CUTL1 is a target of TGF(beta) signaling that enhances cancer cell motility and invasiveness.

CUTL1, also known as CDP, Cut, or Cux-1, is a homeodomain transcriptional regulator known to be involved in development and cell cycle progression. Here we report that CUTL1 activity is associated with increased migration and invasiveness in numerous tumor cell lines, both in vitro and in vivo. Furthermore, we identify CUTL1 as a transcriptional target of transforming growth factor beta and a mediator of its promigratory effects. CUTL1 activates a transcriptional program regulating genes involved in cell motility, invasion, and extracellular matrix composition. CUTL1 expression is significantly increased in high-grade carcinomas and is inversely correlated with survival in breast cancer. This suggests that CUTL1 plays a central role in coordinating a gene expression program associated with cell motility and tumor progression.

Predicting prognosis using molecular profiling in estrogen receptor-positive breast cancer treated with tamoxifen.

BACKGROUND: Estrogen receptor positive (ER+) breast cancers (BC) are heterogeneous with regard to their clinical behavior and response to therapies. The ER is currently the best predictor of response to the anti-estrogen agent tamoxifen, yet up to 30-40% of ER+BC will relapse despite tamoxifen treatment. New prognostic biomarkers and further biological understanding of tamoxifen resistance are required. We used gene expression profiling to develop an outcome-based predictor using a training set of 255 ER+ BC samples from women treated with adjuvant tamoxifen monotherapy. We used clusters of highly correlated genes to develop our predictor to facilitate both signature stability and biological interpretation. Independent validation was performed using 362 tamoxifen-treated ER+ BC samples obtained from multiple institutions and treated with tamoxifen only in the adjuvant and metastatic settings. RESULTS: We developed a gene classifier consisting of 181 genes belonging to 13 biological clusters. In the independent set of adjuvantly-treated samples, it was able to define two distinct prognostic groups (HR 2.01 95%CI: 1.29-3.13; p = 0.002). Six of the 13 gene clusters represented pathways involved in cell cycle and proliferation. In 112 metastatic breast cancer patients treated with tamoxifen, one of the classifier components suggesting a cellular inflammatory mechanism was significantly predictive of response. CONCLUSION: We have developed a gene classifier that can predict clinical outcome in tamoxifen-treated ER+ BC patients. Whilst our study emphasizes the important role of proliferation genes in prognosis, our approach proposes other genes and pathways that may elucidate further mechanisms that influence clinical outcome and prediction of response to tamoxifen.

Risk estimation of distant metastasis in node-negative, estrogen receptor-positive breast cancer patients using an RT-PCR based prognostic expression signature.

BACKGROUND: Given the large number of genes purported to be prognostic for breast cancer, it would be optimal if the genes identified are not confounded by the continuously changing systemic therapies. The aim of this study was to discover and validate a breast cancer prognostic expression signature for distant metastasis in untreated, early stage, lymph node-negative (N-) estrogen receptor-positive (ER+) patients with extensive follow-up times. METHODS: 197 genes previously associated with metastasis and ER status were profiled from 142 untreated breast cancer subjects. A "metastasis score" (MS) representing fourteen differentially expressed genes was developed and evaluated for its association with distant-metastasis-free survival (DMFS). Categorical risk classification was established from the continuous MS and further evaluated on an independent set of 279 untreated subjects. A third set of 45 subjects was tested to determine the prognostic performance of the MS in tamoxifen-treated women. RESULTS: A 14-gene signature was found to be significantly associated (p < 0.05) with distant metastasis in a training set and subsequently in an independent validation set. In the validation set, the hazard ratios (HR) of the high risk compared to low risk groups were 4.02 (95% CI 1.91-8.44) for the endpoint of DMFS and 1.97 (95% CI 1.28 to 3.04) for overall survival after adjustment for age, tumor size and grade. The low and high MS risk groups had 10-year estimates (95% CI) of 96% (90-99%) and 72% (64-78%) respectively, for DMFS and 91% (84-95%) and 68% (61-75%), respectively for overall survival. Performance characteristics of the signature in the two sets were similar. Ki-67 labeling index (LI) was predictive for recurrent disease in the training set, but lost significance after adjustment for the expression signature. In a study of tamoxifen-treated patients, the HR for DMFS in high compared to low risk groups was 3.61 (95% CI 0.86-15.14). CONCLUSION: The 14-gene signature is significantly associated with risk of distant metastasis. The signature has a predominance of proliferation genes which have prognostic significance above that of Ki-67 LI and may aid in prioritizing future mechanistic studies and therapeutic interventions.

