BRAF and RAS mutations in human lung cancer and melanoma

BRAF encodes a RAS-regulated kinase that mediates cell growth and malignant transformation kinase pathway activation. Recently, we have identified activating BRAF mutations in 66% of melanomas and a smaller percentage of many other human cancers. To determine whether BRAF mutations account for the MAP kinase pathway activation common in non-small cell lung carcinomas (NSCLCs) and to extend the initial findings in melanoma, we screened DNA from 179 NSCLCs and 35 melanomas for BRAF mutations (exons 11 and 15). We identified BRAF mutations in 5 NSCLCs (3%; one V599 and four non-V599) and 22 melanomas (63%; 21 V599 and 1 non-V599). Three BRAF mutations identified in this study are novel, altering residues important in AKT-mediated BRAF phosphorylation and suggesting that disruption of AKT-induced BRAF inhibition can play a role in malignant transformation. To our knowledge, this is the first report of mutations documenting this interaction in human cancers. Although >90% of BRAF mutations in melanoma involve codon 599 (57 of 60), 8 of 9 BRAF mutations reported to date in NSCLC are non-V599 (89%; P < 10(-7)), strongly suggesting that BRAF mutations in NSCLC are qualitatively different from those in melanoma; thus, there may be therapeutic differences between lung cancer and melanoma in response to RAF inhibitors. Although uncommon, BRAF mutations in human lung cancers may identify a subset of tumors sensitive to targeted therapy.     

Prognostic variables for response and outcome in patients with extragonadal germ-cell tumors.

BACKGROUND: This investigation evaluates prognostic variables in patients with seminomatous and non-seminomatous extragonadal germ-cell tumors (EGCT) in order to identify relevant factors for long-term outcome following cisplatin-based chemotherapy. PATIENTS AND METHODS: Patients from six countries treated at 11 centers in Europe and the USA from 1975 to 1996 were evaluated retrospectively. Uni- and multivariate analyses of prognostic variables for survival and for response to chemotherapy were performed. RESULTS: Data were available for 635 EGCT patients, 104 with seminomatous and 524 with non-seminomatous EGCT (n = 7 not specified). For non-seminomatous EGCT the following independent adverse factors were identified: presence of either liver, lung or central nervous system metastases, primary mediastinal tumor or elevation of pretreatment beta-human gonadotropin; for extragonadal seminoma (only univariate) adverse factors were: presence of liver metastases, two or greater metastatic sites or International Germ Cell Cancer Collaborative Group (IGCCCG) grouping (intermediate versus good). Integration of these variables produced the following prognostic risk groupings: 'excellent prognosis', all seminomatous EGCT (89% 5-year survival rate); 'intermediate low', 'intermediate high' and 'poor', all non-seminomatous EGCT with a 69, 55 and 17% 5-year survival rate, respectively. The decreased survival among the different groups was due to a lower rate of favorable objective remissions and a higher rate of relapses. Classification and regression tree (CART) modeling confirmed histology and location of primary tumor as the major prognosticators. For the subgroup of patients with mediastinal non-seminoma, the 2-year survival rate ranged from 34 to 84%. Multivariate testing for the probability to respond to chemotherapy revealed non-seminomatous histology, primary mediastinal tumor site, and the presence of liver, lung or CNS metastases as independent adverse factors. CONCLUSIONS: In EGCT, prognostic variables for the outcome and for the response to chemotherapy could be identified, which in part differ from gonadal GCT. The proposed model might help to better understand the specific prognosis of EGCT and to tailor risk-adapted treatment strategies. In addition, CART analysis demonstrated the heterogenous prognosis of patients with mediastinal non-seminoma.     

Deletion of the Ink4-locus (the p16ink4a, p14ARF and p15ink4b genes) predicts relapse in children with ALL treated according to the Nordic protocols NOPHO-86 and NOPHO-92.

Inactivation of the Ink4 gene locus locus on 9p comprising the tumour suppressor gene p16ink4a and its neighbours p14ARF and p15ink4b is common in childhood acute lymphoblastic leukaemia (ALL), but the prognostic significance is controversial. DNA from 230 patients was retrospectively analysed by Southern blotting, single strand conformation polymorphism (SSCP) and sequencing techniques. The results were correlated with clinical characteristics and outcome. One hundred and ninety-four fully analysed patients, similarly treated using the Nordic NOPHO-86 or the current NOPHO-92 protocols, were included in the outcome analysis. Deletions approached a minimally deleted region between the p16ink4a and p15ink4b genes, making the p14ARF gene the most commonly deleted coding sequence. Bi-allelic deletion was associated with high white blood cell count (WBC) (P < 0.001), T cell phenotype (P < 0.001) and mediastinal mass (P < 0.001). Patients with Ink4 locus bi-allelic deletions had an inferior pEFS (P < 0.01) and multivariate analysis indicated that bi-allelic deletion of the p16ink4a and the p14ARF genes was an independent prognostic risk factor (P < 0.05). Sub-group analysis revealed a pronounced impact of deletion status for high-risk patients, ie with high WBC. Deletion-status and clinical risk criteria (WBC) could thus be combined to further differentiate risk within the high-risk group. The analysis of the Ink4 locus adds independent prognostic information in childhood ALL treated by Nordic protocols and may help in selection of patients for alternative treatment.     

