Loss of p27Kip¹ promotes metaplasia in the pancreas via the regulation of Sox9 expression

p27^Kip1 (p27) is a negative regulator of proliferation and a tumor suppressor via the inhibition of cyclin-CDK activity in the nucleus. p27 is also involved in the regulation of other cellular processes, including transcription by acting as a transcriptional co-repressor. Loss of p27 expression is frequently observed in pancreatic adenocarcinomas in human and is associated with decreased patient survival. Similarly, in a mouse model of K-Ras-driven pancreatic cancer, loss of p27 accelerates tumor development and shortens survival, suggesting an important role for p27 in pancreatic tumorigenesis. Here, we sought to determine how p27 might contribute to early events leading to tumor development in the pancreas. We found that K-Ras activation in the pancreas causes p27 mislocalization at pre-neoplastic stages. Moreover, loss of p27 or expression of a mutant p27 that does not bind cyclin-CDKs causes the mislocalization of several acinar polarity markers associated with metaplasia and induces the nuclear expression of Sox9 and Pdx1 two transcription factors involved in acinar-to-ductal metaplasia. Finally, we found that p27 directly represses transcription of Sox9, but not that of Pdx1. Thus, our results suggest that K-Ras activation, the earliest known event in pancreatic carcinogenesis, may cause loss of nuclear p27 expression which results in derepression of Sox9, triggering reprogrammation of acinar cells and metaplasia.

Colorectal Cancer Screening Navigation for the Underserved: Experience of an Urban Program

Colorectal cancer is the third leading cause of cancer deaths in the United States. Although colorectal cancer screenings are effective and recommended by all clinical practice guidelines, only 65.7% of adults ages 50 to 75 years are screened. Colorectal cancer screening is disproportionately underutilized in inner city populations. In 2011, the University of Pennsylvania Health System created a navigation program to specifically address poor colorectal cancer screening rates and increase access to colorectal cancer screening colonoscopies for patients in the underserved areas of West, South, and Southwest Philadelphia. We directed focus on issues surrounding barriers of screening so that we could best leverage our resources and impact the greatest number of patients. The program was designed to target patients who were either due for, never scheduled, or did not keep previously scheduled colorectal cancer screening colonoscopy appointments, or who were referred by providers concerned that the patients would not keep appointments or would misunderstand preprocedural guidelines. The program strives to improve colorectal health by providing free education and screening navigation through a navigator who assists patients from the first phone call to completion of the colonoscopy. This is accomplished by implementing an effective screening program while providing one-on-one service with a cost-effective navigator reaching out to patients who are nonadherent to colorectal cancer screening. Barriers included not having a companion to escort and transport the patient home from the procedure, poor awareness, fear of the procedure or sedation, limited funds to purchase preparation materials, inability to read or comprehend preparation instructions, and hardship in being contacted or scheduling appointments.

Effect of a Financial Incentive for Colorectal Cancer Screening Adherence on the Appropriateness of Colonoscopy Orders

Performance incentives for preventive care may encourage inappropriate testing, such as cancer screening for patients with short life expectancies. Defining screening colonoscopies for patients with a >50% 4-year mortality risk as inappropriate, the authors performed a pre-post analysis assessing the effect of introducing a cancer screening incentive on the proportion of screening colonoscopy orders that were inappropriate. Among 2078 orders placed by 23 attending physicians in 4 academic general internal medicine practices, only 0.6% (n = 6/1057) of screening colonoscopy orders in the preintervention period and 0.6% (n = 6/1021) of screening colonoscopy orders in the postintervention period were deemed "inappropriate." This study found no evidence that the incentive led to an increase in inappropriate screening colonoscopy orders.

