Genetic and epigenetic alterations of netrin-1 receptors in gastric cancer with chromosomal instability

Background

The gene expressions of netrin-1 dependence receptors, DCC and UNC5C, are frequently downregulated in many cancers. We hypothesized that downregulation of DCC and UNC5C has an important growth regulatory function in gastric tumorigenesis.

Results

In the present study, a series of genetic and epigenetic analyses for DCC and UNC5C were performed in a Japanese cohort of 98 sporadic gastric cancers and corresponding normal gastric mucosa specimens. Loss of heterozygosity (LOH) analyses and microsatellite instability (MSI) analysis was applied to determine chromosomal instability (CIN) and MSI phenotypes, respectively. More than 5 % methylation in the DCC and UNC5C promoters were found in 45 % (44/98) and 32 % (31/98) gastric cancers, respectively, and in 9 % (9/105) and 5 % (5/105) normal gastric mucosa, respectively. Overall, 70 % (58 of 83 informative cases) and 51 % (40 of 79 informative cases) of gastric cancers harbored either LOH or aberrant methylation in the DCC and UNC5C genes, respectively. In total, 77 % (51 of 66 informative cases) of gastric cancers showed cumulative defects in these two dependence receptors and were significantly associated with chromosomal instability. Both DCC and UNC5C were inactivated in 97 % of CIN-positive gastric cancers and in 55 % of CIN-negative gastric cancers.

Conclusions

Defect in netrin receptors is a common feature in gastric cancers. DCC alterations are apparent in the early stages, and UNC5C alterations escalate with the progression of the disease, suggesting that the cumulative alterations of netrin-1 receptors was a late event in gastric cancer progression and emphasizing the importance of this growth regulatory pathway in gastric carcinogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0096-y) contains supplementary material, which is available to authorized users.

Correlation of computed tomography imaging features and pathological features of 41 patients with pancreatic neuroendocrine tumors

BACKGROUND/AIMS

Pancreatic neuroendocrine tumors (PNET) are relatively rare. Here, we present clinical and pathological characteristics of PNETs to show a relationship between computed tomography (CT) imaging and the 2010 World Health Organization (WHO) classification.

METHODOLOGY

We retrospectively reviewed the records of 41 PNET patients who were treated between 2002 and 2012. All tumors were classified as neuroendocrine tumor (NET) grade 1 (G1), NET grade 2 (G2), or neuroendocrine carcinoma (NEC) grade 3 (G3) on the basis of the 2010 WHO classification system.

RESULTS

Twenty-five tumors were classified as G1, 11 as G2, and five as G3. Mean sizes of the G1, G2 and G3 tumors were 1.84 ± 0.54, 4.90 ± 0.84, and 5.62 ± 1.18 cm, respectively, (P < 0.01). A PNET is typically hypervascular and exhibits contrast enhancement on enhanced CT. Higher percentage of G1 tumors demonstrated typical imaging and showed a significantly greater distinct mass compared with G2 and G3 tumors.

CONCLUSIONS

Although PNET has many imaging features that appear on CT, G2 and G3 tumors often show atypical imaging features, particularly with large sizes and/or ill-defined features, when compared with G1 tumors. If a PNET has atypical imaging features, possibility of malignancy should be considered.

The rare BRAF VK600-601E mutation as a possible indicator of poor prognosis in rectal carcinoma – a report of a case

Background

The BRAF V600E mutation is reportedly associated with inferior survival among colon cancer patients. Here we report a patient with rectal cancer who carried the novel BRAF mutation VK600–601E, which has analogous molecular functions to those of the conventional BRAF mutation V600E, and may have potential as a prognostic marker for colorectal cancer (CRC).

Case presentation

The present 65-year-old male patient was diagnosed with recurrent rectal adenocarcinoma (stage II by AJCC TNM staging 7th edition) 14 months after surgery and was treated with modified FOLFOX6 (fluorouracil, leucovorin, and oxaliplatin), radiation, and FOLFIRI (fluorouracil, leucovorin, and irinotecan). The tumor progressed before further treatment could be initiated, resulting in death after 15 months. This survival period was similar to the median overall survival among patients with metastatic CRC and BRAF mutations who were treated with the FOLFIRI regimen with or without cetuximab.

