Project description:Genome-wide CRISPR-Cas9 knockout screen using TKOv1 sgRNA library performed in isogenic RBM10-proficient and RBM10-deficient HCC827 cells.
Project description:Genome-wide CRISPR-Cas9 knockout screen using TKOv1 sgRNA library was performed in isogenic RBM10-proficient and RBM10-deficient HCC827 cells.
Project description:To identify the possible genes influencing macrophage pro-inflammatory activation, we designed CRISPR screens using a human metabolic sgRNA library containing metabolism-related transcription factors, small molecule transporters, and metabolic enzymes in a Cas9-expressing lentiviral vector.
Project description:Emerging evidence indicates that metabolic enzymes perform moonlighting functions during tumor progression, including the modulation of chemoresistance. However, the underlying mechanisms of these functions remain elusive. In this study, utilizing a genome-scale metabolic CRISPR-Cas9 knockout library screen, we observed that loss of Glutamate-cysteine ligase modifier subunit (GCLM), a rate-limiting enzyme in glutathione biosynthesis, noticeably heightens the sensitivity of colorectal cancer (CRC) cells to platinum-based chemotherapy. Mechanistically, we unveil a noncanonical mechanism through which nuclear GCLM competitively interacts with NF-kappa-B-repressing factor (NKRF), a known inhibitor of NF-κB signaling, to promote NF-κB activity and subsequently facilitate chemoresistance. In response to platinum drug treatment, P38 phosphorylates GCLM at T17, resulting in its recognition by importin a5 and subsequent nuclear translocation. Furthermore, elevated expression of nuclear GCLM is evident in CRC tissues and correlates with poor prognosis and heightened P38 activity. Overall, our findings shed light on the essential nonmetabolic role and posttranslational regulatory mechanism of GCLM in enhancing NF-κB activity and subsequent chemoresistance.
Project description:HDACs play crucial role in epigenetic modulation through deacetylation of histone and non-histone substrates in critical process of normal development and cancer. Moreover, HDAC inhibitors have been considered as new agent by effects such as cell cycle arrest, apoptosis, anti-angiogenic effects and autophagy and utilized in clinical applications for chemotherapy. we previously reported that HDAC 1, 4, 6 and 8 were higly expressed in MDA-MB-231 than MCF-7 cells and HDAC1, 6 and 8 excepting HDAC4 were associated with invasion that is very important factor in cancer progression. However, HDAC4 did not affect in invasion. To investigate interaction between chemoresistance and HDAC4 expression, we establish stable cells overexpressing HDAC4 in MCF-7 cells. Cells overexpressed HDAC4 were increased cytotoxicity about 5-FU and identified 356 differentially expressed genes using Ilumina array. Based on array result, we selected SMAD4 as a candidate gene related with chemoresistance because SMAD4 was previously reported evaluation of chemoresistance to 5-FU. We purpose that HDAC4 regulated with SMAD4 expression through acetylation in SMAD4 promoter region. HDAC4 directly bound a part of SMAD4 promoter. Total RNA obtained from cells overexpressed HDAC4 cDNA in MCF-7 compared to control cells.
Project description:Ovarian cancer is still the most lethal gynecological cancer, despite advances in patients’ strati-fication and treatment. Only about 80% of patients respond to the first line of treatment and many suffer a relapse with a treatment resistant disease. Here, we have identified three potential markers for chemoresistance using primary tumour samples. Moreover, we have shown their concurrent regulation in a chemoresistant cell line. This implies those cells as a useful model to study chemoresistance and to test novel drugs.
Project description:To identify a common protein that interacts with PAF1 in ovarian cancer, lung Cancer, and pancreatic cancer to mediate chemoresistance.
Project description:Chemoresistance remains a major obstacle to the successful treatment of breast cancer. Especially, more than 80% of cases cannot achieve pathological complete response (pCR) in patients who received neoadjuvant chemotherapy (NAC). Understanding the mechanisms involved in chemoresistance can guide the development of efficient therapies in patients with breast cancer. Herein, we identified a novel p62 isoform with a short 3′UTR (p62-SU, 662-nt) that is associated with chemoresistance by RNA-sequence and verified by qRT-PCR, 3′RACE, and northern blot in breast cancer cells and tissue specimens. Furthermore, enforced expression of p62-SU dramatically promoted the ability of proliferation, migration, invasion, and chemoresistance compared with p62 isoform with a long/full-length 3′UTR (p62-LU, 1485-nt) in vivo and in vitro. Mechanistically, we revealed that CPSF1 could regulate the 3′UTR shorting of p62 by alternative polyadenylation and then enhanced chemoresistance in breast cancer cells. In addition, we found that p62-SU escaped the repression of miR-124-3p and promoted the ability of p62-SU to produce more protein and, subsequently, p62-dependent chemoresistance. Together, our data suggest the p62-SU, generated by CPSF1, plays an essential role in the regulation of breast cancer chemoresistance through CPSF1-p62-miR-124-3p signaling.
Project description:Colorectal cancer is the third most common cancer worldwide and its progression-free survival is still low, around 10 months. Thirthy to 50% of patients do not respond to chemotherapy upon initiation of treatment, suggesting that early development of chemoresistance mechanisms remains a major challenge. In order to better characterize these mechanisms, we aim to develop a model of tumoroids derived from patients with a colorectal tumors prior to any systemic anti cancer treatment. This project will both allow us to study the role of the immunological microenvironment in chemoresistance and identify new predictive markers of tumor response. It will then serve to develop innovative personalized medicine strategies by targeting the newly identified mechanisms. This study should in fine help to improve the cancer patient’s care.