Vγ9Vδ2 T cells are promising candidates for cellular tumor immunotherapy. Due to their HLA-independent mode of action, allogeneic Vγ9Vδ2 T cells can be considered for clinical application. To apply allogeneic Vγ9Vδ2 T cells in adoptive immunotherapy, the methodology used to obtain adequate cell numbers with optimal effector function in vitro needs to be optimized, and clinical safety and efficacy also need to be proven. Therefore, we developed a novel formula to improve the expansion of peripheral γδ T cells from healthy donors. Then, we used a humanized mouse model to validate the therapeutic efficacy of expanded γδ T cells in vivo; furthermore, the expanded γδ T cells were adoptively transferred into late-stage liver and lung cancer patients. We found that the expanded cells possessed significantly improved immune effector functions, including proliferation, differentiation, and cancer cell killing, both in vitro and in the humanized mouse model. Furthermore, a phase I clinical trial in 132 late-stage cancer patients with a total of 414 cell infusions unequivocally validated the clinical safety of allogeneic Vγ9Vδ2 T cells. Among these 132 patients, 8 liver cancer patients and 10 lung cancer patients who received ≥5 cell infusions showed greatly prolonged survival, which preliminarily verified the efficacy of allogeneic Vγ9Vδ2 T-cell therapy. Our clinical studies underscore the safety and efficacy of allogeneic Vγ9Vδ2 T-cell immunotherapy, which will inspire further clinical investigations and eventually benefit cancer patients.
N-doped TiO2 photocatalysts were prepared by pretreating the TiO2 precursor in NH3/ethanol fluid under supercritical conditions, denoted as TiO2N(SC). In contrast to the TiO2N(DC), obtained via direct calcination in which the N dopants were mainly present in the form of surface adsorbed NH3 molecules, most N dopants in the TiO2N(SC) were present in O-Ti-N and N-Ti-N nitrides, as confirmed by either the X-ray photoelectron spectroscopy (XPS) and or the Fourier transform infrared (FTIR) spectra. During liquid-phase oxidative degradation of phenol under irradiation with UV light characteristic of 365 nm, the TiO2N(SC) exhibited much higher activity than either the TiO2N(DC) or the TiO2(SC), i.e., the undoped TiO2 obtained under SCs. According to various characterizations including X-ray diffraction, transmission electron microscopy, FTIR, Brunauer-Emmett-Teller, XPS, and UV-vis diffuse reflectance spectra, the higher activity of the TiO2N(SC) could be attributed to its higher surface area, larger pore volume, well-crystallized anatase, and stronger absorbance of light with longer wavelength. Meanwhile, the OH species resulted from the nitridation of TiO2 could supply more HO* radicals, which were considered as powerful oxidants during phenol degradation. Furthermore, the electron-deficient nitrogen atoms in O-Ti-N nitrides could also account for the higher activity since it could inhibit the recombination between the photoinduced electrons and holes by capturing the photoinduced electrons. The activity of the TiO2N(SC) first increased and then decreased with the increase of the N-content. The TiO2N(SC)-1 with N/Ti molar ratio of 1.73% exhibited maximum activity, which was even much higher than P-25.
Cross talk between NF-κB and c-Jun N-terminal kinases (JNKs) has been implicated in the cell life and death decision under various stresses. Functional suppression of JNK activation by NF-κB has recently been proposed as a key cellular survival mechanism and contributes to cancer cells escaping from apoptosis. We provide a novel scenario of the proapoptotic role of IκB kinase β (IKKβ)–NF-κB, which can act as the activator of the JNK pathway through the induction of GADD45α for triggering MKK4/JNK activation, in response to the stimulation of arsenite, a cancer therapeutic reagent. This effect of IKKβ–NF-κB is dependent on p50 but not the p65/relA NF-κB subunit, which can increase the stability of GADD45α protein through suppressing its ubiquitination and proteasome-dependent degradation. IKKβ–NF-κB can therefore either activate or suppress the JNK cascade and consequently mediate pro- or antiapoptotic effects, depending on the manner of its induction. Furthermore, the NF-κB p50 subunit can exert a novel regulatory function on protein modification independent of the classical NF-κB transcriptional activity.
Trivalent arsenic (arsenite, As3؉ ) is a human carcinogen, which is associated with cancers of skin, lung, liver, and bladder. However, the mechanism by which arsenite causes cancer is not well understood. In this study, we found that exposure of Cl 41 cells, a well characterized mouse epidermal cell model for tumor promotion, to a low concentration of arsenite (<25 M) induces cell transformation. Interestingly, arsenite induces Erk phosphorylation and increased Erk activity at doses ranging from 0.8 to 200 M, while higher doses (more than 50 M) are required for activation of JNK. Arseniteinduced Erk activation was markedly inhibited by introduction of dominant negative Erk2 into cells, while expression of dominant negative Erk2 did not show inhibition of JNK and MEK 1/2 . Furthermore, arsenite-induced cell transformation was blocked in cells expressing the dominant negative Erk2. In contrast, overexpression of dominant negative JNK1 was shown to increase cell transformation even though it inhibits arsenite-induced JNK activation. Our results not only show that arsenite induces Erk activation, but also for the first time demonstrates that activation of Erk, but not JNK, by arsenite is required for its effects on cell transformation.Arsenite is introduced into the environment during energy production based on coal, oil shale, and geothermal sources. Once in the environment, arsenite represents a potential health hazard of unknown magnitude. Arsenite is associated with increased risks of human cancer of the skin, respiratory tract, hematopoietic system, and urinary bladder (1-4). Epidemiological investigations indicated that long-term arsenic exposure results in promotion of carcinogenesis, especially in lung and skin via inhalation and ingestion (5). Many cases of skin cancer have been documented in people exposed to arsenite through medical or other occupational exposures. It has been reported that high arsenic levels in drinking water (0.35-1.14 mg/liter) increased risks of cancer of skin, bladder, kidney, lung, and colon (1, 2, 5, 6). Hence, arsenite is a well documented human carcinogen (5, 7).Previously, several hypotheses have been proposed to describe the mechanism of arsenite-induced carcinogenesis (8 -14). It has been suggested that arsenic induces chromosome aberration and sister chromatid exchange which may be involved in arsenite-induced carcinogenesis (11,12). Recently, Zhao et al. (13) reported that arsenic may act as a carcinogen by inducing DNA hypomethylation, which in turn facilitates aberrant gene expression. Additionally, it was found that arsenite is a potent stimulator of extracellular signal-regulated protein kinase (Erk) 1 and AP-1 transactivational activity and an efficient inducer of c-fos and c-jun gene expression (10,14). Induction of c-jun and c-fos by arsenite is associated with activation of JNK (10). However, the role of JNK activation by arsenite in cell transformation or tumor promotion is unclear. We have established cell culture conditions for studying arsenite-induced cell tr...
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