Spread of lymph node metastasis and adjuvant therapy for distal cholangiocarcinoma.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Molecular Pathogenesis of Colorectal Cancer: Impact of Oncogenic Targets Regulated by Tumor Suppressive miR-139-3p.

We recently determined the RNA sequencing-based microRNA (miRNA) expression signature of colorectal cancer (CRC). Analysis of the signature showed that the expression of both strands of pre-miR-139 (miR-139-5p, the guide strand, and miR-139-3p, the passenger strand) was significantly reduced in CRC tissues. Transient transfection assays revealed that expression of miR-139-3p blocked cancer cell malignant transformation (e.g., cell proliferation, migration, and invasion). Notably, expression of miR-139-3p markedly blocked RAC-alpha serine/threonine-protein kinase (AKT) phosphorylation in CRC cells. A combination of in silico database and gene expression analyses of miR-139-3p-transfected cells revealed 29 putative targets regulated by miR-139-3p in CRC cells. RNA immunoprecipitation analysis using an Argonaute2 (AGO2) antibody revealed that KRT80 was efficiently incorporated into the RNA-induced silencing complex. Aberrant expression of Keratin 80 (KRT80) was detected in CRC clinical specimens by immunostaining. A knockdown assay using small interfering RNA (siRNA) targeting KRT80 showed that reducing KRT80 expression suppressed the malignant transformation (cancer cell migration and invasion) of CRC cells. Importantly, inhibiting KRT80 expression reduced AKT phosphorylation in CRC cells. Moreover, hexokinase-2 (HK2) expression was reduced in cells transfected with the KRT80 siRNAs or miR-139-3p. The involvement of miRNA passenger strands (e.g., miR-139-3p) in CRC cells is a new concept in miRNA studies. Our tumor-suppressive miRNA-based approach helps elucidate the molecular pathogenesis of CRC.

Effectiveness of Adjuvant Therapy in Patients with Pancreatic Cancer Who Underwent Neoadjuvant Therapy.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

RNA-Sequencing Based microRNA Expression Signature of Colorectal Cancer: The Impact of Oncogenic Targets Regulated by miR-490-3p.

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.

Regulation of aberrantly expressed SERPINH1 by antitumor miR-148a-5p inhibits cancer cell aggressiveness in gastric cancer.

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 < 0.05) according to TCGA database analyses. Furthermore, we focused on SERPINH1 as a chaperone protein involved in collagen folding in humans. Aberrant expression of SERPINH1 (mRNA and protein levels) was confirmed in GC clinical specimens. Knockdown assays of SERPINH1 using siRNAs resulted in inhibition of the aggressive phenotype of GC cells. Exploring the molecular networks controlled by miRNAs (including miRNA passenger strands) will broaden our understanding of the molecular pathogenesis of GC.

RNA sequencing-based microRNA expression signature in esophageal squamous cell carcinoma: oncogenic targets by antitumor miR-143-5p and miR-143-3p regulation.

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.

Lung recurrence and its therapeutic strategy in patients with pancreatic cancer.

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.

Role of miR-30a-3p Regulation of Oncogenic Targets in Pancreatic Ductal Adenocarcinoma Pathogenesis.

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 < 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.

Gene regulation by antitumor miR-130b-5p in pancreatic ductal adenocarcinoma: the clinical significance of oncogenic EPS8.

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 < 0.001). Furthermore, we focused on EPS8 because its expression had the greatest impact on patient prognosis (overall survival, p < 0.0001). Overexpression of EPS8 was detected in PDAC clinical specimens. Knockdown assays with siEPS8 showed that its overexpression enhanced cancer cell proliferation, migration, and invasion. Analysis of downstream RNA networks regulated by EPS8 indicated that MET, HMGA2, FERMT1, RARRES3, PTK2, MAD2L1, and FLI1 were closely involved in PDAC pathogenesis. Genes regulated by antitumor miR-130b-5p were closely involved in PDAC molecular pathogenesis. Our approach, discovery of antitumor miRNAs and their target RNAs, will contribute to exploring the causes of this malignant disease.

Molecular pathogenesis of pancreatic ductal adenocarcinoma: Impact of passenger strand of pre-miR-148a on gene regulation.

