• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4751-4756
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• 2012

Colon cancer continues to be one of the most common cancers, and the importance and necessity of new therapies needs to be stressed. The most important proto-oncogen factors for colon cancer appear to be epidermal growth factor receptor, EGFR, and c-Src with high expression and activity leading to tumor growth and ultimately to colon cancer progression. Application of c-Src and EGFR antisense agents simultaneously should theoretically therefore have major benefit. In the present study, anti-EGFR and c-Src specific antisense oligodeoxynucleotides were combined in a formulation using PAMAM dendrimers as a carrier. Nano drug entry into cells was confirmed by flow cytometry and fluorescence microscopy imaging and real time PCR showed gene expression of c-Src and EGFR, as well as downstream STAT5 and MAPK-1 with the tumor suppressor gene P53 to all be downregulated. EGFR and c-Src protein expression was also reduced when assessed by western blotting techniques. The effect of the antisense oligonucleotide on HT29 cell proliferation was determined by MTT assay, reduction beijng observed after 48 hours. In summary, nano-drug, anti-EGFR and c-Src specific antisense oligodeoxynucleotides were effectively transferred into HT-29 cells and inhibited gene expression in target cells. Based on the results of this study it appears that the use of antisense EGFR and c-Src simultaneously might have a significant effect on colon cancer growth by down regulation of EGFR and its downstream genes.

• BMB Reports
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• v.32 no.4
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• pp.414-418
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• 1999

A novel gene for malonyl-CoA decarboxylase was discovered in the mat operon, which encodes a set of genes involved in the malonate metabolism of Rhizobium trifolii (An and Kim, 1998). The subunit mass determined by SDS-PAGE was 53 kDa, which correspond to the deduced mass from the sequence data. The molecular mass of the native enzyme determined by field flow fractionation was 208 kDa, indicating that R. trifolii malonyl-CoA decarboxylase is homotetrameric. R. trifolii malonyl-CoA decarboxylase converted malonyl-CoA to acetyl-CoA with a specific activity of 100 unit/mg protein. Methylmalonyl-CoA was decarboxylated with a specific activity of 0.1 unit/mg protein. p-Chloromercuribenzoate inhibited this enzyme activity, suggesting that thiol group(s) is(are) essential for this enzyme catalysis. Database analysis showed that malonyl-CoA decarboxylase from R. trifolii shared 32.7% and 28.1% identity in amino acid sequence with those from goose and human, respectively, and it would be located in the cytoplasm. However, there is no sequence homology between this enzyme and that from Saccharopolyspora erythreus, suggesting that malonyl-CoA decarboxylases from human, goose, and R. trifolii are in the same class, whereas that from S. erythreus is in a different class or even a different enzyme, methylmalonyl-CoA decarboxylase. According to the homology analysis, Cys-214 among three cysteine residues in the enzyme was found in the homologous region, suggesting that the cysteine was located at or near the active site and plays a critical role in catalysis.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.756-764
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• 2014

Apoptin, a chicken anemia virus-encoded protein, induces apoptosis in chicken or human tumor cells, localizing in their nuclei as opposed to the cytoplasm of non-transformed cells. The present study was undertaken to investigate whether ABPs1 could potentiate apoptin-induced apoptosis in HeLa cells. ABPs1 and the apoptin genes were successfully cloned into pIRES2-EGFP expression vector and expressed in HeLa cells. We report that ABPs1 augments apoptin cell growth inhibition in a concentration- and time-dependent manner. The DAPI staining and scanning electron microscopy observations revealed apoptotic bodies and plasma membrane pores, which were attributed to apoptin and ABPs1, respectively. Further, ABPs1 in combination with apoptin was found to increase the expression of Bax and to decrease the expression of survivin compared with either agent alone or the control. The apoptotic rate of HeLa cells treated with ABPs1 and apoptin in combination for 48 h was 53.95%. The two-gene combination increased the caspase-3 activity of HeLa cells. Taken together, our study suggests that ABPs1 combined with apoptin significantly inhibits HeLa cell proliferation, and induces cell apoptosis through membrane defects, up-regulation of Bax expression, down-regulation of survivin expression, and activation of the caspase-3 pathway. Thus, the combination of ABPs1 and apoptin could serve as a means to develop novel gene therapeutic agents against human cervical cancer.

