Identification of molecular characteristics correlated with glioblastoma sensitivity to EGFR kinase inhibition through use of an intracranial xenograft test panel

In the current study, we examined a panel of serially passaged glioblastoma xenografts, in the context of an intracranial tumor therapy response model, to identify associations between glioblastoma molecular characteristics and tumor sensitivity to the epidermal growth factor receptor (EGFR) kinase inhibitor erlotinib. From an initial evaluation of 11 distinct glioblastoma xenografts, two erlotinib-sensitive tumors were identified, each having amplified EGFR and expressing wild-type PTEN. One of these tumors expressed truncated EGFRvIII, whereas the other expressed full-length EGFR. Subsequent cDNA sequence analysis revealed the latter tumor as expressing an EGFR sequence variant with arginine, rather than leucine, at amino acid position 62; this was the only EGFR sequence variant identified among the 11 xenografts, other than the aforementioned vIII sequence variant. EGFR cDNAs were then examined from 12 more xenografts to determine whether additional missense sequence alterations were evident, and this analysis revealed one such case, expressing threonine, rather than alanine, at amino acid position 289 of the extracellular domain. This glioblastoma was also amplified for EGFR, but did not display significant erlotinib sensitivity, presumably due to its lacking PTEN expression. In total, our study identified two erlotinib-sensitive glioblastoma xenografts, with the common molecular characteristics shared by each being the expression of wild-type PTEN in combination with the expression of amplified and aberrant EGFR.     

Mixed lymphocyte reactivity and cell-mediated lympholysis to trinitrophenyl-modified autologous lymphocytes in C57BL/10 congenic and B10.A recombinant mouse strains

Cell-mediated lympholysis (CML) to trinitrophenyl (TNP)-modified autologous splenic lymphocytes has been recently reported in the mouse (1). Both the sensitization and effector phases of this phenomenon were shown to be T-cell mediated. Effector cell specificity studies indicated that modification of the target cells is a necessary but insufficient requirement for cytolysis, and suggested that altered cell surface components controlled by genes mapping in the mouse major histocompatibility H-2 complex (MHC) are important in the specificity of the cytotoxic reaction (1). In allogeneic models the generation of cytotoxic effector cells has been shown to be preceded or accompanied by immunogen- induced proliferation of responding lymphocytes, i.e. a mixed lymphocyte reaction (MLR) (2-5), although the generation of effectors may not necessarily always be the consequence of extensive cell proliferation (5). If the induction of cytotoxic effector lymphocytes by modified syngeneic spleen cells is characteristic of sensitization with cellular alloantigens, one would expect to find that sensitization with TNP-modified autologous cells would also induce thymidine incorporation by the responding cells in the culture. The present report demonstrates that both stimulation of thymidine incorporation and generation of cytotoxic effector cells are part of the in vitro response to TNP-modified autologous lymphocytes. However, the MLR to TNP- modified autologous cells consistently appeared to be less pronounced when compared with an allogeneic MLR, whereas the cytotoxic activity of the effector cells generated by sensitization against TNP-modified autologous cells was frequently as high as that detected against H-2 alloantigens. These two components of reactivity to “modified self” are verified in several C57BL/10 congenic and B10.A recombinant mouse strains.     

Large-volume leukapheresis in pediatric patients: processing more blood diminishes the apparent magnitude of intra-apheresis recruitment

