Molecular determinants of cell death induction following adenovirus-mediated gene transfer of wild-type p53 in prostate cancer cells

Adenoviral vectors expressing wild-type p53 (Ad-p53) induce apoptosis in different types of cancer cells. The therapeutic utility of Ad-p53 is now being evaluated in prostate-cancer patients. Bcl-2 is frequently expressed by prostate-cancer cells and has previously been shown to inhibit p53-mediated cell death following genotoxic stress. We studied the impact of bcl-2 on Ad-p53-induced cell death in human prostate-cancer cells. Human prostate-cancer cell lines LNCaP (p53 wt) and PC3 (p53 mut) were stably transfected with bcl-2. After p53 transduction, cell viability, apoptosis induction and modulation of specific apoptosis-regulatory proteins were assessed. LNCaP vector control and bcl-2-expressing cells underwent similar decreases in viability associated with apoptosis induction following Ad-p53 infection. Increased bcl-2 expression provided significant protection to PC3 cells transduced with Ad-p53. These findings are correlated with modulations in bax, bcl-2, bcl-x(L) and p21 protein levels. These data suggest that Ad-p53 may be useful in the treatment of some prostate cancers.

NCCN Practice Guidelines for Prostate Cancer

Systemic therapies for prostate cancer are likely to improve, and as they do, they will have enormous impact on the treatment of high-risk and locally advanced cancers. Further technical improvements in radiotherapy and alternative local modalities, such as cryoablation, are also likely, and will bring even more options for local control. It is certain these guidelines will continue to evolve.

A Phase II trial of bryostatin-1 for patients with metastatic renal cell carcinoma

BACKGROUND

Patients with metastatic renal cell carcinoma have a poor prognosis and no standard therapy is available. The authors performed a Phase II trial of the novel agent bryostatin-1 in this patient population.

METHODS

In all, 30 patients with measurable, previously untreated metastatic renal cell carcinoma were studied. Patients had excellent physiologic reserve and preserved performance status. Bryostatin-1 (25 microg/m(2)) was given in the PET (polyethyleneglycol, ethanol, and Tween 80) formulation as a 30-minute intravenous infusion on Days 1, 8, and 15 of each 28-day cycle. In general, treatment was continued until disease progression.

RESULTS

Two patients had significant objective responses, although methodologic problems made interpretation difficult. The median time to progression for all patients was 2.1 months; the median overall survival was 13.1 months. The treatment was generally well tolerated. Myalgia was the most common adverse event. One patient died while on study. This was a sudden death for a patient receiving a 15th cycle of therapy. Aside from this patient (for whom the correlation of study drug to death was not clear), no Grade 4 nonhematologic toxicity was encountered in more than 150 treatment courses delivered.

CONCLUSIONS

There is minimal, if any, clinically relevant single-agent activity of bryostatin-1 at this dose and schedule for patients with metastatic renal cell carcinoma.

Calcium signals in prostate cancer cells: specific activation by bone-matrix proteins

Cancer of the prostate commonly metastasizes to bony sites where cells acquire an aggressive, rapidly proliferating, androgen-independent phenotype. The interaction between bone and prostate, thus, becomes a key factor in disease progression. Fluctuations in intracellular ionized Ca2+ [Ca2+]i are rapid, regulated signal transduction events often associated with cell proliferation. Hence, Ca2+ signals provide a convenient measure of early events in cancer cell growth. This study developed single cell fluorescent imaging techniques to visualize Ca2+ signals in Fura-2 loaded prostatic cancer cell lines of various metastatic phenotypes. Solubilized bone fractions containing extracellular matrix and associated proteins were tested for the ability to trigger Ca2+ signals in prostate cancer cell lines. Fractions representing the complete repertoire of non-collagenous proteins present in mineralized bone were tested. Results demonstrated that two bone fractions termed D3b- and D4a-triggered Ca2+ signals in prostate cancer cells derived from bone (PC-3), but not brain (DU-145) metastases of prostate cancer. Lymph-node derived LNCaP cells also did not produce a Ca2+ signal in response to addition of soluble bone matrix. No other bone fractions produced a Ca2+ signal in PC-3 cells. It is of interest that bone fractions D3b and D4a contain a number of non-collagenous matrix proteins including osteonectin (SPARC) and osteopontin (OPN), as well as prothrombin. Moreover, antibody LM609 that recognizes the alpha v beta 3 integrin, blocks the ability of OPN to trigger a Ca2+ transient in PC-3 cells. These studies support a conclusion that bone-matrix proteins play a role in the growth and progression of metastatic prostate cancer, and that prior growth in bone may be associated with development of a bone-matrix-responsive phenotype.

