Naldemedine for Opioid-Induced Constipation in Patients With Cancer: A Multicenter, Double-Blind, Randomized, Placebo-Controlled Trial.

PURPOSE: Opioid-induced constipation is the most frequent and non-self-limiting adverse effect of opioid analgesia, reducing adherence and interfering with pain relief. This clinical trial aimed to clarify the preventive effect of naldemedine versus placebo for constipation in patients with cancer starting regularly dosed strong opioids therapy. METHODS: This multicenter, double-blinded, randomized, placebo-controlled, confirmatory trial was conducted between July 2021 and May 2023 at four academic hospitals in Japan (ClinicalTrials.gov identifier: jRCTs031200397). Patients with cancer starting a first-time regularly dosed strong opioid for cancer pain and age 20+ years were included. Eligible patients were randomly assigned to the naldemedine (Symproic 0.2 mg) or placebo group in a 1:1 ratio for 14 days with protocol treatment. The primary end point was the proportion of patients with a Bowel Function Index (BFI) of <28.8 on day 14. The secondary end points included frequency of spontaneous bowel movements (SBM), quality of life (QOL), and frequency of opioid-induced nausea and vomiting (OINV). RESULTS: Of the 103 patients assessed for eligibility, 99 received either naldemedine (n = 49) or placebo (n = 50). A BFI of <28.8 on day 14 was significantly more likely to occur in the naldemedine group (64.6%; 95% CI, 51.1 to 78.1) versus placebo (17.0%; 95% CI, 6.3 to 27.8), and the difference between groups was 47.6% (95% CI, 30.3 to 64.8; P < .0001). The frequency of SBM, QOL, and the severity of OINV were nominally significant in the naldemedine group than in the control group. CONCLUSION: Naldemedine prevented constipation and improved constipation-related QOL, with possible preventive effect on OINV in patients with cancer starting regularly dosed opioids therapy.

Real-world treatment costs of first-line treatment for metastatic colorectal cancer: a survey of the JCOG colorectal cancer study group.

BACKGROUND: Although treatment outcomes for metastatic colorectal cancer (mCRC) have dramatically improved over the past few decades, drug costs have also significantly increased. This study aimed to investigate which first-line treatment regimens for mCRC are actually used (frequency) in Japanese practice and at what cost. METHODS: We collected data on patients with mCRC who received first-line treatment at 37 institutions of the Japan Clinical Oncology Group Colorectal Cancer Study Group from July 2021 to June 2022, and calculated the cost of regimens. The cost per month of each regimen was estimated based on standard usage, assuming a patient with a weight of 70 kg and a body surface area of 1.8 m2. We categorized the regimens into very high-cost (≥1 000 000 Japanese yen [JPY]/month), high-cost (≥500 000 JPY/month), and others (<500 000 JPY/month). RESULTS: The study included 1880 participants, 24% of whom were ≥ 75 years. Molecular targeted containing regimens were received by 78% of the patients. The most frequently used regimen was the doublet regimen (fluoropyrimidine with either oxaliplatin or irinotecan) plus bevacizumab (43%), followed by doublet plus cetuximab or panitumumab (21%). The cost of molecular targeted drugs-containing regimens (ranging from 85 406 to 843 602 JPY/month) is much higher than that of only cytotoxic drug regimens (ranging from 17 672 to 51 004 JPY/month). About 16% received high-cost treatments that included panitumumab-containing regimens and pembrolizumab (17% of patients aged ≤74 years and 11% of patients aged ≥75 years). CONCLUSION: About 16% of mCRC patients received first-line treatment with regimens costing >500 000JPY/month, and molecular targeted drugs being the main drivers of cost.

Decoupling of the onset of anharmonicity between a protein and its surface water around 200 K.

