Cell-free DNA methylation analysis as a marker of malignancy in pleural fluid.

Diagnosis of malignant pleural effusion (MPE) is made by cytological examination of pleural fluid or histological examination of pleural tissue from biopsy. Unfortunately, detection of malignancy using cytology has an overall sensitivity of 50%, and is dependent upon tumor load, volume of fluid assessed, and cytopathologist experience. The diagnostic yield of pleural fluid cytology is also compromised by low abundance of tumor cells or when morphology is obscured by inflammation or reactive mesothelial cells. A reliable molecular marker that may complement fluid cytology for the diagnosis of malignant pleural effusion is needed. The purpose of this study was to establish a molecular diagnostic approach based on pleural effusion cell-free DNA methylation analysis for the differential diagnosis of malignant pleural effusion and benign pleural effusion. This was a blind, prospective case-control biomarker study. We recruited 104 patients with pleural effusion for the study. We collected pleural fluid from patients with: MPE (n = 48), indeterminate pleural effusion in subjects with known malignancy or IPE (n = 28), and benign PE (n = 28), and performed the Sentinel-MPE liquid biopsy assay. The methylation level of Sentinel-MPE was markedly higher in the MPE samples compared to BPE control samples (p < 0.0001) and the same tendency was observed relative to IPE (p = 0.004). We also noted that the methylation signal was significantly higher in IPE relative to BPE (p < 0.001). We also assessed the diagnostic efficiency of the Sentinel-MPE test by performing receiver operating characteristic analysis (ROC). For the ROC analysis we combined the malignant and indeterminate pleural effusion groups (n = 76) and compared against the benign group (n = 28). The detection sensitivity and specificity of the Sentinel-MPE test was high (AUC = 0.912). The Sentinel-MPE appears to have better performance characteristics than cytology analysis. However, combining Sentinel-MPE with cytology analysis could be an even more effective approach for the diagnosis of MPE. The Sentinel-MPE test can discriminate between BPE and MPE. The Sentinel-MPE liquid biopsy test can detect aberrant DNA in several different tumor types. The Sentinel-MPE test can be a complementary tool to cytology in the diagnosis of MPE.

Cell-Free DNA Methylation Analysis as a Marker of Malignancy in Pleural Fluid.

Background: Diagnosis of malignant pleural effusion (MPE) is made by cytological examination of pleural fluid or histological examination of pleural tissue from biopsy. Unfortunately, detection of malignancy using cytology has an overall sensitivity of 50%, and is dependent upon tumor load, volume of fluid assessed, and cytopathologist experience. The diagnostic yield of pleural fluid cytology is also compromised by low abundance of tumor cells or when morphology is obscured by inflammation or reactive mesothelial cells. A reliable molecular marker that may complement fluid cytology malignant pleural effusion diagnosis is needed. The purpose of this study was to establish a molecular diagnostic approach based on pleural effusion cell-free DNA methylation analysis for the differential diagnosis of malignant pleural effusion and benign pleural effusion. Results: This was a blind, prospective case-control biomarker study. We recruited 104 patients with pleural effusion for the study. We collected pleural fluid from patients with: MPE (n = 48), PPE (n = 28), and benign PE (n = 28), and performed the Sentinel-MPE liquid biopsy assay. The methylation level of Sentinel-MPE was markedly higher in the MPE samples compared to BPE control samples (p < 0.0001) and the same tendency was observed relative to PPE (p = 0.004). We also noted that the methylation signal was significantly higher in PPE relative to BPE (p < 0.001). We also assessed the diagnostic efficiency of the Sentinel-MPE test by performing receiver operating characteristic analysis (ROC). For the ROC analysis we combined the malignant and paramalignant groups (n = 76) and compared against the benign group (n = 28). The detection sensitivity and specificity of the Sentinel-MPE test was high (AUC = 0.912). The Sentinel-MPE appears to have better performance characteristics than cytology analysis. However, combining Sentinel-MPE with cytology analysis could be an even more effective approach for the diagnosis of MPE. Conclusions: The Sentinel-MPE test can discriminate between BPE and MPE. The Sentinel-MPE liquid biopsy test can detect aberrant DNA in several different tumor types. The Sentinel-MPE test can be a complementary tool to cytology in the diagnosis of MPE.

