Phase I dose-escalating trial of Escherichia coli purine nucleoside phosphorylase and fludarabine gene therapy for advanced solid tumors.

BACKGROUND: The use of Escherichia coli purine nucleoside phosphorylase (PNP) to activate fludarabine has demonstrated safety and antitumor activity during preclinical analysis and has been approved for clinical investigation. PATIENTS AND METHODS: A first-in-human phase I clinical trial (NCT 01310179; IND 14271) was initiated to evaluate safety and efficacy of an intratumoral injection of adenoviral vector expressing E. coli PNP in combination with intravenous fludarabine for the treatment of solid tumors. The study was designed with escalating doses of fludarabine in the first three cohorts (15, 45, and 75 mg/m(2)) and escalating virus in the fourth (10(11)-10(12) viral particles, VP). RESULTS: All 12 study subjects completed therapy without dose-limiting toxicity. Tumor size change from baseline to final measurement demonstrated a dose-dependent response, with 5 of 6 patients in cohorts 3 and 4 achieving significant tumor regression compared with 0 responsive subjects in cohorts 1 and 2. The overall adverse event rate was not dose-dependent. Most common adverse events included pain at the viral injection site (92%), drainage/itching/burning (50%), fatigue (50%), and fever/chills/influenza-like symptoms (42%). Analysis of serum confirmed the lack of systemic exposure to fluoroadenine. Antibody response to adenovirus was detected in two patients, suggesting that neutralizing immune response is not a barrier to efficacy. CONCLUSIONS: This first-in-human clinical trial found that localized generation of fluoroadenine within tumor tissues using E. coli PNP and fludarabine is safe and effective. The pronounced effect on tumor volume after a single treatment cycle suggests that phase II studies are warranted. CLINICALTRIALSGOV IDENTIFIER: NCT01310179.

Preliminary results of Radiation Therapy Oncology Group 97-03: a randomized phase ii trial of concurrent radiation and chemotherapy for advanced squamous cell carcinomas of the head and neck.

PURPOSE: To define further the role of concurrent chemoradiotherapy for patients with advanced squamous carcinoma of the head and neck. PATIENTS AND METHODS: The Radiation Therapy Oncology Group developed this three-arm randomized phase II trial. Patients with stage III or IV squamous carcinoma of the oral cavity, oropharynx, or hypopharynx were eligible. Each of three arms proposed a radiation schedule of 70 Gy in 35 fractions. Patients on arm 1 were to receive cisplatin 10 mg/m(2) daily and fluorouracil (FU) 400 mg/m(2) continuous infusion (CI) daily for the final 10 days of treatment. Treatment on arm 2 consisted of hydroxyurea 1 g every 12 hours and FU 800 mg/m(2)/d CI delivered with each fraction of radiation. Arm 3 patients were to receive weekly paclitaxel 30 mg/m(2) and cisplatin 20 mg/m(2). Patients randomly assigned to arms 1 and 3 were to receive their treatments every week; patients on arm 2 were to receive their therapy every other week. RESULTS: Between 1997 and 1999, 241 patients were entered onto study; 231 were analyzable. Ninety-two percent, 79%, and 83% of patients on arms 1, 2, and 3, respectively, were able to complete their radiation as planned or with an acceptable variation. Fewer than 10% of patients had unacceptable deviations or incomplete chemotherapy in the three arms. Estimated 2-year disease-free and overall survival rates were 38.2% and 57.4% for arm 1, 48.6% and 69.4% for arm 2, and 51.3% and 66.6% for arm 3. CONCLUSION: We have demonstrated that three different approaches of concurrent multiagent chemotherapy and radiation were feasible and could be delivered to patients in a multi-institutional setting with high compliance rates.

NCCN Practice Guidelines for Breast Cancer.

The therapeutic options for patients with noninvasive or invasive breast cancer are complex and varied. In many situations, the patient and physician have the responsibility to jointly explore and ultimately select the most appropriate option from among the available alternatives. With rare exception, the evaluation, treatment, and follow-up recommendations contained within these guidelines were based largely on the results of past and present clinical trials. However, there is not a single clinical situation in which the treatment of breast cancer has been optimized with respect to either maximizing cure or minimizing toxicity and disfigurement. Therefore, patient and physician participation in prospective clinical trials allows patients not only to receive state-of-the-art cancer treatment but also to contribute to the improvement of treatment of future patients.

