• Asian Pacific Journal of Cancer Prevention
• /
• 제13권5호
• /
• pp.2385-2392
• /
• 2012

The lack of effective treatment targets for triple-negative breast cancers make them unfitted for endocrine or HER2 targeted therapy, and their prognosis is poor. Transcription factor ER81, a downstream gene of the HER2, is highly expressed in breast cancer lines, breast atypical hyperplasia and primary breast cancers including triple-negative examples. However, whether and how ER81 affects breast cancer carcinogenesis have remained elusive. We here assessed influence on a triple-negative cell line. ER81-shRNA was employed to silence ER81 expression in the MDA-MB-231 cell line, and MTT, colony-forming assays, and flow cytometry were used to detect cell proliferation, colony-forming capability, cell cycle distribution, and cell apoptosis in vitro. MDA-MB-231 cells stably transfected with ER81-shRNA were inoculated into nude mice, and growth inhibition of the cells was observed in vivo. We found that ER81 mRNA and protein expression in MDA-MB-231 cells was noticeably reduced by ER81-shRNA, and that cell proliferation and clonality were decreased significantly. ER81-shRNA further increased cell apoptosis and the residence time in $G_0/G_1$ phase, while delaying tumor-formation and growth rate in nude mice. It is concluded that ER81 may play an important role in the progression of breast cancer and may be a potentially valuable target for therapy, especially for triple negative breast cancer.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권4호
• /
• pp.489-498
• /
• 2018

Objective: Foot and mouth disease (FMD) and porcine reproductive and respiratory syndrome (PRRS) are major diseases that interrupt porcine production. Because they are viral diseases, vaccinations are of only limited effectiveness in preventing outbreaks. To establish an alternative multi-resistant strategy against FMD virus (FMDV) and PRRS virus (PRRSV), the present study introduced two genetic modification techniques to porcine cells. Methods: First, cluster of differentiation 163 (CD163), the PRRSV viral receptor, was edited with the clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 technique. The CD163 gene sequences of edited cells and control cells differed. Second, short hairpin RNA (shRNAs) were integrated into the cells. The shRNAs, targeting the 3D gene of FMDV and the open reading frame 7 (ORF7) gene of PRRSV, were transferred into fibroblasts. We also developed an in vitro shRNA verification method with a target gene expression vector. Results: shRNA activity was confirmed in vitro with vectors that expressed the 3D and ORF7 genes in the cells. Cells containing shRNAs showed lower transcript levels than cells with only the expression vectors. The shRNAs were integrated into CD163-edited cells to combine the two techniques, and the viral genes were suppressed in these cells. Conclusion: We established a multi-resistant strategy against viral diseases and an in vitro shRNA verification method.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권20호
• /
• pp.8829-8836
• /
• 2014

Background: Cyclooxygenase-2 (COX-2), considered to have tumor-promoting potential, is highly expressed in a variety of tumors, including breast cancer. Since the functions and action mechanisms of COX-2 in breast cancer have not been fully elucidated, in the present study, the effects of target inhibiting COX-2 with recombinant adenovirus Ad-COX-2-shRNA on malignant biological behavior were investigated in representative cell lines. Materials and Methods: Breast cancer MDA-MB-231 and MCF-7 cells were transfected with Ad-COX-2-shRNA and COX-2 expression was tested by RT-PCR and Western blotting. Changes in proliferation, apoptosis and invasion of breast cancer cells were detected with various assays including MTT, colony forming, flowcytometry and Transwell invasion tests. The expression of related proteins involved in the cell cycle, apoptosis, invasion and signaling pathways was assessed by Western blotting. Results: COX-2 expression was significantly reduced in both breast cancer cell lines infected with Ad-COX-2-shRNA, with obvious inhibition of proliferation, colony forming rate, G2/M phase passage and invasion, as well as induction of apoptosis, in MDA-MB-231 and MCF-7 cells, respectively. At the same time, proteins related to the cell cycle, anti-apoptosis and invasion were significantly downregulated. In addition, c-myc expression and phosphorylation activation of Wnt/${\beta}$-catenin and p38MAPK pathways were reduced by the Ad-COX-2-shRNA. Conclusions: COX-2 expression is associated with proliferation, apoptosis and invasion of breast cancer cells, and its mechanisms of action involve regulating expression of c-myc through the p38MAPK and Wnt/${\beta}$-catenin pathways.

