Comparative Expression of the Mitotic Regulators SAK and PLK in Colorectal Cancer

  title={Comparative Expression of the Mitotic Regulators SAK and PLK in Colorectal Cancer},
  author={Jennifer C. Macmillan and John W Hudson and Shelley B. Bull and James W. Dennis and Carol Jane Swallow},
  journal={Annals of Surgical Oncology},
AbstractBackground: Disruption of normal mechanisms for cell cycle regulation is important in carcinogenesis. SAK and PLK are members of the polo family of serine threonine kinases, which in lower organisms have been shown to be required for the precise regulation of mitosis. Studies of human polo family members have focused on PLK, which has been found to be overexpressed in several tumor types, with the degree of overexpression correlating with adverse clinical outcome. However, PLK… 

Oncogenic effect of Polo-like kinase 1 expression in human gastric carcinomas.

Plk1 expression was significantly associated with accumulation of proliferation-related genes and oncogenes, and reversely correlated with tumor suppressor genes, and showed oncogenic potential in gastric cancer.

Polo‐like kinase 1 (PLK1) is overexpressed in primary colorectal cancers

The results suggest over‐expression of PLK1 might be of pathogenic, prognostic and proliferative importance, so that this kinase might have potential as a new tumor marker for colorectal cancers.

Molecular interactions of polo-like kinase 1 in human cancers

Polo-like kinase 1 expression can be affected by many factors and it is possible that PLK1 deregulation in each individual patient tumours could be due to different underlying mechanisms.

PLK4 overexpression and its effect on centrosome regulation and chromosome stability in human gastric cancer

It is suggested that PLK4 is upregulated in a subset of primary gastric cancers and thatPLK4 overexpression induces centrosome amplification and chromosome instability and causes the suppression of primary cilia formation.

Polo-like kinase 1 expression is a prognostic factor in human colon cancer.

PLK1 is a new prognostic marker for colon carcinoma patients and may be involved in tumorigenesis and progression of colon cancer, and strategies focusing on PLK1 inhibition in vivo might represent a promising new therapeutic approach for this tumor entity.

Polo-Like Kinases in Colorectal Cancer: Potential for Targeted Therapy

Encouragement for the use of targeted Plk inhibitors in cancer therapy must be tempered somewhat by the potential for development of second primary tumors in the long term, particularly with aging.

Polo-Like Kinase 4 (PLK4) Function in Cancer Progression

A novel and unexpected localization of Plk4 to the edges of lamellipodia and filopodia of motile cells is discovered, and a gene expression pattern predictive of reduced motility in PlK4 murine embryonic fibroblasts is identified, functionally validated in cancer cells.

Polo-like kinases (Plks) and cancer

Plk1 gene and protein expression has been proposed as a new prognostic marker for many types of malignancies, and Plk1 is a potential target for cancer therapy.

Epigenetic Alteration of Polo-like Kinase 4 Plk4 in Methylation in Colorectal Cancer and Hepatocellular Carcinoma Cell Lines

Polo and Polo-like kinases Plks comprise a serinethreonine kinase family, which is highly conserved from yeasts to humans, and Plk4 is a member of this family and is suggested to play a role in M phase progression and epigenetic alteration in hepatocellular and colorectal cancers.

p53-Dependent and Cell Specific Epigenetic Regulation of the Polo-like kinases under Oxidative Stress

A model in which the PLKs are susceptible to epigenetic changes induced by microenvironmental cues and these modifications may be p53-dependent is supported, which has important implications in HCC and other cancers, where epigenetic alterations of thePLKs could contribute to tumourigenesis and disease progression.



Prognostic significance of polo-like kinase expression in esophageal carcinoma.

It is demonstrated that the PLK overexpression was frequently observed in esophageal and gastric carcinomas, and appeared to be an independent prognostic factor for patients with esophagal carcinoma.

Polo-like kinase, a novel marker for cellular proliferation.

High levels of PLK protein may be useful for improved prediction of the clinical prognosis of cancer patients and for early cancer diagnosis due to its activity late in the cell cycle, and may be a target for cancer chemotherapy.

Prognostic significance of polo-like kinase (PLK) expression in squamous cell carcinomas of the head and neck.

Interestingly, a combination of nodal stage and PLK expression contributed to discriminate patients with a better prognosis in the pN(0/1) and pN (2/3) groups, which could improve the definition of a suitable therapy.

Prognostic significance of polo-like kinase (PLK) expression in non-small cell lung cancer

The results suggest that PLK mRNA expression provides a new independent prognostic indicator for patients with NSCLC.

On the regulation and function of human polo-like kinase 1 (PLK1): effects of overexpression on cell cycle progression.

It is shown that the relative specific activity of Plk1 increases in mitosis, that PlK1 is specifically phosphorylated during mitosis), and that phosphatase treatment reduces mitotic Plk 1 activity to interphase levels.

Polo kinase: the choreographer of the mitotic stage?

The extension of identity beyond the catalytic domain strongly suggests that members of another conserved serine/threonine kinase family appears to be able to control the dynamics of cellular architecture and whether the polo-like kinases of different organisms have equivalent biological functions.

Sak, a murine protein-serine/threonine kinase that is related to the Drosophila polo kinase and involved in cell proliferation.

The pattern of Sak expression and its sequence homology with the polo gene family suggest that the Sak kinase may play a role in cell proliferation, and cell growth was suppressed by expression of a Sak-a-antisense fragment in CHO cells.

Constitutive expression of murine Sak-a suppresses cell growth and induces multinucleation.

The results show that Sak-a transcript levels are controlled in a cell cycle-dependent manner and that this precise regulation is necessary for cell growth and the maintenance of nuclear integrity during cell division.

Malignant transformation of mammalian cells initiated by constitutive expression of the polo-like kinase.

It is reported that microinjection of Plk mRNA is sufficient to drive quiescent cells into mitosis and that constitutive expression of PlK in NIH 3T3 cells causes oncogenic focus formation.

The prognostic value of DNA-ploidy in colorectal carcinoma: a prospective study.

In multiple samples from the same tumour there was on average a 29% difference between the highest and the lowest SPF indicating considerable heterogeneity in proliferative activity within the tumours, and in diploid tumours the variation was even higher.