• Journal of Microbiology and Biotechnology
• /
• 제19권9호
• /
• pp.1070-1076
• /
• 2009

Telomerase reverse transcriptase (TERT), which prolongs the replicative life span of cells, is highly upregulated in 85-90% of human cancers, whereas most normal somatic tissues in humans express limited levels of the telomerase activity. Therefore, TERT has been a potential target for anticancer therapy. Recently, we described a new approach to human cancer gene therapy, which is based on the group I intron of Tetrahymena thermophila. This ribozyme can specifically mediate RNA replacement of human TERT (hTERT) transcript with a new transcript harboring anticancer activity through a trans-splicing reaction, resulting in selective regression of hTERT-positive cancer cells. However, to validate the therapeutic potential of the ribozyme in animal models, ribozymes targeting inherent transcripts of the animal should be developed. In this study, we developed a Tetrahymena-based trans-splicing ribozyme that can specifically target and replace the mouse TERT (mTERT) RNA. This ribozyme can trigger transgene activity not only also in mTERT-expressing cells but hTERT-positive cancer cells. Importantly, the ribozyme could selectively induce activity of the suicide gene, a herpes simplex virus thymidine kinase gene, in cancer cells expressing the TERT RNA and thereby specifically hamper the survival of these cells when treated with ganciclovir. The mTERT-targeting ribozyme will be useful for evaluation of the RNA replacement approach as a cancer gene therapeutic tool in the mouse model with syngeneic tumors.

• Archives of Pharmacal Research
• /
• 제24권1호
• /
• pp.1-15
• /
• 2001

Gene therapy has emerged as a new concept of therapeutic strategies to treat diseases which do not respond to the conventional therapies. The principle of gene therapy is to Introduce genetic materials into patient cells to produce therapeutic proteins in these cells. Gene therapy is now at the stage where a number of clinical trials have been carried out to patients with gene-deficiency disease or cancer. Genetic materials for gene therapy are generally composed of gene expression system and gene delivery system. For the clinical application of gene therapy in a way which conventional drugs are used, researches have been focused on the design of gene delivery system which can offer high transfection efficiency with minimal toxicity. Currently, viral delivery systems generally provide higher transfection efficiency compared with non-viral delivery systems while non-viral delivery systems are less toxic, less immunogenic and manufacturable in large scale compared with viral systems. Recently, novel strategies towards the design of new non-viral delivery system, combination of viral and non-viral delivery systems and targeted delivery system have been extensively studied. The continued effort in this area will lead us to develop gene medicine as "gene as a drug" in the near future.

• 한국독성학회:학술대회논문집
• /
• 한국독성학회 2003년도 추계학술대회
• /
• pp.163-163
• /
• 2003

Difficulties of long-tenn survival of lung cancer patients treated with conventional therapies require the need for novel approaches and gene therapy holds promise in this area. Several genes are known to have anti-tumor activities and have been used as a gene of delivery, however, a number of problems such as efficiency, specificity of the gene delivery hinder the application of gene therapy.(omitted)

• Tuberculosis and Respiratory Diseases
• /
• 제50권1호
• /
• pp.67-75
• /
• 2001

배경 : 대표적인 종양억제유전자인 p53 및 p16은 세포주기 조절 및 자연괴멸 유도에서 서로 다른 역할을 하고 있으며 폐암에서는 동시에 비활성화 되어 있는 경우가 흔하다. 이 종양억제유전자들 동시에 이입시 서로 상호작용을 통해 효과가 증진되리라 기대되고 있다. 방법 : 본 연구에서는 p53 및 p16을 아데노바이러스 벡터를 이용하여 폐암세포주에 동시에 이입하여 그 상호작용을 관찰하였다. 복합투여시 세포성장곡선을 분석하여 isobologra을 이용한 상호작용을 검증하고 세포주기의 변화 및 체외종양형성능의 변화도 관찰하였다. 결과 : Isobologram을 이용한 분석에서 adeno-virus-p53와 adenovirus-p16의 복합투여는 NCI H358에서는 상승적인 성장억제를, NCI H23에서는 부가적인 성장 억제를 보였다. 유세포분석기를 이용한 세포주기의 분석 및 체외종양형성능 검사에서도 p53 및 p16의 복합투여시 단독 투여보다 강한 억제효과를 보였다. 결론 : 이러한 상승적인 p53 및 p16의 상호작용은 이 복합요법이 새로운 유전자치료법으로 발전할 수 있는 가능성을 보였다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권5호
• /
• pp.2309-2312
• /
• 2014

Esophageal squamous cell carcinoma (ESCC) is the most common histologic subtype of esophageal cancer and is characterized by a poor prognosis. Determining gene changes in ESCCs should improve understanding of putative risk factors and provide potential targets for therapy. We sequenced about 55 million pair-end reads from a pair of adjacent normal and ESCC samples to identify the gene expression level and gene fusion. Sanger sequencing was used to verify the result. About 17 thousand genes were expressed in the tissues, of which approximately 2400 demonstrated significant differences between tumor and adjacent non tumor tissue. GO and KEGG pathway analysis revealed that many of these genes were associated with cellular adherence and movement, simulation responses and immune responses. Notably we identified and validated one fusion gene, HLA-E and HLA-B, located 1 MB apart. We also identified thousands of remarkably expressed transcripts. In conclusion, a novel fusion gene HLA-E and HLA-B was identified in ESCC via whole transcriptome sequencing, which would be a biomarker for ESCC diagnosis and target for therapy, shedding new light for better understanding of ESCC tumorigenesis.

