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Microbiota have been reported to influence the development of various gastrointestinal neoplasms through the mechanism of sustained inflammation; however, few data are available regarding their influence on intraductal papillary mucinous neoplasms. The aim of this study was to assess the association between specific microbiota and the clinicopathologic characteristics of intraductal papillary mucinous neoplasms of the pancreas.DNA was extracted from formalin-fixed, paraffin-embedded samples of 30 patients who underwent pancreatectomy for intraductal papillary mucinous neoplasm, and polymerase chain reaction was used to create sequence libraries using the primer set for the V3 and V4 region of 16S recombinant DNA. Filtered sequence reads were then processed into operational taxonomic units with a 97% identity threshold and the relative abundance of bacteria compared between the 2 groups using operational taxonomic units.There was a trend toward fewer Firmicutes and more Proteobacteria and Fusobacteria in the relative abundance of main duct operational taxonomic units than in branch duct operational taxonomic units. The relative abundances of Bacteroidetes (P.01) and Fusobacteria (P = .04) were significantly higher in invasive intraductal papillary mucinous neoplasms than in noninvasive intraductal papillary mucinous neoplasms. The relative abundance of the intestinal type was significantly lower in Firmicutes than the relative abundance of the nonintestinal type (P = .04). Notably, main duct operational taxonomic units with the intestinal subtype were affected by increased proportions of Proteobacteria and Fusobacteria, and Fusobacteria were abundant in the intestinal type of invasive main duct operational taxonomic units.Intratumoral microbiota may be involved in the progression of operational taxonomic units.

Patients diagnosed with resectable pancreatic ductal adenocarcinoma often experience early recurrence even after upfront R0 resection. This study aimed to define early recurrence and identify preoperative risk factors for early recurrence after upfront pancreaticoduodenectomy in patients with resectable pancreatic ductal adenocarcinoma of the pancreatic head.This multicenter, retrospective study involved 500 patients who underwent pancreaticoduodenectomy resectable pancreatic ductal adenocarcinoma of the pancreatic head at 10 institutions between 2007 and 2016. Preoperative, intraoperative, and postoperative clinicopathological results were compared between early and non-early recurrence groups. Predictors of early recurrence were determined using statistical analyses.Log-rank tests revealed a significant difference (P.001) between recurrence within 3 to 6 months and 6 to 9 months. Early recurrence was subsequently defined as recurrence within 6 months. Patients were categorized into early recurrence (n = 104) and non-early recurrence groups (n = 389). The median overall survival of the early and non-early recurrence groups was 8.6 months and 42.6 months (P.001), respectively. Preoperatively, high carbohydrate antigen 19-9 levels ≥120 U/mL, retroperitoneal invasion, and diabetes mellitus were identified as independent predictive risk factors for early recurrence according to multivariate analysis. Comparing survival rates among patients with 3, 2, 1, or none of these factors, the median overall survival was 17.6 (n = 90), 21.2 (n = 184), 47 (n = 141), and 61.5 (n = 73) months, respectively.The optimal period that defines the early recurrence for resectable pancreatic ductal adenocarcinoma of the pancreatic head is 6 months. Tumor size ≥20 mm, preoperative carbohydrate antigen 19-9 levels ≥120 U/mL, retroperitoneal invasion of the tumor, and the presence of diabetes mellitus are independently associated with early recurrence.

Lymphatic metastasis is a major route of metastasis in distal cholangiocarcinoma (DCC). The present study aimed to elucidate the pattern of lymph node (LN) metastasis and the effectiveness of LN dissection and postoperative adjuvant chemotherapy in patients with DCC.Patients who underwent surgical resection with curative intent for DCC were enrolled. The nomenclature of the LN stations was defined according to the Japanese Society of Hepato-Biliary-Pancreatic Surgery guidelines. Effectiveness of LN dissection of each station was calculated using frequency of LN metastasis to the station and 5-year survival rate of patients with LN metastasis to that station.Of the 105 patients included in the study, 46 (43.8%) had LN metastasis, and 43 (41.0%) underwent postoperative adjuvant therapy. LN metastasis, serum carbohydrate antigen (CA) 19-9 level 37 U/mL, and positive bile duct margin were independent risk factors for shorter overall survival (OS). The most common metastatic LN station at surgery was No. 13 (32.7%), followed by No. 12 (19.2%), No. 17 (9.6%), and No. 8 (6.6%). There was no effectiveness of LN dissection of the station No. 8, 14, and 16. Adjuvant chemotherapy was significantly associated with longer OS in patients with LN metastasis but not in those with positive ductal margins or serum CA 19-9 level 37 U/mL.Postoperative adjuvant chemotherapy was associated with a better prognosis in patients with DCC and LN metastasis. However, a more effective therapeutic strategy is required to improve the prognosis of patients with other negative prognostic factors.

Background/aim Our recent miRNA analyses revealed that miR-30a-5p has tumor-suppressive activity in pancreatic ductal adenocarcinoma (PDAC). Herein, we sought to identify tumor-suppressive genes controlled by miR-30a-5p, emphasizing on genes that are closely involved in the molecular pathogenesis of PDAC. We uncovered several novel findings regarding the pathogenesis of this disease. Materials and methods In silico analyses were used to identify the putative target genes of miR-30a-5p and assess their expression levels. Direct regulation of RRM2 by miR-30a-5p and its oncogenic functions were evaluated in PDAC cell lines. Overexpression of RRM2 was demonstrated in clinical samples. Results A total of 24 putative targets were identified by in silico database analysis. High expression of 4 genes (CBFB, RRM2, AHNAK, and DCBLD1) was significantly associated with shorter survival of patients with PDAC. Functional assays demonstrated that knockdown of RRM2 attenuated the malignant phenotype of PDAC cells. Conclusion The miR-30a-5p/RRM2 axis facilitated the malignant transformation of PDAC cells.

