Genome and clonal hematopoiesis stability contrasts with immune, cfDNA, mitochondrial, and telomere length changes during short duration spaceflight

Background

The Inspiration4 (I4) mission, the first all-civilian orbital flight mission, investigated the physiological effects of short-duration spaceflight through a multi-omic approach. Despite advances, there remains much to learn about human adaptation to spaceflight's unique challenges, including microgravity, immune system perturbations, and radiation exposure.

Methods

To provide a detailed genetics analysis of the mission, we collected dried blood spots pre-, during, and post-flight for DNA extraction. Telomere length was measured by quantitative PCR, while whole genome and cfDNA sequencing provided insight into genomic stability and immune adaptations. A robust bioinformatic pipeline was used for data analysis, including variant calling to assess mutational burden.

Result

Telomere elongation occurred during spaceflight and shortened after return to Earth. Cell-free DNA analysis revealed increased immune cell signatures post-flight. No significant clonal hematopoiesis of indeterminate potential (CHIP) or whole-genome instability was observed. The long-term gene expression changes across immune cells suggested cellular adaptations to the space environment persisting months post-flight.

Conclusion

Our findings provide valuable insights into the physiological consequences of short-duration spaceflight, with telomere dynamics and immune cell gene expression adapting to spaceflight and persisting after return to Earth. CHIP sequencing data will serve as a reference point for studying the early development of CHIP in astronauts, an understudied phenomenon as previous studies have focused on career astronauts. This study will serve as a reference point for future commercial and non-commercial spaceflight, low Earth orbit (LEO) missions, and deep-space exploration.

Ectopic Expression of a Truncated Isoform of Hair Keratin 81 in Breast Cancer Alters Biophysical Characteristics to Promote Metastatic Propensity

Keratins are an integral part of cell structure and function. Here, it is shown that ectopic expression of a truncated isoform of keratin 81 (tKRT81) in breast cancer is upregulated in metastatic lesions compared to primary tumors and patient-derived circulating tumor cells, and is associated with more aggressive subtypes. tKRT81 physically interacts with keratin 18 (KRT18) and leads to changes in the cytosolic keratin intermediate filament network and desmosomal plaque formation. These structural changes are associated with a softer, more elastically deformable cancer cell with enhanced adhesion and clustering ability leading to greater in vivo lung metastatic burden. This work describes a novel biomechanical mechanism by which tKRT81 promotes metastasis, highlighting the importance of the biophysical characteristics of tumor cells.

Collection of Biospecimens from the Inspiration4 Mission Establishes the Standards for the Space Omics and Medical Atlas (SOMA)

The SpaceX Inspiration4 mission provided a unique opportunity to study the impact of spaceflight on the human body. Biospecimen samples were collected from the crew at different stages of the mission, including before (L-92, L-44, L-3 days), during (FD1, FD2, FD3), and after (R+1, R+45, R+82, R+194 days) spaceflight, creating a longitudinal sample set. The collection process included samples such as venous blood, capillary dried blood spot cards, saliva, urine, stool, body swabs, capsule swabs, SpaceX Dragon capsule HEPA filter, and skin biopsies, which were processed to obtain aliquots of serum, plasma, extracellular vesicles, and peripheral blood mononuclear cells. All samples were then processed in clinical and research laboratories for optimal isolation and testing of DNA, RNA, proteins, metabolites, and other biomolecules. This paper describes the complete set of collected biospecimens, their processing steps, and long-term biobanking methods, which enable future molecular assays and testing. As such, this study details a robust framework for obtaining and preserving high-quality human, microbial, and environmental samples for aerospace medicine in the Space Omics and Medical Atlas (SOMA) initiative, which can also aid future experiments in human spaceflight and space biology.

Drainless robot-assisted minimally invasive oesophagectomy-randomized controlled trial (RESPECT)

BACKGROUND

The purpose of this randomized trial is to evaluate the early removal of postoperative drains after robot-assisted minimally invasive oesophagectomy (RAMIE). Evidence is lacking about feasibility, associated pain, recovery, and morbidity.

METHODS/DESIGN

This is a randomized controlled multicentric trial involving 72 patients undergoing RAMIE. Patients will be allocated into two groups. The "intervention" group consists of 36 patients. In this group, abdominal and chest drains are removed 3 h after the end of surgery in the absence of contraindications. The control group consists of 36 patients with conventional chest drain management. These drains are removed during the further postoperative course according to a standard algorithm. The primary objective is to investigate whether postoperative pain measured by NRS on the second postoperative day can be significantly reduced in the intervention group. Secondary endpoints are the intensity of pain during the first week, analgesic use, number of postoperative chest X-ray and CT scans, interventions, postoperative mobilization (steps per day as measured with an activity tracker), postoperative morbidity and mortality.

