Outcome of maintenance systemic chemotherapy with drug-free interval for metastatic urothelial carcinoma.

OBJECTIVE: Aiming to achieve long-term disease control, maintenance systemic chemotherapy (MSC) with a 1-3-month drug-free interval is continued in selected patients. We report our experience of MSC for metastatic urothelial carcinoma (UC). METHODS: Of 228 metastatic UC patients treated with systemic chemotherapy, 40 (17.5%, 40/228) had continuously undergone MSC. Data on the regimen, cycle number, and reason for the discontinuation of MSC were also collected. We analyzed OS from the initiation of MSC until death or the last follow-up, using the log-rank test to assess the significance of differences. RESULTS: The median number of cycles of chemotherapy was 6, and the responses were CR in 6, PR in 20, SD in 13, and PD in 1 before MSC. Gemcitabine plus CDDP or carboplatin was mainly performed as MSC (70%, 28/40). MSC was repeated quarterly in 30 (75%, 30/40), every two months in 8 (20%, 8/40), and with other intervals in 2 (5%, 2/40). Overall, a median of 3.5 cycles (range: 1-29) of MSC was performed. The reason for the discontinuation of MSC was PD in 24 (60%, 24/40), favorable disease control in 9 (22.5%, 9/40), and myelosuppression in 3 (7.5%, 3/40), and for other reasons in 2 (5%, 2/40). MSC was ongoing in 2 (5%, 2/40). The median OS was 27 months from the initiation of MSC. PS0 (P = 0.0169), the absence of lung metastasis (P = 0.0387), and resection of the primary site (P = 0.0495) were associated with long-term survival after MSC. CONCLUSIONS: In selected patients, long-term systemic chemotherapy could be performed with a drug-free interval. Our maintenance strategy with cytotoxic drugs may become one of the treatment options for long-term disease control.

Role of lymph node dissection in the treatment of urothelial carcinoma of the upper urinary tract: multi-institutional relapse analysis and immunohistochemical re-evaluation of negative lymph nodes.

AIM: To determine the role of lymph node dissection (LND) in the treatment of urothelial carcinoma (UC) of the upper urinary tract (UUT). PATIENTS AND METHODS: [Study-1] A retrospective multi-institutional study evaluated 293 patients undergoing predominantly nephroureterectomy for UC of the UUT. Of 293 patients, 267 patients had pure UC and 26 demonstrated other histological components. Regarding the pathological node status, 130 patients had pN0 disease, 141 patients had pNx disease and 22 patients had pN+ disease. The sites of initial recurrence and time to first recurrence were reviewed. The sites of recurrence were classified as locoregional or distant recurrence. The relationship between node status and future recurrence was analyzed. [Study-2] Fifty-one patients treated by nephroureterectomy at Hokkaido University Hospital were included. All had LND and all LNs were negative on hematoxylin and eosin staining. We re-evaluated the presence of micrometastasis in LND specimens by anti-cytokeratin immunohistochemistory. RESULTS: [Study-1] Of 293 patients, 76 developed disease relapse. Regional lymph node recurrence was the most common site (34 patients). On multivariate analyses that adjusted for the effect of tumor stage and tumor grade, pNx (skipping LND) was an adverse factor not only for locoregional recurrence, but also for distant relapse. [Study-2] Immunohistochemistry identified micrometastases in 7 (14%) of 51 patients. Regarding survival, 5 of these 7 patients with micrometastases were alive at last follow-up. CONCLUSIONS: On relapse analysis, skipping LND was an adverse factor not only for locoregional recurrence, but also for distant relapse. Immunohistochemistry detected micrometastases in about 14% of patients previously diagnosed as pN0. These findings further support a potential therapeutic benefit of LND by eliminating micrometastases.

Adenovirus-mediated gene therapy for bladder cancer in an orthotopic model using a dominant negative H-ras mutant.

