Mutation detection of urinary cell-free DNA via catch-and-release isolation on nanowires for liquid biopsy.

Cell-free DNA (cfDNA) and extracellular vesicles (EVs) are molecular biomarkers in liquid biopsies that can be applied for cancer detection, which are known to carry information on the necessary conditions for oncogenesis and cancer cell-specific activities after oncogenesis, respectively. Analyses for both cfDNA and EVs from the same body fluid can provide insights into screening and identifying the molecular subtypes of cancer; however, a major bottleneck is the lack of efficient and standardized techniques for the isolation of cfDNA and EVs from clinical specimens. Here, we achieved catch-and-release isolation by hydrogen bond-mediated binding of cfDNA in urine to zinc oxide (ZnO) nanowires, which also capture EVs by surface charge, and subsequently we identified genetic mutations in urinary cfDNA. The binding strength of hydrogen bonds between single-crystal ZnO nanowires and DNA was found to be equal to or larger than that of conventional hydrophobic interactions, suggesting the possibility of isolating trace amounts of cfDNA. Our results demonstrated that nanowire-based cancer screening assay can screen cancer and can identify the molecular subtypes of cancer in urine from brain tumor patients through EV analysis and cfDNA mutation analysis. We anticipate our method to be a starting point for more sophisticated diagnostic models of cancer screening and identification.

Chlorotoxin-Fc fusion inhibits release of MMP-2 from pancreatic cancer cells.

Chlorotoxin (CTX) is a 36-amino acid peptide derived from Leiurus quinquestriatus (scorpion) venom, which inhibits low-conductance chloride channels in colonic epithelial cells. It has been reported that CTX also binds to matrix metalloproteinase-2 (MMP-2), membrane type-1 MMP, and tissue inhibitor of metalloproteinase-2, as well as CLC-3 chloride ion channels and other proteins. Pancreatic cancer cells require the activation of MMP-2 during invasion and migration. In this study, the fusion protein was generated by joining the CTX peptide to the amino terminus of the human IgG-Fc domain without a hinge domain, the monomeric form of chlorotoxin (M-CTX-Fc). The resulting fusion protein was then used to target pancreatic cancer cells (PANC-1) in vitro. M-CTX-Fc decreased MMP-2 release into the media of PANC-1 cells in a dose-dependent manner. M-CTX-Fc internalization into PANC-1 cells was observed. When the cells were treated with chlorpromazine (CPZ), the internalization of the fusion protein was reduced, implicating a clathrin-dependent internalization mechanism of M-CTX-Fc in PANC-1 cells. Furthermore, M-CTX-Fc clearly exhibited the inhibition of the migration depending on the concentration, but human IgG, as negative control of Fc, was not affected. The M-CTX-Fc may be an effective instrument for targeting pancreatic cancer.

CT differentiation of solid serous cystadenoma vs endocrine tumor of the pancreas.

AIM: To differentiate between solid serous cystadenoma (SSCA) and endocrine tumor (ET) of the pancreas using dynamic CT findings. MATERIALS AND METHODS: Between 2001 and 2008, there were 3 SSCA and 15 ET surgically resected in our institute, for whom preoperative multidetector-row CT were available. Various CT features were retrospectively evaluated by two radiologists in consensus for the differentiation between the two entities. Delay time for early and delayed phase images were 40 and 180 or 240s, respectively. For qualitative assessment, density of the tumors relative to the surrounding parenchyma was evaluated, along with other characteristic features. In patients for whom digital data were available, CT values of the tumors were measured, and quantitative assessment was also performed. Relative and absolute washout rate (RWR and AWR, respectively) were also calculated. RESULTS: Mean sizes of the two groups were similar. Tumors were seen as low density area more frequently in SSCA than in ET on unenhanced CT (3/3 vs 1/14), and also on the delayed phase image (2/3 vs 0/14) (p<0.05). Fibrous capsule was observed more frequently in SSCA (2/3) than in ET (0/14). CT value of the tumor on unenhanced CT was significantly lower, and RWR was higher in SSCA than in ET (p<0.05, Mann-Whitney's U test). The difference in delayed phase CT density and AWR did not reach statistically significant level. CONCLUSION: Unenhanced and enhanced CT findings may be of value in differentiation between SSCA and ET.

Pleomorphic adenoma of the submandibular gland in children: a case report and a review of the Japanese literature.

An 8-year-old girl was introduced to our department due to the presence of a left painless submandibular mass. The mass had been initially noticed at 7 years of age. Preoperative imaging showed the mass to have originated from the left submandibular gland. The mass was removed with a part of submandibular gland attached to it. The pathologic findings showed the mass to be pleomorphic adenoma without any malignant components. The postoperative clinical course was uneventful. During the 1-year follow-up period, no recurrence was noticed. In addition to the clinical report of our case, we reviewed the pertinent Japanese literature to clarify the clinical features of this disease in children.

Papillary renal cell carcinoma with extensive paraaortic nodal metastasis mimicking malignant lymphoma.

