1
|
Haderski GJ, Kandar BM, Brackett CM, Toshkov IM, Johnson CP, Paszkiewicz GM, Natarajan V, Gleiberman AS, Gudkov AV, Burdelya LG. TLR5 agonist entolimod reduces the adverse toxicity of TNF while preserving its antitumor effects. PLoS One 2020; 15:e0227940. [PMID: 32027657 PMCID: PMC7004342 DOI: 10.1371/journal.pone.0227940] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/02/2020] [Indexed: 12/24/2022] Open
Abstract
Tumor necrosis factor alpha (TNF) is capable of inducing regression of solid tumors. However, TNF released in response to Toll-like receptor 4 (TLR4) activation by bacterial lipopolysaccharide (LPS) is the key mediator of cytokine storm and septic shock that can cause severe tissue damage limiting anticancer applications of this cytokine. In our previous studies, we demonstrated that activation of another Toll-like receptor, TLR5, could protect from tissue damage caused by a variety of stresses including radiation, chemotherapy, Fas-activating antibody and ischemia-reperfusion. In this study, we tested whether entolimod could counteract TNF-induced toxicity in mouse models. We found that entolimod pretreatment effectively protects livers and lungs from LPS- and TNF-induced toxicity and prevents mortality caused by combining either of these agents with the sensitizer, D-galactosamine. While LPS and TNF induced significant activation of apoptotic caspase 3/7, lipid tissue peroxidation and serum ALT accumulation in mice without entolimod treatment, these indicators of toxicity were reduced by entolimod pretreatment to the levels of untreated control mice. Entolimod was effective when injected 0.5–48 hours prior to, but not when injected simultaneously or after LPS or TNF. Using chimeric mice with hematopoiesis differing in its TLR5 status from the rest of tissues, we showed that this protective activity was dependent on TLR5 expression by non-hematopoietic cells. Gene expression analysis identified multiple genes upregulated by entolimod in the liver and cultured hepatocytes as possible mediators of its protective activity. Entolimod did not interfere with the antitumor activity of TNF in mouse hepatocellular and colorectal tumor models. These results support further development of TLR5 agonists to increase tissue resistance to cytotoxic cytokines, reduce the risk of septic shock and enable safe systemic application of TNF as an anticancer therapy.
Collapse
Affiliation(s)
- Gary J. Haderski
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, United States America
| | - Bojidar M. Kandar
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, United States America
| | - Craig M. Brackett
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, United States America
| | - Ilia M. Toshkov
- Genome Protection, Inc., Buffalo, New York, United States of America
| | - Christopher P. Johnson
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, United States America
| | - Geraldine M. Paszkiewicz
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, United States America
| | - Venkatesh Natarajan
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, United States America
| | | | - Andrei V. Gudkov
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, United States America
- * E-mail: (LGB); (AVG)
| | - Lyudmila G. Burdelya
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, New York, United States America
- * E-mail: (LGB); (AVG)
| |
Collapse
|
2
|
Abstract
TOR is involved in aging in a wide range of species from yeast to mammals. Here we show that, after overnight fasting, mTOR activity is higher in the livers of 28 months old female mice compared with middle-aged mice. Taken together with previous reports, our data predict that the life-extending effect of calorie restriction (CR) may be diminished, if CR is started in very old age. In contrast, rapamycin is known to be effective, even when started late in life.
