Colorectal cancer (CRC) has been assumed for many years to be a homogenous condition with the vast majority developing within preexisting-adenomas. However, over the last two-decades, it has become clear that CRC evolves through multiple pathways at the genetic and the epigenetic level. Each of these processes is associated with a unique genetic or epigenetic signature identifiable in the tumor cells. The pathway may be defined on the basis of three molecular features: 1) chromosomal instability (CIN), 2) microsatellite instability (MSI), and 3) CpG island methylator phenotype (CIMP). Those molecular pathways are determined at an early evolutionary stage and are fully established within early cancer. Recently, five subgroups were outlined by using morphological findings and associated molecular changes: type 1 (CIN-stable/ MSI-H/CIMP-H), type 2 (CIN-stable/MSI-L or MSS/ CIMP-H), type 3 (CIN-unstable/MSI-L or MSS/CIMP-L), type 4 (CIN-instable/MSS/CIMP-neg), and type 5 (CIN- stable/MSI-H/CIMP-neg). This approach to the classification of CRC should accelerate understanding of causation and will have an impact on clinical management in the areas of both prevention and treatment.
Chromosomal Instability ; Colorectal Neoplasms ; CpG Islands ; Epigenomics ; Microsatellite Instability ; Phenotype

Induced pluripotent stem cells (iPSC) are specially manipulated cells from somatic cells by the introduction of four factors that are reprogrammed. The properties of iPSC are similar to embryonic stem cells (ESC) characteristic of self-renewal and pluripotency. The technology of reprogramming somatic cells to iPSC enables the generation of patient-specific cells that can be used as powerful tools for drug screening, in vitro models for human disease and autologous transplantation. The iPSC technology provides a priceless resource for regenerative medicine but there are still changing obstacles over the safety of iPSC in avoiding induction of tumorigenicity and maintaining high purity of re-differentiated cells from iPSC to produce more functional cells for cell therapy. A variety of methods to overcome the limitation of iPSC application applied in the clinical setting have been developed. In this review, we summarize the recent progress in iPSC generation and differentiation techniques to facilitate clinical application of iPSC with future potential in regenerative medicine.
Autografts ; Cell- and Tissue-Based Therapy ; Drug Evaluation, Preclinical ; Embryonic Stem Cells ; Humans ; Induced Pluripotent Stem Cells* ; Regenerative Medicine ; Stem Cells* ; Transplantation, Autologous

Liver transplantation has been regarded as the definitive curative approach for pathologic liver conditions from the acute stage to the chronic end stage for decades. Recently, translational research has been focused on liver stem cell transplantation, using various cell therapies, due to the potential benefit of natural host liver regeneration. Many studies are ongoing utilizing and evaluating the use of either fetal-liver-derived stem cells or oval cells, however many obstacles still remain. Extensive research identifying and characterizimg stem/progenitor cells for potential application to in vitro cell therapy, whereas many questions remain concerning the isolation and identification of adult liver stem cells with adequate capacity for proliferation and the regeneration of injured liver. Recent approaches to liver regeneration include the production of hepatocyte-like cells from other stem cell sources such as mesenchymal stem cells and embryonic stems cells. Another major target for liver regeneration studies include the generation of liver stem cells from induced pluripotent stem cells (IPSC) We review the current data concerning characterization of stem cells and progenitor cells for their capacity to support their potential for re-population and regeneration of normal adult liver from liver damaged due to injury and/or disease.
Adult ; Cell Transplantation ; Cell- and Tissue-Based Therapy ; Humans ; Induced Pluripotent Stem Cells ; Liver Regeneration ; Liver Transplantation ; Liver* ; Mesenchymal Stromal Cells ; Regeneration ; Stem Cell Transplantation ; Stem Cells* ; Translational Medical Research

Herein, we report a case of primary myxoid leiomyoma of the liver. A 60-year-old woman complained of upper abdominal fullness. Computed tomography showed a solid tumor (8 cm) in the liver. The patient underwent right hepatectomy and histological findings from the resected specimen revealed scattered bland spindle cells in a background of exuberant myxoid material. The tumor cells were immunoreactive for smooth muscle actin and desmin. No other lesions were found elsewhere in the body. Thus, the tumor was diagnosed as a primary myxoid leiomyoma of the liver.
Actins ; Desmin ; Female ; Hepatectomy ; Humans ; Immunohistochemistry ; Leiomyoma* ; Liver* ; Middle Aged ; Muscle, Smooth ; Myxoma

Frequent screening for thyroid cancer has been suggested as a probable explanation for the observed high risk of thyroid cancer in nuclear power plant (NPP) areas. We aimed to compare thyroid cancer screening rates of residents living near NPPs to those of the general population. This study utilized data from two national survey-based studies in 2016 and in 2014, respectively, for residents (n = 1,200) living in administrative districts within 5 km of NPP sites as the interest group, and the general population (n = 228,712) including distantliving residents (n = 19,100) in administrative districts within 30 km of NPP sites as reference groups. We observed an increase in screening rates in residents near NPPs, which may lead to a higher possibility of thyroid cancer detection. Therefore, further epidemiological studies investigating radiation-induced thyroid cancer risk among residents near NPPs should be carefully designed and interpreted considering possible detection bias.

