Neuromedin U contributes to radiation resistance in colorectal cancer via YAP/TAZ signaling activation.

Resistance to radiation therapy remains a treatment obstacle for patients with high­risk colorectal cancer. Neuromedin U (NMU) has been identified as a potential predictor of the response to radiation therapy by RNA sequencing analysis of colorectal cancer tissues obtained from patients. However, the role of NMU in colorectal cancer remains unknown. In order to investigate role of NMU in colorectal cancer, NMU expression was regulated using small interfering RNA or an NMU­expression pCMV3 vector, and cell counting, wound­healing and clonogenic assays were subsequently performed. NMU knockdown decreased colorectal cancer cell proliferation and migration, and sensitized the cells to radiation. Conversely, NMU overexpression increased radiation resistance, proliferation and migration of colorectal cancer cells. Furthermore, by western blotting and nuclear fractionation experiments, NMU knockdown inhibited the nuclear translocation of yes­associated protein (YAP) and transcriptional co­activator with PDZ­binding motif (TAZ), resulting from the phosphorylation of these proteins. By contrast, the nuclear translocation of YAP and TAZ was increased following NMU overexpression in colorectal cancer cells. Recombinant NMU regulated YAP and TAZ activity, and the expression of the YAP and TAZ transcriptional target genes AXL, connective tissue growth factor and cysteine­rich angiogenic inducer 61 in an NMU receptor 1 activity­dependent manner. These results suggested that NMU may contribute to the acquisition of radioresistance in colorectal cancer by enhancing the Hippo signaling pathway via YAP and TAZ activation.

IGFL2-AS1, a Long Non-Coding RNA, Is Associated with Radioresistance in Colorectal Cancer.

Precise prediction of radioresistance is an important factor in the treatment of colorectal cancer (CRC). To discover genes that regulate the radioresistance of CRCs, we analyzed an RNA sequencing dataset of patient-originated samples. Among various candidates, IGFL2-AS1, a long non-coding RNA (lncRNA), exhibited an expression pattern that was well correlated with radioresistance. IGFL2-AS1 is known to be highly expressed in various cancers and functions as a competing endogenous RNA. To further investigate the role of IGFL2-AS1 in radioresistance, which has not yet been studied, we assessed the amount of IGFL2-AS1 transcripts in CRC cell lines with varying degrees of radioresistance. This analysis showed that the more radioresistant the cell line, the higher the level of IGFL2-AS1 transcripts-a similar trend was observed in CRC samples. To directly assess the relationship between IGFL2-AS1 and radioresistance, we generated a CRC cell line stably expressing a small hairpin RNA (shRNA) targeting IGFL2-AS1. shRNA-mediated knockdown of IGFL2-AS1 decreased radioresistance and cell migration in vitro, establishing a functional role for IGFL2-AS1 in radioresistance. We also showed that downstream effectors of the AKT pathway played crucial roles. These data suggest that IGFL2-AS1 contributes to the acquisition of radioresistance by regulating the AKT pathway.

An analysis of the policy participation of field response nurses in South Korea: COVID-19 response guidelines and the infectious disease act revision.

