• Archives of Pharmacal Research
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• v.27 no.6
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• pp.633-639
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• 2004

The expression of therapeutic transgenes in recombinant adenoviral vectors is a major cause of toxicity in dividing cancer cells as well as non dividing normal cells. To solve the problem of toxicity to normal cells, we have reported on a recombinant adenoviral vector system （AdLP-） in which the expression of the transgene is directed by the tumor-specific L-plastin promoter （LP） （Chung et al., 1999）. The object of this study was to generate a recombinant adenoviral vector system which would generate tumor cell specific expression of cytosine deaminase （CD） gene. We report the construction of a replication-incompetent adenoviral vector in which CD is driven by the L-plastin promoter （AdLPCD）. Infection of 293 cells by AdLPCD generated the functional CD protein as measured by HPLC analysis for the conversion of 5-Fluorocy-tosine （5-FC） to 5-Fluorouracil （5-FU）. HPLC analysis in conjunction with counting radioactivity for ［6-$^3$H］-5FC and ［6-$^3$H］-5FU demonstrated vector dose-dependent conversion of 5-FC to 5-FU in AdLPCD infected ovarian cancer cells. The results from present and previous studies（Peng et al., 2001； Akbulut et al., 2003） suggest that the use of the AdLPCD／5-FC system may be of value in the treatment of cancer including microscopic ovarian cancer in the peritoneal cavity.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.3711-3719
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• 2016

Drawbacks of conventional cancer treatments, with lack of specificity and cytotoxicity using current approaches, underlies the necessity for development of a novel approach, gene-directed cancer therapy. This has provided novel technological opportunities in vitro and in vivo. This review focuses on a member of an apoptosis inhibitor family, survivin, as a valuable target. Not only the gene but also its promoter are applicable in this context. This article is based on a literature survey, with especial attention to RNA interference as well as tumor-specific promoter action. The search engine and databases utilized were Science direct, PubMed, MEDLINE and Google. In addition to cell-cycle modulation, apoptosis inhibition, interaction in cell-signaling pathways, cancer-selective expression, survivin also may be considered as specific target through its promoter as a novel treatment for cancer. Our purpose in writing this article was to create awareness in researchers, emphasizing relation of survivin gene expression to potential cancer treatment. The principal result and major conclusion of this manuscript are that survivin structure, biological functions and applications of RNA interference systems as well as tumor-specific promoter activity are of major interest for cancer gene therapy.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.143-149
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• 2005

We have demonstrated previously on a replication incompetent recombinant adenoviral vector, AdLPCD, in which the expression of cytosine deaminase (CD) gene is driven by the tumor-specific L-plastin promoter. The object of this study was to evaluate the efficacy of AdLPCD together with 5-fluorocytosine (5-FC) in suppression of the growth of established human tumor cells of ovary, Consistent with the knowledge that infection of OVCAR-3 cells with AdLPCD resulted in expression of a functional intracellular CD enzyme capable of converting 5-FC to 5-fluorouracil (5-FU) (Chung and Deisseroth, 2004), statistically significant differences in cytotoxicity were observed when AdLPCD infected cells were also exposed to 5-FC for 6 days (p=0.05), 9 days (p<0.0005) and 12 days (p<0.005), compared to 5-FC exposure alone, These results indicate that the CD gene delivered by adenoviral vector could efficiently sensitize OVCAR-3, otherwise non-toxic 5-FC. On the other hand, SKOV-3 cells, an ovarian carcinoma cell line, were more resistant to the CD/5-FC strategy compared with OVCAR-3 cells under the same condition. The results of present study suggest that the replacement of 5-FU with CD/5-FC in combination chemotherapy would be less toxic and much greater cytotoxicity than the conventional combination chemotherapy in some patients.

• BMB Reports
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• v.56 no.6
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• pp.347-352
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• 2023

