Biomedical subjects

Czesław Osuch

Publications and source records attributed to Czesław Osuch.

6 recordsLinked to original sources

PubMed2006

The relationship between MSI status and vessel density in colorectal carcinoma.

The development of new blood vessels is a prerequisite for progression of malignant neoplasms. Factors that induce neoangiogenesis include VEGF, VEGF-C, VEGF-D, PD-ECG, ANG-2, TSP-1, HIF-1 and HIF-2. From the etiopathogenetic viewpoint, colorectal carcinoma is heterogenic. It may develop via a sequence of mutations leading to chromosome instability or else result from DNA repair defects, which are manifested as microsatellite instability. The objective of the present investigations was the comparison of neoangiogenesis in microsatellite-stable colorectal carcinomas, as well as in tumors with low and high instability levels. The material included 71 surgical cases of colorectal carcinoma. Vessel density was assessed by immunohistochemical reactions to CD34 and vWf, calculating the number of vessel sections within the invasion margin, in visual fields selected at random, and within hot spots. Microsatellite instability was evaluated in frozen materials employing the PCR reaction with gel and capillary electrophoresis. In all the cases, the authors detected CD34+ and less numerous vWf+ vessels within the tumor and in its vicinity. In 45 cases, no microsatellite instability was found, in 13 cases, low level instability (MSI-L) was observed, and in another 13 - high microsatellite instability (MSI-H). Some differences in vessel density were noted between the above groups, yet they were not statistically significant. On the other hand, the authors observed more numerous CD34+ vessels in cases with metastases to the regional lymph nodes. In conclusion, it is suggested that neoangiogenesis in sporadic colorectal carcinoma is directly related to metastatic potential, but not to MSI status.

Adenocarcinoma↗

PubMed2006

High thymidylate synthase expression is typical for sporadic MSI-H colorectal carcinoma.

Colorectal carcinoma is etiopathologically heterogenic. It may develop through a sequence of mutations leading to chromosome instability or be a result of defects in DNA repair mechanisms manifested by microsatellite instability. Carcinomas of this type are supposed to be characterized by a better prognosis and a different response to chemotherapy. The main target of 5-fluorouracil (5-FU) treatment is thymidylate synthase (TS). High TS expression has been identified as promoting resistance to 5-FU. The objective of the present investigation was to determine whether microsatellite instability is associated with thymidylate synthase expression. Ninety-eight cases of colorectal carcinoma were studied. Microsatellite instability was evaluated in frozen material employing the PCR reaction with gel and capillary electrophoresis. TS expression levels were assessed in preparations stained immunohistochemically using a semiquantitative method on a scale with scores from 0 to 3. The MSI-H phenotype was detected in ten cases, MSI-L in 16, and MSS in 72. The mean TS expression score was 1.79. In the MSS group, the mean TS expression score was 1.69, in the MSI-L group the mean TS expression score was 1.73, and in the MSI-H group the mean TS expression score was 2.67. The differences between MSI-H and MSS/MSI-L were statistically significant (p<0.0002 and p<0.004, respectively). The results may explain the different response of MSI-H carcinomas to 5-FU treatment.

Adenocarcinoma↗

PubMed2006

Tissue microarray FISH applied to colorectal carcinomas with various microsatellite status.

Colorectal carcinoma is etiopathologically heterogenic. It may develop through a sequence of mutations leading to chromosome instability or be a result of defects in DNA repair mechanisms manifested by microsatellite instability of varying degrees. Colorectal carcinoma can thus be classified into microsatellite-stable (MSS), highly microsatellite unstable (MSI-H) and intermediate low-level microsatellite unstable (MSI-L) groups. Fluorescent hybridization in situ (FISH) is a method of detecting specific sequences of nucleic acids that is based on specific bonding of a fluorescent marker-associated probe and specific DNA fragment. The material consisted of 146 non-selected cases of colorectal carcinoma patients operated on at First Chair of General Surgery, Collegium Medicum, Jagiellonian University in Cracow, Poland. Following a standard histopathological evaluation, tissue microarrays were prepared using a Tissue MicroArray Builder, and FISH was performed employing probes specific for chromosomes 1, 8, 17 and 18. Microsatellite instability was evaluated in frozen material using the PCR reaction with gel and capillary electrophoresis. The mean number of signals obtained for chromosome 1 in the entire material was 2.06, while the corresponding mean values in the MSS group equaled 2.07, in the MSI-L group - 2.07, and in the MSI-H group - 2.01. The mean number of signals for chromosome 17 in the entire material was 2.1, in the MSS group - 2.11, in the MSI-L group - 2.13, and in the MSI-H group - 2.01. The number of signals for chromosome 18 in the entire material was 2, in the MSS group - 2, in the MSI-L group - 2, and in the MSI-H group - 2. The means number of signals for chromosome 8 in the entire material was 2.07, in the MSS group - 2.08, in the MSI-L group - 2.01, and in the MSI-H group - 2. These differences are not sufficient for distinguishing colorectal carcinoma molecular forms.

