Bilateral laparosocopic lateral lymph node dissection by the totally extraperitoneal approach after intersphincteric resection of the lower rectum: report of a case.

Introduction and Importance: Lateral lymph node dissection (LLND) for recurrent lateral pelvic lymph node metastasis could be the only surgical treatment to improve its prognosis, but is difficult and challenging technically. Case Presentation: A 75-year-old Japanese man who underwent a radical laparoscopic intersphincteric resection to treat double lower rectal cancer. Computed tomography and MRI showed lower rectal wall thickening and bilateral lateral lymph node swelling. The authors scheduled and performed the LLND for recurrent lateral pelvic lymph nodes after ISR by the totally extraperitoneal (TEP) approach. The bottom of the obturators lymph node (#263D) were positive for metastasis histologically. Clinical Discussion: The TEP approach is an especially effective option for the treatment of bilateral LLND. Conclusion: Herein, the authors introduce our surgical technique: successful challenging treatment of the LLND by the TEP approach after intersphincteric resection of the lower rectum.

Histone deacetylase inhibitor FR901228 enhances the antitumor effect of telomerase-specific replication-selective adenoviral agent OBP-301 in human lung cancer cells.

Replication-competent oncolytic viruses are being developed for human cancer therapy. We previously reported that an attenuated adenovirus OBP-301 (Telomelysin), in which the human telomerase reverse transcriptase promoter element drives expression of E1A and E1B genes linked with an internal ribosome entry site, could replicate in and causes selective lysis of human cancer cells. Infection efficiency in target cancer cells is the most important factor that predicts the antitumor effects of OBP-301. The objectives of this study are to examine the effects of the histone deacetylase inhibitor FR901228 on the level of coxsackie and adenovirus receptor (CAR) expression and OBP-301-mediated oncolysis in human non-small cell lung cancer cell lines. Flow cytometric analysis revealed up-regulated CAR expression in A549 and H460 cells following treatment with 1 ng/ml of FR901228, which was associated with increased infection efficiency as confirmed by replication-deficient beta-galactosidase-expressing adenovirus vector. In contrast, neither CAR expression nor infection efficiency was affected by FR901228 in H1299 cells. To visualize and quantify viral replication in the presence of FR901228, we used OBP-401 (Telomelysin-GFP) that expresses the green fluorescent protein (GFP) reporter gene under the control of the cytomegalovirus promoter in the E3 region. Fluorescence microscopy and flow cytometry showed that FR901228 increased GFP expression in A549 and H460 cells following OBP-401 infection in a dose-dependent manner, but this effect did not occur in H1299 cells. In addition, OBP-301 and FR901228 demonstrated a synergistic antitumor effect in A549 cells in vitro, as confirmed by isobologram analysis. Our data indicate that FR901228 preferentially increases adenovirus infectivity via up-regulation of CAR expression, leading to a profound oncolytic effect, which may have a significant impact on the outcome of adenovirus-based oncolytic virotherapy.

Enhanced oncolysis by a tropism-modified telomerase-specific replication-selective adenoviral agent OBP-405 ('Telomelysin-RGD').

Replication-competent oncolytic viruses are being developed for human cancer therapy. We previously reported that an attenuated adenovirus (OBP-301, 'Telomelysin'), in which the hTERT promoter element drives expression of E1A and E1B genes linked with an IRES, could replicate in cancer cells, and causes selective lysis of cancer cells. We further constructed OBP-405 ('Telomelysin-RGD') that contains an RGD motif in the HI loop of the fiber knob. We examined whether OBP-405 could be effective in overcoming the limitations of OBP-301, specifically their inefficient infection into cells lacking the primary receptor, the coxsackievirus and adenovirus receptor (CAR). By flow cytometric analysis, H1299 (lung) and SW620 (colorectal) tumor cells showed high levels of CAR expression, whereas LN444 (glioblastoma), LNZ308 (glioblastoma), and H1299-R5 (lung) tumor cells were negative for CAR expression. A quantitative real-time PCR analysis demonstrated that fiber-modified OBP-405 infected more efficiently than OBP-301, although the intracellular replication rate of both viruses was consistent. The comparative antitumor effect of fiber-modified OBP-405 and unmodified OBP-301 for human cancer cells was evaluated in vitro by XTT assay as well as in vivo by using athymic mice carrying xenografts. OBP-405 had a profound oncolytic effect on human cancer cell lines compared to OBP-301, in particular on cells with low CAR expression. Intratumoral injection of 10(7) plaque-forming units of OBP-405 into CAR-negative H1299-R5 lung tumor xenografts in nu/nu mice resulted in a significant inhibition of tumor growth and long-term survival in all treated mice. Moreover, selective replication of OBP-405 in the distant, uninjected H1299-R5 tumors was demonstrated. Our results suggest that fiber-modified replication-competent adenovirus OBP-405 exhibits a broad target range by increasing infection efficiency, an outcome that has important implications for the treatment of human cancers.

