Refine
Year of publication
Document Type
- Article (39)
Language
- English (39)
Has Fulltext
- yes (39)
Is part of the Bibliography
- no (39)
Keywords
- - (23)
- Pancreatic cancer (4)
- acute pancreatitis (4)
- pancreatic ductal adenocarcinoma (4)
- Acute pancreatitis (2)
- DNA repair (2)
- IPMN (2)
- Intraductal papillary mucinous neoplasm (2)
- PDAC (2)
- bile acids (2)
Institute
- Kliniken und Polikliniken für Innere Medizin (22)
- Klinik und Poliklinik für Innere Medizin Abt. Gastroenterologie, Endokrinologie und Ernährungsmedizin (8)
- Universitätsmedizin (2)
- Institut für Biochemie (1)
- Institut für Ethik und Geschichte der Medizin (1)
- Institut für Med. Biochemie u. Molekularbiologie (1)
- Institut für Pathologie (1)
- Klinik für Herz-, Thorax- und Gefäßchirurgie - Klinikum Karlsburg (1)
- Klinik für Psychiatrie und Psychotherapie (1)
- Mathematisch-Naturwissenschaftliche Fakultät (1)
Publisher
- MDPI (12)
- S. Karger AG (9)
- Frontiers Media S.A. (4)
- Wiley (4)
- Nature Publishing Group (3)
- BMJ Publishing Group (1)
- BioMed Central (BMC) (1)
- Elsevier (1)
- Public Library of Science (PLoS) (1)
- Thieme (1)
Abstract
Introduction
Transabdominal ultrasound (US) and magnetic resonance imaging (MRI) are commonly used for the examination of the pancreas in clinical routine. We therefore were interested in the concordance of these two imaging methods for the size measurement of the pancreas and how age, gender, and body mass index (BMI) affect the organ size.
Methods
A total of 342 participants from the Study of Health in Pomerania underwent whole‐body MRI and transabdominal US on the same day, and the diameter of the pancreatic head, body, and tail were measured. The agreement between US and MRI measurements was assessed by Bland and Altman plots. Intraclass correlation coefficients were used to compare observers. A multivariable regression model was applied using the independent variables age, gender, and body mass index.
Results
Compared to MRI, abdominal US returned smaller values for each segment of the pancreas, with a high level of inconsistency between these two methods. The mean difference was 0.39, 0.18, and 0.54 cm for the head, body, and tail, respectively. A high interobserver variability was detected for US. Multivariable analysis showed that pancreatic size in all three segments increased with BMI in both genders whereas pancreatic head and tail size decreased with age, an effect more marked in women.
Conclusions
Agreement of pancreatic size measurements is poor between US and MRI. These limitations should be considered when evaluating morphologic features for pathologic conditions or setting limits of normal size. Adjustments for BMI, gender, and age may also be warranted.
Simple Summary
Recent clinical trials suggest that combination therapies that include either gemcitabine or 5-fluorouracil (5-FU) both give significant survival benefits for pancreatic cancer patients. The tumor level of the nucleoside transporter hENT1 is prognostic in patients treated with adjuvant gemcitabine but not adjuvant 5-FU. This work shows for the first time that hENT1 is only predictive of benefit from gemcitabine over 5-FU in patients with low levels of CDA transcript. A choice between adjuvant 5-FU based combination therapies (such as FOLFIRINOX) and gemcitabine-based therapy (e.g., GemCap) could be made based on a combination of hENT1 protein and CDA mRNA measured in a resected tumor.
Abstract
Gemcitabine or 5-fluorouracil (5-FU) based treatments can be selected for pancreatic cancer. Equilibrative nucleoside transporter 1 (hENT1) predicts adjuvant gemcitabine treatment benefit over 5-FU. Cytidine deaminase (CDA), inside or outside of the cancer cell, will deaminate gemcitabine, altering transporter affinity. ESPAC-3(v2) was a pancreatic cancer trial comparing adjuvant gemcitabine and 5-FU. Tissue microarray sections underwent in situ hybridization and immunohistochemistry. Analysis of both CDA and hENT1 was possible with 277 patients. The transcript did not correlate with protein levels for either marker. High hENT1 protein was prognostic with gemcitabine; median overall survival was 26.0 v 16.8 months (p = 0.006). Low CDA transcript was prognostic regardless of arm; 24.8 v 21.2 months with gemcitabine (p = 0.02) and 26.4 v 14.6 months with 5-FU (p = 0.02). Patients with low hENT1 protein did better with 5-FU, but only if the CDA transcript was low (median survival of 5-FU v gemcitabine; 29.3 v 18.3 months, compared with 14.2 v 14.6 with high CDA). CDA mRNA is an independent prognostic biomarker. When added to hENT1 protein status, it may also provide treatment-specific predictive information and, within the frame of a personalized treatment strategy, guide to either gemcitabine or 5FU for the individual patient.
