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Vitamin D3 enhances the tumouricidal effects of 5-Fluorouracil through multipathway mechanisms in azoxymethane rat model of colon cancer.

Refaat B, El-Shemi AG, Kensara OA, Mohamed AM, Idris S, Ahmad J, Khojah A - J. Exp. Clin. Cancer Res. (2015)

Bottom Line: Monotherapy with 5-FU or vitamin D3 significantly decreased the number of grown tumours induced by AOM (P < 0.05); however, their combination resulted in more significant tumouricidal effects (P < 0.05) compared with monotherapy groups.Mechanistically, vitamin D3/5-FU co-therapy significantly decreased the expression of Wnt, β-catenin, iNOS, COX-2 and HSP-90 and significantly increased the expression of DKK-1, TGF-β1, TGF-βR2, smad4 (P < 0.05), in comparison with their corresponding monotherapy groups.Vitamin D3 and 5-FU synergise together and exhibit better anticancer effects by modulating Wnt/β-catenin pathway, TGF-β1 signals, iNOS, COX-2 and HSP-90.

View Article: PubMed Central - PubMed

Affiliation: Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Al-Abdeyah, PO Box 7607, Makkah, Kingdom of Saudi Arabia. bassem.refaat@yahoo.co.uk.

ABSTRACT

Background: Vitamin D3 and its analogues have recently been shown to enhance the anti-tumour effects of 5- Fluorouracil (5-FU) both in vitro and in xenograft mouse model of colon cancer. This study measured the potential mechanism(s) by which vitamin D3 could synergise the tumouricidal activities of 5-FU in azoxymethane (AOM) rat model of colon cancer.

Methods: Seventy-five male Wistar rats were divided equally into 5 groups: Control, AOM, AOM-treated by 5-FU (5-FU), AOM-treated by vitamin D3 (VitD3), and AOM-treated by 5-FU + vitamin D3 (5-FU/D). The study duration was 15 weeks. AOM was injected subcutaneously for 2 weeks (15 mg/kg/week). 5-FU was injected intraperitoneally in the 9th and 10th weeks post AOM (8 total injections were given: 12 mg/kg/day for 4 successive days, then 6 mg/kg every other day for another 4 doses) and oral vitamin D3 (500 IU/rat/day; 3 days/week) was given from week 7 post AOM till the last week of the study. The colons were collected following euthanasia for gross and histopathological examination. The expression of β-catenin, transforming growth factor-β1 (TGF-β1), TGF-β type 2 receptor (TGF-βR2), smad4, inducible nitric oxide synthase (iNOS), and heat shock protein-90 (HSP-90) proteins was measured by immunohistochemistry. In colonic tissue homogenates, quantitative RT-PCR was used to measure the mRNA expression of Wnt, β-catenin, Dickkopf-1 (DKK-1) and cyclooxygenase-2 (COX-2) genes, while ELISA was used to measure the concentrations of TGF-β1, HSP-90 and COX-2 proteins.

Results: Monotherapy with 5-FU or vitamin D3 significantly decreased the number of grown tumours induced by AOM (P < 0.05); however, their combination resulted in more significant tumouricidal effects (P < 0.05) compared with monotherapy groups. Mechanistically, vitamin D3/5-FU co-therapy significantly decreased the expression of Wnt, β-catenin, iNOS, COX-2 and HSP-90 and significantly increased the expression of DKK-1, TGF-β1, TGF-βR2, smad4 (P < 0.05), in comparison with their corresponding monotherapy groups.

Conclusions: Vitamin D3 and 5-FU synergise together and exhibit better anticancer effects by modulating Wnt/β-catenin pathway, TGF-β1 signals, iNOS, COX-2 and HSP-90. Further studies are required to illustrate the clinical value of vitamin D supplementation during the treatment of colon cancer with 5-FU in human patients.

No MeSH data available.


Related in: MedlinePlus

Mean ± SD of tissue homogenate concentrations of (a) TGF-β1, (b) HSP-90 and (c) COX-2 in the different study groups. (a = P < 0.05 compared with control group; b = P < 0.05 compared with AOM group; c = P < 0.05 compared with 5-FU group and d = P < 0.05 compared with VitD group)
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Fig4: Mean ± SD of tissue homogenate concentrations of (a) TGF-β1, (b) HSP-90 and (c) COX-2 in the different study groups. (a = P < 0.05 compared with control group; b = P < 0.05 compared with AOM group; c = P < 0.05 compared with 5-FU group and d = P < 0.05 compared with VitD group)

Mentions: The concentrations of TGF-β1 protein in the colon tissue homogenates showed a significant decrease in the ‘AOM group’ (294.7 ± 61.4 pg/mL; P = 0.003) compared with ‘control group’ (529.6 ± 97.8 pg/mL). A significant increase in the protein concentrations was observed in the ‘5-FU’ (475.2 ± 96 pg/mL; P = 0.006 × 10−3), ‘VitD’ (505.6 ± 56.3 pg/mL; P = 0.03 × 10−4) and ‘5-FU/D’ (600.2 ± 48.7 pg/mL; P = 0.02 × 10−5) groups (Fig. 4).Fig 4


Vitamin D3 enhances the tumouricidal effects of 5-Fluorouracil through multipathway mechanisms in azoxymethane rat model of colon cancer.

