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.

Preoperative oral antibiotic administration in patients undergoing curative resection with stoma creation for colorectal cancer: effectiveness in preventing surgical site infection and the possibility of peristomal candidiasis induced by enterobacterial alteration.

AIM: There are many reports that preoperative oral antibiotics (OAs) are effective in preventing surgical site infections (SSIs) in colorectal surgery. However, there is no consensus on the optimal dose of OAs. In this study, we investigated the efficacy of OAs in preventing SSIs and the possibility that OAs induce enterobacterial alteration in the intestinal tract. METHOD: We performed a retrospective cross-sectional analysis of 389 patients who underwent R0 resection and stoma creation for colorectal cancer in our department between 2009 and 2020. We focused on the incidence of peristomal candidiasis (PSC) as an indicator of enterobacterial alteration and used kanamycin (KM) and metronidazole (MNZ) as the OAs. A low-dose group received 1000 mg/day of both KM and MNZ, and a high-dose group received 2000 mg/day of both KM and MNZ. RESULTS: SSI occurred in 60 of the 389 cases (15.4%). Regardless of stoma type, SSI was significantly more common in the non-OA group, while PSC was significantly less common. When examined by OA dose, the incidence of SSI was not significantly different between the low-dose and high-dose groups. However, PSC was significantly more common in the high-dose group than in the non-OA and low-dose groups. Analysis of bacterial and fungal levels in stool samples showed that bacterial levels after OAs were significantly lower than before OAs, while fungal levels increased. CONCLUSION: OAs significantly reduce SSI in colorectal cancer surgery. However, excess OAs were significantly associated with the occurrence of PSC without contributing to further reduction in SSI.

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.

Postoperative liver dysfunction is associated with poor long-term outcomes in patients with colorectal cancer: a retrospective cohort study.

BACKGROUND: Postoperative hepatobiliary enzyme abnormalities often present as postoperative liver dysfunction in patients with colorectal cancer. This study aimed to clarify the risk factors of postoperative liver dysfunction and its prognostic impact following colorectal cancer surgery. METHODS: We retrospectively analyzed data from 360 consecutive patients who underwent radical resection for Stage I-IV colorectal cancer between 2015 and 2019. A subset of 249 patients with Stage III colorectal cancer were examined to assess the prognostic impact of liver dysfunction. RESULTS: Forty-eight (13.3%) colorectal cancer patients (Stages I-IV) developed postoperative liver dysfunction (Common Terminology Criteria for Adverse Events version 5.0 CTCAE v5.0 ≥ Grade 2). Univariate and multivariate analyses identified the liver-to-spleen ratio on preoperative plain computed tomography (L/S ratio; P = 0.002, Odds ratio 2.66) as an independent risk factor for liver dysfunction. Patients with postoperative liver dysfunction showed significantly poorer disease-free survival than patients without liver dysfunction (P < 0.001). Univariate and multivariate analyses using Cox's proportional hazards model revealed that postoperative liver dysfunction independently was a poor prognostic factor (P = 0.001, Hazard ratio 2.75, 95% CI: 1.54-4.73). CONCLUSIONS: Postoperative liver dysfunction was associated with poor long-term outcomes in patients with Stage III colorectal cancer. A low liver-to-spleen ratio on preoperative plain computed tomography images was an independent risk factor of postoperative liver dysfunction.

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.

Impact of the preoperative clinical N stage on the prognosis of patients with colon cancer.

AIM: Although preoperative clinical staging (cStage) is performed for most cancer patients, limited information is currently available on the relationship with postoperative prognosis. We herein investigated the relationship between cStage and prognosis of colon cancer (CC) patients, particularly focusing on the presence or absence of clinical lymph node (LN) metastasis. METHOD: This was a retrospective study on 840 consecutive patients with colon adenocarcinoma who underwent radical resection at our institution between January 2007 and December 2018. A Kaplan-Meier curve was used to analyse the prognosis of two groups: cN(+)pN(-); a group preoperatively diagnosed with clinical LN metastasis positive, but with no pathological LN metastasis postoperatively, and cN(-)pN(-); a group without clinical and pathological LN metastasis. We also investigated whether a clinical diagnosis is a more accurate prognostic factor than other clinical factors. RESULTS: Among pN(-) cases, the 5-year recurrence-free survival rate was significantly lower in preoperatively diagnosed cN(+) cases than in cN(-) cases (79.4% vs. 95.6%, 3.04 years vs. 3.85 years, p < 0.01). In a multivariate analysis of various preoperative clinical factors in pStage II cases, including high risk factors for pStage II CC, cN(+) was identified as an independent prognostic factor (hazard ratio: 2.06, 95% CI: 1.02-4.27, p = 0.04). CONCLUSION: Preoperatively over-staged cN cases had a poorer prognosis than cases without over-staging, indicating its potential as a prognostic factor. In addition to already known high risk factors in pStage II cases, the preoperative cStage may be an indication for adjuvant chemotherapy.

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.

Calcifying fibrous tumor of the ileum resected by single-port laparoscopic surgery: a case report.