Collapse
Affiliation(s)
- Olga V Leontieva
- a Cell Stress Biology; Roswell Park Cancer Institute ; Buffalo , NY USA
| | | | | |
Collapse
|
3
|
Abstract
At a wide range of doses, rapamycin extends life span in mice. It was shown that intraperitoneal injections (i.p.) of rapamycin prevent weight gain in mice on high-fat diet (HFD). We further investigated the effect of rapamycin on weight gain in female C57BL/6 mice on HFD started at the age of 7.5 months. By the age of 16 and 23 months, mice on HFD weighed significantly more (52 vs 33 g; p = 0.0001 and 70 vs 38 g; p < 0.0001, respectively) than mice on low fat diet (LFD). The i.p. administration of 1.5 mg/kg rapamycin, 3 times a week every other week, completely prevented weight gain, whereas administration of rapamycin by oral gavash did not. Rapamycin given in the drinking water slightly decreased weight gain by the age of 23 months. In addition, metabolic parameters were evaluated at the age of 16 and 23 months, 6 and 13 days after last rapamycin administration, respectively. Plasma leptin levels strongly correlated with body weight, (P < 0.0001, r=0.86), suggesting that the difference in weight was due to fat tissue mass. Levels of insulin, glucose, triglycerides and IGF1 were not statistically different in all groups, indicating that these courses of rapamycin treatment did not impair metabolic parameters at least after rapamycin discontinuation. Despite rapamycin discontinuation, cardiac levels of phospho-S6 and pAKT(S473) were low in the i.p.-treated group. This continuous effect of rapamycin can be explained by prevention of obesity in the i.p. group. We conclude that intermittent i.p. administration of rapamycin prevents weight gain without causing gross metabolic abnormalities. Intermittent gavash administration minimally affected weight gain. Potential clinical applications are discussed.
Collapse
Affiliation(s)
- Olga V Leontieva
- a Cell Stress Biology; Roswell Park Cancer Institute ; Buffalo , NY USA
| | | | | |
Collapse
|
4
|
Leontieva OV, Paszkiewicz GM, Blagosklonny MV. Weekly administration of rapamycin improves survival and biomarkers in obese male mice on high-fat diet. Aging Cell 2014; 13:616-22. [PMID: 24655348 PMCID: PMC4326934 DOI: 10.1111/acel.12211] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2014] [Indexed: 01/03/2023] Open
Abstract
Recent discoveries have revealed the key role of mTOR (target of rapamycin) in aging. Furthermore, rapamycin extends lifespan in mice, especially in female mice. Here, we treated obese male mice on high-fat diet with rapamycin given intermittently: either weekly (once a week) or alternating bi-weekly (three injections every other week). While only marginally reducing obesity, intermittent administration of rapamycin significantly extended lifespan. Significance was achieved for weekly treated group and for the three rapamycin-received groups combined. In weekly treatment group, 100% mice were alive by the age of 2 years, whereas 60% of mice died in untreated group by this age. The effect of weekly treatment on survival was highly significant and cannot be fully explained by partial reduction in obesity. Alternating bi-weekly treatments seem to be less effective than weekly treatment, although effects of additional factors (see Discussion) may not be excluded. After one year of treatment, all survived mice were sacrificed 8 days after the last administration of rapamycin to avoid its direct interference with parameters examined. Fasting levels of cardiac and hepatic p-S6, a marker of mTORC1 activity, were lower in weekly treatment group compared with control mice. In contrast, levels of p-Akt (S473), glucose, triglycerides and insulin were unchanged, whereas leptin and IGF-1 tended to be lower. Thus, weekly treatment with rapamycin may slow down aging in obese male mice on high-fat diet.
Collapse
Affiliation(s)
- Olga V. Leontieva
- Cell Stress Biology Roswell Park Cancer Institute Buffalo NY 14263USA
| | | | | |
Collapse
|
5
|
Leontieva OV, Novototskaya LR, Paszkiewicz GM, Komarova EA, Gudkov AV, Blagosklonny MV. Dysregulation of the mTOR pathway in p53-deficient mice. Cancer Biol Ther 2013; 14:1182-8. [PMID: 24184801 DOI: 10.4161/cbt.26947] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mammalian or mechanistic target of rapamycin (mTOR) is involved in growth, aging, and age-related diseases including cancer. There is an extensive cross talk between p53 and mTOR. In cell culture, p53 inhibits the mTOR pathway in a cell type-dependent manner. p53-deficient mice develop pro-inflammation and cancer. We have shown that rapamycin delayed cancer and extended lifespan, thus partially substituting for p53. Here we show that a marker of mTOR activity, phosphorylated S6 (p-S6), is increased in the hearts of p53-deficient mice. Furthermore, cardiac p-S6 correlated with body weight. Also, p53(-/-) mice were slightly hyperinsulinemic with a tendency to elevated IGF-1. Radiation exacerbated the difference between IGF-1 levels in normal and p53(-/-) mice. Noteworthy, radiation induced Thr-308 Akt phosphorylation in the livers (but not in the hearts) of both p53(+/+) and p53(-/-) mice. Simultaneously, radiation decreased p-S6 in the livers of normal mice, consistent with the negative effect of p53 on mTOR. Our data indicate that the activity of mTOR is increased in some but not all tissues of p53(-/-) mice, associated with the tendency to increased insulin and IGF-1 levels. Therefore, the absence of p53 may create oncophilic microenvironment, favoring cancer.
