Tumor infiltrative pattern predicts sites of recurrence after curative gastrectomy for gastric cancer

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Background: In East Asia, the tumor infiltrative pattern (INF) has been routinely evaluated by hematoxylin and eosin-stained sections as a pathologic characteristic of surgically resected specimens. Methods: The infiltrative pattern of gastric cancer (GC) has been histopathologically classified as INFa (expansive growth), INFb (intermediate type) and INFc (infiltrative growth) according to the Japanese Classification of Gastric Carcinoma. The prognostic value and characteristics of the disease recurrence pattern for each INF type were assessed in 785 patients with various stages of GC and also in 243 patients with stages 2 and 3 GC. Results: Comparison of the overall survival experienced by patients independently of stage showed that INF was significantly associated with prognosis. Specifically, peritoneal metastasis was present in 91 % of stage 4 patients in the INFc group, whereas hepatic metastasis was present in 39 % of stage 4 patients in the INFa and INFb group. After curative gastrectomy of patients with stages 2 or 3 GC, INF was not significantly associated with survival. The prevalence of peritoneal recurrence was significantly higher in the INFc group than in the INFa and INFb group, whereas the prevalence of hepatic recurrence was significantly higher in the INFa and INFb group than in the INFc group. Multivariate analysis identified INFc as an independent risk factor for peritoneal recurrence after curative gastrectomy. The association of the INF type with the incidence of peritoneal recurrence was observed with all disease stages regardless whether the patient was given adjuvant chemotherapy or not. Conclusions: Evaluation of the INF type shows promise for its role as a predictor of postoperative recurrence sites in patients with GC.

The Charlson age comorbidity index to predict prognosis in patients with resected pancreatic cancer

495

Background: The Charlson age comorbidity index (CACI) is a useful measure of comorbidity to standardize the evaluation of surgical patients and has been reported to predict postoperative mortality in various cancers. Methods: A total of 379 patients who underwent R0/R1 resection for pancreatic cancer between 2003 and 2014 were enrolled in this study. According to the CACI, the age-adjusted comorbidity index was calculated by weighting individual comorbidities; CACI < 4 was considered the low-CACI group, whereas CACI ≥ 4 was considered the high-CACI group. The correlations between the CACI and clinicopathologic features and survival outcomes were statistically analyzed. Results: The patients with a high CACI were more likely to be old and had higher CA19-9 levels and lower incidences of portal vein resection and blood transfusion. The rate of patients who received chemotherapy was significantly higher in the low-CACI group than in the high-CACI group (87% vs. 69%, P< 0.0001). There was no difference in relapse-free survival (RFS) between the low- and high-CACI groups; however, the overall survival (OS) rate was significantly higher in the low-CACI group than in the high-CACI group ( P= 0.047). Multivariable analysis showed that a high CACI was a predictor of poor survival. In the high-CACI group, patients with high relative dose intensity (RDI) for postoperative adjuvant chemotherapy had significantly better RFS and OS than those with low RDI (both P< 0.0001). Conclusions: The CACI was a significant independent predictor of prognosis and compliance for postoperative adjuvant chemotherapy and could be clinically useful for decision-making in the treatment strategy for pancreatic cancer.

Clinical implication of inflammation-based prognostic score and perioperative nutrition control in pancreatic cancer

390

Background: Systemic inflammation and nutrition status are considered to influence survival in cancer patients. A variety of systemic inflammation-based prognostic scores have been explored; however, there has been no study to clarify which score could best reflect survival in resected pancreatic cancer patients. Methods: Between 2002 and 2016, 422 consecutive patients who underwent curative resection of pancreatic cancer were enrolled. The Glasgow Prognostic Score (GPS), modified GPS (mGPS), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), prognostic index (PI), and prognostic nutritional index (PNI) scores for each patients were calculated. Survival of each score was evaluated, and correlations between the score selected on the basis of the prognostic significance and various clinicopathological factors were analyzed. On the other hand, the nutrition markers (pre-albumin, transferrin, and retinol-binding protein) of 30 patients who received the enteral nutrition during the perioperative period were also evaluated. Results: In the analysis of the GPS, the median survival time (MST) was 29.4 months for score 0, 25.5 for score 1, and 17.7 for score 2 ( p< 0.001), and mGPS was also found to be significant ( p= 0.003). On the contrary, there were no significance in MST between other scores (NLR, PLR, PI, or PNI). Multivariate analysis revealed that lymph node metastasis, positive peritoneal washing cytology, and a GPS score of 2 were significant prognostic factors. There was also statistically significant correlation between the GPS score and tumor location (head), tumor size ( > 2.0cm), bile duct invasion, and duodenal invasion. In terms of nutrition status, the postoperative nutrition markers of 30 patients managed by enteral nutrition tended to recover earlier than 79 patients managed by intravenous nutrition. Conclusions: Our results demonstrated that the GPS could be an independent predictive marker and was superior to other inflammation-based prognostic scores in patients with resected pancreatic cancer. The results also suggested that perioperative nutrition support and infection control would improve survival of pancreatic cancer patients.

