Project description:To investigate if cetuximab induces epithelial to mesenchymal transition (EMT) and activation of cancer associated fibroblast (CAF) in the tumors of patients with squamous cell carcinoma of the head and neck (SCCHN). Cetuximab was administered for two weeks prior to surgery to 20 treatment-naïve patients (CHIRON study). Five untreated patients were included as controls. Tumor biopsies were performed at baseline and before surgery. Gene expression profiles and quantitative real-time PCR (qRT-PCR) analysis of the pre-and post-treatment biopsies were compared. To further investigate EMT and CAF, correlations between previously described EMT and CAF markers and our microarray data set were calculated.
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:To filter the up-regulated gene induced by miR-451a overexpression and in cetuximab resistant HNSCC cell. We employed whole genome microarray. The HNSCC cell CAL27 was used as a control sample. CAL27_CTX, the cetuximab resistant CAL27 was compared with CAL27. The miR-451a overexpressed CAL27_451a sample was compared with the CAL27_NC sample. CAL27_CTX and CAL27_451A samples were collected after 48h of cetuximab treatment. The microarray results were taken together with ChIRP-seq analysis and bioinformatics analysis for miR-451a binding and enhancer analysis to eventually find the nuclear acticating target of miR-451a
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:First line chemotherapy with platinum and cetuximab is usually offered to RM-HNSCC pts. In the Extreme trial a median progression free survival (PFS) time of 5.6 months was reported. However, a small fraction of pts achieves a prolonged PFS (> than 12 months). Till now, no recognized predictive biological factor has been identified.
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: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.
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.