The protein family of poly (ADP-ribose) polymerases (PARPs) is comprised of multifunctional nuclear enzymes. Several PARP inhibitors have been developed as new anticancer drugs to combat resistance to chemotherapy. Herein, we characterized PARP4 mRNA expression profiles in cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines. PARP4 mRNA expression was significantly upregulated in cisplatin-resistant ovarian cancer cell lines, and this upregulation was associated with the hypomethylation of specific cytosine-phosphate-guanine (CpG) sites (cg18582260 and cg17117459) on its promoter. Reduced PARP4 expression was restored by treating cisplatin-sensitive cell lines with a demethylation agent, implicating the epigenetic regulation of PARP4 expression by promoter methylation. Depletion of PARP4 expression in cisplatin-resistant cell lines reduced cisplatin chemoresistance and promoted cisplatin-induced DNA fragmentation. The differential mRNA expression and DNA methylation status at specific PARP4 promoter CpG sites (cg18582260 and cg17117459) according to cisplatin responses, was further validated in primary ovarian tumor tissues. The results showed significantly increased PARP4 mRNA expressions and decreased DNA methylation levels at specific PARP4 promoter CpG sites (cg18582260 and cg17117459) in cisplatin-resistant patients. Additionally, the DNA methylation status at cg18582260 CpG sites in ovarian tumor tissues showed fairly clear discrimination between cisplatin-resistant patients and cisplatin-sensitive patients, with high accuracy (area under the curve = 0.86, P = 0.003845). Our findings suggest that the DNA methylation status of PARP4 at the specific promoter site (cg18582260) may be a useful diagnostic biomarker for predicting the response to cisplatin in ovarian cancer patients.

• Biomolecules & Therapeutics
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• v.17 no.2
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• pp.138-143
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• 2009

We have reported previously on a replication incompetent recombinant adenoviral vector, AdLPCD, in which the expression of cytosine deaminase gene (CD) is driven by the tumor-specific L-plastin promoter. AdLPCD vector had been evaluated for its efficacy of chemosensitization of ovarian cancer cells to 5-FC. In spite of the fact that ovarian cancer cells, i.e., OVCAR-3 and SK-OV-3, are capable for adenoviral transduction judged by LacZ reporter gene analysis, two cell lines demonstrated quite different sensitivities toward AdLPCD/5-FC system. In OVCAR-3 cells, infection of AdLPCD followed by exposure to 5-FC resulted in the suppression of cell growth with statistical significance. On the other hand, SK-OV-3 cells were more resistant to the CD/5-FC strategy compared with OVCAR-3 cells under the same condition. The object of study was to investigate factors that would determine the sensitivity to AdLPCD/5-FC. We evaluated conversion rate of 5-FC to 5-FU after infection of AdLPCD by HPLC analysis, $IC_{50}$ of 5-FU, the expression level of integrin receptors i.e., ${\alpha}v{\beta}3$ and ${\alpha}v{\beta}5$, and status of p53 in OVCAR-3 and SK-OV-3 cells. The results indicated that OVCAR-3 cells have few favorable features compared with SK-OV-3 cells to be more effective to the AdLPCD/5-FC strategy; higher level of ${\alpha}v{\beta}5$ integrin, higher rate of conversion of 5-FC into 5-FC, and lower $IC_{50}$ of 5-FU. The results suggest that the replacement of 5-FU with CD/5-FC in combination chemotherapy would be less toxic and much greater cytotoxicity than the conventional combination chemotherapy in some patients.

• IMMUNE NETWORK
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• v.8 no.4
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• pp.137-142
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• 2008

Background: CD11c, also known as integrin alpha x, is one of the optimum markers of dendritic cells. However, the regulation of the CD11c expression in mouse has not been identified yet. In this study, in order to analyze the regulation of CD11c expression, the promoter of CD11c was cloned and characterized. Methods: To identify the promoter portion, various sizes of what are considered to be CD11c promoter fragments was amplified by polymerase chain reaction (PCR), using mouse genomic DNA as a template. After sequence was obtained, these fragments were transfected into various cell lines including mouse dendritic cell lines such as JAWSII and DC2.4 and L929 as control cell line.. The promoter activity of three promoter fragments was measured and compared by luciferase activity in the transfected cells. Results: Three clones with size of 1kb, 3kb and 6kb were obtained from mouse genomic DNA. Flow cytometry analysis of JAWSII cells revealed that 52% of the cells expressed CD11c, which was confirmed by RT-PCR analysis. On the contrary, L929 and DC 2.4 cells did not express CD11c. The CD11c+ JAWSII cells were enriched from 52% to 90% with cell sorter. The comparative luciferase activity analyisis demonstrated that the region responsible for tissue specific expression was contained within -3 kb and the clone with size of 3 kb particularly showed higher luciferase activity than 6 kb and 1 kb clones. Conclusion: The CD11c promoter region containing the region responsible for tissue specificity was successfully cloned and -3 kb region showed the highest activity.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.517-521
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• 2003

