Circulating tumor DNA dynamics analysis in a xenograft mouse model with esophageal squamous cell carcinoma

BACKGROUND

It remains unclear which factors, such as tumor volume and tumor invasion, influence circulating tumor DNA (ctDNA), and the origin of ctDNA in liquid biopsy is always problematic. To use liquid biopsies clinically, it will be very important to address these questions.

AIM

To assess the origin of ctDNA, clarify the dynamics of ctDNA levels, assess ctDNA levels by using a xenograft mouse after treatment, and to determine whether tumor volume and invasion are related to ctDNA levels.

METHODS

Tumor xenotransplants were established by inoculating BALB/c-nu/nu mice with the TE11 cell line. Groups of mice were injected with xenografts at two or four sites and sacrificed at the appropriate time point after xenotransplantation for ctDNA analysis. Analysis of ctDNA was performed by droplet digital PCR, using the human telomerase reverse transcriptase (hTERT) gene.

RESULTS

Mice given two-site xenografts were sacrificed for ctDNA at week 4 and week 8. No hTERT was detected at week 4, but it was detected at week 8. However, in four-site xenograft mice, hTERT was detected both at week 4 and week 6. These experiments revealed that both tumor invasion and tumor volume were associated with the detection of ctDNA. In resection experiments, hTERT was detected at resection, but had decreased by 6 h, and was no longer detected 1 and 3 d after resection.

CONCLUSION

We clarified the origin and dynamics of ctDNA, showing that tumor volume is an important factor. We also found that when the tumor was completely resected, ctDNA was absent after one or more days.

Evaluation of complete cold forceps polypectomy resection rate for 3- to 5-mm colorectal polyps

BACKGROUND AND STUDY AIMS

The propriety of cold forceps polypectomy (CFP) using jumbo biopsy forceps for diminutive polyps remains controversial. We conducted a prospective study to evaluate the complete CFP resection rate of 3-5-mm polyps using additional endoscopic mucosal resection (EMR) specimens following CFP.

PATIENTS AND METHODS

Patients with 3-5-mm protruded or flat elevated colorectal polyps diagnosed endoscopically as adenomas or serrated lesions were prospectively enrolled. CFP using jumbo biopsy forceps was used to remove the eligible polyps and repeated until the absence of residuals were confirmed via image-enhanced endoscopy or chromoendoscopy. After CFP, saline was injected at the defect, and the marginal specimen of the defect was resected using EMR to histologically evaluate the residue. The primary outcome was the complete CFP resection rate, which was defined as no residue at the EMR site. Other outcomes were the number of CFP bites and the complete resection rate by lesion size.

RESULTS

Eighty patients with 120 polyps were enrolled. The mean polyp size was 4.1 ± 0.7 mm. The overall complete resection rate was 96.7% (95% confidence interval [CI], 91.7-98.7), and the rates for 3-, 4- and 5-mm polyps were 100% (95% CI, 86.7-100), 96.0% (95% CI, 86.5-98.9) and 95.5% (95% CI, 85.1-98.8), respectively. The one-bite CFP rates were 92%, 60% and 31% for the 3-, 4- and 5-mm polyps, respectively.

CONCLUSIONS

The complete CFP resection rate for 3-5-mm polyps was acceptable, although the one-bite clearance rate decreased as the polyp size increased (UMIN000028841).

Pre-operative endovascular coil embolisation for chronic pulmonary aspergillosis

OBJECTIVE: To retrospectively evaluate the clinical outcomes of pre-operative endovascular coil embolisation (ECE) for chronic pulmonary aspergillosis (CPA).METHODS: We evaluated surgical patients with CPA between November 2016 and April 2020. Pre-operative ECE for CPA with severe adhesions was selectively performed to reduce intra-operative blood loss. ECE procedures, operative procedures, intra-operative blood loss and complications were evaluated.RESULTS: Twenty-eight patients (21 males and 7 females; median age: 55 years) were included in the study. Of the 28 patients, 8 (28.6%) underwent pre-operative ECE. Technical success rate in pre-operative ECE was 100%. The median time required for ECE procedures was 123 min. The median number of vessels embolised per procedure was 2.5. The median period between embolisation and surgery was 5 days. Major complications were observed in three patients (10.7%). There were no significant differences between patients with and without pre-operative ECE in operative time (284 vs. 365 min, respectively, P = 0.7602) and intra-operative blood loss (294 vs. 228 mL, respectively, P = 0.8987).CONCLUSIONS: Pre-operative ECE for CPA appears to be feasible and safe; however, its role in reducing intra-operative blood loss needs further investigation.