Conclusions

Thus, the BRAF VK600–601E mutation may lead to an aggressive clinical course in CRC patients suffering from rapid progression and potential resistance to multiple therapeutic modalities.

Serum Oxidative/anti-oxidative Stress Balance Is Dysregulated in Potentially Pulmonary Hypertensive Patients with Liver Cirrhosis: A Case Control Study

OBJECTIVE

Hepatopulmonary syndrome (HPS) is characterized by vascular dilatation and hyperdynamic circulation, while portopulmonary hypertension (POPH) is characterized by vasoconstriction with fibrous obliteration of the vascular bed. Vasoactive molecules such as nitric oxide (NO) are candidate factors for cirrhotic complications associated with these diseases. However, oxidative stress balance is not well characterized in HPS and POPH. The present objective is to investigate the oxidative stress and anti-oxidative stress balance and NO pathway balance in patients with potential HPS and POPH.

METHODS

We recruited patients with decompensated cirrhosis (n=69) admitted to our hospital as liver transplantation candidates. Patients exhibiting partial pressure of oxygen lower than 80 mmHg and alveolar-arterial oxygen gradient (AaDO2) ≥15 mmHg were categorized as potentially having HPS (23 of 69 patients). Patients exhibiting a tricuspid regurgitation pressure gradient ≥25 mmHg were categorized as potentially having POPH (29 of 61 patients). Serum reactive oxygen metabolites were measured and anti-oxidative OXY-adsorbent test (OXY) were performed, and the balance of these tests was defined as the oxidative index. The correlation between these values and the clinical characteristics of the patients were assessed in a cross-sectional study.

RESULTS

Potential HPS patients exhibited no correlation with oxidative stress markers. Potential POPH patients exhibited lower OXY (p=0.037) and higher oxidative index values (p=0.001). Additionally, the vascular NO synthase enzyme inhibiting protein, asymmetric dimethylarginine, was higher in potential POPH patients (p=0.049). The potential POPH patients exhibited elevated AaDO2, suggesting the presence of pulmonary shunting.

CONCLUSION

Potential POPH patients exhibited elevated oxidative stress with decreased anti-oxidative function accompanied by inhibited NO production. Anti-oxidants represent a candidate treatment for potential POPH patients.

Clinical Significance of MLH1 Methylation and CpG Island Methylator Phenotype as Prognostic Markers in Patients with Gastric Cancer

BACKGROUND

To improve the outcome of patients suffering from gastric cancer, a better understanding of underlying genetic and epigenetic events in this malignancy is required. Although CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) have been shown to play pivotal roles in gastric cancer pathogenesis, the clinical significance of these events on survival outcomes in patients with gastric cancer remains unknown.

METHODS

This study included a patient cohort with pathologically confirmed gastric cancer who had surgical resections. A cohort of 68 gastric cancers was analyzed. CIMP and MSI statuses were determined by analyzing promoter CpG island methylation status of 28 genes/loci, and genomic instability at 10 microsatellite markers, respectively. A Cox's proportional hazards model was performed for multivariate analysis including age, stage, tumor differentiation, KRAS mutation status, and combined CIMP/MLH1 methylation status in relation to overall survival (OS).

RESULTS

By multivariate analysis, longer OS was significantly correlated with lower pathologic stage (P = 0.0088), better tumor differentiation (P = 0.0267) and CIMP-high and MLH1 3' methylated status (P = 0.0312). Stratification of CIMP status with regards to MLH1 methylation status further enabled prediction of gastric cancer prognosis.

CONCLUSIONS

CIMP and/or MLH1 methylation status may have a potential to be prognostic biomarkers for patients with gastric cancer.

Risk factors of morbidity and predictors of long-term survival after hepatopancreatoduodenectomy for biliary cancer

BACKGROUND/AIMS

Hepatopancreatoduodenectomy (HPD) is performed to achieve radical resection of malignant biliary tumors. We reviewed clinical outcomes to evaluate the utility of HPD in terms of morbidity and mortality.

METHODOLOGY

A retrospective analysis was conducted on 17 patients underwent HPD between August 1991 and May 2013; 9 bile duct cancer, 5 advanced gallbladder and 3 pancreatic tumor with liver metastasis.