One of the most common mutations in the serine protease inhibitor Kazal type 1 (SPINK1) gene is the N34S variant which is strongly associated with chronic pancreatitis. Although it is assumed that N34S mutation constitutes a high-risk factor, the underlying pathologic mechanism is still unknown. In the present study, we investigated the impact of physiological stress factors on SPINK1 protein structure and trypsin inhibitor function using biophysical methods. Our circular dichroism spectroscopy data revealed differences in the secondary structure of SPINK1 and N34S mutant suggesting protein structural changes induced by the mutation as an impairment that could be disease-relevant. We further confirmed that both SPINK1 (KD of 0.15 ± 0.06 nM) and its N34S variant (KD of 0.08 ± 0.02 nM) have similar binding affinity and inhibitory effect towards trypsin as shown by surface plasmon resonance and trypsin inhibition assay studies, respectively. We found that stress conditions such as altered ion concentrations (i.e. potassium, calcium), temperature shifts, as well as environmental pH lead to insignificant differences in trypsin inhibition between SPINK1 and N34S mutant. However, we have shown that the environmental pH induces structural changes in both SPINK1 constructs in a different manner. Our findings suggest protein structural changes in the N34S variant as an impairment of SPINK1 and environmental pH shift as a trigger that could play a role in disease progression of pancreatitis.
The Clinical and Socio-Economic Relevance of Increased IPMN Detection Rates and Management Choices
(2015)
Background: Increased usage of computed tomography and magnetic resonance imaging has led to a large increase in identified pancreatic cysts of up to 25% in population-based studies. The clinical and economic relevance of identifying so many cystic lesions has not been established. Compared to other organs such as liver or kidney, dysontogenetic pancreatic cysts are rare. Pancreatic cysts comprise a variety of benign, premalignant or malignant lesions; however, precise diagnosis before resection has an accuracy of only 80%. The focus of recent research was the malignant potential of intraductal papillary mucinous neoplasms (IPMN) with the aim of establishing clinical pathways addressing risk of malignancy, age and comorbidity, treatment-related morbidity and mortality as well as cost-effectiveness of treatment and surveillance. The focus of this review is to analyze the clinical and socio-economic relevance as well as the cost-benefit relation for IPMNs. Methods: For analysis, the following MESH terms were used to identify original articles, reviews, and guidelines in PubMed: (‘intraductal papillary mucinous neoplasm' OR ‘pancreatic cysts') and (incidence OR relevance OR socio-economic OR economic OR cost-effectiveness OR cost-benefit). The retrieved publications were reviewed with a focus on clinical and socio-economic relevance in relation to the increasing incidence of IPMN. Results: Addressing the increasing prevalence of pancreatic cystic lesions, recent consensus guidelines suggested criteria for risk stratification according to ‘worrisome features' and ‘high-risk stigmata'. Recent prospective cohort studies evaluated whether these can be applied in clinical practice. Evaluation of three different clinical scenarios with regard to costs and quality-adjusted life years suggested a better effectiveness of surveillance after initial risk stratification by endoscopic ultrasound-guided fine-needle aspiration with cyst fluid analysis compared with immediate resection or follow-up without further intervention. Of interest, the ‘immediate surgery' strategy was lowest for cost-effectiveness. Conclusions: The increasing incidence of identified pancreatic cysts requires an improved strategy for non-invasive risk stratification based on advanced imaging strategies. In light of a malignancy risk of 2% for branch-duct IPMN, the socio-economic necessity of a balance between surveillance and resection has to be agreed on.
