Heterocyclic complexes of ruthenium(III) induce apoptosis in colorectal carcinoma cells

PURPOSE

The ruthenium complex salt indazolium trans-[tetrachlorobisindazole-ruthenate(III)] (KP1019) and the analogous sodium salt KP1339 are effective tumor-inhibiting drugs in experimental therapy of autochthonous colorectal carcinomas in rats. This paper examines the cell biological mechanisms underlying their antineoplastic effects.

METHODS

Colorectal tumor cell lines were used to analyze uptake of the ruthenium(III) complexes into the cells and the mechanism as well as the efficacy of their cytotoxic effects.

RESULTS

KP1019 and KP1339 are efficiently taken up into the cells: 100 microM ruthenium(III) complex in the growth medium led to the uptake of 120-160 ng ruthenium per 10(6) cells within 30 min. Uptake of KP418 was tenfold lower correlating with its lower cytotoxic efficiency. KP1019 and KP1339 induced apoptosis in SW480 and HT29 cells predominantly by the intrinsic mitochondrial pathway as indicated by loss of mitochondrial membrane potential. Correspondingly sensitivity of the cells paralleled expression of bcl(2) while it was only slightly affected by mutations in Ki-ras.

CONCLUSIONS

Our data demonstrate that trans-[tetrachlorobisindazole-ruthenate(III)] complex salts are promising candidate drugs in the second-line treatment of colorectal cancers resistant to other cytostatic drugs and has been introduced into phase I clinical trials.

Intrinsic and acquired forms of resistance against the anticancer ruthenium compound KP1019 [indazolium trans-[tetrachlorobis(1H-indazole)ruthenate (III)] (FFC14A)

KP1019 [indazolium trans-[tetrachlorobis(1H-indazole)ruthenate (III)] (FFC14A) is a metal complex with promising anticancer activity. Since chemoresistance is a major obstacle in chemotherapy, this study investigated the influence of several drug resistance mechanisms on the anticancer activity of KP1019. Here we demonstrate that the cytotoxic effects of KP1019 are neither substantially hampered by overexpression of the drug resistance proteins multidrug resistance-related protein 1, breast cancer resistance protein, and lung resistance protein nor the transferrin receptor and only marginally by the cellular p53 status. In contrast, P-glycoprotein overexpression weakly but significantly (up to 2-fold) reduced KP1019 activity. P-glycoprotein-related resistance was based on reduced intracellular KP1019 accumulation and reversible by known P-glycoprotein modulators. KP1019 dose dependently inhibited ATPase activity of P-glycoprotein with a K(i) of approximately 31 microM. Furthermore, it potently blocked P-glycoprotein-mediated rhodamine 123 efflux under serum-free conditions (EC(50), approximately 8 microM), however, with reduced activity at increased serum concentrations (EC(50) at 10% serum, approximately 35 microM). Moreover, P-glycoprotein-mediated daunomycin resistance could only be marginally restored by KP1019 in serum-containing medium, also indicating an influence of serum proteins on the interaction between KP1019 and P-glycoprotein. Acquired KP1019 resistance was investigated by selecting KB-3-1 cells against KP1019 for more than 1 year. Only an approximately 2-fold KP1019 resistance could be induced, which unexpectedly was not due to overexpression of P-glycoprotein or other efflux pumps. Accordingly, KP1019-resistant cells did not display reduced drug accumulation. Their unique cross-resistance pattern confirmed an ABC transporter-independent resistance phenotype. In summary, the likeliness of acquiring insensitivity to KP1019 during therapy is expected to be low, and resistance should not be based on overexpression of drug efflux transporters.

Molecular cloning, characterization, and tissue-specific expression of human LANCL2, a novel member of the LanC-like protein family

We identified and characterized the cDNA coding for human LANCL2, a new member of the eukaryotic LanC-like protein family which is related to the bacterial lanthionine synthetase components C (LanC). The composite nucleotide sequence revealed a coding region of 1353 bp, a 5'-UTR of 186 bp and a 3'-UTR of 2421 bp. The deduced sequence of 450 amino acids showed 57.9% identity (74.7% similarity) when compared with the human LANCL1 homologue. In contrast to LANCL1, a unique ATP/GTP-binding site motif A was found in LANCL2. Northern blot analysis revealed the presence of two major transcripts in the brain, 4.7 kb and 4.1 kb in size, and a major 1.8 kb transcript in testis. Accordingly, expression array analysis showed prominent signals in these tissues. Because of the structural similarity to LanC, we postulate that LANCL2 may play a role as a component of a peptide-modifying complex.

[Extrinsic allergic alveolitis in CT and HR-CT]

The CT changes on conventional and high-resolution CT in 14 patients with exogenous allergic alveolitis (EAA) were analysed retrospectively. There were 8 patients with clinically subacute disease, 5 patients in a chronic stage and 1 patient with acute EAA. The appearances and their distribution were examined. Seven of the 8 patients in the subacute stage showed a ground glass pattern and multiple nodules of less than 2 mm. All patients in the chronic stage showed a combination of fine infiltrates, small nodules and irregular linear densities; distortion of the pulmonary pattern was present in 3 cases. The patient with acute EAA showed diffuse dense areas of consolidation in both lungs as well as multiple nodules and a ground glass pattern. The CT appearances of EAA correspond with the basic micropathology and, within the clinical context, permit diagnostic classification.

