Genetic Changes in Mastocytes and Their Significance in Mast Cell Tumor Prognosis and Treatment.

Mast cell tumors are a large group of diseases occurring in dogs, cats, mice, as well as in humans. Systemic mastocytosis (SM) is a disease involving the accumulation of mast cells in organs. KIT gene mutations are very often seen in abnormal mast cells. In SM, high KIT/CD117 expression is observed; however, there are usually no KIT gene mutations present. Mastocytoma (MCT)-a form of cutaneous neoplasm-is common in animals but quite rare in humans. KIT/CD117 receptor mutations were studied as the typical changes for human mastocytosis. In 80% of human cases, the KIT gene substitution p.D816H was present. In about 25% of MCTs, metastasis was observed. Changes in the gene expression of certain genes, such as overexpression of the DNAJ3A3 gene, promote metastasis. In contrast, the SNORD93 gene blocks the expression of metastasis genes. The panel of miR-21-5p, miR-379, and miR-885 has a good efficiency in discriminating healthy and MCT-affected dogs, as well as MCT-affected dogs with and without nodal metastasis. Further studies on the pathobiology of mast cells can lead to clinical improvements, such as better MCT diagnosis and treatment. Our paper reviews studies on the topic of mast cells, which have been carried out over the past few years.

Identification of the c.829_832delAATA Deletion Variants in the BRCA1 Gene Associated with Hereditary Breast/Ovarian Cancer - Case Report.

Determination of the BRCA1/BRCA2 mutation status in patients with breast and/or ovarian cancer is commonly performed using various molecular techniques. The use of targeted PCR-based tests only may not be sufficient, as not all possible variants are investigated. In the present study, we used next-generation sequencing (NGS) techniques to identify novel pathogenic variants in BRCA1 and BRCA2. In this study, material (blood and FFPE) collected from a 67-year-old patient with ovarian cancer was used. The presence of hereditary mutations characteristic for the Polish population was examined using Sanger sequencing. BRCA1 and BRCA2 gene exons were amplified using the Devyser BRCA kit and sequenced on the Miniseq. No germline mutations characteristic for the Polish population were detected. However, 12 single nucleotide variants and 2 indels were identified. We found a new deleterious mutation of gene BRCA1 (c.829_832delAATA). To our knowledge, this mutation has not been reported yet in the Polish population and elsewhere. The use of the NGS technique increases the possibility of detecting mutational changes in patients with ovarian and/or breast cancer. Quick determination of pathogenic variants is important to facilitate specific therapy, in addition to the identification of familial predisposition to cancer.

Do CTRC mutations affect the development of alcoholic chronic pancreatitis and its course among Poles: Preliminary study.

BACKGROUND: Genetic mutations are one of the etiological factors that predispose people to develop chronic pancreatitis. OBJECTIVES: The aim of our study was to examine the effect of p.Trp55*, p.Arg254Trp and c.738_761del mutations in the chemotrypsin gene (CTRC) on the development of alcoholic chronic pancreatitis (ACP) in order to answer the questions whether these mutations vary between gender groups, whether they were related to the age when ACP was first diagnosed, and whether they affected the morphological changes in the pancreas and the course of ACP. MATERIAL AND METHODS: The study included 124 patients with ACP, 52 with nonalcoholic pancreatitis and 52 controls. The p.Trp55*, c.738_761del and p.Arg254Trp mutations in the CTRC gene were tested by the polymerase chain reaction (PCR). RESULTS: The c.738_761del and p.Arg254Trp mutations occurred in 3.07% and 1.31% of cases, respectively. None of the examined patients were found to have the p.Trp55* mutation. The frequency of detected mutations did not significantly differ between the study groups. The c.738_761del mutation was detected more frequently in women than in men. No significant differences were found in the age at ACP onset, morphological changes affecting the pancreas, or in the course of ACP between the patients with and without the 2 examined mutations. The c.738_761del mutation was significantly more frequent in the diabetic patients than in the non-diabetics. The patients with this mutation more frequently required surgery than those without the c.738_761del mutation. CONCLUSIONS: No relationship between the c.738_761del and p.Arg254Trp mutations and the development of APC was found. The c.738_761del mutation was more frequent in females than in males. Neither mutation affected the patient's age at ACP onset or its course. In contrast to p.Arg254Trp, the c.738_761del mutation correlated with diabetes development and the need for surgery in the course of ACP.

