Novel calcitriol analogue with an oxolane group: In vitro, in vivo, and in silico studies.

The active form of vitamin D3 , calcitriol, is a potent antiproliferative compound. However, when effective antitumor doses of calcitriol are used, hypercalcemic effects are observed, thus blocking its therapeutic application. To overcome this problem, structural analogues have been designed with the aim of retaining or even increasing the antitumor effects while decreasing its calcemic activity. This report aims at gaining insights into the structure-activity relationships of the novel oxolane-containing analogue, AM-27, recently synthesized. We herein demonstrate that this compound has antiproliferative and antimigratory effects in squamous cell carcinoma, glioblastoma, and breast cancer cell lines. Analyses of the mechanisms underlying the AM-27 effects on cell viability revealed induction of apoptosis by the analogue. Importantly, nonmalignant cell lines were little or not affected by the compound. In addition, the analogue did not produce hypercalcemia in mice. Also, in silico studies involving docking and molecular dynamics techniques showed that AM-27 is able to bind to the human vitamin D receptor with a higher affinity than the natural ligand calcitriol, a feature that is mostly derived from an electrostatic interaction pattern. Altogether, the proapoptotic effect observed in cancer cells, the lack of calcemic activity in mice, and the differential effects in normal cells suggest the potential of AM-27 as a therapeutic compound for cancer treatment.

Antitumoral Effects of D-Fraction from Grifola Frondosa (Maitake) Mushroom in Breast Cancer.

D-Fraction is protein-bound ß-1,6 and ß-1,3 glucans (proteoglucan) extracted from the edible and medicinal mushroom Grifola frondosa (Maitake). The antitumoral effect of D-Fraction has long been exclusively attributed to their immunostimulatory capacity. However, in recent years increasing evidence showed that D-Fraction directly affects the viability of canine and human tumor cells, independent of the immune system. Previously, we have reported that D-Fraction modulates the expression of genes associated with cell proliferation, cell death, migration, invasion, and metastasis in MCF7 human breast cancer cells. Therefore, the purpose of the current study is to investigate if this modulation of gene expression by Maitake D-Fraction really modulates tumor progression. In the present work, we demonstrate for the first time that Maitake D-Fraction is able to act directly on mammary tumor cells, modulating different cellular processes involved in the development and progression of cancer. We demonstrate that D-Fraction decreases cell viability, increases cell adhesion, and reduces the migration and invasion of mammary tumor cells, generating a less aggressive cell behavior. In concordance with these results, we also demonstrate that D-Fraction decreases tumor burden and the number of lung metastases in a murine model of breast cancer.

Structure-anti-leukemic activity relationship study of ortho-dihydroxycoumarins in U-937 cells: key role of the δ-lactone ring in determining differentiation-inducing potency and selective pro-apoptotic action.

Previous studies indicated the need of at least one phenolic hydroxyl group in the coumarin core for induction of cytotoxicity in different cell lines. Herein, we present an exhaustive structure-activity relationship study including ortho-dihydroxycoumarins (o-DHC) derivatives, cinnamic acid derivatives (as open-chain coumarin analogues) and 1,2-pyrones (representative of the δ-lactone ring of the coumarin core), carried out to further identify the structural features of o-DHC required to induce leukemic cell differentiation and apoptosis in U-937 cells. Our results show for the first time that the δ-lactone ring positively influences the aforementioned biological effects, by conferring greater potency to compounds with an intact coumarin nucleus. Most tellingly, we reveal herein the crucial role of this molecular portion in determining the selective toxicity that o-DHC show for leukemic cells over normal blood cells. From a pharmacological perspective, our findings point out that o-DHC may be useful prototypes for the development of novel chemotherapeutic agents.

Hemoxygenase-1 Promotes Head and Neck Cancer Cell Viability.

Head and neck squamous cell carcinoma (HNSCC) is a remarkably heterogeneous disease with around 50% mortality, a fact that has prompted researchers to try new approaches to improve patient survival. Hemoxygenase-1 (HO-1) is the rate-limiting step for heme degradation into carbon monoxide, free iron and biliverdin. We have previously reported that HO-1 protein is upregulated in human HNSCC samples and that it is localized in the cytoplasmic and nuclear compartments; additionally, we have demonstrated that HO-1 nuclear localization is associated with malignant progression. In this work, by using pharmacological and genetic experimental approaches, we begin to elucidate the mechanisms through which HO-1 plays a role in HNSCC. We found that high HO-1 mRNA was associated with decreased patient survival in early stages of HNSCC. In vitro experiments have shown that full-length HO-1 localizes in the cytoplasm, and that, depending on its enzymatic activity, it increases cell viability and promotes cell cycle progression. Instead, HO-1 does not alter migration capacity. Furthermore, we show that C-terminal truncated HO-1 localizes into the nucleus, increases cell viability and promotes cell cycle progression. In conclusion, we herein demonstrate that HO-1 displays protumor activities in HNSCC that depend, at least in part, on the nuclear localization of HO-1.

