Stromal disrupting effects of nab-paclitaxel in pancreatic cancer

Background:

Nab-paclitaxel and gemcitabine have demonstrated a survival benefit over gemcitabine alone in advanced pancreatic cancer (PDA). This study aimed to investigate the clinical, biological, and imaging effects of the regimen in patients with operable PDA.

Methods:

Patients with operable PDA received two cycles of nab-paclitaxel and gemcitabine before surgical resection. FDG-PET and CA19.9 tumour marker levels were used to measure clinical activity. Effects on tumour stroma were determined by endoscopic ultrasound (EUS) elastography. The collagen content and architecture as well as density of cancer-associated fibroblasts (CAFs) were determined in the resected surgical specimen and compared with a group of untreated and treated with conventional chemoradiation therapy controls. A co-clinical study in a mouse model of PDA was conducted to differentiate between the effects of nab-paclitaxel and gemcitabine.

Results:

A total of 16 patients were enrolled. Treatment resulted in significant antitumour effects with 50% of patients achieving a >75% decrease in circulating CA19.9 tumour marker and a response by FDG-PET. There was also a significant decrement in tumour stiffness as measured by EUS elastography. Seven of 12 patients who completed treatment and were operated had major pathological regressions. Analysis of residual tumours showed a marked disorganised collagen with a very low density of CAF, which was not observed in the untreated or conventionally treated control groups. The preclinical co-clinical study showed that these effects were specific of nab-paclitaxel and not gemcitabine.

Conclusion:

These data suggest that nab-paclitaxel and gemcitabine decreases CAF content inducing a marked alteration in cancer stroma that results in tumour softening. This regimen should be studied in patients with operable PDA.

Association between age and use of intensive care among surgical Medicare beneficiaries

PURPOSE

The purpose of this study is to determine the role age plays in use of intensive care for patients who have major surgery.

MATERIALS AND METHODS

Retrospective cohort study examining the association between age and admission to an intensive care unit (ICU) for all Medicare beneficiaries 65 years or older who had a hospitalization for 1 of 5 surgical procedures: esophagectomy, cystectomy, pancreaticoduodenectomy, elective open abdominal aortic aneurysm repair (open AAA), and elective endovascular abdominal aortic aneurysm repair (endo AAA) from 2004 to 2008. The primary outcome was admission to an ICU. Secondary outcomes were complications and hospital mortality. We used multilevel mixed-effects logistic regression to adjust for other patient and hospital-level factors associated with each outcome.

RESULTS

The percentage of hospitalized patients admitted to ICU ranged from 41.3% for endo AAA to 81.5% for open AAA. In-hospital mortality also varied, from 1.1% for endo AAA to 6.8% for esophagectomy. After adjusting for other factors, age was associated with admission to ICU for cystectomy (adjusted odds ratio [AOR], 1.56 [95% confidence interval, 1.36-1.78] for age 80-84+ years; 2.25 [1.85-2.75] for age 85+ years compared with age 65-69 years), pancreaticoduodenectomy (AOR, 1.26 [1.06-1.50] for age 80-84 years; 1.49 [1.11-1.99] for age 85+ years), and esophagectomy (AOR, 1.26 [1.02-1.55] for age 80-84 years; 1.28 [0.91-1.80] age 85+ years). Age was not associated with use of intensive care for open AAA or endo AAA. Older age was associated with increases in complication rates and in-hospital mortality for all 5 surgical procedures.

CONCLUSIONS

The association between age and use of intensive care was procedure specific. Complication rates and in-hospital mortality increased with age for all 5 surgical procedures.

Genetically engineered mouse models of pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of human cancer for which there are no effective therapies. Deep sequencing of PDAC tumors has revealed the presence of a high number of mutations (>50) that affect at least a dozen key signaling pathways. This scenario highlights the urgent need to develop experimental models that faithfully reproduce the natural history of these human tumors in order to understand their biology and to design therapeutic approaches that might effectively interfere with their multiple mutated pathways. Over the last decade, several models, primarily based on the genetic activation of resident KRas oncogenes knocked-in within the endogenous KRas locus have been generated. These models faithfully reproduce the histological lesions that characterize human pancreatic tumors. Decoration of these models with additional mutations, primarily involving tumor suppressor loci known to be also mutated in human PDAC tumors, results in accelerated tumor progression and in the induction of invasive and metastatic malignancies. Mouse PDACs also display a desmoplastic stroma and inflammatory responses that closely resemble those observed in human patients. Interestingly, adult mice appear to be resistant to PDAC development unless the animals undergo pancreatic damage, mainly in the form of acute, chronic or even temporary pancreatitis. In this review, we describe the most representative models available to date and how their detailed characterization is allowing us to understand their cellular origin as well as the events involved in tumor progression. Moreover, their molecular dissection is starting to unveil novel therapeutic strategies that could be translated to the clinic in the very near future.

