Cancer-Derived Small Extracellular Vesicles Affect Vascular Endothelial Cells and Promote Adhesiveness of Pancreatic Cancer Cells.

OBJECTIVES: Pancreatic cancer (PC) is one of the most aggressive malignancies due to the high rate of metastasis. The mechanisms underlying metastasis need to be elucidated. Small extracellular vesicles (sEVs) mediate cell-to-cell communication, and cancer-derived sEVs contribute to the formation of premetastatic niches. The present study examined changes in adhesiveness by the internalization of PC-derived sEVs into vascular endothelial cells, and investigated the molecular mechanisms underlying metastasis. MATERIALS AND METHODS: Pancreatic cancer-derived sEVs were internalized into vascular endothelial cells, and changes in adhesiveness were evaluated. We evaluated the effects of sEVs on the formation of liver metastasis in vivo. We also assessed molecular changes in vascular endothelial cells by the internalization of PC-derived sEVs. RESULTS: The internalization of PC-derived sEVs into vascular endothelial cells promoted the adhesiveness of vascular endothelial cells and PC cells. Pancreatic cancer-derived sEVs contained high levels of transforming growth factor ß1 mRNA and acted as its transporter. Once PC-derived sEVs were internalized into vascular endothelial cells, the expression of fibronectin 1 increased on the cell surface, and the adhesiveness of vascular endothelial cells was enhanced. CONCLUSIONS: We investigated association between PC-derived sEVs and adhesiveness. Regulation of PC-derived sEVs has potential as a therapeutic modality to suppress the metastasis of PC.

Roles of miR-4442 in Colorectal Cancer: Predicting Early Recurrence and Regulating Epithelial-Mesenchymal Transition.

Early recurrence in patients with colorectal cancer (CRC) is associated with a poor prognosis. We aimed to identify circulating microRNAs that are biomarkers of early CRC recurrence and elucidate their functions. We identified miR-4442 as a candidate biomarker by microRNA array analysis comparing preoperative and postoperative plasma levels in patients with CRC, with and without recurrence. The association between preoperative plasma miR-4442 levels, clinicopathological features, and recurrence-free survival was analyzed in 108 patients with CRC after curative surgery. Furthermore, cell-function analyses were performed, and the involvement of miR-4442 in regulating epithelial-mesenchymal transition (EMT) was examined. Preoperatively plasma miR-4442 levels were associated with CRC recurrence and exhibited an incremental increase with earlier recurrence dates. Moreover, miR-4442 demonstrated high sensitivity and specificity as a potential biomarker for early CRC recurrence. The expression of miR-4442 in cancer tissues of patients with metastatic liver cancer from CRC was higher than in normal liver, CRC, and normal colorectal tissues. The overexpression of miR-4442 promoted the proliferative, migratory, and invasive activities of CRC cells, decreased levels of RBMS1 and E-cadherin, and increased levels of N-cadherin and Snail1. Plasma miR-4442 is a clinically useful biomarker for predicting the early recurrence of CRC. Furthermore, miR-4442 regulates EMT in CRC by directly targeting the messenger RNA of RBMS1.

Clinical Relevance of Proximal Gastrectomy With Double-flap Esophagogastrostomy Reconstruction With Glycemic Profile and Postgastrectomy Syndromes.

