RESUMO
BACKGROUND: Tumor-associated macrophages (TAMs) are the predominant immune cells in the tumor microenvironment and portend poor prognosis. However, the molecular mechanisms underlying the tumor promotion of TAMs have not been fully elucidated. METHODS: Coculture of gastric cancer cells with U937 cells was performed to investigate the impact of TAMs on cancer cell behavior. MicroRNA (miRNA) microarray and bioinformatics were applied to identify the involved miRNAs and the functional target genes. The regulation of the miRNA on its target gene was studied using anti-miRNA and miRNA mimic. RESULTS: Coculture with CD204+ M2-like TAMs increased proliferation, migration, and epithelial-mesenchymal transition of gastric cancer cells. MiR-210 was the most upregulated miRNA in cancer cells identified by miRNA microarray after coculture. In gastric cancer tissues, miR-210 expression was positively correlated with CD204+ M2-like TAM infiltration. Inactivation of miR-210 by antimir attenuated CD204+ M2-like TAMs-induced cancer cell migration. Using pharmacological inhibitors and neutralizing antibodies, CD204+ M2-like TAMs-secreted TNFα was found to upregulate miR-210 through NF-κB/HIF-1α signaling. Bioinformatics analysis showed netrin-4 (NTN4) as a potential target of miR-210 to suppress gastric cancer cell migration. We also found an inverse expression between miR-210 and NTN4 in cancer cells after coculture or in tumor xenografts. Anti-miR-210 increased NTN4 expression, while miR-210 mimics downregulated NTN4 in cancer cells. Reporter luciferase assays showed that MiR-210 mimics suppressed NTN4 3' untranslated region-driven luciferase activity in cancer cells, but this effect was blocked after mutating miR-210 binding site. CONCLUSIONS: CD204+ M2-like TAMs can utilize the TNF-α/NF-κB/HIF-1α/miR-210/NTN4 pathway to facilitate gastric cancer progression.
Assuntos
MicroRNAs , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , NF-kappa B , Macrófagos Associados a Tumor , MicroRNAs/genética , Luciferases , Microambiente Tumoral , NetrinasRESUMO
BACKGROUND: Sorafenib (SOR) is the first line treatment for advanced hepatocellular carcinoma (HCC), but resistance develops frequently. Tumor-associated macrophages (TAMs) have been reported to affect the progression of HCC. We therefore aimed to study the role of TAMs in promoting SOR resistance. METHODS: Immunofluorescence staining for the M2 marker CD204 and the cancer stem cell (CSC) markers CD44 and CD133 was performed in paired HCC and adjacent noncancerous tissues and HCC tissues stratified by response of SOR treatment. HCC/U937 coculture system and cytokines were used to induce M2 polarization for studying the effects of M2 TAMs on CSC properties and apoptotic death of HCC cells after SOR treatment. RESULTS: Higher expression of CD204, CD44, and CD133 was observed in patients with SOR nonresponse (SNR) than in those with SOR response (SR), suggesting that SNR is positively correlated to levels of CSCs and M2 TAMs. After coculture, M2 TAMs could increase the level of CSCs but decrease SOR-induced apoptosis. Incubation of HCC cells with coculture conditioned medium increased the formation of spheres that were resistant to SOR. Furthermore, CXCL1 and CXCL2 were found to be the potential paracrine factors released by M2 TAMs to upregulate SOR resistance in HCC cells. Treatment with CXCL1 and CXCL2 could increase HCC CSC activity but decrease SOR-induced apoptosis by affecting BCL-2 family gene expression. Using pharmacological inhibitors, CXCR2/ERK signaling was found to be critical to CXCL1- and CXCL2-mediated SOR resistance. CONCLUSION: This study identified CXCL1, CXCL2, and their downstream CXCR2/ERK signaling as potential therapeutic targets to overcome SOR resistance in HCC.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Sorafenibe/farmacologia , Macrófagos Associados a Tumor , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Receptores de Interleucina-8B/genéticaRESUMO
Epigenetic inhibitors have shown anticancer effects. Combination chemotherapy with epigenetic inhibitors has shown high effectiveness in gastric cancer clinical trials, but severe side effect and local progression are the causes of treatment failure. Therefore, we sought to develop an acidity-sensitive drug delivery system to release drugs locally to diminish unfavorable outcome of gastric cancer. In this study, we showed that, as compared with single agents, combination treatment with the demethylating agent 5'-aza-2'-deoxycytidine and HDAC inhibitors Trichostatin A or LBH589 decreased cell survival, blocked cell cycle by reducing number of S-phase cells and expression of cyclins, increased cell apoptosis by inducing expression of Bim and cleaved Caspase 3, and reexpressed tumor suppressor genes more effectively in MGCC3I cells. As a carrier, reconstituted apolipoprotein B lipoparticles (rABLs) could release drugs in acidic environments. Orally administrated embedded drugs not only showed inhibitory effects on gastric tumor growth in a syngeneic orthotopic mouse model, but also reduced the hepatic and renal toxicity. In conclusion, we have established rABL-based nanoparticles embedded epigenetic inhibitors for local treatment of gastric cancer, which have good therapeutic effects but do not cause severe side effects.
