Limits...
The polycomb group protein EZH2 is a novel therapeutic target in tongue cancer.

Li Z, Wang Y, Qiu J, Li Q, Yuan C, Zhang W, Wang D, Ye J, Jiang H, Yang J, Cheng J - Oncotarget (2013)

Bottom Line: We found that aberrantly overexpressed EZH2 was associated with pathological grade, cervical nodes metastasis and Ki-67 expression in tongue cancers.Both genetic and pharmacological depletion of EZH2 inhibited cell proliferation, migration, invasion and colony formation and decreased CD44+ subpopulation probably in part through modulating p16, p21 and E-caherin.Moreover, DZNep enhanced the anticancer effects of 5-Fluorouracil.

View Article: PubMed Central - PubMed

Affiliation: Head Neck Cancer Center, Institute of Stomatology, Affiliated Stomatological Hospital, Nanjing Medical University, Jiangsu, China PRC.

ABSTRACT
EZH2, a core member of the Polycomb Repressor Complex 2 (PRC2), mediates transcriptional silencing by catalyzing the trimethylation of histone 3 lysine 27 (H3K27), which plays key roles in cancer initiation and progression. Here, we investigated the expression pattern and biological roles of EZH2 in tongue tumorigenesis by loss-of-function assays using small interference RNA and EZH2 inhibitor DZNep. Also we determined the therapeutic efficiency of DZNep against tongue cancer in vivo. We found that aberrantly overexpressed EZH2 was associated with pathological grade, cervical nodes metastasis and Ki-67 expression in tongue cancers. Elevated EZH2 correlated with shorter overall survival and showed significant and independent prognostic importance in patients with tongue cancer. Both genetic and pharmacological depletion of EZH2 inhibited cell proliferation, migration, invasion and colony formation and decreased CD44+ subpopulation probably in part through modulating p16, p21 and E-caherin. Moreover, DZNep enhanced the anticancer effects of 5-Fluorouracil. Furthermore, intratumoral EZH2 inhibition induced by DZNep intraperitoneal administration significantly attenuated tumor growth in a tongue cancer xenograft model. Taken together, our results indicate that EZH2 serves as a key driver with multiple oncogenic functions during tongue tumorigenesis and a new biomarker for tongue cancer diagnosis and prognostic prediction. These findings open up possibilities for therapeutic intervention against EZH2 in tongue cancer.

Show MeSH

Related in: MedlinePlus

DZNep inhibits tumor growth by inducing intratumoral EZH2 reduction in the TSCC xenograft mouse modelA: Time schedule for establishing the TSCC xenograft mouse model and subsequent DZNep administration (2mg/kg body weight, once every 3 days). B: Tumor xenograft samples in mice bearing Cal27 and Tca8113 cells followed by DZNep intraperitoneal injection or vehicle injection. Representative images of mouse in each group are shown (n=6 each group). C: Tumor weights (when sacrificed) and tumor volumes were compared between the mice which received DZNep or vehicle (n=6 each group). D: HE staining, Ki-67 and active caspase-3 immunohistochemical staining in tissue samples derived from mice inoculated with Cal27. E: EZH2 protein and its associated targets were determined by western blotting in samples from mice bearing Cal27 tumors. Data showed here are mean ± SD from three independent experiments, **p<0.01, Student's t-test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3926847&req=5

Figure 7: DZNep inhibits tumor growth by inducing intratumoral EZH2 reduction in the TSCC xenograft mouse modelA: Time schedule for establishing the TSCC xenograft mouse model and subsequent DZNep administration (2mg/kg body weight, once every 3 days). B: Tumor xenograft samples in mice bearing Cal27 and Tca8113 cells followed by DZNep intraperitoneal injection or vehicle injection. Representative images of mouse in each group are shown (n=6 each group). C: Tumor weights (when sacrificed) and tumor volumes were compared between the mice which received DZNep or vehicle (n=6 each group). D: HE staining, Ki-67 and active caspase-3 immunohistochemical staining in tissue samples derived from mice inoculated with Cal27. E: EZH2 protein and its associated targets were determined by western blotting in samples from mice bearing Cal27 tumors. Data showed here are mean ± SD from three independent experiments, **p<0.01, Student's t-test.