BACKGROUND/AIM: The glycemic profile of patients who have undergone proximal gastrectomy (PG) using a continuous glucose monitoring (CGM) device has not been investigated. We aimed to investigate the association between postgastrectomy syndrome and the glycemic profile of patients who underwent PG and its impact on postoperative body weight loss and nutritional status. PATIENTS AND METHODS: We retrospectively investigated 65 patients with CGM post-surgery. Postoperative glycemic profiles were recorded using a CGM device. To evaluate postgastrectomy syndromes and quality of life (QOL), the Postgastrectomy Syndrome Assessment Scale 37-item questionnaire was employed. The dynamics of albumin and hemoglobin levels were investigated at 1 and 6 months postoperatively. RESULTS: The time below the range (percentage of glucose reading <70 mg/dl) in patients who underwent PG with double-flap (DF) esophagogastrostomy reconstruction was significantly shorter than in those who underwent total gastrectomy (TG). Late dumping scores tended to be better in patients after PG with DF than in those after TG. The body weight loss rate of patients who underwent PG with DF was similar to those who underwent TG. The albumin level at 6 months recovered to the preoperative level in patients who underwent PG with DF, but not in those who underwent TG. Hemoglobin levels at 1 and 6 months postoperatively were significantly higher in patients who underwent PG with DF than in those who underwent TG. CONCLUSION: Proximal gastrectomy with double-flap esophagogastrostomy reconstruction did not improve QOL or body weight loss, as expected, however, suppressed hypoglycemia, late dumping syndrome, and deterioration in nutritional status.

Plasma microRNA-192-5p can predict the response to neoadjuvant chemotherapy and prognosis in esophageal cancer.

Esophageal cancer (EC) is the sixth leading cause of cancer-related death worldwide. Recently, neoadjuvant chemotherapy (NAC) before curative surgery has become a standard treatment for clinical stage II or III EC patients. Some EC patients receive a complete response (CR) by NAC; thus, curative surgery may be unnecessary for such patients. MicroRNA levels in plasma have the potential to be a predictor of response to NAC. In the present study, we focused on miR-192-5p, which is highly expressed in EC tissue. The purpose was to investigate the correlations between levels of plasma miR-192-5p and the response to NAC. Furthermore, molecular functions of miR-192-5p associated with chemosensitivity were examined using EC cell lines. The levels of miR-192-5p in plasma before surgery were evaluated in 113 EC patients. Sixty-nine patients received NAC. miR-192-5p levels in the CR group were significantly higher than in the other groups (p = 0.002). The downregulation of miR-192-5p in the EC cell line inhibited sensitivity to cisplatin, and the overexpression of miR-192-5p in the EC cell line promoted sensitivity to cisplatin. miR-192-5p regulated sensitivity to cisplatin by targeting ERCC3 and ERCC4. Plasma miR-192-5p could be used as a predictor of response to chemotherapy and prognosis in EC patients.

The Role of Inflammation-associated microRNA-4257 as a Promoter of Malignancy in Colorectal Cancer.

BACKGROUND/AIM: The clinical significance ofmiR-4257 in patients with colorectal cancer (CRC) remains unclear. Here, we investigated the usefulness of measuring miR-4257 levels in the plasma and cancer tissues of patients with CRC, and the function of miR-4257 in CRC cell lines. MATERIALS AND METHODS: miR-4257 levels were measured in the plasma and cancer tissues of patients with CRC using quantitative polymerase chain reaction. The relationships between miR-4257 level and clinicopathological features were examined. Proliferation, transwell, wound healing, and adhesion assays were performed using a miR-4257 mimic and inflammatory cytokines. RESULTS: Relapse-free survival was significantly lower in patients with high miR-4257 levels in the plasma and cancer tissue (p<0.001 andp=0.016, respectively). High miR-4257 expression was an independent predictive factor for recurrence (p=0.017 and p=0.028). Addition of inflammatory cytokines to CRC and normal cell lines increased the expression of miR-4257 in the cell lines and cell culture medium. Over-expression of miR-4257 in CRC cells increased malignancy, while over-expression in normal cells increased adhesion to CRC cells. The addition of inflammatory cytokines to normal cell lines enhanced adhesion to CRC cell lines. CONCLUSION: miR-4257 level in plasma and cancer tissues is a biomarker of disease recurrence in patients with CRC. Moreover, miR-4257 promoted tumour growth and was associated with cancer-induced inflammation.

miR­4730 suppresses the progression of liver cancer by targeting the high mobility group A1 pathway.

