Microfluidic live tracking and transcriptomics of cancer-immune cell doublets link intercellular proximity and gene regulation.

Cell-cell communication and physical interactions play a vital role in cancer initiation, homeostasis, progression, and immune response. Here, we report a system that combines live capture of different cell types, co-incubation, time-lapse imaging, and gene expression profiling of doublets using a microfluidic integrated fluidic circuit that enables measurement of physical distances between cells and the associated transcriptional profiles due to cell-cell interactions. We track the temporal variations in natural killer-triple-negative breast cancer cell distances and compare them with terminal cellular transcriptome profiles. The results show the time-bound activities of regulatory modules and allude to the existence of transcriptional memory. Our experimental and bioinformatic approaches serve as a proof of concept for interrogating live-cell interactions at doublet resolution. Together, our findings highlight the use of our approach across different cancers and cell types.

Circulating Tumor Cells in Desmoid Tumors: New Perspectives.

INTRODUCTION: Desmoid tumor (DT) is a rare neoplasm with high local recurrence rates, composed of fibroblastic cells that are characterized by the expression of key molecules, including the intermediate filament vimentin, cyclooxygenase-2 (COX-2), and nuclear ß-catenin, and lack of epithelial markers. Circulating tumor cells (CTCs) isolated from the peripheral blood of patients with sarcomas and other neoplasms can be used as early biomarkers of tumor invasion and dissemination. Moreover, CTCs can also re-colonize their tumors of origin through a process of "tumor self-seeding." OBJECTIVES: We aimed to identify CTCs in the peripheral blood of patients with DT and evaluate their expression of ß-catenin, transforming growth factor receptor I (TGF-ßRI), COX-2, and vimentin proteins. MATERIAL AND METHODS: We conducted a prospective study of patients with initial diagnosis or relapsed DT with measurable disease. Blood samples from each patient were processed and filtered by ISET® (Rarecells, France) for CTC isolation and quantification. The CTC expression of ß-catenin, COX-2, TGF-ßRI, and vimentin was analyzed by immunocytochemistry (ICC). RESULTS: A total of 18 patients were included, and all had detectable CTCs. We found a concordance of ß-catenin expression in both CTCs and primary tumors in 42.8% (6/14) of cases by using ICC and immunohistochemistry, respectively. CONCLUSIONS: Our study identified a high prevalence of CTCs in DT patients. Concordance of ß-catenin expression between primary tumor and CTCs brings new perspectives to assess the dynamics of CTCs in the blood compartment, opening new avenues for studying the biology and behavior of DT. In addition, these results open the possibility of using CTCs to predict DT dynamics at the time of disease progression and treatment. Further studies with larger sample sizes are needed to validate our findings.

Advances in the Characterization of Circulating Tumor Cells in Metastatic Breast Cancer: Single Cell Analyses and Interactions, and Patient-Derived Models for Drug Testing.

Metastasis is the major cause of breast cancer death worldwide. In metastatic breast cancer, circulating tumor cells (CTCs) can be captured from patient blood samples sequentially over time and thereby serve as surrogates to assess the biology of surviving cancer cells that may still persist in solitary or multiple metastatic sites following treatment. CTCs may thus function as potential real-time decision-making guides for selecting appropriate therapies during the course of disease or for the development and testing of new treatments. The heterogeneous nature of CTCs warrants the use of single cell platforms to better inform our understanding of these cancer cells. Current techniques for single cell analyses and techniques for investigating interactions between cancer and immune cells are discussed. In addition, methodologies for growing patient-derived CTCs in vitro or propagating them in vivo to facilitate CTC drug testing are reviewed. We advocate the use of CTCs in appropriate microenvironments to appraise the effectiveness of cancer chemotherapies, immunotherapies, and for the development of new cancer treatments, fundamental to personalizing and improving the clinical management of metastatic breast cancer.

Genomics and epidemiology for gastric adenocarcinomas (GE4GAC): a Brazilian initiative to study gastric cancer

Gastric cancer (GC) is the fifth most common type of cancer worldwide with high incidences in Asia, Central, and South American countries. This patchy distribution means that GC studies are neglected by large research centers from developed countries. The need for further understanding of this complex disease, including the local importance of epidemiological factors and the rich ancestral admixture found in Brazil, stimulated the implementation of the GE4GAC project. GE4GAC aims to embrace epidemiological, clinical, molecular and microbiological data from Brazilian controls and patients with malignant and pre-malignant gastric disease. In this letter, we summarize the main goals of the project, including subject and sample accrual and current findings

Prolonged time to progression with fulvestrant for metastatic breast cancer.

Although the incidence of breast cancer has been declining in recent years, the disease is still one of the leading causes of cancer deaths in women. Recently, breast cancer has been treated with innovative approaches that use hormone-sensitive therapies. This is because in at least one-third of breast cancers, estrogens mediated via the estrogen receptor pathway act as endocrine growth factors. Fulvestrant has been studied as both first- and second-line therapy for locally advanced and metastatic breast cancer, but few studies have shown its effect as third-line therapy alone. To observe the disease time to progression (TTP) obtained with fulvestrant when used on metastatic breast cancer as first-, second-, and also third-line therapy. We also aimed to correlate the TTP obtained with fulvestrant with hormone receptor, HER2 expression, and metastatic site. This was a cohort study that retrospectively examined medical records of 73 postmenopausal women with advanced breast cancer who were treated with fulvestrant (250 mg/month i.m. injection) and followed at the Department of Medical Oncology at Hospital do Cancer A. C. Camargo in São Paulo, Brazil from August 2003 to December 2006. The median TTP with fulvestrant was about 11 months. When used as the first-line therapy, TTP was about 13 months; when used as second-line, TTP was about 6 months; and when used as third-line, it was about 12 months. No statistically significant difference was observed regarding the therapy line. In patients with positive ER tumors, TTP was 11 months. No significant difference in TTP was observed in negative ER tumors (TTP = 10 months). In patients with positive PgR tumors, TTP was 13 months and for negative PgR, TTP was 6 months (P = 0.008). According to the HER2 status, the TTP was 5 months for HER2+ and 10 months for HER2-. Our findings indicate that fulvestrant is an effective alternative for treatment of metastatic breast cancer.

