Naoyuki Tokunaga

Immunological evaluation of personalized peptide vaccination in combination with a 5-fluorouracil derivative (TS-1) for advanced gastric or colorectal carcinoma patients

The aim of the present study was to investigate the safety and immunological responses of personalized peptide vaccination in combination with oral administration of a 5‐fluorouracil derivative (TS‐1) in advanced gastric or colorectal carcinoma patients. Eleven patients (four with gastric cancer and seven with colorectal cancer) who failed to improve by prior TS‐1‐based chemotherapies were enrolled in this study. Peptides to be administered to patients were determined based on the presence of peptide‐specific cytotoxic T lymphocyte (CTL) precursors in peripheral blood mononuclear cells and peptide‐specific IgG in the plasma of cancer patients. Patients were vaccinated with peptides (a maximum of four) biweekly in combination with or without three different doses of TS‐1 (20, 40 and 80 mg/m2/day). Although grade 3 toxicity, including anemia (one patient) and neutropenia (one patient) were observed, the combination therapy was generally well tolerated. An increase in peptide‐specific IgG after the sixth vaccination was observed in the vast majority of patients irrespective of the dose of TS‐1 used. In contrast, an increase in peptide‐specific interferon‐γ production by CTL was most evident in patients who were administered the highest dose of TS‐1. Furthermore, in the patients who received 80 mg/m2/day TS‐1, CTL‐mediated cytotoxicity against cancer cells was maintained at the prevaccination level. These results indicate that administration of the standard dose (80 mg/m2/day) of TS‐1 in combination with a personalized peptide vaccination does not necessarily impede immunological responses in cancer patients, and could actually maintain or augment them. (Cancer Sci 2007; 98: 1113–1119)

Molecular therapy for peritoneal dissemination of xenotransplanted human MKN-45 gastric cancer cells with adenovirus mediated Bax gene transfer

Background: Gene therapy is an innovative therapeutic approach for cancer. An adenoviral vector expressing the tumour suppressor p53 gene (Ad/p53) is currently under clinical evaluation for various cancers. We recently developed a binary adenoviral vector system that can express the strong proapoptotic gene Bax (Ad/PGK-GV16+Ad/GT-Bax: Ad/Bax). Aims: To evaluate the potential of Bax gene therapy for gastric cancer, we assessed its antitumour effect in comparison with that of p53. Methods: The human gastric cancer cell lines MKN-1, MKN-7, MKN-28, and MKN-45 were treated with Ad/Bax or Ad/p53, and cell viability, transgene expression, and caspase activation were assessed in vitro. To compare the antitumour effects of Ad/Bax and Ad/p53 treatment in vivo, subcutaneous tumours and peritoneal dissemination of MKN-45 cells were generated in nude mice. Each mouse underwent intratumoral or intraperitoneal administration of viruses and the growth of implanted tumours was observed after treatment. Results: Treatment with Ad/Bax and Ad/p53 resulted in marked Bax and p53 protein expression and effective apoptosis induction in MKN-1, MKN-7, and MKN-28 cells in vitro. In contrast, MKN-45 cells showed resistance to Ad/p53 and only treatment with Ad/Bax resulted in activation of caspase 3 expression and massive apoptosis. Ad/Bax treatment was more effective in suppressing both subcutaneous and peritoneally disseminated MKN-45 tumours compared with Ad/p53 treatment. Conclusion: Ad/Bax treatment significantly inhibited the growth of even p53 resistant gastric cancer in vitro and in vivo. Therefore, adenovirus mediated Bax gene transfer may be useful in gene therapy for gastric cancers.

Antitumor Effect of Intratumoral Administration of Bone Marrow-Derived Dendritic Cells Transduced with Wild-Type p53 Gene

Purpose: Dendritic cells (DCs) are attractive effectors for cancer immunotherapy because of their potential to function as professional antigen-presenting cells for initiating cellular immune responses. The tumor suppressor gene p53 is pivotal in the regulation of apoptosis, and ∼50% of human malignancies exhibit mutation and aberrant expression of p53. We investigated the antitumor effect of intratumoral administration of bone marrow-derived dendritic cells transduced with wild-type p53 gene. Experimental Design: We examined whether intratumoral administration of DCs infected with recombinant adenovirus expressing murine wild-type p53 (Ad-mp53) could induce systemic antitumor responses against mutant p53-expressing tumors, highly immunogenic MethA, or weakly immunogenic MCA-207 implanted in syngeneic mice. Results: Accumulation of wild-type p53 protein in bone marrow-derived murine DCs could be successfully achieved by Ad-mp53 infection. Treatment with intratumoral injection of Ad-mp53-transduced DCs caused a marked reduction in the in vivo growth of established MethA and MCA-207 tumors with massive cellular infiltrates. Administration of p53-expressing DCs suppressed the growth of both injected MCA-207 tumors and untreated distant MCA-207 tumors, but not unrelated Lewis lung carcinoma tumors, suggesting the augmentation of systemic immunogenicity against MCA-207 tumor cells. Moreover, intratumoral injection of p53-expressing DCs had a greater antitumor effect than did s.c. immunization. Conclusions: Our results indicate that intratumoral administration of DCs expressing murine wild-type p53 leads to significant systemic immune responses and potent antitumor effects in mutant p53-expressing murine cancer models. These findings raise the possibility of using this strategy of intratumoral injection of p53-expressing DCs for human cancer treatment.

