Adrienne Howard

Perifosine plus docetaxel in patients with platinum and taxane resistant or refractory high-grade epithelial ovarian cancer

OBJECTIVES On the basis of reversal of taxane resistance with AKT inhibition, we initiated a phase I trial of the AKT inhibitor perifosine with docetaxel in taxane and platinum-resistant or refractory epithelial ovarian cancer. METHODS Patients with pathologically confirmed high-grade epithelial ovarian cancer (taxane resistant, n=10; taxane refractory, n=11) were enrolled. Peripheral blood samples and tumor biopsies were obtained and (18)F-FDG-PET and DCE-MRI scans were performed for pharmacodynamic and imaging studies. RESULTS Patients received a total of 42 treatment cycles. No dose-limiting toxicity was observed. The median progression-free survival and overall survival were 1.9 months and 4.5 months, respectively. One patient with a PTEN mutation achieved a partial remission (PR) for 7.5 months, and another patient with a PIK3CA mutation had stable disease (SD) for 4 months. Two other patients without apparent PI3K pathway aberrations achieved SD. Two patients with KRAS mutations demonstrated rapid progression. Decreased phosphorylated S6 correlated with (18)F-FDG-PET responses. CONCLUSIONS Patients tolerated perifosine 150 mg PO daily plus docetaxel at 75 mg/m(2) every 4 weeks. Further clinical evaluation of effects of perifosine with docetaxel on biological markers and efficacy in patients with ovarian cancer with defined PI3K pathway mutational status is warranted.

BCR-ABL1 mediates up-regulation of Fyn in chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) invariably progresses to blast crisis, which represents the most proliferative phase of the disease. The BCR-ABL1 oncogene stimulates growth and survival pathways by phosphorylating numerous substrates, including various Src family members. Here we describe up-regulation, in contrast to activation, of the ubiquitously expressed Src kinase, Fyn, by BCR-ABL1. In a tissue microarray, Fyn expression was significantly increased in CML blast crisis compared with chronic phase. Cells overexpressing BCR-ABL1 in vitro and in vivo display an up-regulation of Fyn protein and mRNA. Knockdown of Fyn with shRNA slows leukemia cell growth, inhibits clonogenicity, and leads to increased sensitivity to imatinib, indicating that Fyn mediates CML cell proliferation. In severe combined immunodeficient (SCID) mice injected with Fyn shRNA-expressing cells, myeloid-derived cell numbers dropped by 50% and death from leukemia was delayed. Taken together, these results encourage the development of therapies targeting Fyn expression.

Oxidative Stress Promotes Transcriptional Up-regulation of Fyn in BCR-ABL1-expressing Cells

Signaling initiated by the BCR-ABL1 kinase causes chronic myelogenous leukemia (CML). Recently, we reported that expression of Fyn, a Src kinase, is heightened in CML cells and patient specimens and confers in vitro and in vivo proliferative advantages. Fyn is regulated by redox, and because BCR-ABL1 raises intracellular oxidant levels, which have been implicated in CML progression, we explored the molecular regulation of Fyn. Here we identify the transcription factors that drive redox- and BCR-ABL1-dependent Fyn expression. Promoter deletion analysis in 293T, BaF3, BaF3-p210, and K562 cells identified the region essential for basal transcriptional activity. Mutation of Sp1 and Egr1 binding sites within the essential region diminished Fyn promoter activity and identified Egr1 as conferring redox sensitivity. Gel shift and chromatin immunoprecipitation assays confirmed the binding of Sp1 and Egr1 to the promoter fragments. Importantly, knockdown of Sp1 or Egr1 with small interference RNA or inhibition of Sp1 binding by mithramycin A repressed Fyn protein expression. Our work is the first to define transcription factors that are responsible for endogenous, oxidative stress-dependent and BCR-ABL1-dependent Fyn expression.

