A synthetic matrix metalloproteinase inhibitor prevents squamous carcinoma cell proliferation by interfering with epidermal growth factor receptor autocrine loops

Head and neck squamous cell carcinoma (HNSCC) is characterized by its capacity to invade adjacent tissues and to metastasize locoregionally. Evidence suggests that matrix metalloproteinases (MMPs) may play a causal role in HNSCC progression. While evaluating the role of MMPs in the invasion process, we made the surprising observation that a broad-spectrum MMP inhibitor, (marimastat, BB2516), inhibited the growth in vitro of some HNSCC cell lines. This inhibitory effect was only found in HNSCC cell lines overexpressing epidermal growth factor receptors. The effects of the MMP inhibitor could be reversed by adding exogenous c-erbB ligands, suggesting that the phenomenon may be related to autocrine ligand processing. This hypothesis was supported by the finding that the growth-inhibitory effect of marimastat was directly related to its ability to prevent the release of major c-erbB ligands including transforming growth factor-alpha, betacellulin and heregulin beta1 from HNSCC. Marimastat was also found to potentiate the cytotoxic effects of cisplatin both in vitro and in vivo. Our results indicate that the cleavage of several c-erbB ligands from membrane-anchored precursors requires MMP activity. We conclude that MMP inhibitors could prevent tumor progression not only by inhibiting invasion and angiogenesis, as previously shown, but also by their ability to inhibit autocrine signaling through the c-erbB receptors. Clinical trials to test this hypothesis in HNSCC should be considered.     

血清SOD、MDA、NO与突发性聋的相关研究

目的：通过对突发性聋病人血中一氧化氮（NO）、丙二醛（MDA）、超氧化物歧化酶（SOD）含量的检洲，探讨突聋与血氧自由基和自由基的清除剂SOD之间的关系。方法：采用硝酸还原酶法测定了30例突聋病人血中NO含量，并以25例同期体检正常的健康人为对照组；同时还用硫代巴比妥酸比色法测定MDA含量，用黄嘌呤氧化酶法测定SOD含量。砖呆；应用金纳多、能量合剂、克林臭（即马来酸桂哌齐特，钙通道阻滞药）联合静脉输入，突聋各组的听力均有不同程度提高，有效率在78．57％以上。治疗后同对照组相比，血清NO、MDA水平明显低于患病之初，而SOD活性明显高于治疗之前，P〈0．01。结论；检测突聋病人血中N0、MDA、SOD的含量，能帮助我们探讨突聋的发病机理，估计预后。血氧自由基的升高可能是突聋发病因素之一，而SOD的含量可以帮助我们估计预后。     

Accurate prediction of BRCA1 and BRCA2 heterozygous genotype using expression profiling after induced DNA damage.

PURPOSE: In this study, the differential gene expression changes following radiation-induced DNA damage in healthy cells from BRCA1/BRCA1 mutation carriers have been compared with controls using high-density microarray technology. We aimed to establish if BRCA1/BRCA2 mutation carriers could be distinguished from noncarriers based on expression profiling of normal cells. EXPERIMENTAL DESIGN: Short-term primary fibroblast cultures were established from skin biopsies from 10 BRCA1 and 10 BRCA2 mutation carriers and 10 controls, all of whom had previously had breast cancer. The cells were subjected to 15 Gy ionizing irradiation to induce DNA damage. RNA was extracted from all cell cultures, preirradiation and at 1 hour postirradiation. For expression profiling, 15 K spotted cDNA microarrays manufactured by the Cancer Research UK DNA Microarray Facility were used. Statistical feature selection was used with a support vector machine (SVM) classifier to determine the best feature set for predicting BRCA1 or BRCA2 heterozygous genotype. To investigate prediction accuracy, a nonprobabilistic classifier (SVM) and a probabilistic Gaussian process classifier were used. RESULTS: In the task of distinguishing BRCA1 and BRCA2 mutation carriers from noncarriers and from each other following radiation-induced DNA damage, the SVM achieved 90%, and the Gaussian process classifier achieved 100% accuracy. This effect could not be achieved without irradiation. In addition, the SVM identified a set of BRCA genotype predictor genes. CONCLUSIONS: We conclude that after irradiation-induced DNA damage, BRCA1 and BRCA2 mutation carrier cells have a distinctive expression phenotype, and this may have a future role in predicting genotypes, with application to clinical detection and classification of mutations.     

