Lung cancer is the leading cause of cancer death worldwide. 85 % of lung cancers are categorized by their histological types as a non-small cell lung cancer (NSCLC) subtype. While the MED23 subunit of the mediator complex has been implicated in lung cancer development, the precise underlying mechanism remains unclear. Our research indicates that elevated MED23 expression is linked to reduced overall survival rates in NSCLC. Depletion of MED23 triggers premature senescence in NSCLC cells. Furthermore, through co-IP and mass spectrometry analyses, we have identified BCLAF1 as a binding partner of MED23, with subsequent confirmation via PLA assays. Subsequently, NUPR1, a transcriptional cofactor known to induce premature senescence in lung cancer cells by disrupting autophagic processes, was validated as a downstream target of the MED23/BCLAF1 complex through RNA-seq and ChIP assays. Thus, the interaction between MED23 and BCLAF1 regulates NUPR1 expression, impacting autophagic flux and leading to premature senescence in NSCLC cells.

To support cellular homeostasis and mitigate chemotherapeutic stress, cancer cells must gain a series of adaptive intracellular processes. Here we identify that NUPR1, a tamoxifen (Tam)-induced transcriptional coregulator, is necessary for the maintenance of Tam resistance through physical interaction with ESR1 in breast cancers. Mechanistically, NUPR1 binds to the promoter regions of several genes involved in autophagy process and drug resistance such as BECN1, GREB1, RAB31, PGR, CYP1B1, and regulates their transcription. In Tam-resistant ESR1 breast cancer cells, NUPR1 depletion results in premature senescence in vitro and tumor suppression in vivo. Moreover, enforced-autophagic flux augments cytoplasmic vacuolization in NUPR1-depleted Tam resistant cells, which facilitates the transition from autophagic survival to premature senescence. Collectively, these findings suggest a critical role for NUPR1 as a transcriptional coregulator in enabling endocrine persistence of breast cancers, thus providing a vulnerable diagnostic and/or therapeutic target for endocrine resistance.

Single-domain antibody (sdAb) holds the promising strategies for diverse research and translational applications. Here, we describe a method for the adaptation of the in situ proximity ligation assay (isPLA) followed by sequencing (isPLA-seq) to facilitate screening of a high-sensitive, high-throughput sdAb library for a given protein at subcellular and single-cell resolution. Based on the sequence of complementarity-determining region 3 (CDR3), the recombinant sdAb can be produced for in vitro and in vivo utilities. This method provides a general means to identify the functional measure of sdAb and its complementary epitopes and its potential applications to investigate cellular processes.

Anoikis (detachment-induced cell death) is a specific type of programmed cell death which occurs in response to the loss of the correct extracellular matrix connections. Anoikis resistance is an important mechanism in cancer invasiveness and metastatic behavior. Autophagy, on the other hand, involves the degradation of damaged organelles and the recycling of misfolded proteins and intracellular components. However, the intersection of these two cellular responses in lung cancer cells has not been extensively studied. Here, we identified that upon matrix deprivation, the lymphocyte lineage-specific Ets transcription factor SPIB was activated and directly enhancedSNAP47transcription in certain lung cancer cells. Loss of attachment-induced autophagy significantly increased anoikis resistance by SPIB activation. Consistent with this function,SPIBdepletion by short hairpin RNA abrogatedSNAP47transcriptional activation upon matrix deprivation. Therefore, these data delineate an important role of SPIB in autophagy-mediated anoikis resistance in lung cancer cells. Accordingly, these findings suggest that manipulating SPIB-regulated pathwaysin vivoand evaluating the impact of anoikis resistance warrant further investigation. Database RNA sequencing and ChIP sequencing data are available in Gene Expression Omnibus database under the accession numbers and , respectively.