Background Creating a good surgical visual field is one of the most important factors for performing a successful surgery. Here, we introduce a useful technique for creating a good liver parenchymal visual transection plane during laparoscopic partial hepatectomy and compare the perioperative outcomes of our current technique with those of conventional techniques. Methods We reviewed the data of patients who underwent laparoscopic partial hepatectomy between July 2016 and December 2020. The current technique for creating transection planes was first applied in our department in April 2019. The patients were divided into conventional (forceps) and current (silicone ring) technique groups, depending on the surgical technique. Results Twenty-eight and 12 patients underwent laparoscopic partial hepatectomy using the conventional and current techniques, respectively, when the difficulty level-as determined by IWATE criteria-was low. Although the tumor size was significantly larger (median: 22.5 vs. 15 mm, P=0.04) in the current technique group, the estimated intraoperative blood loss was significantly lower (median: 50 vs. 100 mL, P=0.01), and the median surgical margin was significantly longer (median: 7 vs. 3 mm, P=0.02). There were no significant between-group differences in surgical time (median: 344 vs. 240 min, P=0.14), postoperative hospital stay duration (median: 11 vs. 9.5 d, P=0.051), and the incidence of complications (P=0.63). Conclusion We believe that the technique involving the use of a silicone ring can result in better surgical outcomes as it provides a good visual hepatic transection plane during laparoscopic partial hepatectomy.

BACKGROUND Carcinoma of the ampulla of Vater is an uncommon ampullo-pancreatobiliary neoplasm, and the most common histological type is adenocarcinoma with a tubular growth pattern. Invasive micropapillary carcinoma (IMPC) is an aggressive variant of adenocarcinoma in several organs that is associated with lymph node metastasis and poor prognosis. IMPC was first described as a histological subtype of breast cancer; however, IMPC of the ampulla of Vater is extremely rare, with only three articles reported in the English literature. CASE SUMMARY We have reported a case of IMPC of the ampulla of Vater in an 80-year-old man. Microscopically, the surface area of the carcinoma was composed of tubulopapillary structures mimicking intra-ampullary papillary-tubular neoplasm, and the deep invasive front area exhibited a pattern of IMPC. The carcinoma showed lymphatic invasion and extensive lymph node metastasis. The immunohistochemical study revealed mixed intestinal and gastric/pan-creatobiliary phenotypes. CONCLUSION This rare subtype tumor in the ampulla of Vater showed a histologically mixed phenotype and exhibited aggressive behavior.

Neoadjuvant therapy (NAT) is used to treat not only advanced pancreatic cancer but also resectable lesions. The present study investigated the effectiveness of postoperative adjuvant chemotherapy for patients with pancreatic cancer who underwent surgical resection after NAT. Patients who underwent macroscopically curative resection after NAT for pancreatic cancer were enrolled. Adjuvant chemotherapy was defined as at least 1 cycle of planned chemotherapy within 3 months after the date of surgery and included S-1, gemcitabine, or both. We retrospectively examined the effect of adjuvant chemotherapy on overall survival (OS) and recurrence-free survival (RFS) as a function of patients’ clinicopathological factors. Ninety-seven patients were included in the study, of which 68 (70.1%) underwent adjuvant chemotherapy. Administration of adjuvant chemotherapy was significantly associated with prolonged OS and RFS in patients whose elevated levels of carbohydrate antigen 19-9 or duke pancreatic monoclonal antigen type-2 did not normalize after NAT. In patients with pathological lymph node metastasis, the administration of adjuvant chemotherapy was significantly associated with longer OS but did not improve PFS. Postoperative adjuvant chemotherapy was associated with prolonged postoperative survival in patients with pancreatic cancer who did not sufficiently respond to NAT as judged by tumor marker expression.

Background Cholangiolocellular carcinoma (CoCC) is an extremely rare disease comprising less than 1% of all primary malignant liver tumors. No effective treatment other than resection has been established. Herein, we report a case of locally advanced CoCC diagnosed as unresectable, which was successfully treated with curative resection after downsizing chemotherapy. Case presentation A 59-year-old Japanese woman with chronic hepatitis B was diagnosed with locally advanced intrahepatic cholangiocellular carcinoma. As it was difficult to perform R0 resection in the local hospital, chemotherapy combined with gemcitabine plus cisplatin was administered every 3 weeks. After a total of 10 courses of chemotherapy over 10 months the tumor was shown to be reduced in size by computed tomography imaging, and she was referred to our department for surgical resection. The effect of chemotherapy was classified as a “partial response” in the response evaluation criteria of solid tumors. After adding one course of chemotherapy, an extended left hepatectomy with resection of the caudate lobe was performed. R0 resection was achieved. Based on the pathological findings, the final diagnosis of CoCC was determined and eight courses of S-1 adjuvant chemotherapy were administered. At 14 months after the operation, the patient was alive without tumor recurrence. Conclusions Downsizing chemotherapy with gemcitabine and cisplatin may be an effective treatment strategy in locally advanced CoCC. Further evidence is required to establish an optimal strategy for the treatment of locally advanced CoCC.