Collapse
Affiliation(s)
- Olga V Leontieva
- Department of Cell Stress Biology; Roswell Park Cancer Institute; Buffalo, NY USA
| | | | | | - Elena A Komarova
- Department of Cell Stress Biology; Roswell Park Cancer Institute; Buffalo, NY USA
| | - Andrei V Gudkov
- Department of Cell Stress Biology; Roswell Park Cancer Institute; Buffalo, NY USA
| | | |
Collapse
|
6
|
Leontieva OV, Paszkiewicz GM, Blagosklonny MV. Mechanistic or mammalian target of rapamycin (mTOR) may determine robustness in young male mice at the cost of accelerated aging. Aging (Albany NY) 2012; 4:899-916. [PMID: 23443503 PMCID: PMC3615157 DOI: 10.18632/aging.100528] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 12/20/2012] [Indexed: 01/01/2023]
Abstract
Males, who are bigger and stronger than females, live shorter in most species from flies to mammals including humans. Cellular mass growth is driven in part by mTOR (Target of Rapamycin). When developmental growth is completed, then, instead of growth, mTOR drives aging, manifested by increased cellular functions, such as hyper-secretion by fibroblasts, thus altering homeostasis, leading to age-related diseases and death. We hypothesize that MTOR activity is elevated in male mice compared with females. Noteworthy, 6 months old males were 28 % heavier than females. Also levels of phosphorylated S6 (pS6) and phospho-AKT (p-AKT, Ser 473), markers of the mTOR activity, were higher in male organs tested. Levels of pS6 were highly variable among mice and correlated with body weight and p-AKT. With age, the difference between levels of pS6 between sexes tended to minimize, albeit males still had hyperactive mTOR. Unlike fasting, the intraperitoneal (i.p.) administration of rapamycin eliminated pS6 in all organs of all females measured by immunoblotting and immunohistochemistry without affecting p-AKT and blood insulin. Although i.p. rapamycin dramatically decreased levels of pS6 in males too, it was still detectable by immunoblotting upon longer exposure. Our study demonstrated that both tissue p-AKT and pS6 were higher in young male mice and were associated with increased body weight and insulin. These data can explain bigger body size and faster aging in males. Our data suggest higher efficacy of rapamycin compared to fasting. Higher sensitivity of females to rapamycin may explain more pronounced life extension by rapamycin observed in females compared to males in several studies.
Collapse
Affiliation(s)
- Olga V Leontieva
- Department of Cell Stress Biology, Roswell Park Cancer Institute, BLSC, L3-312, Elm and Carlton Streets, Buffalo, NY 14263, USA
| | | | | |
Collapse
|
7
|
Smith LA, Paszkiewicz GM, Hutson AD, Pauly JL. Inflammatory response of lung macrophages and epithelial cells to tobacco smoke: a literature review of ex vivo investigations. Immunol Res 2010; 46:94-126. [PMID: 20094822 DOI: 10.1007/s12026-009-8133-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Chronic inflammation contributes to the initiation and progression of tumors and tobacco smoke-associated inflammation is associated with malignant and certain non-neoplastic lung diseases. Reported herein are the results of an interpretative synthesis review of the literature assessing the inflammatory response of lung macrophages (MPhi) and epithelial cells to tobacco smoke as measured ex vivo. Papers were retrieved using Boolean operations from PubMed and Scopus. Many writings reported the results of assays of human MPhi from fresh surgically excised human lung tissue, bronchoalveolar lavage, activated blood monocytes, long-term cell lines and MPhi from different laboratory animals. Some publications reported the findings of comparative studies of lung MPhi freshly isolated from the lungs of smokers and non-smokers. Other papers described the effect of tobacco smoke on lung epithelial cells. Most investigators quantified the response of the target cells to tobacco smoke by measuring the production of pro-inflammatory mediators; these included chemokines, cytokines, reactive oxygen species and enzymes. Investigators have reported conflicting observations of the response of human and animal MPhi and epithelial cells to tobacco smoke. The spectrum included papers describing robust production of various inflammatory mediators, significant reduction of a pro-inflammatory response to a known stimulant and overt cytotoxicity. This literature review documents that there exists no consensus, and no emerging trend line, of the reproducible effect(s) of cigarette smoke. This discrepancy reflects the absence of standardized protocols for collecting, processing and bioassaying the smoke, a highly complex aerosol, and identifies the need for establishing collaborative research schemes.
