A crucial role of uridine/cytidine kinase 2 in antitumor activity of 3'-ethynyl nucleosides.

The antitumor 3'-ethynyl nucleosides, 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)cytosine (ECyd) and 1-(3-C-ethynyl-beta-D-ribopentofuranosyl)uridine (EUrd), are potent inhibitors of RNA polymerases and show excellent antitumor activity against various human solid tumors in xenograft models. ECyd is being investigated in phase I clinical trials as a novel anticancer drug possessing a unique antitumor action. ECyd and EUrd require the activity of uridine/cytidine kinase (UCK) to produce the corresponding active metabolite. The UCK family consists of two members, UCK1 and UCK2, and both UCKs are expressed in many tumor cells. It was unclear, however, whether UCK1 or UCK2 is responsible for the phosphorylation of the 3'-ethynyl nucleosides. We therefore established cell lines that are highly resistant to the 3'-ethynyl nucleosides from human fibrosarcoma HT-1080 and gastric carcinoma NUGC-3. All the resistant cell lines showed a high cross-resistance to ECyd and EUrd. As a result of cDNA sequence analysis, we found that UCK2 mRNA expressed in EUrd-resistant HT-1080 cells has a 98-base pair deletion of exon 5, whereas EUrd-resistant NUGC-3 cells were harboring the point mutation at nucleotide position 484 (C to T) within exon 4 of UCK2 mRNA. This mutation was confirmed by genome sequence analysis of the UCK2 gene. Moreover, the expression of UCK2 protein was decreased in these resistant cells. In contrast, no mutation in the mRNA or differences in protein expression levels of UCK1 were shown in the EUrd-resistant HT-1080 and NUGC-3 cells. These results suggest that UCK2 is responsible for the phosphorylation and activation of the antitumor 3'-ethynyl nucleosides.     

Assessment of the new TNM classification for resected lung cancer

To evaluate the revised TNM classification, we investigated the prognoses of 552 consecutive patients who had resection of non-small-cell lung cancer between April 1982 and March 1996. According to the new classification, the 5-year survival rate was 76.9% for stage I A, 57.2% for stage I B (I A versus I B, p < 0.0005), 47.7% for stage IIA, 49.8% for stage IIB, 18.6% for stage IIIA (IIB versus IIIA, p = 0.005), 16.7% for stage IIIB, and 7.9% for stage IV (IIIB versus IV, p = 0.02). Especially for patients in stage I A, there was significant difference in survival between patients with the tumor size within 1.5 cm and those with larger than 1.5 cm. The survival rate for T3N0M0 patients was significantly better than that for T3N1-2M0, but there was no significant difference between patients with T3N0M0 disease and those with T2N1M0 disease. Concerning the pm1 patients, the survival rate was significantly better than other stage IIIB patients. Our results supported the revision for dividing stage I and putting T3N0M0 into stage IIB. However, the classification is controversial about dividing stage II and putting pm1 as T4 disease. Furthermore, subgrouping of T1N0M0 disease by tumor size, T3 by tumor invaded organ will be necessary in the next revisions.     

Percutaneous tumor ablation therapy for the advanced stage of HCC

We have performed percutaneous tumor ablation (PTA) including percutaneous ethanol injection therapy (PEIT) for 90% of the patients with hepatocellular carcinoma. Until December 1998, the 793 patients received PTA, 5 years survival rate reached 39.8%. Excluding the patients with Child C whose hepatic function were extremely low, 5 years survival rate reached to the level of 41.2%. Since 5 years survival rate in stage IV-A reached 24.4%, the patients of stage IV-A may be considered to have an indication for PTA. We have confirmed the effectiveness of the local treatment including radiotherapy for advanced hepatocellular carcinoma with portal vein invasion. We are attempting to perform PTA for the extra-hepatic lesions that had no indication of other treatment. However the indication of PTA is limited by the presence of diffuse nodules, exacerbation of the hepatic function, or tumor invasion to portal vein, bile duct, inferior vena cava.     

Potential of a glucagon‐like peptide‐1 receptor/glucose‐dependent insulinotropic polypeptide receptor/glucagon receptor triagonist for the treatment of obesity and type 2 diabetes

Triagonists of GLP‐1R/ GIPR /GCGR, including SAR441255, bind to each receptor and induce specific effects through each receptor signaling pathway, thus result in weight loss and glycemic control in obese T2D animal models.

