ABSTRACT
Infectious pneumonias are the leading cause of death worldwide, particularly among immunocompromised patients. Therapeutic stimulation of the lungs' intrinsic defenses with a unique combination of inhaled Toll-like receptor (TLR) agonists broadly protects mice against otherwise lethal pneumonias. As the survival benefit persists despite cytotoxic chemotherapy-related neutropenia, the cells required for protection were investigated. The inducibility of resistance was tested in mice with deficiencies of leukocyte lineages due to genetic deletions and in wild-type mice with leukocyte populations significantly reduced by antibodies or toxins. Surprisingly, these serial reductions in leukocyte lineages did not appreciably impair inducible resistance, but targeted disruption of TLR signaling in the lung epithelium resulted in complete abrogation of the protective effect. Isolated lung epithelial cells were also induced to kill pathogens in the absence of leukocytes. Proteomic and gene expression analyses of isolated epithelial cells and whole lungs revealed highly congruent antimicrobial responses. Taken together, these data indicate that lung epithelial cells are necessary and sufficient effectors of inducible resistance. These findings challenge conventional paradigms about the role of epithelia in antimicrobial defense and offer a novel potential intervention to protect patients with impaired leukocyte-mediated immunity from fatal pneumonias.
Subject(s)
Alveolar Epithelial Cells/metabolism , Disease Resistance/immunology , Pneumonia/immunology , Pneumonia/metabolism , Alveolar Epithelial Cells/drug effects , Animals , Disease Models, Animal , Disease Resistance/drug effects , Leukocytes/drug effects , Leukocytes/immunology , Leukocytes/metabolism , Lipopeptides/metabolism , Lipopeptides/pharmacology , Mice , Mice, Knockout , Pneumonia/genetics , Pneumonia/mortality , Signal Transduction , Toll-Like Receptors/metabolismABSTRACT
Recent studies have demonstrated that K-ras mutations in lung epithelial cells elicit inflammation that promotes carcinogenesis in mice (intrinsic inflammation). The finding that patients with chronic obstructive pulmonary disease (COPD), an inflammatory disease of the lung, have an increased risk of lung cancer after controlling for smoking suggests a further link between lung cancer and extrinsic inflammation. Besides exposure to cigarette smoke, it is thought that airway inflammation in COPD is caused by bacterial colonization, particularly with non-typeable Hemophilus influenzae (NTHi). Previously, we have shown that NTHi-induced COPD-like airway inflammation promotes lung cancer in an airway conditional K-ras-induced mouse model. To further test the role of inflammation in cancer promotion, we administered the natural anti-inflammatory agent, curcumin, 1% in diet before and during weekly NTHi exposure. This significantly reduced the number of visible lung tumors in the absence of NTHi exposure by 85% and in the presence of NTHi exposures by 53%. Mechanistically, curcumin markedly suppressed NTHi-induced increased levels of the neutrophil chemoattractant keratinocyte-derived chemokine by 80% and neutrophils by 87% in bronchoalveolar lavage fluid. In vitro studies of murine K-ras-induced lung adenocarcinoma cell lines (LKR-10 and LKR-13) indicated direct anti-tumoral effects of curcumin by reducing cell viability, colony formation and inducing apoptosis. We conclude that curcumin suppresses the progression of K-ras-induced lung cancer in mice by inhibiting intrinsic and extrinsic inflammation and by direct anti-tumoral effects. These findings suggest that curcumin could be used to protract the premalignant phase and inhibit lung cancer progression in high-risk COPD patients.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Antineoplastic Agents/pharmacology , Curcumin/pharmacology , Haemophilus influenzae , Lung Neoplasms/etiology , Lung Neoplasms/prevention & control , Pulmonary Disease, Chronic Obstructive/complications , Animals , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Chemokines/metabolism , Curcumin/therapeutic use , Female , Genes, ras , Haemophilus Infections/complications , Inflammation , Lung Neoplasms/genetics , Male , Mice , Neutrophils/metabolism , Neutrophils/pathology , Pulmonary Disease, Chronic Obstructive/drug therapy , Pulmonary Disease, Chronic Obstructive/physiopathologyABSTRACT
AIM: To study the effect of some genes especially those involved in cell cycle regulation on hepatocellular carcinoma. METHODS: Paraffin-embedded tissue samples of 25 patients (18 males and 7 females) with hepatocellular carcinoma were collected from 22 pathology centers in Tehran during 2000-2001, and stained using immunohistochemistry method (avidin-biotin-peroxidase) for detection of p53, cyclinD1, RB1, c-fos and N-ras proteins. RESULTS: Six (24%), 5 (20%), 12 (48%) and 2 samples (8%) were positive for p53, cyclinD1, C-fos and N-ras expression, respectively. Twenty-two (88%) samples had alterations in the G1 cell-cycle checkpoint protein expression (RB1 or cyclinD1). P53 positive samples showed a higher (9 times) risk of being positive for RB1 protein than p53 negative samples. Loss of expression of RB1 in association with p53 over-expression was observed in 4 (66.7%) of 6 samples. Loss of expression of RB1 was seen in all cyclinD1 positive, 20 (90.9%) N-ras negative, and 11 (50%) C-fos positive samples, respectively. CyclinD1 positive samples showed a higher (2.85 and 4.75 times) risk of being positive for c-fos and N-ras expression than cyclinD1 negative samples. CONCLUSION: The expression of p53, RB1 and c-fos genes appears to have a key role in the pathogenesis of hepatocellular carcinoma in Iran. Simultaneous overexpression of these genes is significantly associated with their loss of expression during development of hepatocellular carcinoma.