Mentions: To further testify the therapeutic efficiency of DZNep in vivo, a tongue cancer xenograft model was developed and utilized as described in Fig.7A. After subcutaneous inoculation of Cal27 and Tca8113 three weeks later, tumor masses were readily established and then mice were randomly grouped for drug treatment. These mice were administered DZNep or vehicle by intraperitoneal injection once every three days. Following the first drug injection, tumor masses volumes were monitored and calculated. As shown in Fig.7C, although the tumor growth did not display completely inhibition or recession in mice receiving DZNep, the mean tumor volumes were much smaller in mice treated with DZNep as compared with the mice treated with vehicle only at multiple time points. The final weight of tumor masses were also significantly less in DZNep-treated mice than that in vehicle-treated mice (Fig.7C). During the whole animal experiment, DZNep were well tolerated by mice without obvious abnormalities of behavior, feeding and weight loss during the experiment. We next examined the expression levels of Ki-67 and cleave caspase-3 as makers of cell proliferation and apoptosis by immunohistochemistry in the tumor samples. The immunohistochemical staining showed that in comparison to the control mice, the percentage of Ki-67 positive cancer cells was strongly reduced, whereas the percentage of cleaved caspase-3 positive cells was significantly increased in mice administered DZNep (Fig.7D). To establish the existence of DZNep-induced EZH2 inhibition in vivo, EZH2, H3K27me3 and other potential downstream effectors of interest were further examined in the tumor samples. As indicated in Fig.7E, intratumoral EZH2 and associated H3K27me3 were significantly inhibited after DZNep administration, while several downstream effectors which were normally epigenetically silenced displayed increase with various degrees. Taken together, our findings indicate that intraperitoneally-administrated DZNep effectively exerted its in vivo therapeutic functions probably by inhibition of EZH2 and derepression of EZH2-mediated epigenetic silencing.


The polycomb group protein EZH2 is a novel therapeutic target in tongue cancer.

Li Z, Wang Y, Qiu J, Li Q, Yuan C, Zhang W, Wang D, Ye J, Jiang H, Yang J, Cheng J - Oncotarget (2013)

DZNep inhibits tumor growth by inducing intratumoral EZH2 reduction in the TSCC xenograft mouse modelA: Time schedule for establishing the TSCC xenograft mouse model and subsequent DZNep administration (2mg/kg body weight, once every 3 days). B: Tumor xenograft samples in mice bearing Cal27 and Tca8113 cells followed by DZNep intraperitoneal injection or vehicle injection. Representative images of mouse in each group are shown (n=6 each group). C: Tumor weights (when sacrificed) and tumor volumes were compared between the mice which received DZNep or vehicle (n=6 each group). D: HE staining, Ki-67 and active caspase-3 immunohistochemical staining in tissue samples derived from mice inoculated with Cal27. E: EZH2 protein and its associated targets were determined by western blotting in samples from mice bearing Cal27 tumors. Data showed here are mean ± SD from three independent experiments, **p<0.01, Student's t-test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3926847&req=5