• Nuclear Medicine and Molecular Imaging
• /
• 제41권3호
• /
• pp.209-217
• /
• 2007

목적: mdr1유전자를 표적으로 한 short hairpin RNA (shMDR)는 다약재내성을 나타내는 암세포에서 효과적으로 mdr1 유전자의 발현을 억제 할 수 있고 sodium iodide symporter (NIS)는 유전자 치료와 리포터로의 기능을 동시에 나타낼 수 있다. 이 연구에서는 사람 대장암세포(HCT15)에 shMDR과 NIS를 동시에 이입하고 Tc-99m sestamibi와 I-125 섭취를 측정하였고 doxorubicin과 I-131 치료효과도 관찰하였다. 대상 및 방법: 사람 태아 신장 세포주(Human Embryonic Kidney cells; HEK293)에 liposome 시약으로 shMDR을 이입하고 RT-PCR과 western blot으로 분석하였다. shMDR와 NIS 유전자가 발현하는 adenovirus를 만들고 HCT15 세포에 이입 후 48시간에 shMDR에 의한 Pgp의 기능 억제를 확인하기위해 Tc-99m sestamibi 섭취와 doxorubicin 세포독성을 측정하였다. 또한 NIS유전자의 기능을 확인 하기위해 I-125 섭취와 I-131 세포독성도 확인하였다. 결과: shMDR이 이입 된 HEK293 세포에서 mdr1의 mRNA와 Pgp의 발현이 각각 75%, 80% 감소하였다. NIS 유전자가 발현하는 adenovirus를 HCT15 세포에 이입하고 NIS 유전자 발현을 확인 한 결과 대조군에 비해 월등히 높게 발현하였다. Ad-shMDR 300 MOI, Ad-shMDR 300 MOI 와 Ad-NIS 10 MOI를 처리한 경우 Tc-99m sestamibi의 섭취가 대조군보다 1.5배 정도 증가하였다. HCT15 세포에 Ad-NIS 10 MOI를 감염시킨 경우 I-125 섭취가 대조군에 비해 25배 이상 증가였다. 또한 Ad-shMDR와 Ad-NIS를 동시 감염 시켰을 경우 doxorubicin의 세포 독성이 증가하여 나타났고 Ad-NIS 20 MOI를 감염시켰을 때 I-131에 의한 세포독성이 대조군보다 증가하였다. 결론: 세포에 shMDR의 이입으로 mdr1 유전자의 발현이 억제되고 Tc-99m sestamibi의 섭취와 doxorubicin의 세포독성이 증가하였으며 NIS 유전자의 이입으로 I-125의 섭취와 I-131의 세포독성이 증가하였다. 다약제내성세포에 shMDR와 NIS 유전자의 동시 이입은 doxorubicin과 방사성 옥소의 이중치료 효과를 높일 수 있을 것으로 본다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권24호
• /
• pp.10597-10601
• /
• 2015

Up-regulation of multidrug resistance-associated protein 1 (MRP1) is regarded as one of the main causes for multidrug resistance (MDR) of tumor cells, leading to failure of chemotherapy-based treatment for a multitude of cancers. However, whether silencing the overexpressed MRP1 is sufficient to reverse MDR has yet to be validated. This study demonstrated that RNAi-based knockdown of MRP1 reversed the increased efflux ability and MDR efficiently. Two different short haipin RNAs (shRNAs) targeting MRP1 were designed and inserted into pSilence-2.1-neo. The shRNA recombinant plasmids were transfected into cis-dichlorodiamineplatinum-resistant A549 lung (A549/DDP) cells, and then shRNA expressing cell clones were collected and maintained. Real time PCR and immunofluorescence staining for MRP1 revealed a high silent efficiency of these two shRNAs. Functionally, shRNA-expressing cells showed increased rhodamine 123 retention in A549/DDP cells, indicating reduced efflux ability of tumor cells in the absence of MRP1. Consistently, MRP1-silent cells exhibited decreased resistance to 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and DDP, suggesting reversal of MDR in these tumor cells. Specifically, MRP1 knockdown increased the DDP-induced apoptosis of A549/DDP cells by increased trapping of their cell cycling in the G2 stage. Taken together, this study demonstrated that RNAi-based silencing of MRP1 is sufficient to reverse MDR in tumor cells, shedding light on possible novel clinical treatment of cancers.

