Comparison of infectious complications after spleen preservation versus splenectomy during laparoscopic distal pancreatectomy for benign or low-grade malignant pancreatic tumors: A multicenter, propensity score-matched analysis.

BACKGROUND: Previous studies have reported contrasting results regarding the advantages of spleen preservation during laparoscopic distal pancreatectomy (LDP) for preventing infectious complications. METHODS: A total of 3787 patients who underwent LDP for benign or low-grade malignant pancreatic disease in 92 centers across Korea and Japan were included in this retrospective study. Postoperative infectious complications and other complications were compared between LDP with splenectomy (LDPS) and LDP with spleen preservation (LSPDP) by propensity score matching (PSM) analysis. RESULTS: After PSM, the LSPDP group had a lower rate of overall infectious complications (P = .079) and a significantly lower rate of intra-abdominal abscess (P = .014) compared with the LDPS group. Within the LSPDP group, the vessel preservation subgroup had a significantly higher rate of infectious complications (P = .002) compared with the vessel resection subgroup. Low-volume centers had a higher rate of intra-abdominal abscess than high-volume centers in the LSPDP group (P = .001) and the splenic vessel preservation subgroup (P = .003). CONCLUSIONS: Spleen preservation in LDP for benign or borderline malignant pancreatic diseases was advantageous in lowering the risk of infectious complications, specifically intra-abdominal abscess. However, the risk of intra-abdominal abscess may differ according to the level of surgeon's experience.

A case of solid-type pancreatic hamartoma presenting high apparent diffusion coefficient value: histopathological correlation and literature review.

Pancreatic hamartoma is a rare tumor-like malformation and could mimic other pancreatic tumors including malignant neoplasm. Due to its rarity, magnetic resonance (MR) imaging findings including those diffusion-weighted (DW) imaging have not been clarified. We present a curious case of pancreatic hamartoma presenting high apparent diffusion coefficient (ADC) value with histopathological correlation. A 49-year-old woman with a pancreatic mass found incidentally on ultrasonography for medical checkup was referred to our institution for further examination and treatment because it slightly enlarged in the follow-up examination. Contrast-enhanced computed tomography (CT) and gadoxetic acid disodium-enhanced MR imaging revealed a well-demarcated solid mass of 13 mm in diameter in the pancreas body, which was gradually and homogeneously enhanced in the delayed/transient phase. It showed hyper intensity on T2-weight and DW images, and the mean ADC value was high (1.86 × 10-3mm2/s). Laparoscopic distal pancreatectomy was conducted with suspicious preoperative diagnosis of pancreatic hypovascular neuroendocrine neoplasm (NEN). Histologically, the mass consisted of many disarranged small ducts without atypia embedded in abundant fibrous stroma and contained scant fatty tissue in the periphery, which was not identified on CT and MR images. There were no islets and peripheral nerves throughout the mass. Finally, it was pathologically diagnosed as a solid-type pancreatic hamartoma. Based on radiological-pathological correlation, it was considered that the abundant fibrous stroma and both the widely distributed myxomatous periductal stroma and scattered edematous stroma corresponded with delayed homogenous enhancement on CT/MR images and high ADC value, respectively. Although it is difficult to distinguish solid-type pancreatic hamartoma from other solid pancreatic neoplasms including hypovascular NEN on the basis of usual radiological findings, the high ADC value reflecting the specific pathology may be helpful for the differential diagnosis.

Pancreas-contactless gastrectomy for gastric cancer prevents postoperative inflammation.

BACKGROUND: Pancreas-related complications after laparoscopic gastrectomy (LG) for gastric cancer can be fatal. We developed a gastrectomy procedure with no pancreas contact to prevent such complications and herein report the surgical outcomes. METHODS: We retrospectively reviewed 182 consecutive patients with gastric cancer who underwent LG at Kitasato University Hospital from January 2017 to January 2020. These patients were divided into a pancreas-contact group (C group) and pancreas-contactless group (CL group) for comparison of postoperative complications, and inflammatory parameters such as body temperature (BT) and C-reactive protein (CRP). RESULTS: Postoperative complications of CDc grade ≧ IIIa were significantly fewer in the CL group than in the C group [0/76 (0%) vs. 6/106 (5.7%), P = 0.035]. The median drain amylase (drain-AMY) on postoperative day 1 (POD1) was significantly lower in the CL group than in the C group (641 vs. 1162 IU/L, P = 0.02), as was BT at POD1 (37.4 °C vs. 37.7 °C, P = 0.04), the patient group with a BT above 37.5 °C at POD3 [5/76 (6.5%) vs. 18/106 (17%), P = 0.037], and those showing a CRP above 20.0 mg/dL at POD3 [5/76 (6.5%) vs. 20/106 (19%), P = 0.018]. CONCLUSIONS: Our technique to prevent pancreas contact during supra-pancreatic lymph node dissection during LG could minimize the inflammatory response and prevent further postoperative complications. Further large-scale, prospective studies are now required.