Recurrent Giant Cell Tumor of Bone with New Pulmonary Metastases 9 Years After En Bloc Distal Radius Resection: A Case Report.

CASE: A 31-year-old man with a history of giant cell tumor of bone (GCTB) in the distal radius presents to clinic 9 years after en bloc distal radius resection. He was found to have a new soft tissue mass consistent with GCTB and new pulmonary metastases. Ultimately, he underwent excision of his soft tissue recurrence and partial lobectomy for his lung metastases. CONCLUSION: This case highlights the importance of having a high level of suspicion for local recurrence or metastasis, even years after wide resection and negative margins.

Liquid biopsy, using a novel DNA methylation signature, distinguishes pancreatic adenocarcinoma from benign pancreatic disease.

We tested the ability of a novel DNA methylation biomarker set to distinguish metastatic pancreatic cancer cases from benign pancreatic cyst patients and to monitor tumor dynamics using quantitative DNA methylation analysis of cell-free DNA (cfDNA) from blood samples. The biomarkers were able to distinguish malignant cases from benign disease with high sensitivity and specificity (AUC = 0.999). Furthermore, the biomarkers detected a consistent decline in tumor-derived cfDNA in samples from patients undergoing chemotherapy. The study indicates that our liquid biopsy assay could be useful for management of pancreatic cancer patients.

A Phase II Study Investigating Cabozantinib in Patients with Refractory Metastatic Colorectal Cancer (AGICC 17CRC01).

Purpose: Multi-tyrosine kinase inhibitors (TKI) have shown clinical activity in patients with metastatic colorectal cancer. Cabozantinib, a multi-TKI, exhibited potent antitumor activity superior to regorafenib in preclinical colorectal cancer patient-derived tumor xenograft models. This phase II study aimed to investigate cabozantinib, a multi-TKI, in patients with refractory, metastatic colorectal cancer (mCRC). Experimental Design: A nonrandomized, two-stage, phase II clinical trial evaluating 12-week progression-free survival (PFS) was conducted in eight cancer centers across the United States between May 2018 and July 2020. Results: A total of 44 patients were enrolled between May 2018 and May 2019, 40 of which were response evaluable. Of the total 769 reported adverse events (AE), 93 (12%) were ≥ grade 3. Five grade 5 AEs were reported of which four were unrelated to study drug and one was reported as possibly related due to bowel perforation. Eighteen patients (45%) achieved 12-week PFS with stable disease or better (confidence interval, 0.29-0.62; P < 0.001). One patient (3%) had a partial response, and 27 other patients achieved stable disease as best response per RECISTv1.1. Median PFS was 3.0 months, and median overall survival was 8.3 months. Of the 18 patients who achieved 12-week PFS, 12 had left-sided primary tumors, 11 were RAS wild type, 11 were PIK3CA wild type, and 6 had previous regorafenib therapy. The 12-week PFS rate was higher in RAS wild-type tumors compared with RAS mutant tumors (0.61 vs. 0.32; P = 0.11). Conclusions: This phase II study demonstrated clinical activity of cabozantinib in heavily pretreated, patients with refractory mCRC, and supports further investigation. Significance: Targeting angiogenesis through VEGF axis blockade provides incremental survival benefit in patients with mCRC. The hepatocyte growth factor/MET signal transduction pathway has been observed as a mechanism for acquired resistance. Dual inhibition of VEGF plus MET is an attractive therapeutic strategy. This phase II trial demonstrated clinical activity with cabozantinib, a multi-TKI targeting VEGFR2 and MET, in patients with refractory, mCRC.

An adaptable and non-invasive method for tracking Bifidobacterium animalis subspecies lactis 420 in the mouse gut.

