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Inhibition of janus kinase 2 by compound AG490 suppresses the proliferation of MDA-MB-231 cells via up-regulating SARI (suppressor of AP-1, regulated by IFN).

Zhang YX, Yan L, Liu GY, Chen WJ, Gong WH, Yu JM - Iran J Basic Med Sci (2015)

Bottom Line: AG490 significantly up-regulated the mRNA and protein levels of SARI in MDA-MB-231 cells.Knockdown of SARI obviously attenuated AG490-induced growth suppression effect in MDA-MB-231 cells.But the transcription activity of truncated SARI promoter, which does not contain STAT3 binding site, cannot be activated by AG490 treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Shandong Cancer Hospital, Shandong University, Jinan, Shandong, China ; Department of Radiation Oncology, Linyi People's Hospital, Linyi, Shandong, China.

ABSTRACT

Objectives: The Janus kinase-signal transducers and activators of transcription signaling pathway (JAK/STAT pathway) play an important role in proliferation of breast cancer cells. Previous data showed that inhibition of STAT3 suppresses the growth of breast cancer cells, but the associated mechanisms are not well understood. This study aims to investigate the effect and associated mechanisms of JAK/STAT pathway inhibitor AG490 on proliferation and suppression of breast cancer cells.

Materials and methods: CCK-8 assay and trypan blue exclusion assay were used to investigate the cytotoxicity of AG490 to MDA-MB-231 cells. Real-time PCR was used to detect the mRNA level of SARI (suppressor of AP-1, regulated by IFN). Western blot was used to analyze the protein levels of SARI, phospho-STAT3 and total STAT3. Luciferase reporter assay was adopted to explore the mechanism of SARI mRNA upregulation.

Results: AG490 suppressed the proliferation of MDA-MB-231 cells in a dose-dependent manner. AG490 significantly up-regulated the mRNA and protein levels of SARI in MDA-MB-231 cells. Knockdown of SARI obviously attenuated AG490-induced growth suppression effect in MDA-MB-231 cells. Furthermore, AG490 dramatically enhanced the transcription activity of SARI promoter. But the transcription activity of truncated SARI promoter, which does not contain STAT3 binding site, cannot be activated by AG490 treatment.

Conclusion: We demonstrate in this study that AG490 suppresses the proliferation of MDA-MB-231 cells through transcriptional activation of SARI.

No MeSH data available.


Related in: MedlinePlus

Knockdown of SARI (suppressor of AP-1, regulated by IFN) attenuated AG490-induced suppression effect on MDA-MB-231 cell growth. A) MDA-MB-231 cells were transfected with SARI siRNA or control siRNA for 36 hr, then SARI protein level was analyzed by Western blot. B) After transfection with SARI siRNA or control siRNA for 24 hr, the MDA-MB-231 cells were treated with 25 μM AG490 or vehicle DMSO for another 36 hr. Then the cell viability was analyzed by CCK-8 kit. Data were expressed as the mean ± SD from three independent experiments. *: P<0.05; **: P<0.01
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Figure 3: Knockdown of SARI (suppressor of AP-1, regulated by IFN) attenuated AG490-induced suppression effect on MDA-MB-231 cell growth. A) MDA-MB-231 cells were transfected with SARI siRNA or control siRNA for 36 hr, then SARI protein level was analyzed by Western blot. B) After transfection with SARI siRNA or control siRNA for 24 hr, the MDA-MB-231 cells were treated with 25 μM AG490 or vehicle DMSO for another 36 hr. Then the cell viability was analyzed by CCK-8 kit. Data were expressed as the mean ± SD from three independent experiments. *: P<0.05; **: P<0.01

Mentions: To test the role of SARI upregulation in AG490-treated cells, we knocked it down by siRNA in MDA-MB-231 cells (Figure 3A). Compared to AG490 treatment alone, knockdown of SARI significantly attenuated AG490-induced suppression effect on MDA-MB-231 cell growth (Figure 3B).