Heterogeneous distribution of Fusobacterium nucleatum in the progression of colorectal cancer

BACKGROUND AND AIM

Fusobacterium nucleatum (Fn) is involved in colorectal cancer (CRC) growth and is a biomarker for patient prognosis and management. However, the ecology of Fn in CRC and the distribution of intratumoral Fn are unknown.

METHODS

We evaluated Fn and the status of KRAS and BRAF in 200 colorectal neoplasms (118 adenomas and 82 cancers) and 149 matched adjacent normal mucosas. The differentiation status between "surface" and "deep" areas of cancer tissue and matched normal mucosa were analyzed in 46 surgical samples; the Ki-67 index was also evaluated in these samples.

RESULTS

Fusobacterium nucleatum presence in the tumor increased according to pathological stage (5.9% [adenoma] to 81.8% [stage III/IV]), while Fn presence in normal mucosa also increased (7.6% [adenoma] to 40.9% [stage III/IV]). The detection rates of Fn on the tumor surface and in deep areas were 45.7% and 32.6%, while that of normal mucosa were 26.1% and 23.9%, respectively. Stage III/IV tumors showed high Fn surface area expression (66.7%). Fn intratumoral heterogeneity (34.8%) was higher than that of KRAS (4.3%; P < 0.001) and BRAF (2.2%; P < 0.001). The Ki-67 index in Fn-positive cases was higher than that in negative cases (93.9% vs 89.0%; P = 0.01).

CONCLUSIONS

Fusobacterium nucleatum was strongly present in CRC superficial areas at stage III/IV. The presence of Fn in the deep areas of adjacent normal mucosa also increased. The intratumoral heterogeneity of Fn is important in the use of Fn as a biomarker, as Fn is associated with CRC proliferative capacity.

Leucine-rich alpha-2 glycoprotein as a marker of mucosal healing in inflammatory bowel disease

Leucine-rich alpha-2 glycoprotein (LRG) may be a novel serum biomarker for patients with inflammatory bowel disease. The association of LRG with the endoscopic activity and predictability of mucosal healing (MH) was determined and compared with those of C-reactive protein (CRP) and fecal markers (fecal immunochemical test [FIT] and fecal calprotectin [Fcal]) in 166 ulcerative colitis (UC) and 56 Crohn's disease (CD) patients. In UC, LRG was correlated with the endoscopic activity and could predict MH, but the performance was not superior to that of fecal markers (areas under the curve [AUCs] for predicting MH: LRG: 0.61, CRP: 0.59, FIT: 0.75, and Fcal: 0.72). In CD, the performance of LRG was equivalent to that of CRP and Fcal (AUCs for predicting MH: LRG: 0.82, CRP: 0.82, FIT: 0.70, and Fcal: 0.88). LRG was able to discriminate patients with MH from those with endoscopic activity among UC and CD patients with normal CRP levels. LRG was associated with endoscopic activity and could predict MH in both UC and CD patients. It may be particularly useful in CD.

Prediction of the prognosis of advanced hepatocellular carcinoma by TERT promoter mutations in circulating tumor DNA

BACKGROUND ANDAIM

Human telomerase reverse transcriptase (TERT) promoter mutations were the most prevalent mutations in patients with hepatocellular carcinoma (HCC). We tried to detect the mutations with plasma circulating tumor DNA (ctDNA) in patients with advanced HCC and elucidated their clinical utility.

METHODS

Circulating tumor DNA in plasma was extracted from 130 patients with advanced HCC who were treated with systemic chemotherapy (n = 86) or transcatheter arterial chemoembolization (n = 44), and TERT promoter mutations were examined with digital droplet polymerase chain reaction. The correlations between these mutations and the clinical outcome of patients were analyzed.

RESULTS

Of the 130 patients examined, 71 patients (54.6%) were positive for TERT promoter mutations in ctDNA, of which 64 patients were -124bp G > A and 10 were -146bp G > A. The presence of TERT promoter mutations was correlated with large intrahepatic tumor size (P = 0.05) and high des-gamma carboxyprothrombin (P = 0.005). Overall survival of the patients with the mutations was significantly shorter than those without them (P < 0.001), and the patients with high (≥ 1%) fractional abundance of the mutant alleles showed shorter survival than those with low (< 1%) fractional abundance. Multivariate analysis revealed that TERT promoter mutation (hazard ratio [HR]: 1.94; 95% confidence interval [CI], 1.18-3.24; P < 0.01), systemic chemotherapy (HR: 2.38; 95% CI, 1.29-4.57; P < 0.01), and vascular invasion (HR: 2.16; 95% CI, 1.22-3.76; P < 0.01) were significant factors for poor overall survival.

