Biochemical and ultrastructural correlations of calreticulin and thioredoxin expression in breast mucinous carcinoma and infiltrating ductal carcinoma non-special type.

Mucinous infiltrating invasive ductal adenocarcinoma consists of 2-4% invasive breast cancer, but is a very interesting type due to its macroscopic similarity to non-special-type (NST) ductal carcinoma. The macroscopic similarity of mucinous and infiltrating ductal carcinoma NST adenocarcinomas consists of a loose and edematous stroma, which is often seen in portions of NST carcinoma and may mimic the mucin pools of mucinous carcinoma. In this study the authors examined the ultrastructural differences between mucinous carcinoma and infiltrating ductal carcinoma NST. They also examined the protein expression of the tissues by 2D electrophoresis due to their belief that from the results of these two levels it is possible to understand the changes that take place both in the ultrastructural and biochemical levels in these two types of breast cancer. The ultrastructural results from mucinous carcinoma have shown many changes in cytoplasmic organelles in comparison to normal samples, depending on the grade and the number of metastatic lymph nodes. At the 2D elecrophoresis level the authors studied two interesting polypeptides, calreticulin and thioredoxin. Both of these proteins were found in patterns of fibroadenoma, mucinous carcinoma, and NST carcinoma, but with different quantitative expression among them. In the future the quantitative differences of these two proteins may provide specific tumor markers for these two types of carcinoma.

Mucinous colorectal adenocarcinoma with signet-ring cells: immunohistochemical and ultrastructural study.

A primary mucinous colorectal adenocarcinoma tissue with signet-ring cells, as revealed after histological evaluation, was examined ultrastructurally. The authors also analyzed the immunohistochemical data of the tissue for serotonin, vasoactive intestinal polypeptide (VIP), bombesin, somatostatin, and glucagon, using the peroxidase anti-peroxidase (PAP) method and the immunogold labeling method for light and electron microscope, respectively. Electron microscopically mucinous adenocarcinoma was characterized by the formation of small lumen. Adenocarcinoma cells were full of mucous granules of varying electron density, providing a good environment for the tumor cells to grow. They also exhibited a significant loss of microvilli and intracytoplasmic junctions, which could allow the cells to disseminate. Signet-ring cells were located in the basal site of the ducts or in the lamina propria and appeared neoplastic, with mucin accumulation intracellularly and an eccentric crescent-shaped nucleus. The cytoplasmic organelles were decreased and at the periphery of the cell. The PAP method demonstrated that these cells were strongly positive for bombesin and also positive for vasointestinal polypeptide (VIP). The immunogold method detected bombesin immunoreactivity in the vacuoles as well as in other cytoplasmic membranes, whereas VIP was localized mainly in the plasma membrane. The location of signet-ring cells combined with the immunoreactivity for bombesin and VIP indicated that signet-ring cells were of neuroendocrine origin and probably dedifferentiated enterochromaffin-like endocrine cells. These findings have implications for understanding the biological behavior of these composite malignant tumors and could help in the knowledge of the origin of signet-ring cells.

Extra-long projections of the cell surface in nonspecial-type ductal carcinoma with vascular invasion under the scanning electron microscope.

In this study, cell surface projections of primary culture cells from tissues of infiltrating ductal carcinoma Non Special Type with vascular invasion are examined by use of the Scanning Electron Microscopy method. In these cases the projections of cell membrane appeared extremely long and bridge-like covering very long distances between the breast cancer cells. Also, the long cell membrane projections, connect cells between them and form a complex. Sometimes, from one edge to another we observed a very long chain of cancer cells reaching sometimes a length of 3, 3 mm. On the other hand the absence of vascular invasion never shows such long projections of the cell membrane even if there are many metastatic nodes. The role of these extra long projections in communication between cancer cells is determinant. Through this communication, these long projections seemed to be responsible for the metastatic process in primary breast cancer with vascular invasion.

Two-dimensional electrophoretic analysis of nuclear matrix proteins in human colon adenocarcinoma.

The aim of the present study was to observe possible qualitative and quantitative expression differences between nuclear matrix proteins (NMPs) of human colon adenocarcinoma and their mirror biopsies, using the technique of two-dimensional gel electrophoresis, in order to identify the existence of specific NMP fingerprints for colon cancer. Colon tissues were examined ultrastructurally and NMPs were isolated biochemically, by serial extraction of lipids, soluble proteins, DNA, RNA, and intermediate filaments and were separated according to their isoelectric point (pI) and their molecular weight (MW) by high-resolution two-dimensional electrophoresis (2D). By comparing the 2D electropherograms of colon cancer tissues and mirror biopsy tissues we observed qualitative and quantitative expression differences between their NMPs but also a differentiation of NMP composition between the stages of malignancy. Moreover, despite the similarities between mirror biopsy samples, a highlight percentage of exception was observed. Electrophoretic results provided in this study demonstrated that the examined NMPs could be further investigated as potential markers for detection of colorectal cancer in an early stage, for the assessment of the disease progression, as well as useful tools for individual therapy and for preventing a possible recurrence of cancer and metastasis.