Collapse
Affiliation(s)
- Lauren A Smith
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | | | | | | |
Collapse
|
8
|
Pauly JL, Smith LA, Rickert MH, Hutson A, Paszkiewicz GM. Review: Is lung inflammation associated with microbes and microbial toxins in cigarette tobacco smoke? Immunol Res 2010; 46:127-36. [PMID: 19763893 DOI: 10.1007/s12026-009-8117-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chronic inflammation that has been observed for malignant and non-neoplastic lung diseases of smokers has been attributed to the numerous and diverse particulate ('tar')-phase and gas-phase chemicals in mainstream smoke, most of which arise from the burning of tobacco. The primary cell-mediator of lung inflammation is the macrophage. Most probably, inflammation is promoted also from some of the more than 50 other cell types of the lung. Cured tobacco in diverse types of cigarettes is known to harbor a plethora of bacteria (Gram-positive and Gram-negative), fungi (mold, yeast), spores, and is rich in endotoxin (lipopolysaccharide). Reviewed herein are recent observations of the authors' team and other investigators that support the hypothesis that lung inflammation of long-term smokers may be attributed in part to tobacco-associated bacterial and fungal components that have been identified in tobacco and tobacco smoke.
Collapse
Affiliation(s)
- John L Pauly
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
| | | | | | | | | |
Collapse
|
9
|
Pauly JL, O'Connor RJ, Paszkiewicz GM, Cummings KM, Djordjevic MV, Shields PG. Cigarette filter-based assays as proxies for toxicant exposure and smoking behavior--a literature review. Cancer Epidemiol Biomarkers Prev 2010; 18:3321-33. [PMID: 19959679 DOI: 10.1158/1055-9965.epi-09-0925] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Cigarettes are being marketed with filters that differ in composition and design. The filters have different toxicant trapping efficiencies, and smoking stains reflect variations in smoking behavior. Presented herein are the results of a structured literature review that was done to identify cigarette filter-based assays that may serve as proxies for mouth-level exposure and assessing smoking methods. METHODS A search of the published scientific literature and internal tobacco company documents from 1954 to 2009 was carried out. RESULTS The literature search identified diverse schemes for assessing cigarette filters, including visual inspection and digital imaging of smoked-stained spent filters, and quantitative determinations for total particulate matter (TPM), nicotine, and solanesol. The results also showed that: (a) there are sufficient data to link filter-based chemical measures to standardized smoking machine-measured yields of tar and nicotine; (b) TPM eluted from filters or in chemical digest of filters can be used to estimate the efficiency of the filter for trapping smoke solids; (c) visual and digital inspection of spent filters is useful in finding indicators of variations in smoking behaviors; and (d) there is a correlation between solanesol and nicotine measured in filters and exposure biomarkers in smokers. CONCLUSIONS The cigarette filter may prove useful in estimating smoking behaviors such as filter vent blocking and puffing intensity, and may have utility as proxy measures of mouth-level smoke exposure in clinical trials. Additional investigations are needed to compare the different proposed assay schemes and the assay results with measurements of human biomarker assays of smoke exposure.
