P-Glycoprotein-Mediated Interaction Is a Risk Factor for QT Prolongation in Concomitant Use of Antipsychotics and SSRIs as P-Glycoprotein-Mediated Inhibitors: Analysis of the Japanese Adverse Drug Event Report Database.

The inhibition of human ether-a-go-go-related gene (hERG) channels is a known cause of QT prolongation triggered by antipsychotic drugs. Our previous studies suggest that P-glycoprotein (P-gp)-mediated drug interactions may lead to increased gastrointestinal absorption of pimozide and its accumulation in cardiomyocytes, thereby enhancing the inhibitory effect of hERG channels. There is a paucity of epidemiological studies examining the risk of QT prolongation by antipsychotic drugs in terms of P-gp-mediated interactions with concomitant drugs. Therefore, using the Japanese Adverse Event Reporting Database, we investigated whether the risk of QT prolongation triggered by antipsychotic drugs associated with hERG inhibition is affected by the concomitant use of selective serotonin reuptake inhibitors (SSRIs) associated with P-gp inhibition. The results showed that the frequency of QT prolongation increased when the antipsychotic drugs quetiapine and sulpiride, which are P-gp substrates, were combined with SSRIs with P-gp inhibition. In contrast, no association with QT prolongation was observed in patients on non-P-gp-substrate antipsychotics, irrespective of the P-gp inhibitory effect of the concomitant SSRI. These results suggest that P-gp-mediated interactions are a risk factor for antipsychotic-induced QT prolongation. There is a need for further investigation into the risks of specific drug combinations.

Soluble PD­L1 reflects cachexia status in patients with gastric cancer and is an independent prognostic marker for relapse­free survival after radical surgery.

Soluble programmed death-ligand 1 (sPD-L1) levels can be used as a biomarker for gastric cancer (GC). However, comprehensive information regarding the sPD-L1 expression profiles and their association with cachexia in GC is lacking. Therefore, the present study evaluated the association between clinicopathological findings and sPD-L1 levels in patients with GC. Serum samples were collected from patients with GC during their first visit to Department of Esophageal-Gastro-Intestinal Surgery, Chiba University Hospital, Chiba, Japan (January 2012-December 2017; n=173), and sPD-L1 levels were measured using an enzyme-linked immunosorbent assay. Survival rates among 116 patients, excluding cases with preoperative chemotherapy or no radical procedures, were analyzed. sPD-L1 levels were associated with factors such as neutrophil-to-lymphocyte ratio, hemoglobin (Hb) and albumin (Alb) levels, total cholesterol and C-reactive protein (CRP) levels, and related to inflammation and nutrition in patients. Notably, the higher the number of applicable indicators related to cachexia (Hb <12 g/dl, Alb <3.2 g/dl, CRP >0.5 mg/dl and low body mass index) was, the higher the sPD-L1 value was. However, the pathological stage did not significantly differ between the groups. Clinicopathologically, there was no association with tumor depth, lymph node metastasis or vascular invasion; however, patients with the intestinal type had significantly higher sPD-L1 levels than patients with the diffuse type (P=0.032; Wilcoxon test). The overall survival did not significantly differ between the groups with low and high sPD-L1 levels; however, among patients who received radical treatment, the relapse-free survival was significantly worse in the high-sPD-L1-level group than in the low-sPD-L1-level group (P=0.025; log-rank test). Multivariate Cox regression analysis revealed that a high sPD-L1 concentration was a sign of poor prognosis, independent of pathological stage and cancer antigen CA19-9 (P=0.0029). Therefore, the present findings suggest that sPD-L1 can reflect cachexia status in patients with GC and may serve as a prognostic marker for relapse-free survival after radical GC surgery.

Gut microbiome can predict chemoradiotherapy efficacy in patients with esophageal squamous cell carcinoma.

PURPOSE: The gut microbiome plays an important role in cancer pathogenesis and therapy. Some studies have reported that specific bacteria in tumor tissues may contribute to the prognosis and treatment of esophageal squamous cell carcinoma (ESCC). However, there is limited evidence that the gut microbiome is associated with ESCC. This study assessed the utility of the gut microbiome as a predictive marker of the therapeutic effect in patients with ESCC undergoing chemo-radiotherapy (CRT). PATIENTS AND METHODS: Fecal samples were collected from 51 patients with ESCC who had never undergone treatment between April 2021 and May 2022 in the Department of Frontier Surgery, Chiba University. The gut microbiome was analyzed using 16S metagenomics sequencing. The association between the gut microbiome composition and stage according to the TNM classification (American Joint Committee on Cancer 7.0) and CRT response according to the RECIST criteria was evaluated. RESULTS: The relative abundance of Fusobacteriaceae was enriched in cStage III-IVb group. Among the 27 patients who received CRT, the relative abundance of Lactobacillaceae was enriched in those with a partial and complete response. Lactobacillaceae also did not correlate with any clinical data, but the high Lactobacillales group had a higher LMR (P = 0.032) and lower PLR (P = 0.045) than in the low Lactobacillales group. CONCLUSIONS: In conclusion, we found that the relative abundance of Lactobacillaceae was enriched in patients with a partial or complete response among CRT those with ESCC, thus suggesting that the relative abundance of Lactobacillaceae can predict the effect of CRT.

