BRAF-mutant microsatellite-stable rectal cancer with acquired KRAS mutation leading to drug resistance in liver metastasis.

BRAF-mutant microsatellite-stable colorectal cancer (CRC), metastasized to distant sites, is associated with a poor prognosis. However, the BEACON CRC regimen, comprising a BRAF inhibitor, MEK inhibitor, and anti-EGFR antibody, offered a prolonged prognosis. Nonetheless, resistance to this regimen may occur, as observed in our reported case of CRC, where a KRAS mutation was identified in addition to the BRAF V600E mutation. Here, we present a case of 74-year-old woman with rectal cancer (pT4bN1bM0 Stage IIIc) harboring the BRAF V600E mutation. After resection of the primary tumor and during adjuvant chemotherapy using CAPOX (capecitabine and oxaliplatin), liver and lung metastases became apparent, and a companion diagnosis test revealed the presence of a BRAF V600E mutation. The new lesions were deemed resistant to the CAPOX regimen, and we decided to introduce encorafenib and cetuximab. After resection of liver metastases, encorafenib and cetuximab were reintroduced, but a new lesion appeared in hepatic S7, indicating resistance to the encorafenib and cetuximab regimen. The resistant liver metastasis was subsequently resected. To elucidate the resistance mechanism, we conducted a comprehensive analysis using the FoundationOne CDx cancer gene panel test, revealing the presence of a KRAS Q61H mutation alongside the BRAF V600E mutation. Subsequent liquid biopsy after liver recurrence confirmed the persistence of the KRAS Q61H mutation. Our results highlight the significance of cancer genome profiling tests (CGP tests) and liquid biopsies in guiding treatment strategies for BRAF-mutant colorectal cancer. Therefore, CGP testing offers valuable information for treatment, even if it does not lead to new drug administrations.

Association between the incidence of functional disability and frequency of eating together among older adults living alone: a 6-year follow-up study from the Japan Gerontological Evaluation Study.

OBJECTIVE: This study aimed to determine whether the frequency of eating together is associated with the incidence of functional disability in older adults who live alone. METHODS: This 6-year observational prospective cohort study utilised self-reported questionnaires. Data were drawn from the participants of the Japan Gerontological Evaluation Study project between 2016 and 2022. The participants were independent older adults aged ≥65 years living alone in Japan. The primary outcome was the incidence of functional disability during the follow-up period, with the self-reported frequency of eating together serving as the explanatory variable. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models after adjusting for confounders associated with incident functional disability. RESULTS: Among the 7167 participants, the mean age at baseline was 75.3 ± 6.5 years and 69.2% were female. About, 12.8% of participants (n = 917) developed functional disabilities during the observation period. The incidence rates were 11.7% for 'every day', 11.3% for 'several times a week', 11.5% for 'several times a month', 12.7% for 'several times a year' and 19.0% for 'seldom'. The frequency of eating together 'seldom' was significantly associated with an increased incidence of functional disability (HR: 1.55, 95% CI: 1.10-2.18). CONCLUSION: Among older adults living alone, infrequent eating together ('seldom') was identified as a risk factor for developing functional disability.

Results of the interim analysis of a prospective, multicenter, observational study of small subepithelial lesions in the stomach.

OBJECTIVES: Long-term outcomes of gastric subepithelial lesions have not been elucidated. To reveal the natural history, we initiated a prospective, 10-year follow-up of patients with small (≤20 mm) gastric subepithelial lesions in September 2014. Here, we report the results of an interim analysis of a prospective observational study. METHODS: In total, 567 patients with 610 lesions were prospectively registered between September 2014 and August 2016. The location, size, morphology, and number of subepithelial lesions were recorded on a web-based case report form. This study has been conducted as an Academic Committee Working Group of the Japan Gastroenterological Endoscopy Society. RESULTS: The endoscopic follow-up period was 4.60 ± 1.73 years (mean ± standard deviation), and survival data were investigated for 5.28 ± 1.68 years. This interim analysis revealed that the estimated cumulative incidence of a size increase ≥5 mm, after accounting for patients' death and resection of the tumor as competing risk events, was 4.5% at 5 years. In addition, the estimated cumulative incidence of lesion size increase ≥5 mm or resection of lesions was 7.9% at 5 years, and that of size increase ≥10 mm or resection of lesions was 4.5% at 5 years. CONCLUSION: These results indicate that approximately one in 13 patients with small (≤20 mm) gastric subepithelial lesions may require resection or further investigation for increased tumor size (≥5 mm) within 5 years.