Predictors of peritoneal carcinomatosis in patients with gastric cancer treated at a single institution in Brazil.

BACKGROUND: Peritoneal carcinomatosis is a common pattern of recurrence in gastric cancer and is associated with a poor prognosis. Determining predictive factors for peritoneal recurrence can help the selection of patients suitable for more aggressive treatment strategies. METHODS: A retrospective chart review of 162 patients diagnosed with gastric cancer with no peritoneal carcinomatosis and treated at a single institution in Brazil from January 1994 to December 2004 was carried out. Univariate and multivariate analyses were performed to identify patient and tumor-related characteristics associated with the development of peritoneal metastasis. RESULTS: Twenty-three (14.2%) patients developed peritoneal carcinomatosis. Three independent factors associated with the development of peritoneal metastasis were identified by multivariate analysis: signet-ring cell histology (odds ratio [OR] = 4.9; P = 0.018), the presence of vascular invasion (OR = 4.8; P = 0.022), and the presence of visceral metastasis at diagnosis (OR = 5.1; P = 0.011). Tumor stages T3 or T4 showed a trend towards significance (P = 0.062). CONCLUSIONS: Patients with gastric cancer presenting with signet-ring histology, vascular invasion, or visceral metastasis appear to be at higher risk for the development of peritoneal carcinomatosis.

Factors correlated with peritoneal carcinomatosis and survival in patients with gastric cancer treated at a single institution in Brazil.

BACKGROUND: Gastric cancer is the second leading cause of death due to cancer worldwide and is particularly prevalent in Brazil. Promising new therapeutic agents have already shown activity in some gastrointestinal malignancies and their role in gastric cancer will need to be evaluated. Determining the prognostic factors of survival for patients with gastric cancer can help in identifying patients with a worse prognosis after treatment with the current chemotherapeutic regimens. METHODS: A retrospective chart review of 186 patients diagnosed with gastric cancer and treated at a single institution in Brazil from January 1994 to December 2004 was carried out. Univariate and multivariate analyses were performed to identify patient- and tumor-related characteristics associated with peritoneal metastasis at diagnosis and with overall survival. RESULTS: Of the 186 patients, 76 were alive at the time of this analysis. The median survival for all patients was 30.1 months. Two independent factors associated with the presence of peritoneal metastasis at diagnosis were identified by multivariate analysis: signet-ring cell type (odds ratio [OR], 10.8; 95% confidence interval [CI], 3.1 to 37.5), and visceral metastasis (OR, 51.8; 95% CI, 12.4 to 215.4). The prognostic factors for poor survival were tumor stage T3 or T4 (hazard ratio [HR], 1.87; 95% CI, 1.09 to 3.22) and visceral metastasis (HR, 4.98; 95% CI, 3.02 to 8.20). CONCLUSION: Two factors correlated with peritoneal metastasis and two prognostic factors for survival were identified. These findings may contribute to clinical decision-making, treatment tailoring, and the design of future trials.

Recombinant interleukin-4-treated macrophages, epithelioid cell surrogates, harbor and arrest Mycobacterium avium multiplication in vitro.

Our group has previously described that murine peritoneal macrophages treated in vitro for 7 days with recombinant interleukin-4 (rIL-4) acquire morphological and functional characteristics of epithelioid cells (ECs) found in granulomatous lesions. Although EC function has not been clarified so far, it has been suggested that these cells could present antigens and control multiplication of mycobacteria. These aspects have been addressed here using in vitro EC surrogates. Using immunocytochemistry and immunofluorescence methods, we have observed an increased expression of CD11b, CD54, CD86 and CD40 molecules on rIL-4-treated macrophages when compared to untreated ones. Cytokine-treated cells were less phagocytic for latex beads (P<0.03) and more pinocytic for dextran particles than untreated macrophages. T-cell lymphoproliferation assays using ovalbumin (OVA) and Mycobacterium avium as antigens showed that both cultured macrophages were equally efficient as antigen presenting cells (APCs). However, M. avium antigens were better presented in vivo by EC surrogates (P<0.01). Both macrophage cultures were similarly infected by M. avium. However, while the infection level was maintained in the cytokine-treated population, untreated macrophages showed a progressive increase in the number of bacilli/cell with time (P<0.01) and a reduction of about 65% in cell population. After 96 h of M. avium infection, untreated cells secreted higher amounts of tumor necrosis factor-alpha (P<0.005) while rIL-4-treated macrophages showed higher, although not significant, transforming growth factor-beta production. Also, EC surrogates produced less nitric oxide than control macrophages (P<0.05). Hence, EC surrogates restrain M. avium growth and act as APCs in vitro and in vivo.