Project description:Cyclins and cyclin-dependent kinases (CDKs) are hyperactivated in nearly all human tumor types. To identify new approaches for interfering with cyclins/CDKs, we systematically searched for microRNAs (miRNAs) regulating these proteins. We uncovered a group of miRNAs that target nearly all cyclins and CDKs, and demonstrated that these miRNAs are very effective in shutting off cancer cell expansion. By profiling the response of over 120 human cancer cell lines representing 12 tumor types to these cell-cycle-targeting miRNAs, we identified miRNAs particularly effective against triple-negative breast cancers and KRAS-mutated cancers. We also derived expression-based algorithm that predicts response of primary tumors to cell-cycle-targeting miRNAs. Using systemic administration of nanoparticle-formulated miRNAs, we halted tumor progression in seven mouse xenograft models, including three highly aggressive and treatment-refractory patient-derived tumors, without affecting normal tissues. Our results highlight the utility of using cell-cycle-targeting miRNAs for treatment of refractory cancer types.
Project description:Cyclins and cyclin-dependent kinases (CDKs) are hyperactivated in nearly all human tumor types. To identify new approaches for interfering with cyclins/CDKs, we systematically searched for microRNAs (miRNAs) regulating these proteins. We uncovered a group of miRNAs that target nearly all cyclins and CDKs, and demonstrated that these miRNAs are very effective in shutting off cancer cell expansion. By profiling the response of over 120 human cancer cell lines representing 12 tumor types to these cell-cycle-targeting miRNAs, we identified miRNAs particularly effective against triple-negative breast cancers and KRAS-mutated cancers. We also derived expression-based algorithm that predicts response of primary tumors to cell-cycle-targeting miRNAs. Using systemic administration of nanoparticle-formulated miRNAs, we halted tumor progression in seven mouse xenograft models, including three highly aggressive and treatment-refractory patient-derived tumors, without affecting normal tissues. Our results highlight the utility of using cell-cycle-targeting miRNAs for treatment of refractory cancer types.
Project description:microRNA dysregulation is a common feature of cancer cells, but the complex roles of microRNAs in cancer are not fully elucidated. Here we used functional genomics to identify oncogenic microRNAs in non-small cell lung cancer and to evaluate their impact on response to EGFR targeting therapy. Our data demonstrate that microRNAs with an AAGUGC-motif in their seed-sequence increase both cancer cell proliferation and sensitivity to EGFR inhibitors. Global transcriptomics, proteomics and target prediction resulted in the identification of several tumor suppressors involved in the G1/S transition as targets of AAGUGC-microRNAs. The clinical implications of our findings were evaluated by analysis of public domain data supporting the link between this microRNA seed-family, their tumor suppressor targets and cancer cell proliferation. In conclusion we propose that AAGUGC-microRNAs are an integral part of an oncogenic signaling network, and that these findings have potential therapeutic implications, especially in selecting patients for EGFR-targeting therapy.
Project description:Some HER2 positive breast cancer patients are refractory to trastuzumab therapy. MicroRNAs have been used to predict therapeutic effects for various cancers, and our study suggests that the serum-based miRNA signature can effectively distinguish HER2+ MBC patients who are sensitive to trastuzumab from those are resistant.
Project description:Multiple myeloma (MM) is a devastating plasma cell malignancy characterized by the expansion of aberrant monoclonal plasma cells in the bone marrow, leading to severe clinical manifestations and poor prognosis, particularly in relapsed/refractory cases. Identifying novel therapeutic targets is crucial to improve treatment outcomes in these patients. In this study, we investigated the role of protein arginine methyltransferase 1 (PRMT1) in MM pathogenesis and explored its potential as a therapeutic target. We observed that PRMT1, responsible for majority of asymmetric di-methylation in cells, exhibited the highest expression among PRMT family members in MM cell lines and primary MM cells. Importantly, PRMT1 expression was significantly elevated in relapsed/refractory patients compared to newly diagnosed patients. High expression of PRMT1 expression was strongly associated with poor prognosis. We found that genetic or enzymatic inhibition of PRMT1 impaired MM cell growth, induced cell cycle arrest, and triggered cell death. Treatment with MS023, a potent PRMT type I inhibitor, demonstrated a robust inhibitory effect on viability of primary cells isolated from both newly diagnosed and proteasome inhibitor-relapsed/refractory patients in a dose-dependent manner. In vivo studies using a xenograft model revealed that targeting PRMT1 by either CRISPR/Cas9-mediated knockout or MS023 treatment significantly attenuated MM tumor growth and prolonged the survival of tumor-bearing mice. Histological analysis further confirmed increased apoptotic cell death in MS023-treated tumors. Collectively, our findings establish PRMT1 as an indispensable and novel therapeutic vulnerability in MM. The elevated expression of PRMT1 in relapsed/refractory patients underscores its potential as a target for overcoming treatment resistance. Moreover, our results highlight the efficacy of MS023 as a promising therapeutic agent against MM, offering new avenues for therapeutic approaches in relapsed/refractory MM.