DISCUSSION

Until now, there have been no trials investigating different intraoperative chest drain strategies in patients undergoing RAMIE for oesophageal cancer with regard to perioperative complications until discharge. Minimally invasive approaches combined with enhanced recovery after surgery (ERAS) protocols lower morbidity but still include the insertion of chest drains. Reduction and early removal have been proposed after pulmonary surgery but not after RAMIE. The study concept is based on our own experience and the promising current results of the RAMIE procedure. Therefore, the presented randomized controlled trial will provide statistical evidence of the effectiveness and feasibility of the "drainless" RAMIE.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05553795. Registered on 23 September 2022.

Finding the best available evidence in pancreatic surgery – the EVIglance randomised controlled trial

Objective

Profound and thorough literature search is a vital element of evidence-based medicine. However, increasing number of publications and limited time make it hard to find the best available evidence. The objective of this randomised controlled trial (RCT) was to demonstrate the superiority of the ISGPS Evidence Map of Pancreatic Surgery (via EVIglance on www.evidencemap.surgery) compared to a conventional literature search via PubMed for answering clinically relevant questions in pancreatic surgery.

Methods

A single-centre, blinded, cross-over RCT including medical students, residents and consultants as participants was performed. Participants conducted literature searches with two predefined PICO (Patient, Intervention, Control, Outcome) questions, one with PubMed and the other with EVIglance. The order of the search tools and the PICO questions were assigned by randomisation. Primary endpoint was time in minutes until a synopsis was made regarding the PICO question. The synopsis was characterised by the direction of the effect and the certainty of evidence. Three times 28 participants were needed to show a minimal difference of 3 minutes at a level of significance of alpha = 1.67%. Furthermore, the correct number of RCTs found by participants that were relevant to answer the PICO question was analysed.

Results

Each 28 medical students, residents and consultants were randomised and analysed. A synopsis for the PICO question was found with PubMed after 10.8 minutes and with EVIglance after 1.7 minutes (95%-CI for difference: 9.9 to 8.3 minutes; p<0.001). EVIglance answered the PICO significantly faster in all groups (medical students, residents and consultants) even after Bonferroni correction. Participants were able to guess both the direction of the effect (95% vs 48%; p<0.001) and the certainty of evidence (99% vs 30%; p<0.001) better with EVIglance than with PubMed. The correct number of relevant RCTs to answer the PICO question was found more often with EVIglance compared to PubMed (99% vs 15%; p<0.001).

Conclusion

Pancreatic surgeons find best available evidence faster via EVIglance on www.evidencemap.surgery. Furthermore, a synopsis made from EVIglance is more concise regarding direction of effect and certainty of evidence. Given the advantages of EVIglance it may be considered the new gold standard for finding best available evidence in pancreatic surgery.

Bowel dysfunction after elective spinal surgery: etiology, diagnostics and management based on the medical literature and experience in a university hospital

BACKGROUND

Bowel dysfunction after spinal surgery is often underestimated and if not treated in a timely manner can lead to undesirable surgical interventions or fatal complications. The current medical literature primarily focuses on bowel dysfunction as a result of spinal injury.

OBJECTIVE

The purpose of this review is to explore this topic in evaluating current evidence regarding the causes of acute bowel dysfunction after elective spinal surgery, primarily the thoracolumbar spine. Since available evidence for recommendations of treatment is scarce, an interdisciplinary management approach for treatment of bowel dysfunction following spinal surgery is also formulated.

MATERIAL AND METHODS

An extensive literature search was carried out on PubMed. Keywords that were used in the search included bowel dysfunction, obstruction, postoperative ileus, spinal surgery, spinal fusion, constipation, opioid-induced constipation, colonic pseudo-obstruction, ischemic colitis, immobility-induced bowel changes, epidural anesthesia and diet. Relevant studies were chosen and included in the review. The treatment approach used in the spine center of a university hospital was included.

