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Ectopic expression of Zmiz1 induces cutaneous squamous cell malignancies in a mouse model of cancer.

Rogers LM, Riordan JD, Swick BL, Meyerholz DK, Dupuy AJ - J. Invest. Dermatol. (2013)

Bottom Line: Here we show that transposon-induced mutations in Zmiz1 drive expression of a truncated transcript that is similar to an alternative endogenous ZMIZ1 transcript found to be overexpressed in human SCCs relative to normal skin.In addition, we found that the alternative Zmiz1 isoform has greater protein stability than its full-length counterpart.Finally, we provide evidence that ZMIZ1 is overexpressed in a significant percentage of human breast, ovarian, and colon cancers in addition to human SCCs, suggesting that ZMIZ1 may play a broader role in epithelial cancers.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy and Cell Biology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.

ABSTRACT
Cutaneous squamous cell carcinoma (SCC) is the second most common form of cancer in the human population, yet the underlying genetic mechanisms contributing to the disease are not well understood. We recently identified Zmiz1 as a candidate oncogene in nonmelanoma skin cancer through a transposon mutagenesis screen. Here we show that transposon-induced mutations in Zmiz1 drive expression of a truncated transcript that is similar to an alternative endogenous ZMIZ1 transcript found to be overexpressed in human SCCs relative to normal skin. We also describe an original mouse model of invasive keratoacanthoma driven by skin-specific expression of the truncated Zmiz1 transcript. Unlike most mouse models, Zmiz1-induced skin tumors develop rapidly and in the absence of promoting agents such as phorbol esters. In addition, we found that the alternative Zmiz1 isoform has greater protein stability than its full-length counterpart. Finally, we provide evidence that ZMIZ1 is overexpressed in a significant percentage of human breast, ovarian, and colon cancers in addition to human SCCs, suggesting that ZMIZ1 may play a broader role in epithelial cancers.

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Zmiz1Δ1-185 transgenic mice develop skin tumors(a) Diagram of the Cre-inducible Zmiz1Δ1-185 transgene. (b) Western blot showing skin from Zmiz1Δ1-185 single transgenic mice has nearly undetectable expression of EGFP, whereas double transgenic mice display detectable EGFP expression. (c) Kaplan-Meier survival curve of mouse line 207 showing tumor-free survival of K14-CreTg/+; Zmiz1Δ1-185 Tg/+ double transgenic mice (circles, n=54), K14-Cre+/+; Zmiz1Δ1-185 Tg/+ single transgenic (squares, n=18), and K14-CreTg/+; Zmiz1Δ1-185 +/+ single transgenic mice (triangles, n=35). Double transgenic mice developed skin tumors with an average latency of 14 weeks after birth, while single transgenic controls did not develop skin tumors (log-rank, P<0.0001). (d) Western blot confirms overexpression of the Zmiz1Δ1-185 transgenic protein in mouse tumors. Endogenous Zmiz1 expression is undetectable in normal skin.
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Figure 2: Zmiz1Δ1-185 transgenic mice develop skin tumors(a) Diagram of the Cre-inducible Zmiz1Δ1-185 transgene. (b) Western blot showing skin from Zmiz1Δ1-185 single transgenic mice has nearly undetectable expression of EGFP, whereas double transgenic mice display detectable EGFP expression. (c) Kaplan-Meier survival curve of mouse line 207 showing tumor-free survival of K14-CreTg/+; Zmiz1Δ1-185 Tg/+ double transgenic mice (circles, n=54), K14-Cre+/+; Zmiz1Δ1-185 Tg/+ single transgenic (squares, n=18), and K14-CreTg/+; Zmiz1Δ1-185 +/+ single transgenic mice (triangles, n=35). Double transgenic mice developed skin tumors with an average latency of 14 weeks after birth, while single transgenic controls did not develop skin tumors (log-rank, P<0.0001). (d) Western blot confirms overexpression of the Zmiz1Δ1-185 transgenic protein in mouse tumors. Endogenous Zmiz1 expression is undetectable in normal skin.

Mentions: As previously mentioned, we predicted that transposon-induced expression of the Zmiz1Δ1-185 is oncogenic. To test this hypothesis, we engineered transgenic mice that conditionally express Zmiz1Δ1-185 (Figure 2a). A lox-stop-lox strategy was employed to prevent ubiquitous expression of Zmiz1Δ1-185. Cre-mediated recombination will delete the DsRed reporter embedded in the lox-stop-lox cassette and induce expression of the downstream Zmiz1Δ1-185-IRES-EGFP cassette. Two Zmiz1Δ1-185 founder animals showed detectable levels of the DsRed reporter in the skin and were used to establish transgenic lines 207-Zmiz1Δ1-185 and 163-Zmiz1Δ1-185.


