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Background: In many primary tumors, parathyroid hormone-related peptide (PTHrP) and PTHrP type 1 receptor (PTH1R) are coexpressed, supporting the possibility that PTHrP/PTH1R system can mediate important signals for tumor progression through paracrine/autocrine mechanisms. In non-small cell lung carcinoma the clinical relevance of the expression of PTH1R remains to be investigated.Methods: Fifty-four lung adenocarcinomas of mixed histologic type from patients with stage I and II cancer were assayed by quantitative immunohistochemistry for the expression of PTHrP and PTH1R.Results: PTHrP and PTH1R were expressed in a wide range of intensity in the cytoplasm of tumor cells, and their values showed a positive correlation. PTH1R, but not PTHrP, was expressed by plasma cells infiltrating the tumor stroma. PTHrP and PTH1R were not associated with age, tumor diameter, or histopathologic grading, whereas they were directly associated with lymph node involvement at presentation. Cox regression analysis, using PTHrP and PTH1R as continuous covariates, showed that the covariate levels were directly associated with the risk of death and metastasis. Patients whose tumors coexpressed high levels of PTHrP and PTH1R showed the highest risk of metastasis (relative risk, 5.89; 95% CI, 2.1-16.6; P = .0003) and death (relative risk, 6.24; 95% CI, 1.6-23.9; P = .0033). The presence of PTH1R-positive plasma cells in the tumor stroma was associated with a more favorable survival rate independently from the PTHrP status of the tumor.Conclusion: The paracrine/autocrine signaling through PTHrP/PTH1R could be important in early-stage lung adenocarcinoma progression. [ABSTRACT FROM AUTHOR]

In this study, we examined possible mechanisms of caspase activation during carotenoid-induced apoptosis in tumor cells. We found that beta-Carotene induces apoptosis by the activation of caspase-3 in human leukemia (HL-60), colon adenocarcinoma (HT-29) as well as melanoma (SK-MEL-2) cell lines. This activation is dose dependent and follows that of caspase-8 and caspase-9. Although caspase-8 cleavage is an early event, reaching its maximum activation at 3 h, caspase-9 reaches its maximum activation only at 6 h. The addition of IETD-CHO, a caspase-8-specific inhibitor, completely prevents beta-Carotene-induced apoptosis, whereas only a partial prevention was observed in the presence of LEHD-CHO, a caspase-9-specific inhibitor. beta-Carotene activates caspase-9 via cytochrome c release from mitochondria and loss of mitochondrial membrane potential (Dym). Concomitantly, a dose-dependent decrease in the antiapoptotic protein Bcl-2 and a dose-dependent increase in the cleaved form of BID (t-BID) are observed. Moreover, NF-kB activation is involved in beta-Carotene-induced caspase cascade. These results support a pharmacological role for beta-Carotene as a candidate antitumor agent and show a possible sequence of molecular events by which this molecule may induce apoptosis in tumor cells. [ABSTRACT FROM AUTHOR]

To investigate the possibility that canthaxanthin inhibits cancer cell growth by inducing apoptosis, human WiDr colon adenocarcinoma and SK-MEL-2 melanoma cells were treated with two different doses of the carotenoid for 48 h. Canthaxantin was incorporated and/or associated to cells. The treatment with the carotenoid caused growth inhibition in both cell types. Concomitantly, apoptosis was induced. Increasing time of exposure and carotenoid concentration, this effect was more pronounced. At 48 h, the percentages of apoptotic cells were 13 and 15, using 1 μM canthaxanthin, and 18 and 20, using 10 μM canthaxanthin in WiDr and SK-MEL-2 cells, respectively. This study represents the first demonstration that canthaxanthin is able to induce apoptosis in tumour cells. [ABSTRACT FROM PUBLISHER]

