Algemir Lunardi Brunetto

Results of the brazilian osteosarcoma treatment group studies III and IV : Prognostic factors and impact on survival

PURPOSE To evaluate the impact of chemotherapy and surgery on the outcome of osteosarcoma (OS) of the extremities and to identify prognostic factors in Brazilian patients. PATIENTS AND METHODS A total of 225 patients with metastatic and nonmetastatic OS of the extremities were enrolled and assessed in two consecutive studies designed and implemented by the Brazilian Osteosarcoma Treatment Group. RESULTS The 5-year survival and event-free survival rates for the 209 assessable patients were 50.1% and 39%, respectively; for the 178 patients with nonmetastatic disease at diagnosis, the rates were 60.5% and 45.5%, respectively. The multivariate analysis showed that the following variables were associated with a shorter survival: metastases at diagnosis (P < .001), necrosis grades 1 and 2 (P = .046), and tumor size (P = .0071). CONCLUSION The overall 5- and 10-year survival rates were lower than the rates reported in North American and European trials. A pattern of advanced disease at diagnosis was often present, with a high proportion of patients having metastases (20.8%) and large tumor size (42.9%). However, these features were not necessarily associated with longer duration of prediagnostic symptoms. These findings were considered in the strategic planning of the current Brazilian cooperative study, with the aim of improving survival and quality of life of a large number of patients with OS.

Ototoxicity From Cisplatin Therapy in Childhood Cancer

Cisplatin has been associated with hearing damage. It is usually irreversible, bilateral, and characterized by high-frequency sensorineural hearing loss. This study was carried out to identify impairment of hearing function in children and adolescents with cancer after cisplatin therapy. Twenty-three survivors of childhood cancer treated with cisplatin at our Unit from 1991 to 2004 performed tympanometry, pure tone audiometry, transient otoacoustic emissions, and distortion product otoacoustic emissions (DPOAE). The median age at diagnosis was 12.3 years and the median total dose of cisplatin received was 406 mg/m2. Fifty-two percent of patients had bilateral and in the high frequencies range hearing loss on audiometry. Transient otoacoustic emission and DPOAE abnormalities were detected in 22% and in 71% of the patients, respectively. We found a high concordance between the findings of audiometry and DPOAE (P=0.01). There was no influence of sex and number of ototoxic drugs other than cisplatin on hearing loss. There was a trend for younger age and higher cumulative dose of cisplatin to be associated with greater severity of hearing damage. Our data provide further evidence on hearing damage due to cisplatin therapy in children. The high incidence of patients with hearing function abnormalities found in this study and in previous reports highlights the importance of monitoring hearing function in children and adolescents undergoing cisplatin therapy, or as early as possible at follow-up. This study also demonstrates that DPOAE should be used for screening of hearing abnormalities and, once hearing damage is identified, patients require expert audiologic pediatric evaluation and (where indicated) use of hearing aids and/or speech therapy.

Influence of low-energy laser in the prevention of oral mucositis in children with cancer receiving chemotherapy

This study assessed the use of low‐energy laser in the prevention or reduction of the severity of oral mucositis.

Low-level Infrared Laser Therapy in Chemotherapy-induced Oral Mucositis: A Randomized Placebo-controlled Trial in Children