As liver cancer (LC) is the sixth most commonly diagnosed malignancy, it is necessary to elucidate the molecular mechanisms responsible for LC progression. MicroRNAs (miRNAs/miRs) play crucial roles in tumor progression by regulating target gene expression. The present study assessed miRNA­4730 expression and function in LC. The effects of miR­4730 overexpression were examined in LC cell lines, and the target genes of miR­4730 were evaluated using microarray analysis and TargetScan data. In addition, the association between miR­4730 expression in tissue samples and the prognosis of 70 patients with LC was evaluated. miR­4730 expression was suppressed in LC tissues and cell lines. miR­4730 overexpression suppressed cell proliferation and cell cycle progression and promoted apoptosis. High mobility group A1 (HMGA1) was revealed as the direct target of miR­4730 using luciferase reporter assay, and the inhibition of downstream integrin­linked kinase (ILK) expression and Akt or glycogen synthase kinase 3ß (GSK3ß) phosphorylation was confirmed. The lower expression of miR­4730 in tissue samples was significantly associated with a worse recurrence­free survival of patients with LC. On the whole, miR­4730 suppressed tumor progression by directly targeting HMGA1 and inhibiting the ILK/Akt/GSK3ß pathway. miR­4730 thus has potential for use as a prognostic marker and may prove to be a therapeutic target for miRNA­based therapies.

Removal of small extracellular vesicles inhibits the progression of peritoneal dissemination in gastric cancer.

BACKGROUND: The prognosis of gastric cancer patients with peritoneal dissemination is extremely poor and effective treatment for peritoneal dissemination has not been established. Gastric cancer-derived small extracellular vesicles play an important role in the development of a favorable microenvironment for peritoneal metastasis and progression of peritoneal dissemination. Here, we aimed to investigate the transformation of gastric cancer cells by removing gastric cancer-derived small extracellular vesicles and to develop a novel therapy for inhibiting peritoneal dissemination. METHODS: Gastric cancer cells were cultured in medium containing gastric cancer- and peritoneal mesothelium-derived small extracellular vesicles and in medium from which small extracellular vesicles were removed by ultracentrifugation. Cell function assays were performed in vitro, and the alternations in gene expression in gastric cancer cells were analyzed. The inhibitory effect of intraperitoneal lavage on peritoneal dissemination was investigated in vivo as a method to remove gastric cancer-derived small extracellular vesicles. RESULTS: Removal of gastric cancer-derived small extracellular vesicles suppressed the proliferative and migrative abilities of gastric cancer cells and the adhesion of gastric cancer cells to peritoneal mesothelial cells. It altered the expression of several genes related to the cell cycle and epithelial-mesenchymal transition pathways of gastric cancer cells, leading to the inhibition of gastric cancer cell growth and peritoneal dissemination in vivo. CONCLUSIONS: Our study provides novel insights into a novel therapy for inhibiting the peritoneal dissemination of gastric cancer by targeting gastric cancer-derived small extracellular vesicles to improve the prognosis of gastric cancer patients with peritoneal metastasis.

Role of Extracellular High-Mobility Group Box-1 as a Therapeutic Target of Gastric Cancer.

Background: High-mobility group box-1 (HMGB1) is involved in the tumorigenesis and metastasis of various cancers. The present study investigated the roles of extracellular HMGB1 in the progression of gastric cancer (GC) and the therapeutic effects of recombinant human soluble thrombomodulin (rTM) targeting HMGB1. Methods: The effects of extracellular HMGB1 and rTM on GC cells were assessed using proliferation and Transwell assays. Their effects on local tumor growth and metastasis were evaluated using subcutaneous tumor and liver metastasis mouse models, respectively. Plasma HMGB1 concentrations in GC patients were measured using ELISA. The relationships between plasma HMGB1 concentrations and the prognosis and clinicopathological factors of patients were also investigated. Results: GC proliferation, migration, and invasion abilities were promoted by increases in extracellular HMGB1 concentrations and alleviated by rTM. In the subcutaneous tumor model, local tumor growth was promoted by the addition of rhHMGB1 and alleviated by rTM. Similar changes occurred in the liver metastasis model. Recurrence-free survival (p < 0.01) and overall survival (p = 0.01) were significantly worse in patients with high plasma HMGB1 concentrations. Conclusion: Plasma HMGB1 concentrations are a prognostic marker in GC patients. Extracellular HMGB1 promotes cancer progression and has potential as a novel treatment target in GC cells for rTM.

