High MYBL2 expression and transcription regulatory activity is associated with poor overall survival in patients with hepatocellular carcinoma.

In this study, we aimed to assess the association between MYBL2 expression/transcription regulatory activity (TRA) and overall survival (OS) in patients with primary hepatocellular carcinoma (HCC) and to explore the factors related to B-Myb TRA. Bioinformatic analysis was performed based on data from the cancer genome atlas-liver hepatocellular carcinoma (TCGA-LIHC) and the human protein atlas (HPA). The death group in TCGA-LIHC had significantly higher MYBL2 RNA and exon expression than the censor group. The high MYBL2 RNA and exon expression groups had significantly worse OS (P<0.01). Univariate and multivariate analysis confirmed that high MYBL2 expression was an independent prognostic factor of unfavourable OS (HR=1.591, 95%CI: 1.119-2.262, P=0.01). One hundred and fourteen out of 188 primary HCC cases in TCGA-LIHC had elevated transcription of B-Myb's downstream genes. High B-Myb TRA was associated with poor OS (P=0.013). Elevated expression of MYBL2, LIN9, LIN52 and FOXM1 were related to the higher TRA of B-Myb in HCC. High MYBL2 expression/TRA are associated with inferior OS in patients with primary HCC. Increased expression of MYBL2, LIN9, LIN52 and FOXM1 are related to higher TRA of B-Myb in HCC.

Guan Z ，Cheng W ，Huang D ，Wei A ... -  《Current Research in Translational Medicine》

Activation of v-Myb avian myeloblastosis viral oncogene homolog-like2 (MYBL2)-LIN9 complex contributes to human hepatocarcinogenesis and identifies a subset of hepatocellular carcinoma with mutant p53.

Up-regulation of the v-Myb avian myeloblastosis viral oncogene homolog-like2 B-Myb (MYBL2) gene occurs in human hepatocellular carcinoma (HCC) and is associated with faster progression of rodent hepatocarcinogenesis. We evaluated, in distinct human HCC prognostic subtypes (as defined by patient survival length), activation of MYBL2 and MYBL2-related genes, and relationships of p53 status with MYBL2 activity. Highest total and phosphorylated protein levels of MYBL2, E2F1-DP1, inactivated retinoblastoma protein (pRB), and cyclin B1 occurred in HCC with poorer outcome (HCCP), compared to HCC with better outcome (HCCB). In HCCP, highest LIN9-MYBL2 complex (LINC) and lowest inactive LIN9-p130 complex levels occurred. MYBL2 positively correlated with HCC genomic instability, proliferation, and microvessel density, and negatively with apoptosis. Higher MYBL2/LINC activation in HCC with mutated p53 was in contrast with LINC inactivation in HCC harboring wildtype p53. Small interfering RNA (siRNA)-mediated MYBL2/LINC silencing reduced proliferation, induced apoptosis, and DNA damage at similar levels in HCC cell lines, irrespective of p53 status. However, association of MYBL2/LINC silencing with doxorubicin-induced DNA damage caused stronger growth restraint in p53(-/-) Huh7 and Hep3B cells than in p53(+/+) Huh6 and HepG2 cells. Doxorubicin triggered LIN9 dissociation from MYBL2 in p53(+/+) cell lines and increased MYBL2-LIN9 complexes in p53(-/-) cells. Doxorubicin-induced MYBL2 dissociation from LIN9 led to p21(WAF1) up-regulation in p53(+/+) but not in p53(-/-) cell lines. Suppression of p53 or p21(WAF1) genes abolished DNA damage response, enhanced apoptosis, and inhibited growth in doxorubicin-treated cells harboring p53(+/+) . We show that MYBL2 activation is crucial for human HCC progression. In particular, our data indicate that MYBL2-LIN9 complex integrity contributes to survival of DNA damaged p53(-/-) cells. Thus, MYBL2 inhibition could represent a valuable adjuvant for treatments against human HCC with mutated p53.

Calvisi DF ，Simile MM ，Ladu S ，Frau M ，Evert M ，Tomasi ML ，Demartis MI ，Daino L ，Seddaiu MA ，Brozzetti S ，Feo F ，Pascale RM ... -  《-》

Mybl2 expression is under genetic control and contributes to determine a hepatocellular carcinoma susceptible phenotype.

MYBL2 is implicated in human malignancies and over expressed in hepatocellular carcinoma (HCC). We investigated Mybl2 role in the acquisition of susceptibility to HCC and tumor progression. MYBL2 mRNA and protein levels were evaluated by quantitative RT-PCR and immunoblotting, respectively. MYBL2 expression in HCC cell lines was controlled through MYBL2 cDNA or anti-MYBL2 siRNA transfection. Gene expression profile of cells transfected with MYBL2 was analyzed by microarray. Low induction of Mybl2 and its target Clusterin mRNAs, in low-grade dysplastic nodules (DN), progressively increased in fast growing high-grade DN and HCC of F344 rats, susceptible to hepatocarcinogenesis, whereas no/lower increases occurred in slow growing lesions of resistant BN rats. Highest Mybl2 protein activation, prevalently nuclear, occurred in F344 than BN lesions. Highest Mybl2, Clusterin, Cdc2, and Cyclin B1 expression occurred in fast progressing DN and HCC of E2f1 transgenics, compared to c-Myc transgenics, and anti-Mybl2 siRNA had highest anti-proliferative and apoptogenic effects in cell lines from HCC of E2f1 transgenics. MYBL2 transfected HepG2 and Huh7 cells exhibited increased cell proliferation and G1-S and G2-M cell cycle phases. The opposite occurred when MYBL2 was silenced by specific siRNA. MYBL2 transfection in Huh7 cells led to upregulation of genes involved in signal transduction, cell proliferation, cell motility, and downregulation of oncosuppressor and apoptogenic genes. mybl2 expression and activation are under genetic control. Mybl2 upregulation induces fast growth and progression of premalignant and malignant liver, through cell cycle deregulation and activation of genes and pathways related to tumor progression.

Frau M ，Ladu S ，Calvisi DF ，Simile MM ，Bonelli P ，Daino L ，Tomasi ML ，Seddaiu MA ，Feo F ，Pascale RM ... -  《-》

Identification of a five-long non-coding RNA signature to improve the prognosis prediction for patients with hepatocellular carcinoma.

Zhao QJ ，Zhang J ，Xu L ，Liu FF ... -  《-》

Elevated expression of the MYB proto-oncogene like 2 (MYBL2)-encoding gene as a prognostic and predictive biomarker in human cancers.

Xin Z ，Li Y ，Meng L ，Dong L ，Ren J ，Men J ... -  《-》