It is now well accepted that oxysterols play important roles in the formation of atherosclerotic plaque, involving cytotoxic, pro-oxidant and proinflammatory processes. It has been recently suggested that tomato lycopene may act as a preventive agent in atherosclerosis, although the exact mechanism of such a protection is not clarified. The main aim of this study was to investigate whether lycopene is able to counteract oxysterol-induced proinflammatory cytokines cascade in human macrophages, limiting the formation of atherosclerotic plaque. Therefore, THP-1 macrophages were exposed to two different oxysterols, such as 7-keto-cholesterol (4-16 μM) and 25-hydroxycholesterol (2-4 μM), alone and in combination with lycopene (0.5-2 μM). Both oxysterols enhanced pro-inflammatory cytokine [interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor α) secretion and mRNA levels in a dose-dependent manner, although at different extent. These effects were associated with an increased reactive oxygen species (ROS) production through an enhanced expression of NAD(P)H oxidase. Moreover, a net increment of phosphorylation of extracellular regulated kinase 1/2, p-38 and Jun N-terminal kinase and of nuclear factor kB (NF-κB) nuclear binding was observed. Lycopene prevented oxysterol-induced increase in pro-inflammatory cytokine secretion and expression. Such an effect was accompanied by an inhibition of oxysterol-induced ROS production, mitogen-activated protein kinase phosphorylation and NF-κB activation. The inhibition of oxysterol-induced cytokine stimulation was also mimicked by the specific NF-κB inhibitor pyrrolidine dithiocarbamate. Moreover, the carotenoid increased peroxisome proliferator-activated receptor γ levels in THP-1 macrophages. Taken all together, these data bring new information on the anti-atherogenic properties of lycopene, and on its mechanisms of action in atherosclerosis prevention. [ABSTRACT FROM AUTHOR]

INTRODUCTION: The full clinical relevance of the expression pattern of HER family of type I receptor tyrosine kinases in laryngeal squamous cell carcinoma remains to be elucidated. We evaluated the clinical relevance of such parameter in our population. PATIENTS AND METHODS: This study examined the expression pattern of HER family receptor members by quantitative immunohistochemistry and the amount of the EGF binding sites by a radioligand binding assay, in the same group of 67 LSCC patients, analysing the correlation between the expression of the four HER receptors and the clinical and prognostic parameters. RESULTS: HER1 levels inversely correlated with that of HER2-4, while HER2-4 directly correlated among them. Cox univariate analysis using HER1-4 values as continuous covariates indicated that HER1 expression was directly associated with the risk of death and relapse while that of HER2-4 was inversely associated with the risk of death. Among the patients with high HER1 expressing tumours, those with tumours co-expressing HER2-4 showed a lower risk of death and relapse (in particular regional relapse) than those with tumours displaying a negative HER2-4 status. CONCLUSIONS: The evaluation of HER2-4 status adds more power to the prognostic role of HER1 detection. In the era of molecularly targeted therapy, the expression of HER family of receptor tyrosine kinases in LSCC may hold relevant clinical significance and turn out to be a key factor in prognostic assessment and in treatment planning. [ABSTRACT FROM AUTHOR]

A relevant percentage of IgAN patients experience a progressive decline in kidney function. According to the KDIGO guidelines, proteinuria and eGFR are the only validated prognostic markers. The role of interstitial macrophages in kidney biopsies of IgAN patients and the outcome of patients treated with renin-angiotensin system inhibitors (RASBs) alone or combined with glucocorticoids were evaluated. Clinical and laboratory records (age, gender, hypertension, hematuria, proteinuria, eGFR, serum creatinine, and therapy), MEST-C parameters of the Oxford classification, C4d deposition, peritubular capillaries, and glomerular and interstitial macrophages in 47 IgAN patients undergoing kidney biopsy consecutively between 2003 and 2016 were examined. A high number of interstitial macrophages significantly correlated with peritubular capillary rarefaction and impairment of kidney function. Cox's multivariable regression analysis revealed that a value > 19.5 macrophages/HPF behaved as an independent marker of an unfavorable outcome. Patients exhibiting > 19.5 macrophages/HPF treated at the time of diagnosis with RASBs combined with methylprednisolone had an estimated probability of a favorable outcome higher than patients treated with RASBs alone. Thus, a value > 19.5 macrophages/HPF in IgAN biopsies can predict an unfavorable outcome and endorse a well-timed administration of glucocorticoids. Studies evaluating urine biomarkers associated with peritubular capillary rarefaction in patients with marked macrophage infiltration may help personalized treatment decisions., Competing Interests: The authors declare no conflicts of interest.