Visualization of intrathoracically disseminated solid tumors in mice with optical imaging by telomerase-specific amplification of a transferred green fluorescent protein gene.

Currently available methods for detection of tumors in vivo such as X-ray, computed tomography, and ultrasonography are noninvasive and have been well studied; the images, however, are not specific for tumors. Direct optical imaging of tumor cells in vivo that can clearly distinguish them from surrounding normal tissues may be clinically useful. Here, we describe a new approach to visualizing tumors whose fluorescence can be detected using tumor-specific replication-competent adenovirus (OBP-301, Telomelysin) in combination with Ad-GFP, a replication-deficient adenovirus expressing green fluorescent protein (GFP). Human telomerase reverse transcriptase is the catalytic subunit of telomerase, which is highly active in cancer cells but quiescent in most normal somatic cells. We constructed an adenovirus 5 vector in which the human telomerase reverse transcriptase promoter element drives expression of E1A and E1B genes linked with an internal ribosome entry site and showed that OBP-301 replicated efficiently in human cancer cells, but not in normal cells such as human fibroblasts. When the human lung and colon cancer cell lines were infected with Ad-GFP at a low multiplicity of infection, GFP expression could not be detected under a fluorescence microscope; in the presence of OBP-301, however, Ad-GFP replicated in these tumor cells and showed strong green signals. In contrast, coinfection with OBP-301 and Ad-GFP did not show any signals in normal cells such as fibroblasts and vascular endothelial cells. We also found that established subcutaneous tumors could be visualized after intratumoral injection of OBP-301 and Ad-GFP. A549 human lung tumors and SW620 human colon tumors transplanted into BALB/c nu/nu mice were intratumorally injected with 8 x 10(5) plaque-forming units of Ad-GFP in combination with 8 x 10(6) plaque-forming units of OBP-301. Within 3 days of treatment, the fluorescence of the expressed GFP became visible by a three-chip color cooled charged-coupled device camera in these tumors, whereas intratumoral injection of Ad-GFP alone could not induce GFP fluorescence. Moreover, intrathoracic administration of Ad-GFP and OBP-301 could visualize disseminated A549 tumor nodules in mice after intrathoracic implantation. Our results indicate that intratumoral or intrathoracic injection of Ad-GFP in combination with OBP-301 might be a useful diagnostic method that provides a foundation for future clinical application.

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 alphaV integrins, which are cellular receptors for attachment and internalization of the virus, respectively, was next investigated in these cell lines. Flow cytometry revealed that alphaVbeta3 and alphaVbeta5 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.

Telomerase-specific replication-selective virotherapy for human cancer.

PURPOSE: Replication-selective tumor-specific viruses present a novel approach for treating neoplastic disease. These vectors are designed to induce virus-mediated lysis of tumor cells after selective viral propagation within the tumor. Telomerase activation is considered to be a critical step in carcinogenesis, and its activity is closely correlated with human telomerase reverse transcriptase (hTERT) expression. We investigated the antitumor effect of the hTERT-specific replication-competent adenovirus on human cancer cells. EXPERIMENTAL DESIGN: We constructed an adenovirus 5 vector [tumor- or telomerase-specific replication-competent adenovirus (TRAD)], in which the hTERT promoter element drives expression of E1A and E1B genes linked with an internal ribosome entry site, and we examined the selective replication and antitumor effect in human cancer cells in vitro and in vivo. RESULTS: TRAD induced selective E1A and E1B expression in human cancer cells, but not in normal cells such as human fibroblasts. TRAD replicated efficiently and induced marked cell killing in a panel of human cancer cell lines, whereas replication as well as cytotoxicity was highly attenuated in normal human fibroblasts lacking telomerase activity. In nu/nu mice carrying s.c. human lung tumor xenografts, intratumoral injection of TRAD resulted in a significant inhibition of tumor growth. No evidence of TRAD was identified in tissues outside of the tumors, despite the presence of TRAD in the circulation. Moreover, TRAD replication in the distant, noninjected tumors was demonstrated. CONCLUSIONS: Our results suggest that the hTERT promoter confers competence for selective replication of TRAD in human cancer cells, an outcome that has important implications for the treatment of human cancers.