C-Myc drives nab-paclitaxel resistance in pancreatic cancer
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ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease with limited and very often, ineffective medical and surgical therapeutic options. The treatment of patients with advanced unresectable PDAC is restricted to systemic chemotherapy, a therapeutic intervention to which most eventually develop resistance. Recently, nab-paclitaxel has been added to the arsenal of first line therapies, and the combination of gemcitabine and nab-paclitaxel has modestly prolonged median overall survival. However, patients almost invariably succumb to the disease, and little is known about the mechanisms underlying nab-paclitaxel (n-PTX) resistance. Using the conditionally reprogrammed (CR) cell approach, we established and verified continuously growing cell cultures from treatment-naive PDAC patients. To study the mechanisms of primary drug resistance, nab-paclitaxel-resistant (n-PTX-R) cells were generated from primary cultures and drug resistance was verified in vivo, both in zebrafish and in athymic nude mouse xenograft models. Molecular analyses identified the sustained induction of c-MYC in the nab-paclitaxel-resistant cells. Depletion of c-Myc restored nab-paclitaxel sensitivity, as did treatment with either the MEK inhibitor, trametinib, or a small molecule activator of protein phosphatase 2a (SMAP). Implications: The strategies we have devised, including the patient-derived primary cells and the unique drug resistant isogenic cells, are rapid and easily applied in vitro and in vivo platforms to better understand the mechanisms of drug resistance and for defining effective therapeutic options on a patient by patient basis
Project description:Tumor-stroma interactions are critical in pancreatic ductal adenocarcinoma (PDAC) progression and therapeutics. Patient-derived xenograft (PDX) models faithfully recapitulate tumor-stroma interactions in PDAC, but conventional antibody-based immunoassay is largely inadequate to resolve or quantify tumor and stromal proteins. A species-deconvolved proteomics approach embedded in the ultra-high-resolution (UHR)-IonStar workflow can unambiguously quantify the proteins from tumor (human-derived) and stroma (mouse-derived) in PDX samples, enabling unbiased investigation of their proteomes with excellent quantitative reproducibility. With this strategy, 3 PDAC PDXs were analyzed. They were showed differential responses to treatment with Gemcitabine combined with nab-Paclitaxel (GEM+PTX), which is a first-line treatment regimen for PDAC. For each PDAC PDX, samples were collected after 24 hour and 192 hour with/without treatment, and each condition contained four biological replicates.
Project description:Aberrant tyrosine kinase activity can influence tumor growth and is regulated by phosphorylation. Pancreatic ductal adenocarcinoma (PDAC) is a very lethal disease, with minimal therapeutic options. We investigated phosphorylated kinases as target in PDAC. Mass spectrometry-based phosphoproteomic analysis was performed of PDAC cell lines to evaluate active kinases. Pathway analysis and inferred kinase activity was performed to identify novel targets. We investigated targeting of focal adhesion kinase in vitro with drug perturbations in combination with chemotherapeutics used against PDAC. Phosphoproteome analysis upon treatment was performed to evaluate signaling..PDAC cell lines portrayed high activity of multiple receptor tyrosine kinases. Non-receptor kinase, focal adhesion kinase (FAK), was identified in all cell lines by our phosphoproteomic screen and pathway analysis. Targeting of this kinase with defactinib validated reduced phosphorylation profiles. Additionally, FAK inhibition had anti-proliferative and anti-migratory effects. Combination with (nab-)paclitaxel had a synergistic effect on cell proliferation in vitro and reduced tumor growth in vivo. In conclusion, our study shows a high phosphorylation of several oncogenic receptor tyrosine kinases in PDAC cells and validated FAK inhibition as potential synergistic target with Nab-paclitaxel
Project description:Chemoresistance hampers the treatment of patients suffering from pancreatic ductal adenocarcinoma (PDAC). The present study aimed to evaluate the proteome and phosphoproteome of gemcitabine-sensitive and -resistant PDAC cells to identify novel targets and predictive biomarkers.The oncogenic capabilities of sensitive and resistant PDAC cells were evaluated in vitro and in vivo. Cultured cells were subsequently analysed by label-free mass spectrometry. Differential proteins and phosphopeptides were evaluated for Gene Ontology and predictive and / or prognostic biomarker potential by immunohistochemistry of tissue microarrays (TMAs). Differential analyses showed that resistant proteins are associated with membrane organization and microtubule regulation. Importantly, resistant cells displayed an increased sensitivity for paclitaxel treatment in vitro (p < 0.001) and nab-paclitaxel had a strong anti-tumour efficacy in vivo. Microtubule-associated protein 2 (MAP2) was found to be highly upregulated and phosphorylated in resistant cells. The identified resistance marker MAP2 emerged as a novel prognostic marker in PDAC patients treated with gemcitabine.