K-Ras(V14I) -induced Noonan syndrome predisposes to tumour development in mice

The Noonan syndrome (NS) is an autosomal dominant genetic disorder characterized by short stature, craniofacial dysmorphism, and congenital heart defects. A significant proportion of NS patients may also develop myeloproliferative disorders (MPDs), including juvenile myelomonocytic leukaemia (JMML). Surprisingly, scarce information is available in relation to other tumour types in these patients. We have previously developed and characterized a knock-in mouse model that carries one of the most frequent KRAS-NS-related mutations, the K-Ras(V14I) substitution, which recapitulates most of the alterations described in NS patients, including MPDs. The K-Ras(V14I) mutation is a mild activating K-Ras protein; thus, we have used this model to study tumour susceptibility in comparison with mice expressing the classical K-Ras(G12V) oncogene. Interestingly, our studies have shown that these mice display a generalized tumour predisposition and not just MPDs. In fact, we have observed that the K-Ras(V14I) mutation is capable of cooperating with the p16Ink4a/p19Arf and Trp53 tumour suppressors, as well as with other risk factors such as pancreatitis, thereby leading to a higher cancer incidence. In conclusion, our results illustrate that the K-Ras(V14I) activating protein is able to induce cancer, although at a much lower level than the classical K-Ras(G12V) oncogene, and that it can be significantly modulated by both genetic and non-genetic events. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Use of Intensive Care Services for Medicare Beneficiaries Undergoing Major Surgical Procedures

BACKGROUND

Use of intensive care after major surgical procedures and whether routinely admitting patients to intensive care units (ICUs) improve outcomes or increase costs is unknown.

METHODS

The authors examined frequency of admission to an ICU during the hospital stay for Medicare beneficiaries undergoing selected major surgical procedures: elective endovascular abdominal aortic aneurysm (AAA) repair, cystectomy, pancreaticoduodenectomy, esophagectomy, and elective open AAA repair. The authors compared hospital mortality, length of stay, and Medicare payments for patients receiving each procedure in hospitals admitting patients to the ICU less than 50% of the time (low use), 50 to 89% (moderate use), and 90% or greater (high use), adjusting for patient and hospital factors.

RESULTS

The cohort ranged from 7,878 patients in 162 hospitals for esophagectomies to 69,989 patients in 866 hospitals for endovascular AAA. Overall admission to ICU ranged from 35.6% (endovascular AAA) to 71.3% (open AAA). Admission to ICU across hospitals ranged from less than 5% to 100% of patients for each surgical procedure. There was no association between hospital use of intensive care and mortality for any of the five surgical procedures. There was a consistent association between high use of intensive care with longer length of hospital stay and higher Medicare payments only for endovascular AAA.

CONCLUSIONS

There is little consensus regarding the need for intensive care for patients undergoing major surgical procedures and no relationship between a hospital's use of intensive care and hospital mortality. There is also no consistent relationship across surgical procedures between use of intensive care and either length of hospital stay or payments for care.

Extracorporeal shockwaves as regenerative therapy in orthopedic traumatology: a narrative review from basic research to clinical practice

Extracorporeal Shock Wave Therapy (ESWT), after its first medical application in the urological field for lithotripsy, nowadays represents a valid therapeutical tool also for many musculoskeletal diseases, as well as for regenerative medicine applications. This is possible thanks to its mechanisms of action, which in the non-urological field are not related to mechanical disruption (as for renal stones), but rather to the capacity, by mechanotransduction, to induce neoangiogenesis, osteogenesis and to improve local tissue trophism, regeneration and remodeling, through stem cell stimulation. On the basis of these biological assumptions, it becomes clear that ESWT can represent a valid therapeutic tool also for all those pathological conditions that derive from musculoskeletal trauma, and are characterized by tissue loss and/or delayed healing and regeneration (mainly bone and skin, but not only). As a safe, repeatable and non–invasive therapy, in many cases it can represent a first–line therapeutic option, as an alternative to surgery (for example, in bone and skin healing disorders), or in combination with some other treatment options. It is hoped that with its use in daily practice also the muscle–skeletal field will grow, not only for standard indications, but also in post–traumatic sequelae, in order to improve recovery and shorten healing time, with undoubted advantages for the patients and lower health service expenses.

The acinar regulator Gata6 suppresses KrasG12V-driven pancreatic tumorigenesis in mice

BACKGROUND AND AIMS

Gata6 is required to complete and maintain acinar differentiation in the mouse pancreas. Pancreas-specific Gata6 ablation during development causes extensive and persistent acinar-ductal metaplasia, which is considered an initial step of mutant KRas-driven carcinogenesis. Therefore, the Gata6-null pancreas might represent a tumour-prone environment. We investigated whether Gata6 plays a role during pancreatic tumorigenesis.