The protein dynamical transition at ~200 K, where the biomolecule transforms from a harmonic, non-functional form to an anharmonic, functional state, has been thought to be slaved to the thermal activation of dynamics in its surface hydration water. Here, by selectively probing the dynamics of protein and hydration water using elastic neutron scattering and isotopic labeling, we found that the onset of anharmonicity in the two components around 200 K is decoupled. The one in protein is an intrinsic transition, whose characteristic temperature is independent of the instrumental resolution time, but varies with the biomolecular structure and the amount of hydration, while the one of water is merely a resolution effect.

Short-term and three-year long-term outcomes of laparoscopic surgery versus open surgery for obstructive colorectal cancer following self-expandable metallic stent placement: a meta-analysis.

BACKGROUND: A bridge to surgery (BTS) after self-expandable metallic stent (SEMS) placement is a widely recognized treatment strategy for obstructive colorectal cancer. However, there is still a lack of evidence for the efficacy and safety of laparoscopic surgery following SEMS placement. The aim of this systematic review and meta-analysis was to compare the short-term and long-term outcomes of laparoscopic surgery with those of open surgery following SEMS placement in patients with obstructive colorectal cancer. METHODS: An electronic literature search through to December 2022 was performed to identify studies comparing short-term and long-term outcomes between laparoscopic and open surgery following SEMS placement for obstructive colorectal cancer. The main outcome measures were postoperative complication rates and mortality. Secondary outcome measures were the 3-year recurrence-free survival (RFS) and 3-year overall survival (OS) rates. The meta-analysis was performed using fixed-effect or random-effects methods to calculate odds ratios (ORs) with 95% confidence intervals (95% CIs). RESULTS: The meta-analysis included 15 studies and 883 patients, of whom 467 (52.9%) underwent laparoscopic surgery and 416 (47.1%) underwent open surgery following SEMS placement. The postoperative complication rate was significantly lower in the laparoscopic surgery group than in the open surgery group (OR 0.47, 95% CI 0.32-0.67, P < 0.001). There was no significant difference in the 3-year RFS rate or 3-year OS rate between the laparoscopic and open surgery groups (3-year RFS, OR 0.78, 95% CI 0.50-1.24, P = 0.30; 3-year OS, OR 0.68, 95% CI 0.41-1.12, P = 0.13). CONCLUSION: This meta-analysis found that the short-term outcome was better in patients who underwent laparoscopic surgery following SEMS placement than in those who underwent open surgery. Furthermore, there was no significant difference in long-term outcomes between the two groups. Laparoscopic surgery following SEMS placement may be a safe and effective treatment option for obstructive colorectal cancer.

Trial Protocol of a Phase II Study of mFOLFOXIRI after Metastasectomy in Patients with Oligometastatic Colorectal Cancer (FANTASTIC Study).

Background: The survival benefit of adjuvant chemotherapy after surgical resection of oligometastases from colorectal cancer (CRC) remains unclear. The prognostic role of circulating-tumor DNA (ctDNA) was reported recently and a risk stratification strategy based on monitoring minimal/molecular residual disease (MRD) has been proposed, however, which drug regimen is most effective for ctDNA-positive patients is unknown. Methods/Design: Oligometastatic CRC patients planning to undergo surgery were registered in this study. After metastasectomy, the registered patients were enrolled in the treatment arm, in which 8 courses of modified-FOLFOXIRI (mFOLFOXIRI; irinotecan 150 mg/m2, oxaliplatin 85 mg/m2, l-leucovorin (l-LV) 200 mg/m2, and 46-h continuous infusion of 5-fluorouracil (5-FU) 2400 mg/m2 every 2 weeks) followed by 4 courses of 5-FU/l-LV are administered. The patients who did not meet the eligibility criteria for the treatment arm or did not consent to mFOLFOXIRI enrolled in the observation arm in which standard of care treatment is provided. Prospective blood collections for retrospective ctDNA analysis are scheduled pre-surgery, and at 28 days, 4 and 7 months after surgery. The primary endpoint is treatment compliance at 8 courses of mFOLFOXIRI and the key secondary endpoints are the ctDNA-positivity rate and survival outcomes in ctDNA-positive and -negative groups. A total of 85 patients will be enrolled from 11 institutions. First patient-in was on July 2020. Accrual completed in February 2024. Discussion: This study will potentially identify a better treatment strategy for patients with resectable oligometastatic CRC having postsurgical ctDNA positivity, compared to the current standard of care approaches.