Probiotic strains from the Bifidobacterium or Lactobacillus genera improve health outcomes in models of metabolic and cardiovascular disease. Yet, underlying mechanisms governing these improved health outcomes are rooted in the interaction of gut microbiota, intestinal interface, and probiotic strain. Central to defining the underlying mechanisms governing these improved health outcomes is the development of adaptable and non-invasive tools to study probiotic localization and colonization within the host gut microbiome. The objective of this study was to test labeling and tracking efficacy of Bifidobacterium animalis subspecies lactis 420 (B420) using a common clinical imaging agent, indocyanine green (ICG). ICG was an effective in situ labeling agent visualized in either intact mouse or excised gastrointestinal (GI) tract at different time intervals. Quantitative PCR was used to validate ICG visualization of B420, which also demonstrated that B420 transit time matched normal murine GI motility (~8 hours). Contrary to previous thoughts, B420 did not colonize any region of the GI tract whether following a single bolus or daily administration for up to 10 days. We conclude that ICG may provide a useful tool to visualize and track probiotic species such as B420 without implementing complex molecular and genetic tools. Proof-of-concept studies indicate that B420 did not colonize and establish residency align the murine GI tract.

Absence of Posttraumatic Bone Marrow Edema in the Setting of Preeclampsia.

Magnetic resonance imaging is a powerful tool in the diagnosis of missed or occult fractures on radiographic and computed tomographic (CT) imaging, through the detection of bone marrow edema. Although radiologists often rely on bone marrow edema as a guide for diagnosing subtle underlying fractures, it is important to recognize its limitations as a diagnostic metric. We present a rare case demonstrating the absence of bone marrow edema after acute trauma and confirmed Lisfranc fracture in a patient with preeclampsia and propose an interesting physiologic mechanism to explain this manifestation.

Tales of Mentoring in Radiology: The Experience of Residents and Mentors at a Single Academic Program.

PURPOSE: To investigate the utility of mentoring groups in radiology residency. METHODS: Five assistant professors of Radiology and 20 radiology residents were divided into 5 groups. One resident from each academic year was randomly paired with a mentor group. Three 1-hour group mentoring sessions took place over the year. Upon completion of the project an anonymous Quality Improvement survey of 20 questions were sent out to participants to assess the utility of these mentoring sessions. RESULTS: Four mentors out of 5 responded. All 4 had prior neutral and positive experiences as mentees involving career advice and subspecialty choice. During this experience all mentors had a positive experience. The majority found it helpful to have residents of different levels in their group to allow for peer to peer mentoring and all thought the mentoring program should continue. The most common topics they covered during the sessions were career advice and specialty choice. Sixteen residents out of 20 responded. The majority had had a previous mentor experience which was mostly positive or very positive and predominantly career and/or research related. Almost all of them had a positive or very positive mentoring experience this year. The high majority found that having residents of different levels was beneficial. Topics that mentoring sessions helped mostly with were career advice, work life balance and study skills. All of the mentees thought the mentoring program should continue. CONCLUSIONS: Mentoring groups can be a valuable addition to residency training, especially in helping with career advice and work life balance.

Still Coming Out of the Dark: Enduring Effects of Simulation-Based Communication Skills Training for Radiology Residents-Four-Year Follow-Up.

PURPOSE: To evaluate the long-term efficacy of simulation-based communication skills training for radiology residents. METHOD AND MATERIALS: The simulation-based communication skills training curriculum was developed in 2014. The curriculum included a teaching module based on the essential elements of communication. Two sets of 6 communication scenarios encountered by radiologist were created. First and fourth year radiology residents reviewed the teaching module and completed the 6 simulated scenarios. They then underwent debriefing sessions, received faculty and staff evaluations. Four years later, the former first year residents (now fourth years) reviewed the teaching module again and repeated the simulation. They again underwent debriefing sessions after the simulation. This time the residents' communication skills were evaluated by faculty and staff. RESULTS: A total of 5 residents participated in this simulation-based skills training. The resident performance 4 years after initial training show not only that residents maintained their improved scores, but also that their scores improved further as compared to after the initial training. The average overall score for all but 1 resident increased at the 4 year follow-up simulation. From 2014 to 2018, the average score of all the residents increased from 72.4% to 81.4%. Comparison of the average scores of each student across 6 stations from 2014 to 2018 showed a statistically significant difference between the scores after 4 years (P = 0.014). CONCLUSIONS: Simulation-based communication skills training is effective and long lasting.

Sarcopenia is associated with longer hospital stay and multiorgan dysfunction in alcoholic hepatitis.

