Search

Cancer cells exert mastery over the local tumor-associated stroma (TAS) to configure protective immunity within the tumor microenvironment. The immunomodulatory character of pancreatic lysates of patients with cancer differs from those with pancreatitis. In this study, we evaluated the cross-talk between pancreatic cancer and its TAS in primary human cell culture models. Upon exposure of TAS to pancreatic cancer cell-conditioned media, we documented robust secretion of IL6 and IL8. This TAS response was MyD88-dependent and sufficient to directly suppress both CD4+ and CD8+ T-cell proliferation, inducing Th17 polarization at the expense of Th1. We found that patients possessed a similar shift in circulating effector memory Th17:Th1 ratios compared with healthy controls. The TAS response also directly suppressed CD8+ T-cell–mediated cytotoxicity. Overall, our results demonstrate how TAS contributes to the production of an immunosuppressive tumor microenvironment in pancreatic cancer. Cancer Res; 77(3); 672–83. ©2016 AACR.

Treatment effect modifiers identify patient characteristics associated with treatment responses. The purpose of this secondary analysis was to identify potential treatment effect modifiers for disability from the TARGET trial that compared usual care (control) with usual care + psychologically informed physical therapy (PIPT). The sample consisted of a STarT Back tool identified high-risk patients with acute low back pain that completed Oswestry Disability Index (ODI) data at index visit and 6 months later (n = 1250). Candidate treatment effect modifiers were identified a priori and informed by the literature. Linear mixed models tested for treatment effect modification through tests of statistical interaction. All statistical interactions ( P ≤ 0.20) were stratified by modifier to inspect for specific effects ( P ≤ 0.05). Smoking was identified as a potential effect modifier (treatment * smoking interaction, P = 0.08). In participants who were smokers, the effect of PIPT was (ODI = 5.5; 95% CI: 0.6-10.4; P = 0.03) compared with usual care. In participants who were nonsmokers, the effect of PIPT was (ODI = 1.5; 95% CI: -1.4 to 4.4; P = 0.31) compared with usual care. Pain medication was also identified as a potential effect modifier (treatment × pain medication interaction, P = 0.10). In participants prescribed ≥3 pain medications, the effect of PIPT was (ODI = 7.1; 95% CI: -0.1 to 14.2; P = 0.05) compared with usual care. The PIPT effect for participants prescribed no pain medication was (ODI = 3.5; 95% CI: -0.4 to 7.4; P = 0.08) and for participants prescribed 1 to 2 pain medications was (ODI = 0.6; 95% CI: -2.5 to 3.7; P = 0.70) when compared with usual care. These findings may be used for generating hypotheses and planning future clinical trials investigating the effectiveness of tailored application of PIPT.

Nicotine treatment does not lead to c-Met activation in PC cells.

Purpose:Mutant KRAS is a major driver of pancreatic oncogenesis and therapy resistance, yet KRAS inhibitors are lacking in the clinic. KRAS requires farnesylation for membrane localization and cancer-causing activity prompting the development of farnesyltransferase inhibitors (FTIs) as anticancer agents. However, KRAS becomes geranylgeranylated and active when cancer cells are treated with FTIs. To overcome this geranylgeranylation-dependent resistance to FTIs, we designed FGTI-2734, a RAS C-terminal mimetic dual FT and geranylgeranyltransferase-1 inhibitor (GGTI).Experimental Design:Immunofluorescence, cellular fractionation, and gel shift assays were used to assess RAS membrane association, Western blotting to evaluate FGTI-2734 effects on signaling, and mouse models to demonstrate its antitumor activity.Results:FGTI-2734, but not the selective FTI-2148 and GGTI-2418, inhibited membrane localization of KRAS in pancreatic, lung, and colon human cancer cells. FGTI-2734 induced apoptosis and inhibited the growth in mice of mutant KRAS–dependent but not mutant KRAS–independent human tumors. Importantly, FGTI-2734 inhibited the growth of xenografts derived from four patients with pancreatic cancer with mutant KRAS (2 G12D and 2 G12V) tumors. FGTI-2734 was also highly effective at inhibiting, in three-dimensional cocultures with resistance promoting pancreatic stellate cells, the viability of primary and metastatic mutant KRAS tumor cells derived from eight patients with pancreatic cancer. Finally, FGTI-2734 suppressed oncogenic pathways mediated by AKT, mTOR, and cMYC while upregulating p53 and inducing apoptosis in patient-derived xenografts in vivo.Conclusions:The development of this novel dual FGTI overcomes a major hurdle in KRAS resistance, thwarting growth of patient-derived mutant KRAS–driven xenografts from patients with pancreatic cancer, and as such it warrants further preclinical and clinical studies.

