org databases to identify the role of RAB25 in PDA cell proliferation, chemotherapy response, expression in tumour versus normal tissues, and overall patients' survival. RNA sequencing show Rab25 to be one of the top upregulated genes in gemcitabine resistant mouse PDA cells. Knockdown of Rab25 in these cells enhanced gemcitabine toxicity. In addition, re-analysis of previously published CRISPR/Cas9 data confirm RAB25 to be responsible for chemotherapy resistance in KRASG12D mutant human pancreatic cancer cell line. Finally, we used publicly available TCGA datasets and identify the upregulation of RAB25 in tumour tissues compared to the adjacent normal tissue, co-occurrence of KRASG12 mutations with RAB25 amplifications, and poor patients' survival in cohorts with higher mRNA expression of RAB25. RAB25 expression is a prognostic marker for patient's survival and gemcitabine resistance in PDA.

The PD-L1 Expression and Tumor-Infiltrating Immune Cells Predict an Unfavorable Prognosis in Pancreatic Ductal Adenocarcinoma and Adenosquamous Carcinoma

The tumor microenvironment (TME) plays a vital role in the development, progression, and metastasis of pancreatic cancer (PC). The composition of the TME and its potential prognostic value remains to be fully understood, especially in adenosquamous carcinoma of pancreas (ASCP) patients. Immunohistochemistry was used to explore the clinical significance of CD3, CD4, CD8, FoxP3, and PD-L1 expression within the TME and to identify correlations with the prognosis of PC in a series of 29 patients with ASCP and 54 patients with pancreatic ductal adenocarcinoma (PDAC). Data from the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) were accessed to obtain the scRNA-seq data and transcriptome profiles. Seurat was used to process the scRNA-seq data, and CellChat was used to analyze cell-cell communication. CIBERSORT was used to approximate the constitution of tumor-infiltrating immune cell (TICs) profiles. Higher levels of PD-L1 were linked with a shorter overall survival in ASCP (p = 0.0007) and PDAC (p = 0.0594). A higher expression of CD3+ and CD8+ T-cell infiltration was significantly correlated with a better prognosis in PC. By influencing the composition of tumor-infiltrating immune cells (TICs), high levels of PD-L1 expression are linked with a shorter overall survival in ASCP and PDAC.