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The prognostic significance and value of cyclin D1, CDK4 and p16 in human breast cancer.

Peurala E, Koivunen P, Haapasaari KM, Bloigu R, Jukkola-Vuorinen A - Breast Cancer Res. (2013)

Bottom Line: CDK4 expression did not correlate with cyclin D1 expression or the survival data. p16 expression was associated with Human Epidermal Growth Factor Receptor 2 (HER2) negativity and increased breast cancer-specific survival and disease-free survival.No statistical correlations between cyclin D1, CDK4 and p16 were found.In conclusion, it appears that cyclin D1, CDK4 and p16 function independently in human breast cancer.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Introduction: Loss of the retinoblastoma protein tumor suppressor gene (RB) coding for a nuclear phosphoprotein that regulates the cell cycle is found in many human cancers and probably leads to disruption of the p16-cyclin D1-CDK4/6-RB pathway. Cyclin D1 is known to activate CDK4, which then phosphorylates the RB protein, leading to cell cycle progression. p16 inhibits CDK4, keeping RB hypophosphorylated and preventing cell cycle progression. The significance of these three markers, cyclin D1, CDK4 and p16, for breast cancer and carcinogenesis is nevertheless still controversial.

Methods: The material consisted of 102 formalin-fixed human breast cancer samples, in which cyclin D1, CDK4 and p16 expression was evaluated immunohistochemically. The amounts of cyclin D1 mRNA present were analyzed by quantitative real time PCR.

Results: High cyclin D1 expression statistically significantly correlated with lower tumor grade, estrogen and progesterone receptor positivity and lower proliferation activity in breast tumors and increased breast cancer-specific survival and overall survival. Tumors with high cyclin D1 protein had 1.8 times higher expression of cyclin D1 mRNA. CDK4 expression did not correlate with cyclin D1 expression or the survival data. p16 expression was associated with Human Epidermal Growth Factor Receptor 2 (HER2) negativity and increased breast cancer-specific survival and disease-free survival. No statistical correlations between cyclin D1, CDK4 and p16 were found.

Conclusions: Cyclin D1 was associated with a good breast cancer prognosis but functioned independently of CDK4. High cyclin D1 expression may be partially due to increased CCND1 transcription. p16 correlated with a better prognosis and may function without CDK4. In conclusion, it appears that cyclin D1, CDK4 and p16 function independently in human breast cancer.

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Relative expression of cyclin D1 mRNA to cyclin D1 protein in breast carcinoma specimens. Expression of cyclin D1 mRNA was studied relative to 18S rRNA (CCND1/18S). High and low cyclin D1 indicate the expression levels of the protein.
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Figure 4: Relative expression of cyclin D1 mRNA to cyclin D1 protein in breast carcinoma specimens. Expression of cyclin D1 mRNA was studied relative to 18S rRNA (CCND1/18S). High and low cyclin D1 indicate the expression levels of the protein.

Mentions: Evaluation of the relation of cyclin D1 protein expression in the histological sections to cyclin D1 mRNA in the corresponding tumor samples by means of Q-PCR showed that tumors with high cyclin D1 protein had 1.8 times higher expression of cyclin D1 mRNA than those with low or negative cyclin D1 in the histological sections (Figure 4), suggesting that the higher cyclin D1 protein level is at least partially due to increased expression of CCND1.


The prognostic significance and value of cyclin D1, CDK4 and p16 in human breast cancer.

Peurala E, Koivunen P, Haapasaari KM, Bloigu R, Jukkola-Vuorinen A - Breast Cancer Res. (2013)

Relative expression of cyclin D1 mRNA to cyclin D1 protein in breast carcinoma specimens. Expression of cyclin D1 mRNA was studied relative to 18S rRNA (CCND1/18S). High and low cyclin D1 indicate the expression levels of the protein.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672746&req=5

Figure 4: Relative expression of cyclin D1 mRNA to cyclin D1 protein in breast carcinoma specimens. Expression of cyclin D1 mRNA was studied relative to 18S rRNA (CCND1/18S). High and low cyclin D1 indicate the expression levels of the protein.
Mentions: Evaluation of the relation of cyclin D1 protein expression in the histological sections to cyclin D1 mRNA in the corresponding tumor samples by means of Q-PCR showed that tumors with high cyclin D1 protein had 1.8 times higher expression of cyclin D1 mRNA than those with low or negative cyclin D1 in the histological sections (Figure 4), suggesting that the higher cyclin D1 protein level is at least partially due to increased expression of CCND1.

Bottom Line: CDK4 expression did not correlate with cyclin D1 expression or the survival data. p16 expression was associated with Human Epidermal Growth Factor Receptor 2 (HER2) negativity and increased breast cancer-specific survival and disease-free survival.No statistical correlations between cyclin D1, CDK4 and p16 were found.In conclusion, it appears that cyclin D1, CDK4 and p16 function independently in human breast cancer.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Introduction: Loss of the retinoblastoma protein tumor suppressor gene (RB) coding for a nuclear phosphoprotein that regulates the cell cycle is found in many human cancers and probably leads to disruption of the p16-cyclin D1-CDK4/6-RB pathway. Cyclin D1 is known to activate CDK4, which then phosphorylates the RB protein, leading to cell cycle progression. p16 inhibits CDK4, keeping RB hypophosphorylated and preventing cell cycle progression. The significance of these three markers, cyclin D1, CDK4 and p16, for breast cancer and carcinogenesis is nevertheless still controversial.

Methods: The material consisted of 102 formalin-fixed human breast cancer samples, in which cyclin D1, CDK4 and p16 expression was evaluated immunohistochemically. The amounts of cyclin D1 mRNA present were analyzed by quantitative real time PCR.

Results: High cyclin D1 expression statistically significantly correlated with lower tumor grade, estrogen and progesterone receptor positivity and lower proliferation activity in breast tumors and increased breast cancer-specific survival and overall survival. Tumors with high cyclin D1 protein had 1.8 times higher expression of cyclin D1 mRNA. CDK4 expression did not correlate with cyclin D1 expression or the survival data. p16 expression was associated with Human Epidermal Growth Factor Receptor 2 (HER2) negativity and increased breast cancer-specific survival and disease-free survival. No statistical correlations between cyclin D1, CDK4 and p16 were found.

Conclusions: Cyclin D1 was associated with a good breast cancer prognosis but functioned independently of CDK4. High cyclin D1 expression may be partially due to increased CCND1 transcription. p16 correlated with a better prognosis and may function without CDK4. In conclusion, it appears that cyclin D1, CDK4 and p16 function independently in human breast cancer.

Show MeSH
Related in: MedlinePlus