The development and application of cancer immunotherapy to pancreatic cancer has not progressed because its efficacy has not been proven in clinical trials. In this study, we aimed to explore potential targets of immune checkpoint inhibitor therapy for pancreatic cancer treatment.We collected resected specimens from 40 patients with pancreatic cancer who underwent resection at our Institution without any preoperative treatment. We evaluated the expression of molecules in the programmed death receptor-1 (PD-1), T cell immunoglobulin mucin-3 (Tim-3)/Galectin-9, and CD155/T cell immunoreceptor with Ig and ITIM domains (TIGIT) pathways using immunohistochemical staining. The correlation between the expression pattern of these molecules and patient prognosis were assessed using Kaplan-Meier analysis.An increased number of CD8Modifications in the immune environment to increase T cell infiltration into tumors could result in the PD-1 pathway becoming a potential target to treat pancreatic cancer using immune checkpoint inhibition.

Aberrantly expressed microRNAs (miRNAs) disrupt intracellular RNA networks and contribute to malignant transformation of cancer cells. Utilizing the latest RNA sequencing technology, we newly created the miRNA expression signature of esophageal squamous cell carcinoma (ESCC). A total of 47 miRNAs were downregulated in ESCC tissues, and these miRNAs were candidates for antitumor miRNAs in ESCC cells. Analysis of the signature revealed that several passenger strands of miRNAs were significantly downregulated in ESCC, e.g., miR-28-3p, miR-30a-3p, miR-30c-3p, miR-133a-3p, miR-139-3p, miR-143-5p, and miR-145-3p. Recent studies indicate that some passenger strands of miRNAs closely involved in cancer pathogenesis. In this study, we focused on both strands of pre-miR-143, and investigated their antitumor roles and target oncogenes in ESCC. Ectopic expression of miR-143-5p and miR-143-3p significantly attenuated malignant phenotypes (e.g., proliferation, migration, and invasive abilities) in ESCC cell lines. We revealed that six genes (HN1, HMGA2, NETO2, STMN1, TCF3, and MET) were putative targets of miR-143-5p regulation, and one gene (KRT80) was a putative target of miR-143-3p regulation in ESCC cells. Our ESCC miRNA signature and analysis strategy provided important insights into the molecular pathogenesis of ESCC.

Introduction In closure of a stoma, the small working space and adhesions hinder a precise surgical procedure, compared with conventional approaches to digestive surgery. The aim of this prospective study was to introduce a new technique of laparoscopic stoma closure (LASC). Materials and surgical techniques After starting with three trocars, it is a priority to dissect around the arising ileum; a linear stapler is precisely inserted in both orifices of the loop stoma and applied two times, extracorporeally. Ultimately, both the oral and anal sides of the loop ileum are cut and closed using a linear cutter stapler in a delta‐shaped manner just under the abdominal wall, intracorporeally. Eventually, the arising stoma is removed using an intra‐abdominal and cutaneous approach. Discussion LASC for patients with a temporary loop ileostomy is safe and feasible. More data and experience will be required to verify the benefits of this new technique.

Highlights • Retroperitoneal schwannomas in the abdominal cavity are rare and pose difficulty in preoperative diagnosis and management. • Imaging modalities are usually not sufficient to conclude a diagnosis. • EUS-FNA is useful to confirm preoperative diagnosis. • In EUS-FNA, diagnosis can be accurate if the tumor size is small and tumor is devoid of intratumoral degenerations., Introduction Schwannomas are tumors that originate from the Schwann cells present in the nerve sheath of peripheral nerves. They are commonly seen in cephalocervical areas. Schwannomas in the abdominal cavity are rare. Here, we discuss a case of retroperitoneal schwannoma lying dorsal to pancreas with critical relations to surrounding vessels. Presentation of case A 74 years old asymptomatic male was found with elevated amylase level on his routine blood examination. MR imaging revealed retroperitoneal mass of size 21*18*24 mm. EUS-FNA confirmed retroperitoneal schwannoma. The patient had co-morbid renal disease and was on hemodialysis. During the latest follow up, the tumor was 41*37*41 mm in size located dorsal to the confluence of right renal vein and inferior vena cava. The tumor was in contact with inferior vena cava, horizontal part of duodenum, right renal artery, right kidney, and adrenal gland. The patient underwent laparotomy and the tumor was extract with intact capsule. There were no post-operative complications. Discussion Pre-operative diagnosis in retroperitoneal schwannomas is challenging because imaging features are usually non-specific, and biopsy is the only diagnostic technique. EUS-FNA, which has low diagnostic accuracy, is useful in pre-operative diagnosis of small tumors devoid of intra-tumoral degeneration. Conclusion Retroperitoneal schwannoma is a rare entity. Preoperative diagnosis and curative resection are technically difficult. Care should be given during preoperative investigations and surgical resection of the tumor. EUS-FNA can be a useful diagnostic tool.

