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Cucurbitacin I blocks cerebrospinal fluid and platelet derived growth factor-BB stimulation of leptomeningeal and meningioma DNA synthesis.

Johnson MD, O'Connell MJ, Walter K - BMC Complement Altern Med (2013)

Bottom Line: Co-administration of cucurbitacin I (250 nM) produces a significant blockade of this effect.Cucurbitacin I alone also produced a significant reduction in basal DNA synthesis.Cucurbitacin I had no effect on basal phosphorylation of STAT3 but reduced phorphorylated p44/42 MAPK in 2 grade II meningioma cells lines.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Neuropathology, Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Box 626, 601 Elmwood Ave,, Rochester, NY 14642, USA. mahlon_johnson@urmc.rochester.edu.

ABSTRACT

Background: Currently, there are no consistently effective chemotherapies for recurrent and inoperable meningiomas. Recently, cucurbitacin I (JSI-124), a naturally occurring tetracyclic triterpenoid compound used as folk medicines has been found to have cytoxic and anti-proliferative properties in several malignancies thru inhibition of activator of transcription (STAT3) activation. Previously, we have found STAT3 to be activated in meningiomas, particularly higher grade tumors.

Methods: Primary leptomeningeal cultures were established from 17, 20 and 22 week human fetuses and meningioma cell cultures were established from 6 World Health Organization (WHO) grade I or II meningiomas. Cells were treated with cerebrospinal fluid from patients without neurologic disease. The effects of cucurbitacin I on cerebrospinal fluid stimulation of meningioma cell DNA synthesis phosphorylation/activation of JAK1, STAT3, pMEK1/2, p44/42MAPK, Akt, mTOR, Rb and caspase 3 activation were analyzed in human leptomeningeal and meningioma cells.

Results: Cerebrospinal fluid significantly stimulated DNA synthesis in leptomeningeal cells. Co-administration of cucurbitacin I (250 nM) produces a significant blockade of this effect. Cucurbitacin I alone also produced a significant reduction in basal DNA synthesis. In grade I and II meningiomas, cerebrospinal fluid also significantly stimulated DNA synthesis. Co-administration of cucurbitacin I (250 nM) blocked this effect.In the leptomeningeal cultures, cerebrospinal fluid stimulated STAT3 phosphorylation but not p44/42MAPK, Akt or mTOR. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased MEK1/2 and cucurbitacin I had no effect on basal STAT3, p44/42MAPK, Akt, JAK1, mTOR, or Rb phosphorylation. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin I had no effect on basal phosphorylation of STAT3 but reduced phorphorylated p44/42 MAPK in 2 grade II meningioma cells lines.

Conclusions: These studies raise the possibility that cucurbitacin I might have value as an adjunct chemotherapy. Additional studies are warranted to evaluate the effects of cucurbitacin I on meningiomas in vivo.

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Western blot analysis of effects of cucurbitacin I on phosphorylation/activation of signaling pathways in human leptomeningeal and meningioma cells. a. Effects of cucurbitacin I on phosphorylation/activation of STAT3, and p44/42MAPK in human leptomeningeal cells. Leptomeningeal cells from 17 (L1) and 20 wk (L2) were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. Cerebrospinal fluid stimulated STAT3 phosphorylation. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. b. Effects of cucurbitacin I on phosphorylation/activation of JAK, STAT3, pMEK1/2, p44/42MAPK and mTOR in meningioma cells. WHO grade I (M2 and 3) and (B) WHO grade II (M4 and 5) meningiomas were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased it in MEK1/2. Cucurbitacin I had no effect. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin reduced basal p44/42 MAPK phosphorylation.
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Figure 4: Western blot analysis of effects of cucurbitacin I on phosphorylation/activation of signaling pathways in human leptomeningeal and meningioma cells. a. Effects of cucurbitacin I on phosphorylation/activation of STAT3, and p44/42MAPK in human leptomeningeal cells. Leptomeningeal cells from 17 (L1) and 20 wk (L2) were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. Cerebrospinal fluid stimulated STAT3 phosphorylation. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. b. Effects of cucurbitacin I on phosphorylation/activation of JAK, STAT3, pMEK1/2, p44/42MAPK and mTOR in meningioma cells. WHO grade I (M2 and 3) and (B) WHO grade II (M4 and 5) meningiomas were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased it in MEK1/2. Cucurbitacin I had no effect. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin reduced basal p44/42 MAPK phosphorylation.

