Composite score of physiomechanical esophageal function using functional lumen imaging probe panometry in eosinophilic esophagitis

BACKGROUND AND AIMS

The evaluation provided by functional lumen imaging probe (FLIP) panometry includes esophageal distensibility/compliance (mechanics) of the esophageal body and esophagogastric junction (EGJ) and esophageal motility (secondary peristalsis). We developed a composite score using these parameters to characterize physiomechanical function in patients with eosinophilic esophagitis (EoE).

METHODS

Two hundred fifteen adult patients with EoE who completed FLIP panometry during sedated endoscopy with esophageal biopsy sampling were included. FLIP metrics of esophageal body Compliance, Contractile response, Distensibility plateau, and maximum EGJ Diameter (C2D2) were scored as 0 for normal versus 1 or 2 for increasing degree of abnormality. Scores were summed to calculate the composite C2D2 score.

RESULTS

The C2D2 score had a significant positive correlation with mucosal eosinophil count (ρ = .241) and total Endoscopic EoE Reference Score (ρ = .467). Among 46 patients off treatment at the baseline evaluation, future proton pump inhibitor (PPI) responders (ie, achieved mucosal eosinophil count <15 per high-powered field after PPI treatment) had lower C2D2 scores than PPI nonresponders (median, 2 [interquartile range, 1-3] vs 4 [interquartile range, 2-6], respectively; P = .003). A regression model (that controlled for age, sex, and baseline eosinophil count) showed a C2D2 score ≤3 had an odds ratio of 14.5 (95% confidence interval, 2.6-85) to predict future PPI response. However, total Endoscopic EoE Reference Scores (P = .142) and baseline eosinophil count (P = .480) did not differ between PPI responders and PPI nonresponders.

CONCLUSIONS

This composite score of FLIP panometry metrics, the C2D2 score, may facilitate characterizing physiomechanical function in EoE and serve as an objective outcome measure.

The Severity of Reduced Esophageal Distensibility Parallels Eosinophilic Esophagitis Disease Duration

BACKGROUND & AIMS

Chronic inflammation of eosinophilic esophagitis (EoE) results in progressive, fibrostenotic remodeling of the esophageal wall. This study aimed to demonstrate objective changes in esophageal distensibility relative to duration of EoE disease using a functional lumen imaging probe (FLIP).

METHODS

Adult patients with EoE who completed a 16-cm FLIP protocol during endoscopy were evaluated in a cross-sectional study. FLIP analysis focused on distensibility plateau (DP) of the esophageal body. The time from onset of symptoms to time of endoscopy with FLIP was assessed, as was time from symptom onset to EoE diagnosis (ie, diagnostic delay).

RESULTS

A total of 171 patients (mean age 38 ± 12 years; 31% female) were included; the median symptom duration was 8 (interquartile range, 3-15) years and diagnostic delay was 4 (interquartile range, 1-12) years. At the time of endoscopy with FLIP, there were 54 patients (39%) in histologic remission (<15 eosinophils per high-power field [eos/hpf]). Symptom duration and diagnostic delay were negatively correlated with DP (rho = -0.326 and -0.309; P values < .001). Abnormal esophageal distensibility (DP ≤17 mm) was more prevalent with increased duration of symptoms (P < .004): 23% at <5 years to 64% at ≥25 years. When stratifying the cohort based on mucosal eosinophil density, patients with ≥15 eos/hpf had significantly lower DP with greater symptom duration (P = .004), while there was not a significant difference among patients with <15 eos/hpf (P = .060).

CONCLUSIONS

Esophageal distensibility objectively measured with FLIP was reduced in EoE patients with greater symptom duration and diagnostic delay. This supports that EoE is a progressive, fibrostenotic disease and that FLIP may be a useful tool to monitor disease progression in EoE.

