Ovarian cancer BRCA1 gene therapy: Phase I and II trial differences in immune response and vector stability.

Gene therapy with viral vectors has shown some promise in nude mice models and in initial Phase I trials of patients with extensive metastatic cancer. A Phase I clinical trial (D. L. Tait et al., Clin. Cancer Res., 3: 1959-1968, 1997) of ovarian cancer patients treated with i.p. retroviral LXSN-BRCA1sv gene therapy reported stable vector, minimal antibody response, and tumor reduction. We initiated a Phase II trial on patients with less extensive disease to evaluate vector pharmacokinetics, immune response, toxicity, and efficacy. Patients received a surgically implanted peritoneal catheter to administer infusions of vector, as well as to retrieve daily samples of peritoneal fluid for analysis. Ovarian cancer patients received four daily i.p. injections of LXSN-BRCA1sv vector therapy for three cycles, 4 weeks apart. Patient peritoneal fluid and plasma were analyzed extensively by PCR, Western blot, complement level (CH50), and chemical and hematological tests. Phase II patients showed no response, no disease stabilization, and little or no vector stability. Because of vector instability and rapid antibody development, which differed dramatically from the Phase I trial data, the trial was terminated after treatment of six patients. Immune system status appears to have played a major role in whether gene therapy was effective. Comparison of Phase I and II patients showed significant differences in tumor burden, immune system status, and response to BRCA1 gene therapy.

A phase I trial of retroviral BRCA1sv gene therapy in ovarian cancer.

Gene transfer of BRCA1sv (a normal splice variant of BRCA1) into ovarian cancer cells produces growth inhibition in vitro and tumor suppression in nude mouse xenografts. As an initial step toward gene replacement therapy for ovarian cancer, we conducted a Phase I trial to assess the pharmacokinetics and toxicity of i.p. BRCA1sv retroviral vector therapy. Following placement of an indwelling Port-a-Cath in patients, a dose escalation study was performed of four daily i.p. infusions spanning doses from 3 to 300 ml (i.e., 10(10) viral particles) at half-log intervals (23 cycles in 12 patients). Gene transfer and expression were documented by PCR, Southern blot, reverse transcription-PCR, and nuclease protection assays. Pharmacokinetics were assessed by PCR and Southern blots detecting vector DNA, and toxicity was evaluated by clinical exam and fluid analysis. Three of 12 patients developed an acute sterile peritonitis, which spontaneously resolved within 48 h. Plasma and peritoneal antibodies to the retroviral envelope protein were detected only in patients treated with the highest dose levels but not in others, despite repeat dosing for an interval of up to 4 months. Eight patients showed stable disease for 4-16 weeks, and three patients showed tumor reduction with diminished miliary tumor implants at reoperation (two patients) and radiographic shrinkage of measurable disease (one patient). The vector-related complication of peritonitis was observed in three patients but resolved quickly as in preclinical mouse studies. Ovarian cancer may provide an important model for retroviral gene therapy studies due to vector stability, minimal antibody response, and access to tumor by i.p. therapy.

Ovarian cancer gene therapy.

Retroviral-mediated delivery of BRCA1 gene therapy (LXN-BRCA1sv, a normal splice variant form of BRCA1) was tested extensively in mouse models. It was found to be effective in reducing tumor burden and to be minimally toxic. Twelve phase I clinical trial patients with recurrent or persistent epithelial ovarian cancer were treated with one to three cycles of intraperitoneal vector. There was minimal toxicity, four patients developed fevers (< 102.5 degrees F) and three had sterile peritonitis, which resolved within 48 hours. The vector was found to be fairly stable in some patients at 24 hours as well as transferred into and expressed in patient tissues. Stable disease was noticed in 8 of the 12 patients, suggesting that the peritoneal cavity may be an appropriate site for gene therapy.

Gene therapy for breast and ovarian cancer with BRCA1.

As an initial step toward gene therapy for ovarian cancer, we conducted a Phase 1 trial to assess the pharmacokinetics and toxicity of intraperitoneal BRCA1sv retroviral vector therapy. Gene transfer and expression were documented by PCR, southern blot, RT-PCR and nuclease protection assays. Pharmacokinetics were assessed by PCR and southern blots detecting vector DNA, and toxicity was evaluated by clinical exam and fluid analysis. Three of twelve patients developed an acute sterile peritonitis which spontaneously resolved within 48 hours. Plasma and peritoneal antibodies to the retroviral envelope protein were detected only in patients treated with the highest dose levels but not in others, despite repeat dosing for an interval of up to four months. Eight patients showed stable disease for 4 to 16 weeks. Three patients showed tumor reduction with diminished miliary tumor implants at reoperation (two patients) and radiographic shrinkage of measurable disease (one patient). Ovarian cancer may provide an imporant model for retroviral gene therapy studies due to vector stability, minimal antibody response, and access to tumor by intraperitoneal therapy.

Michael-type reactions of tenulin, a biologically active sesquiterpene lactone.

The antitumor pseudoguaianolide tenulin has been exposed to a wide variety of biological and model nucleophilic reagents and has been shown to react exclusively with sulfur nucleophiles in a Michael-like fashion. The biological implications of these results are discussed.

Multicystic ovarian tumor weighing 156 lbs: the second largest tumor in Texas.

A woman's lifetime risk of developing an ovarian neoplasm is approximately 7%. A small subset of these neoplasms comprises the gigantic ovarian tumors (> 25 lbs) that often present challenging and difficult problems. We present a case of a 156-lb ovarian tumor with emphasis on the diagnostic and therapeutic approaches to successful management.

Preclinical studies of a new generation retroviral vector for ovarian cancer BRCA1 gene therapy.