• Journal of Microbiology
• /
• 제33권2호
• /
• pp.154-159
• /
• 1995

SH-14, a novel killer strain of Ustilago maydis was isolated in Korea. It has been reported in other papers that the toxin specificity and double-stranded RNA pattern of SH-14 strain were different from other laboratory strains. In this paper, we analyzed the biochemical characteristics of U. maydis SH-14 virus. Three distinctive peaks were isolated from CsCl density gradient, designated as top (T), intermediate (I) and bottom (B) components. We found that the densities of each components, 1.285, 1.408 g/cm$\^$3/, respectively, are very similar to those of other strains. As previously reported by the analysis of dsRNA in each component, the dsRNA segments are separately encapsidated. Capsid protein of SH-14 virus consists of two proteins about 70 Kd shown by SDS-PAGE analysis. Electron microscopic examination of the virus particles revealed that UmV particles are very similar in size and morphology to all isolates as well as all lab-strains. In order to test immunological cross reactivity of UmV, werstern bolt analysis was carriedout with antiserum against A8 virus. All capsid protein had positive reaction against A8 antibody which indicated that UmV are immunologically cross-reactive with all isolates from Korea. The results presented in this paper may show that UmV isolated from SH-14 strain has very similar biochemical characteristics to those of other UmV. However, the difference in the toxin specificity and the molecular weight of toxin protein from the SH-14 strain has us to conclude that U. maydis SH-14 strain is a new killer type.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권11호
• /
• pp.5865-5869
• /
• 2012

RHOXF1 has been shown to be expressed in embryonic stem cells, adult germline stem cells and some cancer lines. It has been proposed as a candidate gene to encode transcription factors regulating downstream genes in the human testis with antiapoptotic effects. Its expression in cancer cell lines has implied a similar role in the process of tumorigenesis. The human breast cancer cell lines MDA-MB-231 and MCF-7 were cultured in DMEM medium and transfected with a pGFP-V-RS plasmid bearing an RHOXF1 specific shRNA. Quantitative real-time RT-PCR was performed for RHOXF1, CASP8, BCL2 and HPRT genes. Decreased RHOXF1 expression was confirmed in cells after transfection. shRNA knock down of RHOXF1 resulted in significantly decreased BCL2 expression in both cell lines but no change in CASP8 expression. shRNA targeting RHOXF1 was shown to specifically mediate RHOXF1 gene silencing, so RHOXF1 can mediate transcriptional activation of the BCL2 in cancers and may render tumor cells resistant to apoptotic cell death induced by anticancer therapy. shRNA mediated knock down of RHOXF1 can be effective in induction of apoptotic pathway in cancer cells via BCL2 downregulation, so it can have potential therapeutic utility for human breast cancer.

• Molecules and Cells
• /
• 제38권11호
• /
• pp.959-965
• /
• 2015

Inducible and reversible gene silencing in desired types of cells is instrumental for deciphering gene functions using cultured cells or in vivo models. However, efficient conditional gene knockdown systems remain to be established. Here, we report the generation of an inducible expression system for short hairpin RNA (shRNA) targeted to PTEN, a well-documented dual-specificity phosphatase involved in tumor suppression and ontogenesis. Upon induction by doxycycline (DOX), the reverse tetracycline transcriptional activator (rtTA) switched on the concomitant expression of GFP and a miR-30 precursor, the subsequent processing of which released the embedded PTEN-targeted shRNA. The efficacy and reversibility of PTEN knockdown by this construct was validated in normal and neoplastic cells, in which PTEN deficiency resulted in accelerated cell proliferation, suppressed apoptosis, and increased invasiveness. Transgenic mice harboring the conditional shRNA-expression cassette were obtained; GFP expression and concurrent PTEN silencing were observed upon ectopic expression of rtTA and induction with Dox. Therefore, this study provides novel tools for the precise dissection of PTEN functions and the generation of PTEN loss of function models in specific subsets of cells during carcinogenesis and ontogenesis.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권16호
• /
• pp.7205-7210
• /
• 2015