INTRODUCTION: The Republic of Korea's response to Coronavirus disease 2019 was divided before and after global vaccine development at the end of 2020. It also varied according to the size of confirmed patients in the non-pharmaceutical intervention. Therefore, this study aimed to analyze the contribution of frontline nurses to the policy and law revision on infectious diseases and suggest health and nursing policies for emerging infectious diseases in the future. DESIGN: This case evaluation study analyzed the significant policy decisions that nurses' roles brought on changes in the infectious disease response system in the Republic of Korea and applying the health system model and those capacities on resilience under emerging infectious diseases. METHODS: Objective data that contributed directly to the revision of infectious disease-related Acts and policies in 2020 were collected and analyzed through literature search and information disclosure claims from the first to third waves of Coronavirus disease 2019 in one city. RESULTS: With the rapid outbreak of COVID-19 confirmed cases at the end of February 2020, a pan-government support group was formed and dispatched to D City. In addition, central quarantine officials worked with local quarantine officials to share real-time situations and find out on-site difficulties and support requests. As a result, inquiry of opinions to working staff before changing the "response guidelines to Coronavirus disease 2019" was reflected in major contents on the revision of "policy on infectious disease response" and "Infectious Disease Prevention and Management Act." With the establishment of an epidemiological investigation team in September 2020, the number of new nurses in 17 cities and provinces increased by 19.1% compared to the previous year, the most significant increase compared to doctors (-2.3), dentists (-1.6), and health workers (3.7). CONCLUSION: The experience of responding to Coronavirus was a reminder that the curriculum needed to be improved so that nurses will be recognized to have leadership competencies and as field experts regarding social determinants of health for population groups in the decision-making process. In the initial COVID-19 response process, nurses showed excellence in analyzing patient interviews and various information as field epidemiological investigation response personnel, making comprehensive judgments, and solving problems in cooperation with related agencies and severe patients' bedside nursing care. Continuous primary care and management of infectious diseases for the vulnerable should be prepared on an ongoing basis to assure the quality of care. CLINICAL RELEVANCE: Action strategies for developing leadership to enable nurses to have participated in the social determinants of health and the nursing policy formation for health equity should be applied in nursing education and practice, and global monitoring efforts were accelerated.

Advanced Xenograft Model with Cotransplantation of Patient-Derived Organoids and Endothelial Colony-Forming Cells for Precision Medicine.

Preclinical evaluation models have been developed for precision medicine, with patient-derived xenograft models (PDXs) and patient-derived organoids (PDOs) attracting increasing attention. However, each of these models has application limitations. In this study, an advanced xenograft model was established and used for drug screening. PDO and endothelial colony-forming cells (ECFCs) were cotransplanted in NRGA mice (PDOXwE) to prepare the model, which could also be subcultured in Balb/c nude mice. Our DNA sequencing analysis and immunohistochemistry results indicated that PDOXwE maintained patient genetic information and tumor heterogeneity. Moreover, the model enhanced tumor growth more than the PDO-bearing xenograft model (PDOX). The PDO, PDOXwE, and clinical data were also compared in the liver metastasis of a colorectal cancer patient, demonstrating that the chemosensitivity of PDO and PDOXwE coincided with the clinical data. These results suggest that PDOXwE is an improvement of PDOX and is suitable as an evaluation model for precision medicine.

A Patient-Derived Organoid-Based Radiosensitivity Model for the Prediction of Radiation Responses in Patients with Rectal Cancer.

Patient-derived tumor organoids closely resemble original patient tumors. We conducted this co-clinical trial with treatment-naive rectal cancer patients and matched patient-derived tumor organoids to determine whether a correlation exists between experimental results obtained after irradiation in patients and organoids. Between November 2017 and March 2020, we prospectively enrolled 33 patients who were diagnosed with mid-to-lower rectal adenocarcinoma based on endoscopic biopsy findings. We constructed a prediction model through a machine learning algorithm using clinical and experimental radioresponse data. Our data confirmed that patient-derived tumor organoids closely recapitulated original tumors, both pathophysiologically and genetically. Radiation responses in patients were positively correlated with those in patient-derived tumor organoids. Our machine learning-based prediction model showed excellent performance. In the prediction model for good responders trained using the random forest algorithm, the area under the curve, accuracy, and kappa value were 0.918, 81.5%, and 0.51, respectively. In the prediction model for poor responders, the area under the curve, accuracy, and kappa value were 0.971, 92.1%, and 0.75, respectively. Our patient-derived tumor organoid-based radiosensitivity model could lead to more advanced precision medicine for treating patients with rectal cancer.

Implication of FDG-PET/CT without synchronous colonic lesion in patients with stenotic left-sided colorectal cancer.

