Hiroe Kitahara

Identification of oligopeptide binding to colon cancer cells separated from patients using laser capture microdissection

The development of intravascular conjugates that efficiently deliver genes or drugs to tumors is limited by the lack of efficacious targeting ligands. Small targeting peptides, such as those iterated by phage display technology, offer enormous potential for these applications. The majority of reports published to date have focused on the identification of peptides isolated for their ability to bind to human cancer cell lines in vitro, and have failed to account for the loss of polarization and de-differentiation of such cells from their in vivo state. Here, we report a novel approach for the identification of peptides capable of binding specifically to cancer cells derived from clinically resected human colon cancer. In this strategy, laser capture microdissection (LCM) is performed on a surgically resected colon cancer specimen to separate only cancer cells from the specimen. Subsequently, biopanning was performed on the LCM-selected colon cancer cells to identify peptide sequences that bound specifically to them. A peptide containing the SPT motif was selected as the most promising consensus sequence binding specifically to the LCM-selected colon cancer cells. Phage clones displaying the SPT motif demonstrated 9-fold higher binding to colon cancer cells derived from a patient than insertless phage (p < 0.05), while, recovery of the SPT phage from the colon cancer cell lines DLD-1 and HCT-15 was 7-fold higher than that of the control insertless phage (p < 0.05). The binding of SPT phage to colon cancer cells from the patient was confirmed by immunofluorescence. Additionally, a synthesized SPT-containing peptide (SPTKSNS) showed binding activity in the absence of mitogenic effects on colon cancer cells in vitro. In summary, we have introduced LCM into a biopanning procedure and identified a small peptide that binds preferentially to colon cancer cells derived from a clinically resected sample. This procedure could be applicable for the design of customized cancer cell targeting methodologies using clinical biopsy samples from human subjects.

Hepatectomy preserving drainage veins of the posterior section for liver malignancy invading the right hepatic vein: an alternative to right hepatectomy.

BACKGROUND Although a right hepatectomy (RH) traditionally has been performed for liver tumors infiltrating the main trunk of the right hepatic vein (RHV), the presence of drainage veins of the posterior section (DVPS) beside the RHV provides a chance to preserve their draining area even if the main trunk of the RHV is removed. METHODS Since 2005, we systematically have performed DVPS-preserving hepatectomies whenever possible. In the present study, we describe our experience treating 12 consecutive patients who underwent this procedure. RESULTS We performed the following types of liver resections concomitant with the main trunk of the RHV without packed red cell transfusion, liver failure, or 90-day mortality: extended right anterior sectionectomy in 2 patients, extended segmentectomy 7 in 3, extended segmentectomy 8 in 2, and partial resection of segment 7 in 2 and segment 8 in 3. Postoperative morbidity was observed in 4 (33%) cases, all of which had pleural effusion requiring a tap. A free resection margin was obtained in all patients. CONCLUSIONS This procedure could be a useful alternative to RH, providing a chance for radical liver resection with minimal parenchymal sacrifice in selected patients with DVPS.

COP35, a Cholangiocarcinoma-Binding Oligopeptide, Interacts with the Clathrin Heavy Chain Accompanied by GRP78

Cholangiocarcinoma (CCA) is a common carcinoma of the liver, and the majority of patients with CCA have a poor prognosis due to the lack of effective nonsurgical therapies in addition to its rapid progression and inoperability at the time of diagnosis. The development of novel nonsurgical therapeutics that efficiently target CCA could significantly improve the prognosis for patients presenting with CCA. Here, we describe the iterative production and characterization of a novel peptide, designated COP35 (CCA-binding oligopeptide 35), which binds selectively to human CCA, identified by bacteriophage biopanning using the intrahepatic CCA cell line RBE and the normal cholangiocyte cell line MMNK-1. COP35 was found to augment the growth inhibitory effects of 5-fluorouracil (5-FU) against RBE cells. Utilizing pull-down assay and liquid chromatography, we identify the clathrin heavy chain accompanied by GRP78/BiP as a COP35-binding partner. In summary, we identify COP35 as a possible candidate for peptide-targeted therapies for CCA. Mol Cancer Res; 9(6); 688–701. ©2011 AACR.

Efficacy of Self-Expandable Metallic Stent Inserted for Refractory Hemorrhage of Duodenal Cancer

Because of advances in the technology of gastrointestinal endoscopy and improvements in the quality of stents, it has become routine to place a stent as palliative therapy for malignant gastrointestinal obstruction. On the other hand, stent placement for malignant gastrointestinal hemorrhage has scarcely been reported, although it may be performed for hemorrhage of the esophageal varicose vein. We recently experienced a patient with refractory hemorrhage from an unresectable duodenal cancer who underwent placement of a self-expandable metallic stent (SEMS) and thereafter had no recurrence of the hemorrhage. A 46-year-old man underwent laparotomy to radically resect a cancer in the third portion of the duodenum, which invaded widely to the superior mesenteric vein and its branches and was considered unresectable. After stomach-partitioning gastrojejunostomy was performed, chemotherapy was initiated according to the regimen of chemotherapy of far advanced gastric cancer. One year and 4 months after induction of chemotherapy, gastrointestinal hemorrhage occurred. Upper gastrointestinal endoscopy revealed the hemorrhage oozing from the duodenal cancer, and endoscopic hemostasis, such as injection of hypertonic saline epinephrine and argon plasma coagulation, was unsuccessful. Twenty days after emergence of the hemorrhage, an endoscopic covered SEMS was placed with confirmation by fluoroscopy. Immediately after placement of the stent, the tarry stool stopped and the anemia ceased to progress. The recurrence of the hemorrhage has not been confirmed without migration of the stent. SEMS is an effective hemostatic procedure for malignant refractory hemorrhage.