In vitro: |
Anticancer Res. 2009 Nov;29(11):4629-32. | Cyclopamine and quercetin suppress the growth of leukemia and lymphoma cells.[Pubmed: 20032413] | Hedgehog (Hh) and Wnt signaling pathways are involved in the stimulation of growth of leukemia and lymphoma cells. In the present study, whether or not the Hh inhibitor, cyclopamine, and the Wnt inhibitor, quercetin, suppress cell growth was investigated.
METHODS AND RESULTS:
The effects of cyclopamine and quercetin on the in vitro growth and protein expression of ten acute leukemia and B-cell lymphoma cell lines were examined.
Cyclopamine and quercetin suppressed cell growth and induced apoptosis in seven and eight cell lines respectively. Cyclopamine decreased the level of Gli1 protein, a target gene product of Hh signaling. Quercetin decreased the level of Notch1 protein and its active fragment in the DND-41 T-lymphoblastic leukemia cell line with constitutive Notch activation.
CONCLUSIONS:
Cyclopamine and quercetin suppress the growth of a number of leukemia and lymphoma cells. This finding suggests the potential use of these compounds in molecularly-targeted therapy for leukemia and lymphoma. | Cancer Chemother Pharmacol. 2006 Dec;58(6):765-70. | Cyclopamine increases the cytotoxic effects of paclitaxel and radiation but not cisplatin and gemcitabine in Hedgehog expressing pancreatic cancer cells.[Pubmed: 16552573 ] | The hedgehog signaling pathway (Hh) is frequently over expressed in pancreatic adenocarcinomas. We studied the potential cytotoxic interactions between cyclopamine, a Hh pathway inhibitor and paclitaxel, cisplatin, gemcitabine and ionizing radiation (IR).
METHODS AND RESULTS:
In vitro clonogenic survival analysis was performed with cyclopamine alone or cyclopamine in combination with paclitaxel, gemcitabine, cisplatin and IR in Hh expressing human pancreatic tumor cells and Hh non-expressing colon cancer cells. Relative cytotoxicity was assessed in combination treatment compared with exposure to single agents. Assays of apoptosis (annexin V) were performed in the presence of cyclopamine, chemotherapeutic agents, and IR.
We report that cyclopamine increased the cytotoxic effects of paclitaxel and IR in Hh expressing pancreatic carcinoma cells. These effects were not observed in Hh non-expressing cells. Cyclopamine did not significantly increase killing by cisplatin or gemcitabine in Hh expressing pancreatic cancer cells.
CONCLUSIONS:
These data suggest strategies to combine Hh inhibitors with radiotherapy and chemotherapeutic agents, specifically paclitaxel and related compounds in the treatment of pancreatic cancer. |
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