Distinct Expression Levels and Patterns of Stem Cell Marker,Aldehyde Dehydrogenase Isoform 1 (ALDH1), in Human Epithelial Cancers

Aldehyde dehydrogenase isoform 1 (ALDH1) has been proved useful for the identification of cancer stem cells. However, our knowledge of the expression and activity of ALDH1 in common epithelial cancers and their corresponding normal tissues is still largely absent. Therefore, we characterized ALDH1 expression in 24 types of normal tissues and a large collection of epithelial tumor specimens (six cancer types, n = 792) by immunohistochemical staining. Using the ALDEFUOR assay, ALDH1 activity was also examined in 16 primary tumor specimens and 43 established epithelial cancer cell lines. In addition, an ovarian cancer transgenic mouse model and 7 murine ovarian cancer cell lines were analyzed. We found that the expression levels and patterns of ALDH1 in epithelial cancers are remarkably distinct, and they correlate with their corresponding normal tissues. ALDH1 protein expression levels are positively correlated with ALDH1 enzymatic activity measured by ALDEFLUOR assay. Long-term in vitro culture doesn''t significantly affect ALDH1 activity in epithelial tumor cells. Consistent with research on other cancers, we found that high ALDH1 expression is significantly associated with poor clinical outcomes in serous ovarian cancer patients (n = 439, p = 0.0036). Finally, ALDH^br tumor cells exhibit cancer stem cell properties and are resistant to chemotherapy. As a novel cancer stem cell marker, ALDH1 can be used for tumors whose corresponding normal tissues express ALDH1 in relatively restricted or limited levels such as breast, lung, ovarian or colon cancer.     

蜜蜂表皮蛋白apidermin (apd)基因家族3个新成员的特性鉴定及昆虫APD家族序列特征的分析

Apidermin (APD)蛋白家族是一个新的昆虫结构性表皮蛋白家族。本研究结合生物信息学和RT-PCR扩增, 对意大利蜜蜂Apis mellifera ligustica（简称“意蜂”）的apd-1-like, apd-3-like和中华蜜蜂Apis cerena cerena（简称“中蜂”）的apd-2 等3个新的apd基因的结构特征和表达进行了分析, 并分析了昆虫APD蛋白家族的序列特征。结果显示, 在西方蜜蜂Apis mellifera（简称“西蜂”）中, apd基因家族的6个成员串联排列在基因组序列第4号连锁群上, 它们在A. m. ligustica雄蜂头部中的转录水平差异明显, 且其启动子序列所含顺式元件也不同。中蜂apd-2和意蜂apd-1-like都含有3个外显子和2个内含子, 而意蜂apd-3-like则由4个外显子和3个内含子组成。蛋白序列分析结果显示, 目前已知的10条APD蛋白序列N末端均具有相似的信号肽序列, 其成熟蛋白分子量为6.0~37.0 kD, pI为6.2~10.8。其中西蜂的APD1-3、APD-like和东方蜜蜂Apis cerena的APD-2等5条较短的多肽中疏水氨基酸残基达52%~67%, 且Ala含量最为丰富（占25%~34%）; 而丽蝇蛹集金小蜂Nasonia vitripennis的APD 1-3和西蜂APD-1-like, APD-3-like等另外5条APD多肽富含Gly（21%~30%）, 其序列中疏水氨基酸残基含量为35%~41%。多肽序列多重比对和系统进化分析结果显示, APD家族可划分为2个亚家族。亚家族Ⅰ含有西蜂APD 1-3和东方蜜蜂APD-2等4条较短的多肽序列, 其N末端为一个长33 aa的保守基序; 亚家族Ⅱ由另外6条相对较长的多肽序列组成, 其N末端保守基序长50 aa, C末端保守基序长16 aa。本文所描述的APD蛋白家族序列特征有助于以后从其他昆虫中鉴定新的apd基因。     

NaNO3胁迫对两种微囊藻VOCs释放的影响

为了揭示硝酸盐过量积累对藻类产生胁迫后对藻类挥发性有机化合物(VOCs)释放以及水体气味的影响, 研究以形成蓝藻水华的主要种类铜绿微囊藻和水华微囊藻为材料, 在NaNO3胁迫下, 对其细胞生长和释放的VOCs进行测定分析。结果表明, NaNO3胁迫24h后, 铜绿微囊藻和水华微囊藻细胞生长均受到明显影响, 与对照相比细胞密度分别降低了29.6%和43.0%。在正常条件下, 铜绿微囊藻和水华微囊藻分别释放出26和27种化合物, 其主要类型是硫化物、烃类、萜烯类、苯类、醛类和酯类化合物。在NaNO3胁迫下, VOCs含量均明显增加, 其中铜绿微囊藻释放的此6类VOCs含量分别增加了60.5%、14.3%、136.6%、92.1%、730.0%和120.7%, 水华微囊分别增加了172.7%、162.5%、154.0%、55.9%、51.2%和109.4%。此外, 铜绿微囊藻VOCs中出现4种新成分, 水华微囊藻VOCs中出现1种新成分。由此可见, 硝酸盐过量积累对藻细胞产生胁迫后会诱导其释放出大量VOCs, 从而增加水体气味、破坏水质。       

