Project description:The transcriptome changes of breast cancer cell SUM1315, with or without co-culture with bone marrow stroma cells, upon cisplatin (CDDP) treatment.
Project description:Chemotherapy resistance presents a major hurdle for cancer treatment. We proposed to identify the molecular changes through which breast cancer cells evolve resistance to conventional treatment, here cisplatin, so targeted therapy can be developed. Candidate approach RNAi screening was combined with cisplatin treatment in order to identify molecular pathways conferring survival advantages. The screening identified ATP7A, a copper transport ATPase responsible for the intercellular movement and sequestering of cisplatin, as a therapeutic target. Copper chelation with tetrathiomolybdate (TM) targets ATP7A. TM in combination with cisplatin sensitized drug-resistant breast cancer cells. Allograft and xenograft models in aythymic mice treated with TM/cisplatin combination therapy inhibited tumor growth and increased survival compared with monotreated mice. Examination of the molecular effects of TM on cisplatin efficacy in drug-resistant tumors revealed reduced levels of APT7A, reduced cisplatin sequestering by ATP7A and increased nuclear availability of cisplatin. Further, we showed that TM treatment combined with cisplatin reduced the half-life of ATP7A in human breast cancer cell lines. This finding offered the potential to combat drug platinum-resistant tumors and sensitize patients to conventional breast cancer treatments by identifying and targeting resistant tumors’ unique molecular adaptations.
Project description:Abstract:
The cancer stem cell hypothesis has gained currency in recent times but concerns remain about its scientific foundations because of significant gaps that exist between research findings and comprehensive knowledge about cancer stem cells (CSCs). In this light, a mathematical model that considers hematopoietic dynamics in the diseased state of the bone marrow and peripheral blood is proposed and used to address findings about CSCs. The ensuing model, resulting from a modification and refinement of a recent model, develops out of the position that mathematical models of CSC development, that are few at this time, are needed to provide insightful underpinnings for biomedical findings about CSCs as the CSC idea gains traction. Accordingly, the mathematical challenges brought on by the model that mirror general challenges in dealing with nonlinear phenomena are discussed and placed in context. The proposed model describes the logical occurrence of discrete time delays, that by themselves present mathematical challenges, in the evolving cell populations under consideration. Under the challenging circumstances, the steady state properties of the model system of delay differential equations are obtained, analyzed, and the resulting mathematical predictions arising therefrom are interpreted and placed within the framework of findings regarding CSCs. Simulations of the model are carried out by considering various parameter scenarios that reflect different experimental situations involving disease evolution in human hosts.
Model analyses and simulations suggest that the emergence of the cancer stem cell population alongside other malignant cells engenders higher dimensions of complexity in the evolution of malignancy in the bone marrow and peripheral blood at the expense of healthy hematopoietic development. The model predicts the evolution of an aberrant environment in which the malignant population particularly in the bone marrow shows tendencies of reaching an uncontrollable equilibrium state. Essentially, the model shows that a structural relationship exists between CSCs and non-stem malignant cells that confers on CSCs the role of temporally enhancing and stimulating the expansion of non-stem malignant cells while also benefitting from increases in their own population and these CSCs may be the main protagonists that drive the ultimate evolution of the uncontrollable equilibrium state of such malignant cells and these may have implications for treatment.
Project description:A mesenchymal rich stroma such as cancer-associated fibroblasts (CAFs) in breast tumors favors the selection of cancer clones with enhanced bone metastatic ability. To determine the cancer cell transcriptomic response to the mesenchymal stroma, we supplemented experimental mammary tumours with or without exogenous mesenchymal cells. We used bone marrow-derived human mesenchymal stem cells (MSCs) as a source of mesenchymal stroma, as MSCs have been shown to undergo CAF-like differentiation. We engineered the cancer cells to express an EGFP-tagged version of ribosomal protein L10a (EGFP-L10a). This allows the retrieval of cancer cell specific transcripts rapidly from whole tumor lysates by translating ribosome affinity purification (TRAP) and direct profiling of cancer cell gene expression patterns when they are in situ.
Project description:A mesenchymal rich stroma such as cancer-associated fibroblasts (CAFs) in breast tumors favors the selection of cancer clones with enhanced bone metastatic ability. To determine the cancer cell transcriptomic response to the mesenchymal stroma, we supplemented experimental mammary tumours with or without exogenous mesenchymal cells. We used bone marrow-derived human mesenchymal stem cells (MSCs) as a source of mesenchymal stroma, as MSCs have been shown to undergo CAF-like differentiation. We engineered the cancer cells to express an EGFP-tagged version of ribosomal protein L10a (EGFP-L10a). This allows the retrieval of cancer cell specific transcripts rapidly from whole tumor lysates by translating ribosome affinity purification (TRAP) and direct profiling of cancer cell gene expression patterns when they are in situ. EGFP-10a+ MDA-MB-231 cells were orthotopically injected into the mammary fat pad with or without 1:1 ratio of MSCs. The mammary tumors were retrieved for TRAP-RNAseq profiling after 3 weeks.
Project description:Breast tumor cells were found to remodel the bone marrow vascular microenviornment to support metastatic expansion. To identify tumor-derived factors that stimulate marrow endothelium, we studied the transcriptomes of four isogenic murine mammary tumor cell lines, 4T1.2, 4T1, 66cl4 and 67NR. To gain insight into the host vasculature in response to tumor colonization, we analysed the transcriptional signatures of EMCNhi/CD31hi endothelial cells extracted from heavily infiltrated bone marrow stroma (Metastatic) and from adjacent tumour-free bone marrow stroma (Non-metastatic), as well as from healthy bones (Control). This SuperSeries is composed of the SubSeries listed below.
Project description:Ammonium tetrathiomolybdate treatment targets the copper transporter ATP7A in cisplatin-resistant breast cancer TM and cisplatin sensitize resistant breast cancer.