• 대한의생명과학회지
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• 제28권4호
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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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.

• 대한의생명과학회지
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• 제22권3호
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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.

• 생명과학회지
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• 제24권9호
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• pp.1025-1029
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• 2014

자궁경부암은 전세계 여성의 사망원인 2위를 차지하며, 인유두종바이러스 감염과 상관성이 있다. 인유두종바이러스의 백신정책, 병인론, 추적관찰, 역학에서 유전형 검사는 중요하다. 후향적 연구를 위하여 파라핀 조직에서 역교잡반응을 이용하여 인유두종바이러스의 유전형을 검사하는 것은 명확하게 증명된 것은 아니다. 본 연구에서는 자궁경부암 파라핀 조직에서 역교잡반응을 사용하여 인유두종바이러스의 유전형 검사의 유용성을 평가하였다. 총 52개의 자궁경부암 파라핀 조직을 사용하여 역교잡반응을 실시하여 인유두종바이러스의 유전형을 검출하였다. 52개의 파라핀 조직중에서 32(61.5%) 건에서 인유두종바이러스가 검출되었으며, 단순감염이 27(84.4%) 건, 복합감염이 5(15.6%) 건으로 검출되었다. 단순감염에서 인유두종바이러스 유전형은 고위험군 18(8), 58(6), 16(5), 33(1), 35(1), 39(1), 56(1) 유전형과, 저위험군 11(2), 6(1), 70(1) 유전형으로 분석되었다. 복합감염에서 인유두종바이러스 유전형은 16/18(2), 18/52(1), 16/56(1), 16/18/33(1) 유전형으로 검출되었다. 본 연구를 통하여, 파라핀 조직으로 후향적 연구를 위한 인유두종바이러스 유전형 검사가 가능할 것으로 기대된다.

• 대한의생명과학회지
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• 제19권2호
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• pp.153-157
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• 2013

Although culture is the gold standard method to identify mycobacteria, its use in tuberculous lymphadenitis (TBL) is limited due to formalin fixation of the submitted specimens. We evaluated the performance of quantitative real-time PCR (q-PCR) for Mycobacterium Tuberculosis (MTB) in granulomatous lymphadenitis using formalin-fixed paraffin-embedded (FFPE) tissues. From 2000 to 2010, a total number of 117 cases of lymph node samples with granulomatous inflammation which were surgically removed and fixed in formalin were studied. Hematoxylin & Eosin (H&E) and Ziehl-Neelsen-stained (ZN) slides were reviewed. qPCR using Real TB-Taq$^{(R)}$ was performed for all cases to identify Mycobacterium tuberculosis. Thirteen non-tuberculous lymphadenopathy cases were used as negative control. Cervical lymph nodes were more frequently affected (60%, 70/117) than other sites. ZN stain for acid fast bacilli was positive in 19 (16.24%) cases. qPCR for tuberculosis was positive in 92 (78.63%) cases. Caseous necrosis was found in 103 (88.03%) cases. While the ZN stain and qPCR were both negative in all control cases, the qPCR showed a significantly higher positive rate (78.63% vs. 16.24%) compared to ZN stain in histologically diagnosed TBL. Quantitative real-time PCR proves to be more sensitive than ZN stain for diagnosis of tuberculous lymphadenitis.

• 대한의생명과학회지
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• 제29권1호
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• pp.48-52
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• 2023

Formaldehyde use is associated with serious health risks, which can affect medical personnel and technicians. Therefore, we investigated the efficacy of an alternative fixative, with respect to two types of formalin fixatives, by hematoxylin and eosin (H&E) staining, periodic acid Schiff (PAS) staining, immunohistochemical (IHC) staining, and RNA extraction. For H&E staining, the circular nucleus was stained dark blue by the basic dye hematoxylin and the cytoplasm was stained red by the acid dye eosin in all three fixative samples. No difference was found in the Duksan General Science (DGS), Sigma-Aldrich, and Core-Fix fixative samples (Corebiotech) used to fix kidney tissue, after PAS staining. IHC staining showed that CD4 was significantly increased in the lippolysaccharide (LPS)-treated group compared to the control group (vehicle), confirming the changes in specific molecules. The quantity and quality of RNA from tissues fixed in the three types of fixatives were evaluated. The average concentration of RNA was 106 ng/µL and average purity at A 260/280 ratio was 1.7~2.0, regardless of fixative used. For quality of protein, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) protein was confirmed by Western blotting. In conclusion, Core-Fix can be used as a fixative for pathological tissues, in histological and molecular diagnoses.

• Molecules and Cells
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• 제40권5호
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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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• 제15권7호
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제14권4호
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• pp.2521-2523
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• 2013

Background: Papillary thyroid cancer or papillary thyroid carcinoma (PTC) is the most common thyroid cancer. The fact that it occasionally occurs in women aged 30-40 years old suggests that genetic alterations are involved its genesis. Recently, activator mutations in BRAF gene have been relatively frequently discovered. Materials and Methods: In this study, we tested 63 DNA samples from PTC patients to identify the V600E mutation frequency in the Ahvaz population. DNA was isolated from formalin fixed paraffin-embedded (FFPE) PTC tumor tissues. Genotyping was performed by PCR-RFLP and confirmed by direct DNA sequencing of a subset of PCR products. PCR-RFLP data were reported as genotype frequencies and percentages. Results: Forty nine out of 63 patients (77.8%) had a mutated heterozygote form while 14 (22.2%) showed normal genotype but none demonstrated a mutant homozygote genotype. The frequency of V600E mutation was significantly high in PTC patients. Conclusions: These findings support involvement of V600E mutations in PTC occurrence in Iran. Assessment of correlations between BRAF V600E mutations and papillary thyroid cancer progression needs to be performed.