RESULTS

Current research mainly focuses on investigating the nature and symptomatology of chronic bowel dysfunction after spinal cord injury. Emphasis on the acute phase of bowel dysfunction in patients after elective spinal surgery is lacking. The comorbidities that exacerbate bowel dysfunction postoperatively are well-defined. There has been refinement and expansion of the pharmacological and nonpharmacological treatment that could be implemented. Enough evidence exists to provide sufficient care.

CONCLUSION

Management of acute bowel dysfunction after spinal surgery requires a comprehensive and individualized approach, encompassing comorbidities, behavioral changes, medications and surgery. Close supervision and timely treatment could minimize further complications. Research is required to identify patients who are at a higher risk of developing bowel dysfunction after specific spinal procedures.

Author Correction: PIC&RUN: An integrated assay for the detection and retrieval of single viable circulating tumor cells

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Insights into brain metastasis: Recent advances in circulating tumor cell research

Background

How tumor cells disseminate to brain and establish brain metastasis remains partly an unsolved problem. This devastating complication of many cancers is initiated by a rare subset of the circulating tumor cells (CTCs) shed into the blood stream. Thus, the profiling of the molecular properties in these brain metastasis‐initiating CTCs is essential to uncover the mechanisms underlying brain metastasis.

Recent Findings

Important efforts to improve the enrichment and detection of CTCs enabled the detailed molecular and functional analysis of CTCs that drive brain metastasis. In this review, we highlight key findings on existing preclinical studies that provide insights toward a comprehensive picture of brain metastasis‐precursors in CTCs and the potential clinical implications.

Conclusion

A deeper understanding of the brain metastasis precursors should help to stratify high‐risk patients and improve preventive therapeutic strategies. Although all these preclinical evidences have yet to be translated into patients, they provide considerable hope to benefit patients with brain metastases in the future.

Circulating Tumor Cells Exhibit Metastatic Tropism and Reveal Brain Metastasis Drivers

Hematogenous metastasis is initiated by a subset of circulating tumor cells (CTC) shed from primary or metastatic tumors into the blood circulation. Thus, CTCs provide a unique patient biopsy resource to decipher the cellular subpopulations that initiate metastasis and their molecular properties. However, one crucial question is whether CTCs derived and expanded ex vivo from patients recapitulate human metastatic disease in an animal model. Here, we show that CTC lines established from patients with breast cancer are capable of generating metastases in mice with a pattern recapitulating most major organs from corresponding patients. Genome-wide sequencing analyses of metastatic variants identified semaphorin 4D as a regulator of tumor cell transmigration through the blood-brain barrier and MYC as a crucial regulator for the adaptation of disseminated tumor cells to the activated brain microenvironment. These data provide the direct experimental evidence of the promising role of CTCs as a prognostic factor for site-specific metastasis. SIGNIFICANCE: Interests abound in gaining new knowledge of the physiopathology of brain metastasis. In a direct metastatic tropism analysis, we demonstrated that ex vivo-cultured CTCs from 4 patients with breast cancer showed organotropism, revealing molecular features that allow a subset of CTCs to enter and grow in the brain.This article is highlighted in the In This Issue feature, p. 1.

Abstract 3023: Dissecting mechanisms of breast cancer metastasis through patient-derived circulating tumor cells

During tumor progression, tumor cells invade the primary tumor microenvironment and intravasate into blood vessels, where they are referred to as circulating tumor cells (CTCs). These CTCs disseminate to other organs, and a subset of these cells will form metastasis. The growing interest for CTCs is confronted with the difficulty associated with their isolation and scarcity of material. To address this challenge, our established CTC lines from breast cancer patients offered a unique opportunity to investigate the signal pathways involved in the metastatic cascade. We assessed the metastatic potential of breast cancer patient-derived CTC lines by injecting them directly into the left ventricle of the heart in NSG mice. CTC lines are capable of generating metastases in most organs that are listed as common sites of metastases from breast cancer, such as the brain, lungs, bones and ovaries. Two patient-derived CTC lines harbored a high metastatic potential (over 80% of mice had metastases after 3 months) with generation of simultaneous metastases in the bones, lungs and ovaries. These mice remained brain-metastases free for up to 8 months. However, in 2 patient-derived CTC lines we demonstrated the brain as the preferential site of metastasis despite their low metastatic potential. Interestingly, in our mouse model, CTC lines recapitulated human cancer metastatic progression, as shown by the clinical data collected from patients where CTC lines were generated. We further investigated genetic and epigenetic determinants that regulate the organotropism of CTCs. To address this we isolated metastatic variants with a preferential tropism for the brain, lungs and bones. Investigating the gene expression signatures of metastatic variants lead us to identify the semaphorin 4D as a possible regulator of the brain metastasis. High SEMA4D expression at the primary site correlated with decreased brain metastasis-free survival in the breast cancer patients. Amplification of the chromosome 9 where the SEMA4D gene resides was also found in CTC-derived brain metastases. The SEMA4D overexpression promoted the ability of CTCs to transmigrate the blood-brain-barrier in vitro. We simultaneously investigated expression changes in stromal cells in organ-specific metastases, and among the pathways with the highest enrichment scores we found TNF and IFN signaling in the brain metastatic microenvironment. Next we used ATAC-seq to assay chromatin accessibility and identified potential regulatory factors mediating the brain metastasis formation. These data provides the evidence for the promising role of CTCs as an early prognostic factor for metastasis. Additionally, we expect to develop novel organ tropism associated markers, which can be considered for potential therapeutic targets in breast cancer.

