Dongjun Jeong

The role of vimentin as a methylation biomarker for early diagnosis of cervical cancer

Multiple cytosine guanine dinucleotides (CpG island) are found in the VIM promoter region. The levels of VIM promoter methylation and VIM gene expression were investigated in 7 cervical cancer cell lines and 50 human tissue samples with a distinctive degree of malignant trans-formation. While multiple CpG sites in the VIM promoter were highly methylated in CIN III and invasive carcinoma cells, they were rarely methylated in normal cells. Our result shows that methylation in the VIM promoter appears to start from CIN I and CIN II, relatively early stages of multistep carcinogenesis. This epigenetic alteration in VIM promoter suggests the availability as a biomarker for the early diagnosis and prevention of cervical cancer. We also show that hypermethylation in the VIM promoter is responsible for transcriptional silencing of the VIM gene in cervical cancer cells. In addition, our result shows that exogenous overexpression of the VIM gene in SiHa cervical cancer cells slightly activated cell proliferation and migration as shown in soft agar colony formation and migration assays.

Oncogenic function of p34SEI-1 via NEDD4‑1‑mediated PTEN ubiquitination/degradation and activation of the PI3K/AKT pathway

A 34-KD protein encoded by the SEI-1 gene (p34(SEI‑1)), is a relatively recently discovered oncoprotein that has multiple important biological functions. Our data show that p34(SEI-1) enhances cancer cell survival and promotes tumorigenesis by downregulating the tumor suppressor PTEN, a negative regulator of the PI3K/AKT signaling pathway, and therefore activating the PI3K/AKT signaling pathway. In this process, p34(SEI-1) positively affects NEDD4-1 gene expression both at the transcriptional and protein levels. Furthermore, the expression levels of p34(SEI-1) and NEDD4-1 were found to be coordinated in tumor tissues obtained from patients with breast cancer. We also show that p34(SEI-1) affects the subcellular localization of PTEN.

Overexpression of PD-L1 and PD-L2 Is Associated with Poor Prognosis in Patients with Hepatocellular Carcinoma

Purpose Hepatocellular carcinoma (HCC) is one of the most aggressive malignancies. Recently, the overexpression of programmed cell death 1 (PD-1) and PD-1 ligand 1 (PD-L1) has been shown to correlate with poor prognosis in many cancers. However, the expression of PD-L1 or PD-1 ligand 2 (PD-L2) and clinical outcomes have not been fully investigated in HCC. Materials and Methods Formalin-fixed paraffin-embedded samples were obtained from 85 patients with HCC who underwent surgery. The expression of PD-Ls (PD-L1, PD-L2) was evaluated by immunohistochemical analysis. Results The proportion of high expression groups of PD-L1 and PD-L2 was 27.1% and 23.5%, respectively. Univariate analysis revealed that tumor size (p < 0.001), histological differentiation (p=0.010), PD-L1 expression (p < 0.001), and PD-L2 expression (p=0.039) were significant prognostic factors of overall survival in patients with HCC. Multivariate analysis revealed that overall tumor size (hazard ratio [HR], 4.131; 95% confidence interval [CI], 2.233 to 7.643; p < 0.001 and HR, 3.455; 95% CI, 1.967 to 6.067; p < 0.001) and PD-L1 expression (HR, 5.172; 95% CI, 2.661 to 10.054; p < 0.001 and HR, 3.730; 95% CI, 1.453 to 9.574; p=0.006) were independent prognostic values for overall and disease-free survival. Patients with high expression of PD-Ls had a significantly poorer survival than those with low expression (p < 0.001, p=0.034). Conclusion The overexpression of PD-Ls in HCC patients is correlated with survival and tumor recurrence. Further evaluation of PD-1 and PD-Ls as therapeutic targets and predictive biomarkers for HCC is warranted.

Detection of BRAF V600E Mutations in Papillary Thyroid Carcinomas by Peptide Nucleic Acid Clamp Real-Time PCR: A Comparison with Direct Sequencing

Background Papillary thyroid carcinoma (PTC) of the thyroid is the most common endocrine malignancy. High prevalence of an activating point mutation of BRAF gene, BRAFV600E, has been reported in PTC. We assessed the efficiency of peptide nucleic acid clamp real-time polymerase chain reaction (PNAcqPCR) for the detection of BRAFV600E mutation in PTC in comparison with direct sequencing (DS). Methods A total of 265 thyroid lesions including 200 PTCs, 5 follicular carcinomas, 60 benign lesions and 10 normal thyroid tissues were tested for BRAFV600E mutation by PNAcqPCR and DS. Results The sensitivity and accuracy of the PNAcqPCR method were both higher than those of DS for the detection of the BRAFV600E mutation. In clinical samples, 89% of PTCs harbored the BRAFV600E mutation, whereas 5 follicular carcinomas, 50 benign lesions and 10 normal thyroid tissues lacked the mutation. The mutation was associated with aggressive clinical behaviors as extrathyroid invasion (p=0.015), lymph node metastasis (p=0.002) and multiple tumor numbers (p=0.016) with statistical significance. Conclusions The PNAcqPCR method is efficiently applicable for the detection of the BRAFV600E mutation in PTCs in a clinical setting.