Immune Assessment Today: Optimizing and Standardizing Efforts to Monitor Immune Responses in Cancer and Beyond

As part of a symposium, current and former directors of Immune Monitoring cores and investigative oncologists presented insights into the past, present and future of immune assessment. Dr. Gnjatic presented a classification of immune monitoring technologies ranging from universally applicable to experimental protocols, while emphasizing the need for assay harmonization. Dr. Obeng discussed physiologic differences among CD8 T cells that align with anti-tumor responses. Dr. Lyerly presented the Soldano Ferrone lecture, commemorating the passionate tumor immunologist who inspired many, and covered a timeline of monitoring technology development and its importance to immuno-oncology. Dr. Sonabend presented recent achievements in glioblastoma treatment, accentuating the range of monitoring techniques that allowed him to refine patient selection for clinical trials. Dr. Guevara-Patiño focused on hypoxia within the tumor environment and stressed that T cell viability is not to be confused with functionality. Dr. Butterfield accentuated monitoring of dendritic cell metabolic (dys)function as a determinant for tumor vaccine success. Lectures were interspersed with select abstract presentations. To summarize the concepts, Dr. Maecker from Stanford led an informative forum discussion, pointing towards the future of immune monitoring. Immune monitoring continues to be a guiding light towards effective immunotherapeutic strategies.

A PhysioMechanical Model of Esophageal Function in Eosinophilic Esophagitis

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is characterized by eosinophilic inflammation, but also heterogeneous presentations involving fibrostenotic esophageal remodeling and esophageal dysmotility. We aimed to define and evaluate phenotypes of EoE using functional lumen imaging probe (FLIP) panometry (ie, a PhysioMechanical classification of EoE).

METHODS

Patients with EoE who completed FLIP during endoscopy were included in a cross-sectional study. FLIP studies were analyzed for distensibility plateau and compliance of the esophageal body, maximum esophagogastric junction diameter, and contractile response pattern. These FLIP features were then applied to define PhysioMechanical classifications.

RESULTS

A total of 215 patients with EoE (mean [standard deviation] age 38 [12] years; 31% female) were included. Seven PhysioMechanical classifications were identified that differed by various clinical characteristics, including symptom duration (P < .001) and Endoscopic EoE Reference Scores (EREFS) (P < .001). In particular, patients with "nonreactive fibrostenosis" (n = 14), had greater symptom duration (median [interquartile range] 20 [10-30] years) and more frequently had EREFS grade 2 or 3 ring scores (14 of 14 patients) than patients with a "normal" PhysioMechanical classification (symptom duration: 3 [1-8] years; 4 of 50 [8%] had EREFS grade 2 or 3 rings). In addition, among patients off treatment at cross-sectional evaluation (n = 46), there was a difference between PhysioMechanical classifications in future proton pump inhibitor (PPI) response rates (ie, achieving peak mucosal eosinophil count <15 per high-powered field after PPI treatment); P = .009. PPI response ranged from 87% (13 of 15 patients) with "isolated esophagogastric junction outflow obstruction" to 11% (1 of 9 patients) with "spastic-reactive fibrostenosis."

CONCLUSIONS

Classifying PhysioMechanical esophageal function in EoE based on FLIP panometry features may facilitate defining disease severity and directing management in EoE.

Aging is associated with a systemic length-associated transcriptome imbalance

Aging is among the most important risk factors for morbidity and mortality. To contribute toward a molecular understanding of aging, we analyzed age-resolved transcriptomic data from multiple studies. Here, we show that transcript length alone explains most transcriptional changes observed with aging in mice and humans. We present three lines of evidence supporting the biological importance of the uncovered transcriptome imbalance. First, in vertebrates the length association primarily displays a lower relative abundance of long transcripts in aging. Second, eight antiaging interventions of the Interventions Testing Program of the National Institute on Aging can counter this length association. Third, we find that in humans and mice the genes with the longest transcripts enrich for genes reported to extend lifespan, whereas those with the shortest transcripts enrich for genes reported to shorten lifespan. Our study opens fundamental questions on aging and the organization of transcriptomes.

Heterogeneity of primary and secondary peristalsis in systemic sclerosis: A new model of "scleroderma esophagus"

BACKGROUND

Although esophageal dysmotility is common in systemic sclerosis (SSc)/scleroderma, little is known regarding the pathophysiology of motor abnormalities driving reflux severity and dysphagia. This study aimed to assess primary and secondary peristalsis in SSc using a comprehensive esophageal motility assessment applying high-resolution manometry (HRM) and functional luminal imaging probe (FLIP) Panometry.

