TOPK (T–lymphokine-activated killer cell–originated protein kinase) is highly and frequently transactivated in various cancer tissues, including lung and triple-negative breast cancers, and plays an indispensable role in the mitosis of cancer cells.
We report the development of a potent TOPK inhibitor, OTS964 {(R)-9-(4-(1-(dimethylamino)propan-2-yl)phenyl)-8-hydroxy-6-methylthieno[2,3-c]quinolin-4(5H)-one}, which inhibits TOPK kinase activity with high affinity and selectivity. Similar to the knockdown effect of TOPK small interfering RNAs (siRNAs), this inhibitor causes a cytokinesis defect and the subsequent apoptosis of cancer cells in vitro as well as in xenograft models of human lung cancer.
Although administration of the free compound induced hematopoietic adverse reactions (leukocytopenia associated with thrombocytosis), the drug delivered in a liposomal formulation effectively caused complete regression of transplanted tumors without showing any adverse reactions in mice. Our results suggest that the inhibition of TOPK activity may be a viable therapeutic option for the treatment of various human cancers.
Citation: Y. Matsuo, J.-H. Park, T. Miyamoto, S. Yamamoto, S. Hisada, H. Alachkar, Y. Nakamura, TOPK inhibitor induces complete tumor regression in xenograft models of human cancer through inhibition of cytokinesis. Sci. Transl. Med. 6, 259ra145 (2014).
1 Takasaki
University Health & Welfare, 2Dousisya University, 3Tokushima
University, 4Gunma University,
5 DNP Fine Chemicals Utsunomiya, Ltd.,
In order to gain knowledge about pleiotropic effect of
Statins, we are now interested in the tau aggregation inhibition and ROCK
signal modulation by such heterocyclic statin as Pitavastatin (PTA),
Rosvastatin and related hererocyclic structures.
According to the previous report on the improvement of
Alzheimer’s disease (AD) by PTA [1], we are carefully investigated on the tau-aggregation
inhibitory effect of PTA and other quinolones. In our in vitro assays, however,
any distinctive activity was found towards tau segment aggregation, while
PTA-lactone showed marginal inhibition activity.
These initial results showed us that solubility problem
was an important factor, and also, signal modulation assays with other ROCK
system is essential. Thus, the in vitro tumor growth inhibitory assays are
conducted, and the ROCK signal modulation of PTA and PTA-BGL was observed in
our preliminary experiments. Further insights into the pleiotropic Statins by
MO calculation are addressed in the presentation.
Co-amorphous drug mixtures with low-molecular-weight excipients have recently been shown to be a promising approach for stabilization of amorphous drugs and thus to be an alternative to the traditional amorphous solid dispersion approach using polymers.
However, the previous studies are limited to a few drugs and amino acids.
To facilitate the rational selection of amino acids, the practical importance of the amino acid coming from the biological target site of the drug (and associated intermolecular interactions) needs to be established. In the present study, the formation of co-amorphous systems using cryomilling and combinations of two poorly water-soluble drugs (simvastatin and glibenclamide) with the amino acids aspartic acid, lysine, serine, and threonine was investigated.
Solid-state characterization with X-ray powder diffraction, differential scanning calorimetry, and Fourier-transform infrared spectroscopy revealed that the 1:1 molar combinations simvastatin–lysine, glibenclamide–serine, and glibenclamide–threonine and the 1:1:1 molar combination glibenclamide–serine–threonine formed co-amorphous mixtures.
These were homogeneous single-phase blends with weak intermolecular interactions in the mixtures.
Interestingly, a favorable effect by the excipients on the tautomerism of amorphous glibenclamide in the co-amorphous blends was seen, as the formation of the thermodynamically less stable imidic acid tautomer of glibenclamide was suppressed compared to that of the pure amorphous drug.
Furthermore, the co-amorphous mixtures provided a physical stability advantage over the amorphous drugs alone.
ある種の癌において、セレコキシブがその発生率を抑制する可能性については、多くの研究が行われてきた。しかし、心血管系のリスクを考慮し、癌の発生を軽減する目的でセレコキシブを使用することへの医学的推奨は今のところ行われていない。 アスピリンやセレコキシブ等のNSAIDsを服用している患者の場合、大腸癌リスクは明らかに減少する。さらにセレコキシブを含む特定のCOX-2阻害剤は、従来のNSAIDsと比較して癌抑制作用があり、毒性も低いことがいくつかの疫学研究や前臨床試験で指摘されている。12件の癌原性試験で、セレコキシブにラットやマウスの腸に対して癌発生の抑制作用があることが裏づけられた(Chemoprevention Databaseでデータの入手が可能)。非常にハイリスクな患者(家族性大腸腺腫症の家族歴あり)を対象とした小規模な臨床試験でも、セレコキシブがポリープの成長を抑制することが示されている。このため大規模無作為臨床試験が実施され、臨床成績が2006年8月にNew England Journal of Medicineで報告された[17]。試験では、セレコキシブを400~800mg/日投与した患者において、ポリープの再発が33~45%減少したことが示された。この試験におけるセレコキシブの心血管系イベントの頻度はプラセボと比べ高いことが認められた。しかし、その差に有意差はなかったことが示されている[18]。