Highlights • Detection of colorectal cancer liver metastasis (CRCLM) with the infiltration of lymph nodes (LNs) in the hepatic pedicle is not so simple. • When detecting tumor progression from CRCLM along with Glisson branch, the possibility of hepatic hilar LNs involvement should be considered. • Surgical approach against CRCLM with hepatic hilar LNs involvement is controversial, but could be acceptable., Background Colorectal cancer liver metastasis (CRCLM) concomitant with infiltration of lymph nodes (LNs) in the hepatic pedicle is difficult to manage, and is regarded as an extrahepatic metastasis; undertaking hepatectomy is controversial in such a scenario. Case presentation Case 1, A 55-year-old woman was diagnosed with multiple liver metastases arising from rectal cancer along with enlargement of a retropancreatic LN. A characteristic image prior to hepatectomy demonstrated evident tumor progression from a metastatic lesion in segment 5 of the liver (S5) to the hepatic hilum along with Glisson 5. Post-operative histopathological examination revealed viable adenocarcinoma cancer cells originating from rectal cancer in all the liver metastatic lesions and retropancreatic LN. Case 2, A 89-year-old woman was diagnosed with transverse colon cancer with multiple liver metastases. Radiological examination before hepatectomy revealed tumor progression from a metastatic lesion in the segment 6 of the liver (S6) to the hepatic hilum along with Glisson 6 and LN involvement in the hepatoduodenal ligament. Post-operative histopathological examination demonstrated adenocarcinoma cancer cells in the liver metastatic lesions and in a hepatoduodenal LN. Conclusion When encountering tumor progression from liver metastatic lesions to hepatic hilum along with its Glisson branch, the possibility of hepatic hilar LN involvement should be considered. Indeed, the surgical management of CRCLM with hepatic hilar LN involvement is controversial, but could be acceptable if the positive LNs are limited to the hepatic pedicle and retropancreatic area.

To elucidate novel aspects of the molecular pathogenesis of colorectal cancer (CRC), we have created a new microRNA (miRNA) expression signature based on RNA-sequencing. Analysis of the signature showed that 84 miRNAs were upregulated, and 70 were downregulated in CRC tissues. Interestingly, our signature indicated that both guide and passenger strands of some miRNAs were significantly dysregulated in CRC tissues. These findings support our earlier data demonstrating the involvement of miRNA passenger strands in cancer pathogenesis. Our study focused on downregulated miR-490-3p and investigated its tumor-suppressive function in CRC cells. We successfully identified a total of 38 putative oncogenic targets regulated by miR-490-3p in CRC cells. Among these targets, the expression of three genes (IRAK1: p = 0.0427, FUT1: p = 0.0468, and GPRIN2: p = 0.0080) significantly predicted 5-year overall survival of CRC patients. Moreover, we analyzed the direct regulation of IRAK1 by miR-490-3p, and its resultant oncogenic function in CRC cells. Thus, we have clarified a part of the molecular pathway of CRC based on the action of tumor-suppressive miR-490-3p. This new miRNA expression signature of CRC will be a useful tool for elucidating new molecular pathogenesis in this disease.

Our recent miRNA analyses revealed that miR-30a-5p has tumor-suppressive activity in pancreatic ductal adenocarcinoma (PDAC). Herein, we sought to identify tumor-suppressive genes controlled by miR-30a-5p, emphasizing on genes that are closely involved in the molecular pathogenesis of PDAC. We uncovered several novel findings regarding the pathogenesis of this disease.In silico analyses were used to identify the putative target genes of miR-30a-5p and assess their expression levels. Direct regulation of RRM2 by miR-30a-5p and its oncogenic functions were evaluated in PDAC cell lines. Overexpression of RRM2 was demonstrated in clinical samples.A total of 24 putative targets were identified by in silico database analysis. High expression of 4 genes (CBFB, RRM2, AHNAK, and DCBLD1) was significantly associated with shorter survival of patients with PDAC. Functional assays demonstrated that knockdown of RRM2 attenuated the malignant phenotype of PDAC cells.The miR-30a-5p/RRM2 axis facilitated the malignant transformation of PDAC cells.

Simple Summary Even today, there are no effective targeted therapies for intrahepatic cholangiocarcinoma (ICC) patients. Clarifying the molecular pathogenesis of ICC will contribute to the development of treatment strategies for this disease. In this study, we searched for the role of the miR-29-3p-family and its association with oncogenic pathway. Interestingly, aberrant expression of ITGA6 and ITGB1 was directly regulated by the miR-29-3p-family which are involved in multiple oncogenic pathways in ICC, and enhanced malignant transformation of ICC cells. Furthermore, SP1 which is a transcriptional activator of ITGA6/ITGB1, is regulated by the miR-29-3p-family. These molecules may be novel therapeutic targets for ICC. Abstract The aggressive nature of intrahepatic cholangiocarcinoma (ICC) renders it a particularly lethal solid tumor. Searching for therapeutic targets for ICC is an essential challenge in the development of an effective treatment strategy. Our previous studies showed that the miR-29-3p-family members (miR-29a-3p, miR-29b-3p and miR-29c-3p) are key tumor-suppressive microRNAs that control many oncogenic genes/pathways in several cancers. In this study, we searched for therapeutic targets for ICC using the miR-29-3p-family as a starting point. Our functional studies of cell proliferation, migration and invasion confirmed that the miR-29-3p-family act as tumor-suppressors in ICC cells. Moreover, in silico analysis revealed that “focal adhesion”, “ECM-receptor”, “endocytosis”, “PI3K-Akt signaling” and “Hippo signaling” were involved in oncogenic pathways in ICC cells. Our analysis focused on the genes for integrin-α6 (ITGA6) and integrin-β1 (ITGB1), which are involved in multiple pathways. Overexpression of ITGA6 and ITGB1 enhanced malignant transformation of ICC cells. Both ITGA6 and ITGB1 were directly regulated by the miR-29-3p-family in ICC cells. Interestingly, expression of ITGA6/ITGB1 was positively controlled by the transcription factor SP1, and SP1 was negatively controlled by the miR-29-3p-family. Downregulation of the miR-29-3p-family enhanced SP1-mediated ITGA6/ITGB1 expression in ICC cells. MicroRNA-based exploration is an attractive strategy for identifying therapeutic targets for ICC.

