GRP78/BiP determines senescence evasion cell fate after cisplatin-based chemotherapy

Zin Zin Ei,Pithi Chanvorachote,Maneewan Suksomtip,Chanida Vinayanuwattikun,Alisa Tubsuwan,Decha Pinkaew,Preedakorn Chunhacha,Kanuengnit Choochuay

doi:10.1038/s41598-021-01540-8

Abstract

Cisplatin (CDDP) induces senescence characterized by senescence-associated secretory phenotypes (SASP) and the unfolded protein response (UPR). In this study, we investigated the proteins related to the UPR during the senescence cell fate. Strikingly, we found that one of the critical ER-resident proteins, GRP78/BiP, was significantly altered. Here we show that GRP78 levels differentially expressed depending on non-small lung cancer subtypes. GRP78 indeed regulates the evasion of senescence in adenocarcinoma A549 cells, in which the increased GRP78 levels enable them to re-proliferate after CDDP removal. Conversely, GRP78 is downregulated in the senescence H460 cells, making them lacking senescence evasion capability. We observed that the translational regulation critically contributed to the GRP78 protein levels in CDDP-induces senescence. Furthermore, the increased GRP78 level during senescence confers resistance to senolytic drug, Bortezomib, as observed by a twofold increase in IC50 in A549 senescence cells compared to the wild-type. This observation is also consistent in the cells that have undergone genetic manipulation by transfection with pcDNA3.1(+)-GRP78/BiP plasmids and pSpCas9(BB)-2A-Puro containing guide RNA sequence targeting GRP78 exon 3 to induce the overexpression and downregulation of GRP78 in H460 cells, respectively. Our findings reveal a unique role of GRP78 on the senescence evasion cell fate and senolytic drug resistance after cisplatin-based chemotherapy.

Highlights

Cisplatin (CDDP) induces senescence characterized by senescence-associated secretory phenotypes (SASP) and the unfolded protein response (UPR)
We firstly investigate the IC50 of CDDP in 2 non-small cell lung cancer (NSCLC) cell lines including H460, A549 cells by treating the cells with various doses of CDDP and measuring the cell viability after 24 h treatment (Fig. 1a)
Among various doses of CDDP tested, CDDP 5 μM causes the cell proliferation inhibition over the 6 days in two cell lines used in this study, suggesting that they are all of comparable sensitivity to CDDP (Fig. 1b)

Summary

Introduction

Cisplatin (CDDP) induces senescence characterized by senescence-associated secretory phenotypes (SASP) and the unfolded protein response (UPR). CDDP treatment induces robust senescence-associated genes including p53, p16 as well as DNA damage markers such as γH2AX, DDB27 These senescence cells elicit non-cellautonomous effects by producing a mixture of either soluble and insoluble factors which can be referred to as senescence-associated secretory phenotype (SASP). When considering in the context of CDDP induces senescence, GRP78 was downregulated in the ovarian cancer model, A27806 This finding was performed in a single cell line in which the extrapolation into more diverse types of cancers may be limited. We demonstrated that during the senescence cell fate, GRP78 may be expressed differentially in a different subtype of NSCLC cell lines This differential expression contributed to a different ability to evade senescence as well as the response to the senolytic drug, Bortezomib. This finding provides more insight into the role of GRP78 in senescence cells, in which it might be a potential target to eliminate senescence cancer cells

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