RESUMEN
The immunoregulatory cation channel TMEM176B plays a dual role in tumor immunity. On the one hand, TMEM176B promotes antigen cross-presentation to CD8+ T cells by regulating phagosomal pH in dendritic cells (DCs). On the other hand, it inhibits NLRP3 inflammasome activation through ionic mechanisms in DCs, monocytes and macrophages. We speculated that formulating BayK8644 in PEGylated chitosan nanoparticles (NP-PEG-BayK8644) should slowly release the compound and by that mean avoid cross-presentation inhibition (which happens with a fast 30 min kinetics) while still triggering inflammasome activation. Chitosan nanocarriers were successfully obtained, exhibiting a particle size within the range of 200 nm; they had a high positive surface charge and a 99 % encapsulation efficiency. In in vitro studies, NP-PEG-BayK8644 did not inhibit antigen cross-presentation by DCs, unlike the free compound. The NP-PEG-BayK8644 activated the inflammasome in a Tmem176b-dependent manner in DCs. We administered either empty (eNP-PEG) or NP-PEG-BayK8644 to mice with established tumors. NP-PEG-BayK8644 significantly controlled tumor growth and improved mice survival compared to both eNP-PEG and free BayK8644 in melanoma and lymphoma models. This effect was associated with enhanced inflammasome activation by DCs in the tumor-draining lymph node and infiltration of the tumor by CD8+ T cells. Thus, encapsulation of BayK8644 in chitosan NPs improves the anti-tumoral properties of the compound by avoiding inhibition of antigen cross-presentation.
Asunto(s)
Inmunidad Adaptativa , Quitosano , Células Dendríticas , Inmunidad Innata , Nanopartículas , Quitosano/química , Quitosano/farmacología , Animales , Nanopartículas/química , Ratones , Inmunidad Adaptativa/efectos de los fármacos , Células Dendríticas/inmunología , Células Dendríticas/efectos de los fármacos , Inmunidad Innata/efectos de los fármacos , Proteínas de la Membrana/inmunología , Inflamasomas/metabolismo , Línea Celular Tumoral , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/efectos de los fármacos , Ratones Endogámicos C57BL , Melanoma Experimental/inmunología , Melanoma Experimental/patología , Melanoma Experimental/tratamiento farmacológico , Polietilenglicoles/química , Polietilenglicoles/farmacologíaRESUMEN
Cellular senescence is an endpoint of chemotherapy, and targeted therapies in melanoma and the senescence-associated secretory phenotype (SASP) can affect tumor growth and microenvironment, influencing treatment outcomes. Metabolic interventions can modulate the SASP, and an enhanced mitochondrial energy metabolism supports resistance to therapy in melanoma cells. Herein, we assessed the mitochondrial function of therapy-induced senescent melanoma cells obtained after exposing the cells to temozolomide (TMZ), a methylating chemotherapeutic agent. Senescence induction in melanoma was accompanied by a substantial increase in mitochondrial basal, ATP-linked, and maximum respiration rates and in coupling efficiency, spare respiratory capacity, and respiratory control ratio. Further examinations revealed an increase in mitochondrial mass and length. Alterations in mitochondrial function and morphology were confirmed in isolated senescent cells, obtained by cell-size sorting. An increase in mitofusin 1 and 2 (MFN1 and 2) expression and levels was observed in senescent cells, pointing to alterations in mitochondrial fusion. Silencing mitofusin expression with short hairpin RNA (shRNA) prevented the increase in mitochondrial length, oxygen consumption rate and secretion of interleukin 6 (IL-6), a component of the SASP, in melanoma senescent cells. Our results represent the first in-depth study of mitochondrial function in therapy-induced senescence in melanoma. They indicate that senescence increases mitochondrial mass, length and energy metabolism; and highlight mitochondria as potential pharmacological targets to modulate senescence and the SASP.
Asunto(s)
Senescencia Celular , Metabolismo Energético , GTP Fosfohidrolasas/metabolismo , Melanoma Experimental/metabolismo , Mitocondrias/metabolismo , Proteínas de Neoplasias/metabolismo , Animales , GTP Fosfohidrolasas/genética , Silenciador del Gen , Interleucina-6/genética , Interleucina-6/metabolismo , Melanoma Experimental/genética , Melanoma Experimental/patología , Ratones , Mitocondrias/genética , Mitocondrias/patología , Dinámicas Mitocondriales/efectos de los fármacos , Dinámicas Mitocondriales/genética , Proteínas de Neoplasias/genética , Temozolomida/farmacologíaRESUMEN
Although immune checkpoint blockers have yielded significant clinical benefits in patients with different malignancies, the efficacy of these therapies is still limited. Here, we show that disruption of transmembrane protein 176B (TMEM176B) contributes to CD8+ T cell-mediated tumor growth inhibition by unleashing inflammasome activation. Lack of Tmem176b enhances the antitumor activity of anti-CTLA-4 antibodies through mechanisms involving caspase-1/IL-1ß activation. Accordingly, patients responding to checkpoint blockade therapies display an activated inflammasome signature. Finally, we identify BayK8644 as a potent TMEM176B inhibitor that promotes CD8+ T cell-mediated tumor control and reinforces the antitumor activity of both anti-CTLA-4 and anti-PD-1 antibodies. Thus, pharmacologic de-repression of the inflammasome by targeting TMEM176B may enhance the therapeutic efficacy of immune checkpoint blockers.