Background: Unresectable pancreatic ductal adenocarcinoma (UR-PDAC) has a poor prognosis. Conversion surgery is considered a promising strategy for improving the prognosis of UR-PDAC. This study aimed to investigate the clinical benefits of conversion surgery in patients with UR-PDAC. Methods: We retrospectively evaluated patients with PDAC who were referred to our department for possible surgical resection between January 2006 and December 2019. Conversion surgery was performed only in patients with UR-PDAC who could expect R0 resection. We analyzed the prognostic factors for overall survival among patients who underwent conversion surgery. Results: Overall, 638 patients with advanced pancreatic cancer were enrolled in this study. According to resectability, resectable cancer (R) was present in 180 patients, borderline resectable cancer (BR) was present in 60 patients, unresectable locally advanced cancer (UR-LA) was present in 252 patients, and unresectable cancer with distant metastasis (UR-M) was present in 146 patients. Conversion surgery was performed in 20 of the 398 UR cases (5.1%). The median period between the initial therapy and conversion surgery was 15.5 months. According to the Response Evaluation Criteria in Solid Tumors (RECIST) evaluation, the treatment response was CR in one patient, PR in 13, SD in five, and PD in one. Downstaging was pathologically determined in all cases. According to the Evans grading system, grade I was observed in four patients (20%), grade IIb was observed in seven (35%), III was observed in seven (35%), and IV was observed in two (10%). We compared the overall survival period from initial treatment among patients undergoing conversion surgery, the median overall survival durations in the conversion surgery, R, BR, UR-LA, and UR-M groups were 73.7, 32.7, 22.7, 15.7, and 8.8 months, respectively. Multivariate analysis revealed that the presence or absence of chemoradiotherapy (CRT) and the RECIST partial response (PR)/complete response (CR) for the main tumor were statistically significant prognostic factors for overall survival among patients undergoing conversion surgery (p = 0.004 and 0.03, respectively). Conclusion: In UR-PDAC, it is important to perform multidisciplinary treatment, including CRT with conversion surgery.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive types of cancer, and its prognosis is abysmal, only 25% of patients survive one year, and 5% live for five years. MicroRNA (miRNA) signature analysis of PDAC revealed that both strands of pre-miR-30c (miR-30c-5p, guide strand, miR-30c-2-3p, passenger strand) were significantly downregulated, suggesting they function as tumor-suppressors in PDAC cells. Ectopic expression assays demonstrated that these miRNAs attenuated the aggressiveness of PDAC cells, e.g., cell proliferation, migration, and invasiveness. Through a combination of in silico analyses and gene expression data, we identified 216 genes as putative oncogenic targets of miR-30c-5p and miR-30c-2-3p regulation in PDAC cells. Among these, the expression of 18 genes significantly predicted the 5-year survival rates of PDAC patients (p &lt, 0.01). Importantly, the expression levels of 10 genes (YWHAZ, F3, TMOD3, NFE2L3, ENDOD1, ITGA3, RRAS, PRSS23, TOP2A, and LRRFIP1) were found to be independent prognostic factors for patient survival (p &lt, 0.01). We focused on TOP2A (DNA Topoisomerase II Alpha) and investigated its potential as a therapeutic target for PDAC. The overexpression of TOP2A and its transcriptional activators (SP1 and HMGB2) was detected in PDAC clinical specimens. Moreover, the knockdown of TOP2A enhanced the sensitivity of PDAC cells to anticancer drugs. Our analyses of the PDAC miRNA signature and tumor-suppressive miRNAs provide important insights into the molecular pathogenesis of PDAC.

Our recent studies have implicated some passenger strands of miRNAs in the molecular pathogenesis of human cancers. Analysis of the microRNA (miRNA) expression signature in pancreatic ductal adenocarcinoma (PDAC) has shown that levels of miR-30a-3p, the passenger strand derived from pre-mir-30a, are significantly downregulated in PDAC tissues. This study aimed to identify the oncogenes closely involved in PDAC molecular pathogenesis under the regulation of miR-30a-3p. Ectopic expression assays showed that miR-30a-3p expression inhibited the aggressiveness of the PDAC cells, suggesting that miR-30a-3p acts as a tumor-suppressive miRNA in PDAC cells. We further identified 102 putative targets of miR-30a-3p regulation in PDAC cells by combining in silico analysis with gene expression data. Of these, ten genes (EPS8, HMGA2, ENDOD1, SLC39A10, TGM2, MGLL, SERPINE1, ITGA2, DTL, and UACA) were independent prognostic factors in multivariate analysis of survival of patients with PDAC (p &lt, 0.01). We also investigated the oncogenic function of the integrin ITGA2 in PDAC cell lines. The integrin family comprises cell adhesion molecules expressed as heterodimeric, transmembrane proteins on the surface of various cells. Overexpression of ITGA2/ITGB1 (an ITGA2 binding partner) was detected in the PDAC clinical specimens. The knockdown of ITGA2 expression attenuated the malignant phenotypes of the PDAC cells. Together, results from these microRNA-based approaches can accelerate our understanding of PDAC molecular pathogenesis.