ADAR1 is a promising risk stratification biomarker of remnant liver recurrence after hepatic metastasectomy for colorectal cancer.

Adenosine-to-inosine RNA editing is a process mediated by adenosine deaminases that act on the RNA (ADAR) gene family. It has been discovered recently as an epigenetic modification dysregulated in human cancers. However, the clinical significance of RNA editing in patients with liver metastasis from colorectal cancer (CRC) remains unclear. The current study aimed to systematically and comprehensively investigate the significance of adenosine deaminase acting on RNA 1 (ADAR1) expression status in 83 liver metastatic tissue samples collected from 36 patients with CRC. The ADAR1 expression level was significantly elevated in liver metastatic tissue samples obtained from patients with right-sided, synchronous, or RAS mutant-type CRC. ADAR1-high liver metastasis was significantly correlated with remnant liver recurrence after hepatic metastasectomy. A high ADAR1 expression was a predictive factor of remnant liver recurrence (area under the curve = 0.72). Results showed that the ADAR1 expression level could be a clinically relevant predictive indicator of remnant liver recurrence. Patients with liver metastases who have a high ADAR1 expression requires adjuvant chemotherapy after hepatic metastasectomy.

[Surgical Treatment of Congenital Absence of the Pericardium Found by Chance at Pulmonary Surgery:Report of a Case].

Absence of the pericardium is generally asymptomatic rare congenital disorder. However, it may be life-threatening problem due to cardiac deviation or herniation after the pulmonary resection. We described a case of complete defect of the pericardium found at surgery for metastatic lung cancer. Since the left lower lobectomy was necessary, the pericardium was reconstructed with an ePTFE sheet. Postoperative course was uneventful without any symptoms at two years post-surgery.

A Case Report of Non-typical Annular Pancreas Diagnosed during Laparoscopic Gastric Surgery.

An annular pancreas is a rare anomaly of the pancreas, defined as pancreatic tissue that totally or partly encircles the duodenum, usually the descending portion. A 76-year-old man who was diagnosed with gastric cancer cT3N0M0 Stage IIB underwent laparoscopic distal gastrectomy with D2 lymph node dissection. Intraoperatively, the dorsal half of the duodenal bulb was seen to be half surrounded by the pancreas, and a non-typical annular pancreas was diagnosed. Because of the risk to the pancreas, it was considered impossible to perform anastomosis by a linear stapler as in the usual laparoscopic procedure. Therefore, we performed laparoscopically assisted distal gastrectomy and Billroth-I reconstruction using a circular stapler, and the surgery was completed without difficulties. His postoperative course was good despite the development of a pancreatic fistula, which was an International Study Group for Pancreas Fistula biochemical leak. Some APs can be diagnosed preoperatively, but the rarer subtypes such as ours are more difficult to visualize on imaging. In gastrectomy, it is both oncologically important and technically challenging to perform lymph node dissection around the pancreas. In this case with an especially proximal pancreas, a circular stapler was considered better suited for gastroduodenal anastomosis and required a broader field than that afforded by laparoscopy. A case of non-typical annular pancreas diagnosed during laparoscopic gastric surgery is described.

RNA Editing is a Valuable Biomarker for Predicting Carcinogenesis in Ulcerative Colitis.

BACKGROUND AND AIMS: Ulcerative colitis [UC] can lead to colitis-associated colorectal neoplasm [CAN]. Adenosine-to-inosine RNA editing, which is regulated by adenosine deaminase acting on RNA [ADAR], induces the post-transcriptional modification of critical oncogenes, including antizyme inhibitor 1 [AZIN1], leading to colorectal carcinogenesis. Therefore, we hypothesized that ADAR1 might be involved in the development of CAN in UC. METHODS: We systematically analysed a cohort of 139 UC cases [40 acute phase, 73 remission phase, 26 CAN]. The degree of inflammation was evaluated using the Mayo endoscopic score [MES]. RESULTS: The type 1 interferon [IFN]-related inflammation pathway was upregulated in the rectum of active UC, rectum of UC-CAN and tumour site of UC-CAN patients. ADAR1 expression was upregulated in the entire colon of CAN cases, while it was downregulated in non-CAN MES0 cases. ADAR1 expression in the rectum predicted the development of CAN better than p53 or ß-catenin, with an area under the curve of 0.93. The high expression of ADAR1 and high AZIN1 RNA editing in UC was triggered by type 1 IFN stimulation from UC-specific microbiomes, such as seen in Fusobacterium in vitro analyses. The induction of AZIN1 RNA editing by ADAR1, whose expression is promoted by Fusobacterium, may induce carcinogenesis in UC. CONCLUSIONS: The risk of CAN can be evaluated by assessing ADAR1 expression in the rectum of MES0 UC patients, freeing UC patients from unnecessary colonoscopy and reducing their physical burden. RNA editing may be involved in UC carcinogenesis, and may be used to facilitate the prevention and treatment of CAN in UC.