Type 2 diabetes, which often accompanies obesity, is one of the major health‐threatening diseases worldwide. Incretin‐based therapies, such as dipeptidyl peptidase‐4 inhibitors and glucagon‐like peptide‐1 receptor (GLP‐1R) agonists, are used for the treatment of type 2 diabetes. The GLP‐1R agonists have been shown to improve glycemic control and reduce bodyweight through its various actions, including glucose‐dependent insulin secretion, suppression of glucagon secretion, and inhibition of gastric emptying and food intake ¹ .Recently, dual agonists of GLP‐1R and glucose‐dependent insulinotropic polypeptide receptor (GIPR), and those of GLP‐1R and glucagon receptor (GCGR) have been developed. One of the dual agonists of GLP‐1R and GIPR, named tirzepatide, has been shown to bind and activate both GLP‐1R and GIPR in vitro and in vivo, its efficacy for the treatment of type 2 diabetes has been proven in a phase III trial, and it has recently been approved by the US Food and Drug Administration ^{2 , 3} . In the phase III trial, once‐weekly injection of trizepatide (5, 10 or 15 mg) for 40 weeks reduced glycated hemoglobin (HbA1c) from baseline by 1.87, 1.89 or 2.07%, respectively, and reduced bodyweight from baseline by 7.0, 7.8 or 9.5 kg, respectively, in type 2 diabetes patients. The most frequent adverse events with trizepatide were gastrointestinal events ³ . In the clinical trial that compared trizepatide (5, 10 or 15 mg) with once‐weekly semaglutide (1 mg) in type 2 diabetes patients, trizepatide showed non‐inferior and superior reductions in HbA1c levels and in bodyweight ⁴ . For both treatments, gastrointestinal events were the most common adverse events ⁴ . The possible additional effects of GIP signaling in type 2 diabetes patients might depend on its augmentation of insulin secretion during hyperglycemic states ⁵ .The dual agonists of GLP‐1R and GCGR specific for mice or monkeys have been developed and were investigated their effects in each species. In obese and diabetic cynomolgus monkeys induced by high‐fat diet feeding, the monkey‐specific dual agonist of GLP‐1R and GCGR reduced total energy intake, decreased bodyweight and improved glucose tolerance ⁶ . However, in another study using obese diabetic monkeys, glycemic control was worse when they were co‐administered with both GLP‐1R and GCGR agonists compared with that treated with an GLP‐1R agonist alone ⁷ . Therefore, the significance of the activation of GCGR signaling has not yet been fully clarified.In 2015, Finan et al. ⁸ created a triagonist that activates GLP‐1R, GIPR and GCGR by selecting amino acids from the three peptide hormones, GLP‐1, GIP and glucagon, and reported that the triagonist reduced bodyweight and improved glucose control in rodent models of obesity and diabetes.More recently, Bossart et al. ⁹ developed a novel GLP‐1R, GIPR and GCGR triagonist, SAR441255. SAR441255 was confirmed to efficiently bind to and stimulate all three receptors in in vitro studies. In a diet‐induced obesity mouse model, subcutaneous injection of SAR441255 (0.3, 1, 3, 10 or 30 μg/kg) showed a dose‐dependent effect on bodyweight (+9.7%, +6.9%, +5.8%, −4.8% and −14.1%, respectively) compared with injection of vehicle (+11.5%). Non‐fasted blood glucose levels were significantly lower in mice treated with SAR441255 at doses of ≥1 μg/kg when compared with vehicle‐treated controls. In obese diabetic cynomolgus monkeys, treatment with SAR441255 (11 μg/kg) or a monkey‐specific GLP‐1R/GCGR dual agonist (4 μg/kg) ⁶ significantly reduced the bodyweight by −12.6% or −8.1%, respectively, and decreased the HbA1c levels by −1.37% or −1.85%, respectively. Fasting plasma glucose and alanine aminotransferase levels were significantly reduced with SAR441255, but not with the dual agonist (Figure 1).Open in a separate windowFigure 1Possible mechanisms of glucagon‐like peptide‐1 receptor (GLP‐1R)/glucose dependent insulinotropic polypeptide receptor (GIPR)/glucagon receptor (GCGR) triagonist in weight loss and glycemic control in obese type 2 diabetes animal models. Triagonists of GLP‐1R/GIPR/GCGR, including SAR441255, bind to each receptor and induce specific effects through each receptor signaling pathway, thus resulting in