Elevated EVL Methylation Level in the Normal Colon Mucosa Is a Potential Risk Biomarker for Developing Recurrent Adenomas

BACKGROUND

Individuals with adenomatous colorectal polyps undergo repeated colonoscopy surveillance to identify and remove metachronous adenomas. However, many patients with adenomas do not develop recurrent adenomas. Better methods to evaluate who benefits from increased surveillance are needed. We evaluated the use of altered EVL methylation as a potential biomarker for risk of recurrent adenomas.

METHODS

Patients with ≥1 colonoscopy had EVL methylation (mEVL) measured with an ultra-accurate methylation-specific droplet digital PCR assay on normal colon mucosa. The association between EVL methylation levels and adenoma or colorectal cancer was evaluated using three case/control definitions in three models: unadjusted (model 1), adjusting for baseline characteristics (model 2), and an adjusted model excluding patients with colorectal cancer at baseline (model 3).

RESULTS

Between 2001 and 2020, 136 patients were included; 74 healthy patients and 62 patients with a history of colorectal cancer. Older age, never smoking, and baseline colorectal cancer were associated with higher levels of mEVL (P ≤ 0.05). Each log base 10 difference in mEVL was associated with an increased risk of adenoma(s) or cancer at/after baseline for model 1 [OR, 2.64; 95% confidence interval (CI), 1.09-6.36], and adenoma(s) or cancer after baseline for models 1 (OR, 2.01; 95% CI, 1.04-3.90) and model 2 (OR, 3.17; 95% CI, 1.30-7.72).

CONCLUSIONS

Our results suggest that EVL methylation level detected in the normal colon mucosa has the potential to be a biomarker for monitoring the risk for recurrent adenomas.

IMPACT

These findings support the potential utility of EVL methylation for improving the accuracy for assigning risk for recurrent colorectal adenomas and cancer.

Generation of three CRISPR/Cas9 edited human induced pluripotent stem cell lines (DHMi005-A-5, DHMi005-A-6 and DHMi005-A-7) carrying a Holt-Oram Syndrome patient-specific TBX5 mutation with known cardiac phenotype and a FLAG-tag after exon 9 of the TBX5 gene

TBX5 is a transcription factor (TF) playing essential role during cardiogenesis. It is well known that TF mutations possibly result in non- or additional binding of the DNA due to conformational changes of the protein. We introduced a Holt-Oram Syndrome (HOS) patient-specific TBX5 mutation c.920_C > A heterozygously in a healthy induced pluripotent stell cell (iPSC) line. This TBX5 mutation results in conformational changes of the protein and displayed ventricular septal defects in the patient itself. Additionally we introduced a FLAG-tag on the TBX5 mutation-carrying allele. The resulting heterozygous TBX5-FLAG iPSC lines are a powerful tool to investigate altered TF activity bonding.

Generation of two CRISPR/Cas edited human induced pluripotent stem cell lines (DHMi005-A-3 and DHMi005-A-4) carrying a FLAG-tag after exon 9 of the TBX5 gene

Although TBX5 plays a major role during human cardiogenesis and initiates and controls limb development, many of its interactions with genomic DNA and the resulting biological consequences are not well known. Existing anti-TBX5-antibodies work very inefficiently in certain applications such as ChIP-Seq analysis. To circumvent this drawback, we introduced a FLAG-tag sequence into the TBX5 locus at the end of exon 9 prior to the stop codon by CRISPR/Cas9. The expressed TBX5-FLAG fusion protein can effectively be precipitated by anti-FLAG antibodies. Therefore, these gene-edited iPSC lines represent powerful cellular in vitro tools to unravel TBX5:DNA interactions in detail.

