The hedgehog pathway inhibitor GDC-0449 alters intracellular Ca2+ homeostasis and inhibits cell growth in cisplatin-resistant lung cancer cells.

Aim: Cisplatin resistance is an important issue in lung cancer. We aimed at investigating if the Hedgehog pathway inhibitor GDC-0449 is effective in cisplatin-resistant cells and if it alters intracellular Ca(2+)-homeostasis.

Materials And Methods: The cytoplasmatic ([Ca(2+)](cyto)) and endoplasmatic ([Ca(2+)])(ER) Ca(2+) concentration of HCC (adeno carcinoma of the lung) and H1339 (small cell lung carcinoma) cells were measured with the calcium indicator dye Fura-2 AM.

Effects of the Hedgehog pathway inhibitor GDC-0449 on lung cancer cell lines are mediated by side populations.

The hedgehog (Hh) signaling pathway has been shown to be activated in the cancer stem cells of several tumor entities. The Hh inhibitor GDC-0449 has been proven to be effective in some cancers but not yet in lung cancer. We aimed at investigating whether GDC-0449 is effective in the lung cancer cell lines HCC (adenocarcinoma) and H1339 (small-cell-lung carcinoma), whether in these cell lines stem cell-like side populations (SPs) can be identified, and whether possible effects of GDC-0449 are mediated via SPs.

The dual PI3K/mTOR inhibitor BEZ235 is effective in lung cancer cell lines.

Background: BEZ235 is a dual phosphatidylinositol 3-kinase (PI(3)K)/mammalian target of rapamycin (mTOR) inhibitor that is orally available and that has been shown to be effective in several malignancies in vitro. Recently, BEZ235 entered clinical trials for solid tumors. We aimed at investigating if BEZ235 is effective in lung cancer cell lines.

Reduced expression of Bax in small cell lung cancer cells is not sufficient to induce cisplatin-resistance.

Resistance to cisplatin in the course of chemotherapy contributes to the poor prognosis of small cell lung cancer (SCLC). B cell lymphoma-2 is the founding member of a large family of proteins that either promote or inhibit apoptosis. We aimed at investigating if the pro-apoptotic members Bad, Bax, Bim and Bid are involved in cisplatin-resistance.

Altered Ca2+-homeostasis of cisplatin-treated and low level resistant non-small-cell and small-cell lung cancer cells.

Background: Chemotherapy often leads to encouraging responses in lung cancer. But, in the course of the treatment, resistance to chemotherapy ultimately limits the life expectancy of the patient. We aimed at investigating if treatment with cisplatin alters the intracellular Ca2+-homeostasis of lung cancer cells and how this may be related to cisplatin resistance.

Endoplasmic reticulum Ca2+-homeostasis is altered in Small and non-small Cell Lung Cancer cell lines.

Background: Knowledge of differences in the cellular physiology of malignant and non-malignant cells is a prerequisite for the development of cancer treatments that effectively kill cancer without damaging normal cells. Calcium is a ubiquitous signal molecule that is involved in the control of proliferation and apoptosis. We aimed to investigate if the endoplasmic reticulum (ER) Ca2+-homeostasis is different in lung cancer and normal human bronchial epithelial (NHBE) cells.

Mechanisms altering airway smooth muscle cell Ca+ homeostasis in two asthma models.

Background: Asthma is characterized by airway remodeling, altered mucus production and airway smooth muscle cell (ASMC) contraction causing extensive airway narrowing. In particular, alterations of ASMC contractility seem to be of crucial importance. The elevation of the cytoplasmic Ca(2+) concentration is a key event leading to ASMC contraction and changes in the agonist-induced Ca(2+) increase in ASMC have been reported in asthma.

IL-13Ralpha2 reverses the effects of IL-13 and IL-4 on bronchial reactivity and acetylcholine-induced Ca+ signaling.

Background: The interleukins IL-4 and IL-13 play a key role in the pathophysiology of asthma. The interleukin receptor IL-13Ralpha2 is believed to act as a decoy receptor, but until now, the functional significance of IL-13Ralpha2 remains vague.

Methods: Bronchial reactivity was quantified in murine lung slices by digital video microscopy and acetylcholine (ACH)-induced Ca(2+) signaling was measured in human airway smooth muscle cells (ASMC) using fluorescence microscopy.