Assuntos
Apolipoproteínas B/farmacologia , Sistemas de Liberação de Medicamentos , Epigênese Genética/efeitos dos fármacos , Lipossomos/farmacologia , Neoplasias Gástricas/terapia , Ácidos/metabolismo , Animais , Apolipoproteínas B/química , Apolipoproteínas B/genética , Apoptose/efeitos dos fármacos , Proteína 11 Semelhante a Bcl-2/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Decitabina/farmacologia , Epigênese Genética/genética , Regulação Neoplásica da Expressão Gênica/genética , Inibidores de Histona Desacetilases/farmacologia , Humanos , Ácidos Hidroxâmicos/farmacologia , Lipossomos/química , Camundongos , Nanopartículas/química , Panobinostat/farmacologia , Fase S/efeitos dos fármacos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologiaRESUMO
Traumatic brain injury (TBI) is a complex injury that can cause severe disabilities and even death. TBI can induce secondary injury cascades, including but not limited to endoplasmic reticulum (ER) stress, apoptosis and autophagy. Although the investigators has previously shown that salubrinal, the selective phosphatase inhibitor of p-eIF2α, ameliorated neurologic deficits in murine TBI model, the neuroprotective mechanisms of salubrinal need further research to warrant the preclinical value. This study was undertaken to characterize the effects of salubrinal on cell death and neurological outcomes following TBI in mice and the potential mechanisms. In the current study, ER stress-related proteins including p-eIF2α, GRP78 and CHOP showed peak expressions both in the cortex and hippocampus from day 2 to day 3 after TBI, indicating ER stress was activated in our TBI model. Immunofluorescence staining showed that CHOP co-located NeuN-positive neuron, GFAP-positive astrocyte, Iba-1-positive microglia, CD31-positive vascular endothelial cell and PDGFR-ß-positive pericyte in the cortex on day 2 after TBI, and these cells mentioned above constitute the neurovascular unit (NVU). We also found TBI-induced plasmalemma permeability, motor dysfunction, spatial learning and memory deficits and brain lesion volume were alleviated by continuous intraperitoneal administration of salubrinal post TBI. To investigate the underlying mechanisms further, we determined that salubrinal suppressed the expression of ER stress, autophagy and apoptosis related proteins on day 2 after TBI. In addition, salubrinal administration decreased the number of CHOP+/TUNEL+ and CHOP+/LC3+ cells on day 2 after TBI, detected by immunofluorescence. In conclusion, these data imply that salubrinal treatment improves morphological and functional outcomes caused by TBI in mice and these neuroprotective effects may be associated with inhibiting apoptosis, at least in part by suppressing ER stress-autophagy pathway.
Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Lesões Encefálicas Traumáticas/tratamento farmacológico , Cinamatos/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Tioureia/análogos & derivados , Animais , Modelos Animais de Doenças , Chaperona BiP do Retículo Endoplasmático , Masculino , Camundongos , Camundongos Endogâmicos ICR , Tioureia/farmacologiaRESUMO
BACKGROUND: Cancer stem cells (CSCs) are considered responsible for the recurrence and chemoresistance of cancer. Dysregulated autophagy is highly prevalent in many types of cancer including pancreatic cancer and has been implicated in cytoprotection and tumor promotion. This study aimed to investigate the role of autophagy in regulating cancer stemness and chemoresistance of pancreatic cancer. METHODS: The correlation between autophagy and CSCs and its clinical significance were analyzed using pancreatic cancer tissue microarrays. Genetic and pharmacological approaches were applied to explore the function of autophagy on CSC activity and gemcitabine resistance of pancreatic cancer cells in vitro and in vivo. RESULTS: LC3 expression positively correlated with the expression of CSC markers aldehyde dehydrogenase 1 (ALDH1), CD44, and CD133 in pancreatic cancer tissues. High coexpression of LC3/ALDH1 was associated with both poor overall survival and progression-free survival. In pancreatic cancer cell lines, higher LC3-II expression was observed in the sphere-forming cells than in the bulk cells. Blockade of autophagy by silencing ATG5, ATG7, and BECN1 or the administration of autophagy inhibitor chloroquine markedly reduced the CSC populations, ALDH1 activity, sphere formation, and resistance to gemcitabine in vitro and in vivo. Furthermore, osteopontin (OPN) was found to stimulate LC3-II, ALDH1, CD44, and CD133 expression in PANC-1 cells, whereas this effect could be prevented by OPN knockdown and autophagy blockade. After treatment with various inhibitors against the major signaling pathways downstream of OPN, only the inhibitor of NF-κB activation, BAY 1170-82, could effectively counteract OPN-induced autophagy and CSC activity. According to the histochemical results, pancreatic cancer patients manifesting high levels of OPN/LC3/ALDH1 and OPN/CD44/CD133 had poor survival. CONCLUSIONS: Induction of autophagy mediated by OPN/NF-κB signaling is required for maintenance of pancreatic CSC activity. Combination of gemcitabine with pharmacological autophagy inhibitors is a promising therapeutic strategy for pancreatic cancer.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Desoxicitidina/análogos & derivados , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Neoplasias Pancreáticas/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Desoxicitidina/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas , GencitabinaRESUMO
BACKGROUND: The interactions between cancer stem cells (CSCs) and tumor-associated macrophages (TAMs) can promote tumor progression, maintain the CSCs population, and reduce therapeutic effects. The objective of this study was to investigate the coexpression of CSCs and TAMs and its clinical significance in pancreatic ductal adenocarcinoma (PDAC). METHODS: Ninety-six patients with PDAC were included in this study. Tissue microarrays were constructed for immunostaining of the CSCs markers CD44 and CD133 and the TAMs marker CD204. Correlations between the expression of CSCs and TAMs markers and clinicopathologic characteristics or disease progression were analyzed. RESULTS: Expression levels of CD44/CD133 and CD204 were significantly higher in tumor tissues than in normal tissues (P < .0001). The variables associated with survival were high coexpression of CD44/CD133 (P = .000), high expression of CD204 (P = .011), and tumor grade (P = .014). There was a positive correlation between CD44/CD133 and CD204 expression (r = 0.294; P = .004). Survival analysis indicated that high coexpression of CD44/CD133 and CD204 was associated significantly with shorter overall survival (P = .000) and disease-free survival (P = .003). Multivariate analysis revealed that high CD44/CD133 expression was an independent prognostic factor for disease-free survival, whereas high CD204 expression was an independent predictor for both overall and disease-free survival. CONCLUSIONS: Coexpression of CD44/CD133 and CD204 is a useful survival prediction marker for patients with PDAC.
Assuntos
Antígenos CD/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Glicoproteínas/metabolismo , Receptores de Hialuronatos/metabolismo , Macrófagos/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias Pancreáticas/metabolismo , Peptídeos/metabolismo , Receptores Depuradores Classe A/metabolismo , Antígeno AC133 , Biomarcadores Tumorais/metabolismo , Carcinoma Ductal Pancreático/mortalidade , Carcinoma Ductal Pancreático/patologia , Comunicação Celular , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Prognóstico , Modelos de Riscos ProporcionaisRESUMO
Donation after brain death followed by circulatory death (DBCD) is a unique practice in China. The aim of this study was to define the pathologic characteristics of DBCD liver allografts in a porcine model. Fifteen male pigs (25-30 kg) were allocated randomly into donation after brain death (DBD), donation after circulatory death (DCD) and DBCD groups. Brain death was induced by augmenting intracranial pressure. Circulatory death was induced by withdrawal of life support in DBCD group and by venous injection of 40 mL 10% potassium chloride in DCD group. The donor livers were perfused in situ and kept in cold storage for 4 h. Liver tissue and common bile duct samples were collected for hematoxylin and eosin staining, TUNEL testing and electron microscopic examination. Spot necrosis was found in hepatic parenchyma of DBD and DBCD groups, while a large area of necrosis was shown in DCD group. The apoptosis rate of hepatocytes in DBD [(0.56±0.30)%] and DBCD [(0.50 ± 0.11)%] groups was much lower than that in DCD group [(3.78±0.33)%] (P<0.05). And there was no significant difference between DBD group and DBCD group (P>0.05)). The structures of bile duct were intact in both DBD and DBCD groups, while the biliary epithelium was totally damaged in DCD group. Under electron microscope, the DBD hepatocytes were characterized by intact cell membrane, well-organized endoplasmic reticulum, mild mitochondria edema and abundant glycogens. Broken cell membrane, mild inflammatory cell infiltration and sinusoidal epithelium edema, as well as reduced glycogen volume, were found in the DBCD hepatocytes. The DCD hepatocytes had more profound cell organelle injury and much less glycogen storage. In conclusion, the preservation injury of DBCD liver allografts is much less severe than that of un-controlled DCD, but more severe than that of DBD liver allografts under electron microscope, which might reflect post-transplant liver function to some extent.
