Project description:Unraveling the underlying mechanisms of cetuximab resistance in head and neck squamous cell carcinoma (HNSCC) is of major importance as many tumors remain non-responsive or become resistant. Out microarray results suggest that resistant cells still exhibit RAS-MAPK pathway signaling contributing to drug resistance, as witnessed by low expression of DUSP 5 and DUSP6, negative regulators of ERK1/2, and increased expression of AURKB, a key regulator of mitosis. Therefore, interrupting the RAS-MAPK pathway by an ERK1/2 inhibitor (apigenin) or an AURKB inhibitor (barasertib) might be a new strategy for overcoming cetuximab resistance in HNSCC 4 head and neck squamous cell carcinoma (HNSCC) cell lines were treated with either 15 nM cetuximab or PBS during 13 hours. For each cell line, differential gene expression was assessed between cetuximab and PBS treatments.
Project description:Unraveling the underlying mechanisms of cetuximab resistance in head and neck squamous cell carcinoma (HNSCC) is of major importance as many tumors remain non-responsive or become resistant. Out microarray results suggest that resistant cells still exhibit RAS-MAPK pathway signaling contributing to drug resistance, as witnessed by low expression of DUSP 5 and DUSP6, negative regulators of ERK1/2, and increased expression of AURKB, a key regulator of mitosis. Therefore, interrupting the RAS-MAPK pathway by an ERK1/2 inhibitor (apigenin) or an AURKB inhibitor (barasertib) might be a new strategy for overcoming cetuximab resistance in HNSCC
Project description:Cetuximab resistance has been a major challenge for head and neck squamous cell carcinoma (HNSCC) during target therapy. Yet the mechanism that caused cetuximab resistance, especially the miRNA regulation therein remains unclear. With growing evidence suggests that miRNAs may function within the cell nucleus and act as “nuclear activating miRNAs” for targeting the promoter region or enhancers related to target genes. They are believed to regulate diseases development including tumorigenesis. This study elucidates a novel mechanism underlying cetuximab resistance in HNSCC involving the nuclear activation of KDM7A transcription via miR-451a. Herein, small RNA sequencing, qRT-PCR and FISH results provide compelling evidence of miR-451a nuclear enrichment with cetuximab treatment. ChIRP-seq, microarray, bioinformatic analysis and dual luciferase reporter assay results show that miR-451a interacts with an enhancer region in KDM7A, activating its expression and further facilitating cetuximab resistance. It is also demonstrated that activation of KDM7A by nuclear miR-451a is induced by cetuximab treatment and is AGO2 dependent. Analyses of HNSCC samples through logistic regression indicated the significance of miR-451a and KDM7A in cetuximab resistance. These discoveries hold promise for the potential utilization of miR-451a and KDM7A as valuable biomarkers for cetuximab resistance and emphasize the function of nuclear activating miRNAs.
Project description:Cetuximab resistance has been a major challenge for head and neck squamous cell carcinoma (HNSCC) during target therapy. Yet the mechanism that caused cetuximab resistance, especially the miRNA regulation therein remains unclear. With growing evidence suggests that miRNAs may function within the cell nucleus and act as “nuclear activating miRNAs” for targeting the promoter region or enhancers related to target genes. They are believed to regulate diseases development including tumorigenesis. This study elucidates a novel mechanism underlying cetuximab resistance in HNSCC involving the nuclear activation of KDM7A transcription via miR-451a. Herein, small RNA sequencing, qRT-PCR and FISH results provide compelling evidence of miR-451a nuclear enrichment with cetuximab treatment. ChIRP-seq, microarray, bioinformatic analysis and dual luciferase reporter assay results show that miR-451a interacts with an enhancer region in KDM7A, activating its expression and further facilitating cetuximab resistance. It is also demonstrated that activation of KDM7A by nuclear miR-451a is induced by cetuximab treatment and is AGO2 dependent. Analyses of HNSCC samples through logistic regression indicated the significance of miR-451a and KDM7A in cetuximab resistance. These discoveries hold promise for the potential utilization of miR-451a and KDM7A as valuable biomarkers for cetuximab resistance and emphasize the function of nuclear activating miRNAs.
Project description:To investigate the mechanism of cetuximab resistance in head and neck squamous cell carcinoma (HNSCC), we performed single-cell RNA sequencing analysis in biopsy from two HNSCC patients before and after cetuximab treatment.
Project description:We deciphered molecular mechanisms associated with acquired resistance to anti-EGFR targeted therapy in head and neck squamous cell carcinoma (HNSCC) by comparing gene expression profiles in cetuximab-sensitive and -resistant patient-derived xenograft (PDX) models of HNSCC. We generated and validated several HNSCC PDX models. Resistance mechanisms to anti-EGFR therapy were investigated in one of these PDX models (UCLHN04). First, sensitivity to cetuximab treatment was tested. This model showed high sensitivity to this drug. We induced acquired resistance to anti-EGFR therapy in this sensitive model by treating it chronically with anti-EGFR monoclonal antibody (cetuximab, 30 mg/kg/week) until resistance ensues. RNA-seq analysis was performed on samples coming from untreated and cetuximab-resistant PDX, revealing major changes of expression at the mRNA level.
