IFN-γ and other serum cytokines in head and neck squamous cell carcinomas

SUMMARY

Altered immune responses have been reported in head and neck cancer, and some of these responses have been associated with poor clinical outcomes. A multiple-array technology platform was used to simultaneously evaluate the levels of 25 cytokines. Pre-treatment serum levels were evaluated in 31 HNSCC patients and 6 healthy controls. The levels of 8 cytokines, specifically IL-1ra, IL-2, IL-5, IL-6, IL-8, IL-17, IFN-γ and IP-10, were significantly higher in patients than in controls. Among cancer patients we observed lower levels of IFN-γ and IL-7 in cases with nodal metastases compared to those with cN0 disease. We observed increases in the levels of some serum cytokines in HNSCC patients, as well as reductions in selected cytokines associated with regional progression. These findings provide an intriguing perspective on the development and validation of novel markers for follow-up evaluations and predictions of regional spreading in HNSCC patients.

Immunopathological characterization of cryptoglandular anal fistula: a pilot study investigating its pathogenesis

AIM

The pathogenesis of cryptoglandular anal fistula (AF) is still under debate. Tissue inflammation could play a primary role. The pathological process of epithelial mesenchymal transition (EMT) might be involved but has never been investigated.

METHOD

In a prospective pilot study, 12 patients with an AF had a fistulectomy. The excised track was divided into proximal (intrasphincteric) and distal (extrasphincteric) parts which were subjected to standard histopathological examination. The cytokines IL-8 and IL-1beta were analysed as markers of inflammation, while EMT was evaluated by expression of TGF-beta, Vimentin, Zeb-1, Snail and E-cadherin. The mRNA and protein expression of these molecules was investigated by real-time PCR (RT-PCR), Western blot analysis and immunohistochemistry and was compared with that of the normal adjacent tissue.

RESULTS

Chronic inflammation and granulation tissue and a stratified epithelium were evident on standard histopathological examination. The cytokine IL-8 was more expressed in the proximal than the distal part of the track (fold increase 4.34 vs 3.60), while the reverse was found for IL-1beta (fold increase 1.33 vs 2.01); both were more intensely expressed compared with the normal anal mucosa. EMT was demonstrated, in both proximal and distal parts of the track, with an increase of TGF-beta, Vimentin, Zeb-1 and Snail and a mean decrease of E-cadherin. Western blot analysis and immunohistochemistry confirmed the protein expression.

CONCLUSION

The study suggests that chronic inflammation is present in cryptoglandular fistulas. The inflammatory pattern might be different in the proximal than in the distal part of the fistula track. The cytokines IL-1beta and IL-8 could play a possible role in fistula formation. The study demonstrates for the first time the potential importance of EMT in the pathogenesis of cryptoglandular AF.

Expression of alpha-dystroglycan correlates with tumour grade and predicts survival in oral squamous cell carcinoma

AIMS

Dystroglycan (DG) is a non-integrin adhesion molecule connecting the extracellular matrix to the actin cytoskeleton. Decreased expression of DG has been reported in several human cancers and related to tumour aggressiveness.

METHODS

Expression of the alpha-DG subunit was evaluated by immunostaining in a series of oral squamous cell carcinoma (OSCC) and its relation with traditional prognostic indicators and with the clinical outcome of the patients was evaluated.

RESULTS

Alpha-DG expression was easily detected in normal epithelium with a mean percentage of positive cells >80% but was undetectable in a significant fraction (59%) of OSCC. Loss of alpha-DG staining correlated with higher tumour grade (p = 0.04) and stage (p = 0.01), with nodal involvement (p = 0.001) and with an increased risk of recurrence (p = 0.002) and death (p = 0.004) in a univariate analysis, but it was not confirmed as an independent predictor of clinical outcome in a multivariate analysis.

CONCLUSIONS

Loss of alpha-DG expression, which corresponds to loss of a functional DG complex, is a frequent event in human OSCC. Further studies are warranted on the role of this molecule in the entire multistep process of oral squamous tumorigenesis.

Post-translational modulation of CD133 expression during sodium butyrate-induced differentiation of HT29 human colon cancer cells: implications for its detection

The CD133 molecule has been proposed as a surface marker of cancer stem cells in several human malignancies, including colon cancers. The function and the mechanisms regulating CD133 expression remain unknown. The HT29 human colon cancer cells undergo differentiation following treatment with various agents and represent a useful in vitro model of colon differentiation. This study evaluated the behavior of CD133 during sodium butyrate-induced differentiation of HT29 cells. Treatment with sodium butyrate induced a progressive decrease of CD133 expression, as assessed by flow cytometry using the AC133 monoclonal antibody. Indeed, expression of CD133, which was about 47% in untreated control cells, gradually decreased down to about 3% after 72 h in a time- and dose-dependent manner. No relationship was observed between CD133 protein evaluated by flow cytometry and mRNA expression level, and no changes were detected in the methylation status of the CD133 gene promoter during HT29 differentiation. Moreover, the expression of the CD133 protein, evaluated by Western blot analysis using a specific anti-CD133 antibody directed against the C-terminal intracytoplasmic region of human CD133 protein, did not correlate with flow cytometry results. Different results were also obtained using the two antibodies to analyze the expression of the CD133 molecule in human colon cancers. These findings demonstrate that membrane expression of the CD133 stem cell marker might undergo a complex regulation during differentiation of colon cells and suggest that HT29 cells are a useful in vitro model to study the mechanisms involved in this regulation which likely occurs at a post-transcriptional level.

