Overexpression of SSTR2 inhibits growth of SSTR2-positive tumors via multiple signaling pathways

AIM: To study the anti-proliferation effect of overexpressed SSTR2 in experimental cancer with different profiles of endogenous SSTRs expressions and the possible signaling pathways involved. METHODS: In the first experiment, the growth of the tumor xenografts of the inoculated capan-2 cells and A549 cells overexpressing SSTR2 or LacZ was investigated in nude mice. In the second experiment, the adenoviral vector expressing SSTR2 were introduced into experimental capan-2 xenografts by intratumoral injection. The growth inhibition of these experiment tumors was observed and the potential influences on different signaling pathways were analyzed by immunoassays. RESULTS: Overexpression of SSTR2 inhibited the growth of tumors with different profiles of endogenous SSTRs, including experimental capan-2 xenografts that had endogenous SSTR2 expression. Overexpression significantly affected a number of components in apoptotic pathway, MAPK pathway and angiogenesis. CONCLUSION: SSTR2 is a promising candidate for gene therapy in a wide spectrum of cancers.     

Role of A3 adenosine receptor on vascular reactivity of superior mesenteric artery in hemorrhagic shock in rat

AIM: To explore whether A3 adenosine receptor plays a role in the modulation of vascular reactivity after hemorrhagic shock in rat, and to find out the prospective drug target to restore the decreased vascular reactivity following hemorrhagic shock. METHODS: The hemorrhagic shock (40 mmHg) model was established in rat, and the reactivity of superior mesenteric artery (SMA) to norepinephrine (NE) was observed. A3AR expression at protein level and mRNA level were measured by Western blotting and RT-PCR respectively. RESULTS: The vascular reactivity of SMA to NE after hemorrhagic shock (40 mmHg) was decreased significantly in a biphasic response manner. The expression of A3AR mRNA in SMA after hemorrhagic shock decreased without significant difference. The expression of A3AR protein has a slight increase without statistical difference after 30 min of hemorrhagic shock and then has a significant decrease (especially at 2 h and 4 h after hemorrhagic shock). The usage of IB-MECA, a selective A3AR agonist, significantly increased the responsiveness of SMA to NE in hemorrhagic shock in rat. MRS1523, the selective A3AR antagonist, significantly abolished the restoration of the vascular reactivity to NE by IB-MECA in hemorrhagic shock in rat. CONCLUSION: A3AR plays a role in the modulation of vascular responsiveness to NE in hemorrhagic shock in rat, and the selective agonist of A3AR could restore the reactivity of SMA to NE in hemorrhagic shock in rat.     

Jagged1 knocking down in endothelial cells accelerates PDGF induced proliferation and migration of vascular smooth muscle cells in rats

AIM: To investigate the effect of Jagged1 expression in endothelial cells (EC) on platelet derived growth factor (PDGF) induced proliferation and migration of vascular smooth muscle cells (VSMC) in rat.METHODS: Rat aorta EC was inoculated in the lower chamber and VSMC were in the upper chamber of the cell coculture system. Three groups were divided: control, sicontrol and siJagged1. The EC Jagged1 protein expression was assayed by Western blotting to evaluate small RNA interfering (RNAi) efficiency. After the cells were cocultured with PDGF for 24 h, the proliferation and migration of VSMC were respectively evaluated by ［3H］-TdR incorporation and migrating cells counting. Protein expression of α-SM-actin in VSMC was assayed by Western blotting. RESULTS: The Jagged1 protein expression in EC was significantly lower in siJagged1 group than that in control group (0.26±0.02 vs 0.67±0.02, P<0.05), and no statistic significance was observed between control and sicontrol groups. The VSMC ［3H］-TdR incorporation and migration were higher in PDGF +siJagged1 group than those in PDGF group {［3H］-TdR incorporation (23 074±2 702) counts·min-1·well-1 vs (16 442±1 803)counts·min-1·well-1, n=5, P<0.05; migration (27±4) cells/field vs (15±3)cells/field, n=5, P<0.05}. The α-SM-actin protein in VSMC was lower in PDGF + siJagged1 group than that in PDGF group (0.25±0.06 vs 0.49±0.04, n=3, P<0.05).CONCLUSION: Jagged1 knock down in rat EC accelerates PDGF induced proliferation and migration of VSMC. These results suggest that Jagged1 expression in EC plays an important role in maintaining VSMC contract phenotype and inhibiting VSMC overgrowth after arterial injury.     