Predictive modeling for the germline pathogenic variant of the APC gene in patients with adenomatous polyposis: proposing a new APC score.

BACKGROUND: The precise diagnosis and medical management of patients with suspected familial adenomatous polyposis should be based on genetic testing, which may not always be available. Therefore, establishing a new model for predicting the likelihood of a germline pathogenic variant (GPV) of APC based on its clinical manifestations could prove to be useful in clinical practice. METHODS: The presence of GPVs of APC gene was investigated in 162 patients with adenomatous polyposis (≥ 10 polyps) using a multigene panel or single-gene testing. To generate a predictive model for GPV of the APC gene, a logistic regression analysis was performed using the clinicopathological variables available at the time of the diagnosis of adenomatous polyposis. RESULTS: Ninety (55.6%) patients had GPV of the APC gene. According to a multivariate logistic regression analysis, age < 40 years, polyps ≥ 100, fundic gland polyposis, and a family history of colorectal polyposis were found to be independent predictors of the GPV of APC and were used to establish a formula for predicting the GPV of APC using the four predictors. The prediction model had an area under the curve of 0.91 (0.86-0.96) according to a receiver operating characteristic analysis. CONCLUSION: The model for predicting the GPV of APC will help patients with adenomatous polyposis and physicians make decisions about genetic testing.

Ramucirumab in second­line advanced colorectal cancer therapy: A study on therapeutic outcomes and hepatic sinusoidal platelet aggregation.

The present study investigated the role of ramucirumab (RAM) in treating liver metastases (LMs) as a second-line or salvage treatment in patients with advanced CRC. Of the 36 patients, 21 (58%) received RAM plus folinic acid, fluorouracil and irinotecan (FOLFIRI) as second-line treatment, whereas 15 (42%) received it in a salvage setting. The median overall survival time was 23 months [95% confidence interval (CI), 12-34 months] for those in the second-line treatment group and 8 months (95% CI, 5-19 months) for those in the salvage treatment group. Of the 36 patients, 14 (39%) underwent surgical resection of LMs during chemotherapy. A total of 6 patients underwent surgical resection for LMs for the first time during second-line RAM plus FOLFIRI (RAM-LM); of the remaining 8 patients, 6 underwent resection of LMs during first-line bevacizumab (BEV)-based chemotherapy (BEV-LM). Immunohistochemical analysis of CD42b showed that the platelet aggregation score (CD42b score), which ranges from 0 (absence of deposition) to 3 (presence of linear deposition), tended to decrease with the increasing duration of treatment with both RAM and BEV. Although there was no significant difference in the mean duration of anti-VEGF antibody treatment between the BEV-LM and RAM-LM groups, the median CD42b score was higher in the RAM-LM group (median CD42b score, 3; range, 0-3) compared with that in the BEV-LM group (median CD42b score, 1; range, 0-3; P=0.01), suggesting that RAM induces a different degree of platelet aggregation in liver sinusoids compared to BEV.

Multiple systemic thromboembolism secondary to acute myocardial infarction in a young patient with coronavirus disease 2019 pneumonia: A case report.