Expression of the CDK inhibitor p27kip1 and oxidative DNA damage in renal cell carcinoma

e16008

Background: Deregulation of the normal cell cycle is a frequent event in human tumors and plays an important role in malignant transformation. p27kip1 is a negative regulator of the G1 phase, is frequently lost in tumor cells and, in some cases, its alteration is coupled with oxidative DNA damage. Methods: We evaluated the expression of p27kip1 and the extent of endogenous oxidative DNA damage (by means of 8-hydroxydeoxyguanosine [8-OHdG] levels) by immunostaining in a series of 125 (median age 64[range23–86]yrs) renal cell carcinomas (RCCs); furthermore, the prognostic significance of their alterations was tested. Median values of expression were used as cut-off. p27kip1 expression was also evaluated by Western Blot in a second series of 34 fresh-frozen RCCs. Results: to date, median follow-up is 29[range 4 - 104] months. p27kip1expression was lost in a significant fraction of tumors (55%) with a median percentage of positive cells of 20% [range 0–60%). Loss of p27kip1 staining correlated with higher tumor grade (p=0.049). Recurrence (p=0.007) and death (p=0.006) from RCCs were significantly more frequent in patients p27kip1-negative compared with positive ones. Kaplan-Meier analysis showed a significant separation between high vs low p27kip1 expression groups for both disease-free (p=0.011) and overall (p=0.002) survival. At multivariate analysis, loss of p27kip1expression was the only independent risk predictor for recurrence (HR=4.326, p=0.014) and death (HR=4.915, p=0.012) from RCCs when tumor size, tumor grade and stage were included. No significant correlation with clinical or pathological parameters and outcome was found for 8- OHdG. p27kip1 total protein levels showed a variable behaviour at WB analysis with a modest trend toward a global reduction but an elevation in some cases. Conclusions: loss of p27kip1 is frequent in human RCCs and is a powerful predictor of poor outcome. p27kip1 alteration are not related to endogenous oxidative DNA damage. The behaviour of p27kip1at WB analysis is probably related to the elevation of the cytoplasmatic (and inactive) fraction.

No significant financial relationships to disclose.

Differential toxic effects of methyl tertiary butyl ether and tert-butanol on rat fibroblasts in vitro

Methyl tertiary butyl ether (MTBE) is the most widely used motor vehicle fuel oxygenate since it reduces harmful emissions due to gasoline combustion. However, the significant increase in its use in recent years has raised new questions related to its potential toxicity. In fact, although available data are somehow conflicting, there is evidence that MTBE is a toxic substance that may have harmful effects on both animals and humans and an unresolved problem is the role played by MTBE metabolites, especially tertiary butyl alcohol (TBA), in determining toxic effects due to MTBE exposure. In this study, the toxic effects of MTBE have been analyzed on a normal diploid rat fibroblast cell line (Rat-1) and compared to the effects of TBA. The results obtained suggest that both MTBE and TBA inhibit cell growth in vitro but with different mechanisms in terms of effects on the cell cycle progression and on the modulation of cell cycle regulatory proteins. In fact, MTBE caused an accumulation of cells in the S-phase of the cell cycle, whereas TBA caused an accumulation in the G0/G1-phase with different effects on the expression of cyclin D1, p27Kip1, and p53. Moreover, both MTBE and TBA were also shown to induce DNA damage, as assessed in terms of oxidative DNA damage and nuclear DNA fragmentation, that appeared to be susceptible of repair by the cell DNA-repair machinery. In conclusion, these findings suggest that both MTBE and TBA can exert, by acting through different molecular mechanisms, important biological effects on fibroblasts in vitro. Further studies are warranted to shed light on the mechanisms responsible for the observed effects and on their potential significance for the in-vivo exposure.

Isolation and characterization of CD133+ cell population within human primary and metastatic colon cancer

BACKGROUND

"Cancer stem cells" (CSC) have been identified as a minority of cancer cells responsible for tumor initiation, maintenance and spreading. Although a universal marker for CSC has not yet been identified, CD133 has been proposed as the hallmark of CSC in colon cancer. The aim of our study was to assess the presence of a CD133+ cell fraction in samples of colon cancer and liver metastasis from colon cancer and evaluate their potential as tumor-initiating cells.

METHODS

Tissue samples from 17 colon cancers and 8 liver metastasis were fragmented and digested using collagenase. Cell suspensions were characterized by flow cytometry using anti-CD133, CD45 and CD31 antibodies. CD133+ cells were also isolated by magnetic cell sorting and their tumor-initiating potential was assessed versus the remaining CD133- fraction by soft-agar assay.

RESULTS

Our results confirmed the existence of a subset of CD133+ tumor cells within human colon cancers. Interestingly, CD133+ cells were detectable in liver metastasis at a higher percentage when compared to primary tumors. Soft-agar assay showed that CD133+ cell fraction was able to induce larger and more numerous colonies than CD133-cells.

CONCLUSION

Our findings data that the CD133+ colon cancer cells might play an important role in both primary tumors as well as in metastatic lesions thus warranting further studies on the role(s) of this subset of cells in the metastatic process.

