Characterization of sphere-forming HCT116 clones by whole RNA sequencing

PURPOSE: To determine CD133+ cells defined as cancer stem cells (CSCs) in colon cancer, we examined whether CD133+ clones in HCT116 demonstrate known features of CSCs like sphere-forming ability, chemodrug-resistance, and metastatic potential. METHODS: Magnetic cell isolation and cell separation demonstrated that <1% of HCT116 cells expressed CD133, with the remaining cells being CD133- clones. In colon cancer cells, radioresistance is also considered a CSC characteristic. We performed clonogenic assay using 0.4 Gy γ-irradiation. RESULTS: Interestingly, there were no differences between HCT116 parental and HCT116 CD133+ clones when the cells comprised 0.5% of the total cells, and CD133- clone demonstrated radiosensitive changes compared with parental and CD133+ clones. Comparing gene expression profiles between sphere-forming and nonforming culture conditions of HCT116 subclones by whole RNA sequencing failed to obtain specific genes expressed in CD133+ clones. CONCLUSION: Despite no differences of gene expression profiles in monolayer attached culture conditions of each clone, sphere-forming conditions of whole HCT116 subclones, parental, CD133+, and CD133- increased 1,761 coding genes and downregulated 1,384 genes related to CSCs self-renewal and survival. Thus, spheroid cultures of HCT116 cells could be useful to expand colorectal CSCs rather than clonal expansion depending on CD133 expressions.

A Preliminary Study for the Standardization of the Korean Version of the GBS Scale

OBJECTIVES: The Gottfries-Brane-Steen (GBS) Scale was developed to assess cognition, emotion, activities of daily living (ADL), and behavioral and psychological symptoms of dementia (BPSD) among patient with dementia. The aim of the present study was to provide preliminary evidences for the standardization of the Korean Version of the GBS Scale. METHODS: The GBS scale was administered among caregivers of 31 patients with dementia. Reliability and validity analysis were performed, and factor structure was explored. RESULTS: The internal reliabilities using Cronbach's alpha of the four subscales of the GBS were relatively high (intellectual impairment : 0.954, emotional impairment : 0.860, impairment of ADL performance : 0.877, some symptoms common in dementia : 0.847). The cognitive and ADL subscales of the GBS significantly correlated with the Korean mini-mental state examination and Barthel ADL Index (r=-0.648, r=-0.739, p<.01, respectively), whereas the emotion and BPSD subscales did not correlated with the Korean form of geriatric depression scale and Korean version of the Neuropsychiatric inventory, respectively. Factor analysis showed that the GBS scale was comprised of three factors unlike original article which had reported four factors of the scale. CONCLUSION: Although internal reliabilities and concurrent validities were relatively high, a factor analysis raised questions concerning the construct validity of the GBS scale.