Two-dimensional electrophoresis and immunohistochemical study of calreticulin in colorectal adenocarcinoma and mirror biopsies.

PURPOSE: The purpose of this study was to analyse the polypeptide patterns of colorectal adenocarcinomas and mirror biopsies and to investigate the expression of calreticulin and the relationship of this chaperon to colon cancer. MATERIALS AND METHODS: The investigation was carried out on 21 adenocarcinomas and 21 mirror biopsies using high-resolution two-dimensional (2D) electrophoresis and immunohistochemical PAP method. RESULTS: 2D electrophoresis revealed several polypeptide patterns that were shown to be upregulated in colorectal adenocarcinomas compared to their mirror biopsies. One polypeptide spot being upregulated in colorectal adenocarcinoma, turned out to be calreticulin. The overexpression of calreticulin was confirmed by further examination in immunohistochemical level. CONCLUSION: Calreticulin was found overexpressed in colon cancer tissues as compared to the corresponding mirror biopsy tissues. The overexpression was particularly intense to high-malignancy tissues and particularly in the poorly differentiated regions of the tissue. Calreticulin showed a direct relationship to the disease stage, a fact strongly indicating that the functional role of calreticulin is directly associated with tumor growth and metastasis.

Surface topography and ultrastructural changes of mucinous carcinoma breast cells.

Mucinous carcinoma of the breast (MCB) is histologically classified into 2 groups: (1) pure MCB and (2) mixed MCB. Pure MCB carries a better diagnosis than mixed MCB. This research relates to the cell surface topography and ultrastructure of the cells in the above cases and aims to find the differences between them, by means of two methods: scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For the SEM examination, it was necessary to initially culture the MCB tissues and then proceed with the usual SEM method. In contrast, for the TEM technique, MCB tissues were initially fixed followed by the classic TEM method. The authors found the topography of pure MCB cases to be without nodes. The cell membrane was smooth, with numerous pores and small ruffles that covered the entire cell. The ultrastructural appearance of the same cases was with a normal cell membrane containing abundant collagen fibers. They also had many small vesicles containing mucin as well as secretory droplets. In contrast the mixed MCB had a number of lymph nodes and their cell surface topography showed stronger changes such as microvilli, numerous blebs, ruffles and many long projections. Their ultrastructure showed very long microvilli with large cytoplasmic inclusions and extracellular mucin collections, electron-dense material vacuoles, and many important cytoplasmic organelles. An important fact is that mixed MCB also contains areas of infiltrating ductal carcinoma. These cells of the cytoplasmic organelles are clearly responsible for the synthesis, storage, and secretion of the characteristic mucin of this tumor type. Evidently, this abnormal mucin production and the abundance of secretory granules along with the long projections observed in the topographical structure might be responsible for transferring tumor cells to neighboring organs, thus being responsible for metastatic disease.

Immunoelectron study of pancreatic carcinomas using antibodies to gastrointestinal hormones.

The aim of this study was to investigate the ultrastructural appearance of pancreatic adenocarcinoma combined with glucagon and gastrin/cholecystokinin (CCK) expression. The authors investigated the ultrastructure and the immunocytochemistry of 12 human pancreatic cancer specimens and used 3 chronic pancreatitis samples and 6 adjacent histological normal pancreatic tissues (away from the tumor) as controls. The ultrastructural study revealed that chronic pancreatitis tissues were characterized by alterations of the secretory cells. The enzymic and secretory changes were confirmed by electron immunogold results. Glucagon appeared to be located not only in islet alpha cells but also in intermediate alpha acinar cells. The changes were more significant in adenocarcinoma cases. Abnormality in the immunoreaction of the peptides was indicated not only in the tumor area but also in the islets near the cancer. Cells immunoreactive with antibodies were found in all 12 adenocarcinoma cases. Abnormal co-location of both hormones in the same type of endocrine cell was also found. Moderately to poorly differentiated adenocarcinomas were poorly granulated compared with differentiated tumors. Increased and ectopic gastrin/CCK expression was correlated with pancreatic adenocarcinomas exhibiting poor histological grade and neoplastic endocrine cells, providing a potential marker for pancreatic adenocarcinomas with aggressive behavior.

Surface topography and ultrastructure correlation between human breast infiltrating ductal carcinoma of non special type and coexisting human breast infiltrating ductal carcinoma of non special type with in situ comedo carcinoma.