Collapse
Affiliation(s)
- John L Pauly
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
| | | | | | | | | | | |
Collapse
|
10
|
Abstract
Almost all cigarettes sold have a filter (United States, >98%; worldwide, >95%). In the last 25 years cigarette manufacturers have introduced diverse filters designed to reduce components in tobacco smoke. Today, there exists a need to establish assays to assess the efficacy of cigarette filters to retain total particulate matter (TPM), particularly unique filters of cigarettes that are being marketed as potential reduced exposure products (PREPs). We report the results of studies that were undertaken to test the hypothesis that a technique could be established for dissolving cigarette filters, and that the TPM in the fluid could be quantified by spectrofluorometry. Described here are procedures for assaying TPM on both Cambridge filter pads (glass fibres) of smoking machines and on cigarette filters (cellulose acetate fibres). The principle of the assays is based upon the observation that there exists a direct correlation between the amount of tobacco product emission TPM and fluorescence. In the absence of a tobacco tar or TPM standard, the fluorescent dye acridine orange was confirmed as a useful surrogate. Filters assayed included those of Kentucky reference cigarettes 2R4F and popular US brand cigarettes. The proposed assays are inexpensive, expedient, reproducible and amendable for large-scale studies.
Collapse
Affiliation(s)
- G M Paszkiewicz
- Department of Immunology, Cancer Cell Center, Room CCC-307, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York 14263, USA.
| | | |
Collapse
|
11
|
Abstract
Bacterial growth from a single flake of tobacco was documented for cigarettes that had been purchased recently from local vendors and from cigarettes that had been stored for more than six years in a warehouse. In a novel tobacco flake assay, a pack of cigarettes was opened within the sterile environment of a laminar flow hood. A single flake of tobacco was collected randomly and aseptically from the middle of the cigarette column and placed onto the surface of a blood agar plate. The test cigarettes included eight different popular US brands, and these were from three different tobacco companies. After 24 hours of incubation at 37 degrees C, the plates showed bacterial growth for tobacco from all brands of cigarettes. Further, more than 90% of the individual tobacco flakes of a given brand grew bacteria. Likewise, bacteria grew from microparticulate tobacco that had been sieved from cigarettes. Tobacco flakes were observed lying loosely on the cut surface of the filter of cigarettes in newly opened packs, and bacteria grew from cigarette filters that had been touched to the surface of a blood agar plate. In conclusion, the results of these studies predict that diverse microbes and microbial toxins are carried by tobacco microparticulates that are released from the cigarette during smoking, and carried into mainstream smoke that is sucked deep into the lung.
Collapse
Affiliation(s)
- J L Pauly
- Department of Immunology, Cancer Cell Center, Room CCC-307, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA.
| | | | | |
Collapse
|
12
|
Proia NK, Paszkiewicz GM, Nasca MAS, Franke GE, Pauly JL. Smoking and smokeless tobacco-associated human buccal cell mutations and their association with oral cancer--a review. Cancer Epidemiol Biomarkers Prev 2006; 15:1061-77. [PMID: 16775162 DOI: 10.1158/1055-9965.epi-05-0983] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Reported herein are the results of a structured literature review that was undertaken to (a) determine if human buccal (mouth) cell changes are associated with smoking and smokeless ("chewing") tobacco, (b) tabulate different buccal cell alterations that have been reported, (c) delineate buccal cell assays that have been used successfully, (d) determine whether buccal cell changes correlate with oral cancer as defined in clinicopathologic investigations, and (e) assess the feasibility of developing a high-throughput buccal cell assay for screening smokers for the early detection of oral cancer. The results of the studies reported herein have established that diverse buccal cell changes are associated with smoking and smokeless tobacco. This review documents also that buccal cells have been collected in a noninvasive manner, and repetitively for serial studies, from different sites of the mouth (e.g., cheek, gum, and tongue) and from normal tissue, preneoplastic lesions (leukoplakia), and malignant tumors. Tobacco-associated genetic mutations and nongenetic changes have been reported; a partial listing includes (a) micronuclei, (b) bacterial adherence, (c) genetic mutations, (d) DNA polymorphisms, (d) carcinogen-DNA adducts, and (e) chromosomal abnormalities. Clinical studies have correlated buccal cell changes with malignant tumors, and some oral oncologists have reported that the buccal cell changes are practical biomarkers. Summarily, the literature has established that buccal cells are useful not only for characterizing the molecular mechanisms underlying tobacco-associated oral cancers but also as exfoliative cells that express diverse changes that offer promise as candidate biomarkers for the early detection of oral cancer.