Background/Aims: Acute pancreatitis (AP) is characterized by premature zymogen activation, systemic inflammatory response resulting in inflammatory infiltrates, sustained intracellular calcium, neurogenic inflammation and pain. The inhibitory neurotransmitter and cytoprotective amino acid glycine exerts a direct inhibitory effect on inflammatory cells, inhibits calcium influx and neuronal activation and therefore represents a putative therapeutic agent in AP. Methods: To explore the impact of glycine, mild AP was induced in rats by supramaximal cerulein stimulation (10 µg/kg BW/h) and severe AP by retrograde injection of sodium taurocholate solution (3%) into the common biliopancreatic duct. 100/300 mmol glycine was administered intravenously before induction of AP. To elucidate the effect of glycine on AP, we determined pathomorphology, pancreatic cytokines as well as proteases, serum lipase and amylase, pancreatic and lung MPO activity and pain sensation. Results: Glycine administration resulted in a noticeable improvement of pathomorphological alterations in AP, such as a reduction of necrosis, inflammatory infiltrates and cytoplasmic vacuoles in cerulein pancreatitis. In taurocholate pancreatitis, glycine additionally diminished pancreatic cytokines and MPO activity, as well as serum lipase and amylase levels. Conclusions: Glycine reduced the severity of mild and much more of severe AP by attenuating the intrapancreatic and systemic inflammatory response. Therefore, glycine seems to be a promising tool for prophylactic treatment of AP.
Histopathologic and Clinical Subtypes of Autoimmune Pancreatitis: The Honolulu Consensus Document
(2011)
Autoimmune pancreatitis (AIP) has been extensively reported from Japan, Europe and the USA. While the descriptions of AIP from Japan have predominantly been based on the presence of a distinct clinical phenotype, reports from Europe and the USA describe at least 2 histopathologic patterns in patients diagnosed with AIP, namely lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct-centric pancreatitis (IDCP) or granulocytic epithelial lesion- positive pancreatitis. While the 2 entities share common histopathologic features (periductal lymphoplasmacytic infiltration and peculiar periductal fibrosis), expert pathologists can accurately distinguish them on the basis of other unique histopathologic features. Clinically, the 2 entities have a similar presentation (obstructive jaundice/pancreatic mass and a dramatic response to steroids), but they differ significantly in their demography, serology, involvement of other organs and disease relapse rate. While LPSP is associated with elevation of titers of nonspecific autoantibodies and serum IgG4 levels, IDCP does not have definitive serologic autoimmune markers. All experts agreed that the clinical phenotypes associated with LPSP and IDCP should be nosologically distinguished; however, their terminology was controversial. While most experts agreed that the entities should be referred to as type 1 and type 2 AIP, respectively, others had concerns regarding use of the term ‘autoimmune’ to describe IDCP.
Abstract
Background and aims: Intestinal adaptation in short bowel syndrome (SBS) includes morphologic processes and functional mechanisms. This study investigated whether digestive enzyme expression in the duodenum and colon is upregulated in SBS patients. Method: Sucrase‐isomaltase (SI), lactase‐phlorizin hydrolase (LPH), and neutral Aminopeptidase N (ApN) were analyzed in duodenal and colonic biopsies from nine SBS patients in a late stage of adaptation as well as healthy and disease controls by immunoelectron microscopy (IEM), Western blots, and enzyme activities. Furthermore, proliferation rates and intestinal microbiota were analyzed in the mucosal specimen. Results: We found significantly increased amounts of SI, LPH, and ApN in colonocytes in most SBS patients with large variation and strongest effect for SI and ApN. Digestive enzyme expression was only partially elevated in duodenal enterocytes due to a low proliferation level measured by Ki‐67 staining. Microbiome analysis revealed high amounts of Lactobacillus resp. low amounts of Proteobacteria in SBS patients with preservation of colon and ileocecal valve. Colonic expression was associated with a better clinical course in single cases. Conclusion: In SBS patients disaccharidases and peptidases can be upregulated in the colon. Stimulation of this colonic intestinalization process by drugs, nutrients, and pre‐ or probiotics might offer better therapeutic approaches.
Determination of the Pathological Features of NPC1 Variants in a Cellular Complementation Test
(2019)
Niemann-Pick Type C (NP-C) is a rare disorder of lipid metabolism caused by mutations
within the NPC1 and NPC2 genes. NP-C is a neurovisceral disease leading to a heterogeneous,
multisystemic spectrum of symptoms in those affected. Until now, there is no investigative tool to
demonstrate the significance of single variants within the NPC genes. Hence, the aim of the study
was to establish a test that allows for an objective assessment of the pathological potential of NPC1
gene variants. Chinese hamster ovary cells defective in the NPC1 gene accumulate cholesterol in
lysosomal storage organelles. The cells were transfected with NPC1-GFP plasmid vectors carrying
distinct sequence variants. Filipin staining was used to test for complementation of the phenotype.