Clinical impact of sarcopenia on prognosis in pancreatic ductal adenocarcinoma

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Background: In the past, various prognostic factors in pancreatic ductal carcinoma (PDAC) have been identified, and there found to be not only tumor-specific clinicopathological factors but also individual patient characteristics. In particular, weight loss, muscle wasting and cachexia are hallmarks of PDAC that may be associated with depletion of both skeletal muscle and adipose tissue. Most notably, sarcopenia is defined to be degenerative loss of skeletal muscle mass that is quantifiable using cross sectional imaging computed tomography (CT) by measurement of psoas area and the muscle’s density. Furthermore, visceral adipose tissue loss also has been reported to associate with a poor survival among patients with PDAC. Methods: A total of 265 patients who underwent curative surgery for PDAC were examined in this study. The total skeletal muscle and fat tissue areas were evaluated in a single image obtained at the third lumber vertebra during a preoperative computed tomography (CT) scan. The patients were assigned to either the sarcopenia or non-sarcopenia group based on their skeletal muscle index (SMI) and classified into high visceral fat area (H-VFA) or low VFA (L-VFA) groups. The association of clinicopathological features and prognosis with the body composition were statistically analyzed. Results: There were 170 patients (64.2%) with sarcopenia. The median survival time (MST) was 23.7 months for sarcopenia patients and 25.8 months for patients without sarcopenia. The MST was 24.4 months for H-VFA patients and 25.8 months for L-VFA patients. However, sarcopenia patients with BMI ≥ 22 exhibited significantly poorer survival than patients without sarcopenia (MST: 19.2 vs. 35.4 months, P = 0.025). There was a significant difference between patients with and without sarcopenia who did not receive chemotherapy (5-year survival rate: 0% vs. 68.3%, P = 0.003). The multivariate analysis revealed that tumor size, positive dissected peripancreatic tissue margin, and sarcopenia were independent prognostic factors. Conclusions: Sarcopenia is an independent prognostic factor in PDAC patients with a BMI ≥ 22. Therefore, evaluating skeletal muscle mass may be a simple and useful approach for predicting patient prognosis.

Association of Inflammasome Components in Background Liver with Poor Prognosis After Curatively-resected Hepatocellular Carcinoma

BACKGROUND/AIM

Inflammasomes are multiprotein complexes that evoke key inflammatory cascades. The present study evaluated the influence of inflammasome component expression in non-tumorous tissue on postsurgical hepatocellular carcinoma (HCC) prognosis.

MATERIALS AND METHODS

The expressions of candidate genes were investigated using real-time quantitative reverse-transcription polymerase chain reaction in resected HCC cases. In order to identify potential prognostic factors, statistical analyses were performed for each gene.

RESULTS

The expression of nod-like receptor family, pyrin domain containing 3 (NLRP3), nod-like receptor family, CARD domain containing 4 (NLRC4), and absent in melanoma 2 (AIM2) was significantly higher in corresponding normal tissue (CN) compared to those in HCC. High expression of NLRP3, NLRC4, and caspase 1 (CASP1) in CN was significantly correlated with worse overall survival. Furthermore, multivariate analysis revealed that NLRP3 expression in CN greater than the median was an independent prognostic factor for poorer overall survival.

CONCLUSION

High expression of NLRP3, NLRC4, and CASP1 in background non-tumorous liver is significantly correlated with poor prognosis of patients after resection of HCC.

The protein arginine methyltransferase 5 promotes malignant phenotype of hepatocellular carcinoma cells and is associated with adverse patient outcomes after curative hepatectomy

The prognosis of advanced hepatocellular carcinoma (HCC) is dismal. Novel molecular targets for diagnosis and therapy is urgently required. This study evaluated expression and functions of the protein arginine methyltransferase 5 (PRMT5) in HCC. Using HCC cell lines, the expression levels of PRMT5 mRNA were determined using the quantitative real-time reverse-transcription polymerase chain reaction, and the effect of a small interfering PRMT5-siRNA on cell phenotype was evaluated. Further, PRMT5 expression was determined in 144 pairs of resected liver tissues to evaluate its clinical significance. Regardless of their differentiated phenotypes, nine HCC cell lines expressed different levels of PRMT5 mRNA. Inhibition of PRMT5 expression significantly decreased the proliferation, invasion, and migration of HCC cell lines. Although the level of PRMT5 mRNA was not influenced by patient's background liver status, it was significantly higher in HCC tissues than in the corresponding noncancerous tissues. High levels of PRMT5 mRNA in HCC tissues were significantly associated with advanced disease stage and adverse prognosis. In conclusion, our results indicate that PRMT5 may act as a putative oncogene in HCC and that the levels of PRMT5 mRNA represent a promising prognostic marker and a potential target of molecular therapy for HCC.

Matrix-assisted laser desorption/ionization imaging mass spectrometry reveals changes of phospholipid distribution in induced pluripotent stem cell colony differentiation

Induced pluripotent stem cells (iPSCs) are opening up new possibilities for medicine. Understanding the regulation of iPSC biology is important when attempting to apply these cells to disease models or therapy. Changes of lipid metabolism in iPSCs were investigated by matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF-IMS). Analysis revealed changes of the intensity and distribution of peaks at m/z 782.5 and 798.5 in iPSC colonies during spontaneous differentiation. Two phosphatidylcholines (PCs) were identified: C₄₄H₈₁NO₈P, PC(36:4)[M+H]+ at m/z 782.5 and C₄₂H₈₂NO₈P, PC(34:1)[M+K]+ at m/z 798.5. The intensity of PC(36:4) showed an inverse relation between undifferentiated and differentiated iPSC colonies. PC(34:1) displayed a diffuse distribution in undifferentiated iPSC colonies, while it showed a concentric distribution in differentiated iPSC colonies, and was localized at the border of the differentiated and undifferentiated areas or the border between undifferentiated iPSC and feeder cells. These findings suggested that the distribution of lipids changes during the growth and differentiation of iPSCs and that MALDI-TOF-IMS was useful for analyzing these changes. PC(36:4) might play a role in maintaining pluripotency, while PC(34:1) might play a role in the differentiation and spread of iPSCs. Graphical Abstract MALDI Imaging for phosphatidylcholine distribution changes during sponteneous differentiaton of induced pluiripotent stem cells colonies.