Activation of iNKT Cells Facilitates Liver Repair After Hepatic Ischemia Reperfusion Injury Through Acceleration of Macrophage Polarization.

Macrophage polarization is critical for liver tissue repair following acute liver injury. However, the underlying mechanisms of macrophage phenotype switching are not well defined. Invariant natural killer T (iNKT) cells orchestrate tissue inflammation and tissue repair by regulating cytokine production. Herein, we examined whether iNKT cells played an important role in liver repair after hepatic ischemia-reperfusion (I/R) injury by affecting macrophage polarization. To this end, we subjected male C57BL/6 mice to hepatic I/R injury, and mice received an intraperitoneal (ip) injection of α-galactosylceramide (α-GalCer) or vehicle. Compared with that of the vehicle, α-GalCer administration resulted in the promotion of liver repair accompanied by acceleration of macrophage differentiation and by increases in the numbers of Ly6Chigh pro-inflammatory macrophages and Ly6Clow reparative macrophages. iNKT cells activated with α-GalCer produced interleukin (IL)-4 and interferon (IFN)-γ. Treatment with anti-IL-4 antibodies delayed liver repair, which was associated with an increased number of Ly6Chigh macrophages and a decreased number of Ly6Clow macrophages. Treatment with anti-IFN-γ antibodies promoted liver repair, associated with reduced the number of Ly6Chigh macrophages, but did not change the number of Ly6Clow macrophages. Bone marrow-derived macrophages up-regulated the expression of genes related to both a pro-inflammatory and a reparative phenotype when co-cultured with activated iNKT cells. Anti-IL-4 antibodies increased the levels of pro-inflammatory macrophage-related genes and decreased those of reparative macrophage-related genes in cultured macrophages, while anti-IFN-γ antibodies reversed the polarization of macrophages. Cd1d-deficient mice showed delayed liver repair and suppressed macrophage switching, compared with that in wild-type mice. These results suggest that the activation of iNKT cells by α-GalCer facilitated liver repair after hepatic I/R injury by both IL-4-and IFN-γ-mediated acceleration of macrophage polarization. Therefore, the activation of iNKT cells may represent a therapeutic tool for liver repair after hepatic I/R injury.

Prospective study to validate the clinical utility of DNA diagnosis of peritoneal fluid cytology test in gastric cancer.

The clinical efficacy of DNA cytology test (CY) in gastric cancer (GC) has been retrospectively proposed using cancer-specific methylation of cysteine dioxygenase type 1 (CDO1). We confirmed the clinical utility of DNA CY in a prospective cohort. Four hundred GC samples were prospectively collected for washing cytology (UMIN000026191), and detection of the DNA methylation of CDO1 was assessed by quantitative methylation-specific PCR in the sediments. Endpoint was defined as the match rate between conventional CY1 and DNA CY1 (diagnostic sensitivity), and the DNA CY0 rate (diagnostic specificity) in pStage IA. DNA CY1 was detected in 45 cases (12.5%), while CY1 was seen in 31 cases (8.6%) of 361 chemotherapy-naïve samples, where the sensitivity and specificity of the DNA CY in the peritoneal solutions were 74.2% and 96.5%, respectively. The DNA CY was positive for 3.5/0/4.9/11.4/58.8% in pStage IA/IB/II/III/IV, respectively (P < .01). In the multivariate analysis, DNA CY1 was independently correlated with pathological tumor depth (pT) (P = .0012), female gender (P = .0099), CY1 (P = .0135), P1 (P = .019), and carcinoembryonic antigen (CEA) (P = .036). The combination of DNA CY1 and P factor nearly all covered the potential peritoneal dissemination (P1 and/or CY1 and/or DNA CY1) (58/61:95.1%). DNA CY1 had a significantly poorer prognosis than DNA CY0 in GC patients (P < .0001). DNA CY1 detected by CDO1 promoter DNA methylation has a great value to detect minimal residual disease of the peritoneum in GC clinics, representing poor prognosis as a novel single DNA marker.