IRE1-mediated cytoplasmic splicing and regulated IRE1-dependent decay of mRNA in the liverwort Marchantia polymorpha.

The unfolded protein response (UPR) or the endoplasmic reticulum (ER) stress response is a homeostatic cellular response conserved in eukaryotes to alleviate the accumulation of unfolded proteins in the ER. In the present study, we characterized the UPR in the liverwort Marchantia polymorpha to obtain insights into the conservation and divergence of the UPR in the land plants. We demonstrate that the most conserved UPR transducer in eukaryotes, IRE1, is conserved in M. polymorpha, which harbors a single gene encoding IRE1. We showed that MpIRE1 mediates cytoplasmic splicing of mRNA encoding MpbZIP7, a M. polymorpha homolog of bZIP60 in flowering plants, and upregulation of ER chaperone genes in response to the ER stress inducer tunicamycin. We further showed that MpIRE1 also mediates downregulation of genes encoding secretory and membrane proteins in response to ER stress, indicating the conservation of regulated IRE1-dependent decay of mRNA. Consistent with their roles in the UPR, Mpire1 ge and Mpbzip7 ge mutants exhibited higher sensitivity to ER stress. Furthermore, an Mpire1 ge mutant also exhibited retarded growth even without ER stress inducers, indicating the importance of MpIRE1 for vegetative growth in addition to alleviation of ER stress. The present study provides insights into the evolution of the UPR in land plants.

RNA editing facilitates the enhanced production of neoantigens during the simultaneous administration of oxaliplatin and radiotherapy in colorectal cancer.

Most cases of colorectal cancers (CRCs) are microsatellite stable (MSS), which frequently demonstrate lower response rates to immune checkpoint inhibitors (ICIs). RNA editing produces neoantigens by altering amino acid sequences. In this study, RNA editing was induced artificially by chemoradiation therapy (CRT) to generate neoantigens in MSS CRCs. Altogether, 543 CRC specimens were systematically analyzed, and the expression pattern of ADAR1 was investigated. In vitro and in vivo experiments were also performed. The RNA editing enzyme ADAR1 was upregulated in microsatellite instability-high CRCs, leading to their high affinity for ICIs. Although ADAR1 expression was low in MSS CRC, CRT including oxaliplatin (OX) treatment upregulated RNA editing levels by inducing ADAR1. Immunohistochemistry analyses showed the upregulation of ADAR1 in patients with CRC treated with CAPOX (capecitabine + OX) radiation therapy relative to ADAR1 expression in patients with CRC treated only by surgery (p < 0.001). Compared with other regimens, CRT with OX effectively induced RNA editing in MSS CRC cell lines (HT29 and Caco2, p < 0.001) via the induction of type 1 interferon-triggered ADAR1 expression. CRT with OX promoted the RNA editing of cyclin I, a neoantigen candidate. Neoantigens can be artificially induced by RNA editing via an OX-CRT regimen. CRT can promote proteomic diversity via RNA editing.

Regulatory T cells induce a suppressive immune milieu and promote lymph node metastasis in intrahepatic cholangiocarcinoma.