Dystroglycan expression is reduced during prostate tumorigenesis and is regulated by androgens in prostate cancer cells

Prostate cancer, the most frequently diagnosed cancer in Western men, can display a high variability in term of clinical aggressiveness and prognosis and none of the available markers is able to accurately predict its clinical course. Dystroglycan (DG), a non-integrin adhesion molecule, is a complex formed by two subunits, alpha- and beta-DG, which bind to extracellular matrix molecules and cytoskeleton, respectively. DG expression is frequently reduced in human cancers and has been related to tumor grade and aggressiveness. This study investigated the role of DG in human prostate tumorigenesis and its suitability as a prognostic marker. The expression level of extracellular alpha-DG subunit was frequently reduced in human prostate cancer cell lines and primary tumors and the percentage of positive tumor cells was significantly further decreased in vivo following androgen ablation therapy (median = 1%) compared to pre-treatment samples (median = 28%). A significant relationship was observed between alpha-DG staining on the post-treatment samples and tumor recurrence. A dose- and time-dependent decrease of DG expression also occurred in human prostate cancer cells following treatment with the anti-androgen flutamide. Stable expression of an exogenous DG cDNA in the LNCaP human prostate carcinoma cell line resulted in a marked inhibition of both anchorage-dependent and independent growth and of the in vivo tumorigenicity. These findings confirm and extend previous evidence that disturbances in the function of the DG complex might contribute to the definition of the malignant behavior of prostate cancer cells and suggest that androgens might regulate DG expression in these cells.

Analysis of dystroglycan regulation and functions in mouse mammary epithelial cells and implications for mammary tumorigenesis

Abnormalities in the interactions of cells with the extracellular matrix (ECM) play an important role in the development and progression of many types of cancer and are a hallmark of malignant transformation. The dystroglycan (DG) complex is a transmembrane glycoprotein that forms a continuous link from the ECM to the actin cytoskeleton, providing structural integrity and perhaps transducing signal, in a manner similar to integrins. Deregulated expression of DG has been reported in a variety of human malignancies and related to tumor differentiation and aggressiveness. In breast cancer, reduced DG expression has been associated with patient survival and with loss of differentiation of tumor cells. Limited data are available on DG physiology in epithelial cells. In this study, we used the HC11 spontaneously immortalized murine mammary epithelial cells to study DG function(s) and regulation in normal cells. We found that expression of DG protein and mRNA is cell-cycle and cell-density regulated in these cells. Moreover, expression of both DG subunits increased upon lactogenic differentiation of the HC11 cells. The turnover of cell-surface-expressed DG was evaluated in the same cells and half-life of DG subunits was evaluated to be about 12 h. DG-specific small inhibitory RNAs were used to analyze the effects of a reduced expression of DG in these cells. Cells in which DG expression was suppressed were growth inhibited, accumulated in the S-phase of the cell cycle, failed to undergo lactogenic differentiation, and displayed an increase in the percentage of apoptotic cells. Moreover, changes were observed in the expression and/or activity of several molecules involved in cell growth control. These results demonstrate that DG expression is tightly regulated in normal mammary epithelial cells and support the hypothesis that DG is involved in several functions other than structural integrity in these cells. This finding provides new insight into the roles played by DG in epithelial cell physiology and will contribute to our understanding of its involvement in the process of epithelial cell transformation.

Lycopene induces apoptosis in immortalized fibroblasts exposed to tobacco smoke condensate through arresting cell cycle and down-regulating cyclin D1, pAKT and pBad

There is a lot of interest in the health benefits of dietary carotenoids and on the relationship of these compounds with smoke. In particular, it is unknown if the enhanced cancer risk observed in smokers following beta-carotene supplementation can be also found using other carotenoids. Here, we studied the effects of the tomato carotenoid lycopene on molecular pathways involved in cell cycle progression, apoptosis and survival in immortalized RAT-1 fibroblasts exposed to cigarette smoke condensate (TAR). Lycopene (0.5-2.0 microM) inhibited cell growth in a dose-and time-dependent manner, by arresting cell cycle progression and by promoting apoptosis in cells exposed to TAR. The arrest of cell cycle was independent of p53 and of 8-OH-dG DNA damage and related to a decreased expression of cyclin D1. Moreover, the carotenoid up-regulated apoptosis and down-regulated the phosphorylation of AKT and Bad in cells exposed to TAR. Such an effect was associated to an inhibition of TAR-induced expression of Cox-2 and hsp90, which is known to maintain AKT activity. This study suggests that lycopene, differently from beta-carotene, can exert protective effects against cigarette smoke condensate.

Redox regulation of cell proliferation by pyrrolidine dithiocarbamate in murine thymoma cells transplanted in vivo

Pyrrolidine dithiocarbamate (PDTC) is a synthetic compound largely used in cell biological studies and known to exert either antioxidant or pro-oxidant effects. Recently, its antitumoral activity has been proposed on the basis of its antioxidant and proapoptotic effects. In the present study, we evaluated the effect of increasing i.p. doses of PDTC on the growth of a strain of highly malignant thymoma cells inoculated in the peritoneum of inbred Balb/c mice. PDTC treatment increased the number of thymoma cells in a dose-dependent manner, enhancing the percentage of proliferating tumor cells. PDTC exerted regulatory effects on cell cycle distribution, decreasing the expression of cell cycle inhibitors. Alterations in the production of intracellular reactive oxygen species, levels of oxidized glutathione, and intracellular levels of the redox-active metals iron and copper were also observed. The above results represent the first evidence that PDTC may induce in vivo cell proliferation in a murine thymoma cell model. In addition, we suggest that the ability of PDTC to bind and transport metals inside the cell and its pro-oxidant property may be factors underlying its effects on thymoma cell proliferation and cell cycle distribution.