Project description:ATC is a very rare, but extremely aggressive form of thyroid malignancy, responsible for the highest mortality rate registered for thyroid cancer. In the patients without known genetic aberrations, the current treatment is still represented by palliative surgery and systemic mono- or combined-chemotherapy, which is often not fully effective for appearance of drug resistance. Comprehension of the mechanisms involved in the development of the resistance is therefore an urgent issue to suggest novel therapeutic approaches of this very aggressive malignancy. In this study, we created a model of anaplastic thyroid cancer (ATC) cells resistant to paclitaxel, to investigate the characteristics of these cells by analyzing the profile of gene expression and comparing with that of paclitaxel-sensitive original ATC cell lines. In addition, we evaluated the effects of Dihydrotanshinone I (DHT) on the viability and invasiveness of paclitaxel-resistant cells. ATC paclitaxel-resistant cells highlighted an overexpression of ABCB1 and a hyper-activation of the NF-κB compared to sensitive cells. DHT treatment results in a reduction of cell viability, and clonogenic ability of resistant cells. Moreover, DHT induces a decrement of NF-κB activity in SW1736-PTX and 8505C-PTX cells. In conclusion, to the best of our knowledge, the results of the present study are the first to demonstrate the antitumor effects of DHT on ATC cells resistant to Paclitaxel in vitro.
Project description:Oncolytic vaccinia virus (OVV) has demonstrated appropriate safety profiles for clinical development. Although OVV was designed to kill cancer cells efficiently, sensitivity to OVV varies in individual cancers. Here, we found that OVV was much more efficient in KFTX paclitaxel (PTX)-resistant ovarian cancer cells, compared to that in KFlow PTX-sensitive cells. Microarray analysis showed that urothelial carcinoma-associated 1 (UCA1) upregulation contributed to both enhanced PTX resistance and OVV spread.
Project description:N6-methyladenosine (m6A) is the most printed and prevalent mRNA modification, which was verified to be closely correlated with cancer occurrence and progression. As m6A demethlyase, the dysregulation of ALKBH5 was observed in various cancer. However, the role and underlying machinery of ALKBH5 in NSCLC pathogenesis, especially the chemo-resistance was poorly elucidated. The current study indicated that ALKBH5 was decreased during paclitaxel (PTX) resistant process and its down-regulation usually implied poor prognosis of NSCLC patients. Over-expression of ALKBH5 in PTX-resistant cells could suppressed cell proliferation and enhanced chemo-sensitivity. Whereas, knockdown of ALKBH5 exerted opposite effect, which further supported the tumor suppressive role of ALKBH5. Over-expression of ALKBH5 also could reverse the EMT process in PTX-resistant cancer cells. Mechanistically, data of RNA-seq, Real-time PCR and western blotting indicted that CEMIP, also known as KIAA1199, may be the downstream target of ALKBH5. And ALKBH5 could negatively regulated the CEMIP level by decreasing its mRNA stability. Collectively, current data demonstrated that ALKBH5/CEMIP axis modulates the EMT process in NSCLC, which in turn regulates chemo-sensitivity of cancer cells to PTX.
Project description:The goal of this study is to find a molecular signature that can predict response or resistance to Gemcitabine + Nab-paclitaxel therapy in pancreatic cancer (PC), to aid treatment selection for each patient. To this end, we analyzed blood-derived extracellular vesicles (EV).
Project description:FastQ files from 16S sequencing of fecal samples from pancreatic cancer xenografted mice not treated (CTRL) and treated with chemotherapy (GEM+nab-PTX), probiotics (PRO) and chemotherapy + probiotics (GEM+nab-PTX+PRO)
Project description:Pancreatic adenocarcinoma is one of the most aggressive and lethal forms of cancer. Chemotherapy is the primary treatment for pancreatic cancer, but resistance to the drugs used remains a major challenge. A genome-wide CRISPR interference and knockout screen in the PANC-1 cell line with the drug nab-paclitaxel has identified a group of spindle assembly checkpoint (SAC) genes that enhance survival in nab-paclitaxel. Knockdown of these SAC genes (BUB1B, BUB3, and TTK) attenuates paclitaxel-induced cell death. Cells treated with the small molecule inhibitors BAY 1217389 or MPI 0479605, targeting the threonine tyrosine kinase (TTK), also enhance survival in paclitaxel. Overexpression of these SAC genes does not affect sensitivity to paclitaxel. These discoveries have helped to elucidate the mechanisms behind paclitaxel cytotoxicity. The outcomes of this investigation may pave the way for a deeper comprehension of the diverse responses of pancreatic cancer to therapies including paclitaxel. Additionally, they could facilitate the formulation of novel treatment approaches for pancreatic cancer.
Project description:The microtubule-stabilising drug paclitaxel has activity in relapsed ovarian cancer. However, resistance frequently develops. Oncolytic adenoviruses are a novel cancer therapy, and replicate selectively within and lyse malignant cells, leading to productive infection of neighbouring cells. We found increased efficacy of adenoviruses of multiple subtypes in paclitaxel-resistant ovarian cancer cells. There was increased expression of a key adenovirus receptor, CAR (coxsackie adenovirus receptor), due to increased transcription that resulted from histone modification. Moreover, CAR transcription increased in intraperitoneal xenografts with acquired paclitaxel resistance and in tumours from patients with paclitaxel-resistant ovarian cancer. Finally, we identified dysregulated cell cycle control as a second mechanism of increased adenovirus efficacy in paclitaxel-resistant ovarian cancer and that inhibition of CDK4/6 using PD-0332991 was able both to reverse paclitaxel resistance and reduce adenovirus efficacy. Thus, paclitaxel resistance increases oncolytic adenovirus efficacy via at least two separate mechanisms. Parental SKOV3 and paclitaxel-resistant SKOV3-TR cells were analysed in duplicate