Arianna Petracca

Epithelial-mesenchymal transition and stemness features in circulating tumor cells from breast cancer patients.

Currently used methods to detect and enumerate circulating tumor cells (CTCs) rely on the expression of the epithelial cell adhesion molecule (EpCAM) and cytokeratins. This selection may exclude cells that have undergone intrinsic modifications of their phenotype, as epithelial-mesenchymal transition (EMT). Aim of the study was to investigate the expression of EMT and stemness markers in CTCs from breast cancer patients in all stages of disease. 92 female breast cancer patients were enrolled. CTCs were isolated by CELLection™ Dynabeads® coated with the monoclonal antibody toward EpCam. Samples found positive for CTCs presence (CD45−/CK+) were evaluated for the expression of ER alpha, HER2, ALDH1, vimentin, and fibronectin. Samples negative for CTCs presence (CD45−/CK−) were also evaluated for the expression of vimentin and fibronectin, used as markers of EMT. CTCs were found in 66% of patients. The distribution of CTCs presence according to stage and grade of disease was found statistically significant. The expression of ALDH1 on CTCs was found to correlate to stage of disease and to the expression of vimentin and fibronectin. In 34% of patients, we detected cells with negative CK/CD45 expression but positive expression of vimentin and fibronectin. There is an urgent need for optimizing CTCs detection methods through the inclusion of EMT markers. The detection of cells in mesenchymal transition, retaining EMT and stemness features, may contribute to discover additional therapeutic targets useful to eradicate micrometastatic disease in breast cancer.

Circulating tumour cells lacking cytokeratin in breast cancer: the importance of being mesenchymal

Circulating tumour cells (CTCs) are independent predictor of prognosis in metastatic breast cancer. Nevertheless, in one third of patients, circulating tumour cells are undetected by conventional methods. Aim of the study was to assess the prognostic value of circulating tumour cells expressing mesenchymal markers in metastatic breast cancer patients. We isolated CTC from blood of 55 metastatic breast cancer patients. CTC were characterized for cytokeratins and markers of epithelial mesenchymal transition. The gain of mesenchymal markers in CTC was correlated to prognosis of patients in a follow‐up of 24 months. The presence of mesenchymal markers on CTC more accurately predicted worse prognosis than the expression of cytokeratins alone. Because of the frequent loss of epithelial antigens by CTC, assays targeting epithelial antigens may miss the most invasive cell population. Thus, there is an urgent need to improve detection methods to identify CTC which undergone epithelial mesenchymal transition program.

Prognostic value of circulating tumor cells in nonmuscle invasive bladder cancer: a CellSearch analysis

BACKGROUND Circulating tumor cells (CTCs) provide prognostic information in patients with metastatic tumors. Recent studies have shown that CTCs are released in circulation in an early phase of cancer disease so that their presence is under investigation in the adjuvant setting. Few studies investigated the prognostic significance of CTCs enumeration in patients with metastatic and advanced bladder cancer. The current study has analyzed the presence of CTC in patients with nonmuscle-invasive bladder cancer (NMIBC). PATIENTS AND METHODS Forty-four NMIBC patients were enrolled and included in a 24-month follow-up program. Blood drawings were carried out in all patients at the first diagnosis. CellSearch system (Veridex; LLC, Raritan, NJ) was used for CTCs enumeration. RESULTS CTC were detectable in 8/44 patients (18%). Presence of CTC was found significantly associated to shorter time to first recurrence (6.5 versus 21.7 months, P < 0.001). Median time to progression was not reached, due to the short follow-up period. CTC presence was found associated to concomitant carcinoma in situ and higher T category. CONCLUSION The detection of CTC in this setting of disease may allow to distinguish patients with high risk of recurrence from those with high risk of progression, as well as to early identify patients candidate for adjuvant treatment.BACKGROUND Circulating tumor cells (CTCs) provide prognostic information in patients with metastatic tumors. Recent studies have shown that CTCs are released in circulation in an early phase of cancer disease so that their presence is under investigation in the adjuvant setting. Few studies investigated the prognostic significance of CTCs enumeration in patients with metastatic and advanced bladder cancer. The current study has analyzed the presence of CTC in patients with nonmuscle-invasive bladder cancer (NMIBC). PATIENTS AND METHODS Forty-four NMIBC patients were enrolled and included in a 24-month follow-up program. Blood drawings were carried out in all patients at the first diagnosis. CellSearch system (Veridex; LLC, Raritan, NJ) was used for CTCs enumeration. RESULTS CTC were detectable in 8/44 patients (18%). Presence of CTC was found significantly associated to shorter time to first recurrence (6.5 versus 21.7 months, P<0.001). Median time to progression was not reached, due to the short follow-up period. CTC presence was found associated to concomitant carcinoma in situ and higher T category. CONCLUSION The detection of CTC in this setting of disease may allow to distinguish patients with high risk of recurrence from those with high risk of progression, as well as to early identify patients candidate for adjuvant treatment.

