Limits...
Dietary compound isoliquiritigenin prevents mammary carcinogenesis by inhibiting breast cancer stem cells through WIF1 demethylation.

Wang N, Wang Z, Wang Y, Xie X, Shen J, Peng C, You J, Peng F, Tang H, Guan X, Chen J - Oncotarget (2015)

Bottom Line: In addition, WIF1 inhibition significantly relieved the CSC-limiting effects of ISL and methylation analysis further revealed that ISL enhanced WIF1 gene expression via promoting the demethylation of its promoter, which was closely correlated with the inhibition of DNMT1 methyltransferase.Molecular docking analysis finally revealed that ISL could stably dock into the catalytic domain of DNMT1.Taken together, our findings not only provide preclinical evidence to demonstrate the use of ISL as a dietary supplement to inhibit mammary carcinogenesis but also shed novel light on WIF1 as an epigenetic target for breast cancer prevention.

View Article: PubMed Central - PubMed

Affiliation: School of Chinese Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong.

ABSTRACT
Breast cancer stem cells (CSCs) are considered as the root of mammary tumorigenesis. Previous studies have demonstrated that ISL efficiently limited the activities of breast CSCs. However, the cancer prevention activities of ISL and its precise molecular mechanisms remain largely unknown. Here, we report a novel function of ISL as a natural demethylation agent targeting WIF1 to prevent breast cancer. ISL administration suppressed in vivo breast cancer initiation and progression, accompanied by reduced CSC-like populations. A global gene expression profile assay further identified WIF1 as the main response gene of ISL treatment, accompanied by the simultaneous downregulation of β-catenin signaling and G0/G1 phase arrest in breast CSCs. In addition, WIF1 inhibition significantly relieved the CSC-limiting effects of ISL and methylation analysis further revealed that ISL enhanced WIF1 gene expression via promoting the demethylation of its promoter, which was closely correlated with the inhibition of DNMT1 methyltransferase. Molecular docking analysis finally revealed that ISL could stably dock into the catalytic domain of DNMT1. Taken together, our findings not only provide preclinical evidence to demonstrate the use of ISL as a dietary supplement to inhibit mammary carcinogenesis but also shed novel light on WIF1 as an epigenetic target for breast cancer prevention.

No MeSH data available.


Related in: MedlinePlus

Identification of WIF1 as the main target of ISL by microarray profilingA. Representative SP analysis using primary mouse mammary cells freshly harvested from the spontaneous mammary tumors of vehicle or ISL-treated MMTV-PyMT mice. The SP (the framed area) was shown as a percentage of the viable cell population and analyzed by FlowJo software; B. The ALDEFLUOR assay was then used to determine the population of CSCs in the spontaneous mammary tumors of vehicle or ISL-treated MMTV-PyMT mice. An ALDH-specific inhibitor DEAB was used as a negative control for minimizing background fluorescence. ALDHhi cells were shown as cells residing in the framed area analyzed by FlowJo software; C. Affymetrix Mouse Gene 2.0 ST GeneChip was utilized to reveal the gene expression changes after ISL treatment in MMTV-PyMT mice. Through GeneSpring12.6 analysis, 132 genes were upregulated, whereas 117 genes were downregulated; D. 14 genes including Smad7, Bmp2, Klf4, Abca12, Abca9, Ca4, Fzd4, Nkd1, Nkd2, Ptch2, Shh, Axin2, WIF1 and Dkk1 were identified as CSC-related genes affected by ISL. Real-time PCR analysis was then applied to validate their expression changes and WIF1 was finally determined as the main response gene of ISL.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4496402&req=5