黄瓜果实曲直性评价方法及相关性分析

以48份黄瓜品种为试材,采用刨分法测量其果实弯曲度,通过黄瓜果实形态指标和相关分析可知弯曲度与果长、果柄长、果柄长/果长、果长/果横径显著正相关,与种腔大小、种腔/果横径极显著负相关,与果横径显著负相关,与果肉厚不相关。依据果形指数和弯曲度对黄瓜进行了分级。筛选出顺直品种8份,次弯曲品种9份,弯曲品种31份。     

食用菊花扦插繁殖影响因素的初步研究

从基质选择、插穗长度、生根粉处理及食用菊花品种几个方面,对影响食用菊花扦插繁殖成活率的有关因素进行了研究。结果表明,珍珠岩是食用菊花扦插的首选基质;插穗长度为10 cm时生根情况较好;生根粉能够显著促进插穗生根;食用菊花插穗生根能力不同品种间差异较大。     

甘蓝小孢子植株倍性简易鉴定方法研究

以编号为12、22的甘蓝材料（F1）经小孢子培养得到的植株为试材,先利用流式细胞仪对供试材料进行倍性鉴定,再利用普通光学显微镜观察已通过倍性鉴定的双单倍体与单倍体的气孔保卫细胞,以测定其大小与叶绿体数。结果表明：气孔保卫细胞叶绿体数与甘蓝倍性高低呈正比关系,甘蓝双单倍体气孔保卫细胞叶绿体数变异幅度为12~17,单倍体气孔保卫细胞叶绿体数的变异幅度为6~10;同一材料双单倍体与单倍体气孔保卫细胞叶绿体数的比值≈2,两者数值差异非常显著直观,易于辨别。因此观测气孔保卫细胞叶绿体数是鉴定甘蓝小孢子植株倍性的简易有效手段。     

月季干燥花护形护色的研究

以广州当地红色切花月季为试材,分别采用细沙、硅胶、硅胶+细沙这3种包埋剂,结合高火、中高火、中火这3种微波火力和5个不同干燥时间的试验处理组合,通过分析月季花朵在干燥过程中花色、花瓣质感、花瓣牢固性等指标的变化规律,研究了鲜花干制过程中的保色保形问题.结果表明:包埋剂结合微波处理能有效的降低干燥花花瓣的皱缩程度,提高干花的综合外观品质;其中硅胶+细沙包埋结合微波中高火4min处理的保色保形效果最佳.     

高产虫草菌素蛹虫草菌株的紫外线诱变选育

蛹虫草是重要的药食用真菌。通过对蛹虫草原生质体进行紫外诱变处理,筛选到1株优良的菌株CMM-81。经固体发酵,虫草菌素和腺苷含量分别为0．437％和0．036％,是出发菌株的2倍。菌株CMM-81经连续15代传代培养,虫草菌素和腺苷的含量保持稳定。     

送春与多花兰杂种的非共生萌发与快速繁殖

用地生兰送春和附生兰多花兰进行种间杂交,对杂交种子进行非共生萌发和快速繁殖研究.结果表明:胚龄7个月、0.1 mol/L KOH处理10 min的种子萌发率最高;种子萌发后原球茎的增殖以Z4 (KC+BA 0.4 mg/L+NAA 0.6 mg/L+KT 0.2 mg/L ) 培养基为最好,增殖系数可达到12.8;在原球茎增殖和分化成苗过程中加入活性碳能够有效地防止切口褐化.     

氮磷不同配比施肥对加工番茄生长及产量的影响

配方施肥明显改善了加工番茄的生长,增加了植株分枝数、单株坐果数和单果重,对提高加工番茄的产量有显著效果;过多的氮肥投入反而影响番茄的产量.结果表明:N:P2O5=1:1,投肥总量为施纯N 1.073～1.38 kg/hm2,P2O50.981～1.38 kg/hm2,产量和效益最佳.