BACKGROUND: Emerging evidence indicates that immunogenicity plays an important role in intrahepatic cholangiocarcinoma (ICC). Herein, we systematically evaluated the clinical relevance of immunogenicity in ICC. METHODS: Highly immunogenic ICCs identified in the public dataset and the Cancer Immunome Atlas (TCIA) were assessed to determine the prognostic impact of immunogenicity in ICC and key components after curative resection. We also investigated the clinical relevance of the immune milieu in ICC. RESULTS: Using the Gene Expression Omnibus dataset 89749 and TCIA, we identified CD8+/forkhead box P3 (FoxP3)+ tumour-infiltrating lymphocytes (TILs), T-cell immunoglobulin and mucin domain 3 (TIM-3) and human leukocyte antigen-A (HLA-A) in highly immunogenic ICCs. Immunohistochemical analysis of the in-house cohort showed that intratumoral FoxP3+ TILs correlated with CD8+ TILs (P = 0.045, Fisher's exact test) and that high FoxP3+/CD8+ ratio (FCR) was an important marker for poor survival (P < 0.001, log-rank test). Furthermore, the FCR was higher in tumour-free lymph nodes in ICCs with lymph node metastases than in those without lymph node metastases (P = 0.003, Mann-Whitney U test). CONCLUSIONS: FCR should be considered an important biomarker that represents the immune environment of ICC based on its potentially important role in tumour progression, especially lymph node metastasis.

Surgical technique of suprapancreatic D2 lymphadenectomy focusing on the posterior hepatic plexus for advanced gastric cancer.

PURPOSE: Although D2 lymphadenectomy is currently considered a standard procedure for advanced gastric cancer (GC) worldwide, there is room for discussion about the appropriate range of suprapancreatic D2 lymphadenectomy. Focusing on the posterior hepatic plexus (PHP), which is not well recognized, we developed a surgical technique of suprapancreatic D2 lymphadenectomy, which we have called PHP-D2, and its short-term and long-term efficacies were evaluated in comparison with non-PHP-D2. METHODS: GC patients who underwent distal gastrectomy with D2 lymphadenectomy between July 2006 and May 2013 were enrolled, from which patients who had peritoneal metastasis and/or were peritoneal cytology-positive during surgery were excluded. Their medical records were retrospectively reviewed. RESULTS: Ninety-two patients (non-PHP-D2: 48, PHP-D2: 44) were enrolled. Shorter operation time (330 min vs 275 min, p < 0.0001) and less blood loss (290 mL vs 125 mL, p < 0.0001) were observed in PHP-D2, and no pancreatic fistulas were observed in PHP-D2. More lymph nodes of #11p (1 vs 1.5, p = 0.0328) and #12a lymph nodes (0 vs 1, p = 0.0034) were retrieved in PHP-D2, with no significant differences in #8a and #9 lymph nodes. Lymphatic recurrence was significantly less in PHP-D2 (p = 0.0166), and univariate and multivariate analyses showed that non-PHP-D2 was a significant risk factor for lymphatic recurrence (p = 0.0158), although there were no significant differences between non-PHP-D2 and PHP-D2 in 5-year overall survival and 5-year relapse-free survival. CONCLUSION: PHP-D2 was a safe and feasible procedure that had the potential to reduce lymphatic recurrence, and it can be a standard procedure of D2 lymphadenectomy for advanced GC.

Immuno-hyperthermia effected by antibody-conjugated nanoparticles selectively targets and eradicates individual cancer cells.

Hyperthermia has been used for cancer therapy for a long period of time, but has shown limited clinical efficacy. Induction-heating hyperthermia using the combination of magnetic nanoparticles (MNPs) and an alternating magnetic field (AMF), termed magnetic hyperthermia (MHT), has previously shown efficacy in an orthotopic mouse model of disseminated gastric cancer. In the present study, superparamagnetic iron oxide nanoparticles (SPIONs), a type of MNP, were conjugated with an anti-HER2 antibody, trastuzumab and termed anti-HER2-antibody-linked SPION nanoparticles (anti-HER2 SPIONs). Anti-HER2 SPIONs selectively targeted HER2-expressing cancer cells co-cultured along with normal fibroblasts and HER2-negative cancer cells and caused apoptosis only in the HER2-expressing individual cancer cells. The results of the present study show proof-of-concept of a novel hyperthermia technology, immuno-MHT for selective cancer therapy, that targets individual cancer cells.Abbreviations: AMF: alternating magnetic field; DDW: double distilled water; DMEM: Dulbecco's Modified Eagle's; Medium; f: frequency; FBS: fetal bovine serum; FITC: Fluorescein isothiocyanate; GFP: green fluorescent protein; H: amplitude; Hsp: heat shock protein; MHT: magnetic hyperthermia; MNPs: magnetic nanoparticles; PI: propidium iodide; RFP: red fluorescent protein; SPION: superparamagnetic iron oxide (Fe3O4) nanoparticle.