Prediction of Efficacy of Postoperative Chemotherapy by DNA Methylation of CDO1 in Gastric Cancer.

BACKGROUND: CDO1 is a presumed tumor suppressor gene in human cancers, the expression of which is silenced by promoter DNA methylation. Moreover, CDO1 harbors functionally oncogenic aspects through modification of mitochondrial membrane potential. We recently proposed that this oncogenic feature allows for the prediction of the efficacy of postoperative chemotherapy in colon cancer. The present study aims to elucidate the efficacy of prediction of success of postoperative chemotherapy in advanced gastric cancer to improve the treatment strategy of patients. MATERIALS AND METHODS: Forced expression of CDO1 in gastric cancer cell lines was assessed using the JC-1 assay. Promoter DNA methylation was investigated in quantitative TaqMan methylation-specific polymerase chain reaction in 321 pathological stage II/III advanced gastric cancer cases treated by curative gastrectomy with or without postoperative chemotherapy. RESULTS: (1) Forced expression of CDO1 led to increased mitochondrial membrane potential, accompanied by augmented survival in gastric cancer cells under anaerobic conditions. These results suggest that CDO1-expressing cancer cells survive more easily in anaerobic lesions which are inaccessible to anticancer drugs. (2) Intriguingly, in cases with the highest CDO1 methylation (ranging from 15% to 40%), patients with postoperative chemotherapy showed significantly better survival than those with no postoperative chemotherapy. (3) A robust prognostic difference was observed that was explained by differential recurrences of distant metastasis (P = 0.0031), followed by lymph node (P = 0.0142) and peritoneal dissemination (P = 0.0472). CONCLUSIONS: The oncogenic aspects of CDO1 can be of use to determine patients with gastric cancer who will likely respond to treatment of invisible systemic dissemination by postoperative adjuvant chemotherapy.

Lymphangiogenesis and accumulation of reparative macrophages contribute to liver repair after hepatic ischemia-reperfusion injury.

Hepatic tissue repair plays a critical role in determining the outcome of hepatic ischemia-reperfusion (I/R) injury. Hepatic lymphatics participate in the clearance of dead tissues and contribute to the reparative process after acute hepatic injury; however, it remains unknown whether lymphangiogenesis in response to hepatic inflammation is involved in liver repair. Herein, we determined if hepatic lymphangiogenesis improves liver repair after hepatic I/R injury. Using a mouse model of hepatic I/R injury, we investigated hepatic lymphatic structure, growth, and function in injured murine livers. Hepatic I/R injury enhanced lymphangiogenesis around the portal tract and this was associated with increased expression of pro-lymphangiogenic growth factors including vascular endothelial growth factor (VEGF)-C and VEGF-D. Recombinant VEGF-D treatment facilitated liver repair in association with the expansion of lymphatic vessels and increased expression of genes related to the reparative macrophage phenotype. Treatment with a VEGF receptor 3 (VEGFR3) inhibitor suppressed liver repair, lymphangiogenesis, drainage function, and accumulation of VEGFR3-expressing reparative macrophages. VEGF-C and VEGF-D upregulated expression of genes related to lymphangiogenic factors and the reparative macrophage phenotype in cultured macrophages. These results suggest that activation of VEGFR3 signaling increases lymphangiogenesis and the number of reparative macrophages, both of which play roles in liver repair. Expanded lymphatics and induction of reparative macrophage accumulation may be therapeutic targets to enhance liver repair after hepatic injury.

Promoter DNA Hypermethylation of the Cysteine Dioxygenase 1 (CDO1) Gene in Intraductal Papillary Mucinous Neoplasm (IPMN).

