Examination of survivin expression in 50 chordoma specimens--A histological and in vitro study

Chordomas mainly arise along the axial skeleton and are characterized by their slow but destructive growth. Prognosis and quality of life are poor because treatment options are mainly limited to surgery and radiotherapy. Survivin, a member of the apoptosis inhibitor protein family, functions as a key regulator of mitosis and programmed cell death, and is overexpressed in many tumor types. The aim of this study was to determine the role of survivin in chordomas. Survivin expression was investigated in 50 chordoma samples and three chordoma cell lines using immunohistochemistry. The intensity of immunostaining was evaluated in regard to the development of recurrences. The immunohistochemical results were correlated with clinical parameters like gender, age, tumor size, and location and were performed in primary chordomas as well as in recurrent lesions. Furthermore, survivin knockdown experiments on chordoma cell lines were performed. YM155 decreased the growth behavior of chordoma cells dose- and time dependently. Transient knockdown of survivin led to a G2/M arrest, decreased proliferation, consistently induced an increase of polyploidy and morphological changes, and induced apoptosis. The resultant data from this study suggest that survivin plays a cell cycle-progressive role in chordomas. Hence, regulation of survivin by YM155 is a promising new target for the development of new therapeutic drugs.

Potential of immune biomarkers for predicting survival in glioblastoma patients receiving dendritic cell cancer immunotherapy (VAC12P.1012)

Activartis is developing AV0113, an autologous dendritic cell (DC)-based cancer vaccine for glioblastoma multiforme (GBM). AV0113 is characterized by high release of IL-12, Th1 polarization and a potent anti-tumor immune response. A total of 78 GBM patients have been recruited into a randomized Phase II clinical trial. All patients received first line standard therapy for GBM and patients in the treatment group received AV0113 as an add-on treatment. A recent evaluation revealed a clear trend towards survival benefit for patients receiving AV0113 compared to the control group. In the treatment group 3 of 19 patients had died (16%), whereas in the control group 9 of 20 patients had died (45%). Patients’ chances to survive the first year are close to 3 times greater if they receive AV0113. Based on the hypothesis that there are immune parameters that could predict response to cancer immunotherapy (CIT), we investigated a total of 90 variables in the peripheral blood of GBM patients before, during and after CIT. We detected pre-existing anti-tumor immune responses and found that these responses were higher in patients that survived longer after CIT. Furthermore, a high increase in the anti-tumor responses after CIT was observed in long-term survivor patients and was associated with high percentage of CD3, CD8, NK and Th1 phenotypes as well as lower T regulatory cells in the peripheral blood. These Immune Parameters might be used as prognostic biomarkers and guidance for CIT.

TGF-β1 and TNF-α differentially regulate Twist1 mediated resistance towards BRAF/MEK inhibition in melanoma

Resistance to BRAF and MEK inhibition is a common phenomenon in melanoma. Cytokines and transcription factors have been attributed to contribute to the loss of sensitivity towards these inhibitors. Here, we show that transforming growth factor (TGF)-β1 if combined with PLX4032, a BRAF inhibitor, or GSK1120212, a MEK inhibitor, substantially increased cell death in BRAF-mutant melanoma cell lines. This increase was based on the combined regulatory decrease in Twist1, an antiapoptotic protein. Overexpression or silencing of Twist1 attenuated or aggravated induction of apoptosis through PLX4032 or GSK1120212, respectively. Exposure to tumour necrosis factor (TNF)-α, however, led to increased Twist1 levels and oppositional decrease in cell death if exposed to PLX4032 or GSK1120212. This increase in drug resistance again depended on Twist1 levels. Our studies suggest that Twist1 as a common downstream target of multiple signalling cascades plays a crucial role in mediating drug resistance to BRAF- and MEK-targeted molecular inhibitors.

Naphthoquinones from Onosma paniculata induce cell-cycle arrest and apoptosis in melanoma Cells

Activity-guided fractionation of a petroleum ether-soluble extract of the roots of Onosma paniculata, which has been shown to affect the cell cycle and to induce apoptosis in melanoma cells, led to the isolation of several shikonin derivatives, namely, β-hydroxyisovalerylshikonin (1), acetylshikonin (2), dimethylacrylshikonin (3), and a mixture of α-methylbutyrylshikonin and isovalerylshikonin (4+5). All compounds exhibited strong cytotoxicity against eight cancer cell lines and MRC-5 lung fibroblasts, with 3 found to possess the most potent cytotoxicity toward four melanoma cell lines (SBcl2, WM35, WM9, and WM164). Furthermore, 3 and the mixture of 4+5 were found to interfere with cell-cycle progression in these cell lines and led to an increasing number of cells in the subG1 region as well as to caspase-3/7 activation, indicating apoptotic cell death.

Establishment and detailed functional and molecular genetic characterisation of a novel sacral chordoma cell line, MUG-Chor1

Chordomas are rare, low to intermediate grade malignant bone tumors of the axial skeleton. Current treatment options are limited to surgical procedures, as chordomas are largely resistant to conventional radiation and chemotherapy. Cell lines are valuable tools for exploring molecular mechan-isms involved in tumorigenesis and they have a fundamental impact on the development of new anticancer agents. To date, only two chordoma cell lines exist world-wide. In the present study we report a third chordoma cell line, MUG-Chor1, as well as corresponding cultured fibroblasts established from a recur-rent morphologically 'classic' sacrococcygeal chordoma of a 58-year-old Caucasian female. The cells are brachyury-positive and have the characteristics of chordoma. The genetic profile of the primary chordoma and the established chordoma cell line was investigated during the culturing period (early and late passage). MUG-Chor1 is karyotypically, <2n>43-47,XX,del(3)(q1?)[11], +7,del(9)(p1?),der(9;15)(q10;q10),-10,+der(12)t(9;12)(p2?;q1?),der (12)t(12;19)(p;p)t(17;19)(q;q),-15,der(17;21)(q10;q10),der(20)t(10;20) (q25?26?;q11?12?),-21,-22[20]/idemx2[5] and displays known, chordoma-typical genetic changes, such as chromosomal gains at T/brachyury locus (6q27), losses at 9p24.3-p13.1 (includes the CDKN2a/CDKN2b locus), 10p15.3-q23.32 (includes the PTEN locus) and losses of 10q25.2 (includes the PDCD4 locus). MUG-Chor1 bears a marked resemblance to chordomas in vivo and is, therefore, an optimal in vitro chordoma model.

A petrol ether extract of the roots of Onosma paniculatum induces cell death in a caspase dependent manner

AIM OF THE STUDY

Traditional Chinese medicine (TCM) has become very popular in Western countries during the last years. Zicao, a remedy of TCM, has been traditionally used to treat cancer, and, its main constituents, naphthoquinones, have been reported to possess antitumor activity (Chen et al., 2002; Papageorgiou et al., 1999). Here, we prepared extracts of different polarities of Onosma paniculatum Bur. & Franch., a plant which is amongst others used as Zicao, but, much less investigated. The extracts were analyzed concerning their growth inhibitory and apoptosis-inducing activity in various tumor cells.

MATERIALS AND METHODS

Cell viability was measured by XTT viability and a growth inhibition assay. Effects on the cell cycle and caspase-3 were determined by flow cytometry.

RESULTS

From three different extracts, a petrol ether extract showed significant growth inhibitory effect, cell cycle influence and caspase-3 dependent induction of apoptosis which was time and dose dependent.

CONCLUSION

To further determine the activity and mechanism of action of the petrol ether extract, we would like to isolate and identify the active principle and investigate the effects in more detail.