Sialylated core 1 based O-linked glycans enhance the growth rate of mammary carcinoma cells in MUC1 transgenic mice.

The MUC1 mucin, found on the luminal surface of simple epithelial cells is upregulated and aberrantly glycosylated in many carcinomas particularly breast and ovarian. MUC1 expressed by normal mammary epithelial cells, carries core 2 glycans but in breast carcinomas the simple core 1 based glycans are added. The binding of the monoclonal antibody SM3 to its peptide epitope in the tandem repeat of MUC1 is blocked by the branched core 2 glycans found on MUC1 expressed by normal cells. Thus SM3 does not bind to MUC1 expressed by normal mammary epithelial cells but reacts with more than 90% of breast carcinomas, suggesting that the loss of at least some core 2 glycans is a very common event in breast carcinogenesis. To determine if the change in glycosylation observed in breast carcinomas confers an advantage to cancer cells, murine mammary carcinoma cell lines were developed that express MUC1 carrying core 2 or core 1 linked glycans. The in vivo growth rate in wild-type and nude mice were identical regardless of the O-glycosylation patterns. However, the tumors that grew out of wild-type mice lost most of their MUC1 expression. In contrast, in MUC1 transgenic mice, where expression of MUC1 was retained by the tumor, a striking difference in growth rate was observed. In these mice, cells expressing core 1 glycans grew significantly faster than cells expressing core 2 glycans. These data suggest that MUC1 transgenic mice are more tolerant to core 1 expressing tumors than to tumors expressing core 2.

Discrepancies between reported self-monitored blood glucose results and point-of-care hemoglobin A1c in children with diabetes: lessons to be learned.

BACKGROUND: The hemoglobin A1c (HbA1c) assay is considered the gold standard for assessing glycemic control in children and adolescents with type 1 diabetes mellitus (T1DM). In recent years, point-of-care (POC) testing has been more commonly used in the outpatient clinic. However, despite its popularity, little is known about the accuracy of the POC methods in children. PATIENTS AND METHODS: In this case series, we describe seven children-six with T1DM and one with type 2 diabetes mellitus-who had major discrepancies between measured POC HbA1c via A1cNow+(®) (Bayer Healthcare Metrika, Sunnyvale, CA) and self-monitored blood glucose records. RESULTS: In six subjects, the discrepancy was explained by the presence of the hemoglobin S trait, and an additional subject had the hemoglobin C trait. CONCLUSIONS: This report demonstrates that as with all laboratory tests, the HbA1c test is subject to limitations, particularly in children with hemoglobin variants. Increased awareness regarding these limitations among healthcare professionals is paramount, especially with the increased use of the HbA1c POC method in the medical community. Failure to recognize these limitations can lead to unnecessary medical, financial, and social interventions that could have profound impact on the patient-doctor relationship.

Assay interference leading to misdiagnosis of central precocious puberty.

Immunoassays are widely used to determine hormone levels. Antibodies directed against components of the immunoassay system can interfere with analyte concentration estimates. When unrecognized by clinicians, inappropriate clinical intervention may follow. The case of a young child with premature thelarche and elevated basal and stimulated luteinizing hormone (LH) levels is presented, in whom it is hypothesized that heterophile antibodies (HAs) caused interference in the LH immunoassay. LH concentrations were measured in two different assays: LH-microparticle enzyme immunoassay (MEIA) and LH-immunochemiluminometric assay (ICMA). To detect HA interference, LH level was remeasured after both preincubation with mouse serum to neutralize human anti-mouse antibodies, and treatment with a heterophile-blocking tube. The mean basal LH concentration by LH-MEIA was 7.4 mIU/mL and for LH-ICMA was 0.08 mIU/mL (normal range for age: 0.02-0.3 mIU/mL). LH concentration by MEIA was 0.08 mIU/mL after preincubation with mouse serum and 2.7 mIU/mL after preincubation with a heterophile blocking tube. In conclusion, HAs were identified in the serum of a child with premature thelarche. The presence of HAs led to spuriously elevated basal and gonadotropin-releasing hormone-stimulated LH concentrations, resulting in a diagnosis of central precocious puberty and unnecessary therapy. To avoid similar cases in the future, clinicians should consider the possibility of assay interference when the clinical picture is incongruent with the laboratory data.