CONCLUSIONS

TERT promoter mutations in ctDNA were associated with short survival and could be a valuable biomarker for predicting the prognosis of patients with advanced HCC.

Ion tracks in silicon formed by much lower energy deposition than the track formation threshold

Damaged regions of cylindrical shapes called ion tracks, typically in nano-meters wide and tens micro-meters long, are formed along the ion trajectories in many insulators, when high energy ions in the electronic stopping regime are injected. In most cases, the ion tracks were assumed as consequences of dense electronic energy deposition from the high energy ions, except some cases where the synergy effect with the nuclear energy deposition plays an important role. In crystalline Si (c-Si), no tracks have been observed with any monomer ions up to GeV. Tracks are formed in c-Si under 40 MeV fullerene (C₆₀) cluster ion irradiation, which provides much higher energy deposition than monomer ions. The track diameter decreases with decreasing the ion energy until they disappear at an extrapolated value of ~ 17 MeV. However, here we report the track formation of 10 nm in diameter under C₆₀ ion irradiation of 6 MeV, i.e., much lower than the extrapolated threshold. The diameters of 10 nm were comparable to those under 40 MeV C₆₀ irradiation. Furthermore, the tracks formed by 6 MeV C₆₀ irradiation consisted of damaged crystalline, while those formed by 40 MeV C₆₀ irradiation were amorphous. The track formation was observed down to 1 MeV and probably lower with decreasing the track diameters. The track lengths were much shorter than those expected from the drop of S_e below the threshold. These track formations at such low energies cannot be explained by the conventional purely electronic energy deposition mechanism, indicating another origin, e.g., the synergy effect between the electronic and nuclear energy depositions, or dual transitions of transient melting and boiling.

Liquid biopsy for patients with IBD-associated neoplasia

Background

It is often difficult to diagnose inflammatory bowel disease (IBD)-associated neoplasia endoscopically due to background inflammation. In addition, due to the absence of sensitive tumor biomarkers, countermeasures against IBD-associated neoplasia are crucial. The purpose of this study is to develop a new diagnostic method through the application of liquid biopsy.

Methods

Ten patients with IBD-associated cancers and high-grade dysplasia (HGD) with preserved tumor tissue and blood were included. Tumor and non-tumor tissues were analyzed for 48 cancer-related genes using next-generation sequencing. Simultaneously, circulating tumor DNA (ctDNA) was analyzed for mutations in the target genes using digital PCR.

Results

Out of 10 patients, seven had IBD-related cancer and three had IBD-related HGD. Two patients had carcinoma in situ; moreover, three had stageII and two had stage III. To avoid false positives, the mutation rate cutoff was set at 5% based on the control results; seven of 10 (70%) tumor tissue samples were mutation-positive. Mutation frequencies for each gene were as follows: TP53 (20.9%; R136H), TP53 (25.0%; C110W), TP53 (8.5%; H140Q), TP53 (31.1%; R150W), TP53 (12.8%; R141H), KRAS (40.0%; G12V), and PIK3CA (34.1%; R 88Q). The same mutations were detected in the blood of these seven patients. However, no mutations were detected in the blood of the remaining three patients with no tumor tissue mutations. The concordance rate between tumor tissue DNA and blood ctDNA was 100%.

Conclusion

Blood liquid biopsy has the potential to be a new method for non-invasive diagnosis of IBD-associated neoplasia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07699-z.

The Early Decline of α-Fetoprotein and Des-γ-Carboxy Prothrombin Predicts the Response of Hepatic Arterial Infusion Chemotherapy in Hepatocellular Carcinoma Patients

Introduction

Molecular targeting drugs are recommended as second-line treatment for intrahepatic advanced hepatocellular carcinoma (HCC). However, in Asia, hepatic arterial infusion chemotherapy (HAIC) is also considered as a second-line treatment because it improves the survival of responders. The aim of this study was to predict responders and non-responders to HAIC with low-dose cisplatin plus 5-fluorouracil (LFP) using tumor markers.

Objective and Methods

The data of 47 patients who received LFP for the first time in our hospital were analyzed retrospectively. We evaluated the association between treatment response by Response Evaluation Criteria in Solid Tumors and the changing ratio of the serum concentration of α-fetoprotein (AFP), Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3), and des-γ-carboxy prothrombin (DCP) 2 weeks after LFP initiation.