Abstract P010: Molecular mediators of the energy balance-colorectal cancer link: evaluating the gut microbiome and pro-inflammatory biomarkers

Background: Physical activity and BMI are convincingly associated with colorectal cancer risk, yet the underlying molecular mediators and their interplay in the energy balance-cancer link remain unclear. Possible counteracting effects of physical activity on obesity-induced metabolic changes, including systemic inflammation and changes in the gut microbiome, have yet to be studied. Here, we investigated associations of several combinations of physical activity and BMI with pro-inflammatory biomarkers and the gut microbiome and relationships between these two mediators among patients with colorectal cancer. Methods: N=579 patients with newly diagnosed colorectal cancer (stages I-IV) were included. Physical activity at baseline was assessed using an adapted International Physical Activity Questionnaire (IPAQ) and participants were classified as being ‘active’ or ‘inactive’ based on physical activity guidelines. BMI at baseline was abstracted from medical records and categorized into ‘normal weight’ and ‘overweight/obese’. Pro-inflammatory biomarkers (CRP, SAA, IL-6, IL-8, and TNF-α) were measured in pre-surgery serum samples. In a subset of patients (n=179), 16S rRNA gene sequencing was additionally performed in pre-surgery stool samples. Relative abundances were determined for each taxonomic level and used to calculate diversity metrics. Analyses were adjusted for sex, stage at diagnosis, neoadjuvant treatment, and study site. Results: ‘Obese’ patients had 88% and 17% higher CRP and TNF-α levels compared to ‘normal weight’ patients (p=0.03 and 0.02, respectively). Highest CRP levels were observed among ‘overweight or obese/inactive’ compared to ‘normal weight/active’ patients (p=0.03). Lower gut microbial diversity was observed among ‘inactive’ vs. ‘active’ patients (Shannon index: p=0.01, Simpson: p=0.03), ‘obese’ vs. ‘normal weight’ patients (Shannon index, Simpson, and Observed species: p=0.02, respectively), and ‘overweight or obese/inactive’ vs. ‘normal weight/active’ patients (Shannon index: p=0.02, Observed species: p=0.04). Two phyla and 12 genera (e.g., Actinobacteria and Fusobacteria, and Ruminococcus, Succinivibrio, Succiniclasticum) were differentially abundant across physical activity and BMI groups. High CRP and TNF-α levels were statistically significantly associated with lower alpha diversity metrics (p=0.02-0.05). Conclusions: This is the first evidence indicating that the gut microbiome may be a molecular mediator of the energy balance-colorectal cancer link. We further provide evidence of associations between physical activity and BMI groups with pro-inflammatory biomarkers. While BMI was identified as the key driver of inflammation, biomarker levels were higher among ‘inactive’ patients across BMI groups. Physical activity may offset obesity-induced inflammation and gut microbiome dysbiosis. Our results further provide new insights into the host-microbiome interactions with respect to systemic inflammation.

Citation Format: Caroline Himbert, W. Zac Stephens, Biljana Gigic, Tengda Lin, Jennifer Ose, Anjelica Ashworth, Christy Warby, David Nix, Jolanta Jedrzkiewicz, Anita R Peoples, Mary Bronner, Bartley Pickron, Courtney Scaife, Jessica N. Cohan, William M. Grady, Stacey A. Cohen, Mukta Krane, Petra Schrotz-King, Jane C. Figueiredo, Adetunji T. Toriola, Erin M. Siegel, Christopher I. Li, Alexis Ulrich, David Shibata, June L. Round, Lyen C. Huang, Martin Schneider, Sheetal Hardikar, Cornelia M Ulrich. Molecular mediators of the energy balance-colorectal cancer link: evaluating the gut microbiome and pro-inflammatory biomarkers. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P010.

Associations of individual and combined physical activity and body mass index groups with pro-inflammatory biomarkers among colorectal cancer patients

BACKGROUND

Physical activity and obesity are well-established factors of colorectal cancer (CRC) risk and prognosis. Here, we investigate associations of individual and combined physical activity and BMI groups with pro-inflammatory biomarkers in CRC patients.

