Key role of dual specificity kinase TTK in proliferation and survival of pancreatic cancer cells.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is among the most aggressive human malignancies with an overall 5-year survival rate of <5%. Despite significant advances in treatment of the disease during the past decade, the median survival rate (∼6 months) has hardly improved, warranting the need to identify novel targets for therapeutic approaches. METHODS: Quantitative real time PCR, western blot analyses and immunohistochemical staining of tissue microarrays were used to analyse the expression of TTK gene in primary PDAC tissues and cell lines. To inhibit TTK kinase expression in a variety of pancreatic cancer cell lines, RNA interference was used. Functional roles of this kinase in the context of PDAC were studied using cell proliferation, viability and anchorage-independent growth assays. Western blotting, fluorescence-activated cell sorting analyses and fluorescence microscopy were used to gain mechanistic insight into the functional effects. CONCLUSIONS: We show that the dual specificity kinase TTK (also known as Mps1), is strongly overexpressed in human PDAC. Functionally, cell proliferation was significantly attenuated following TTK knockdown, whereas apoptosis and necrosis rates were significantly increased. In addition, anchorage-independent growth, a hallmark of malignant transformation and metastatic potential, was strongly impaired in the absence of TTK gene function. Interestingly, immortalised normal pancreatic hTERT-HPNE cells were not affected by loss of TTK function. Mechanistically, these effects in cancer cells were associated with increased formation of micronuclei, suggesting that loss of TTK function in pancreatic cancer cells results in chromosomal instability and mitotic catastrophe. Taken together, our data show that TTK function is critical for growth and proliferation of pancreatic cancer cells, thus establishing this kinase as an interesting new target for novel therapeutic approaches in combating this malignancy.

Observations on a calcium hydroxide lining in retrieved deciduous teeth, with proximal amalgam fillings.

The integrity and thickness of Dycal linings were determined on exfoliated deciduous teeth in which proximal fillings had been placed in vivo. The teeth remained in the oral cavity for more than 18 months after placement of the restorations. The average lining thickness was found to be 114 microns. One-third of the samples showed evidence for the presence of Dycal at the gingival floor, up to the proximal tooth wall. Wash-out of the lining was observed for most teeth in which Dycal had been present near the proximal tooth wall. Incipient caries formation, associated with wash-out of the lining, was noted in a few samples. Contact between amalgam and dentine was frequently observed at the line angle, pulpal floor and axial wall.

[Disorders of the menstrual cycle in women after entering military training. IV. FSH, LH, prolactin, estradiol, progesterone and cortisol in the first week after beginning training]. / Poruchy menstruacního cyklu u zen po nástupu do vojenského uciliste. IV. FSH, LH, prolaktin, estradiol, progesteron a kortizol v prvním týdnu po nástupu do uciliste.

The authors investigated the hormonal levels of FSH, LH, oestradiol, cortisol and progesterone in women after entering a military training contre. The specimens were collected on the fourth day after admission to the Centre and the results correlated with later "separation" disorders of the menstrual cycle in these women. The authors did not find differences in the mean levels of any hormone in normally regularly menstruating women and in women with disorders of the cycle. They found, however, a significantly higher variance of LH and oestradiol levels in women with disorders of the cycle. When investigating the correlation of different hormone levels, they found a significant positive correlation of FSH:LH, LH:oestradiol, FSH:oestradiol, prolactin:cortisol, and an indirect correlation of LH:cortisol.