PURPOSE: To examine the topographical and ultrastructural correlations and differences between breast infiltrating ductal carcinoma (DC) non-special type (NST) and coexisting infiltrating DC NST with in situ comedo, in order to possibly detect differences in their metastatic potential. MATERIALS AND METHODS: The material examined derived from 22 women with breast cancer. Sixteen breast infiltrating DC NST tissue samples and 6 breast infiltrating DC NST with in situ comedo were studied with primary culture techniques, using transmission and scanning electron microscopy methods. RESULTS: The surface topography from infiltrating DC NST cells showed microvilli, blebs, ruffles, short and long projections. These features were absent in the normal breast cells. The intensity of these features was dependent on several histological characteristics. Also, the above features in coexisting DC NST with in situ comedo were related to more aggressive cases. The findings concerning the surface topography features have been also found in the ultrastructural level. A very interesting point was that these features consisted partly of cytoplasmic material. CONCLUSION: We believe that the presence of the features described above might be related to the metastatic potential of breast cancer and in particular to DC NST with in situ comedo.

Two-dimensional electrophoretic analysis of cytoplasmic polypeptides expressed by normal and cancerous colon tissues.

PURPOSE: To analyse the cytoplasmic polypeptides from malignant and nonmalignant tissues of the large intestine and investigate their relationship to colon cancer. MATERIALS AND METHODS: The investigation was carried out in 64 large intestinal tissues coming from 32 individuals, using high-resolution 2-dimensional (2D) electrophoresis (2D-PAGE). Thirty specimens were diagnosed as primary adenocarcinomas and 2 were nonmalignant. The other 32 specimens represented mirror biopsies from the respective patient obtained far from the tumor area. RESULTS: Pathological and nonpathological protein maps from the same patient highlighted several differences associated with malignancy, over and above natural complexity. Polypeptide overexpression was observed in adenocarcinomas, however in poorly differentiated tissues a decline in number and density of protein spots was observed in an area of isoelectric point (PI) between pH 6.3-7.2 and molecular weight (MW) 17.5-24 kDa. Three polypeptides, Pa (51/4.2), Pb (30/6.1) and Pc (21/7.3), were not detected in normal tissues and 27 polypeptides showed significantly increased densities in adenocarcinomas. CONCLUSION: Pa and Pb polypeptides show significantly increased densities in premature stages of the disease, and Pc provides a promising monitoring tool for the progress of metastases. The low prevalence of the above mentioned polypeptides in tissues from mirror biopsies raises questions as to the extent of the disease far from the tumor area. Also, the quantitative differences are associated with the appearance and development of the disease. We believe that these findings are important, highlighting the complexity and scope for further research in the diagnosis, monitoring and potential therapy of human colon cancer.

Immunoelectron study of somatostatin, gastrin and glucagon in human colorectal adenocarcinomas and liver metastases.

The aim of this study was to investigate the role and function of somatostatin, glucagon and gastrin in 35 colorectal adenocarcinoma and 25 liver metastases. The investigation was carried out at the electron immunocytochemistry level. Our results showed that well-differentiated tissues have the highest somatostatin levels compared to poorly-differentiated tumors while glucagon levels remain high. We also found gastrin immunoreactivity in cell membranes of poorly-differentiated primary adenocarcinoma tissues and in liver metastases. Low somatostatin expression, high glucagon expression and the presence of gastrin were found in tumors of poor grading and therefore poor prognosis.

Comparative study of serotonin and bombesin in adenocarcinomas and neuroendocrine tumors of the colon.

The aim of this study was to investigate serotonin and bombesin expression in colorectal adenocarcinomas and neuroendocrine colorectal tumors to clarify their role in the progression of colon cancer. The investigation was carried out by electron microscope immunocytochemistry. The ultrastructural study revealed that some cases of colorectal adenocarcinomas were characterized by the presence of amphicrine cells containing endocrine granules and mucus granules. Poorly differentiated adenocarcinomas and liver metastases were poorly granulated compared with highly differentiated tumors. Neuroendocrine tumors nevertheless were characterized by the presence of numerous malignant neuroendocrine cells filled with secretory granules and mucus granules. Bombesin appeared to be located in enterochromaffin-like endocrine cells, which are primarily responsible for the production of serotonin. In colorectal adenocarcinomas there was an inverse correlation between serotonin levels and the degree of differentiation. High serotonin levels characterized colorectal adenocarcinomas with composite phenotype and colorectal neuroendocrine tumors. Increased bombesin expression was correlated with colorectal adenocarcinomas exhibiting poor histological grade and their liver metastases. In conclusion, the findings suggest that high serotonin levels may be an indicator of neuroendocrine differentiation, and bombesin may be a useful marker for colorectal adenocarcinomas with aggressive behavior,