Josip Lukač

Salivary and serum interleukin 1 beta, interleukin 6 and tumor necrosis factor alpha in patients with leukoplakia and oral cancer

Objectives: The aim of study was to compare salivary and serum concentrations of interleukin 1 beta (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in patients with oral leukoplakia, oral cancer and healthy controls. Study design: Eighty eight patients (28 with oral cancer, 29 leukoplakia, and 31 healthy controls) were included in this study. Cytokine concentrations were measured by commercial enzyme linked immunoassay. Results: Salivary IL-1β and IL-6 were significantly higher in oral cancer patients than in patients with leukoplakia and control group (p<0.05). No differences in concentrations of salivary TNF-α between either of the groups were observed. Serum concentrations of IL-1β were below level of detection in all but two participants. No significant differences between the groups were observed in serum concentrations of IL-6. Serum TNF-α was significantly higher in control subjects than in oral cancer patients. Conclusions: Patients with oral cancer have elevated levels of inflammatory cytokines in their saliva. Whether this elevation can be used for monitoring the malignant transformation of oral leukoplakia remains to be answered by further follow up studies. Key words: Cytokines, oral, leukoplakia, cancer.

Humoral immune response to p53 correlates with clinical course in colorectal cancer patients during adjuvant chemotherapy

Background and aimsOverexpression of p53 protein in malignancies induces an immune response in some cancer patients. We investigated whether production of serum antibodies against p53 (p53-Ab) is associated with pathohistological parameters of colorectal carcinoma and whether p53-Ab can serve as a tumor marker during cancer treatment.Patients and methodsSerum samples from 220 colorectal cancer patients during surgery and adjuvant chemotherapy and 42 healthy controls were tested for the presence of p53-Ab by ELISA. Expression of p53 protein in tumors was determined using mouse anti-human p53-Ab.ResultsSerum p53-Ab were detected in 18% of patients while all controls were negative. A strong correlation between p53-Ab production and p53 protein expression was observed: 70% of p53-Ab positive cases had tumors positive for p53 vs. 52% of p53-Ab negative cases. There was also a significant predominance of p53-Ab positive cases in Dukes’ stages B and C over stage A. Although surgery alone reduced p53-Ab levels, decreases in p53-Ab titer became significant midterm through chemotherapy compared to both pre- and postoperative values and remained decreased until the completion of treatment.ConclusionThe presence of p53-Ab in sera of patients with colorectal cancer indicates tumors in more advanced histopathologic stages (Dukes’ B, C). Due to low sensitivity (18%) p53-Ab are not recommendable as a preoperative marker for colorectal cancer. However, due to high specificity (100%), their monitoring after surgery and adjuvant chemotherapy has potential for early diagnosis of tumor relapse in p53-Ab positive cases.

Effect of the nonsteroidal anti-inflammatory drug indomethacin on proliferation and apoptosis of colon carcinoma cells

Purpose: Nonsteroidal anti-inflammatory drugs lower the incidence of and mortality from colon cancer. In this paper, we present the effect of indomethacin on growth inhibition and alterations in the expression of several genes involved in cell cycle and apoptosis in CaCo-2 colon adenocarcinoma cells. Methods: We used the MTT test to evaluate the effect of indomethacin on the proliferation rate of colon cancer and normal fibroblast cells in vitro. The expression of c-myc oncoprotein and p53 and p27 suppressor proteins was examined using the immunocytochemical method. Results: We have shown that indomethacin reduces the proliferation rate of CaCo-2 colon cancer cells (up to 60% at the concentration of 4 × 10−4 M), alters their morphology, and induces cell death by apoptosis. The most pronounced inhibitory effect was observed at the concentration of 6 × 10−4 M where the growth was completely suppressed. However, the growth of normal fibroblasts (Hef 522) was much less inhibited (about 30% of inhibition at the concentration of 6 × 10−4 M). Indomethacin reduces the proliferation rate and induces apoptosis in CaCo-2 colon cancer cells through enhanced expression of c-myc, p53, and p27 proteins. Conclusions: This is the first report about p27-increased expression in colon carcinoma cells induced by indomethacin treatment. Increased expression of p27 represents a new mechanism of apoptosis in cells treated with NSAIDs (indomethacin). This effect probably contributes to the anti-proliferative effect on colon cancer cells in vitro.

