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Hiwi Promotes the Proliferation of Colorectal Cancer Cells via Upregulating Global DNA Methylation.

Yang L, Bi L, Liu Q, Zhao M, Cao B, Li D, Xiu J - Dis. Markers (2015)

Bottom Line: And the chemical inhibition of DNA methylation significantly restrained such proliferation promotion.In summary, we confirmed that Hiwi was overexpressed in CRC tissues and that the forced Hiwi overexpression promoted the proliferation and global DNA methylation of CRC cell lines.Our results imply for the first time that Hiwi promotes the proliferation of CRC cells via promoting global DNA methylation.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China.

ABSTRACT
Hiwi is well known for its role in stem cell renewal, maintaining the resting stage, and downregulating cell cycle of stem cells via RNA silencing. And Hiwi overexpression has been recognized in several types of cancers. In the present study, we examined the Hiwi expression in colorectal cancer (CRC) specimens in both mRNA and protein levels via real-time quantitative PCR, western blot assay, and immunohistochemical staining. Then we explored the role of Hiwi in the cancer cell proliferation and in the DNA methylation in human CRC Caro-2 and HT-29 cell lines. Results demonstrated that both mRNA and protein levels of Hiwi were significantly higher in 38 CRC tissues than in 38 peritumor tissues. Moreover, the Hiwi overexpression with an adenovirus vector significantly promoted the proliferation of Caro-2 and HT-29 cells, associated with significant increase in the global DNA methylation levels. And the chemical inhibition of DNA methylation significantly restrained such proliferation promotion. In summary, we confirmed that Hiwi was overexpressed in CRC tissues and that the forced Hiwi overexpression promoted the proliferation and global DNA methylation of CRC cell lines. Our results imply for the first time that Hiwi promotes the proliferation of CRC cells via promoting global DNA methylation.

No MeSH data available.


Related in: MedlinePlus

Overexpression of Hiwi protein in CRC specimens. (a) and (b): immunohistochemical staining for Hiwi expression in CRC tissues (n = 38) and peritumor specimens (n = 38); (c): relative mRNA level of Hiwi in the CRC specimens or the colorectal noncancer specimens by quantitative real-time RT-PCR; (d): Hiwi overexpression at protein level in the CRC or noncolon specimens, revealed by the western blot analysis; (e): percentage of Hiwi to GAPDH in protein level. The p value was indicated accordingly.
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fig1: Overexpression of Hiwi protein in CRC specimens. (a) and (b): immunohistochemical staining for Hiwi expression in CRC tissues (n = 38) and peritumor specimens (n = 38); (c): relative mRNA level of Hiwi in the CRC specimens or the colorectal noncancer specimens by quantitative real-time RT-PCR; (d): Hiwi overexpression at protein level in the CRC or noncolon specimens, revealed by the western blot analysis; (e): percentage of Hiwi to GAPDH in protein level. The p value was indicated accordingly.

Mentions: The expression of Hiwi was firstly evaluated by immunohistochemical staining in 15 CRC specimens and 15 peritumor colorectal specimens. The representative staining for Hiwi in CRC specimens (Figure 1(a)) and peritumor specimens (Figure 1(b)) was indicated. The average staining score for CRC specimens was 2.50 ± 0.67, whereas it was 1.33 ± 0.50 for peritumor specimens (p < 0.05). Then all 38 CRC specimens and 38 colorectal peritumor colorectal specimens were examined for Hiwi expression in both mRNA and protein levels by quantitative real-time RT-PCR and western blot analysis. There was a significantly high level of Hiwi mRNA expression in the CRC specimens, compared to the expression in noncancer colorectal specimens (Figure 1(c), 2.009 ± 0.198 versus 1.005 ± 0.07768, p < 0.001, paired-samples t-test). Then the Hiwi protein level in cells was analyzed by western blot analysis, as shown in Figures 1(d) and 1(e), and the difference at Hiwi protein level was also significant between CRC specimens and noncancer specimens (Figure 1(e), p = 0.016). These findings indicated that Hiwi expression is closely associated with the CRC.


