Katsuyuki Hamada

Cytotoxic Effects of Recombinant Adenovirus p53 and Cell Cycle Regulator Genes (p21 sup WAF1/CIP1 and p16 sup CDKN4) in Human Prostate Cancers

AbstractPurpose: Overexpressing or restoring the basal levels of tumor suppressor genes in cancer cells can suppress tumorigenicity of cancer cells. In this communication, we compared tumor suppressive activities of three well-defined tumor suppressive genes (p53, p21WAF1/CIP1, and p16CDKN2) delivered individually to prostate cancer cells with adenoviral vector (Ad).Materials and Methods: Efficacy of growth inhibition by recombinant adenoviruses bearing p53, p21WAF1/CIP1, or p16CDKN2 (Ad5CMV-p53, Ad5CMV-p21, Ad5CMV-p16) genes were tested in vitro on androgen-dependent (LNCaP) and androgen-independent (C4-2, DU-145, and PC-3) human prostate cancer cells, ex vivo and in vivo on PC-3 tumor.Results: Ad5CMV-p53 was observed to exert the greatest growth inhibitory action on all of the cell lines tested; inhibition appeared to be cytolytic. In comparison to control Ad5CMV-PA added samples, the growth inhibitory action of Ad5CMV-p21 and Ad5CMV-p16 appeared to be cytostatic. Ad5CMV-p53 is more effective than Ad5CM...

Molecular cloning of human squamous cell carcinoma antigen 1 gene and characterization of its promoter.

The squamous cell carcinoma antigen (SCCA) serves as a serological marker for squamous cell carcinomas. Molecular cloning of the SCCA genomic region has revealed the presence of two tandemly arrayed genes, SCCA1 and SCCA2, which are 95% identical in nucleotide sequence. SCCA1 is a papain-like cysteine proteinase inhibitor, while SCCA2 is a chymotrypsin-like serine proteinase inhibitor. We analyzed here the sequence and the promoter activity of the 5-flanking region of the SCCA1 gene. Deletion analysis of SCCA1 and SCCA2 promoter identified a 471-bp core promoter region upstream of the transcription start site. The transcriptional activity of SCCA1 promoter was up-regulated in squamous cell carcinoma cells, compared with keratinocyte and adenocarcinoma cells. The ratios of SCCA1 to SCCA2 promoter activity in squamous cell carcinoma, keratinocyte and adenocarcinoma cells were respectively 1.6, 5.3 and 2.8. Position -50 of SCCA1 and SCCA2 promoters played an important role in determining the promoter activities of SCCA1 and SCCA2. These findings suggest that the transcriptional regulation of SCCA1 and SCCA2 might differ among squamous cell carcinoma, keratinocyte and adenocarcinoma cells, and that SCCA1 promoter might be a potential target of gene therapy for squamous cell carcinoma.

Urinary Disturbance after Therapy for Cervical Cancer: Urodynamic Evaluation and β2-Agonist Medication

Abstract: Urinary disturbance frequently develops following therapy for cervical cancer; however, no effective medical treatment has so far been reported. Sixty-five patients who developed urinary disturbance after radiation therapy, radical hysterectomy or radical hysterectomy with radiation therapy for cervical cancer underwent urodynamic assessment. Those who underwent radical hysterectomy with radiation therapy experienced the most severe urine loss, as determined by the pad test. All patients showed markedly reduced bladder compliance. A β2-agonist (mabuterol) significantly improved compliance, bladder capacity and flow rate. It is suggested that medication with mabuterol is a potential novel approach to the treatment of urinary disturbance after therapy for cervical cancer.

Evaluation of cellular immune responses in rhesus monkeys subjected to adenovirus-mediated gene transfer into the cervix

We reported previously that direct injection of a recombinant adenovirus (rAd), Ad5CMV-β-gal, into the cervix of the rhesus monkey resulted in efficient β-galactosidase expression in the cervix within 3 days. In these studies, we also observed the induction of anti-adenovirus (Ad)-specific immunoglobulin G responses after 22 days. In the continuation of evaluating the anti-Ad-specific immune responses resulting from this approach of gene targeting to the cervix, we measured the cellular immune responses. The introduction of Ad5CMV-β-gal into the cervix by direct injection, but not by the abrasion technique, resulted in the induction of strong proliferative responses against extracts of cells infected with Ad5CMV-β-gal but not against control uninfected cells. These responses were initially detected at 22 days postinjection and coincided with the abrogation of transgene expression. Significant levels of proliferative responses were maintained for ≤83 days. Multiple injections of rAds had no significant enhancing effect on either the level or longevity of the proliferative responses. At 3 days after the injection of Ad5CMV-β-gal, when the transgene expression in the cervix was clearly evident, proliferative responses against the rAd were not detectable. However, the production of low but significant amounts of interleukin-10, a cytokine characteristic of T helper type 2 responses that promote humoral immune responses, was observed at the 3-day point in these animals. These results suggest that significant differences exist between the kinetics of transgene expression and the priming of specific host immune responses, and that these differences may be important for devising alternate strategies to improve techniques for Ad-mediated gene therapy of cervical cancer.