Cyclophosphamide and carboplatin and selective consolidation in advanced seminoma

This prospective Phase II study assesses the clinical efficacy and complications of a treatment regimen of combination chemotherapy with cyclophosphamide and carboplatin and selective consolidation in advanced seminoma. Of 46 patients who entered the study between December 1992 and October 1998, 46 were evaluable. Thirty-two achieved a complete remission (70%; 95% confidence interval, 56-83%) after chemotherapy alone. Fourteen achieved a complete remission (30%; 95% confidence interval, 18-46%) after chemotherapy plus consolidation. Forty-three of the 46 patients (93%; 95% confidence interval, 82-97%) remained in remission after a median follow-up period of 27.4 months. No patient experienced nephrotoxic, neurotoxic, or ototoxic effects or hemorrhagic cystitis. No patient had neutropenic fever requiring hospitalization. Thirteen % required platelet transfusions, and 9% required transfusions of packed RBCs. For patients with advanced seminoma, treatment with cyclophosphamide and carboplatin and selective consolidation is safe and effective.

Superimposed histologic and genetic mapping of chromosome 9 in progression of human urinary bladder neoplasia: implications for a genetic model of multistep urothelial carcinogenesis and early detection of urinary bladder cancer

The evolution of alterations on chromosome 9, including the putative tumor suppressor genes mapped to the 9p21-22 region (the MTS genes), was studied in relation to the progression of human urinary bladder neoplasia by using whole organ superimposed histologic and genetic mapping in cystectomy specimens and was verified in urinary bladder tumors of various pathogenetic subsets with longterm follow-up. The applicability of chromosome 9 allelic losses as non-invasive markers of urothelial neoplasia was tested on voided urine and/or bladder washings of patients with urinary bladder cancer. Although sequential multiple hits in the MTS locus were documented in the development of intraurothelial precursor lesions, the MTS genes do not seem to represent a major target for p21-23 deletions in bladder cancer. Two additional tumor suppressor genes involved in bladder neoplasia located distally and proximally to the MTS locus within p22-23 and p11-13 regions respectively were identified. Several distinct putative tumor suppressor gene loci within the q12-13, q21-22, and q34 regions were identified on the q arm. In particular, the pericentromeric q12-13 area may contain the critical tumor suppressor gene or genes for the development of early urothelial neoplasia. Allelic losses of chromosome 9 were associated with expansion of the abnormal urothelial clone which frequently involved large areas of urinary bladder mucosa. These losses could be found in a high proportion of urothelial tumors and in voided urine or bladder washing samples of nearly all patients with urinary bladder carcinoma.

Development of an adenovirus vector with tetracycline-regulatable human tumor necrosis factor alpha gene expression

Tumor necrosis factor alpha (TNF-alpha) is a multifunctional cytokine with direct antitumor activity. However, clinical trials using TNF-alpha for cancer treatment have been disappointing due in part to its severe side effects, and it has been estimated that TNF-alpha therapy would be effective only at 5-25 times the maximum tolerated dose. We have recently modified a tetracycline (Tc) repressor/operator-based mammalian gene expression system and have generated a Tc-responsive recombinant adenovirus vector, AdVtTA.TNF-alpha. A variety of human tumor cells and T lymphocytes transduced by AdVtTA.TNF-alpha secreted high-titer (5,000-100,000 pg/10(6) cells/24 h) and biologically active TNF-alpha in the absence of Tc. Expression of TNF-alpha in the transduced cells was nondetectable when the culture medium contained as little as 0.1 microg/ml of Tc. At least a fraction of the clonogenic cells from human peripheral blood stem cell concentrates were also transducible by AdVtTA.TNF-alpha. The availability of this type of adenovirus vector opens a door to tumor- or organ-specific delivery of high-dose TNF-alpha and other therapeutic gene products for systemic cancer gene therapy.

