Search

Abstract The fluorinated thymidine analog trifluridine (FTD) is a chemotherapeutic drug commonly used to treat cancer; however, the mechanism by which FTD induces cytotoxicity is not fully understood. In addition, the effect of gain-of-function (GOF) missense mutations of the TP53 gene (encoding p53), which promote cancer progression and chemotherapeutic drug resistance, on the chemotherapeutic efficacy of FTD is unclear. Here, we revealed the mechanisms by which FTD-induced aberrant mitosis and contributed to cytotoxicity in both p53-null and p53-GOF missense mutant cells. In p53-null mutant cells, FTD-induced DNA double-stranded breaks, single-stranded DNA accumulation, and the associated DNA damage responses during the G2 phase. Nevertheless, FTD-induced DNA damage and the related responses were not sufficient to trigger strict G2/M checkpoint arrest. Thus, these features were carried over into mitosis, resulting in chromosome breaks and bridges, and subsequent cytokinesis failure. Improper mitotic exit eventually led to cell apoptosis, caused by the accumulation of extensive DNA damage and the presence of micronuclei encapsulated in the disrupted nuclear envelope. Upon FTD treatment, the behavior of the p53-GOF-missense mutant, isogenic cell lines, generated by CRISPR/Cas9 genome editing, was similar to that of p53-null mutant cells. Thus, our data suggest that FTD treatment overrode the effect on gene expression induced by p53-GOF mutants and exerted its anti-tumor activity in a manner that was independent of the p53 function.

Abstract Background Systemic sclerosis (SSc) is an autoimmune disease characterized by frequent esophageal involvement. However, there are few reports on esophagectomy for esophageal strictures associated with SSc. Herein, we present a case of successful treatment of an esophageal stricture associated with SSc through subtotal esophagectomy. Case presentation A 53-year-old female patient was diagnosed with SSc, interstitial pneumonia, and gastroesophageal reflux disease (GERD). The patient developed an esophageal ulcer and benign stricture that required a subtotal esophagectomy 10 years after the diagnosis. Histopathological findings revealed thinning of the muscle layer, a characteristic feature of SSc. The patient was free of dysphagia or regurgitation. Conclusions An esophagectomy is a valuable option for treating esophageal strictures in SSc. Therefore, surgical approaches should be established for patients with SSc.

Abstract Background Because the robotic arm is located on the dorsal side of the patient, when the esophagus is pulled dorsally for the left recurrent nerve lymph node (LRLN) dissection, the robotic arm interferes with the surgical field. This made it difficult to prepare for the left recurrent lymph node dissection. We developed LRLN dissection in robotic surgery with natural space creation by physiological organ movement and evaluated the short-term results. Methods In this retrospective study, we analyzed 102 cases of robot-assisted thoracoscopic subtotal esophagectomy (RATE) among radical subtotal esophagectomies performed between December 2018 and December 2022 using medical records. LRLN dissection is preceded by a dissection of the esophagus from the trachea. Leaving the esophagus on the vertebral side and away from the trachea resulted in a physiological elevation of the esophagus, providing space between the trachea and esophagus. Results The thoracic surgery time in RATE was 181 (115–394) min. The number of LRLNs dissected was 4 (1–14). Six patients (6%) had a postoperative recurrence in the mediastinal lymph nodes. Seven patients (7%) had grade ≥ 1 left recurrent nerve palsy. Conclusions LRLN dissection with RATE using natural space creation was performed safely with a sufficient number of dissected lymph nodes and little left recurrent nerve palsy.

Abstract Background Intramural metastasis (IM) of esophageal cancer is classified as distant metastasis according to the Japanese Classification of Esophageal Cancer, and it is well-known to be associated with a poor prognosis. We herein report a case of perforated gastric IM of esophageal cancer that was successfully controlled with nonradical surgery and subsequent immune checkpoint inhibitor (ICI) treatment. Case presentation A 72-year-old woman was referred to our department for the treatment of esophageal cancer and perforated gastric ulcer. A histological examination of the main tumor and gastric ulcer lesion revealed squamous cell carcinoma. Since the gastric wall tumor had invaded the celiac artery, complete resection was considered impossible. Chemotherapy was administered but led to severe adverse events, so palliative resection was performed. Two months after surgery, computed tomography revealed enlargement of the residual tumor around the celiac artery. However, after nivolumab monotherapy was started, the tumor diminished remarkably, and the quality of life of the patient dramatically improved. Nine months after nonradical surgery, she is surviving without any disease concern. Conclusions With the increased availability of ICIs, multidisciplinary treatment with surgery and ICIs can potentially lead to long-term survival, even in cases expected to have a poor prognosis.

