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Project description:Small cell lung cancer (SCLC) responds exceptionally well to cytotoxic chemotherapy. However, relapse with the emergence of chemoresistant disease is rapid and accompanied by poor treatment outcomes. To understand the genetic basis of chemoresistance in SCLC, we applied in vivo CRISPR deletion screening to patient-derived xenograft (PDX) models. Top screen hits included genes encoding components of the transcriptional co-activator SAGA (Spt-Ada-Gcn5 acetyltransferase) complex. We demonstrate that deletion of the SAGA deubiquitylase USP22 conferred cisplatin/etoposide resistance in two chemosensitive PDX models, and that restoring expression in a PDX model harboring homozygous truncating mutation of USP22 re-sensitized tumors to chemotherapy. USP22 loss increased gene body histone H2A-K119 monoubiquitylation in genes encoding key regulators of neuronal differentiation, and suppressed neural and neuroendocrine gene expression including targets of ASCL1. Chemoresistance following USP22 loss reflected attenuated DNA damage-driven phosphorylation events and apoptosis, in conjunction with increased expression of glycolysis and hypoxia-related genes. Glycolysis program upregulation may reflect a targetable vulnerability, as inhibition of GLUT1 re-sensitized USP22-null tumors to chemotherapy.
2025-05-08 | GSE296258 | GEO
Project description:Small cell lung cancer (SCLC) responds exceptionally well to cytotoxic chemotherapy. However, relapse with the emergence of chemoresistant disease is rapid and accompanied by poor treatment outcomes. To understand the genetic basis of chemoresistance in SCLC, we applied in vivo CRISPR deletion screening to patient-derived xenograft (PDX) models. Top screen hits included genes encoding components of the transcriptional co-activator SAGA (Spt-Ada-Gcn5 acetyltransferase) complex. We demonstrate that deletion of the SAGA deubiquitylase USP22 conferred cisplatin/etoposide resistance in two chemosensitive PDX models, and that restoring expression in a PDX model harboring homozygous truncating mutation of USP22 re-sensitized tumors to chemotherapy. USP22 loss increased gene body histone H2A-K119 monoubiquitylation in genes encoding key regulators of neuronal differentiation, and suppressed neural and neuroendocrine gene expression including targets of ASCL1. Chemoresistance following USP22 loss reflected attenuated DNA damage-driven phosphorylation events and apoptosis, in conjunction with increased expression of glycolysis and hypoxia-related genes. Glycolysis program upregulation may reflect a targetable vulnerability, as inhibition of GLUT1 re-sensitized USP22-null tumors to chemotherapy.
2025-05-08 | GSE296155 | GEO
Project description:Loss of the USP22 deubiquitylase confers resistance to chemotherapy in small cell lung cancer
| PRJNA1258286 | ENA
Project description:Loss of the USP22 deubiquitylase confers resistance to chemotherapy in small cell lung cancer [CUT&Tag]
| PRJNA1258284 | ENA
Project description:Loss of the USP22 deubiquitylase confers resistance to chemotherapy in small cell lung cancer [RNA-seq]
| PRJNA1257930 | ENA
Project description:Evidence exists suggesting tumor-inhibiting properties of deubiquitylase OTUD1 in various malignancies. We herein investigated the anti-tumor effect and clarified the downstream mechanisms of OTUD1 in the chemoresistance of non-small cell lung cancer (NSCLC) cells. Expression of OTUD1 was examined in NSCLC (PC-9 cells) and erlotinib-resistant NSCLC (PC-9/ER) cell lines. OTUD1 was bioinformatically predicted to be weakly expressed in NSCLC tissue samples and verified in PC-9/ER cells. PC-9/ER cells were subsequently subjected to ectopic expression of OTUD1 alone or combined with SOX9 to dissect out the effect of OTUD1 on the proliferation, chemoresistance and apoptosis in vitro and in vivo. OTUD1 upregulation sensitized NSCLC cells to erlotinib both in vitro and in vivo. In the presence of OTUD1 overexpression, nuclear translocation of YAP1 was inhibited and its expression was inactivated. This effect of OTUD1 was associated with the decreased ubiquitination level of YAP1. SOX9/SPP1 inactivation was the consequence of inhibited nuclear translocation of YAP1. Overexpression of SOX9 reversed the inhibitory effect of OTUD1 on the resistance of NSCLC cells to erlotinib. In conclusion, our study reveals that OTUD1 potentially acts as a tumor suppressor and suppresses erlotinib resistance of NSCLC through the YAP1/SOX9/SPP1 axis, suggesting that OTUD1 may serve as a target for reducing chemoresistance for NSCLC.