Hyperthermia generated by magnetic nanoparticles for effective treatment of disseminated peritoneal cancer in an orthotopic nude-mouse model.

Magnetic hyperthermia (MHT), which combines magnetic nanoparticles (MNPs) with an alternating magnetic field (AMF), holds promise as a cancer therapy. There have been many studies about hyperthermia, most of which have been performed by direct injection of MNPs into tumor tissues. However, there have been no reports of treating peritoneal disseminated disease with MHT to date. In the present study, we treated peritoneal metastasis of gastric cancer with MHT using superparamagnetic iron oxide (Fe3O4) nanoparticle (SPION) coated with carboxydextran as an MNP, in an orthotopic mouse model mimicking early peritoneal disseminated disease of gastric cancer. SPIONs of an optimal size were intraperitoneally administered, and an AMF (390 kHz, 28 kAm-1) was applied for 10 minutes, four times every three days. Three weeks after the first MHT treatment, the peritoneal metastases were significantly inhibited compared with the AMF-alone group or the untreated-control group. The results of the present study show that MHT can be applied as a new treatment option for disseminated peritoneal gastric cancer.Abbreviations: AMF: alternating magnetic field; Cy1: cytology-positive; DMEM: Dulbecco's Modified Eagle's Medium; FBS: fetal bovine serum; H&E: hematoxylin and eosin; HIPEC: hyperthermic intraperitoneal chemotherapy; MEM: Minimum Essential Medium; MHT: magnetic hyperthermia; MNPs: magnetic nanoparticles; P0: macroscopic peritoneal dissemination; RFP: red fluorescent protein; SPION: superparamagnetic iron oxide (Fe3O4) nanoparticle.

SMAD4 Germline Pathogenic Variant-Related Gastric Juvenile Polyposis with Adenocarcinoma Treated with Laparoscopic Total Gastrectomy: A Case Report.

BACKGROUND Juvenile polyposis syndrome is an uncommon, autosomal-dominant hereditary disease that is distinguished by multiple polyps in the stomach or intestinal tract. It is associated with a high risk of malignancy. Pathogenic variants in SMAD4 or BMPR1A account for 40% of all cases. CASE REPORT A 49-year-old woman underwent esophagogastroduodenoscopy because of exacerbation of anemia. She had numerous erythematous polyps in most parts of her stomach. Based on biopsy findings, juvenile polyposis syndrome (JPS) was suspected morphologically, but there was no evidence of malignancy. Colonoscopy showed stemmed hyperplastic polyps and an adenoma; video capsule endoscopy revealed no lesions in the small intestine. After preoperative surveillance, laparoscopic total gastrectomy with D1 lymph node dissection was performed to prevent malignant transformation. The pathological diagnosis was juvenile polyp-like polyposis with adenocarcinoma. In addition, a germline pathogenic variant in the SMAD4 gene was detected with genetic testing. CONCLUSIONS JPS can be diagnosed with endoscopy and genetic testing. Further, appropriate surgical management may prevent cancer-related death in patients with this condition.

Long-term Survival with a Rare Advanced Primary Gastrointestinal Malignant Melanoma Treated with Laparoscopic Surgery/Immune Checkpoint Inhibitor.

Targeted therapies for malignant melanoma have improved patients' prognoses. A primary gastrointestinal malignant melanoma is very rare, with no standard treatment strategy. We treated a 78-year-old Japanese female with advanced primary gastrointestinal melanoma of the descending colon and gallbladder. We administered a multidisciplinary treatment: surgical resection of the descending colon and gallbladder tumors, resection of the metastatic lymph nodes behind the pancreas head, and immune checkpoint antibody-blockade therapy (nivolumab) for ~4 years. PET/CT demonstrated no recurrent lesion for > 3 years. Multidisciplinary therapies (e.g., surgery, chemotherapy, radiotherapy, target therapy, and immune checkpoint antibody-blockade therapy) can successfully treat primary gastrointestinal malignant melanoma.

Influence of Percutaneous Occlusion of Atrial Septal Defect on Left Atrial Function Evaluated Using 2D Speckle Tracking Echocardiography.

