Truncated oncoproteins of retroviruses and hepatitis B virus: A lesson in contrasts

Dysregulated microRNAs as a biomarker for diagnosis and prognosis of hepatitis B virus-associated hepatocellular carcinoma

“…Carboxyl-terminal truncated HBx proteins (Ct-HBx, also called HBxΔC or trHBx) are variants transcribed from the mutant HBV X gene whose 3′-end are deleted during HBV genome integration into the host cells. Ct-HBx plays a pivotal role in hepatocarcinogenesis[ 183 , 184 ]. Ct-HBx regulates specific miRNAs more effectively than full-length HBx (HBx-FL).…”

“…HBxD127 also remarkably increases miR-215 expression relative to HBx[ 185 ]. A possible explanation is that C-terminal truncation may affect the binding of HBx to cellular proteins, resulting in altered miRNA gene expression patterns in cells[ 184 ]. Notably, Ct-HBx directly binds to some miRNAs promotors, such as miR-26a and miR-29c, resulting in direct transcriptional suppression which HBx-FL is unable to induce.…”

HBV evolution and genetic variability: Impact on prevention, treatment and development of antivirals

“…The three envelope proteins are expressed from a single ORF (PreS1/PreS2/S) by utilization of alternative in-frame start codons (Heermann et al, 1984). The fourth ORF codes for the X protein (HBx) required for establishment and maintenance of infection and involved in hepatocarcinogenesis (Minarovits and Niller, 2019;Slagle and Bouchard, 2018) (Figure 1C).…”