Kazuhiro Noma

Localization of heparanase in esophageal cancer cells: Respective roles in prognosis and differentiation

In this study, we examined the distribution of heparanase protein in 75 esophageal squamous cell carcinomas by immunohistochemistry and analyzed the relationship between heparanase expression and clinicopathological characteristics. In situ hybridization showed that the mRNA expression pattern of heparanase was similar to that of the protein, suggesting that increased expression of the heparanase protein at the invasive front was caused by an increase of heparanase mRNA in tumor cells. Heparanase expression correlated significantly with depth of tumor invasion, lymph node metastasis, tumor node metastasis (TNM) stage and lymphatic invasion. Overexpression of heparanase in esophageal cancers was also associated with poor survival. In addition to its localization in the cytoplasm and cell membrane, heparanase was also identified in the nuclei of normal epithelial and tumor cells by immunohistochemistry. Furthermore, nuclear heparanase was detected in nuclear extract of cancer cell lines by Western blot and immunohistochemistry. Examination of the role of nuclear heparanase in cell proliferation and differentiation by double immunostaining for proliferating cell nuclear antigen (PCNA) and cytokeratin 10 (CK10) showed significant relationship between nuclear heparanase expression and differentiation (heparanase vs CK10), but not for proliferative state of esophageal cancer cells (heparanase vs PCNA). Our results suggest that cytoplasmic heparanase appears to be a useful prognostic marker in patients with esophageal cancer and that nuclear heparanase protein may play a role in differentiation. Inhibition of heparanase activity may be effective in the control of esophageal tumor invasion and metastasis.

Inhibition of focal adhesion kinase as a potential therapeutic strategy for imatinib-resistant gastrointestinal stromal tumor

Focal adhesion kinase (FAK) is often up-regulated in a variety of malignancies, including gastrointestinal stromal tumor (GIST), and its overexpression seems to be associated with tumor progressiveness and poor prognosis. GIST is well known to have a mutation to c-KIT; thus, a specific c-KIT inhibitor (imatinib) is recognized as the first-line chemotherapy for GIST, although a certain type of c-KIT mutation reveals a resistance to imatinib due to as yet uncertain molecular mechanisms. To assess the c-KIT mutation-related variation of cellular responses to imatinib, murine lymphocyte-derived Ba/F3 cells, which are stably transduced with different types of c-KIT mutation, were treated with either imatinib or a FAK inhibitor (TAE226), and their antitumor effects were determined in vitro and in vivo. A mutation at exon 11 (KITdel559-560) displayed a high sensitivity to imatinib, whereas that at exon 17 (KIT820Tyr) showed a significant resistance to imatinib in vitro and in vivo. KIT820Tyr cells appeared to maintain the activities of FAK and AKT under the imatinib treatment, suggesting that FAK might play a role in cell survival in imatinib-resistant cells. When FAK activity in those cells was inhibited by TAE226, cell growth was equally suppressed and the cells underwent apoptosis regardless of the c-KIT mutation types. Oral administration of TAE226 significantly diminished tumor growth in nude mice bearing KIT820Tyr xenografts. In summary, c-KIT mutation at exon 17 displayed a resistance to imatinib with maintained activations of FAK and subsequent survival signals. Targeting FAK could be a potential therapeutic strategy for imatinib-resistant GISTs. [Mol Cancer Ther 2009;8(1):127–34]

Telomerase-Dependent Oncolytic Adenovirus Sensitizes Human Cancer Cells to Ionizing Radiation via Inhibition of DNA Repair Machinery

The inability to repair DNA double-strand breaks (DSB) leads to radiosensitization, such that ionizing radiation combined with molecular inhibition of cellular DSB processing may greatly affect treatment of human cancer. As a variety of viral products interact with the DNA repair machinery, oncolytic virotherapy may improve the therapeutic window of conventional radiotherapy. Here, we describe the mechanistic basis for synergy of irradiation and OBP-301 (Telomelysin), an attenuated type-5 adenovirus with oncolytic potency that contains the human telomerase reverse transcriptase promoter to regulate viral replication. OBP-301 infection led to E1B55kDa viral protein expression that degraded the complex formed by Mre11, Rad50, and NBS1, which senses DSBs. Subsequently, the phosphorylation of cellular ataxia-telangiectasia mutated protein was inhibited, disrupting the signaling pathway controlling DNA repair. Thus, tumor cells infected with OBP-301 could be rendered sensitive to ionizing radiation. Moreover, by using noninvasive whole-body imaging, we showed that intratumoral injection of OBP-301 followed by regional irradiation induces a substantial antitumor effect, resulting from tumor cell-specific radiosensitization, in an orthotopic human esophageal cancer xenograft model. These results illustrate the potential of combining oncolytic virotherapy and ionizing radiation as a promising strategy in the management of human cancer.