DESIGN

We analysed genetically engineered mouse models and human pancreatic ductal adenocarcinoma (PDAC) cell lines, using a combination of histopathological studies, genome-wide expression and chromatin immunoprecipitation experiments to understand the role of Gata6 in the initiation and progression of KRas(G12V)-driven tumours

RESULTS

We show that Gata6 maintains the acinar differentiation programme, both directly and indirectly, and it concomitantly suppresses ectopic programmes in the pancreas. Gata6 ablation renders acinar cells more sensitive to KRas(G12V), thereby accelerating tumour development. Gata6 expression is spontaneously lost in a mouse model of KRas(G12V)-driven PDAC, in association with altered cell differentiation. Using a combination of ChIP-Seq and RNA-Seq, we show that Gata6 exerts its tumour-suppressive effect through the promotion of cell differentiation, the suppression of inflammatory pathways, and the direct repression of cancer-related pathways. Among them is the epidermal growth factor receptor (EGFR) pathway, the activity of which is upregulated in the normal and preneoplastic Gata6-null pancreas. Accordingly, GATA6-silencing in human PDAC cells leads to an upregulation of EGFR.

CONCLUSIONS

We propose that, in the pancreas, Gata6 acts as a tumour suppressor by enforcing acinar cell differentiation, by directly and indirectly repressing ectopic differentiation programmes, and by regulating crucial cancer-related gene expression pathways.

Frailty Before Critical Illness and Mortality for Elderly Medicare Beneficiaries

OBJECTIVES

To estimate the effect of pre-intensive care unit (ICU) health categories on mortality during and after critical illness, focusing specifically on the effect of pre-ICU frailty on short- and long-term mortality.

DESIGN

Retrospective cohort study.

SETTING

Medicare claims data from 2004 to 2008.

PARTICIPANTS

A nationally representative sample of elderly Medicare beneficiaries admitted to an ICU in 2005.

MEASUREMENTS

Participants were classified into four pre-ICU health categories (robust, cancer, chronic organ failure, frailty) using claims data from the year before admission, allowing for assignment to multiple categories. The association between pre-ICU health category and hospital and 3-year mortality was assessed using multivariable logistic regression and Cox proportional hazards models.

RESULTS

Of 47,427 elderly individuals in the ICU, 18.8% were robust, 28.6% had cancer, 68.1% had chronic organ failure, and 34.0% were frail; 41.3% qualified for multiple categories. Overall hospital mortality was 12.6%, with the lowest mortality for robust participants (9.7%). Participants with pre-ICU frailty had higher hospital mortality than those with the same pre-ICU health categories without frailty. (Adjusted odds ratios ranged from 1.27 (95% confidence interval (CI) 1.10-1.47) to 1.52 (95% CI = 1.35-1.63).) Robust hospital survivors had the lowest 3-year mortality (24.6%). Pre-ICU frailty conferred higher 3-year mortality than pre-ICU categories without frailty. (Adjusted hazard ratios ranged from 1.54 (95% CI = 1.45-1.64) to 1.84 (95% CI = 1.70-1.99).)

CONCLUSION

Critically ill elderly adults can be categorized according to pre-ICU health categories. These categories, particularly pre-ICU frailty, may be important for understanding risk of death during and after critical illness.

Abstract A44: Targeting cancer-associated fibroblasts in pancreatic ductal adenocarcinoma: Identification and characterization of therapeutic candidates