Coronavirus disease 2019 (COVID-19) is associated with an increased risk of thromboembolic events. However, there are few reports on multiple thromboembolic events in young patients with COVID-19. Herein, we report a case of multiple visceral arterial embolisms secondary to acute myocardial infarction in a young patient with COVID-19. A 36-year-old male developed sudden chest pain after being diagnosed with COVID-19. Emergency coronary angiography revealed total occlusion of the right coronary artery, and the patient underwent a subsequent emergency percutaneous coronary intervention (PCI) which achieved successful recanalization. The patient was administered a loading dose and a subsequent maintenance dose of aspirin and prasugrel and a continuous intravenous infusion of unfractionated heparin at 10,000 units per day. Echocardiography detected a left ventricular apical thrombus 3 days after PCI; a loading dose of warfarin was administered and promptly reached the therapeutic range. However, the patient developed superior mesenteric artery embolism and renal infarction on the 12th day after PCI. COVID-19 was considered to play a role in the thromboembolic events observed in this patient. This case highlights the need for individualized antithrombotic regimens when managing patients with COVID-19 who develop acute myocardial infarction. Learning objective: Reportedly, coronavirus disease 2019 (COVID-19) is associated with an increased risk of venous and arterial thromboembolic events. However, few reports have described multiple thromboembolic events in younger patients with COVID-19. This case report describes arterial thromboembolism secondary to acute myocardial infection (AMI) in a patient with COVID-19. It highlights the need for individualized antithrombotic regimens when managing patients with COVID-19 who develop AMI.

Genomic landscape of comprehensive genomic profiling in patients with malignant solid tumors in Japan.

BACKGROUND: Comprehensive genomic profiling (CGP) can aid the discovery of clinically useful, candidate antitumor agents; however, the variant annotations sometimes differ among the various types of CGP tests as well as the public database. The aim of this study is to clarify the genomic landscape of evaluating detected variants in patients with a malignant solid tumor. METHODS: The present, cross-sectional study used data from 57,084 patients with a malignant solid tumor who underwent CGP at the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) between June 1, 2019 and August 18, 2023. The pathogenicity of the variants was annotated using public databases. RESULTS: As a result of re-annotation of the detected variants, 20.1% were pathogenic and 1.4% were benign. The mean number of pathogenic variants was 4.30 (95% confidence interval: 4.27-4.32) per patient. Of the entire cohort, 5.7% had no pathogenic variant. The co-occurrence of the genes depended on the tumor type. Germline findings were detected in 6.2%, 8.8%, and 15.8% of the patients using a tumor/normal panel, tumor-only panel, and liquid panel, respectively, with the most common gene being BRCA2 followed by TP53 and BRCA1. CONCLUSIONS: The detected variants should be re-annotated because several benign variants or variants of unknown significance were included in the CGP, and the genomic landscape derived from these results will help researchers and physicians interpret the results of CGP tests. The method of extracting presumptive, germline, pathogenic variants from patients using a tumor-only panel or circulating tumor DNA panel requires improvement.

Lymphatic spread patterns in young versus elderly patients with stage III colon cancer.

BACKGROUND: The anatomical pattern of lymph nodes spread differs between young (aged 45 years or younger) and elderly (aged 80 years or older) patients with stage III colon cancer and is poorly investigated. METHODS: Two groups of patients (young and elderly) with stage III colon cancer who underwent upfront extensive (D3) lymphadenectomy at eight Japanese centres between 1998 and 2018 were retrospectively analysed. The primary endpoint was the proportion of positive central lymph nodes. The lymph nodes spreading pattern and its prognostic impact on recurrence-free survival and overall survival in the two groups were also compared. RESULTS: Two hundred and ten young patients and 348 elderly patients were identified and compared. The total number of lymph nodes harvested and the total number of invaded lymph nodes were significantly higher in younger patients compared with elderly patients (median of 31.5 (3-151) versus 21 (3-116), P < 0.001 and median of 3 (1-21) versus 2 (1-25), P < 0.001 respectively). The proportion of positive central lymph nodes were higher in younger patients than in elderly patients (9.52% (95% c.i. 6.24 to 14.2%) versus 4.59% (95% c.i. 2.84 to 7.31%), P = 0.012). In multivariate models for recurrence-free survival, central lymph nodes invasion were identified as a poor prognostic factor in younger patients (HR 5.21 (95% c.i. 1.76 to 15.39)) but not in elderly patients (HR 1.73 (95% c.i. 0.80 to 3.76)). CONCLUSION: Young patients with stage III colon cancer have a higher risk of central lymph nodes invasion, suggesting a more aggressive disease biology. The presence of central lymph nodes invasion are associated with a worse outcome in young patients.