| S-EPMC9526728 | biostudies-literature
Project description:BackgroundNIPBL, the sister chromatid cohesion 2 (SCC2) human homolog, is a cohesin loading factor which is essential for deposition of cohesin onto the sister chromatid. Recent studies have shown that NIPBL contribute to sister chromatid cohesion and plays a critical role in development, DNA repair, and gene regulation. In this study, we measured the expression of NIPBL in clinical non-small cell lung cancer specimens, and determined its effects on cellular processes and chemosensitivity in vitro.MethodsNIPBL immunohistochemistry was performed on 123 lung adenocarcinoma samples. Through knockdown of NIPBL protein expression, non-small cell lung cancer cell lines were used to test the potential involvement of NIPBL silencing on cell proliferation, migration, invasion, and apoptosis. Chemosensitivity was assessed with clonogenic assays, and chromatin immunoprecipitation assays were performed to analyze the relationship between NIPBL and signal transducers and activators of transcription 3 (STAT3).ResultsImmunohistochemical analysis showed that high expression of NIPBL was strongly correlated with poor prognosis, tumor differentiation, and lymph node metastasis. Survival analysis further indicated that NIPBL expression was a potential prognostic factor for non-small cell lung cancer. Knockdown of NIPBL in non-small cell lung cancer cell lines significantly reduced cellular proliferation, migration, and invasion, and enhanced cellular apoptosis and sensitivity to cisplatin, paclitaxel, and gemcitabine hydrochloride. NIPBL bound to the promoter region of the STAT3 gene, directly regulating the expression of STAT3.ConclusionsThese data suggested that NIPBL played a significant role in lung carcinogenesis. NIPBL expression conferred poor prognosis and resistance to chemotherapy in non-small cell lung cancer, suggesting that NIPBL may be a novel therapeutic target.
| S-EPMC4438579 | biostudies-literature
Project description:Radiotherapy is standard of care for inoperable non-small cell lung cancers (NSCLC) but adenocarcinoma NSCLC respond more poorly than squamous cell NSCLC. Transforming growth factor β (TGFβ) activity is induced by radiation and plays a recently recognized role in the DNA damage response. Here we show in murine lung tumor model that radiation activates TGFβ acutely and persistently and that TGFβ neutralizing antibody, 1D11, systemic treatment increased tumor control following either fractionated or single high dose radiation regimes. TGFβ dependent genes in the irradiated tumor indicated crosstalk between innate and adaptive immunity but therapeutic benefit of 1D11 in irradiated tumors in immunocompromised mice suggested that innate immune cells are more influential than the adaptive immune response. Irradiated tumors in which TGFβ was blocked were highly hypoxic, exhibit pronounced microvascular damage and promoted neither cancer-associated fibroblasts nor recruit bone marrow derived cells (BMDC). Tumor educated immature BMDC were significant sources of TGFβ and inhibiting BMDC recruitment achieved tumor growth control in response to RT comparable to TGFβ inhibition. Thus, radiation-induced TGFβ both compromises tumor control by RT and promotes reestablishment of the tumor microenvironment. Concordant with the critical role of TGFβ activity in RT, radiation resistant NSCLC adenocarcinomas exhibit higher TGFβ activity compared to squamous cell NSCLC, which suggests a rationale for using TGFβ inhibition to augment radiotherapy. Lewis lung cancer (LLC) model were established in 6 to 8 week-old C57BL/6 female mice by subcutaneous injection. When tumors were 60-80 mm3, Mice were randomized to achieve comparable mean tumor size for each treatment group as indicated below. Tumor growth were monitored and tumors were collected and characterized by gene expression profiling and immunostaining.
