Robert P. Edwards

Positive feedback between PGE2 and COX2 redirects the differentiation of human dendritic cells toward stable myeloid-derived suppressor cells

Dendritic cells (DCs) and myeloid-derived suppressor cells (MDSCs) show opposing roles in the immune system. In the present study, we report that the establishment of a positive feedback loop between prostaglandin E(2) (PGE(2)) and cyclooxygenase 2 (COX2), the key regulator of PGE(2) synthesis, represents the determining factor in redirecting the development of CD1a(+) DCs to CD14(+)CD33(+)CD34(+) monocytic MDSCs. Exogenous PGE(2) and such diverse COX2 activators as lipopolysaccharide, IL-1β, and IFNγ all induce monocyte expression of COX2, blocking their differentiation into CD1a(+) DCs and inducing endogenous PGE(2), IDO1, IL-4Rα, NOS2, and IL-10, typical MDSC-associated suppressive factors. The addition of PGE(2) to GM-CSF/IL-4-supplemented monocyte cultures is sufficient to induce the MDSC phenotype and cytotoxic T lymphocyte (CTL)-suppressive function. In accordance with the key role of PGE(2) in the physiologic induction of human MDSCs, the frequencies of CD11b(+)CD33(+) MDSCs in ovarian cancer are closely correlated with local PGE(2) production, whereas the cancer-promoted induction of MDSCs is strictly COX2 dependent. The disruption of COX2-PGE(2) feedback using COX2 inhibitors or EP2 and EP4 antagonists suppresses the production of MDSC-associated suppressive factors and the CTL-inhibitory function of fully developed MDSCs from cancer patients. The central role of COX2-PGE(2) feedback in the induction and persistence of MDSCs highlights the potential for its manipulation to enhance or suppress immune responses in cancer, autoimmunity, or transplantation.

Physiological and molecular effects of Apo2L/TRAIL and cisplatin in ovarian carcinoma cell lines.

Combining of tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) with a chemotherapeutic drug, cisplatin, in ovarian carcinoma cell lines exerted potent anti-tumor effects that exceeded the effects of each drug alone. In order to investigate mechanisms of anti-tumor activity of cisplatin/Apo2L/TRAIL combination, we assessed in detail the molecular effects of cisplatin and Apo2L/TRAIL-activated cell death in two ovarian carcinoma cell lines, OVCAR3 and SKOV3, using cDNA array hybridization, Western blot and flow cytometry. We observed differential induction of apoptosis-related molecules by cisplatin and Apo2L/TRAIL. Cisplatin upregulated the expression of both death and decoy TRAIL receptors, as well as of TRAF5 and -6, downregulated the anti-apoptotic proteins, Bcl-2, and induced activation of caspases-3, -8 and -9. Apo2L/TRAIL induced the expression of pro-apoptotic proteins, Bad and Bax; downregulated the anti-apoptotic proteins, Bcl-2 and Bcl-xL; and activated caspases-3, -7, -8, -9 and -10. Cisplatin/Apo2L/TRAIL combination resulted in further downregulation of expression of anti-apoptotic proteins, Bcl-2 and Bcl-xL, as well as an increase in mitochondrial permeability transition and activation of caspases-3, -8, and -10. These data demonstrate positive cooperation of cisplatin and Apo2L/TRAIL and emphasize the potential clinical usefulness of cisplatin/Apo2L/TRAIL combination therapy.

The factor V Leiden mutation and the risk of venous thromboembolism in gynecologic oncology patients

OBJECTIVE To measure the strength of the association between the factor V Leiden mutation and venous thromboembolism in gynecologic oncology patients. METHODS We conducted a case‐control study of gynecologic cancer patients in a referral center who were group matched for demographics, tumor type, and treatment. The prevalence of the factor V Leiden mutation was determined in both cases and controls, and an odds ratio was calculated. The factor V Leiden mutation was detected using polymerase chain reaction amplification and nucleic acid restriction digest of deoxyribonucleic acid extracted from leukocytes. RESULTS Seventy‐five patients were enrolled in the study. Seventy‐four samples were available for analysis. There were no differences between the cases and controls with respect to age, race, body mass index, smoking, cancer type, high stage (III or IV) of cancer, or treatment modality. The odds ratio for having the factor V Leiden mutation in patients with venous thromboembolism was 0.3 (95% confidence interval 0.1, 1.7). CONCLUSION This study suggests that the factor V Leiden mutation is not associated with an increased risk of venous thromboembolism in gynecologic oncology patients. This contrasts with other studies showing a strong association between the factor V Leiden mutation and venous thromboembolism in cases of previously unexplained venous thromboembolism, and venous thromboembolism associated with other hypercoagulable states, such as pregnancy and oral contraceptive use. The risk of venous thromboembolism due to cancer outweighs the contribution of the factor V Leiden mutation.