Primary osteosarcoma of the skull

Primary osteogenic sarcoma of the skull is an exceedingly rare condition. An adult male patient is described, who had a painless swelling in the right forehead that had rapidly enlarged in the previous 6 months. Radiological investigations showed a large destructive mass lesion involving the right side of the frontal bone with extension into the frontal sinus, causing marked extradural compression of brain parenchyma. Histopathological examination confirmed the lesion to be primary osteogenic sarcoma.     

Toxicity of phorbol esters for human epithelial cells expressing a mutant ras Oncogene

Phorbol esters and related compounds provide a promising source of potential anticancer agents. The mechanism of their toxicity, however, is unclear, and interpretation has been complicated by the conflicting responses exhibited by different transformed cell lines. Previously we showed that in primary thyroid follicular cells, expression of mutant p21^ras conferred a striking sensitivity to the toxic effects of phorbol esters. We have now extended this work using a thyroid cell line with an inducible mutant ras gene to exclude the possibility that this result was a trivial consequence of the marked growth stimulation induced in these cells by mutant p21^ras. Furthermore, by assessing the action of a panel of phorbol esters and a potential chemotherapeutic agent, bryostatin, we demonstrated that this phenomenon was only a function of biologically active phorbol esters. These results provide a molecular rationale for the development of phorbol ester analogues as chemotherapeutic agents.     

Relations between age, metabolic control, disease adjustment and psychological aspects in insulin-dependent diabetes mellitus

The relations between age, metabolic control, disease adjustment, and psychological factors in boys and girls with recently diagnosed insulin-dependent diabetes mellitus (IDDM) were studied. Older girls had significant higher postremission glycosylated haemoglobin A (Hb A_lc) levels ( p = 0.008). Girls with more hospitalizations had a lower developmental level ( p = 0.05), and had significantly more problems in the behavioural rating ( p = 0.05). Boys with more hospitalizations had a more external locus of control ( p = 0.01), more difficulties with disease adjustment, more emotional problems, and were also clinically assessed as having more behavioural problems. Boys showing more difficulties in psychological adjustment to the disease also had higher postremission Hb A_1clevels ( p = 0.02). Although Swedish children with IDDM of short disease duration do not differ from healthy children in important psychological aspects, older girls and a small group of problematic younger boys are at risk of developing metabolic imbalance after a short disease duration.     

Metabolic effects of growth hormone treatment: an early predictor of growth response?

Fourteen children receiving one year of recombinant human growth hormone (rhGH) treatment underwent measurement of serial changes in body composition (measured by skinfold thickness, bioelectrical impedance, and H2(18)O dilution), resting energy expenditure (REE, estimated by ventilated hood indirect calorimetry), and total free living daily energy expenditure (TEE, measured by the doubly labelled water technique). Mean height velocity increased from 4.9 to 8.6 cm/year after six months of treatment. Fat free mass (FFM) increased more during the first six weeks (24.4 g/day) than from six to 26 weeks of treatment (6.8 g/day); fat mass decreased by 7.2 g/day and 1.1 g/day respectively. The six week increase in REE (kJ/day) was maintained after six months of treatment, though expressed per kilogram FFM (kJ/kgFFM/day), returned to pretreatment values by three months. Height velocity increases at six months correlated with six week changes in fat mass measured by skinfold thickness and REE, though use of this relationship to predict growth response in individuals is limited by the wide 95% prediction intervals. No significant changes in growth, body composition, or energy expenditure were observed between six and 12 months of treatment, in either patients who had initially responded well to treatment or those who were poor initial responders to treatment and who had their dose of rhGH doubled after six months.