losartan-potassium and Mesothelioma

The combination of cisplatin and pemetrexed represents the newly established standard of care for patients with unresectable malignant mesothelioma (MM). However, this chemotherapy regimen appears to be associated with an increased prevalence of higher grade anemia as compared to treatment with cisplatin alone. Human recombinant erythropoietin (rHuEpo) is currently used for the treatment of anemia in cancer patients. Still, following the finding that the erythropoietin receptor (EpoR) is expressed by several tumor cells types and after the trials reporting that the recombinant cytokine can adversely affect tumor progression and patient survival, the clinical safety of rHuEpo administration to neoplastic patients has recently been questioned. The observation that the expression of EpoR, variably associated with the expression of the cognate ligand, is a common feature of MM cells prompted us to investigate whether treatment with rHuEpo could elicit proliferative and cytoprotective signals in EpoR-positive MM cell lines. Biochemical responsiveness of MM cells to rHuEpo was demonstrated by the time-course activation of both ERK1/2 and AKT following treatment with the recombinant cytokine. A moderately increased mitogenic activity was observed in two out of five MM cell lines treated with pharmacologically relevant concentrations of rHuEpo. On the other hand, the recombinant cytokine, administered either before or after cisplatin and pemetrexed, failed to interfere with the cytotoxic effects exerted by the chemotherapeutic drugs on the five MM cell lines. According to the presented findings, rHuEpo appears to have an overall limited impact on cell growth and no effect on MM sensitivity to chemotherapy.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cisplatin; Drug Interactions; Erythropoietin; Gene Expression; Glutamates; Guanine; Humans; Immunoblotting; Mesothelioma; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Pemetrexed; Proto-Oncogene Proteins c-akt; Receptors, Erythropoietin; Recombinant Proteins

Metastatic renal cell carcinoma (MRCC) involving the thorax can be difficult to distinguish from diffuse malignant mesothelioma (DMM) using traditional morphologic approaches. Standard panels of immunohistochemical markers are of limited benefit.. To investigate several antibodies to renal cell carcinoma-associated proteins for differentiating MRCC from DMM.. One hundred DMMs and 20 MRCCs were evaluated for immunoexpression of erythropoietin. The same cases and an additional 45 DMMs were evaluated for CD10 and renal cell carcinoma marker (RCCMa) immunoreactivity.. Erythropoietin was expressed in 100% of DMMs and MRCCs. Staining for CD10 was observed in 54% of DMMs and 100% of MRCCs. RCCMa stained 26% of DMMs and 55% of MRCCs. Although erythropoietin staining was similarly strong and diffuse in both DMM and MRC, patterns of staining for RCCMa and CD10 differed between MRCC and DMM. Immunoreactivity was strong and diffuse for both RCCMa and CD10 in most MRCCs. Of CD10-positive DMMs, nearly half showed staining in less than 50% of tumor cells and about one fourth of positive cases exhibited only weak to moderately intense staining. Only half of RCCMa-positive DMMs showed staining in more than 49% of tumor cells and staining was only weak to moderately intense in most cases.. Given the overlap in the expression of renal cell carcinoma markers in MRCC and DMM, results with these markers must be interpreted cautiously and should be used in conjunction with mesothelium-associated markers. Differences in expression may potentially help distinguish MRCC from DMM inasmuch as strong and diffuse expression of RCCMa and CD10 supports a diagnosis of MRCC over DMM.

Topics: Biomarkers, Tumor; Carcinoma, Renal Cell; Diagnosis, Differential; Erythropoietin; Humans; Immunoenzyme Techniques; Kidney Neoplasms; Mesothelioma; Neprilysin; Pleural Neoplasms

A mesothelioma cell line, termed T-85, was established from a patient with malignant peritoneal mesothelioma and remarkable thrombocytosis (1.4 x 10(6)/mm3). Electron microscopically, two types of mesothelioma cells have been characterized; the major type of cells with dense-cored granules in the cytoplasm and the minor one with evenly dense granules. Immunologically, the cells showed staining for interleukin-6 (IL-6), cytokeratin, collagen type IV, vimentin, laminin, fibronectin and Factor VIII-related antigen. Quantitation by ELISA revealed a high concentration of IL-6 in T-85 cell culture supernatants. RT-polymerase chain reaction of T-85 cells showed two positive bands of cDNA at 628 and 251 base pairs indicating the constitutive expression of IL-6 and IL-6 receptor mRNA. Moreover, prominent pro-platelet process formation activity in T-85 cell culture supernatants indicated the presence of a thrombopoietic activity due mainly to IL-6 but not the c-Mpl ligand or erythropoietin. However, the fact that 15% of PPF activity remained in the supernatants treated with anti-IL-6 antibody indicated the presence of another thrombopoietic substance. T-85 is so far the first mesothelioma cell line derived from a case with remarkable thrombocytosis.

Topics: Base Sequence; Blood Platelets; Cell Differentiation; Cell-Free System; Erythropoietin; Humans; Immunoenzyme Techniques; Male; Megakaryocytes; Mesothelioma; Middle Aged; Molecular Sequence Data; Thrombocytosis; Thrombopoietin; Tumor Cells, Cultured

Recombinant glycosylated erythropoietin (EPO) was biotinylated with biotin-aminocaproyl hydrazide via periodate-treated sialic acid moieties and applied to sections of 64 tumors of the lower respiratory tract, comprising 19 primary adenocarcinomas, 19 epidermoid carcinomas, 13 large cell anaplastic carcinomas, 11 small cell lung carcinomas, 11 intrapulmonary metastases, 1 mesothelioma and 1 lymphocytic interstitial pneumonia. The formalin-fixed, paraffin-embedded specimens were incubated with labelled EPO at room temperature and a concentration of 10 micrograms/ml for 60 min. The expression of the EPO-binding sites was visualized by the ABC technique. All of the analyzed large cell anaplastic carcinomas and the majority of the epidermoid carcinoma (89%), adenocarcinoma (79%), and metastases (82%) displayed binding capacities for EPO. Five out of the eleven small cell lung carcinomas, the analyzed mesothelioma and lymphocytic interstitial pneumonia revealed definite staining, too. Binding sites could, in addition, be seen in air dried, non-fixed, acetone-fixed, and ether-ethanol-fixed cytological specimens. The data indicate that the expression of binding sites with specificity for EPO can be frequently seen in human bronchial malignancies.

Topics: Binding Sites; Biotin; Carcinoma; Erythropoietin; Glycosylation; Humans; Lung; Lung Neoplasms; Mesothelioma; Pneumonia; Receptors, Erythropoietin; Recombinant Proteins