Clinicopathologic significance of an immunohistochemical expression of p27 in scirrhous carcinoma of the breast

Loss of p27kip1 expression is associated with poor prognosis in patients with taxane-treated breast cancer

PURPOSE

Decreased expression of p27^kip1 and p57^kip2 is considered as a prognostic indicator in patients with breast cancer receiving adjuvant chemotherapy. Previous in vitro studies have reported that reduced expression of p27^kip1 and p57^kip2 is associated with resistance to taxane, which is one of the most effective chemotherapeutic agents. In this study, we investigated the association of low p27^kip1 and p57^kip2 expression with outcomes in patients with breast cancer.

METHODS

We investigated 226 cases of breast cancer from Kangbuk SMC between 2000 and 2005. Levels of p27^kip1 and p57^kip2 expression were evaluated using immunohistochemical staining of tumor tissue microarray specimens. The relationships between the expression levels of the markers and patients' outcomes were analyzed using the Kaplan-Meier method and Cox proportional hazard model.

RESULTS

Low p57^kip2 expression was only associated with negative progesterone receptor status (p = 0.034), whereas p27^kip1 expression was associated with poor prognosis of patients receiving adjuvant chemotherapy (p = 0.005). More detailed analysis revealed that low p27^kip1 expression affects the overall survival rate of patients receiving adjuvant chemotherapy including taxane (p = 0.026), but not that of patients receiving chemotherapy without taxane.

CONCLUSIONS

Low p27^kip1 expression may be useful to predict overall survival in patients with breast cancer who are treated with taxane. Evaluation of p27^kip1 expression may provide further prognostic information beyond traditional prognostic biomarkers and an understanding of the mechanisms that impart resistance against chemotherapy.

From top to bottom: midkine and pleiotrophin as emerging players in immune regulation

Cytokines are pivotal in the generation and resolution of the inflammatory response. The midkine/pleiotrophin (MK/PTN) family of cytokines, composed of just two members, was discovered as heparin-binding neurite outgrowth-promoting factors. Since their discovery, expression of this cytokine family has been reported in a wide array of inflammatory diseases and cancer. In this minireview, we will discuss the emerging appreciation of the functions of the MK/PTN family in the immune system, which include promoting lymphocyte survival, sculpting myeloid cell phenotype, driving immune cell chemotaxis, and maintaining hematopoiesis.

Expression of mucin 1 possessing a 3'-sulfated core1 in recurrent and metastatic breast cancer

Breast cancer is the most frequent cancer threatening the lives of women between the ages of 30 and 64. The cancer antigen 15-3 assay (CA15-3) has been widely used for the detection of breast cancer recurrence; however, its sensitivity and specificity are inadequate. We previously found that the breast cancer cell line YMBS secretes mucin 1 possessing 3'-sulfated core1 (3Score1-MUC1) into the medium. Therefore, we here evaluated whether 3Score1-MUC1 is secreted into the blood streams of breast cancer patients, and whether it can serve as an improved breast cancer marker. We developed a lectin-sandwich immunoassay, called Gal4/MUC1, using a 3'-sulfated core1-specific galectin-4 and a MUC1 monoclonal antibody. Using the Gal4/MUC1 assay method, we found that 3Score1-MUC1 was profoundly expressed in the blood streams of patients with recurrent and/or metastatic breast cancer. The positive ratio of the Gal4/MUC1 assay was higher than that of the CA15-3 assay in both primary (n = 240) and relapsed (n = 43) patients, especially in the latter of which the positive ratio of Gal4/MUC1 was 86%. whereas that of CA15-3 was 47%. Furthermore, serum Gal4/MUC1 levels could more sensitively reflect the recurrence of primary breast cancer patients after surgery. Therefore, the Gal4/MUC1 assay should be an excellent alternative to the CA15-3 tumor marker for tracking the recurrence and metastasis of breast cancer.

Pathologic progression of mammary carcinomas in a C3(1)/SV40 T/t-antigen transgenic rat model of human triple-negative and Her2-positive breast cancer

The C3(1) component of the rat prostate steroid binding protein has been used to target expression of the SV40 T/t-antigen to the mammary epithelium of mice resulting in pre-neoplastic lesions that progress to invasive and metastatic cancer with molecular features of human basal-type breast cancer. However, there are major differences in the histologic architecture of the stromal and epithelial elements between the mouse and human mammary glands. The rat mammary gland is more enriched with epithelial and stromal components than the mouse and more closely resembles the cellular composition of the human gland. Additionally, existing rat models of mammary cancer are typically estrogen receptor positive and hormone responsive, unlike most genetically engineered mouse mammary cancer models. In an attempt to develop a mammary cancer model that might more closely resemble the pathology of human breast cancer, we generated a novel C3(1)/SV40 T/t-antigen transgenic rat model that developed progressive mammary lesions leading to highly invasive adenocarcinomas. However, aggressive tumor development prevented the establishment of transgenic lines. Characterization of the tumors revealed that they were primarily estrogen receptor and progesterone receptor negative, and either her2/neu positive or negative, resembling human triple-negative or Her2 positive breast cancer. Tumors expressed the basal marker K14, as well as the luminal marker K18, and were negative for smooth muscle actin. The triple negative phenotype has not been previously reported in a rat mammary cancer model. Further development of a C3(1)SV40 T/t-antigen based model could establish valuable transgenic rat lines that develop basal-type mammary tumors.