DNA oxidative damage during differentiation of HL-60 human promyelocytic leukemia cells

DNA oxidative damage was measured in human promyelocytic leukemia HL-60 cells, in the same cells committed to granulocytic differentiation with dimethyl sulfoxide (DMSO) or all-trans-retinoic acid (RA) and in mature human peripheral granulocytes (HPG). DNA damage was evaluated as single strand breaks and 8-OHdG adducts, measured by single cell electrophoresis or by monoclonal antibodies, respectively. The basal levels of either marker of DNA damage were higher in undifferentiated HL-60 cells than in HPG and DMSO- or RA-differentiated cells. Treatment with H(2)O(2) increased 8-OHdG formation in all cells, but the levels of DNA damage remained higher in undifferentiated cells as compared to the differentiated ones. Three lines of evidence suggested that the higher levels of DNA damage observed in undifferentiated cells were at least in part attributable to a reduced detoxification of reactive oxygen species (ROS). First, undifferentiated cells were shown to accumulate higher levels of dichlorodihydrofluorescein-detectable ROS than HPG and DMSO- or RA-differentiated cells. Second, undifferentiated HL-60 cells were characterized by reduced levels of GSH and lower GSH/GSSG ratios as compared to the differentiated cells. Third, pretreatment of undifferentiated HL-60 cells with antioxidants such as alpha-tocopherol or beta-carotene suppressed the elevation of ROS and the formation of 8-OHdG induced by H(2)O(2). Further evidence for the importance of the oxidant/antioxidant balance was obtained by modulating the iron-catalyzed decomposition of H(2)O(2) to hydroxyl radicals in undifferentiated HL-60 cells. In fact, pretreatment with FeSO(4) increased the formation of 8-OHdG induced by H(2)O(2), whereas pretreatment with the iron chelator deferoxamine produced the opposite effect. These results illustrate correlations between the oxidant/antioxidant balance and DNA damage and suggest that the capability of a cell population to withstand oxidative stress and DNA damage may depend on its degree of differentiation.

Resveratrol, a natural phenolic compound, inhibits cell proliferation and prevents oxidative DNA damage

Resveratrol (3,4',5-trihydroxystilbene) is a naturally occurring phenolic compound which is present at high levels in wine and has been recently proposed as a potential cancer chemopreventive and chemoterapeutic agent. In this study, we evaluated the antiproliferative activity of resveratrol on a panel of cell lines of various histogenetic origin, including normal rat fibroblasts and mouse mammary epithelial cells compared to human breast, colon and prostate cancer cells. The concentration of resveratrol inhibiting cell growth by 50% (IC(50)) ranged from about 20 to 100 microM. At such concentration, we were unable to detect a significant increase in the apoptotic index in most of the cell lines analyzed. We also studied the effects of resveratrol on cell cycle distribution. The most striking effect was a reduction in the percentage of cells in the G2/M phase which was most frequently associated with an increase of cells in the S phase of the cell cycle. We also found that resveratrol is able to prevent the increase in reactive oxygen species (ROS) following exposure to oxidative agents (i.e. tobacco-smoke condensate (TAR) and H(2)O(2)). Resveratrol also reduced nuclear DNA fragmentation, as assessed by single cell gel electrophoresis (comet test). Taken together our results suggest that resveratrol can act as an antimutagenic/anticarcinogenic agent by preventing oxidative DNA damage which plays a pivotal role in the carcinogenic activity of many genotoxic agents.

Isolation of normal epithelial cells adapted to grow at nonphysiological concentration of magnesium

Extracellular magnesium (Mg) depletion inhibits the growth of the HC11 normal mammary epithelial cells. In this study we found that an acute increase in extracellular Mg generally exerts a positive effect on the growth of these cells. We also isolated and characterized two derivatives adapted to grow and proliferate at nonphysiological concentration of Mg. The growth properties of the HC-LMg cells at 25 microM Mg were comparable to those of the parental HC11 cells in the regular medium (0.5 mM Mg) despite an increased expression of the CDK inhibitor p27(Kip1). They also showed a reduced dependence from serum to grow. The HC-HMg cells have been adapted to grow and proliferate at an increased (45 mM) Mg concentration. Cell total Mg content was 19.6, 9.7, and 20.1 nmol/mg protein in the HC11, HC-LMg, and HC-HMg cells, respectively. Thus, we have isolated derivatives of normal epithelial cells which are able to maintain Mg content in a physiological range in the face of different extracellular concentration gradients and will be a valuable tool for further studies on the regulation of Mg homeostasis in eukaryotic cells.

