Project description:Ribosome profiling is a widespread tool for studying translational dynamics in human cells. Its central assumption is that ribosome footprint density on a transcript quantitatively reflects protein synthesis. Here, we test this assumption using pulsed-SILAC (pSILAC) high-accuracy targeted proteomics. We focus on multiple myeloma cells exposed to bortezomib, a first-line chemotherapy and proteasome inhibitor. In the absence of drug effects, we found that direct measurement of protein synthesis by pSILAC correlated well with indirect measurement of synthesis from ribosome footprint density. This correlation, however, broke down under bortezomib-induced stress. By developing a statistical model integrating longitudinal proteomic and mRNA-seq measurements, we found that proteomics could directly detect global alterations in translational rate caused by bortezomib; these changes are not detectable by ribosomal profiling alone. Further, by incorporating pSILAC data into a gene expression model, we predict cell-stress specific proteome remodeling events. These results demonstrate that pSILAC provides an important complement to ribosome profiling in measuring proteome dynamics. Timecourse experiment with six points over 48hr after bortezomib exposure in MM.1S myeloma cells. mRNA-seq and ribosome profiling data at each time point.
Project description:Oxaliplatin as a first-line drug frequently causes the chemo-resistance on colorectal cancer (CRC). N6-methyladenosine (m6A) methylation has been largely acknowledged in multiple biological functions. However, the molecular mechanisms underlying the m6A methylation in modulating anticancer drug resistance in CRC are still obscure. In present study, RNA-seq was conducted to investigate the transcriptome of HCT116, HCT116 cells with oxaliplatin resistance (HCT116R), HCT8 and HCT8 cells with oxaliplatin resistance (HCT8R).
Project description:Oxaliplatin as a first-line drug frequently causes the chemo-resistance on colorectal cancer (CRC). N6-methyladenosine (m6A) methylation has been largely acknowledged in multiple biological functions. However, the molecular mechanisms underlying the m6A methylation in modulating anticancer drug resistance in CRC are still obscure. In present study, RNA-seq was conducted to investigate the transcriptome of CRC tissues from three patients at different disease stages (CapeOx combined chemotherapy sensitivity and resistance).
Project description:Ribosome profiling is a widespread tool for studying translational dynamics in human cells. Its central assumption is that ribosome footprint density on a transcript quantitatively reflects protein synthesis. Here, we test this assumption using pulsed-SILAC (pSILAC) high-accuracy targeted proteomics. We focus on multiple myeloma cells exposed to bortezomib, a first-line chemotherapy and proteasome inhibitor. In the absence of drug effects, we found that direct measurement of protein synthesis by pSILAC correlated well with indirect measurement of synthesis from ribosome footprint density. This correlation, however, broke down under bortezomib-induced stress. By developing a statistical model integrating longitudinal proteomic and mRNA-seq measurements, we found that proteomics could directly detect global alterations in translational rate caused by bortezomib; these changes are not detectable by ribosomal profiling alone. Further, by incorporating pSILAC data into a gene expression model, we predict cell-stress specific proteome remodeling events. These results demonstrate that pSILAC provides an important complement to ribosome profiling in measuring proteome dynamics.
Project description:The study was done to identify the differentially expressed genes in response to Doxorubicin drug resistance in the 143B human osteosarcoma cell line, using the Microarray technology. Keywords: drug resistance; dual channel; cell line based; doxorubicin resistance; Human osteosarcoma cell line
Project description:Chemotherapeutics cause the detachment and death of adherent cancer cells. When studying the proteome changes to determine the protein target and mechanism of action of anticancer drugs, the still-attached cells are normally used, while the detached cells are usually ignored. Here we tested the hypothesis that proteomes of detached cells contain valuable information and therefore separately analyzed the proteomes of detached and attached HCT-116, A375 and RKO cells obtained 48 h after treatment with 5-fluorouracil, methotrexate and paclitaxel. Combined proteome data provided a more accurate identification of drug targets. Six proteins consistently up- or down-regulated in the detached vs attached cells regardless of the drug and cell type were targeted by siRNA. Knocking down USP11, CTTN, ACAA2 and EIF4H had anti-proliferative effects, targeting UHRF1 additionally sensitized the cells to the anticancer drugs, while knocking down RNF-40 increased cell survival against the treatments. Therefore, these proteins are likely to be involved in general cell death and survival decisions. Adding detached cells to the analysis could become a standard practice in expression proteomics of drug-treated cells.
Project description:Integrins are heterodimeric cell surface glycoproteins used by cells to bind to the extracellular matrix (ECM) and regulate tumor cell proliferation, migration and survival. A causative relationship between integrin expression and resistance to anticancer drugs has been demonstrated in different tumors, including head and neck squamous cell carcinoma. Using a Cal27 tongue squamous cell carcinoma model, we have previously demonstrated that de novo expression of integrin αVβ3 confers resistance to several anticancer drugs (cisplatin, mitomycin C and doxorubicin) through a mechanism involving downregulation of active Src, increased cell migration and invasion. In the integrin αVβ3 expressing Cal27-derived cell clone 2B1, αVβ5 expression was also increased, but unrelated to drug resistance. To identify the integrin adhesion complex (IAC) components that contribute to the changes in Cal27 and 2B1 cell adhesion and anticancer drug resistance, we isolated IACs from both cell lines. Mass spectrometry (MS)-based proteomics analysis indicated that both cell lines preferentially use integrin α6β4, which is classically found in hemidesmosomes. The anticancer drug resistant cell clone 2B1 demonstrated an increased level of α6β4 accompanied with increased deposition of a laminin-332-containing ECM. Immunofluorescence and electron microscopy demonstrated the formation of type II hemidesmosomes by both cell types. Furthermore, suppression of α6β4 expression in both lines conferred resistance to anticancer drugs. Taken together, our results identify a key role for α6β4-containing type II hemidesmosomes in regulating anticancer drug sensitivity.