Collapse
Affiliation(s)
- Nicole K Proia
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | | | | | | | | |
Collapse
|
13
|
Pauly JL, Allison EM, Hurley EL, Nwogu CE, Wallace PK, Paszkiewicz GM. Fluorescent human lung macrophages analyzed by spectral confocal laser scanning microscopy and multispectral cytometry. Microsc Res Tech 2005; 67:79-89. [PMID: 16037980 DOI: 10.1002/jemt.20191] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Numerous highly fluorescent macrophages (MPhi), designated "smoker cells," exist in the lungs of smokers and subjects who have quit smoking within 5 years. The brightly fluorescent MPhi, however, are not present in the lungs of never smokers. Some investigators have speculated that the intense fluorescence of the MPhi is due to smoke-induced changes in the autofluorescence of naturally occurring (i.e., endogenous) compounds (e.g., NADP). In contrast, other researchers have theorized that the fluorescence is due to the uptake of tobacco smoke particulates (i.e., "tar"). Studies reported herein were undertaken to test the hypothesis that the origin of the MPhi fluorescence could be profiled with the novel technologies afforded by spectral confocal laser scanning microscopy (sCLSM) and multispectral cytometry (MSC). To this end, spectral emissions were obtained by sCLSM of optical sections of live MPhi isolated from fresh surgically excised human lung tissue and in air-dried lung tissue imprints. Confirmation of spectral profiles of these single cell observations was obtained in population studies with the use of high-throughput MSC in which multispectral analyses were performed with three different lasers. Proof of concept experiments demonstrated that relatively nonfluorescent MPhi from the lungs of nonsmokers became fluorescent upon short-term ex vivo exposure to tobacco smoke tar. Summarily, the studies reported herein document that the fluorescence of human lung MPhi is due to tobacco tar.
Collapse
Affiliation(s)
- John L Pauly
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New York 14263, USA.
| | | | | | | | | | | |
Collapse
|
14
|
MacDonald IJ, Morgan J, Bellnier DA, Paszkiewicz GM, Whitaker JE, Litchfield DJ, Dougherty TJ. Subcellular localization patterns and their relationship to photodynamic activity of pyropheophorbide-a derivatives. Photochem Photobiol 1999; 70:789-97. [PMID: 10568171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
To determine if subcellular localization is important to photodynamic therapy (PDT) efficacy, an in vitro fluorescence microscopy study was conducted with a congeneric series of pyropheophorbide-a derivatives in human pharyngeal squamous cell carcinoma (FaDu) cells and murine radiation-induced fibrosarcoma (RIF) mutant cells. In the FaDu cells the octyl, decyl and dodecyl ether derivatives localized to the lysosomes at extracellular concentrations less than needed to produce a 50% cell kill (LD50). At extracellular concentrations equal or greater than the LD50 the compounds localized mainly to mitochondria. The propyl, pentyl, hexyl and heptyl ether derivatives localized mainly to the mitochondria at all concentrations studied. This suggested that mitochondria are a sensitive PDT target for these derivatives. Similar experiments were performed with two Photofrin-PDT resistant RIF cell lines, one of which was found to be resistant to hexyl ether derivative (C6) mediated-PDT and the other sensitive to C6-PDT relative to the parent line. At extracellular concentrations of C6 below the LD50 of each cell line, the mutants exhibited lysosomal localization. At concentrations above these values the patterns shifted to a mainly mitochondrial pattern. In these cell lines mitochondrial localization also correlated with PDT sensitivity. Localization to mitochondria or lysosomes appeared to be affected by the aggregation state of the congeners, all of which are highly aggregated in aqueous medium. Monomers apparently were the active fraction of these compounds because equalizing the extracellular monomer concentrations produced equivalent intracellular concentrations, photoxicity and localization patterns. Compounds that were mainly aggregates localized to the lysosomes where they were rendered less active. Mitochondria appear to be a sensitive target for pyropheophorbide-a-mediated photodamage, and the degree of aggregation seems to be a determinant of the localization site.
Collapse
Affiliation(s)
- I J MacDonald
- Photodynamic Therapy Center, Roswell Park Cancer Institute, Buffalo, NY, USA
| | | | | | | | | | | | | |
Collapse
|