Background Oral mucositis (OM) is one of the most frequent complications of chemotherapy for which there is no standard therapy; treatment is mostly conservative. This study was conducted to determine whether low-intensity laser therapy (LLLT) can reduce the duration of chemotherapy-induced OM. Procedure A placebo-controlled randomized trial was carried out using LLLT or placebo (sham treatment). Children and adolescents with cancer receiving chemotherapy or hematopoietic stem-cell transplantation between October 2005 and May 2006 were eligible as soon as they developed OM. Patients received intervention for 5 days. The LLLT group was treated with laser GaAlAs, wavelength (λ): 830 nm (infrared), power: 100 mW, dose: 4 J/cm2, and placebo group underwent sham treatment. The grade of OM was clinically assessed by the National Cancer Institute, Common Toxicity Criteria scale. Results Twenty-one patients developed OM and were evaluable for analysis; 18 (86%) patients had a diagnosis of leukemia or lymphoma and 3(14%) had solid tumors. The mean age was 8.2 (±3.1) years. Nine patients were randomized in the laser group and 12 in the placebo-control group. Once OM was diagnosed, the patients had daily OM grading assessments before laser or sham application and thereafter until complete healing of the lesions. On day 7 after OM diagnosis, 1/9 of patients remained with lesions in laser group and 9/12 of patients in the placebo-control group (P=0.029). In the laser group, the mean of OM duration was 5.8±2 days and in the placebo group was 8.9±2.4 days (P=0.004). Conclusions Our study has shown evidence that laser therapy in addition to oral care can decrease the duration of chemotherapy-induced OM. Our results confirm the promising results observed in adult cancer patients and should encourage pediatric oncologists to use laser therapy as first-line option in children with chemotherapy-induced OM.

Stimulation of Proliferation of U138-MG Glioblastoma Cells by Gastrin-Releasing Peptide in Combination with Agents That Enhance cAMP Signaling

Increasing evidence indicates that gastrin-releasing peptide (GRP) acts as an autocrine growth factor for brain tumors. However, it remains unclear whether the cAMP/protein kinase A (PKA) signaling pathway plays a role in mediating the mitogenic effects of GRP. We show here that GRP combined with agents that stimulate the cAMP/PKA pathway promotes proliferation of human gliobastoma cells. Treatment with GRP combined with the adenylyl cyclase activator forskolin, the cAMP analog 8-Br-cAMP or the phosphodiesterase type IV inhibitor rolipram increased proliferation of U138-MG cells in vitro measured by MTT assay. None of the compounds had an effect when given alone. GRP receptor (GRPR) mRNA and protein expression in U138-MG cells was detected by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. The results suggest that GRP and the GRPR interact with the cAMP/PKA signaling pathway in stimulating cancer cell proliferation.

Gastrin-Releasing Peptide Receptors Regulate Proliferation of C6 Glioma Cells through a Phosphatidylinositol 3-Kinase-Dependent Mechanism

Gastrin-releasing peptide (GRP) has been proposed as a major growth factor in brain tumors, and GRP receptor (GRPR) antagonists show antiproliferative effects in experimental gliomas. However, the underlying molecular events downstream of GRPR activation remain poorly understood. In the present study, we examined the role of the GRPR in regulating proliferation of glioma cells in vitro and its possible interaction with the phosphatidylinositol 3-kinase (PI3K) signaling pathway. Expression of GRPR mRNA and protein in C6, U-87MG, and U-373MG glioma cells was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. Proliferation of C6 and U-87MG, but not U-373MG cells was significantly inhibited by the GRPR antagonist RC-3095, whereas the GRPR agonist bombesin (BB) significantly enhanced proliferation of C6 cells. The BB-induced stimulatory effect on cell proliferation was prevented by either RC-3095 or the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. Our results provide the first evidence that the GRPR regulates proliferation of C6 glioma cells and suggest that PI3K is required for GRPR-mediated stimulation of glioma growth.

Systemic administration of doxorubicin impairs aversively motivated memory in rats.

There is growing clinical evidence of cognitive impairment in cancer patients treated with chemotherapy, especially in women treated with drug combinations for breast cancer. Clinical studies have a difficult task of defining which drugs individually are responsible for the cognitive changes and published papers evaluating single agents in experimental models are scanty. In the present study we have investigated the effect of single escalating doses of doxorubicin (DOX) on memory for inhibitory avoidance conditioning (IA) in rats. The doses used were comparable to those applied in the clinic. When given systemically before training, higher doses of DOX impaired IA memory retention measured 24h and 7days, but not 3h after training. DOX did not affect IA retention when given either before or after training in a multiple-trial IA training protocol. Control experiments showed that DOX produced a decrease in exploratory behavior assessed by the number of rearings performed during exploration of an open field. The results indicate that a single systemic administration of DOX might impair long-term aversive learning.