We previously used RNA sequencing to establish the microRNA (miRNA) expression signature of pancreatic ductal adenocarcinoma (PDAC). We found that both strands of pre-miR-148a (miR-148a-5p: the passenger strand and miR-148a-3p: the guide strand) were downregulated in cancer tissues. Ectopic expression of miR-148a-5p and miR-148a-3p significantly inhibited cancer cell migration and invasion, indicating that both strands of pre-miR-148a had tumor-suppressive roles in PDAC cells. In silico database and genome-wide gene expression analyses identified a total of 15 genes that were putative targets regulated by these miRNAs. High expression of miR-148a-5p targets (PHLDA2, LPCAT2 and AP1S3) and miR-148a-3p targets (SMA, ENDOD1 and UHMK1) was associated with poor prognosis of patients with PDAC. Moreover, knockdown of PHLDA2 expression inhibited cancer cell aggressiveness, suggesting PHLDA2 acted as an oncogene in PDAC cells. Involvement of the passenger strand of pre-miR-148a (miR-148-5p) is a new concept in cancer research. Novel approaches that identify tumor-suppressive miRNA regulatory networks in lethal PDAC might provide new prognostic markers and therapeutic targets for this disease.

Dual strands of the miR-223 duplex (miR-223-5p and miR-223-3p) inhibit cancer cell aggressiveness: targeted genes are involved in bladder cancer pathogenesis.

Analyses of microRNA (miRNA) expression signatures obtained by RNA sequencing revealed that some passenger miRNAs (miR-144-5p, miR-145-3p, miR-149-3p, miR-150-3p, and miR-199a-3p) acted as anti-tumor miRNAs in several types of cancer cells. The involvement of passenger strands in the pathogenesis of human cancer is a novel concept. Based on the miRNA signature of bladder cancer (BC) obtained by RNA sequencing, we focused on both strands of the miR-223-duplex (miR-223-5p and miR-223-3p) and investigated their functional significance in BC cells. Ectopic expression of these miRNAs showed that both miR-223-3p (the guide strand) and miR-223-5p (the passenger strand) inhibited cancer cell migration and invasion of BC cells. The role of miR-223-5p (the passenger strand) has not been well studied. Combining gene expression studies and in silico database analyses, we demonstrated the presence of 20 putative target genes that could be regulated by miR-223-5p in BC cells. Among these targets, high expression of five genes (ANLN, INHBA, OIP5, CCNB1, and CDCA2) was significantly associated with poor prognosis of BC patients based on The Cancer Genome Atlas (TCGA) database. Moreover, we showed that a gene (ANLN) encoding a multifunctional actin-binding protein was directly regulated by miR-223-5p in BC cells. Overexpression of ANLN was observed in BC clinical specimens and high expression of ANLN was significantly associated with poor prognosis of BC patients. We suggest that studies of regulatory cancer networks, including the passenger strands of miRNAs, may provide new insights into the pathogenic mechanisms of BC.

Molecular pathogenesis of triple-negative breast cancer based on microRNA expression signatures: antitumor miR-204-5p targets AP1S3.

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.

ZFP36L2 promotes cancer cell aggressiveness and is regulated by antitumor microRNA-375 in pancreatic ductal adenocarcinoma.

Due to its aggressive nature, pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal and hard-to-treat malignancies. Recently developed targeted molecular strategies have contributed to remarkable improvements in the treatment of several cancers. However, such therapies have not been applied to PDAC. Therefore, new treatment options are needed for PDAC based on current genomic approaches. Expression of microRNA-375 (miR-375) was significantly reduced in miRNA expression signatures of several types of cancers, including PDAC. The aim of the present study was to investigate the functional roles of miR-375 in PDAC cells and to identify miR-375-regulated molecular networks involved in PDAC aggressiveness. The expression levels of miR-375 were markedly downregulated in PDAC clinical specimens and cell lines (PANC-1 and SW1990). Ectopic expression of miR-375 significantly suppressed cancer cell proliferation, migration and invasion. Our in silico and gene expression analyses and luciferase reporter assay showed that zinc finger protein 36 ring finger protein-like 2 (ZFP36L2) was a direct target of miR-375 in PDAC cells. Silencing ZFP36L2 inhibited cancer cell aggressiveness in PDAC cell lines, and overexpression of ZFP36L2 was confirmed in PDAC clinical specimens. Interestingly, Kaplan-Meier survival curves showed that high expression of ZFP36L2 predicted shorter survival in patients with PDAC. Moreover, we investigated the downstream molecular networks of the miR-375/ZFP36L2 axis in PDAC cells. Elucidation of tumor-suppressive miR-375-mediated PDAC molecular networks may provide new insights into the potential mechanisms of PDAC pathogenesis.

Regulation of spindle and kinetochore-associated protein 1 by antitumor miR-10a-5p in renal cell carcinoma.

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.

Regulation of SPOCK1 by dual strands of pre-miR-150 inhibit cancer cell migration and invasion in esophageal squamous cell carcinoma.

