CaSm (LSm-1) overexpression in lung cancer and mesothelioma is required for transformed phenotypes.

CaSm (cancer-associated Sm-like) was originally identified based on elevated expression in pancreatic cancer and in several cancer-derived cell lines. It encodes a 133-amino acid protein that contains two Sm motifs found in the common snRNP proteins and the LSm (like-Sm) family of proteins. Lung tumors and mesotheliomas express high levels of CaSm mRNA and protein compared with adjacent nontumor and normal lung tissue, measured by immunohistochemistry, qRT-PCR, and Western blot analyses. In addition, several human lung cancer- and mesothelioma-derived cell lines have elevated CaSm expression. Two cell lines, transfected with and expressing antisense CaSm RNA, demonstrate altered transformed phenotypes, reducing their ability to form colonies in soft agar and tumors in SCID mice. Furthermore, RNAi-mediated reduction of CaSm RNA and protein is associated with inhibition of cellular growth. These data support the model that elevated CaSm expression in epithelial tissue contributes to the transformed state. Cell lines expressing exogenous CaSm also exhibit transformed characteristics, including increased anchorage-independent colony formation and tumor growth. Thus, the results of loss of function and gain of function studies presented both indicate that CaSm functions as an oncogene in the promotion of cellular transformation and cancer progression.

Common problems in critically ill obstetric patients, with an emphasis on pharmacotherapy.

Pharmacological treatment of critically ill obstetric patients can be especially challenging due to the complexity of caring for 2 patients, with a paucity of research to support practice. This review will provide practitioners with primary recommendations for management of the critical illnesses most commonly encountered in pregnancy and will discuss the scientific and clinical merit of these recommendations.

CaSm-mediated cellular transformation is associated with altered gene expression and messenger RNA stability.

CaSm (cancer-associated Sm-like) was originally identified based on elevated expression in pancreatic cancer and in several cancer-derived cell lines. CaSm encodes a 133 amino acid protein that contains two Sm motifs found in the common small nuclear RNA proteins and the LSm (like-Sm) family of proteins. Compared with normal human prostate tissue and primary prostate epithelial cells, some primary prostate tumors and prostate cancer-derived cell lines have elevated CaSm expression. Expression of antisense CaSm RNA in DU145 cells results in reduced CaSm protein levels and less transformed phenotype, measured by anchorage-independent growth in vitro and tumor formation in severe combined immunodeficient mice in vivo. Additional data shows that adenoviral delivery of antisense CaSm inhibits the growth of prostate cancer cell lines by altering cell cycle progression, and is associated with reduced expression of cyclin B1 and CDK1 proteins. Consistent with failure of antisense-treated cells to enter mitosis, microarray analysis identified altered expression of NEK2 and nucleophosmin/B23. Although the mechanisms by which CaSm contributes to neoplastic transformation and cellular proliferation are unknown, it has been shown that the yeast homologue (spb8/LSm1) of CaSm is required for 5' to 3' degradation of specific mRNAs. We provide data consistent with a similar role for CaSm in human cells, supporting the hypothesis that elevated CaSm expression observed in cancer leads to destabilization of multiple gene transcripts, contributing to the mutator phenotype of cancer cells.

Immunohistochemical distribution of sphingosine kinase 1 in normal and tumor lung tissue.

Sphingosine kinase 1 (SK1) is a key enzyme critical to the sphingolipid metabolic pathway responsible for catalyzing the formation of the bioactive lipid sphingosine-1-phosphate. SK1-mediated production of sphingosine-1-phosphate has been shown to stimulate such biological processes as cell growth, differentiation, migration, angiogenesis, and inhibition of apoptosis. In this study, cell type-specific immunolocalization of SK1 was examined in the bronchus/terminal bronchiole of the lung. Strong immunopositive staining was evident at the apical surface of pseudostratified epithelial cells of the bronchus and underlying smooth muscle cells, submucosal serous glands, immature chondrocytes, type II alveolar cells, foamy macrophages, endothelial cells of blood vessels, and neural bundles. Immunohistochemical screening for SK1 expression was performed in 25 samples of normal/tumor patient matched non-small-cell lung cancer tissue and found that 25 of 25 tumor samples (carcinoid [5 samples], squamous [10 samples], and adenocarcinoma tumors [10 samples]), exhibited overwhelmingly positive immunostaining for SK1 as compared with patient-matched normal tissue. In addition, an approximately 2-fold elevation of SK1 mRNA expression was observed in lung cancer tissue versus normal tissue, as well as in several other solid tumors. Taken together, these findings define the localization of SK1 in lung and provide clues as to how SK1 may play a role in normal lung physiology and the pathophysiology of lung cancer.

Detection of human telomerase reverse transcriptase mRNA in cells obtained by lavage of the pleura is not associated with worse outcome in patients with stage I/II non-small cell lung cancer: results from Cancer and Leukemia Group B 159902.

OBJECTIVE: Previous studies suggest that cytologic analysis of cells obtained by lavage of the pleural surfaces at the time of resection of non-small cell lung cancer can identify patients at risk for recurrence. Because telomerase gene expression has been associated with worse outcome in non-small cell lung cancer, we hypothesized that identification of cells obtained from pleural lavage that express telomerase would identify patients at risk for recurrent disease. METHODS: Patients with presumed non-small cell lung cancer underwent thoracotomy with curative intent. Cells obtained by lavage of the pleural surfaces were analyzed for telomerase catalytic subunit human telomerase reverse transcriptase mRNA expression using reverse transcriptase polymerase chain reaction. RESULTS: A total of 194 patients with stage I/II non-small cell lung cancer had adequate samples, and median follow-up was 60 months (17-91 months). By using Cox models, no statistical differences were found between human telomerase reverse transcriptase-negative and positive patients in disease-free survival (hazard ratio, 1.28; 95% confidence interval, 0.85-1.94; log-rank test, P = .2349) or overall survival (hazard ratio, 1.13; 95% confidence interval, 0.72-1.79; log-rank test, P = .5912) CONCLUSIONS: Detection of human telomerase reverse transcriptase in cells obtained from pleural lavage of patients with stage I/II non-small cell lung cancer does not identify patients at risk for recurrent disease.

Establishing a murine pancreatic cancer CaSm model: up-regulation of CaSm is required for the transformed phenotype of murine pancreatic adenocarcinoma.

We have recently shown that the cancer-associated Sm-like protein (CaSm) is overexpressed in human pancreatic adenocarcinoma (PC). However, the role of CaSm in the process of neoplastic transformation remains unclear. To define further the role of CaSm in PC transformation, we have established a murine model based on the murine pancreatic cancer cell lines Panc02 and Panc03. CaSm is overexpressed in the aggressive Panc02 cells and expressed at much lower levels in the more indolent Panc03 cells. Up-regulation of CaSm in Panc03 cells increased in vitro proliferation and anchorage-independent growth and promoted subcutaneous tumor establishment and growth in syngeneic mice. Conversely, adenoviral down-regulation of CaSm in Panc02 led to significant inhibition of cellular proliferation and anchorage-independent growth in vitro and complete abolition of tumor growth and metastasis in vivo. Up-regulation of CaSm in NIH3T3 resulted in loss of contact inhibition and increased soft agar colony formation in vitro. The requirement for CaSm overexpression for neoplastic transformation confirms the concept that CaSm is a critical oncogene and potential target for molecular intervention. Furthermore, establishment of the murine clinically relevant model of pancreatic metastases provides a framework for the generation of preclinical data to support the development of novel molecular therapies targeting CaSm.