Tsutomu Nomura

Relationship between altered expression levels of MIR21, MIR143, MIR145, and MIR205 and clinicopathologic features of esophageal squamous cell carcinoma

In spite of the undisputed importance of altered expression patterns of microRNAs (miRNAs) in various cancers, there is little information on the clinicopathologic significance of cancer-related miRNAs (MIR21, MIR143, MIR144, MIR145, and MIR205) in esophageal squamous cell carcinoma (ESCC). We examined the expression levels of the precursor and mature miRNA genes in ESCC using real-time polymerase chain reaction (PCR). We also investigated the mRNA expression levels of processing elements (RNASEN, DGCR8, and DICER1) that participate in miRNA-biogenesis pathway. Furthermore, we analyzed the relationships between the expression levels of these five miRNAs and the clinicopathologic parameters of ESCC patients. The expression levels of mature MIR21 and mature MIR145 were higher in ESCC than those in normal epithelium (P < 0.05). The mature/pre ratio of MIR21 in ESCC was higher than that in normal epithelium (P < 0.05). With regard to miRNA-processing elements, the expression level of RNASEN was higher in ESCC than in normal epithelium (P < 0.05). Furthermore, altered expression of these miRNAs was related to the clinicopathologic features of ESCC patients. The high expression of mature MIR21 and mature MIR205 was associated with lymph node positivity in ESCC patients (P < 0.05). The high levels of expression of mature MIR143 and mature MIR145 were associated with recurrence of metastasis in ESCC patients (P < 0.05). The findings may imply that miRNA biogenesis is aberrantly accelerated in ESCC. Analysis of the expression levels of miRNAs should provide useful information for evaluation of the staging, prognosis, and treatment of ESCC patients.

Quantitative Detection of p53 Mutations in Plasma DNA from Tobacco Smokers

In lung tumors, the p53 tumor suppressor gene is commonly mutated with a characteristic mutation spectrum. The amount of and alterations in plasma DNA, such as mutations in p53, were associated with several cancers. Few studies used quantitative methods of high sensitivity. Previously, we observed p53 mutations in the noncancerous tissue that differed from those in lung tumors using the highly sensitive p53 mutation load assay. Based on our observation of an increased p53 mutation load in nontumorous lung tissue in smokers, we hypothesized that plasma DNA may contain mutant p53 indicative of tobacco smoke exposure and will be an effective biomarker of lung cancer or smoking exposure. We modified the p53 mutation load assay to detect mutations at p53 codons 248 and 249, common mutations in lung cancer, in plasma DNA samples with a sensitivity of 1:5,000. The assay was applied to a set of lung cancer cases (n = 39), hospital controls (n = 21), and population controls (n = 20) from a larger study. Controls were selected to consist of equal numbers of both ever and never smokers. The p53 mutation load (mutated p53 copies per total number of p53 copies) was associated with smoking (P = 0.06), but not with lung cancer (P = 0.59). Most of the individuals with p53 mutations observed in plasma DNA were ever smokers and the p53 mutation load was higher in those who smoked for longer durations (P = 0.04). In summary, we were able to detect p53 mutations in plasma DNA from healthy individuals and our data suggest that p53 mutations in plasma DNA may be a marker of carcinogen exposure from tobacco smoke.

Laparoscopic pancreatic resection: some benefits of evolving surgical techniques

Laparoscopic pancreatic resection began to be reported in the first half of the 1990s, with subsequent reports focusing primarily on the safety and usefulness of laparoscopic distal pancreatectomy (Lap-DP) for benign and low-malignancy lesions of the pancreatic body and tail (such as chronic pancreatitis, neuroendocrine tumor, mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm). Recently we have also begun to see retrospective case-control studies comparing these techniques with open surgery, with Lap-DP showing advantages not only in terms of esthetics related to the surgical wound, but also with regard to reduced intraoperative bleeding, postoperative recovery time, and days of postoperative hospitalization. Prospective randomized controlled trials are still needed for confirmation, but it appears likely that this technique will become a standard surgical procedure for the treatment of diseases of the pancreatic body and tail. In contrast, laparoscopic pancreatoduodenectomy (Lap-PD) remains controversial in the minds of many pancreatic surgeons. This is primarily due to the difficulty of laparoscopic reconstruction following resection. However, there have recently been a number of single-center reports on the use of this procedure in at least 20 patients per center, showing that Lap-PD is associated with considerable reduction in intraoperative bleeding. Our own experience has been similar. In carefully selected patients, we find Lap-PD to be a useful surgical procedure.