METHODS

A total of 32 patients with scleroderma (28 female; ages 38-77; 20 limited SSc, 12 diffuse SSc) completed FLIP Panometry and HRM. Secondary peristalsis, i.e., contractile responses (CR), was classified on FLIP Panometry by pattern of contractility as normal (NCR), borderline (BCR), impaired/disordered (IDCR), or absent (ACR). Primary peristalsis on HRM was assessed according to the Chicago classification.

RESULTS

The manometric diagnoses were 56% (n = 18) absent contractility, 22% (n = 7) ineffective esophageal motility (IEM), and 22% (n = 7) normal motility. Secondary peristalsis (CRs) included 38% (n = 12) ACR, 38% (n = 12) IDCR, 19% (n = 6) BCR, and 15% (n = 5) NCR. The median (IQR) esophagogastric junction (EGJ) distensibility index (DI) was 5.8 mm² /mmHg (4.8-10.1) mm² /mmHg; EGJ-DI was >8.0 mm² /mmHg in 31%, and >2.0 mm² /mmHg in 100% of patients. Among 18 patients with absent contractility on HRM, 11 had ACR, 5 had IDCR, and 2 had BCR. Among 7 patients with IEM, 1 had ACR, 5 had IDCR, and 1 NCR. All of the patients with normal peristalsis had NCR or BCR.

CONCLUSIONS

This was the first study assessing combined HRM and FLIP Panometry in a cohort of SSc patients, which demonstrated heterogeneity in primary and secondary peristalsis. This complementary approach facilitates characterizing esophageal function in SSc, although future study to examine clinical outcomes remains necessary.

Indoleamine 2,3-dioxygenase 1 and overall survival of patients diagnosed with esophageal cancer

BACKGROUND

Indoleamine 2,3-dioxygenase 1 (IDO1) is an enzyme with immunomodulatory properties that has emerged as a potential immunotherapeutic target in human cancer. However, the role, expression pattern, and relevance of IDO1 in esophageal cancer (EC) are poorly understood. Here, we utilize gene expression analysis of the cancer genome atlas (TCGA) and immunohistochemistry (IHC) to better understand the role and prognostic significance of IDO1 in EC.

RESULTS

High IDO1 mRNA levels were associated with worse overall survival (OS) in both esophageal squamous cell carcinoma (SCC) (P = 0.02) and adenocarcinoma (AC) (P = 0.036). High co-expression of IDO1 and programmed death ligand 1 (PD-L1) was associated with worse OS in SCC (P = 0.0031) and AC (P = 0.0186). IHC for IDO1 in SCC showed a significant correlation with PD-L1 (P < 0.0001) and CD3ε (P < 0.0001).

CONCLUSIONS

EC with high IDO1 and PD-L1 expression is significantly correlated with decreased patient survival, and may correlate with increased T-cells. These data suggest that simultaneous inhibition of IDO1 and PD-(L)1 may overcome important barriers to T-cell mediated immune rejection of EC.

MATERIALS AND METHODS

mRNA expression data from TCGA (SCC N = 87; AC N = 97). IHC in a second cohort of EC (N = 93) were stained for IDO1, PD-L1, and CD3ε, followed by light microscopic analysis.

Krüppel-like factors in cancer

Krüppel-like factors (KLFs) are a family of DNA-binding transcriptional regulators with diverse and essential functions in a multitude of cellular processes, including proliferation, differentiation, migration, inflammation and pluripotency. In this Review, we discuss the roles and regulation of the 17 known KLFs in various cancer-relevant processes. Importantly, the functions of KLFs are context dependent, with some KLFs having different roles in normal cells and cancer, during cancer development and progression and in different cancer types. We also identify key questions for the field that are likely to lead to important new translational research and discoveries in cancer biology.

p53 mutation alters the effect of the esophageal tumor suppressor KLF5 on keratinocyte proliferation