Free jejunal graft for hypopharyngeal and esophageal reconstruction

AimsThis study assessed the techniques of the free jejunal graft for the reconstruction of hypopharynx or cervical esophagus and discussed the main aspects related to those procedures.Methods and resultsBy using free jejunal grafts, we reconstructed 54 hypopharyngeal and cervical esophageal cancers. In this study, 23 out of 54 patients had a malignant tumor located in the hypopharynx and 31 in the cervical esophagus (27 primary cases and four secondary cases). Despite the multi-step and time-consuming procedure, we did not incur any trans-operative complication. Furthermore, we undertook the larynx preserving cervical esophagectomy and free jejunal graft reconstruction in six patients with cervical esophageal cancer, and those patients acquired a good quality of life.ConclusionFor the reconstruction of hypopharynx or cervical esophagus, the free jejunal graft is a very useful technique and improves the patient’s quality of life.

Colonic interposition and supercharge for esophageal reconstruction.

AimsWe evaluated the techniques of colonic interposition and supercharge for esophageal reconstruction and discussed the main considerations related to these procedures.Patients and methodsIn this study, we performed 51 esophageal reconstructions using colonic interposition. Twenty-eight of the 51 patients had synchronous or allochronic gastric malignancy. We selected colonic interposition for high anastomosis in 11 patients and also for esophageal bypass in 3 patients. This procedure was also selected to preserve gastric function in 5 patients. We recently performed the supercharge technique for colonic interposition in 41 patients.ResultsDespite the long duration and multistep nature of the operation procedure, no perioperative complications were noted. The patients returned to a good quality of life. The incidence of postoperative weight loss did not differ significantly between the colonic reconstruction group and the gastric reconstruction group. In terms of heartburn and dumping syndrome, the outcome was markedly better in the colonic reconstruction group (no cases of heartburn or dumping syndrome) than that in the gastric reconstruction group.ConclusionFor reconstruction of the esophagus, the colonic interposition and supercharge technique is advantageous and contributes to the patient’s quality of life.

HSP90 and its inhibitors.

The HSP90 molecular chaperone family is highly conserved and expressed in various organisms ranging from prokaryotes to eukaryotes. HSP90 proteins play essential housekeeping functions, such as controlling the activity, turnover and trafficking of various proteins, promoting cell survival through maintaining the structural and functional integrity of some client proteins which control cell survival, proliferation and apoptosis, and play an important role in the progression of malignant disease. HSP90 proteins are ATP-dependent chaperones and the binding and hydrolysis of ATP are coupled to conformation changes of HSP90, which facilitate client protein folding and maturation. Many natural and synthetic molecular compounds have been proposed as promising cancer therapy via disrupting the formation of complex ATP-HSP90-client proteins.

Preferential up-regulation of heparanase and cyclooxygenase-2 in carcinogenesis of Barrett's oesophagus and intestinal-type gastric carcinoma

Sonoda R, Naomoto Y, Shirakawa Y, Fujiwara Y, Yamatsuji T, Noma K, Tanabe S, Takaoka M, Gunduz M, Tsujigiwa H, Nagatsuka H, Ohara N, Yoshino T, Takubo K, Vieth M & Tanaka N
(2010) Histopathology 57, 90–100
Preferential up‐regulation of heparanase and cyclooxygenase‐2 in carcinogenesis of Barrett’s oesophagus and intestinal‐type gastric carcinoma

F-18 FDG-PET/CT Contributes to More Accurate Detection of Lymph Nodal Metastasis From Actively Proliferating Esophageal Squamous Cell Carcinoma