Although 18-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) is useful for detecting synchronous colorectal cancer (CRC) in stenotic CRC, long-term outcomes of patients without synchronous FDG-avid lesions are not well reported. We investigated postoperative colonoscopy results in patients with left-sided stenosing CRC without synchronous FDG-avid lesions. In this retrospective review, 754 patients with left-sided CRC without synchronous FDG-avid lesions on preoperative 18F-FDG PET/CT were divided into two groups based on the completeness of preoperative colonoscopy. Propensity score matching was performed to balance baseline characteristics. Results of postoperative colonoscopy were compared in both the unmatched and matched cohorts. At 1 and 5 years after surgery, the cumulative risk of advanced adenoma (AA) or carcinoma (CA) in all patients, risk of CA, and additional surgical risk were 1.8% and 10.1%, 0.1% and 0.4%, and 0% and 0.5%, respectively. In both cohorts, the AA risk was significantly higher in the incomplete colonoscopy group. However, the risk of CA showed no between-group difference in the matched cohort. Additional surgical risk did not differ between the two groups. Thus, the finding of negative FDG-avid lesions in the proximal colon in addition to the target CRC ensures the absence of additional lesions warranting surgical plan changes.

Gene Expression Profiles Associated with Radio-Responsiveness in Locally Advanced Rectal Cancer.

LARC patients were sorted according to their radio-responsiveness and patient-derived organoids were established from the respective cancer tissues. Expression profiles for each group were obtained using RNA-seq. Biological and bioinformatic analysis approaches were used in deciphering genes and pathways that participate in the radio-resistance of LARC. Thirty candidate genes encoding proteins involved in radio-responsiveness-related pathways, including the immune system, DNA repair and cell-cycle control, were identified. Interestingly, one of the candidate genes, cathepsin E (CTSE), exhibited differential methylation at the promoter region that was inversely correlated with the radio-resistance of patient-derived organoids, suggesting that methylation status could contribute to radio-responsiveness. On the basis of these results, we plan to pursue development of a gene chip for diagnosing the radio-responsiveness of LARC patients, with the hope that our efforts will ultimately improve the prognosis of LARC patients.

Valproic acid protects intestinal organoids against radiation via NOTCH signaling.

Radiotherapy is a leading treatment for various types of cancer. However, exposure to high-dose ionizing radiation causes acute gastrointestinal injury and gastrointestinal syndrome. This has significant implications for human health, and therefore, radioprotection is a major area of research. Radiation induces the loss of intestinal stem cells; hence, the protection of stem cells expressing LGR5 (a marker of intestinal epithelial stem cells) is a key strategy for the prevention of radiation-induced injury. In this study, we identified valproic acid (VPA) as a potent radioprotector using an intestinal organoid culture system. VPA treatment increased the number of LGR5+ stem cells and organoid regeneration after irradiation. N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT, an inhibitor of NOTCH signaling) blocked the radioprotective effects of VPA, indicating that NOTCH signaling is a likely mechanism underlying the observed effects of VPA. In addition, VPA acted as a radiosensitizer via the inhibition of histone deacetylase (HDAC) in a colorectal cancer organoid. These results demonstrate that VPA exerts strong protective effects on LGR5+ stem cells via NOTCH signaling and that the inhibition of NOTCH signaling reduces these protective effects, providing a basis for the improved management of radiation injury.

Butyrate enhances the efficacy of radiotherapy via FOXO3A in colorectal cancer patient­derived organoids.