• Molecules and Cells
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• v.40 no.12
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• pp.916-924
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• 2017

MicroRNAs are widely involved in the pathogenesis of cardiovascular diseases through regulating gene expression via translational inhibition or degradation of their target mRNAs. Recent studies have indicated a critical role of microRNA-206 in myocardial ischaemia-reperfusion (I/R) injury. However, the function of miR-206 in myocardial I/R injury is currently unclear. The present study was aimed to identify the specific role of miR-206 in myocardial I/R injury and explore the underlying molecular mechanism. Our results revealed that the expression level of miR-206 was significantly decreased both in rat I/R group and H9c2 cells subjected to hypoxia/reoxygenation (H/R) compared with the corresponding control. Overexpression of miR-206 observably decreased infarct size and inhibited the cardiomyocyte apoptosis induced by I/R injury. Furthermore, bioinformatics analysis, luciferase activity and western blot assay proved that $Gadd45{\beta}$ (growth arrest DNA damage-inducible gene $45{\beta}$) was a direct target gene of miR-206. In addition, the expression of pro-apoptotic-related genes, such as p53, Bax and cleaved caspase3, was decreased in association with the down-regulation of $Gadd45{\beta}$. In summary, this study demonstrates that miR-206 could protect against myocardial I/R injury by targeting $Gadd45{\beta}$.

• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.73-77
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• 2005

Nickel is the one of potent environmental, the occupational pollutants and the classified human carcinogens. It is a serious hazard to human health, when the metal exposure. To prevent human diseases from the heavy metals, it is seemingly important that understanding of how nickel exerts their toxicity and carcinogenic effect at a molecular and a genomic level. The process of nickel absorption has been demonstrated as phagocytosis, iron channel and diffusion. Uptaked nickel has been suggested to induce carcinogenesis via two pathways, a direct DNA damaging pathway and an indirect DNA damaging pathway. The former was originated from the ability of metal to generate Reactive Oxygen Species (ROS) and the reactive intermediates to interact with DNA directly. Ni-generated ROS or Nickel itself, interacts with DNAs and histones to cause DNA damage and chromosomal abnormality. The latter was originated from an indirect DNA damage via inhibition of DNA repair, or condensation and methylation of DNA. Cells have ability to protect from the genotoxic stresses by changing gene expression. Microarray analysis of the cells treated with nickel or nickel compounds, show the specific altered gene expression profile. For example, HIF-I (Hypoxia-Inducible Factor I) and p53 were well known as transcription factors, which are upregulated in response to stress and activated by both soluble and insoluble nickel compounds. The induction of these important transcription factors exert potent selective pressure and leading to cell transformation. Genes of metallothionein and family of heat shock proteins which have been known to play role in protection and damage control, were also induced by nickel treatment. These gene expressions may give us a clue to understand of the carcinogenesis mechanism of nickel. Further discussions on molecular and genomic, are need in order to understand the specific mechanism of nickel toxicity and carcinogenicity.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3805-3810
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• 2015

Arsenic trioxide (ATO) has been found to exert anti-cancer activity in various human malignancies. However, the molecular mechanisms by which ATO inhibits tumorigenesis are not fully elucidated. In the current study, we explored the molecular basis of ATO-mediated tumor growth inhibition in pancreatic cancer cells. We used multiple approaches such as MTT assay, wound healing assay, Transwell invasion assay, annexin V-FITC, cell cycle analysis, RT-PCR and Western blotting to achieve our goal. We found that ATO treatment effectively caused cell growth inhibition, suppressed clonogenic potential and induced G2-M cell cycle arrest and apoptosis in pancreatic cancer cells. Moreover, we observed a significant down-regulation of Skp2 after treatment with ATO. Furthermore, we revealed that ATO regulated Skp2 downstream genes such as FOXO1 and p53. These findings demonstrate that inhibition of Skp2 could be a novel strategy for the treatment of pancreatic cancer by ATO.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6645-6650
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• 2015