Background The clamp crushing method and the use of the Cavitron ultrasonic surgical aspirator (CUSA) are widely accepted techniques for hepatic parenchymal transection. The actuator-driven pulsed water jet (ADPJ) with high tissue selectivity is a new technology that was shown as a safe transection tool in preclinical models, although not much is known about its safety criteria in patients. Therefore, its strongest advantage, the best indications for its use, and its performance in comparison with other transection methods remain to be clarified. In this report, we present several representative cases to help answer these questions. Methods We started using the ADPJ in December 2017, only in cases where the tumor was very close to major vessels or attached to them, along a considerable length, to preserve vessels and prevent postoperative liver failure. All the cases underwent highly demanding procedures. We avoided using this device in cases such as liver cirrhosis, where the hepatic parenchyma was very hard. Results Six cases fulfilled our limited indications for using ADPJ. The median age and number of tumors were 55 years (10 to 69 y) and 2.5 years (1 to 4 y), respectively. The mean tumor size was 7.8 cm (2.8 to 21 cm), the minimum distance between the tumor and major vessels to be preserved was 0 mm (0 to 4 mm), and the contact length of the tumor and major vessels was 26 mm (19 to 40 mm). Regarding the surgical outcome, the median operation time and blood loss were 559 minutes (508 to 919 min) and 620 mL (230 to 860 mL), respectively. We achieved a negative surgical margin (R0 resection) in all cases. Conclusions Using ADPJ, we could perform R0 hepatectomy in all cases, which preoperatively were considered to have a high chance of being margin positive. We consider the best indication for using ADPJ is when the tumor and vessels to be preserved are attached or very close over a long distance.

RNA-sequencing-based microRNA (miRNA) expression signatures have revealed that miR-148a-5p (the passenger strand of the miR-148a-duplex) is downregulated in various kinds of cancer tissues. Analysis of The Cancer Genome Atlas (TCGA) database showed that low expression of miR-148a-5p was predictive of a lower survival rate (p = 0.041) in patients with gastric cancer (GC). Downregulation of miR-148a-5p was confirmed in GC clinical specimens, and its ectopic expression attenuated GC cell proliferation. Our search for miRNA target genes identified a total of 18 oncogenic targets of miR-148a-5p in GC cells. Among these targets, high expression levels of six genes (THBS2, P4HA3, SERPINH1, CDH11, BCAT1, and KCNG3) were closely associated with a poor prognosis (10-year survival rates) in GC patients (p

Triple-negative breast cancer (TNBC) is an aggressive type of cancer associated with a poor prognosis. Identification of novel therapeutic targets in TNBC is urgently needed. Here, we investigated the microRNA (miRNA) expression signature of TNBC using clinical specimens. In total, 104 miRNAs (56 upregulated and 48 downregulated) were significantly dysregulated in TNBC tissues; miR-204-5p showed the most dramatic downregulation. We then examined the antitumor roles of miR-204-5p in breast cancer (BC) cells. Notably, cancer cell migration and invasion were significantly reduced by ectopic expression of miR-204-5p in BC cells. Genome-wide gene expression analysis and in silico database search revealed that 32 genes were putative miR-204-5p targets. High expression of AP1S3, RACGAP1, ELOVL6, and LRRC59 was significantly associated with poor prognosis in patients with BC, and adaptor-related protein complex 1 sigma 3 subunit (AP1S3) was directly regulated by miR-204-5p, as demonstrated by luciferase reporter assays. AP1S3 overexpression was detected in TNBC clinical specimens and enhanced cancer cell aggressiveness. We further analyzed downstream RNA networks regulated by AP1S3 in BC cells. Overall, this miRNA signature is expected to be an effective tool for identification of miRNA-mediated molecular mechanisms of TNBC pathogenesis.

MicroRNAs (miRNAs) are unique in that a single miRNA molecule regulates a vast number of RNA transcripts. Thus, aberrantly expressed miRNAs disrupt tightly controlled RNA networks in cancer cells. Our functional screening showed that expression of miR-124-3p was downregulated in pancreatic ductal adenocarcinoma (PDAC) tissues. Here, we aimed to investigate the anti-tumor roles of miR-124-3p in PDAC cells and to identify miR-124-3p-mediated oncogenic signaling in this disease. Ectopic expression of miR-124-3p inhibited cancer cell migration and invasion in PDAC cells. Moreover, restoration of miR-124-3p suppressed oncogenic signaling, as demonstrated by reduced phosphorylation of focal adhesion kinase, AKT, and extracellular signal-regulated kinase, in PDAC cells. Our in silico database analyses and luciferase reporter assays showed that two cell-surface matrix receptors, integrin α3 (ITGA3) and integrin β1 (ITGB1), were directly regulated by miR-124-3p in PDAC cells. Overexpression of ITGA3 and ITGB1 was confirmed in PDAC clinical specimens. Interestingly, a large number of cohort analyses from TCGA database showed that high expressions of ITGA3 and ITGB1 were significantly associated with poor prognosis of patients with PDAC. Knockdown of ITGA3 and ITGB1 by siRNAs markedly suppressed the migration and invasion abilities of PDAC cells. Moreover, downstream oncogenic signaling was inhibited by ectopic expression of miR-124-3p or knockdown of the two integrins. The discovery of anti-tumor miRNAs and miRNA-mediated oncogenic signaling may provide novel therapeutic targets for the treatment of PDAC.

