Spread of lymph node metastasis and adjuvant therapy for distal cholangiocarcinoma

International Journal of Clinical Oncology - Lymphatic metastasis is a major route of metastasis in distal cholangiocarcinoma (DCC). The present study aimed to elucidate the pattern of lymph node...     

Rare histological subtype of invasive micropapillary carcinoma in the ampulla of Vater: A case report

BACKGROUNDCarcinoma 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 SUMMARYWe 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.CONCLUSIONThis rare subtype tumor in the ampulla of Vater showed a histologically mixed phenotype and exhibited aggressive behavior.     

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.     

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.     

Antitumor miR-150-5p and miR-150-3p inhibit cancer cell aggressiveness by targeting SPOCK1 in head and neck squamous cell carcinoma

Objective

Our recent studies have revealed that both strands of pre-miRNAs, the guide strand and the passenger strand, are involved in cancer pathogenesis. Analyses of miRNA expression signatures by RNA sequencing in head and neck squamous cell carcinoma (HNSCC) showed that both of the strands of pre-miR-150 (miR-150-5p and miR-150-3p) were significantly downregulated, and that these miRNAs acted as antitumor miRNAs in HNSCC cells. The aim of this study was to identify oncogenic genes in HNSCC cells that were regulated by miR-150-5p and miR-150-3p.

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.     

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.