Proton Pump Inhibitors Enhance the Antitumor Effect of Chemotherapy for Esophageal Squamous Cell Carcinoma.

BACKGROUND: Vacuolar ATPase (V-ATPase) is involved in cancer development. The use of proton pump inhibitors (PPIs) as V-ATPase inhibitors has been reported to enhance the effectiveness of chemotherapy in certain cancers. This study aimed to evaluate the effect of PPIs on chemotherapy for esophageal cancer. METHODS: To investigate the effects of PPIs on esophageal cancer cells, human KYSE50 and 70 cells were plated and 3 PPIs (lansoprazole, esomeprazole, vonoprazan) were added at various concentrations with 5-Fluorouracil (5-FU) to the corresponding cells for a cell viability assay. To investigate the effects of PPI treatment on patients undergoing 5-FU-based therapy in the clinical setting, we retrospectively analyzed the clinical outcomes and chemotherapy-related adverse events in 40 esophageal cancer patients who received 5-FU chemotherapy in our hospital between May 2013 and April 2017. RESULTS: In the viability assays, all PPIs significantly enhanced the cytotoxic effect of 5-FU on the two esophageal cancer cell lines. In the clinical study, PPI-treated patients showed better overall survival (OS) than patients managed without PPI treatment. A multivariate analysis revealed that PPI treatment was independently associated with OS (p = 0.009, HR, 0.33; 95% CI, 0.12-0.76). CONCLUSIONS: PPI treatment may safely enhance chemosensitivity in esophageal cancer patients.

Water-soluble dietary fiber alleviates cancer-induced muscle wasting through changes in gut microenvironment in mice.

Cancer cachexia and the associated skeletal muscle wasting are considered poor prognostic factors, although effective treatment has not yet been established. Recent studies have indicated that the pathogenesis of skeletal muscle loss may involve dysbiosis of the gut microbiota and the accompanying chronic inflammation or altered metabolism. In this study, we evaluated the possible effects of modifying the gut microenvironment with partially hydrolyzed guar gum (PHGG), a soluble dietary fiber, on cancer-related muscle wasting and its mechanism using a colon-26 murine cachexia model. Compared with a fiber-free (FF) diet, PHGG contained fiber-rich (FR) diet-attenuated skeletal muscle loss in cachectic mice by suppressing the elevation of the major muscle-specific ubiquitin ligases Atrogin-1 and MuRF1, as well as the autophagy markers LC3 and Bnip3. Although tight-junction markers were partially reduced in both FR and FF diet-fed cachectic mice, the abundance of Bifidobacterium, Akkermansia, and unclassified S24-7 family increased by FR diet, contributing to the retention of the colonic mucus layer. The reinforcement of the gut barrier function resulted in the controlled entry of pathogens into the host system and reduced circulating levels of lipopolysaccharide-binding protein (LBP) and IL-6, which in turn led to the suppression of proteolysis by downregulating the ubiquitin-proteasome system and autophagy pathway. These results suggest that dietary fiber may have the potential to alleviate skeletal muscle loss in cancer cachexia, providing new insights for developing effective strategies in the future.

Metformin inhibits TGF­ß1­induced epithelial­mesenchymal transition and liver metastasis of pancreatic cancer cells.