Risk factors for dementia after critical illness in elderly Medicare beneficiaries

Introduction

Hospitalization increases the risk of a subsequent diagnosis of dementia. We aimed to identify diagnoses or events during a hospitalization requiring critical care that are associated with a subsequent dementia diagnosis in the elderly.

Methods

A cohort study of a random 5% sample of Medicare beneficiaries who received intensive care in 2005 and survived to hospital discharge, with three years of follow-up (through 2008) was conducted using Medicare claims files. We defined dementia using the International Classification of Diseases, 9th edition, clinical modification (ICD-9-CM) codes and excluded patients with any prior diagnosis of dementia or cognitive impairment in the year prior to admission. We used an extended Cox model to examine the association between diagnoses and events associated with the critical illness and a subsequent diagnosis of dementia, adjusting for known risk factors for dementia.

Results

Over the three years of follow-up, dementia was newly diagnosed in 4,519 (17.8%) of 25,368 patients who received intensive care and survived to hospital discharge. After accounting for known risk factors, having an infection (adjusted hazard ratio (AHR) = 1.25; 95% CI, 1.17 to 1.35), or a diagnosis of severe sepsis (AHR = 1.40; 95% CI, 1.28 to 1.53), acute neurologic dysfunction (AHR = 2.06; 95% CI, 1.72 to 2.46), and acute dialysis (AHR = 1.70; 95% CI, 1.30 to 2.23) were all independently associated with a subsequent diagnosis of dementia. No other measured ICU factors, such as need for mechanical ventilation, were independently associated.

Conclusions

Among ICU events, infection or severe sepsis, neurologic dysfunction, and acute dialysis were independently associated with a subsequent diagnosis of dementia. Patient prognostication, as well as future research into post-ICU cognitive decline, should focus on these higher-risk subgroups.

EGF receptor signaling is essential for k-ras oncogene-driven pancreatic ductal adenocarcinoma

Clinical evidence indicates that mutation/activation of EGF receptors (EGFRs) is mutually exclusive with the presence of K-RAS oncogenes in lung and colon tumors. We have validated these observations using genetically engineered mouse models. However, development of pancreatic ductal adenocarcinomas driven by K-Ras oncogenes are totally dependent on EGFR signaling. Similar results were obtained using human pancreatic tumor cell lines. EGFRs were also essential even in the context of pancreatic injury and absence of p16Ink4a/p19Arf. Only loss of p53 made pancreatic tumors independent of EGFR signaling. Additional inhibition of PI3K and STAT3 effectively prevented proliferation of explants derived from these p53-defective pancreatic tumors. These findings may provide the bases for more rational approaches to treat pancreatic tumors in the clinic.

Control of Mycobacterium tuberculosis growth by activated natural killer cells

We characterized the underlying mechanisms by which glutathione (GSH)-enhanced natural killer (NK) cells inhibit the growth of Mycobacterium tuberculosis (M. tb) inside human monocytes. We observed that in healthy individuals, treatment of NK cells with N-acetyl cysteine (NAC), a GSH prodrug in conjunction with cytokines such as interleukin (IL)-2 + IL-12, resulted in enhanced expression of NK cytotoxic ligands (FasL and CD40L) with concomitant stasis in the intracellular growth of M. tb. Neutralization of FasL and CD40L in IL-2 + IL-12 + NAC-treated NK cells resulted in abrogation in the growth inhibition of M. tb inside monocytes. Importantly, we observed that the levels of GSH are decreased significantly in NK cells derived from individuals with HIV infection compared to healthy subjects, and this decrease correlated with a several-fold increase in the growth of M. tb inside monocytes. This study describes a novel innate defence mechanism adopted by NK cells to control M. tb infection.

Efficient identification and referral of low-income women at high risk for hereditary breast cancer: a practice-based approach

BACKGROUND

Identification of low-income women with the rare but serious risk of hereditary cancer and their referral to appropriate services presents an important public health challenge. We report the results of formative research to reach thousands of women for efficient identification of those at high risk and expedient access to free genetic services. External validity is maximized by emphasizing intervention fit with the two end-user organizations who must connect to make this possible. This study phase informed the design of a subsequent randomized controlled trial.