INTRODUCTION: Excessive alcohol consumption has steadily risen to become the third leading cause of preventable death in the USA. One consequence of heavy alcohol use recently under considerable investigation is alcoholic hepatitis. Although many risk factors for developing alcoholic hepatitis have been documented, our aim in this study was to examine the potential association between sarcopenia and severity, mortality, 30 days readmission rate, complication, infections and length of hospital stay in alcoholic hepatitis patients. METHODS: A retrospective analysis was performed at a large, academic hospital in 194 alcoholic hepatitis patients aged 18-60 who had cross-sectional computed tomography imaging and met our clinical definition of alcoholic hepatitis. The fifth percentile of the psoas muscle index was used as a cutoff for sarcopenia. RESULTS: One hundred ninety-four patients met the criteria for alcoholic hepatitis and had cross-sectional imaging. Higher Model for End-Stage Liver disease score was found in the sarcopenia group when compared to the non-sarcopenia group (mean Model for End-Stage Liver disease 21.5 and 24.2, respectively, P = 0.03). Sarcopenia also correlated with significantly longer hospital stay; the average length of stay in the sarcopenia group was 17.2 days while the non-sarcopenia patients had an average of 12.4 days. We found higher risk of developing pneumonia, sepsis and hepatic encephalopathy in sarcopenic patients. CONCLUSION: Alcoholic hepatitis patients with sarcopenia have significantly worse outcomes when compared with the patients without sarcopenia, including a severe form of alcoholic hepatitis, longer hospital stays, higher risk of developing pneumonia, sepsis and hepatic encephalopathy.

Identification and quantitation of clinically relevant microbes in patient samples: Comparison of three k-mer based classifiers for speed, accuracy, and sensitivity.

Infections are a serious health concern worldwide, particularly in vulnerable populations such as the immunocompromised, elderly, and young. Advances in metagenomic sequencing availability, speed, and decreased cost offer the opportunity to supplement or even replace culture-based identification of pathogens with DNA sequence-based diagnostics. Adopting metagenomic analysis for clinical use requires that all aspects of the workflow are optimized and tested, including data analysis and computational time and resources. We tested the accuracy, sensitivity, and resource requirements of three top metagenomic taxonomic classifiers that use fast k-mer based algorithms: Centrifuge, CLARK, and KrakenUniq. Binary mixtures of bacteria showed all three reliably identified organisms down to 1% relative abundance, while only the relative abundance estimates of Centrifuge and CLARK were accurate. All three classifiers identified the organisms present in their default databases from a mock bacterial community of 20 organisms, but only Centrifuge had no false positives. In addition, Centrifuge required far less computational resources and time for analysis. Centrifuge analysis of metagenomes obtained from samples of VAP, infected DFUs, and FN showed Centrifuge identified pathogenic bacteria and one virus that were corroborated by culture or a clinical PCR assay. Importantly, in both diabetic foot ulcer patients, metagenomic sequencing identified pathogens 4-6 weeks before culture. Finally, we show that Centrifuge results were minimally affected by elimination of time-consuming read quality control and host screening steps.

PET-CT reveals increased intestinal glucose uptake after gastric surgery.

BACKGROUND: Mechanisms of metabolic improvement after bariatric surgery remain incompletely understood. Intestinal glucose uptake is increased after gastric bypass in rodents, potentially contributing to reduced blood glucose and type 2 diabetes remission. OBJECTIVE: We assessed whether intestinal glucose uptake is increased in humans after gastric surgery. SETTING: University Hospital, United States. METHODS: In a retrospective, case-control cohort study, positron emission tomography-computerized tomography scans performed for clinical indications were analyzed to quantify intestinal glucose uptake in patients with or without history of gastric surgery. We identified 19 cases, defined as patients over age 18 with prior gastric surgery (Roux-en-Y gastric bypass [n = 10], sleeve gastrectomy [n = 1], or Billroth I [n = 2] or II gastrectomy [n = 6]), and 43 controls without gastric surgery, matched for age, sex, and indication for positron emission tomography-computerized tomography. Individuals with gastrointestinal malignancy or metformin treatment were excluded. Images were obtained 60 minutes after 18F-fluorodeoxyglucose injection (4.2 MBq/kg), and corrected by attenuation; noncontrast low-dose computerized tomography was obtained in parallel. Fused and nonfused images were analyzed; standardized uptake values were calculated for each region by volumes of interest at the region of highest activity. RESULTS: Both standardized uptake values maximum and mean were significantly increased by 41% to 98% in jejunum, ascending, and transverse colon in patients with prior gastric surgery (P < .05 versus controls). CONCLUSION: Intestinal glucose uptake is increased in patients with prior gastric surgery. Prospective studies are important to dissect the contributions of weight loss, dietary factors, and systemic metabolism, and to determine the relationship with increased insulin-independent glucose uptake and reductions in glycemia.