Streptozotocin induces neurite outgrowth via PI3K-Akt and glycogen synthase kinase 3β in Neuro2a cells

Streptozotocin (STZ), a naturally occurring chemical, is toxic to the various kinds of cells such as insulin-producing beta cells. However, the beneficial effect of STZ on neuronal cells such as neurite outgrowth-inducing activity has been unknown. In this study, we examined the effect of STZ on neurite outgrowth in mouse neuronal Neuro2a cells. STZ (0.01 mM~5 mM) exerted remarkable neurite outgrowth-inducing activity in Neuro2a cells in a concentration dependent manner. STZ also had the same neurite outgrowth-inducing activity as that of retinoic acid (RA), which is well known neurite outgrowth inducer. As with the result of RA treatment, STZ administration increased MAP2-positive cells. The MAP2-positive cells reflect neurite outgrowth-induced cells. STZ (0.01 mM~5 mM) did not induce cell death, but significantly decreased cell proliferation. The serine/threonine kinase Akt, a downstream target of phosphatidylinositol-3 kinase (PI3K), was transiently phosphorylated at Ser473 and at Thr303 by STZ (5 mM) administration. Glycogen synthase kinase 3β (GSK3β), which has been reported to be inactivated by Akt, was also transiently phosphorylated at Ser9 by STZ (5 mM) administration. In addition, a blocker of PI3K, LY294002 (10 μM), significantly attenuated STZ-induced neurite outgrowth. These results suggest that STZ induces neurite outgrowth via activation of PI3K-Akt signaling pathway and GSK3β inhibition.

FAM46C Serves as a Predictor of Hepatic Recurrence in Patients with Resectable Gastric Cancer

BACKGROUND

Gastric cancer (GC) relapse can occur even if curative resection is achieved. Biomarkers predicting recurrence are needed to provide appropriate postoperative surveillance and perioperative therapeutic strategy.

METHODS

A global expression profiling was performed using tissues from GC patients with synchronous liver-confined metastasis. Family with sequence similarity 46, member C (FAM46C), was identified as a candidate biomarker. mRNA expression analysis, direct nucleotide sequencing, bisulfite sequencing and copy number assays for FAM46C were performed with eleven GC cell lines. Expression levels of FAM46C in primary GC tissues from 129 patients who underwent curative GC resection were determined and correlated with clinicopathological factors, including postoperative outcome.

RESULTS

Levels of FAM46C mRNA differed among GC cell lines. Point mutations in FAM46C were detected in five GC cell lines accompanied with reduced FAM46C transcription. No hypermethylation was found in the promoter region of FAM46C. Copy number alterations were found in six GC cell lines with differing FAM46C transcription levels. Reduced FAM46C mRNA expression levels were detected in 117 (91 %) GC specimens compared with adjacent noncancerous tissues. Low FAM46C expression levels were significantly associated with larger macroscopic GC tumor sizes. The low FAM46C expression group was likely to have shorter disease-free survival than the high group and low FAM46C level was identified as an independent risk factor for recurrence after curative resection. FAM46C expression levels were low in all cases that were later found to have hepatic recurrence.

CONCLUSIONS

Reduced GC expression of FAM46C is a potential biomarker to predict hepatic recurrence after curative gastrectomy.

Prognostic significance of AKR1B10 gene expression in hepatocellular carcinoma and surrounding non-tumorous liver tissue

When assessing outcome in hepatocellular carcinoma (HCC), it is important to consider prognostic factors in background non-tumorous liver tissue as well as in the tumor, since multiple occurrence is associated with background liver status such as hepatitis. The current study aimed to elucidate molecular prognostic predictors that have an association with HCC background non-tumorous tissue. Microarray expression profiling identified aldo-keto reductase family 1, member B10 (AKR1B10) as a putative non-tumorous prognostic factor, and AKR1B10 gene expression was investigated in 158 curatively resected HCC cases by reverse transcription-quantitative polymerase chain reaction. AKR1B10 expression (AKR1B10 value/GAPDH value × 1,000) was significantly higher in tumor tissue (median, 9.2200; range, 0.0003-611.0200; n=158) than in the corresponding non-tumorous tissue (median, 0.5461; range, 0.0018-69.0300; n=158) (P<0.001). When the samples were grouped according to AKR1B10 expression in tumor tissue relative to non-tumorous tissue, tumor<non-tumorous expression (n=26) significantly correlated with poor recurrence-free survival (P=0.0074) and overall survival (OS) (P<0.0001), and was an independent prognostic factor for OS (P=0.0011) in a multivariate analysis. The ratio of AKR1B10 messenger RNA levels in HCC and corresponding non-tumorous tissues may predict prognosis after curative hepatectomy, with low expression in HCC tissue relative to non-tumorous tissue indicative of poor prognosis.

