Donnah Jones

Granulocyte colony-stimulating factor (G-CSF) is essential for the host response to bacterial infection by controlling neutrophil production in the bone marrow. The G-CSF receptor (G-CSFR) activates the Jak/STAT pathway, although little is understood about how these signals regulate basal and stress-induced granulopoiesis. We examined STAT3 function in granulocytes using a bone marrow conditional knockout mouse model. Our results show that STAT3 has a crucial role in emergency granulopoiesis and mature neutrophil function. STAT3-deficient mice have an aberrant response to G-CSF in vivo, characterized by failure to accumulate immature granulocytes and an increased ratio of mature to immature neutrophils in the bone marrow, peripheral blood, and spleen. Acute neutrophil mobilization is impaired in STAT3-deficient mice as judged by their failure to up-regulate circulating neutrophils following short-term G-CSF exposure. STAT3 also controls neutrophil chemotactic responses to natural ligands for CXCR2 and regulates the magnitude of chemoattractant-induced actin polymerization. These functions of STAT3 are independent of its principal target gene Socs3, which encodes a crucial feedback inhibitor of cytokine signaling. Our results demonstrate the existence of distinct STAT3 target pathways in neutrophils required for granulopoiesis and innate immunity.

Several cytokines including gamma-interferon, tumor necrosis factor alpha, interleukin 1 beta (IL-1 beta), and interleukin 6 (IL-6) are pyrogenic and can inhibit lipogenic processes. Because patients with lymphoma often suffer from fever, weight loss, and night sweats (B symptoms), the etiology of which is unknown, the authors investigated serum levels of these cytokines in normal volunteers and in patients with Hodgkin's and non-Hodgkin's lymphoma. Sixty serum samples from patients with Hodgkin's disease (28 patients) or non-Hodgkin's lymphoma (32 patients), as well as 20 samples from normal volunteers, were collected. The majority of patients had advanced (Stage III or IV) or relapsed disease. The assay for gamma-interferon was a specific and sensitive radioimmunoassay (lower limit of detection = 0.1 unit/ml); the assays for tumor necrosis factor alpha, IL-1 beta, and IL-6 were enzyme-linked immunoassays with lower limits of sensitivity of 10 pg/ml, 20 pg/ml, and 22 pg/ml, respectively. There were no statistically significant differences in gamma-interferon, tumor necrosis factor alpha, or IL-1 beta levels between lymphoma patients and normal subjects. In contrast, 20 of 57 patients (35%) with lymphoma as compared with 0 of 19 normal volunteers (0%) had detectable serum IL-6 levels (P < 0.005, chi 2 test). Interestingly, 17 of 29 lymphoma patients with B symptoms (59%) as opposed to 3 of 28 lymphoma patients without B symptoms (11%) had detectable serum IL-6 levels (P < 0.001, chi 2 test); the median IL-6 level was 28.9 pg/ml (B symptoms present) versus undetectable (no B symptoms) (P < 0.005, Mann-Whitney U test). Analyzing Hodgkin's and non-Hodgkin's lymphoma groups separately revealed similar results. IL-6 levels showed no significant correlation with time from diagnosis, beta 2-microglobulin, or lactate dehydrogenase levels. However, analysis by the method of Kaplan and Meir demonstrated that the median survival of Hodgkin's disease patients with detectable IL-6 levels (> or = 22 pg/ml) was 10 mo, whereas the median survival has not been reached at a median follow-up time of 37.5 mo in those patients with lower values (Wilcoxon P value = 0.0012). There were too few patients in each subset of non-Hodgkin's lymphoma to determine the correlation between IL-6 and survival but, considered as a single group, a statistically significant correlation was not found.(ABSTRACT TRUNCATED AT 400 WORDS)

PURPOSE: To study the platelet-derived growth factor receptor (PDGFR) inhibitor imatinib mesylate in androgen-independent prostate cancer (AIPC), alone and in combination with docetaxel, we designed a modular phase I trial. Our goals were to (1) evaluate the toxicity and maximum-tolerated dose of docetaxel with imatinib, and (2) evaluate the decline of prostate-specific antigen (PSA) induced by imatinib alone, and imatinib and docetaxel. PATIENTS AND METHODS: Twenty-eight men with AIPC and bone metastases were enrolled to receive imatinib 600 mg daily lead-in for 30 days, then imatinib 600 mg daily and one of six possible doses of docetaxel weekly for 4 weeks every 6 weeks. RESULTS: During the imatinib lead-in module, one dose-limiting toxicity (DLT) event was observed, while two (7%) of 28 had PSA decline (both < 50%). With imatinib and docetaxel, cycle 1 DLT was found in three of 12 patients at docetaxel 30 mg/m(2), in three of four patients at docetaxel 45 mg/m(2), and in five of six patients at docetaxel 35 mg/m(2). DLTs (n = 40 total events) were principally fatigue (35%) and nausea (20%). Eight (38%) of 21 had PSA decline greater than 50%, and six (29%) of 21 had PSA decline less than 50%. Serial PSA declines beyond 18 months were observed. PDGFR-expressing tumor declined on serial bone marrow biopsies with combination therapy alone. CONCLUSION: With imatinib 600 mg daily, the maximum-tolerated dose of docetaxel was determined to be 30 mg/m(2) weekly for 4 weeks every 6 weeks. Long-term responses were observed. The role of imatinib in modulating outcomes to docetaxel in AIPC is being tested in a randomized phase II trial.