Glucose variability and predicted cardiovascular risk after gastrectomy.

PURPOSE: To investigate the correlation between glycemic trends and cardiovascular risk after gastrectomy for gastric cancer. METHODS: We enrolled 105 gastric cancer patients who underwent gastrectomy at our hospital between October 2017 and July 2020. Postoperative glucose concentrations, trends, and patterns were recorded using a continuous glucose monitoring (CGM) device. Cardiovascular risk was calculated using the Framingham stroke risk profile score (FSRPS), the Framingham risk score (FRS), and the Suita score. We examined the correlations between glycemic variability and cardiovascular risk scores. RESULTS: There were significant differences in the standard deviation (SD) of glucose levels between the high and low FSRPS groups (p = 0.049), the high and low FRS groups (p = 0.011), and the high and low Suita score groups (p = 0.044). The SD of glucose levels was significantly higher in patients with diabetes mellitus (DM) (p < 0.001) and those who underwent total gastrectomy (TG) (p = 0.017). Additionally, the CGM data available for 38 patients 1 year post-gastrectomy were analyzed for glucose level dynamics, and the SD was found to be significantly higher than that at 1 month (p < 0.001). CONCLUSION: Our findings suggest that long-term follow-up and therapeutic strategies tailored to glycemic trends may be necessary for gastric cancer patients after gastrectomy, especially those with DM and those who have undergone TG, to prevent cardiovascular events.

Anterior gradient 2 regulates cancer progression in TP53­wild­type esophageal squamous cell carcinoma.

Anterior gradient 2 (AGR2) reportedly promotes tumor growth and has an unfavorable impact on survival in several cancers. However, no comprehensive functional analysis of AGR2 in esophageal squamous cell carcinoma (ESCC) has been performed. In the present study, the function and clinical significance of AGR2 were examined using ESCC cell lines and clinical samples. AGR2 was upregulated in EC tissue and ESCC cell lines. The downregulation of AGR2 suppressed cell proliferation and increased the proportion of G2/M­phase cells and phosphorylation of p53 in TP53­wild­type ESCC and osteosarcoma cells. However, these changes were not observed in TP53­mutant ESCC cells. In addition, immunohistochemistry results demonstrated that high AGR2 and low p53 expression levels in ESCC tissues were correlated with a worse prognosis. These results suggested that although AGR2 enhanced cell proliferation by inhibiting p53 phosphorylation in TP53­wild­type ESCC, the same mechanism did not regulate cell functions in TP53­mutant ESCC. Thus, AGR2 served an important role in ESCC progression and might be a useful prognostic marker in patients with TP53­wild­type ESCC.

Significance of Circular FAT1 as a Prognostic Factor and Tumor Suppressor for Esophageal Squamous Cell Carcinoma.

