Chang Suk Kang

Somatic mutations of TRAIL-receptor 1 and TRAIL-receptor 2 genes in non-Hodgkin's lymphoma

Tumor necrosis factor-related apoptosis-inducing ligand-receptor 1 (TRAIL-R1) and tumor necrosis factor-related apoptosis-inducing ligand-receptor 2 (TRAIL-R2) are cell-surface receptors involved in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell-death signaling. TRAIL-R1 and TRAIL-R2 genes have recently been mapped to chromosome 8p21-22, which is a frequent site of allelic deletions in many types of human tumors, including non-Hodgkins lymphoma (NHL). Because TRAIL/TRAIL receptor system plays an important role in lymphocyte homeostasis, we hypothesized that the mutations of TRAIL-R1 and TRAIL-R2 may be involved in the development of NHL and that such mutations may be responsible for the allelic losses of 8p21-22 in NHL. In this study, we analysed the entire coding region of TRAIL-R2 gene and the death domain region of TRAIL-R1 gene for the detection of the somatic mutations in a series of 117 human NHLs using polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) analysis. Overall, eight tumors (6.8%) were found to have two TRAIL-R1 gene mutations or six TRAIL-R2 gene mutations. Interestingly, of the eight mutations, six missense mutations (two TRAIL-R1 and four TRAIL-R2) were detected in the death domains and one nonsense mutation of TRAIL-R2 was detected just before the death domain. Our data suggest that somatic mutations of TRAIL-R1 and TRAIL-R2 genes may play a role in the pathogenesis of some NHLs and that TRAIL-R1 and TRAIL-R2 genes might be the relevant genes to the frequent loss of chromosome 8p21-22 in human NHL.

Molecular genotyping of follicular variant of papillary thyroid carcinoma correlates with diagnostic category of fine-needle aspiration cytology: values of RAS mutation testing.

BACKGROUND The follicular variant of papillary thyroid carcinoma (FVPTC) presents distinct histologic subtypes and molecular genotyping. The preoperative diagnosis of FVPTC through fine-needle aspiration cytology (FNAC) is challenging. METHODS We reviewed 59 archival thyroid FNAC specimens of surgically confirmed FVPTC according to histologic subtype: encapsulated FVPTC (n = 30) and infiltrative FVPTC (n = 29). Galectin-3 immunostaining and molecular analyses for BRAF and three RAS genes (NRAS, HRAS, and KRAS) were performed. RESULTS FNAC diagnoses of FVPTC included benign (5%), atypia of undetermined significance (19%), follicular neoplasm/suspicious for follicular neoplasm (14%), suspicious for PTC (29%), and PTC (34%). Galectin-3 immunostaining was positive in 50% of FNAC specimens. A BRAF mutation was found only in 14 (24%) tumors with the FNAC diagnosis of PTC or suspicious for PTC: 13 cases with the usual c.1799T>A (p.V600E) mutation and 1 case with a 3 base-pair deletion (c.1799_1801delTGA), resulting in a deletion of lysine at codon 601 and a deletion c.1799_1801delTGA that results in a valine-to-glutamate substitution at codon 600 (p.V600_K601>E) while preserving the reading frame. A BRAF K601E mutation was not found. RAS mutations were observed in 18 (33%) tumors (NRAS, 22%; HRAS, 6%; KRAS, 6%). Mutations of the three RAS genes were detected in codon 61 but not in codons 12 and 13. There was a decreasing trend of RAS mutation rates associated with an increasing risk of malignancy in the FNAC diagnostic categories. The triage efficacy of FNAC to make a recommendation for surgery was 73% for encapsulated tumors and 79% for infiltrative tumors. Addition of galectin-3 or the BRAF test to FNAC showed no significant improvement in the triage efficacy. However, RAS mutations significantly improved the triage efficacy of FNAC. There was no significant difference in the triage efficacy of FNAC, galectin-3 expression, and the prevalence of somatic mutations between encapsulated and infiltrative tumors. CONCLUSION Thyroid FNAC has a low sensitivity for the detection of FVPTC regardless of histologic subtype. Encapsulated FVPTC and infiltrative FVPTC have similar molecular profiles and rates of galectin-3 expression. RAS mutational analysis is more useful than BRAF testing to improve the triage efficacy of FNAC for FVPTC.