Targeted expression of a dominant negative epidermal growth factor receptor in the mammary gland of transgenic mice inhibits pubertal mammary duct development.

The epidermal growth factor (EGF) system has been thought to play an important role in normal mammary development and carcinogenesis. To study the role of the EGF receptor (EGFR) in mammary development, we developed a transgenic mouse model in which a C-terminal truncated mouse EGFR (EGFR-TR) was expressed in the mouse mammary epithelium under the control of the mouse mammary tumor virus long terminal repeat. The EGFR-TR lacks most of the cytoplasmic domain of the receptor, including the entire protein tyrosine kinase domain. In cultured cells, we show that it acts in a dominant negative manner in EGF-signaled EGFR autophosphorylation. Several lines of mice were characterized and shown to express the transgene at the mRNA and protein levels not only in the mammary gland but also in the salivary glands, epididymis, and prostate. In postpubertal virgin female mice, the expression of the EGFR-TR in the mammary glands was greater than the expression of the endogenous wild type EGFR. In these virgin mice, inhibition in mammary ductal development and a decrease of mammary epithelial DNA synthesis were observed beginning at 5-6 weeks. The inhibition of duct development was most apparent by 15-16 weeks, resulting in a significant defect in ductal branching and outgrowth and an apparent overall decrease in the size of the mammary glands. However, during pregnancy, expression of the endogenous wild type EGFR was markedly increased relative to the EGFR-TR and, at this stage, normal presecretory alveoli developed from the hypoplastic duct tree. Postpartum, normal lactation occurred. Despite EGFR-TR expression in other tissues, no morphological abnormalities were observed. This model demonstrates that the EGFR-TR behaves as a dominant negative regulator of the EGFR system in vivo and that the EGFR system plays an important role in mammary ductal development.

Signal transduction by a CD16/CD7/Jak2 fusion protein.

The addition of interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) to hormone-dependent cells induces tyrosine phosphorylation of Janus protein kinase 2 (Jak2) and activates its in vitro kinase activity. To explore the role of Jak2 in IL-3/GM-CSF-mediated signal transduction, we constructed a CD16/CD7/Jak2 (CD16/Jak2) fusion gene containing the external domain of CD16 and the entire Jak2 molecule and expressed this fusion protein using a recombinant vaccinia virus. The clustering of CD16/Jak2 fusion protein by cross-linking with an anti-CD16 antibody induced autophosphorylation of the fusion protein but did not induce the phosphorylation of either the endogenous Jak2 or the beta chain. Cross-linking of CD16/Jak2 stimulates the tyrosine phosphorylation of a large group of proteins that are also phosphorylated after the addition of IL-3 or GM-CSF and include proteins of 145, 97, 67, 52, and 42 kDa. Closer analysis demonstrated that the CD16/Jak2 phosphorylates Shc, a 52-kDa protein, and the 145-kDa protein associated tightly with Shc, as well as mitogen-associated protein kinase (pp42). Electrophoretic mobility shift assays demonstrate that CD16/Jak2 activates the ability of signal transduction and activation of transcription (STAT) proteins to bind to an interferon-gamma-activated sequence oligonucleotide in a manner similar to that seen after IL-3 treatment. Cross-linking of the CD16/Jak2 protein stimulated increases in c-fos and junB similar to IL-3 but did not cause major changes in the levels of the c-myc message, which normally increases after IL-3 treatment. Thus, a transmembrane CD16/Jak2 fusion is capable of activating protein phosphorylation and mRNA transcription in a manner similar but not identical to hematopoietic growth factors.

Human immunodeficiency virus 1 Tat stimulates transcription of the transforming growth factor alpha gene in an epidermal growth factor-dependent manner.

