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Chromatin folding and DNA replication inhibition mediated by a highly antitumor-active tetrazolato-bridged dinuclear platinum(II) complex.

Imai R, Komeda S, Shimura M, Tamura S, Matsuyama S, Nishimura K, Rogge R, Matsunaga A, Hiratani I, Takata H, Uemura M, Iida Y, Yoshikawa Y, Hansen JC, Yamauchi K, Kanemaki MT, Maeshima K - Sci Rep (2016)

Bottom Line: Platinum-based drugs, such as cisplatin, have been used extensively in cancer chemotherapy.The drug-DNA interaction causes DNA crosslinks and subsequent cytotoxicity.Recently, it was reported that an azolato-bridged dinuclear platinum(II) complex, 5-H-Y, exhibits a different anticancer spectrum from cisplatin.

View Article: PubMed Central - PubMed

Affiliation: Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.

ABSTRACT
Chromatin DNA must be read out for various cellular functions, and copied for the next cell division. These processes are targets of many anticancer agents. Platinum-based drugs, such as cisplatin, have been used extensively in cancer chemotherapy. The drug-DNA interaction causes DNA crosslinks and subsequent cytotoxicity. Recently, it was reported that an azolato-bridged dinuclear platinum(II) complex, 5-H-Y, exhibits a different anticancer spectrum from cisplatin. Here, using an interdisciplinary approach, we reveal that the cytotoxic mechanism of 5-H-Y is distinct from that of cisplatin. 5-H-Y inhibits DNA replication and also RNA transcription, arresting cells in the S/G2 phase, and are effective against cisplatin-resistant cancer cells. Moreover, it causes much less DNA crosslinking than cisplatin, and induces chromatin folding. 5-H-Y will expand the clinical applications for the treatment of chemotherapy-insensitive cancers.

No MeSH data available.


Related in: MedlinePlus

5-H-Y inhibits DNA replication and RNA transcription, arresting the cells in the S/G2 phase.(A) Flow cytometry results for HeLa cells (upper row) and PC9 cells (lower row) with/without 5-H-Y (2 μM) or cisplatin (2 μM). Vertical and horizontal axes show DNA synthesis activity (EdU incorporation) and DNA amount, respectively. Each dot represents a single cell and results using 10,000 cells are plotted. In the plot of control HeLa, the corresponding cell cycle stages are indicated. Percentages of each cell cycle population are indicated. See also Fig. S2. (B) EdU incorporation versus cell numbers plots of (A). Left panel shows a representative plot (control HeLa). Note that EdU incorporation was high in the S-phase. Fold decreases in EdU incorporation upon 5-H-Y (red) or cisplatin (blue) treatment are indicated in the plots of HeLa (middle) and PC9 (right). Note the several-fold decreases in EdU incorporation in the 5-H-Y (red) or cisplatin (blue) treated cells. (C) Results for HeLa cells synchronized at G1/S by nocodazole-thymidine block with/without 5-H-Y (2 μM) or cisplatin (2 μM). 5-H-Y and cisplatin both inhibit very early phases of DNA replication. (D) Effect of 5-H-Y on RNA transcription in vivo. (Left) Fluorescence microscopy images of 5-H-Y or cisplatin-treated cells. DNA stain, upper; EU fluorescent labeling, lower. (Right) Dot plot of the mean intensity of EU fluorescence in each nucleus (each group, n = 27–30). **p < 0.01, Student’s t-test.
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f2: 5-H-Y inhibits DNA replication and RNA transcription, arresting the cells in the S/G2 phase.(A) Flow cytometry results for HeLa cells (upper row) and PC9 cells (lower row) with/without 5-H-Y (2 μM) or cisplatin (2 μM). Vertical and horizontal axes show DNA synthesis activity (EdU incorporation) and DNA amount, respectively. Each dot represents a single cell and results using 10,000 cells are plotted. In the plot of control HeLa, the corresponding cell cycle stages are indicated. Percentages of each cell cycle population are indicated. See also Fig. S2. (B) EdU incorporation versus cell numbers plots of (A). Left panel shows a representative plot (control HeLa). Note that EdU incorporation was high in the S-phase. Fold decreases in EdU incorporation upon 5-H-Y (red) or cisplatin (blue) treatment are indicated in the plots of HeLa (middle) and PC9 (right). Note the several-fold decreases in EdU incorporation in the 5-H-Y (red) or cisplatin (blue) treated cells. (C) Results for HeLa cells synchronized at G1/S by nocodazole-thymidine block with/without 5-H-Y (2 μM) or cisplatin (2 μM). 5-H-Y and cisplatin both inhibit very early phases of DNA replication. (D) Effect of 5-H-Y on RNA transcription in vivo. (Left) Fluorescence microscopy images of 5-H-Y or cisplatin-treated cells. DNA stain, upper; EU fluorescent labeling, lower. (Right) Dot plot of the mean intensity of EU fluorescence in each nucleus (each group, n = 27–30). **p < 0.01, Student’s t-test.