Superimposed histologic and genetic mapping of chromosome 17 alterations in human urinary bladder neoplasia

Multistep alterations of chromosome 17 in the progression of human urinary bladder neoplasia were studied by superimposed histologic and genetic mapping. The p53 gene was included in the analysis as a model tumor suppressor gene that is frequently involved in urothelial carcinogenesis. The strategy provided a systematic approach to the study of multistep genomic alterations that occur as neoplasia progresses from precursor intraurothelial conditions to invasive cancer. This was accomplished by sampling the entire mucosa of the organ and displaying microscopically identified invasive cancer and precursor conditions in the form of a histologic map. Subsequent isolation of DNA provided a set of samples in which the search for genetic alterations was performed and superimposed on the histologic map. This approach disclosed multifocal allelic losses of chromosome 17 in the early preinvasive phases of urothelial neoplasia. The alterations were predominantly confined to the p12-13, q22-11 and q24-25 regions. Mutations and allelic losses of the p53 gene were mapped to early preinvasive phases of urothelial neoplasia. The data provide detailed analysis of chromosome 17 allelic losses that occur in the development and progression of urothelial neoplasia and represent the first step for genome-wide modeling of multistep human urothelial carcinogenesis.

Optimal delivery of perioperative chemotherapy: preliminary results of a randomized, prospective, comparative trial of preoperative and postoperative chemotherapy for invasive bladder carcinoma

PURPOSE

We performed a planned interim analysis of a randomized trial comparing initial to postoperative chemotherapy for bladder cancer. The purpose of our analysis was to detect early evidence of survival differences, tolerance to therapy influenced by the sequence of treatment, predictive value of clinical state and influence of methotrexate, vinblastine, doxorubucin and cisplatin (M-VAC) on bladder resectability.

MATERIALS AND METHODS

A total of 100 consecutive patients were randomized to receive 2 M-VAC courses before and 3 courses after surgery (group 1) or 5 adjuvant M-VAC courses following cystectomy (group 2). Survival, clinical response, clinical and pathological stage, and toxicity were evaluated in this second timed interim analysis.

RESULTS

Of all patients 70% received at least 4 M-VAC courses. Overall survival at 31.7 months (range 1.8 to 87.7) was similar in groups 1 (60%) and 2 (63%), and independent of clinical stage. Preoperative clinical staging accurately identified patients at high risk for recurrence, while 37 of the 48 group 2 patients (77%) were considered at high risk by pathological staging (P3b, P4a, node-positive and unresectable disease). Comparison of pathological stage revealed that 14 of the 51 group 1 patients (28%) achieved stage P0 while only 1 of the 48 group 2 patients (2%) had P0 disease at surgery (p= 0.00043). Disease was unresectable in 3 group 1 (6%) and 8 group 2 patients (17%, p= 0.09). Tolerance to treatment was not significantly different in the 2 study arms.

CONCLUSIONS

No survival advantage was noted between neoadjuvant and adjuvant M-VAC in our interim analysis. However, results suggest that M-VAC chemotherapy may be effective in increasing the resectability of localized bladder cancer and may contribute to organ preservation. Clinical stage was a reliable predictor of pathological findings at surgery. Future studies can use clinical staging to determine therapy before surgery for the select stages that we treated. Identification of the subset likely to achieve complete pathological remission will permit the selection of patients for organ preservation strategies.