The human immunodeficiency virus 1 (HIV-1) tat gene encodes a protein of critical importance for viral transcription. In addition, Tat has been shown capable of entering cells, stimulating cell proliferation, and altering host cell gene expression. We examined the effect of Tat on the expression of the transforming growth factor alpha (TGF-alpha) gene in MDA468 human breast carcinoma cells. We showed that these cells were capable of supporting the activation of the HIV-1 long terminal repeat by Tat. Then, in cotransfection assays, in which the TGF-alpha promoter was linked to a luciferase reporter gene and the tat gene was expressed under the control of the SV40 early promoter, we showed that tat gene expression increased TGF-alpha-luciferase reporter function but only in cells stimulated with epidermal growth factor (EGF). The effects of tat and EGF were dose dependent. To confirm these cotransfection data, Tat was expressed in Escherichia coli as a fusion protein with glutathione-S-transferase (GST) and purified on glutathione-agarose. GST-Tat was introduced into the MDA468 cells either in the presence of chloroquine or by scrape loading. The biological activity of GST-Tat was tested on cells that had been stablely transfected with the HIV-1 long terminal repeat linked to luciferase as a reporter. GST-Tat was then introduced into the cells, and the level of TGF-alpha mRNA was determined.(ABSTRACT TRUNCATED AT 250 WORDS)

17 beta-estradiol acts directly on the clonal osteoblastic cell line UMR106.

We studied the effect of 17 beta-estradiol (E) on the proliferation and alkaline phosphatase activity of cultured UMR106 cells, a clonal osteoblastic cell line. Growth rates were reduced and alkaline phosphatase activity was increased in cells incubated for 2 days in medium containing E (10(-8) M). In contrast, E had no effect on the growth rates or alkaline phosphatase of a human fibroblastic cell line, S90E. The effect of E was not observed with low cell density or at confluence. 1,25-Dihydroxyvitamin D3 antagonized the response to E. Preincubation of the cells with dexamethasone, a potent inducer of differentiation, reversed the effect of E or 1,25-dihydroxyvitamin D3. These results indicate that cellular and/or extracellular factors such as cell density, the phase of the cell cycle, the state of differentiation, and the presence or absence of other steroids influenced the response of UMR106 cells to E. Serum was removed from the culture medium to minimize the effect of the steroids, growth factors, and nutrients present in serum. A striking stimulation of alkaline phosphatase by E occurred with serum-free conditions. This stimulation was biphasic over an E concentration from 10(-12) to 10(-8) M, with the peak response at 10(-10) M. The action of E on UMR106 cells was metabolite-specific, since the isomer 17 alpha-estradiol produced no effect on proliferation rates or alkaline phosphatase activity. The cyclic AMP response to parathyroid hormone (residues 1-34) was not altered by E treatment of these cells. In contrast, dexamethasone exposure did increase the cyclic AMP response to parathyroid hormone. These results demonstrate a direct effect of E on an osteoblastic cell line. They also raise the possibility that similar or identical actions of E occur in cultured normal osteoblasts.

Actin filament organization of the Dunning R3327 rat prostatic adenocarcinoma system: correlation with metastatic potential.

Recently, Volk, Geiger, and Raz (Cancer Res., 44: 811-824, 1984) addressed the question of whether variations in actin organization in clones of the murine K-1735 melanoma tumor correlated with their metastatic capability. Using immunofluorescence techniques, they found that clones which had a more ordered actin network were less metastatic, whereas clones having a diffuse actin staining pattern were more metastatic. Similarly, we have found that in the Dunning rat R3327 prostatic adenocarcinoma tumor system, the non-metastatic (less than 0.1%) H-prostatic tumor cell line has a prominent network of actin filament bundles, whereas the highly metastatic (greater than 90%) MatLyLu cell line has a diffuse actin staining pattern. In the low-metastatic (less than 10%) AT1 cell line an intermediate actin organization between H and MatLyLu was observed. Analysis of cell extracts from H- and MatLyLu-cells revealed differences in the level of activity of cellular proteins which affect actin filament assembly and structure in a manner similar to that of the cytochalasins, fungal metabolites which bind with high affinity to the fast-growing end of actin filaments. Extracts of MatLyLu were significantly more effective than those of H-cells in decreasing the extent of actin filament network formation and in inhibiting the rate of filament assembly by blocking monomer addition onto the fast-growing end. Measurements of spin-lattice nuclear magnetic resonance water proton relaxation times (T1) were made in surgically removed tumor tissue from four sublines (H, AT1, MatLyLu, and MatLu) of the Dunning R3327 tumor system. The highly metastatic cell lines had significantly longer water proton T1 relaxation times than did the lines with low metastatic potential. These differences in T1 may reflect the observed alterations in organization of actin filaments within these various sublines of the Dunning R3327 prostatic adenocarcinoma tumor system.