Expression of genes encoding extracellular matrix proteins: a macroarray study.

Endometrial cancer (EC) is one of the most common gynecological malignancies in Poland, with well-established risk factors. Genetic instability and molecular alterations responsible for endometrial carcinogenesis have been systematically investigated. The aim of the present study was to investigate, by means of cDNA macroarrays, the expression profiles of genes encoding extracellular matrix (ECM) proteins in ECs. Tissue specimens were collected during surgical procedures from 40 patients with EC, and control tissue was collected from 9 patients with uterine leiomyomas. RNA was isolated and RT-PCR with radioisotope-labeled cDNA was performed. The levels of ECM protein gene expression in normal endometrial tissues were compared to the expression of these genes in EC specimens. Statistically significant differences in gene expression, stratified by clinical stage of the ECs, were detected for aggrecan, vitronectin, tenascin R, nidogen and two collagen proteins: type VIII chain α1 and type XI chain α2. All of these proteins were overexpressed in stage III endometrial carcinomas compared to levels in stage I and II uterine neoplasms. In conclusion, increased expression of genes encoding ECM proteins may play an important role in facilitating accelerated disease progression of human ECs.

The N34S mutation of the SPINK1 gene and alcoholic chronic pancreatitis.

INTRODUCTION:  Recent studies have shown the key role of genetic factors in the development of chronic pancreatitis. OBJECTIVES:  The aim of the study was to establish whether the frequency of the N34S mutation of serine protease inhibitor Kazal type 1 (SPINK1) gene differs between patients with alcoholic chronic pancreatitis, patients with nonalcoholic chronic pancreatitis, alcoholics without any digestive organ damage, and controls. We also sought to investigate whether the frequency of this mutation differs between women and men, and whether the mutation is associated with the age of patients at first diagnosis of chronic pancreatitis. PATIENTS AND METHODS:  The study included 207 patients: 67 with alcoholic chronic pancreatitis, 35 with nonalcoholic chronic pancreatitis, 43 alcoholics with no damage to digestive organs, and 62 healthy volunteers who served as controls. The N34S mutation of the SPINK1 gene was detected with the polymerase chain reaction. RESULTS:  The N34S mutation of the SPINK1 gene occurred in 15 of 207 patients (7.25%). The mutation was most frequent in patients with alcoholic chronic pancreatitis (10 patients, 16.39%) and was more frequent compared with the control group (2 patients, 3.23%) (P = 0.047). There were no statistically significant differences between the other groups: patients with nonalcoholic chronic pancreatitis (2 patients, 5.71%), alcoholics without digestive organ damage (1 patient, 2.33%), and controls. The mutation was more frequent in men than in women (P = 0.043). There were no differences between patients with and without the mutation in terms of the age at first diagnosis of chronic pancreatitis (P >0.05). CONCLUSIONS:  The N34S mutation of the SPINK1 gene seems to be significantly correlated with alcoholic chronic pancreatitis.

Polymorphisms of the 5-HT2A receptor gene and clinical response to olanzapine in paranoid schizophrenia.