RESULTS

The morbidity and mortality rates were 88.3% and 0%, respectively. Univariate analysis showed that a body mass index of ≥22 and preoperative total bilirubin level ≥0.8 mg/dl were significantly associated with severe complications. One-, 3- and 5-year survival rate were 73.3%, 60.0% and 30.0%. In 14 patients with biliary carcinoma, univariate analysis showed that a histological grade of G1 was significantly associated with survival. Patients without pancreatic invasion or portal vein invasion tended to survive longer than patients with these types of invasion, although the difference was not significant.

CONCLUSIONS

HPD can be performed with no mortality and provides a survival benefit for some patients with biliary carcinoma undergoing curative resection. In patients with grade G1 biliary carcinoma without pancreatic or portal vein invasion in particular, this aggressive surgery might offer a chance of long-term survival.

First successful case of simultaneous liver and kidney transplantation for patients with chronic liver and renal failure in Japan

Establishment of a preferential liver allocation rule for simultaneous liver and kidney transplantation (SLK) and revisions of laws regarding organ transplants from deceased donors have paved the way for SLK in Japan. Very few cases of SLK have been attempted in Japan, and no such recipients have survived for longer than 40 days. The present report describes a case of a 50-year-old woman who had undergone living donor liver transplantation at the age of 38 years for management of post-partum liver failure. After the first transplant surgery, she developed hepatic vein stenosis and severe hypersplenism requiring splenectomy. She was then initiated on hemodialysis (HD) due to the deterioration of renal function after insertion of a hepatic vein stent. She was listed as a candidate for SLK in 2011 because she required frequent plasma exchange for hepatic coma. When her Model for End-stage Liver Disease score reached 46, the new liver was donated 46 days after registration. The reduced trisegment liver and the kidney grafts were simultaneously transplanted under veno-venous bypass and intraoperative HD. The hepatic artery was reconstructed prior to portal reconstruction in order to shorten anhepatic time. Although she developed subcapsular bleeding caused by hepatic contusion on the next day, subsequent hemostasis was obtained by transcatheter embolization. Thereafter, her recovery was uneventful, except for mild rejection and renal tubular acidosis of the kidney graft. This case highlights the need to establish Japanese criteria for SLK.

Risk factors for acute renal injury in living donor liver transplantation: evaluation of the RIFLE criteria

Acute renal injury (ARI) is a serious complication after liver transplantation. This study investigated the usefulness of the RIFLE criteria in living donor liver transplantation (LDLT) and the prognostic impact of ARI after LDLT. We analyzed 200 consecutive adult LDLT patients, categorized as risk (R), injury (I), or failure (F), according to the RIFLE criteria. ARI occurred in 60.5% of patients: R-class, 23.5%; I-class, 21%; and F-class, 16%. Four patients in Group-A (normal renal function and R-class) and 26 patients in Group-B (severe ARI: I- and F-class) required renal replacement therapy (P < 0.001). Mild ARI did not affect postoperative prognosis regarding hospital mortality rate in Group A (3.2%), which was superior to that in Group B (15.8%; P = 0.0015). Fourteen patients in Group B developed chronic kidney disease (KDIGO stage 3/4). The 1-, 5- and 10-year survival rates were 96.7%, 90.6%, and 88.1% for Group A and 71.1%, 65.9%, and 59.3% for Group B, respectively (P < 0.0001). Multivariate analysis revealed risk factors for severe ARI as MELD ≥ 20 [odds ratio (OR) 2.9], small-for-size graft (GW/RBW <0.7%; OR 3.1), blood loss/body weight >55 ml/kg (OR 3.7), overexposure to calcineurin inhibitor (OR 2.5), and preoperative diabetes mellitus (OR 3.2). The RIFLE criteria offer a useful predictive tool after LDLT. Severe ARI, defined beyond class-I, could have negative prognostic impact in the acute and late postoperative phases. Perioperative treatment strategies should be designed and balanced based on the risk factors for the further improvement of transplant prognosis.

