• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2733-2737
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• 2014

Objective: Molecular pathology tests are often carried for clinicopathological diagnosis and pathologists have established large collections of formalin-fixed, paraffin-embedded tissue (FFPE) banks. However, extraction of DNA from FFPE is a laborious and challenging for researchers in clinical laboratories. The aim of this study was to compare two widely used DNA extraction methods: using a QIAamp DNA FFPE kit from Qiagen and a Cobas Sample Preparation Kit from Roche, and evaluated the effect of the DNA quality on molecular diagnostics. Methods: DNA from FFPE non-small cell lung carcinoma tissues including biopsy and surgical specimens was extracted with both QIAamp DNA FFPE and Cobas Sample Preparation Kits and EGFR mutations of non-small cell lung carcinomas were detected by real-time quantitative PCR using the extracted DNA. Results and Conclusion: Our results showed that DNA extracted by QIAamp and Cobas methods were both suitable to detect downstream EGFR mutation in surgical specimens. Howover, Cobas method could yield more DNA from biopsy specimens, and gain much better EGFR mutation results.

• Biomedical Science Letters
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• v.22 no.3
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• pp.98-106
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• 2016

Investigation of human papillomavirus (HPV) in archival formalin-fixed paraffin-embedded (FFPE) material is important for understanding cervical carcinogenesis. The objective of the present study was to identify the high risk HPVs (HR-HPVs) using HPV E6/E7 mRNA testing from archival tissues in cervical cancer and the relation to HR-HPVs genotypes in paired cervical exfoliated cells. HPV E6/E7 mRNA testing and DNA chip testing were performed in 79 paired cervical FFPE tissues and exfoliated cells from women with histologically confirmed squamous cell carcinoma and adenocarcinoma. Overall agreement in HR-HPVs detection from FFPE samples and cytology samples were 98.5% in HPV 16, 100% in HPV 18, HPV 31, HPV 33, HPV 58, HPV 66, and HPV 68. Type-specific agreement between FFPE samples and cytology samples was 89.1% in HPV positive, 93.5% in HPV 16 and more than 70% in the other HR-HPVs. In conclusion, HR-HPVs were reliably detected in paired FFPE and cytology samples with some variation in type-specific detection.

• Biomedical Science Letters
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• v.28 no.4
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• pp.298-306
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• 2022

Pathological tissue fixation using formalin has been widely used for histological samples in many hospitals and institutions. In general, formalin fixatives were either manufactured in laboratories or purchased commercially because of the risks and environmental concerns of handling organic compounds. In this study, the efficacy of three kinds of commercially purchased and one laboratory-made formalin fixative was compared in the PCR-based molecular diagnosis using the extracted DNA from formalin-fixed paraffin-embedded (FFPE) tissues. The quality of extracted DNA from FFPE tonsil tissues with four kinds of formalin solutions was evaluated, and PCR for beta-globin gene and microsatellite instabilities (MSI) tests for pentaplex panel markers were performed using the extracted DNA. There was no difference in PCR and MSI tests as molecular diagnoses regardless of the types of formalin used in this study. However, the total amount and average length of double-stranded DNA extracted from FFPE tonsil tissue showed significant differences according to the type of formalin fixative. Optimized formalin fixatives and methods for DNA extraction might be sophisticated to extract good quality DNA from the small size of specific tissue samples. Further studies are needed to select the most effective formalin fixative for histology and molecular pathology using human FFPE tissues.

• Molecules and Cells
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• v.40 no.5
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• pp.346-354
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• 2017

Long interspersed nuclear element-1 (LINE-1) is a retrotransposon that contains a CpG island in its 5'-untranslated region. The CpG island of LINE-1 is often heavily methylated in normal somatic cells, which is associated with poor prognosis in various cancers. DNA methylation can differ between formalin-fixed paraffin-embedded (FFPE) and frozen tissues. Therefore, this study aimed to compare the LINE-1 methylation status between the two tissue-storage conditions in gastric cancer (GC) clinical samples and to evaluate whether LINE-1 can be used as an independent prognostic marker for each tissue-storage type. We analyzed four CpG sites of LINE-1 and examined the methylation levels at these sites in 25 FFPE and 41 frozen GC tissues by quantitative bisulfite pyrosequencing. The LINE-1 methylation status was significantly different between the FFPE and frozen GC tissues (p < 0.001). We further analyzed the clinicopathological features in the two groups separately. In the frozen GC tissues, LINE-1 was significantly hypomethylated in GC tissues compared to their corresponding normal gastric mucosa tissues (p < 0.001), and its methylation status was associated with gender, differentiation state, and lymphatic and venous invasion of GC. In the FFPE GC tissues, the methylation levels of LINE-1 differed according to tumor location and venous invasion of GC. In conclusion, LINE-1 can be used as a useful methylation marker for venous invasion in both FFPE and frozen tumor tissues of GC.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6619-6623
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• 2013