BDNF and PDE4, but not the GRPR, Regulate Viability of Human Medulloblastoma Cells

Medulloblastoma is the most common brain tumor of childhood. Emerging molecular targets in medulloblastoma include neurotrophin and neuropeptide receptors. In the present study, we have examined the influence of brain-derived neurotrophic factor (BDNF)/TrkB receptor- and gastrin-releasing peptide receptor (GRPR)-mediated signaling on the viability of human medulloblastoma cells. The expression of TrkB and GRPR was confirmed by immunohistochemistry and mRNA for both BDNF and GRPR was detected by reverse transcriptase polymerase chain reaction in Daoy, D283, and ONS76 cells. Treatment with BDNF significantly inhibited the viability of Daoy and D283, but not ONS76 cells, measured with the MTT assay. Neither the GRPR agonists GRP and bombesin nor the GRPR antagonist RC-3095 affected cell viability. Because previous findings have indicated that the viability of glioma cells might be enhanced by GRP when combined with the cAMP phosphodiesterase-4 (PDE4) inhibitor rolipram, we also examined the effects of rolipram alone or combined with GRP on cell viability. Rolipram significantly reduced the viability of all three cell lines, and the inhibitory effect of rolipram in Daoy cells was not modified by cotreatment with GRP. The results suggest that BDNF/TrkB and PDE4, but not the GRPR, regulate the viability of medulloblastoma cells.

Transplante de medula óssea e transplante de sangue de cordão umbilical em pediatria

Objective: to review the indications, main steps and complications of bone marrow transplantation in children. Sources: Medline-based literature review. Summary of the findings: we comment about the indications of autologous, allogeneic and syngeneic bone marrow transplantation, donor selections, harvest and infusion of the hematopoietic progenitor cells that will reconstitute the hematopoietic and immune systems. We describe the different conditioning regimens and the new sources of cells, such as cord blood. We also describe the most common events after the procedure, including infections, graft versus host disease, and cardiovascular, pulmonary, hepatic, genitourinary, and gastrointestinal complications. The late effects and their impact on quality of life are also discussed. Conclusions: bone marrow transplantation does not confer an absolutely normal life span to all the patients; however, it represents the only chance of cure for children with certain neoplastic or immunological diseases. By knowing the steps of the procedure, pediatricians can be a source of information on bone marrow transplantation to the patients and their families.

BDNF/TrkB Content and Interaction with Gastrin-Releasing Peptide Receptor Blockade in Colorectal Cancer

Objective: Neurotrophin and neuropeptide pathways are emerging targets in cancer. Here we show that brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, are present in colorectal cancer and that BDNF levels are increased in tumors compared to nontumor tissue. In addition, we investigate the role of BDNF in influencing the response of colorectal cancer cells to inhibition of gastrin-releasing peptide receptors (GRPR). Methods: Fresh-frozen sporadic colorectal adenocarcinoma specimens and adjacent nonneoplastic tissue from 30 patients, as well as paraffin-embedded colorectal cancer samples from 21 patients, were used in this study. Cell proliferation and mRNA and protein levels were examined in HT-29 or SW620 cells treated with a GRPR antagonist, human recombinant BDNF (hrBDNF), a Trk antagonist K252a, or cetuximab. Results: Expression of BDNF and TrkB was detected in tumor samples and cell lines. BDNF levels were higher in tumor samples compared to nonneoplastic tissue. BDNF expression and secretion were increased by GRPR blockade in HT-29 cells through a mechanism dependent on epidermal growth factor receptors. Treatment with hrBDNF prevented the effect of GRPR blockade on cell proliferation, whereas a Trk inhibitor reduced proliferation. Conclusions: BDNF and TrkB are present in colorectal cancer and might contribute to resistance to GRPR antagonists.