Innovative qPCR using interfacial effects to enable low threshold cycle detection and inhibition relief.

Molecular diagnostics offers quick access to information but fails to operate at a speed required for clinical decision-making. Our novel methodology, droplet-on-thermocouple silhouette real-time polymerase chain reaction (DOTS qPCR), uses interfacial effects for droplet actuation, inhibition relief, and amplification sensing. DOTS qPCR has sample-to-answer times as short as 3 min 30 s. In infective endocarditis diagnosis, DOTS qPCR demonstrates reproducibility, differentiation of antibiotic susceptibility, subpicogram limit of detection, and thermocycling speeds of up to 28 s/cycle in the presence of tissue contaminants. Langmuir and Gibbs adsorption isotherms are used to describe the decreasing interfacial tension upon amplification. Moreover, a log-linear relationship with low threshold cycles is presented for real-time quantification by imaging the droplet-on-thermocouple silhouette with a smartphone. DOTS qPCR resolves several limitations of commercially available real-time PCR systems, which rely on fluorescence detection, have substantially higher threshold cycles, and require expensive optical components and extensive sample preparation. Due to the advantages of low threshold cycle detection, we anticipate extending this technology to biological research applications such as single cell, single nucleus, and single DNA molecule analyses. Our work is the first demonstrated use of interfacial effects for sensing reaction progress, and it will enable point-of-care molecular diagnosis of infections.

Characterization of a novel radiation-induced sarcoma cell line.

BACKGROUND: Radiation-induced sarcoma (RIS) is a potential complication of cancer treatment. No widely available cell line models exist to facilitate studies of RIS. METHODS: We derived a spontaneously immortalized primary human cell line, UACC-SARC1, from a RIS. RESULTS: Short tandem repeat (STR) profiling of UACC-SARC1 was virtually identical to its parental tumor. Immunohistochemistry (IHC) analysis of the tumor and immunocytochemistry (ICC) analysis of UACC-SARC1 revealed shared expression of vimentin, osteonectin, CD68, Ki67 and PTEN but tumor-restricted expression of the histiocyte markers α1-antitrypsin and α1-antichymotrypsin. Karyotyping of the tumor demonstrated aneuploidy. Comparative genomic hybridization (CGH) provided direct genetic comparison between the tumor and UACC-SARC1. Sequencing of 740 mutation hotspots revealed no mutations in UACC-SARC1 nor in the tumor. NOD/SCID gamma mouse xenografts demonstrated tumor formation and metastasis. Clonogenicity assays demonstrated that 90% of single cells produced viable colonies. NOD/SCID gamma mice produced useful patient-derived xenografts for orthotopic or metastatic models. CONCLUSION: Our novel RIS strain constitutes a useful tool for pre-clinical studies of this rare, aggressive disease. UACC-SARC1 is an aneuploid cell line with complex genomics lacking common oncogenes or tumor suppressor genes as drivers of its biology. The UACC-SARC1 cell line will enable further studies of the drivers of RIS.

Immortalization of normal human mammary epithelial cells in two steps by direct targeting of senescence barriers does not require gross genomic alterations.