BACKGROUND: Circular RNA is a novel endogenous non-coding RNA with a stable loop structure, and theories for its biogenesis and usefulness as a biomarker in various cancers have been proposed. The present study investigated the significance of circular FAT1 (circFAT1) as a novel biomarker in esophageal squamous cell carcinoma (ESCC). METHOD: CircFAT1 expression levels were measured in ESCC cell lines and the effects of downregulating circFAT1 on cell migration and invasion were examined using a transwell assay. The functions of miR-548g, which will be sponged by circFAT1, were assessed. Furthermore, the expression of circFAT1 was evaluated in 51 radically resected ESCC tissue samples using quantitative reverse transcription polymerase chain reaction (qRT-PCR). The relationships between circFAT1 expression, clinicopathological factors, and patient prognosis were analyzed. RESULTS: CircFAT1 expression levels were significantly lower in tumor tissue than in adjacent non-tumorous mucosal tissue (p = 0.01). The downregulation of circFAT1 expression promoted ESCC cell migration and invasive ability, but not proliferation. The expression of miR-548g was upregulated by the downregulation of circFAT1. The overexpression of miR-548g also promoted ESCC cell migration and invasion. Recurrence-free survival (p = 0.02) and cancer-specific survival (p = 0.04) rates were significantly higher in patients with elevated circFAT1 expression levels. CONCLUSION: The expression level of circFAT1 is a novel prognostic marker in ESCC patients. New treatment strategies may be developed using the tumor suppressive functions of circFAT1.

Evaluation of subcarinal lymph node dissection and metastasis in transmediastinal radical esophagectomy.

BACKGROUND: The aim of the present study was to evaluate subcarinal lymph node dissection in transmediastinal radical esophagectomy and subcarinal lymph node metastasis in patients with esophageal cancer. METHODS: Three hundred and twenty-three patients with primary esophageal cancer who underwent transmediastinal or transthoracic esophagectomy with radical two- or three-field lymph node dissection were retrospectively investigated. The clinicopathological characteristics of patients with subcarinal lymph node metastasis were analyzed in detail. RESULTS: The median of dissected subcarinal lymph nodes in transmediastinal and transthoracic esophagectomy groups was 6 and 7, respectively, and there was no significant difference between the two groups (p = 0.12). Of all patients, 26 (8.0%) were pathologically diagnosed as positive for subcarinal lymph node metastasis, whereas only 7 (26.9%) of those with metastasis were preoperatively diagnosed as positive. In addition, all patients with subcarinal lymph node metastasis had other non-subcarinal lymph node metastasis. By univariate analysis, subcarinal lymph node metastasis was found in larger (≥ 30 mm) and deeper (T3/T4a) primary lesions (p = 0.02 and 0.02, respectively), but it was not found in 49 patients with the primary lesion located in the upper thoracic esophagus. CONCLUSIONS: Subcarinal lymph nodes can be dissected in transmediastinal esophagectomy, almost equivalent to transthoracic esophagectomy. The tumor size, depth, and location may be predictive factors for subcarinal lymph node metastasis.

Prognostic impact of the preoperative hemoglobin A1c levels in patients with gastric cancer surgery depends on postoperative complications.

PURPOSE: The long-term prognostic impact of the hemoglobin A1c levels has not yet been evaluated in patients with gastric cancer. The present study investigated the clinical significance of the hemoglobin A1c levels in patients with gastric cancer. METHODS: We enrolled 294 patients with stage II, III, or IV gastric cancer who underwent gastrectomy. The patients were divided into high preoperative hemoglobin A1c (> 6.0%) and low preoperative hemoglobin A1c (≤ 6.0%) groups. RESULTS: In patients with stage III gastric cancer with severe postoperative complications, the high preoperative hemoglobin A1c group had a significantly worse prognosis than the low preoperative hemoglobin A1c group (p = 0.0409). In patients without severe postoperative complications, the high preoperative hemoglobin A1c group had a significantly favorable prognosis compared with the low preoperative hemoglobin A1c group (p = 0.0348). CONCLUSION: The prognosis of patients with stage III gastric cancer having high preoperative hemoglobin A1c levels greatly depended on the presence or absence of postoperative complications. To avoid postoperative complications, optimal perioperative management and personalized treatments are critical, particularly for these patients.

[Efficacy of Palliative Radiotherapy for Unresectable Advanced Gastric Cancer with Bleeding].

