Vimentin Association with Nuclear Grooves in Normal MEF 3T3 Cells

Vimentin, an intermediate filament protein present in leukocytes, blood vessel endothelial cells, and multiple mesenchymal cells, such as mouse embryonic fibroblasts (MEF 3T3), is crucial for various cellular processes, as well as for maintaining the integrity and durability (stability) of the cell cytoskeleton. Vimentin intermediate filaments (VIFs) adhere tightly to the nucleus and spread to the lamellipodium and tail of the cell, serving as a connector between the nucleus, and the cell's edges, especially in terms of transferring mechanical signals throughout the cell. How these signals are transmitted exactly remains under investigation. In the presented work, we propose that vimentin is involved in that transition by influencing the shape of the nucleus through the formation of nuclear blebs and grooves, as demonstrated by microscopic observations of healthy MEF (3T3) cells. Grooved, or "coffee beans" nuclei, have, to date, been noticed in several healthy cells; however, these structures are especially frequent in cancer cells-they serve as a significant marker for recognition of multiple cancers. We observed 288 MEF3T3 cells cultured on polyhydroxyoctanoate (PHO), polylactide (PLA), and glass, and we identified grooves, coaligned with vimentin fibers in the nuclei of 47% of cells cultured on PHO, 50% of cells on glass, and 59% of cells growing on PLA. We also observed nuclear blebs and associated their occurrence with the type of substrate used for cell culture. We propose that the higher rate of blebs in the nuclei of cells, cultured on PLA, is related to the microenvironmental features of the substrate, pH in particular.

Image analysis of the nuclear characteristics of emerin protein and the correlation with nuclear grooves and intranuclear cytoplasmic inclusions in lung adenocarcinoma

Nuclear size and shape are important components in the diagnosis of pathological specimens. However, a qualitative evaluation is typically applied rather than a quantitative evaluation technique. In the present study, we sought to evaluate the nuclear morphological characteristics of lung adenocarcinoma using whole-slide imaging (WSI) and computer-assisted image analysis (IA). We evaluated the nuclear characteristics of 106 cases of surgically resected lung adenocarcinoma according to Feulgen staining and immunohistochemistry (IHC) for the inner nuclear membrane protein emerin. According to the Feulgen reaction, although the nuclear area (size) of the carcinoma cells was correlated with the nuclear perimeter (NP) (R=0.8973), the nuclear staining intensity of carcinoma cells was not correlated with the nuclear area. Using emerin IHC, we used IA software that was able to detect both the NP and the emerin-stained nuclear membrane length (ENML) in the nucleus, and found that the more nuclei exhibited a longer ENML relative to the NP, the more nuclear grooves and intranuclear cytoplasmic inclusions were present. In addition, the nuclear area was correlated with the percentage of nuclei that had a longer ENML compared to the NP against the total nuclei (R=0.7759). Furthermore, the emerin low expression group showed an enlarged nuclear area (P=0.0264), elongated NP (P=0.0091), and lower shape factor (P=0.0486) compared with the normal emerin expression group. Our data indicated the usefulness of WSI and IA for pathological specimen analysis. In addition, this study is the first to report that the low expression of emerin in cancer cell results in an oval shape of nuclei and nuclear enlargement in clinical samples.

Nuclear pseudoinclusions in melanoma cells: prognostic fact or artifact? The possible role of Golgi phosphoprotein 3 overexpression in nuclear pseudoinclusions generation

Nuclear pseudoinclusions (NPIs) are classically found in papillary thyroid carcinoma and meningioma. Although NPIs have been described in melanocytic lesions, there is no systematic analysis of potential relationship between NPIs and other clinicopathological characteristics of melanoma. We examined the presence of NPIs in H&E-stained tissue sections form 96 melanomas and analyzed statistical associations with important clinicopathological parameters and tissue immunoreactivity for selected proteins involved in epithelial-mesenchymal transition (SPARC, N-cadherin), cell adhesion and mobility (ALCAM, ADAM-10), regulation of mitosis (PLK1), cell survival (FOXP1) and functioning of Golgi apparatus (GOLPH3, GP73). NPIs were observed in 20% of melanomas and their presence correlated with high mitotic rate and ulceration of the tumor, but not with Breslow thickness, histologic type, or presence of metastases. We observed a significant correlation with shorter cancer-specific survival, but not disease-free survival. Presence of NPIs was related to high expression of GOLPH3 in melanoma cells, whereas their absence was linked to enhanced immunoreactivity of GOLPH3 in tumor-associated macrophages. NPIs are not an uncommon finding in skin melanoma and their diagnostic and prognostic utility could be helpful in the daily routine histopathological practice. The possible explanation of NPI generation is associated with enhanced activity of Golgi apparatus in melanoma cells.

Intranuclear Inclusions in Conventional Clear Cell Renal Cell Carcinoma (ccRCC): Diagnosis and Differential Diagnosis

Intranuclear inclusions are important diagnostic features in many benign and malignant neoplasms. It has also been identified in major epithelial subtypes of renal cell carcinomas (RCCs), particularly in the chromophobe RCC. However, the finding in ccRCC has not been well studied. The finding of intranuclear inclusions may cause diagnostic difficulty, particularly in metastatic lesions. Herein, we reported a case of ccRCC with prominent intranuclear inclusions. The tumor also metastasized to local lymph nodes. Furthermore, in contrast to previous publications, we also found that intranuclear inclusions were immunoreactive with anti-PAX8 (paired box8) antibody. The potential diagnostic and clinical implications of intranuclear inclusions in ccRCC need to be addressed.

Mucin-secreting clear cell renal cell carcinoma. A rare variant of conventional renal cell carcinoma

We report herein one case of conventional renal cell carcinoma (RCC) producing extensive extracellular mucinous secretion in a 71-year-old man. To the best of our knowledge, the presence of mucinous secretion in this tumor has not been documented. Mucin production, despite its low frequency, can be considered an additional feature of conventional RCC. Therefore, clear cell RCC should be added to the list of parenchymal renal tumors that can show significant mucin secretion; and it should be included in the inventory of morphologic variations of this tumor, which may cause diagnostic difficulties. It is of primary importance to distinguish mucin-secreting clear cell RCC from the metastasis of a mucin-secreting tumor to conventional RCC. Presence of mucin in a clear cell carcinoma does not exclude a renal origin.