Evaluation of 8-hydroxydeoxyguanosine in human oral cells: the importance of tobacco smoke and urban environment

The DNA adduct 8-hydroxydeoxyguanosine (8-OHdG) has been widely used as a sensitive biomarker for oxidative damage. To investigate the role of environmental factors on oxidative DNA damage formation, the level of 8-OHdG was determined in oral cells from 109 healthy volunteers by an immunohistochemical method. A statistically significantly higher content of 8-OHdG was detected in oral cells from smokers (111 +/- 55, n = 38) compared with non smokers (78 +/- 48, n = 71), (p < 0.01). Moreover, subjects living in an urban area showed a higher level of oxidative damage with respect to those living in a countryside-suburban area (99 +/- 53, n = 58 vs. 78 +/- 51, n = 51), (p = 0.03). No significant association was detected between 8-OHdG in oral cells and other variables such as passive smoke, oral infections, alcohol or vitamin intake and grilled food consumption. This work suggests that tobacco smoke and environmental exposure to pollutants lead to a measurable increase of oxidative damage in oral cells and confirms that the immunoperoxidase method is an appropriate approach for epidemiological analyses.

8-hydroxy-2'-deoxyguanosine in cervical cells: correlation with grade of dysplasia and human papillomavirus infection

In this study, the 8-hydroxy-2'-deoxyguanosine (8-OHdG) level was assessed in human cervical cells by an immunoperoxidase method and was related to the presence of human papillomavirus (HPV) infection and precancerous lesions. After optimizing the immunohistochemical method of detecting oxidative DNA damage in whole cells, we have used this technique to estimate the oxidative damage in cervical cells collected during a routine PAP test. The analysis of variance (ANOVA) of the data from human samples showed significant differences in the 8-OHdG content among normal, low-grade and high-grade squamous intraepithelial lesion (SIL, HGSIL and LGSIL, respectively; P < 0.001). In the comparison of the three groups, statistically significant differences were detected between normal SIL and HGSIL (P < 0.001) and between LGSIL and HGSIL (P = 0.003), whereas no statistically significant difference was found between normal SIL and LGSIL (P = 0.1). Grouping observations by HPV status, no significant difference was detected in 8-OHdG levels between HPV(+) and HPV(-) subjects (P = 0.8). The polytomous and proportional odds models, extensions of the logistic regression analysis, showed that the effect of 8-OHdG levels in rising the risk of dysplasia was roughly constant through SIL grades. In conclusion, the immunoperoxidase method, applied to single human cervical cells, provides clear evidence that significant differences exist in 8-OHdG content between normal and dysplastic cells and that oxidative DNA damage might play an important role in cervical carcinogenesis.

Polycyclic aromatic hydrocarbon-DNA adducts in cervical smears of smokers and nonsmokers

OBJECTIVES

The aim of this study was to detect polycyclic aromatic hydrocarbon-DNA (PAH-DNA) adducts in single cervical cells collected during a routine Papanicolaou smear and to relate this carcinogen exposure dose marker to smoking habit.

METHODS

An immunohistochemical assay, using a polyclonal antiserum raised against benzo[a]pyrene diol epoxide-DNA adducts, was performed to evaluate PAH-DNA adducts in cervical cells collected from 16 volunteers who smoked at least 20 cigarettes/day and 16 nonsmokers.

RESULTS

The mean adduct level, determined as relative staining intensity by an optical density image analyzer, was significantly higher in smokers compared to nonsmokers (AOD x 1000 +/- SD = 98 +/- 32 and 73 +/- 25, respectively) (P = 0.04).

CONCLUSIONS

These results demonstrate that this immunohistochemical assay, much simpler than other methodologies used to evaluate PAH-DNA adducts in cervical tissue, is sufficiently sensitive for quantitative adduct evaluation in single epithelial cervical cells, as already verified for other exfoliated material. This work thus confirms that tobacco smoke is a risk factor for genotoxic damage generation in cervical cells and indicates a procedure likely adaptable to a large population screening.

Analysis of 4-ABP-DNA adducts and p53 alterations in urinary bladder carcinoma

BACKGROUND

Activated intermediates of 4-aminobiphenyl (4-ABP) are able to covalently interact with DNA to form adducts. There is a large body of evidence indicating that carcinogen-DNA adduct formation can be one of the cancer initiating mechanisms.

MATERIALS AND METHODS

(4-ABP)-induced DNA damage in association with p53 overexpression and mutations were evaluated in specimens of urothelial bladder cancers from 106 patients.

RESULTS

4-ABP-DNA adduct levels resulted higher in smokers compared to non smokers, with a borderline statistical value. p53 nuclear overexpression was related to tumor grading, while no significant correlation with stage, 4-ABP-DNA adducts, smoking habit, and disease recurrence could be observed. Concerning molecular analysis, p53 point mutations were found in 17 of 106 cases (16%) and mutational pattern was significantly associated both with higher grade and stage, but no correlation was found with disease recurrence.

CONCLUSIONS

These results suggest that other sources, in addition to tobacco smoke, may contribute to 4-ABP-DNA adducts formation in bladder tissue and that p53 expression/mutation cannot be considered a prognostic factor in bladder cancer.

Biological characterization of central and peripheral primary non small cell lung cancers (NSCLC)

BACKGROUND

Non Small Cell Lung Carcinomas (NSCLC) comprise 90% of all lung carcinomas. Studies have demonstrated a preferential central (bronchus-derived) localization for squamous cells, whereas adenocarcinomas are frequently peripheral (bronchiolo-alveolus derived). It has been suggested that exposure to carcinogenic insults including cigarette smoke, may induce different types of tumors in different locations.