Expression of transforming acidic coiled-coil containing protein 3 is a novel independent prognostic marker in non-small cell lung cancer

Transforming acidic coiled‐coil containing protein 3 (TACC3) is known to be involved in the control of normal cell growth and differentiation and in mechanisms of unregulated growth leading to tumorigenesis. The aim of the present paper was to determine the rate of TACC3 expression in a non‐small cell lung cancer (NSCLC) collection and to clarify its correlation with clinicopathological parameters. A total of 163 NSCLC were analyzed immunohistochemically using a polyclonal TACC3 antibody and monoclonal p53 and Ki‐67 antibodies on NSCLC tissue microarrays. A high level of TACC3 expression was observed in 14.8% of cases, preferentially squamous cell carcinomas. Patients whose tumors had a high TACC3 expression had a significantly shorter median survival time. In the Cox regression‐based multivariate analysis, TACC3 expression proved to be an independent prognostic parameter (P = 0.031). TACC3 expression was correlated with p53 expression, and patient whose tumors highly expressed TACC3 and p53 had a significantly poorer prognosis than patients whose tumors had low‐level expression for both immunostainings (P = 0.006). It is suggested that increase in TACC3 may impart a proliferative advantage to NSCLC and contribute to tumor progression, and that TACC3 expression is a strong prognostic indicator of clinical outcome in NSCLC.

Expression of miRNAs and PTEN in endometrial specimens ranging from histologically normal to hyperplasia and endometrial adenocarcinoma

We investigated the relationship between frequently deregulated microRNAs (miRNAs) and enodometrial pathology in an attempt to find the most dependable miRNA or combination of miRNAs to identify normal, hyperplastic and malignant endometrial tissues. We also investigated the association between those miRNAs and PTEN status. We measured the expression of six miRNAs (miR-21, 182, 183, 200a, 200c and 205) in 75 formalin-fixed, paraffin-embedded normal, hyperplastic, and malignant endometrial tissue blocks using Taqman-based real-time PCR assays. PTEN loss of expression was assessed in the same endometrial tissues by immunohistochemistry. Expression of five miRNAs (miR-182, 183, 200a, 200c and 205) was significantly higher in endometrial carcinoma (CA) when compared with complex atypical hyperplasia (CAH), simple hyperplasia (SH) and normal endometrial tissue (P<0.05, respectively). Considering the likelihood ratio and number of parameters, the composite panel of six miRNAs was the best marker, revealing a sensitivity of 91% and a specificity of 94% in differentiating endometrial CA from endometrial hyperplasia or normal endometrium while the individual miRNAs exhibited 64–77% sensitivity and 66–91% specificity. Interestingly, in distinguishing endometrial CA from CAH, the composite panel of four miRNAs (miR-182, 183, 200a, 200c) was the best marker, producing 95% sensitivity and 91% specificity. The percentage of PTEN loss was significantly higher in endometrial CA compared with SH (68% vs 24%, P<0.05), and it was also higher in CAH compared with SH (71% vs 24%, P<005). Aberrant expression of miRNAs and loss of PTEN expression are common in endometrial hyperplasia and CA. They might serve to increase the diagnostic reproducibility and improve discrimination, especially, between CAH and CA by miRNA expression profiles and between simple and complex hyperplasia through PTEN expression patterns. Those expression profiles of biomarkers also might be used to predict the potential for progression from endometrial hyperplasia to invasive CA.

Mutational Patterns and Novel Mutations of the BRAF Gene in a Large Cohort of Korean Patients with Papillary Thyroid Carcinoma