Inhibition of janus kinase 2 by compound AG490 suppresses the proliferation of MDA-MB-231 cells via up-regulating SARI (suppressor of AP-1, regulated by IFN).

Zhang YX, Yan L, Liu GY, Chen WJ, Gong WH, Yu JM - Iran J Basic Med Sci (2015)

Knockdown of SARI (suppressor of AP-1, regulated by IFN) attenuated AG490-induced suppression effect on MDA-MB-231 cell growth. A) MDA-MB-231 cells were transfected with SARI siRNA or control siRNA for 36 hr, then SARI protein level was analyzed by Western blot. B) After transfection with SARI siRNA or control siRNA for 24 hr, the MDA-MB-231 cells were treated with 25 μM AG490 or vehicle DMSO for another 36 hr. Then the cell viability was analyzed by CCK-8 kit. Data were expressed as the mean ± SD from three independent experiments. *: P<0.05; **: P<0.01
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4509956&req=5

Figure 3: Knockdown of SARI (suppressor of AP-1, regulated by IFN) attenuated AG490-induced suppression effect on MDA-MB-231 cell growth. A) MDA-MB-231 cells were transfected with SARI siRNA or control siRNA for 36 hr, then SARI protein level was analyzed by Western blot. B) After transfection with SARI siRNA or control siRNA for 24 hr, the MDA-MB-231 cells were treated with 25 μM AG490 or vehicle DMSO for another 36 hr. Then the cell viability was analyzed by CCK-8 kit. Data were expressed as the mean ± SD from three independent experiments. *: P<0.05; **: P<0.01
Mentions: To test the role of SARI upregulation in AG490-treated cells, we knocked it down by siRNA in MDA-MB-231 cells (Figure 3A). Compared to AG490 treatment alone, knockdown of SARI significantly attenuated AG490-induced suppression effect on MDA-MB-231 cell growth (Figure 3B).

Bottom Line: AG490 significantly up-regulated the mRNA and protein levels of SARI in MDA-MB-231 cells.Knockdown of SARI obviously attenuated AG490-induced growth suppression effect in MDA-MB-231 cells.But the transcription activity of truncated SARI promoter, which does not contain STAT3 binding site, cannot be activated by AG490 treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Shandong Cancer Hospital, Shandong University, Jinan, Shandong, China ; Department of Radiation Oncology, Linyi People's Hospital, Linyi, Shandong, China.

ABSTRACT

Objectives: The Janus kinase-signal transducers and activators of transcription signaling pathway (JAK/STAT pathway) play an important role in proliferation of breast cancer cells. Previous data showed that inhibition of STAT3 suppresses the growth of breast cancer cells, but the associated mechanisms are not well understood. This study aims to investigate the effect and associated mechanisms of JAK/STAT pathway inhibitor AG490 on proliferation and suppression of breast cancer cells.

Materials and methods: CCK-8 assay and trypan blue exclusion assay were used to investigate the cytotoxicity of AG490 to MDA-MB-231 cells. Real-time PCR was used to detect the mRNA level of SARI (suppressor of AP-1, regulated by IFN). Western blot was used to analyze the protein levels of SARI, phospho-STAT3 and total STAT3. Luciferase reporter assay was adopted to explore the mechanism of SARI mRNA upregulation.

Results: AG490 suppressed the proliferation of MDA-MB-231 cells in a dose-dependent manner. AG490 significantly up-regulated the mRNA and protein levels of SARI in MDA-MB-231 cells. Knockdown of SARI obviously attenuated AG490-induced growth suppression effect in MDA-MB-231 cells. Furthermore, AG490 dramatically enhanced the transcription activity of SARI promoter. But the transcription activity of truncated SARI promoter, which does not contain STAT3 binding site, cannot be activated by AG490 treatment.

Conclusion: We demonstrate in this study that AG490 suppresses the proliferation of MDA-MB-231 cells through transcriptional activation of SARI.

No MeSH data available.


Related in: MedlinePlus