Abstract Background A simple measure of immune cytolytic activity (CYT) base on mRNA expression levels of two genes, GZMA and PRF1, was recently reported. Here, we aimed to evaluate the CYT score's potential as a measure of antitumor immunity and predictor of clinical outcome in gastric cancer (GC) patients. Materials and Methods We evaluated the correlations between tumor‐infiltrating immune cells and the CYT score in 238 GC samples from The Cancer Genome Atlas (TCGA). Next, we investigated CYT score associations with molecular subtypes, somatic mutation load, and immune checkpoint molecules in GC samples from TCGA and Asian Cancer Research Group (ACRG). Moreover, we evaluated the clinical significance of the CYT score calculated by reverse transcription (RT)‐quantitative PCR (qPCR) data in 123 GC samples and the association of the CYT score with the response to anti‐PD‐1 therapy in 7 GC samples from Kyushu University Hospital. Results The CYT score positively correlated with the proportions of tumor‐infiltrating CD8+ T cells and macrophages and negatively correlated with the proportion of regulatory T cells in GC tissues. A high CYT score was associated with common immune checkpoint molecules, a high mutation, the Epstein–Barr virus subtype, and the microsatellite instability subtype in GC. Moreover, a low CYT score was a poor prognosis factor in patients with GC. Finally, the CYT score was higher in a responder to anti‐PD‐1 therapy compared to nonresponders. Conclusion The CYT score reflects antitumor immunity and predicts clinical outcome in GC patients.

Leigh syndrome is a highly heterogeneous condition caused by pathological mutations in either nuclear or mitochondrial DNA regions encoding molecules involved in mitochondrial oxidative phosphorylation, in which many organs including the brain can be affected. Among these organs, a high incidence of poor bone health has been recognized in primary mitochondrial diseases including Leigh syndrome. However, the direct association between mitochondrial dysfunction and poor bone health has not been fully elucidated. Mitochondrial biosynthesis is a potential therapeutic target for this syndrome, as it can ameliorate the impairment of oxidative phosphorylation without altering these gene mutations. A recent study has shown the impaired osteogenesis in the dental pulp stem cells derived from the deciduous teeth of a child with Leigh syndrome, harboring the heteroplasmic mutation G13513A in the mitochondrial DNA region encoding the ND5 subunit of the respiratory chain complex I. The present study aimed to investigate whether mitochondrial biogenesis could be a therapeutic target for improving osteogenesis, using the same stem cells in a patient-specific cellular model. For this purpose, bezafibrate was used because it has been reported to induce mitochondrial biogenesis as well as to improve bone metabolism and osteoporosis. Bezafibrate clearly improved the differentiation of patient-derived stem cells into osteoblasts and the mineralization of differentiated osteoblasts. The mRNA expression of peroxisome proliferator-activated receptor-gamma coactivator-1α, ATP production, and mitochondrial Ca2+ levels were all significantly increased by bezafibrate in the patient-derived cells. In addition, the increased amount and morphological shift from the fragmentary to network shape associated with DRP1 downregulation were also observed in the bezafibrate-treated patient-derived cells. These results suggest that mitochondrial biogenesis may be a potential therapeutic target for improving osteogenesis in patients with Leigh syndrome, and bezafibrate may be one of the candidate treatment agents. Keywords: Bezafibrate, Dental pulp stem cell, Leigh syndrome, Mitochondrial biogenesis, Osteogenesis

A 75-year-old male was admitted to our hospital because of bile duct stenosis. He had no medical history of autoimmune disease. The level of tumor markers, serum IgG, and IgG4 were within normal ranges. Computed tomography showed perihilar and distal bile duct stenosis and wall thickening without swelling or abnormal enhancement of the pancreas. Endoscopic retrograde cholangiopancreatography showed perihilar and distal bile duct stenosis. A biopsy and cytology from the distal bile duct stenosis suggested adenocarcinoma, and cytology from the perihilar bile duct also suggested adenocarcinoma. A preoperative diagnosis of perihilar and distal bile duct cancer was made, and the patient underwent left hepatectomy and pancreaticoduodenectomy. Resected specimens showed wall thickening in the perihilar and distal bile duct; however, tumors were unclear. A histopathological examination revealed lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis in the perihilar and distal bile ducts. Immunohistochemistry revealed diffuse infiltration of IgG4-positive plasma cells in the perihilar and distal bile ducts. Lymphoplasmacytic infiltration, inflammatory change, storiform fibrosis, and obliterative phlebitis were shown in the pancreas. A final diagnosis of IgG4-related sclerosing cholangitis (IgG4-SC) with autoimmune pancreatitis was made. We herein report a case in which a preoperative diagnosis of IgG4-SC was difficult due to normal serum IgG4 levels and no obvious pancreatic lesion.