METHODS

Self-reported physical activity levels were classified as 'active' (≥8.75 MET-hrs/wk) vs. 'inactive' (<8.75 MET-hrs/wk) in n=579 stage I-IV CRC patients enrolled in the ColoCare Study. BMI [normal weight (≥18.5-<25kg/m2), overweight (≥25-<30kg/m2), and obese (≥30kg/m2)] was abstracted from medical records. Patients were classified into four combinations of physical activity levels and BMI. Biomarkers (CRP, SAA, IL-6, IL-8, and TNF-α) in pre-surgery serum samples were measured using Meso-Scale-Discovery platform. Regression models were used to compute relative percent differences in biomarker levels by physical activity and BMI groups.

RESULTS

'Inactive' patients had non-statistically significant higher IL-6 levels compared to 'active' patients (+36%, p=0.10). 'Obese' patients had 88% and 17% higher CRP and TNF-α levels compared to 'normal weight' patients (p=0.03 and 0.02, respectively). Highest CRP levels were observed among 'overweight or obese/inactive' compared to 'normal weight/active' patients (p=0.03).

CONCLUSION

We provide evidence of associations between individual and combined physical activity and BMI groups with pro-inflammatory biomarkers. While BMI was identified as the key driver of inflammation, biomarker levels were higher among 'inactive' patients across BMI groups.

IMPACT

This is the largest study in CRC patients investigating associations of energy balance components with inflammatory biomarkers. Our results suggest that physical activity may reduce obesity-induced inflammation in CRC patients and support the design of randomized controlled trials testing this hypothesis.

Establishment of an induced pluripotent stem cell line DHMi005-A from a healthy male proband

We generated an induced pluripotent stem cell (iPSC) line from a healthy male 29-year-old proband. Adipose fibroblasts (AFs) were reprogrammed using Sendai virus. Generated iPSCs showed typical stem cell morphology. From passage 9 on, iPSCs were free of virus. Pluripotency in the iPSCs was verified and spontaneous differentiation showed expression of all three germ layers. Karyotyping indicated no anomalies for the generated iPSCs. Many patient-specific iPSCs are generated from subcutaneous fat fibroblasts obtained during surgical procedure. The described control iPSC line was generated equally and therefore serves as an ideal control for adipose-fibroblast-based patient-specific iPSC lines in disease modeling.

Establishment of a patient-specific induced pluripotent stem cell line DHMi004-A from a male Holt-Oram syndrome patient with verified TBX5 mutation

The Holt-Oram syndrome (HOS) is a rare autosomal dominant disorder, mostly based on mutations in the TBX5 gene. Patients show malformation of at least one upper limb along with congenital heart defects. The established induced pluripotent stem cell (iPSC) line was generated from a patient displaying pronounced and typical features of HOS and carrying a single-nucleotide change c.920_C>A leading to an amino acid change from proline to threonine at amino acid position 85, which appeared de novo. Adipose fibroblasts from the patient were reprogrammed using Sendai virus. Pluripotency of the iPSCs was fully demonstrated.

Clinical Characteristics and Outcomes of Colorectal Cancer in the ColoCare Study: Differences by Age of Onset

Early-onset colorectal cancer has been on the rise in Western populations. Here, we compare patient characteristics between those with early- (<50 years) vs. late-onset (≥50 years) disease in a large multinational cohort of colorectal cancer patients (n = 2193). We calculated descriptive statistics and assessed associations of clinicodemographic factors with age of onset using mutually-adjusted logistic regression models. Patients were on average 60 years old, with BMI of 29 kg/m², 52% colon cancers, 21% early-onset, and presented with stage II or III (60%) disease. Early-onset patients presented with more advanced disease (stages III-IV: 63% vs. 51%, respectively), and received more neo and adjuvant treatment compared to late-onset patients, after controlling for stage (odds ratio (OR) (95% confidence interval (CI)) = 2.30 (1.82-3.83) and 2.00 (1.43-2.81), respectively). Early-onset rectal cancer patients across all stages more commonly received neoadjuvant treatment, even when not indicated as the standard of care, e.g., during stage I disease. The odds of early-onset disease were higher among never smokers and lower among overweight patients (1.55 (1.21-1.98) and 0.56 (0.41-0.76), respectively). Patients with early-onset colorectal cancer were more likely to be diagnosed with advanced stage disease, to have received systemic treatments regardless of stage at diagnosis, and were less likely to be ever smokers or overweight.