Assuntos
Transplante de Fígado/métodos , Preservação de Órgãos/métodos , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/métodos , Aloenxertos , Animais , Apoptose , Morte Encefálica , China , Morte , Parada Cardíaca , Hepatócitos/patologia , Hepatócitos/ultraestrutura , Humanos , Marcação In Situ das Extremidades Cortadas , Fígado/patologia , Fígado/ultraestrutura , Microscopia Eletrônica , SuínosRESUMO
M2-like macrophages exhibit immunosuppressive activity and promote pancreatic cancer progression. Reactive oxygen species (ROS) affect macrophage polarization; however, the mechanism remains unclear. This study aimed to elucidate the underlying molecular basis and design a gene therapy to inhibit M2-like polarization. Microarray analysis and IF staining were performed in M1-like and M2-like macrophages to ascertain the expression of CYBB, a major intracellular ROS source. Co-culture assay and syngeneic orthotopic pancreatic cancer mouse models were used to study the mechanism of M2-like skewing. Decoy oligodeoxynucleotides (ODNs) were designed to manipulate CYBB transcription to inhibit M2-like polarization and control tumor growth. Lipopolysaccharide (LPS) treatment polarized U937 cells to M1-like macrophages in which CYBB expression was increased. In contrast, co-culture with PANC-1 cells induced M2-like polarization in U937 cells with CYBB downregulation. High CD204 M2-like expression in combination with low CYBB expression was associated with the worst prognosis in pancreatic cancer patients. STAT6 and HDAC2 in U937 cells were activated by cancer cell-derived IL-4 after coculture and then bound to the CYBB promoter to repress CYBB expression, resulting in M2-like polarization. DPI that inhibits ROS production could block this action. Knockdown of STAT6 and HDAC2 also inhibited M2-like polarization and maintained the M1-like phenotype of U937 cells after coculture. Decoy ODNs interrupting the binding of STAT6 to the CYBB promoter counteracted M2-like polarization and tumor growth and triggered antitumor immunity in vivo. Gene therapy using STAT6-CYBB decoy ODNs can inhibit M2-like polarization, representing a potential therapeutic tool for pancreatic cancer.
RESUMO
Pancreatic cancer (PC) remains one of the most lethal malignancies across the world, which is due to delayed diagnosis and resistance to current therapies. The interactions between pancreatic tumor cells and their tumor microenvironment (TME) allow cancer cells to escape from anti-cancer therapies, leading to difficulties in treating PC. With endocrine function and lipid storage capacity, adipose tissue can maintain energy homeostasis. Direct or indirect interaction between adipocytes and PC cells leads to adipocyte dysfunction characterized by morphological change, fat loss, abnormal adipokine secretion, and fibroblast-like transformation. Various adipokines released from dysfunctional adipocytes have been reported to promote proliferation, invasion, metastasis, stemness, and chemoresistance of PC cells via different mechanisms. Additional lipid outflow from adipocytes can be taken into the TME and thus alter the metabolism in PC cells and surrounding stromal cells. Besides, the trans-differentiation potential enables adipocytes to turn into various cell types, which may give rise to an inflammatory response as well as extracellular matrix reorganization to modulate tumor burden. Understanding the molecular basis behind the protumor functions of adipocytes in PC may offer new therapeutic targets.