Serum Versus Tissue SIRT1 as Potentially Valuable Biomarkers in Gastric Cancer.

BACKGROUND/AIM: We lack reports on the clinicopathological characteristics and prognostic value of serum sirtuin 1 (SIRT1) levels and their association with SIRT1 expression in tissues of patients with gastric cancer (GC). Thus, we investigated the pathological characteristics and prognostic values of SIRT1 tissue expression and its serum concentration in GC. Moreover, we investigated the correlation between these two factors. MATERIALS AND METHODS: A total of 78 patients with GC who underwent curative gastrectomy were evaluated in this study. The expression of SIRT1 in the surgical specimens was assessed using immunohistochemistry. Serum levels of SIRT1 were measured using an enzyme-linked immunosorbent assay. The association of tissue and serum SIRT1 with the clinicopathological features and prognosis were evaluated. RESULTS: Positive SIRT1 tissue expression was significantly related to an advanced cancer stage (p=0.017). Furthermore, a significant relationship existed between a positive SIRT1 tissue expression and poorer overall survival (OS) and relapse-free survival (RFS) (p=0.033 and p=0.033, respectively). In contrast, serum SIRT1 levels showed no significant association with clinicopathological characteristics besides age. In addition, no significant correlation was observed between tissue SIRT1 expression and serum SIRT1 concentration. CONCLUSION: Tissue SIRT1 expression may be a valuable novel prognostic biomarker; nonetheless, further studies are required to clarify the relationship between tissue SIRT1 expression and serum SIRT1 levels in GC.

[A Case of Resection of Overlapping Ascending Colon Cancer and Primary Malignant Lymphoma of the Cecum].

The patient was a 90-year-old man. He was referred to our department with a diagnosis of ascending colon cancer after lower gastrointestinal endoscopy for a positive stool occult blood test. Lower gastrointestinal endoscopy revealed a type 1 tumor 30 mm in the ascending colon and a type 3 tumor 50 mm in the cecum. Biopsy revealed Group 5(tub1)for the ascending colon lesion, but Group 2 for the cecum lesion. The patient was clinically diagnosed as having overlapping ascending colon cancer and cecum cancer, and a right hemicolectomy of the colon was performed. Histopathological examination revealed ascending colon cancer and primary malignant lymphoma of the cecum.

[A Case of Postoperative Lymph Node Metastatic Recurrence of Ascending Colon Cancer Invading the Primary Branch of Superior Mesenteric Artery during Hemodialysis].

A 58-year-old man with chronic renal disease underwent ileo-cecal resection with lymph node dissection for cancer of the ascending colon at his previous physician. The pathological diagnosis was pT3N0M0, pStage Ⅱa. One year and 7 months after surgery, he was diagnosed with local and lymph node recurrence and referred to our department. Contrast- enhanced CT revealed that an irregular nodal shadow 25 mm in size adjacent to the superior mesenteric artery and the transvers part of duodenum, which was suspicious for lymph node recurrence. We regarded this patient as marginally resectable and neoadjuvant treatment was considered, but because the patient was on dialysis, we decided to operate without pre-operative treatment. Surgical findings showed invasion of a recurrent lymph node into a primary branch of the superior mesenteric artery and vein. We temporarily blocked these vessels and cut off these vessels after checking that blood flow in the intestine was maintained by intravenous injection of ICG. The lymph node was also invading the uncinate process of the pancreas and the transvers part of duodenum, we performed partial resection of those organs. Pathology revealed no tumor exposure on the dissected surface and R0 resection was achieved. The patient received 5 courses of postoperative folinate/ uracil/tegafur therapy and is alive 1 year postoperatively without recurrence.

P-Glycoprotein-Mediated Pharmacokinetic Interactions Increase Pimozide hERG Channel Inhibition.

Pimozide, an antipsychotic drug, is a potent inhibitor of the hERG channel. A case of death due to cardiac arrest has been reported in a boy who received pimozide together with sertraline and aripiprazole. In this study, we focused on drug-drug interactions and investigated the relationships between transporter-mediated intracellular accumulation and the hERG inhibitory effect of pimozide. The accumulation of pimozide in cardiomyocyte-derived AC16 cells was significantly increased by sertraline and aripiprazole, which are thought to have a P-glycoprotein (P-gp) inhibitory effect, and under P-gp siRNA conditions. These results suggest P-gp inhibition increases pimozide accumulation in AC16 cells. We introduced the hERG plasmid into AC16 cells and investigated the concentration-dependent hERG inhibitory effect of pimozide from within AC16 cells. Addition of 10 nM or more pimozide significantly inhibited the hERG current with concentration dependence. These results indicate P-gp-mediated pharmacokinetic interaction increases pimozide accumulation in AC16 cells, and the subsequent elevated pimozide levels within the cells may result in an increased risk of hERG channel inhibition. Our present study calls attention to the risks associated with the combined use of cardiotoxic P-gp substrate(s) and P-gp inhibitory medicines.