Open-window thoracostomy in pleural empyema

Open-window thoracostomy (OWT) was performed in 21 cases of empyema. The indications were postpneumonectomy empyema with (n = 6) or without (n = 1) fistula, early recurrent empyema after decortication (n = 6), chronical empyema in ill elderly patients with (n = 5) or without fistula (n = 2), and total unilateral lung gangrene with a large fistula of the main bronchus after radiotherapy and chemotherapy (n = 1). All cases presented with severe sepsis, eight of them with acute septic shock, and six with signs of multiorgan failure. Three to five ribs were resected, the muscles and skin were sutured to the ribs confining the window located at the lowest point of the empyema cavity, while the intercostal muscles of the resected ribs were used to close fistulae. The cavity was packed with dressings every day. In all cases, the sepsis subsided immediately after OWT. With the exception of one patient with postpneumonectomy empyema, who died of contralateral pneumonia on day 36, no surgery-related complications were seen. Four further patients died of unrelated causes 2, 4, 5, and 7 months, respectively, after OWT. In one of them, the OWT had been closed. Up to this time, obliteration and closure of the cavity has been carried out in 7 cases by using thoracoplasty (n = 2) or predicted muscle flaps (n = 5) either in the early course or after a delay of 11 to 23 months, with fair functional and cosmetic results. In one further case, operative closure has been planned. In seven of the eight remaining patients, four of whom declined further operations, the cavities closed spontaneously, despite their initial size after intervals of between 11 and 21 months.

The importance of early detection and therapy of reexpansion pulmonary edema

Three cases are reported of unilateral pulmonary edema, two following rapid reexpansion after prolonged tension pneumothorax, with total collapse of the right lung and one after reexpanded atelectasis following left intrabronchial obstruction. In all cases decrease of blood pressure and tachycardia not responding to intravenous fluid substitution were already present within the first 15 min after chest drainage or after removal of the intrabronchial obstruction. The preexistent dyspnea failed to improve. A cloudy opacity of the reexpanded lung was found immediately after drainage in 2 cases. After immediate application of a continuous positive airway pressure mask no more extensive therapy was necessary in one patient. The two others in whom treatment was begun with more than 1 hour delay required artificial ventilation and adrenergics for 2 and 4 days, respectively.

[Computerized tomography in the diagnosis of allergic bronchopulmonary aspergillosis]

In four patients with immunologic and laboratory findings consistent with allergic bronchopulmonary aspergillosis a CT of the chest was performed. CT revealed central bronchiectasis in all patients. Other features of the condition revealed by CT were mucoid impaction, peripheral alveolar infiltrates, and segmental or subsegmental atelectasis. Owing to their central location the bronchiectatic bronchi always appear parallel to the image plane. This means they can generally be visualized by CT.

[Value and indications for bronchoalveolar lavage combined with transbronchial lung biopsy]

Bronchioloalveolar lavage (BAL) enables diffuse interstitial lung disease to be divided into lymphocytic and granulocytic alveolitis. The combination of BAL and transbronchial lung biopsies using modern flexible fiberoptic bronchoscopes allows the subdivision of lymphocytic alveolitis into sarcoidosis, exogenic allergic alveolitis (synonym: hypersensitivity pneumonitis: EAA) and granulomatous pneumonias caused by infectious agents. The use of immunohistochemical surface markers of lymphocytes in conjunction with BAL provides further differentiation of lymphocytes into T- and B-, T-helper and T-suppressor types, natural killer cells (NK cells) and cytotoxic T-cells. A predominance of T-suppressor lymphocytes is an indication of EAA, whereas a predominance of T-helper lymphocytes is positively correlated with sarcoidosis. Other markers, e.g. HLA-DR, when expressed on the surface of alveolar macrophages, merely indicate activation unrelated to a specific type of lymphocytic alveolitis. BAL is also a new and promising diagnostic tool for pneumoconioses and other types of lung disease caused by inhaled industrial pollutants. Ferruginous bodies and silica crystals, free or ingested by alveolar macrophages, can be found more easily than by scraping tissue blocks or from multiple sections of transbronchial biopsies. BAL cells can easily be processed for electron microscopy and inhaled foreign material can be analysed in an electron microscope using X-ray diffraction analysis (EDAX) or electron spectroscopic imaging (ESI). BAL is also of value in the diagnosis of peripheral lung carcinomas, in addition to cytological sputum analysis, brush smears, transthoracic fine needle aspiration and transbronchial biopsies. BAL is a valuable diagnostic tool in cases of unusual pneumonia where fungi can be visualized by silver impregnation techniques and viruses by antibodies using immunofluorescence microscopy.

[Combination radiochemotherapy in the limited-disease stage of small-cell bronchial carcinoma. Results following high-dosage radiotherapy]

From 1980 through 1984, 72 patients with small cell bronchial carcinomas were treated by radiotherapy. Twenty-one patients who were in a limited disease stage (LD) received chemotherapy according to the ACO scheme and high-dose radiotherapy with 50 Gy. These patients had a complete remission rate of 67% and a partial remission rate of 33%. The median control period was 37 months. At the time of diagnosis, patients had a median survival time of ten months (six to 36 months). A recurrence in the irradiated region was seen in none of the patients, however, 14% of patients developed a recurrence beyond the irradiation field. The results are compared to literature and discussed.

IgA2-alveolitis and eosinophilic pneumonia--a possibly virus-triggered allergy

A case of severe therapy-resistant asthma in a young girl with a duration of two years prior to death is reported. At autopsy antibodies of the IgA2-subtype were demonstrated in the lungs on the alveolar basement membranes. We were able to demonstrate intracellular virus-like structures by electron microscopy; this virus infection is taken to be the cause of antibody production. Following antigen-antibody reaction a non-complement-mediated eosinophilic pneumonia with numerous macrophages developed. This inflammatory reaction showed the injurious effect of eosinophilic granulocytes causing fibrinoid necrosis; this is confirmed by the pronounced depletion of the Charcot-Leyden-granules, equivalent to the release of the major basic protein and the Charcot-Leyden crystal protein. Death was caused by IgA2 deposition in the myocardial vessels with consequent eosinophilic myocarditis.