Esophageal motility in Japanese patients with Barrett's esophagus

BackgroundThe prevalence of gastroesophageal reflux disease has been increasing in Japan as it has in Western countries, but Barrett’s esophagus (BE) is less common in Japan than in Western countries. The aim of this study, therefore, was to investigate esophageal motility and clinical characteristics in Japanese patients with BE.MethodsTen patients with BE were compared with ten patients with mild reflux esophagitis (RE), ten patients with severe RE, and ten healthy subjects of comparable age and sex. The prevalence of Helicobacter pylori was investigated in the patients with BE. The intraluminal microtransducer method was used to test for esophageal motility. Basal lower esophageal sphincter (LES) pressure was assessed by the rapid pull-through method. The esophageal wave after ten repeated 5-ml water swallowings at 30-s intervals was measured at 3, 8, 13, and 18 cm above the LES.ResultsThe basal LES pressure, the amplitude of the esophageal wave at 3 and 8 cm above the LES, and the frequency of primary peristalsis in the severe RE group and BE group were significantly lower than the values in the healthy subjects and the mild RE group. The amplitude of the esophageal wave 13 cm above the LES in the BE group was significantly lower than that in the healthy subjects and the mild RE group. There was no difference between the severe RE group and the BE group in the basal LES pressure and the amplitude of the esophageal wave. The frequency of primary peristalsis in the BE group, however, was significantly lower than that in the severe RE group. Nine of the ten patients with BE were H. pylori-negative.ConclusionsOur conclusions are that esophageal dysmotility in Japanese patients with BE represents an advanced stage of severe RE, and that most Japanese patients with BE are H. pylori-negative.

Efficacy of Vonoprazan for Proton Pump Inhibitor-Resistant Reflux Esophagitis

Background: Vonoprazan (VPZ) is a novel potassium-competitive acid blocker that may be clinically beneficial for proton pump inhibitor (PPI)-resistant reflux esophagitis (RE). The aim of this study was to investigate the efficacies of VPZ therapy at 20 mg for 4 weeks in patients with PPI-resistant RE and VPZ maintenance therapy at 10 mg for 8 weeks in patients who have been successfully treated. Methods: Subjects comprised 24 patients with PPI-resistant RE (Los Angeles classification grade A/B/C/D: 3/7/11/3). After confirming PPI-resistant RE by endoscopy, 20 mg VPZ was administered. Endoscopy was performed 4 weeks after the initiation of VPZ. Symptoms were evaluated using the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG). Maintenance therapy with 10 mg VPZ was performed and endoscopy was conducted after 8 weeks. Results: In 21 (87.5%) out of 24 patients, esophageal mucosal breaks were successfully treated by 20 mg VPZ. The median FSSG score was significantly lower on days 1-7, 14, and 28 after the initiation of VPZ than before its administration. Maintenance therapy with 10 mg VPZ prevented the relapse of esophageal mucosal breaks in 16 (76.2%) out of 21 patients. Conclusion: VPZ was effective for most patients with PPI-resistant RE.

Characteristics of symptomatic reflux episodes in patients with non-erosive reflux disease who have a positive symptom index on proton pump inhibitor therapy.

Background and Aim: The reason that some reflux episodes evoke symptoms is poorly understood, therefore the aim of this study is to assess the determinants of reflux perception in patients with non-erosive reflux disease (NERD) on proton pump inhibitor (PPI) therapy. Methods: Ten NERD patients with persistent symptoms, despite double-dose PPI therapy, were included in this study. All patients had a positive symptom index (SI), which was determined by ambulatory 24-hour combined impedance-pH monitoring. Reflux episodes were identified and classified as acid, weakly acidic or weakly alkaline reflux and were considered symptomatic if patients recorded a symptom within 5 min after a reflux episode. Results: A total of 954 liquid reflux episodes were detected, including 135 (14.2%) acid, 782 (82.0%) weakly acidic, and 37 (3.9%) weakly alkaline. Overall, 59 (6.2%) reflux episodes were symptomatic and the majority (88.1%) of symptomatic reflux episodes were weakly acidic reflux. When reflux episodes were confined to the distal esophagus, there were very few reflux symptoms. Proximal reflux is significantly more likely to be associated with reflux symptoms, irrespective of the acidity of the refluxate or the duration of proximal reflux episodes. Conclusions: In NERD patients who have a positive SI on double-dose PPI therapy, the high proximal extent of refluxate is a major factor associated with reflux perception.

SnoN Overexpression is Predictive of Poor Survival in Patients with Esophageal Squamous Cell Carcinoma