Rotation frequency of human bronchial and nasal epithelial spheroids as an indicator of mucociliary function.

Background: We evaluated a new in vitro model for mucociliary transport function. Spheroids of human respiratory epithelium show beating cilia at their surface. When cultured in their own mucus, spheroids can rotate along their axis due to coordinated ciliary beating.

Ca2+-signaling in airway smooth muscle cells is altered in T-bet knock-out mice.

Background: Airway smooth muscle cells (ASMC) play a key role in bronchial hyperresponsiveness (BHR). A major component of the signaling cascade leading to ASMC contraction is calcium. So far, agonist-induced Ca2+-signaling in asthma has been studied by comparing innate properties of inbred rat or mouse strains, or by using selected mediators known to be involved in asthma.

Nucleosomes indicate the in vitro radiosensitivity of irradiated bronchoepithelial and lung cancer cells.

Nucleosomes, which are typical cell death products, are elevated in the serum of cancer patients and are known to rapidly increase during radiotherapy. As both normal and malignant cells are damaged by irradiation, we investigated to which extent both cell types contribute to the release of nucleosomes. We cultured monolayers of normal bronchoepithelial lung cells (BEAS-2B, n = 18) and epithelial lung cancer cells (EPLC, n = 18), exposed them to various radiation doses (0, 10 and 30 Gy) and observed them for 5 days.

The use of mini-organ cultures of human upper aerodigestive tract epithelia in ecogenotoxicology.

The carcinogenic potential of xenobiotics and possible confounders are often difficult to differentiate in in vivo studies. In contrast, in vitro studies allow investigation of the impact of carcinogens on human target cells under standardized conditions. The aim of the present study is to demonstrate whether three-dimensional mini organ-cultures (MOCs) of human inferior nasal turbinate epithelia may represent a useful model to study genotoxic effects of xenobiotics in vitro.

Airway contractility and smooth muscle Ca(2+) signaling in lung slices from different mouse strains.

To investigate the hypothesis that altered Ca2+ signaling in airway smooth muscle cells (SMCs) is responsible for airway hyperreactivity, we compared, with the use of confocal and phase-contrast microscopy, the airway contractility and Ca2+ changes in SMCs induced by acetylcholine (ACh) in lung slices from different mouse strains (A/J, Balb/C, and C3H/ HeJ). The airways from each mouse strain displayed a concentration-dependent contraction to ACh. The contractile response of the airways of the C3H/HeJ mice was found, in contrast to earlier studies, to be much greater and faster than that of A/J and Balb/C mice.

ATP stimulates Ca2+ oscillations and contraction in airway smooth muscle cells of mouse lung slices.

In airway smooth muscle cells (SMCs) from mouse lung slices, > or =10 microM ATP induced Ca2+ oscillations that were accompanied by airway contraction. After approximately 1 min, the Ca2+ oscillations subsided and the airway relaxed. By contrast, > or =0.

Kinetics of 5-aminolevulinic acid-induced fluorescence in organ cultures of bronchial epithelium and tumor.

Background: 5-Aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PPIX) fluorescence improves the differentiation of tumor and normal tissue in the bladder, skin and brain.

Objective: The kinetics of 5-ALA-induced protoporphyrin IX (PPIX) fluorescence in organ cultures of normal human bronchial epithelium and cocultures of bronchial epithelium and tumor have been studied.

Methods: Cultured biopsies of bronchial epithelium were exposed for 5 or 15 min, or continuously to 5-ALA.

Acetylcholine-induced calcium signaling and contraction of airway smooth muscle cells in lung slices.

The Ca(2+) signaling and contractility of airway smooth muscle cells (SMCs) were investigated with confocal microscopy in murine lung slices (approximately 75-microm thick) that maintained the in situ organization of the airways and the contractility of the SMCs for at least 5 d. 10--500 nM acetylcholine (ACH) induced a contraction of the airway lumen and a transient increase in [Ca(2+)](i) in individual SMCs that subsequently declined to initiate multiple intracellular Ca(2+) oscillations. These Ca(2+) oscillations spread as Ca(2+) waves through the SMCs at approximately 48 microm/s.