Phase II trial of piroxantrone in metastatic breast cancer

Summary Thirty-two eligible patients with advanced metastatic breast cancer who had received no more than 1 prior chemotherapy regimen for metastatic disease (16 had received prior doxorubicin) were treated with piroxantrone at a dose of 120 mg/m² intravenously every 21 days. In the twenty-seven patients evaluable for response, two partial responses were seen. Toxicities observed were primarily hematologic with grade 3 or greater granulocytopenia occurring in 34% of the patients. One patient developed symptomatic congestive heart failure at a total cumulative dose of 960 mg/m². We conclude that piroxantrone given at this dose and schedule has minimal activity in patients with metastatic breast cancer.     

SHP-2对人胃癌细胞克隆增殖的影响

目的研究SHP-2对人胃癌细胞SGC-7901细胞克隆增殖的影响。方法采用重组腺病毒Ad-GFP(GFP)、Ad-GFP-SHP-2(WT)转染SGC-7901细胞;采用蛋白印迹技术(Western blot)检测SHP-2蛋白的表达;同时进行集落形成实验检测SGC-7901细胞克隆形成能力。另外,观察SHP-2抑制剂NSC-87877作用后,对SGC-7901集落形成的影响。结果当胃癌细胞感染复数为150时,转染成功的细胞数占总细胞数的0.9。WT组SHP-2蛋白过表达。WT组的平板克隆数明显高于SGC-7901亲本细胞组(Control 1)和GFP组,P<0.05。SHP-2抑制剂组(NSC-87877)的平板克隆数及软琼脂克隆数分别明显低于SGC-7901亲本细胞组(Control2),P<0.05。结论 SHP-2对SGC-7901细胞克隆增殖有明显促进作用。     

Cis-diamminedichloroplatinum (NSC-119875) in childhood malignancies: A southwest oncology group study

Children with malignancies resistant to conventional therapy were treated with cis-diamminedichloroplatinum (PDD), 1 5 to 20 mg/m², given daily by rapid intravenous infusion for 5 days at 3-wk intervals. Eleven of 24 children with acute lymphocytic leukemia (ALL) received two or more courses; among these no remissions occurred. Fifty-four children with solid tumors were treated: 25 neuroblastoma, 9 rhabdomyosarcoma, 4 Ewing sarcoma, 2 testicular embryonal carcinoma, 2 retinoblastoma, and 12 miscellaneous tumors. One complete remission, 3 partial remissions, and 2 improvements were observed in children with neuroblastoma. One girl with metastatic osteogenic sarcoma achieved a partial remission. One child with metastatic testicular embryonal carcinoma showed improvement. The side effects were vomiting controlled by antiemetics in 26 children and transient elevations of serum creatinine and BUN in 14 children. Nineteen of 39 children with solid tumors, who received more than one course of PDD, had moderately severe myelosuppression caused by PDD. In summary, PDD is a promising agent in neuroblastoma, osteogenic sarcoma, and testicular embryonal carcinoma, and an ineffective agent in ALL. The effect of PDD on other types of solid tumors should be evaluated in the future.     

抗肿瘤药物NSC-639829的合成

目的合成抗肿瘤药物NSC-639829。方法以4-氨基-2-甲基苯酚为起始原料,经亲核取代、异氰酸酯化合成4-（5-溴-2-嘧啶氧基）-3-甲基苯基异氰酸酯,再与2-二甲氨基苯甲酰胺缩合得目标化合物NSC-639829。结果目标化合物经质谱、核磁共振氢谱和元素分析确证其化学结构,经HPLC分析纯度达99．5％,总收率达40．2％。结论此工艺路线原料易得,产品收率高,操作安全,适用于工业化生产。     

Neurotoxic injury pathways in differentiated mouse motor neuron-neuroblastoma hybrid (NSC-34D) cells in vitro--limited effect of riluzole on thapsigargin, but not staurosporine, hydrogen peroxide and homocysteine neurotoxicity

