Amane Takahashi

MicroRNA Expression Profiling of Exfoliated Colonocytes Isolated from Feces for Colorectal Cancer Screening

To reduce the colorectal cancer (CRC) mortality rate, we have reported several CRC screening methods using colonocytes isolated from feces. Expression analysis of oncogenic microRNA (miRNA) in peripheral blood was recently reported for CRC detection. In the present study, we conducted miRNA expression analysis of exfoliated colonocytes isolated from feces for CRC screening. Two hundred six CRC patients and 134 healthy volunteers were enrolled in the study. miRNA expression of the miR-17-92 cluster, miR-21, and miR-135 in colonocytes isolated from feces as well as frozen tissues was analyzed by quantitative real-time PCR. The expression of the miR-17-92 cluster, miR-21, and miR-135 was significantly higher in CRC tissues compared with normal tissues. The exfoliated colonocytes of 197 CRC patients and 119 healthy volunteers were analyzed because of the presence of sufficient miRNA concentration. miR-21 expression did not differ significantly between CRC patients and healthy volunteers (P = 0.6). The expression of miR-17-92 cluster and miR-135 was significantly higher in CRC patients than in healthy volunteers (P < 0.0001). The overall sensitivity and specificity by using miRNA expression was 74.1% (146/197; 95% confidence interval, 67.4-80.1) and 79.0% (94/119; 95% confidence interval, 70.6-85.9), respectively. Sensitivity was dependent only on tumor location (P = 0.0001). miRNA was relatively well conserved in exfoliated colonocytes from feces both of CRC patients and healthy volunteers. miRNA expression analysis of the isolated colonocytes may be a useful method for CRC screening. Furthermore, oncogenic miRNA highly expressed in CRC should be investigated for CRC screening tests in the future. Cancer Prev Res; 3(11); 1435–42. ©2010 AACR.

NC-6300, an epirubicin-incorporating micelle, extends the antitumor effect and reduces the cardiotoxicity of epirubicin

Epirubicin is widely used to treat various human tumors. However, it is difficult to achieve a sufficient antitumor effect because of dosage limitation to prevent cardiotoxicity. We hypothesized that epirubicin‐incorporating micelle would reduce cardiotoxicity and improve the antitumor effect. NC‐6300 comprises epirubicin covalently bound to PEG polyaspartate block copolymer through an acid–labile hydrazone bond. The conjugate forms a micellar structure of 40–80 nm in diameter in an aqueous milieu. NC‐6300 (10, 15 mg/kg) and epirubicin (10 mg/kg) were given i.v. three times to mice bearing s.c. or liver xenograft of human hepatocellular carcinoma Hep3B cells. Cardiotoxicity was evaluated by echocardiography in C57BL/6 mice that were given NC‐6300 (10 mg/kg) or epirubicin (10 mg/kg) in nine doses over 12 weeks. NC‐6300 showed a significantly potent antitumor effect against Hep3B s.c. tumors compared with epirubicin. Moreover, NC‐6300 also produced a significantly longer survival rate than epirubicin against the liver orthotopic tumor of Hep3B. With respect to cardiotoxicity, epirubicin‐treated mice showed significant deteriorations in fractional shortening and ejection fraction. In contrast, cardiac functions of NC‐6300 treated mice were no less well maintained than in control mice. This study warrants a clinical evaluation of NC‐6300 in patients with hepatocellular carcinoma or other cancers.

The inhibition of pancreatic cancer invasion-metastasis cascade in both cellular signal and blood coagulation cascade of tissue factor by its neutralisation antibody

Tissue factor (TF), the initiating cell surface receptor for the blood coagulation cascade, plays an important role in malignant transformation of the pancreas, although the precise mechanism remains unresolved. Here, we report that the TF - factor VIIa complex in human pancreatic cancer cells produced a significant amount of MMP-9 and promoted invasion ability in vitro and invasion and metastasis in vivo. For treatment, we successfully developed an anti-human TF monoclonal antibody that inhibits both cellular signalling and blood coagulation cascade via TF. Invasive capability and MMP-9 expression were significantly reduced by the antibody. The antibody inhibited not only tumour invasion in the orthotopic model, but also haematogenous metastasis in the portal-injection liver metastasis model. In conclusion, the TF-VIIa complex plays an important role in invasion-metastasis by enhancing tumour cell infiltration ability and forming microthrombi. The newly established anti-human TF neutralisation antibody may be useful for the treatment of pancreatic and other invasive cancers.