The aim of the study was to evaluate survival in patients with advanced glottic laryngeal squamous cell carcinoma treated by bioradiotherapy (BioRT) with cetuximab and eventual salvage surgery (group A, n = 66) or upfront surgery (total laryngectomy or near-total laryngectomy) with or without postoperative radiotherapy (PORT) (group B, n = 66). The predictive role of HER1 expression in the bioselection of tumors was evaluated. Relapse-free (RFS), metastasis-free (MFS), overall (OS) survivals, salvageability, and rates of larynx preservation were analyzed. The two groups were balanced by propensity score method on their baseline characteristics. No significant differences in RFS and OS were found, while MFS results were significantly higher in group A (p = 0.04). Group A showed a 22% reduction in the probability of nodal metastasis (p = 0.0023), mostly in tumors with higher HER1 expression. The salvageability with TL at 3 years was 54% after prior BioRT and 18% after prior upfront NTL (p < 0.05). BioRT with cetuximab showed a reduction in the risk of lymph node relapse, particularly in the case of HER1 positive tumors, and it allowed to achieve a higher rate of functional larynx preservation and a higher salvageability compared with upfront surgery. HER1 analysis could be clinically useful in the bioselection of tumors that may benefit from BioRT with cetuximab, particularly in those with neck node metastatic propensity.

Background: Parathyroid hormone-related peptide (PTHrP) overexpression and poor patient outcome have been reported for many human tumors, but no studies are available in laryngeal cancer. Therefore, we studied the expression of PTHrP and its receptor, parathyroid hormone-related peptide receptor type 1 (PTH1R), in primary locally advanced laryngeal squamous cell carcinomas (LALSCC) also in relation to the clinical outcome of patients., Methods: We conducted a retrospective exploratory study, using immunohistochemistry, on PTHrP, PTH1R and HER1 expressions in LALSCC of 66 patients treated with bio-radiotherapy with cetuximab., Results: The expressions of PTHrP and PTH1R in LALSCC were associated with the degree of tumor differentiation (p = 0.01 and 0.04, respectively). Poorly differentiated tumors, with worse prognosis, expressed PTHrP at nuclear level and were PTH1R negative. PTHrP and PTH1R were expressed at cytoplasmic level in normal larynx epithelium and more differentiated laryngeal cancer cells, suggesting an autocrine/paracrine role of PTHrP in squamous cell differentiation of well differentiated tumors with good prognosis. Eighty-one percent HER1 positive tumors expressed PTHrP (p < 0.0001), mainly at nuclear level, consistent with the known up-regulation of PTHrP gene by HER1 signaling. In multivariable analyses, patients with PTHrP positive tumors had a higher relative risk of relapse (HR = 5.49; CI 95% = 1.62-22.24; p = 0.006) and survival (HR = 8.21; CI 95% = 1.19-105.00; p = 0.031) while those with PTH1R positive tumors showed a lower relative risk of relapse (HR = 0.18; CI 95% = 0.04-0.62; p = 0.002) and survival (HR = 0.18; CI 95% = 0.04-0.91; p = 0.029)., Conclusions: In LALSCC nuclear PTHrP and absence of PTH1R expressions could be useful in predicting response and/or resistance to cetuximab in combined therapies, contributing to an aggressive behavior of tumor cells downstream to HER1., (© 2022. The Author(s).)