BACKGROUND: Intraductal papillary mucinous neoplasm (IPMN) involves adenoma (IPMA), a precancerous lesion, cancer (IPMC) including high-grade dysplasia (HGD), and invasive carcinoma (IC). DNA markers of IPMN are required for detection of invasive disease, and cysteine dioxygenase 1 (CDO1) gene promoter hypermethylation is a potential candidate. However, it has never been investigated in the context of IPMN. PATIENTS AND METHODS: A total of 107 IPMN tumor tissues, including 41 IPMC and 66 IPMA, were studied. CDO1 promoter methylation was quantified using TaqMan quantitative methylation-specific polymerase chain reaction (qMSP) in patients with IPMN and other pancreatic cystic disorders after pancreatectomy. RESULTS: The methylation values (TaqMeth Vs) of CDO1 increased when noncancerous pancreas tissues were compared with IPMA and HGD (p < 0.0001). Among IPMC, the TaqMeth Vs in IC were not significantly higher than in HGD. The TaqMeth Vs of the solid tumors were higher than those of the cystic tumors (p = 0.0016), which were in turn higher than the corresponding noncancerous tissues (p < 0.0001). Prognostic analysis revealed that high TaqMeth Vs (≥ 14.1) resulted in a poorer prognosis than low TaqMeth Vs (< 14.1) (p < 0.0001). In other pancreatic cystic diseases, only malignant mucinous cystic neoplasm showed DNA hypermethylation of its promoter. A pilot study in pancreatic juice confirmed methylation in all IPMN samples but not in benign pancreatic diseases (p = 0.0277). CONCLUSIONS: CDO1 promoter hypermethylation is extremely specific to IPMN and may accumulate with IPMN tumor progression during the adenoma-carcinoma sequence. It might be a promising candidate as a diagnostic marker of pancreatic cystic diseases.

EP3 signaling in dendritic cells promotes liver repair by inducing IL-13-mediated macrophage differentiation in mice.

Macrophage plasticity is essential for liver wound healing; however, the mechanisms underlying macrophage phenotype switching are largely unknown. Dendritic cells (DCs) are critical initiators of innate immune responses; as such, they orchestrate inflammation following hepatic injury. Here, we subjected EP3-deficient (Ptger3-/- ) and wild-type (WT) mice to hepatic ischemia-reperfusion (I/R) and demonstrate that signaling via the prostaglandin E (PGE) receptor EP3 in DCs regulates macrophage plasticity during liver repair. Compared with WT mice, Ptger3-/- mice showed delayed liver repair accompanied by reduced expression of hepatic growth factors and accumulation of Ly6Clow reparative macrophages and monocyte-derived DCs (moDCs). MoDCs were recruited to the boundary between damaged and undamaged liver tissue in an EP3-dependent manner. Adoptive transfer of moDCs from Ptger3-/- mice resulted in impaired repair, along with increased numbers of Ly6Chigh inflammatory macrophages. Bone marrow macrophages (BMMs) up-regulated expression of genes related to a reparative macrophage phenotype when co-cultured with moDCs; this phenomenon was dependent on EP3 signaling. In the presence of an EP3 agonist, interleukin (IL)-13 derived from moDCs drove BMMs to increase expression of genes characteristic of a reparative macrophage phenotype. The results suggest that EP3 signaling in moDCs facilitates liver repair by inducing IL-13-mediated switching of macrophage phenotype from pro-inflammatory to pro-reparative.

Comprehensive Exploration to Identify Predictive DNA Markers of ΔNp63/SOX2 in Drug Resistance in Human Esophageal Squamous Cell Carcinoma.

BACKGROUND: OBP-801 is a novel histone deacetylase inhibitor being developed as an anticancer drug. In this study, we explored genes to predict drug resistance in human cancer. METHODS: OBP-801 resistance was assessed in 37 strains of human cancer cell lines. Expression microarrays harboring 54,675 genes were used to focus on candidate genes, which were validated for both functional and clinical relevance in esophageal squamous cell carcinoma (ESCC). RESULTS: OBP-801 is sensitive to esophageal, gastric, and thyroid cancer, and resistant to some esophageal and colorectal cancers. We therefore used ESCC to explore genes. Comprehensive exploration focused on ΔNp63/SOX2, which were both genetically and epigenetically overexpressed in ESCC. Genomic amplifications of ΔNp63/SOX2 were tightly correlated each other (r = 0.81). Importantly, genomic amplification of ΔNp63/SOX2 in the resected tumors after neoadjuvant chemotherapy was significantly associated with histological grade of response (G1). Forced expression of either of these two genes did not induce each other, suggesting that their functional relevances were independent and showed robust drug resistance in OBP-801, as well as 5-fluorouracil. Furthermore, ΔNp63 could exert a potent oncogenic potential. RNA interference of ΔNp63 supported its oncological properties, as well as drug resistance. CONCLUSION: Comprehensive exploration of genes involved in anticancer drug residence could identify critical oncogenes of ΔNp63/SOX2 that would predict chemotherapy response in ESCC.