BACKGROUND BRAF mutation is the most common genetic event in papillary thyroid carcinoma (PTC); however, the prevalence and patterns of the mutation vary worldwide. We investigated the frequency and type of BRAF mutations based on the histologic subtypes in a large cohort of Korean patients with PTC. METHODS A total of 1041 consecutive PTCs were classified according to histologic subtypes. BRAF mutations were examined by denaturing high-performance liquid chromatography and direct sequencing. Rare complex mutations were confirmed by molecular cloning of polymerase chain reaction amplicons and sequencing of the products. RESULTS BRAF mutations were found in 839 (80.6%) of 1041 patients with PTC. The histologic subtype-specific prevalence of BRAF mutation was as follows: 85.3% (249/292) were classic, 45.8% (11/24) were follicular, 79.9% (576/721) were microcarcinoma, and 75.0% (3/4) were other variants. In addition to the usual c.1799T>A mutation, we identified other four mutation types: c.[1795_1796insA;1770_1795dup26], c.[1742-10T>C;1799T>A] and c.[1796C>G;1799T>A], and c.1799_1800TG>AA, respectively. The former three were novel mutations in thyroid tumors. Within the series of microcarcinoma variants, the BRAF mutation rate was lower in tumors with follicular morphology than those with nonfollicular types (66.7% vs. 80.9%, p=0.0145). CONCLUSION Out of 1041 Korean patients with PTC, 0.4% had rare types of BRAF mutation and three new somatic mutations were identified. The BRAF mutation rate was quite low in PTC with follicular morphology regardless of tumor size. However, the prevalence of BRAF mutation in microcarcinoma and follicular variants of PTC is relatively high in Korea and its analysis may be clinically useful for managing the patients.

Granulomatous gastritis: A clinicopathologic analysis of 18 biopsy cases

Granulomas in gastric biopsy specimens are extremely rare, and in Western countries, more than half are associated with Crohn’s disease. To evaluate the incidence and their etiology in a gastric carcinoma (and Helicobater pylori infection)-prevalent area, gastric mucosal biopsies were reviewed and their clinicopathologic findings were analyzed. The clinicopathologic diagnoses of the 18 patients with granulomatous gastritis were as follows: chronic gastritis with (n = 14) and without (n = 1) H. pylori infection; gastric adenocarcinomas (n = 2); and Crohn’s disease (n = 1). Almost all cases of granulomatous gastritis in this study showed small erosions or ulcers on the endoscopic examinations. H. pylori were found to be one of the most common causes of granulomatous gastritis after excluding all other causes for the granulomas in this study. The granulomas were more frequently found in the antrum, superficially located, and were related to damage within a pit in which the H. pylori were commonly observed. These findings suggest that H. pylori can be causal in the pathogenesis of granulomatous gastritis.

Loss of heterozygosity of chromosome 8p and 11p in the dysplastic nodule and hepatocellular carcinoma

Background and Aim: In hepatocarcinogenesis, both de novo and multistep pathways have been suggested, and in the latter a dysplastic nodule is the proposed precancerous lesion. But genetic changes involved in the dysplastic nodule are not well understood. In this study, we tried to determine whether allelic loss of the chromosome 8p and/or 11p could be involved in the development of the dysplastic nodule and/or hepatocellular carcinoma. Platelet‐derived growth factor‐receptor beta‐like tumor suppressor gene (PRLTS) and deletion in liver cancer‐1 tumor suppressor gene are located at 8p21.3‐p22. The hepatitis B virus integration site and WT1 tumor suppressor gene are located at 11p13.

Detection of tumor markers including carcinoembryonic antigen, APC, and cyclin D2 in fine-needle aspiration fluid of breast