Purpose: The relationship between smoking and pancreatic cancer biology, particularly in the context of the heterogeneous microenvironment, remains incompletely defined. We hypothesized that nicotine exposure would lead to the augmentation of paracrine growth factor signaling between tumor-associated stroma (TAS) and pancreatic cancer cells, ultimately resulting in accelerated tumor growth and metastasis.Experimental Design: The effect of tobacco use on overall survival was analyzed using a prospectively maintained database of surgically resected patients with pancreatic cancer. Nicotine exposure was evaluated in vitro using primary patient–derived TAS and pancreatic cancer cells independently and in coculture. Nicotine administration was then assessed in vivo using a patient-derived pancreatic cancer xenograft model.Results: Continued smoking was associated with reduced overall survival after surgical resection. In culture, nicotine-stimulated hepatocyte growth factor (HGF) secretion in primary patient-derived TAS and nicotine stimulation was required for persistent pancreatic cancer cell c-Met activation in a coculture model. c-Met activation in this manner led to the induction of inhibitor of differentiation-1 (Id1) in pancreatic cancer cells, previously established as a mediator of growth, invasion and chemoresistance. HGF-induced Id1 expression was abrogated by both epigenetic and pharmacologic c-Met inhibition. In patient-derived pancreatic cancer xenografts, nicotine treatment augmented tumor growth and metastasis; tumor lysates from nicotine-treated mice demonstrated elevated HGF expression by qRT-PCR and phospho-Met levels by ELISA. Similarly, elevated levels of phospho-Met in surgically resected pancreatic cancer specimens correlated with reduced overall survival.Conclusions: Taken together, these data demonstrate a novel, microenvironment-dependent paracrine signaling mechanism by which nicotine exposure promotes the growth and metastasis of pancreatic cancer. Clin Cancer Res; 22(7); 1787–99. ©2015 AACR.

As a member of the Back Pain Consortium (BACPAC), the University of Pittsburgh Mechanistic Research Center's research goal is to phenotype chronic low back pain using biological, biomechanical, and behavioral domains using a prospective, observational cohort study. Data will be collected from 1,000 participants with chronic low back pain according to BACPAC-wide harmonized and study-specific protocols. Participation lasts 12 months with one required in person baseline visit, an optional second in person visit for advanced biomechanical assessment, and electronic follow ups at months 1, 2, 3, 4, 5, 6, 9, and 12 to assess low back pain status and response to prescribed treatments. Behavioral data analysis includes a battery of patient-reported outcomes, social determinants of health, quantitative sensory testing, and physical activity. Biological data analysis includes omics generated from blood, saliva, and spine tissue. Biomechanical data analysis includes a physical examination, lumbopelvic kinematics, and intervertebral kinematics. The statistical analysis includes traditional unsupervised machine learning approaches to categorize participants into groups and determine the variables that differentiate patients. Additional analysis includes the creation of a series of decision rules based on baseline measures and treatment pathways as inputs to predict clinical outcomes. The characteristics identified will contribute to future studies to assist clinicians in designing a personalized, optimal treatment approach for each patient.