MATERIALS AND METHODS

Forty one NSCLC patients staged according to WHO and TNM were considered for localization and biological parameters (p53 expression, cell ploidy and S-phase).

RESULTS

p53 overexpression was found more frequently in central than in peripheral tumors (69% vs 39%) (p = 0.074). Central tumors were more aneuploid (69%) than peripheral ones (46%) (p = 0.03) No difference in smoking habit was observed in the two groups.

CONCLUSIONS

Our results suggest that there is no apparent biological difference between these two groups of NSCLCs, and that the smoking does not play a role in either histotype determination or biological behavior.

Evaluation of polycyclic aromatic hydrocarbon-DNA adducts in exfoliated oral cells by an immunohistochemical assay

Polycyclic aromatic hydrocarbon-DNA adducts were evaluated in oral cells from 98 healthy volunteers by an immunohistochemical method using a specific antiserum against benzo(a)pyrene-DNA adducts revealed by the immunoperoxidase reaction. Mean adduct content, determined as relative staining intensity by absorbance image analyzer, was significantly higher in the cells from tobacco smokers compared with nonsmokers (330 +/- 98, n = 33 versus 286 +/- 83, n = 64, respectively) with a P = 0.013 obtained by two-sample t test with equal variances. We found that in the smoker group, the PAH-DNA adduct content increases with the number of cigarettes. Thus, the relative staining intensity was 305 +/- 105 in the group smoking 1-10 cigarettes/day (n = 16), 347 +/- 77 in the 11-20 group (n = 14), and 386 +/- 112 in the group smoking more than 20 cigarettes/day (n = 3; P = 0.03 by nonparametric test for trend). No significant association was detected between PAH-DNA adducts in oral cells and variables such as residential area, oral infections, alcohol or vitamin intake, grilled food consumption, and professional activity. This work confirms and extends previous data suggesting that this immunohistochemical method might be used as a valuable dosimeter of genotoxic damage in a carcinogen-exposed population, although further studies are needed to verify the applicability of the test in high-risk populations other than smokers.

P-170 Glycoprotein (MDR) and p53 Expression in Breast Cancer

An immunohistochemical comparative analysis of P-170 glycoprotein and p53 was performed in 37 breast cancer patients who underwent curative resection without preoperative chemotherapy. The antibodies utilized were C-219 and JSB-1 for P-gp and DO-7 for p53. Positive cytoplasmic and membrance positivity for P-gp was found in 22 (59.45%) of the 37 tumor specimens. In comparing tissue immunoreactivity by the specific antibodies, 15 (40.54%) samples showed immunostaining for C-219, 12 (32.43%) for JSB-1, and 5 (23%) for both. P-gp expression was not statistically related with the clinicopathological variables analyzed, that is, age, TNM stage, histologic type, lymph node involvement, tumor diameter, and hormone receptor status. p53 overexpression was observed in 22 (59.45%) of the 37 tumor samples analyzed. There was a significant correlation between p53 overexpression and P-gp positive immunostaining (p = .007). p53 was also significantly correlated with TNM stage (p < .05) and lymph node involvement (p < .02). Our results demonstrated that the three distinct patterns of reactivity with the two antibodies result from the combined expression of each of the three P-gp isoforms. An immunohistochemical analysis with different antibodies may be used to determine and correlate the expression pattern of P-gp isoforms with response to chemotherapy.

4-Aminobiphenyl-DNA adducts in laryngeal tissue and smoking habits: an immunohistochemical study

4-Aminobiphenyl (4-ABP)-DNA adducts and p53 overexpression were evaluated in laryngeal biopsies from 38 patients by immunohistochemical methods. Samples were categorized as tumors (n = 9), polyps (n = 28) or normal tissue (n = 1). 4-ABP-DNA adducts were evaluated with a quantitative immunoperoxidase method using monoclonal antibody 3C8 in both the lesion and adjacent tissue. Relative staining intensity data showed a log-normal distribution and values found in adjacent tissue from smokers were significantly higher (median: 173.5, geometric mean: 159.9) than those measured in adjacent tissue from non-smokers (median: 75.5, geometric mean: 7.40). Statistical significance was assessed both by non-parametric testing on raw data (P = 0.0007 on rank sum test) and by parametric testing on log-transformed data (P = 0.0002 on an unpaired t-test). Furthermore, relative staining intensity in the lesional tissue showed the same significant difference between smokers and non-smokers in patients affected by polyps, whereas no significant difference was detected in patients with laryngeal tumors. Overexpression of p53, also measured with an immunoperoxidase method, was observed in 44% of the malignant tumors and in 3.5% of the polyps. This work demonstrates that 4-ABP-DNA adducts can be evaluated in laryngeal tissue and are related to smoking exposure.

Immunohistochemical analysis of 4-aminobiphenyl-DNA adducts in oral mucosal cells of smokers and nonsmokers

BACKGROUND

The "biologically effective dose markers", DNA and protein adducts, are a direct index of carcinogen induced cell damage and an indirect one of genetic susceptibility. This study aimed to examine the dose-response relationship for 4-Aminobiphenyl-DNA adducts in oral cells of smokers and non smokers.