CONTEXT The traditional triple test for breast cancer diagnosis is physical examination, mammography, and aspiration cytology. However, the accuracy of mammography on young women with nonatrophied breasts is poor compared with that for women older than 50 years, and additional methods for diagnosis of breast cancer are needed. OBJECTIVE To investigate whether carcinoembryonic antigen (CEA), CA 15-3, and CA 125 concentrations in breast aspiration fluid are useful as breast cancer biochemical markers and whether APC and cyclin D2 gene promoter hypermethylation could be regarded as a breast cancer molecular marker. DESIGN CEA, CA 15-3, and CA 125 concentrations were measured, and methylation status of the APC gene promoter 1A and the promoter region of the cyclin D2 gene were analyzed using a methylation-specific polymerase chain reaction assay of ex vivo breast aspiration fluid obtained from 49 samples of excised breast tissue. SETTING The specimens were collected during a 1-year period in the tertiary care teaching hospital in Seoul, Korea. PATIENTS Forty-nine patients with breast masses were surgically treated. Thirty-four patients had breast cancer, and 15 had benign breast disease. RESULTS Aspiration fluid CEA concentrations were significantly higher in breast cancer cases than in cases of benign breast disease (mean, 69.90 ng/mg protein vs 0.68 ng/mg protein, respectively; P < .001). At 90% specificity of the assay (CEA, 2.13 ng/mg protein), the corresponding sensitivity for breast cancer detection was 62%, according to the receiver operating characteristic curve drawn. The APC gene promoter 1A and the promoter region of the cyclin D2 gene were methylated in 42% (14/33) and 70% (23/33) of the breast cancer aspiration fluid samples, respectively. A cumulative incidence of methylation of these 2 genes was 85% (28/33). The APC and cyclin D2 gene promoters were both unmethylated in the aspiration fluids from 19 women with nonmalignant breast disease. CONCLUSIONS Breast aspiration fluid CEA concentration and the methylation of the APC gene promoter 1A and the promoter region of the cyclin D2 gene can be used as tumor markers to overcome some of the limitations of aspiration cytology. In combination with the mammogram and physical examination, assays for these markers could be used to help determine a definitive diagnosis when cytologic results are suspicious for malignancy.

Expression of Functional Markers in Acute Nonlymphoblastic Leukemia

Multidrug resistance parameters, tissue infiltration parameters, receptors for colony-stimulating factors (CSFr) and cell cycle parameters were analyzed using flow cytometry in 145, 109 initial and 36 relapsed or refractory, acute nonlymphoblastic leukemia (ANLL) patients to find out clinically more reliable functional parameters. Lung resistance-associated protein (LRP) was most frequently expressed in ANLL (44.1%) followed by P-glycoprotein (PGP) (35.9%) and multidrug resistance-associated protein (MRP) (8.3%). LRP and PGP were expressed more frequently in relapsed or refractory ANLL than initial ANLL cases. Complete remission rate after standard chemotherapy falls in PGP-positive cases (p = 0.001). CD44-positive ANLL cases relapsed more frequently. The organ tropism is different depending on the infiltration parameters, vascular cell adhesion molecule to splenomegaly, matrix metalloprotease-2 to hepatomegaly and to extramedullary infiltration other than spleen, liver or lymph node. The percentage of the granulocyte-macrophage-CSFr expression was high in M4 and M5, and granulocyte-CSFr-positive ANLL showed less extramedullary infiltration (p = 0.007) and more PGP expression. Ki-67 was expressed significantly less in refractory ANLL than initial ANLL and DNA topisomerase IIα was expressed significantly more in the surviving patients group. In conclusion, analysis of these new functional parameters could help to predict and overcome the clinical behavior of each ANLL at the time of diagnosis.

Reduced expression of TFF1 and increased expression of TFF3 in gastric cancer: correlation with clinicopathological parameters and prognosis.

Objectives: The trefoil factor family (TFF) is composed of three thermostable, and protease-resistant proteins, named TFF1, TFF2 and TFF3, and plays a role in gastrointestinal mucosal defence and repair. Recently, TFFs have been found to be related to the development of various types of cancer. This study assessed the relationship between the expression of TFF1 and TFF3 and the clinicopathological parameters in gastric carcinoma (GC). Materials and Methods: The expression of TFF1 and TFF3 was analyzed by immunohistochemistry in 292 GCs and 20 normal gastric tissues. Results: All normal gastric tissues expressed TFF1, but 53.8% of GCs showed reduced TFF1 expression. However, TFF3 was not detected in normal gastric tissues and 44.2% of GCs showed a high level of expression. Highly expressed TFF3 was significantly correlated with lymph node metastasis, lymphatic invasion, vein invasion, and advanced stage. The overall survival was shorter in patients with high expression of TFF3 than in those with low expression of TFF3 in 292 GCs and in 125 early GCs (EGCs). Moreover, in patients with EGCs, high expression of TFF3, associated with reduced expression of TFF1, was determined as an independent poor prognostic marker. Conclusions: Reduced expression of TFF1 and increased expression of TFF3 may play a role in the carcinogenesis of gastric cancer. Furthermore, high expression of TFF3 with reduced expression of TFF1 may be a marker of poor prognosis for patients with EGC.