Background: Compared to the other members of human epidermal growth factor family receptors (HER), the role of HER3 has not been well defined in laryngeal cancer. The predictive and prognostic role of HER3 has been the focus of clinical attention but the research findings are contradictory, especially in laryngeal squamous cell carcinoma (LSCC). The variable localization of HER3 within cancer cells and the role of HER3 in primary and acquired resistance to HER1-targeted therapies remain unclear., Methods: We performed a retrospective analysis of two cohorts of 66 homogeneous consecutive untreated primary advanced LSCC patients, in which co-expression of HER1, HER2 and HER3 receptors was investigated by semi-quantitative immunohistochemistry. The association of their pattern of expression with survival was evaluated by Kaplan-Meier and Cox's proportional hazard analyses. Multivariable Cox proportional hazards models were developed to predict median 2- and 3-year RFS and 2.5- and 5-year OS. The Akaike information criterion technique and backwards stepwise procedure were used for model selections. The performance of the final Cox models was assessed with respect to calibration and discrimination., Results: Immunohistochemical labeling for HER1 and HER2 was localized both in the cell membrane and in the cytoplasm, while HER3 labeling was observed both in the cell cytoplasm and in the nucleus. HER3 expression was inversely correlated with HER1 positivity. The expression patterns of HERs were associated with tumor differentiation. In both cohorts of patients, HER1 expression was associated with reduced relapse-free (RFS) and overall survival (OS). In HER1 positive tumors, the co-expression with nuclear HER3 was associated with better RFS and OS, compared with HER3 negative tumors or tumors expressing HER3 at cytoplasmic level. HER3 expressing tumors had a higher Geminin/MCM7 ratio than HER3 negative ones, regardless of HER1 co-expression. Multivariable analyses identified age at diagnosis, tumor site, HER1, HER3 and age at diagnosis, tumor stage, HER1, HER3, as covariates significantly associated with RFS and OS, respectively. Bootstrapping verified the good fitness of these models for predicting survivals and the optimism-corrected C-indices were 0.76 and 0.77 for RFS and OS, respectively., Conclusions: Nuclear HER3 expression was strongly associated with favourable prognosis and allows to improve the prognostic stratification of patients with HER1 positive advanced LSCC carcinoma., (© 2021. The Author(s).)

Background: Cardiac synovial sarcoma (CSS) is an extremely rare malignant tumor with a severe prognosis, due to frequent relapses and metastases. To obtain useful information for treatment protocols, we analyzed survival and therapy data from the cases reported in the literature., Methods: A search of MEDLINE was performed throughout December 2018. Using key words relating to primary CSS, we collected from the literature a total of 97 cases, mainly consisting of single case reports. To identify predictors of overall survival, statistical analyses were performed on a selected cohort of 55 patients for whom relevant clinicopathological data were available, including surgery and adjuvant therapy., Results: The univariable analysis revealed that patients in their first three decades of life have better overall survival. The univariable analysis also showed that patients not receiving adjuvant chemotherapy are at increased risk of death. In the multivariable analysis, tumor resection and chemotherapy are factors significantly improving overall survival., Conclusion: The survival of patients with CSS is positively influenced by a young patient's age and greatly improved by the administration of chemotherapy, even in the absence of tumor resection., (© 2019 Wiley Periodicals, Inc.)

Background: Minichromosome maintenance protein 7 (MCM7) is a downstream of human epidermal growth receptor (HER1) signaling. We examined MCM7, geminin, and HER1 expression in patients with laryngeal squamous cell carcinoma (SCC) treated with radiotherapy and cetuximab., Methods: MCM7, geminin, and HER1 were evaluated by immunohistochemistry on 61 patients with laryngeal SCC. The follow-up (median, 32.1 months; range, 2-139 months) went from the beginning of therapy to tumor progression-free survival (PFS) and death (overall survival [OS])., Results: MCM7, but not geminin, was associated only with HER1 expression, whereas no association was found with other clinicopathological characteristics. Patients with MCM7 high - geminin high and MCM7 high - geminin low tumor status had a risk of progression 3.1 times and 17.7 times greater, respectively, than patients with MCM7 low - geminin high tumor status. Tumor site, MCM7, and geminin were independent determinants of PFS, whereas MCM7 was an independent prognostic marker of OS., Conclusion: MCM7-geminin tumor status may be prognostic for patients with laryngeal SCC treated with cetuximab and radiotherapy. © 2016 Wiley Periodicals, Inc. Head Neck 39: 684-693, 2017., (© 2016 Wiley Periodicals, Inc.)