Thromboxane A2 receptor signaling in endothelial cells attenuates monocrotaline-induced liver injury.

Sinusoidal obstruction syndrome (SOS) is a major complication of chemotherapy and hematopoietic stem cell transplantation. The early stage of SOS is characterized by liver sinusoidal endothelial cell (LSEC) injury accompanied by platelet aggregation. Thromboxane A2 (TxA2) induces platelet aggregation through the thromboxane prostanoid (TP) receptor. In this study, we explored the role of TP signaling in a monocrotaline (MCT)-induced mouse model of SOS. Relative to wild-type (WT) mice, TP-deficient (TP-/-) mice exhibited more severe MCT-liver injury, as indicated by elevated levels of alanine aminotransferase (ALT) and coagulative necrosis. Extensive accumulation of platelets in the liver was observed in both WT and TP-/- mice. TP expression co-localized with CD31-positive LSECs. MCT treatment caused LSEC destruction, concomitant with elevated expression of matrix metalloproteinases (MMPs) and adhesion molecules in WT mice, and LSEC damage was further exacerbated in TP-/- mice. Viability of isolated LSECs was lower in cells from TP-/- mice, whereas mRNA levels of MMPs and adhesion molecules were higher; U46619, a TxA2 agonist, reduced these levels in WT mice. These data suggest that TP signaling has no effect on platelet accumulation during MCT-induced liver injury, but instead prevents injury by suppressing LSEC damage.

Diagnostic potential of hypermethylation of the cysteine dioxygenase 1 gene (CDO1) promoter DNA in pancreatic cancer.

DNA markers for pancreatic ductal adenocarcinoma (PDAC) are urgently needed for detection of minimally invasive disease. The epigenetic relevance of the cysteine dioxygenase 1 gene (CDO1) has been never investigated in PDAC. Three studies, including cellular experiments, tissue validation, and pilot testing for pancreatic cytology, were carried out. Promoter DNA methylation value (MV) of CDO1 was quantified by quantitative methylation-specific PCR. CDO1 expression was consistent with its promoter DNA methylation in 7 PDAC cell lines. In 160 retrospectively collected primary PDAC tumor tissues, MV was significantly higher compared to the corresponding noncancerous pancreas (area under the receiver operating characteristic curve [AUC] = 0.97, P < .0001), and CDO1 hypermethylation was highly specific to PDAC tumor tissues. CDO1 hypermethylation group (MV over 19) was significantly associated with diverse prognostic factors in PDAC. Surprisingly, it was significantly higher in prospectively collected PDAC cytology samples (n = 37), including both pancreatic juice (n = 12) and endoscopic ultrasound-fine needle aspiration (EUS-FNA) cytology (n = 25) compared to pancreatic benign diseases (AUC = 0.96, P < .0001). Detection of PDAC was confirmed by DNA testing in 35 of 37 patients (95% sensitivity); thus, it was more sensitive than cytology (33%) or EUS-FNA cytology (88%). Promoter DNA methylation of CDO1 is extremely specific for PDAC tumors, and accumulates with PDAC tumor progression. It could be a definitive diagnostic marker of PDAC in pancreatic juice or EUS-FNA cytology.

Prediction of onset of remnant gastric cancer by promoter DNA methylation of CDO1/HOPX/Reprimo/E-cadherin.

BACKGROUND: Early detection of remnant gastric cancer (RGC) is required to reduce the risk of death, but long-term endoscopic surveillance is difficult after gastrectomy. In this study, data for the methylation status of 4 methylation genes (CDO1, HOPX, Reprimo, and E-cadherin) to predict the onset of RGC are presented. RESULTS: The 4 genes showed hypermethylation in RGC tumors in contrast to the corresponding non-cancerous mucosa tissues. The methylation level in the non-cancerous mucosa tissues of the initial surgery was obviously high in initial malignant disease for CDO1 (P = 0.0001), while in initial benign one for E-cadherin (P = 0.003). Promoter DNA methylation status in the remnant non-cancerous mucosa tissues together with the basic clinical data in turn predicted either initial malignant disease or initial benign disease with a high AUC score of 0.94, suggesting that methylation events are differentially recognized between the initial malignant and benign disease. We then finally confirmed that 4 genes hypermethylation of the non-cancerous tissues by biopsy prior to onset of RGC could predict terms until RGC occurred (P < 0.0001). METHODS: A total of 58 RGC patients were used to establish the model. The 4 genes promoter methylation were analyzed for DNA obtained from the patient's specimens using quantitative methylation specific polymerase chain reaction. CONCLUSIONS: This risk model would help provide guidance for endoscopic surveillance plan of RGC after gastrectomy.