BACKGROUND: 5-HT2A receptor is strongly implicated in the mode of action of atypical antipsychotic drugs. The aim of the study was to investigate whether the 5-HT2A receptor gene's polymorphisms (His452Tyr and T102C) have an influence on the response to olanzapine in patients with schizophrenia. METHODS: We studied 99 Caucasian schizophrenia patients treated with olanzapine. Psychopathology was measured before and after 6 weeks of treatment. Clinical improvement was quantified as change in Positive and Negative Syndrome Scale (PANSS) total scores and subscores as shown by percentage improvement below the baseline score. The clinical response to antipsychotic treatment was defined as 30% improvement from baseline in PANSS scores. RESULTS: The His/Tyr polymorphism was significantly associated with a percentage improvement in PANSS positive symptom subscore (better response in His/His homozygotes; p<0.05) after treatment with olanzapine. As for the T102C polymorphism, a better response in terms of PANSS positive subscore improvement was observed for C/C homozygotes (p<0.01). A significant association of 5-HT2A genotype distribution of the T102C polymorphism with a categorical measure of response, but only in terms of PANSS positive symptom subscores, was observed (p<0.01). CONCLUSIONS: Variations in the 5-HT2A receptor gene may influence individual and particularly positive symptom response to olanzapine.

[Decreased osteonectin and fibronectin gene expression in endometrial cancer cancer as a prognostic marker]. / Zmniejszona ekspresja genu osteonektyny i fibronektyny w nowotworach endometrium--markery rozwoju i przebiegu choroby.

OBJECTIVES: The aim of this study was to investigate, by means of cDNA macroarrays, the expression profile of genes coding the ECM proteins in endometrial cancer. MATERIAL AND METHODS: Tissue specimens were collected during surgical procedures. 40 patients were operated due to endometrial cancer and 9 patients because of uterine myomas. RNA was isolated and reverse transcriptase reaction with radioisotope labeling of cDNA were performed. PCR reaction was performed with labeled cDNA. All steps of macroarray hybridization were done according to the protocol. Statistical analysis was done with different tests, including artificial neural network method. RESULTS: The level of ECM protein genes expression in normal endometrial tissue was compared to the expression of these genes in endometrial cancer specimens. Statistical significances were found only for fibronectin and osteonectin genes and for both genes decreased expression was observed in cancer tissues (p = 0.009, p = 0.0003, respectively). Moreover fibronectin and osteonectin genes expression decreased along with increase of clinical staging and histological grading of the endometrial cancer but no statistical significance for this trend was found. CONCLUSIONS: Decreased expression of fibronectin and osteonectin genes, when compared to normal endometrial tissue expression, in endometrial cancer may play an important role as a stimulus for disease development and, on the other hand, may be used as an additional marker for the progression of the disease.

Alcohol dehydrogenase and aldehyde dehydrogenase gene polymorphism in alcohol liver cirrhosis and alcohol chronic pancreatitis among Polish individuals.

OBJECTIVE: To investigate the effects of ADH and ALDH gene polymorphism on the development of alcoholism, alcohol liver cirrhosis and alcohol chronic pancreatitis among Polish individuals. MATERIAL AND METHODS: We determined the allele and genotype of ADH2, ADH3 and ALDH2 in 198 subjects: 57 with alcohol cirrhosis, 44 with alcohol chronic pancreatitis and 43 "healthy alcoholics"; 54 healthy non-drinkers served as controls. Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method on white cell DNA. RESULTS: In the population examined the ADH2*1 allele frequency was 97.97%. The tests did not show the ADH2*3 allele. The ADH3*1 allele frequency was 57.07%. The ADH2*1 and the ADH3*1 alleles were statistically more common among patients who abuse alcohol in comparison with the controls. The ADH2*2 allele was not detected in any of the patients with chronic alcohol pancreatitis. The ADH2*1/*1 and the ADH3*1/*1 genotypes were statistically significantly more common among the patients who abuse alcohol than in the control group. All patients were ALDH2*1/*1 homozygotic. Patients with the ADH3*1 allele and the ADH3*1/*1 genotype started to abuse alcohol significantly earlier in comparison to the patients with the ADH3*2 allele and the ADH3*2 /*2 genotype. CONCLUSIONS: In the Polish population examined, the ADH3*1 allele and the ADH3*1/*1 genotype are conducive to the development of alcoholism, alcohol liver cirrhosis and alcohol chronic pancreatitis. However, the ADH2*2 allele is likely to protect against these conditions. Genetic polymorphism of ALDH2 shows no correlation with alcohol addiction or alcohol cirrhosis and alcohol chronic pancreatitis. The ADH3*1 allele and the ADH3*1/*1 genotype are conducive to alcohol abuse starting at a younger age.