Analysis of our microRNA (miRNA) expression signatures of human cancers based on RNA sequencing have shown that both strands of pre-miR-150, miR-150-5p (the guide strand) and miR-150-3p (the passenger strand), are significantly reduced in cancer tissues. We have investigated the functional significance of both strands of pre-miR-150 in cancer cells. The aim of this study was to investigate the antitumor function of these miRNAs and how these miRNAs regulated oncogenic targets in esophageal squamous cell carcinoma (ESCC). Ectopic expression studies demonstrated that both strands of pre-miR-150 miRNA inhibited ESCC cancer cell migration and invasion, indicating that both miR-150-5p and miR-150-3p acted as antitumor miRNAs. A combination of genome-wide gene expression analyses and in silico database searches showed that SPOCK1 (SPARC/osteonectin, cwcv and kazal-like domains proteoglycan 1) was a candidate target of miR-150-5p and miR-150-3p in ESCC cells. Luciferase reporter assays showed that SPOCK1 was directly regulated by these miRNAs. Silencing of SPOCK1 by small interfering RNA inhibited cancer cell migration and invasion. Overexpression of SPOCK1/SPOCK1 was confirmed by real-time PCR methods and immunohistochemistry. Taken together, downregulation of both strands of pre-miR-150 and overexpression of SPOCK1 are involved in ESCC pathogenesis. The involvement of passenger strand miRNAs in the regulation of cancer cell aggressiveness is a novel concept in RNA research.

Impact of pancreatic ductal occlusion on postoperative outcomes in pancreatic head cancer patients undergoing neoadjuvant therapy.

BACKGROUND: Pancreatic ductal occlusion can accompany pancreatic head cancer, leading to pancreatic exocrine insufficiency (PEI) and adverse effects on nutritional status and postoperative outcomes. We investigated its impact on nutritional status, body composition, and postoperative outcomes in patients with pancreatic head cancer undergoing neoadjuvant therapy (NAT). METHODS: We analyzed 136 patients with pancreatic head cancer who underwent NAT prior to intended pancreaticoduodenectomy (PD) between 2015 and 2022. Nutritional and anthropometric indices (body mass index [BMI], albumin, prognostic nutritional index [PNI], Glasgow prognostic score, psoas muscle index, subcutaneous adipose tissue index [SATI], and visceral adipose tissue index) and postoperative outcomes were compared between the occlusion (n = 78) and non-occlusion (n = 58) groups, in which 61 and 44 patients, respectively, ultimately underwent PD. RESULTS: The occlusion group showed significantly lower post-NAT BMI, PNI, and SATI (p = 0.011, 0.005, and 0.015, respectively) in the PD cohort. The occlusion group showed significantly larger main pancreatic duct, smaller pancreatic parenchyma, and greater duct-parenchymal ratio (p < 0.001), and these morphological parameters significantly correlating with post-NAT nutritional and anthropometric indices. Postoperative 3-year survival and recurrence-free survival (RFS) rates were significantly poorer (p = 0.004 and 0.013) with pancreatic ductal occlusion, also identified as an independent postoperative risk factor for overall survival (hazard ratio [HR]: 2.31, 95% confidence interval [CI] 1.08-4.94, p = 0.030) and RFS (HR: 2.03, 95% CI 1.10-3.72, p = 0.023), in multivariate analysis. CONCLUSIONS: Pancreatic ductal occlusion may be linked to poorer postoperative outcomes due to PEI-related malnutrition.

Genetic assessment of IPMN for predicting concomitant pancreatic ductal adenocarcinoma.

OBJECTIVE: Krüppel-like transcription factor 4(KLF4) mutations are more frequently observed in low-grade lesions than in high-grade lesions of intraductal papillary mucinous neoplasms (IPMN) of the pancreas. However, the role of KLF4 mutations in IPMNs with concomitant pancreatic ductal adenocarcinoma (PDAC) remains unclear. This study clarified the rate and effect of KLF4 mutations in IPMN with concomitant PDAC. METHODS: DNA was extracted from 65 formalin-fixed and paraffin-embedded samples from 52 patients including 13 IPMN with concomitant PDAC and 39 IPMN alone. A comprehensive screening was performed using next-generation sequencing (NGS) for the 5 IPMNs with concomitant PDAC and 5 IPMNs alone, followed by targeted sequencing for KLF4, GNAS, and KRAS mutations. RESULTS: In NGS screening, KRAS mutations were observed in all samples except for one, GNAS mutation in two IPMNs with concomitant PDAC, and a KLF4 mutation in one IPMN with concomitant PDAC. Targeted sequence detected KLF4 mutations in 11 of the 52 IPMNs. Concomitant PDAC developed only in the non-intestinal, non-invasive, and branch duct IPMN cases, and KLF4 mutations were more frequent in this IPMN type than in the other type (36% vs. 10%, p = 0.04). For this IPMN type with KLF4 mutation, PDAC-prediction sensitivity, specificity, and accuracy were 63%, 82%, and 79%, respectively. CONCLUSION: For selected IPMNs with non-intestinal, non-invasive, and branch duct, genetic assessment might be a helpful tool for predicting the possible development of concomitant PDAC, although a prospective validation study using a larger study population is needed.