MATERIALS AND METHODS

An immunoperoxidase method with the monoclonal 3C8 antibody, which recognizes 4-Aminobiphenyl-DNA, has been used for detecting DNA damage in oral cells of 12 smokers and 12 non smokers.

RESULTS

Higher staining for 4-Aminobiphenyl-DNA was detected in the cells of smokers (187 +/- 42) vs. non smokers (135 +/- 35) (p = 0.004), with a twofold range in relative staining for both groups, suggesting individual differences relevance in metabolizing carcinogens and/or repairing DNA damage.

CONCLUSIONS

This non invasive method requiring small cell amounts is a tool for monitoring large groups of subjects at risk in primary prevention programs.

Immunohistochemical analysis of p53 protein in transplant recipients with Kaposi's sarcoma

PURPOSE

Kaposi's sarcoma (KS) is a proliferative process of suspected viral aetiology associated with immune deficiency. In transplanted patients, lesions regress on discontinuation of immunosuppressive therapy. The purpose of this work was to analyse the expression of the p53 oncosuppressor gene product, a proliferation regulator overexpressed in both malignant and non-malignant conditions, with the aim of better qualifying KS proliferation characteristics.

METHODS

We analysed p53 expression in a group of transplanted, cyclosporin A-treated, KS patients by immunohistochemistry, utilizing the DO-7 (with and without the antigen retrieval pretreatment), and the PAb 240 monoclonal anti-p53 antibodies, the latter of which is able to detect a mutated epitope, and evaluating staining intensity and localization, whether cytoplasmic or nuclear.

RESULTS

Seventy five percent of KS lesions from transplanted patients presented both nuclear and cytoplasmic positive p53 immunostaining with DO-7 antibody, thus demonstrating a presumably functional inactivation; one case also presented immunoreactivity with the PAb 240 antibody.

CONCLUSIONS

On the basis of the results obtained and in the presence of lesion regression upon immunosuppression withdrawal, it may be concluded that KS in transplanted patients can be considered a non-malignant proliferative process, and that the cytoplasmic expression of p53 may stand for a functional inactivation pattern.

Prognostic significance of cytoplasmic p53 overexpression in colorectal cancer. An immunohistochemical analysis

p53 overexpression was studied by immunohistochemistry in 96 consecutive colorectal cancer patients, subdividing positive specimens according to two staining patterns: cytoplasmic or nuclear. Forty-seven per cent of the cases were p53 positive, a significant correlation being found with Dukes' stage (P = 0.0036). A prevalence of nuclear staining was observed in Dukes' B and cytoplasmic in Dukes' D stages. After 36 months, 23% of the patients had a recurrence, and 45% were p53 positive, all Dukes' C-D stage with cytoplasmic staining. The Kaplan-Meier curve showed a significant correlation between p53 cytoplasmic staining and disease-free survival period (P = 0.002). With respect to disease-free survival, the Cox proportional hazard regression test, comparing p53 positivity with Dukes' stage, showed the latter to be the most significant variable. In our series of patients, advanced Dukes' stage tumours were localised in the right colon, where a higher percentage of p53 positivity (67% versus 40% of the left side), as well as a higher frequency of cytoplasmic staining was observed. In conclusion, from the data obtained, a strong correlation between p53 cytoplasmic staining and patient prognosis is clearly indicated.

[Lipolysis and ketosis during swimming in thermal water]

Plasma free fatty acids, blood glucose, beta-hydroxybutyrate and acetoacetate variations were studied in rats during swimming. Rats were forced to swim for 30 min in thermal water (source of Abano Terme) at 35 degrees and in normal water at 25 degrees. During swimming in thermal water plasma free fatty acids were increased, the glycemia remained unaffected, the beta-hydroxybutyrate and acetoacetate decreased. The swim in normal water induced a sharp increase of plasma free fatty acids, a decrease of blood glucose, an increase of blood beta-hydroxybutyrate and a marked decrease of acetoacetate. From these data, some indications of clinical interest are presented and discussed.

[Beneficial effect of swimming in thermal waters on muscle glycogen depletion]

The effect of swimming in the termal water on muscle glycogen stores was studied. After 30 min the muscle glycogen results in a diminution, but it is not depleted. On the contrary, 30 min of swimming in normal water results in a depletion of muscle glycogene stores. The glycemic homeostasis is well maintained in thermal water, and hypoglicemia occurs only after swimming in normal water.

The effect of portocaval shunt on hepatic glycogen stores during fasting

The effect of a prolonged fast was studied in surgically portocaval shunted (PCS) rats. This shunt excludes the liver from the direct effect of pancreatic and enteric hormones, thus facilitating the study of the biochemical and metabolic effects of these hormones. In portocaval shunted rats, liver glycogen was lower than that of control rats, and remained unaffected during fasting. No remarkable difference was observed in blood glucose, plasma and liver free fatty acids and blood ketone bodies. Among blood nitrogen compounds, total protein, alanine and urea did not show any significant variation, while, in PCS rats, the initial low levels of creatinine resulted in an increase after fast. Skeletal muscle protein decreased only slightly in control rats, while their loss was remarkable in PCS rats. The possibility of a differential activation of gluconeogenesis and glycogenolysis in control and PCS rats is discussed.