Analysis of our original microRNA (miRNA) expression signature of patients with advanced renal cell carcinoma (RCC) showed that microRNA-10a-5p (miR-10a-5p) was significantly downregulated in RCC specimens. The aims of the present study were to investigate the antitumor roles of miR-10a-5p and the novel cancer networks regulated by this miRNA in RCC cells. Downregulation of miR-10a-5p was confirmed in RCC tissues and RCC tissues from patients treated with tyrosine kinase inhibitors (TKI). Ectopic expression of miR-10a-5p in RCC cell lines (786-O and A498 cells) inhibited cancer cell migration and invasion. Spindle and kinetochore-associated protein 1 (SKA1) was identified as an antitumor miR-10a-5p target by genome-based approaches, and direct regulation was validated by luciferase reporter assays. Knockdown of SKA1 inhibited cancer cell migration and invasion in RCC cells. Overexpression of SKA1 was observed in RCC tissues and TKI-treated RCC tissues. Moreover, analysis of The Cancer Genome Atlas database demonstrated that low expression of miR-10a-5p and high expression of SKA1 were significantly associated with overall survival in patients with RCC. These findings showed that downregulation of miR-10a-5p and overexpression of the SKA1 axis were highly involved in RCC pathogenesis and resistance to TKI treatment in RCC.

// Keiichi Yonemori 1 , Naohiko Seki 2 , Tetsuya Idichi 1 , Hiroshi Kurahara 1 , Yusaku Osako 1 , Keiichi Koshizuka 2 , Takayuki Arai 2 , Atsushi Okato 2 , Yoshiaki Kita 1 , Takaaki Arigami 1 , Yuko Mataki 1 , Yuko Kijima 1 , Kosei Maemura 1 and Shoji Natsugoe 1 1 Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, Sakuragaoka, Kagoshima 890-8520, Japan 2 Department of Functional Genomics, Chiba University Graduate School of Medicine, Chuo-ku, Chiba 260-8670, Japan Correspondence to: Naohiko Seki, email: naoseki@faculty.chiba-u.jp Keywords: pancreatic ductal adenocarcinoma, microRNA, expression signature, miR-216b-3p , FOXQ1 Received: February 07, 2017 Accepted: June 26, 2017 Published: July 26, 2017 ABSTRACT We analysed the RNA sequence-based microRNA (miRNA) signature of pancreatic ductal adenocarcinoma (PDAC). Aberrantly expressed miRNAs were successfully identified in this signature. Using the PDAC signature, we focused on 4 clustered miRNAs, miR-216a-5p , miR-216a-3p , miR-216b-5p and miR-216b-3p on human chromosome 2p16.1. All members of the miR-216 cluster were significantly reduced in PDAC specimens. Ectopic expression of these miRNAs suppressed cancer cell aggressiveness, suggesting miR-216 cluster as anti-tumour miRNAs in PDAC cells. The impact of miR-216b-3p (passenger strand of pre- miR-216b ) on cancer cells is still ambiguous. Forkhead box Q1 ( FOXQ1 ) was directly regulated by miR-216b-3p and overexpression of FOXQ1 was confirmed in clinical specimens. High expression of FOXQ1 predicted a shorter survival of patients with PDAC by Kaplan–Meier analysis. Loss-of-function assays showed that cancer cell migration and invasion activities were significantly reduced by si FOXQ1 transfectants. We investigated pathways downstream from FOXQ1 by using genome-wide gene expression analysis. Identification of the miR-216-3p/FOXQ1 -mediated network in PDAC should enhance understanding of PDAC aggressiveness at the molecular level.

// Tetsuya Idichi 1 , Naohiko Seki 2 , Hiroshi Kurahara 1 , Keiichi Yonemori 1 , Yusaku Osako 1 , Takayuki Arai 2 , Atsushi Okato 2 , Yoshiaki Kita 1 , Takaaki Arigami 1 , Yuko Mataki 1 , Yuko Kijima 1 , Kosei Maemura 1 and Shoji Natsugoe 1 1 Department of Digestive Surgery, Breast and Thyroid Surgery, Graduate School of Medical Sciences, Kagoshima University, Kagoshima, Japan 2 Department of Functional Genomics, Chiba University Graduate School of Medicine, Chiba, Japan Correspondence to: Naohiko Seki, email: naoseki@faculty.chiba-u.jp Keywords: microRNA, miR-217 , pancreatic ductal adenocarcinoma, ANLN , tumor-suppressor Received: January 11, 2017 Accepted: May 08, 2017 Published: May 29, 2017 ABSTRACT Analysis of our microRNA (miRNA) expression signature of pancreatic ductal adenocarcinoma (PDAC) revealed that microRNA-217 ( miR-217 ) was significantly reduced in cancer tissues. The aim of this study was to investigate the antitumor roles of miR-217 in PDAC cells and to identify miR-217 -mediated molecular pathways involved in PDAC aggressiveness. The expression levels of miR-217 were significantly reduced in PDAC clinical specimens. Ectopic expression of miR-217 significantly suppressed cancer cell migration and invasion. Transcription of actin-binding protein Anillin (coded by ANLN ) was detected by our in silico and gene expression analyses. Moreover, luciferase reporter assays showed that ANLN was a direct target of miR-217 in PDAC cells. Overexpression of ANLN was detected in PDAC clinical specimens by real-time PCR methods and immunohistochemistry. Interestingly, Kaplan–Meier survival curves showed that high expression of ANLN predicted shorter survival in patients with PDAC by TCGA database analysis. Silencing ANLN expression markedly inhibited cancer cell migration and invasion capabilities of PDAC cell lines. We further investigated ANLN -mediated downstream pathways in PDAC cells. “Focal adhesion” and “Regulation of actin binding protein” were identified as ANLN -modulated downstream pathways in PDAC cells. Identification of antitumor miR-217 / ANLN -mediated PDAC pathways will provide new insights into the potential mechanisms underlying the aggressive course of PDAC.

