Tristetraprolin regulates phagocytosis through interaction with CD47 in head and neck cancer

CD47 is expressed in all human cancer cells, including head and neck cancer, and initiates a signaling cascade to inhibit macrophage phagocytosis. However, the mechanism underlying CD47 overexpression has not been elucidated in radioresistant head and neck cancer. The present study demonstrated that decreased Tristetraprolin (TTP) expression induced a sustained overexpression of CD47 using reverse transcription‑quantitative PCR and western blotting, and that CD47 overexpression prevented phagocytosis using a phagocytosis assay in a radioresistant HN31R cell line. Subsequently, using TTP transfection, RNA interference, duel‑luciferase assay and EMSA, it was revealed that TTP transfection enhanced phagocytosis through degradation of CD47 mRNA by directly binding to CD47 AREs within the CD47 3'UTR. Based on our previous study, methyla‑tion‑specific PCR and western blotting revealed that DNMT1 was overexpressed in radioresistant HN31R cell line and TTP expression was decreased epigenetically by DMNT1 associ‑ated DNA methylation. Overall, these findings provided novel insight into the role of TTP as a biomarker of CD47‑positive head and neck cancer patients.Maste

The Relation between the Social Network of the Female University Graduates and the Job Search Activity

본 연구는 대졸 여성들의 구직경로와 취업을 위해 동원한 사회적 관계망의 특성을 살펴보고 이것이 취업결과 간에 차이를 가져오는지 분석하였다. 우선, 구직경로를 보면 성별, 대학서열에 상관없이 대부분의 대졸자들이 구직정보 채널로 인터넷을 가장 많이 활용했지만 실제 구직경로는 성별, 여성집단 내 대학서열에 따라 차이를 보였다. 한편, 대졸 여성들의 사회적 관계망 특성을 보면, 대부분 대졸 이상의 학력을 지니고 자신의 경제적 지위와 비슷한 남성이 주류를 이루지만 연결강도는 여성 집단 내 대학서열에 따라 달라졌다. 그리고 비슷한 사회적 관계망을 구직과정에서 동원했어도 협력자로부터 받은 도움유형은 성별에 따라 달랐다. 이를 통해 대졸 여성의 구직과정은 젠더화 된 사회적 관계망이 개입되는 역동적 과정이라 하겠다.The purpose of this study is to analyze that the social network of female university graduates affect their job search process and job. This study intends to analyze that the female university graduates' job search activity is influenced by discriminate approach and utilization of social network along hakbol and sexism. For this study, the sample consisted of 293 persons who graduated from universities in Seoul from 2003 to 2004. The results of this study are as follows : First, there is a difference between the most used job search channel and the most successful job search channel by university hierarchy and gender. And the effect of institutional social network differs between genders. Secondly, the social network that female university graduates use to obtain job information is characterized by strong ties with university friends who are similar to respondents' economic position and educational level. Thirdly, these characters are interrelated with the information by their helpers and the job results

EPHA3 Contributes to Epigenetic Suppression of PTEN in Radioresistant Head and Neck Cancer

EPHA3, a member of the EPH family, is overexpressed in various cancers. We demonstrated previously that EPHA3 is associated with radiation resistance in head and neck cancer via the PTEN/Akt/EMT pathway; the inhibition of EPHA3 significantly enhances the efficacy of radiotherapy in vitro and in vivo. In this study, we investigated the mechanisms of PTEN regulation through EPHA3-related signaling. Increased DNA methyltransferase 1 (DNMT1) and enhancer of zeste homolog 2 (EZH2) levels, along with increased histone H3 lysine 27 trimethylation (H3K27me3) levels, correlated with decreased levels of PTEN in radioresistant head and neck cancer cells. Furthermore, PTEN is regulated in two ways: DNMT1-mediated DNA methylation, and EZH2-mediated histone methylation through EPHA3/C-myc signaling. Our results suggest that EPHA3 could display a novel regulatory mechanism for the epigenetic regulation of PTEN in radioresistant head and neck cancer cells