YAP inhibits autophagy and promotes progression of colorectal cancer via upregulating Bcl-2 expression.

Colorectal cancer (CRC) is one of the most aggressive and lethal cancers. The role of autophagy in the pathobiology of CRC is intricate, with opposing functions manifested in different cellular contexts. The Yes-associated protein (YAP), a transcriptional coactivator inactivated by the Hippo tumor-suppressor pathway, functions as an oncoprotein in a variety of cancers. In this study, we found that YAP could negatively regulate autophagy in CRC cells, and consequently, promote tumor progression of CRC in vitro and in vivo. Mechanistically, YAP interacts with TEAD forming a complex to upregulate the transcription of the apoptosis-inhibitory protein Bcl-2, which may subsequently facilitate cell survival by suppressing autophagy-related cell death; silencing Bcl-2 expression could alleviate YAP-induced autophagy inhibition without affecting YAP expression. Collectively, our data provide evidence for YAP/Bcl-2 as a potential therapeutic target for drug exploration against CRC.

Histone lysine demethylase KDM5B maintains chronic myeloid leukemia via multiple epigenetic actions.

The histone lysine demethylase KDM5 family is implicated in normal development and stem cell maintenance by epigenetic modulation of histone methylation status. Deregulation of the KDM5 family has been reported in various types of cancers, including hematological malignancies. However, their transcriptional regulatory roles in the context of leukemia remain unclear. Here, we find that KDM5B is strongly expressed in normal CD34+ hematopoietic stem/progenitor cells and chronic myeloid leukemia (CML) cells. Knockdown of KDM5B in K562 CML cells reduced leukemia colony-forming potential. Transcriptome profiling of KDM5B knockdown K562 cells revealed the deregulation of genes involved in myeloid differentiation and Toll-like receptor signaling. Through the integration of transcriptome and ChIP-seq profiling data, we show that KDM5B is enriched at the binding sites of the GATA and AP-1 transcription factor families, suggesting their collaborations in the regulation of transcription. Even though the binding of KDM5B substantially overlapped with H3K4me1 or H3K4me3 mark at gene promoters, only a small subset of the KDM5B targets showed differential expression in association with the histone demethylation activity. By characterizing the interacting proteins in K562 cells, we discovered that KDM5B recruits protein complexes involved in the mRNA processing machinery, implying an alternative epigenetic action mediated by KDM5B in gene regulation. Our study highlights the oncogenic functions of KDM5B in CML cells and suggests that KDM5B is vital to the transcriptional regulation via multiple epigenetic mechanisms.

[Expression Levels of JARID1B, Hes1 and MMP-9 Genes in CML Patients Treated with Imatinib Mesylate].

OBJECTIVE: To explore the relationship between the expression levels of JARID1B,Hes1 and MMP-9 genes and the stages of chronic myelogenous leukemia(CML) and the curative effect of imatinib mesylate (IM). METHODS: Peripheral blood samples of 15 cases of CML in chronic phase and 10 cases of CML in progressive phase were collected from the Hematology Department of Taihe Hospital affiliated to Hubei University of Medicine and 15 cases of healthy people in the Physical Examination Center. CML patients were divided into effective group and ineffective group based on the efficacy after treatment with IM, then real-time PCR was used to detect the expression levels of JARID1B, Hes1 and MMP-9 mRNA, finally, the differences in the level of gene expression and their correlations with CML stages and IM curative efficacy were analysed. RESULTS: The expression levels of Hes1 and MMP-9 in initially diagnosed patients in chronic and progressive phase without IM treatment were significantly higher than those of health people（P＜0.05）. There was no significant difference in the expression level of JARID1B between chronic phase patients and health people（P＞0.05）, but the expression level of JARID1B in the progressive phase patients was higher than that of health people （P＜0.05）. The expression levels of JARID1B and Hes1 in the IM-effective group were not significantly different from those in the IM-ineffective group (P=0.85,P=0.82）, while the expression level of MMP-9 in the IM-effective group [JP2]was significantly lower than that in the IM-ineffective group（P＜0.05）. CONCLUSION: The expression levels of JARID1B Hes1 and MMP-9 relate with the different phase of CML; The expression levels of JARID1B and Hes1 have not significant relationship with IM curative efficacy, the MMP-9 gene expression level relates with IM curative efficacy.