Figure 3: Identification of WIF1 as the main target of ISL by microarray profilingA. Representative SP analysis using primary mouse mammary cells freshly harvested from the spontaneous mammary tumors of vehicle or ISL-treated MMTV-PyMT mice. The SP (the framed area) was shown as a percentage of the viable cell population and analyzed by FlowJo software; B. The ALDEFLUOR assay was then used to determine the population of CSCs in the spontaneous mammary tumors of vehicle or ISL-treated MMTV-PyMT mice. An ALDH-specific inhibitor DEAB was used as a negative control for minimizing background fluorescence. ALDHhi cells were shown as cells residing in the framed area analyzed by FlowJo software; C. Affymetrix Mouse Gene 2.0 ST GeneChip was utilized to reveal the gene expression changes after ISL treatment in MMTV-PyMT mice. Through GeneSpring12.6 analysis, 132 genes were upregulated, whereas 117 genes were downregulated; D. 14 genes including Smad7, Bmp2, Klf4, Abca12, Abca9, Ca4, Fzd4, Nkd1, Nkd2, Ptch2, Shh, Axin2, WIF1 and Dkk1 were identified as CSC-related genes affected by ISL. Real-time PCR analysis was then applied to validate their expression changes and WIF1 was finally determined as the main response gene of ISL.

Mentions: Accumulating evidence has suggested that cancer is a stem cell disorder. These rare CSCs are possibly the ultimate roots of tumorigenesis, tumor recurrence and metastasis [33]. To investigate the effects of ISL on the origination of breast CSCs, we harvested primary cells from the spontaneous mammary tumors of MMTV-PyMT mice for flow cytometry analysis. Two independent markers for breast CSCs were applied. First, a Hoechst 33342-based “side population” (SP) assay was utilized for detecting the effects of ISL on the CSC population. ISL treatment reduced the cancer stem-like cell proportion from 15.7 ± 1.23 to 2.36 ± 0.24 (Figure 3A). Aldehyde dehydrogenase (ALDH) was then applied as another marker for detection of stem-like cells and a specific inhibitor diethylaminobenzaldehude (DEAB) against ALDH was used as a negative control to minimize the influence of background fluorescence [34]. Compared with the DEAB negative control, tumors from untreated mice consisted of approximately 2% ALDHhi cells, while ISL administration dramatically decreased ALDHhi cells to 0.4% (Figure 3B). Both results indicated that ISL might prevent breast cancer occurrence and development via limiting breast CSCs.


Dietary compound isoliquiritigenin prevents mammary carcinogenesis by inhibiting breast cancer stem cells through WIF1 demethylation.

Wang N, Wang Z, Wang Y, Xie X, Shen J, Peng C, You J, Peng F, Tang H, Guan X, Chen J - Oncotarget (2015)

Identification of WIF1 as the main target of ISL by microarray profilingA. Representative SP analysis using primary mouse mammary cells freshly harvested from the spontaneous mammary tumors of vehicle or ISL-treated MMTV-PyMT mice. The SP (the framed area) was shown as a percentage of the viable cell population and analyzed by FlowJo software; B. The ALDEFLUOR assay was then used to determine the population of CSCs in the spontaneous mammary tumors of vehicle or ISL-treated MMTV-PyMT mice. An ALDH-specific inhibitor DEAB was used as a negative control for minimizing background fluorescence. ALDHhi cells were shown as cells residing in the framed area analyzed by FlowJo software; C. Affymetrix Mouse Gene 2.0 ST GeneChip was utilized to reveal the gene expression changes after ISL treatment in MMTV-PyMT mice. Through GeneSpring12.6 analysis, 132 genes were upregulated, whereas 117 genes were downregulated; D. 14 genes including Smad7, Bmp2, Klf4, Abca12, Abca9, Ca4, Fzd4, Nkd1, Nkd2, Ptch2, Shh, Axin2, WIF1 and Dkk1 were identified as CSC-related genes affected by ISL. Real-time PCR analysis was then applied to validate their expression changes and WIF1 was finally determined as the main response gene of ISL.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496402&req=5