A 52-year-old woman with abdominal distension underwent computed tomography (CT) that demonstrated extensive paraaortic lymphadenopathy and a right renal mass. Compared to the renal cortex, the lesions exhibited low signal intensity on T(1)- and T(2)-weighted images and high intensity on diffusion-weighted magnetic resonance (MR) images. We suspected malignant lymphoma and performed excisional biopsy, which revealed metastatic papillary renal cell carcinoma. Retrospectively, significantly reduced signal on in-phase chemical shift MR images compared to out-of-phase images suggested the presence of intratumoral hemosiderin, a characteristic finding of this entity.

Multinodular pseudolymphoma of the liver: computed tomography and magnetic resonance imaging findings.

A 60-year-old woman who had had a history of renal cell carcinoma with intraperitoneal recurrence presented with multiple liver masses. Computed tomography demonstrated multiple enhancing lesions in the both lobes of the liver, and there was an apparent small vessel coursing within one of the lesions. On magnetic resonance imaging, masses showed slight T1 and T2 prolongation, and restricted diffusion: On the hepatobiliary phase of liver-specific contrast agent enhancement, lesions were shown as low signal intensity of varying degree. Liver metastases from renal cell carcinoma were suspected, and partial hepatectomy was performed for the superficially located nodules to make a definitive diagnosis. The final pathological diagnosis was reactive lymphoid hyperplasia or pseudolymphoma of the liver.

Pseudolesion of the liver observed on gadoxetate disodium-enhanced magnetic resonance imaging obtained shortly after transarterial chemoembolization for hepatocellular carcinoma.

The purpose of this report was to describe pseudolesions of the liver that mimicked residual hypervascular hepatocellular carcinoma (HCC), as observed on gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI) obtained shortly after transarterial chemoembolization (TACE). Between June 2008 and December 2008, three patients underwent MRI within 12 days after TACE to rule out remaining viable cancerous tissue or to assess the treatment effect. In all three patients, nontumorous liver tissue adjacent to the treated HCC exhibited focal arterial enhancement on dynamic phase and subsequent diminished uptake of gadoxetate disodium on hepatocellular phase images, which mimicked residual HCC. All three patients had mild postembolization syndrome at the time of EOB-MRI and showed no evidence of residual or recurrent tumors on follow-up. The findings of these areas may represent transient focal hyperemia and damage to the liver cell function caused by TACE. Radiologists should be aware that EOB-MRI obtained shortly after TACE may show pseudolesions around the treated tumors and should not mistake them for residual or recurrent tumors.

MR diagnosis of steroid cell tumor of the ovary: value of chemical shift imaging.

A 53-year-old asymptomatic woman was found to have a pelvic mass at medical examination. Magnetic resonance (MR) imaging revealed a 4-cm solid mass at the right adnexal region, which showed marked hyperintensity on T(2)-weighted imaging and marked enhancement on post-contrast T(1)-weighted imaging. Chemical-shift imaging showed slight but significant signal loss on out-of-phase images, which suggested the presence of intratumoral lipid. The resected specimen exhibited typical features of steroid cell tumor, and Oil Red O stain was positive for cytoplasmic lipid.

Identification of serum proteins related to adverse effects induced by docetaxel infusion from protein expression profiles of serum using SELDI ProteinChip system.

BACKGROUND: For the development of quick and easy methods for screening and identifying treatment-responsive proteins, we determined the protein expression profile of the serum after docetaxel infusion using a surface-enhanced laser desorption/ionization time-of-flight mass spectroscopy (SELDI TOF-MS) system. MATERIALS AND METHODS: Blood from breast cancer patients was collected before and 4, 8, 24 and 48 hours after docetaxel infusion. The protein expression profile was determined by a SELDI TOF-MS system. The relative expression levels of target proteins were compared during the time-course after docetaxel injection. RESULTS: We identified two representative proteins with molecular weights of 7790 Da and 9285 Da. The 7790 Da protein was high molecular weight kininogen, and the 9285 Da protein was apolipoprotein A-II. These two proteins had similar expression patterns in 5 patients, except one patient who experienced severe, acute, adverse effects. CONCLUSION: These results suggest that protein expression profiles determined by SELDI TOF-MS represent useful data for the identification of treatment-responsive proteins.

Expression of cyclooxygenase-2, Fas and Fas ligand in pulmonary adenocarcinoma and atypical adenomatous hyperplasia.

BACKGROUND: Atypical adenomatous hyperplasia (AAH) has been reported to be a precancerous lesion of pulmonary adenocarcinoma. Cyclooxygenase-2 (COX-2), Fas and Fas ligand (FasL) are believed to be involved in the pathogenesis and progression of cancer. PATIENTS AND METHODS: We examined the expression of COX-2, Fas and FasL in 31 tissue specimens of adenocarcinoma and 9 of AAH using an immunohistochemical method. RESULTS: COX-2 staining was observed in 20 (65%) specimens of adenocarcinoma and 2 (22%) of AAH. There was a significant difference in incidence of expression between these two groups (p = 0.025). All tumor specimens obtained from three patients with simultaneous multiple adenocarcinoma showed positive COX-2 staining. In two patients having both adenocarcinoma and AAH, COX-2 expression was detected in adenocarcinoma but not in AAH. Fas was expressed in 5 (16%) adenocarcinoma and 2 (22%) AAH specimens. FasL was detected in 3 (9.7%) adenocarcinoma and 1 (11%) AAH specimen. CONCLUSION: These findings suggest that COX-2 might play a role in the progression from AAH to adenocarcinoma.