Ectopic expression of Zmiz1 induces cutaneous squamous cell malignancies in a mouse model of cancer.

Rogers LM, Riordan JD, Swick BL, Meyerholz DK, Dupuy AJ - J. Invest. Dermatol. (2013)

Zmiz1Δ1-185 transgenic mice develop skin tumors(a) Diagram of the Cre-inducible Zmiz1Δ1-185 transgene. (b) Western blot showing skin from Zmiz1Δ1-185 single transgenic mice has nearly undetectable expression of EGFP, whereas double transgenic mice display detectable EGFP expression. (c) Kaplan-Meier survival curve of mouse line 207 showing tumor-free survival of K14-CreTg/+; Zmiz1Δ1-185 Tg/+ double transgenic mice (circles, n=54), K14-Cre+/+; Zmiz1Δ1-185 Tg/+ single transgenic (squares, n=18), and K14-CreTg/+; Zmiz1Δ1-185 +/+ single transgenic mice (triangles, n=35). Double transgenic mice developed skin tumors with an average latency of 14 weeks after birth, while single transgenic controls did not develop skin tumors (log-rank, P<0.0001). (d) Western blot confirms overexpression of the Zmiz1Δ1-185 transgenic protein in mouse tumors. Endogenous Zmiz1 expression is undetectable in normal skin.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3672356&req=5

Figure 2: Zmiz1Δ1-185 transgenic mice develop skin tumors(a) Diagram of the Cre-inducible Zmiz1Δ1-185 transgene. (b) Western blot showing skin from Zmiz1Δ1-185 single transgenic mice has nearly undetectable expression of EGFP, whereas double transgenic mice display detectable EGFP expression. (c) Kaplan-Meier survival curve of mouse line 207 showing tumor-free survival of K14-CreTg/+; Zmiz1Δ1-185 Tg/+ double transgenic mice (circles, n=54), K14-Cre+/+; Zmiz1Δ1-185 Tg/+ single transgenic (squares, n=18), and K14-CreTg/+; Zmiz1Δ1-185 +/+ single transgenic mice (triangles, n=35). Double transgenic mice developed skin tumors with an average latency of 14 weeks after birth, while single transgenic controls did not develop skin tumors (log-rank, P<0.0001). (d) Western blot confirms overexpression of the Zmiz1Δ1-185 transgenic protein in mouse tumors. Endogenous Zmiz1 expression is undetectable in normal skin.
Mentions: As previously mentioned, we predicted that transposon-induced expression of the Zmiz1Δ1-185 is oncogenic. To test this hypothesis, we engineered transgenic mice that conditionally express Zmiz1Δ1-185 (Figure 2a). A lox-stop-lox strategy was employed to prevent ubiquitous expression of Zmiz1Δ1-185. Cre-mediated recombination will delete the DsRed reporter embedded in the lox-stop-lox cassette and induce expression of the downstream Zmiz1Δ1-185-IRES-EGFP cassette. Two Zmiz1Δ1-185 founder animals showed detectable levels of the DsRed reporter in the skin and were used to establish transgenic lines 207-Zmiz1Δ1-185 and 163-Zmiz1Δ1-185.

Bottom Line: Here we show that transposon-induced mutations in Zmiz1 drive expression of a truncated transcript that is similar to an alternative endogenous ZMIZ1 transcript found to be overexpressed in human SCCs relative to normal skin.In addition, we found that the alternative Zmiz1 isoform has greater protein stability than its full-length counterpart.Finally, we provide evidence that ZMIZ1 is overexpressed in a significant percentage of human breast, ovarian, and colon cancers in addition to human SCCs, suggesting that ZMIZ1 may play a broader role in epithelial cancers.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy and Cell Biology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.

ABSTRACT
Cutaneous squamous cell carcinoma (SCC) is the second most common form of cancer in the human population, yet the underlying genetic mechanisms contributing to the disease are not well understood. We recently identified Zmiz1 as a candidate oncogene in nonmelanoma skin cancer through a transposon mutagenesis screen. Here we show that transposon-induced mutations in Zmiz1 drive expression of a truncated transcript that is similar to an alternative endogenous ZMIZ1 transcript found to be overexpressed in human SCCs relative to normal skin. We also describe an original mouse model of invasive keratoacanthoma driven by skin-specific expression of the truncated Zmiz1 transcript. Unlike most mouse models, Zmiz1-induced skin tumors develop rapidly and in the absence of promoting agents such as phorbol esters. In addition, we found that the alternative Zmiz1 isoform has greater protein stability than its full-length counterpart. Finally, we provide evidence that ZMIZ1 is overexpressed in a significant percentage of human breast, ovarian, and colon cancers in addition to human SCCs, suggesting that ZMIZ1 may play a broader role in epithelial cancers.

Show MeSH
Related in: MedlinePlus