Prognostic relevance of SAMSN1 expression in gastric cancer

The prognosis for patients with advanced gastric cancer (GC) remains poor. The identification of biomarkers relevant to the recurrence and metastasis of GC is advantageous for stratifying patients and proposing novel molecular targets. In the present study the oncological roles of SAM domain, SH3 domain and nuclear localization signals 1 (SAMSN1), a mediator of B-cell function, were elucidated in GC. The expression and methylation status of SAMSN1 were investigated in a panel of 11 GC cell lines. Immunohistochemical staining was performed to determine the pattern of SAMSN1 protein expression in gastric tissues. The prognostic impact of SAMSN1 expression was determined by analyzing 175 pairs of surgically resected gastric tissues. A marked decrease in the level of SAMSN1 mRNA was detected in 8/11 GC cell lines as compared with that in a non-transformed intestinal epithelium cell line (FHs 74) without promoter methylation. The mean expression level of SAMSN1 mRNA was reduced in GC tissues compared with normal adjacent tissues, an observation that was independent of tumor differentiation. The pattern of SAMSN1 protein expression was significantly correlated with that of SAMSN1 mRNA. Low SAMSN1 mRNA expression was significantly associated with tumor size (>60 mm; P=0.026) and shorter overall survival times (P=0.004). Multivariate analysis identified low SAMSN1 mRNA expression as an independent prognostic factor for poor overall survival (hazard ratio, 1.80; 95% confidence interval, 1.07-3.05; P=0.025). The difference in survival between the low and high SAMSN1 expression groups was more marked in patients with stage II/III GC compared to those with stage IV GC. In patients with stage II/III GC who underwent curative surgery, low SAMSN1 expression was associated with reduced disease free survival times. The results of the present study indicate that downregulation of SAMSN1 transcription may affect the progression and recurrence of GC, and therefore may represent a novel biomarker of GC.

StarD7 Protein Deficiency Adversely Affects the Phosphatidylcholine Composition, Respiratory Activity, and Cristae Structure of Mitochondria

Phosphatidylcholine (PC) is a major phospholipid of mitochondria, comprising 40-50% of both the outer and the inner membranes. However, PC must be imported from its production organelles because mitochondria lack the enzymes essential for PC biosynthesis. In a previous study, we found that StarD7 mediates the intracellular transfer of PC to mitochondria. Therefore, in this study, we analyzed the contribution of StarD7 to the maintenance of mitochondrial phospholipid content and function using siRNA-mediated knockdown and knock-out (KO) of the StarD7 gene in HEPA-1 cells. Real time analysis of respiratory activity demonstrated that the oxygen consumption rate and activity of mitochondrial complexes were impaired in StarD7-KD cells. To confirm these results, we established StarD7-KO HEPA-1 cells by double nicking using CRISPR/Cas9n. As expected, StarD7-KD and -KO cells showed a significant reduction in mitochondrial PC content. The ATP level and growth rate of KO cells were notably lower compared with wild-type cells when cultured in glucose-free galactose-containing medium to force cells to rely on mitochondrial ATP production. In KO cells, the level of the MTCO1 protein, a primary subunit of complex IV, was reduced without a concomitant decrease in its mRNA, but the level was restored when StarD7-I was overexpressed. StarD7-KO cells showed impaired formation of the mitochondrial supercomplexes and exhibited a disorganized cristae structure, with no changes in optic atrophy 1 protein. These findings indicate that StarD7 plays important roles in maintaining the proper composition of mitochondrial phospholipids as well as mitochondrial function and morphogenesis.

Quantitative evaluation of pancreatic tumor fibrosis using shear wave elastography

BACKGROUND & AIMS

There is no established non-invasive method for diagnosis of pancreatic fibrosis. Shear wave elastography (SW-EG) may be a candidate for this purpose. The aims of this study were to assess the reproducibility of SW-EG in the normal imaging pancreas (Phase 1) and to evaluate the diagnostic performance of SW-EG for pancreatic fibrosis classified histologically (Phase 2).

METHODS

Phase 1: This included 127 cases that underwent SW-EG of the normal imaging pancreas. SW-EG was measured at least five times in the pancreatic parenchyma and the median of repeated measurements was defined as the pancreatic elastic modulus (PEM). Phase 2: This included 53 cases that underwent SW-EG of the pancreatic parenchyma preoperatively and in which pancreas parenchyma were evaluated histologically. Histological fibrosis was graded in 4 stages: normal, mild, moderate, and severe.

RESULTS

Phase 1: Median PEM in the head, body, and tail of the pancreas were 3.23, 3.17, and 2.91 kPa, respectively, with no significant difference among regions (P = 0.554). The intraclass correlation coefficient showed good reproducibility (ρ = 0.71) after 5 measurements. Phase 2: There was a significant positive correlation between PEM and the histological pancreatic fibrosis stage (r_s = 0.63, P < 0.001). Areas under the receiver operating characteristic curve for the accuracy of SW-EG for diagnosis of pancreatic fibrosis were 0.85 (≥mild), 0.84 (≥moderate), and 0.87 (severe).

CONCLUSION

SW-EG can be used to determine the stage of pancreatic fibrosis non-invasively with high accuracy and reproducibility.

