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Gli1 maintains cell survival by up-regulating IGFBP6 and Bcl-2 through promoter regions in parallel manner in pancreatic cancer cells.

Xu XF, Guo CY, Liu J, Yang WJ, Xia YJ, Xu L, Yu YC, Wang XP - J Carcinog (2009)

Bottom Line: Cyclopamine inhibited cell proliferation at low concentration and induced apoptosis at high concentration.Effect of RNA interference (RNAi) for Gli1 to cell survival is mainly due to proliferation inhibition though involved in apoptosis.The transcription factor Gli1 bound to promoter regions of Bcl-2 and IGFBP6 genes and the levels of IGFBP6, proliferating cell nuclear antigen (PCNA) and Bcl-2 messenger RNA (mRNA) were decreased as well as Gli1 mRNA significantly by cyclopamine or RNAi in cultured pancreatic cancer cells (p < 0.01).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Gastroenterology, The Tenth Hospital, Tongji University, Shanghai, China. wangxp1965@yahoo.com.cn.

ABSTRACT

Background: Aberrant activation of Hedgehog (Hh) signaling pathway has been reported to be related to malignant biological behavior of pancreatic cancer but its mechanism is unclear yet. Since IGF pathway and Bcl-2 family are involved in proliferation and apoptosis of pancreatic cancer cells, we hypothesize that they are possibly associated with Hh pathway.

Materials and methods: We studied the relationship of Shh-Gli1 signaling pathway with proliferation and apoptosis of pancreatic cancer cells and the regulation of transcription factor Gli1 to insulin-like growth factor binding protein 6 (IGFBP6) and Bcl-2 genes at the level of transcription.

Results: Sonic hedgehog (Shh), Smoothened (Smo), patched and Gli1 were expressed in pancreatic cancer cells. Cyclopamine inhibited cell proliferation at low concentration and induced apoptosis at high concentration. Effect of RNA interference (RNAi) for Gli1 to cell survival is mainly due to proliferation inhibition though involved in apoptosis. The transcription factor Gli1 bound to promoter regions of Bcl-2 and IGFBP6 genes and the levels of IGFBP6, proliferating cell nuclear antigen (PCNA) and Bcl-2 messenger RNA (mRNA) were decreased as well as Gli1 mRNA significantly by cyclopamine or RNAi in cultured pancreatic cancer cells (p < 0.01). Finally PCNA, IGFBP6 and Bcl-2 mRNA were upregulated as well as Shh or Gli1 in pancreatic cancer tissues (p < 0.01).

Conclusions: Our study reveals that Gli1 maintained cell survival by binding the promoter regions and facilitating transcription of IGFBP6 and Bcl-2 genes in a parallel manner in pancreatic cancer cells and suggests it may be one of the mechanisms of Shh-Gli1 signaling pathway in pancreatic cancer.

No MeSH data available.


Related in: MedlinePlus

Expression analysis of relative genes mRNA by using QRT-PCR assay as described in the Materials and Methods section. A: Regulation of mRNA levels of Shh, Gli1, IGFBP6, IGF2, PCNA, Bcl-2, Bax and Bak1 genes by cyclopamine; B: Regulation of mRNA levels by RNAi for Gli1
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Figure 0006: Expression analysis of relative genes mRNA by using QRT-PCR assay as described in the Materials and Methods section. A: Regulation of mRNA levels of Shh, Gli1, IGFBP6, IGF2, PCNA, Bcl-2, Bax and Bak1 genes by cyclopamine; B: Regulation of mRNA levels by RNAi for Gli1

Mentions: Pancreatic cancer cell lines BxPC-3, AsPC-1, Panc-1 and SW1990 were treated with cyclopamine at final concentrations of 15 μM or exposed to 100 nM duplexed siRNA oligonucleotides for 24 h. The results of qRT-PCR showed that regulation effects of 100 nM siRNA were similar to 15 μM cyclopamine roughly. The main difference is that the inhibition to Gli1 and Bcl-2 were weaker and to IFGBP6 were stronger than that of cyclopamine. The relative mRNA levels of Gli1 were decreased to 0.23–0.34 folds in cyclopamine group (p < 0.01) and to 0.39–0.42 folds in RNAi group compared with negative control (p < 0.05). At the same time, relative expressions of IGFBP6, PCNA and Bcl-2 mRNA were decreased significantly (p < 0.05) and the levels of Bax and Bak1 mRNA were increased (p < 0.05) and Shh and IGF2 were not influenced (p > 0.05) [Figure 6].