The known variant p.Ile1061Thr showed a significantly impaired cholesterol clearance after 12 and
24 h compared to the wild type. Among the investigated variants, p.Ser954Leu and p.Glu1273Lys
showed decelerated cholesterol clearance as well. The remaining variants p.Gln60His, p.Val494Met,
and p.Ile787Val showed a cholesterol clearance indistinguishable from wild type. Further, p.Ile1061Thr
acquired an enhanced clearance ability upon 25-hydroxycholesterol treatment. We conclude that the
variants that caused an abnormal clearance phenotype are highly likely to be of clinical relevance.
Moreover, we present a system that can be utilized to screen for new drugs.
Background: With the use of modern cross-sectional abdominal imaging modalities, an increasing number of cystic pancreatic lesions are identified incidentally. Although there is no pathological diagnosis available in most cases, it is believed that the majority of these lesions display small branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) of the pancreas. Even though a number of large clinical series have been published, many uncertainties remain with regard to this entity of mucinous cystic neoplasms. Methods: Systematic literature review. Results: Main-duct (MD) and mixed-type IPMNs harbor a high risk of malignant transformation. It is conceivable that most IPMNs with involvement of the main duct tend to progress to invasive carcinoma over time. Thus, formal oncologic resection is the treatment of choice in surgically fit patients. In contrast, the data regarding BD-IPMN remain equivocal, resulting in conflicting concepts. To date, it is not clear whether and which BD-IPMNs progress to carcinoma and how long this progression takes. Conclusion: While patients with MD-IPMNs should undergo surgical resection if comorbidities and life expectancy permit this, the management of small BD-IPMNs remains controversial. Population-based studies with long-term follow-up are needed to define which cohort of patients can be observed safely without immediate resection.
Pancreatic necroses are a major challenge in the treatment of patients with pancreatitis, causing high morbidity. When indicated, these lesions are usually drained endoscopically using plastic or metal stents. However, data on factors associated with the occurrence of failure or adverse events during stent therapy are scarce. We retrospectively analyzed all adverse events and their associated features which occurred in patients who underwent a first-time endoscopic drainage of pancreatic necrosis from 2009 to 2019. During the observation period, a total of 89 eligible cases were identified. Adverse events occurred in 58.4% of the cases, of which 76.9% were minor (e.g., stent dislocation, residual lesions, or stent obstruction). However, these events triggered repeated interventions (63.5% vs. 0%, p < 0.001) and prolonged hospital stays (21.0 [11.8–63.0] vs. 14.0 [7.0–31.0], p = 0.003) compared to controls without any adverse event. Important factors associated with the occurrence of adverse events during endoscopic drainage therapy were positive necrosis cultures (6.1 [2.3–16.1], OR [95% CI], p < 0.001) and a larger diameter of the treated lesion (1.3 [1.1–1.5], p < 0.001). Superinfection of pancreatic necrosis is the most significant factor increasing the likelihood of adverse events during endoscopic drainage. Therefore, control of infection is crucial for successful drainage therapy, and future studies need to consider superinfection of pancreatic necrosis as a possible confounding factor when comparing different therapeutic modalities.
Objective: In acute pancreatitis (AP), bacterial translocation and subsequent infection of pancreatic necrosis are the main risk factors for severe disease and late death. Understanding how immunological host defence mechanisms fail to protect the intestinal barrier is of great importance in reducing the mortality risk of the disease. Here, we studied the role of the Treg/Th17 balance for maintaining the intestinal barrier function in a mouse model of severe AP.
Design: AP was induced by partial duct ligation in C57Bl/6 or DEREG mice, in which regulatory T-cells (Treg) were depleted by intraperitoneal injection of diphtheria toxin. By flow cytometry, functional suppression assays and transcriptional profiling we analysed Treg activation and characterised T-cells of the lamina propria as well as intraepithelial lymphocytes (IELs) regarding their activation and differentiation. Microbiota composition was examined in intestinal samples as well as in murine and human pancreatic necrosis by 16S rRNA gene sequencing.