Objective We assessed whether race or ethnicity was associated with the incidence of high-impact chronic low back pain (cLBP) among adults consulting a primary care provider for acute low back pain (aLBP). Methods In this secondary analysis of a prospective cohort study, patients with aLBP were identified through screening at seventy-seven primary care practices from four geographic regions. Incidence of high-impact cLBP was defined as the subset of patients with cLBP and at least moderate disability on Oswestry Disability Index [ODI >30]) at 6 months. General linear mixed models provided adjusted estimates of association between race/ethnicity and high-impact cLBP. Results We identified 9,088 patients with aLBP (81.3% White; 14.3% Black; 4.4% Hispanic). Black/Hispanic patients compared to White patients, were younger and more likely to be female, obese, have Medicaid insurance, worse disability on ODI, and were at higher risk of persistent disability on STarT Back Tool (all P Conclusions We observed an increased incidence of high-impact cLBP among Black and Hispanic patients compared to White patients. This disparity was partly explained by racial/ethnic differences in socioeconomic and back-related risk factors. Interventions that target these factors to reduce pain-related disparities should be evaluated. ClinicalTrials.gov Identifier NCT02647658.

Background Cancer cachexia is a life‐threatening metabolic syndrome that causes significant loss of skeletal muscle mass and significantly increases mortality in cancer patients. Currently, there is an urgent need for better understanding of the molecular pathophysiology of this disease so that effective therapies can be developed. The majority of pre‐clinical studies evaluating skeletal muscle's response to cancer have focused on one or two pre‐clinical models, and almost all have focused specifically on limb muscles. In the current study, we reveal key differences in the histology and transcriptomic signatures of a limb muscle and a respiratory muscle in orthotopic pancreatic cancer patient‐derived xenograft (PDX) mice. Methods To create four cohorts of PDX mice evaluated in this study, tumours resected from four pancreatic ductal adenocarcinoma patients were portioned and attached to the pancreas of immunodeficient NSG mice. Results Body weight, muscle mass, and fat mass were significantly decreased in each PDX line. Histological assessment of cryosections taken from the tibialis anterior (TA) and diaphragm (DIA) revealed differential effects of tumour burden on their morphology. Subsequent genome‐wide microarray analysis on TA and DIA also revealed key differences between their transcriptomes in response to cancer. Genes up‐regulated in the DIA were enriched for extracellular matrix protein‐encoding genes and genes related to the inflammatory response, while down‐regulated genes were enriched for mitochondria related protein‐encoding genes. Conversely, the TA showed up‐regulation of canonical atrophy‐associated pathways such as ubiquitin‐mediated protein degradation and apoptosis, and down‐regulation of genes encoding extracellular matrix proteins. Conclusions These data suggest that distinct biological processes may account for wasting in different skeletal muscles in response to the same tumour burden. Further investigation into these differences will be critical for the future development of effective clinical strategies to counter cancer cachexia.

Background Historically, a positive margin after pancreatectomy for pancreatic ductal adenocarcinoma (PDAC) was associated with decreased survival. In an era when neoadjuvant chemotherapy (NAC) is being used frequently, the prognostic significance of margin status is unclear. Study Design Patients with localized PDAC who received NAC and underwent pancreatectomy from 2011 to 2018 were identified from a single-institution database. Patients with fewer than 2 months of NAC, R2 resection, or fewer than 90 days of follow-up were excluded. A positive margin included tumors within 1 mm of the surgical margin. Results Four hundred and sixty-eight patients met inclusion criteria. Median age was 65 years and 53% were female. Preoperative clinical staging demonstrated that most had locally advanced (n = 222 [47%]) or borderline resectable (n = 172 [37%]) disease. Median follow-up was 18.5 months (interquartile range 10.6 to 30.0 months). Median duration of NAC was 119 days (interquartile range 87 to 168 days). FOLFIRINOX was first-line therapy for 67%, and 73% received neoadjuvant radiotherapy. Most underwent pancreaticoduodenectomy (69%). Forty percent were node-positive and 80% had an R0 resection. Fifty-six percent received at least 1 cycle of adjuvant therapy. Median overall survival and recurrence-free survival were 22.0 months (95% CI, 19.4 to 25.1 months) and 11.0 months (95% CI, 10.0 to 12.1 months). On multivariate analysis, margin status was not a significant predictor of overall survival or recurrence-free survival. Factors associated with overall survival included clinical stage, duration of NAC, nodal status, histopathologic treatment response score, and receipt of adjuvant chemotherapy. Conclusions Microscopic margin positivity is not associated with recurrence and survival in localized PDAC patients resected after treatment with NAC. Aggressive surgical extirpation in high-volume centers should be considered in selected patients after extensive NAC.