Background:The aim of the research was to explore a cost effective, fast, easy to perform, and sensitive method for epidermal growth factor receptor (EGFR) mutation testing. Methods: High resolution melting analysis (HRM) was introduced to evaluate the efficacy of the analysis for dectecting EGFR mutations in exons 18 to 21 using formalin-fixed paraffin-embedded (FFPE) tissues and plasma free DNA from 120 patients. Results: The total EGFR mutation rate was 37.5% (45/120) detected by direct sequencing. There were 48 mutations in 120 FFPE tissues assessed by HRM. For plasma free DNA, the EGFR mutation rate was 25.8% (31/120). The sensitivity of HRM assays in FFPE samples was 100% by HRM. There was a low false-positive mutation rate but a high false-negative rate in plasma free DNA detected by HRM. Conclusions: Our results show that HRM analysis has the advantage of small tumor sample need. HRM applied with plasma free DNA showed a high false-negative rate but a low false-positive rate. Further research into appropriate methods and analysis needs to be performed before HRM for plasma free DNA could be accepted as an option in diagnostic or screening settings.

• Journal of Life Science
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• v.24 no.9
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• pp.1025-1029
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• 2014

Cervical carcinoma is the second leading cause of cancer-related deaths in women around the world, and it is associated with the Human Papillomavirus (HPV) infection. HPV genotyping is important for vaccine policy, etiology, natural history, and epidemiology studies. The use of formalin-fixed paraffin-embedded (FFPE) tissues for HPV genotyping by reverse blot hybridization assays (REBA) has not been clearly confirmed in retrospective studies. The aim of this study was to evaluate the usefulness and efficiency of FFPE tissues from cervical cancers for HPV genotyping. HPV genotypes were detected in 52 FFPE tissues from cervical carcinoma specimens by REBA. HPV was detected in 32 (61.5%) of 52 specimens from FFPE, among which 27 (84.4%) harbored single infections and 5(15.6%) contained multiple infections. The HPV single infections (27) were analyzed by high-risk type 18(8), 58(6), 16(5), 33(1), 35(1), 39(1), 56(1) and low risk type 11(2), 6(1), 70(1). The HPV multiple infections (5) included 16/18(2), 18/52(1), 16/56(1), 16/18/33(1). Please consider being more specific here. Do you mean the analysis? Please clarify what you mean by "included."Through this study, it has been determined that the FFPE specimen is feasible and can be used in HPV genotyping, as well as in retrospective studies.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3437-3445
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• 2016

Background: There is an increasing concern in the role of microRNA (miRNA) in the pathogenesis of bone metastasis (BM) secondary to prostate cancer (CaP). In this exploratory study, we hypothesized that the expression of vinculin (VCL) and chemokine X3C ligand 1 (CX3CL1) might be down-regulated in clinical samples, most likely due to the post-transcriptional modification by microRNAs. Targeted genes would be up-regulated upon transfection of the bone metastatic prostate cancer cell line, PC3, with specific microRNA inhibitors. Materials and Methods: MicroRNA software predicted that miR-21 targets VCL while miR-29a targets CX3CL1. Twenty benign prostatic hyperplasia (BPH) and 16 high grade CaP formalin-fixed paraffin embedded (FFPE) specimens were analysed. From the bone scan results, high grade CaP samples were further classified into CaP with no BM and CaP with BM. Transient transfection with respective microRNA inhibitors was done in both RWPE-1 (normal) and PC3 cell lines. QPCR was performed in all FFPE samples and transfected cell lines to measure VCL and CX3CL1 levels. Results: QPCR confirmed that VCL messenger RNA (mRNA) was significantly down-regulated while CX3CL1 was up-regulated in all FFPE specimens. Transient transfection with microRNA inhibitors in PC3 cells followed by qPCR of the targeted genes showed that VCL mRNA was significantly upregulated while CX3CL1 mRNA was significantly down-regulated compared to the RWPE-1 case. Conclusions: The down-regulation of VCL in FFPE specimens is most likely regulated by miR-21 based on the in vitro evidence but the exact mechanism of how miR-21 can regulate VCL is unclear. Up-regulated in CaP, CX3CL1 was found not regulated by miR-29a. More microRNA screening is required to understand the regulation of this chemokine in CaP with bone metastasis. Understanding miRNA-mRNA interactions may provide additional knowledge for individualized study of cancers.