Gastrointestinal absorption of pimozide is enhanced by inhibition of P-glycoprotein.

Drug-drug interaction was suggested to have played a role in the recent death due to cardiac arrest of a patient taking pimozide, sertraline and aripiprazole antipsychotic/antidepressant combination therapy. Here, we investigated the possible involvement of P-glycoprotein (P-gp)-mediated interaction among these drugs, using in vitro methods. ATPase assay confirmed that pimozide is a P-gp substrate, and might act as a P-gp inhibitor at higher concentrations. The maximum transport rate (Jmax) and half-saturation concentration (Kt) for the carrier-mediated transport estimated by means of pimozide efflux assay using P-gp-overexpressing LLC-GA5-CoL150 cells were 84.9 ± 8.9 pmol/min/mg protein, and 10.6 ± 4.7 µM, respectively. These results indicate that pimozide is a good P-gp substrate, and it appears to have the potential to cause drug-drug interactions in the digestive tract at clinically relevant gastrointestinal concentrations. Moreover, sertraline or aripiprazole significantly decreased the efflux ratio of pimozide in LLC-GA5-CoL150 cells. Transport studies using Caco-2 cell monolayers were consistent with the results in LLC-GA5-CoL150 cells, and indicate that P-gp-mediated drug-drug interaction may occur in the gastrointestinal tract. Thus, P-gp inhibition by sertraline and/or aripiprazole may increase the gastrointestinal permeability of co-administered pimozide, resulting in an increased blood concentration of pimozide, which is known to be associated with an increased risk of QT prolongation, a life-threatening side effect.

Contribution of Na+-independent nucleoside transport to ribavirin uptake in the rat intestine and human epithelial LS180 cells.

The aim of the present study was to characterize the intestinal absorption of ribavirin (1-beta-d-ribofuranosyl-1, 2, 4-trizole-3-carboxamide). We evaluated the contribution of Na(+)-dependent and -independent transport to ribavirin absorption in the rat intestine using an in situ closed loop method. In addition, we performed pharmacokinetic analysis of the uptake of ribavirin in human intestinal epithelial LS180 cells, and also evaluated the effect of extracellular Na(+) concentration and an inhibitor of the Na(+)-independent equilibrative nucleoside transporter, nitrobenzylmercaptopurine ribonucleoside (NBMPR), on the uptake of ribavirin in the cells. In the presence and also absence of Na(+) in rat intestinal loops, more than 80% of the administered dose (50 microg at a concentration of 100 microg/ml=409 microM) of ribavirin was absorbed in 40 min. The absorption of ribavirin in the rat intestine was significantly reduced by coadministration of 10 mg/ml (=37.3 mM) inosine. In LS180 cells, 100 microM ribavirin was taken up time-dependently, and the influx clearance of the drug was similar to the efflux clearance. Five mM inosine and mizoribine reduced the uptake of 100 microM ribavirin in LS180 cells. The absence of extracellular Na(+) decreased the uptake of 100 microM ribavirin only weakly in the cells, whereas the uptake of 100 microM-2 mM ribavirin was markedly decreased by 100 microM NBMPR. These findings suggested that Na(+)-independent nucleoside transport contributes significantly to intestinal absorption of ribavirin at relatively high concentrations (>or=100 microM).

Stereoselective oxidation and glucuronidation of carvedilol in human liver and intestinal microsomes.

The aim of the present study was to investigate the mechanism for the stereoselective presystemic clearance of carvedilol. We examined the oxidation and glucuronidation of carvedilol in human liver microsomes (HLM) and human intestinal microsomes (HIM). The oxidation of carvedilol in HLM and HIM was evaluated in the presence of NADPH, whereas glucuronidation was evaluated in the presence of UDP-glucuronic acid. Oxidation of S-carvedilol in HLM and HIM was greater than that of R-carvedilol. In addition, the oxidation of R-carvedilol in HLM was inhibited by quinidine, whereas that of S-carvedilol was inhibited by both quinidine and furafylline. On the other hand, R- and S-carvedilol oxidation in HIM was inhibited by ketoconazole. Glucuronidation of S-carvedilol in HLM and HIM was also higher than that of R-carvedilol. These results suggested that cytochrome P450 (CYP) 2D6 and CYP1A2 are involved in the stereoselective oxidation of carvedilol in the liver, that CYP3A4 is involved in intestinal oxidation, and that glucuronidation in the liver and intestine is at least partly responsible for stereoselective presystemic clearance.