METHODS

We conducted a randomized controlled pilot study (n = 38) to compare two intervention models for feasibility and impact. The main outcome was receipt of genetic counseling during a two-month intervention period. Model 1 was based on the usual outcall protocol of an academic hospital genetic risk program, and Model 2 drew on the screening and referral procedures of a statewide toll-free phone line through which large numbers of high-risk women can be identified. In Model 1, the risk program proactively calls patients to schedule genetic counseling; for Model 2, women are notified of their eligibility for counseling and make the call themselves. We also developed and pretested a family history screener for administration by phone to identify women appropriate for genetic counseling.

RESULTS

There was no statistically significant difference in receipt of genetic counseling between women randomized to Model 1 (3/18) compared with Model 2 (3/20) during the intervention period. However, when unresponsive women in Model 2 were called after 2 months, 7 more obtained counseling; 4 women from Model 1 were also counseled after the intervention. Thus, the intervention model that closely aligned with the risk program's outcall to high-risk women was found to be feasible and brought more low-income women to free genetic counseling. Our screener was easy to administer by phone and appeared to identify high-risk callers effectively. The model and screener are now in use in the main trial to test the effectiveness of this screening and referral intervention. A validation analysis of the screener is also underway.

CONCLUSION

Identification of intervention strategies and tools, and their systematic comparison for impact and efficiency in the context where they will ultimately be used are critical elements of practice-based research.

Health literacy and breast cancer screening among Mexican American women in South Texas

Breast cancer is the main cause of cancer deaths for Hispanic women. This study analyzes the role of functional health literacy on mammography screening behavior and adherence of Hispanic women. Survey data from 722 Mexican American women age 40 and over residing in the Lower Rio Grande Valley of Texas in 2008 were used to estimate logistic regression models to assess the role of functional health literacy on mammography screening behavior and adherence. About 51% of survey respondents had a functional health literacy level deemed as inadequate or marginally functional. After adjusting for other factors, women with adequate health literacy levels were more likely to report to have ever had a mammogram (odds ratio [OR] = 2.92; 95% confidence interval [CI] = 1.62-5.28), to have had a mammogram within the last 2 years (OR = 1.70; 95% CI = 1.14-2.53) or to have had one within the last year (OR = 2.30; 95% CI = 1.54-3.43), compared to women with inadequate or marginally adequate functional health literacy levels. Inadequate/marginal functional health literacy is strongly associated with lower mammography screening. Large improvements in breast cancer control in this population may come from either basic advances in health literacy or by tailored approaches to help women with low literacy navigate local health care systems.

Pancreatitis-induced inflammation contributes to pancreatic cancer by inhibiting oncogene-induced senescence

Pancreatic acinar cells of adult mice (≥P60) are resistant to transformation by some of the most robust oncogenic insults including expression of K-Ras oncogenes and loss of p16Ink4a/p19Arf or Trp53 tumor suppressors. Yet, these acinar cells yield pancreatic intraepithelial neoplasias (mPanIN) and ductal adenocarcinomas (mPDAC) if exposed to limited bouts of non-acute pancreatitis, providing they harbor K-Ras oncogenes. Pancreatitis contributes to tumor progression by abrogating the senescence barrier characteristic of low-grade mPanINs. Attenuation of pancreatitis-induced inflammation also accelerates tissue repair and thwarts mPanIN expansion. Patients with chronic pancreatitis display senescent PanINs, providing they have received antiinflammatory drugs. These results support the concept that antiinflammatory treatment of people diagnosed with pancreatitis may reduce their risk of developing PDAC.

Delirium and parkinsonic syndrome in elderly

Delirium is an acute or subacute syndrome characterized by a fluctuating global disorder of cognition, impairment of attention and awareness, disorganization of thought and speech, perceptual disturbances, hallucinations, as well as hypo or hyperactivity.

We present a case report of a 76-year-old woman who developed disorientation, lack of familiar recognition and functional impairment, three days before admission. She was admitted to a Medicine Department and submitted to several laboratory and imaging studies.

During this period she presented attention, consciousness fluctuations and agitation that required several treatments, including neuroleptics. Like these symptoms were linked to an important life even that triggered reactive depression, she was transferred to a psychiatric ward. Progressively her clinical state worsened, she became permanently bedridden and was observed by Neurology. She presented moderate to severe parkinsonian signs, namely akinesia and rigidity, predominantly on her left side. Reviewing her clinical past, she had suffered these symptoms during the two years before this episode (apathy, small stepped gait, flexed posture, and left hand rest tremor). Treatment with antiparkinsonic drugs produced a dramatic improvement in the patient’s mental and physical status. A I-Ioflupane-SPECT (DaTscan) confirmed striatal presynaptic dopaminergic degeneration, more on the right side, which was the proof of the presence of a degenerative parkinsonian syndrome.