Results: The prophylactic Treg-depletion enhanced the proinflammatory response in an experimental mouse model of AP but stabilised the intestinal immunological barrier function of Th17 cells and CD8+/γδTCR+ IELs. Treg depleted animals developed less bacterial translocation to the pancreas. Duodenal overgrowth of the facultative pathogenic taxa Escherichia/Shigella which associates with severe disease and infected necrosis was diminished in Treg depleted animals.
Conclusion: Tregs play a crucial role in the counterbalance against systemic inflammatory response syndrome. In AP, Treg-activation disturbs the duodenal barrier function and permits translocation of commensal bacteria into pancreatic necrosis. Targeting Tregs in AP may help to ameliorate the disease course.
Chronic pancreatitis (CP) is characterized by chronic inflammation and the progressive fibrotic replacement of exocrine and endocrine pancreatic tissue. We identify Treg cells as central regulators of the fibroinflammatory reaction by a selective depletion of FOXP3-positive cells in a transgenic mouse model (DEREG-mice) of experimental CP. In Treg-depleted DEREG-mice, the induction of CP results in a significantly increased stroma deposition, the development of exocrine insufficiency and significant weight loss starting from day 14 after disease onset. In CP, FOXP3+CD25+ Treg cells suppress the type-2 immune response by a repression of GATA3+ T helper cells (Th2), GATA3+ innate lymphoid cells type 2 (ILC2) and CD206+ M2-macrophages. A suspected pathomechanism behind the fibrotic tissue replacement may involve an observed dysbalance of Activin A expression in macrophages and of its counter regulator follistatin. Our study identified Treg cells as key regulators of the type-2 immune response and of organ remodeling during CP. The Treg/Th2 axis could be a therapeutic target to prevent fibrosis and preserve functional pancreatic tissue.
Background: Pancreatic cancer is the fourth leading cause of cancer-related mortality in both genders. More than 80% of patients suffer from significant weight loss at diagnosis and over time develop severe cachexia. Early nutritional support is therefore essential. Summary: This review evaluates the different nutritional therapies, such as enteral nutrition, parenteral nutrition and special nutritional supplements, on nutritional status, quality of life and survival. Key Message: Due to the high prevalence of malnutrition and the rapid development of anorexia-cachexia-syndrome, early nutritional intervention is crucial and supported by clinical data. Practical Implications: Enteral nutrition should be preferred over parenteral nutrition. Omega-3 fatty acids and <smlcap>L</smlcap>-carnitine are promising substances for the prevention of severe cachexia, but further randomized controlled trials are needed to establish generally accepted guidelines on nutrition in pancreatic cancer.
Microbial metabolites measured using NMR may serve as markers for physiological or pathological host–microbe interactions and possibly mediate the beneficial effects of microbiome diversity. Yet, comprehensive analyses of gut microbiome data and the urine NMR metabolome from large general population cohorts are missing. Here, we report the associations between gut microbiota abundances or metrics of alpha diversity, quantified from stool samples using 16S rRNA gene sequencing, with targeted urine NMR metabolites measures from 951 participants of the Study of Health in Pomerania (SHIP). We detected significant genus–metabolite associations for hippurate, succinate, indoxyl sulfate, and formate. Moreover, while replicating the previously reported association between hippurate and measures of alpha diversity, we identified formate and 4-hydroxyphenylacetate as novel markers of gut microbiome alpha diversity. Next, we predicted the urinary concentrations of each metabolite using genus abundances via an elastic net regression methodology. We found profound associations of the microbiome-based hippurate prediction score with markers of liver injury, inflammation, and metabolic health. Moreover, the microbiome-based prediction score for hippurate completely mediated the clinical association pattern of microbial diversity, hinting at a role of benzoate metabolism underlying the positive associations between high alpha diversity and healthy states. In conclusion, large-scale NMR urine metabolomics delivered novel insights into metabolic host–microbiome interactions, identifying pathways of benzoate metabolism as relevant candidates mediating the beneficial health effects of high microbial alpha diversity.
Genetic testing is associated with many ethical challenges on the individual, organizational and macro level of health care systems. The provision of genetic testing for rare diseases in particular requires a full understanding of the complexity and multiplicity of related ethical aspects. This systematic review presents a detailed overview of ethical aspects relevant to genetic testing for rare diseases as discussed in the literature. The electronic databases Pubmed, Science Direct and Web of Science were searched, resulting in 55 relevant publications. From the latter, a total of 93 different ethical aspects were identified. These ethical aspects were structured into three main categories (process of testing, consequences of the test outcome and contextual challenges) and 20 subcategories highlighting the diversity and complexity of ethical aspects relevant to genetic testing for rare diseases. This review can serve as a starting point for the further in-depth investigation of particular ethical issues, the education of healthcare professionals regarding this matter and for informing international policy development on genetic testing for rare diseases.