Background: Ki-67 labeling index (LI) is currently regarded as a useful prognostic marker of pituitary adenoma (PA) clinical behavior, although its relevance as a reliable clinical indicator is far from being universally accepted, since both validations and criticisms are found in the literature. Minichromosome maintenance 7 (MCM7), a cell-cycle regulator protein, has been recently proposed as a marker of tumor aggressiveness in tumors from many sites, including the CNS. Therefore, we evaluated MCM7, in comparison to Ki-67, as a potential marker of clinical outcome in PA., Design and Methods: In this single-institution retrospective study, 97 patients with PA (23 ACTH, 12 GH, 29 PRL, 10 FSH/LH, and 23 non-secreting adenomas) were recruited and the prognostic value of both MCM7 and Ki-67 was evaluated by immunohistochemical techniques. In addition, p53 nuclear expression and mitotic index were also evaluated., Results: Twenty-six of the 97 PA patients recurred during the follow-up period. Cox's regression analysis showed that high nuclear expression of MCM7 LI, unlike Ki-67 LI, was directly associated with a higher (7.7-fold) risk of recurrence/progression. Kaplan-Meier analysis of recurrence/progression-free survival curves revealed that patients with high MCM7 LI (≥15%) had a shorter recurrence/progression-free survival than those with low MCM7 LI (<15%). Moreover, among patients with invasive tumors, high MCM7 LI identified those with the highest risk of recurrence/progression., Conclusions: Data from this study suggest that MCM7 is a prognostic marker of clinical outcome in PA patients, more reliable and informative than Ki-67., (© 2016 European Society of Endocrinology.)

Previous studies suggest that cyclooxygenase-2 (COX-2) might influence megakaryocyte (MK) maturation and platelet production in vitro. Using a gene deletion model, we analysed the effect of COX-2 deficiency on megakaryopoiesis and platelet function. COX-2-/- mice (10-12 weeks old) have hyper-responsive platelets as suggested by their enhanced aggregation, TXA2 biosynthesis, CD62P and CD41/CD61 expression, platelet-fibrinogen binding, and increased thromboembolic death after collagen/epinephrine injection compared to wild-type (WT). Moreover, increased platelet COX-1 expression and reticulated platelet fraction were observed in COX-2-/- mice while platelet count was similar to WT. MKs were significantly reduced in COX-2-/- bone marrows (BMs), with high nuclear/cytoplasmic ratios, low ploidy and poor expression of lineage markers of maturation (CD42d, CD49b). However, MKs were significantly increased in COX-2-/- spleens, with features of MK maturation markers which were not observed in MKs of WT spleens. Interestingly, the expression of COX-1, prostacyclin and PGE2 synthases and prostanoid pattern were modified in BMs and spleens of COX-2-/- mice. Moreover, COX-2 ablation reduced the percentage of CD49b+ cells, the platelet formation and the haematopoietic stem cells in bone marrow and increased their accumulation in the spleen. Splenectomy decreased peripheral platelet number, reverted their hyper-responsive phenotype and protected COX-2-/- mice from thromboembolism. Interestingly, fibrosis was observed in spleens of old COX-2-/- mice (28 weeks old). In conclusion, COX-2 deletion delays BM megakaryopoiesis promoting a compensatory splenic MK hyperplasia, with a release of hyper-responsive platelets and increased thrombogenicity in vivo. COX-2 seems to contribute to physiological MK maturation and pro-platelet formation.

In 54 stage I and II human lung adenocarcinomas, HuR and PTHrP levels were positively correlated and the PTHrP-HuR status of the tumor was an independent prognostic marker of the clinical outcomes of patients. The possibility that HuR could upregulate PTHrP expression in lung adenocarcinoma was investigated by immunohistochemical, Western blot and RT-PCR analyses in HCC44 and DV90 human lung adenocarcinoma cell lines. In both cell lines, knockdown of HuR by specific siRNAs reduced PTHrP mRNAs and both cellular and secreted protein. Moreover, it inhibited cell growth and induced cell apoptosis, as revealed by the increase of caspase-3 activity. These effects were partially rescued by the addition of exogenous PTHrP (1-34). Analysis by actinomycin D assay revealed that in both cell lines HuR silencing produced a decrease of PTHrP mRNA half-life by about 70%. These findings add PTHrP to the list of lung cancer-associated genes, whose mRNA is stabilized by HuR.

