A new approach to epithelial-mesenchymal transition diagnostics in epithelial tumors: double immunofluorescent staining and flow cytometry

Ultra high content analyses of circulating and tumor associated hybrid cells reveal phenotypic heterogeneity

Persistently high, worldwide mortality from cancer highlights the unresolved challenges of disease surveillance and detection that impact survival. Development of a non-invasive, blood-based biomarker would transform survival from cancer. We demonstrate the functionality of ultra-high content analyses of a newly identified population of tumor cells that are hybrids between neoplastic and immune cells in patient matched tumor and peripheral blood specimens. Using oligonucleotide conjugated antibodies (Ab-oligo) permitting cyclic immunofluorescence (cyCIF), we present analyses of phenotypes among tumor and peripheral blood hybrid cells. Interestingly, the majority of circulating hybrid cell (CHC) subpopulations were not identified in tumor-associated hybrids. These results highlight the efficacy of ultra-high content phenotypic analyses using Ab-oligo based cyCIF applied to both tumor and peripheral blood specimens. The combination of a multiplex phenotypic profiling platform that is gentle enough to analyze blood to detect and evaluate disseminated tumor cells represents a novel approach to exploring novel tumor biology and potential utility for developing the population as a blood-based biomarker in cancer.

Pathophysiological Role of Vimentin Intermediate Filaments in Lung Diseases

Vimentin intermediate filaments, a type III intermediate filament, are among the most widely studied IFs and are found abundantly in mesenchymal cells. Vimentin intermediate filaments localize primarily in the cytoplasm but can also be found on the cell surface and extracellular space. The cytoplasmic vimentin is well-recognized for its role in providing mechanical strength and regulating cell migration, adhesion, and division. The post-translationally modified forms of Vimentin intermediate filaments have several implications in host-pathogen interactions, cancers, and non-malignant lung diseases. This review will analyze the role of vimentin beyond just the epithelial to mesenchymal transition (EMT) marker highlighting its role as a regulator of host-pathogen interactions and signaling pathways for the pathophysiology of various lung diseases. In addition, we will also examine the clinically relevant anti-vimentin compounds and antibodies that could potentially interfere with the pathogenic role of Vimentin intermediate filaments in lung disease.

Dynamic Monitoring of EMT in CTCs as an Indicator of Cancer Metastasis

Epithelial to mesenchymal transition (EMT) results in the genesis of circulating tumor cells (CTCs) from tumor sites and promotes the metastatic capability of CTCs in circulation. In this study, we develop a multiplex surface-enhanced Raman scattering nanotechnology for comprehensive characterization of EMT-associated phenotypes in CTCs, to monitor cancer metastasis. We observe the downregulation of the CTC marker (EpCAM) and the epithelial marker (E-cadherin), as well as the upregulation of a mesenchymal marker (N-cadherin) and a stem cell marker (ABCB5) during the transforming growth factor-β-induced EMT process in breast cancer cell line models. Additionally, we also find changes in the heterogeneity levels of these selected markers in cells. With this method, we successfully detect the presence of disease in samples from breast cancer patients and characterize EMT-associated phenotypes in their CTCs. Overall, this approach and findings provide a new means for monitoring the EMT process in cancer, insights into the detailed mechanistic progress of the diseases, and have potential for detecting the early occurrence of cancer metastasis.

The expression and clinical significance of ERβ/ERα in ovarian cancer: can we predict the effectiveness of platinum plus taxane therapy?

Estrogens play an extremely important role in regulating the proliferation of ovarian cancer. The estrogen receptor alpha (ERα) stimulates cell growth, whereas ERβ can be attributed to tumor suppressors. The study aims to assess the relationship between the expression of estrogen receptors in tumors and the efficacy of front-line platinum plus taxane chemotherapy in ovarian cancer patients.

MATERIALS AND METHODS

ERα and ERβ tumor expression was evaluated quantitatively by flow cytometry in a narrowly defined group (31 patients): stage III high-grade serous ovarian carcinoma (HGSOC), suboptimal surgical cytoreduction, front-line platinum plus taxane chemotherapy (front-line, six cycles).

RESULTS

The median of progression-free survival (PFS) was 2 times greater (18 vs 8 months, p = 0.04) and the recurrence risk (HR) was 2.2 times (95 % CI: 1.1-6.2, p = 0.04) lower in the group with high (in more than 40% of the cells) vs low level of ERβ tumor expression. The statistically significant difference between PFS in the groups with high vs low tumor ERα expression was not revealed.

CONCLUSION

A high level of ERβ and not ERα expression can predict the efficacy of front-line platinum plus taxane chemotherapy in stage III HGSOC patients. The status of estrogen receptor beta can be considered as one of the possible predictors for evaluating the effectiveness of ovarian cancer therapy.

Quantitative spectrofluorometric assay detecting nuclear condensation and fragmentation in intact cells

At present, nuclear condensation and fragmentation have been estimated also using Hoechst probes in fluorescence microscopy and flow cytometry. However, none of the methods used the Hoechst probes for quantitative spectrofluorometric assessment. Therefore, the aim of the present study was to develop a spectrofluorometric assay for detection of nuclear condensation and fragmentation in the intact cells. We used human hepatoma HepG2 and renal HK-2 cells cultured in 96-well plates treated with potent apoptotic inducers (i.e. cisplatin, staurosporine, camptothecin) for 6-48 h. Afterwards, the cells were incubated with Hoechst 33258 (2 µg/mL) and the increase of fluorescence after binding of the dye to DNA was measured. The developed spectrofluorometric assay was capable to detect nuclear changes caused by all tested apoptotic inducers. Then, we compared the outcomes of the spectrofluorometric assay with other methods detecting cell impairment and apoptosis (i.e. WST-1 and glutathione tests, TUNEL, DNA ladder, caspase activity, PARP-1 and JNKs expressions). We found that our developed spectrofluorometric assay provided results of the same sensitivity as the TUNEL assay but with the advantages of being fast processing, low-cost and a high throughput. Because nuclear condensation and fragmentation can be typical markers of cell death, especially in apoptosis, we suppose that the spectrofluorometric assay could become a routinely used method for characterizing cell death processes.