Bleeding and obstruction negativelyimpact qualityof life for patients with unresectable advanced gastric cancer. There are several choices against bleeding and obstruction such as surgery, endoscopic therapy, radiotherapy and interventional radiology. We report on an 85-year-old woman with StageIV gastric cancer with tumor bleeding. Radiation therapyof 30 Gyin 10 fractions was performed. Anyadverse events were not confirmed. Bleeding or obstruction did not occur for 7 months after radiation therapy. Palliative radiation therapy to gastric cancer can be a reasonable option for patients with unsuitable general conditions for surgical intervention.

[A Case of Laparoscopic Cholecystectomy(TANKO)for Gallbladder Cancer with Torsion].

Gallbladder torsion is comparatively rare. Gallbladder cancer is found in 1.5% of cases of acute cholecystitis. We report a case of laparoscopic cholecystectomy(TANKO)for gallbladder cancer with torsion. CASE: A 54-year-old woman with epigastric pain underwent enhanced computed tomography. Gallbladder torsion and a tumor at the gallbladder neck were suspected, and ascites was observed. She was diagnosed with gallbladder torsion, and surgery was performed the same day. Intraoperative findings: The gallbladder was movable, minimally attached to the liver bed, rotated 360°around the cystic duct and cystic artery, and appeared necrotic. The torsion was relieved and laparoscopic cholecystectomy(TANKO)was performed. We accidentally perforated the gallbladder and bile leaked out. COURSE: The patient did well postoperatively. Pathological diagnosis revealed gallbladder cancer. DISCUSSION: Gallbladder cancer with torsion has been reported in 14 cases, not including ours. Among these, none were performed using laparoscopic cholecystectomy(TANKO). We believe that laparoscopic cholecystectomy is appropriate for such cases, but the approach must be carefully considered because of the risk of perforation.

[A Case of Gemcitabine and Nab-Paclitaxel Therapy for Multiple Metastatic Pancreatic Cancer].

Pancreatic cancer is one of the leading causes of cancer-related death in Japan. Nab-paclitaxel(nab-PTX)and gemcitabine( GEM)combination chemotherapysignificantlyimproved overall survival in a phase III trial(MPACT). This combination chemotherapyhas become one of the first-line treatments for patients with metastatic pancreatic cancer since December 2014. We report a case of a patient who underwent this chemotherapyfor recurrence of pancreatic head cancer. A 64-yearold man, who underwent curative resection of pancreatic cancer 2 years ago, relapsed with multiple lung metastases and a para-aortic nodal metastasis. The patient was treated with combination chemotherapyof nab-PTX 125mg/m2 plus GEM 1,000mg/m2. He died from carcinomatous pleurisy1 9 months after starting the chemotherapy. The patient skipped scheduled chemotherapyonly3 times due to Grade 3 neutropenia during his clinical course over 19 months. The combination regimen of nab-paclitaxel and gemcitabine is thought to be a well-tolerated and standard treatment for metastatic pancreatic cancer.

[A Case of Giant Liver Metastasis from Gastric Cancer after Surgery for Which Transcatheter Arterial Embolization and Chemotherapy Made Hepatic Resection Possible].

The prognosis of liver metastasis from gastric cancer, which often exhibits incurable factors, is dismal, and no effective therapy exists. We report a case of giant liver metastasis from gastric cancer after surgery, for which transcatheter arterial embolism and chemotherapy(G-SOX)made it possible to perform hepatic resection. The patient was a 78-year-old woman who underwent distal gastrectomy combined with D2 lymphadenectomy at our department in August 2014. She complained of abdominal distension, and a liver metastasis measuring more than 16 cm in diameter was found on computed tomography in April 2015. Transcatheter arterial embolization was performed followed by chemotherapy(9 courses of G-SOX were administered). These therapies were effective, enabling partial hepatic resection to be performed. The patient remains alive and free from recurrence 4 months after surgery. Although no effective therapy exists for liver metastasis from gastric cancer, intensive therapies may enable curative resection.