Significance of Adjuvant Chemotherapy for Obstructive Colorectal Cancer After Stent Placement: A Multicenter Retrospective Study.

BACKGROUND/AIM: To explore the survival benefit of adjuvant chemotherapy for obstructive colorectal cancer (OCRC) managed by self-expandable metallic stent (SEMS) placement as a bridge to surgery (BTS). PATIENTS AND METHODS: One hundred twenty-nine patients with pathological stage II/III OCRC who underwent BTS using a SEMS were included in this multicenter retrospective study. Patients were divided into the no-adjuvant chemotherapy group (No-Adj group) (n=52) and adjuvant chemotherapy group (Adj group) (n=77), and relapse-free survival (RFS) was compared. RESULTS: The No-Adj group had more fragile patient background factors, such as higher age, higher American Society of Anesthesiologists score, and lower preoperative albumin compared with the Adj group. The 3-year RFS rates for the overall cohort were significantly different between the No-Adj and Adj groups (56.4% and 78.5%, respectively; p=0.003). Significant RFS benefits of adjuvant chemotherapy were observed in both pathological stage II and III cancer. Characteristics of more advanced cancer, such as high carcinoembryonic antigen (CEA), pathological T4, and lymphovascular invasion, were associated with survival improvement by adjuvant chemotherapy. T4 and adjuvant chemotherapy were significantly associated with RFS in the multivariate Cox proportional analysis. CONCLUSION: To our knowledge, this is the first study to show a survival benefit of adjuvant chemotherapy in patients with OCRC undergoing BTS using a SEMS. Adjuvant chemotherapy is basically recommended regardless of the cancer stage and is strongly recommended with more advanced characteristics, such as high CEA, T4, and lymphovascular invasion.

J-AVENUE: A retrospective, real-world study evaluating patient characteristics and outcomes in patients with advanced urothelial carcinoma treated with avelumab first-line maintenance therapy in Japan.

OBJECTIVES: The JAVELIN Bladder 100 phase 3 trial showed that avelumab first-line maintenance + best supportive care significantly prolonged overall survival and progression-free survival versus best supportive care alone in patients with advanced urothelial carcinoma who were progression-free following first-line platinum-based chemotherapy. We report findings from J-AVENUE (NCT05431777), a real-world study of avelumab first-line maintenance therapy in Japan. METHODS: Medical charts of patients with advanced urothelial carcinoma without disease progression following first-line platinum-based chemotherapy, who received avelumab maintenance between February and November 2021, were reviewed. Patients were followed until June 2022. The primary endpoint was patient characteristics; secondary endpoints included time to treatment failure and progression-free survival. RESULTS: In 79 patients analyzed, median age was 72 years (range, 44-86). Primary tumor site was upper tract in 45.6% and bladder in 54.4%. The most common first-line chemotherapy regimen was cisplatin + gemcitabine (63.3%). Median number of chemotherapy cycles received was four. Best response to chemotherapy was complete response in 10.1%, partial response in 58.2%, and stable disease in 31.6%. Median treatment-free interval before avelumab was 4.9 weeks. With avelumab first-line maintenance therapy, the disease control rate was 58.2%, median time to treatment failure was 4.6 months (95% CI, 3.3-6.4), and median progression-free survival was 6.1 months (95% CI, 3.6-9.7). CONCLUSIONS: Findings from J-AVENUE show the effectiveness of avelumab first-line maintenance in patients with advanced urothelial carcinoma in Japan in clinical practice, with similar progression-free survival to JAVELIN Bladder 100 and previous real-world studies, supporting its use as a standard of care.

Presurgical mild anemia is a risk factor for severe postoperative complications of rectal cancer surgery: A Japanese nationwide retrospective cohort study.