Figure 3: Identification of WIF1 as the main target of ISL by microarray profilingA. Representative SP analysis using primary mouse mammary cells freshly harvested from the spontaneous mammary tumors of vehicle or ISL-treated MMTV-PyMT mice. The SP (the framed area) was shown as a percentage of the viable cell population and analyzed by FlowJo software; B. The ALDEFLUOR assay was then used to determine the population of CSCs in the spontaneous mammary tumors of vehicle or ISL-treated MMTV-PyMT mice. An ALDH-specific inhibitor DEAB was used as a negative control for minimizing background fluorescence. ALDHhi cells were shown as cells residing in the framed area analyzed by FlowJo software; C. Affymetrix Mouse Gene 2.0 ST GeneChip was utilized to reveal the gene expression changes after ISL treatment in MMTV-PyMT mice. Through GeneSpring12.6 analysis, 132 genes were upregulated, whereas 117 genes were downregulated; D. 14 genes including Smad7, Bmp2, Klf4, Abca12, Abca9, Ca4, Fzd4, Nkd1, Nkd2, Ptch2, Shh, Axin2, WIF1 and Dkk1 were identified as CSC-related genes affected by ISL. Real-time PCR analysis was then applied to validate their expression changes and WIF1 was finally determined as the main response gene of ISL.
Mentions: Accumulating evidence has suggested that cancer is a stem cell disorder. These rare CSCs are possibly the ultimate roots of tumorigenesis, tumor recurrence and metastasis [33]. To investigate the effects of ISL on the origination of breast CSCs, we harvested primary cells from the spontaneous mammary tumors of MMTV-PyMT mice for flow cytometry analysis. Two independent markers for breast CSCs were applied. First, a Hoechst 33342-based “side population” (SP) assay was utilized for detecting the effects of ISL on the CSC population. ISL treatment reduced the cancer stem-like cell proportion from 15.7 ± 1.23 to 2.36 ± 0.24 (Figure 3A). Aldehyde dehydrogenase (ALDH) was then applied as another marker for detection of stem-like cells and a specific inhibitor diethylaminobenzaldehude (DEAB) against ALDH was used as a negative control to minimize the influence of background fluorescence [34]. Compared with the DEAB negative control, tumors from untreated mice consisted of approximately 2% ALDHhi cells, while ISL administration dramatically decreased ALDHhi cells to 0.4% (Figure 3B). Both results indicated that ISL might prevent breast cancer occurrence and development via limiting breast CSCs.

Bottom Line: In addition, WIF1 inhibition significantly relieved the CSC-limiting effects of ISL and methylation analysis further revealed that ISL enhanced WIF1 gene expression via promoting the demethylation of its promoter, which was closely correlated with the inhibition of DNMT1 methyltransferase.Molecular docking analysis finally revealed that ISL could stably dock into the catalytic domain of DNMT1.Taken together, our findings not only provide preclinical evidence to demonstrate the use of ISL as a dietary supplement to inhibit mammary carcinogenesis but also shed novel light on WIF1 as an epigenetic target for breast cancer prevention.

View Article: PubMed Central - PubMed

Affiliation: School of Chinese Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong.

ABSTRACT
Breast cancer stem cells (CSCs) are considered as the root of mammary tumorigenesis. Previous studies have demonstrated that ISL efficiently limited the activities of breast CSCs. However, the cancer prevention activities of ISL and its precise molecular mechanisms remain largely unknown. Here, we report a novel function of ISL as a natural demethylation agent targeting WIF1 to prevent breast cancer. ISL administration suppressed in vivo breast cancer initiation and progression, accompanied by reduced CSC-like populations. A global gene expression profile assay further identified WIF1 as the main response gene of ISL treatment, accompanied by the simultaneous downregulation of β-catenin signaling and G0/G1 phase arrest in breast CSCs. In addition, WIF1 inhibition significantly relieved the CSC-limiting effects of ISL and methylation analysis further revealed that ISL enhanced WIF1 gene expression via promoting the demethylation of its promoter, which was closely correlated with the inhibition of DNMT1 methyltransferase. Molecular docking analysis finally revealed that ISL could stably dock into the catalytic domain of DNMT1. Taken together, our findings not only provide preclinical evidence to demonstrate the use of ISL as a dietary supplement to inhibit mammary carcinogenesis but also shed novel light on WIF1 as an epigenetic target for breast cancer prevention.

No MeSH data available.


Related in: MedlinePlus