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with an overall survival rate of less than 5%. One of the main reasons for the poor prognosis of PDAC is thought to be due to its abundant fibrotic stromal tissue, which may act as a barrier for drug delivery, thus resulting in inefficient therapeutic treatments. Moreover, it is believed that the interactions between tumor and stromal cells play a very important role in disease progression. In this complex tumor microenvironment, cancer associated fibroblasts (CAFs) are the most significant cell type responsible for the production of extracellular matrix proteins resulting in increased stiffness of the tumor. Therefore, targeting CAFs in PDAC represents a promising therapeutic approach. In order to find attractive candidates to target the stromal tissue, we have isolated CAFs from our K-Ras driven PDAC mouse model [K-Ras+/LSLG12V;p53lox/lox;Elas-tTA/TetO-Cre strain] by cell sorting taking advantage of the high levels of expression of the PGDF Receptor-Alpha in this cell type. Next, we performed gene expression profiling by RNA sequencing comparing isolated normal pancreatic fibroblasts and CAFs. In order to complete our findings and direct our attention to tumor stromal communication we have also sequenced the transcriptome of the correspondent tumoral cells. Differential expression analysis showed significant upregulation in CAFs of a variety of functionally cancer associated cellular processes such as extracellular matrix remodeling, growth factor induced tumor growth, invasion and metastatic dissemination. Moreover, we observed a strong pro-inflammatory gene signature as well as upregulated chemokine, cytokine and adipocytokine signaling and amyloidosis in CAFs compared to normal fibroblasts through complement and coagulation cascade activation. Regulation of the inflammatory response included hyperactivity of AP1/JNK, IL6, Toll-like Receptor and NFKB pathways. However, we detected downregulation of cell cycle components, metabolic pathways and a significant decrease in the expression of p53 pathway related genes, an observation that has been already reported in CAFs associated with other cancer types. Connecting pathway mapping by Gene Set Enrichment Analysis to a novel method for generation and integration of druggable genes by cell-drug interactions offered a pool of candidates for final selection of our therapeutic approach. To further investigate the molecular mechanisms that control the fibroinflammatory stroma in PDAC, we have validated this signature by qRT-PCR in a set of CAFs and tumor samples derived from our tumor model as well as from human patients. Functional validation in vitro and in vivo of candidate genes derived from this experimental approach should lead us to identify new therapeutic targets against this deadly disease by targeting tumor-stromal cell interactions.

Citation Format: Magdolna Djurec, Osvaldo Grana, David Pisano, Albert Lee, Raul Rabadan, Carmen Guerra, Mariano Barbacid. Targeting cancer-associated fibroblasts in pancreatic ductal adenocarcinoma: Identification and characterization of therapeutic candidates. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr A44.

The impact of the genetic background in the Noonan syndrome phenotype induced by K-Ras(V14I)

Noonan syndrome (NS) is an autosomal dominant genetic disorder characterized by short stature, craniofacial dysmorphism, and congenital heart defects. A significant fraction of NS-patients also develop myeloproliferative disorders. The penetrance of these defects varies considerably among patients. In this study, we have examined the effect of 2 genetic backgrounds (C57BL/6J.OlaHsd and 129S2/SvPasCrl) on the phenotypes displayed by a mouse model of NS induced by germline expression of the mutated K-Ras^V14I allele, one of the most frequent NS-KRAS mutations. Our results suggest the presence of genetic modifiers associated to the genetic background that are essential for heart development and function at early stages of postnatal life as well as in the severity of the haematopoietic alterations.

Nosocomial bloodstream infections in a nationwide study: comparison between solid organ transplant patients and the general population

BACKGROUND

The incidence of bloodstream infection (BSI) varies according to the transplanted organ. Mortality can be as high as 24%, with a significant impact on graft survival. Transplantation is a risk factor for multidrug-resistant (MDR) organisms, but comparison with a non-transplanted population in a single large cohort has not been described.

METHODS

This is a prospective nationwide study (16 centers) reporting data on 2364 monomicrobial nosocomial BSIs, comparing 83 episodes in solid organ transplant patients with 2447 BSIs occurring in the general hospital population.

RESULTS

The prevalence of groups of infecting organisms (gram-positive, gram-negative, and fungi) was similar between transplant patients and the general population and a similar crude mortality rate was observed (34.9% in transplant vs. 43.3% in non-transplant patients). Staphylococcus aureus was the single most frequently isolated organism in both groups, and Acinetobacter species was more frequently isolated in the general population. Regarding MDR organisms, Klebsiella species, and Enterobacter species resistant to cefepime, as well as Acinetobacter species resistant to meropenem, were significantly more frequent in transplant patients.

CONCLUSION

Antimicrobial resistance is higher, particularly among gram-negative bacteria in the transplant population, although the overall mortality rate between transplant and non-transplant patients with nosocomial BSI is similar.