Background: In this study, influence caused by expression plasmids of connective tissue growth factor (CTGF) and tissue inhibitor of metalloproteinase-1 (TIMP-1) short hairpin RNA (shRNA) on mRNA expression of CTGF,TIMP-1,procol-${\alpha}1$ and PCIII in hepatic tissue with hepatic fibrosis, a precancerous condition, in rats is analyzed. Materials and Methods: To screen and construct shRNA expression plasimid which effectively interferes RNA targets of CTGF and TIMP-1 in rats. 50 cleaning Wistar male rats are allocated randomly at 5 different groups after precancerous fibrosis models and then injection of shRNA expression plasimids. Plasmid psiRNA-GFP-Com (CTGF and TIMP-1 included), psiRNA-GFP-CTGF, psiRNA-GFP-TIMP-1 and psiRNA-DUO-GFPzeo of blank plasmid are injected at group A, B, C and D, respectively, and as model control group that none plasimid is injected at group E. In 2 weeks after last injection, to hepatic tissue at different groups, protein expression of CTGF, TIMP-1, procol-${\alpha}1$ and PC III is tested by immunohistochemical method and,mRNA expression of CTGF,TIMP-1,procol-${\alpha}1$ and PCIII is measured by real-time PCR. One-way ANOVA is used to comparison between-groups. Results: Compared with model group, there is no obvious difference of mRNA expression among CTGF,TIMP-1,procol-${\alpha}1$, PC III and of protein expression among CTGF, TIMP-1, procol-${\alpha}1$, PC III in hepatic tissue at group injected with blank plasmid. Expression quantity of mRNA of CTGF, TIMP-1, procol-${\alpha}1$ and PCIII at group A, B and C decreases, protein expression of CTGF, TIMP-1, procol-${\alpha}1$, PC III in hepatic tissue is lower, where the inhibition of combination RNA interference group (group A) on procol-${\alpha}1$ mRNA transcription and procol-${\alpha}1$ protein expression is superior to that of single interference group (group B and C) (P<0.01 or P<0.05). Conclusions: RNA interference on CTGF and/or TIMP-1 is obviously a inhibiting factor for mRNA and protein expression of CTGF, TIMP-1, procol-${\alpha}1$ and PCIII. Combination RNA interference on genes of CTGF and TIMP-1 is superior to that of single RNA interference, and this could be a contribution for prevention of precancerous condition.

• Reproductive and Developmental Biology
• /
• 제38권3호
• /
• pp.99-105
• /
• 2014

In this study, to further understand the mechanism of animal growth and to develop a miniature transgenic animal model, we constructed and tested tetracycline-inducible RNAi system using shRNA targeting the mRNA of mouse insulin-like growth factor (mIGF-1) or mouse growth hormone receptor (mGHR) gene. Quantitative real-time PCR analysis of mouse liver cell (Hepa1c1c7) cells transfected with these vectors showed 85% or 90% of expression inhibition effect of IGF-1 or GHR, respectively. In ELISA analysis, the protein level of IGF-1 in the cells expressing the shRNA targeting IGF-1 mRNA was reduced to 26% of non-transformed control cells. Unexpectedly, in case of using shRNA targeting GHR, the IGF-1 protein level was decreased to 75% of control cells. Further experiments are needed to explain the lower interference effect of GHR shRNA in IGF-1 protein. Accumulated knowledge of this approach could be applicable to a variety of related biological area including gene function study, gene therapy, development of miniature animals, etc.