Lung neoplasm, in place of gastric cancer, is the major cause of cancer mortality in Japan as well as in the USA (Travis et al, 1995). Despite the advances in diagnostic techniques for the early detection of lung cancer and the significant improvement in surgical procedures, the survival rate of lung cancer patients is poor even in the early stages of cancer as compared to the other malignant neoplasms. From a clinical point of view, one of the most troublesome impediments for treatment of lung cancer is the metastasis to mediastinal lymph nodes (n = 2 and n = 3 lung cancer) from the primary lesion (Jefferson et al, 1996). If metastases were inhibited by the present and/or new therapies, the prognosis of patients with lung cancer would improve. According to new TNM revisions (Mountain, 1997), it is difficult to say if the 5-year survival rate of n ³ 2 in lung cancer patients is an improvement, although a standard operative technique has been established to resect mediastinal lymph nodes (Vansteenkiste et al, 1997), except for aortic lymph node metastasis (Nakanishi et al, 1997). Therefore, biological approaches and studies, such as interference with lymph node metastasis or management of downstaging to the patients with lymph node metastasis, combined with surgery are required for lung cancer therapy. To do this, suitable animal models that conform to the clinical features are also necessary to search for novel therapies of lung cancer and to evaluate the efficacy of new drugs. However, there are few models for the formation of a solitary pulmonary nodule by orthotopic implantation of lung cancer cells and subsequent lymph node metastasis. In the present study, we attempted to establish a simple model for a solitary lung tumour and its lymph node metastasis by intrapulmonary implantation of Lewis lung carcinoma (LLC) cells in mice. MATERIAL AND METHODS AnimalsSpecific pathogen-free female C57BL/6 mice at 6 weeks old, were purchased from Japan SLC, Inc, Hamamatsu, Japan. They were maintained in the Laboratory for Animal Experiments, Research Institute for Wakan-Yaku Toyama Medical and Pharmaceutical University, under laminar air-flow conditions. All animals had free access to standard laboratory mouse food and water ad libitum. Housing was temperature controlled with a 12-h light and dark cycle. This study was conducted in accordance with the standards established by the Guidelines for the Care and Use of Laboratory Animals of Toyama Medical and Pharmaceutical University. Summary This study is designed to establish a pulmonary tumour model to investigate the biology and therapy of lung cancer in mice. Current methods for forming a solitary intrapulmonary nodule and subsequent metastasis to mediastinal lymph nodes are not well defined. Lewis lung carcinoma (LLC) cell suspensions were orthotopically introduced into the lung parenchyma of C57/BL6 mice via a limited skin incision without thoracotomy followed by direct puncture through the intercostal space. The implantation process was performed within approximately ...

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We examined the tumorigenic and metastatic potentials of three human non-small cell lung cancer (NSCLC) cell lines, PC-14, A549 or Lu-99 cell lines suspended in Matrigel-containing phosphate-buffered saline were orthotopically implanted into the lungs of nude mice. The formation of a solitary tumor nodule in the lung was observed after the implantation of all cell lines. Intrapulmonary implantation of PC-14 or Lu-99 cells resulted in spontaneous distant metastases. In contrast, A549 cells caused multiple intrapulmonary metastases to the right and left lobes of the lung without producing visible lymphatic metastasis. We also investigated the expression of matrix metalloproteinases (MMPs), urokinase-type plasminogen activator (u-PA), u-PA receptor (u-PAR) and c-MET in these cell lines in vitro and in vivo. Reverse transcription polymerase chain reaction (RT-PCR) analysis showed that the expression of MMP-2 and membrane-type 1 MMP (MT1-MMP) was elevated in PC-14 as compared with the other two cell lines. In contrast, stronger expression of c-MET was observed in A549 than in PC-14 or Lu-99. These results indicate that differential patterns of metastasis of lung cancer might be associated with differential expression of metastasis-associated molecules. Our orthotopic implantation models display clinical features resembling those of NSCLC, and may provide a useful basis for lung cancer research.

SUMMARYBradykinin (BK ) is a potent inflammatory mediator that is generated from kininogens by the actions of plasma and tissue kallikreins. Lung fibroblasts have the potential to participate in the inflammatory responses by releasing proinflammatory cytokines in response to a variety of stimuli. We postulated that human lung fibroblasts might produce interleukin-8 (IL-8) in response to BK stimulation. The present study showed that BK stimulated human lung fibroblasts to produce IL-8 in a dose-and time-dependent manner. Furthermore, Northern blot analysis showed that BK increased IL-8 mRNA expression. The stimulatory effect of BK on IL-8 production was detected at the concentration of 10 n, and the maximal stimulation was achieved with 100 to 1000 n. Phorbol 12-myristate 13-acetate pretreatment diminished the ability of BK to stimulate IL-8 production. In addition, GF109203X, a selective protein kinase C inhibitor, blocked BK-induced IL-8 production. These observations suggest that the stimulatory effect of BK on IL-8 production by lung fibroblasts is, at least partially, mediated through protein kinase C. These data suggest that BK may be involved in the inflammatory reaction leading to interstitial lung disorders through stimulating IL-8 production by lung fibroblasts.

It is important to perform surgery for SHP at the appropriate time. VATS was found to be an easily performed and safe procedure for initial treatment in patients with active hemorrhaging and massive blood clotting in the thorax. The long-term outcome of our patients with early surgical indication was excellent and we recommend early surgical treatment for SHP.