Results

The number of patients showing a complete response (CR), a partial response (PR), stable disease (SD), and progressive disease (PD) was 0 (0%), 20 (43%), 18 (38%), and 9 (19%), respectively. The AFP ratio showed significant positive correlations for PR vs. SD (p = 0.004) and PR vs. PD (p = 0.003). The DCP ratio correlated significantly for PR vs. SD (p = 0.02). The optimal cutoff values for responders were 0.79 for the AFP ratio and 0.53 for the DCP ratio. Prediction using both or either cutoff value showed 93% sensitivity, 53% specificity, a 94% negative predictive value, and a 57% positive predictive value.

Conclusion

Optimal cutoff values for AFP and DCP ratios enable prediction of nonresponders to HAIC with LFP. This simple and early assessment method allows the use of HAIC and molecular targeting drugs for HCC treatment.

The ELFIN Mission

The Electron Loss and Fields Investigation with a Spatio-Temporal Ambiguity-Resolving option (ELFIN-STAR, or heretoforth simply: ELFIN) mission comprises two identical 3-Unit (3U) CubeSats on a polar (∼93^∘ inclination), nearly circular, low-Earth (∼450 km altitude) orbit. Launched on September 15, 2018, ELFIN is expected to have a >2.5 year lifetime. Its primary science objective is to resolve the mechanism of storm-time relativistic electron precipitation, for which electromagnetic ion cyclotron (EMIC) waves are a prime candidate. From its ionospheric vantage point, ELFIN uses its unique pitch-angle-resolving capability to determine whether measured relativistic electron pitch-angle and energy spectra within the loss cone bear the characteristic signatures of scattering by EMIC waves or whether such scattering may be due to other processes. Pairing identical ELFIN satellites with slowly-variable along-track separation allows disambiguation of spatial and temporal evolution of the precipitation over minutes-to-tens-of-minutes timescales, faster than the orbit period of a single low-altitude satellite (T_orbit ∼ 90 min). Each satellite carries an energetic particle detector for electrons (EPDE) that measures 50 keV to 5 MeV electrons with Δ E/E < 40% and a fluxgate magnetometer (FGM) on a ∼72 cm boom that measures magnetic field waves (e.g., EMIC waves) in the range from DC to 5 Hz Nyquist (nominally) with <0.3 nT/sqrt(Hz) noise at 1 Hz. The spinning satellites (T_spin ∼ 3 s) are equipped with magnetorquers (air coils) that permit spin-up or -down and reorientation maneuvers. Using those, the spin axis is placed normal to the orbit plane (nominally), allowing full pitch-angle resolution twice per spin. An energetic particle detector for ions (EPDI) measures 250 keV - 5 MeV ions, addressing secondary science. Funded initially by CalSpace and the University Nanosat Program, ELFIN was selected for flight with joint support from NSF and NASA between 2014 and 2018 and launched by the ELaNa XVIII program on a Delta II rocket (with IceSatII as the primary). Mission operations are currently funded by NASA. Working under experienced UCLA mentors, with advice from The Aerospace Corporation and NASA personnel, more than 250 undergraduates have matured the ELFIN implementation strategy; developed the instruments, satellite, and ground systems and operate the two satellites. ELFIN's already high potential for cutting-edge science return is compounded by concurrent equatorial Heliophysics missions (THEMIS, Arase, Van Allen Probes, MMS) and ground stations. ELFIN's integrated data analysis approach, rapid dissemination strategies via the SPace Environment Data Analysis System (SPEDAS), and data coordination with the Heliophysics/Geospace System Observatory (H/GSO) optimize science yield, enabling the widest community benefits. Several storm-time events have already been captured and are presented herein to demonstrate ELFIN's data analysis methods and potential. These form the basis of on-going studies to resolve the primary mission science objective. Broad energy precipitation events, precipitation bands, and microbursts, clearly seen both at dawn and dusk, extend from tens of keV to >1 MeV. This broad energy range of precipitation indicates that multiple waves are providing scattering concurrently. Many observed events show significant backscattered fluxes, which in the past were hard to resolve by equatorial spacecraft or non-pitch-angle-resolving ionospheric missions. These observations suggest that the ionosphere plays a significant role in modifying magnetospheric electron fluxes and wave-particle interactions. Routine data captures starting in February 2020 and lasting for at least another year, approximately the remainder of the mission lifetime, are expected to provide a very rich dataset to address questions even beyond the primary mission science objective.