n-3 polyunsaturated fatty acids exert growth-inhibitory and pro-apoptotic effects in colon cancer cells. We hypothesized that the anti-apoptotic glucose related protein of 78kDa (GRP78), originally described as a component of the unfolded protein response in endoplasmic reticulum (ER), could be a molecular target for docosahexaenoic acid (DHA) in these cells. GRP78 total and surface overexpression was previously associated with a poor prognosis in several cancers, whereas its down-regulation with decreased cancer growth in animal models. DHA treatment induced apoptosis in three colon cancer cell lines (HT-29, HCT116 and SW480), and inhibited their total and surface GRP78 expression. The cell ability to undergo DHA-induced apoptosis was inversely related to their level of GRP78 expression. The transfection of the low GRP78-expressing SW480 cells with GRP78-GFP cDNA significantly induced cell growth and inhibited the DHA-driven apoptosis, thus supporting the essential role of GRP78 in DHA pro-apoptotic effect. We suggest that pERK1/2 could be the first upstream target for DHA, and demonstrate that, downstream of GRP78, DHA may exert its proapoptotic role by augmenting the expression of the ER resident factors ERdj5 and inhibiting the phosphorylation of PKR-like ER kinase (PERK), known to be both physically associated with GRP78, and by activating caspase-4. Overall, the regulation of cellular GRP78 expression and location is suggested as a possible route through which DHA can exert pro-apoptotic and antitumoral effects in colon cancer cells., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Objectives/hypothesis: The prognosis for laryngeal squamous cell carcinoma (LSCC) has not shown any improvement in the last 30 years because of inadequate prognostic stratification. Therefore, the detection of reliable molecular markers may have a significant impact on clinical practice. As promising data regarding HER1/EGFR have been published, the purpose of the present study was to elucidate the role of the other receptors of the HER family., Study Design: Retrospective., Methods: We used quantitative immunohistochemistry to evaluate the expression pattern of the HER4 receptors cytokeratin (CK)-14, CK-17, and proliferating cell nuclear antigen in 67 LSCCs and assessed correlations with various prognostic parameters., Results: HER1 levels inversely correlated with those of HER2-4. The negative prognostic value of HER1 was confirmed, and a protective role for HER2-4 was found. Specifically, the overexpression of HER4 and its nuclear localization are protective and are associated with a better prognosis., Conclusions: Semiquantitative evaluation of HER2-4 provides predictive information that can be combined with HER1 expression data for molecular characterization of LSCC. The pattern of localization of HER4 is an easily evaluable qualitative parameter with a clear correlation with prognosis. The immunohistochemical methods described in this article are reliable, reproducible, and potentially translatable to clinical practice., (Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.)

The ubiquitously expressed RNA-binding protein Hu antigen (HuR) participates in the post-transcriptional regulation of mRNAs bearing U- and AU-rich sequences. Expression of HuR is increased in cancers of the breast, colon, ovary and lung and cytoplasmic immunoreactivity for HuR was found to be closely related to poor outcomes in patients with these tumors. Since the regulation of HuR function is closely linked to its subcellular localization, we evaluated, by quantitative immunohistochemistry, the impact on clinical outcome of both nuclear and cytoplasmic levels (integrated density: ID) of HuR and of nuclear/cytoplasmic ratio (N/C) in 54 lung adenocarcinomas from stage I and II patients. Nuclear and cytoplasmic Hur IDs and N/C were not associated with age, smoking or tumor diameter. Low N/C was significantly associated with lymph-node involvement at presentation. Cox's regression analysis showed that high cytoplasmic, but not nuclear, HuR ID and low N/C were directly associated with the risk of death and metastasis. In the multivariate analysis, low HuR N/C retained an independent negative prognostic significance relative to the risk of metastasis and death. Moreover, the levels of N/C allowed us to discriminate subjects with the highest risk of metastasis and death among patients with lung adenocarcinomas expressing high levels of cytoplasmic HuR. In conclusion, the measure of the ratio between nuclear and cytoplasmic HuR levels allows a sensitive prognostic evaluation of the clinical outcome in early stage lung adenocarcinoma patients.