Systemic hemodynamics in advanced cirrhosis: Concerns during perioperative period of liver transplantation

Advanced liver cirrhosis is usually accompanied by portal hypertension. Long-term portal hypertension results in various vascular alterations. The systemic hemodynamic state in patients with cirrhosis is termed a hyperdynamic state. This peculiar hemodynamic state is characterized by an expanded blood volume, high cardiac output, and low total peripheral resistance. Vascular alterations do not disappear even long after liver transplantation (LT), and recipients with cirrhosis exhibit a persistent systemic hyperdynamic state even after LT. Stability of optimal systemic hemodynamics is indispensable for adequate portal venous flow (PVF) and successful LT, and reliable parameters for optimal systemic hemodynamics and adequate PVF are required. Even a subtle disorder in systemic hemodynamics is precisely indicated by the balance between cardiac output and blood volume. The indocyanine green (ICG) kinetics reflect the patient’s functional hepatocytes and effective PVF, and PVF is a major determinant of the ICG elimination constant (kICG) in the well-preserved allograft. The kICG value is useful to set the optimal PVF during living-donor LT and to evaluate adequate PVF after LT. Perioperative management has a large influence on the postoperative course and outcome; therefore, key points and unexpected pitfalls for intensive management are herein summarized. Transplant physicians should fully understand the peculiar systemic hemodynamic behavior in LT recipients with cirrhosis and recognize the critical importance of PVF after LT.

Proposal of the Coagulation Score as a Predictor for Short-Term and Long-Term Outcomes of Patients with Resectable Gastric Cancer

BACKGROUND

Systemic hemostasis and thrombosis activation has been implicated in tumor progression and metastasis. This study aimed to investigate the use of coagulation factors as a novel prediction method for postoperative outcomes after curative gastrectomy in patients with stage II/III gastric cancer (GC).

METHODS

Overall, 126 patients with stage II/III GC who underwent gastrectomy between May 2003 and February 2016 were eligible for inclusion in the study. We retrospectively evaluated the predictive value of preoperative platelet count and plasma fibrinogen and d-dimer levels, and coagulation score (0: fibrinogen and d-dimer both below upper limits; 1: either fibrinogen or d-dimer over upper limits; 2: both fibrinogen and d-dimer over upper limits) for short- and long-term outcomes.

RESULTS

Postoperative complications were significantly more frequent in patients with elevated preoperative d-dimer levels compared with those with normal d-dimer levels (26 vs. 10 %; p = 0.032). The prevalence of postoperative complications showed a stepwise increase in proportion to the coagulation score. Patients with a coagulation score of 2 had significantly larger tumors (p = 0.013) and significantly greater intraoperative blood loss (p = 0.004) than those who scored 0 or 1. Coagulation score showed the highest values distinguished high-risk patients in overall and disease-free survival, and a coagulation score of 2 was an independent prognostic factor for recurrence. Patients with a coagulation score of 2 experienced a significantly higher prevalence of liver metastasis as an initial recurrence than those who scored 0 or 1 (p = 0.019).

CONCLUSIONS

The coagulation score is a simple and promising predictor for postoperative complications and recurrence after gastrectomy in stage II/III GC patients.

Detection of serum melanoma-associated antigen D4 in patients with squamous cell carcinoma of the esophagus

Despite improvements in surgical techniques, perioperative management, and multidisciplinary therapy, treatment outcomes of patients with esophageal squamous cell carcinoma (ESCC) remain poor. Therefore, development of novel molecular biomarkers, which either predict patient survival or become therapeutic targets, is urgently required. In the present study, to facilitate early detection of ESCC and predict its clinical course, we investigated the relationship of the serum level of melanoma-associated antigen (MAGE)-D4 to patients' clinicopathological characteristics. Using quantitative real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assays, we determined the levels of MAGE-D4 mRNA and protein in cell lysates and conditioned medium of cultures, respectively, of nine ESCC cell lines. Further, we determined MAGE-D4 levels in serum samples collected from 44 patients with ESCC who underwent radical esophagectomy without neoadjuvant therapy as well as from 40 healthy volunteers. Samples of conditioned medium and cell lysates contained comparable levels of MAGE-D4 that correlated closely with the levels of MAGE-D4 mRNA. Preoperative MAGE-D4 levels in the sera of 44 patients with ESCC, which varied from 0 to 2,354 pg/mL (314 ± 505 pg/mL, mean ± standard deviation), were significantly higher compared with those of healthy volunteers. By setting the cutoff at the highest value for healthy volunteers (50 pg/mL), the MAGE-D4-positive group of patients was more likely to have shorter disease-specific and disease-free survival compared with those of the MAGE-D4-negative group, although the differences were not statistically significant. Our results indicate that the elevation of preoperative serum MAGE-D4 levels in some patients with ESCC was possibly caused by excess production of MAGE-D4 by tumor cells followed by its release into the circulation. Clinical implications of serum MAGE-D4 levels should be validated in a large population of patients with ESCC.

Salvage pharyngolaryngectomy with total esophagectomy following definitive chemoradiotherapy

Historically, total pharyngolaryngectomy with total esophagectomy has been the standard radical surgical treatment for synchronous cancer of the thoracoabdominal esophagus and pharyngolaryngeal region, and for cancer of the cervical esophagus that has invaded as far as the thoracic esophagus. Although definitive chemoradiotherapy that enables preservation of the larynx has often been the first choice of treatment for cancers involving the cervical esophagus, total pharyngolaryngectomy with total esophagectomy is required as a salvage therapy for cases involving failure of complete remission or locoregional recurrence after chemoradiotherapy. However, salvage esophageal surgery after definitive high-dose chemoradiotherapy is generally associated with high morbidity and mortality. The aim of this study was to examine the short-term outcome of salvage total pharyngolaryngectomy with total esophagectomy. From 2001 to 2014, nine patients underwent salvage total pharyngolaryngectomy with total esophagectomy at the Department of Gastroenterological Surgery, Nagoya University. The mortality and morbidity rates were high at 22% and 89%, respectively. Four patients (44%) developed tracheal necrosis, which in two patients eventually led to lethal hemorrhage. Salvage total pharyngolaryngectomy with total esophagectomy is an uncommon and highly demanding surgical procedure that should be carefully planned and conducted in selected centers of excellence. Measures must be taken to preserve the tracheal blood supply, thus avoiding fatal complications.