Assuntos
Adipócitos , Neoplasias Pancreáticas , Humanos , Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Neoplasias Pancreáticas/patologia , Adipocinas , Lipídeos , Microambiente Tumoral , Neoplasias PancreáticasRESUMO
Growing evidence suggests that Stat3 contributes to chemoresistance. However, the impact of chemotherapy on Stat3 activity is unclear. We found that paclitaxel activated Stat3 in the human lung cancer cell lines PC14PE6AS2 (AS2) and H157, whereas it reduced Stat3 activation in A549 and H460 cells. Pretreatment of AS2 and H157 cells with rotenone, an inhibitor of mitochondrially produced reactive oxygen species (ROS), or carbonyl cyanide p-(trifluoromethoxy)-phenylhydrazone (FCCP), a mitochondrial uncoupler, suppressed the paclitaxel-induced activation of Stat3. Uncoupling protein 2 (UCP-2), located in the inner membrane of the mitochondria, can reduce ROS production in conditions of oxidative stress. UCP-2 protein expression in the four cancer cell lines was higher than that in normal lung epithelial cells (NL-20), but its expression was lower in AS2 and H157 cells relative to A549 and H460 cells. Silencing high UCP-2 expression with small interfering RNA (siRNA) in A549 and H460 cells restored paclitaxel-induced Stat3 activation. In addition, paclitaxel-induced Stat3 activation led to the upregulation of survivin and Mcl-1, which in turn facilitated cell survival. Moreover, the CL1-5 subline had lower UCP-2 expression relative to the parental CL1-0 cells. Treatment with paclitaxel activated Stat3 in CL1-5 but not in CL1-0 cells, whereas in CL1-5 cells, the overexpression of UCP-2 with complementary DNA (cDNA) blocked Stat3 activation. In lung cancer patients, low UCP-2 expression in cancer cells was a predictor of a poor response to chemotherapy. Therefore, UCP-2 modulates the ROS/Stat3 signaling pathway and response to chemotherapy treatment in lung cancer cells. Targeting UCP-2, ROS and Stat3 pathways may improve anticancer therapies.
Assuntos
Adenocarcinoma/patologia , Apoptose/efeitos dos fármacos , Canais Iônicos/metabolismo , Neoplasias Pulmonares/patologia , Proteínas Mitocondriais/metabolismo , Paclitaxel/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição STAT3/metabolismo , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Antineoplásicos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Western Blotting , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cisplatino/farmacologia , Humanos , Técnicas Imunoenzimáticas , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/mortalidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , RNA Interferente Pequeno/genética , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Transdução de Sinais/efeitos dos fármacos , Taxa de Sobrevida , Proteína Desacopladora 2RESUMO
BACKGROUND: Rocuronium, a nondepolarizing muscle relaxant, is usually administered during general anesthesia to facilitate endotracheal intubation and keep patients immobile during the surgery. Sugammadex, the selective reversal agent of rocuronium, fully reverses the neuromuscular blockade (NMB) at the end of surgery. Most reports show that sugammadex rapidly achieves a ratio of train-of-four (TOF), a quantitative method of neuromuscular monitoring, of 0.9 which ensures adequate recovery for safe extubation. However, very rare patients with neuromuscular diseases may respond poorly to sugammadex. CASE SUMMARY: A 69-year-old female presented with abdominal fullness and nausea, and was diagnosed with gastroparesis. She underwent gastric peroral endoscopic myotomy under general anesthesia with rocuronium (0.7 mg/kg). At the end of surgery, sugammadex 3.6 mg/kg was administered when TOF showed 2 counts. Afterward, the TOF ratio recovered to 0.65 in 30 min. She was awake but could not fully open her eyelids. The tidal volume during spontaneous breathing was low. After additional doses of sugammadex (up to 7.3 mg/kg) in the following 3 h, the TOF ratio was 0.9, and the endotracheal tube was smoothly removed. After excluding possible mechanisms underlying the prolonged recovery course, we speculated our patient may have had an undiagnosed neuromuscular disease, hinted by her involuntary movement of the tongue and mouth. Furthermore, her poor renal function and history of delayed recovery from general anesthesia may be related to the long duration of rocuronium. CONCLUSION: In our case, both prolonged rocuronium-induced NMB and poor response to sugammadex were noted. To optimize the dose of rocuronium, perioperative TOF combined with other neuromuscular monitoring is suggested.
RESUMO
BACKGROUND: Solitary necrotic nodule of the liver (SNNL) is a rare benign lesion with a complete necrotic core and a clear fibrous capsule containing elastic fibers. We present the case of a patient with a radiographic computed tomography (CT) finding of "ring"-like annular calcification within the lesion and postoperative pathologic diagnosis of necrotic nodules wrapped by dense fibers in liver tissue, as well as the patient's subsequent management and outcome. CASE SUMMARY: A 38-year-old Chinese woman with a history of systemic lupus erythematosus treated with prednisone and hydroxychloroquine, without any symptoms, was found to have hepatic space-occupying lesions by imaging examination at a health examination. A subsequent CT scan suggested a space-occupying lesion of the liver with annular calcification, which was not defined to be benign or malignant. After that, a laparoscopic hepatic space-occupying resection was performed. The postoperative pathological diagnosis was necrotic nodules wrapped by dense fibers in the liver tissue, and the final diagnosis was SNNL. The patient had an uneventful postoperative recovery. CONCLUSION: There is a "ring"-like calcification in SNNL. This patient had a history of systemic lupus erythematosus, without a history of parasite infection, trauma, or tumor. Therefore, whether the etiology and pathological changes of SNNL are related to rheumatic immune diseases remains to be investigated.