Background /Objectives: The lung is a major metastatic site of pancreatic cancer (PC). We aimed to assess the features and prognosis of patients with PC according to the recurrence pattern and the effect of resection of recurrent lung lesion. Methods We enrolled 168 PC patients who had undergone macroscopically curative resection. All resected lung tumors were evaluated immunohistochemically for expressions of thyroid transcription factor-1 (TTF-1) and napsin A. Results The most common site of first recurrence was the liver and local site, followed by the lung, peritoneum, and lymph node. Lung recurrence was observed significantly later than was liver recurrence. The median survival time (MST) after recurrence in patients with first recurrence in the lung was significantly longer than MST in patients with first recurrence in the liver (15.2 months vs 5.2 months, p = 0.039). Seven patients with lung recurrence underwent resection of the recurrent lesion. Surgical resection of single metastasis limited to the lung showed favorable overall survival after recurrence (MST = 36.5 months). Patients with single metastasis limited to the lung showed significantly lower value of FDG-PET SUVmax of the primary pancreatic tumor. Conclusions Patients with first recurrence in the lung showed better prognosis than did patients with first recurrence in the liver. Single metastasis limited to the lung could benefit from surgical resection and was significantly associated with lower FDG-PET SUVmax of the primary pancreatic tumor.

Aberrantly expressed microRNA (miRNA) are known to disrupt intracellular RNA networks in cancer cells. Exploring miRNA‐dependent molecular networks is a major challenge in cancer research. In this study, we performed RNA‐sequencing of breast cancer (BrCa) clinical specimens to identify tumor‐suppressive miRNA in BrCa. In total, 64 miRNA were identified as candidate tumor‐suppressive miRNA in BrCa cells. Analysis of our BrCa signature revealed that several miRNA duplexes (guide strand/passenger strand) derived from pre‐miRNA were downregulated in BrCa tissues (e.g. miR‐99a‐5p/‐3p, miR‐101‐5p/‐3p, miR‐126‐5p/‐3p, miR‐143‐5p/‐3p, and miR‐144‐5p/‐3p). Among these miRNA, we focused on miR‐101‐5p, the passenger strand of pre‐miR‐101, and investigated its tumor‐suppressive roles and oncogenic targets in BrCa cells. Low expression of miR‐101‐5p predicted poor prognosis in patients with BrCa (overall survival rate: P = 0.0316). Ectopic expression of miR‐101‐5p attenuated aggressive phenotypes, e.g. proliferation, migration, and invasion, in BrCa cells. Finally, we identified seven putative oncogenic genes (i.e. High Mobility Group Box 3, Epithelial splicing regulatory protein 1, GINS complex subunit 1 (GINS1), Tumor Protein D52, Serine/Arginine‐Rich Splicing Factor Kinase 1, Vang‐like protein 1, and Mago Homolog B) regulated by miR‐101‐5p in BrCa cells. The expression of these target genes was associated with the molecular pathogenesis of BrCa. Furthermore, we explored the oncogenic roles of GINS1, whose function had not been previously elucidated, in BrCa cells. Aberrant expression of GINS1 mRNA and protein was observed in BrCa clinical specimens, and high GINS1 expression significantly predicted poor prognosis in patients with BrCa (overall survival rate: P = 0.0126). Knockdown of GINS1 inhibited the malignant features of BrCa cells. Thus, identification of tumor‐suppressive miRNA and molecular networks controlled by these miRNA in BrCa cells may be an effective strategy for elucidation of the molecular pathogenesis of this disease., We showed that miR‐101‐5p acted as an anti‐tumor miRNA in breast cancer (BrCa) cells through targeting several oncogenic genes (i.e. High Mobility Group Box 3, Epithelial splicing regulatory protein 1, GINS complex subunit 1 (GINS1), Tumor Protein D52, Serine/Arginine‐Rich Splicing Factor Kinase 1, Vang‐like protein 1, and Mago Homolog B). Aberrant expression of GINS1 mRNA and protein was observed in BrCa clinical specimens, and high GINS1 expression significantly predicted poor prognosis in patients with BrCa (overall survival rate: P = 0.0126).

Our ongoing analyses identifying dysregulated microRNAs (miRNAs) and their controlled target RNAs have shed light on novel oncogenic pathways in pancreatic ductal adenocarcinoma (PDAC). The PDAC miRNA signature obtained by RNA sequencing showed that both strands of pre-miR-130b (miR-130b-5p, the passenger strand and miR-130b-3p, the guide strand) were significantly downregulated in cancer tissues. Our functional assays revealed that miR-130b-5p significantly blocked the malignant abilities of PDAC cell lines (PANC-1 and SW1990), e.g., cancer cell proliferation, migration, and invasion. A total of 103 genes were identified as possible oncogenic targets by miR-130b-5p regulation in PDAC cells based on genome-wide gene expression analysis and in silico database search. Among the possible targets, high expression of 9 genes (EPS8, ZWINT, SMC4, LDHA, GJB2, ZCCHC24, TOP2A, ANLN, and ADCY3) predicted a significantly poorer prognosis of PDAC patients (5-year overall survival, p