AFM-compatible microfluidic platform for affinity-based capture and nanomechanical characterization of circulating tumor cells.

Circulating tumor cells (CTCs) carried by the patient's bloodstream are known to lead to the metastatic spread of cancer. It is becoming increasingly clear that an understanding of the nanomechanical characteristics of CTCs, such as elasticity and adhesiveness, represents advancements in tracking and monitoring cancer progression and metastasis. In the present work, we describe a combined microfluidic-atomic force microscopy (AFM) platform that uses antibody-antigen capture to routinely isolate and nanomechanically characterize CTCs present in blood samples from prostate cancer patients. We introduce the reversible assembly of a microfluidic device and apply refined and robust chemistry to covalently bond antibodies onto its glass substrate with high density and the desired orientation. As a result, we show that the device can efficiently capture CTCs from patients with localized and metastatic prostate cancer through anti-EpCAM, anti-PSA, and anti-PSMA antibodies, and it is suitable for AFM measurements of captured intact CTCs. When nanomechanically characterized, CTCs originating from metastatic cancer demonstrate decreased elasticity and increased deformability compared to those originating from localized cancer. While the average adhesion of CTCs to the AFM tip surface remained the same in both the groups, there were fewer multiple adhesion events in metastatic CTCs than there were in their counterparts. The developed platform is simple, robust, and reliable and can be useful in the diagnosis and prognosis of prostate cancer as well as other forms of cancer.

Proliferative Index (Ki67) for Prediction in Breast Duct Carcinomas

Background and objectives: To date, many tumor markers have been used to predict prognosis and therapeutic response in patients with breast cancer. The well established and routinely applied tumor markers are the estrogen-receptor, progesterone-receptor and Her2/neu-receptor. In the current study, we aimed to highlight any association of the proliferation index (Ki67) in breast infiltrative duct carcinoma with the tumor grade, tumor size and nodal status in addition to hormone receptor status. Tissue sections were stained immunohistochemically for Ki67 nuclear antigen, estrogen, progesterone and Her2/neu receptors using an automated Dako machine (Dako Denmark. There was a significant inverse relationship of Ki67 levels with ER and PR, while values were directly proportional to the tumor grade and Her2/neu status. No significant association was found between Ki67 and size of tumor or nodal status. Ki67 immunoexpression may offer an independent predictive tumor marker and for routine application in cases of breast cancer.

Pretransplant cardiac investigations in the Irish renal transplant population--the effectiveness of our current screening techniques in predicting cardiac events.

BACKGROUND: Coronary artery disease (CAD) is prevalent among endstage renal failure patients and remains the major cause of mortality following renal transplantation. Death with a functioning transplant institute remains the most common cause of kidney graft failure. In this study we attempt to evaluate the effectiveness of the clinical history and current screening techniques available in predicting posttransplant CAD and also assess the role of coronary angiography as a pretransplant screening technique. METHODS: Clinical data of 190 renal transplant patients was analyzed. Any clinical history of cardiac disease and all preoperative cardiac screening data was recorded for each patient. The study endpoints were the subsequent development of myocardial infarction (MI), undergoing coronary artery bypass graft (CABG) or death. RESULTS: Factors that were significantly associated with reaching a study endpoint included: age at transplant [Hazard Ratio (HR) 1.91, P<0.001], history of heart failure (HR 8.22, P<0.001), presence of CAD on coronary angiography (HR 5.55, P=0.033), anterior Q wave on electrocardiograph (ECG) (HR 8.6, P<0.001), carotid artery disease (HR 3.74, P=0.030) and history of a cerebrovascular accident (HR of 4.32, P=0.008). The screening techniques of exercise stress testing and echocardiography were not conclusive as predictive variables of outcome. CONCLUSION: Clinical history and ECG results are good, practical and low-cost screening methods. In our study exercise stress testing and echocardiography were found to be of limited value. Coronary angiography is appropriate in certain high-risk groups but not necessary as part of screening in all potential renal transplant recipients.