Abstract 5025: PAX5 methylation as a novel biomarker of esophageal cancer for both potential tumor malignancy and cisplatin sensitivity

Therapeutic strategy of esophageal cancer largely depends on histopathological assessment just like tumor differentiation and TNM stage. In order to make appropriate choice for individual case, we have to pay attention to background molecular characteristics about tumor malignancy or chemotherapy sensitivity.

In order to find extremely tumor-specific marker of esophageal cancer, we picked several methylation markers from what we previously used in the research of head and neck cancer, which has the same background of smoking and alcohol and the same tissue-type. As a result, we identified PAX5 gene methylation as a very tumor-specific marker also in surgically resected 90 esophageal cancer cases. Then, we continued to examine PAX5 expression, function and other functions.

Quantitative MSP (QMSP) assay revealed significantly higher methylation score (100x[PAX5 QMSP]/[ACTB QMSP]) in tumor tissues (16.2±2.4) than in normal tissues (0.4±0.2) (P&lt;0.001, Mann-Whitney U test). Also, 77/90 (85.6%) of these cases showed tumor-specific QMSP elevation. Similarly, all 9 esophageal cancer cell lines (TE1, TE2, TE3, NUEC1, NUEC2, NUEC3, T.T, T.Tn and WSSC) showed high QMSP scores over 10. The inverse correlation of PAX5 methylation and expression was confirmed by Quantitative RT-PCR of clinical samples and 5-aza-dC treated cell lines. PAX5 downregulated cases indicated significantly poor overall survival (P = 0.037, log-rank test). For functional analysis, we examined WST1 assay and BrdU assay using ectopically PAX5 knock down NUEC1 cell line, which has secondly high PAX5 expression. The result showed significantly high cell proliferation and cell cycle acceleration. Since PAX5 is reported to bind p53 promoter and regulate its expression, we hypothesized epigenetically downregulated PAX5 might affect p53 expression and therefore cisplatin sensitivity of esophageal cancer. Actually, PAX5 downregulated NUEC1 cell line acquired significantly cisplatin-resistant character after siRNA transfection. Moreover, among postoperatively cisplatin-treated cases (25 cases), PAX5 hyper-methylated clinical cases (n = 6) demonstrated significantly worse survival than PAX5 hypo-methylated cases (n = 19) (P = 0.002, log-rank test). We also surveyed another downstream mechanism of PAX5 dysregulation. Human Cancer Pathway Finder PCR Assay identified three key molecules including SLC2A1 (Fold change: 4.6), CCL2 (12.5) and IGFBP5 (-5.0).

Epigenetic inactivation of PAX5 gene may affects malignant potential of esophageal cancers and cisplatin-based chemotherapy through p53 dysregulation or other carcinogenic pathways. It could be utilized for planning individual multidisciplinary therapy.

Citation Format: Keisuke Kurimoto, Masamichi Hayashi, Masahiko Koike, Mitsuro Kanda, Yoko Nishikawa, Naoki Iwata, Yukiko Niwa, Hideki Takami, Daisuke Kobayashi, Chie Tanaka, Suguru Yamada, Goro Nakayama, Hiroyuki Sugimoto, Michitaka Fujiwara, Tsutomu Fujii, Guerrero-Preston Rafael, Yasuhiro Kodera. PAX5 methylation as a novel biomarker of esophageal cancer for both potential tumor malignancy and cisplatin sensitivity. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5025.

Age-related changes in pancreatic elasticity: When should we be concerned about their effect on strain elastography?

BACKGROUND

Ultrasound strain elastography is one of the useful methods for evaluating pancreatic lesions. During aging, several pancreatic parenchymal changes occur that may interfere with the interpretation of the ultrasound images. We studied age-related changes in pancreatic elasticity using transabdominal ultrasound strain elastography in subjects without known pancreatic disease.

METHODS

This study was conducted at Nagoya University Hospital, which is an academic medical center, and included 102 subjects (66 women and 39 men) aged 20-85years (mean 58.6±17.5) who underwent transabdominal ultrasonography for screening and follow-up for non-pancreatic diseases. Strain elastography of the pancreas was performed, and the results were subjected to quantitative strain histogram analysis. The correlations of age with four elastographic parameters (Mean, Standard deviation, Skewness, and Kurtosis) and other findings, including hyperechoic pancreas, hyperechoic liver, and diabetes, were evaluated.

RESULTS

There was a significant correlation between increasing age and elastographic parameters such as the Mean (P=0.004), Skewness (P=0.007), and Kurtosis (P=0.03), and these differences became significant after the age of 40. The prevalence of hyperechoic pancreas increased with age (P<0.001), and the Means were lower in those with hyperechoic pancreas (P=0.004) and a higher body mass index (BMI, P=0.008). No significant correlations with diabetes, hyperechoic liver, or elastographic parameters were demonstrated.