Citation Format: Remi Klotz, Amal Thomas, Sara Restrepo-Vassalli, Oihana Iriondo, Jane Han, Teng Teng, Matthew MacKay, Alan Wang, Negeen Izadian, Byoung-San Moon, Aditya Bardia, James Hicks, Andrew Smith, Min Yu. Dissecting mechanisms of breast cancer metastasis through patient-derived circulating tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3023.

Abstract 1045: Understanding breast cancer metastasis through circulating tumor cells

Due to the advance in technologies for rare cell isolation, circulating tumor cells (CTC) have recently received vast interest. During tumor progression tumor cells invade the primary tumor microenvironment and intravasate into blood vessels, where they are referred as CTCs. These CTCs disseminate to other organs and a subset of these cells will be able to form metastasis. The growing interest for CTC is confronted with the difficulty associated with their isolation and characterization. To address this challenge, our lab has recently optimized the ex vivo culture condition and was able to establish CTC lines from breast cancer patients. These CTC lines constitute a unique cell population in the metastatic process and gave us a rare opportunity to investigate the signal pathways involved in each step of the metastatic cascade. To assess the metastatic potential of breast cancer patient-derived CTC lines we utilized an experimental mouse model for metastasis by injecting CTCs directly into the left ventricle of the heart in female immuodeficient NSG mice. The ability of 4 CTC lines to arrest and colonize in organ was monitored by bioluminescence imaging once every 2 weeks for 5 months. CTC lines were capable of generating brain, lung, bone and ovary metastases. Most of those organs are common sites of metastases in breast cancer patients. Two patient-derived CTC lines have a high metastatic potential (over 80% of mice had metastases after 3 months) with generation of simultaneous metastases in multiple organs such as bone, lung and Ovary. These mice remained brain-metastases free for up to 8 months. However, two other patient-derived CTC lines demonstrated the brain as preferential site of metastasis despite their overall low metastatic potential. Interestingly, of 4 breast cancer patients where CTC lines were generated, one developed a metastatic brain tumor and her CTC line has the highest risk of brain metastases in our mouse model. We further investigated genetic and epigenetic determinants that regulate the organotropism of CTCs. We isolated metastatic variants corresponding to a subpopulation of CTCs with a preferential tropism for the brain, lung and bone. Gene expression analysis (RNA-seq) of these variants identified potential gene signatures of breast cancer metastasis. The pathways with the highest enrichment scores were glioblastoma multiform, ceramide biosynthesis and PCP pathway for the brain metastatic variants and were interferon and mTOR signaling for the lung metastatic variants. Next we used a method for assaying chromatin accessibility (ATAC-seq) and identified potential regulatory regions mediating the organ tropism in breast cancer. Together our data provide the evidence of a promising role of CTC as an early prognostic factor in metastasis. Additionally, we expect to develop novel organ tropism associated markers, which can be considered for potential therapeutic targets in breast cancers.