RESUMO
Dysregulated hepatic steatosis may lead to chronic liver inflammation and nonalcoholic steatohepatitis (NASH). Recent studies have suggested that exendin-4, a glucagon-like peptide-1 agonist, may be a promising therapeutic for hepatic steatosis and NASH. However, the molecular mechanisms underlying the antihepatic steatosis actions of exendin-4 are not fully clear. Here, we demonstrate that autophagy is activated by either palmitic acid (PA) or oleic acid (OA) in HepG2 cells, and exendin-4 further enhances the autophagy-lysosomal pathway. We show that inhibition of autophagy by shLC3 attenuates exendin-4-mediated antisteatotic activity. Furthermore, expression of a key lysosomal marker, lysosome associated membrane protein 1 (LAMP1), is upregulated in OA + exendin-4-treated cells. The colocalization of LAMP1 and LC3 puncta further suggests that autophagic flux was enhanced by the cotreatment. Based on these findings, we conclude that autophagic flux might play an important role in the antisteatotic action of exendin-4.
Assuntos
Exenatida , Hepatopatia Gordurosa não Alcoólica , Autofagia/fisiologia , Exenatida/farmacologia , Células Hep G2 , Humanos , Lisossomos/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismoRESUMO
A facile iridium/graphene-catalyzed methodology providing an efficient synthetic route for C-N bond formation is reported. This catalyst can directly promote the formation of C-N bonds, without pre-activation steps, and without solvents, alkalis and other additives. This protocol provides a direct N-alkylation of amines using a variety of primary and secondary alcohols with good selectivity and excellent yields. Charmingly, the use of diols resulted in intermolecular cyclization of amines, and such products are privileged structures in biologically active compounds. Two examples illustrate the advantages of this catalyst in organic synthesis: the tandem catalysis to synthesize hydroxyzine, and the intermolecular cyclization to synthesize cyclizine. Water is the only by-product, which makes this catalytic process sustainable and environmentally friendly.
RESUMO
Pancreatic cancer (PC) has the highest frequency of developing cancer cachexia (CC)-sarcopenia (SC) syndrome, which negatively influences patients' outcome, quality of life, and tolerance/response to treatments. However, the clinical impacts of CC, SC, and their associated factors on outcomes for advanced PC has yet to be fully investigated. A total of 232 patients were enrolled in this study for the retrospective review of their clinical information and the measurement of skeletal muscle areas at the third lumber vertebra by computed tomography scan to identify CC or SC. The association and concurrent occurrence of clinicopathological features in each patient, prevalence rates, and prognosis with the CC or SC were calculated. CC and SC were observed in 83.6% (n = 194) and 49.1% (n = 114) of PC patients, respectively. Low hemoglobin levels more often occurred in CC patients than in non-CC patients (p = 0.014). Older age (p = 0.000), female gender (p = 0.024), low body mass index (BMI) values (p = 0.004), low hemoglobin levels (p = 0.036), and low albumin levels (p = 0.001) were more often found in SC patients than in non-SC patients. Univariate and multivariate analyses showed that CC was an independent poor prognostic factor of overall survival (OS) and progression-free survival for all patients, the chemotherapy (C/T) subgroup, and the high BMI subgroup. Meanwhile, SC was an independent predictor of poor OS for the subgroups of C/T or high BMI but not for all patients. These findings reveal the clinical differences for CC and SC and provide useful information for predicting the prognosis of advanced PC patients and conducting personalized medicine.