Enhancing the radioresponsiveness of colorectal cancer (CRC) is essential for local control and prognosis. However, consequent damage to surrounding healthy cells can lead to treatment failure. We hypothesized that short­chain fatty acids (SCFAs) could act as radiosensitizers for cancer cells, allowing the administration of a lower and safer dose of radiation. To test this hypothesis, the responses of three­dimensional­cultured organoids, derived from CRC patients, to radiotherapy, as well as the effects of combined radiotherapy with the SCFAs butyrate, propionate and acetate as candidate radiosensitizers, were evaluated via reverse transcription­quantitative polymerase chain reaction, immunohistochemistry and organoid viability assay. Of the three SCFAs tested, only butyrate suppressed the proliferation of the organoids. Moreover, butyrate significantly enhanced radiation­induced cell death and enhanced treatment effects compared with administration of radiation alone. The radiation­butyrate combination reduced the proportion of Ki­67 (proliferation marker)­positive cells and decreased the number of S phase cells via FOXO3A. Meanwhile, 3/8 CRC organoids were found to be non­responsive to butyrate with lower expression levels of FOXO3A compared with the responsive cases. Notably, butyrate did not increase radiation­induced cell death and improved regeneration capacity after irradiation in normal organoids. These results suggest that butyrate could enhance the efficacy of radiotherapy while protecting the normal mucosa, thus highlighting a potential strategy for minimizing the associated toxicity of radiotherapy.

Potentiation of calcium-activated chloride secretion and barrier dysfunction may underlie EGF receptor tyrosine kinase inhibitor-induced diarrhea.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFr TKIs) are first-line therapies for various cancers, and cause dose-limiting severe diarrhea in many patients. We hypothesized that diarrhea caused by EGFr TKIs might reflect actions on epithelial transport, barrier function, or both, which we tested using cell cultures including murine and human enteroid-derived monolayers (EDMs), analyzed using electrophysiological and other relevant methods. EGFr TKIs (such as afatinib, erlotinib, and osimertinib) reversed the acute inhibitory effect of EGF on chloride secretion induced by carbachol (CCh) across T84 human colonic epithelial cells, which correlated with the diarrhea-inducing effect of each agent clinically. EGFr TKIs also reduced transepithelial electrical resistance (TEER), whereas co-treatment with CCh delayed the decrease in TEER compared with that of cells co-treated with EGF. Furthermore, afatinib and erlotinib prevented EGF- or CCh-induced EGFr phosphorylation. EGFr TKIs also suppressed phosphorylation of extracellular signal-regulated kinase (Erk)1/2 in response to EGF, whereas they had weaker effects on CCh-induced Erk1/2 phosphorylation. In human EDMs, EGF potentiated ion transport induced by CCh, whereas afatinib reversed this effect. The ability of EGFr TKIs to reverse the effects of EGF on calcium-dependent chloride secretion could contribute to the diarrheal side effects of these agents, and their disruption of epithelial barrier dysfunction is likely also pathophysiologically significant. CCh-activated Erk1/2 phosphorylation was relatively insensitive to EGFr TKIs and delayed the deleterious effects of EGFr TKIs on barrier function. These findings confirm and extend those of other authors, and may be relevant to designing strategies to overcome the diarrheal side effects of EGFr TKIs.

Covered metallic stents with an anti-migration design vs. uncovered stents for the palliation of malignant gastric outlet obstruction: a multicenter, randomized trial.

OBJECTIVES: Previous studies reported comparable stent patency between covered self-expandable metallic stents (SEMS) and uncovered SEMS (UCS) for palliation of malignant gastric outlet obstruction (GOO). The aim of this study was to evaluate the efficacy and safety of the newly developed WAVE-covered SEMS (WCS), which has an anti-migration design, compared with UCS in gastric cancer patients with symptomatic GOO. METHODS: A total of 102 inoperable gastric cancer patients with symptomatic GOO were prospectively enrolled from five referral centers and randomized to undergo UCS or WCS placement. Stent patency and recurrence of obstructive symptoms were assessed at 8 weeks and 16 weeks after stent placement. RESULTS: At the 8-week follow-up, both stent patency rates (72.5% vs. 62.7%) and re-intervention rates (19.6% vs. 19.6%) were comparable between the WCS and the UCS groups. Both stent stenosis (2.4% vs. 8.1%) and migration rates (9.5% vs. 5.4%) were comparable between WCS and UCS groups. At the 16-week follow-up, however, the WCS group had a significantly higher stent patency rate than the UCS group (68.6% vs. 41.2%). Re-intervention rates in the WCS and UCS groups were 23.5% and 39.2%, respectively. Compared with the UCS group, the WCS group had a significantly lower stent restenosis rate (7.1% vs. 37.8%) and a comparable migration rate (9.5% vs. 5.4%). Overall stent patency was significantly longer in the WCS group than in the UCS group. No stent-associated significant adverse events occurred in either the WCS or UCS groups. In the multivariate analysis, WCS placement and chemotherapy were identified as independent predictors of 16-week stent patency. CONCLUSIONS: WCS group showed comparable migration rate and significantly more durable long-term stent patency compared with UCS group for the palliation of GOO in patients with inoperable gastric cancer.