Cancer-specific promoter DNA methylation of Cysteine dioxygenase type 1 (CDO1) gene as an important prognostic biomarker of gastric cancer.

BACKGROUND: There have been few available prognostic biomarkers in gastric cancer. We rigorously assessed the clinical relevance of promoter DNA methylation of Cysteine dioxygenase type 1 (CDO1) gene, a cancer-specific aberration, in human gastric cancer. METHODS: Quantitative CDO1 methylation value (TaqMeth V) was initially calculated in 138 gastric cancer patients operated in 2005, and its clinical significance was elucidated. As a subsequent expanded set, 154 gastric cancer patients with pathological stage (pStage) II / III with no postoperative therapy were validated between 2000 and 2010. RESULTS: (1) Median TaqMeth V of CDO1 gene methylation of gastric cancer was 25.6, ranging from 0 to 120.9. As pStage progressed, CDO1 TaqMeth V became higher (p < 0.0001). (2) The optimal cut-off value was determined to be 32.6; gastric cancer patients with high CDO1 gene methylation showed a significantly worse prognosis than those with low CDO1 gene methylation (p < 0.0001). (3) A multivariate cox proportional hazards model identified high CDO1 gene methylation (p = 0.033) as an independent prognostic factor. (4) The results were recapitulated in the expanded set in pStage III, where high CDO1 gene methylation group had a significantly worse prognosis than low CDO1 gene methylation group (p = 0.0065). Hematogenous metastasis was unique in pStage III with high CDO1 gene methylation (p = 0.0075). (5) Anchorage independent growth was reduced in several gastric cancer cell lines due to forced expression of the CDO1 gene, suggesting that abnormal CDO1 gene expression may represent distant metastatic ability. CONCLUSIONS: Promoter DNA hypermethylation of CDO1 gene was rigorously validated as an important prognostic biomarker in primary gastric cancer with specific stage.

Comprehensive Genetic Search to Clarify the Molecular Mechanism of Drug Resistance Identifies ASCL2-LEF1/TSPAN8 Axis in Colorectal Cancer.

BACKGROUND: Treatment-resistance genes limiting anticancer therapy have not been well clarified in colorectal cancer (CRC). We explored gene expression profiles to identify biomarkers for predicting treatment resistance to an anticancer drug in CRC. METHODS: Six CRC cell lines were treated with phenylbutyrate (PB). The gene expression profiles were then compared using microarrays (harboring 54,675 genes), and genes associated with PB resistance were identified. Candidate genes were functionally examined in cell lines and clinically validated for treatment resistance in clinical samples. RESULTS: Both DLD1 and HCT15 cells were PB resistant, while HCT116 cells were identified as PB sensitive. On microarray analysis, among the PB resistance-related genes, the expression of the genes ASCL2, LEF1, and TSPAN8 was clearly associated with PB resistance. PB-sensitive cells transfected with one of these three genes exhibited significant (P < 0.001) augmentation of PB resistance; ASCL2 induced expression of both LEF1 and TSPAN8, while neither LEF1 nor TSPAN8 induced ASCL2. RNA interference via ASCL2 knockdown made PB-resistant cells sensitive to PB and inhibited both genes. ASCL2 knockdown also played a critical role in sensitivity to treatment by 5-fluorouracil and radiotherapy in addition to PB. Finally, ASCL2 expression was significantly correlated with histological grade of rectal cancer with preoperative chemoradiation therapy. CONCLUSIONS: ASCL2 was identified as a causative gene involved in therapeutic resistance against anticancer treatments in CRC.

Critical relevance of genomic gains of PRL-3/EGFR/c-myc pathway genes in liver metastasis of colorectal cancer.