The present clinical case shows Delirium with degenerative Parkinsonism comorbidity, worsened by the use of neuroleptics. We emphasize the importance previously undiagnosed Parkinsonism in old age which is highlighted by usefulness of dopamine transporter imaging in this scenery.

Upregulation of miR-21 by Ras in vivo and its role in tumor growth

miR-21 is a microRNA (miRNA) frequently overexpressed in human cancers. Here we show that miR-21 is upregulated both in vitro and in vivo by oncogenic Ras, thus linking this miRNA to one of the most frequently activated oncogenes in human cancers. Ras regulation of miR-21 occurs with a delayed kinetic and requires at least two Ras downstream pathways. A screen of human thyroid cancers and non-small-cell lung cancers for the expression of miR-21 reveals that it is overexpressed mainly in anaplastic thyroid carcinomas, the most aggressive form of thyroid cancer, whereas in lung its overexpression appears to be inversely correlated with tumor progression. We also show that a LNA directed against miR-21 slows down tumor growth in mice. Consistently, a search for mRNAs downregulated by miR-21 shows an enrichment for mRNAs encoding cell cycle checkpoints regulators, suggesting an important role for miR-21 in oncogenic Ras-induced cell proliferation.

Midrapidity antiproton-to-proton ratio in pp collisons at sqrt[s]=0.9 and 7 TeV measured by the ALICE experiment

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45<p_{t}<1.05  GeV/c and rapidity |y|<0.5. The ratio is measured to be R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst) at 0.9 TeV and R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.

A synthetic lethal interaction between K-Ras oncogenes and Cdk4 unveils a therapeutic strategy for non-small cell lung carcinoma

We have unveiled a synthetic lethal interaction between K-Ras oncogenes and Cdk4 in a mouse tumor model that closely recapitulates human non-small cell lung carcinoma (NSCLC). Ablation of Cdk4, but not Cdk2 or Cdk6, induces an immediate senescence response only in lung cells that express an endogenous K-Ras oncogene. No such response occurs in lungs expressing a single Cdk4 allele or in other K-Ras-expressing tissues. More importantly, targeting Cdk4 alleles in advanced tumors detectable by computed tomography scanning also induces senescence and prevents tumor progression. These observations suggest that robust and selective pharmacological inhibition of Cdk4 may provide therapeutic benefit for NSCLC patients carrying K-RAS oncogenes.

DYRK1B-dependent autocrine-to-paracrine shift of Hedgehog signaling by mutant RAS

Synergism between the RAS and Hedgehog (HH) pathways has been suggested for carcinogenesis in the pancreas, lung and colon. We investigated the molecular cross-talk between RAS and HH signaling and found that, although mutant RAS induces or enhances SHH expression and favors paracrine HH signaling, it antagonizes autocrine HH signal transduction. Activated RAS can be found in primary cilia, the central organelle of HH signal transduction, but functions in a cilium-independent manner and interferes with Gli2 function and Gli3 processing. In addition, the cell-autonomous negative regulation of HH signal transduction involves the RAS effector molecule dual specificity tyrosine phosphorylated and regulated kinase 1B (DYRK1B). In line with a redirection of autocrine toward paracrine HH signaling by a KRAS-DYRK1B network, we find high levels of GLI1 expression restricted to the stromal compartment and not to SHH-expressing tumor cells in human pancreatic adenocarcinoma.

Proceedings from the 2009 genetic syndromes of the Ras/MAPK pathway: From bedside to bench and back

The RASopathies are a group of genetic syndromes caused by germline mutations in genes that encode components of the Ras/mitogen-activated protein kinase (MAPK) pathway. Some of these syndromes are neurofibromatosis type 1, Noonan syndrome, Costello syndrome, cardio-facio-cutaneous syndrome, LEOPARD syndrome and Legius syndrome. Their common underlying pathogenetic mechanism brings about significant overlap in phenotypic features and includes craniofacial dysmorphology, cardiac, cutaneous, musculoskeletal, GI and ocular abnormalities, and a predisposition to cancer. The proceedings from the symposium "Genetic Syndromes of the Ras/MAPK Pathway: From Bedside to Bench and Back" chronicle the timely and typical research symposium which brought together clinicians, basic scientists, physician-scientists, advocate leaders, trainees, students and individuals with Ras syndromes and their families. The goals, to discuss basic science and clinical issues, to set forth a solid framework for future research, to direct translational applications towards therapy and to set forth best practices for individuals with RASopathies were successfully meet with a commitment to begin to move towards clinical trials.