Mentions: Cisplatin binds covalently to DNA, which trigger inhibition of DNA replication, causing cell cycle arrest in the S/G2 phase32. To examine the effects of 5-H-Y on the cell cycle, we monitored the cell cycle stages of drug-treated (24 h) HeLa, U2OS, PC9, and TIG-1 cells, using flow cytometry (FCM) (Figs 2A,B and S2). Cisplatin inhibited the incorporation of a thymidine analog, 5-ethynyl-2′-deoxyuridine (EdU), into newly synthesized DNA, suggesting that DNA replication was inhibited (Figs 2A,B and S2). Consistently, cisplatin-treated cells were arrested in the S/G2 phase (Figs 2A and S2A). In 5-H-Y-treated cells, a 3- to 10-fold reduction of EdU incorporation and cell cycle arrest in S/G2 were observed, similar to the effects of cisplatin (Figs 2A and S2A). Furthermore, we synchronized HeLa cells at the G1/S phase boundary before treatment with 5-H-Y for 15 h (Experimental scheme is shown in Fig. S3). EdU incorporation was almost completely inhibited after release from the G1/S block (Fig. 2C). These results suggest that 5-H-Y has an inhibitory effect on DNA replication, as does cisplatin.


Chromatin folding and DNA replication inhibition mediated by a highly antitumor-active tetrazolato-bridged dinuclear platinum(II) complex.

Imai R, Komeda S, Shimura M, Tamura S, Matsuyama S, Nishimura K, Rogge R, Matsunaga A, Hiratani I, Takata H, Uemura M, Iida Y, Yoshikawa Y, Hansen JC, Yamauchi K, Kanemaki MT, Maeshima K - Sci Rep (2016)

5-H-Y inhibits DNA replication and RNA transcription, arresting the cells in the S/G2 phase.(A) Flow cytometry results for HeLa cells (upper row) and PC9 cells (lower row) with/without 5-H-Y (2 μM) or cisplatin (2 μM). Vertical and horizontal axes show DNA synthesis activity (EdU incorporation) and DNA amount, respectively. Each dot represents a single cell and results using 10,000 cells are plotted. In the plot of control HeLa, the corresponding cell cycle stages are indicated. Percentages of each cell cycle population are indicated. See also Fig. S2. (B) EdU incorporation versus cell numbers plots of (A). Left panel shows a representative plot (control HeLa). Note that EdU incorporation was high in the S-phase. Fold decreases in EdU incorporation upon 5-H-Y (red) or cisplatin (blue) treatment are indicated in the plots of HeLa (middle) and PC9 (right). Note the several-fold decreases in EdU incorporation in the 5-H-Y (red) or cisplatin (blue) treated cells. (C) Results for HeLa cells synchronized at G1/S by nocodazole-thymidine block with/without 5-H-Y (2 μM) or cisplatin (2 μM). 5-H-Y and cisplatin both inhibit very early phases of DNA replication. (D) Effect of 5-H-Y on RNA transcription in vivo. (Left) Fluorescence microscopy images of 5-H-Y or cisplatin-treated cells. DNA stain, upper; EU fluorescent labeling, lower. (Right) Dot plot of the mean intensity of EU fluorescence in each nucleus (each group, n = 27–30). **p < 0.01, Student’s t-test.
© Copyright Policy - open-access
Related In: Results  -  Collection