Utilizing past and present mouse systems to engineer more relevant pancreatic cancer models

The study of pancreatic cancer has prompted the development of numerous mouse models that aim to recapitulate the phenotypic and mechanistic features of this deadly malignancy. This review accomplishes two tasks. First, it provides an overview of the models that have been used as representations of both the neoplastic and carcinoma phenotypes. Second, it presents new modeling schemes that ultimately will serve to more faithfully capture the temporal and spatial progression of the human disease, providing platforms for improved understanding of the role of non-epithelial compartments in disease etiology as well as evaluating therapeutic approaches.

Nicotine promotes initiation and progression of KRAS-induced pancreatic cancer via Gata6-dependent dedifferentiation of acinar cells in mice

BACKGROUND & AIMS

Although smoking is a leading risk factor for pancreatic ductal adenocarcinoma (PDAC), little is known about the mechanisms by which smoking promotes initiation or progression of PDAC.

METHODS

We studied the effects of nicotine administration on pancreatic cancer development in Kras(+/LSLG12Vgeo);Elas-tTA/tetO-Cre (Ela-KRAS) mice, Kras(+/LSLG12D);Trp53+/LSLR172H;Pdx-1-Cre (KPC) mice (which express constitutively active forms of KRAS), and C57/B6 mice. Mice were given nicotine for up to 86 weeks to produce blood levels comparable with those of intermediate smokers. Pancreatic tissues were collected and analyzed by immunohistochemistry and reverse transcriptase polymerase chain reaction; cells were isolated and assayed for colony and sphere formation and gene expression. The effects of nicotine were also evaluated in primary pancreatic acinar cells isolated from wild-type, nAChR7a(-/-), Trp53(-/-), and Gata6(-/-);Trp53(-/-) mice. We also analyzed primary PDAC cells that overexpressed GATA6 from lentiviral expression vectors.

RESULTS

Administration of nicotine accelerated transformation of pancreatic cells and tumor formation in Ela-KRAS and KPC mice. Nicotine induced dedifferentiation of acinar cells by activating AKT-ERK-MYC signaling; this led to inhibition of Gata6 promoter activity, loss of GATA6 protein, and subsequent loss of acinar differentiation and hyperactivation of oncogenic KRAS. Nicotine also promoted aggressiveness of established tumors as well as the epithelial-mesenchymal transition, increasing numbers of circulating cancer cells and their dissemination to the liver, compared with mice not exposed to nicotine. Nicotine induced pancreatic cells to acquire gene expression patterns and functional characteristics of cancer stem cells. These effects were markedly attenuated in K-Ras(+/LSL-G12D);Trp53(+/LSLR172H);Pdx-1-Cre mice given metformin. Metformin prevented nicotine-induced pancreatic carcinogenesis and tumor growth by up-regulating GATA6 and promoting differentiation toward an acinar cell program.

CONCLUSIONS

In mice, nicotine promotes pancreatic carcinogenesis and tumor development via down-regulation of Gata6 to induce acinar cell dedifferentiation.

Parp-1 genetic ablation in Ela-myc mice unveils novel roles for Parp-1 in pancreatic cancer

