N-cadherin expression is a potential survival mechanism of gefitinib-resistant lung cancer cells

Non-small cell lung cancer (NSCLC) is a major subtype of lung cancer and is the most common and fatal cancer worldwide. Specific tyrosine kinase inhibitors for epidermal growth factor receptor (EGFR), such as gefitinib, have been effective in some NSCLC patients and are being used in the clinical setting as pioneer molecularly targeted cancer drugs. However, many patients have not responded to these drugs, and have acquired resistance after long-term treatment. To identify other potential NSCLC molecular targets, we used DNA microarrays to examine gene expression profiles of gefitinib-resistant PC9/ZD cells that are derived from gefitinib-sensitive PC9 cells and harbor a threonine to methionine mutation at codon 790 (T790M) in EGFR, a known mechanism of acquired resistance to gefitinib. We found that N-cadherin expression was significantly upregulated in PC9/ZD cells compared with PC9 cells. Inhibition of N-cadherin expression by siRNA or treatment with antibodies against N-cadherin induced apoptosis of PC9/ZD cells in association with reduced phosphorylation of Akt and Bad, a proapoptotic protein. Moreover, inhibition of Akt expression by siRNA or treatment with an inhibitor for phosphatidylinositol (PI)-3 kinase reduced survival of PC9/ZD cells. In addition, we found several N-cadherin-expressing lung cancer cells that showed inherent resistance to gefitinib treatment and reduced survival owing to siRNA-induced inhibition of N-cadherin expression. Thus, it appears that N-cadherin maintains the survival of the gefitinib-resistant lung cancer cells via the PI-3 kinase/Akt survival pathway. From these results, we propose that N-cadherin signaling contributes, at least in part, to the survival mechanisms of gefitinib-resistant NSCLC cells and that N-cadherin is a potential molecular target in the treatment of NSCLC.     

Discovery, synthesis, and pharmacological evaluation of spiropiperidine hydroxamic acid based derivatives as structurally novel histone deacetylase (HDAC) inhibitors

New spiro[chromane-2,4'-piperidine] and spiro[benzofuran-2,4'-piperidine] hydroxamic acid derivatives as HDAC inhibitors have been identified by combining privileged structures with a hydroxamic acid moiety as zinc binding group. The compounds were evaluated for their ability to inhibit nuclear extract HDACs and for their in vitro antiproliferative activity on different tumor cell lines. This work resulted in the discovery of spirocycle 30d that shows good oral bioavailability and tumor growth inhibition in an HCT-116 murine xenograft model.     

Lignans and other constituents from the roots of the Vietnamese medicinal plant Pseuderanthemum palatiferum

Two new lignans, palatiferin A (1) and palatiferin B (2), were isolated from the roots of Pseuderanthemum palatiferum, together with five known triterpenes, epifriedelanol (3), lupeol (4), lupenone (5), betulin (6), pomolic acid (7), and a dipeptide asperglaucide (8). Their structures were established from 2D?NMR and mass spectroscopy. The absolute configuration of 1 and 2 was proposed based on the comparison of their optical rotation activities with those of compounds with similar structures such as wodeshiol and paulownin. The new lignans, palatiferin A (1) and palatiferin B (2) exhibited a moderate cytotoxicity against KB and HepG2 cell lines. However, betulin and lupeol, two abundant compounds from the roots of P. palatiferum, showed cytotoxic and antimicrobial activities.     

CD10 down expression in follicular lymphoma correlates with gastrointestinal lesion involving the stomach and large intestine