Determination of leucocyte subsets in human saliva by flow cytometry

OBJECTIVE Validation of a flow cytometry-based method for the determination of major leucocyte subsets [polymorphonuclear (PMN) cells, monocytes, T cells and B cells] in paraffin-stimulated whole human saliva. DESIGN Salivary leucocyte subsets were determined by four-colour flow cytometry in eight healthy volunteers on three consecutive days. Comparison of leucocyte subsets between saliva and whole blood was also performed. Day-to-day variability and intraclass correlation coefficients (ICC) were determined as indicators of assay reliability. RESULTS It was observed that PMN cells were the predominant cells in the saliva. Percentages of mononuclear cells ranged from 0.3% to 7.2%, with monocytes composing the highest percentage, followed by T cells and B cells. Regardless of high intra-individual day-to-day variability, proportions of leucocyte subsets did not significantly change over three measurements, and high ICCs were calculated for T cells and monocytes. CONCLUSION Flow cytometry can be used as non-invasive and reproducible method for the analysis of leucocyte subsets in human saliva. Further investigation of pathological and other conditions that have the potential to influence salivary leucocyte subsets is warranted.

Detection and typing of human papillomaviruses by polymerase chain reaction in cervical scrapes of Croatian women with abnormal cytology

The association between certain human papillomaviruses (HPV) and cervical intraepithelial neoplasia (CIN) is well documented, but still unknown among Croatian women. In 1995, women between the age of 17 and 64 with cytomorphologically abnormal smears (CIN I–IV) were tested for the presence of HPV. Consensus and specific primers were used in the polymerase chain reaction (PCR) to detect the most common types: 6, 11, 16, 18, 31 and 33, as well as the unknown-risk HPV types (HPV X). Out of 379 specimens, 163 (43%) contained one or more HPV types. Coinfection with different HPV types in the same sample was observed in 16 cases. Beside low-risk HPV 6/11 (25.8%) the most frequently observed types were high-risk HPV types 16 (20.2%) and 31 (17.8%). Globally, the HPV positivity rate declines with age. The presence of HPV DNA significantly increased from 35.5 to 61.1% along with the severity of the cervical intraepithelial neoplasia (CIN I– IV). HPV type 6/11 was strongly associated with CIN I (33.8%), HPV type 31 with CIN II (22.9%), and HPV type 16 with CIN III (50%).

Prognostic value of microphthalmia-associated transcription factor and tyrosinase as markers for circulating tumor cells detection in patients with melanoma

The aim of this study was to analyze microphthalmia-associated transcription factor (MITF) as a marker for the detection of circulating melanoma cells, determine its prognostic value in melanoma patients, and compare it with tyrosinase. Blood samples from 201 melanoma patients in all stages of the disease and 40 healthy volunteers were analyzed. RNA was isolated from mononuclear cell fraction of the blood and assayed by reverse transcription-PCR for the expression of MITF and tyrosinase. All samples from healthy volunteers were negative for both MITF and tyrosinase. Out of 201 blood samples from melanoma patients 32 were positive for MITF, 20 for tyrosinase, and four for both MITF and tyrosinase. Analysis of MITF as an additional marker to tyrosinase allowed for detection of circulating melanoma cells in a larger number of melanoma patients in comparison to tyrosinase analysis alone (48 vs. 20 positive). A positive value of MITF was associated with shorter progression-free (P=0.005) and overall survival (P=0.042). A positive value of tyrosinase was associated with shorter overall survival (P=0.012), whereas there was no significant association between the value of tyrosinase and progression-free survival. The value of MITF was selected with multivariate analysis as the independent prognostic factor for progression-free survival, whereas the only independent prognostic factor for overall survival was the stage of disease. This study has shown that MITF is a specific marker for detection of circulating melanoma cells that has a prognostic value in melanoma patients. Determination of MITF in addition to tyrosinase improved the detection of circulating melanoma cells in melanoma patients.

Loss of heterozygosity of APC and DCC tumor suppressor genes in human sporadic colon cancer

We examined 36 cases of human sporadic colon carcinoma and corresponding normal tissue samples to evaluate loss of heterozygosity at the APC and DCC tumor suppressor genes loci using restriction fragment length polymorphism polymerase chain reaction and variable nucleotide tandem repeat analysis. Observed informativity was 83% for APC and 75% for DCC. DNA from 6 (20%) of 30 informative tumors exhibited loss of heterozygosity at the APC locus. Loss of heterozygosity at the DCC locus was observed in 7 (26%) of 27 informative tumor DNAs. Our results support the view that malignant progression is a consequence of more than one genetic change and suggest that inactivation of APC and DCC genes plays a role in a multistep process of colon tumor progression.