The antitumor activity of NK012, an SN-38-incorporating micelle, in combination with bevacizumab against lung cancer xenografts.

It has been demonstrated that NK012, a novel 7‐ethyl‐10‐hydroxycamptothecin (SN‐38)‐incorporating polymeric micelle, exerts significantly more potent antitumor activity against various human tumor xenografts than irinotecan (CPT‐11) (a water‐soluble prodrug of SN‐38). Combination therapy of anticancer agents with bevacizumab (Bv), an anti‐vascualr endothelial growth factor humanized monoclonal antibody, has more potently inhibited tumor growth than either agent alone. In the current study, the authors examined the antitumor effect of NK012 in combination with Bv against human lung cancer.

Survival of surgery for recurrent biliary tract cancer: a single-center experience and systematic review of literature.

Background For recurrent biliary tract cancer, chemotherapy is the standard treatment. However, the efficacy of surgery is unknown. Here, the prognostic benefit of surgery for recurrent biliary tract cancer was investigated. Methods Data of 206 patients who underwent surgery for biliary tract cancer between 2005 and 2015 were retrospectively analyzed. Of these, 107 recurrent patients were divided into two groups, surgery (n = 14) and non-surgery (n = 93) groups. In the latter group, 45 patients received chemotherapy and 48 received best supportive care. Results Of the total 121 sites of recurrence, the liver was the most common (n = 41), followed by locoregional recurrence (n = 32) and lymph nodes (n = 18). Surgery was performed in the 14 patients with recurrence, comprising nine patients with intrahepatic cholangiocarcinoma, three with perihilar cholangiocarcinoma, one with distal cholangiocarcinoma and one with gallbladder carcinoma. Survival after recurrence was significantly better after surgery than after chemotherapy or best supportive care (38% vs. 5.3% vs. 0% at 3 years and 19% vs. 5.3% vs. 0% at 5 years; P < 0.0001). Multivariate analysis identified the residual status of the primary tumor (hazard ratio = 1.58, 95% confidence interval = 1.00-2.44; P = 0.047), time to recurrence ≥1 year (hazard ratio = 0.62, 95% confidence interval = 0.39-0.97; P = 0.037) and surgery for recurrence (hazard ratio = 0.32, 95% confidence interval = 0.14-0.62; P < 0.001) as independent prognostic factors. Conclusions Surgery for recurrent biliary tract cancer may prolong survival in patients with time to recurrence ≥1 year.

Age does not affect complications and overall survival rate after pancreaticoduodenectomy: Single-center experience and systematic review of literature

We aimed to evaluate the feasibility of pancreaticoduodenectomy (PD) in elderly patients. We retrospectively analyzed data from 206 patients who underwent PD between 2008 and 2015. The patients were divided into two groups: patients aged < 70 years (n = 117) and those aged ≥ 70 years (n = 89). To update the outcome of PD in elderly patients, we performed a systematic review of published work. The preoperative patient characteristics were similar between the two groups except for hypertension, which was significantly more frequent in the older group (25% vs. 52%; p < 0.001). There was no difference in the mortality (0% vs. 1%; p = 0.43) or morbidity (26% vs. 20%; p = 0.41) rates between the two groups. The overall survival rate in patients with pancreatic cancer between the two groups did not differ (p = 0.40). Twenty-one studies, including our own, were identified in the published work. The overall median morbidity and mortality rates of the elderly patients were 41.5% (range, 20-78%) and 5.8% (range, 0-10.5%), respectively. PD is feasible in elderly patients with acceptable morbidity and mortality rates.

The RAS mutation status predicts survival in patients undergoing hepatic resection for colorectal liver metastases: The results from a genetic analysis of all-RAS

We investigated the impact of mutations in KRAS exons 3‐4 and NRAS exons 2‐3 in addition to KRAS exon 2, so‐called all‐RAS mutations, in patients with colorectal liver metastasis (CLM) undergoing hepatic resection.

