Knockdown of ZFPL1 results in increased autophagy and autophagy-related cell death in NCI-N87 and BGC-823 human gastric carcinoma cell lines

Abstract

Macroautophagy, which will hereafter be referred to as autophagy, is an evolutionarily conserved process, during which cells recycle and remove damaged organelles and proteins in response to cellular stress. However, the mechanisms underlying the regulation of autophagy remain to be fully elucidated. The present study demonstrated that knockdown of zinc finger protein like 1 (ZFPL1) induces autophagy and increases autophagic cell death in NCI‑N87 and BGC‑823 human gastric carcinoma cell lines. To examine the role of ZFPL1 in gastric carcinoma cells, ZFPL1 expression was downregulated by lentiviral infection. Zinc finger domain‑FLAG was used to compete with ZFPL1 for golgin A2/GM130 binding. Autophagy was analyzed by red fluorescent protein‑microtubule‑associated protein 1A/1B‑light chain 3 (LC3) puncta, LC3I to LC3II conversion, and p62 expression. The results demonstrated that knockdown of ZFPL1 was able to significantly increase cell death rate. However, ZFPL1 knockdown exerted almost no effect on the expression of apoptosis‑associated markers, including B cell lymphoma 2 (Bcl‑2), Bcl‑x, Bcl‑2‑associated X protein, BH3 interacting domain death agonist, p53, and the classical caspase family members, caspase‑3, caspase‑8 and caspase‑9. An endogenous ZFPL1‑GM130 association was identified in NCI‑N87 cells and BGC‑823 cells by co‑immunoprecipitation. Furthermore, cell death was restricted following treatment of ZFPL1 knockdown cells with an autophagy inhibitor. Therefore, knockdown of ZFPL1 expression may induce cell death via autophagy, rather than apoptosis. These results suggest that ZFPL1 may serve an important role in regulating autophagy in NCI‑N87 and BGC‑823 cells.

Compartmentalized Proteomic Profiling Outlines the Crucial Role of the Classical Secretory Pathway during Recombinant Protein Production in Chinese Hamster Ovary Cells

“… 110 The O-glycosylation appears to be disturbed as well given that TMF1 maintains Golgi localization of GalNAc-T2 93 and knockdown of ZFPL1 decreases O-linked N-acetylglucosamine. 166 In this context, a carbohydrate analysis of mAb is necessary to confirm a disturbed glycosylation in detriment to O-glycan and complex N-glycan patterns in the higher producer cells. MAb N-glycosylation occurs mainly at Asn297 in the Fc region, modulating antibody effector functions through binding to Fcγ receptors and complement activation, whereas O-glycosylation occurs at serine and threonine residues without a consensus sequence.…”

“…Loss of PRKCD and ZFPL1 triggers autophagy in rat proximal tubular cells 168 , 169 and human gastric carcinoma cell lines. 166 On the other hand, overexpression of RAB32 increases the number of autophagosomes, whereas its knockdown leads to autophagy blockade. 170 , 171 SCFD1 is required for transport of lysosomal enzymes from ER to Golgi apparatus and, although its knockdown triggers induction of autophagosomes as a consequence of ER stress and UPR, autophagy does not occur in its absence because of the lack of lysosomal enzymatic activities.…”

“…GOLGB1 knockdown decreases protein concentration and induces mislocalization of many glycosyltransferases, such as B4GALT1, MGAT1, and ST6GAL1, and shifts N-glycans toward a high-mannose type in cancer cell lines . The O-glycosylation appears to be disturbed as well given that TMF1 maintains Golgi localization of GalNAc-T2 and knockdown of ZFPL1 decreases O-linked N-acetylglucosamine . In this context, a carbohydrate analysis of mAb is necessary to confirm a disturbed glycosylation in detriment to O-glycan and complex N-glycan patterns in the higher producer cells.…”

Comprehensive analysis of alternative splicing profiling reveals novel events associated with prognosis and the infiltration of immune cells in prostate cancer

“…SMAD4 loss is correlated with worse clinical outcomes, resistance to chemotherapy, and decreased immune infiltrate, supporting its use as a prognostic marker in patients with CRC (33). In gastric cancer, knocking down of ZFPL1 can significantly increase cell mortality via autophagy, not apoptosis (34).…”