The PRL-3 gene is involved in the liver metastasis of colorectal cancer (CRC) and oncogene addiction to anticancer therapy. In the present study genomic gains in PRL-3 and its pathway genes, c-myc and EGFR, were investigated in order to determine their clinical relevance during metastatic formation in primary CRC and corresponding liver metastases. The genomic gain statuses of PRL-3, EGFR, and c-myc were investigated using quantitative polymerase chain reaction (qPCR) analysis in 35 samples of CRC and corresponding liver metastases. In the primary CRC specimens, genomic gains in PRL-3, c-myc, and EGFR were observed in 4, 4, and 13 cases, respectively. A genomic gain in one gene was observed in 18 cases, and these genomic gains were mutually exclusive. In the liver metastasis specimens, genomic gains were observed in 14, 8, and 13 cases, respectively. The copy numbers of PRL-3 and c-myc were significantly higher in the liver metastases than in the primary CRC specimens (P=0.03, P=0.009, respectively). A genomic gain in PRL-3 was the most frequent gain in the liver metastases (P=0.004) and was partially redundant with a c-myc genomic gain. EGFR genomic gains were consistent between the primary CRC and the liver metastases (P=0.0000008). In addition, a genomic gain in any of the 3 genes was observed in 23 cases (66%). Among the clinicopathological factors that were assessed, an EGFR genomic gain was significantly associated with tumour size in the primary CRC and the liver metastases (P=0.04). A c-myc genomic gain was also significantly associated with the v factor of the primary tumours in the liver metastases (P<0.01). In conclusion, the genomic copy numbers of PRL-3, c-myc and EGFR were frequently characterised by aberrations in genomic gain in liver metastases from CRC; thus, these gene statuses exhibit potential for the identification of patients who are likely to respond positively to anticancer therapies.

Clinical significance of cancer specific methylation of the CDO1 gene in small bowel cancer.

Although small bowel cancer (SBC) is extremely rare, its prognosis is poor, and molecular mechanism of the SBC development remains unclear. The aim of our study is to elucidate whether DNA methylation of the promoter region of the cancer-specific methylation gene, cysteine dioxygenase 1 (CDO1), contributes to the carcinogenic process in SBC. The study group comprised patients with 53 patients with SBC, 107 colorectal cancer (CRC), and other rare tumors of the small intestine such as 4 malignant lymphomas, 2 leiomyosarcomas, and 9 gastrointestinal stromal tumors. We analyzed the extent of methylation in each tissue using quantitative TaqMan methylation-specific PCR for CDO1. Significantly higher CDO1 methylation was observed in cancer tissues compared with non-cancerous mucosa of the small intestine (ROC = 0.96). Among the various clinicopathological factors, positive correlation of CDO1 methylation with tumor diameter was observed (R = 0.31, p = 0.03), and the CDO1 methylation level was a possible prognostic factor for relapse-free survival (p = 0.09). Compared with CRC, SBC had a significantly poorer prognosis (p = 0.007) and displayed a significantly higher CDO1 methylation level (p < 0.0001). Intriguingly, especially in pStage I/II, there were robust prognostic difference between SBC and CRC (p = 0.08 / p < 0.0001), which may reflect CDO1 methylation status (p = 0.02 / p = 0.001). Among small bowel tumors, CDO1 methylation in SBC was higher in order of malignant lymphoma, cancer, and leiomyosarcoma/GIST (p = 0.002) by ANOVA. The CDO1 gene shows extremely cancer-specific hypermethylation, and it can be a prognostic marker in SBC.

Dissected peripancreatic tissue margin is a critical prognostic factor and is associated with a K-ras gene mutation in pancreatic ductal adenocarcinoma.