It has been suggested that abnormal Ras function is important in the carcinogenesis and progression of bladder cancer. Our aim was to investigate the efficacy of transurethral inoculation of an adenovirus expressing the dominant negative H-ras mutant N116Y against orthotopically implanted human bladder-cancer cells in nude mice. We used a replication-defective adenovirus vector containing the beta-galactosidase gene (AdCMV-LacZ) as a control and the N116Y gene (AdCMV-N116Y) as the therapeutic vector under the transcriptional control of the cytomegalovirus promoter. We initially investigated the in vitro growth-suppressive effects of AdCMV-N116Y on 2 human bladder-cancer cell lines, KU-7 and UMUC-2. Thereafter, we examined the inhibitory effects of AdCMV-N116Y on the 2 orthotopically implanted cell lines in nude mice. Intravesically created, orthotopic human bladder cancers were established in female KSN athymic nude mice with 1x 10(7) cancer cells. Then, 2, 3 and 4 days following implantation, 1 x 10(9) pfu of AdCMV-LacZ or AdCMV-N116Y were administered transurethrally. In vitro growth assays revealed significant growth suppression (>95%) with apoptosis of target cells treated with AdCMV-N116Y compared to AdCMV-LacZ. Transurethral inoculation of AdCMV-N116Y into the bladder brought about a significant reduction in size (73% to 90%) and number (47% to 78%) of orthotopically implanted human bladder tumors compared to AdCMV-LacZ or PBS. Normal mucosa in nude mice had minor inflammation with the infiltration of mononuclear cells. Our results suggest that gene therapy via transurethral inoculation of AdCMV-N116Y holds promise for the treatment of human bladder cancer.

Significance of the Grb2 and son of sevenless (Sos) proteins in human bladder cancer cell lines.

The epidermal growth factor (EGF) receptor has been suggested to have an important role in tumor initiation and progression of human bladder cancers. Grb2 protein, which is the downstream effector of the EGF receptor, acts as an adaptor protein between the EGF receptor and the Ras guanine-nucleotide exchange factor, son of sevenless (Sos) protein. Sos protein regulates the action of Ras protein by promoting the exchange of GDP for GTP. However, the significance of Grb2 and Sos proteins, which is related to EGF-triggered Ras activation, has not been elucidated in human bladder cancer. The aim of the present study is to clarify the significance of these proteins in human bladder cancer cell lines. In the present study, we used four human bladder cancer cell lines (T24, KU-7, UMUC-2, UMUC-6) and two kinds of cultured normal urothelial cells (HMKU-1, HMKU-2) isolated from patients with no malignancy. We examined the expression of EGF receptor, Grb2, and Sos proteins in these cells by Western blot analysis. Furthermore, the bladder cancer cell lines were subjected to sequence analysis to identify a point mutation in the c-H-ras gene at codon 12. There was no marked difference in the expression of the EGF receptor between human bladder cancer cell lines and cultured normal urothelial cells. On the other hand, expression of Grb2 and Sos proteins was substantially increased in all human bladder cancer cell lines examined in comparison with cultured normal urothelial cells, whether codon 12 of H-ras was mutated or not. These results suggest that the amplification of both Grb2 and SOS proteins plays an important role in the carcinogenesis of human bladder cancer.

Suppressive effects of dominant negative ras mutant N116Y on transformed phenotypes of human bladder cancer cells.

To investigate the suppressive effect of dominant negative H-ras mutant N116Y on transformed phenotypes, we established two N116Y ras mutant stable transfectant clones (C5, C13) of human bladder cancer cell line, UMUC-2. These N116Y ras mutant transfectants, especially the C5 cells, showed a dramatic change of cellular morphology and significantly reduced growth in soft agar compared to their control. Furthermore, phosphorylation of the Jun NH2-terminal kinase (JNK) was significantly decreased in these transfectants compared to the control. These results suggest that the N116Y-induced suppression of transformed phenotypes in UMUC-2 cells is associated with inhibition of JNK phosphorylation.

An improved intravesical model using human bladder cancer cell lines to optimize gene and other therapies.

Orthotopic implantation of human bladder cancer cells into immunodeficient mice is an important tool for studying the biology and effects of therapy. Nevertheless, the incidence of tumor implantation and growth by transurethral instillation of the human bladder cancer cells into murine bladders has been low or not reproducible. However, using a modified intravesical technique and the human bladder cancer cell lines, KU-7 and UM-UC-2, we have been able to obtain a high and reproducible incidence of superficial bladder tumors. Furthermore, intravesical administration of the LacZ adenovirus vector resulted in significant beta-galactosidase expression in these bladder tumors as well as the normal urothelium, which was associated with the removal of the glycosoaminoglycan layer. Because this modified technique produces a high incidence of superficial human tumor growth and allows the efficacy of gene transfer to be evaluated, it should be a useful model for the study of intravesical gene therapy for human bladder cancer.