Helicobacter (H.) pylori is the most important cause for peptic ulcer disease and a risk factor for gastric carcinoma. How colonization with H. pylori affects the intestinal microbiota composition in humans is unknown. We investigated the association of H. pylori infection with intestinal microbiota composition in the population-based cohort Study-of-Health-in-pomerania (SHip)-tRenD. Anti-H. pylori serology and H. pylori stool antigen tests were used to determine the H. pylori infection status. the fecal microbiota composition of 212 H. pylori positive subjects and 212 matched negative control individuals was assessed using 16S rRNA gene sequencing. H. pylori infection was found to be significantly associated with fecal microbiota alterations and a general increase in fecal microbial diversity. in infected individuals, the H. pylori stool antigen load determined a larger portion of the microbial variation than age or sex. the highest H. pylori stool antigen loads were associated with a putatively harmful microbiota composition. this study demonstrates profound alterations in human fecal microbiota of H. pylori infected individuals. While the increased microbiota diversity associated with H. pylori infection as well as changes in abundance of specific genera could be considered to be beneficial, others may be associated with adverse health effects, reflecting the complex relationship between H. pylori and its human host.
Background: Pancreatic ductal adenocarcinoma (PDAC) is the 4th leading cause of cancer death worldwide and compared to other malignancies its share in cancer mortality is expected to rise further. This is due to a lack of sensitive diagnostic tools that would permit earlier detection in a potentially curable stage and the very slow progress in finding effective drug treatments for pancreatic cancer. Key Messages: Aside from genetic predispositions and environmental agents, chronic pancreatitis is by far the greatest risk factor for PDAC. It also shares several etiological factors with pancreatic cancer and represents its most challenging differential diagnosis. Biomarkers that can distinguish between chronic pancreatitis and PDAC may therefore be suitable for the latter's early detection. Moreover, targeting the natural history of chronic pancreatitis would be one approach to prevent PDAC. Targeting tumor-cell signaling directly by interfering with receptor tyrosine kinases has shown some efficacy, although the results in clinical trials were less encouraging than for other cancers. Other compounds developed have targeted the formation of extracellular matrix around the tumor, the proteolytic activity in the tumor environment, histone deacetylases, hedgehog signaling and heat shock proteins, but none has yet found its way into routine patient care. Attempts to individualize treatment according to the tumor's somatic mutation profile are novel but so far impractical. Conclusions: Progress in the treatment of pancreatic cancer has been exceedingly slow and mostly dependent on improved pharmaceutical preparations or combinations of established chemotherapeutic agents. The promise of major breakthroughs implied in targeting tumor signal transduction events has so far not materialized.
Abstract
Body weight loss is frequently regarded as negatively related to outcomes in patients with malignancies. This retrospective analysis of the FIRE‐3 study evaluated the evolution of body weight in patients with metastatic colorectal cancer (mCRC). FIRE‐3 evaluated first‐line FOLFIRI (folinic acid, fluorouracil and irinotecan) plus cetuximab or bevacizumab in mCRC patients with RAS‐WT tumors (ie, wild‐type in KRAS and NRAS exons 2‐4). The prognostic and predictive relevance of early weight loss (EWL) regarding patient outcomes and treatment side effects were evaluated. Retrospective data on body weight during first 6 months of treatment were evaluated (N = 326). To correlate with efficacy endpoints and treatment side effects, patients were grouped according to clinically significant EWL ≥5% and <5% at Month 3. Age constituted the only significant predictor of EWL following a linear relationship with the corresponding log odds ratio (P = .016). EWL was significantly associated with the incident frequencies of diarrhea, edema, fatigue, nausea and vomiting. Further, a multivariate analysis revealed EWL to be an independent negative prognostic factor for overall survival (32.4 vs 21.1 months; hazard ratio [HR]: 1.64; 95% confidence interval [CI] = 1.13‐2.38; P = .0098) and progression‐free survival (11.8 vs 9.0 months; HR: 1.72; 95% CI = 1.18‐2.5; P = .0048). In conclusion, EWL during systemic treatment against mCRC is significantly associated with patient age. Patients exhibiting EWL had worse survival and higher frequencies of adverse events. Early preventative measures targeted at weight maintenance should be evaluated, especially in elderly patients being at highest risk of EWL.
