C－myc反义寡聚脱氧核苷酸抑制人脑胶质瘤细胞系BT_（325）Myc蛋白合成和细胞增殖并诱导其分化的研究

目的：探讨在体外ｃ－ｍｙｃ反义核酸是否可通过阻断人脑胶质瘤细胞中ｃ－ｍｙｃ基因的表达而抑制细胞增殖并诱导分化．方法：人工合成与ｃ－ｍｙｃｍＲＮＡ起始码及其后四个密码子互补的寡聚脱氧核苷酸（简称反义核酸）片段，用它处理培养的ＢＴ３２５细胞，观察它对细胞增殖的影响．同时用免疫细胞化学方法检测细胞中Ｍｙｃ蛋白的水平以及能反映胶质瘤细胞分化的Ｓ－１００和ＧＦＡＰ两种蛋白的水平，分析这些指标的变化．结果：发现４ｕｍｏｌ／Ｌ的ｃ－ｍｙｃ反义核酸明显抑制ＢＴ３２５细胞的增殖和Ｍｙｃ蛋白的合成，且后者发生在加入反义核酸后１ｈ，并持续２４ｈ以上，而细胞增殖受抑制要到第５日才明显．从第２日到第５日细胞中Ｓ－１００和ＧＦＡＰ染色明显加深，反映细胞有分化趋势．用同样长度的无关序列寡聚脱氧核苷酸作对照，则未见上述变化，表明ｃ－ｍｙｃ反义核酸的作用是序列特异性的．结论：ｃ－ｍｙｃ反义核酸可特异地抑制ＢＴ３２５细胞中Ｍｙｃ蛋白的合成和细胞增殖，并能诱导其分化．     

Neuronal expression of Raf protooncogene in the brain stem of adult guinea pig

The Raf protooncogenes encode for cytoplasmic serine/threonine-specific protein kinases which can be activated via growth factor receptors by phosphorylation. Immunohistochemical and Western blotting studies have proven the existence of Raf protein kinases in neurons of the cerebral cortex of rats and guinea pigs. The aim of the present study was to map the immunohistochemical distribution of Raf kinase-like staining in the brain stem of guinea pig. Polyclonal antibodies were used that were raised against a recombinant viral protein in combination with the avidin-biotin-peroxidase system for detection of immunoreactivity. Specificity of the antibodies was tested in Western blotting experiments. Cytoplasmic immunostaining was observed in motor nuclei of hypoglossal, accessory, vagus, facial, trigeminal, abducent, oculomotor and trochlear nerves, and in the nucleus ambiguus, nucleus retroambigualis, lateral vestibular nucleus, mesencephalic nucleus of the trigeminal nerve, the red nucleus, raphe nuclei and reticular formation. Scattered neurons were stained in other sensory nuclei, such as solitary tract nuclei, medial, dorsal and ventral vestibular nuclei and cochlear nuclei. The spinal trigeminal nucleus and the main sensory nucleus of the trigeminal nerve contained few medium-sized immunoreactive cells. In general, staining was mainly somatodendritic; the axonal plexus was not positive. It is concluded, that the widespread neuronal appearance of cytoplasmic Raf kinase suggests an important role in transmission of trophic and growth factor signals in these neurons.     

表皮生长因子和甲硫氨酸脑啡肽诱导人白细胞c—fos基因表达的研究

由健康人外周血分离淋巴细胞及溶血处理后的全白细胞，以外源性表皮生长因子和甲硫氨酸脑啡肽培育后取细胞液帛晟滴片和滴膜，用生物素标记的ｃ－ｆｏｓｃＤＮＡ探针进行原位杂交和斑点印迹杂交。结果显示表皮生升因子和甲硫氨酸脑啡肽两组ｃ－ｆｏｓ原癌基因的表达对照组增。     

自发性脑卒中诱导原癌基因c－fos在大鼠脑内的表达

用免疫组织化学（ＡＢＣ）方法，对易卒中型肾血管性高血压大鼠高血压晚期自发形成脑卒中时以及高血压早期和中期脑内ｃ－ｆｏｓ原癌基因蛋白（ＦＯＳ）的表达进行了观察．在高血压晚期，假手术组不出现脑卒中，但个别大鼠的扣带皮质和梨状皮质出现微弱的ＦＯＳ表达；手术组都出现脑卒中，其中３例脑内未见ＦＯＳ表达，４例则于大脑皮质、海马、黑质和下丘脑等处出现程度不等的ＦＯＳ表达．高血压早期，手术组和假手术组的下丘脑、隔核、中脑中央灰质和丘脑室旁核出现分布状态和强弱都相似的ＦＯＳ表达．高血压中期，手术组和假手术组脑内未见ＦＯＳ表达．本研究结果提示：（１）高血压晚期，自发性脑卒中能诱导ｃ－ｆｏｓ在脑内的广泛表达，脑内不同部位ＦＯＳ表达的机制和功能意义不同，本文对其进行了讨论；（２）腹部手术能诱导下丘脑等与内脏功能调节有关的功能区ＦＯＳ的表达；（３）高血压早期和中期，通过ｃ－ｆｏｓ表达的方法未能发现高血压对大鼠脑功能活动的影响。     