Apoptotic markers in various stages of amygdala kindled seizures in rats.

The aim of the study was to elucidate the relationship between various stages of amygdala kindling in rats and neuronal apoptosis. We used the unbiased method of RNase protection assay (RPA), measuring expression of several apoptosis-associated genes (for: caspase 1, caspase 2, caspase 3, FAS antigen, bax and bcl-x, bcl-2). The obtained results were also verified in situ in hippocampal slices, using the TUNEL method. The mRNA level of the investigated genes was estimated by densitometry and standardized according to the amount of L32 RNA. Only the expression of bcl-x L, caspase 2, caspase 3 and bax genes was measureable. In all experimental groups, the mRNA levels of bax and bcl-x genes were higher than mRNA of caspase-2 and caspase-3 genes. However, there were no statistically significant differences between the control and kindled animals. On the other hand, the TUNEL positive cells were found in total contralateral hippocampus of investigated animals belonging to C(0) (control group), C(3) (rats with 3rd stage of seizures) and c(5) (rats with 5th stage of seizures) groups. The number of TUNEL positive cells in the hippocampus was significantly higher in C(3) and C(5) groups (4.0 +/- 0.40 and 3.75 +/- 0.49) when compared to C(0) group (1.25 +/- 0.25). In conclusion, although apoptotic cells were found in situ in the hippocampus of kindled rats, RNase protection assay failed to measure any changes in mRNA levels of the chosen apoptotic genes. In our opinion, apoptotic cells might be too rare to detect any changes in gene expression. Therefore, the TUNEL procedure still remains the most favorable method of apoptotic cell death evaluation in the brain structures.

Genetic polymorphism of CYP2E1 and digestive tract alcohol damage among Polish individuals.

BACKGROUND: Genetic polymorphism of enzymes involved in alcohol metabolism plays a relevant role in etiopathogenesis of alcohol disease. The aim of the present study was to find in the Polish population the CYP2E1 genotypes that are likely to be responsible for higher susceptibility to alcohol disease of the liver and chronic alcohol pancreatitis. METHODS: The CYP2E1 genotype and c1 and c2 alleles frequency were examined in 198 patients. Genotyping of the CYP2E1 was performed using polymerase chain reaction-restriction fragment length polymorphism methods on white cell DNA. RESULTS: In the examined population encompassing 198 subjects, the c2 allele was present only in 1.5% of patients. It was found only in patients abusing alcohol. In the group of patients with alcoholic cirrhosis, it was present in 3.5% of cases, whereas in patients with chronic alcoholic pancreatitis, in 2.3%. The genotype c1/c2 was present in 3% of subjects. The genotype c2/c2 was not found in any patient. Heterozygotes c1/c2 were present only in patients consuming excessive amounts of ethanol; in 7% of patients with alcoholic cirrhosis and in 4.5% of those with chronic alcoholic pancreatitis. The c2 allele occurred only in men. None of the examined women had the genotype c1/c2. CONCLUSIONS: Our studies suggest that the frequency of the c2 alleles in Polish population is low. Because of their rare frequency, it is difficult to conclude explicitly that the presence of the c2 allele promotes alcoholic damage to alimentary organs among Poles. It seems, however, that they pose the risk of alcoholic cirrhosis; their role in chronic alcoholic pancreatitis is difficult to assess.

Genetic polymorphism of alcohol dehydrogenase 3 in alcohol liver cirrhosis and in alcohol chronic pancreatitis.