Human Engineered Heart Tissue Patches Remuscularize the Injured Heart in a Dose-Dependent Manner

Supplemental Digital Content is available in the text.

Human engineered heart tissue (EHT) transplantation represents a potential regenerative strategy for patients with heart failure and has been successful in preclinical models. Clinical application requires upscaling, adaptation to good manufacturing practices, and determination of the effective dose.

P913What can we expect after valve-in-valve procedures in failed transcatheter aortic valves?

Background/Purpose

With the growing use of transcatheter aortic valve replacement (TAVR), we need to determine if repeat TAVR (TAV-in-TAV) is comparable or even superior to surgical aortic valve replacement followed by TAVR (TAV-in-SAV). Although TAV-in-SAV procedures were shown to provide an almost complete sealing of paravalvular leakage at the expense of elevated gradients, data for TAV-in-TAV are lacking. Hence, we compared echocardiographic and clinical outcome in all TAV-in-TAV and TAV-in-SAV procedures in our institution between Oct. 2007 and July 2017.

Methods

130 consecutive valve-in-valve patients out of 2351 TAVR-patients were identified. 24 patients were excluded. Patient data were analysed from our prospectively collected, institutional database. 93% underwent routine out-patient follow-up at 12 months.

Results

75 TAV-in-SAV (75±8 years, male 60%; STS score 5.2±4.0%) and 31 TAV-in-TAV patients (78±8 years, male 65%; STS score 4.6±2.8%) formed the final study population. The type of TAV was similarly distributed in both groups (self-/balloon-expandable valves [%] 57/43 vs. 61/39) with transfemoral being the most frequent access site (68% vs. 87%). The mode of prosthesis failure was mainly stenosis in the TAV-in-SAV group (77%), whereas it was mainly intraoperative paravalvular regurgitation (90%) in the TAV-in-TAV group. 10% TAV-in-TAV patients (78±10 years, 33% male, STS score 5.1±1.5%) underwent redo-TAVR for prosthesis-degeneration after a mean time of 2614±862 days. The TAV-in-TAV group (90% single session vs. 10% staged: mean gradient 10±4 mmHg vs. 15±3 mmHg, p=0.096; aortic valve area 1.62±0.36 cm2 vs. 1.45±0.18 cm2, p=0.240) showed lower gradients and larger aortic valve areas (Table 1). No major intraprocedural complications occurred in either group. 30-day mortality was 0%.

Table 1 75 TAV-in-SAV discharge 31 TAV-in-TAV discharge p-value 69 TAV-in-SAV 12mFU 30 TAV-in-TAV 12mFU p-value AVA (cm2) * 1.18±0.32 1.61±0.35 <0.001† 1.21±0.36 1.63±0.43 <0.001† Peak Gradient (mmHg) 33±14 23±8 <0.001† 31±14 21±8 <0.001† Mean Gradient (mmHg) 19±8 12±5 <0.001† 18±9 11±4 <0.001† AR (0–3)** 0.4±0.5 0.8±0.7 0.003† 0.4±0.5 0.8±0.6 0.001† LV ejection fraction (%) 49±12 49±16 0.970 54±12 50±10 0.081 *AVA = Aortic valve area; **AR = Aortic regurgitation. 0 = none, 1 = mild, 2 = moderate, 3 = severe. †p<0,05 significant.

Conclusion

Indications for TAV-in-TAV differ from those for TAV-in-SAV. TAV-in-TAV results in significantly lower gradients and larger aortic valve areas with no relevant aortic regurgitation. Accordingly, failed TAV valves may be treated with TAV-in-TAV in the future.

Perceptions Regarding Mentorship Among General Surgery Trainees With Academic Career Intentions

OBJECTIVE

Effective mentorship may be an opportunity to mitigate career de-prioritization, improve stress management, and bolster professional growth. Relatively few studies address specific challenges that occur for general surgery trainees. We conducted a focus group-based investigation to determine facilitators/barriers to effective mentorship among general surgery residents, who are intending to pursue an academic career.