Purpose: Evaluating the status of disease progression is critical for planning a therapeutic strategy for esophageal cancer. In this regard, F-18 fluorodeoxyglucose-labeled positron emission tomography (PET) is one of the most useful diagnostic modalities. However, there is room to improve its diagnostic performance, such as distinguishing lymph nodal metastases from false positives. In this study, we examined the diagnostic accuracy of fluorodeoxyglucose PET accompanied by computed tomography imaging (PET/CT) to detect regional lymph nodal metastasis from esophageal squamous cell carcinoma (ESCC). Methods: A total of 102 patients diagnosed as ESCC were subjected to this study. These patients had a preoperative PET/CT examination to evaluate the existence of metastasis. The values of maximum standardized uptake value (SUVmax) in primary tumors and in metastasized lymph nodes were measured to analyze their relationship with various clinicopathologic characteristics including the status of tumor cell proliferation, which was assessed by immunohistochemistry for Ki-67. Results: The SUVmax of the primary tumor was positively correlated with tumor size and vessel invasion, and was positively related with the SUVmax of lymph nodal metastasis, especially in cases of poorly differentiated ESCC. The SUVmax of metastasized lymph nodes was higher in larger-sized metastasized lymph nodes, whereas the Ki-labeling index of lymph nodal metastasis was positively related with the SUVmax per unit area (SUVmax/mm2). The diagnostic accuracy of PET/CT (87.3%) was higher than that of conventional CT scans (78.4%). Conclusions: The improved diagnostic accuracy of PET/CT can be explained by its ability to detect actively progressive metastasis at an early phase regardless of size.

Jejunal interposition reconstruction with a stomach preserving esophagectomy improves postoperative weight loss and reflux symptoms for esophageal cancer patients

BACKGROUND Conventional reconstruction after an esophagectomy uses a gastric tube, which commonly causes several postoperative complaints such as gastric acid reflux in long-term survival cases. Intestinal interposition between the remnant esophagus and the stomach is an option to reduce complaints, and in this study, the advantages of jejunal interposition reconstruction with a stomach preserving esophagectomy (SPE) were assessed. MATERIALS AND METHODS Eleven cases of jejunal interposition with an SPE and 16 cases with gastric tube reconstruction as a control were subject to a comparison of operation time, amount of bleeding, postoperative quality of life, and endoscopic findings. RESULTS The SPE group had a longer operation time (SPE: 560 ± 121 min, control 414 ± 83 min, P = 0.038), whereas there was no significant difference in blood loss. Postoperative weight loss was significantly recovered in the SPE group (SPE versus control = 94.0 ± 5.4% versus 87.5 ± 4.7% at 3 mo, P = 0.017; 97.2 ± 7.5% versus 85.0 ± 5.2% at 6 mo, P = 0.010), and there was a significant decrease in the occurrence of reflux symptoms such as heartburn, odynophagia, and cough when jejunal interposition with an SPE was done. Furthermore, reflux esophagitis and Barretts epithelium were found in six out of 12 cases (50%) of the control group by postoperative endoscopy, while no cases in the SPE group had either condition (P < 0.01). CONCLUSIONS This reconstruction method is a promising option to improve postoperative quality of life, mainly due to the long-term elimination of reflux esophagitis, which assists in the recovery of postoperative weight loss.

Trastuzumab-Based Photoimmunotherapy Integrated with Viral HER2 Transduction Inhibits Peritoneally Disseminated HER2-Negative Cancer

Peritoneal dissemination is the most frequent metastasis in gastric cancer and is associated with poor prognosis. The lack of particular target antigens in gastric cancer other than HER2 has hampered the development of treatments for peritoneal dissemination of gastric cancer. We hypothesized that HER2-extracellular domain (HER2-ECD) gene transduction combined with trastuzumab-based photoimmunotherapy (PIT) might provide excellent and selective antitumor effects for peritoneal dissemination of gastric cancer. In vitro, adenovirus/HER2-ECD (Ad/HER2-ECD) efficiently transduced HER2-ECD into HER2-negative gastric cancer cells. Trastuzumab-IR700 (Tra-IR700)–mediated PIT induced selective cell death of HER2-ECD–transduced tumor cells. Ad/HER2-ECD also induced homogenous expression of HER2 in heterogeneous gastric cancer cells, resulting in uniform sensitivity of the cells to Tra-IR700–mediated PIT. Anti-HER2 PIT integrated with adenoviral HER2-ECD gene transfer was applied in mice bearing peritoneal dissemination of HER2-negative gastric cancer. Intraperitoneal administration of Ad/HER2-ECD and Tra-IR700 with PIT inhibited peritoneal metastasis and prolonged the survival of mice bearing MKN45. Furthermore, minimal side effects allowed the integrated therapy to be used repeatedly, providing better control of peritoneal dissemination. In conclusion, the novel therapy of molecular-targeted PIT integrated with gene transfer technology is a promising approach for the treatment of peritoneal dissemination in gastric cancer. Mol Cancer Ther; 15(3); 402–11. ©2016 AACR.