Gli1 maintains cell survival by up-regulating IGFBP6 and Bcl-2 through promoter regions in parallel manner in pancreatic cancer cells.

Xu XF, Guo CY, Liu J, Yang WJ, Xia YJ, Xu L, Yu YC, Wang XP - J Carcinog (2009)

Expression analysis of relative genes mRNA by using QRT-PCR assay as described in the Materials and Methods section. A: Regulation of mRNA levels of Shh, Gli1, IGFBP6, IGF2, PCNA, Bcl-2, Bax and Bak1 genes by cyclopamine; B: Regulation of mRNA levels by RNAi for Gli1
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2746911&req=5

Figure 0006: Expression analysis of relative genes mRNA by using QRT-PCR assay as described in the Materials and Methods section. A: Regulation of mRNA levels of Shh, Gli1, IGFBP6, IGF2, PCNA, Bcl-2, Bax and Bak1 genes by cyclopamine; B: Regulation of mRNA levels by RNAi for Gli1
Mentions: Pancreatic cancer cell lines BxPC-3, AsPC-1, Panc-1 and SW1990 were treated with cyclopamine at final concentrations of 15 μM or exposed to 100 nM duplexed siRNA oligonucleotides for 24 h. The results of qRT-PCR showed that regulation effects of 100 nM siRNA were similar to 15 μM cyclopamine roughly. The main difference is that the inhibition to Gli1 and Bcl-2 were weaker and to IFGBP6 were stronger than that of cyclopamine. The relative mRNA levels of Gli1 were decreased to 0.23–0.34 folds in cyclopamine group (p < 0.01) and to 0.39–0.42 folds in RNAi group compared with negative control (p < 0.05). At the same time, relative expressions of IGFBP6, PCNA and Bcl-2 mRNA were decreased significantly (p < 0.05) and the levels of Bax and Bak1 mRNA were increased (p < 0.05) and Shh and IGF2 were not influenced (p > 0.05) [Figure 6].

Bottom Line: Cyclopamine inhibited cell proliferation at low concentration and induced apoptosis at high concentration.Effect of RNA interference (RNAi) for Gli1 to cell survival is mainly due to proliferation inhibition though involved in apoptosis.The transcription factor Gli1 bound to promoter regions of Bcl-2 and IGFBP6 genes and the levels of IGFBP6, proliferating cell nuclear antigen (PCNA) and Bcl-2 messenger RNA (mRNA) were decreased as well as Gli1 mRNA significantly by cyclopamine or RNAi in cultured pancreatic cancer cells (p < 0.01).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Gastroenterology, The Tenth Hospital, Tongji University, Shanghai, China. wangxp1965@yahoo.com.cn.

ABSTRACT

Background: Aberrant activation of Hedgehog (Hh) signaling pathway has been reported to be related to malignant biological behavior of pancreatic cancer but its mechanism is unclear yet. Since IGF pathway and Bcl-2 family are involved in proliferation and apoptosis of pancreatic cancer cells, we hypothesize that they are possibly associated with Hh pathway.

Materials and methods: We studied the relationship of Shh-Gli1 signaling pathway with proliferation and apoptosis of pancreatic cancer cells and the regulation of transcription factor Gli1 to insulin-like growth factor binding protein 6 (IGFBP6) and Bcl-2 genes at the level of transcription.

Results: Sonic hedgehog (Shh), Smoothened (Smo), patched and Gli1 were expressed in pancreatic cancer cells. Cyclopamine inhibited cell proliferation at low concentration and induced apoptosis at high concentration. Effect of RNA interference (RNAi) for Gli1 to cell survival is mainly due to proliferation inhibition though involved in apoptosis. The transcription factor Gli1 bound to promoter regions of Bcl-2 and IGFBP6 genes and the levels of IGFBP6, proliferating cell nuclear antigen (PCNA) and Bcl-2 messenger RNA (mRNA) were decreased as well as Gli1 mRNA significantly by cyclopamine or RNAi in cultured pancreatic cancer cells (p < 0.01). Finally PCNA, IGFBP6 and Bcl-2 mRNA were upregulated as well as Shh or Gli1 in pancreatic cancer tissues (p < 0.01).

Conclusions: Our study reveals that Gli1 maintained cell survival by binding the promoter regions and facilitating transcription of IGFBP6 and Bcl-2 genes in a parallel manner in pancreatic cancer cells and suggests it may be one of the mechanisms of Shh-Gli1 signaling pathway in pancreatic cancer.

No MeSH data available.


Related in: MedlinePlus