Refaat B, El-Shemi AG, Kensara OA, Mohamed AM, Idris S, Ahmad J, Khojah A - J. Exp. Clin. Cancer Res. (2015)

Mean ± SD of tissue homogenate concentrations of (a) TGF-β1, (b) HSP-90 and (c) COX-2 in the different study groups. (a = P < 0.05 compared with control group; b = P < 0.05 compared with AOM group; c = P < 0.05 compared with 5-FU group and d = P < 0.05 compared with VitD group)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4513788&req=5

Fig4: Mean ± SD of tissue homogenate concentrations of (a) TGF-β1, (b) HSP-90 and (c) COX-2 in the different study groups. (a = P < 0.05 compared with control group; b = P < 0.05 compared with AOM group; c = P < 0.05 compared with 5-FU group and d = P < 0.05 compared with VitD group)
Mentions: The concentrations of TGF-β1 protein in the colon tissue homogenates showed a significant decrease in the ‘AOM group’ (294.7 ± 61.4 pg/mL; P = 0.003) compared with ‘control group’ (529.6 ± 97.8 pg/mL). A significant increase in the protein concentrations was observed in the ‘5-FU’ (475.2 ± 96 pg/mL; P = 0.006 × 10−3), ‘VitD’ (505.6 ± 56.3 pg/mL; P = 0.03 × 10−4) and ‘5-FU/D’ (600.2 ± 48.7 pg/mL; P = 0.02 × 10−5) groups (Fig. 4).Fig 4

Bottom Line: Monotherapy with 5-FU or vitamin D3 significantly decreased the number of grown tumours induced by AOM (P < 0.05); however, their combination resulted in more significant tumouricidal effects (P < 0.05) compared with monotherapy groups.Mechanistically, vitamin D3/5-FU co-therapy significantly decreased the expression of Wnt, β-catenin, iNOS, COX-2 and HSP-90 and significantly increased the expression of DKK-1, TGF-β1, TGF-βR2, smad4 (P < 0.05), in comparison with their corresponding monotherapy groups.Vitamin D3 and 5-FU synergise together and exhibit better anticancer effects by modulating Wnt/β-catenin pathway, TGF-β1 signals, iNOS, COX-2 and HSP-90.

View Article: PubMed Central - PubMed

Affiliation: Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Al-Abdeyah, PO Box 7607, Makkah, Kingdom of Saudi Arabia. bassem.refaat@yahoo.co.uk.

ABSTRACT

Background: Vitamin D3 and its analogues have recently been shown to enhance the anti-tumour effects of 5- Fluorouracil (5-FU) both in vitro and in xenograft mouse model of colon cancer. This study measured the potential mechanism(s) by which vitamin D3 could synergise the tumouricidal activities of 5-FU in azoxymethane (AOM) rat model of colon cancer.

Methods: Seventy-five male Wistar rats were divided equally into 5 groups: Control, AOM, AOM-treated by 5-FU (5-FU), AOM-treated by vitamin D3 (VitD3), and AOM-treated by 5-FU + vitamin D3 (5-FU/D). The study duration was 15 weeks. AOM was injected subcutaneously for 2 weeks (15 mg/kg/week). 5-FU was injected intraperitoneally in the 9th and 10th weeks post AOM (8 total injections were given: 12 mg/kg/day for 4 successive days, then 6 mg/kg every other day for another 4 doses) and oral vitamin D3 (500 IU/rat/day; 3 days/week) was given from week 7 post AOM till the last week of the study. The colons were collected following euthanasia for gross and histopathological examination. The expression of β-catenin, transforming growth factor-β1 (TGF-β1), TGF-β type 2 receptor (TGF-βR2), smad4, inducible nitric oxide synthase (iNOS), and heat shock protein-90 (HSP-90) proteins was measured by immunohistochemistry. In colonic tissue homogenates, quantitative RT-PCR was used to measure the mRNA expression of Wnt, β-catenin, Dickkopf-1 (DKK-1) and cyclooxygenase-2 (COX-2) genes, while ELISA was used to measure the concentrations of TGF-β1, HSP-90 and COX-2 proteins.

Results: Monotherapy with 5-FU or vitamin D3 significantly decreased the number of grown tumours induced by AOM (P < 0.05); however, their combination resulted in more significant tumouricidal effects (P < 0.05) compared with monotherapy groups. Mechanistically, vitamin D3/5-FU co-therapy significantly decreased the expression of Wnt, β-catenin, iNOS, COX-2 and HSP-90 and significantly increased the expression of DKK-1, TGF-β1, TGF-βR2, smad4 (P < 0.05), in comparison with their corresponding monotherapy groups.

Conclusions: Vitamin D3 and 5-FU synergise together and exhibit better anticancer effects by modulating Wnt/β-catenin pathway, TGF-β1 signals, iNOS, COX-2 and HSP-90. Further studies are required to illustrate the clinical value of vitamin D supplementation during the treatment of colon cancer with 5-FU in human patients.

No MeSH data available.


Related in: MedlinePlus