Project description:Due to lack of targetable receptors and intertumoral heterogeneity, triple negative breast cancer (TNBC) remains particularly difficult to treat. Doxorubicin (DOX) is typically used as nonselective neoadjuvant chemotherapy, but the diversity of treatment efficacy remains unclear. Comparable to variability in clinical response, an experimental model of TNBC using a 4T1 syngeneic mouse model was found to elicit a differential response to a seven-day treatment regimen of DOX. Single-cell RNA sequencing identified an increase in T cells in tumors that responded to DOX treatment compared to tumors that continued to grow uninhibited. Additionally, compared to resistant tumors, DOX sensitive tumors contained significantly more CD4 T helper cells (339%), γδ T cells (727%), Naïve T cells (278%), and activated CD8 T cells (130%). Furthermore, transcriptional profiles of tumor infiltrated T cells in DOX responsive tumors revealed decreased exhaustion, increased chemokine/cytokine expression, and increased activation and cytotoxic activity. γδ T cell derived IL-17A was identified to be highly abundant in the sensitive tumor microenvironment. IL-17A was also found to directly increase sensitivity of TNBC cells in combination with DOX treatment. In TNBC tumors sensitive to DOX, increased IL-17A levels lead to a direct effect on cancer cell responsiveness and chronic stimulation of tumor infiltrated T cells leading to improved chemotherapeutic efficacy. IL-17A's role as a chemosensitive cytokine in TNBC may offer new opportunities for treating chemoresistant breast tumors and other cancer types.
Project description:Due to lack of targetable receptors and intertumoral heterogeneity, triple negative breast cancer (TNBC) remains particularly difficult to treat. Doxorubicin (DOX) is typically used as nonselective neoadjuvant chemotherapy, but the diversity of treatment efficacy remains unclear. Comparable to variability in clinical response, an experimental model of TNBC using a 4T1 syngeneic mouse model was found to elicit a differential response to a seven-day treatment regimen of DOX. Single-cell RNA sequencing identified an increase in T cells in tumors that responded to DOX treatment compared to tumors that continued to grow uninhibited. Additionally, compared to resistant tumors, DOX sensitive tumors contained significantly more CD4 T helper cells (339%), γδ T cells (727%), Naïve T cells (278%), and activated CD8 T cells (130%). Furthermore, transcriptional profiles of tumor infiltrated T cells in DOX responsive tumors revealed decreased exhaustion, increased chemokine/cytokine expression, and increased activation and cytotoxic activity. γδ T cell derived IL-17A was identified to be highly abundant in the sensitive tumor microenvironment. IL-17A was also found to directly increase sensitivity of TNBC cells in combination with DOX treatment. In TNBC tumors sensitive to DOX, increased IL-17A levels lead to a direct effect on cancer cell responsiveness and chronic stimulation of tumor infiltrated T cells leading to improved chemotherapeutic efficacy. IL-17A's role as a chemosensitive cytokine in TNBC may offer new opportunities for treating chemoresistant breast tumors and other cancer types.
Project description:An immunosuppressive tumor microenvironment is one of the major obstacles to the efficacy of standard chemotherapies, such as doxorubicin, used to treat triple negative breast cancer (TNBC). Combination therapy may be a potential way to overcome this barrier. A nitric oxide (NO) donor such as glyceryl trinitrate (GTN) has shown beneficial effects in combination with standard chemotherapy/radiotherapy in patients with cancer. In this study, we investigated the combination of doxorubicin/GTN in a mouse model of TNBC. The results indicated that GTN significantly improved the anti-tumor efficacy of doxorubicin in mouse models of BC. Flow cytometry and immunohistochemistry analysis revealed that the GTN/doxorubicin combination increases the intra-tumor recruitment and activation of CD8+ lymphocytes that is associated with the ability of doxorubicin and doxorubicin/GTN to recruit and dampen the immunosuppressive function of PMN-MDSCs PD-L1low. Mechanistically, in PMN-MDSC, doxorubicin/GTN combination reduced STAT5 phosphorylation, while GTN +/- doxorubicin induced a ROS-dependent cleavage of STAT5 associated with a decrease of FATP2. Our results identify a new combination enhancing the immune-mediated anticancer therapy in a TNBC mouse model through a ROS-dependent reprograming of PMN-MDSCs towards a less immunosuppressive phenotype. These findings open up a new therapeutic perspective by combining GTN to doxorubicin for patients with TNBC.
