TALENs-directed knockout of the full-length transcription factor Nrf1? that represses malignant behaviour of human hepatocellular carcinoma (HepG2) cells.

ABSTRACT: The full-length Nrf1? is processed into distinct isoforms, which together regulate genes essential for maintaining cellular homeostasis and organ integrity, and liver-specific loss of Nrf1 in mice results in spontaneous hepatoma. Herein, we report that the human constitutive Nrf1?, rather than smaller Nrf1?/?, expression is attenuated or abolished in the case of low-differentiated high-metastatic hepatocellular carcinomas. Therefore, Nrf1? is of importance in the physio-pathological origin and development, but its specific pathobiological function(s) remains elusive. To address this, TALENs-directed knockout of Nrf1?, but not Nrf1?/?, is created in the human hepatocellular carcinoma (HepG2) cells. The resulting Nrf1?(-/-) cells are elongated, with slender spindle-shapes and enlarged gaps between cells observed under scanning electron microscope. When compared with wild-type controls, the invasive and migratory abilities of Nrf1?(-/-) cells are increased significantly, along with the cell-cycle G2-M arrest and S-phase reduction, as accompanied by suppressed apoptosis. Despite a modest increase in the soft-agar colony formation of Nrf1?(-/-) cells, its loss-of-function markedly promotes malgrowth of the subcutaneous carcinoma xenograft in nude mice with hepatic metastasis. Together with molecular expression results, we thus suppose requirement of Nrf1? (and major derivates) for gene regulatory mechanisms repressing cancer cell process (e.g. EMT) and malignant behaviour (e.g. migration).

SUBMITTER: Ren Y 

PROVIDER: S-EPMC4827396 | biostudies-other | 2016 Apr

REPOSITORIES: biostudies-other