AIM: To find the ADH3 genotypes in the Polish population likely to be responsible for higher susceptibility to alcohol disease of the liver and chronic alcohol pancreatitis. METHOD: The ADH3 genotype and ADH3*1 and ADH3*2 alleles frequencies were examined in 198 patients. Genotyping of the ADH3 was performed using PCR-restriction fragment length polymorphism methods on a white cell DNA. RESULTS: The genotype ADH3*1/ADH3*1 was found to be significantly more frequent in alcohol abusers compared with non-drinkers. The examinations of the group of alcohol abusers showed that the genotype ADH3*2/ADH3*2 occurred statistically significantly less frequently in patients with chronic pancreatitis than in those without alimentary lesions (healthy drinkers). The alleles ADH3*1 and genotype ADH3*1/ADH3*1 were significantly more frequent in men than in women, whereas alleles ADH3*2 and genotype ADH3*2/ADH3*2 were more common in women. CONCLUSIONS: The genotype ADH3*2/ADH3*2 is likely to be a protective factor for chronic pancreatitis. Variations in ADH3 genotypes may account for some of the differences in prevalence of alcohol dependence between genders in the Polish population.

Estimation of prognostic value of Bcl-xL gene expression in non-small cell lung cancer.

The aim of our study was to estimate the expression of the Bcl-xL gene, a member of Bcl-2 family, in NSCLC patients. A total of 60 consecutive patients diagnosed with NSCLC that underwent chemotherapy prior to surgery were reviewed. Bcl-xL expression was assessed on paraffin sections by in situ hybridization (ISH) and immunohistochemistry (IMH). We observed the presence of mRNA of Bcl-xL gene and its protein product overexpression in most patients (60 and 81.7%, respectively). In material examined no significant correlation was observed between the pattern of Bcl-xL or protein expression and any clinicopathological factors evaluated. The expression of Bcl-xL protein was low (less than 10% positive cells) in 11 patients (median survival time 29 months) as compared to 49 patients with overexpression (median survival time 21.0 months). The difference was not of statistic significance (p=0.27). In examined group the Bcl-xL mRNA was found in 36 patients, while it was absent in 24 cases. Median survival time was 14.5 and 86.5 months, respectively (p=0.001). In addition, 19.4% of 5-year survivals were achieved in patients with overexpression and 54.2% in patients with no mRNA present (p=0.002). The percentage of 5-year survival in patients with protein expression assessed by IMH was 30.6% (p=0.31). The estimation of Bcl-xL expression on mRNA and protein level was compared by the means of sign test and the significant difference was found (p=0.009). The inconsistency was related to 35% of cases. In comparison with IMH, ISH technique appeared to be more specific and accurate in assessment of 5-year survival (25 and 65%; 65 and 70%, respectively). The results of our study indicate that Bcl-xL mRNA overexpression may suggest poor prognosis in NSCLC.

Analysis of most common CFTR mutations in patients affected by nasal polyps.

Nasal polyps, a chronic inflammatory disease occurring in the nose and para-nasal sinuses, result from several different causes, including cystic fibrosis (CF). Forty-four patients affected by nasal polyps were admitted to the Department of Otolaryngology, Lublin University School of Medicine, Lublin, Poland, and screened for the most-commonly identified CFTR mutations [DeltaF508, G542X, N1303 K, 1717-1 (G to A), W1282X, G551D, R553X and DeltaI507] by applying the INNO-LIPA CF2 test strips. None of the patients had symptoms that allowed for the diagnosis of CF, including the negative sweat test. We detected 5 of 44 (11.4%) carriers of the CFTR mutations. All patients positive for this test were heterozygous carriers of DeltaF508. In the control group, only 1 of 70 (1.4%) cases showed DeltaF508 heterozygosity. The frequency of DeltaF508 mutation herein reported was significantly higher than in the control group (P = 0.0312) and in the general Polish population as well (P = 0.0059). Our data suggest that a heterozygous manifestation of the DeltaF508 may exist in a selected group of patients affected by nasal polyps, who have no other clinical features of CF.