Impaired liver function attenuates liver regeneration and hypertrophy after portal vein embolization

AIM To clarify the clinical factors associated with liver regeneration after major hepatectomy and the hypertrophic rate after portal vein embolization (PVE). METHODS A total of 63 patients who underwent major hepatectomy and 13 patients who underwent PVE in a tertiary care hospital between January 2012 and August 2015 were included in the analysis. We calculated the remnant liver volume following hepatectomy using contrast-enhanced computed tomography (CT) performed before and approximately 3-6 mo after hepatectomy. Furthermore, we calculated the liver volume using CT performed 2-4 wk after PVE. Preoperative patient characteristics and laboratory data were analyzed to identify factors affecting postoperative liver regeneration or hypertrophy rate following PVE. RESULTS The remnant liver volume/total liver volume ratio negatively correlated with the liver regeneration rate after hepatectomy (ρ = -0.850, P < 0.001). The regeneration rate was significantly lower in patients with an indocyanine green retention rate at 15 min (ICG-R15) of ≥ 20% in the right hepatectomy group but not in the left hepatectomy group. The hypertrophic rate after PVE positively correlated with the regeneration rate after hepatectomy (ρ = 0.648, P = 0.017). In addition, the hypertrophic rate after PVE was significantly lower in patients with an ICG-R15 ≥ 20% and a serum total bilirubin ≥ 1.5 mg/dL. CONCLUSION The regeneration rate after major hepatectomy correlated with hypertrophic rate after PVE. Both of them were attenuated in the presence of impaired liver function.

The arc of Buhler: special considerations when performing pancreaticoduodenectomy

A 74-year-old female was diagnosed as having a carcinoma of the papilla of Vater. Preoperative computed tomography showed stenosis of the celiac trunk and an enlarged artery arising from the superior mesenteric artery (SMA) joining the root of the splenic artery. Since this artery communicated with the SMA and the celiac trunk, independently of the gastroduodenal and dorsal pancreatic arteries, it was considered to be the arc of Buhler (AOB). The arterial blood flow to the liver, spleen, and stomach appeared to depend on the AOB, such that AOB preservation was considered to be essential. A subtotal stomach-preserving pancreaticoduodenectomy with preservation of the AOB was thus performed. Although AOB is a relatively infrequent type of arterial communication between the SMA and the celiac trunk, it needs to be preserved during pancreaticoduodenectomy when celiac trunk stenosis is present.

Abstract 1819: Fecal RNA test using microRNA expressions of exfoliated colonocytes for colorectal cancer screening

Background & Aims: To reduce the mortality rate of several cancers, the development of a screening test is needed. We have been developing new screening methods for colorectal cancer (CRC) by applying molecular biological tools to exfoliated colonocytes. In the last few years especially, we have reported the fecal RNA test including the CRC-related gene expression analysis. Here, we investigated the potential of a fecal miRNA test for the early detection of CRC. Methods: CRC patients (n = 299) and healthy volunteers (n = 116) with no abnormalities detected by screening colonoscopy were enrolled in this case control study. The miRNA expressions in the colonocytes of CRC patients (n = 47) and healthy volunteers (n = 35) were analyzed in the training study and the miRNA expressions in the colonocytes of CRC patients (n = 252) and healthy volunteers (n = 81) were validated in the validation study. First, CRC related oncogenic miRNAs for CRC detection were selected by TaqMan MicroRNA Array v3.0 (corresponded to miRBase release 14). Next, the expressions of the most suitable oncogenic miRNAs were analyzed by quantitative real-time PCR in the training study. Lastly, the sensitivity and specificity of fecal miRNA test was validated by quantitative real-time PCR in the validation study. Results: According to the results of miRNA array, 20 miRNAs were selected as candidate of miRNA analysis. In the training study, significant differences in the relative expression level of miR-17, -18a, -19a, -19b, -20a, -92a, -106a, -135a, -135b, and -146a were observed between the CRC patients and the healthy volunteers (P 0.1) AUC of ROC curve using miR-17, -18a, -19a, -19b, -20a, -92a, -106a, -135b, and -146a were more than 0.7. The overall sensitivity and specificity in the training study using these miRNAs were 70.2% (33/47) and 74.3% (26/35), respectively. The overall sensitivity and specificity in the validation study were 67.5% (170/252) and 75.3% (61/81), respectively. Conclusions: We selected the suitable miRNAs for CRC detection in exfoliated colonocytes. Fecal miRNA test may be useful for CRC screening. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4448. doi:1538-7445.AM2012-4448