2015-12-15 | E-GEOD-73095 | biostudies-arrayexpress
Project description:The dismal lethality of lung cancer is due to late stage at diagnosis and inherent therapeutic resistance. The incorporation of targeted therapies has modestly improved clinical outcomes, but the identification of new targets could further improve clinical outcomes by guiding stratification of poor-risk early-stage patients and individualizing therapeutic choices. We hypothesized that a sequential, combined microarray approach would be valuable to identify and validate new targets in lung cancer. We profiled gene expression signatures during lung epithelial cell immortalization and transformation, and showed that genes involved in mitosis were progressively enhanced in carcinogenesis. 28 genes were validated by immunoblotting and 4 genes were further evaluated in non-small cell lung cancer tissue microarrays. Although CDK1 was highly expressed in tumor tissues, its loss from the cytoplasm unexpectedly predicted poor survival and conferred resistance to chemotherapy in multiple cell lines, especially microtubule-directed agents. An analysis of expression of CDK1 and CDK1-associated genes in the NCI60 cell line database confirmed the broad association of these genes with chemotherapeutic responsiveness. These results have implications for personalizing lung cancer therapy and highlight the potential of combined approaches for biomarker discovery. In these studies, we systematically profiled gene expression in normal (NHBE), immortalized (BEAS-2B) and fully transformed (NNK-BEAS-2B) human bronchial epithelial cells, as well as a non-small cell lung cancer (NSCLC) cell line (H157) from a smoker. Expression profiles that accompany the immortalization and/or transformation of bronchial epithelial cells were generated, and expression of 28 genes was validated by immunoblotting. 4 of them were further evaluated in immunohistochemical analyses of tissue microarrays that contain NSCLC specimens, surrounding non-diseased tissues and non-pulmonary normal tissues. Although all 4 genes were predominantly expressed in tumor tissues, loss of expression of cytoplasmic CDK1 was clinically important because it was associated with a poor prognosis for NSCLC patients. This poor prognostic value may be associated with therapeutic resistance because decreasing levels of cytoplasmic CDK1 in vitro increased resistance to standard chemotherapies used in the treatment of NSCLC, especially microtubule agents where resistance was almost complete. These studies illustrate how a combined microarray approach can facilitate the identification of new, relevant targets in cancer. Fluorescently labeled cDNA were synthesized from 100 microgram RNA by oligo(dT)-primed reverse transcription in the presence of Cy3- or Cy5-dUTP (Amersham Bisciences, Piscataway, NJ). Purified Cy3/Cy5-labelled probes were combined and hybridized in the presence of 2x Denhart's solution, 3.2x saline sodium citrate (SSC), and 0.5% sodium dodecyl sulfate (SDS) in a humidified chamber at 65°C overnight. Prior to scanning (Agilent Technologies, Foster City, CA), slides were successively washed at 22°C in 0.5x SSC/0.1% SDS for 2 min, 0.5x SSC/0.01% SDS for 2 min, and 0.06x SSC for 2 min. Image analyses were performed with the IPLab software (Fairfax, VA). The reference cell (NHBE) was included in every individual hybridization to allow for normalization of each clone’s expression relative to the reference for each cell line (BEAS-2B, NNK-BEAS-2B or H157). A self-to-self hybridization with dye reversal was performed to exclude preferential differences in probe labeling (not included here). Every sample was labeled with Cy5 and Cy3 and hybridized twice. The two fluorescent images (red and green channels) obtained from the scanner constituted the intensity raw data from which differential gene expression ratios and quality control values were calculated. All data were entered into a relational database, using the FileMaker Pro 5 software (Santa Clara, CA). Genes were identified as differentially regulated only if corrected red/green hybridization signals differed by at least two-fold. The genes in each group were alphabetically listed and the ratios of BEAS-2B/NHBE, NNK-BEAS-2B/NHBE or H157/NHBE were graphically visualized by Cluster and TreeView programs (http://rana.lbl.gov/EisenSoftware.htm). These methods fulfilled the MIAME criteria (http://www.mged.org/miame).
| S-ECPF-GEOD-28282 | biostudies-other
Project description:The bromodomain and extra-terminal domain (BET) proteins are promising therapeutic targets to treat refractory solid tumors; however, inherent resistance remains a major challenge in the clinic. Recently, the emerging role of the oncoprotein B cell lymphoma 6 (BCL6) in tumorigenesis and stress response has been unveiled. Here, we demonstrate that BCL6 was upregulated upon BET inhibition in KRAS-mutant cancers, including non-small-cell lung cancer (NSCLC). We further found that BRD3, not BRD2 or BRD4, directly interacted with BCL6 and maintained the negative autoregulatory circuit of BCL6. Disrupting this negative autoregulation by BET inhibitors (BETi) resulted in a striking increase in BCL6 transcription, which further activated the mTOR signaling pathway through repression of the tumor suppressor death-associated protein kinase 2. Importantly, pharmacological inhibition of either BCL6 or mTOR improved the tumor response and enhanced the sensitivity of KRAS-mutant NSCLC to BETi in both in vitro and in vivo settings. Overall, our findings identify a mechanism of BRD3-mediated BCL6 autoregulation and further develop an effective combinatorial strategy to circumvent BETi resistance in KRAS-driven NSCLC.
| S-EPMC7773368 | biostudies-literature