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f2: 5-H-Y inhibits DNA replication and RNA transcription, arresting the cells in the S/G2 phase.(A) Flow cytometry results for HeLa cells (upper row) and PC9 cells (lower row) with/without 5-H-Y (2 μM) or cisplatin (2 μM). Vertical and horizontal axes show DNA synthesis activity (EdU incorporation) and DNA amount, respectively. Each dot represents a single cell and results using 10,000 cells are plotted. In the plot of control HeLa, the corresponding cell cycle stages are indicated. Percentages of each cell cycle population are indicated. See also Fig. S2. (B) EdU incorporation versus cell numbers plots of (A). Left panel shows a representative plot (control HeLa). Note that EdU incorporation was high in the S-phase. Fold decreases in EdU incorporation upon 5-H-Y (red) or cisplatin (blue) treatment are indicated in the plots of HeLa (middle) and PC9 (right). Note the several-fold decreases in EdU incorporation in the 5-H-Y (red) or cisplatin (blue) treated cells. (C) Results for HeLa cells synchronized at G1/S by nocodazole-thymidine block with/without 5-H-Y (2 μM) or cisplatin (2 μM). 5-H-Y and cisplatin both inhibit very early phases of DNA replication. (D) Effect of 5-H-Y on RNA transcription in vivo. (Left) Fluorescence microscopy images of 5-H-Y or cisplatin-treated cells. DNA stain, upper; EU fluorescent labeling, lower. (Right) Dot plot of the mean intensity of EU fluorescence in each nucleus (each group, n = 27–30). **p < 0.01, Student’s t-test.
Mentions: Cisplatin binds covalently to DNA, which trigger inhibition of DNA replication, causing cell cycle arrest in the S/G2 phase32. To examine the effects of 5-H-Y on the cell cycle, we monitored the cell cycle stages of drug-treated (24 h) HeLa, U2OS, PC9, and TIG-1 cells, using flow cytometry (FCM) (Figs 2A,B and S2). Cisplatin inhibited the incorporation of a thymidine analog, 5-ethynyl-2′-deoxyuridine (EdU), into newly synthesized DNA, suggesting that DNA replication was inhibited (Figs 2A,B and S2). Consistently, cisplatin-treated cells were arrested in the S/G2 phase (Figs 2A and S2A). In 5-H-Y-treated cells, a 3- to 10-fold reduction of EdU incorporation and cell cycle arrest in S/G2 were observed, similar to the effects of cisplatin (Figs 2A and S2A). Furthermore, we synchronized HeLa cells at the G1/S phase boundary before treatment with 5-H-Y for 15 h (Experimental scheme is shown in Fig. S3). EdU incorporation was almost completely inhibited after release from the G1/S block (Fig. 2C). These results suggest that 5-H-Y has an inhibitory effect on DNA replication, as does cisplatin.

Bottom Line: Platinum-based drugs, such as cisplatin, have been used extensively in cancer chemotherapy.The drug-DNA interaction causes DNA crosslinks and subsequent cytotoxicity.Recently, it was reported that an azolato-bridged dinuclear platinum(II) complex, 5-H-Y, exhibits a different anticancer spectrum from cisplatin.

View Article: PubMed Central - PubMed

Affiliation: Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.

ABSTRACT
Chromatin DNA must be read out for various cellular functions, and copied for the next cell division. These processes are targets of many anticancer agents. Platinum-based drugs, such as cisplatin, have been used extensively in cancer chemotherapy. The drug-DNA interaction causes DNA crosslinks and subsequent cytotoxicity. Recently, it was reported that an azolato-bridged dinuclear platinum(II) complex, 5-H-Y, exhibits a different anticancer spectrum from cisplatin. Here, using an interdisciplinary approach, we reveal that the cytotoxic mechanism of 5-H-Y is distinct from that of cisplatin. 5-H-Y inhibits DNA replication and also RNA transcription, arresting cells in the S/G2 phase, and are effective against cisplatin-resistant cancer cells. Moreover, it causes much less DNA crosslinking than cisplatin, and induces chromatin folding. 5-H-Y will expand the clinical applications for the treatment of chemotherapy-insensitive cancers.

No MeSH data available.


Related in: MedlinePlus