Mechanisms of drugs-resistance in small cell lung cancer II
Ontology highlight
ABSTRACT: Malignant transformation of SCLC often occurs simultaneously with the acquisition of chemotherapy resistance, suggesting that phenotypic malignant transformation is associated with adaptation to chemotherapy-induced stress. Recently, it has been reported that autophagy deficiency is involved in chemotherapy resistance in SCLC. To analyze gene expression changes associated with SCLC malignant transformation, we established ATG7 knockout and ATG7/SQSTM1 double knockout SCLC cell lines and performed RNA sequencing.
Project description:Lung cancer is the leading cause of cancer mortality and is classified by the World Health Organization into two broad histological subtypes. Non–small cell lung cancer (NSCLC), including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, accounts for ~85% of all lung cancer cases, with the remaining 15% of cases being due to small cell lung cancer (SCLC), which arises from neuroendocrine cells in the lung. Although most SCLC tumors are initially responsive to chemotherapy and radiation, patients often experience relapse, with the tumor acquiring an aggressiveness and therapeutic resistance that lead to a poor clinical outcome. Improvement of overall survival in individuals with SCLC will require the identification of novel therapeutic targets based on a better understanding of the changes in intracellular signaling of aggressive SCLC cells. The malignant progression of SCLC often occurs concomitantly with the acquisition of chemoresistance, suggesting that phenotypic malignant change is related to adaptation to the stresses induced by chemotherapy. In order to analyze gene expression changes associated with malignant transformation in SCLC, we established a cisplatin-resistant SCLC cell line and performed RNA sequencing.
Project description:Lung cancer is the leading cause of cancer mortality and is classified by the World Health Organization into two broad histological subtypes. Non–small cell lung cancer (NSCLC), including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, accounts for ~85% of all lung cancer cases, with the remaining 15% of cases being due to small cell lung cancer (SCLC), which arises from neuroendocrine cells in the lung. Although most SCLC tumors are initially responsive to chemotherapy and radiation, patients often experience relapse, with the tumor acquiring an aggressiveness and therapeutic resistance that lead to a poor clinical outcome. Improvement of overall survival in individuals with SCLC will require the identification of novel therapeutic targets based on a better understanding of the changes in intracellular signaling of aggressive SCLC cells. The malignant progression of SCLC often occurs concomitantly with the acquisition of chemoresistance, suggesting that phenotypic malignant change is related to adaptation to the stresses induced by chemotherapy. In order to analyze gene expression changes associated with malignant transformation in SCLC, we established a cisplatin-resistant SCLC cell line and performed RNA sequencing.
Project description:Autophagy deficiency caused by conditional knockout of Atg7 results in severe hepatitis accompanied by abundant accumulation of p62. p62 stablizes Nrf2 by disrupting the association between Keap1 and Nrf2. To understand the pathogenesis of hepatitis under the autophagy deficiency, we examined gene expression profiles of livers from Atg7-null, Nrf2-null and Atg7-Nrf2 double mutant mice. Eight week old Atg7F/F:Mx1-Cre mice and Atg7F/F:Mx1-Cre:Nrf2-/- together with control mice were injected with pIpC. At 4 weeks after pIpC injection, total RNAs were purified from each mouse liver.
Project description:Autophagy deficiency caused by conditional knockout of Atg7 results in severe hepatitis accompanied by abundant accumulation of p62. p62 stablizes Nrf2 by disrupting the association between Keap1 and Nrf2. To understand the pathogenesis of hepatitis under the autophagy deficiency, we examined gene expression profiles of livers from Atg7-null, Nrf2-null and Atg7-Nrf2 double mutant mice.
Project description:Autophagy is a recycling program for cells to adapt to metabolic needs and to stress. Defects in autophagy can affect metabolism, aging, proteostasis and inflammation. We used microarrays to determine the changes in global gene expression in murine melanocyte upon genetic inactivation of the essential autophagy gene Atg7 and as secondary aim wheter the gene regulation by ultraviolet A light is affected by the Atg7 knockout
Project description:Small cell lung cancer (SCLC) is characterized by exquisite chemosensitivity followed by rapid emergence of chemoresistance. To identify genetic events that drive resistance to cisplatin-etoposide chemotherapy, we conducted cDNA overexpression and CRISPR knockout screens in an in vivo platform centered on chemosensitive patient derived xenograft (PDX) models of SCLC. cDNA overexpression screens revealed MYC, MYCN and MYCL as drivers of tumor cell growth through chemotherapy. CRISPR knockout screens identified the KEAP1/NRF2 pathway and members of the SAGA (Spt-Ada-Gcn5 acetyltransferase) complex, including the deubiquitylase USP22. We demonstrated that knockout of either KEAP1 or USP22 switches chemosensitive PDX models to become chemoresistant, with our data supporting distinct molecular consequences of each, including suppression of DNA damage signaling upon USP22 deletion. Data from the IMpower133 clinical trial revealed that a substantial proportion of SCLC patients exhibit KEAP1/NFE2L2 genetic alterations, with activation of an NRF2 transcriptional signature associated with reduced SCLC patient survival with chemotherapy.
Project description:Transcriptome analysis of NesCre:Atg7 conditional knockout mice. Autophagy plays an important role in regulating protein metabolism and tissue homeostasis. Recent studies have reported that neural stem cell-specific Atg7 knockout mice (NesCre:Atg7f/f cKO mice) exhibit neonatal lethal due to severe neurodegeneration. However, the precise mechanisms of how neuronal fate is regulated by the autophagic pathway have not been elucidated. Here, we performed microarray experiments to analyze the changes in gene expression patterns in NesCre:Atg7 cKO mice. As a result, we could find a lot of candidate genes changed by Atg7 deficiency.
Project description:We report an upregulation of miR-16 in Paget's disease of bone which is to target the SQSTM1. When miR-16 is lost in Paget's disease, there is malignant transformation.
Project description:Small cell lung cancer (SCLC) is the most aggressive subtype of lung cancer. Although most patients are initially sensitive to first-line chemotherapy with combined cisplatin and etoposide, chemotherapy drugs resistance easily develops and quickly leads to tumor progression. Therefore, understanding mechanisms of chemotherapy drugs resistance and how to reverse it is key to improving the prognosis of patients with SCLC. The parental SCLC cell lines H69 and corresponding doxorubicin-induced multidrug resistant variant (H69AR) were used to explore the mechanism of chemoresistance in SCLC.
Project description:To explore the mechanisms of autophagy in the regulation of vascular tumour cells, we generated three autophagy-related genes, Fip200, Atg5 and Atg7, knockout vascular tumor cells in 562 cell line by CRISPR-Cas9-based sgRNAs. Three independent replicates of mRNA samples were prepared from each KO cells and subjected to RNA-sequencing in comparison to three samples from control 562 cells. We examined changes in gene expression by transcriptional profiling of Fip200 KO, Atg5 KO, and Atg7 KO cells, compared to control 562 cells respectively.