• 한국생물정보학회:학술대회논문집
• /
• 한국생물정보시스템생물학회 2000년도 International Symposium on Bioinformatics
• /
• pp.74-82
• /
• 2000

Prostate cancer initially responds and regresses in response to androgen depletion therapy, but most human prostate cancers will eventually recur, and re-grow as an androgen independent tumor. Once these tumors become hormone refractory, they usually are incurable leading to death for the patient. Little is known about the molecular details of how prostate cancer cells regress following androgen ablation and which genes are involved in the androgen independent growth following the development of resistance to therapy. Such knowledge would reveal putative drug targets useful in the rational therapeutic design to prevent therapy resistance and control androgen independent growth. The application of genome scale technologies have permitted new insights into the molecular mechanisms associated with these processes. Specifically, we have applied functional genomics using high density cDNA microarray analysis for parallel gene expression analysis of prostate cancer in an experimental xenograft system during androgen withdrawal therapy, and following therapy resistance, The large amount of expression data generated posed a formidable bioinformatics challenge. A novel template based gene clustering algorithm was developed and applied to the data to discover the genes that respond to androgen ablation. The data show restoration of expression of androgen dependent genes in the recurrent tumors and other signaling genes. Together, the discovered genes appear to be involved in prostate cancer cell growth and therapy resistance in this system. We have also developed and applied tissue microarray (TMA) technology for high throughput molecular analysis of hundreds to thousands of clinical specimens simultaneously. TMA analysis was used for rapid clinical translation of candidate genes discovered by cDNA microarray analysis to determine their clinical utility as diagnostic, prognostic, and therapeutic targets. Finally, we have developed a bioinformatic approach to combine pharmacogenomic data on the efficacy and specificity of various drugs to target the discovered prostate cancer growth associated candidate genes in an attempt to improve current therapeutics.

• 대한의생명과학회지
• /
• 제8권2호
• /
• pp.53-62
• /
• 2002

• 한국미생물학회:학술대회논문집
• /
• 한국미생물학회 1998년도 제38회 춘계학술발표대회
• /
• pp.63.1-63.1
• /
• 1998

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권5호
• /
• pp.3187-3190
• /
• 2013

Background: Epidermal growth factor receptor (EGFR) is a transmembrane receptor which contributes to many processes involved in cell survival, proliferation and inhibits apoptosis, that may lead to cancer development. Gastric cancer is one of the most common diseases of digestive system that has low 5-year-survival. The aim of this research was to determine the significance of EGFR tyrosine kinase domain gene polymorphisms in gastric cancer in Iran. Materials and Methods: In the present study, 83 patients with gastric cancer and 40 normal subjects were investigated for EGFR gene polymorphisms in exons 18-21 by PCR-SSCP. Then, DNA sequencing was conducted for different mobility shift bands. Finally the data were statistically analyzed using the chi-2 test and the SPSSver.16 program. Results: Exon 18 of EGFR gene showed three different bands in SSCP pattern and DNA sequencing displayed one mutation. SSCP pattern of Exons 19 and 21 did not show different migration bands. Exon 20 of EGFR gene revealed multiple migrate bands in SSCP pattern. DNA sequencing displayed 2 mutations in this exon: one mutation was caused amino acid change and another mutation was silent. Conclusion: It may be that EGFR tyrosine kinase gene polymorphisms differ between populations and screening could be useful in gastric cancer patients who might benefit from tyrosine kinase inhibitor therapy.

• International Journal of Stem Cells
• /
• 제16권4호
• /
• pp.438-447
• /
• 2023

Recently, ex-vivo gene therapy has emerged as a promising approach to enhance the therapeutic potential of mesenchymal stem cells (MSCs) by introducing functional genes in vitro. Here, we explored the need of using selection markers to increase the gene delivery efficiency and evaluated the potential risks associated with their use in the manufacturing process. We used MSCs/CD that carry the cytosine deaminase gene (CD) as a therapeutic gene and a puromycin resistance gene (PuroR) as a selection marker. We evaluated the correlation between the therapeutic efficacy and the purity of therapeutic MSCs/CD by examining their anti-cancer effect on co-cultured U87/GFP cells. To simulate in vivo horizontal transfer of the PuroR gene in vivo, we generated a puromycin-resistant E. coli (E. coli/PuroR) by introducing the PuroR gene and assessed its responsiveness to various antibiotics. We found that the anti-cancer effect of MSCs/CD was directly proportional to their purity, suggesting the crucial role of the PuroR gene in eliminating impure unmodified MSCs and enhancing the purity of MSCs/CD during the manufacturing process. Additionally, we found that clinically available antibiotics were effective in inhibiting the growth of hypothetical microorganism, E. coli/PuroR. In summary, our study highlights the potential benefits of using the PuroR gene as a selection marker to enhance the purity and efficacy of therapeutic cells in MSC-based gene therapy. Furthermore, our study suggests that the potential risk of horizontal transfer of antibiotics resistance genes in vivo can be effectively managed by clinically available antibiotics.