Simple Summary
Small molecule inhibitors and targeted therapy are considered to have significant potential for pancreatic ductal adenocarcinoma therapies. Preclinical studies of novel inhibitors and inhibitor combinations can elucidate their acting mechanisms and provide valuable data for in vivo research and clinical trials. We explored the antitumor efficacy of KRAS inhibitors BI-3406 and sotorasib alone or in combination with the downstream inhibitors trametinib and buparlisib in PDAC cell lines, characterized by different KRAS mutational statuses. The two KRAS inhibitors demonstrated different anti-tumor efficacy and displayed synergistic or additive effects, when combined with downstream pathway inhibitors. These data emphasized the importance of KRAS as a therapeutic target for PDAC and indicate two distinct mechanisms of KRAS inhibition and their interactions with downstream pathway inhibitors.
Abstract
Kirsten rat sarcoma virus (KRAS) mutations are widespread in pancreatic ductal adenocarcinoma (PDAC) and contribute significantly to tumor initiation, progression, tumor relapse/resistance, and prognosis of patients. Although inhibitors against KRAS mutations have been developed, this therapeutic approach is not routinely used in PDAC patients. We investigated the anti-tumor efficacy of two KRAS inhibitors BI-3406 (KRAS::SOS1 inhibitor) and sotorasib (KRAS G12C inhibitor) alone or in combination with MEK1/2 inhibitor trametinib and/or PI3K inhibitor buparlisib in seven PDAC cell lines. Whole transcriptomic analysis of combined inhibition and control groups were comparatively analyzed to explore the corresponding mechanisms of inhibitor combination. Both KRAS inhibitors and corresponding combinations exhibited cytotoxicity against specific PDAC cell lines. BI-3406 enhance the efficacy of trametinib and buparlisib in BXPC-3, ASPC-1 and MIA PACA-2, but not in CAPAN-1, while sotorasib enhances the efficacy of trametinib and buparlisib only in MIA PACA-2. The whole transcriptomic analysis demonstrates that the two triple-inhibitor combinations exert antitumor effects by affecting related cell functions, such as affecting the immune system, cell adhesion, cell migration, and cytokine binding. As well as directly involved in RAF/MEK/ERK pathway and PI3K/AKT pathway affect cell survival. Our current study confirmed inhibition of KRAS and its downstream pathways as a potential novel therapy for PDAC and provides fundamental data for in vivo evaluations.
The aberrant activation of the phosphoinositide 3-kinase (PI3K)/ protein kinase B (AKT) pathway is common in pancreatic ductal adenocarcinomas (PDAC). The application of inhibitors against PI3K and AKT has been considered as a therapeutic option. We investigated PDAC cell lines exposed to increasing concentrations of MK-2206 (an AKT1/2/3 inhibitor) and Buparlisib (a pan-PI3K inhibitor). Cell proliferation, metabolic activity, biomass, and apoptosis/necrosis were evaluated. Further, whole-exome sequencing (WES) and RNA sequencing (RNA-seq) were performed to analyze the recurrent aberrations and expression profiles of the inhibitor target genes and the genes frequently mutated in PDAC (Kirsten rat sarcoma virus (KRAS), Tumor protein p53 (TP53)). MK-2206 and Buparlisib demonstrated pronounced cytotoxic effects and limited cell-line-specific effects in cell death induction. WES revealed two sequence variants within the direct target genes (PIK3CA c.1143C > G in Colo357 and PIK3CD c.2480C > G in Capan-1), but a direct link to the Buparlisib response was not observed. RNA-seq demonstrated that the expression level of the inhibitor target genes did not affect the efficacy of the corresponding inhibitors. Moreover, increased resistance to MK-2206 was observed in the analyzed cell lines carrying a KRAS variant. Further, increased resistance to both inhibitors was observed in SU.86.86 carrying two TP53 missense variants. Additionally, the presence of the PIK3CA c.1143C > G in KRAS-variant-carrying cell lines was observed to correlate with increased sensitivity to Buparlisib. In conclusion, the present study reveals the distinct antitumor effects of PI3K/AKT pathway inhibitors against PDAC cell lines. Aberrations in specific target genes, as well as KRAS and TP53, individually or together, affect the efficacy of the two PI3K/AKT pathway inhibitors.