Hiwi Promotes the Proliferation of Colorectal Cancer Cells via Upregulating Global DNA Methylation.

Yang L, Bi L, Liu Q, Zhao M, Cao B, Li D, Xiu J - Dis. Markers (2015)

Overexpression of Hiwi protein in CRC specimens. (a) and (b): immunohistochemical staining for Hiwi expression in CRC tissues (n = 38) and peritumor specimens (n = 38); (c): relative mRNA level of Hiwi in the CRC specimens or the colorectal noncancer specimens by quantitative real-time RT-PCR; (d): Hiwi overexpression at protein level in the CRC or noncolon specimens, revealed by the western blot analysis; (e): percentage of Hiwi to GAPDH in protein level. The p value was indicated accordingly.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4556077&req=5

fig1: Overexpression of Hiwi protein in CRC specimens. (a) and (b): immunohistochemical staining for Hiwi expression in CRC tissues (n = 38) and peritumor specimens (n = 38); (c): relative mRNA level of Hiwi in the CRC specimens or the colorectal noncancer specimens by quantitative real-time RT-PCR; (d): Hiwi overexpression at protein level in the CRC or noncolon specimens, revealed by the western blot analysis; (e): percentage of Hiwi to GAPDH in protein level. The p value was indicated accordingly.
Mentions: The expression of Hiwi was firstly evaluated by immunohistochemical staining in 15 CRC specimens and 15 peritumor colorectal specimens. The representative staining for Hiwi in CRC specimens (Figure 1(a)) and peritumor specimens (Figure 1(b)) was indicated. The average staining score for CRC specimens was 2.50 ± 0.67, whereas it was 1.33 ± 0.50 for peritumor specimens (p < 0.05). Then all 38 CRC specimens and 38 colorectal peritumor colorectal specimens were examined for Hiwi expression in both mRNA and protein levels by quantitative real-time RT-PCR and western blot analysis. There was a significantly high level of Hiwi mRNA expression in the CRC specimens, compared to the expression in noncancer colorectal specimens (Figure 1(c), 2.009 ± 0.198 versus 1.005 ± 0.07768, p < 0.001, paired-samples t-test). Then the Hiwi protein level in cells was analyzed by western blot analysis, as shown in Figures 1(d) and 1(e), and the difference at Hiwi protein level was also significant between CRC specimens and noncancer specimens (Figure 1(e), p = 0.016). These findings indicated that Hiwi expression is closely associated with the CRC.

Bottom Line: And the chemical inhibition of DNA methylation significantly restrained such proliferation promotion.In summary, we confirmed that Hiwi was overexpressed in CRC tissues and that the forced Hiwi overexpression promoted the proliferation and global DNA methylation of CRC cell lines.Our results imply for the first time that Hiwi promotes the proliferation of CRC cells via promoting global DNA methylation.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China.

ABSTRACT
Hiwi is well known for its role in stem cell renewal, maintaining the resting stage, and downregulating cell cycle of stem cells via RNA silencing. And Hiwi overexpression has been recognized in several types of cancers. In the present study, we examined the Hiwi expression in colorectal cancer (CRC) specimens in both mRNA and protein levels via real-time quantitative PCR, western blot assay, and immunohistochemical staining. Then we explored the role of Hiwi in the cancer cell proliferation and in the DNA methylation in human CRC Caro-2 and HT-29 cell lines. Results demonstrated that both mRNA and protein levels of Hiwi were significantly higher in 38 CRC tissues than in 38 peritumor tissues. Moreover, the Hiwi overexpression with an adenovirus vector significantly promoted the proliferation of Caro-2 and HT-29 cells, associated with significant increase in the global DNA methylation levels. And the chemical inhibition of DNA methylation significantly restrained such proliferation promotion. In summary, we confirmed that Hiwi was overexpressed in CRC tissues and that the forced Hiwi overexpression promoted the proliferation and global DNA methylation of CRC cell lines. Our results imply for the first time that Hiwi promotes the proliferation of CRC cells via promoting global DNA methylation.

No MeSH data available.


Related in: MedlinePlus