Epigenetic regulation of the potential tumor suppressor gene, hLHX6.1, in human cervical cancer.

It is well known that the Homo sapiens LIM homeobox domain 6 gene (hLHX6), a putative transcription regulator, controls the differentiation and development of neural and lymphoid cells, particularly in the central nervous system. In this study, we investigated hLHX6.1 (an isoform of hLHX6), which functions as a tumor suppressor gene in the cervix. Firstly, the methylation levels of the hLHX6 and hLHX6.1 promoters were investigated in 8 cervical cancer cell lines and human tissue samples with a distinctive degree of malignant transformation. In spite of the presence of multiple cytosine guanine dinucleotides (CpG islands) in 2 proximal promoters of the hLHX6 and hLHX6.1 genes, only the hLHX6.1 promoters were found to be mostly hypermethylated and associated with transcriptional silencing by promoter methylation, whereas the hLHX6 promoters were not. Methylation levels in the hLHX6.1 promoter were also found to be strongly related to cervical cancer development. The level of hLHX6.1 gene expression was found to be relatively high in normal cells, in which the hLHX6.1 promoter was mostly unmethylated. However, the hLHX6.1 gene expression was down-regulated or undetectable in cervical cancer cell lines and cancer tissues, in which the hLHX6.1 promoter was hypermethylated. This epigenetic alteration in the hLHX6.1 promoter begins at a relatively early stage, suggesting its potential as a biomarker for the early diagnosis and prevention of cervical cancer. Moreover, the overexpression of the hLHX6.1 gene in cervical cancer cells suppressed the tumorigenic phenotype, as shown by soft agar colony formation and migration assays, suggesting that hLHX6.1 could be a new tumor suppressor gene in the cervix.

Cyr61 Expression is associated with prognosis in patients with colorectal cancer

BackgroundCysteine-rich 61 (Cyr61), a member of the CCN protein family, possesses diverse functionality in cellular processes such as adhesion, migration, proliferation, and survival. Cyr61 can also function as an oncogene or a tumour suppressor, depending on the origin of the cancer. Only a few studies have reported Cyr61 expression in colorectal cancer. In this study, we assessed the Cyr61 expression in 251 colorectal cancers with clinical follow up.MethodsWe examined Cyr61 expression in 6 colorectal cancer cell lines (HT29, Colo205, Lovo, HCT116, SW480, SW620) and 20 sets of paired normal and colorectal cancer tissues by western blot. To validate the association of Cyr61 expression with clinicopathological parameters, we assessed Cyr61 expression using tissue microarray analysis of primary colorectal cancer by immunohistochemical analysis.ResultsWe verified that all of the cancer cell lines expressed Cyr61; 2 cell lines (HT29 and Colo205) demonstrated Cyr61 expression to a slight extent, while 4 cell lines (Lovo, HCT116, SW480, SW620) demonstrated greater Cyr61 expression than HT29 and Colo205 cell lines. Among the 20 cases of paired normal and tumour tissues, greater Cyr61 expression was observed in 16 (80%) tumour tissues than in normal tissues. Furthermore, 157 out of 251 cases (62.5%) of colorectal cancer examined in this study displayed strong Cyr61 expression. Cyr61 expression was found to be associated with pN (p = 0.018). Moreover, Cyr61 expression was associated with statistically significant cancer-specific mortality (p = 0.029). The duration of survival was significantly lesser in patients with Cyr61 high expression than in patients with Cyr61 low expression (p = 0.001). These results suggest that Cyr61 expression plays several important roles in carcinogenesis and may also be a good prognostic marker for colorectal cancer.ConclusionsOur data confirmed that Cyr61 was expressed in colorectal cancers and the expression was correlated with worse prognosis of colorectal cancers.