Project description:A major limitation in the cancer treatment is the ability of cancer cells to become resistant to chemotherapeutic drugs, by multidrug establishment. Here, we evaluate the possibility to utilize MC70, either as ABC transporters inhibitor or as anticancer agent, in monotherapy or in combination with doxorubicin for cancer treatment. The study was carried out in MCF7/ADR and Caco-2, breast and colon cancer cells, respectively. Cell growth and apoptosis were measured by MTT assay and DNA laddering Elisa kit, respectively. Cell cycle perturbation and cellular targets modulation were analyzed by flow cytometry and western blotting, respectively. MC70 was analyzed for its interaction with ABC transporters, MDR-1, BCRP and MRP-1, and for its anticancer activity. In MCF7/ADR, MC70 slight inhibited cell proliferation and strongly enhanced doxorubicin effectiveness; conversely in Caco-2, it inhibited cell growth without affecting doxorubicin efficacy. In addition, it induced apoptosis, canceled in favor of necrosis when it was given in combination with high doses of the anthracycline. Moreover, MC70 inhibited cell migration probably through its residual activity as sigma-1 ligand. Among the hypothesized molecular and cellular mechanisms responsible for all these effects, modulations of cell cycle, of pAkt and of the three MAPKs phosphorylation were evidenced while activity at transcription level was excluded. MC70 can be considered as a potential new anticancer agent with the capability to enhance doxorubicin effectiveness and an interesting role in the treatment of chemotherapy resistant tumors. The study included the basic characterization of MC70 efficacy as inhibitor of MDR transporters, the investigation of its anticancer behavior and the exploration of the molecular and cellular mechanisms responsible for it
Project description:We have used a cell model for triple negative breast cancer, CAL51 cells, to study the transcriptional profiling of chemotherapy drug response. A doxorubicin resistant derivative has been generated, named CALDOX, which is able to proliferate in the continuos presence of 0.4 micro molar doxorubicin in the culture medium. In addition, both naive CAL51 and drug resistant CALDOX cells, the short-term response to doxorubicin treatment has been studied.
Project description:The anthracycline doxorubicin is a highly effective anti-cancer drug associated with severe side effects, including secondary tumors and cardiotoxicity. Doxorubicin induces DNA damage through double-strand breaks (DSBs) and epigenetic or chromatin damage through histone eviction. We examined whether separation of these activities can help to detoxify doxorubicin, while maintaining its chemotherapeutic efficacy. We show that anthracycline variants harboring the histone eviction activity alone remain potent anti-cancer drugs, while greatly alleviating cardiotoxicity and secondary tumor formation. We thus demonstrate that treatment-limited side effects of doxorubicin can be synthesized away, yielding effective chemotherapeutics towards improved and prolonged treatment responses and higher patient quality of life.
Project description:A major limitation in the cancer treatment is the ability of cancer cells to become resistant to chemotherapeutic drugs, by multidrug establishment. Here, we evaluate the possibility to utilize MC70, either as ABC transporters inhibitor or as anticancer agent, in monotherapy or in combination with doxorubicin for cancer treatment. The study was carried out in MCF7/ADR and Caco-2, breast and colon cancer cells, respectively. Cell growth and apoptosis were measured by MTT assay and DNA laddering Elisa kit, respectively. Cell cycle perturbation and cellular targets modulation were analyzed by flowcytometry and western blotting, respectively. MC70 was analyzed for its interaction with ABC transporters, MDR-1, BCRP and MRP-1, and for its anticancer activity. In MCF7/ADR, MC70 slight inhibited cell proliferation and strongly enhanced doxorubicin effectiveness; conversely in Caco-2, it inhibited cell growth without affecting doxorubicin efficacy. In addition, it induced apoptosis, canceled in favor of necrosis when it was given in combination with high doses of the anthracycline. Moreover, MC70 inhibited cell migration probably through its residual activity as sigma-1 ligand. Among the hypothesized molecular and cellular mechanisms responsible for all these effects, modulations of cell cycle, of pAkt and of the three MAPKs phosphorylation were evidenced while activity at transcription level was excluded. MC70 can be considered as a potential new anticancer agent with the capability to enhance doxorubicin effectiveness and an interesting role in the treatment of chemotherapy resistant tumors.