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Multiple systemic treatments are currently available for advanced cancers of the digestive tract, but none of them is curative. Adoptive T-cell immunotherapy refers to the extraction, modification and re-infusion of autologous or allogenic T lymphocytes for therapeutic purposes. A number of clinical trials have investigated either non-engineered T cells (i.e., lymphokine-activated killer cells, cytokine induced killer cells, or tumor-infiltrating lymphocytes) or engineered T cells (T cell receptor-redirected T cells or chimeric antigen receptor T cells) in patients with digestive tract malignancies over the past two decades, with variable degrees of success. While the majority of completed trials have been primarily aimed at assessing the safety of T-cell transfer strategies, a new generation of studies is being designed to formally evaluate the antitumor potential of adoptive T-cell immunotherapy in both the metastatic and adjuvant settings. In this review, we provide an overview of completed and ongoing clinical trials of passive T-cell immunotherapy in patients with cancers of the digestive tract, focusing on present obstacles and future strategies for achieving potential success., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Ozone, one of the main components of photochemical smog, represents an important source of environmental oxidative stress to which the skin is exposed, especially during smoggy and ozone-alert days. However, very little is known about the effects of ozone exposure on human skin. Here, we used normal human epidermal keratinocytes (NHEKs) to determine the effects of attainable levels of ozone exposure on the family of cytochrome P450 (CYP) isoforms, which plays a determinant role in the biotransformation of many environmental pollutants. NHEK exposure to ozone (0.3 ppm) resulted in an increase in protein and messenger RNA (mRNA) expression of CYP1A1, CYP1A2, and CYP1B1. NHEK exposure to ozone also resulted in nuclear translocation of the aryl hydrocarbon receptor (AhR) and in phosphorylation of epidermal growth factor receptor (EGFR). The effect of ozone on events downstream of EGFR was an increased activation of phosphoinositide 3-kinase and phosphorylation of protein kinase B and mitogen-activated protein kinases. We found that AhR silencing by small interfering RNA abolished the capacity of these cells to increase the protein and mRNA expression of CYPs on ozone exposure. Thus, AhR signaling is an integral part of the induction of CYPs by ozone. These studies strongly suggest that there are toxicological consequences of ozone to human skin.

Overproduction of sebum, especially during adolescence, is causally related to acne and inflammation. As a way to reduce sebum and its interference with the process of follicular keratinization in the pilosebaceous unit leading to inflammatory acne lesions, antihistamines were investigated for their effect on sebocytes, the major cell of the sebaceous gland responsible for producing sebum. Reverse transcriptase-PCR analysis and immunofluorescence of an immortalized sebocyte cell line (SZ95) revealed the presence of histamine-1 receptor (H-1 receptor), and thus indicated that histamines and, conversely, antihistamines could potentially modulate sebocyte function directly. When sebocytes were incubated with an H-1 receptor antagonist, diphenhydramine (DPH), at non-cytotoxic doses, a significant decrease in squalene levels, a biomarker for sebum, was observed. As determined by high-performance liquid chromatography, untreated sebocytes contained 6.27 (+/-0.73) nmol squalene per 10(6) cells, whereas for DPH-treated cells, the levels were 2.37 (+/-0.24) and 2.03 (+/-0.97) nmol squalene per 10(6) cells at 50 and 100 microM, respectively. These data were further substantiated by the identification of histamine receptors in human sebaceous glands. In conclusion, our data show the presence of histamine receptors on sebocytes, demonstrate how an antagonist to these receptors modulated cellular function, and may indicate a new paradigm for acne therapy involving an H-1 receptor-mediated pathway.

Basal hydrogen peroxide (H(2)O(2)) levels in normal human epidermal keratinocytes (NHEK) and melanocytes (mel) were compared on a per cell basis and found to be significantly higher in keratinocytes. Since H(2)O(2) is a neutral molecule capable of permeating through cellular membranes, we then investigated the possibility that H(2)O(2) transfer might occur between these two types of cells. Because the ratio of keratinocytes to mel in skin is 36:1, keratinocytes may act as a source of reactive oxygen species (ROS) even by passive diffusion and, thus, affect melanocytic functions. In order to measure H(2)O(2) transfer, a fluorescence-based co-culture system was developed in which mel were first pre-labeled with 5-(and-6)-chloromethyl-2',7'-dichlorodihydro-fluorescein diacetate (DCFdA). When mel were co-cultured with keratinocytes, fluorescence increased as a function of keratinocyte cell number. Thus, for mel incubated with 1-, 1.5-, and 2-fold the number of keratinocytes, fluorescence increased by 22.6% (+/-2.8%), 25.6% (+/-4.8%), and 39.9% (+/-4.1%), respectively. Separating the cells with a transwell membrane did not prevent the transfer, whereas the addition of catalase to media significantly reduced the transfer of H(2)O(2) to mel. In conclusion, keratinocytes appear to be a previously unexamined source of ROS that may affect neighboring skin cells, such as mel, and, as a result, may influence the process of melanogenesis or contribute to the progression of vitiliginous lesions.