Outcome Analyses After the First Admission to an Intensive Care Unit in Patients With Advanced Cancer Referred to a Phase I Clinical Trials Program

PURPOSE This study assessed outcomes of individuals with advanced cancer who required admission to an intensive care unit (ICU) after referral for an early clinical trial because they did not respond to conventional therapy. PATIENTS AND METHODS Outcome analyses were conducted for 212 consecutive patients admitted to The University of Texas MD Anderson Cancer Center ICU after being seen in the phase I clinic starting on May 1, 2007. All data were obtained by a review of electronic medical records of patients. RESULTS The median survival of 212 patients with advanced cancer referred to phase I care after the initial ICU admission was 3.2 weeks (95% CI, 2.5 to 4.9 weeks). Patients who underwent cardiopulmonary resuscitation (CPR) succumbed within a median survival of 1 day (75% and 25% estimated survival of 1 and 3 days, respectively). Patients admitted for a postsurgical intervention did better than patients admitted for a nonsurgical intervention (median survival, 21.5 versus 2.1 weeks; P < .0001). The multivariate analysis revealed that a nonsurgical intervention, hypoalbuminemia, and higher Acute Physiology and Chronic Health Evaluation II scores were associated with poor overall survival. CONCLUSION The outcome of patients in a phase I clinic after initial ICU admission was poor, particularly when admission was for a nonsurgical intervention and/or when CPR was needed.

ABT-737, a BH3 mimetic, induces glutathione depletion and oxidative stress

PurposeThis study assessed the role of oxidative stress and loss of glutathione in ABT-737-induced apoptosis.MethodsJurkat human acute lymphocytic leukemia cells and HeLa cells transfected with a tet-regulated Bcl-2 expression system were treated with ABT-737 or its less active stereoisomer. GSH concentrations, intracellular reactive oxygen species (ROS), caspase activation and apoptotic DNA fragmentation were measured.ResultsABT-737 induced oxidative stress through decreased GSH and increased intracellular hydrogen peroxide and superoxide levels. Apoptotic DNA fragmentation and caspase activation were the consequences of this oxidative stress. Combining ABT-737 with ROS-inducing agents such as adaphostin or etoposide enhanced cell death.ConclusionsThese results demonstrate that inhibition of Bcl-2 causes a loss of GSH, an increase in ROS, caspase activation and subsequent apoptosis. Clinically, redox alterations as a consequence of Bcl-2 inhibition by ABT-737 should be considered in devising combination therapies with this novel agent or its derivatives.

Advance Care Planning in Patients With Cancer Referred to a Phase I Clinical Trials Program: The MD Anderson Cancer Center Experience

PURPOSE Patients with advanced malignancies referred for early clinical trials have a short life expectancy. We designed this survey to ascertain the status of advance care planning in this population. PATIENTS AND METHODS Patients who were seen in a phase I clinic were asked to anonymously complete an investigator-designed survey. RESULTS Of 435 individuals approached, 215 (49%) returned completed or partially completed surveys, whereas many others stated that they wanted to avoid the topic, because they had come to the phase I clinic for cancer therapy. Most patients (n = 149; 69%) were still hopeful about their future. Approximately 42% of patients (n = 90) reported having a living will, 46% had a medical power of attorney (n = 98), and 19% had a do-not-resuscitate (DNR) order (n = 40). Approximately 20% of participants (n = 43) had not discussed advance care planning. Fifty-nine percent of patients wanted to discuss advance care planning with their physician. Having a DNR order in place was significantly more common in individuals who had a living will and/or a medical power of attorney. CONCLUSION Although most patients referred to a phase I clinic remained optimistic, many had discussed a living will, medical power of attorney, and/or DNR order with their physician, family, and/or attorney. However, a significant minority had not addressed this issue with anyone, and many refused to take a survey on the topic. More than half of the patients wanted to discuss these matters with their physician. These observations suggest that extra effort to address advance care planning is needed for these patients.

Expression and Activity of Fyn Mediate Proliferation and Blastic Features of Chronic Myelogenous Leukemia

The BCR-ABL1 oncogene is a tyrosine kinase that activates many signaling pathways, resulting in the induction of chronic myeloid leukemia (CML). Kinase inhibitors, such as imatinib, have been developed for the treatment of CML; however, the terminal, blast crisis phase of the disease remains a clinical challenge. Blast crisis CML is difficult to treat due to resistance to tyrosine kinase inhibitors, increased genomic instability and acquired secondary mutations. Our recent studies uncovered a role for Fyn in promoting BCR-ABL1 mediated cell growth and sensitivity to imatinib. Here we demonstrate that Fyn contributes to BCR-ABL1 induced genomic instability, a feature of blast crisis CML. Bone marrow cells and mouse embryonic fibroblasts derived from Fyn knockout mice transduced with BCR-ABL1 display slowed growth and clonogenic potential as compared to Fyn wild-type BCR-ABL1 expressing counterparts. K562 cells overexpressing constitutively active Fyn kinase were larger in size and displayed an accumulation of genomic abnormalities such as chromosomal aberrations and polyploidy. Importantly, loss of Fyn protected mouse embryonic fibroblast cells from increased number of chromosomal aberrations and fragments induced by BCR-ABL1. Together, these results reveal a novel role for Fyn in regulating events required for genomic maintenance and suggest that Fyn kinase activity plays a role in the progression of CML to blast crisis.

