Shortened snRNA promoters for efficient CRISPR/Cas-based multiplex genome editing in monocot plants

正Dear Editor,CRISPR (clustered regularly interspaced short palindromic repeats)/Cas genome editing is a powerful tool for introducing specific mutations in organisms including plants. The system is composed of a nuclease such as Cas9 or Cas12a and an engineered single-guide RNA (sgRNA) incorporating a target sequence (Li et al., 2019). A Cas9/sgRNA complex re-     

An HPLC method for the pharmacokinetic study of vincristine sulfate-loaded PLGA-PEG nanoparticle formulations after injection to rats

The aim of this study is to develop a simple and applicable HPLC method for the detection of vincristine in rat plasma after administration of poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) nanoparticles loaded with vincristine sulfate (VCR). Vincristine was extracted from rat plasma and vinblastine sulfate was chosen as the internal standard (IS). Chromatographic separation of VCR and IS was achieved by a Dikma Dimonsil C?? column (200 mm×4.6 mm) with the mobile phase consisting of 0.02 M sodium dihydrogen phosphate-methanol (36:64, v/v, pH=4.7) at a flow rate of 1.0 mL/min. The ultraviolet detection wavelength was set at 276 nm. The calibration curve was linear over a concentration range of 0.05-5.0 μg/mL. The intra-day and inter-day accuracy for three quality controls (QC) samples was 93.48-107.74% and 92.61-96.58%, respectively; the precision was less than 9%. The average method recoveries for vincristine from spiked plasma at all QC levels were over 83%; and extraction recoveries were between 66 and 70%. Vincristine was stable in rat plasma for one month at -80°C, for 8 h at room temperature, as well as during three freeze-thaw cycles. This HPLC method was applied successfully to the pharmacokinetic study of vincristine in rats after a single intravenous injection of VCR in physiological saline (F-VCR) solution, VCR-loaded PLGA-mPEG nanoparticles with (NP1) and PLGA-PEG-folate nanoparticles (NP2) suspension, respectively. There were significant differences in main pharmacokinetic parameters between F-VCR and the nanoparticles. Both kinds of VCR-loaded nanoparticles displayed improved pharmacokinetic profiles.     

A Unique Feature of Iron Loss via Close Adhesion of Helicobacter pylori to Host Erythrocytes

Iron deficiency anemia is an extra-stomach disease experienced in H. pylori carriers. Individuals with type A blood are more prone to suffering from H. pylori infection than other individuals. To clarify the molecular mechanisms underlying H. pylori-associated anemia, we collected erythrocytes from A, B, O, and AB blood donors and analyzed morphology, the number of erythrocytes with H. pylori colonies attached to them, and iron contents in erythrocytes and H. pylori (NCTC11637 and SS1 strains) by means of optical microscopy, scanning electron microscopy, and synchrotron radiation soft X-ray imaging. The number of type A erythrocytes with H. pylori attached to them was significantly higher than that of other erythrocytes (P<0.05). Far more iron distribution was observed in H. pylori bacteria using dual energy analysis near the iron L2, 3 edges by soft X-ray imaging. Iron content was significantly reduced in host erythrocytes after 4 hours of exposure to H. pylori. H. pylori are able to adhere more strongly to type A erythrocytes, and this is related to iron shift from the host to the bacteria. This may explain the reasons for refractory iron deficiency anemia and elevated susceptibility to H. pylori infection in individuals with type A blood.     

日本沼虾卵黄蛋白原合成部位的初步研究

十足目卵巢中卵黄的来源,在过去的几十年研究中一直存在争议,内源性合成和外源性合成均有报道。以雌性日本沼虾为实验材料,根据外形观察和组织学研究确定其发育阶段,可以分为:卵原细胞增殖期;卵黄发生前期;初级卵黄发生期;次级卵黄发生期;成熟期和抱卵期(消退期)。从处于不同发育期的卵巢和肝胰腺中提取总RNA,用RT-PCR方法探讨不同发育期的日本沼虾卵巢和肝胰腺卵黄蛋白原mRNA表达,确定是否有卵黄蛋白原的合成功能。检测结果可以初步判定日本沼虾卵巢和肝胰腺都具有卵黄蛋白原mRNA表达功能,都是卵黄蛋白原的合成部位,其合成的量与沼虾卵巢的发育阶段相关。     

Inactivation of tumor suppressor gene HIC1 in gastric cancer is reversed via small activating RNAs

HIC1 is a tumor suppressor gene that is down-expressed in different malignancies, in part, because of promoter hypermethylation. However, the biological function of HIC1 in gastric cancer remains unclear. It is known that small double-stranded RNAs can induce gene expression by targeting promoter sequences. In the present study, we examined the expression levels of HIC1 in gastric cancer tissue. Several pieces of small double-stranded RNAs were used for the activation of HIC1. Tissue microarray analysis of gastric cancer indicated that down-regulation of HIC1 in gastric cancer tissue was dramatic compared with the adjacent gastric mucosa. Gastric cancer cell lines also showed down-regulated HIC1 expression compared with a human immortalized gastric mucosa cell line. One out of four dsRNAs produced activation of HIC1 as assessed by real-time PCR and Western blotting. Use of a cell counting kit 8 and clonogenicity assays indicated that dsRNA-mediated re-expression of HIC1 inhibited cell proliferation and clonogenicity in gastric cancer. Reactivation of HIC1 suppressed cell migration and induced cell cycle arrest in the G0/G1 phase, as well as induced apoptosis. These results suggest that HIC1 is a potential target of gene therapy against gastric cancer, and that dsRNAs could function as a therapeutic option for up-regulating tumor suppressor genes in gastric cancer and other malignancies.     

CEACAM6 promotes tumor migration,invasion, and metastasis in gastric cancer

Carcinoembryonic antigen-related cell adhesion molecule 6 （CEACAM6） shows increased expression in a wide variety of human cancers, and its over-expression is associated with enhanced migration, invasion, and in vivo metastasis. Here, we reported that CEACAM6 was up-regulated in gastric cancer （GC） cell lines and tumor tissues. Overexpression of CEACAM6 in MKN-45 and SGC-7901 GC cells promoted migration and invasion in vitro and metastasis in athymic mice, whereas migration and invasion of MKN-28 and SNU-16 GC cells were suppressed by knockdown of CEACAM6. We also observed that steroid receptor coactivator （C-SRC） phosphorylation was increased when CEACAM6 was over-expressed in SGC-7901 cells. Taken together, these results suggested that CEACAM6 functions as an oncoprotein in GC and may be an important metastatic biomarker and therapeutic target.