BACKGROUND/AIMS: Cancer is known to be a disease by many factors. However, specific results of reprogramming by pluripotency-related transcription factors remain to be scarcely reported. Here, we verified potential effects of pluripotent-related genes in hepatocellular carcinoma cancer cells. METHODS: To better understand reprogramming of cancer cells in different genetic backgrounds, we used four liver cancer cell lines representing different states of p53 (HepG2, Hep3B, Huh7 and PLC). Retroviral-mediated introduction of reprogramming related genes (KLF4, Oct4, Sox2, and Myc) was used to induce the expression of proteins related to a pluripotent status in liver cancer cells. RESULTS: Hep3B cells (null p53) exhibited a higher efficiency of reprogramming in comparison to the other liver cancer cell lines. The reprogrammed Hep3B cells acquired similar characteristics to pluripotent stem cells. However, loss of stemness in Hep3B-iPCs was detected during continual passage. CONCLUSIONS: We demonstrated that reprogramming was achieved in tumor cells through retroviral induction of genes associated with reprogramming. Interestingly, the reprogrammed pluripotent cancer cells (iPCs) were very different from original cancer cells in terms of colony shape and expressed markers. The induction of pluripotency of liver cancer cells correlated with the status of p53, suggesting that different expression level of p53 in cancer cells may affect their reprogramming.
Carcinoma, Hepatocellular ; Cell Line ; Genetic Background ; Induced Pluripotent Stem Cells* ; Liver Neoplasms* ; Pluripotent Stem Cells ; Transcription Factors ; Zidovudine

No abstract available.
Granular Cell Tumor*

PURPOSE: Although serosal invasion is a critical predisposing factor for peritoneal dissemination in advanced gastric cancer, the accuracy of preoperative assessment using routine imaging studies is unsatisfactory. This study was conducted to identify high-risk group for serosal invasion using preoperative factors in patients with advanced gastric cancer. MATERIALS AND METHODS: We retrospectively analyzed clinicopathological features of 3,529 advanced gastric cancer patients with Borrmann type I/II/III who underwent gastrectomy at Korea Cancer Center Hospital between 1991 and 2005. We stratified patients into low- (< or =40%), intermediate- (40~70%), and high-risk (>70%) groups, according to the probability of serosal invasion. RESULTS: Borrmann type, size, longitudinal and circumferential location, and histology of tumors were independent risk factors for serosal invasion. Most tumors of whole stomach location or encircling type had serosal invasion, so they belonged to high-risk group. Patients were subdivided into 12 subgroups in combination of Borrmann type, size, and histology. A subgroup with Borrmann type II, large size (> or =7 cm), and undifferentiated histology and 2 subgroups with Borrmann type III, large size, and regardless of histology belonged to high-risk group and corresponded to 25% of eligible patients. CONCLUSIONS: This study have documented high-risk group for serosal invasion using preoperative predictors. And risk stratification for serosal invasion through the combination with imaging studies may collaboratively improve the accuracy of preoperative assessment, reduce the number of eligible patients for further staging laparoscopy, and optimize therapeutic strategy for each individual patient prior to surgery.
Gastrectomy ; Humans ; Korea ; Laparoscopy ; Retrospective Studies ; Risk Factors ; Stomach ; Stomach Neoplasms

Adenoid basal carcinoma of the uterine cervix is rare tumors that have often been regarded as a single entity. 14 cases with adenoid basal carcinoma of the uterine cervix have been reported in the literature. We experienced a case of 36-year female with adenoid basal carcinoma of the uterine cervix. We report this case with a brief review of the literature.
Adenoids* ; Cervix Uteri* ; Female ; Humans

Background: This study aimed to evaluate the reliability and validity of the self-administered questionnaire for Korean radiation workers. Methods: From May 24, 2016, to June 30, 2017, 20,608 participants completed the questionnaire, providing information on sociodemographics, lifestyle, work history and practices, medical radiation exposure, and medical history, which was linked to the National Dose Registry and the National Cancer Registry. The validity of the questionnaire was evaluated using the responses of 20,608 workers, and reliability was evaluated using the responses of 3043 workers who responded to the survey twice. Results: Responses concerning demographic characteristics and lifestyle showed reliability with a moderate-to-high agreement (kappa: 0.43–0.99), whereas responses concerning occupation and medical radiation exposure had a wide range of agreement (kappa: 0.05–0.95), possibly owing to temporal variability during employment. Regarding validity, responses to the question about the first year of employment had an excellent agreement with the national registry (intraclass correlation coefficient = 0.9); however, responses on cancer history had a wide range of agreement (kappa: 0.22–0.85). Conclusion Although the reliability and validity of the questionnaire were not distinguished by demographic characteristics, they tended to be low among participants whose occupational radiation exposure was minimal. Overall, the information collected can be reliable for epidemiological studies; however, caution must be exercised when using information such as medical exposure and work practices, which are prone to temporal variability.