Paclitaxel and Carboplatin for Recurrent or Persistent Cancer of the Cervix

Objective. The objective of this study was to evaluate the effectiveness and degree of toxicity of paclitaxel and carboplatin (PC) combination chemotherapy in patients with recurrent or persistent cervical carcinoma. Methods. Fifteen patients who received PC chemotherapy for recurrent or persistent carcinoma of the cervix at the Magee-Womens Hospital from 1994–1998 were studied retrospectively. Demographic data, pathology, radiation treatment response, site of recurrence, chemotherapy response, survival rates, and toxicities were reviewed. Months of survival were calculated by the method of Kaplan–Meier from the date after initiation of chemotherapy to death or the last date of follow-up. Results. Fifteen patients received PC for recurrence or persistence of disease with a median of six courses of PC (range, four to 26). Fourteen patients (93.3%) had received prior radiation, and one patient had received surgery as the primary therapy. Four (26.7%) of 15 patients had complete response and five (33.3%) had partial response for an overall clinical response rate of 60%. The median survival of all 15 patients treated with PC was 17 months (range, four to 39). Four patients demonstrated progression of disease while two patients had stable disease. Grade 3 or 4 neutropenia occurred in four patients (26.7%) while one patient (6.7%) suffered from sepsis. Three patients (20%) suffered from Grade 2 anemia and four patients (26.7%) patients developed Grade 2 or Grade 3 neuropathy. There was no incidence of nephrotoxicity. Conclusions. Paclitaxel/carboplatin chemotherapy appears to have promising activity in recurrent or persistent carcinoma of the cervix with an acceptable toxicity profile. Due to patient convenience and tolerance, consideration should be given to carboplatin as an alternative regimen to cisplatin in combination with paclitaxel.

Cytoreduction and intraperitoneal heated chemotherapy for the treatment of endometrial carcinoma recurrent within the peritoneal cavity

Our experience with hyperthermic intraperitoneal chemotherapy (IPHC) in conjunction with surgical resection for endometrial cancer recurrent within the abdominal cavity was reviewed. Eligible patients underwent exploratory laparotomy with the aim of resecting disease to ≤5 mm maximum dimension followed immediately by intraperitoneal perfusion of cisplatin (100 mg/m2) heated to 41–43°C (105.8–109.4°F) for 1.5 h. Data for analysis was extracted from retrospective chart review. Five patients underwent surgery and IPHC between September 2002 and January 2005 for abdomino-pelvic recurrence. Original stage and histology were 1A papillary serous (1), 1C endometrioid with clear cell features (1), and 1B endometrioid (3). Mean age was 61 (41–75) years, mean prior laparotomies were 1.4 (1–2), and mean chemotherapy agent exposure was 1.6 (0–4). Mean time from initial treatment to surgery and IPHC was 47 (29–66) months. Mean length of surgery was 9.8 (7–11) h after which three patients had no residual disease and two had ≤5 mm disease. The mean duration of hospital stay was 12.6 (6–20) days. Postoperative surgical complications included wound infection with septicemia in one patient. Mean maximum postoperative serum creatinine was 1.02 (0.6–1.70) mg/dL. There was no ototoxicity or neuropathy and no perioperative mortality. No patients have been lost to follow-up. Two are living disease free at 28 and 32 m and two are living with disease at 12 and 36 m. One patient died at 3 m without evidence of cancer. Two patients who had no residual macroscopic disease at the end of surgery are alive at 32 and 36 m. The combination of IPHC with surgery for recurrent endometrial carcinoma is relatively well tolerated. The unexpectedly long survival seen in this cohort supports a phase II trial of IPHC with cisplatin for recurrent endometrial cancer.