Krüppel-like factor 5 (KLF5) is a key transcriptional regulator that is typically pro-proliferative in non-transformed epithelial cells but inhibits proliferation in transformed epithelial cells. However, the underlying mechanisms for this context-dependent function are not known. KLF5 is epigenetically silenced and exhibits a tumor suppressive function in esophageal squamous cell cancer (ESCC). Since p53 mutation is the most common genetic alteration in ESCC, as in other human epithelial cancers, we hypothesized that the context-dependent functions of KLF5 in cell proliferation were dependent on p53 status. In fact, in non-transformed human primary esophageal keratinocytes, when p53 was wild-type, KLF5 was pro-proliferative; however, KLF5 became anti-proliferative when p53 was mutated. KLF5 loss in human primary keratinocytes harboring p53 mutation accelerated the cell cycle and decreased expression of p21Waf1/Cip1; similar effects were also seen in ESCC cells with established p53 mutations. Further, p21Waf1/Cip1 was directly and differentially bound and regulated by KLF5 in the presence or absence of mutant p53, and suppression of p21Waf1/Cip1 reversed the antiproliferative effects of KLF5 in the presence of p53 mutation. Thus, KLF5 is a critical brake on an aberrant cell cycle, with important tumor suppressive functions in esophageal squamous cell and potentially other epithelial cancers.

Krüppel-like factor 5 protects against murine colitis and activates JAK-STAT signaling in vivo

Inflammatory bowel disease (IBD), which is characterized by chronic or recurring inflammation of the gastrointestinal tract, affects 1.4 million persons in the United States alone. KLF5, a Krüppel-like factor (KLF) family member, is expressed within the epithelia of the gastrointestinal tract and has been implicated in rapid cell proliferation, migration, and remodeling in a number of tissues. Given these functions, we hypothesized that constitutive Klf5 expression would protect against the development of colitis in vivo. To examine the role of KLF5 in vivo, we used the Villin promoter to target Klf5 to the entire horizontal axis of the small intestine and colon. Villin-Klf5 transgenic mice were born at normal Mendelian ratios and appeared grossly normal to at least 1 year of age. Surprisingly, there were no significant changes in cell proliferation or in the differentiation of any of the intestinal lineages within the duodenum, jejunum, ileum, and colon of Villin-Klf5 mice, compared to littermate controls. However, when Villin-Klf5 mice were treated with dextran sodium sulfate (DSS) to induce colitis, they developed less colonic injury and significantly reduced disease activity scores than littermate controls. The mechanism for this decreased injury may come via JAK-STAT signaling, the activation of which was increased in colonic mucosa of DSS treated Villin-Klf5 mice compared to controls. Thus, KLF5 and its downstream mediators may provide therapeutic targets and disease markers for IBD or other diseases characterized by injury and disruption of intestinal epithelia.

Abstract 2035: The effect of KLF5 on cell cycle progression depends upon p53 status

Background: p53 mutation is one of the most common genetic events in esophageal squamous cell cancer (ESCC), and loss of Krüppel-like factor 5 (KLF5) in the context of p53 mutation transforms primary esophageal squamous epithelial cells. Interestingly, while KLF5 promotes proliferation in non-transformed esophageal squamous epithelial cells, KLF5 is growth inhibitory in ESCC. The mechanisms of this context dependent effect of KLF5 on cell Hypothesis: We hypothesized that the effect of KLF5 on cell cycle progression is dependent on p53 status. Methods: Human primary esophageal keratinocytes with or without either wild type or mutant p53R175H were transduced with lentivirus expressing inducible KLF5 shRNA or control. We investigated cell proliferation by MTT assay and cell cycle progression by flow cytometry. The expression of the cyclins and cyclin-dependent kinases were assessed by quantitave PCR. p21waf/cip1 activity was determined using a luciferase reporter. Results: In the context of wild-type p53, KLF5 suppression decreased cell proliferation and produced growth arrest at G2/M, with decreases in cyclin A2 and cyclin E1expression. In contrast, KLF5 loss in human primary keratinocytes harboring the common human p53 mutation p53R175H accelerated the cell cycle with more cells in G1/S and increased cyclin D1 expression. Interestingly, KLF5 directly bound within the p53 response elements in the regulatory region of p21waf/cip1 and activated its promoter activity only in cell with mutant p53. In addition, KLF5 suppression diminished p21waf/cip1 responsiveness to UV irradiation and growth factor depletion only in p53 mutant cells. Conclusions: Here, we identify a novel mechanism for context dependent effects of KLF5 on cell cycle via p53. These findings, in combination with the previously-established effects of KLF5 and p53 loss on cellular transformation, suggest that KLF5 is an important brake on the cell cycle and may function as a tumor suppressor in esophageal squamous cell cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2035. doi:1538-7445.AM2012-2035