A phase I trial of intermittent high-dose alpha-interferon and dexamethasone in metastatic renal cell carcinoma

BACKGROUND

Evidence exists that the toxic of alpha-interferon can be ameliorated by co-administration of dexamethasone without compromise of therapeutic efficacy. We therefore conducted a phase I trial to determine the maximum tolerated dose of intermittent interferon when combined with oral dexamethasone.

PATIENTS AND METHODS

Thirty patients with metastatic renal cell carcinoma were enrolled. The starting dose of interferon was 20 million IU/m2/day given as a subcutaneous injection days 1 to 4 of each 14 day cycle. Dose levels were escalated at increments of 5 million IU/m2. Dexamethasone 4 mg was administered orally every 6 hours during administration of high-dose interferon. Low-dose maintenance interferon, 3 million IU/m2/day, was administered without dose escalation on days 5 to 14 of each cycle.

RESULTS

The maximum tolerated dose of intermittent high-dose interferon was 40 million IU/m2/day. The dose limiting toxicity was fatigue. EEG abnormalities developed in five patients and neuropsychiatric parameters deteriorated significantly in seventeen.

CONCLUSIONS

We conclude that co-administration of dexamethasone improves the tolerance of intermittent high-dose interferon. The results of this trial may be useful in designing high-dose interferon regimens for renal cell carcinoma and other interferon-sensitive diseases.

Expression of the protooncogene bcl-2 in the prostate and its association with emergence of androgen-independent prostate cancer

The significance of apoptosis in relation to the development and progression of prostate cancer remains largely undefined. bcl-2 is an oncogene that functions by overriding apoptosis. bcl-2 expression was localized to the basal epithelial cells in the normal human prostate with the use of immunohistochemistry. Androgen-dependent and androgen-independent prostate carcinomas were evaluated immunohistochemically for bcl-2 expression. bcl-2 was undetectable in 13 of 19 cases of androgen-dependent cancers. In contrast, androgen-independent cancers displayed diffuse, high levels of bcl-2 staining (P < 0.01). In rats, steady-state levels of bcl-2 mRNA, assessed by S1 assays, reached maximum levels 10 days following castration. Addition of exogenous testosterone with, or without, flutamide demonstrated that the increased bcl-2 mRNA resulted from androgen ablation. Our findings indicate that bcl-2 expression is augmented following androgen ablation and is correlated with the progression of prostate cancer from androgen dependence to androgen independence.

Treatment of chemotherapy-refractory metastatic urothelial tumors

Patients with unresectable bladder carcinoma unresponsive to standard chemotherapy have a short survival, but recent clinical trials of salvage treatment have produced some good results. Changes in the dosage of M-VAC; 5-fluorouracil, alpha-interferon, and cisplatin; and gallium nitrate show promise.

The inhibition of the paracrine progression of prostate cancer as an approach to early therapy of prostatic carcinoma

The prevalence of neural elements in prostatic carcinoma and their effects on the behavior of the lesion have recently been recognized. Recent reports suggest that chromogranin-A- and neuron-specific enolase-expressing tumors have an earlier progression and a lower response rate to hormonal therapy. The extreme presentation of this tumor is presumed to be small cell carcinoma of the prostate. This bombesin-secreting tumor, which has a characteristic clinical picture of early visceral involvement, wide-ranging metastases, and a relatively low rate of expression of PSA and PAP, is highly responsive to chemotherapy. The relatively high rate of expression of neural elements in primary prostatic carcinoma is discordant with the low frequency of clinical small cell carcinoma of the prostate. In order to account for these differences, one can assume that neural elements may play a role in the progression of this disease by either developing their own neoplastic process (small cell carcinoma of the prostate) or, in the majority of cases, causing paracrine progression of the tumor. Bombesin is typically secreted by small cell carcinoma of the lung and possibly by the prostate. It has been shown to be a growth factor mediating the progression of this disease in a number of experiments. Preclinical data demonstrate increased invasiveness and increased proliferation associated with bombesin in the treatment of prostatic carcinoma. Based on the hypothesis that neural peptides may be important mediators of androgen-independent growth of prostatic carcinoma as well as predicting poor prognosis, inhibition of these factors may represent a therapeutic strategy of relevance for the treatment of patients with prostatic carcinoma.