Late resistance to adenoviral p53-mediated apoptosis caused by decreased expression of Coxsackie-adenovirus receptors in human lung cancer cells

Adenovirus‐mediated wild‐type p53 gene transfer induces apoptosis in a variety of human cancer cells. Although clinical trials have demonstrated that a replication‐deficient recombinant adenovirus expressing the wild‐type p53 gene (Ad‐p53) is effective in suppressing growth of non‐small cell lung cancer (NSCLC), we often experienced late resistance to this treatment. To elucidate the mechanism of late resistance to Ad‐p53 in human lung cancer cells, we generated 5 different resistant variants from p53‐susceptible H1299 NSCLC cells by repeated infections with Ad‐p53. We first examined the transduction efficiency of adenoviral vector by Ad‐LacZ transduction followed by X‐gal staining in parental and 5 resistant H1299 cell lines. Their sensitivity to viral infection decreased in correlation with the magnitude of resistance, and Ad‐p53‐mediated tumor suppression could be restored by dose escalation of Ad‐p53 in the resistant variants. The expression of Coxsackie and adenovirus receptor (CAR) and αV integrins, which are cellular receptors for attachment and internalization of the virus, respectively, was next investigated in these cell lines. Flow cytometry revealed that αVβ3 and αVβ5 integrin expression was consistent, while p53‐resistant cell lines showed that diminished CAR expression correlated with the magnitude of the resistance. Our results demonstrated that decreased CAR expression could be one of the mechanisms of late resistance to Ad‐p53, which may have a significant impact on the outcome of adenovirus‐based cancer gene therapy.

A Case of Resected Cholangiolocellular Carcinomaduring Treatment for Lung Cancer

A Case of Resected Cholangiolocellular Carcinoma during Treatment for Lung Cancer Cholangiolocellular carcinoma is an extremely rare malignant primary liver tumor, accounting for less than 1% of primary liver tumors. We herein report a case of cholangiolocellular carcinoma during treatment for lung cancer. A woman following up after operation for lung cancer was found to have a solitary hepatic tumor in the left lobe of the liver at an abdominal computed tomography checkup. It showed early enhancement with hypovascular area of the center in the arterial phase and enhancement contrast retention in the delayed phase. The tumor was seen as a hypointense nodule in the hepatocellular phase of EOB magnetic resonance imaging. We diagnosed liver metastasis of lung cancer with differential diagnosis of cholangiocellular carcinoma. We performed extended left lobectomy of the liver. Histological and immunohistochemistry findings were compatible with cholangiolocellular carcinoma./p>

成人鼠径ヘルニア手術症例の臨床的検討：Mesh plug 法と PROLENE hernia system の比較

To compare the results of the PROLENE hernia system (PHS) and mesh-plug technique (MPT), a retrospective study of adult patients with inguinal hernia was performed. The total number of inguinal herniorrhaphies for the past 9 years was 376, and the numbers of operative treatments by PHS, MPT and the Bassini procedure were 79, 291 and 6, respectively. There were no significant differences either in the operating time or the hospitalization days. No postoperative complications were observed in the PHS group; however, 8 complications were found among the 291 cases (2.75 %) of the MPT group (hematoma, 3 ; seroma, 2 ; testitis, 1 ; mesh infection, 2). Out of the total 376 cases, the number of initial and recurrence cases was 355 and 21, respectively, and out of the 21 recurrence cases the number of initial surgeries by Bassini and MPT was 14 and 7, respectively. Among the 21 recurrence cases there were no recurrences after PHS.

A retrospective study of the PROLENE hernia system compared with the mesh‑plug technique

To compare the results of the PROLENE hernia system (PHS) and mesh-plug technique (MPT), a retrospective study of adult patients with inguinal hernia was performed. The total number of inguinal herniorrhaphies for the past 9 years was 376, and the numbers of operative treatments by PHS, MPT and the Bassini procedure were 79, 291 and 6, respectively. There were no significant differences either in the operating time or the hospitalization days. No postoperative complications were observed in the PHS group; however, 8 complications were found among the 291 cases (2.75 %) of the MPT group (hematoma, 3 ; seroma, 2 ; testitis, 1 ; mesh infection, 2). Out of the total 376 cases, the number of initial and recurrence cases was 355 and 21, respectively, and out of the 21 recurrence cases the number of initial surgeries by Bassini and MPT was 14 and 7, respectively. Among the 21 recurrence cases there were no recurrences after PHS.

Nonfunctioning endocrine tumor of the pancreas: A case report

We report a rare case of a very large nonfunctioning endocrine tumor of the pancreas without malignant histological features. A 63-year-old woman referred for appetite loss and general fatigue was found to have a tumor in the pancreas head. Computed tomography demonstrated a well-defined pancreatic tumor 45mm in diameter with hypervascular staining in the pancreas head. Angiography showed a hypervascular tumor of the pancreas head and a dilatation of the anterior superior and posterior superior pancreaticoduodenal arteries. The preoperative diagnosis was an endocrine tumor of the pancreas, with undeniable malignancy. Pylorus-preserving pancreaticoduodenectomy was performed. The histopathological diagnosis was a benign nonfunctioning endocrine tumor of the pancreas based on immunohistochemical staining for Chromogranin A, Synaptophysin, and NSE, but not for hormones. The tumor revealed a low labeling index (<2.0%) of Ki-67 indicating its benign character. No tumor recurrence has been identified in the 18 months since surgery.