Project description:The identification of the potential mechanisms of resistance while tumor cells still respond to therapy is critical to develop combination therapies to delay acquired resistance. Cetuximab, an anti-EGFR therapy, is the only targeted therapy available for head and neck squamous cell carcinoma (HNSCC). We generated the first comprehensive multi-omics, bulk and single cell data in sensitive HNSCC cells to identify relevant transcriptional and epigenetic changes that are an immediate response to cetuximab in sensitive cells. These changes include genes from two pathways potentially associated with resistance: regulation of growth factor receptors through the transcription factor TFAP2A, and epithelial-to-mesenchymal transition (EMT) process. Single cell RNA-sequencing demonstrates inter-cell lines heterogeneity, with cell specific expression profiles of TFAP2A and VIM gene expression in cetuximab treated and untreated clones, and an independent role of each pathway. RNA-seq and ATAC-seq demonstrate that there are global transcriptional and epigenetic changes within the first five days of anti-EGFR therapy. We also experimentally verified that lack of TFAP2A reduces HNSCC growth in vitro and that this effect is enhanced with cetuximab and a stronger effect is observed with JQ1, an inhibitor of alternative receptor tyrosine kinases. Corroborating our scRNA-seq observation, TFAP2A silencing does not affect cell migration, supporting the lack of interplay with the EMT pathway. Overall, our study shows that the immediate adaptive transcriptional and epigenetic changes induced by cetuximab include relevant pathways associated with acquired resistance. Although heterogeneous, these changes can be targeted by a multiple-target drug as JQ1 that in combination with cetuximab in the early stage of treatment present better efficacy in controlling tumor growth.
Project description:Cetuximab (Erbitux) is an antibody drug against EGFR and commonly used in late stage HNSCC and metastatic colorectal cancer. The oncogenic mutation of certain genes are known to drive Cetuximab resistance such as K-RAS or b-RAF mutation. The aberrant activation of signaling pathways in the presence of Cetuximab treatment to overcome cellular stress contribute to acquired resistance to Cetuximab as well. To better understand the mechanisms and molecular patterns of Cetuximab resistant cells, the Cetuximab resistant cells are trained for examining the gene expression profile. The gene expression array is used for identify the molecular signature governing the Cetuximab resitance.
Project description:The identification of the potential mechanisms of resistance while tumor cells still respond to therapy is critical to develop combination therapies to delay acquired resistance. Cetuximab, an anti-EGFR therapy, is the only targeted therapy available for head and neck squamous cell carcinoma (HNSCC). We generated the first comprehensive multi-omics, bulk and single cell data in sensitive HNSCC cells to identify relevant transcriptional and epigenetic changes that are an immediate response to cetuximab in sensitive cells. These changes include genes from two pathways potentially associated with resistance: regulation of growth factor receptors through the transcription factor TFAP2A, and epithelial-to-mesenchymal transition (EMT) process. Single cell RNA-sequencing demonstrates inter-cell lines heterogeneity, with cell specific expression profiles of TFAP2A and VIM gene expression in cetuximab treated and untreated clones, and an independent role of each pathway. RNA-seq and ATAC-seq demonstrate that there are global transcriptional and epigenetic changes within the first five days of anti-EGFR therapy. We also experimentally verified that lack of TFAP2A reduces HNSCC growth in vitro and that this effect is enhanced with cetuximab and a stronger effect is observed with JQ1, an inhibitor of alternative receptor tyrosine kinases. Corroborating our scRNA-seq observation, TFAP2A silencing does not affect cell migration, supporting the lack of interplay with the EMT pathway. Overall, our study shows that the immediate adaptive transcriptional and epigenetic changes induced by cetuximab include relevant pathways associated with acquired resistance. Although heterogeneous, these changes can be targeted by a multiple-target drug as JQ1 that in combination with cetuximab in the early stage of treatment present better efficacy in controlling tumor growth.
Project description:Background: Identifying potential resistance mechanisms while tumour cells still respond to therapy is critical to delay acquired resistance. Methods: We generated the first comprehensive multi-omics, bulk and single-cell data in sensitive head and neck squamous cell carcinoma (HNSCC) cells to identify immediate responses to cetuximab. Two pathways potentially associated with resistance were focus of the study: regulation of receptor tyrosine kinases by TFAP2A transcription factor, and epithelial-to-mesenchymal transition (EMT). Results: Single-cell RNA-seq demonstrates heterogeneity, with cell-specific TFAP2A and VIM expression profiles in response to treatment and also with global changes to various signalling pathways. RNA-seq and ATAC-seq reveal global changes within 5 days of therapy, suggesting early onset of mechanisms of resistance; and corroborates cell line heterogeneity, with different TFAP2A targets or EMT markers affected by therapy. Lack of TFAP2A expression is associated with HNSCC decreased growth, with cetuximab and JQ1 increasing the inhibitory effect. Regarding the EMT process, short-term cetuximab therapy has the strongest effect on inhibiting migration. TFAP2A silencing does not affect cell migration, supporting an independent role for both mechanisms in resistance. Conclusion: Overall, we show that immediate adaptive transcriptional and epigenetic changes induced by cetuximab are heterogeneous and cell type dependent; and independent mechanisms of resistance arise while tumour cells are still sensitive to therapy.