Blue laser imaging and linked color imaging improve the color difference value and visibility of colorectal polyps in underwater conditions

BACKGROUND AND AIM

Underwater endoscopic mucosal resection (UEMR) has become widespread for treating colorectal polyps. However, which observational mode is best suited for determining polyp margins underwater remains unclear. To determine the best mode, we analyzed three imaging modes: white light imaging (WLI), blue laser imaging (BLI) and linked color imaging (LCI).

METHODS

Images of consecutive colorectal polyps previously examined by these three modes before UEMR were analyzed according to the degree of underwater turbidity (transparent or cloudy). Color differences between the polyps and their surroundings were calculated using the Commission Internationale d'Eclairage Lab color space in which 3-D color parameters were expressed. Eight evaluators, who were blinded to the histology, scored the visibility from one (undetectable) to four (easily detectable) in both underwater conditions. The color differences and visibility scores were compared.

RESULTS

Seventy-three polyps were evaluated. Sixty-one polyps (44 adenomatous, 17 serrated) were observed under transparent conditions, and 12 polyps (seven adenomatous, five serrated) were observed under cloudy conditions. Under transparent conditions, color differences for the BLI (8.5) and LCI (7.9) were significantly higher than that of WLI (5.7; P < 0.001). Visibility scores for BLI (3.6) and LCI (3.4) were also higher than that of WLI (3.1; P < 0.0001). Under cloudy conditions, visibility scores for LCI (2.9) and WLI (2.7) were significantly higher than that of BLI (2.2; P < 0.0001 and P = 0.04, respectively).

CONCLUSIONS

BLI and LCI were better observational modes in transparent water; however, BLI was unsuitable for cloudy conditions.

Effect of Vonoprazan on Delayed Bleeding after Endoscopic Submucosal Dissection for Gastric Neoplasia among Antithrombotic Drug Users: A Single-Center, Single-Arm Prospective Observational Case Control Study

Antithrombotic therapy is a major risk factor for delayed bleeding after endoscopic submucosal dissection (ESD) for gastric neoplasia. A potassium-competitive acid blocker, vonoprazan, is expected to prevent delayed bleeding better than conventional proton pomp inhibitors (PPIs), but the evidence is controversial. We sought to clarify the efficacy of vonoprazan for prevention of delayed bleeding after gastric ESD in patients under antithrombotic therapy. We prospectively registered 50 patients who underwent gastric ESD while receiving antithrombotic therapy and vonoprazan in our institution between October 2017 and September 2018. The incidence of delayed bleeding was compared with that in a historical control group of 116 patients treated with conventional PPI. We also evaluated risk factors associated with delayed bleeding. Delayed bleeding was observed in 8 of 50 patients (16.0%), which was not dissimilar from the incidence in the historical control group (12.1%) (p=0.49). In the univariate analysis, age (> 70 years) (p=0.034), multiple antithrombotic drug use (p<0.01), procedure time (> 200 min) (p=0.038) and tumor size (> 40 mm) (p<0.01) were associated with delayed bleeding after gastric ESD, but vonoprazan was not (p=0.49). Vonoprazan may not be more effective than conventional PPIs in preventing delayed bleeding after gastric ESD in patients receiving antithrombotic therapy.

Matrix-material dependence on the elongation of embedded gold nanoparticles induced by 4 MeV C60 and 200 MeV Xe ion irradiation

We report the elongation of embedded Au nanoparticles (NPs) in three different matrices, i.e. amorphous carbon (a-C), crystalline indium tin oxide (In_xSn_1-xO_z; ITO) and crystalline calcium fluoride (CaF₂), under irradiations of 4 MeV C₆₀ ⁺ cluster ions and 200 MeV Xe¹⁴⁺ ions. Under 4 MeV C₆₀ cluster irradiation, strong sputtering is induced in CaF₂ layer so that the whole the layer was completely lost at a fluence of 5 × 10¹³ ions cm^-2. Au NPs were partly observed in the SiO₂, probably due to the recoil implantation. Amorphous carbon (a-C) layer exhibits low sputtering loss even under 4 MeV C₆₀ irradiation. However, the elongation in a-C layer was low. While the ITO layer showed a certain decrease in thickness under 4 MeV C₆₀ irradiation, large elongation of Au NPs was observed under both 4 MeV C₆₀ and 200 MeV Xe irradiation. The ITO layer preserved the crystallinity even after large elongation was induced. This is the first report of the elongation of metal NPs in a crystalline matrix.