OBJECTIVE: The aim of this study was to determine the preclinical stability, toxicity, and efficacy of a second-generation complement-resistant retroviral BRCA1 vector, MFG-BRCA1, for ovarian cancer gene therapy. METHODS: MFG-BRCA1 was packaged in human 293 renal cells and manufactured and tested under cGMP conditions and is allowed for use in humans by the Food and Drug Administration. Vector stability studies were performed in mice and human serum by PCR analysis. Toxicity in the animals was assessed at necropsy, evaluating for histological signs of inflammation and organ damage. Tissue culture efficacy studies were performed on ovarian and breast cancer cells. Animal efficacy studies were conducted in female nu/nu mice. Mice were injected intraperitoneally with SKOV-3 ovarian cancer cells and tumors were allowed to grow for 4 weeks. Mice were treated intraperitoneally with MFG-BRCA1 or control vectors. Survival of animals was compared in the MFG-BRCA1 versus the control groups. RESULTS: MFG-BRCA1 was more stable in human serum than LXSN-BRCA1sv. Toxicity as demonstrated by an inflammatory peritonitis was minimal. Significantly fewer clones were obtained using the MFG-BRCA1 versus the MFG vector alone in both cell lines. Efficacy studies in animals of MFG-BRCA1 demonstrated a near threefold increase in survival over control vector and twofold increase compared to the first generation LXSN-BRCA1sv vector. CONCLUSION: The reengineered complement-resistant MFG-BRCA1 retroviral vector is more effective and more stable than the previous generation LXSN-BRCA1sv vector.

Gene therapy for carcinoma of the breast: Therapeutic genetic correction strategies.

Gene therapy is a therapeutic approach that is designed to correct specific molecular defects that contribute to the cause or progression of cancer. Genes that are mutated or deleted in cancers include the cancer susceptibility genes p53 and BRCA1. Because mutational inactivation of gene function is specific to tumor cells in these settings, cancer gene correction strategies may provide an opportunity for selective targeting without significant toxicity for normal nontumor cells. Both p53 and BRCA1 appear to inhibit cancer cells that lack mutations in these genes, suggesting that the so-called gene correction strategies may have broader potential than initially believed. Increasing knowledge of cancer genetics has identified these and other genes as potential targets for gene replacement therapy. Initial patient trials of p53 and BRCA1 gene therapy have provided some indications of potential efficacy, but have also identified areas of basic and clinical research that are needed before these approaches may be widely used in patient care.

Parathyroid hormone-related protein expression in gynecic squamous carcinoma cells.

BACKGROUND: The regulation of parathyroid hormone-related protein (PTH-rP) mRNA levels and immunoreactive (ir)PTH-rP formation by peptide growth factors, particularly transforming growth factor-beta (TGF-beta) and epidermal growth factor (EGF), in squamous cell carcinomas of gynecologic origin is largely unknown. METHODS: PTH-rP mRNA levels were evaluated by Northern analysis in A431 cells (derived from a human vulvar epidermoid carcinoma) and ME-180 cells (derived from a human papillomavirus-infected squamous cell carcinoma of the cervix). PTH-rP protein levels in cell culture media were evaluated using both radioimmunoassay and immunoradiometric assay techniques. These results were compared with those from a lung carcinoid cell line known to produce PTH-rP, namely, NCI-H727 cells. RESULTS: TGF-beta 1 or EGF treatment caused an increase in the levels of PTH-rP mRNA in A431 cells; these increases in PTH-rP mRNA were detectable after 60 minutes of treatment, were maximal at approximately 4-8 hours, and were approximately additive. Immunoreactive PTH-rP was not detectable (using two different PTH-rP immunoassays) in the culture medium or cell sonicates of A431 cells before or after treatment with TGF-beta 1, EGF, or TGF-beta 1 plus EGF. ME-180 cells responded to EGF (but not to TGF-beta 1) with an increase in the level of PTH-rP mRNA as early as 2 hours; irPTH-rP was present (by use of either immunoassay) in the medium of these cells at 8 and 24 hours. In NCI-H727 (human lung carcinoid) cells, TGF-beta 1 and EGF acted alone and synergistically to effect increases in PTH-rP mRNA and the accumulation of irPTH-rP. CONCLUSIONS: TGF-beta 1 and EGF regulation of PTH-rP gene expression in squamous cell carcinomas of gynecologic origin is unique for each cell line studied and different from that in human lung carcinoid cells.

Benign adrenal cyst presenting in a pregnant patient.

Cystic lesions of the adrenal gland are uncommon, most often diagnosed incidentally during diagnostic imaging or autopsy. An adrenal cyst presenting as a pelvic mass in pregnancy offers the clinician a diagnostic and therapeutic dilemma. A 28-year-old black female presented for routine obstetric care at 26 weeks' gestation and was found on examination to have a 40-cm pelvic-abdominal mass. Ultrasound confirmation revealed the mass to be cystic and arising from the right pelvis. Laboratory tests including hematocrit, white blood cell count, electrolytes, rapid plasma reagin (RPR), and CA-125 were within normal limits. The patient underwent exploratory laparotomy and a 40 x 20 cm right adrenal cyst was identified and resected. Postoperatively, the patient developed preterm labor and delivered a 955-g infant; the infant was discharged home 3 months later with bronchopulmonary dysplasia and delayed developmental milestones. The woman was discharged home without complication on postoperative Day 8. Accurate preoperative determination of the origin of a pelvic mass occurring in pregnancy is helpful in timing therapeutic intervention. Use of ultrasound and magnetic resonance imaging (MRI) modalities can provide detailed anatomical information without risk to mother or fetus. Conservative management of adrenal cyst in pregnancy may lower the morbidity and mortality of the mother and fetus.