Miscellaneous terpenoid constituents of Abies nephrolepis and their moderate cytotoxic activities

Three monoterpenoids and two triterpenoids were isolated from Abiesnephrolepis together with 53 known terpenoids. The structures of the compounds were established by 1D and 2D NMR spectroscopy. The absolute configuration of 3-hydroxycamphane-2-carboxylic acid was established as (1S,2R,3S,4R) by Cu-Kα X-ray crystallography. All 58 isolates were tested for cytotoxic activity against four tumor cells viz. A549 (human lung adenocarcinoma), Colo205 (colon adenocarcinoma), QGY-7703 (human hepatoma) and THP-1 (human monocytic leukemia). α-Cadinol exhibited the best effects on A549, Colo205 and QGY-7703 with IC₅₀ values of 8.6, 8.1 and 4.6 μg/mL, respectively.     

Effects of neonatal isolation stress on hyperlocomotion of complexin II knockout mouse

The aim of this study was to investigate the influence of neonatal isolation stress on hyperlocomotion in complexin II knockout mouse (Cplx2(-/-)). The mice were randomly divided into 4 groups: Cplx2(-/-) with stress, Cplx2(+/+) with stress, Cplx2(-/-) without stress and Cplx2(+/+) without stress. Isolation stress was employed on the pups of stress groups from the 2nd day after the postnatal to the 21st day. The PCR was used to determine the gene type and the hyperlocomotion test was employed to detect the change of animal behavior after methamphetamine or saline injection (i.p.). The results showed that the animals of all groups increased their movement after injection of 0.2 mg/kg methamphetamine in different levels (P < 0.01), compared with those injected with saline. The Cplx2(-/-) mouse with stress revealed a significant increase in the distance of free movement after injection of 0.2 mg/kg methamphetamine compared with the knockout mouse without stress (P < 0.001). When Cplx2(-/-) mouse with stress was compared with wild type with stress, Cplx2(-/-) mouse with stress had more movement (P < 0.001), indicating that Cplx2 has effect on the hyperlocomotion as well. These results suggest an involvement of stress and Cplx2 in the movement behavior of mice.     

The complete mitochondrial genome of the leafminer Liriomyza sativae (Diptera: Agromyzidae): great difference in the A+T-rich region compared to Liriomyza trifolii

The complete mitochondrial genome sequence of Liriomyza sativae Blanchard (15,551 bp) was determined and analyzed in this study. The circular genome contained 37 genes including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and an A + T-rich region. The initiation codons of COI and ND1 were ‘ATCA’ and ‘GTG’, respectively. ND2 gene used the truncated termination codon ‘T’. All the tRNA genes had the typical cloverleaf secondary structures except for tRNA^Ser(AGN) gene, which was found with the absence of a DHU arm. In addition, a tRNA-like secondary structure (tRNA^Met) was found in the A + T-rich region. The great difference was that the length of L. sativae A + T-rich region was 597 bp shorter than that of Liriomyza trifolii (Burgess). Meanwhile, some minor differences such as ‘TATA’ block were also observed in L. sativae in contrast to ‘TACA’ block in L. trifolii. There were also some essential structure elements such as ‘TATA’ block, ‘G(A)_nT’ block, poly-T stretch and stem-and-loop structure in the A + T-rich region of L. sativae mitochondrial genome.     

Protection of CHO cells by transfer of survivin driven by ovarian-specific promoter OSP-2

Chemotherapy is the major therapy for cancer in clinic. However, chemotherapeutic agents can harm the other tissues/organs besides cancer. Thus, there are great interests in protecting the innocents by the transfer of protective genes. There are two problems to be solved, one is the selection of protective genes and the other is the orientation of the exotic genes. Recent researches demonstrated that the principal mechanism of chemotherapeutics was through apoptosis. Hereby, introduction of anti-apoptosis genes might interrupt the processes of apoptosis to avoid side effect from chemotherapeutics. On the other hand, tissue-specific promoters, which control gene expression in a tissue-specific manner, might be an alternative tool to guarantee the location of target genes. In this research, we applied gene therapy to chemoprotection using anti-apoptosis gene survivin and ovarian-specific promoter OSP-2. The results showed that OSP-2 could specifically drive the expression of survivin in ovarian cells and survivin could protect cells via inhibiting apoptosis. This might put a light on the future of chemoprotective gene therapy.