Immunobiology of human mucin 1 in a preclinical ovarian tumor model

Epithelial ovarian cancer is an aggressive malignancy, with a low 5-year median survival. Continued improvement on the development of more effective therapies depends in part on the availability of adequate preclinical models for in vivo testing of treatment efficacy. Mucin 1 (MUC1) glycoprotein is a tumor-associated antigen overexpressed in ovarian cancer cells, making it a potential target for immune therapy. To create a preclinical mouse model for MUC1-positive ovarian tumors, we generated triple transgenic (Tg) mice that heterozygously express human MUC1+/− as a transgene, and carry the conditional K-rasG12D oncoallele (loxP-Stop-loxP-K-rasG12D/+) and the floxed Pten gene (Pten/loxP/loxP). Injection of Cre recombinase-encoding adenovirus (AdCre) in the ovarian bursa of triple (MUC1KrasPten) Tg mice triggers ovarian tumors that, in analogy to human ovarian cancer, express strongly elevated MUC1 levels. The tumors metastasize loco-regionally and are accompanied by high serum MUC1, closely mimicking the human disease. Compared with the KrasPten mice with tumors, the MUC1KrasPten mice show increased loco-regional metastasis and augmented accumulation of CD4+Foxp3+ immune-suppressive regulatory T cells. Vaccination of MUC1KrasPten mice with type 1 polarized dendritic cells (DC1) loaded with a MUC1 peptide (DC1–MUC1) can circumvent tumor-mediated immune suppression in the host, activate multiple immune effector genes and effectively prolong survival. Our studies report the first human MUC1-expressing, orthotopic ovarian tumor model, reveal novel MUC1 functions in ovarian cancer biology and demonstrate its suitability as a target for immune-based therapies.

IL-12 receptor-mediated upregulation of FasL in human ovarian carcinoma cells

The expression and functions of IL‐12 receptor (IL‐12R) in human ovarian carcinoma cell lines have been investigated. Ovarian carcinoma cells express both the IL‐12Rβ1 and the IL‐12Rβ2 subunits. IL‐12R crosslinking resulted in phosphorylation of Tyk2, p44 (ERK1) and Akt kinases and activation of STATs 2, 3, 4 and 5. IL‐12 induced substantial upregulation of Fas ligand (FasL) surface expression in ovarian carcinoma cells paralleled by an increased ability to induce apoptosis in Jurkat cells and PHA‐activated lymphocytes. The induction of surface expression of FasL by IL‐12 was not due to upregulation of FasL gene expression, but resulted from downregulation of matrix metalloproteinases (MMPs)‐3 and ‐7 and consequently reduced cleavage of FasL from the cell surface. These findings bring new insights into the significance of IL‐12‐mediated effects in nonlymphoid cancer cells that might be of importance for improving the design of IL‐12‐based therapies for ovarian cancer.

Intraperitoneal chemotherapy for recurrent epithelial ovarian cancer is feasible with high completion rates, low complications, and acceptable patient outcomes.

Objectives Three large randomized clinical trials have shown a survival benefit for patients treated with intraperitoneal (IP) compared with intravenous chemotherapy for advanced stage epithelial ovarian cancer (EOC). However, the use of IP chemotherapy in recurrent EOC is controversial. The purpose of this study was to determine outcomes, completion rates, and frequency of complications in patients with platinum-sensitive recurrent EOC treated with IP chemotherapy. Methods A retrospective, single-institution analysis of women who received IP chemotherapy for recurrent EOC from January 2003 to April 2010 was conducted. Study patients were identified from the Tumor Registry and office records. Demographic factors, stage, histology, surgical findings, cytoreduction status, and subsequent therapies were abstracted. Progression-free (PFS) and overall survival (OS) were estimated by Kaplan-Meier methods. Results Fifty-six women who received IP chemotherapy for their first EOC recurrence were identified. The mean age of patients was 56.7 years (range, 40–79 y). Fifty-five patients (98.3%) had previously completed at least 6 cycles of intravenous chemotherapy. Of all patients, 87.5% were initially diagnosed with advanced stage disease (stage IIA–IV). All patients underwent secondary cytoreduction at the time of IP port placement. Moreover, 67.9% of patients were considered optimally cytoreduced (<1 cm residual disease) at the end of the secondary debulking surgery. Forty-two patients (75%) were able to successfully complete at least 6 cycles of IP chemotherapy. Reasons for noncompletion were disease progression, allergic reaction, renal failure, pain, severe nausea and vomiting, death, and patient refusal. Six patients (10.7%) developed port complications including pain around port site, port malfunction, and port erosion into small bowel. Median PFS since the initiation of IP chemotherapy was 10.5 months (95% confidence interval, 7.5–16.4 months) and median OS was 51 months (95% confidence interval, 40.8–61.1 months). Conclusions Intraperitoneal chemotherapy is a feasible option for patients with recurrent EOC, with high completion rates, low frequency of complications, and acceptable PFS and OS.