Asunto(s)
Antineoplásicos/farmacología , Inflamasomas/efectos de los fármacos , Inflamasomas/inmunología , Proteínas de la Membrana/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/farmacología , Animales , Anticuerpos Monoclonales/farmacología , Linfocitos T CD8-positivos/efectos de los fármacos , Células CHO , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cricetulus , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Neoplasias/metabolismo , Xenopus laevis/metabolismoRESUMEN
Colorectal carcinoma (CRC) is the second leading cause of cancer mortality worldwide. O-glycosylated mucins at the cell surface of colonic mucosa exhibit alterations in cancer and are involved in fundamental biological processes, including invasion and metastasis. Certain members of the GalNAc-transferase family may be responsible for these changes and are being investigated as novel biomarkers of cancer. In the present study the prognostic significance of GalNAc-T6 was investigated in patients with CRC patients. GalNAc-T6 expression was observed in all three colon cancer cell lines analyzed by reverse transcription-polymerase chain reaction, immunofluorescence and flow cytometry. A cohort of 81 colon cancer specimens was analyzed by immunohistochemical staining using MAb T6.3. It was demonstrated that GalNAc-T6 was expressed in 35/81 (43%) cases of colon cancer but not in the normal colonic mucosa. No association was observed with the clinical-pathologic parameters. However, patients expressing GalNAc-T6 had a significantly increased overall survival (median, 58 months; P<0.001) compared with GalNAc-T6 negative patients, especially those with advanced disease. These results suggest that GalNAc-T6 expression predicts an improved outcome in patients with CRC. The molecular mechanism underlying the less aggressive behavior of colon cancer cells expressing GalNAc-T6 remains to be elucidated.
RESUMEN
A one-pot efficient, practical and eco-friendly synthesis of tocopherol analogues has been developed using water or solvent free conditions via Passerini and Ugi multicomponent reactions. These reactions can be optimized using microwave irradiation or ultrasound as the energy source. Accordingly, a small library of 30 compounds was prepared for biological tests. The evaluation of the antiproliferative activity in the human solid tumor cell lines A549 (lung), HBL-100 (breast), HeLa (cervix), SW1573 (lung), T-47D (breast), and WiDr (colon) provided lead compounds with GI50 values between 1 and 5 µM. A structure-activity relationship is also discussed. One of the studied compounds comes up as a future candidate for the development of potent tocopherol-mimetic therapeutic agents for cancer.
Asunto(s)
Antineoplásicos/farmacología , Tocoferoles/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Relación Estructura-Actividad , Tocoferoles/síntesis química , Tocoferoles/químicaRESUMEN
CIGB-552 is a second generation antitumor peptide that displays potent cytotoxicity in lung and colon cancer cells. The nuclear subproteome of HT-29 colon adenocarcinoma cells treated with CIGB-552 peptide was identified and analyzed [1]. This data article provides supporting evidence for the above analysis.
RESUMEN
The second generation peptide CIGB-552 has a pro-apoptotic effect on H460 non-small cell lung cancer cells and displays a potent cytotoxic effect in HT-29 colon adenocarcinoma cells though its action mechanism is ill defined. Here, we present the first proteomic study of peptide effect in HT-29 cells using subcellular fractionation, protein and peptide fractionation by DF-PAGE and LC-MS/MS peptide identification. In particular, we explored the nuclear proteome of HT-29 cells at a 5h treatment identifying a total of 68 differentially modulated proteins, 49 of which localize to the nucleus. The differentially modulated proteins were analyzed following a system biology approach. Results pointed to a modulation of apoptosis, oxidative damage removal, NF-κB activation, inflammatory signaling and of cell adhesion and motility. Further Western blot and flow-cytometry experiments confirmed both pro-apoptotic and anti-inflammatory effects of CIGB-552 peptide in HT-29 cells.
Asunto(s)
Adenocarcinoma , Antineoplásicos/farmacología , Péptidos de Penetración Celular/farmacología , Neoplasias del Colon , Proteínas de Neoplasias/biosíntesis , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Apoptosis/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Humanos , Proteómica , Transducción de Señal/efectos de los fármacosRESUMEN
Patients infected with HIV-1, the etiological agent of AIDS, have increased intestinal permeability, which allows for the passage of microbial products, including Toll-like receptor (TLR) ligands, into circulation. The exposure of HIV-1-infected cells to certain TLR agonists affects viral replication, but studies associating viral production with the activation of TLR2 in HIV-1-infected cells are rare and controversial. Here, we report that the TLR2 ligands Zymosan and Pam3CSK4 potently inhibit HIV-1 replication in acutely infected monocyte-derived macrophages and the exposure to TLR2 ligands prior to infection renders macrophages refractory to HIV-1 production. Macrophage treatment with Pam3CSK4 did not change the cellular expression of the HIV-1 entry receptors CD4 and CCR5. Both TLR2 ligands increased the macrophage production of ß-chemokines and IL-10, and the blockage of these soluble factors prevented the inhibitory effect of TLR2 activation on HIV-1 replication. Our findings show that the direct engagement of TLR2 in HIV-1-infected macrophages increase cellular resistance to HIV-1 infection, and that controlling HIV-1 replication with agonists for TLR2 might have implications for the development of antiretroviral therapies.