The pro-inflammatory phenotype accompanying melanoma progression includes an enhanced expression of cyclooxygenase-2 (COX-2), which plays an important role in the acquisition of apoptosis resistance, and is a suitable target for melanoma prevention and therapy. We observed that the WM266-4 metastatic melanoma cell line showed a constitutive COX-2 expression higher than that of the primary WM115 cells, an increased cytosolic level of the COX-2 messenger RNA (mRNA)-stabilizer human antigen R (HuR) and a lower susceptibility to basal apoptosis. The transfection of HuR siRNA induced apoptosis and reduced COX-2 protein abundance in both the cells. The same effects were observed treating the cells with the n-3 polyunsaturated fatty acid docosahexaenoic acid (DHA), which reduced the cytoplasmic location and expression of HuR and, correspondently, decreased COX-2 protein expression and induced apoptosis. DHA also decreased the expression and stability of COX-2 mRNA, increased the β-catenin expression in the nuclei and reduced it in the cytosol, where it forms a complex with HuR and COX-2 mRNA. DHA had also a pro-differentiating effect, which is compatible with the nuclear translocation of β-catenin. These findings allow us to associate for the first time the constitutive expression of COX-2 in melanoma cells to the HuR-mediated stabilization of its mRNA and suggest that also β-catenin may play a role in HuR-mediated COX-2 stabilization in these cells. The data demonstrate that the HuR-mediated stabilization of COX-2 may represent a target of DHA action in melanoma cells and suggest the application of DHA in the prevention and therapy of melanoma.

Hypercholesterolemia is one of the most important risk factors for atherosclerosis, and tomato lycopene has been suggested to have beneficial effects against such a disease, although the exact molecular mechanism is unknown. We tested the hypothesis that lycopene may exert its antiatherogenic role through changes in cholesterol metabolism. Incubation of THP-1 cells with lycopene (0.5-2 μM) dose-dependently reduced intracellular total cholesterol. Such an effect was associated with a decrease in reduction of 3-hydroxy-3-methylglutaryl coenzyme A reductase expression and with an increase in ABCA1 and caveolin-1 (cav-1) expressions. In addition, lycopene enhanced RhoA levels in the cytosolic fraction, activating peroxisome proliferator-activated receptor gamma (PPARγ) and liver X receptor alpha expressions. Concomitant addition of lycopene and the PPARγ inhibitor GW9662 or lycopene and mevalonate blocked the carotenoid-induced increase in ABCA1 and cav-1 expressions. These results imply a potential role of lycopene in attenuating foam cell formation and, therefore, in preventing atherosclerosis by a cascade mechanism involving inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase, RhoA inactivation and subsequent increase in PPARγ and liver X receptor alpha activities and enhancement of ABCA1 and cav-1 expressions., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The dramatic increase in the incidence of nonmelanoma skin cancer over the last decades has been related to the augmented exposure to ultraviolet (UV) radiation (UVR). It is known that apoptosis is induced as a protective mechanism after the acute irradiation of keratinocytes, whereas apoptotic resistance and carcinogenesis may follow the chronic exposure to UVR. We found that not all the human keratinocytes lines studied underwent apoptosis following acute exposure to UVR (10-60 mJ/cm(2)). Whereas UVR induced apoptosis in the HaCaT cells, NCTC 2544 and nr-HaCaT cells showed apoptosis resistance. The cytokeratin pattern of the apoptosis-resistant cells indicated that they possessed a degree of differentiation lower than that of HaCaT cells. They also showed an enhanced expression of cyclooxygenase-2 (COX-2), an early marker of carcinogenesis in various tissues, including skin. n-3 polyunsaturated fatty acids have drawn increasing interest as nutritional factors with the potential to reduce UVR carcinogenesis, and since they are apoptosis inducers and COX-2 inhibitors in cancer cells, we investigated the ability of n-3 polyunsaturated fatty acids to influence the resistance to UVR-induced apoptosis in keratinocytes. We observed that docosahexaenoic acid (DHA) reverted the resistance of nr-HaCaT cells to UVR-induced apoptosis, increasing the Bax/Bcl-2 ratio and caspase-3 activity, and reduced COX-2 levels by inhibiting the expression of the human antigen R (HuR), a known COX-2 mRNA stabilizer in keratinocytes. The transfection of nr-HaCaT cells with HuR siRNA mimicked the proapoptotic effect of DHA. Overall, our findings further support the role of DHA as a suitable anticarcinogenic factor against nonmelanoma skin cancers., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Activated human platelets synthesize prostaglandin (PG) E(2), although at lower rate than thromboxane A(2). PGE(2) acts through different receptors (EP1-4), but its role in human platelet function remains poorly characterized compared with thromboxane. We studied the effect of PGE(2) and its analogs on in vitro human platelet function and platelet and megakaryocyte EP expression. Platelets preincubated with PGE(2) or its analogs were stimulated with agonists and studied by optical aggregometry. Intraplatelet calcium mobilization was investigated by the stopped flow method; platelet vasodilator-stimulated phosphoprotein (VASP), P-selectin, and microaggregates were investigated by flow cytometry. PGE(2) at nanomolar concentrations dose-dependently increased the slope (velocity) of the secondary phase of ADP-induced platelet aggregation (EC(50), 25.6 ± 6 nM; E(max) of 100 ± 19% increase versus vehicle-treated), without affecting final maximal aggregation. PGE(2) stabilized reversible aggregation induced by low ADP concentrations (EC(50), 37.7 ± 9 nM). The EP3 agonists, 11-deoxy-16,16-dimethyl PGE(2) (11d-16dm PGE(2)) and sulprostone enhanced the secondary wave of ADP-induced aggregation, with EC(50) of 48.6 ± 10 nM (E(max), 252 ± 51%) and 5 ± 2 nM (E(max), 300 ± 35%), respectively. The EP2 agonist butaprost inhibited ADP-induced secondary phase slopes (IC(50), 40 ± 20 nM). EP4 stimulation had minor inhibitory effects. 11d-16dm PGE(2) alone raised intraplatelet Ca(2+) and enhanced ADP-induced Ca(2+) increase. 11d-16dm PGE(2) and 17-phenyltrinor PGE(2) (EP3 > EP1 agonist) at nanomolar concentrations counteracted PGE(1)-induced VASP phosphorylation and induced platelet microaggregates and P-selectin expression. EP1, EP2, EP3, and EP4 were expressed on human platelets and megakaryocytes. PGE(2) through different EPs finely modulates human platelet responsiveness. These findings should inform the rational selection of novel antithrombotic strategies based on EP modulation.