Adenocarcinoma↗

PubMed2006

Correlation of microsatellite status, proliferation, apoptotic and selected immunohistochemical markers in colorectal carcinoma studied with tissue microarray.

Colorectal carcinoma is a frequent malignant tumor, characterized by varying clinical course and response to treatment. At the molecular level, colorectal carcinomas are divided into tumors with chromosomal instability (microsatellite-stable, MSS), microsatellite instability (MSI-H) and low microsatellite instability (MSI-L). The method of tissue microarrays allows for combining materials originating from multiple patients into a single slide, what makes possible to simultaneously investigate large material for the presence of numerous, diversified markers. The study material consisted of 208 cases of colorectal carcinoma. Microsatellite instability was evaluated in frozen material employing the PCR reaction with gel and capillary electrophoresis. Following a standard histopathological assessment, tissue microarrays were prepared using a MTA-1 microarrayer (Beecher) and standard immunohistochemical reactions were performed to detect the presence of bcl-2, CDX-2, Ki67, MLH1, MSH2, MSH6, p16, p53 and survivin. Apoptotic cells were detected using the TUNEL method. The correlations between the reactions were investigated and differences in the expression of the investigated proteins noted in carcinomas with various degrees of microsatellite instability. The agglomeration analysis showed differences in patterns of expression between MSS, MSI-L and MSI-H carcinomas. The discriminant function analysis demonstrated that the MSI-H carcinomas were best differentiated by MLH1, survivin and Ki67 expression, while the MSI-L tumors differed from the remaining colorectal carcinomas by their apoptotic index, local tumor stage (pT), the presence of angioinvasion and mucin production.

Adenocarcinoma↗

PubMed2005

Gastrointestinal stromal tumors. A multicenter experience.

The report presents 200 cases of gastrointestinal stromal tumors (GIST). The material originated from six diagnostic centers in Poland and was reclassified according to the current criteria. Among lesions other than GISTs, 14 were identified as smooth muscle tumors and seven as neural tumors. GISTs were located in the stomach (51-63.3% of the investigated series), small intestine (27.4-33.8%), colon (approximately 4.5%), abdominal cavity, i.e. in the peritoneum and omentum (6%), and in the retroperitoneal space (2.5%). A slight predominance of women was noted (53-56%). The age of the patients ranged between 14 and 93 years of life, with the mean age of 62.4 years. Individuals younger than 45 years of age accounted for 10% of the group. In ten patients (five of them less than 45 years of life), multiple tumors were detected, their number ranging from two to less than 20; these individuals constituted 5% of the entire series. Moderately and highly aggressive tumors predominated. In the series, when multiple tumors were excluded, a total of 24 epithelioid GISTs (12%) were observed; of this number, 13 were situated in the stomach, six--in the small intestine, two--in the abdominal cavity and another two in the retroperitoneal space. Synchronic tumors observed in patients with GISTs were seen in seven patients, including an adenocarcinoma of the colon, two adenocarcinomas of the stomach, a carcinoid tumor of the small intestine, a pheochromocytoma of the retroperitoneal space, an anaplastic lymphoma and a disseminated squamous cell carcinoma. In immunohistochemical reactions (CD117, CD34, SMA, S-100, DES), attention was focused on the immunoreactivity of small GISTs, below 2 cm in size, and of multiple tumors. Immunohistochemical reactions were equally differentiated as to their presence and intensity in small tumors and in highly aggressive lesions above 5-10 cm in size. In multiple GISTs, immunohistochemical tests strongly indicated the heterogeneity of neoplastic cells, which, nevertheless, showed no consistent association with the location of the tumor, its aggressiveness, cellular structure or a tendency to form multiple foci.

Adolescent↗

PubMed2004

CDX-2 expression is reduced in colorectal carcinomas with solid growth pattern and proximal location, but is largely independent of MSI status.

The homeobox genes are transcription factors that control the development of tissues and organs. In the colon one of such genes is CDX-2. In colorectal carcinomas, the CDX-2 expression is reduced. The aim of the present study was to investigate the presence of CDX-2 in colorectal carcinomas and to relate it to the histological features and microsatellite stability status. The material consisted of 20 carcinomas without microsatellite instability, 19 cases with low microsatellite instability and 19 cases with high microsatellite instability. CDX-2 expression was investigated using immunohistochemistry with CDX2-88 monoclonal antibody and assessed semiquantitatively. In 10 cases no expression of CDX-2 was observed, while in 6 the protein was present in less than 25% of tumor cells. It was noted that reduced expression of CDX-2 was more frequent in carcinomas situated proximally to the splenic flexure (p < 0.015) and in tumors with solid growth pattern (p < 0.03). On the other hand, no significant differences were encountered between groups differing in microsatellite stability. The results suggest that the major factors that determine the presence of CDX-2 in colorectal carcinomas at the protein product level may include cancer location and the solid phenotype of the tumor.

Adenocarcinoma↗