It is well known that pressure is an important parameter in the SCWO process, because it produces changes in the phase behavior and thermodynamics properties of the system. The influence of pressure on the oxidation efficiency of feeds containing isopropyl alcohol as fuel and acetic acid as waste was studied in an autothermal adiabatic transpiring wall reactor at pilot‐plant scale, at pressures from 13 to 25 Mpa, and temperatures from 600 to 750°C. It was found that reaction temperature decreased between 40 and 100°C, when pressure was lowered, and, subsequently TOC removal decreased. At higher‐temperatures, the decreasing of TOC removal due to pressure difference was reduced. The process was simulated at different pressures using a mathematical model previously developed for the reactor. The Anderko‐Pitzer EoS, especially developed for aqueous systems at high‐temperatures and pressures, was used to have accurate values of the heat capacities of the reaction mixture. It was found that having into account only the effect of pressure in the thermodynamical properties and in the concentration of the reagents, the experimental results could not be explained. Thus, the influence of the pressure in the reaction rate equation had to be considered. Results were qualitatively reproduced considering the reaction rate constant variable with pressure, using a constant volume of activation of −1400 cm3/mol. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Human papillomavirus (HPV) has been the leading cause of cervical cancer for over 25 years. Approximately 5.5–11% of all cervical cancers are reported to be HPV-negative, which can be attributed to truly negative and false-negative results. The truly HPV-negative cervical cancers are almost all cervical adenocarcinomas with unclear etiology. False HPV negativity can arise from histological misclassification, latent HPV infection, disruption of the targeting fragment, non-high risk HPV infection, and HPV testing methods. HPV-negative cervical cancers are often diagnosed at an advanced FIGO stage and have a poor prognosis; thus, the management of these cases requires greater attention.
Background Programmed cell death protein 1 (PD-1) antibody has been approved for a variety of tumors, but its effective rate is unsatisfactory. New evidence suggests that mast cells are an important component of the tumor microenvironment and are associated with resistance to immunotherapy, but the underlying mechanism is not clear. Methods Bioinformatics analysis of patients with melanoma in TCGA-SKCM and GSE91061 was used to determine the prognostic value of mast cells and their association with anti-PD-1 immunotherapy. HMC-1 cells (mast cell line) and bone marrow-derived mast cells (BMMCs) were used to verify the effect of PD-1 antibody and cromolyn sodium in vitro. The mouse subcutaneous melanoma model was used to verify the effect of the PD-1 antibody on mast cells in vivo. Results Bioinformatics analysis showed that mast cells were a poor prognostic factor associated with resistance to anti-PD-1 immunotherapy. PD-1 was expressed on the mast cell membrane. The PD-1 antibody promoted the release of histamine and cytokines from mast cells via the PI3K/AKT pathway and calcium signaling pathway. The activation of mast cells induced by PD-1 antibody could be partially inhibited by cromolyn sodium. In vivo, cromolyn sodium increased the efficacy of PD-1 antibody and decreased the infiltration of mast cells and the density of microvessels. Conclusion PD-1+ mast cell activated by PD-1 antibody plays a negative role in the tumor microenvironment via the enhanced function of releasing histamine and cytokines. Inhibition of mast cell may provide a new solution to solve the low response rate of anti-PD-1 immunotherapy.
REV1 is the central member of the family of TLS polymerases, which participate in various DNA damage repair and tolerance pathways and play a significant role in maintaining genomic stability. However, the role of REV1 in tumors is rarely reported. In this study, we found that the expression of REV1 was significantly upregulated in lung cancer tissues compared with matched adjacent tissues and was associated with poor prognosis. Functional experiments demonstrated that REV1 silencing decreased the growth and proliferation capacity of lung cancer cells. Mechanistically, REV1 upregulated the expression of SERTAD2 in a Rad18-dependent manner, thereby promoting lung carcinogenesis. A novel REV1 inhibitor, JH-RE-06, suppressed lung tumorigenesis in vivo and in vitro and was shown to be safe and well tolerated. Our study confirmed that REV1 is a potential diagnostic marker and therapeutic target for lung cancer and that JH-RE-06 may be a safe and efficient therapeutic agent for NSCLC.
Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) tyrosine kinase inhibitors (TKIs) have achieved remarkable clinical progress in the treatment of non-small-cell lung cancer; however, resistance has limited their therapeutic efficacy. Therefore, understanding the mechanisms of VEGF-TKI and ICI resistance will help to develop effective treatment strategies for patients with advanced NSCLC. Our results suggested that treatment with VEGFR2-TKIs upregulated ADRB2 expression in NSCLC cells. Propranolol, a common ADRB2 antagonist, significantly enhanced the therapeutic effect of VEGFR2-TKIs by inhibiting the ADRB2 signaling pathway in NSCLC cells in vitro and in vivo. Mechanically, the treatment-induced ADRB2 upregulation and the enhancement of ADRB2/VEGFR2 interaction caused resistance to VEGFR2-TKIs in NSCLC. And the inhibition of the ADRB2/CREB/PSAT1 signaling pathway sensitized cells to VEGFR2-TKIs. We demonstrated that ADRB2 signaling is crucial in mediating resistance to VEGFR2-TKIs and provided a novel promising combinatory approach to enhance the antitumor effect of VEGFR2-TKIs in NSCLC combining with propranolol.
Metastasis remains the primary cause of small cell lung cancer (SCLC)-related deaths. Growing evidence links tumor metastasis with a pre-metastatic microenvironment characterized by an anti-inflammatory response, immunosuppression, and the presence of tumor-derived exosomes. To clarify the relationships among these factors in SCLC, we analyzed SCLC patient samples as well as a mouse model. Among the infiltrating immune cells, our study focused on the tumor-associated macrophages (TAMs), that are well-known to promote tumor progression and metastasis. We found that high expression of the alternatively activated (M2) TAM marker, CD206+ was associated clinically with a poorer prognosis and metastasis state in patients with SCLC. Moreover, infiltrating macrophages (MØ) were found in the metastatic foci of an SCLC mouse model. Additionally, we observed dominant switching to M2 phenotype, accompanied by increased NLRP6 expression. Since tumor-derived exosomes are the key links between the tumor and its immune microenvironment, we further investigated whether SCLC-derived exosomes contributed to the MØ phenotype switch. Our findings showed for the first time that SCLC-derived exosomes induce the M2 switch via the NLRP6/NF-κB pathway, and thus, promote SCLC metastasis in vitro and in vivo. Collectively, these results indicate a novel mechanism by which SCLC-derived exosomes induce immunosuppression of distant MØ to promote systemic metastasis by activating NLRP6. Here, we highlight the close relationship between the tumor-derived exosomes, inflammasomes and immune microenvironment in SCLC metastasis.
Radioresistance remains a major obstacle to efficacious radiotherapy in non–small‐cell lung cancer (NSCLC). DNA replication proteins are novel targets for radiosensitizers. POLQ is a DNA polymerase involved in DNA damage response and repair. We found that POLQ is overexpressed in NSCLC and is clinically correlated with high tumor stage, poor prognosis, increased tumor mutational burden, and ALK and TP5 mutation status; POLQ inhibition impaired lung tumorigenesis. Notably, POLQ expression was higher in radioresistant lung cancer cells than in wild‐type cancer cells. Moreover, POLQ expression was further increased in radioresistant cells after radiation. Enhanced radioresistance is through a prolonged G2/M phase and faster repair of DNA damage, leading to reduced radiation‐induced apoptosis. Novobiocin (NVB), a POLQ inhibitor, specifically targeted cancer cells. Genetic knockdown of POLQ or pharmacological inhibition by NVB decreased radioresistance in lung adenocarcinoma while causing little toxicity to normal pulmonary epithelial cells. In conclusion, POLQ is a promising and practical cancer‐specific target to impair tumorigenesis and enhance radiosensitivity in NSCLC.
Radiotherapy, including brachytherapy, is a major therapeutic regimen for cervical cancer. Radioresistance is a decisive factor in radiation treatment failure. Tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) in the tumor microenvironment are critical factors in the curative effects of cancer therapies. However, the interactions between TAMs and CAFs in the context of ionizing radiation are not fully understood. This study was undertaken to investigate whether M2 macrophages induce radioresistance in cervical cancer and to explore the TAMs’ phenotypic transformation after IR and its underlying mechanisms. The radioresistance of cervical cancer cells was enhanced after being co-cultured with M2 macrophages. TAMs tended to undergo M2 polarization after high-dose irradiation, which was strongly associated with CAFs in both mouse models and patients with cervical cancer. Additionally, cytokine and chemokine analysis was performed to find that high-dose irradiated CAFs promoted macrophage polarization towards the M2 phenotype through chemokine (C-C motif) ligand 2. Collectively, our results highlight the crucial role that high-dose irradiated CAFs play in the regulation of M2 phenotype polarization, which ultimately induces radioresistance in cervical cancer.
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