Xue Wang1, Wen Sun1, Weifeng Shen2, Mingyang Xia1, Cheng Chen1, Daimin Xiang1, Beifang Ning3, Xiuliang Cui1, Hengyu Li1, Xiaofeng Li1, Jin Ding4, Hongyang Wang5. 1. The International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, 200438 Shanghai, China. 2. The Department of Hepatic Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, 200438 Shanghai, China. 3. The Department of Gastroenterology, Changzheng Hospital, 200003 Shanghai, China. 4. The International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, 200438 Shanghai, China; National Center for Liver Cancer, 201805 Shanghai, China. Electronic address: dingjin1103@163.com. 5. The International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, 200438 Shanghai, China; National Center for Liver Cancer, 201805 Shanghai, China. Electronic address: hywangk@vip.sina.com.
Abstract
BACKGROUND & AIMS: Emerging evidence has demonstrated the aberrant expression of long non-coding RNAs (lncRNAs) in various malignancies including HCC. However, the knowledge of cancer stem cell-related lncRNAs remains limited. METHODS: lnc-DILC (lncRNA downregulated in liver cancer stem cells (LCSCs)) was identified by microarray and validated by real-time PCR. The role of lnc-DILC in LCSCs was assessed both in vitro and in vivo. Pull down assay and oligoribonucleotides or oligodeoxynucleotides treatment were conducted to evaluate the interaction between lnc-DILC and interleukin-6 (IL-6) promoter. RESULTS: Depletion of lnc-DILC markedly enhanced LCSC expansion and facilitated HCC initiation and progression, whereas ectopic expression of lnc-DILC dramatically inhibited LCSC expansion. Mechanistically, lnc-DILC inhibited the autocrine IL-6/STAT3 signaling. The putative binding locus of lnc-DILC within IL-6 promoter was confirmed by pull down assay. Consistently, the oligoribonucleotide mimics and an oligodeoxynucleotide decoy of lnc-DILC abrogated the effects on IL-6 transcription, STAT3 activation and LCSC expansion triggered by lnc-DILC depletion and lnc-DILC overexpression. Moreover, our data suggested that lnc-DILC mediated the crosstalk between TNF-α/NF-κB signaling and IL-6/STAT3 cascade. Clinical investigation demonstrated the reduction of lnc-DILC in patient HCCs, and suggested the correlation between lnc-DILC levels and IL-6, EpCAM or CD24 expression. Decreased lnc-DILC expression in HCCs predicts early recurrence and short survival of patients, highlighting its prognostic value. CONCLUSIONS: lnc-DILC mediates the crosstalk between TNF-α/NF-κB signaling and autocrine IL-6/STAT3 cascade and connects hepatic inflammation with LCSC expansion, suggesting that lnc-DILC could be not only a potential prognostic biomarker, but also a possible therapeutic target against LCSCs.
BACKGROUND & AIMS: Emerging evidence has demonstrated the aberrant expression of long non-coding RNAs (lncRNAs) in various malignancies including HCC. However, the knowledge of cancer stem cell-related lncRNAs remains limited. METHODS: lnc-DILC (lncRNA downregulated in liver cancer stem cells (LCSCs)) was identified by microarray and validated by real-time PCR. The role of lnc-DILC in LCSCs was assessed both in vitro and in vivo. Pull down assay and oligoribonucleotides or oligodeoxynucleotides treatment were conducted to evaluate the interaction between lnc-DILC and interleukin-6 (IL-6) promoter. RESULTS: Depletion of lnc-DILC markedly enhanced LCSC expansion and facilitated HCC initiation and progression, whereas ectopic expression of lnc-DILC dramatically inhibited LCSC expansion. Mechanistically, lnc-DILC inhibited the autocrine IL-6/STAT3 signaling. The putative binding locus of lnc-DILC within IL-6 promoter was confirmed by pull down assay. Consistently, the oligoribonucleotide mimics and an oligodeoxynucleotide decoy of lnc-DILC abrogated the effects on IL-6 transcription, STAT3 activation and LCSC expansion triggered by lnc-DILC depletion and lnc-DILC overexpression. Moreover, our data suggested that lnc-DILC mediated the crosstalk between TNF-α/NF-κB signaling and IL-6/STAT3 cascade. Clinical investigation demonstrated the reduction of lnc-DILC in patient HCCs, and suggested the correlation between lnc-DILC levels and IL-6, EpCAM or CD24 expression. Decreased lnc-DILC expression in HCCs predicts early recurrence and short survival of patients, highlighting its prognostic value. CONCLUSIONS: lnc-DILC mediates the crosstalk between TNF-α/NF-κB signaling and autocrine IL-6/STAT3 cascade and connects hepatic inflammation with LCSC expansion, suggesting that lnc-DILC could be not only a potential prognostic biomarker, but also a possible therapeutic target against LCSCs.