BackgroundEarlier studies have identified the minimal overlapping region of amplification at 3q26 in esophageal squamous cell carcinoma (ESCC) by comparative genomic hybridization (CGH) analysis. These include PIK3CA which encodes the p110α catalytic subunit of phosphatidylinositol (PI) 3-kinase, a telomerase RNA component (TERC), a squamous cell carcinoma-related oncogene (SCCRO), ecotropic viral integration site-1 (EVI-1), and a Ski-related novel oncogene (SnoN). In the present study, we investigated the mRNA levels of four candidate genes (TERC, SCCRO, EVI-1, and SnoN) to determine whether genes other than PIK3CA are targets for amplification at 3q26 in ESCC. And also, we examined SnoN expression in ESCC samples.MethodsFifty-nine representative cases with ESCC were selected from our archives. We performed quantitative RT-PCR of four candidate genes (TERC, SCCRO, EVI-1, and SnoN) and immunohistochemistry for SnoN. Finally, we correlated these findings with the clinicopathological characteristics to determine their interrelationship.ResultsAmong the four genes we tested, only SnoN mRNA was consistently overexpressed in primary ESCC, compared with those in corresponding nontumorous esophageal epithelia (P < 0.001). Immunoreactive SnoN was detectable in 31 of 59 (52.5%) esophageal squamous cell carcinoma specimens. The levels of SnoN expression were found to correlate with the depth of invasion and recurrence (P < 0.05). Furthermore, patients with positive staining for SnoN displayed more unfavorable outcomes than patients with negative staining (P < 0.05).ConclusionSnoN is likely to be the target of the amplification at 3q26 in ESCC and plays an important role in the development of ESCC, influencing disease-specific survival.

A Rare Case of Primary Squamous Cell Carcinoma of the Stomach and a Review of the 56 Cases Reported in Japan

We report an extremely rare case of primary squamous cell carcinoma of the stomach. A 69-year-old man was admitted to our hospital with a 2-month history of dysphagia and tarry stools. Endoscopic examination revealed a cauliflower-shaped protruding mass along the lesser curvature of the gastric cardia. Biopsy of the lesion revealed squamous cell carcinoma of the stomach. Computed tomography revealed a thickened stomach wall and a mass protruding into the gastric lumen. Total gastrectomy with splenectomy, distal pancreatectomy, and Roux-en-Y reconstruction was performed, together with a lower thoracic esophagectomy via a left thoracotomy. Histopathological examination of the specimen revealed well-differentiated squamous cell carcinoma of the stomach. Postoperative follow-up was uneventful for the first 18 months. However, multiple liver metastases and para-aortic lymph node metastasis developed subsequently. Despite systemic combination chemotherapy, the patient died because of progression of the recurrent tumors. Here, we review the characteristics of 56 cases of gastric squamous cell carcinoma reported in Japan.

SnoN/SKIL modulates proliferation through control of hsa-miR-720 transcription in esophageal cancer cells.

It is now evident that changes in microRNA are involved in cancer progression, but the mechanisms of transcriptional regulation of miRNAs remain unknown. Ski-related novel gene (SnoN/SKIL), a transcription co-factor, acts as a potential key regulator within a complex network of p53 transcriptional repressors. SnoN has pro- and anti-oncogenic functions in the regulation of cell proliferation, senescence, apoptosis, and differentiation. We characterized the roles of SnoN in miRNA transcriptional regulation and its effects on cell proliferation using esophageal squamous cell carcinoma (ESCC) cells. Silencing of SnoN altered a set of miRNA expression profiles in TE-1cells, and the expression levels of miR-720, miR-1274A, and miR-1274B were modulated by SnoN. The expression of these miRNAs resulted in changes to the target protein p63 and a disintegrin and metalloproteinase domain 9 (ADAM9). Furthermore, silencing of SnoN significantly upregulated cell proliferation in TE-1 cells, indicating a potential anti-oncogenic function. These results support our observation that cancer tissues have lower expression levels of SnoN, miR-720, and miR-1274A compared to adjacent normal tissues from ESCC patients. These data demonstrate a novel mechanism of miRNA regulation, leading to changes in cell proliferation.

The appearance of rosette-like esophageal folds (“esophageal rosette”) in the lower esophagus after a deep inspiration is a characteristic endoscopic finding of primary achalasia

BackgroundIn healthy subjects who inspire deeply the lower esophagus usually opens, and the esophageal palisade vessels (EPVs) become visible. However, in patients with achalasia, the full extent of the EPVs does not become visible and, in addition, rosette-like esophageal folds appear in the lower esophagus. The aim of this study was to investigate whether or not these changes at the lower esophagus are characteristic findings of achalasia.MethodsA total of 34 patients with achalasia and no esophageal dilatation following deep inspiration were compared with 34 sex- and age-matched control subjects. Following a deep inspiration, the lower esophagus of all study cohorts was evaluated on (1) whether or not the full extent of the EPVs was visible, (2) whether or not rosette-like esophageal folds appeared in the lower esophagus, and (3) whether or not there were any gastric lesions.ResultsOne patient had secondary achalasia, and the remaining 33 patients had primary achalasia. In the control subjects, the full extent of the EPVs was clearly visible after a deep inspiration, and no esophageal folds appeared in the lower esophagus. In contrast, in the achalasia patients, EPVs were not observed in all patients after a deep inspiration, and rosette-like esophageal folds appeared in 33 of the 34 patients.ConclusionAfter a deep inspiration, the non-visibility of the EPVs and the appearance of rosette-like esophageal folds at the lower esophagus, which we have called “esophageal rosette”, are characteristic endoscopic findings of primary achalasia.