Results of modern therapy for patients with mediastinal nonseminomatous germ cell tumors

BACKGROUND: The aim of this study was to determine the effects of independent prognostic variables, such as prechemotherapy tumor markers, the extent of disease at diagnosis, the tumor markers postchemotherapy (PC), and the pathology of the PC residual mass on the overall survival of patients with primary mediastinal nonseminomatous germ cell tumors (PMNSGCT). METHODS: The authors undertook a retrospective review of 39 patients with PMNSGCT between 1983 and 1997 who received their initial chemotherapy at Indiana University and 36 additional patients referred for PC resection. All patients received chemotherapy based on the combination of cisplatin and etoposide. The median follow-up was 22 months (range, 12-144 months). RESULTS: The prechemotherapy tumor markers did not affect overall survival. Extent of disease (mediastinal only vs. visceral metastases) was an important prognostic factor for survival in univariate analysis (P = 0.042). Sixty-two of 75 patients underwent PC resection of residual disease. Fifteen of the 62 patients achieved a CR with chemotherapy alone, as the PC resection revealed only necrosis. Fourteen of these 15 patients continuously had no evidence of disease (NED). Forty-seven of the 62 patients had NED with chemotherapy and PC resection, including 31 with teratoma and 16 with carcinoma. However, 11 of 31 with teratoma and 11 of 16 with carcinoma subsequently relapsed. Although 18 patients had elevated tumor markers at the time of PC resection, 6 of 18 had only necrosis and 4 had teratoma. The PC tumor markers did not affect survival. The pathology of the resected specimen was the most significant predictor of survival in multivariate analysis (P < 0.001). CONCLUSIONS: Twenty-eight of 39 patients (71.8%) with PMNSGCT treated at Indiana University achieved NED status, but only 16 (41%) continuously had NED. Twenty of 36 (55.5%) referred for resection continuously had NED. Disease confined to the mediastinum and necrosis in the PC specimen were important prognostic factors for survival.     

The effects of prior exposure to bleomycin on the incidence of pulmonary toxicities in a group of patients with disseminated testicular carcinomas.

The incidence of pulmonary toxicities in 12 patients with prior exposure to bleomycin (BLM) was compared to the incidence of pulmonary toxicities in a matched group of 73 patients with state II or IV testicular carcinomas treated with a regimen containing vinblastine, bleomycin, and cis-diamminedichloroplatinum. The comparison demonstrates that prior exposure to bleomycin constitutes a significant risk factor and that the risk is additive; ie, prior doses should be added to current doses to determine the cumulative dose-related probablity of development of pulmonary toxicities.     

Functions of human neutrophilic granulocytes after in vivo exposure to interferon alpha.

The ability of neutrophilic granulocytes to phagocytize yeast particles and to reduce Nitro Blue Tetrazolium at rest and on activation with bacterial stimuli was monitored in 32 patients receiving treatment with human interferon alpha. The ability of these cells to attach to and ingest yeast particles was not altered to any major extent during 1 year of interferon treatment. In most patients, the Nitro Blue Tetrazolium-reducing activity increased after the first injection of interferon. During prolonged treatment with interferon alpha, 1 week to 1 year, granulocytes activated with bacteria exhibited a reduced Nitro Blue Tetrazolium activity in most patients.     

Interferon and spontaneous cytotoxicity in man. III. Effect of interferon on lymphocytes and target cells in vitro.

Human leukocyte interferon (IF) was tested for its capacity to modify the spontaneous cytotoxicity of human peripheral lymphocytes for allogeneic target cells in vitro. Pretreatment of lymphocytes with IF augmented their cytotoxicity whereas pretreatment of the target cells did not increase but possibly decreased their sensitivity to the spontaneous cytotoxicity of lymphocytes.     

Recombinant human bone morphogenetic proteins in the treatment of fractures

Recently, several prospective randomized clinical trials have resulted in the publication of critical studies on the efficacy of recombinant human morphogenetic proteins BMP-2 (rhBMP-2) and BMP-7 (OP-1) in spinal fusion and fracture healing. The clinical use of BMPs is now in its infancy and understanding the mechanism and the appropriate application of these proteins is necessary for all practicing orthopedic surgeons. This article will revisit some of the early studies using rhBMPs and review the current literature on their role in fracture healing.     

Effects of low-dose, intermittent treatment with recombinant human parathyroid hormone (1-34) on chondrogenesis in a model of experimental fracture healing

Recent studies have demonstrated that intermittent administration of parathyroid hormone (PTH) enhances osteogenesis (hard callus formation) and increases mechanical strength in experimental fracture healing. Thus far, however, effects of PTH on chondrogenesis (soft callus formation) during fracture healing have not been fully elucidated. In the present study, we analyzed the underlying molecular mechanism by which exogenous PTH would affect chondrogenesis in a model of experimental fracture healing. Unilateral femoral fractures were produced in 2-month-old Sprague-Dawley rats. Daily subcutaneous injections of 10 microg/kg of recombinant human PTH(1-34) [rhPTH(1-34)] were administered over a 28-day period of fracture healing. Control animals were injected with vehicle solution (normal saline) alone. The results showed that, on day 14 after fracture, cartilage area in the PTH-treated group was significantly increased (1.4-fold) compared with the controls, but this increase was not observed at days 21 and 28. In the early stage of chondrogenesis (days 4-7), cell proliferation, expressed as the rate of proliferating cell nuclear antigen-positive cells, was increased in mesenchymal (chondroprogenitor) cells but not chondrocytes in the PTH-treated group compared with controls. In addition, gene expression of SOX-9 was up-regulated in the PTH-treated group on day 4 (1.4-fold), and this was accompanied by enhanced expression of pro-alpha1 (II) collagen (1.8-fold). After 14 days, there were no significant differences between groups in either cell proliferation or the expression levels of cartilage differentiation-related genes (SOX-9, pro-alpha1 (II) collagen, pro-alpha1 (X) collagen and osteopontin). These results suggest that intermittent treatment with low-dose rhPTH(1-34) induces a larger cartilaginous callus but does not delay chondrocyte differentiation during fracture healing.