Figure 7: DZNep inhibits tumor growth by inducing intratumoral EZH2 reduction in the TSCC xenograft mouse modelA: Time schedule for establishing the TSCC xenograft mouse model and subsequent DZNep administration (2mg/kg body weight, once every 3 days). B: Tumor xenograft samples in mice bearing Cal27 and Tca8113 cells followed by DZNep intraperitoneal injection or vehicle injection. Representative images of mouse in each group are shown (n=6 each group). C: Tumor weights (when sacrificed) and tumor volumes were compared between the mice which received DZNep or vehicle (n=6 each group). D: HE staining, Ki-67 and active caspase-3 immunohistochemical staining in tissue samples derived from mice inoculated with Cal27. E: EZH2 protein and its associated targets were determined by western blotting in samples from mice bearing Cal27 tumors. Data showed here are mean ± SD from three independent experiments, **p<0.01, Student's t-test.
Mentions: To further testify the therapeutic efficiency of DZNep in vivo, a tongue cancer xenograft model was developed and utilized as described in Fig.7A. After subcutaneous inoculation of Cal27 and Tca8113 three weeks later, tumor masses were readily established and then mice were randomly grouped for drug treatment. These mice were administered DZNep or vehicle by intraperitoneal injection once every three days. Following the first drug injection, tumor masses volumes were monitored and calculated. As shown in Fig.7C, although the tumor growth did not display completely inhibition or recession in mice receiving DZNep, the mean tumor volumes were much smaller in mice treated with DZNep as compared with the mice treated with vehicle only at multiple time points. The final weight of tumor masses were also significantly less in DZNep-treated mice than that in vehicle-treated mice (Fig.7C). During the whole animal experiment, DZNep were well tolerated by mice without obvious abnormalities of behavior, feeding and weight loss during the experiment. We next examined the expression levels of Ki-67 and cleave caspase-3 as makers of cell proliferation and apoptosis by immunohistochemistry in the tumor samples. The immunohistochemical staining showed that in comparison to the control mice, the percentage of Ki-67 positive cancer cells was strongly reduced, whereas the percentage of cleaved caspase-3 positive cells was significantly increased in mice administered DZNep (Fig.7D). To establish the existence of DZNep-induced EZH2 inhibition in vivo, EZH2, H3K27me3 and other potential downstream effectors of interest were further examined in the tumor samples. As indicated in Fig.7E, intratumoral EZH2 and associated H3K27me3 were significantly inhibited after DZNep administration, while several downstream effectors which were normally epigenetically silenced displayed increase with various degrees. Taken together, our findings indicate that intraperitoneally-administrated DZNep effectively exerted its in vivo therapeutic functions probably by inhibition of EZH2 and derepression of EZH2-mediated epigenetic silencing.

Bottom Line: We found that aberrantly overexpressed EZH2 was associated with pathological grade, cervical nodes metastasis and Ki-67 expression in tongue cancers.Both genetic and pharmacological depletion of EZH2 inhibited cell proliferation, migration, invasion and colony formation and decreased CD44+ subpopulation probably in part through modulating p16, p21 and E-caherin.Moreover, DZNep enhanced the anticancer effects of 5-Fluorouracil.

View Article: PubMed Central - PubMed

Affiliation: Head Neck Cancer Center, Institute of Stomatology, Affiliated Stomatological Hospital, Nanjing Medical University, Jiangsu, China PRC.

ABSTRACT
EZH2, a core member of the Polycomb Repressor Complex 2 (PRC2), mediates transcriptional silencing by catalyzing the trimethylation of histone 3 lysine 27 (H3K27), which plays key roles in cancer initiation and progression. Here, we investigated the expression pattern and biological roles of EZH2 in tongue tumorigenesis by loss-of-function assays using small interference RNA and EZH2 inhibitor DZNep. Also we determined the therapeutic efficiency of DZNep against tongue cancer in vivo. We found that aberrantly overexpressed EZH2 was associated with pathological grade, cervical nodes metastasis and Ki-67 expression in tongue cancers. Elevated EZH2 correlated with shorter overall survival and showed significant and independent prognostic importance in patients with tongue cancer. Both genetic and pharmacological depletion of EZH2 inhibited cell proliferation, migration, invasion and colony formation and decreased CD44+ subpopulation probably in part through modulating p16, p21 and E-caherin. Moreover, DZNep enhanced the anticancer effects of 5-Fluorouracil. Furthermore, intratumoral EZH2 inhibition induced by DZNep intraperitoneal administration significantly attenuated tumor growth in a tongue cancer xenograft model. Taken together, our results indicate that EZH2 serves as a key driver with multiple oncogenic functions during tongue tumorigenesis and a new biomarker for tongue cancer diagnosis and prognostic prediction. These findings open up possibilities for therapeutic intervention against EZH2 in tongue cancer.

Show MeSH
Related in: MedlinePlus