Project description:The interplay between cancer cells and microenvironment can influence treatment response and plays a key role in the emergence of drug resistance. Rapidly acquired resistance prevents proteasome inhibitors (PIs) therapies from achieving stable and complete responses. Investigating the underlying mechanisms and developing effective strategies against PI resistance are highly desired in the clinic. Here we uncovered that PI resistance was reversible in MLL leukemia, which consistent with the finding that patients could regain sensitivity to PIs after a drug holiday. Exosomes derived from drug-tolerant cells could transmit PI resistance to sensitive cells via facilitating cell cycle arrest and stemness pathway in MLL leukemia cells. Furthermore, TieDIE algorithm integration analysis of transcriptome and proteome datasets identified candidate exosomal proteins, providing potential therapeutic targets for treating refractory MLL leukemia. Therefore, exosomal regulatory proteins may serve as a predictor and a potential therapeutic target for PI resistance, and inhibiting the secretion of exosomes is a promising strategy for restoring PI resistance in vivo, which provides a paradigm and may also be applied for the treatment of other cancers resulting from chemotherapy relapse.
Project description:microRNA dysregulation is a common feature of cancer cells, but the complex roles of microRNAs in cancer are not fully elucidated. Here we used functional genomics to identify oncogenic microRNAs in non-small cell lung cancer and to evaluate their impact on response to EGFR targeting therapy. Our data demonstrate that microRNAs with an AAGUGC-motif in their seed-sequence increase both cancer cell proliferation and sensitivity to EGFR inhibitors. Global transcriptomics, proteomics and target prediction resulted in the identification of several tumor suppressors involved in the G1/S transition as targets of AAGUGC-microRNAs. The clinical implications of our findings were evaluated by analysis of public domain data supporting the link between this microRNA seed-family, their tumor suppressor targets and cancer cell proliferation. In conclusion we propose that AAGUGC-microRNAs are an integral part of an oncogenic signaling network, and that these findings have potential therapeutic implications, especially in selecting patients for EGFR-targeting therapy.
Project description:Breast cancers with HER2 overexpression are sensitive to drugs targeting the receptor or its kinase activity. HER2-targeting drugs are initially effective against HER2- positive breast cancer, but resistance inevitably occurs. We previously found that nuclear factor kappa B is hyper-activated in the subset of HER-2 positive breast cancer cells and tissue specimens. In this study, we report that constitutively active NF-κB rendered HER2-positive cancer cells resistant to anti-HER2 drugs, and cells selected for Lapatinib resistance up-regulated NF-κB. In both circumstances, cells were anti-apoptotic and grew rapidly as xenografts. Lapatinib-resistant cells were refractory to HER2 and NF-κB inhibitors alone but were sensitive to their combination, suggesting a novel therapeutic strategy. A subset of NF-κB-responsive genes was overexpressed in HER2-positive and triple-negative breast cancers, and patients with this NF-κB signature had poor clinical outcome. Anti-HER2 drug resistance may be a consequence of NF-κB activation, and selection for resistance results in NF-κB activation, suggesting this transcription factor is central to oncogenesis and drug resistance. Clinically, the combined targeting of HER2 and NF-κB suggests a potential treatment paradigm for patients who relapse after anti-HER2 therapy. Patients with these cancers may be treated by simultaneously suppressing HER2 signaling and NF-κB activation. We used microarrays to detail the gene expression differences underlying the characterictic survival differences between the SKR6, SKR6-Vector, SKR6CA, and SKR6LR cell lines, which are defined as follows: SKR6: A clonal derivative of SKBR3 cells isolated by fluorescence-activated cell sorting (FACS) to enrich for elevated HER2 levels, SKR6CA: SKR6 cells retrovirally transduced with constitutively active NF-κB relA/p65 (CAp65) and selected with puromycin, SKR6 vector: SKR6 cells transduced with the pQCXIP empty retroviral vector and selected with puromycin, and SKR6LR: SKR6 cells treated with increasing lapatinib concentrations (0.2 to 5 μM) for several months. We sorted SKBR-3 cells by fluorescence-activated cell sorting (FACS) to enriched for cell population with elevated HER2 expression, which we termed SKR6. The following cell lines were then created from SKR6 cells: SKR6CA: SKR6 cells retrovirally transduced with constitutively active NF-κB relA/p65 (CAp65), SKR6 vector: SKR6 cells transduced with the pQCXIP empty retroviral vector and selected with puromycin, and SKR6LR: SKR6 cells treated with increasing lapatinib concentrations (0.2 to 5 μM) for several months.