Epithelial­mesenchymal transition (EMT) is considered a crucial event in the development of cancer metastasis. Metformin is a drug used in the treatment of type 2 diabetes. Recently, increasing evidence has indicated that metformin possesses anti­tumor activities. However, the effects of metformin on EMT and metastases in pancreatic cancer remain unknown. Thus, the present study investigated whether metformin inhibits EMT of human pancreatic cancer cell lines. Pancreatic cancer cells were stimulated with transforming growth factor ß1 (TGF­ß1), an activator of EMT signaling, with or without metformin. After 48 h, the levels of epithelial and mesenchymal markers were evaluated by western blot analysis, immunocytochemistry and RT­qPCR. Cancer cell migration was evaluated by an in vitro wound healing assay. The cells stimulated with TGF­ß1 acquired an elongated and fusiform morphology, which was inhibited by metformin. The wound healing assay revealed that metformin significantly suppressed the TGF­ß1­stimulated migration of pancreatic cancer cells. Following treatment with metformin, E­cadherin expression (epithelial marker) was upregulated, and the levels of mesenchymal markers were downregulated, which had been increased by TGF­ß1 in these cells. Exposure of the cells to TGF­ß1 activated the Smad2/3 and Akt/mammalian target of rapamycin (mTOR) pathways, and this effect was inhibited by metformin, suggesting that metformin inhibits TGF­ß1­induced­EMT through the down­regulation of the Smad pathway in PANC­1 cells and the downregulation of the Akt/mTOR pathway in BxPC­3 cells. In an animal model of surgical orthotopic implantation, metformin inhibited liver metastasis without a significant reduction in the size of the primary pancreatic tumor. On the whole, the findings of the present study suggest that metformin inhibits EMT and cancer metastasis through the Smad or Akt/mTOR pathway.

Clinical significance of soluble forms of immune checkpoint molecules in advanced esophageal cancer.

Immune checkpoint molecules are expressed on cancer cells and regulate tumor immunity by binding to ligands on immune cells. Although soluble forms of immune checkpoint molecules have been detected in the blood of patients with some types of tumors, their roles have not been fully elucidated. Soluble PD-L1, PD-1, CD155, LAG3, and CD226 (sPD-L1, sPD-1, sCD155, sLAG3, and sCD226, respectively) were measured in the sera of 47 patients with advanced esophageal cancer and compared with those of 24 control subjects. Pretreatment levels of sPD-1 and sCD155 were significantly higher in the patients with cancer than in the control subjects (P = 0.023, P = 0.001). The sPD-1 levels tended to be higher in the patients with lymph node metastasis, a large tumor diameter, and higher levels of serum SCC antigen (P = 0.150, P = 0.189, and P = 0.078, respectively). However, higher levels of sCD155 were associated with a better response to chemotherapy and favorable overall survival (P = 0.111 and P = 0.068, respectively). After 2 courses of chemotherapy, the levels of sCD155 and sCD226 were significantly increased (P < 0.001 and P = 0.002, respectively). Moreover, the increase in sCD226 during chemotherapy was associated with poor treatment response (P = 0.019). sPD-1 levels are possibly dependent on the tumor aggressiveness of the esophageal cancer. Furthermore, the pretreatment levels of sCD155 and kinetic change of sCD226 after chemotherapy may be used as biomarkers of the treatment response and prognosis in patients with esophageal cancer.

[Impact of Primary Prophylaxis with Pegfilgrastim on Clinical Outcomes in Patients with Advanced Esophageal Cancer Receiving Chemotherapy with Docetaxel, Cisplatin ,and 5-FU].

It has been reported that docetaxel, cisplatin, and 5-FU combination chemotherapy(DCF)is effective for advanced esophageal cancer. However, we often encounter severe hematotoxicity during DCF therapy. Here, we retrospectively analyzed the data of patients with advanced esophageal cancer treated with DCF at our department, and assessed the efficacy of pegfilgrastim and the issues associated with its use. According to the results, pegfilgrastim may reduce the severe hematotoxicity associated with DCF therapy and may contribute to the maintenance of the intensity of DCF. However, neutropenia had already occurred before pegfilgrastim administration on day 7 in most patients. Therefore, the appropriate timing of pegfilgrastim administration in DCF must be determined in a future prospective study.

[A case of freeze-dried gas gangrene antitoxin for the treatment of Clostridium perfringens sepsis].

A 66-year-old man was admitted to our hospital with high fever. We diagnosed a gas-containing liver abscess and performed percutaneous abscess drainage. However, 15 hours after admission, he developed massive intravascular hemolysis and acidosis. Sepsis due to Clostridium perfringens was suspected and we treated the patient intensively with multidisciplinary approaches, including antibiotics, mechanical ventilation, and renal replacement therapy. Furthermore, we administered freeze-dried gas gangrene antitoxin. Despite intensive care, the patient died 43 hours after admission.