Purpose: The possible involvement of gender-dependent factors has been suggested in human non-small cell lung carcinomas (NSCLC), but their precise roles remain largely unclear. Therefore, we examined intratumoral estradiol concentrations in NSCLC to examine local actions of estrogens in NSCLC. Experimental Design: Fifty-nine frozen specimens of NSCLC were available for liquid chromatography/electrospray tandem mass spectrometry to study intratumoral estradiol concentrations. In addition, A549 NSCLC cells stably expressing estrogen receptor (ER) a (A549 + ERa) or ERh (A549 + ERh) were used in vitro studies. Results: Forty-three (73%) of 59 NSCLC showed higher concentration of estradiol in carcinoma tissues than the corresponding nonneoplastic lung tissues from the same patient, and intratumoral estradiol concentrations were significantly (P = 0.0002 and 2.2-fold) higher than the corresponding nonneoplastic lungs. The intratumoral concentration of estradiol was positively correlated with aromatase expression, tumor size, and Ki-67 status in ERa-or ERh-positive cases. In in vitro studies, estradiol significantly increased cell proliferation of A549 + ERa orA549 + ERh, which was significantly suppressed by selective ER modulators, tamoxifen or raloxifene. Both A549 + ERa and A549 + ERh cells expressed aromatase. The cell proliferation level in these cells was significantly increased under treatment with testosterone, and it was inhibited by addition of the aromatase inhibitor letrozole. Conclusions: These results suggest that estradiol is locally produced in NSCLC mainly by aromatase and plays an important role in the growth of ERa-or ERh-positive NSCLC. Therefore, use of selective ER modulators and/or aromatase inhibitors may be clinically effective in NSCLC that are positive for both ER and aromatase.

Chronic hypoxia causes pulmonary hypertension and right ventricular hypertrophy associated with pulmonary vascular remodeling. Because hypoxia might promote generation of oxidative stress in vivo, we hypothesized that oxidative stress may play a role in the hypoxia-induced cardiopulmonary changes and examined the effect of treatment with the antioxidant N-acetylcysteine (NAC) in rats. NAC reduced hypoxia-induced cardiopulmonary alterations at 3 wk of hypoxia. Lung phosphatidylcholine hydroperoxide (PCOOH) increased at days 1 and 7 of the hypoxic exposure, and NAC attenuated the increase in lung PCOOH. Lung xanthine oxidase (XO) activity was elevated from day 1 through day 21, especially during the initial 3 days of the hypoxic exposure. The XO inhibitor allopurinol significantly inhibited the hypoxia-induced increase in lung PCOOH and pulmonary hypertension, and allopurinol treatment only for the initial 3 days also reduced the hypoxia-induced right ventricular hypertrophy and pulmonary vascular thickening. These results suggest that oxidative stress produced by activated XO in the induction phase of hypoxic exposure contributes to the development of chronic hypoxic pulmonary hypertension.

Because beta-adrenergic agonist therapy may be useful clinically as a treatment to hasten the resolution of alveolar edema, this study was designed to examine the dose-dependent effects of beta-adrenergic agonist therapy on alveolar epithelial fluid clearance. The studies were done by instilling an isosmolar 5% albumin solution into the distal air spaces of both ex vivo rat and ex vivo human lungs that were inflated with 8 to 10 cm H2O with 100% oxygen and placed in a 37 degrees C humid incubator. Alveolar fluid clearance was measured by the progressive increase in concentration of protein over 1 or 4 h. Salmeterol, a new long-acting lipophilic agent, was more potent than terbutaline in stimulating alveolar fluid clearance from the ex vivo human lung. Therefore, salmeterol was used for these studies. The results indicated that: (1) basal, unstimulated alveolar fluid clearance in rat lungs was significantly faster than in human lungs (24 +/- 4% over 4 h in rat lungs compared with 11 +/- 2% over 4 h in human lungs, p < 0.05); (2) comparison of equivalent doses of beta-adrenergic stimulation indicated that stimulated clearance rates were also faster in rat lungs than in human lungs; (3) very low doses of salmeterol were effective in ex vivo rat lungs (10(-8) M); and (4) relatively low doses were effective in the ex vivo human lungs (10(-6) M) as a treatment for increasing alveolar fluid clearance. In summary, there are significant differences in the basal and stimulated rates of alveolar epithelial fluid clearance in rat and human lungs, although the ex vivo human studies may have underestimated maximal alveolar fluid clearance in the intact human lung. The human lung responds well to relatively low doses of beta-adrenergic agonist therapy, a finding with potentially important clinical implications for hastening the resolution of alveolar edema.

In this study we examined the immunohistochemical localization of sex steroid receptors for estrogen alpha (ER alpha) and ER beta, progesterone-A (PR-A) and PR-B, and androgen (AR) in human thymoma (n = 132) and correlated these findings with various clinicopathological parameters. We used RT-PCR and real-time PCR to further study the expression of these receptors in 20 thymoma cases. Immunoreactivity for all sex steroid receptors was detected in the nuclei of thymoma epithelial cells. The percentage of immunopositive cases and the H-score values for each receptor (mean +/- SD) were: ER alpha, 66% and 85.8 +/- 80.2; ER beta, 7% and 7.2 +/- 8.7; PR-A, 4% and 2.7 +/- 4.9; PR-B, 49% and 55.8 +/- 68.3; and AR, 15% and 14.1 +/- 11.7, respectively. The results of real-time PCR were consistent with those of immunohistochemistry, especially results for ER alpha, PR-B, and AR. A significant positive correlation was detected between immunoreactivity for ER alpha and PR-B. ER alpha immunoreactivity was inversely correlated with tumor size, clinical stage, WHO classification, and Ki-67 labeling index. In addition, the status of ER alpha immunoreactivity was significantly associated with a better clinical outcome in thymoma patients. Results from our study suggest that estrogens may inhibit thymoma growth via ER alpha, and that ER alpha immunoreactivity may act as a prognostic factor in human thymoma.

Heme oxygenase-1 (HO-1) confers cytoprotection against oxidative stress. A (GT)n dinucleotide repeat in the 5-flanking region of human HO-1 gene shows length polymorphism, which was classified into S (< 27 GT), M (27-32 GT), and L alleles (> 33 GT). Polymorphism in the HO-1 gene promoter was shown to be associated with susceptibility to pulmonary emphysema and restenosis after angioplasty. However, the biologic mechanism underlying these associations is still unclear. To examine this issue, we established lymphoblastoid cell lines (LCLs) from subjects possessing S/S or L/L genotypes. HO-1 mRNA expressions and HO activities induced by oxidative stress were significantly higher in LCLs with S/S than those with L/L. Furthermore, LCLs with S/S were significantly more resistant to oxidant-induced apoptosis than those with L/L. These findings suggested that the polymorphism of the HO-1 gene is associated with the strength of antiapoptotic effects of HO-1, resulting in an association with susceptibility to oxidative stress-mediated diseases.