Pancreatic cancer has a dismal prognosis and is currently the fourth leading cause of cancer-related death in developed countries. The inhibition of poly(ADP-ribose) polymerase-1 (Parp-1), the major protein responsible for poly(ADP-ribosy)lation in response to DNA damage, has emerged as a promising treatment for several tumour types. Here we aimed to elucidate the involvement of Parp-1 in pancreatic tumour progression. We assessed Parp-1 protein expression in normal, preneoplastic and pancreatic tumour samples from humans and from K-Ras- and c-myc-driven mouse models of pancreatic cancer. Parp-1 was highly expressed in acinar cells in normal and cancer tissues. In contrast, ductal cells expressed very low or undetectable levels of this protein, both in a normal and in a tumour context. The Parp-1 expression pattern was similar in human and mouse samples, thereby validating the use of animal models for further studies. To determine the in vivo effects of Parp-1 depletion on pancreatic cancer progression, Ela-myc-driven pancreatic tumour development was analysed in a Parp-1 knock-out background. Loss of Parp-1 resulted in increased tumour necrosis and decreased proliferation, apoptosis and angiogenesis. Interestingly, Ela-myc:Parp-1(-/-) mice displayed fewer ductal tumours than their Ela-myc:Parp-1(+/+) counterparts, suggesting that Parp-1 participates in promoting acinar-to-ductal metaplasia, a key event in pancreatic cancer initiation. Moreover, impaired macrophage recruitment can be responsible for the ADM blockade found in the Ela-myc:Parp-1(-/-) mice. Finally, molecular analysis revealed that Parp-1 modulates ADM downstream of the Stat3-MMP7 axis and is also involved in transcriptional up-regulation of the MDM2, VEGFR1 and MMP28 cancer-related genes. In conclusion, the expression pattern of Parp-1 in normal and cancer tissue and the in vivo functional effects of Parp-1 depletion point to a novel role for this protein in pancreatic carcinogenesis and shed light into the clinical use of Parp-1 inhibitors.

Galectin-1 drives pancreatic carcinogenesis through stroma remodeling and Hedgehog signaling activation

Despite some advances, pancreatic ductal adenocarcinoma (PDAC) remains generally refractory to current treatments. Desmoplastic stroma, a consistent hallmark of PDAC, has emerged as a major source of therapeutic resistance and thus potentially promising targets for improved treatment. The glycan-binding protein galectin-1 (Gal1) is highly expressed in PDAC stroma, but its roles there have not been studied. Here we report functions and molecular pathways of Gal1 that mediate its oncogenic properties in this setting. Genetic ablation of Gal1 in a mouse model of PDAC (EIa-myc mice) dampened tumor progression by inhibiting proliferation, angiogenesis, desmoplasic reaction and by stimulating a tumor-associated immune response, yielding a 20% increase in relative lifesplan. Cellular analyses in vitro and in vivo suggested these effects were mediated through the tumor microenvironment. Importantly, acinar-to-ductal metaplasia, a crucial step for initiation of PDAC, was found to be regulated by Gal1. Mechanistic investigations revealed that Gal1 promoted Hedgehog pathway signaling in PDAC cells and stromal fibroblasts as well as in Ela-myc tumors. Taken together, our findings establish a function for Gal1 in tumor-stroma crosstalk in PDAC and provide a preclinical rationale for Gal1 targeting as a microenvironment-based therapeutic strategy.

Improving utilization of patient portals through a multifaceted intervention strategy

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Background: Healthcare’s paradigm shift is in full swing. Electronic medical record (EMR) systems are up and running across the country, creating the potential for a more interactive environment for patients. With Stage 2 of the Affordable Care Act’s Meaningful Use requirements approaching in 2014, health systems are being challenged to determine how to effectively engage with patients electronically. MyPennMedicine is the portal used at the Abramson Cancer Center, and its use has been incredibly low since its introduction in 2009. Methods: Our assessment focused on patient portal account activations, messaging volume, and follow-through. Baseline measurements of these variables were abysmal. We convened an inter-disciplinary team of stakeholders (including patients, physicians, nurses, IT, front desk, and marketing) to understand current barriers to portal use, and to develop innovative methods aimed at improving use of the tool. Our team cultivated a strategy that included system upgrades based on end-user feedback, provider education about the benefits of the portal, patient demonstrations, and improving the ease of patient sign-ups. Results: At baseline (February, 2013), we determined that only 13% (18/139) of patients who had been assigned a code to access the patient portal actually did so. Our response to patient requests via the portal was only 58% (216/374). Moreover, the average time it took providers and staff to complete patient requests was 17.1 hours. After our first round of interventions (May, 2013), the rate of account activation increased to 45% (110/244) and our response to patient requests increased to 73% (331/455). The average time to complete the requests actually increased to 21.3 hours perhaps as a result of the increased volume. Conclusions: EMRs will continue to change the way we engage with patients. The clinical significance of our increase in patient portal usage is yet to be fully appreciated. Our initial interventions have resulted in significant increases patient awareness and utilization as well as improved follow-through by clinicians and staff. Future directions include additional interventions focused on technological improvements and continued education and clinician support.