Mentions: Cerebrospinal fluid had no effect on JAK1 phosphorylation in any of the meningioma cells studies (M2-M6) but stimulated STAT3 phosphorylation in all 3 leptomeningeal cultures and meningioma cells M1, M3–M6. Cucurbitacin I decreased STAT3 phosphorylation in L1-L3. Co-administration of cerebrospinal fluid and cucurbitacin I decreased phosphorylation in M5. In M4 an increase was seen with co-administration. Cerebrospinal fluid reduced MEK1/2 phosphorylation in M2, M4-M6. Cerebrospinal fluid with and without cucurbitacin I was also associated with a reduction of MEK1/2 phosphorylation in M2, M4-M6. Cerebrospinal fluid with or without cucurbitacin I also decreased p44/42MAPK phosphorylation in L2, M4-M6 (Figure 4 and data not shown). Cerebrospinal fluid increased Akt phosphorylation in M6. Cucurbitacin I alone and with cerebrospinal fluid had no effect on Akt phosphorylation in M3, 5 and 6. Cerebrospinal fluid, curbitacin I with or without cerebrospinal fluid had no effect on mTOR phosphorylation in M2-M6. Neither cerebrospinal fluid nor cucurbitacin 1 with or without cerebrospinal fluid had an effect on Rb phosphorylation (Figure 4 and data and not shown).


Cucurbitacin I blocks cerebrospinal fluid and platelet derived growth factor-BB stimulation of leptomeningeal and meningioma DNA synthesis.

Johnson MD, O'Connell MJ, Walter K - BMC Complement Altern Med (2013)

Western blot analysis of effects of cucurbitacin I on phosphorylation/activation of signaling pathways in human leptomeningeal and meningioma cells. a. Effects of cucurbitacin I on phosphorylation/activation of STAT3, and p44/42MAPK in human leptomeningeal cells. Leptomeningeal cells from 17 (L1) and 20 wk (L2) were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. Cerebrospinal fluid stimulated STAT3 phosphorylation. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. b. Effects of cucurbitacin I on phosphorylation/activation of JAK, STAT3, pMEK1/2, p44/42MAPK and mTOR in meningioma cells. WHO grade I (M2 and 3) and (B) WHO grade II (M4 and 5) meningiomas were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased it in MEK1/2. Cucurbitacin I had no effect. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin reduced basal p44/42 MAPK phosphorylation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4228312&req=5

