KB-68A7.1 Inhibits Hepatocellular Carcinoma Development Through Binding to NSD1 and Suppressing Wnt/β-Catenin Signalling

Abstract

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies with extremely poor prognosis. Therefore, revealing the critical molecules involved in HCC progression and prognosis is urgently needed. In this study, through combining public dataset and our cohort, we found a novel prognosis-related long non-coding RNA KB-68A7.1 in HCC. KB-68A7.1 was lowly expressed in HCC, whose low expression was associated with large tumour size, aggressive clinical characteristic, and poor survival. Gain- and loss-of-function assays demonstrated that KB-68A7.1 restricted HCC cellular proliferation, induced HCC cellular apoptosis, and suppressed HCC cellular migration and invasion in vitro. Xenograft assays demonstrated that KB-68A7.1 suppressed HCC tumour growth and metastasis in vivo. These functional assays suggested KB-68A7.1 as a tumour suppressor in HCC. Histone methyltransferase nuclear receptor binding SET domain-containing protein 1 (NSD1) was found to bind to KB-68A7.1. KB-68A7.1 was mainly distributed in the cytoplasm. The binding of KB-68A7.1 to NSD1 sequestrated NSD1 in the cytoplasm, leading to the reduction in nuclear NSD1 level. Through decreasing nuclear NSD1 level, KB-68A7.1 reduced di-methylation of histone H3 at lysine 36 (H3K36me2) and increased tri-methylation of histone H3 at lysine 27 (H3K27me3) at the promoter of WNT10B, a target of NSD1. Thus, KB-68A7.1 repressed WNT10B transcription. The expression of WNT10B was negatively correlated with that of KB-68A7.1 in HCC tissues. Through repressing WNT10B, KB-68A7.1 further repressed Wnt/β-catenin signalling. Functional rescue assays showed that overexpression of WNT10B reversed the tumour-suppressive roles of KB-68A7.1, whereas the oncogenic roles of KB-68A7.1 depletion were abolished by Wnt/β-catenin signalling inhibitor. Overall, this study identified KB-68A7.1 as a lowly expressed and prognosis-related lncRNA in HCC, which suppressed HCC progression through binding to NSD1 and repressing Wnt/β-catenin signalling.

The role of WNT10B in physiology and disease: A 10-year update

“…Furthermore, overexpression of KB-68A7.1 reduced proliferation, migration, invasion, and increased apoptosis rates, whereas WNT10B overexpression attenuated these effects. These results suggest a mechanism in which KB-68A7.1 functions as a tumor suppressor by sequestering NSD1 to the cytoplasm and inhibiting the transcription of WNT10B ( Zhang S. et al, 2021 ) .…”

“…In vivo , WNT10B knockdown and NSD1 knockout were sufficient to reduce tumor volume and weight, and the combination knockdown/knockout further suppressed tumor volume and weight and reduced pulmonary metastasis significantly ( Zhang et al, 2019 ). Using The Cancer Genome Atlas Liver Hepatocellular Carcinoma dataset, Zhang S. et al (2021) identified the lncRNA KB-68A7.1, which inversely correlated with HCC prognosis. In their model system, they found that expression of KB-68A7.1 reduced the demethylation of histone 3 at lysine 36 (H3K36me2) and increased histone 3 lysine 27 trimethylation (H3K27me3) at the WNT10B promoter to decrease WNT10B expression.…”

Mitochondrial respiration during normothermic liver machine perfusion predicts clinical outcome

“…The following immunohistochemical stainings were applied using commercially available and validated antibodies: CD3 (mouse monoclonal anti-CD3, dilution 1:100, Cat# MA1-80469, RRID: AB_928106 , ThermoFisher, Waltham, MA, USA), CD68 (mouse monoclonal anti-CD68, Cat# MA5-13324, RRID: AB_10987212 , ThermoFisher, Waltham, MA, USA), 24 CD20 (mouse monoclonal anti-CD20, dilution 1:100, Cat# sc-70582, RRID: AB_1120279 , Santa Cruz Biotechnology, Dallas, TX, USA), Toll-like receptor 4 (TLR4; mouse monoclonal anti-TLR4, dilution 1:200, Cat# ab22048, RRID: AB_446735 , Abcam, Cambridge, UK), cleaved caspase 3 (CCasp3; polyclonal anti-CCasp3, dilution 1:400, Cat# 9661, RRID: AB_2341188 , Cell Signaling Technology, Danvers, MA, USA). 25 Scoring was based on the H-Score previously described elsewhere. 26 …”

Structural and functional specificity of H3K36 methylation

“…NSD1 promotes the progression of acute myeloid leukemia, multiple myeloma, and lung cancer, as well as cancer cell migration and invasion in hepatocellular carcinoma (HCC), pediatric glioma, and breast cancer [ 90 – 95 ]. The carcinogenic potential of NSD1 is mediated via activation of Wnt/β-catenin signaling [ 90 , 94 ].…”