Risk and prognostic factors of status epilepticus in the elderly: a case-control study.

PURPOSE: The aim of this study was to assess the risk and prognostic factors of status epilepticus (SE) among elderly inpatients. METHODS: From May 2003 to April 2005, 63 consecutive patients aged 70 years or older with SE were included. Each patient was matched to three controls without SE seen during the same period. Matching variables were age (±3 years), gender, and comorbidity index (±3). Multivariate logistic regression model were used to compare cases to controls and, among the cases, nonsurvivors to survivors. KEY FINDINGS: By multivariate analysis, factors independently associated with SE were acute decompensation (cardiac, respiratory, or hepatic) [adjusted odds ratio (OR(a) ) 2.57, 95% confidence interval (95% CI) 1.05-6.25] history of epilepsy (OR(a) 3.93, 95% CI 1.27-12.14), chronic cerebrovascular disease (OR(a) 7.96, 95% CI 3.31-19.15), nonvascular dementia (OR(a) 4.16, 95% CI 1.86-9.29), and dysnatremia (OR(a) 5.08, 95% CI 2.34-11.04). In-hospital 1-month mortality was 2.3 times higher among cases than controls (14/63, 22.0%; 95% CI 12.7-34.5%; vs. 18/189, 9.5%; 95% CI 5.7-14.7%; p = 0.01). Among the cases, factors independently associated with in-hospital death within 1 month were younger age (OR(a) per 1-year increase 0.87, 95% CI 0.76-0.98), higher comorbidity index (OR(a) per 1-point increase 1.27, 95% CI 1.07-1.55), and de novo SE (OR(a) 14.95, 95% CI 2.24-192.8). SIGNIFICANCE: Independent predictors of SE in hospitalized patients aged 70 years or older were acute decompensation (cardiac, respiratory, or hepatic), history of epilepsy, chronic cerebrovascular disease, nonvascular dementia, and dysnatremia. Factors that independently predicted death in patients with SE were younger age, higher comorbidity index, and de novo SE.

Nuclear Localization of Heme Oxygenase-1 in Pathophysiological Conditions: Does It Explain the Dual Role in Cancer?

Heme Oxygenase-1 (HO-1) is a type II detoxifying enzyme that catalyzes the rate-limiting step in heme degradation leading to the formation of equimolar quantities of carbon monoxide (CO), free iron and biliverdin. HO-1 was originally shown to localize at the smooth endoplasmic reticulum membrane (sER), although increasing evidence demonstrates that the protein translocates to other subcellular compartments including the nucleus. The nuclear translocation occurs after proteolytic cleavage by proteases including signal peptide peptidase and some cysteine proteases. In addition, nuclear translocation has been demonstrated to be involved in several cellular processes leading to cancer progression, including induction of resistance to therapy and enhanced metastatic activity. In this review, we focus on nuclear HO-1 implication in pathophysiological conditions with special emphasis on malignant processes. We provide a brief background on the current understanding of the mechanisms underlying how HO-1 leaves the sER membrane and migrates to the nucleus, the circumstances under which it does so and, maybe the most important and unknown aspect, what the function of HO-1 in the nucleus is.

Structure-Activity Relationship Study of an Alkynylphosphonate and Vynilphosphonate Analogues of Calcitriol.