Figure 4: Western blot analysis of effects of cucurbitacin I on phosphorylation/activation of signaling pathways in human leptomeningeal and meningioma cells. a. Effects of cucurbitacin I on phosphorylation/activation of STAT3, and p44/42MAPK in human leptomeningeal cells. Leptomeningeal cells from 17 (L1) and 20 wk (L2) were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. Cerebrospinal fluid stimulated STAT3 phosphorylation. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. b. Effects of cucurbitacin I on phosphorylation/activation of JAK, STAT3, pMEK1/2, p44/42MAPK and mTOR in meningioma cells. WHO grade I (M2 and 3) and (B) WHO grade II (M4 and 5) meningiomas were treated with serum free media (C), cerebrospinal fluid (CF) without or with cucurbitacin I (Cu) (250 nM) for 72 hrs. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased it in MEK1/2. Cucurbitacin I had no effect. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin reduced basal p44/42 MAPK phosphorylation.
Mentions: Cerebrospinal fluid had no effect on JAK1 phosphorylation in any of the meningioma cells studies (M2-M6) but stimulated STAT3 phosphorylation in all 3 leptomeningeal cultures and meningioma cells M1, M3–M6. Cucurbitacin I decreased STAT3 phosphorylation in L1-L3. Co-administration of cerebrospinal fluid and cucurbitacin I decreased phosphorylation in M5. In M4 an increase was seen with co-administration. Cerebrospinal fluid reduced MEK1/2 phosphorylation in M2, M4-M6. Cerebrospinal fluid with and without cucurbitacin I was also associated with a reduction of MEK1/2 phosphorylation in M2, M4-M6. Cerebrospinal fluid with or without cucurbitacin I also decreased p44/42MAPK phosphorylation in L2, M4-M6 (Figure 4 and data not shown). Cerebrospinal fluid increased Akt phosphorylation in M6. Cucurbitacin I alone and with cerebrospinal fluid had no effect on Akt phosphorylation in M3, 5 and 6. Cerebrospinal fluid, curbitacin I with or without cerebrospinal fluid had no effect on mTOR phosphorylation in M2-M6. Neither cerebrospinal fluid nor cucurbitacin 1 with or without cerebrospinal fluid had an effect on Rb phosphorylation (Figure 4 and data and not shown).

Bottom Line: Co-administration of cucurbitacin I (250 nM) produces a significant blockade of this effect.Cucurbitacin I alone also produced a significant reduction in basal DNA synthesis.Cucurbitacin I had no effect on basal phosphorylation of STAT3 but reduced phorphorylated p44/42 MAPK in 2 grade II meningioma cells lines.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Neuropathology, Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Box 626, 601 Elmwood Ave,, Rochester, NY 14642, USA. mahlon_johnson@urmc.rochester.edu.

ABSTRACT

Background: Currently, there are no consistently effective chemotherapies for recurrent and inoperable meningiomas. Recently, cucurbitacin I (JSI-124), a naturally occurring tetracyclic triterpenoid compound used as folk medicines has been found to have cytoxic and anti-proliferative properties in several malignancies thru inhibition of activator of transcription (STAT3) activation. Previously, we have found STAT3 to be activated in meningiomas, particularly higher grade tumors.

Methods: Primary leptomeningeal cultures were established from 17, 20 and 22 week human fetuses and meningioma cell cultures were established from 6 World Health Organization (WHO) grade I or II meningiomas. Cells were treated with cerebrospinal fluid from patients without neurologic disease. The effects of cucurbitacin I on cerebrospinal fluid stimulation of meningioma cell DNA synthesis phosphorylation/activation of JAK1, STAT3, pMEK1/2, p44/42MAPK, Akt, mTOR, Rb and caspase 3 activation were analyzed in human leptomeningeal and meningioma cells.

Results: Cerebrospinal fluid significantly stimulated DNA synthesis in leptomeningeal cells. Co-administration of cucurbitacin I (250 nM) produces a significant blockade of this effect. Cucurbitacin I alone also produced a significant reduction in basal DNA synthesis. In grade I and II meningiomas, cerebrospinal fluid also significantly stimulated DNA synthesis. Co-administration of cucurbitacin I (250 nM) blocked this effect.In the leptomeningeal cultures, cerebrospinal fluid stimulated STAT3 phosphorylation but not p44/42MAPK, Akt or mTOR. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased MEK1/2 and cucurbitacin I had no effect on basal STAT3, p44/42MAPK, Akt, JAK1, mTOR, or Rb phosphorylation. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin I had no effect on basal phosphorylation of STAT3 but reduced phorphorylated p44/42 MAPK in 2 grade II meningioma cells lines.

Conclusions: These studies raise the possibility that cucurbitacin I might have value as an adjunct chemotherapy. Additional studies are warranted to evaluate the effects of cucurbitacin I on meningiomas in vivo.

Show MeSH
Related in: MedlinePlus