The activity of human telomerase in the cells of acute leukaemias.

Telomeres are the end fragments of chromosomes formed by a number of non-coding double-stranded TTAGGG repeats in vertebrates. During cell division the number of repeats decreases, leading to cell senescence or apoptosis. In immortal cells, including cancer cells, the telomere length is stable and maintained by, among other factors, telomerase. The aim of the study is to compare telomerase activity in normal lymphocytes and in leukaemic cells. Samples of acute leukaemia cells, HL 60 cell line and the lymphocytes of healthy volunteers were examined. Telomerase analysis was performed using TeloTAGGG Telomerase PCR ELISAplus (Roche). The relative telomerase activities (RTA) in leukaemic and normal cells were analysed. A high level of RTA was observed in leukaemic cells.

Molecular diagnostics of promyelocytic leukaemia.

Acute promyelocytic leukaemia (APL) is characterised by proliferation of abnormal promyelocytes. The reciprocal translocation between the long arms of chromosomes 15 and 17, and the fusion between the retinoic acid receptor (RARa) gene, and PML gene, is unique to APL. Because of unsuccessful cytogenetic analysis of conventional G-banding technique (mitoses were not observed), we diagnosed three non-treatment patients with APL by following molecular methods: reverse transcription-polymerase chain reaction (RT-PCR), fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH). At the time of diagnosis our patients showed reciprocal translocation t(15;17)(q22;q12) in all cases studied (66-85% of positive bone marrow cells). With the use of CGH we observed the unbalanced chromosomal aberrations: losses of 5q13.1, 5q31.3, 9p21 regions, gain of 5q32 region and trisomy of 18 chromosome.

[Role and significance of DNA methylation]. / Rola i znaczenie metylacji DNA.

DNA methylation is covalent addition of a methyl group to cytosine within the CpG dinucleotide. It has profound effects on the mammalian genome. These effects include transcriptional repression via inhibition of transcription factor binding, X chromosome inactivation, and imprinting. DNA methylation is important for both DNA repair and genome stability. Normal methylation patterns are frequently disrupted in tumour cells with global hypomethylation accompanying region-specific hypermethylation. When this hypermethylation occurs within the promoter of a tumour suppressor gene it could silence the gene and provide the cell with a growth advantage in a way similar to deletions or mutations. There is considerable evidence suggesting that alterations in DNA methylation play an important role in tumorigenesis and tumour progression.

The preliminary estimation of bcl-2, bcl-X(L) and p53 genes expression in locally advanced non-small cell lung cancer.

Cell neoplastic transformation results from disturbances in expression of genes regulating its basic functions like cell cycle and apoptosis. Our paper presents preliminary estimation of expression of protooncogenes: bcl-2 and bcl-X(L) as well as of p53 suppressor gene in (NSCLC) non-small-cell lung cancer patients. The study comprised 16 NSCLC patients subjected to chemotherapy before operative procedure. Gene expression was evaluated on paraffin embedded specimens using in situ hybridization assay and immunohistochemical method. In the majority of examined patients, high expression of bcl-X(L) gene both at mRNA and protein level was ascertained. In the case of 10 patients (62.5%), higher p53 gene expression at mRNA level was observed, whereas higher level of P53 protein was determined only in four subjects (25%). In two of 16 cases (12.5%), protein product of bcl-2 gene was found, while in eight subjects (50%)--mRNA expression of the gene.

Expression of p21 and bcl-2 proteins in paraffin-embedded preparations of non-small cell lung cancer in stage IIIA after Etoposide and Cisplatin induced chemotherapy.