To evaluate the effects of ultraviolet-induced environmental trauma on human skin cells, primary normal human epidermal keratinocytes were exposed to ultraviolet-B radiation (290-320 nm). We found that relatively low doses of ultraviolet-B (62.5-500 mJ per cm2) caused dose-dependent increases in 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG), a biomarker of oxidative DNA damage. Unirradiated normal human epidermal keratinocytes contained 1.49 (+/- 0.11) 8-oxo-dG per 10(6) 2'-deoxyguanosine (dG) residues in cellular DNA, which increased linearly to as high as 6.24 (+/- 0.85) 8-oxo-dG per 10(6) dG after irradiation with 500 mJ per cm2. Further, this oxidative damage was reduced by 60.7% when the cells were pretreated with 1 mM mannitol. As hydrogen peroxide (H2O2) is known to be generated during oxidative stress, its accumulation in ultraviolet-B-irradiated normal human epidermal keratinocytes was also assessed and correlated to 8-oxo-dG formation. An ultraviolet-B-induced increase in H2O2 was observed in normal human epidermal keratinocytes and its production was inhibited by the addition of catalase. Based on the ability of a neutral molecule like H2O2 to permeate membranes, our data indicate that, after ultraviolet-B irradiation, H2O2 migrates from the cytosol to the nucleus where it participates in a Fenton-like reaction that results in the production of hydroxyl radicals (OH*), which may then cause 8-oxo-dG formation in cellular DNA. This conclusion is supported by our data showing that OH* scavengers, such as mannitol, are effective inhibitors of oxidative DNA base damage. Although increased levels of 8-oxo-dG were previously found in immortalized mouse keratinocytes exposed to ultraviolet-B radiation, we now report the induction of 8-oxo-dG in normal human skin keratinocytes at ultraviolet-B doses relevant to human skin exposure.

Since antioxidants have been shown to play a major role in preventing some of the effects of aging and photoaging in skin, it is important to study this phenomenon in a controlled manner. This was accomplished by developing a simple and reliable in vitro technique to assay antioxidant efficacy. Inhibition of peroxidation by antioxidants was used as a measure of relative antioxidant potential. Liposomes, high in polyunsaturated fatty acids (PUFA), were dispersed in buffer and irradiated with ultraviolet (UV) light. Irradiated liposomes exhibited a significantly higher amount of hydroperoxides than liposomes containing antioxidants in a dose- and concentration-dependent manner. Lipid peroxidation was determined spectrophotometrically by an increase in thiobarbituric acid reacting substances. To further substantiate the production of lipid peroxides, gas chromatography was used to measure a decrease in PUFA substrate. In order of decreasing antioxidant effectiveness, the following results were found among lipophilic antioxidants: BHA greater than catechin greater than BHT greater than alpha-tocopherol greater than chlorogenic acid. Among hydrophilic antioxidants, ascorbic acid and dithiothreitol were effective while glutathione was ineffective. In addition, ascorbic acid was observed to act synergistically with alpha-tocopherol, which is in agreement with other published reports on the interaction of these two antioxidants. Although peroxyl radical scavengers seem to be at a selective advantage in this liposomal/UV system, these results demonstrate the validity of this technique as an assay for measuring an antioxidant's potential to inhibit UV-induced peroxidation.

The electrophoretic mobility distributions of hairy cells, normal monocytes. CLL, and normal lymphocytes isolated from blood were determined by electrophoretic light scattering. Values obtained for hairy cells, 1.52 X 10(-4) cm2/V . sec, were indistinguishable from that of normal monocytes. The mobility of CLL lymphocytes was similar to that of normal B cells. After exposure to neuraminidase, hairy cells revealed a homogeneous distribution with a reduced mobility of 0.55 X 10(-4) cm2/V . sec, while normal monocytes showed a heterogeneous distribution of electrophoretic mobilities suggestive of subpopulations. The electrokinetic behavior of hairy cells thus differs from that or normal and CLL lymphocytes before, and from that of monocytes after, treatment with neuraminidase. The hairy cell therefore possesses a distinct pattern of surface charge properties that clearly distinguish it from the circulating B cells, T cells, or monocytes.

Two patients with progressive hairy cell leukemia following splenectomy were treated with low-dose daily chlorambucil. Both had an objective hematologic response as determined by a return to normal hematocrit and platelet count. This was also reflected in the mononuclear cell fraction by the normalization of cholesterol content, cholesterol/phospholipid ratio, and the lymphocyte subpopulations. This article confirms previous reports on the efficacy of chlorambucil in this setting and describes some morphological, and biochemical concomitant events.