A simplified and computerizable regulatory enzyme model

The concept of enzymes as simple biological catalysts has become too limiting and the kinetic behaviour has evidenced that the interaction of an enzyme with its substrate is more complex and can be influenced by various regulatory effectors. The resulting activity should be exactly what is required for the control of the overall flux through the metabolic pathway. A simplified enzyme model which can explain the sigmoidicity and the heterotropic effect involves the introduction of a limited number of kinetic parameters to obtain the best fit from v and s experimental values. This results in a more useful way to evaluate the possible regulatory effects of various substances such as metabolites, hormones and drugs.

Kinetic alterations of the divalent cation-dependent ATPase activities of human erythrocyte membranes induced by blocking the membrane amino groups

Treatment of erythrocyte membrane fragments with the amino group reagent sodium trinitrobenzenesulphonate (TNBS) leads to significant alteration of the kinetic properties of the membrane-bound (Ca2+ + Mg2+) and Mg2+-dependent ATPases, which appear to increase their affinity towards divalent cations and to decrease their maximal rates. Although it has not been possible to ascertain whether the amino groups involved in the TNBS effect belong to the membrane phospholipids or to the ATPase proteins, it appears that such groups play an essential role in the hydrolytic activity of the divalent cation-dependent ATPases, either by affecting the enzymes' microenvironment or by being directly involved in the enzymes'catalytic mechanism.

A new procedure for calculating the kinetic parameters of enzyme reactions

The possibilities of computer and some mathematical and statistical considerations may renew the interest and reevaluate the advantages of the double reciprocal plot proposed by Lineweaver and Burk. From the experimental values of substrate concentration and reaction velocity, the best-fitting line can be statistically obtained using nonparametric criteria. Computer programs in FORTRAN and BASIC permit easy and elegant resolutions.

[Osteopathies and vitamin D. New concepts and prospects in the light of recent advances]

Recognition over the last ten years of the fact that vitamin D does not act as such, but must be converted into a hormonal form, has filled in the picture physiological endocrine regulation of calcium and phosphate homeostasis. While vitamin D has thus lost the dietetic significance associated with it for over 50 years. Nevertheless, new interpretations of the aetiopathogenesis of many demineralizing bone diseases are of much greater utility. Nor is it futuristic to suppose that all the biochemical parameters establishing one of the metabolisms that are under strict homeostatic control in the body, such as that of calcium and that of phosphate, are understood.

Sensitivity to radiations of Mg2+ and (Ca2+ + Mg2+) ATPase activities associated with erythrocyte membrane fragments

Treatment of disrupted erythrocyte membranes with ionizing radiation induces a partial oxidation of -SH groups (as expected from reported data) and a loss of membrane phospholipids as confirmed by the decrease of membrane amino groups. The resulting disturbance of the membrane assembly strongly affects the membrane bound divalent cation-dependent ATPase activities, possibly by causing the formation of a dead-end enzyme complex unable to complete the ATP splitting cycle.

Effect of portacaval shunt on circulating free fatty acids and ketone bodies in rats

To ascertain whether portal diversion affects ketone body (KB) metabolism, fasting circulating levels of free fatty acids (FFA), acetoacetate (AcAc) and B-hydroxybutyrate (3-OH-B) were measured in portacaval shunted (PCS), sham-operated (S-O) and unoperated control (C) rats. In PCS animals blood KB concentration was clearly reduced when compared with S-O and C rats. Beta-hydroxybutyrate level was significantly lower in PCS rats, whereas AcAc concentration did not appear significantly modified in these animals. The hypothesis is proposed that hypoketonemia induced by portal diversion is due to reduced hepatic availability of fatty acids.

Studies on metabolic alterations after a mixed meal and during a 39-hour fast in thyrotoxicosis

In order to determine the endocrine and metabolic state of thyrotoxicosis we measured blood glucose and plasma insulin response to ingestion of a mixed meal in 19 euthyroid and 9 hyperthyroid subjects. Moreover concentrations of glucose, free fatty acids (FFA), glycerol, acetoacetate (AcAc) beta-hydroxybutyrate (beta-OHB), insulin and human growth hormone (hGH) were determined in the blood of both healthy and hyperthyroid patients after an overnight and a 39-h fast. In another group of thyrotoxics the overnight fasting respiratory quotient (RQ) was measured. After a mixed meal blood glucose and plasma insulin changes of FFA, AcAc and beta-OHB was significantly higher in thyrotoxics, whereas hGH increase did not appear significantly greater in these subjects. There was no statistical difference between the respiratory quotient mean values found in hyperthyroid and in control subjects. In conclusion, these data indicate that in thyrotoxicosis absolute insulin response to a mixed meal is normal and that food deprivation considerably increase lipid mobilization from adipose tissue and causes an exaggerated starvation ketosis. The RQ mean valoue suggests that in the hyperthyroid state lipid-derived fuel as well as carbohydrate-derived fuel contributes to the increased oxygen consumption.

A processing system for elaboration of data obtained by the oxygraph

A Data Processing System is presented to resolve some problems usually present in the oxygraph research. The possibility to obtain a file of data in which each experiment is arranged as completely as possible in the description of experimental conditions and the corresponding data permits the execution of some operations such as calculations, statistical elaborations, kinetic studies, research and comparation of experiments and plotting. This system may result very helpful in the programmation of the experiments and in the elaboration of the data obtained by the oxygraph technique.