BACKGROUND: Calcifying fibrous tumors (CFTs) are rare benign tumors. Because CFTs sometimes relapse, radical resection with adequate margins is necessary. We report a case of ileal CFT resected using single-port laparoscopic surgery. CASE PRESENTATION: A 33-year-old man presented with chief complaints of abdominal pain and vomiting. Computed tomography demonstrated a 45-mm-sized pelvic mass with partial calcification in the ileum. The patient was diagnosed with an ileal tumor, and partial resection of the ileum was performed using the single-port laparoscopic technique. Pathologic findings revealed hypocellular spindle cells with dense hyalinized collagen, interspersed calcification, and infiltration of lymphoplasmacytic cells. Immunohistochemical analysis showed that the factor XIIIa was positive and other tumor-specific markers were negative. Based on these findings, the tumor was finally diagnosed as a CFT. CONCLUSIONS: Although CFT is benign, multifocal and recurrent CFTs have been reported. Therefore, careful intraperitoneal observation and curative resection are necessary. Single-port laparoscopic surgery is acceptable, both in terms of curability and minimal invasiveness.

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.

[Reasonable Surgery for Sigmoid Colon Cancer with Asymptomatic Celiac Artery Stenosis and Superior Mesenteric Artery Stenosis-A Case Report].

A 79-year-old woman was diagnosed with cT2N0M0, cStage Ⅰ sigmoid colon cancer. Preoperative staging computed tomography(CT)incidentally revealed severe stenosis of the celiac and superior mesenteric arteries. A collateral blood channel communicating between the inferior mesenteric artery and the celiac artery region was well developed. Therefore, a sigmoidectomy with D1 lymph node dissection was performed to preserve this collateral blood channel as a surgery for sigmoid colon cancer. There are few reports on surgical procedures for patients with simultaneous stenosis of multiple major abdominal arteries. In addition, there are no consensus about the optimal surgical procedure and extent of lymph node dissection for colorectal cancer with well-developed collateral vessels that should be preserved. Preoperative three-dimensional CT angiography(3D-CTA)and intraoperative blood-flow assessment using Indocyanine Green help risk management of multi- organ ischemia due to misidentification and injury of collateral arteries. It is important to keep oncological validity as well as risk management. We report a case of sigmoid colon cancer with asymptomatic stenosis of the celiac and superior mesenteric arteries.

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.

Significance of Plasma UCA1 for Predicting Colorectal Cancer and BRAF Mutation Status.

BACKGROUND: Clinical significance of plasma urothelial carcinoma associated 1 (UCA1) in patients with colorectal cancer (CRC) remains unclear. This study investigated the usefulness of plasma UCA1 as a biomarker in patients with CRC. MATERIALS AND METHODS: UCA1 levels were measured in the plasma and tissue from patients with CRC by quantitative polymerase chain reaction. Relationships between plasma UCA1 and clinicopathological features were examined. RESULTS: Plasma UCA1 levels were significantly lower in patients with CRC than in healthy volunteers. UCA1 expression in B-Raf proto-oncogene serine/threonine kinase (BRAF)-mutant CRC tissue was also lower than that in non-cancerous tissue, although it was higher in CRC with wild-type BRAF. In right-sided CRC, a lower plasma UCA1 level was associated with pT4 and BRAF mutation. In contrast, in left-sided CRC, higher plasma UCA1 was associated with pT4 and pStage 3b-4. CONCLUSION: Plasma UCA1 is a useful biomarker for CRC detection and predicting clinicopathological features, particularly BRAF mutation.

[Strangulation Ileus Caused by Incarcerated Esophageal Hiatal Hernia after Laparoscopic Total Gastrectomy - A Case Report].

Laparoscopic total gastrectomy(LTG)is one of the most increasing surgeries among gastric cancer surgery. Although LTG has many advantages on the patient, we should be more careful of its specific complications. Here we report a case of 72- year-old man with the complaint of severe acute upper abdominal pain due to strangulation ileus caused by incarcerated esophageal hiatal hernia(EHH)after LTG. Emergent operation has performed on the patient and total 180 cm length of necrotic small intestine was resected. EHH after gastrectomy was thought to be rare complication. However, some literature reported that EHH after gastrectomy, especially after LTG has more possibility than it has ever thought to be. Laparoscopic surgery has more advantages than open surgery in terms of less invasiveness, rapid postoperative recovery, and less intraabdominal adhesion. One of the causes for EHH after LTG is ironically thought to be its less intraabdominal adhesion. We concluded that crus repair is one of the effective methods for the prevention of EHH after LTG through experiencing this case.

Granulocyte colony-stimulating factor-producing hepatocellular carcinoma with abrupt changes.

Granulocyte colony-stimulating factor (G-CSF)-producing tumor is one of the rare types of cancer clinically characterized by an elevated fever and white blood cell (WBC) increment. Although G-CSF producing tumors have been reported in several types of cancer including those of the lungs, cervix and bladder, G-CSF producing hepatocellular carcinoma is extremely rare. Here, we report the case of a rapidly growing and poorly differentiated hepatocellular carcinoma producing G-CSF. The patient showed symptoms of continuous high fever, stomach pain and cough, and high serum WBC counts, C-reactive protein (CRP) and G-CSF levels were found in laboratory tests. After a radical hepatectomy, the patient completely recovered from the above symptoms and inflammatory state. The serum levels of G-CSF were reduced to normal levels after radical surgery. An immunohistochemical analysis revealed the overexpression of G-CSF in the cytoplasm of certain hepatocellular carcinoma (HCC) cell. The patient's serum WBC, CRP and G-CSF levels remained within normal levels in the six months after surgery without recurrence. This is the 9th case report of G-CSF producing hepatocellular carcinoma in English literature. We review the clinical characteristics of the G-CSF producing HCC and discuss a possible treatment strategy.