The neuroblastoma-spinal motor neuron fusion cell line, NSC-34, in its differentiated form, NSC-34D, permits examining the effects of riluzole, a proven treatment for amyotrophic lateral sclerosis (ALS) on cell death induction by staurosporine (STS), thapsigargin (Thaps), hydrogen peroxide (H₂O₂) and homocysteine (HCy). These neurotoxins, applied exogenously, have mechanisms of action related to the various proposed molecular pathogenetic pathways in ALS and are differentiated from endogenous cell death that is associated with cytoplasmic aggregate formation in motor neurons. Nuclear morphology, caspase-3/7 activation and high content imaging were used to assess toxicity of these neurotoxins with and without co-treatment with riluzole, a benzothiazole compound with multiple pharmacological actions. STS was the most potent neurotoxin at killing NSC-34D cells with a toxic concentration at which 50% of maximal cell death is achieved (TC₅₀ = 0.01 μM), followed by Thaps (TC₅₀ = 0.9 μM) and H₂O₂ (TC₅₀ = 15 μM) with HCy requiring higher concentrations to kill at the same level (TC₅₀ = 2200 μM). Riluzole provided neurorescue with a 20% absolute reduction (47.6% relative reduction) in apoptotic cell death against Thaps-induced NSC-34D cell (p ≤ 0.05), but had no effect on STS-, H₂O₂- and HCy-induced NSC-34D cell death. This effect of riluzole on Thaps induction of cell death was independent of caspase-3/7 activation. Riluzole mitigated a toxin that can cause intracellular calcium dysregulation associated with endoplasmic reticulum (ER) stress but not toxins associated with other cell death mechanisms.     

Mutant superoxide dismutase 1 overexpression in NSC-34 cells: Effect of trehalose on aggregation,TDP-43 localization and levels of co-expressed glycoproteins

Protein inclusions rich in mutant Cu,Zn superoxide dismutase (SOD1) have been found in tissues from patients with familial amyotrophic lateral sclerosis (ALS). Here, the mouse motor neuron-like NSC-34 cell line transiently transfected with human SOD1^G93A fused to enhanced green fluorescent protein exhibited aggregates contrary to cells overexpressing wild-type human SOD1. The aggregates were immunoreactive for ubiquitin but not for the TAR DNA binding protein (TDP-43) that was found in the nucleus. These characteristics mimicked the pathology of mutant SOD1 associated familial ALS. Aggregate formation and mutant SOD1 detergent insolubility were significantly decreased in the presence of millimolar concentrations of trehalose possibly due to its capacity to induce autophagy or to its properties as chemical chaperone. Mutant SOD1, aggregated and non-aggregated, caused decreased levels of concomitantly expressed secretory (β-trace protein and erythropoietin) and plasma membrane (L1 cell adhesion molecule) glycoproteins, which were not due to their intracellular accumulation. These cells may be used to study mechanisms of pathogenesis associated with ALS and to test potential therapeutic compounds.     

Cell culture models to investigate the selective vulnerability of motoneuronal mitochondria to familial ALS-linked G93ASOD1

Mitochondrial damage induced by superoxide dismutase (SOD1) mutants has been proposed to have a causative role in the selective degeneration of motoneurons in amyotrophic lateral sclerosis (ALS). In order to investigate the basis of the tissue specificity of mutant SOD1 we compared the effect of the continuous expression of wild-type or mutant (G93A) human SOD1 on mitochondrial morphology in the NSC-34 motoneuronal-like, the N18TG2 neuroblastoma and the non-neuronal Madin-Darby Canine Kidney (MDCK) cell lines. Morphological alterations of mitochondria were observed in NSC-34 expressing the G93A mutant (NSC-G93A) but not the wild-type SOD1, whereas a ten-fold greater level of total expression of the mutant had no effect on mitochondria of non-motoneuronal cell lines. Fragmented network, swelling and cristae remodelling but not vacuolization of mitochondria or other intracellular organelles were observed only in NSC-G93A cells. The mitochondrial alterations were not explained by a preferential localization of the mutant within NSC-G93A mitochondria, as a higher amount of the mutant SOD1 was found in mitochondria of MDCK-G93A cells. Our results suggest that mitochondrial vulnerability of motoneurons to G93ASOD1 is recapitulated in NSC-34 cells, and that peculiar features in network dynamics may account for the selective alterations of motoneuronal mitochondria.     

利美尼定促进突变SOD1蛋白质降解的作用研究

目的利美尼定对家族性肌萎缩侧索硬化症(ALS)相关突变蛋白质SOD1G93A的作用机制.方法用瞬时转染的方法在运动神经元样细胞系NSC-34中过表达WTSOD1,与家族型ALS相关的SOD1G93A突变蛋白,再给予自噬通路的特异性诱导剂和阻断剂,通过Western blot蛋白印迹法检测突变SOD1、自噬标记物的蛋白质表达水平.结果自噬诱导剂trehalose可以使SOD1G93A蛋白质表达水平明显减少.在自噬阻断剂3-甲基腺嘌呤(3-MA)的干预下,SOD1G93A蛋白质表达水平明显升高.l0uM利美尼定能够明显降低G93A SOD1的表达,但对WT SOD1的表达水平无明显影响.结论SOD1G93A主要经由自噬途径降解,利美尼定能够明显促进G93A SOD1的降解,但对WT SOD1的蛋白质表达水平无明显促进作用.