CONCLUSION

Strain elastography demonstrated elastographic changes in the pancreas with aging that included a decreasing Mean and increasing Skewness and Kurtosis after the age of 40. The prevalence of pancreatic hyperechogenicity increased, and the pancreatic hyperechogenicity was significantly negatively correlated with the Mean.

The significance of relative dose intensity in adjuvant chemotherapy of pancreatic ductal adenocarcinoma-including the analysis of clinicopathological factors influencing relative dose intensity

Recently, it has been reported that the relative dose intensity (RDI) of adjuvant chemotherapy (AC) influences survival in various cancers, but there are very few reports about RDI in pancreatic ductal adenocarcinoma (PDAC). The optimal timing for initiation of AC for PDAC also remains unknown. The aim of this study was to identify the significance of RDI and the time interval between surgery and initiation of AC on survival of patients with PDAC. Clinicopathological factors that affect RDI were also investigated.A total of 311 consecutive PDAC patients who underwent curative resection between May 2005 and January 2015 were enrolled. Patients who underwent neoadjuvant chemoradiation, had UICC stage IV disease, or had early recurrences within 6 months were excluded, and the remaining 168 cases were analyzed.Patients with RDIs ≥80% (n = 79) showed significantly better overall survival (OS) compared to patients with RDIs <80% (n = 55) (median survival time (MST): 45.6 months, 26.0 months, P < 0.001). Patients with no AC (n = 34) showed the worst OS (MST: 20.8 months). Whether the AC was initiated earlier or later than 8 weeks after surgery did not influence survival, either in patients with RDIs ≥80% (P = 0.79) or in those with <80% (P = 0.73). Patients in the S-1 monotherapy group (n = 49) showed significantly better OS than patients in the gemcitabine monotherapy group (n = 51) (MST: 95.0 months, 26.0 months, respectively; P = 0.001). Univariate analysis conducted after adjusting for the chemotherapeutic drug used identified several prognostic factors; male gender (P = 0.01), intraoperative blood transfusion (P = 0.005), lymph node metastasis (P = 0.03), and postoperative WBC count (P = 0.03). Multivariate analysis identified intra-plus postoperative blood transfusion (P = 0.002) and high postoperative platelet-to-lymphocyte ratios (PLR) (P = 0.04) as independent predictors of poor RDI.Efforts to maintain RDI had a greater impact on survival than the struggle to start AC early after surgery. Intra-plus postoperative blood transfusion and a high postoperative PLR could be predictive markers of reduced RDI in AC of PDAC patients. Avoidance of perioperative blood transfusions where possible and nutritional support during the perioperative period could maintain adequate RDI and may lead to improved long-term outcome.

Neurotrophin Receptor-Interacting Melanoma Antigen-Encoding Gene Homolog is Associated with Malignant Phenotype of Gastric Cancer

BACKGROUND

Identification of novel molecules implicated in the malignancy of gastric cancer (GC) is key to the development of personalized treatments and the improvement of patient outcome. Neurotrophin receptor-interacting melanoma antigen-encoding protein (NRAGE) regulates apoptosis and metastasis via interactions with various genes. This study aimed to evaluate the function and clinical significance of NRAGE in GC.

METHODS

The expression of NRAGE and its putative interacting genes apoptosis antagonizing transcription factor (AATF), p75 neurotrophin receptor (p75NTR), and proliferating cell nuclear antigen (PCNA) were determined in GC cell lines using reverse transcription-polymerase chain reaction (RT-PCR). The effect of NRAGE knockdown by small interfering RNA (siRNA) on GC cell behavior also was evaluated. In addition, NRAGE expression was determined in 179 pairs of resected gastric tissues.

RESULTS

Expression of NRAGE mRNA positively correlated with that of AATF, and NRAGE knockdown significantly decreased the proliferation, migration, and invasion of GC cells. The mean level of NRAGE mRNA expression was significantly higher in GC tissues than in corresponding adjacent normal tissues. The expression patterns of NRAGE mRNA and protein were closely correlated. A stepwise elevation in NRAGE mRNA expression in GC tissues was observed with increasing Union for International Cancer Control (UICC) stage. High NRAGE expression in GCs was associated with shortened recurrence-free survival and identified as an independent prognostic factor (hazard ratio, 1.83; 95 % CI, 1.12-3.02, p = 0.017).

CONCLUSIONS

The results indicate that NRAGE represents a putative oncogene associated with a malignant phenotype of GC. In GC, NRAGE may serve as a predictive biomarker and a target of molecular therapy.

Protein arginine methyltransferase 5 is associated with malignant phenotype and peritoneal metastasis in gastric cancer

Identification of novel gastric cancer (GC)-related molecules is necessary to improve management of patients with GC in both diagnostic and therapeutic aspects. The aim of the present study was to determine whether protein arginine methyltransferase 5 (PRMT5) acts as an oncogene in the progression of GC and whether it serves as a novel diagnostic marker and therapeutic target. We conducted global expression profiling of GC cell lines and RNA interference experiments to evaluate the effect of PRMT5 expression on the phenotype of GC cells. We analysed tissues of 179 patients with GC to assess the association of PRMT5 mRNA levels with clinicopathological factors. Differential expression of PRMT5 mRNA by GC cell lines correlated positively with the levels of GEMIN2, STAT3 and TGFB3. PRMT5 knockdown reduced the proliferation, invasion and migration of a GC cell line. PRMT5 mRNA levels were significantly higher in GC tissues than the corresponding adjacent normal tissues and were independent of tumour depth, differentiation and lymph node metastasis. High PRMT5 expression was an independent risk factor of positive peritoneal lavage cytology (odds ratio 3.90, P=0.003) and decreased survival. PRMT5 enhances the malignant phenotype of GC cell lines and its expression in gastric tissues may serve as a biomarker for patient stratification and a potential target of therapy.