Percutaneous occlusion of atrial septal defect (ASD) has recently become a standard therapeutic strategy, but little is known about left atrial (LA) function thereafter. The present study aimed to determine LA function in 43 children with ASD and 13 controls based on LA strain measured by two-dimensional echocardiographic speckle tracking (2DE-ST). Among these children, 12 underwent surgery (ASD-S), 31 had device closure (ASD-D), and 13 were included as controls. LA strain was significantly decreased after ASD-D but was not significantly altered after ASD-S, indicating that percutaneous occlusion of an ASD might decrease LA function. Furthermore, the size of the ASD device negatively correlated with LA strain. These results imply that ASD occlusion devices negatively influence LA function and might be important when decided therapeutic strategies for ASD. LA strain measured by 2DE-ST should become a good indicator of LA function after ASD treatment in children.

A Bezoar Composed of Bilirubin Calcium, Calcium Carbonate, and Fatty Acid Calcium.

A 68-year-old Japanese man was diagnosed with bezoar in the stomach, which was endoscopically retrieved. The bezoar was composed of bilirubin calcium, calcium carbonate, and fatty acid calcium. Due to the presence of bilirubin calcium in the bezoar, we performed imaging studies of the bile duct; gallstones and common bile duct stones were identified. Although bezoar with components similar to bile is infrequently encountered, our findings suggest that a bezoar originating from bile should be considered among the differential diagnoses in patients without a recent consumption history of persimmons who demonstrate a mass in the digestive tract. This case highlights the importance of component analysis of gastric bezoars because its findings may alter the treatment plan.

Case report: Atrioventricular block after transcatheter atrial septal closure using the Figulla® Flex II ASD occluder.

We report a 7-year-old male patient who developed severe atrioventricular block after transcatheter closure of the atrial septal defect with an Occlutech Figulla® Flex II ASD occluder (FSO). He had a small aortic rim and the defect measuring 22.3 mm by balloon sizing. When a 24 mm FSO was deployed, he developed Wenckebach second-degree heart block; however, it recovered to sinus rhythm. Hence, the device was implanted. The rhythm deteriorated to a fixed 2:1 heart block within 7 hr. He underwent surgical retrieval of the device and closure of the defect. Intraoperative findings demonstrated the right atrium disk compressing the triangle of Koch, resulting in a small hematoma. The rhythm recovered completely by 7 days after the surgery. Care must be taken when a relatively large device is deployed in a patient with small rims as even "soft and flexible" device like the FSO can injure the endocardium.

Activation of AZIN1 RNA editing is a novel mechanism that promotes invasive potential of cancer-associated fibroblasts in colorectal cancer.

Adenosine-to-inosine (A-to-I) RNA editing is a recently described epigenetic modification, which is believed to constitute a key oncogenic mechanism in human cancers. However, its functional role in cancer-associated fibroblasts (CAFs) within the tumor microenvironment (TME) and its clinical significance remains unclear. Herein, we systematically analyzed a large cohort of 627 colorectal cancer (CRC) specimens, and investigated the expression pattern of ADAR1 and its biological significance on the antizyme inhibitor 1 (AZIN1) RNA editing levels. Both ADAR1 expression and AZIN1 RNA editing levels were significantly elevated in CRC tissues vs. normal mucosa, and these findings correlated with the increased expression of mesenchymal markers, Vimentin (ρ = 0.44) and Fibroblast activation protein (ρ = 0.38). Intriguingly, ADAR1 expression was specifically upregulated in both cancer cells and fibroblasts from cancerous lesions. Conditioned medium from cancer cells led to induction of ADAR1 expression and activation of AZIN1 RNA editing in fibroblasts (p < 0.05). Additionally, edited AZIN1 enhanced the invasive potential of fibroblasts. In conclusion, we provide novel evidence that hyper-editing of AZIN1 enhances the invasive potential of CAFs within the TME in colon and is an important predictor of tumor invasiveness in CRC.

Synthesis and in vitro antitumor activity of novel 2-alkyl-5-methoxycarbonyl-11-methyl-6H-pyrido[4,3-b]carbazol-2-ium and 2-alkylellipticin-2-ium chloride derivatives.

Twenty-one types of novel ellipticine derivatives and pyridocarbazoles (5-methoxycarbonyl-11-methyl-6H-pyrido[4,3-b]carbazoles) with a nitrosourea moiety, linked by an oxydiethylene unit at the 2 position, were synthesized, and their cytotoxicity against HeLa S-3 cells was evaluated. Some of these new compounds exhibited potent antitumor activity by comparison with that of ellipticine.