DESIGN

A semistructured focus group study was conducted to explore residents' attitudes and experiences regarding (1) needs for mentorship, (2) barriers to identifying mentors, and (3) characteristics of successful mentor-mentee interactions. Subjects self-identified and were characterized as either "Mentored" or "Nonmentored." Transcriptions were independently reviewed by 3 coders. Inter-rater reliability between the coders was evaluated by calculating Cohen's kappa for each coded item.

SETTING

General surgery residents from 2 academic tertiary hospitals, University of Pittsburgh Medical Center, and University of Washington, participated.

PARTICIPANTS

Thirty-four general surgery trainees were divided into 8 focus groups.

RESULTS

There were no gender-based differences in mentoring needs among residents. Barriers to establishing a relationship with a mentor, such as lack of exposure to faculty, and time and determination on the part of both mentor and mentee, were exacerbated by aspects of surgical culture including gender dynamics, criticism, and hierarchy. Successful relationships between mentee and mentor were perceived to require personal/professional compatibility and a feeling that the mentor is invested in the mentee, while conflicts of interest and neglect detracted from a successful relationship.

CONCLUSIONS

Our investigations demonstrate the importance of surgical hierarchy and culture in facilitating interpersonal interactions with potential mentors. Further studies will be necessary to determine how best to address these barriers.

Corpuls cpr resuscitation device generates superior emulated flows and pressures than LUCAS II in a mechanical thorax model

The provision of sufficient chest compression is among the most important factors influencing patient survival during cardiopulmonary resuscitation (CPR). One approach to optimize the quality of chest compressions is to use mechanical-resuscitation devices. The aim of this study was to compare a new device for chest compression (corpuls cpr) with an established device (LUCAS II). We used a mechanical thorax model consisting of a chest with variable stiffness and an integrated heart chamber which generated blood flow dependent on the compression depth and waveform. The method of blood-flow generation could be changed between direct cardiac-compression mode and thoracic-pump mode. Different chest-stiffness settings and compression modes were tested to generate various blood-flow profiles. Additionally, an endurance test at high stiffness was performed to measure overall performance and compression consistency. Both resuscitation machines were able to compress the model thorax with a frequency of 100/min and a depth of 5 cm, independent of the chosen chest stiffness. Both devices passed the endurance test without difficulty. The corpuls cpr device was able to generate about 10-40% more blood flow than the LUCAS II device, depending on the model settings. In most scenarios, the corpuls cpr device also generated a higher blood pressure than the LUCAS II. The peak compression forces during CPR were about 30% higher using the corpuls cpr device than with the LUCAS II. In this study, the corpuls cpr device had improved blood flow and pressure outcomes than the LUCAS II device. Further examination in an animal model is required to prove the findings of this preliminary study.

Kono-S Anastomosis for Surgical Prophylaxis of Anastomotic Recurrence in Crohn's Disease: an International Multicenter Study

INTRODUCTION

The Kono-S (antimesenteric functional end-to-end handsewn) anastomosis has been used for Crohn's disease in Japan and the USA since 2003 and 2010, respectively. This technique was designed to reduce the risk of anastomotic surgical recurrence. This study reviews the outcomes a decade after the introduction of the Kono-S anastomosis to clinical practice.

METHODS

This study was conducted at five hospitals (four in Japan and one in the USA). A total of 187 patients in Japan (144 patients, group J) and the USA (43 patients, group US) who underwent Kono-S anastomosis for Crohn's disease between September 2003 and September 2011 were included.

RESULTS

With a median follow-up of 65 months, two surgical anastomotic recurrences have occurred in group J. Kaplan-Meier analysis showed that 5 and 10 years surgical recurrence-free survival rate was 98.6% in group J. No surgical anastomotic recurrences have been detected in group US with a median follow-up of 32 months. The Kono-S anastomosis was technically feasible and performed in all patients.

CONCLUSION

The Kono-S anastomosis appears to be safe and effective in reducing the risk of surgical recurrence in Crohn's disease.