Background: Recruitment of progenitors during a large-volume collection, as defined by increasing relative and absolute numbers of progenitors (colony-forming units-granulocyte-macrophage [CFU-GM] of CD34+ cells), has been reported previously. Study Design and Methods: To ascertain whether intra-apheresis recruitment occurs in pediatric patients who have undergone mobilization with chemotherapy and granulocyte-colony-stimulating factor (G-CSF), each hour's portion of a 4-hour leukapheresis was collected into separate bags, and assessed by complete blood count, CFU-GM, and CD34+ cell assays. Seven pediatric patients (median age, 7; range, 2–19) were studied in connection with 2 to 4 collections each, for a total of 21 collections (with hourly samples). The collections lasted for 4 hours, at an inlet rate of 1 to 3 mL per kg per minute, for daily processing totals of 5 to 12 blood volumes. (One blood volume [mL] is estimated by the patient's weight in kg × 70 mL/kg.) Smaller (younger) patients had inlet rates exceeding 2 mL per kg per minute, and larger (older) patients had rates of 1 to 1.5 mL per kg per minute. CFU-GM and CD34+ cell counts obtained each hour of the collection and divided by the first hour's value were compared by nonparametric repeated-measures ANOVA. Results: Second-, third- and fourth-hour CD34+ progenitor cell counts were arithmetically higher than first-hour counts, but the trend did not reach significance (p = 0.1561). Second-hour counts were higher than first-hour counts in the overall analysis (mean ± standard error [SE], 1.00 and 1.39 ± 0.1, respectively; p = 0.0525) and in children older than 5 years (1.00 vs. 1.70 ± 0.30, respectively; p = 0.0259), but not in children younger than 5 years (p = 0.8125). CFU-GM counts did not differ among the 4 hours of collection (p = 0.1717) or between the first and second hour (p = 0.9587). Conclusion: In larger (older) patients, from whom fewer blood volumes were collected, there is a trend toward intra-apheresis recruitment, although less than reported previously. In the smaller (younger) patients, from whom more blood volumes were collected, no trend was observed. Lack of (or submaximal) prior mobilization in previously reported studies may have facilitated intracollection recruitment. Alternatively, the larger number of blood volumes collected from the smaller (younger) patients may have masked intra-apheresis recruitment. The study documents the feasibility of large-volume, 4-hour leukapheresis in pediatric patients.     

Phase I-II trial of ONYX-015 in combination with MAP chemotherapy in patients with advanced sarcomas

ONYX-015 is a provisionally replication competent adenovirus with oncolytic activity in cells with malfunctioning p53. Sarcomas represent a rational target for this approach given the high frequency of p53 mutations (40-75%) and MDM-2 amplification (10-30%). We, therefore, undertook a phase I/II study of ONYX-015, days 1-5 every month administered intratumorally under radiographic guidance, in combination with MAP (mitomycin-C, doxorubicin, cisplatin) chemotherapy in patients with advanced sarcoma. Six patients were treated. Injected lesions included liver metastases in four patients and chest wall metastases in two patients. Sarcoma histologies were gastrointestinal stromal tumors (GIST, two patients), leiomyosarcoma (two patients), liposarcoma (one patient), and malignant peripheral nerve sheath tumor (1 patient). Dose escalation was performed from 10(9) plaque forming units (PFU)/dose (total dose of 5 x 10(9) PFU/cycle) to 10(10) PFU/dose (total dose of 5 x 10(10) PFU/cycle) without dose-limiting toxicity being encountered. Immunohistochemistry of the metastatic lesions prior to treatment showed that five out of six patients were positive for p53, while two patients also had mdm-2 overexpression. Adenoviral replication was detected in two out of six patient biopsies on day 5 of the first cycle, by in situ hybridization (ISH). Both patients were treated at the highest dose level. ONYX-015 viral DNA was detected by quantitative PCR in the plasma of 5/6 patients on day 5 of the first cycle, and up to day 12 (7 days after the last viral dose) in one patient who had extended sampling for viral kinetics performed, suggesting viral replication in sarcoma tissue. One patient with p53 mutation and MDM-2 amplification achieved a partial response to treatment that lasted 11 months. In conclusion, intratumoral administration of ONYX-015 in combination with MAP chemotherapy is well tolerated with no significant toxicity due to ONYX-015 being encountered. Detection of viral DNA in post treatment tumor specimens by ISH and detection of the ONYX-015 genome in the peripheral blood by quantitative PCR, up to 7 days after the last viral dose provide evidence for adenoviral replication. There was evidence of antitumor activity in one out of six patients. Further investigation of this approach in patients with recurrent sarcomas is warranted.     