A 69-year-old woman with chronic hepatitis B was admitted to our hospital with a hepatic tumor. The levels of 2 tumor markers, carcinoembryonic antigen and carbohydrate antigen 19-9, were slightly elevated; however, the α-fetoprotein and protein levels induced by vitamin K antagonist II were within the normal limits. Abdominal ultrasonography showed a well-defined peripheral hypoechoic mass that was isoechoic and homogeneous on the inside. Computed tomography showed a poorly enhanced tumor of 13 mm in diameter in the 5th segment of the liver. Fluorodeoxyglucose positron emission tomography showed a slight uptake (maximum standard uptake value 3.4) by the hepatic tumor. These findings suggested cholangiocellular carcinoma, and we performed anterior segmentectomy of the liver. A histopathological examination showed a hepatic pseudolymphoma. The patient’s postoperative course was uneventful, and she remains alive without recurrence 5 months after undergoing surgery. In most cases, hepatic pseudolymphoma is preoperatively diagnosed as a malignant tumor and a definite diagnosis is made after resection. It is therefore necessary to consider hepatic pseudolymphoma as a differential diagnosis in patients with hepatic tumors.

Metatropic dysplasia is a congenital skeletal dysplasia characterized by severe platyspondyly, dumbbell-like deformity of long tubular bones, and progressive kyphoscoliosis with growth. It is caused by mutations in the gene TRPV4, encoding the transient receptor potential vanilloid 4, which acts as a calcium channel. Many heterozygous single base mutations of this gene have been associated with the disorder, showing autosomal dominant inheritance. Although abnormal endochondral ossification has been observed by histological examination of bone in a patient with lethal metatropic dysplasia, the etiology of the disorder remains largely unresolved. As dental pulp stem cells (DPSCs) are mesenchymal stem cells that differentiate into bone lineage cells, DPSCs derived from patients with congenital skeletal dysplasia might be useful as a disease-specific cellular model for etiological investigation. The purpose of this study was to clarify the pathological association between TRPV4 mutation and chondrocyte differentiation by analyzing DPSCs from a patient with non-lethal metatropic dysplasia. We identified a novel heterozygous single base mutation, c.1855C>T in TRPV4. This was predicted to be a missense mutation, p.L619F, in putative transmembrane segment 5. The mutation was repaired by CRISPR/Cas9 system to obtain isogenic control DPSCs for further analysis. The expression of stem cell markers and fibroblast-like morphology were comparable between patient-derived mutant and control DPSCs, although expression of TRPV4 was lower in mutant DPSCs than control DPSCs. Despite the lower TRPV4 expression in mutant DPSCs, the intracellular Ca2+ level was comparable at the basal level between mutant and control DPSCs, while its level was markedly higher following stimulation with 4α-phorbol 12,13-didecanoate (4αPDD), a specific agonist for TRPV4, in mutant DPSCs than in control DPSCs. In the presence of 4αPDD, we observed accelerated early chondrocyte differentiation and upregulated mRNA expression of SRY-box 9 (SOX9) in mutant DPSCs. Our findings suggested that the novel missense mutation c.1855C>T of TRPV4 was a gain-of-function mutation leading to enhanced intracellular Ca2+ level, which was associated with accelerated chondrocyte differentiation and SOX9 upregulation. Our results also suggest that patient-derived DPSCs can be a useful disease-specific cellular model for elucidating the pathological mechanism of metatropic dysplasia. Keywords: Chondrocyte differentiation, Dental pulp stem cell, Metatropic dysplasia, Transient receptor potential vanilloid 4

Background/Aim: Recent research has demonstrated that laparoscopic multivisceral resection (MVR) for advanced colorectal cancer is safe, practicable, and yields satisfactory oncological results, which is in line with the growing usage of laparoscopic surgery. The effectiveness of laparoscopic MVR is still debatable, though. The goal of this study was to compare the short- and long-term results of patients with advanced colorectal cancer treated with open MVR with laparoscopic procedures. Patients and Methods: Data on 3,571 consecutive patients hospitalized at the Kyushu University National Kyushu Cancer Center for colorectal cancer surgery between 2004 and 2020 were gathered retrospectively. In the end, 84 individuals with advanced colorectal cancer who had a colectomy with MVR were examined. We evaluated invasiveness in terms of complications, blood loss, and operating time. Recurrence-free survival rates and overall 5-year survival were among the oncological outcomes. Results: Of the 84 patients examined, 29 underwent laparoscopic treatment, and 55 underwent open treatment. The laparoscopic surgery group experienced shorter hospital stays (15 vs. 18 days, p<0.05) and much less blood loss (median volume: 167 vs. 1,058 g, p<0.005) than the open surgery group. Following the exclusion of patients with stage IV colorectal cancer from the study (groups undergoing laparoscopic surgery, n=25; open surgery, n=38), the groups displayed comparable pathologic results and no discernible variations in either the 5-year overall survival (p=0.87) or recurrence-free survival (p=0.86). Conclusion: In certain individuals with advanced colorectal cancer, a laparoscopic method of manipulation with MVR may be less invasive than an open method without compromising the prognosis. [ABSTRACT FROM AUTHOR]