Hepatitis C virus-specific T-cell response correlates with hepatitis activity and donor IL28B genotype early after liver transplantation

It is not known how the immune system targets hepatitis C virus (HCV)-infected HLA-mismatched hepatocytes under immune-suppressed conditions after orthotopic liver transplantation (OLT). In addition, the relationship between the HCV-specific immune response and IL28B variants as predictors of HCV clearance has not been well-characterized. We determined the IL28B polymorphisms for 57 post-OLT HCV carriers, and we assessed the HCV-specific immune responses by measuring the peripheral blood mononuclear cell-derived HCV-specific interferon-gamma (IFN-γ) response using an enzyme-linked immunospot assay. At 1-3 years after OLT, patients with no active hepatitis showed higher total spots on the immunospot assay. At＞3 years after OLT, patients with resolved HCV showed higher levels of core, NS3, NS5A, and total spots compared to the chronic hepatitis patients. The IL28B major genotype in the donors correlated with higher spot counts for NS5A and NS5B proteins at 1-3 years after OLT. In the post-OLT setting, the HCV-specific immune response could be strongly induced in patients with no active hepatitis with an IL28B major donor or sustained virological response. Strong immune responses in the patients with no active hepatitis could only be maintained for 3 years and diminished later. It may be beneficial to administer IFN treatment starting 3 years after OLT, to induce the maximum immunological effect.

Advanced hepatocellular carcinoma with lymph node metastases showing epithelial to mesenchymal transition effectively treated with systemic chemotherapy: Report of a case

We present a case in which combination chemotherapy was used to successfully treat hepatocellular carcinoma (HCC) with rapid progression of lymph node (LN) metastases after liver resection. In addition, epithelial to mesenchymal transition (EMT) markers were examined immunohistochemically. A 43-year-old man who had been diagnosed with HCC showed an enlarged LN near the hepatic artery proper. After extended left lobectomy with lymphadenectomy in the hepatoduodenal ligament, he experienced rapid progression of metastases to the para-aortic and mediastinal LN. Partial remission was achieved after induction and maintenance of combination chemotherapy using etoposide, carboplatin, epirubicin and 5-fluorouracil. As a consequence of this treatment, the patient survived 10 months. Immunohistochemical studies demonstrated that HCC cells in the metastatic LN showed low expression of E-cadherin and high expression of N-cadherin and vimentin, indicating EMT. Combination chemotherapy may prove effective for patients with HCC accompanied by LN metastases that show features of EMT.

[A case of advanced sigmoid colon cancer successfully treated with multimodality therapy]

A 61-year-old man underwent sigmoidectomy with partial cystectomy for advanced sigmoid colon cancer with unresectable multiple liver metastases at the Okayama University Hospital in June 2006. Pathological examination revealed moderately differentiated adenocarcinoma, pStage IV( pSI[ bladder], pN0, pH2, pP0, pM0), as per the Japanese Classification of Colorectal Carcinoma, seventh edition. The patient underwent systematic chemotherapy with irinotecan, 5-fluorouraci( l 5-FU), and folinic acid( FOLFIRI) and oxaliplatin, Leucovorin, and 5-FU( mFOLFOX6) for 13 months. In July 2007, hepatectomy was performed as the liver metastatic lesions had shrunk to a resectable size. Follow-up computed tomography (CT) in November 2009 revealed recurrence in the liver and lung. Subsequently, lateral segmentectomy was performed for the recurrent liver lesions, and radiofrequency ablation( RFA) was performed for the lung lesions. After having undergone RFA, the patient is doing well without any re-recurrence. We encountered a patient with advanced sigmoid colon cancer who was successfully treated with multimodality therapy. For patients with advanced or recurrent colorectal cancers, curative resection can lead to a good prognosis; however, in most patients, it is difficult to achieve curative resection by upfront surgery. Multimodality therapy could facilitate curative resection, thereby resulting in a good prognosis.

