Effect of Linc00152 targeting miR-376c-3p on viability,apoptosis and radiosensitivity of cervical cancer cells

AIM: To investigate the effect of Linc00152 on the viability, apoptosis and radiosensitivity of cervical cancer cells. METHODS: RT-qPCR was used to detect the expression levels of Linc00152 and microRNA-376c-3p(miR-376c-3p) in human cervical cancer HeLa cells and SiHa cells, and normal cervical Ect1/E6E7 cells. The cervical cancer HeLa cells with low Linc00152 expression or miR-376c-3p over-expression were established. MTT assay, flow cytometry, colony formation assay and Western blot were used to determine the cell viability, apoptosis, radiosensitivity and related protein expression. The dual-luciferase reporter assay was used to verify the regulatory relationship between Linc00152 and miR-376c-3p in the HeLa cells. RESULTS: Compared with the Ect1/E6E7 cells, Linc00152 was up-regulated in the HeLa cells and SiHa cells, and miR-376c-3p was down-regulated (P < 0.05). Low expression of Linc00152 or over-expression of miR-376c-3p inhibited the viability of HeLa cells, induced apoptosis, enhanced the radiosensitivity, inhibited the protein expression of cyclin D and Bcl-2, and promoted the protein expression of P21 and Bax (P < 0.05). Linc00152 negatively regulated miR-376c-3p expression in the HeLa cells, and inhibition of miR-376c-3p expression reversed the effect of low expression of Linc00152 on HeLa cell viability, apoptosis and radiosensitivity. CONCLUSION: Linc00152 is highly expressed in the cervical cancer cells. Linc00152 affects the viability, apoptosis and radiosensitivity of HeLa cells by targeting miR-376c-3p, which is a potential diagnosis and treatment target for cervical cancer.     

Mechanism of elemene enhancing radiosensitivity of human glioma U251 cells

AIM To investigate the effect of elemene on the radiosensitivity of human glioma U251 cells and its mechanism. METHODS The U251 cells were used as a glioma model in vitro, and were exposed to different concentrations of elemene and different doses of radiation. The cell viability was measured by MTT assay, the apoptosis and cell cycle distribution were analyzed by flow cytometry, and the related protein levels were determined by Western blot. RESULTS Elemene inhibited the viability of U251 cells in vitro and enhanced the radiosensitivity of the cells. The cells in radiotherapy combined with elemene group had higher rates of early apoptosis, secondary necrosis and total cell death than those in radiation group. Elemene induced G₂/M phase arrest in the U251 cells. Elemene reduced the protein expression of cell division cycle protein 2 （Cdc2）, which resulted in the decrease in cyclin B1 expression induced by radiotherapy, thereby inhibiting the formation of cyclin B-Cdc2 complex. Elemene reduced Cdc2 activity by inhibiting the phosphorylation of Cdc2 protein at threonine 161, thereby inducing G₂/M phase arrest in the cells. It also mediated apoptosis by down-regulating survivin expression. CONCLUSION Elemene may increase the sensitivity of U251 cells to radiotherapy by down-regulating Cdc2 protein, decreasing cyclin B1 expression, inhibiting the formation of cylcin B-Cdc2 complex and down-regulating the expression of survivin.     

Sodium dichloroacetate improves radiosensitivity of U251 cells

AIM: To study the change of radiosensitivity of U251 cells after treated with sodium dichloroacetate (DCA) and further to explore the possible mechanism.METHODS: The U251 cells were divided into 4 groups: control group, DCA group, X-ray irradiation without DCA pretreatment (IR) group and X-ray irradiation with DCA pretreatment (DIR) group. MTT assay was applied to determine the cell viability. The intracellular reactive oxygen species (ROS) were detected by DHE fluorescence. The expression level of Bcl-2 was assessed by Western blot. The percentage of apoptosis of cells was determined by flow cytometry. RESULTS: No difference between control group and DCA group in cell viability (P>0.05) was observed. However, the cell viability of both IR group and DIR group was markedly reduced compared with control group (P<0.05). Furthermore, the viability of DIR group was significantly decreased compared with IR group (P<0.05). The percentage of ROS positive cells was obviously increased in DIR group compared with IR group (P<0.05). The expression level of Bcl-2 was sharply decreased in DIR group (P<0.05) and the percentage of apoptosis of cells was significantly elevated (P<0.05) in DIR group compared with IR group.CONCLUSION: The better antitumor effect was obtained by improving the radiosensitivity through pretreating the cells with DCA, and the possible mechanism was down-regulation of the Bcl-2 expression by developing the intracellular ROS.     