Telomerase reactivation and immortalization are critical for human carcinoma progression. However, little is known about the mechanisms controlling this crucial step, due in part to the paucity of experimentally tractable model systems that can examine human epithelial cell immortalization as it might occur in vivo. We achieved efficient non-clonal immortalization of normal human mammary epithelial cells (HMEC) by directly targeting the 2 main senescence barriers encountered by cultured HMEC. The stress-associated stasis barrier was bypassed using shRNA to p16(INK4); replicative senescence due to critically shortened telomeres was bypassed in post-stasis HMEC by c-MYC transduction. Thus, 2 pathologically relevant oncogenic agents are sufficient to immortally transform normal HMEC. The resultant non-clonal immortalized lines exhibited normal karyotypes. Most human carcinomas contain genomically unstable cells, with widespread instability first observed in vivo in pre-malignant stages; in vitro, instability is seen as finite cells with critically shortened telomeres approach replicative senescence. Our results support our hypotheses that: (1) telomere-dysfunction induced genomic instability in pre-malignant finite cells may generate the errors required for telomerase reactivation and immortalization, as well as many additional "passenger" errors carried forward into resulting carcinomas; (2) genomic instability during cancer progression is needed to generate errors that overcome tumor suppressive barriers, but not required per se; bypassing the senescence barriers by direct targeting eliminated a need for genomic errors to generate immortalization. Achieving efficient HMEC immortalization, in the absence of "passenger" genomic errors, should facilitate examination of telomerase regulation during human carcinoma progression, and exploration of agents that could prevent immortalization.

Three-dimensional printing surgical instruments: are we there yet?

BACKGROUND: The applications for rapid prototyping have expanded dramatically over the last 20 y. In recent years, additive manufacturing has been intensely investigated for surgical implants, tissue scaffolds, and organs. There is, however, scant literature to date that has investigated the viability of three-dimensional (3D) printing of surgical instruments. MATERIALS AND METHODS: Using a fused deposition modeling printer, an Army/Navy surgical retractor was replicated from polylactic acid (PLA) filament. The retractor was sterilized using standard Food and Drug Administration approved glutaraldehyde protocols, tested for bacteria by polymerase chain reaction, and stressed until fracture to determine if the printed instrument could tolerate force beyond the demands of an operating room (OR). RESULTS: Printing required roughly 90 min. The instrument tolerated 13.6 kg of tangential force before failure, both before and after exposure to the sterilant. Freshly extruded PLA from the printer was sterile and produced no polymerase chain reaction product. Each instrument weighed 16 g and required only $0.46 of PLA. CONCLUSIONS: Our estimates place the cost per unit of a 3D-printed retractor to be roughly 1/10th the cost of a stainless steel instrument. The PLA Army/Navy retractor is strong enough for the demands of the OR. Freshly extruded PLA in a clean environment, such as an OR, would produce a sterile ready-to-use instrument. Because of the unprecedented accessibility of 3D printing technology world wide and the cost efficiency of these instruments, there are far reaching implications for surgery in some underserved and less developed parts of the world.

Environmental arsenic exposure and microbiota in induced sputum.

Arsenic exposure from drinking water is associated with adverse respiratory outcomes, but it is unknown whether arsenic affects pulmonary microbiota. This exploratory study assessed the effect of exposure to arsenic in drinking water on bacterial diversity in the respiratory tract of non-smokers. Induced sputum was collected from 10 subjects with moderate mean household water arsenic concentration (21.1 ± 6.4 ppb) and 10 subjects with low household water arsenic (2.4 ± 0.8 ppb). To assess microbiota in sputum, the V6 hypervariable region amplicons of bacterial 16s rRNA genes were sequenced using the Ion Torrent Personal Genome Machine. Microbial community differences between arsenic exposure groups were evaluated using QIIME and Metastats. A total of 3,920,441 sequence reads, ranging from 37,935 to 508,787 per sample for 316 chips after QIIME quality filtering, were taxonomically classified into 142 individual genera and five phyla. Firmicutes (22%), Proteobacteria (17%) and Bacteriodetes (12%) were the main phyla in all samples, with Neisseriaceae (15%), Prevotellaceae (12%) and Veillonellacea (7%) being most common at the genus level. Some genera, including Gemella, Lactobacillales, Streptococcus, Neisseria and Pasteurellaceae were elevated in the moderate arsenic exposure group, while Rothia, Prevotella, Prevotellaceae Fusobacterium and Neisseriaceae were decreased, although none of these differences was statistically significant. Future studies with more participants and a greater range of arsenic exposure are needed to further elucidate the effects of drinking water arsenic consumption on respiratory microbiota.

Maintenance of mitochondrial genomic integrity in the absence of manganese superoxide dismutase in mouse liver hepatocytes.