Metal-free laparoscopic distal pancreatectomy using transpancreatic mattress suture with polyglycolic acid sheet and fibrin glue: A case report.

Laparoscopic distal pancreatectomy (LDP) is the standard surgery for malignant and premalignant tumors of the pancreatic body and tail. A stapler is commonly used to close the pancreatic stump due to its simplicity; however, the use of a stapler is associated with the risk of metal allergy and postoperative pancreatic fistula, especially in thick pancreases. Here, we present a case of LDP without metal instruments, including staplers and clips, in a 54-year-old woman with a metal allergy and a thick pancreas. The pancreatic stump was closed using the transpancreatic mattress suture method with a polyglycolic acid sheet (PGA) and fibrin glue. The postoperative course was uneventful. Metal-free LDP is useful and can be adopted regardless of the patient's background, such as a metal allergy or pancreatic thickness.

Usefulness of cranio-dorsal approach for laparoscopic left lateral sectionectomy.

Most surgeons perform laparoscopic left lateral sectionectomy (Lap LLS) using the caudo-peripheral approach (C-P approach). However, recently, a cranio-dorsal approach (C-D approach) has been applied to various types of hepatectomy owing to its advantage of preventing split injury. No studies yet have compared the perioperative outcomes of Lap LLS using each approach. Therefore, this study aimed to determine whether the C-D approach is useful for Lap LLS by comparing its perioperative outcomes with the C-P approach. Data of patients who underwent Lap LLS in our institution between 2010 and 2022 for liver tumors were retrospectively collected. We compared the perioperative outcomes of Lap LLS using a conventional C-P approach, which transects hepatic parenchyma in the caudo-peripheral direction and a C-D approach, which transects hepatic parenchyma in the cranio-caudal direction. All surgeries were performed only by board-certified expert surgeons to minimize technical bias. Furthermore, the perioperative procedures employed at our institution remained unchanged throughout the study period. A total of 36 patients were included in the study (C-P approach, n = 25; C-D approach, n = 11). The C-D approach showed a significantly shorter operation time than the C-P approach (median, 225 min vs. 262 min, p = 0.04). In addition, the C-D approach showed significantly lower blood loss than the C-P approach (median, 20 mL vs. 100 mL, p < 0.01). Other parameters, such as morbidity and hospital stay, were comparable between groups. The C-D approach could offer better surgical outcomes than the conventional C-P approach.

Coronin 1C, Regulated by Multiple microRNAs, Facilitates Cancer Cell Aggressiveness in Pancreatic Ductal Adenocarcinoma.

Coronin proteins are actin-related proteins containing WD repeat domains encoded by seven genes (CORO1A, CORO1B, CORO1C, CORO2A, CORO2B, CORO6, and CORO7) in the human genome. Analysis of large cohort data from The Cancer Genome Atlas revealed that expression of CORO1A, CORO1B, CORO1C, CORO2A, and CORO7 was significantly upregulated in pancreatic ductal adenocarcinoma (PDAC) tissues (p < 0.05). Moreover, high expression of CORO1C and CORO2A significantly predicted the 5 year survival rate of patients with PDAC (p = 0.0071 and p = 0.0389, respectively). In this study, we focused on CORO1C and investigated its functional significance and epigenetic regulation in PDAC cells. Knockdown assays using siRNAs targeting CORO1C were performed in PDAC cells. Aggressive cancer cell phenotypes, especially cancer cell migration and invasion, were inhibited by CORO1C knockdown. The involvement of microRNAs (miRNAs) is a molecular mechanism underlying the aberrant expression of cancer-related genes in cancer cells. Our in silico analysis revealed that five miRNAs (miR-26a-5p, miR-29c-3p, miR-130b-5p, miR-148a-5p, and miR-217) are putative candidate miRNAs regulating CORO1C expression in PDAC cells. Importantly, all five miRNAs exhibited tumor-suppressive functions and four miRNAs except miR-130b-5p negatively regulated CORO1C expression in PDAC cells. CORO1C and its downstream signaling molecules are potential therapeutic targets in PDAC.