We previously reported that the dissected pancreatic tissue margin (DPM) and the preoperative serum level of carbohydrate antigen 19-9 (preCA19-9) were independent prognostic factors in pancreatic ductal adenocarcinoma (PDAC). In the current study, the prognostic relevance of these factors, including their molecular associations, were validated. A total of 161 patients with PDAC underwent a pancreatectomy between 1986 and 2013, and a multivariate Cox proportional hazards model and a propensity score-based model validated the prognostic importance of DPM. The prognostic factors were compared with the mutation profiles of the K-ras and TP53 genes. Univariate prognostic analysis of disease-specific survival (DSS) demonstrated that DPM (P<0.0001), preCA19-9 (P<0.0001) and Union for International Cancer Control (UICC) stage (P<0.0001), were all significantly associated with poor outcome in PDAC. A multivariate Cox proportional hazards model confirmed that preCA19-9 (P=0.0002) and DPM (P=0.0002) remained as prognostic factors independent of UICC stage (P=0.0015). The combination of preCA19-9 and DPM to predict prognosis could accurately identify the long-term survivors of PDAC (70% 5-year DSS), and a multivariate logistic regression model identified that DPM was the most effective predictor of mortality. The prognostic relevance of DPM was also confirmed (P=0.0008) through propensity score-based background adjustment of patient bias. K-ras gene mutation was significantly associated with DPM (P=0.0002), and DPM-positive patients demonstrated recurrence of distant metastasis in 67% of cases. Therefore, DPM is a critical prognostic indicator in PDAC. In combination with preCA19-9, DPM may be useful to identify long-term survivors of PDAC. Furthermore, to the best of our knowledge, the current study was the first to discover that DPM can represent a poor prognosis based putatively on its association with the K-ras gene mutation.

Epigenetic Status of CDO1 Gene May Reflect Chemosensitivity in Colon Cancer with Postoperative Adjuvant Chemotherapy.

BACKGROUND: Cysteine dioxygenase type 1 (CDO1) acts as a tumor suppressor gene, and its expression is regulated by promoter DNA methylation in human cancer. The metabolic product mediated by CDO1 enzyme increases mitochondrial membrane potential (MMP), putatively representing chemoresistance. The aim of this study is to investigate the functional relevance of CDO1 gene in colon cancer with chemotherapy. PATIENTS AND METHODS: We investigated 170 stage III colon cancer patients for CDO1 methylation by using quantitative methylation-specific polymerase chain reaction (PCR). To elucidate the functional role of CDO1 gene in colorectal cancer (CRC) biology, we established cell lines that stably express CDO1 gene and evaluated chemosensitivity, MMP, and tolerability assay including anaerobic environment. RESULTS: Hypermethylation of CDO1 gene was an independent prognostic factor for stage III colon cancer on multivariate prognostic analysis. Surprisingly, patients with CDO1 hypermethylation exhibited better prognosis than those with CDO1 hypomethylation in stage III colon cancer with postoperative chemotherapy (P = 0.03); however, a similar finding was not seen in those without postoperative chemotherapy. In some CRC cell lines, forced expression of CDO1 gene increased MMP accompanied by chemoresistance and/or tolerance under hypoxia. CONCLUSION: CDO1 methylation may be a useful biomarker to increase the number of stage III colon cancer patients who can be saved by adjuvant therapy. Such clinical relevance may represent the functionally oncogenic property of CDO1 gene through MMP activity.

Methylated promoter DNA of CDO1 gene and preoperative serum CA19-9 are prognostic biomarkers in primary extrahepatic cholangiocarcinoma.

BACKGROUND: Promoter DNA methylation of Cysteine dioxygenase type1 (CDO1) gene has been clarified as a molecular diagnostic and prognostic indicator in various human cancers. The aim of this study is to investigate the clinical relevance of CDO1 methylation in primary biliary tract cancer (BTC). METHODS: CDO1 DNA methylation was assessed by quantitative methylation-specific PCR in 108 BTC tumor tissues and 101 corresponding normal tissues. BTC was composed of extrahepatic cholangiocarcinoma (EHCC) (n = 81) and ampullary carcinoma (AC) (n = 27). RESULTS: The CDO1 methylation value in the tumor tissues was significantly higher than that in the corresponding normal tissues (p<0.0001). The overall survival (OS) in EHCC patients with hypermethylation was poorer than those with hypomethylation (p = 0.0018), whereas there was no significant difference in AC patients. Multivariate analysis identified that CDO1 hypermethylation, preoperative serum CA19-9 and perineural invasion were independent prognostic factors in EHCC. The EHCC patients with CDO1 hypermethylation exhibited more dismal prognosis than those with hypomethylation even in low group of CA19-9 level (p = 0.0006). CONCLUSIONS: Our study provided evidence that promoter DNA methylation of CDO1 gene could be an excellent molecular diagnostic and prognostic biomarker in primary EHCC. The combination of CDO1 methylation and preoperative serum CA19-9 effectively enriched EHCC patients who showed the most dismal prognosis. These markers would be beneficial for clinical clarification of the optimal strategies in EHCC.