原癌基因bc1-2在眼科领域的研究进展

原癌基因bc1 2属抗凋亡基因 ,它不促进细胞增殖 ,但能延长细胞的生命期限。Bc1 2在许多细胞增殖性疾病的发生中起着非常重要的作用。通过影响组织细胞内bc1 2基因的表达 ,为临床上一些退行性疾病及细胞增殖性疾病的治疗提供新的思路。Bc1 2在眼科领域的研究主要集中于遗传性和环境因素所致的视网膜变性。Bc1 2的过表达可以阻止实验性缺血、视神经挫伤、光诱导损伤以及一些视蛋白和cGMP磷酸二酯酶缺陷所致的视网膜光感受器凋亡 ,但对由于某些基因突变所致的凋亡无阻止作用     

A Phase II Study of CLAG Regimen Combined With Imatinib Mesylate for Relapsed or Refractory Acute Myeloid Leukemia

IntroductionNo standard salvage chemotherapy regimen is available for relapsed or refractory (RR) acute myeloid leukemia (AML). Preclinical data have suggested synergy in vitro between cytarabine and imatinib mesylate (IM) on AML cell growth inhibition. After demonstrating the safety and feasibility in a phase I study, we conducted a phase II clinical study of CLAG (cladribine, cytarabine, granulocyte colony-stimulating factor) regimen combined with IM for patients with RR-AML.Patients and MethodsWe performed a single-institution 2-stage phase II study. The primary endpoint was the remission rate measured using the standard AML response criteria. The secondary endpoints included overall survival (OS) and progression-free survival (PFS).ResultsFrom August 2009 to April 2011, 38 patients were treated at the Moffitt Cancer Center. Their median age was 62 years (range, 26-79 years). Of the 38 patients, 7 (18%) had refractory AML, 19 (50%) had early relapse, and 12 (32%) had late relapse. At the original diagnosis, only 2 patients had favorable risk factors, 18 had intermediate risk, and 16 had poor risk; for 2 patients, the karyotype was missing. The overall response rate for all 38 evaluable patients was 37%. The median OS was 11.1 months (95% CI, 4.8-13.4 months), the median PFS was 4.9 months (95% CI, 1.6-11.7 months). Among the responders, 8 of 14 patients subsequently underwent allogeneic hematopoietic cell transplantation.ConclusionCLAG plus IM was well tolerated, with encouraging signs of activity in patients with poor-risk AML.     

Gastric undifferentiated carcinoma with diffuse c-kit overexpression and focal neuroendocrine differentiation

A case of gastric undifferentiated carcinoma with diffuse c-kit overexpression and focal neuroendocrine differentiation is described. A 76-year-old man presented appetite loss for 1 month. Gastric endoscopy showed an exophytic huge nodular mass with central ulceration at the gastric prepylorus. Distal gastrectomy was performed with lymph node dissection. Histology indicated anaplastic medium- to large-sized round tumor cells in discohesive sheets. Adenocarcinomatous areas forming tubular glands or with intracytoplasmic mucin on PAS and Alcian-blue staining were not found in any sections. Immunohistochemistry showed that the tumor cells were diffusely positive for cytokeratin, vimentin, c-kit and focally positive for chromogranin A and synaptophysin.     

腹泻型肠易激综合征大鼠SCF/C-kit信号的变化及其与免疫功能的关系

目的探索腹泻型肠易激综合征(IBS-D)大鼠干细胞因子/酪氨酸激酶受体(SCF/C-kit)系统的变化及其与IBS-D免疫功能紊乱的相关性。方法 12只新生大鼠分为正常组和模型组,每组6只。模型组大鼠采用母婴分离、醋酸刺激、束缚应激三因素法制备IBS-D模型。免疫组化法检测两组大鼠结肠组织中SCF和C-kit的蛋白表达;q PCR法检测SCF和C-kit的mRNA表达;统计学分析SCF和C-kit的表达与IBS-D脾系数、胸腺系数、TNF-α、IL-8、IL-10的相关性。结果与正常组相比,模型组的SCF和C-kit的蛋白表达阳性率减少,同时二者的mRNA表达降低。SCF的表达与脾系数、TNF-α、IL-8呈负相关,与IL-10呈正相关;C-kit的表达与胸腺系数、脾系数、TNF-α呈负相关。结论 IBS-D大鼠SCF/C-kit系统异常,可能与IBS-D免疫功能紊乱有关。     

C-kit overexpression is not associated with KIT gene mutations in chromophobe renal cell carcinoma or renal oncocytoma

Introduction

C-kit overexpression has previously been described in chromophobe renal cell carcinoma (cpRCC) and renal oncocytoma (RO). However, so far no KIT mutations have been found. The objective of our study was to analyse c-kit in a large cohort of renal tumors and to perform KIT mutation analysis in a subset cpRCC and RO cases with overexpression of c-kit.

Materials and methods

We studied the immunohistochemical expression of c-kit on tissue microarrays containing formalin-fixed, paraffin-embedded samples of 948 patients with renal tumors. CpRCC and RO cases with c-kit overexpression (n = 23) were analyzed for KIT mutations in exons 9, 11, 13, 14, 15, and 17.

Results

Expression of c-kit was found in 6/642 (0.9%) clear cell RCC, 3/154 (1.9%) papillary RCC, 54/69 (78.3%) cpRCC, 37/45 (82.2%) RO and 2/30 (6.7%) of other unclassified tumor types. In none of the RO and cpRCC cases analyzed, a KIT gene mutation was found.

Conclusion

C-kit expression is found in the majority of cpRCC and RO, but these tumors do not harbor the usual c-kit activating mutations. This may have implications for the use of tyrosine kinase inhibitors in patients with advanced cpRCC and c-kit expression.