Barriers to Study Enrollment in Patients With Advanced Cancer Referred to a Phase I Clinical Trials Unit

UNLABELLED We conducted this retrospective study to identify reasons that patients referred to a phase I clinical trial failed to enroll or delayed enrollment onto the trial. MATERIALS AND METHODS Outcome analyses were conducted independently on data collected from electronic medical records of two sets of consecutive patients referred to a phase I clinical trial facility at MD Anderson Cancer Center. Data from the first set of 300 patients were used to determine relevant variables affecting enrollment; data from the second set of 957 patients were then analyzed for these variables. RESULTS Results from the two sets of patients were similar. Approximately 55% of patients were enrolled in a phase I trial. Patients referred from within MD Anderson were more likely to be enrolled than patients seen originally outside the institution (p = .006); black patients were more likely than white patients to enroll (69% vs. 43%; p = .04). The median interval from the initial visit to initiation of treatments was 19 days. Major reasons for failure to enroll included failure to return to the clinic (36%), opting for treatment in another clinic (17%), hospice referral (11%), early death (10%), and lack of financial clearance (5%). Treatment was delayed for three weeks or more in 250 patients; in 85 patients (34%), the delay was caused by financial and insurance issues. CONCLUSION Failure to return to the clinic, pursuit of other therapy, and rapid deterioration were the major reasons for failure to enroll; lengthy financial clearance was the most common reason for delayed enrollment onto a phase I trial.

Abstract 1627: Requirement for the Src family kinase, Fyn, in proliferation of BCR-ABL1 transduced bone marrow and aneuploidy in CML

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Oncogenic signals stemming from the BCR/ABL kinase drive the development and progression of chronic myeloid leukemia (CML). Hence, therapies blocking kinase activity have proven extremely successful at managing this hematological malignancy. However, treatment of the terminal and progressed state of CML, blast crisis, remains difficult. Previous work from our group has identified the Src family kinase, Fyn, as being upregulated in blast crisis CML. We also reported that knockdown of Fyn slowed CML growth in vitro and in vivo and sensitized cells to BCR-ABL1 kinase inhibition with imatinib. Recent work using microarray profiling of kinase inhibitor resistant cells from a separate group has shown that imatinib resistance is associated with Fyn expression. In the current study, we utilized bone marrow cells from Fyn deficient mice to test the requirement for Fyn in p210 BCR-ABL1 mediated survival. Bone marrow cells from Fyn knockout and Fyn wildtype mice were harvested and transduced with a GFP expressing retroviral construct (MigR1) or MigR1-p210 BCR-ABL1. Cells were sorted for GFP expression and BCR-ABL1 expression was confirmed by Western blotting. Cell growth in culture was monitored over the course of three weeks in Fyn deficient and wildtype cells expressing BCR-ABL1. Fourteen days post sorting, the number of cells lacking Fyn were more than 50% lower than Fyn wildtype cells transduced with BCR-ABL1. Clonogenic assays further indicated that Fyn significantly promotes BCR-ABL1 induced bone marrow cell growth. Colony numbers in Fyn deficient cells expressing BCR-ABL1 were less than half that seen in Fyn wildtype cells. To address the role for Fyn kinase activity in these effects, constitutively active and dominant negative Fyn constructs have been transduced into BCR-ABL1 expressing cells. Constitutively active Fyn caused a high degree of chromosomal aberrations, fusions and aneuploidy suggestive of genomic instability. Taken together, these data highlight a significant role for Fyn in BCR-ABL1 mediated proliferation and secondary chromosomal aberrations, which are both features characteristic of blast crisis CML. Our results indicate that strategies to inhibit Fyn expression and kinase activity will be therapeutically relevant for progressed and/or refractory CML patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1627.