Comparison of Antiretroviral Regimens: Adverse Effects and Tolerability Failure that Cause Regimen Switching.

BACKGROUND: The efficacy of antiretroviral therapy (ART) has improved, and the adverse effects of antiretroviral drugs have been reduced. However, these adverse effects still significantly influence patient compliance, increasing the risk of tolerability failure. Therefore, we investigated the adverse effects and tolerability failure causing changes in the first ART regimen, and identified the regimens that were most vulnerable to switching. MATERIALS AND METHODS: We enrolled patients with human immunodeficiency virus (HIV) who commenced their first ART between January 1, 2011 and July 30, 2014. Patients who started their first ART regimen at the Kyungpook National University Hospital were included in the study if they were aged ≥18 years and were followed-up for ≥12 weeks. The primary dependent variable was the duration of treatment on the same ART regimen. We analyzed the maintenance rate of the first ART regimen based on the treatment duration between these groups using survival analysis and log rank test. The frequency of the adverse effects of ART regimens was analyzed by multiple response data analysis. RESULTS: During the investigation period, 137 patients were enrolled. Eighty-one patients were maintained on the initial treatment regimen (59.1%). In protease inhibitor (PI)-based regimen group, 54 patients were maintained on the initial treatment regimen (54/98, 55.1%). In non-nucleoside reverse transcriptase inhibitor (NNRTI)-and integrase inhibitor (II)-based regimen group, 15 (15/26, 57.7%) and 12 (12/13, 92.3%) patients were maintained on the initial treatment regimen, respectively. Adverse effects that induced ART switching included rash (16/35, 45.7%), gastrointestinal discomfort or pain (7/35, 20%), diarrhea (7/35, 20%), hyperbilirubinemia (6/35, 17.1%), headache or dizziness (3/35, 8.5%). Among the treatment regimens, the group receiving an II-based regimen showed the least switching. The group receiving PI-and NRTI-based regimens were most likely to switch due to adverse effects during the early treatment period. However, after about 18 months, switching was rarely observed in these groups. Among the PI drugs, darunavir/ritonavir showed fewer drug changes than atazanavir/ritonavir (P = 0.004, log rank test) and lopinavir/ritonavir (P = 0.010). Among the NNRTI drugs, rilpivirne produced less switching than efavirenz (P = 0.045). CONCLUSIONS: Adverse effects to ART resulted in about a quarter of patients switching drugs during the early treatment period. II-based regimens were advantageous because they were less likely to induce switching within 18 months of treatment commencement. These findings indicated the importance of considering and monitoring the adverse effects of ART in order to improve adherence.

Hedgehog signaling between cancer cells and hepatic stellate cells in promoting cholangiocarcinoma.

