Quantitative analysis of nuclear shape in oral squamous cell carcinoma is useful for predicting the chemotherapeutic response

Effect of human survivin-2B-specific cytotoxic CD8+ T lymphocytes on CD44+/- HSC-2 and HSC-3 oral cancer cells

Despite advancements in the treatment of oral cancer, cancer survival rates remain low, highlighting the need for new therapeutic strategies targeting cancer stem-like cells. Cancer stem-like cells are a small population of cancer cells within tumors that drive recurrence and metastasis. They are often resistant to conventional treatments. Immunotherapy has shown promise against cancer stem-like cells, particularly with the use of cytotoxic T lymphocytes targeting specific markers. Survivin, an apoptosis protein inhibitor, is overexpressed in several malignancies, including oral cancer, and is associated with tumor recurrence and reduced survival. Survivin-2B-specific cytotoxic T lymphocytes were produced and evaluated for their ability to target CD44+ (cancer stem-like cells) and CD44- cells (non-cancer stem-like cells), respectively, from oral cancer cell lines (HSC-2 and HSC-3, respectively). Quantitative polymerase chain reaction (qPCR) analysis confirmed similar survivin-2B expression in both cell types. Cytotoxic T lymphocyte assays revealed the effective lysis of both cancer stem-like cells and CD44- cell populations, supporting the potential of survivin-2B-specific cytotoxic T lymphocytes to overcome cancer stem-like cell-associated resistance. These findings suggest that survivin-2B peptide vaccines are effective in preventing cancer relapse by targeting cancer stem-like cells, with future directions aimed at developing multipeptide "cocktail" vaccines to reduce the risk of immune evasion.

A Study of Gene Expression, Structure, and Contractility of iPSC-Derived Cardiac Myocytes from a Family with Heart Disease due to LMNA Mutation

Genetic mutations to the Lamin A/C gene (LMNA) can cause heart disease, but the mechanisms making cardiac tissues uniquely vulnerable to the mutations remain largely unknown. Further, patients with LMNA mutations have highly variable presentation of heart disease progression and type. In vitro patient-specific experiments could provide a powerful platform for studying this phenomenon, but the use of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) introduces heterogeneity in maturity and function thus complicating the interpretation of the results of any single experiment. We hypothesized that integrating single cell RNA sequencing (scRNA-seq) with analysis of the tissue architecture and contractile function would elucidate some of the probable mechanisms. To test this, we investigated five iPSC-CM lines, three controls and two patients with a (c.357-2A>G) mutation. The patient iPSC-CM tissues had significantly weaker stress generation potential than control iPSC-CM tissues demonstrating the viability of our in vitro approach. Through scRNA-seq, differentially expressed genes between control and patient lines were identified. Some of these genes, linked to quantitative structural and functional changes, were cardiac specific, explaining the targeted nature of the disease progression seen in patients. The results of this work demonstrate the utility of combining in vitro tools in exploring heart disease mechanics.

nPAsym: an open-source plugin for ImageJ to quantify nuclear shape asymmetry

BACKGROUND AND OBJECTIVES

The nucleus is a complex and dynamic organelle enclosing the major part of the cell's genome. A growing body of evidence suggests that changes in the shape of this organelle can influence cell activities. The other way around, altered nuclear shape may be indicative of impaired cell function. Symmetry is an important aspect of nuclear shape not receiving the attention it merits. We address this problem by presenting a software tool allowing to quantify nuclear shape asymmetry in light microscopy images.

METHODS

The software named nPAsym is written in Scala and implemented as a plugin to ImageJ making possible to use it in combination with other ImageJ tools. The plugin works with 8-bit images segmented into black nuclear masks and white background. It performs a number of operations allowing to analyze multiple objects within a single image, removing some segmentation artefacts, filtering out objects incomplete and below a specified size. The feature of interest is quantified using the notion of point asymmetry. The performance of nPAsym was tested in a small-scale study comparing nuclear shapes for cells of nodular goiter, follicular thyroid adenoma and papillary thyroid carcinoma.

RESULTS

We present nPAsym, the ImageJ plugin, that measures nuclear shape asymmetry. It works with digital microscopic images segmented using either a raster graphics editor or built-in ImageJ functions. nPAsym is packaged in a single .jar file and does not require installation as well as configuration. It has proved effective in distinguishing between some of the nuclear shape phenotypes.

CONCLUSIONS

nPAsym is the user-friendly, platform-independent and open-source software tool allowing to quantify nuclear shape asymmetry in digital images captured from cytologic and histologic preparations. It has a potential to become useful for both experimental research and diagnostics.

Age of heart disease presentation and dysmorphic nuclei in patients with LMNA mutations

Nuclear shape defects are a distinguishing characteristic in laminopathies, cancers, and other pathologies. Correlating these defects to the symptoms, mechanisms, and progression of disease requires unbiased, quantitative, and high-throughput means of quantifying nuclear morphology. To accomplish this, we developed a method of automatically segmenting fluorescently stained nuclei in 2D microscopy images and then classifying them as normal or dysmorphic based on three geometric features of the nucleus using a package of Matlab codes. As a test case, cultured skin-fibroblast nuclei of individuals possessing LMNA splice-site mutation (c.357-2A>G), LMNA nonsense mutation (c.736 C>T, pQ246X) in exon 4, LMNA missense mutation (c.1003C>T, pR335W) in exon 6, Hutchinson-Gilford Progeria Syndrome, and no LMNA mutations were analyzed. For each cell type, the percentage of dysmorphic nuclei, and other morphological features such as average nuclear area and average eccentricity were obtained. Compared to blind observers, our procedure implemented in Matlab codes possessed similar accuracy to manual counting of dysmorphic nuclei while being significantly more consistent. The automatic quantification of nuclear defects revealed a correlation between in vitro results and age of patients for initial symptom onset. Our results demonstrate the method’s utility in experimental studies of diseases affecting nuclear shape through automated, unbiased, and accurate identification of dysmorphic nuclei.

Nuclear morphologies: their diversity and functional relevance

Studies of chromosome and genome biology often focus on condensed chromatin in the form of chromosomes and neglect the non-dividing cells. Even when interphase nuclei are considered, they are often then treated as interchangeable round objects. However, different cell types can have very different nuclear shapes, and these shapes have impacts on cellular function; indeed, many pathologies are linked with alterations to nuclear shape. In this review, we describe some of the nuclear morphologies beyond the spherical and ovoid. Many of the leukocytes of the immune system have lobed nuclei, which aid their flexibility and migration; smooth muscle cells have a spindle shaped nucleus, which must deform during muscle contractions; spermatozoa have highly condensed nuclei which adopt varied shapes, potentially associated with swimming efficiency. Nuclei are not passive passengers within the cell. There are clear effects of nuclear shape on the transcriptional activity of the cell. Recent work has shown that regulation of gene expression can be influenced by nuclear morphology, and that cells can drastically remodel their chromatin during differentiation. The link between the nucleoskeleton and the cytoskeleton at the nuclear envelope provides a mechanism for transmission of mechanical forces into the nucleus, directly affecting chromatin compaction and organisation.