weight loss and glycemic control in obese type 2 diabetes animal models. Potential effects of each receptor signaling that contribute to weight loss and/or better glycemic control are listed below each receptor.To further understand engagement of the different receptors in vivo, receptor occupancy of SAR441255 at the GLP‐1 and the GCG receptors was studied with the use of positron emission tomography imaging after radiotracer administration in lean cynomolgus monkeys. A subcutaneous injection of 11 μg/kg SAR411255 together with radiotracers specific for GLP‐1R and GCGR showed the significant signals of both receptors in the liver and pancreas of monkeys, suggesting the binding of SAR411255 to both receptors existing in these organs. Cardiovascular safety of SAR411255 was further confirmed in lean cynomolgus monkeys.Finally, a phase I study with SAR411255 in lean to overweight healthy participants was carried out to assess the safety, tolerability, pharmacokinetics and pharmacodynamics. After subcutaneous administration, SAR441255 concentration reached the median maximum serum concentration by 3.0–3.5 h, and was eliminated with a mean elimination terminal half‐life of 3.5–6.1 h. After administration of single doses (80 and 150 mg) of SAR441255 in the fasting state, maximal reduction in blood glucose levels were observed at 1 h post‐dose. At this time point, three of six participants who received the 80 mg dose and all six participants who received the 150 mg dose showed hypoglycemia (<70 mg/dL) without any clinical signs or symptoms. No further low blood glucose values were observed in either dose group. Blood glucose levels subsequently returned to baseline levels within 1–2 h. In contrast, fasting insulin and C‐peptide levels were relatively stable, and showed no correlation with the glucose levels. Therefore, the mechanisms of this early phase hypoglycemia have not yet been clarified. After the mixed‐meal test 3 h after the SAR441255 administration (80 and 150 mg), a dose‐dependent reduction in postprandial plasma glucose was observed. Because insulin and C‐peptide levels were also reduced during mixed‐meal test, postprandial plasma glucose reduction was suggested to be due to inhibition of gastric emptying, as observed with GLP‐1R engagement.Gastrointestinal disorders (nausea, vomiting, dry mouth and mouth ulceration) were the most frequent treatment‐emergent adverse events after treatment with SAR441255. All events were mild in severity, and occurred between 3 and 4 h after SAR441255 administration.To clarify the effects of SAR441255 on GIPR and GCGR in humans, specific biomarkers for each receptor were measured. As expected, a biomarker for GIPR activation, C‐telopeptide of cross‐linked type I collagen, which is a marker of bone turnover, was significantly reduced by >50% in participants who received SAR441255 administration (80 and 150 mg). Likely, plasma amino acids levels, which are sensitive biomarkers of GCGR activation, were reduced after SAR441255 administration in these individuals.As aforementioned, the dual agonists of GLP‐1R and GIPR might have comparable or even more stronger effects in reductions of HbA1c and bodyweight in obese type 2 diabetes patients ⁴ ; the significance of the activation of GCGR signaling should be evaluated to confirm the benefits of the triagonists of GLP‐1R, GIPR and GCGR. In this regard, the effects of glucagon to enhance energy expenditure partly through enhancement of fat and glucose oxidation could cover some of the benefits ⁷ , but further investigations should be necessary. In addition, it has recently been reported that GLP‐1R agonists have clinically significant cardiovascular benefits in type 2 diabetes patients ¹ . Therefore, it should be clarified if the dual or triagonists also have comparable cardiovascular benefits, as observed in GLP‐1R agonists in type 2 diabetes patients.Because triagonists have been shown to have better profiles in weight loss and glycemic control in animal models of obese type 2 diabetes compared with GLP‐1R agonists and dual agonists of GLP‐1R and GIPR or GLP‐1R and GCGR ^{8 , 9} , clinical studies that investigate the efficacy in type 2 diabetes patients should be of great interest.     