Loss of transcription factor KLF5 in the context of p53 ablation drives invasive progression of human squamous cell cancer

Squamous cell cancers account for more than half of all human cancers, and esophageal cancer is the sixth leading cause of cancer death worldwide. The majority of esophageal squamous cell carcinomas have identifiable p53 mutations, yet the same p53 mutations are found at comparable frequencies in precancerous dysplasia, indicating that transformation requires additional somatic changes yet to be defined. Here, we show that the zinc finger transcription factor Krüppel-like factor 5 (KLF5) transactivates NOTCH1 in the context of p53 mutation or loss. KLF5 loss limited NOTCH1 activity and was sufficient on its own to transform primary human keratinocytes harboring mutant p53, leading to the formation of invasive tumors. Restoration of NOTCH1 blocked transformation of KLF5-deficient and p53-mutant keratinocytes. Although human dysplastic epithelia accumulated KLF5, KLF5 expression was lost concurrently with NOTCH1 in squamous cell cancers. Taken together, these results define KLF5 loss as a critical event in squamous cell transformation and invasion. Our findings suggest that KLF5 may be a useful diagnostic and therapeutic target in esophageal squamous carcinomas and possibly more generally in other cancers associated with p53 loss of function.

Esophageal squamous cell dysplasia and delayed differentiation with deletion of krüppel-like factor 4 in murine esophagus

BACKGROUND & AIMS

Krüppel-like factor 4 (Klf; previously known a gut-enriched Krüppel-like factor) is a DNA-binding transcriptional regulator highly expressed in skin and gastrointestinal epithelia, specifically in regions of cellular differentiation. Homozygous null mice for Klf4 die shortly after birth from skin defects, precluding their analysis at later stages. The aim of this study was to analyze the function of Klf4 in keratinocyte biology and epithelial homeostasis in the adult by focusing on the squamous lined esophagus.

METHODS

By using the ED-L2 promoter of Epstein-Barr virus to drive Cre, we obtained tissue-specific ablation of Klf4 in the squamous epithelia of the tongue, esophagus, and forestomach.

RESULTS

Mice with loss of Klf4 in esophageal epithelia survived to adulthood, bypassing the early lethality. Tissue-specific Klf4 knockout mice had increased basal cell proliferation and a delay in cellular maturation; these mice developed epithelial hypertrophy and subsequent dysplasia by 6 months of age. Moreover, loss of Klf4 in vivo was associated with increased expression of the pro-proliferative Klf5, and Klf4 down-regulated Klf5 both transcriptionally and posttranscriptionally. By using gene expression profiling, we also showed decreased expression of critical late-stage differentiation factors and identified alterations of several genes important in cellular differentiation.

CONCLUSIONS

Klf4 is essential for squamous epithelial differentiation in vivo and interacts with Klf5 to maintain normal epithelial homeostasis.

Krüppel-like factor 5 controls keratinocyte migration via the integrin-linked kinase

Migration of epithelial cells is critical for normal homeostasis in gut and skin, but the factors regulating this process are not completely understood. The zinc finger transcription factor Klf5 (IKLF; BTEB2) is highly expressed in proliferating cells of esophagus, skin, and other organs. We hypothesized that Klf5 regulates keratinocyte migration via the integrin-linked kinase (ILK), which, like Klf5, is localized to basal keratinocytes. We stably transduced mouse primary esophageal keratinocytes to overexpress Klf5 or small interfering RNA against Klf5. Klf5 overexpression in keratinocytes increased migration and correlated directly with ILK expression and activation. ILK expression restored migratory capacity in keratinocytes with suppression of Klf5, whereas ILK small interfering RNA blocked the increased migration resulting from Klf5 overexpression. By chromatin immunoprecipitation, electromobility shift assay, and luciferase reporter assays, we confirmed that ILK was a direct target for Klf5. In addition, Klf5 induced the activation of the ILK targets Cdc42 and myosin light chain, which are critical for cell migration and motility but not Rac1, AKT, or GSK3beta. Overall, these results demonstrate that Klf5 is a key regulator of cell migration via ILK and provide new insight into the regulation of epithelial cell migration.