Follicular lymphoma (FL) shows co‐expression of B‐cell lymphoma 2 (BCL2) and CD10, whereas downexpression of CD10 is occasionally experienced in gastrointestinal (GI) FL with unknown significance. Gastrointestinal FL is a rare variant of FL, and its similarity with mucosa‐associated lymphoid tissue lymphoma was reported. We investigated the clinicopathological and genetic features of CD10 downexpressed (CD10^down) GI‐FL. The diagnosis of CD10^down FL was carried out with a combination of pathological and molecular analyses. The incidence of CD10^down GI‐FL was shown in 35/172 (20.3%) cases, which was more frequent than nodal FL (3.5%, P < 0.001). The difference was additionally significant between GI‐FL and nodal FL when the analysis was confined to primary GI‐FL (55.2% vs 3.5%, P < 0.001). Compared to CD10⁺ GI‐FL, CD10^down GI‐FL significantly involved the stomach or large intestine (P = 0.015), and additionally showed the downexpression of BCL6 (P < 0.001). The follicular dendritic cell meshwork often showed a duodenal pattern in the CD10^down group (P = 0.12). Furthermore, a lymphoepithelial lesion was observed in 5/12 (40%) gastric FL cases, which indicated caution in the differentiation of mucosa‐associated lymphoid tissue lymphoma. Molecular analyses were undertaken in seven cases of CD10^down GI‐FL, and an identical clone was found between CD10^down follicles and CD10⁺BCL2⁺ neoplastic follicles. In the diagnosis of cases with CD10^down BCL2⁺ follicles, careful examination with molecular studies should be carried out.     

胃癌7号染色体长臂的杂合性缺失分析

目的:检测胃癌患者7号染色体长臂微卫星位点的杂合性缺失(loss of heterozygosity,LOH),以初步确定7号染色体长臂上与胃癌相关基因连锁最密切的微卫星多态位点及LOH的临床意义.方法:在70例原发性胃癌中应用多重PCR技术扩增覆盖整个7号染色体长臂的9个微卫星位点(平均遗传距离为10cm),聚丙烯酰胺凝胶电泳分离PCR产物,用GeneScan、Genotyper软件进行分析.结果:9个微卫星位点的LOH均可发生于原发性胃癌,总的LOH频率为34.3%(24/70),其中D7S486和D7S798位点的LOH频率较高,分别为24.0%(12/50)和19.2%(5/26);总的LOH频率随临床分期而显著增高(P=0.046),D7S486位点的LOH频率在淋巴结转移者显著高于无淋巴结转移者(P=0.015).结论:在7号染色体长臂D7S486和D7S798位点附近,可能存在与胃癌发展相关的抑癌基因.     

Therapeutic effects of Anastrozole in patients with advanced and recurrent breast cancer

We reviewed therapeutic effects and harmful side effects in 33 patients with advanced or recurrent breast cancer who underwent treatment with Anastrozole 1 mg/day in our department. The patients ranged in age from 40 to 83 years old (median, 59). The Performance Status was 0-2, and there was 1 case of advanced breast cancer and 32 cases of recurrent breast cancer. The duration of disease was from 5 to 233 months (median, 50 months). The estrogen and/or progesterone receptor-positive rate was 72.7%. Metastatic sites were in multiple organs in 9 cases, in the lung only in 1 case, in bone only in 12 cases, and in soft tissue only in 10 cases. First-line therapy was used in 10 cases, second-line therapy in 6 cases, and above third-line therapy in 17 cases. There was a complete response in 3 cases, partial response in 5 cases, no long change in 13 cases, no change in 9 cases, and progressive disease in 3 cases. The response rate was 24.3%, The response period ranged from 2 to 22 months (median, 8 months), and clinical benefit was achieved in 63.7%. The clinical benefit rates for first-line were 60%, second-line 83.3% and above third-line therapy 58.8%. The response rate for patients with breast cancer resistant to Anthracyclines and/or Taxanes was 20%. Time-to-progression ranged from 2 to 28 months (median, 11 months), and overall survival ranged from 7 to 30 months (median, 15 months). The most frequent harmful side effects were rise in total cholesterol, general fatigue, hot flashes and arthralgia (9.1%). In this study, we confirmed the availability and safety of Anastrozole, which was suggested to be a useful drug in salvage therapy for patients having resistance to Anthracyclines and/or Taxanes, not only but also useful as a first- or second-line therapy.     

左旋多巴对弱视眼视诱发电位影响的研究

目的:探讨左旋多巴治疗弱视的效果。方法:正常眼和弱视眼服用单次剂量左旋多巴前后进行图形视诱发电位(pattem visual evoked poten-tial,PVEP)检测。结果:正常眼服药后中空间频率PVEP的N_1P_1振幅和高空间频率PVEP的P_1N_2振幅增大,弱视眼服药后低空间频率PVEP的N_1波潜伏期和中空间频率PVEP的P_1波潜伏期缩短。结论:左旋多巴可改善弱视眼的视功能,可作为弱视的一种新的治疗方法。眼科学报1997;13:182—185。