Effect of ligand troglitazone on peroxisome proliferator-activated receptor gamma expression and cellular growth in human colon cancer cells.

AIM: To investigate the effect of troglitazone on pe-roxisome proliferator-activated receptor gamma (PPARgamma) expression and cellular growth in human colon cancer HCT-116 and HCT-15 cells and to explore the related molecular mechanism. METHODS: Human colon cancer HCT-116 and HCT-15 cells cultured in vitro were treated with troglitazone. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were employed to detect the effect of troglitazone on PPARgamma expression. The proliferative activity was determined by MTT assay, cell cycle and apoptosis were detected by flow cytometry. Apoptosis-related genes, cell cycle regulatory genes and p53 were examined by RT-PCR and Western blot respectively. RESULTS: The expression of PPARgamma in colon cancer HCT-116 and HCT-15 cells was up-regulated by troglitazone. Troglitazone inhibited proliferation, induced apoptosis and cell cycle G1 arrest in colon cancer cells. Troglitazone induced p53 expression in HCT-116 cells, but not in HCT-15 cells. The down-regulation of survivin and bcl-2 was found in both cell lines and up-regulation of bax was found only in HCT-116 cells, being consistent with growth inhibition in HCT-116 cells but not in HCT-15 cells. Troglitazone increased expression of p21(WAF1/CIP1) (p21), p27(KIP1) (p27) and reduced cyclin D1 in HCT-116 cells while only a minor decrease of cyclin D1 was found in HCT-15 cells. CONCLUSION: Troglitazone is an inductor of PPARgamma in colon cancer cells and inhibits PPARgamma-dependently proliferation, which may attribute to cell cycle G1 arrest and apoptosis in colon cancer cells. Troglitazone may induce p53-independent apoptosis and p53-dependent expression of p21 and p27. Depending on cell background, different activation pathways may exist in colon cancer cells.

[Immunohistochemical observation of heart-type fatty acid binding-protein in early myocardial ischemia].

OBJECTIVE: The sensitivity of heart-type fatty acid binding-protein (H-FABP) in the postmortem diagnosis of myocardial ischemia was explored. METHODS: The changes of H-FABP staining in normal, infarcted and suspected ischemia of myocardial cells were studied by immunohistochemistry. RESULTS: There was no depletion in normal control group, and obvious depletion was observed in myocardial infarcted group. Among 9 suspected myocardial ischemia group, 3 cases showed obvious depletion and 3 cases showed vague depletion for H-FABP, there were obvious depletion of Mb in 4 suspected myocardial ischemia cases and vague depletion in 2 cases for Mb. It is indicated that H-FABP can be used to diagnose early myocardial ischemia. CONCLUSION: H-FABP is quite sensitive and useful for the diagnosis of early myocardial ischemia.

[Molecular characterization of hantavirus Shandong isolate JNL virus strain].

OBJECTIVE: To understand the molecular epidemiologic characteristics of hantavirus Shandong isolate JNL virus strain. METHODS: The complete M and S gene of the JNL virus isolated from Shandong Province was amplified by RT- PCR, and the purified PCR product was cloned into T vector for sequencing. RESULTS: The results revealed that the JNL M segment was 3615 bp in length, encoding 1135 amino acids, and the S segment was 1698 bp encoding 429 amino acids, JNL belongs to HTN virus. The comparison of homology with HTN and SEO types showed that the difference of M and S complete sequences between JNL and all other HTN virus strains reached 20.0%-20.6%, and 15.5%-16.0%, respectively. Phylogenetic tree also showed that the position of JNL is located at a different clade. CONCLUSIONS: HTN virus Shandong local isolate JNL strain is a new specific HTN subtype virus.