Natural killer cell activity, phagocytosis, and number of peripheral blood cells in breast cancer patients treated with tamoxifen

SummaryThe number of leukocytes, proportion and absolute number of granulocytes, lymphocytes, CD4+ cells, CD8+ cells, CD16+ cells, B-lymphocytes, monocytes, natural killer cell (NK) activity, and granulocyte and monocyte phagocytic functions - ingestion and intracellular killing - were determined in a group of 27 patients with ductal invasive breast carcinoma, stage I-III, before and 7 months following postsurgical telecobalt radiotherapy, divided into two subgroups, one of them receiving tamoxifen (TMX group) and the other one not receiving any further therapy (control group). In control group, proportion of all lymphocytes and CD8+ cells as well as absolute number of all lymphocytes, CD4+, CD8+, CD16+ and B lymphocytes were decreased following TCT in comparison to their pre-TCT values, while in TMX group only absolute number of all lymphocytes remained decreased following TCT. Moreover, post-TCT proportions of all and CD8+ lymphocytes as well as absolute numbers of all and CD4+ and CD8+ lymphocytes in TMX patients were significantly increased in comparison to the same parameters in control post-TCT patients, although there was no difference between the two subgroups before TCT. At the other hand, granulocyte ingestion was decreased in post-TCT TMX patients compared to post-TCT values in control patients and NK cell activity showed a similar, although statistically not significant, tendency. It seems that TMX helps recovery of lymphocyte populations decreased by radiotherapy, probably by stimulation of cells carrying estrogen receptors, but its effects on phagocytic functions and probably NK cell activity seemed to be rather inhibitory than stimulatory.

Modulating role of alcohol and acetaldehyde on neutrophil and monocyte functions in vitro

Moderate alcohol intake lowers coronary heart disease risk. Because polymorphonuclear neutrophils (PMN) and monocytes (Mo) play a role in atherosclerotic plaque destabilization we investigated in vitro effects of clinically relevant concentrations of ethanol (0.05, 0.125, 0.25, and 0.5%) and its metabolite acetaldehyde (0.0625, 0.125, and 0.5 mM) on human PMN and Mo phagocytic functions. PMN and Mo from healthy volunteers were separated and purified according standard methods and the following parameters were determined: phagocytic activity (percent of phagocytes with at least one ingested particle), ingestion index (number of ingested particles per 100 phagocytic cells), and intracellular killing (percent of dead ingested particles per 100 phagocytes) using acridine orange method and living yeast cells as targets. Reactive oxygen species (ROS) formation of ethanol-treated PMN and Mo was evaluated using 2,7-dichlorofluorescin method and results were expressed as percent of fluorescence-positive cells. Ethanol and acetaldehyde significantly reduced PMN phagocytic functions, with the exception of phagocytic activity, starting at 0.125% for ethanol and 0.0625 mM for acetaldehyde. Mo ingestion and microbicidity were decreased at ethanol concentrations of 0.5% without effect on Mo phagocytic activity. Acetaldehyde impaired Mo ingestion ability starting at 0.0625 mM and phagocytic activity at 0.5 mM while was without effect on Mo microbicidity. ROS production was significantly increased at ethanol concentrations 0.25 and 0.5% in PMN and at 0.5% in Mo. These results might partly explain the benefitial role of moderate use of alcohol on cardiovascular disease.

Structural study of picolinamide complexes of Ni(II), Zn(II), Cd(II), and Hg(II) nitrates in solid state and solution

Three picolinamide complexes of nickel(II) (1), zinc(II) (2), and cadmium(II) (3) have been prepared and their solid state structures were determined by single-crystal X-ray diffraction analysis. Their structures in DMSO solutions as well as the structure of similar mercury(II) complex, [Hg(NO3)(pia)2](NO3) (4), have been elucidated by 1H and 13C NMR spectra. The picolinamide is bound through the N,O-donors in all four complexes in solid state, but only in 4 it is in solution state. In nickel (1), zinc (2), and cadmium (3) complexes the pia-N coordination in solution is suggested. The X-ray analysis revealed that isomorphous nickel (1) and zinc (2) crystal structures comprise the centrosymmetrical trans-[M(H2O)2(pia)2]2+ (M = Ni, Zn; pia = picolinamide) and nitrate. The crystal lattices also contain two non-coordinated H2O molecules. In 3, each cadmium(II) is N,O-chelated by two cis-oriented pia ligands, while remaining coordination sites of the capped pentagonal bipyramid are occupied by three oxygen atoms from two nitrates. Crystal structures are dominated by O/N/C–H···O hydrogen bonds. The carboxamide moieties in 1 and 2 do not form any head-to-head or catemeric supramolecular synthons, but participate in the formation of (12) motifs with solely the amide nitrogen atoms as double hydrogen bond donors. In 3, neighboring molecules are linked into head-to-head amide dimers. The biological effect of picolinamide and [Zn(pia)2(H2O)2](NO3)2 on ingestion and intracellular microbicidal capacities of human peripheral blood phagocytes was also assessed.