Astrocyte elevated gene-1 overexpression in hepatocellular carcinoma: an independent prognostic factor

Purpose Astrocyte elevated gene-1 (AEG-1) plays important roles in tumorigenesis such as proliferation, invasion, metastasis, angiogenesis, and chemoresistance. We examined the expression of AEG-1 in patients with hepatocellular carcinoma (HCC). Methods Eighty-five samples were collected from patients with HCC who underwent surgery and were histopathologically confirmed to have HCC. Two independent pathologists, experienced in evaluating immunohistochemistry and blinded to the clinical outcomes of the patients, reviewed all samples. They determined AEG-1 expression semiquantitatively by assessing the percentage of positively stained immunoreactive cells and staining intensity. Clinicopathological data were analyzed in association with prognosis. Results The association was estimated by univariate and multivariate analyses with Cox regression. Tumor size (hazard ratio [HR], 2.285; 95% confidence interval [CI], 1.175-4.447; P = 0.015), microvascular invasion (HR, 6.754; 95% CI, 1.631-27.965; P = 0.008), and AEG-1 expression (HR, 4.756; 95% CI, 1.697-13.329; P = 0.003) were independent prognostic factors for overall survival. Those for disease-free survival rate were tumor size (HR, 2.245; 95% CI, 1.282-3.933; P = 0.005) and AEG-1 expression (HR, 1.916; 95% CI, 1.035-3.545; P = 0.038). The cumulative 5-year survival and recurrence rates were 89.2% and 50.0% in the low-expressing group and 24.5% and 82.4% in the high-expressing group, respectively. Conclusion The results suggest that AEG-1 overexpression could serve as a valuable prognostic marker in patients with HCC.

Interferon-induced transmembrane protein 1 (IFITM1) is required for the progression of colorectal cancer

Interferon-induced transmembrane protein 1 (IFITM1) has been shown to be implicated in multiple cancers, yet little is known about biological significance of IFITM1 in colorectal cancer. Here, we show that IFITM1 is highly expressed in metastatic colorectal cancer cell lines as well as colorectal patient-derived tumor samples, and its expression is associated with a poor prognosis of the disease. Also, IFITM1 depletion resulted in a significant reduction in the mobility of cancer cell lines, whereas ectopic expression of IFITM1 promoted the migration of cancer cells. Epithelial-mesenchymal transition (EMT) signature was dysregulated by both loss and gain of function of IFITM1, which was partially reverted by Caveolin-1 (CAV1). Therefore, these results suggest that IFITM1 may be a prognostic marker and an attractive target to achieve better therapeutic outcomes in colorectal cancer.

Prognostic Significance of EDIL3 Expression and Correlation with Mesenchymal Phenotype and Microvessel Density in Lung Adenocarcinoma

We examined the prognostic significance of Epidermal Growth Factor-like repeats and Discoidin I-Like Domains 3 (EDIL3) expression and its correlations with mesenchymal phenotype and microvessel density in non-small cell lung carcinoma (NSCLC). A total of 268 NSCLC specimens were evaluated retrospectively by immunohistochemical staining for EDIL3, EMT markers (e-cadherin, β-catenin, and vimentin), and CD31 to measure microvessel density. EDIL3, e-cadherin, β-catenin, and vimentin were expressed in 16%, 22.8%, 3.7%, and 10.1% of the specimens, respectively. The mRNA level of EDIL3 in tumor was correlated with the level of EDIL3 protein expression using immunohistochemistry. In lung adenocarcinoma patients, EDIL3 expression was significantly correlated with low e-cadherin expression, high vimentin expression, and increased microvessel density (P < 0.001, P = 0.001, and P = 0.023, respectively). In lung squamous cell carcinoma patients, EDIL3 expression was significantly correlated with low e-cadherin expression and high vimentin expression (P = 0.021 and P = 0.002, respectively). In lung adenocarcinoma patients, EDIL3 was an independent prognostic factor for overall survival in a multivariate analysis (hazard ratio: 2.552, P = 0.004). EDIL3 is significantly correlated with mesenchymal phenotype, angiogenesis, and tumor progression in lung adenocarcinoma.

Q787Q EGFR Polymorphism as a Prognostic Factor for Lung Squamous Cell Carcinoma

Objective: EGFR genetic polymorphisms have been investigated for carcinogenesis in various tumors including lung cancer. We evaluated EGFR mutations in four exons, with an emphasis on the Q787Q EGFR polymorphism in non-small-cell lung cancer. Methods: To determine the presence of the Q787Q polymorphism in patients with lung cancer, we performed direct sequencing analyses of four exons for 83 squamous cell carcinomas and 80 adenocarcinomas untreated with EGFR tyrosine kinase inhibitors. Results: The Q787Q EGFR polymorphism was more frequently detected in squamous cell carcinoma patients than in adenocarcinoma patients (24 vs. 15.9%). The group of patients with the Q787Q EGFR polymorphism included more males and heavy smokers compared with other patient groups. The presence of the Q787Q EGFR polymorphism significantly and negatively affected the overall survival rate among patients with non-small-cell carcinoma (p = 0.011), particularly those with squamous cell carcinoma (p = 0.037). Among stage I and II squamous cell carcinoma patients, those with the Q787Q EGFR polymorphism had a poor prognosis (p = 0.032). Conclusions: The Q787Q EGFR polymorphism allows stratifying lung squamous cell carcinoma patients and could be an independent prognostic marker, particularly among those in stages I and II.