Nuclear protein 1 (NUPR1)/p8, a transcriptional regulator, has the ability to facilitate lung cancer cell survival. Adeno-associated virus (AAV)-based vectors are efficient vehicles for gene transfer and expression. In this study, an AAV-mediated NUPR1 shRNA vector was constructed that effectively inhibited the expression of NUPR1 in a tumor xenograft model derived from lung adenocarcinoma A549 cells. Trifluoperazine (TFP), which is an antipsychotic drug, has the ability to bind to NUPR1 and mimic NUPR1 deficiency in cancer cells. It was also found that the combination of TFP and AAV-mediated NUPR1 shRNA delivery led to significant tumor growth inhibition in nude mice bearing human lung cancer xenografts. Moreover, AAV-mediated NUPR1 shRNA therapy induced premature senescence in vitro and in vivo. Collectively, the findings of this study suggest a putative role for the combination of AAV-NUPR1 shRNA and TFP in lung cancer therapy.

Autophagy is a lysosome-dependent catabolic process. Both extra- and intra-cellular components are engulfed in autophagic vacuoles and degraded to simple molecules, such as monosaccharides, fatty acids and amino acids. Then, these molecules can be further used to produce ATP through catabolic reactions and/or provide building blocks for the synthesis of essential proteins. Therefore, we consider autophagy a critical and fine-tuned process in maintaining energy homeostasis. The complicated relationships between autophagy and energy metabolism have raised broad interest and have been extensively studied. In this chapter, we summarize the relationships enabling autophagy to control or modulate energy metabolism and allowing metabolic pathways to regulate autophagy. Specifically, we review the correlations between autophagy and energy homeostasis in terms of oxidative phosphorylation, reactive oxygen species in mitochondria, glycolysis, metabolism of glycogen and protein, and so on. An understanding of the role of autophagy in energy homeostasis could help us better appreciate how autophagy determines cell fate under stressful conditions or pathological processes.

Autophagy, which is one of the most important ways to maintain cell homeostasis plays an important regulatory role in cell survival and death. Currently, it is agreed that autophagy promotes or inhibits cell death depending on the internal and external environment and cell type. On the one hand, under normal nutritional conditions autophagy regulates cell survival by energy sensing through the main energy sensing cascade kinases. On the other hand, autophagy regulates the process of cell death. mTOR, Beclin 1, caspases, FLIPs, DAPK, and Tp53 play important regulatory roles in autophagy and apoptosis highlighting the crosstalk between the mechanisms underlying the two death modes. However, energy deficiency caused by PARP1 over-activation and DAPK-PKD pathway activation induces necrosis and autophagy, highlighting the interaction between the two pathways. In addition, autophagy regulates cell death through epigenetic regulation such as histone modification. More investigations on the relationship between autophagy and cell death is ongoing. In the future, there will be more challenges in the study of the relationship between autophagy and cell survival and death. As research increasingly focuses on cell death, the relationship between autophagy and existing and newly discovered cell death types is likely to become more complex. The elucidation of the regulatory role of autophagy in cell survival and death requiresmore research. Some research results are likely to provide hot topics for further investigations on diseases related to cell death disorders and an experimental basis for the targeted regulation of autophagy for specific treatment of diseases.

Spleen tyrosine kinase (SYK) is a nonreceptor tyrosine kinase with dual properties of an oncoprotein and an oncosuppressor in distinctive cell types. In solid cancers, two isoforms SYK(L) and SYK(S) of SYK were recently identified due to its alternative mRNA splicing. However, the cellular activity and the biological significance of the long isoform of SYK, SYK(L), is still not well defined in human lung cancers. Here, we describe an interaction between SYK(L) and the ubiquitously expressed transcription regulator Yin Yang 1 (YY1) in the nucleus, which suppresses the epithelial-to-mesenchymal transition (EMT) by inactivating SNAI2 (coding transcription factor SLUG) transcription. ChIP indicated that endogenous SYK(L) interacts directly with a YY1 binding cis-regulatory element in the SNAI2 promoter. Importantly, knockdown of YY1 activates SYK(L)-dependent EMT suppression in human lung cancer H1155 cells. We also found that the protein level of SYK(L) is markedly upregulated in various types of human lung cancers, and its nuclear localization is strongly correlated with clinical benefits of lung adenocarcinomas. Collectively, our data reveal a SYK(L)-dependent transcriptional regulation of EMT through SLUG as a potential biomarker for lung cancer aggressiveness.