Gelsolin gene therapy by retrovirus producer cells for human bladder cancer in nude mice.

Gelsolin, a regulator of the actin cytoskeleton, has been shown previously to act as a tumor suppressor in vitro and in vivo when introduced into certain cancer cell lines. To investigate the in vivo efficacy of gene therapy with the gelsolin gene, we inoculated nude mice with human urinary bladder cancer cells (UMUC-2 or DAB-1) and tested the effects of adding either retroviral DNA constructs containing gelsolin cDNA or retrovirus producer cells that produce the same retroviral constructs at high levels. The addition of retroviral gelsolin cDNA constructs did not inhibit tumor growth; however, this form of gene therapy, in which retrovirus producer cells were introduced, resulted in marked and reproducible tumor growth inhibition and prolonged survival time in the majority of animals tested. These findings demonstrate the potential for treating human urinary bladder carcinomas with the gelsolin gene.

Suppression of Erk activation and in vivo growth in esophageal cancer cells by the dominant negative Ras mutant, N116Y.

Our previous studies demonstrated that introduction of a dominant negative H-ras mutant, N116Y, inhibits the growth of various types of cancer cells in vitro. In this study, we tested the efficacy of N116Y in blocking the growth of esophageal cancer cells using an adenoviral vector. Infection with N116Y adenovirus, (AdCMV-N116Y), in which N116Y expression is driven by the cytomegalovirus promoter, significantly reduced the in vitro growth of all esophageal cancer cell lines studied. Esophageal cancer cells that contained wild-type K-ras and H-ras (TE8, SGF3, SGF7) were more sensitive to AdCMV-N116Y than HEC46 cells that expressed mutant K-ras protein. Most importantly, direct injection of AdCMV-N116Y into TE8- or SGF3-induced tumors in nude mice suppressed their growth significantly. To examine the suppressive mechanism of N116Y, cell cycle profile and the activation of extracellular signal-regulated kinase 2 (Erk2) were examined by flow cytometry and Western blot analysis, respectively. In TE8 cells, progression into S phase was clearly blocked after infection with AdCMV-N116Y. Infection with AdCMV-N116Y did not strongly suppress the activation of Erk2 after EGF stimulation in serum-starved HEC46 cells, whereas it completely suppressed activation in TE8, SGF3 and SGF7 cells. Our observations suggest that N116Y reduces growth of human esophageal cancer cells and suppresses the activation of Erk2; they also indicate that N116Y is a potential candidate gene for human esophageal cancer gene therapy.

The significance of Ras guanine nucleotide exchange factor, son of sevenless protein, in renal cell carcinoma cell lines.

PURPOSE: The aim of the present study is to clarify the significance of the Ras guanine-nucleotide exchange reaction in the proliferation of human renal cell carcinoma cell lines. MATERIALS AND METHODS: We examined the expression of human son of sevenless-1 (hSos-1) protein and the epidermal growth factor (EGF) receptor in human renal cell carcinoma cell lines by Western blot analysis. Additionally, a dominant negative H-ras mutant, N116Y, which is known to inhibit the Ras guanine-nucleotide exchange reaction, was transfected into these cell lines by lipofection. RESULTS: Human renal cell carcinoma cell lines expressed much higher amounts of the EGF receptor and hSos-1 protein than normal kidney tissue. Moreover, the N116Y ras mutant could strongly suppress cellular proliferation in these cell lines. CONCLUSIONS: Augmentation of the Ras guanine-nucleotide exchange reaction might be essential to the proliferation of human renal cell carcinoma cells.

Long term urinary prognosis of cervical cord injury patients.

We made a retrospective comparative study of 88 cervical cord injury patients concerning their long term urological prognosis. In all, 129 urinary complications have occurred in 54 cases (61.4%). The incidence of urinary complications was high in those with higher levels of injury (except C integral of 4 lesions), a complete injury, a younger age of onset and a longer period after injury. Patients who had an indwelling catheter and a suprapubic cystostomy showed a higher rate of urinary complications. Urodynamically, there was no significant difference between the presence and absence of detrusor hyperreflexia. Those with detrusor-sphincter dyssynergia (DSD) also showed no difference compared to those without DSD. For the prevention of urinary complications in cervical cord injury patients, proper urinary management with clean intermittent catheterisation (CIC), or low pressure voiding is necessary in the early period after the onset of the injury.