BACKGROUND: Aberrant Hedgehog (HH) signaling activation is important in cancer growth and mediates the interaction between cancer cells and the surrounding stromal cells. This study investigated the role of HH signaling on the growth of cholangiocarcinoma (CC), focusing on the interaction of CC cells with stromal cells. METHODS: To evaluate the interaction between human CC cells (SNU-1196, SNU-246, SNU-308, SNU-1079, and HuCCT-1) and stromal cells (hepatic stellate cell line, Lx-2), co-culture proliferation, migration, and invasion assays were performed. In vivo nude mice experiments were conducted using two groups-HuCCT-1 single implant xenograft (SX) and co-implant xenograft (CX) with HuCCT-1 and Lx-2. RESULTS: When HuCCT-1 cells were co-cultured with Lx-2 cells, the expression of HH signaling-related proteins increased in both HuCCT-1 and Lx-2 cells. Co-culture with Lx-2 cells stimulated the proliferation, migration, and invasion of CC cells, and these effects were mediated by HH signaling. Co-culture of HuCCT-1 and Lx-2 cells increased the secretion of several cytokines. In an ectopic xenograft model, Lx-2 co-implantation increased CC tumor growth and stimulated angiogenesis. Cyclopamine attenuated tumor growth in the CX group, but not in the HuCCT-1 mono-implant (SX) group. Cyclopamine treatment decreased CC cell proliferation, suppressed microvessel density, and increased tumor necrosis in the CX group, but not in the SX group. CONCLUSION: Hepatic stellate cells stimulate the proliferation, migration, and invasion of CC cells, promote angiogenesis through HH signaling activation, and render CC more susceptible to necrosis by HH inhibitor.

Evaluation of anti-oxidant and anti-cancer properties of Dendropanax morbifera Léveille.

Dendropanax morbifera Léveille, an endemic species in Korea, is best known as a tree that produces a resinous sap. Although D. morbifera is used in folk medicine, its biological activities are poorly understood. In this study, the methanolic extracts of D. morbifera branches, debarked stems, bark, and two different stages of leaves were evaluated for anti-oxidant activity and anti-cancer potential. The debarked stem extract exhibited strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and reducing power compared with other samples. In addition, the cytotoxic activities of these extracts were investigated in human tumour cell lines. The results suggested that the extracts of debarked stems, green leaves, and yellow leaves were the potent source of anti-cancer compounds, particularly in Huh-7 cells. Furthermore, treatment with the extracts of debarked stems, green leaves, and yellow leaves caused an increase of apoptotic or senescent cells in Huh-7 cells. Twenty-four hour treatment with debarked stems extract resulted in the strong induction of p53 and p16, whereas both leaf extracts inhibited the activation of ERK. The debarked stems and green leaf extracts reduced Akt levels in Huh-7 cells, indicating that D. morbifera extracts caused the activation of p16 and p53 pathways. This, together with the inhibition of Akt or ERK signalling, resulted in suppression of Huh-7 cell proliferation. These results suggest that methanolic leaf and debarked stems extracts are a source of anti-oxidant and anti-cancer compounds, and could be developed as a botanical drug.

[Effect of after-hours emergency endoscopy on the outcome of acute upper gastrointestinal bleeding].

BACKGROUND/AIMS: Gastrointestinal endoscopy is imperative for acute upper gastrointestinal bleeding (AUGIB) to find bleeding focus and stop bleeding. This study was designed to assess the necessity of emergency endoscopy and determine screening criteria for the patients who presented to emergency room (ER) with after-hours AUGIB. METHODS: The medical records of 383 patents with AUGIB who presented to ER at after-hours were reviewed. Patients were divided into 2 groups: emergency endoscopy (EE) group (<12 hours after arrival) or delayed endoscopy (DE) group (12-24 hours after arrival). We compared the severity, hemostatic procedures, rebleeding rate, length of hospitalization and 30-day mortality between the two groups. RESULTS: Ninety-eight patients in EE group and 137 patients in DE group were evaluated among patients with non-variceal upper gastrointestinal bleeding. No significant differences in clinical severity, finding the bleeding focus, hemostasis, 30-day mortality, hospital stay, and rebleeding rate were observed between the two groups. Among 148 patients with variceal upper gastrointestinal bleeding, 65 patients were in EE group and 83 patients in DE group. Most clinical severity index were not different between the groups. In EE group, the rate of finding bleeding foci was lower (p=0.043), and 30-day mortality was higher than in DE group (p=0.023). CONCLUSIONS: Emergency endoscopy within 12 hours after arrival at after-hours do not lead to better prognosis in AUGIB.