Centrosomes maintain genomic stability by establishing the bipolar spindles during cell division and, execute accurate segregation of chromosomes during mitosis. In this study, we have demonstrated that there are three forms of STK-15 gene in breast cancer cell lines. Alternative splice positions are located in 5'-untranslated region of STK15 gene. The results of in vitro translation experiments revealed that the alternative splicing in the 5'-untranslated region of STK15 had no effect on protein translation. The differential expression patterns of these alternatively spliced STK15 in breast cell lines and primary tumors therefore suggest that STK15 gene transcription may be differentially regulated or stabilized in these cells.
*5' Untranslated Regions ; *Alternative Splicing ; Base Sequence ; Breast Neoplasms/enzymology/*genetics ; Centrosome/*enzymology ; Female ; Human ; Molecular Sequence Data ; Protein-Serine-Threonine Kinases/*genetics ; Tumor Cells, Cultured

PURPOSE: To measure the hypermethylation of four genes in primary tumors and paired plasma samples to determine the feasibility of gene promoter hypermethylation markers for detecting breast cancer in the plasma. MATERIALS AND METHODS: DNA was extracted from the tumor tissues and peripheral blood plasma of 34 patients with invasive breast cancer, and the samples examined for aberrant hypermethylation in cyclin D2, retinoic acid receptor beta (RARbeta), twist and high in normal-1 (HIN-1) genes using methylation-specific PCR (MSP), and the results correlated with the clinicopathological parameters. RESULTS: Promoter hypermethylation was detected at high frequency in the primary tumors for cyclin D2 (53%), RARbeta (56%), twist (41%) and HIN-1 (77%). Thirty-three of the 34 (97%) primary tumors displayed promoter hypermethylation in at least one of the genes examined. The corresponding plasma samples showed hyperme thylation of the same genes, although at lower frequencies (6% for cyclin D2, 16% for RARbeta, 36% for twist, and 54% for HIN-1). Overall, 22 of the 33 (67%) primary tumors with hypermethylation of at least one of the four genes also had abnormally hypermethylated DNA in their matched plasma samples. No significant relationship was recognized between any of the clinical or pathological parameters (tumor size, axillary lymph node metastasis, stage, or Ki-67 labeling index) with the frequency of hypermethylated DNA in the primary tumor or plasma. CONCLUSION: The detection of aberrant promoter hypermethylation of cancer-related genes in the plasma may be a useful tool for the detection of breast cancer.
Breast Neoplasms* ; Breast* ; Cyclin D2 ; DNA ; Humans ; Lymph Nodes ; Methylation ; Neoplasm Metastasis ; Plasma* ; Polymerase Chain Reaction ; Receptors, Retinoic Acid