Serial changes of serum growth factor levels and liver regeneration after partial hepatectomy in healthy humans

This study aimed to investigate the associations of the serial changes of serum levels of various growth factors with liver regeneration after hepatectomy in healthy liver donors. Sixteen healthy liver donors who underwent conventional liver resection were included. Serum levels of various growth factors before hepatectomy and on postoperative day (POD) 1, 3, 5 and 7 were measured. Liver volume data calculated by multi-detector computed tomography using workstation. The ratio of remnant liver volume on POD 0 to liver volume before the operation was 51% ± 20%. The ratio of liver volume on POD 14 to liver volume on POD 0 were inversely correlated with remnant liver volume on POD 0 (r = −0.91). The ratio of liver volume on POD 14 to liver volume on POD 0 were significantly correlated with serum hepatocyte growth factor (HGF) levels on POD 1 (r = 0.54), serum leptin levels on POD 1 (r = 0.54), and serum macrophage colony-stimulating factor (M-CSF) levels on POD 5 (r = 0.76) and POD 7 (r = 0.80). These results suggest that early-phase elevation of serum levels of HGF, leptin and M-CSF may be associated with the acceleration of liver regeneration after hepatectomy in humans.

Poor prognosis of KRAS or BRAF mutant colorectal liver metastasis without microsatellite instability

BACKGROUND

The discovery of practical biomarkers is important to realize personalized medicine for patients with malignant neoplasias, including colorectal cancer (CRC).

PURPOSE

The aim of this study was to determine reliable prognostic biomarkers by the analysis of patients with resectable colorectal liver metastases (CRLM).

METHODS

Genomic DNA was obtained from the CRLM tissues of a cohort of 126 patients with CRLM with curative hepatic resection. The KRAS/BRAF mutation spectrum and microsatellite instability (MSI) status were successfully analyzed in 100 of the 126 CRLM tissues and these findings were examined in relation to the patients' clinical outcomes.

RESULTS

The cohort of 100 CRLM patients consisted of 46 with synchronous and 54 with metachronous liver metastasis. Overall survival and disease-free survival at 5 years were 57.4 and 24.9 %, respectively. MSI analysis revealed that none of the 100 CRLM specimens showed any evidence of MSI. By KRAS/BRAF mutation analysis, the analyzed CRLM patients were divided into 3 groups; KRAS-mutant (KRAS-Mt; n = 27), BRAF-mutant (BRAF-Mt; n = 3), and wild-types of both genes (Wild-type; n = 70). In the survival analysis, both KRAS-Mt and BRAF-Mt patients showed significantly poorer prognoses compared with Wild-type patients. Furthermore, although the population with the BRAF mutation was small, this mutation had a significant negative impact on disease-free survival.

CONCLUSIONS

In this study, all tumors in the cohort of CRLM patients were non-MSI tumors, suggesting MSI cancer in primary CRC would rarely reveal metastatic potential. KRAS and BRAF mutations are suggested to be poor prognostic factors in CRLM. Genetic information has an essential role as a prognostic marker and could contribute to the decisions on treatment strategy for CRLM.

Sevelamer hydrochloride dose-dependent increase in prevalence of severe acidosis in hemodialysis patients: analysis of nationwide statistical survey in Japan

Metabolic acidosis has a negative impact on prognosis of dialysis patients. The aim of this study was to determine the prevalence of severe metabolic acidosis in dialysis patients treated with sevelamer hydrochloride. In 2004, a nationwide survey (101,516 dialysis patients) was conducted by the Japanese Society for Dialysis Therapy. We analyzed 32,686 dialysis patients whose bicarbonate levels were measured in the survey. Sevelamer hydrochloride was prescribed to 9231 dialysis patients while 23,455 dialysis patients were not prescribed sevelamer hydrochloride. In the present study, we defined severe acidosis as bicarbonate <15.8 mmol/L. The mean serum bicarbonate level correlated significantly and negatively with the daily dose of sevelamer hydrochloride (R(2) = 0.806, P < 0.0001). Logistic regression analysis indicated that the percentage of patients with severe acidosis increased significantly with increased dose of sevelamer hydrochloride (R(2) = 0.885, P < 0.00001). The estimated doses of sevelamer hydrochloride associated with severe acidosis in 10% and 15% of patients were 3.5 g/day (95% confidence interval [95%CI], 2.8-4.4) and 7.7 g/day (95%CI = 5.9-10.9), respectively. Severe acidosis was noted in 4.5% of patients who were not treated with sevelamer hydrochloride and in 16.1% of patients treated with sevelamer hydrochloride at ≥ 5.25 g/day (P < 0.0001). The results call for careful monitoring of serum bicarbonate level in hemodialysis patients treated with sevelamer hydrochloride.