Several evidences suggest that cancer cells have abnormal cholesterol biosynthetic pathways and prenylation of small guanosine triphosphatase proteins. Tomato lycopene has been suggested to have beneficial effects against certain types of cancer, including that of prostate, although the exact molecular mechanism(s) is unknown. We tested the hypothesis that lycopene may exert its antitumor effects through changes in mevalonate pathway and in Ras activation. Incubation of the Ras-activated prostatic carcinoma LNCaP cells with a 24 h lycopene treatment (2.5-10 μM) dose dependently reduced intracellular total cholesterol by decreasing 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase expression and by inactivating Ras, as evidenced by its translocation from cell membranes to cytosol. Concomitantly, lycopene reduced the Ras-dependent activation of nuclear factor-kappaB (NF-κB). Such a reduction was parallel to an inhibition of reactive oxygen species production and to a decrease in the phosphorylation ofc-jun N-terminal kinase, extracellular signal-regulated kinase 1/2 and p38. These effects were also accompanied by an arrest of cell cycle progression and by apoptosis induction, as evidenced by a decrease in cyclin D1 and phospho-AKT levels and by an increase in p21, p27 and p53 levels and in Bax:Bcl-2 ratio. The addition of mevalonate prevented the growth-inhibitory effects of lycopene as well as its increase in Ras cytoplasmatic accumulation and the subsequent changes in NF-κB. The ability of lycopene in inhibiting HMG-CoA reductase expression and cell growth and in inactivating Ras was also found in prostate PC-3, colon HCT-116 and HT-29 and lung BEN cancer cells. These findings provide a novel mechanistic insight into the growth-inhibitory effects of lycopene in cancer.