Background: Anemia has negative effects on long-term outcomes of rectal cancer patients; however, its status as a risk factor for severe complications is disputed. Perioperative risks may differ based on the severity of pre-surgical anemia; nonetheless, no previous study has investigated these differences. This study identified risks of severe postoperative complications in rectal cancer patients based on severity of their pre-surgical anemia. Materials and Methods: This study enrolled patients who underwent low anterior resection for rectal cancer and were registered in the Japanese National Clinical Database (NCD) between 2017 and 2019. Anemia severity was categorized into three levels: mild, moderate, and severe. A logistic regression model was applied to calculate the risk-adjusted odds ratio (OR) of severe complications after surgery. Results: This study analyzed a cohort of 51 765 rectal cancer patients who underwent low anterior resection. Results showed that severe complications occurred in 10.9% of patients and were significantly more frequent in patients with anemia (13.6%) than those with normal hemoglobin levels (9.2%). Risk-adjusted ORs of severe complications in the severe, moderate, and mild anemia groups versus the normal group for males were 1.19 (95% confidence interval [CI]: 0.89-1.58), 1.47 (1.34-1.62), and 1.21 (1.12-1.31), respectively. Those for females were 1.39 (0.90-2.15), 1.64 (1.37-1.97), and 1.36 (1.16-1.58), respectively. Conclusions: According to this large cohort study, pre-surgical anemia significantly increases the risk of severe postoperative complications in rectal cancer patients. Even mild anemia presents a significant risk.

Monitoring ctDNA RAS Mutational Status in Metastatic Colorectal Cancer: A Trial Protocol of RAS-trace and RAS-trace-2 Studies.

Background: Spatial and temporal heterogeneities of RAS and other molecular genes should be considered in the treatment of metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs); acquired RAS mutation is sometimes observed at disease progression of treatment with the anti-EGFR mAb. At the same time, discrepancy of RAS status from tissues and circulating tumor DNA (ctDNA) in the same patient is sometimes observed. Based on this, we commenced two observational studies to clarify these heterogeneities of RAS and BRAF in mCRC, using next generation sequencing from liquid biopsy. Methods/Design: RAS-trace study is an observational study to monitor ctDNA RAS/BRAF/PIK3CA status every 4-12 weeks using the Plasma-SeqSensei™ CRC RUO Kit (Sysmex Inostics GmbH) in mCRC with RAS/BRAF wild-type (wt) on tumor tissue. The primary endpoint was the time to the acquired RAS mutations. A total of 42 patients has been accrued. RAS-trace-2 study is also an observational study aimed at comparing the efficacy of the anti-EGFR mAb in ctDNA RAS/BRAF wt with ctDNA RAS or BRAF mutant mCRC patients, whose RAS/BRAF are wt in tumor tissue. The primary endpoint was progression-free survival in patients with ctDNA RAS/BRAF wt and RAS or BRAF mutant. A total of 240 patients will be accrued over 2 years. Discussion: These trials will help us understanding the clinical significance of spatial and temporal heterogeneities of RAS, BRAF and other genes, while optimizing the anti-EGFR mAb treatment strategies in mCRC.

Surface proton hopping conduction mechanism dominant polymer electrolytes created by self-assembly of bicontinuous cubic liquid crystals.

For the development of the next generation of fuel cells, it is essential to create an innovative design principle of polymer electrolytes that is beyond extension of the existing strategy. In the present study, we focused on the surface hopping proton conduction mechanism where an activation energy for proton conduction is greatly reduced by decreasing the distance between SO3- groups. Our gyroid nanostructured polymer film (Film-G), with a hydrophilic surface where the SO3- groups are aligned densely and precisely, shows high proton conductivity of the order of 10-2 S cm-1 when the water content is about 15 wt%. We reveal that the high proton conductivity of Film-G is attributed to the exhibition of an extremely-fast surface hopping conduction mechanism due to the reduced activation energy barrier along the gyroid minimal surface. This finding should introduce a game-changing novel opportunity in polymer electrolyte design.

The benefits of interval appendectomy and risk factors for nonoperative management failure in the therapeutic strategy for complicated appendicitis.