V_C和V_E对大豆油菜的抗辐射效应

以培养5d的大豆油菜幼苗为材料，研究辐射敏感性与VC、VE、MDA和SOD的关系。结果表明，随辐照剂量的增大，幼苗下胚轴中VC、VE的含量逐渐下降，膜脂过氧化物丙二醛的含量逐渐上升，超氧化物歧化酶活性呈先增后减趋势。辐照后的幼苗分别在VC、VE中培养5h，均可提高大豆和油菜幼苗超氧化物歧化酶活性，降低丙二醇含量。     

Tetrandrine enhances radiosensitivity of human nasophayrngeal carcinoma cell lines

AIM: To study whether tetrandrine (Tet) enhances the radiosensitivity of human nasopharyngeal carcinoma cell lines in vitro and its mechanism.METHODS: The inhibitory effect on proliferation was evaluated by MTT assay. The radiosensitivity of the cells was compared by colony formation assay. The cell cycle was analyzed by flow cytometry. RESULTS: The maximum non-cytotoxic doses of Tet for CNE1 and CNE2 cells were 1.5 and 1.8 μmol/L, respectively. Compared with radiation group, the cell proliferation in Tet plus radiation group was significantly inhibited on the 4th to 6th days (P<0.01). The mean lethal doses for CNE1 and CNE2 cells in radiation group were (1.26±0.02) Gy and (2.27±0.04) Gy, respectively,and the values changed to (0.73±0.05) Gy and (1.61±0.08) Gy in Tet plus radiation group, respectively, resulting in the sensitivity enhancement ratio of 1.73 and 1.40, respectively (P<0.05). The CNE1 and CNE2 cells in G₂ phase of the cell cycle in radiation group were (42.62±2.07)% and (34.82±2.74)%, respectively, while those in Tet plus radiation group were (17.02±1.87)% and (19.64±4.82)%, respectively. CONCLUSION: Tetrandrine enhances the radiosensitivity of human nasopharyngeal carcinoma cell lines and the mechanism may be related to the abrogation of radiation-induced G₂ phase arrest.     

空间环境和地面γ辐照对水稻诱变的差异

研究了不同类型的水稻品种空间搭载和地面⁶⁰Co γ辐照两种条件下的诱变敏感性和诱变效应。结果表明，诱变的敏感性均以粳稻强于籼稻，推广种强于农家种，籼稻中以中籼和晚籼>早籼，而不同粳稻气候生态型间的差异较小。对γ辐照不敏感的品种大多数对空间诱变也不敏感，而对γ辐照敏感的品种中仅有1/4对空间诱变敏感。空间搭载对54.2%的品种的处理当代秧苗生长具有加速作用，有的同时提高结实率。M₂代研究表明，两种诱变处理均能诱发株高和抽穗期突变，但其突变频率差异较大。空间搭载处理的M₂代矮秆、高秆和早熟的突变频率与M₁代总生理损伤存在显著正相关。表明空间环境与地面γ辐照的诱变机制可能不完全相同。本研究结果对开展水稻空间诱变育种具有一定的指导意义。     

芽用豆科作物的辐射敏感性研究进展

芽菜专用豆科作物优良品种的缺乏已成为制约我国现代芽菜产业快速发展的瓶颈.辐射诱变具有安全简便经济、突变频率高、变异性状稳定早等特点,可缩短育种年限,创造新的基因型,是现代作物育种的重要方法之一;作物辐射敏感性评价研究,是辐射育种的前提和基础,对芽用豆科作物辐射敏感性的研究有助于提高辐射育种的效率.文章从大豆、绿豆、蚕豆...     

普通小麦辐射敏感性的多样性模糊聚类分析

研究采用４９个普通小麦品种组成的样本群体，对小麦辐射敏感性进行了模糊聚类分析。结果表明，小麦辐射敏感性呈连续性变异，表现为丰富的多样性。     

Pulsatilla saponin A affects proliferation and radiosensitivity of breast cancer cells by regulating miR-24-3p/RNF2 expression

AIMTo investigate the effect of Pulsatilla saponin A on proliferation and radiosensitivity of breast cancer cells and its mechanism. METHODSHuman breast cancer MCF-7 cells were treated with Pulsatilla saponin A at concentrations of 0, 5, 10, 15 and 20 mg/L and transfected with microRNA-24-3p (miR-24-3p) over-expression vector or inhibitory expression vector. The proliferation and radiosensitivity of the MCF-7 cells were measured by MTT assay and colony formation assay. The miR-24-3p expression and ring finger protein 2 （RNF2） mRNA level were detected by RT-qPCR. The protein expression of RNF2 was determined by Western blot. The luciferase reporter assay was used to detect the targeting relationship between miR-24-3p and RNF2. RESULTSCompared with control group (0 mg/L), the proliferation inhibitory rate of the MCF-7 cells was significantly increased in 5, 10, 15 and 20 mg/L Pulsatilla saponin A groups (P<0.05). The survival score of the MCF-7 cells treated with Pulsatilla saponin A was significantly decreased after irradiation, and the expression of RNF2 was significantly decreased (P<0.05). miR-24-3p targeted RNF2 and negatively regulated its expression. When the MCF-7 cells were simultaneously treated with Pulsatilla saponin A and miR-24-3p, the cell survival curve significantly shifted down. Inhibition of miR-24-3p expression reversed the proliferation-inhibiting and radiation-sensitizing effects of Pulsatilla saponin A on the MCF-7 cells. CONCLUSION Pulsatilla saponin A may affect the proliferation and radiosensitivity of breast cancer cells through miR-24-3p/RNF2 signaling pathway.