Telomerase is a ribonucleoprotein complex whose function is to add telomeric repeats to chromosomal ends. Telomerase consists of two essential components, telomerase RNA template (hTR) and catalytic subunit (hTERT). hTERT is expressed only in cells and tissues positive for telomerase activity, i.e., tumor and fetal cells. In this report, the possibility of utilization of the hTERT promoter in targeted cancer gene therapy was tested. The hTERT promoter was cloned in the replacement of the CMV promoter, and the HSV-TK gene was subcloned to be controlled by the hTERT gene promoter in the adenovirus shuttle plasmid. Then, the recombinant adenovirus Ad-hT-TK was constructed and was infected into normal and human gynecological cancer cell lines. The selective tumor specific cell death by Ad-hT-TK was identified through these experiments, showing that Ad-hT-TK could be used for targeted cancer gene therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.1235-1239
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• 2015

Background: Fragile histidine triad (FHIT) gene is a tumor suppressor gene which involved in breast cancer pathogenesis. Epigenetics alterations in FHIT contributes to tumorigenesis of breast cancer. Objective: Our objective was to study FHIT promoter region hypermethylation in Egyptian breast cancer patients and its association with clinicopathological features. Materials and Methods: Methylation-specific polymerase chain reaction was performed to study the hypermethylation of FHIT promoter region in 20 benign breast tissues and 30 breast cancer tissues. Results: The frequency of hypermethylation of FHIT promoter region was significantly increased in breast cancer patients compared to bengin breast disease patients. The Odd's ratio (95%CI) of development of breast cancer in individuals with FHIT promoter hypermethylation (MM) was 11.0 (1.22-250.8). There were also significant associations between FHIT promoter hypermethylation and estrogen, progesterone receptors negativity, tumor stage and nodal involvment in breast cancer pateints. Conclusions: Our results support an association between FHIT promotor hypermethylation and development of breast cancer in Egyptian breast cancer patients. FHIT promoter hypermethylation is associated with some poor prognostic features of breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8247-8252
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• 2016

Background: The ubiquitin-proteasome system (UPS) degrades a variety of proteins which attach to specific signals. The ubiquitination pathway facilitates degradation of damaged proteins and regulates growth and stress responses. This pathway is altered in various cancers, including acute lymphoblastic leukemia, head and neck squamous cell carcinoma and breast cancer. Recently it has been reported that expression of newly characterized human genes, UBE2Q1 and UBE2Q2, putative members of ubiquitin-conjugating enzyme family (E2), has been also changed in colorectal cancer. Epigenetics is one of the fastest-growing areas of science and nowadays has become a central issue in biological studies of diseases. According to the lack of information about the role of epigenetic changes on gene expression profiling of UBE2Q1 and UBE2Q2, and the presence of CpG islands in the promoter of these two human genes, we decided to evaluate the promoter methylation status of these genes as a first step. Materials and Methods: The promoter methylation status of UBE2Q1 and UBE2Q2 was studied by methylation-specific PCR (MSP) in tumor samples of 60 colorectal cancer patients compared to adjacent normal tissues and 20 non-malignant controls. The frequency of the methylation for each gene was analyzed by chi-square method. Results: MSP results revealed that UBE2Q2 gene promoter were more unmethylated, while a higher level of methylated allele was observed for UBE2Q1 in tumor tissues compared to the adjacent normal tissues and the non malignant controls. Conclusions: UBE2Q1 and UBE2Q2 genes show different methylation profiles in CRC cases.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4965-4969
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• 2015

LCN2 (Lipocalin 2) is a 25 KD secreted acute phase protein, reported to be a novel regulator of angiogenesis in breast cancer. Up regulation of LCN2 had been observed in multiple cancers including breast cancer, pancreatic cancer and ovarian cancer. However, the role of LCN2 promoter methylation in the formation of microvessels is poorly understood. The aim of this study was to analyze the association of LCN 2 promoter methylation with microvessel formation and tumor cell proliferation in breast cancer patients. The LCN2 promoter methylation status was studied in 64 breast cancer tumors by methylation specific PCR (MSP). Evaluation of microvessel density (MVD) and Ki67 cell proliferation index was achieved by immunohistochemical staining using CD34 and MIB-1 antibodies, respectively. LCN2 promoter unmethylation status was observed in 43 (67.2%) of breast cancer patients whereas LCN2 methylation status was seen in 21 (32.8%). Further, LCN2 promoter unmethylation status was associated with aggressive tumor phenotype and elevated mean MVD in breast cancer patients.