Apoptosis plays an important role in cancer pathogenesis. Several oncogenes and antioncogenes regulate this process. Loss of their normal function leading to cell resistance to apoptosis seems to be a key factor of neoplasm development. In tumour cells, programmed cell death is a spontaneous process and its intensity increases after chemo-, radio- and hormonotherapy. Amongst several genes and their products, bcl-2 and p21 genes play a significant role in the process. p21 gene product, cyclin-dependent kinase inhibitor, along with p53 gene take part in cell cycle regulation. Our study aimed at evaluating p21 and Bcl-2 protein expression in the cells of patients afflicted with stage IIIA of non-small cell lung cancer who underwent neoadjuvant chemotherapy (three courses of Vepesid and Cisplatin). Protein expression was evaluated in slides of tissue material obtained before pharmacological treatment (during bronchofiberoscopy) and after three courses of Vepesid and Cisplatin (during surgical tumour resection). Protein activity in tissue slides was conducted using histochemical method with labelled antibodies (immunoperoxidase staining procedure). The control material was obtained from patients who had not undergone inductive chemotherapy. The results were documented as photographs and presented as charts after extinction level measurement using cytophotometric technique. Decrease in Bcl-2 protein activity and increase in p21 protein level in tumour cells of patients after inductive chemotherapy were observed.

Expression of p53 gene in stage IIIA non-small cell lung cancer in patients after neoadjuvant chemotherapy with Vepesid and Cisplatin.

Apoptosis (programmed cell death) plays a very important role in the development regulation, homeostasis maintenance as well as in the origin of many diseases, including neoplasms. This process is genetically regulated and reflected in characteristic morphological and biochemical changes taking place in cells. The process is considered to be of great significance in tumour originating and growth as well as in tumour cell response to chemotherapy. There are many genes and their products that are involved in apoptosis. The following genes: p53, bcl-2 and p21 seem to have the greatest significance. Our study aimed at evaluating p53 gene expression in non-small-cell lung cancer patients after neoadjuvant chemotherapy. We examined the tissue material from 35 patients after three-cycle inductive chemotherapy (Vepesid and Cisplatin). The material was obtained before chemotherapy during bronchofiberoscopy and four weeks after drug treatment during surgery. The control group comprised patients who had not undergone inductive chemotherapy. After deparaffinising of tissue slides, gene p53 activity using in situ hybridisation technique was evaluated. Moreover, apoptosis valuation with TUNEL method was performed. The results were documented as photographs. Gene p53 activity level was estimated using cytophotometric technique. Our study revealed significantly higher percentage of cells undergoing apoptosis and increased gene p53 activity in tumour tissue slides of patients after neoadjuvant chemotherapy.

Loss of heterozygosity of the retinoblastoma gene is correlated with the altered pRb expression in human endometrial cancer.

The retinoblastoma (Rb) gene was the first tumor suppressor gene to be discovered; however, data on the influence of Rb inactivation on endometrial carcinogenesis are scarce. We investigated 46 paired primary human endometrial carcinomas and normal tissues to assess the frequency of loss of heterozygosity (LOH) in Rb and 20 tumor pairs to detect the frequency of p53 LOH. Moreover, expression of the retinoblastoma protein (pRb) was assessed immunohistochemically. Of 44 informative cases 8 showed loss of one allele in at least one Rb marker; Rb LOH frequency thus reached 18%. Two omental metastases of endometrial origin showed a heterogeneity pattern similar to that of the primary tumors. We did not find a significant correlation between Rb LOH and patient age, clinical stage, histological grade or muscle invasion of the tumor. Nevertheless, Rb LOH was demonstrated at early (stage I, 5/27, 18%) and advanced (stages II-IV; 3/9, 33%) clinical stages of the neoplasm, suggesting that LOH at the Rb locus occurs before the clonal expansion of the tumor. There was a significant correlation between Rb LOH and weak/absent pRb expression. We noted a single case of p53 LOH at intron 1, but no tumor showed both alterations simultaneously. Our data suggest that LOH at the Rb locus plays a role in the oncogenesis of a subset of uterine neoplasms and corresponds with the altered expression of the pRb.