PURPOSE: The prognosis of patients with advanced squamous cell carcinoma of genitourinary origin is poor. While single agent chemotherapy results mainly in partial responses of short duration, data on the efficacy of combination chemotherapy are extremely limited. We determined the response rate and toxicity of a combination of 3 of the most active agents, methotrexate, cisplatin and bleomycin, in patients with advanced genitourinary squamous cell carcinoma. MATERIALS AND METHODS: Patients with metastatic or locally advanced genitourinary squamous cell carcinoma were eligible for study. Treatment consisted of 200 mg./m.2 methotrexate on days 1, 15 and 22, and 20 mg./m.2 cisplatin and 10 mg./m.2 bleomycin on days 2 through 6 during a 28-day cycle. RESULTS: Of the 30 patients who enrolled in the trial 29 were evaluable for response. Objective response was achieved in 16 patients (55%, 95% confidence interval 36 to 72), 4 of whom achieved a complete response (14%). Median objective response duration was 4.7 months (range 1.9 to 39.5). Median survival of the entire group was 11.5 months (range 1.5 to 87.0). Of the patients 9 achieved disease-free status, including 6 following consolidation surgery or radiation therapy. Median survival of these 9 patients (34.4 months, range 9.6 to 87.0) was significantly greater (p = 0.0003) than that of patients who did not become disease-free (7.0 months, range 1.5 to 38.6). Grade III or IV hematological toxicity in 116 courses included neutropenia (13%) and thrombocytopenia (6%). Among 30 patients evaluable for toxicity serious nonhematological toxic effects included stomatitis (3%) and renal toxicity (7%). There was 1 death from neutropenic sepsis. CONCLUSIONS: Methotrexate, cisplatin and bleomycin combination chemotherapy for genitourinary squamous cell carcinoma results in a high but short lived overall response rate, and a low complete response rate with manageable toxicity. A multidisciplinary approach to achieve disease-free status may provide the best opportunity to effect survival and should be the focus of future trials.

PURPOSE: To further assess preclinical and early clinical evidence that imatinib mesylate, a platelet-derived growth factor receptor (PDGFR) inhibitor, modulates taxane activity in prostate cancer and bone metastases, a randomized study was conducted. EXPERIMENTAL DESIGN: Men with progressive castration-resistant prostate cancer with bone metastases (n = 144) were planned for equal randomization to i.v. 30 mg/m(2) docetaxel on days 1, 8, 15, and 22 every 42 days with 600 mg imatinib daily or placebo, for an improvement in median progression-free survival from 4.5 to 7.5 months (two-sided alpha = 0.05 and beta = 0.20). Secondary end points included differential toxicity and bone turnover markers, tumor phosphorylated PDGFR (p-PDGFR) expression, and modulation of p-PDGFR in peripheral blood leukocytes. RESULTS: Accrual was halted early because of adverse gastrointestinal events. Among 116 evaluable men (57 docetaxel + imatinib; 59 docetaxel + placebo), respective median times to progression were 4.2 months (95% confidence interval, 3.1-7.5) and 4.2 months (95% confidence interval, 3.0-6.8; P = 0.58, log-rank test). Excess grade 3 toxicities (n = 23) in the docetaxel + imatinib group were principally fatigue and gastrointestinal. Tumor p-PDGFR expression was observed in 12 of 14 (86%) evaluable bone specimens. In peripheral blood leukocytes, p-PDGFR reduction was more likely in docetaxel + imatinib-treated patients compared with docetaxel + placebo (P < 0.0001), as were reductions in urine N-telopeptides (P = 0.004) but not serum bone-specific alkaline phosphatase (P = 0.099). CONCLUSIONS: These clinical and translational results question the value of PDGFR inhibition with taxane chemotherapy in prostate cancer bone metastases and are at variance with the preclinical studies. This discordance requires explanation.