Panoply™ Human HDAC4 Knockdown Stable Cell Line

Blocking cancer cell metabolism by inhibiting glutaminase (GAC) is a promising strategy for inhibiting tumor progression. However, the mechanisms of GAC acetylation remain poorly understood. Here, researchers demonstrate that lysine acetylation is an important post-translational modification that inhibits GAC activity in non-small cell lung cancer (NSCLC). They found that Lys311 is a key acetylation site on GAC, which is deacetylated by the class II deacetylase HDAC4. Acetylation of Lys311 promotes the interaction of GAC with TRIM21, an E3 ubiquitin ligase of the tripartite motif (TRIM) family, thereby promoting K63-linked ubiquitination of GAC and inhibiting GAC activity. Furthermore, the GAC^K311Q mutation in A549 cells reduces cell proliferation and attenuates tumor malignancy. These findings reveal a novel mechanism by which acetylation and ubiquitination regulate GAC, a mechanism involved in the development and progression of non-small cell lung cancer.

HDAC4 activates GAC, an oncogene involved in the development and progression of various human cancers. Therefore, researchers investigated the effects of HDAC4 on the proliferation and migration of non-small cell lung cancer (NSCLC) cells. Overexpression of HDAC4 promoted the growth of H1299 and A549 cells (Figure 1A, B). Conversely, cell proliferation was inhibited in HDAC4 knockdown H1299 and A549 cells (Figure 1C, D). Colony formation assays showed similar results. HDAC4 overexpression promoted colony formation, while HDAC4 knockdown significantly reduced the colony-forming ability of NSCLC cells. To investigate whether HDAC4 promotes cell growth by regulating GAC, researchers overexpressed V5-tagged GAC in HDAC4 knockdown cells. Interestingly, overexpression of GAC partially rescued the proliferation defects in H1299 and A549 cells caused by HDAC4 knockdown (Figure 1E, F), suggesting that the biological function of HDAC4 is not limited to regulating GAC.

Next, the researchers evaluated the effect of HDAC4 on cell migration. The results showed that cell migration was significantly inhibited in HDAC4-knockdown H1299 and H292 cells (Figure 1G, H). Statistical analysis indicated that the "wound" in untreated H1299 and H292 cells was almost completely healed after 24 hours. In contrast, the degree of "wound" healing was significantly reduced in HDAC4-knockdown cells, with the migration rate of H1299 cells decreasing to 40.6% and that of H292 cells decreasing to 65.9%.

Figure 1. HDAC4 promoted cell proliferation and migration in NSCLC cells. (Wang T, et al., 2022)