Incorporation of Biomarker Assessment in Novel Clinical Trial Designs: Personalizing Brain Tumor Treatments

Advances in molecular genetics have aided the identification of potential biomarkers with significant clinical promise in neurooncology. These advances and the evolution of targeted therapeutics necessitate the development and incorporation of innovative clinical trial designs that can effectively validate and assess the clinical utility of biomarkers. In this article, we review the use and potential of several such designs in neurooncology trials in order to support the development of personalized treatment approaches for brain tumor patients.     

Factors that influence Greeks' decision to register as potential bone marrow donors

Hemopoietic stem cells can be used from bone marrow or blood or umbilical cord blood of matched siblings or appropriately matched unrelated volunteers. Today, large bone marrow registries have been established to help identify volunteer unrelated bone marrow donors for patients lacking a family donor. Despite there being almost 10 million registered potential bone marrow donors (PBMD) worldwide, only 50% of white patients have a suitable bone marrow match. Growth in the number of PBMD increases the likelihood of finding a compatible donor for a patient. The attitudes and knowledge of 250 registered PBMD and 315 not registered PBMD toward bone marrow donation, tissues and organs donation, and blood donation were surveyed, using a questionnaire with 27 items. Multivariate logistic regression identified gender (females more often than males), regular blood donation, having a relative or a friend who has already been registered as PBMD, having a relative or a friend who needs bone marrow transplantation, family discussion about tissue and organ donation, knowledge about bone marrow transplantation, information about bone marrow transplantation, and trust in health professionals were independent predictive factors influencing people's decision to register as PBMD. Knowledge of these factors is important to target recruitment efforts.     

Scales for the measurement of attitudes toward blood donation

Attitudes toward blood donation are frequently assumed to vary along a single dimension from unfavorable to favorable. In contrast, theories of attitude structure specify three distinct attitude components: affect, cognition, and behavior. This article describes the development of three new scales for the measurement of affective, cognitive, and behavioral components of attitudes toward blood donation. The scales were developed using the method of equal-appearing intervals and were administered to both donors of blood and nondonors. Correlations among the scales were relatively small and supported the three-component distinction. Affect was more strongly correlated with the number of prior donations than was cognition, which suggested an important role for emotional factors in blood donation. Scores on all three scales showed the attitudes of blood donors to be more favorable than those of nondonors.     

The influence of bright light during the daytime upon circadian rhythm of core temperature and its implications for nocturnal sleep

Abstract The purpose of the present study was to investigate how bright light during the daytime could influence circadian rhythms of core temperature and nocturnal sleep. Seven females (age 20 ± 2 years) served as participants. The participants lived in the experimental unit for 4 days and were exposed to either 6000 lx (bright) or 200 lx (dim) light during the daytime. Rectal temperature (T_re) was measured during the experimental period. Subjective alertness was measured by the Kansei-gakuin Sleeping Scale five times a day. The minimum T_re was significantly lower after bright exposure ( P < 0.05). The T_re fell rapidly after bright exposure before they retired ( P < 0.05) and increased more rapidly during bright light after they woke up ( P < 0.05). The morning wakefulness under bright exposure was more active than under dim exposure ( P < 0.05). The melatonin secretion at wake up during bright exposure was significantly lower than during dim exposure ( P < 0.05). Exposure to bright light during daytime lowered the nocturnal level of T_re, its evening fall was faster and the morning rise quicker. This suggests that indoor light during daytime should be bright enough to promote healthy sleep at night.     

Transforming growth factor beta-1 (TGFB1) and peak bone mass: association between intragenic polymorphisms and quantitative ultrasound of the heel

Background  

Variance of peak bone mass has a substantial genetic component, as has been shown with twin studies examining quantitative measures such as bone mineral density (BMD) and quantitative ultrasound (QUS). Evidence implicating single nucleotide polymorphisms (SNPs) of the transforming growth factor beta-1 (TGFB1) gene is steadily accumulating. However, a comprehensive look at multiple SNPs at this locus for their association with indices of peak bone mass has not been reported.