RESUMO
BACKGROUND: Cancer subtype switching, which involves unclear cancer cell origin, cell fate decision, and transdifferentiation of cells within a confined tumor microenvironment, remains a major problem in pancreatic cancer (PDA). RESULTS: By analyzing PDA subtypes in The Cancer Genome Atlas, we identified that epigenetic silencing of apoptosis-associated tyrosine kinase (AATK) inversely was correlated with mRNA expression and was enriched in the quasi-mesenchymal cancer subtype. By comparing early mouse pancreatic lesions, the non-invasive regions showed AATK co-expression in cells with acinar-to-ductal metaplasia, nuclear VAV1 localization, and cell cycle suppression; but the invasive lesions conversely revealed diminished AATK expression in those with poorly differentiated histology, cytosolic VAV1 localization, and co-expression of p63 and HNF1α. Transiently activated AATK initiates acinar differentiation into a ductal cell fate to establish apical-basal polarization in acinar-to-ductal metaplasia. Silenced AATK and ectopically expressed p63 and HNF1α allow the proliferation of ductal PanINs in mice. CONCLUSION: Epigenetic silencing of AATK regulates the cellular transdifferentiation, proliferation, and cell cycle progression in converting PDA-subtypes.
Assuntos
Proteínas Reguladoras de Apoptose/genética , Epigênese Genética/genética , Metaplasia/genética , Neoplasias Pancreáticas/genética , Proteínas Tirosina Quinases/genética , Idoso , Animais , Diferenciação Celular , Metilação de DNA/genética , Modelos Animais de Doenças , Feminino , Inativação Gênica , Fator 1-alfa Nuclear de Hepatócito/genética , Humanos , Metaplasia/diagnóstico , Camundongos , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , Gravidez , Proteínas Proto-Oncogênicas c-vav/genética , RNA Mensageiro/genética , Transativadores/genética , Microambiente Tumoral/genéticaRESUMO
Cancer immunotherapy targeting immune checkpoints has exhibited promising clinical outcomes in many cancers, but it offers only limited benefits for pancreatic cancer (PC). Cancer stem cells (CSCs), a minor subpopulation of cancer cells, play important roles in tumor initiation, progression, and drug resistance. Accumulating evidence suggests that CSCs employ immunosuppressive effects to evade immune system recognition. However, the clinical implications of the associations among CD8⺠T cells infiltration, programmed death receptor ligand-1 (PD-L1) expression, and CSCs existence are poorly understood in PC. Immunostaining and quantitative analysis were performed to assess CD8⺠T cells infiltration, PD-L1 expression, and their relationship with CD44âº/CD133⺠CSCs and disease progression in PC. CD8⺠T cells infiltration was associated with better survival while PD-L1 expression was correlated with PC recurrence. Both the low CD8⺠T cells infiltration/high PD-L1 expression group and the high CD8⺠T cells infiltration/high PD-L1 expression group show high levels of CD44âº/CD133⺠CSCs, but patients with low CD8⺠T cells infiltration/high PD-L1 expression had worse survival and higher recurrence risk than those with high CD8⺠T cells infiltration/high PD-L1 expression. Moreover, high infiltration of CD8⺠T cells could reduce unfavorable prognostic effect of high co-expression of PD-L1 and CD44/CD133. Our study highlights an interaction among CD8⺠T cells infiltration, PD-L1 expression, and CD44âº/CD133⺠CSCs existence, which contributes to PC progression and immune evasion.
RESUMO
Background: The dense fibrotic stroma enveloping pancreatic tumors is a major cause of drug resistance. Pancreatic stellate cells (PSCs) in the stroma can be activated to induce intra-tumor fibrosis and worsen patient survival; however, the molecular basics for the regulation of PSC activation remains unclear. Methods: The in vitro coculture system was used to study cancer cell-PSC interactions. Atomic force microscopy was used to measure the stiffness of tumor tissues and coculture gels. Cytokine arrays, qPCR, and Western blotting were performed to identify the potential factors involved in PSC activation and to elucidate underlying pathways. Results: PSC activation characterized by α-SMA expression was associated with increased pancreatic tumor stiffness and poor prognosis. Coculture with cancer cells induced PSC activation, which increased organotypic coculture gel stiffness and cancer cell invasion. Cancer cells-derived PAI-1 identified from coculture medium could activate PSCs, consistent with pancreatic cancer tissue microarray analysis showing a strong positive correlation between PAI-1 and α-SMA expression. Suppression by knocking down PAI-1 in cancer cells demonstrated the requirement of PAI-1 for coculture-induced PSC activation and gel stiffness. PAI-1 could be upregulated by KRAS in pancreatic cancer cells through ERK. In PSCs, inhibition of LRP-1, ERK, and c-JUN neutralized the effect of PAI-1, suggesting the contribution of LRP-1/ERK/c-JUN signaling. Furthermore, activated PSCs might exacerbate malignant behavior of cancer cells via IL-8 because suppression of IL-8 signaling reduced pancreatic tumor growth and fibrosis in vivo. Conclusions: KRAS-mutant pancreatic cancer cells can activate PSCs through PAI-1/LRP-1 signaling to promote fibrosis and cancer progression.