• Biomedical Science Letters
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• v.26 no.1
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• pp.8-13
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• 2020

Cervical cancer is the fourth most common cancer in women, with approximately 528,000 new cases and 266,000 women dying of it per year in the world. MicroRNAs have recently been in the spotlight as potential biomarkers that regulate gene expression and are involved in tumorigenesis. In the present study, we evaluated miR-1260b as a potential biomarker for screening of cervical cancer by quantitative reverse transcription PCR. We profiled the TCGA data of miR-1260b in 307 cervical cancer tissues. Then, miR-1260b expression levels in 10 cervical cancer tissues and 10 noncancerous tissues were investigated in a pilot study. miR-1260b was found to be significantly up-regulated in cervical cancer FFPE tissues as compared to those in cervical normal FFPE tissues (P = 0.006). The mean expression level of miR-1260b in late-stage (IIB-IVB) was higher than in those with early-stage (IA-IIA). Furthermore, high miR-1260b was found to be associated with high hTERT and Ki-67 mRNA expression, which are representative of tumor prognosis. The results of the pilot study suggest that miR-1260b may be used as a novel biomarker for improving the diagnosis of cervical cancer.

• Biomedical Science Letters
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• v.21 no.4
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• pp.227-232
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• 2015

Epstein-Barr virus (EBV) has a pathogenic role in several lymphomas including diffuse large B-cell lymphoma (DLBCL). In this study, we detected EBV from formalin-fixed paraffin embedded (FFPE) tissues of DLBCL patients by RT-PCR and compared the sensitivity of the RT-PCR method to in situ hybridization (ISH) method. The RNA was extracted from 91 FFPE samples with DLBCL and amplified with primers targeting EBV-encoded small RNA (EBER) by RT-PCR. When using the RT-PCR method, 13 of 91 patients (14.3%) were positive and among these 13 cases, 7 cases (7.7%) were from > 50-year-old patients that is classified as EBV positive DLBCL of the elderly. In previous results using ISH method, 3 of 91 patients (3.3%) were positive and 2 case (2.4%) were older than 50-year-old. These results indicate that RT-PCR method used in this study shows a higher sensitivity than ISH method. The ratio of male versus female among the EBV positive samples was 1.2:1 with the ratio of male higher. If RT-PCR method having high sensitivity is used simultaneously as well as the ISH method providing the information of the EBV positive cellular location, it is expected that EBV will be more accurately detected.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.2971-2977
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• 2014

Background: Long non-coding RNAs (lncRNAs) have been recently observed in various human cancers. However, the role of lncRNAs in pancreatic duct adenocarcinoma (PDAC) remains unclarified. The aim of this study was to detect the expression of lncRNA MALAT1 in PDAC formalin-fixed, paraffin embedded (FFPE) tissues and to investigate the clinical significance of the MALAT1 level. Methods: The expression of MALAT1 was examined in 45 PDAC and 25 adjacent non-cancerous FFPE tissues, as well as in five PDAC cell lines and a normal pancreatic epithelium cell line HPDE6c-7, using qRT-PCR. The relationship between MALAT1 level and clinicopathological parameters of PDAC was analyzed with the Kaplan-Meier method and Cox proportional hazards model. Results: The relative level of MALAT1 was significantly higher in PDAC compared to the adjacent normal pancreatic tissues (p=0.009). When comparing the MALAT1 level in the cultured cell lines, remarkably higher expression of MALAT1 was found in aspc-1 PDAC cells compared with the immortal pancreatic duct epithelial cell line HPDE6c-7 (q=7.573, p<0.05). Furthermore, MALAT1 expression level showed significant correlation with tumor size (r=0.35, p=0.018), tumor stage (r=0.439, p=0.003) and depth of invasion (r=0.334, p=0.025). Kaplan-Meier analysis revealed that patients with higher MALAT1 expression had a poorer disease free survival (p=0.043). Additionally, multivariate analysis indicated that overexpression of MALAT1, as well as the tumor location and nerve invasion, was an independent predictor of disease-specific survival of PDAC. Conclusion: MALAT1 might be considered as a potential prognostic indicator and may be a target for diagnosis and gene therapy for PDAC.