Manganese superoxide dismutase, encoded by the Sod2 gene, is a ubiquitously expressed mitochondrial antioxidant enzyme that is essential for mammalian life. Mice born with constitutive genetic knockout of Sod2 do not survive the neonatal stage, which renders the longitudinal study of the biochemical and metabolic effects of Sod2 loss difficult. However, multiple studies have demonstrated that tissue-specific knockout of Sod2 in murine liver yields no observable gross pathology or injury to the mouse. We hypothesized that Sod2 loss may have sub-pathologic effects on liver biology, including the acquisition of reactive oxygen species-mediated mitochondrial DNA mutations. To evaluate this, we established and verified a hepatocyte-specific knockout of Sod2 in C57/B6 mice using Cre-LoxP recombination technology. We utilized deep sequencing to identify possible mutations in Sod2 (-/-) mitochondrial DNA as compared to wt, and both RT-PCR and traditional biochemical assays to evaluate baseline differences in redox-sensitive pathways in Sod2 (-/-) hepatocytes. Surprisingly, no mutations in Sod2 (-/-) mitochondrial DNA were detected despite measurable increases in dihydroethidium staining in situ and concomitant decreases in complex II activity indicative of elevated superoxide in the Sod2 (-/-) hepatocytes. In contrast, numerous compensatory alterations in gene expression were identified that suggest hepatocytes have a remarkable capacity to adapt and overcome the loss of Sod2 through transcriptional means. Taken together, these results suggest that murine hepatocytes have a large reserve capacity to cope with the presence of additional mitochondrial reactive oxygen species.

The matrix protein CCN1/CYR61 is required for α(V)ß5-mediated cancer cell migration.

CYR61 is one of the six proteins of the CCN family of proteins known to play diverse roles in angiogenesis, cellular proliferation, survival, migration and wound healing. However, the specific function of CYR61 in cancer is unclear, and the literature remains controversial. We used quantitative real-time PCR to establish the expression profile of CYR61 and integrin α(V)ß5 in three non-small cell lung cancer, five colorectal cancer, one breast cancer and one oesophageal squamous carcinoma cell lines. We showed that the levels of CYR61 were significantly increased in oesophageal squamous carcinoma cell line along with the enhanced levels of α(V)ß5 integrin. Further, we investigated whether tumour cell-secreted CYR61 can facilitate cell migration by interacting with the α(V)ß5 integrin. Using tumour cell lines with low, intermediate and high CYR61 expression and their isogenic variants as a cellular model, we determined that integrin α(V)ß5 expressed on these tumour cells is required for cell migration. Moreover, we showed that the modulation of expression levels of CYR61 in these cancer cells affected their capacity for migration. These results represent an advance to the understanding of the role of CYR61 and α(V)ß5 integrin as proteins that cooperate to mediate cancer cell migration.

The decreased expression of Beclin-1 correlates with progression to esophageal adenocarcinoma: the role of deoxycholic acid.

Beclin-1 has a central role in the regulation of autophagy. Barrett's esophagus (BE) is associated with a significantly increased risk for the development of esophageal adenocarcinoma (EAC). In the current study, we evaluated the role of Beclin-1 and autophagy in the EAC. Biopsies obtained from patients with BE and EAC, tissues from a rat model of BE and EAC, and esophageal cell lines were evaluated for the expression of Beclin-1 by immunohistochemistry, immunoblotting, or RT-PCR. Since reflux of bile acids is important in EAC, we also evaluated the effect of exposure to deoxycholic acid (DCA) on autophagy and Beclin-1 expression. Beclin-1 expression was high in squamous epithelium and nondysplastic BE, whereas its expression was low in dysplastic BE and EAC. The same pattern of expression was observed in rat tissues and in esophageal cell lines. Normal esophageal epithelium and HET-1A cells (derived from normal squamous epithelium) show high levels of Beclin-1, but lower levels of Beclin-1 were found in BE and EAC cell lines (CP-A, CP-C, and OE33). Acute exposure to DCA led to increased Beclin-1 expression and increased autophagy as evaluated by electron microscopy and counting percentage of GFP-LC3-positive BE cells with punctate pattern. In contrast, chronic exposure to DCA did not result in the alteration of Beclin-1 levels or autophagy. In summary, these data suggest that autophagy is initially activated in response to bile acids, but chronic exposure to bile acids leads to decreased Beclin-1 expression and autophagy resistance.