Uniportal thoracoscopic pulmonary segmentectomy provides good perioperative results and early postoperative recovery

BackgroundAlthough video-assisted thoracoscopic surgery (VATS) segmentectomy has become widespread, the advantage of uniportal VATS (U-VATS) segmentectomy over multiportal VATS (M-VATS) remains controversial. The purpose of this study was to verify the safety and usefulness of U-VATS segmentectomy compared with conventional hybrid/multiportal segmentectomy.MethodsHere, we retrospectively reviewed the data from anatomical pulmonary segmentectomy cases in a single institution from March 2010 to March 2021. Patients were divided into the U-VATS and hybrid/multiportal VATS (H/M-VATS) groups. Perioperative results were compared between the groups after matching for patient background characteristics. In addition, cases of complex segmentectomy were selected from each group and compared in terms of perioperative results.ResultsA total of 180 patients underwent pulmonary segmentectomy during the study period at this institution, comprising 57 cases in the U-VATS group and 123 cases in the H/M-VATS group. After matching for age, sex, disease, tumor location, and type of segmentectomy, no significant differences between the groups were seen in blood loss, major intraoperative bleeding, rate of conversion to thoracotomy, postoperative complications, or re-hospitalization within 30 days after discharge. Operation time (141±46 vs. 174±45 min, P<0.001), postoperative drainage duration (1.5±1.2 vs. 2.3±1.8 days, P=0.007), and postoperative hospital stay (3.4±2.0 vs. 4.6±2.5 days, P=0.006) were significantly lower in the U-VATS group. Subgroup analysis of the complex segmentectomy cases also revealed that operation time (146±34 vs. 185±47 min, P<0.001), postoperative drainage duration (1.5±1.3 vs. 2.2±1.2 days, P=0.021), and postoperative hospital stay (3.0±1.4 vs. 4.9±2.1 days, P<0.001) were significantly reduced in the U-VATS group.ConclusionsU-VATS segmentectomy appears as safe and feasible as H/M-VATS segmentectomy. An experienced surgeon can make a smooth transition to U-VATS.     

Ten-Year Clinical Follow-Up Following Bare-Nitinol Stent Implantation for Femoropopliteal Artery Disease

Aim: More than 5-year clinical outcomes after femoropopliteal (FP) stenting with bare-nitinol stent (BNS) have not yet been unclear. We investigate the long-term patency and mortality following FP stenting with BNS. Methods: This study was a multicenter retrospective study of a prospectively maintained database. From April 2004 to December 2011, 1824 consecutive patients (2211 limbs) who underwent FP stenting with BNS for de novo lesions were selected and analyzed. Primary endpoint was primary patency which was defined as treated vessel without restenosis and reintervention and its associated factors. Results: The prevalence of diabetes mellitus and dialysis was 60.5% and 23.8%, respectively. Chronic limb-threatening ischemia (CLTI) accounted for 30.8%. Chronic total occlusion (CTO) was found in 52.7%, and lesion length was more than 20 cm in 22.6%. During the median follow-up of 3.8 years (interquartile range, 1.4 to 7.4 years), 1049 cases lost patency, whereas 355 cases were dead without experiencing loss of patency. The primary patency (95% CI) was estimated to be 74.8%, 47.3% and 29.1% at 1-, 5- and 10-year. On multivariate analysis, female sex, age ≥ 80 years, diabetes, dialysis, CLTI, CTO, arterial calcification, long lesion (＞20 cm), and small vessel (≤ 4 mm) were the independent predictors of primary patency after FP stenting. In addition, the prognostic impact of age ≥ 80 years, CLTI, and arterial calcification was significantly attenuated afterwards (P＜0.05). Conclusions: Ten-year patency after BNS implantation for FP disease has been continuously reducing up to 10 years and the prognostic impact of risk factors was changed over time.     

Bufadienolide and spirostanol glycosides from the rhizomes of helleborusorientalis

The rhizomes of Helleborus orientalis have been analyzed for the bufadienolide glycoside and spirostanol saponin constituents, resulting in the isolation of a new bufadienolide rhamnoside (1), along with two known bufadienolide glycosides (2 and 3) and five new spirostanol saponins (4-8). The structures of the new compounds were determined on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activities against cultured tumor and normal cells.     

Nonsurgical therapy to preserve oviduct function in patients with tubal pregnancies

Surgical treatment for tubal pregnancies greatly impairs the subsequent fertility of patients because of salpingectomy and its complicated adhesions. Nonsurgical methotrexate therapy was developed to avoid such complications. Although early detection was of prime importance, resolution of ectopic pregnancy was obtained in 22 patients (95.7%) with methotrexate administration alone. Patency of the oviducts was evaluated with hysterosalpingography and/or laparoscopy in 19 patients after termination of methotrexate treatment. In 10 of 19 patients (52.6%), complete patency of the involved oviduct confirmed the validity of this regimen. Severe side effects were not observed in any of the 23 patients.