Citation Format: Remi Klotz, Thomas Amal, Alan Wang, Matthew Mackay, Kathleen Heller, Lin Li, Maxwell Serowoky, Grace Lee, Jane Han, Andrew Smith, Min Yu. Understanding breast cancer metastasis through circulating tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1045. doi:10.1158/1538-7445.AM2017-1045

Abstract P6-01-04: DDB2 a new regulator of metabolism and cell death in human breast tumor cells

The protein Damaged DNA Binding-2 (DDB2) is well known for its role in DNA repair by nucleotide excision repair. Interestingly, DDB2 is differentially expressed in breast cancer expressing the estrogen receptor alpha or not. Recent works performed in our laboratory showed a new role of DDB2 in the control of proliferation and invasive abilities in different breast tumor cells through its involvement in the transcriptional regulation of target genes. Two genes involved in tumorigenic processes, MnSOD (manganese superoxide dismutase) and IκBα (inhibitor alpha of Nuclear Factor-kappa B), have been found to be regulated by DDB2. In addition, transcriptomic analyses on cells that differentially express DDB2 showed that several genes involved in the regulation of cellular metabolism are modulated. Our aim is now to focus on the effects of DDB2 expression on cellular metabolism and glycolysis. The results indicated that the overexpression of DDB2 leads to a respiratory chain dysfunction and an increase of the glycolytic pathway. Moreover, we observed an increased production of reactive oxygen species in these cells, compared to parental cells. As mitochondria are involved in cell death, we performed different experiments to evaluate the impact of DDB2 in the response to anticancer agents (Doxorubicin, and 5-fluorouracile (5-FU)) commonly used in the treatment of breast cancer. Interestingly, the cells exhibit a greater sensitivity to anticancer drugs when DDB2 is overexpressed. As these two agents are related to DNA damaged, we have also used other molecules, the apoptotic inducer, TNFα (Tumor Necrosis Factor alpha), and the Paclitaxel (an antimicrotubule agent) to precise the role of DDB2 on cell death. Similar results were obtained, thus demonstrating the influence of DDB2 overexpression in the response to cell death. The identification of molecular mechanisms responsible for these cellular modifications could place DDB2 and these target genes as predictive markers of sensitivity to anticancer drugs in breast cancer.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-01-04.

Why do patients with erectile dysfunction abandon effective therapy with sildenafil (Viagra)?

This prospective study determined the rate of abandonment of sildenafil therapy and assessed the reasons for abandonment. Between January 2001 and December 2002, 234 patients with erectile dysfunction (ED) at three independent centers successfully began therapy with sildenafil 50 or 100 mg. The rate of noncompliance was 31%. A telephone survey of these patients was conducted to determine the reasons for abandonment. The majority reported that they had had no opportunity or desire for sexual intercourse or that their partners had shown no sexual interest. Few patients stated that the high cost of the medication or that adverse events were the cause.

The Tetrafigap Survey on the long-term outcome of tetraplegic spinal cord injured persons: Part III. Medical complications and associated factors

STUDY DESIGN

To study the short- and long-term medical complications encountered in tetraplegic spinal cord injured persons (TSCI) and to give prominence to both the medical and socio-economic factors with which they are respectively associated.

METHODS

The Tetrafigap Study is a multicentre epidemiological survey carried out using self-administered questionnaires studying the global long-term outcome of TSCI patients after the initial phase of rehabilitation.

RESULTS

The data for 1668 patients were analyzed. The rate of rehospitalizations was 74.4% with on average three stays per patient and as reported causes, in descending order: urinary complications, systematic follow-up, pressure sores, respiratory complications, contractures, bowel complications, pains and secondary fractures of the lower limbs. At the time of the survey, 84.7% of patients mentioned awkward contractures, 73.8% pains, 55.9% embarrassing urinary leakage and 14.1% pressure sores. With regard to persons suffering from complete motor lesion, urinary complications and pressure sores were more frequently reported, whereas for persons suffering from incomplete motor lesions, awkward contractures and pains were more frequent. In the elderly, pains were more often mentioned, and pressure sores and pain were also the most common in patients coming from lower socio-professional status. Contractures and pain decreased with time. All these complications but pressure sores and pain are statistically interrelated.

CONCLUSION

The medical complications of spinal cord injured persons are frequent, they are linked to biological, psychological and environmental factors, and are interrelated. Therefore, seeking mid- and long-term risk factors must be given priority in order to better adapt attempts at increasing secondary prevention.

Enterobacter aerogenes primary bacteremia in pediatric patients

Enterobacter aerogenes bacteremia associated with the infusion of contaminated admixed intravenous (IV) fluid occurred in seven patients in a pediatric hospital over a five-day period. Clinical illness was characterized by spiking fever in all patients. The temporal clustering of cases allowed for rapid recognition of the problem. The primary control measure was the prompt replacement of the IV fluids, although IV antibiotics were also administered. Hospital pharmacy practices for admixing IV solutions should follow published recommendations to minimize this source of potential contamination of fluids.