Effects of granulocyte-macrophage colony-stimulating factor in iatrogenic myelosuppression, bone marrow failure, and regulation of host defense

In early studies, recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) has been found to reduce the depth and duration of granulocytopenia in the settings of cancer chemotherapy and autologous bone marrow transplantation. In patients with myelodysplastic syndrome or aplastic anemia. GM-CSF has produced increased marrow cellularity and marked leukocyte responses, and multilineage effects have been observed in some patients. The available data suggest that the use of GM-CSF in these settings is associated with a decreased incidence of infection as compared with that in historical controls or pretreatment periods and that it may enhance the ability to deliver optimal doses of cancer chemotherapy. Other findings suggest that GM-CSF may be useful in regulating host response to infection when used in combination with antimicrobial therapy in neutropenic patients. However, a precise determination of the ability of this agent to significantly affect patient morbidity or mortality in these various contexts awaits the results of larger, longer-term, randomized, controlled trials.

Clinical stage I nonseminomatous and mixed germ cell tumors of the testis. A clinicopathologic study of 93 patients on a surveillance protocol after orchiectomy alone

This study of 93 patients with Stage I nonseminomatous and mixed germ cell testicular tumors who were placed in a surveillance study following orchiectomy was designed to evaluate pathologic prognostic factors. Follow-up was at least 12 months post-orchiectomy except for one patient who was followed for 9 months. Lymphatic invasion was identified in 26 patients, 62% of whom developed distant metastases; metastasis developed in only 18% of 67 patients without lymphatic invasion (P less than 0.01). Relapse was also associated with the presence of embryonal carcinoma. Of 81 patients with an embryonal carcinoma component, 35% developed metastases, whereas none of those without an embryonal carcinoma developed metastasis (P = 0.05). Effects of other histologic features and tumor size were not significant. Lymphatic invasion appeared to be a significant poor prognostic factor, and embryonal carcinoma was an independent poor prognostic factor.

Carcinoembryonic antigen and beta-human chorionic gonadotropin as serum markers for advanced urothelial malignancies

Serum levels of carcinoembryonic antigen and beta-subunit of human chorionic gonadotropin were measured in 92 patients with advanced urothelial malignancies referred to us for chemotherapy. Elevations of carcinoembryonic antigen and/or beta-human chorionic gonadotropin occurred in 60 of the 92 patients (65 per cent). Minimal elevations (less than 50 per cent above the normal range) occurred in 25 patients (27 per cent), while 35 (38 per cent) had significant elevations (more than 50 per cent above the normal range). Of the latter patients carcinoembryonic antigen alone was elevated in 16 (17 per cent), beta-human chorionic gonadotropin alone in 13 (14 per cent) and both in 6 (6 per cent). Among the 24 patients with initially elevated levels whose markers were re-evaluated during therapy the marker levels correlated with disease course in all 15 whose elevations were more than 50 per cent and in 4 of 9 with minimal elevations. In patients with adenocarcinoma of the bladder the carcinoembryonic antigen level frequently was elevated (9 of 10). We conclude that serum levels of carcinoembryonic antigen or beta-human chorionic gonadotropin are significantly elevated (more than 50 per cent above the normal range) in 38 per cent of the patients with advanced urothelial malignancies and can be used as tumor markers, since they correlate with the clinical course of the patient and the response to therapy. Serum carcinoembryonic antigen levels usually are elevated in patients with bladder adenocarcinoma.

Endodermal sinus tumor of the mediastinum. Report of apparent cure in two patients with extensive disease

Primary endodermal sinus tumor (EST) of the mediastinum has been regarded as a rare and rapidly fatal germ cell neoplasm. We describe two cases of extensive EST treated with a new high-dose sequential combination chemotherapy regimen (CISCA-VB) followed by radical surgical excision. They are alive at 11 and 20 months, respectively, postoperatively. These cases stand in marked contrast to previously reported series. A new approach to the management of this tumor is proposed.