Background: Gastric cancer (GC) is the third most common cancer regarding mortality in the world. The cag pathogenicity island (PAI) of Helicobacter pylori which contains genes associated with a more aggressive phenotype may involve in the pathogenesis of gastrointestinal disease. We here aimed to examine the associations of cagH, cagL, orf17, and cagG genotypes of H. pylori cag PAI with severe gastrointestinal disease. Materials and Methods: A total of 242 H. pylori strains were genotyped. Histopathological examination and classification of subjects were performed. Results: The frequencies of the cagH, cagL, cagG, and orf17 genotypes were 40/54 (74.1%), 53/54 (98.1%), 38/54 (70.4%), and 43/54 (79.6%), respectively, in patients with peptidic ulceration (PU),while in the control group, the frequencies were 87/147 (59.6%) for cagH, 121/146 (82.9%) for cagL, 109/146 (74.7%) for cagG, and 89/146 (61.0%) for orf17. The results of simple logistic regression analysis showed that the cagL and orf17 genotypes were significantly associated with an increased risk of PU not GC; the ORs (95% CI) were 10.950 (1.446-82.935), and 2.504 (1.193-5.253), respectively. No significant association was found between the cagH and cagG genotypes and the risk of both the PU and the GC in Iran (P>0.05). Finally, multiple logistic regression analysis showed that the cagL genotype was independently and significantly associated with the age-and sex-adjusted risk for PU; the OR (95% CI) was 9.557 (1.219-17.185). Conclusions: We conclude that the orf17 and especially cagL genotypes of H. pylori cag PAI could be factors for risk prediction of PU, but not GC in Iran.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5191-5197
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• 2015

A partial response or resistance to chemotherapeutic agents is considered as a main obstacle in treatment of patients with cancer, including breast cancer. Refining taxane-based treatment procedures using adjuvant or combination treatment is a novel strategy to increase the efficiency of chemotherapy. PPM1D is a molecule activated by reactive oxygen species. whose expression is reported to modulate the recruitment of DNA repair molecules. In this study we examined the impact of arsenic trioxide on efficacy of paclitaxel-induced apoptosis in paclitaxel-resistant MCF-7 cells. We also investigated the expression of PPM1D and TP53 genes in response to this combination treatment. Resistant cells were developed from the parent MCF-7 cell line by applying increasing concentrations of paclitaxel. MTT assays were applied to determine the rate of cell survival. DAPI staining using fluorescent microscopy was employed to study apoptotic bodies. Real-time RT-PCR analysis was also applied to determine PPM1D mRNA levels. Our results revealed that combination of arsenic trioxide and paclitaxel elevates the efficacy of the latter in induction of apoptosis in MCF-7/PAC resistant cells. Applying arsenic trioxide also caused significant decreases in PPM1D mRNA levels (p<0.05). Our findings suggest that arsenic trioxide increases paclitaxel-induced apoptosis by down regulation of PPM1D expression. PPM1D dependent signaling can be considered as a novel target to improve the efficacy of chemotherapeutic agents in resistant breast cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4621-4625
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• 2013

The purpose of this study was to construct a protein-protein interaction (PPI) network related to oral squamous cell carcinoma (OSCC). Each protein was ranked and those most associated with OSCC were mined within the network. First, OSCC-related genes were retrieved from the Online Mendelian Inheritance in Man (OMIM) database. Then they were mapped to their protein identifiers and a seed set of proteins was built. The seed proteins were expanded using the nearest neighbor expansion method to construct a PPI network through the Online Predicated Human Interaction Database (OPHID). The network was verified to be statistically significant, the score of each protein was evaluated by algorithm, then the OSCC-related proteins were ranked. 38 OSCC related seed proteins were expanded to 750 protein pairs. A protein-protein interaction nerwork was then constructed and the 30 top-ranked proteins listed. The four highest-scoring seed proteins were SMAD4, CTNNB1, HRAS, NOTCH1, and four non-seed proteins P53, EP300, SMAD3, SRC were mined using the nearest neighbor expansion method. The methods shown here may facilitate the discovery of important OSCC proteins and guide medical researchers in further pertinent studies.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1833-1836
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• 2012

Objective: Promoter methylation, which can be regulated by MTHFR activity, is associated with silencing of genes. In this study we evaluated the methylation status (type) of the BRCA2 promoter in ovarian cancer patients carrying different genotypes of the MTHFR gene (A or C polymorphisms at position 1298). Methods: The methylation type of the BRCA2 promoter was evaluated using bisulfate-modified DNA in methylation-specific PCR and the MTHFRa1278c polymorphism was assessed by PCR-RFLP. Results: Analysis of the BRCA2 promoter methylation type of cases showed that 7 out of 60 cases (11.7%) were methylated while the remaining 53 (88.3%) were unmethylated. In methylated cases, one out of the 7 cases had a CC genotype and the remaining 6 methylated cases had an AC genotype. The AA genotype was absent. In unmethylated cases, 34, 18, and one out of these had AC, AA and CC genotype, respectively. Conclusion: There was no significant relationship between the methylation types of the BRCA2 promoter in different genotypes of MTHFRa1298c polymorphism in ovarian cancer; p=0.255. There was no significant relation between the methylation types of the BRCA2 promoter in different genotypes of the MTHFRa1298c polymorphism in ovarian cancer.