Assuntos
Progressão da Doença , Interleucina-8/metabolismo , Mutação/genética , Neoplasias Pancreáticas/patologia , Células Estreladas do Pâncreas/metabolismo , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Regulação para Cima , Animais , Linhagem Celular Tumoral , Géis , Técnicas de Silenciamento de Genes , Humanos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos Transgênicos , Invasividade Neoplásica , Neoplasias Pancreáticas/genética , Células Estreladas do Pâncreas/patologia , Ligação Proteica , Análise de Sobrevida , Resultado do TratamentoRESUMO
The novel immunomodulator FTY720 is a prototypic sphingosine-1-phosphate (S1P) receptor agonist that regulates lymphocyte migration and prolongs allograft survival. Skin dendritic cells (DC) play important roles in cutaneous immunity. We investigated the migration and function of skin DC exposed to FTY720 in vivo, or to its metabolite FTY720 phosphate (P) in vitro. C57BL/10 (H2(b)) recipient (but not donor) FTY720 treatment prolonged median skin C3H (H2(k)) allograft survival significantly, from 12 to 34.5 days. Non-transplanted, FTY720-treated mice revealed a marked increase in skin DC, although total DC in skin-draining lymph nodes (DLN) were unchanged compared with controls. Fewer allogeneic donor DC migrated to DLN of FTY720-treated graft recipients. DC that migrated from the skin of FTY720-treated mice showed reduced MHC class II, CD86 and CCR7 expression, suggesting impaired migratory potential to secondary lymphoid tissue, that correlated with DC retention in skin, and reduced T cell stimulatory activity. Fewer DC migrated from normal skin explants exposed to the FTY720 metabolite, FTY720P than to control medium. DC that did migrate expressed lower levels of MHC class II, CD86 and CCR7, and inferior T cell stimulatory ability. These data demonstrate S1P signaling regulates skin DC trafficking and modulates MHC class II, costimulatory, and homing receptor molecule expression that impairs their ability to elicit allogeneic T cell responses.
Assuntos
Movimento Celular/efeitos dos fármacos , Sobrevivência de Enxerto/efeitos dos fármacos , Células de Langerhans/efeitos dos fármacos , Propilenoglicóis/farmacologia , Receptores de Lisoesfingolipídeo/agonistas , Transplante de Pele/imunologia , Esfingosina/análogos & derivados , Animais , Antígeno B7-2/metabolismo , Movimento Celular/imunologia , Cloridrato de Fingolimode , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Imunossupressores/farmacologia , Células de Langerhans/imunologia , Linfonodos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Organofosfatos/farmacologia , Receptores CCR7/metabolismo , Receptores de Lisoesfingolipídeo/imunologia , Esfingosina/farmacologia , Transplante Homólogo/imunologiaRESUMO
Interleukin-33 (IL-33) is a member of the interleukin-1 (IL-1) cytokine family and an extracellular ligand for the orphan IL-1 receptor ST2. Accumulated evidence shows that the IL-33/ST2 axis plays a crucial role in the pathogenesis of central nervous system (CNS) diseases and injury, including traumatic brain injury (TBI). However, the roles and molecular mechanisms of the IL-33/ST2 axis after TBI remain poorly understood. In this study, we investigated the role of IL-33/ST2 signaling in mouse TBI-induced brain edema and neurobehavioral deficits, and further exploited underlying mechanisms, using salubrinal (SAL), the endoplasmic reticulum (ER) stress inhibitor and anti-ST2L. The increase in IL-33 level and the decrease in ST2L level at injured cortex were first observed at 24 h post-TBI. By immunofluorescent double-labeled staining, IL-33 co-localized in GFAP-positive astrocytes, and Olig-2-positive oligodendrocytes, and predominantly presented in their nucleus. Additionally, TBI-induced brain water content, motor function outcome, and spatial learning and memory deficits were alleviated by IL-33 treatment. Moreover, IL-33 and SAL alone, or their combination prevented TBI-induced the increase of IL-1ß and TNF-α levels, suppressed the up-regulation of ER stress, apoptosis and autophagy after TBI. However, anti-ST2L treatment could significantly invert the above effects of IL-33. Together, these data demonstrate that IL-33/ST2 signaling mitigates TBI-induced brain edema, motor function outcome, spatial learning and memory deficits, at least in part, by a mechanism involving suppressing autophagy, ER stress, apoptosis and neuroinflammation.