Autoantibodies from a patient with scleroderma CREST recognized kinetochores of the higher plant Haemanthus.

Human autoantibodies from a patient with scleroderma CREST (calcinosis, Raynaud phenomenon, esophageal dismotility, sclerodactyly, telangiectasia) were used to immunostain kinetochores on chromosomes in endosperm of the seed of the monocot Haemanthus katherinae Bak. Kinetochores of mitotic chromosomes and prekinetochores of interphase cells were specifically stained using conventional indirect immunofluorescence procedures as well as a nonfading immunogold-silver-enhanced technique and analyzed by fluorescence and video microscopy. In interphase, prekinetochores were either single or double structures depending on the stage of the cell cycle but became quadruple (two distinct stained dots on each chromatid) in mid-to-late prophase. In favorable preparations of prometaphase chromosomes, multiple subunits could be resolved within each sister kinetochore suggesting a compound organization. Western blot analysis demonstrated common epitopes in centromeric peptides of HeLa and Haemanthus cell extracts. Although the molecular mass of individual polypeptides differed in the two species, the presence of shared epitopes indicates striking conservation of centromere/kinetochore components throughout evolution.     

Embryonic implantation, dietary intake, and plasma GH concentration in pregnant mice exposed to hypoxia

Inseminated mice were: 1) exposed to 8% O2, 2) pair fed to mice exposed to 8% O2, 3) fasted at 21% O2 or 4) maintained at 21% O2 (control) between Days 1-3 of pregnancy. The frequency of embryonic implantation sites in mice was reduced by greater than 60% in 8% O2 exposed and pair fed animals, and by 100% in fasted mice. During the initial 24 h of exposure to 8% O2, a significant component of the body weight lost by hypoxic mice was associated with the reduction in dietary intake. The contragestational effects of hypoxia and fasting were attributed to the endocrine consequences of inanition induced by hypophagia and adypsia. Plasma samples collected at 6-h intervals revealed a significant reduction in GH concentration in treatment groups compared to the controls.     

Treatment of hilar carcinoma by bile drainage combined with internal radiotherapy using 192iridium wire

Eighteen patients with a cholangiocarcinoma involving the hilum of the liver, and one patient with a carcinoma of the gall bladder causing obstruction of the common hepatic duct, have been treated with bile drainage using a U-tube (8 patients) or a percutaneous transhepatic catheter (11 patients) followed by internal radiotherapy with 192iridium wire. The median survival is 11 months, and 9 patients (47 per cent) have survived for 12 months or longer. The addition of internal radiotherapy may be beneficial to patients with hilar cholangiocarcinoma causing biliary obstruction in whom bile drainage can be established.     

Centrosome amplification and overexpression of aurora A are early events in rat mammary carcinogenesis

The cells of many solid tumors have been found to contain supernumerary centrosomes, a condition known as centrosome amplification. Centrosome amplification, accompanied by the overexpression of an associated kinase, Aurora A (AurA), has been implicated in mechanisms leading to mitotic spindle aberrations, aneuploidy, and genomic instability. Using a well-established rat mammary model favorable for experimental carcinogenesis, we analyzed centrosome amplification as a cellular marker for early stages of transformation and its regulation by the kinase ratAurA. Parity or treatment with estrogen and progesterone conferred resistance to tumorigenesis, as well as to overexpression of ratAurA and to centrosome amplification. ratAurA, cloned from a rat mammary gland cDNA library, is a bona fide Ser/Thr kinase, and sequence comparison demonstrated high homology to members of the entire AurA kinase family. Using immunocytochemical localization with confocal microscopy, we found ratAurA to be localized at the centrosome in normal and neoplastic tissues of the rat mammary gland. Normal ductal epithelium and stromal cells displayed an expected complement of one to two centrosomes/cell, whereas comparable cells in methylnitrosourea-treated animals displayed significantly elevated centrosome numbers. In tumors, 46% of cells showed more than two centrosomes/cell, and ratAurA expression levels coincided with higher centrosome numbers. Both centrosome numbers and ratAurA expression were permanently elevated. Centrosome amplification was found to occur at a very early, premalignant stage prior to detectable lesions after treatment with methylnitrosourea, a condition that was not detected in mammary glands of rats made refractory to the carcinogen via pregnancy or estrogen and progesterone treatment. Our results indicate that hormones influence kinase expression, and progesterone had the major effect on ratAurA expression levels. Cumulatively, these results suggest that ratAurA overexpression and centrosome amplification were linked to tumor development and progression and may serve as early markers in tumorigenesis.     

Amplification/overexpression of a mitotic kinase gene in human bladder cancer

BACKGROUND: The mitotic kinase-encoding gene STK15/BTAK/ AuroraA is associated with aneuploidy and transformation when overexpressed in mammalian cells. STK15 overexpression activates an unknown oncogenic pathway that involves centrosome amplification and results in missegregation of chromosomes. Because clinical prognosis and tumor aneuploidy are tightly linked in human bladder cancer, we examined whether increased STK15 copy number and protein levels are linked to aneuploidy in bladder cancers. METHODS: STK15 protein was visualized by immunohistochemistry in 205 formalin-fixed, paraffin-embedded human bladder tumors. STK15 gene copy number was evaluated in 61 tumors by Southern blot hybridization and in 21 of these 61 tumors by fluorescence in situ hybridization (FISH). Copy numbers of chromosomes 3, 17, 20, and 21 were evaluated by FISH with chromosome-specific probes. STK15 expression levels were related to histologic grade, stage, and DNA ploidy of the tumors and to the patients' follow-up data. The chi-square test for association was used to analyze the relationship between STK15 expression and pathologic features. All statistical tests were two-sided. RESULTS: Tumors with low levels of STK15 amplification (3-4 copies) showed minimal deviation in their chromosome copy number and diploid or near-diploid total nuclear DNA content. Tumors with higher levels of STK15 amplification (>4 copies) had a major increase of chromosome copy number and of their total nuclear DNA content, i.e., exhibited pronounced aneuploidy. Elevated expression of STK15 was strongly associated with parameters of clinical aggressiveness including high histologic grade (P<.001), invasion (P<.001), increased rate of metastasis (P<.001), and decreased metastasis-free (P<.001) and overall (P<.001) survival of patients with bladder cancer. CONCLUSION: STK15 gene amplification and associated increased expression of the mitotic kinase it encodes are associated with aneuploidy and aggressive clinical behavior in human bladder cancer.