Improvement of gemcitabine sensitivity of p53-mutated pancreatic cancer MiaPaCa-2 cells by RUNX2 depletion-mediated augmentation of TAp73-dependent cell death

Pancreatic cancer exhibits the worst prognostic outcome among human cancers. Recently, we have described that depletion of RUNX2 enhances gemcitabine (GEM) sensitivity of p53-deficient pancreatic cancer AsPC-1 cells through the activation of TAp63-mediated cell death pathway. These findings raised a question whether RUNX2 silencing could also improve GEM efficacy on pancreatic cancer cells bearing p53 mutation. In the present study, we have extended our study to p53-mutated pancreatic cancer MiaPaCa-2 cells. Based on our current results, MiaPaCa-2 cells were much more resistant to GEM as compared with p53-proficient pancreatic cancer SW1990 cells, and there existed a clear inverse relationship between the expression levels of TAp73 and RUNX2 in response to GEM. Forced expression of TAp73α in MiaPaCa-2 cells significantly promoted cell cycle arrest and/or cell death, indicating that a large amount of TAp73 might induce cell death even in the presence of mutant p53. Consistent with this notion, overexpression of TAp73α stimulated luciferase activity driven by p53/TAp73-target gene promoters in MiaPaCa-2 cells. Similar to AsPC-1 cells, small interfering RNA-mediated knockdown of RUNX2 remarkably enhanced GEM sensitivity of MiPaCa-2 cells. Under our experimental conditions, TAp73 further accumulated in RUNX2-depleted MiaPaCa-2 cells exposed to GEM relative to GEM-treated non-silencing control cells. As expected, silencing of p73 reduced GEM sensitivity of MiPaCa-2 cells. Moreover, GEM-mediated Tyr phosphorylation level of TAp73 was much more elevated in RUNX2-depleted MiaPaCa-2 cells. Collectively, our present findings strongly suggest that knockdown of RUNX2 contributes to a prominent enhancement of GEM sensitivity of p53-mutated pancreatic cancer cells through the activation of TAp73-mediated cell death pathway, and also provides a promising strategy for the treatment of patients with pancreatic cancer bearing p53 mutation.

Silicon nanocrystal-noble metal hybrid nanoparticles

We report a novel and facile self-limiting synthesis route of silicon nanocrystal (Si NC)-based colloidally stable semiconductor-metal (gold, silver and platinum) hybrid nanoparticles (NPs). For the formation of hybrid NPs, we employ ligand-free colloidal Si NCs with heavily boron (B) and phosphorus (P) doped shells. By simply mixing B and P codoped colloidal Si NCs with metal salts, hybrid NPs consisting of metal cores and Si NC shells are spontaneously formed. We demonstrate the synthesis of highly uniform and size controllable hybrid NPs. It is shown that codoped Si NCs act as a reducing agent for metal salts and also as a protecting layer to stop metal NP growth. The process is thus self-limiting. The development of a variety of Si NC-based hybrid NPs is a promising first step for the design of biocompatible multifunctional NPs with broad material choices for biosensing, bioimaging and solar energy conversion.

Mole ghrelin: cDNA cloning, gene expression, and diverse molecular forms in Mogera imaizumii

Here, we describe cDNA cloning and purification of the ghrelin gene sequences and ghrelin peptides from the Japanese true mole, Mogera imaizumii. The gene spans >2.9kbp, has four exons and three introns, and shares structural similarity with those of terrestrial animals. Mature mole ghrelin peptide was predicted to be 28 amino acids long (GSSFLSPEHQKVQQRKESKKPPSKPQPR) and processed from a prepropeptide of 116 amino acids. To further elucidate molecular characteristics, we purified ghrelin peptides from mole stomach. By mass spectrometry, we found that the mole ghrelin peptides had higher ratios of the odd-number fatty acids (C9 and C11 as much as C8) attached to the third serine residue than other vertebrate ghrelin. Truncated forms of ghrelins such as [1-27], [1-19], [1-16] and [1-15], and that lacked the 14th glutamine residue (des-Gln14 ghrelin) were produced in the stomach. Marked expression of ghrelin mRNA in lung was observed as in stomach and brain. Phylogenetic analysis indicated that the branch of M. imaizumii has slightly higher dN/dS ratios (the nucleotide substitution rates at non-synonymous and synonymous sites) than did other eulipotyphlans. Peptide length was positively correlated with human ghrelin receptor activation, whereas the length of fatty-acyl chains showed no obvious functional correlation. The basal higher luciferase activities of the 5'-proximal promoter region of mole ghrelin were detected in ghrelin-negative C2C12 cells and hypoxic culture conditions impaired transcriptional activity. These results indicated that moles have acquired diverse species of ghrelin probably through distinctive fatty acid metabolism because of their food preferences. The results provide a gateway to understanding ghrelin metabolism in fossorial animals.