Prognostic significance of survivin‐expressing circulating tumour cells in T1G3 bladder cancer

To evaluate the prognostic significance of survivin in tumour tissues and that of survivin‐expressing circulating tumour cells (CTCs) in T1G3 bladder tumours, as the prognosis of T1G3 bladder cancer is highly variable and unpredictable from clinical and pathological prognostic factors.

CD133 and ABCB5 as stem cell markers on sentinel lymph node from melanoma patients

In the last years the nature of initiating melanoma cells has been discussed and the melanoma stem cell theory has been proposed as and alternative and/or supplemental view of newborning melanoma cells. It has been described that melanoma cells derived from metastatic melanoma specimens as well as melanoma cell lines are able to grow in an embryonic stem cell-based media and these melanoma stem-like cells possess capacity of self-renewal and high tumorigenicity. In 2005 the first evidence of a stem-cell like population existence in human melanoma has been provided. CD133 or prominin-1 is one of most studied marker of staminality expressed by melanoma cells; specifically, the down regulation of CD133 leads to a reduced cell capacity to metastatize. Nevertheless, there is disagreement concerning the constant presence of CD133þ cells in primary and metastatic melanomas. ABCB5, the third member of the human P-gp family, is a rhodamine and doxorubicin efflux transporter, identified as a novel drug transporter involved in drugresistance in human malignant melanoma. ABCB5 was found to be specifically expressed on CD133þ tumor

Circulating tumor cells count and characterization in a male breast cancer patient.

A 64-y-old man presented to Medical Oncology Department a metastatic invasive ductal breast carcinoma, positive for estrogen (ER) and progesterone receptors (PR) and Her2/neu negative. The patient was treated with different lines of therapy, with rapid radiological progression of disease. After four courses of a third-line chemotherapy, a radiological stable disease was maintained. The patient was followed by serial blood drawings for the characterization and count of circulating tumor cells (CTC). This is the first report concerning the predictive and prognostic value of CTC in a male breast cancer patient.

55 Circulating tumor cells and their prognostic significance in non-muscle invasive bladder cancer: A cell search analysis

INTRODUCTION & OBJECTIVES: Although most cases of bladder cancer patients present with a disease that is confined to mucosa (Ta) or submucosa (T1), recurrence rate is greater than 50%. Furthermore, some non-muscleinvasive bladder cancer (NMIBC), more frequently T1G3, present with biological features of invasiveness, leading to cancer death after bladder-sparing treatment within 5 years in about 16–23% of cases. Circulating tumor cells (CTCs) play a crucial role for distant failure in different types of solid tumors. Their enumeration through Cell Search system (Veridex) is widely used for prognostic information in patients with metastatic breast, colon and prostate cancer. Recent studies have shown that CTCs are released in circulation in a very early phase of cancer disease where their presence is associated with a worse prognosis of patients and CTC count could reflect the ongoing progression of cancer disease.