Co-expression of RelA/p65 and ACTN4 induces apoptosis in non-small lung carcinoma cells

Abstract

Alpha-actinin 4 (ACTN4) is an actin-binding protein of the spectrin superfamily. ACTN4 is found both in the cytoplasm and nucleus of eukaryotic cells. The main function of cytoplasmic ACTN4 is stabilization of actin filaments and their binding to focal contacts. Nuclear ACTN4 takes part in the regulation of gene expression following by activation of certain transcription factors, but the mechanisms of regulation are not completely understood. Our previous studies have demonstrated the interaction of ACTN4 with the RelA/p65 subunit of NF-kappaB factor and the effect on its transcriptional activity in A431 and HEK293T cells. In the present work, we investigated changes in the composition of nuclear ACTN4-interacting proteins in non-small cell lung cancer cells H1299 upon stable RELA overexpression. We showed that ACTN4 was present in the nuclei of H1299 cells, regardless of the RELA expression level. The presence of ectopic RelA/p65 in H1299 cells increased the number of proteins interacting with nuclear ACTN4. Stable expression of RELA in these cells suppressed cell proliferation, which was further affected by simultaneous ACTN4 overexpression. We detected no significant effect on cell cycle but the apoptosis rate was increased in cells with a double RELA/ACTN4 overexpression. Interestingly, when expressed individually ACTN4 promoted proliferation of lung cancer cells. Furthermore, the bioinformatics analysis of gene expression in lung cancer patients suggested that overexpression of ACTN4 correlated with poor survival prognosis. We hypothesize that the effect of RELA on proliferation and apoptosis of H1299 cells can be mediated via affecting the interactome of ACTN4.

ACTN4 Promotes the Proliferation, Migration, Metastasis of Osteosarcoma and Enhances its Invasive Ability through the NF-κB Pathway

“…Studies have shown that aberrantly activated p65 (RelA) contributes to tumor development and progression [19,20]. In addition, the existence of co-immunoprecipitation between p65 and ACTN4 in non-small lung carcinoma cells has been reported [21]. Our study will further verify whether ACTN4 affects the progression of OS through the NF-κB pathway.…”

“…The activation of the NF-κB subunit P65 promotes the development of urothelial cancer and other tumors [28]. However, some researchers have found that P65 inhibits the proliferation of the lung cancer cell line H1299, and that overexpression of ACTN4 enhances this inhibitory effect [21]. Obviously, these two conclusions are in conflict with each other.…”

Ceramide Pathway Regulators Predict Clinical Prognostic Risk and Affect the Tumor Immune Microenvironment in Lung Adenocarcinoma

“…RELA, also known as p65, is one of the most common NF-kB subunits, and is involved in the classical NF-kB pathway (39). Previous research has demonstrated that RELA interacts with Alpha-actinin 4 (ACTN4) to induce proliferation and apoptosis in NSCLC cells (40). Furthermore, the nuclear overexpression of RELA was found to be significantly associated with a poor prognosis in patients with diffuse large B-cell lymphoma.…”

Functional Characterization and Proteomic Analysis of Porcine Deltacoronavirus Accessory Protein NS7

“…Since ACTN4 resides in both the cytoplasm and the nucleus of eukaryotic cells, it has dual roles; the cytoplasmic and nuclear functions [68]. The former mainly involves actin filament organization as described above, while the latter takes part in the regulation of gene expression by the activation of various transcription factors, including nuclear factor-κB (NF-κB).…”

“…The former mainly involves actin filament organization as described above, while the latter takes part in the regulation of gene expression by the activation of various transcription factors, including nuclear factor-κB (NF-κB). The transcriptional regulatory function is independent of the cytoskeletal functions associated with cytoplasmic actin binding [53,[68][69][70]. Nuclear factor-κB (NF-κB) is a family of transcription factors that regulate immune responses, cell proliferation, apoptosis, and differentiation, through controlling the synthesis of target genes encoding pro-inflammatory cytokines, chemokines, and adhesion molecules [71,72].…”