PURPOSE: Emergency surgery (ES) for complicated appendicitis (CA) is associated with high morbidity. Interval appendectomy (IA) decreases this rate; however, nonoperative management (NOM) is not always successful. Some patients require unplanned ES due to NOM failure (IA failure: IA-F). This study aimed to verify the benefits of IA and to evaluate the risk factors for NOM failure. METHODS: Patients diagnosed with CA who underwent surgery between January 2012 and December 2021 were included in this study. We compared the surgical outcomes of the ES group with those of the IA success (IA-S) and IA-F groups. We also analyzed 14 factors that predicted NOM failure. RESULTS: Among 302 patients, the rate of severe complications (Clavien-Dindo grade ≥ III) was significantly higher in the ES group (N = 165) than in the IA-S group (N = 102). The rates were equal between the ES (N = 165) and IA-F (N = 35) groups. NOM was successful in 110 patients and failed in 27. Lack of abscesses, comorbidities, high WBC count, and free air were independent risk factors for NOM failure. CONCLUSIONS: Considering the benefits of IA and the non-inferior surgical outcomes of IA-F compared to ES, IA is a good therapeutic strategy for CA. However, in patients exhibiting four independent risk factors for NOM failure, careful monitoring of unplanned ES is necessary.

Utility of oligonucleotide in upregulating circular RNA production in a cellular model.

Circular RNAs (circRNAs), are a covalently closed, single-stranded RNA without 5'- and 3'-termini, commonly stem from the exons of precursor mRNAs (pre-mRNAs). They have recently garnered interest, with studies uncovering their pivotal roles in regulating various aspects of cell functions and disease progressions. A notable feature of circRNA lies in the mechanism of its biogenesis involving a specialized form of splicing: back-splicing. A splicing process that relies on interactions between introns flanking the circularizing exon to bring the up and downstream splice sites in proximity through the formation of a prerequisite hairpin structure, allowing the spliceosomes to join the two splice sites together to produce a circular RNA molecule. Based on this mechanism, we explored the feasibility of facilitating the formation of such a prerequisite hairpin structure by utilizing a newly designed oligonucleotide, CircuLarIzation Promoting OligoNucleotide (CLIP-ON), to promote the production of circRNA in cells. CLIP-ON was designed to hybridize with and physically bridge two distal sequences in the flanking introns of the circularizing exons. The feasibility of CLIP-ON was confirmed in HeLa cells using a model pre-mRNA, demonstrating the applicability of CLIP-ON as a trans-acting modulator to upregulate the production of circRNAs in a cellular environment.

Ascorbic acid predominantly kills cancer stem cell-like cells in the hepatocellular carcinoma cell line Li-7 and is more effective at low cell density and in small spheroids.

The development of therapies that target cancer stem cells (CSCs) is an important challenge in cancer research. The antioxidant system is enhanced in CSCs, which may lead to resistance to existing therapies. Ascorbic acid (AA) has the potential to act as both an antioxidant and a pro-oxidant agent, but its effects on CSCs are a subject of current research. Here, we investigated the effect of AA focusing specifically on CSCs with the hepatocellular carcinoma cell line Li-7. The Li-7 cell line is heterogenous consisting of CD166- and CD166+ cells; CD166- cells include CSC-like cells (CD13+CD166- cells) and CD13-CD166- cells that can revert to CD13+CD166- cells. The addition of AA to the culture medium caused cell death in both cell populations in CD166- cells in a concentration dependent manner. In contrast, AA administration had a limited effect on CD166+ non-CSC cells. The level of reactive oxygen species after AA treatment was elevated only in CD166- cells. The effect of AA only occurred at low cell densities in 2D and 3D cultures. In a mouse tumor model injected with Li-7 cells, intraperitoneal administration of AA failed to prevent tumor formation but appeared to delay tumor growth. Our findings shed light on why AA administration has not become a mainstream treatment for cancer treatment; however, they also show the possibility that AA can be used in therapies to suppress CSCs.