BACKGROUND: 1α,25-dihydroxy vitamin D3 (calcitriol) shows potent growth-inhibitory properties on different cancer cell lines, but its hypercalcemic effects have severely hampered its therapeutic application. Therefore, it is important to develop synthetic calcitriol analogues that retain or even increase its antitumoral effects and lack hypercalcemic activity. Based on previous evidence of the potent antitumor effects of the synthetic alkynylphosphonate EM1 analogue, we have now synthesized a derivative called SG. OBJECTIVE: The aim of the present work is to evaluate the calcemic activity and the antitumor effect of SG, comparing these effects with those exerted by calcitriol and with those previously published for EM1. In addition, we propose to analyze by in silico studies, the chemical structure-biological function relationship of these molecules. METHODS: We performed the synthesis of vinylphosphonate SG analogue; in vitro assays on different cancer cell lines; in vivo assays on mice; and in silico assays applying computational molecular modeling. RESULTS: The SG compound lacks hypercalcemic activity, similar to the parent compound EM1. However, the antitumor activity was blunted, as no antiproliferative or anti-migratory effects were observed. By in silico assays, we demonstrated that SG analogue has a lower affinity for the VDRligand- binding domain than the EM1 compound due to lack of interaction with the important residues His305 and His397. CONCLUSION: These results demonstrate that the chemical modification in the lateral side chain of the SG analogue affects the antitumoral activity observed previously for EM1 but does not affect the calcemic activity. These results contribute to the rational design and synthesis of novel calcitriol analogues.

Synthesis of a novel analog of calcitriol and its biological evaluation as antitumor agent.

Calcitriol analogs have shown promising potential as compounds to be used in cancer chemotherapy. This report presents the synthesis of a novel vitamin D3 derivative with an amide and a carboxyl group in its side chain, called ML-344. In addition, we report its in vitro antitumor activity and its in vivo calcemic effects. We demonstrate that the analog decreases cell viability and retards cell migration of different breast, glioblastoma and head and neck cancer cell lines. Additionally, unlike calcitriol, ML-344 does not display citotoxicity to the murine non-malignant mammary cells and human astrocytes. In concordance with the antimigratory effects found in breast cancer cells, ML-344 decreased the invasive capacity and induced a rearrangement of the actin cytoskeleton in the LM3 breast cancer cell line. In relation to the in vivo studies, the analog did not cause hypercalcemic effects in CF1 mice administered daily at 5 µg/Kg of body weight during a period of 264 h. Finally, computational studies were performed to evaluate the potential binding of the analog to the vitamin D receptor and the in silico assays showed that ML-344 is able to bind to VDR with interesting particularities and greater affinity than calcitriol. Altogether, these results suggest that ML-344 has a promising potential as an antitumor agent with a differential effect between tumor and non-malignant cells.

Heme Oxygenase-1 Has an Antitumor Role in Breast Cancer.

Aims: Heme oxygenase-1 (HO-1) is an enzyme involved in cellular responses to oxidative stress and has also been shown to regulate processes related to cancer progression. In this regard, HO-1 has been shown to display a dual effect with either antitumor or protumor activity, which is also true for breast cancer (BC). In this work, we address this discrepancy regarding the role of HO-1 in BC. Results: HO-1 was detected in human BC tissues, and its protein levels correlated with reduced tumor size and longer overall survival time of patients, thus suggesting the clinical importance of HO-1 in this type of cancer. Contrariwise, nuclear localization of HO-1 correlated with higher tumor grade suggesting that the effect of HO-1 is dependent on its cellular localization. In vivo experiments showed that both pharmacological activation and genetic overexpression of HO-1 reduce the tumor burden in two different animal models of BC. Furthermore, the pharmacological and genetic activation of HO-1 in several BC cell lines reduce the cellular viability by inducing apoptosis and cell cycle arrest and decrease the cellular migration and invasion rates by modulating pathways involved in the epithelial-mesenchymal transition. Furthermore, HO-1 activation impaired in vivo the metastatic dissemination. Innovation and Conclusion: By using various BC cell lines and animal models as well as human tumor samples, we demonstrated that total HO-1 displays antitumor activities in BC. Furthermore, our study suggests that HO-1 subcellular localization may explain the differential effects observed for the protein in different tumor types.

Antitumoral effects of the alkynylphosphonate analogue of calcitriol EM1 on glioblastoma multiforme cells.

Glioblastoma multiforme (GBM) is the worst and most common brain tumor, characterized by high proliferation and invasion rates. The current standard treatment is mainly based on chemoradiotherapy and this approach has slightly improved patient survival. Thus, novel strategies aimed at prolonging the survival and ensuring a better quality of life are necessary. In the present work, we investigated the antitumoral effect of the novel analogue of calcitriol EM1 on GBM cells employing in vitro, in silico, and in vivo assays. In vitro, we demonstrated that EM1 treatment selectively decreases the viability of murine and human tumor cells without affecting that of normal human astrocytes. The analysis of the mechanisms showed that EM1 produces cell cycle arrest in the T98G cell line, which is accompanied by an increase in p21, p27, p57 protein levels and a decrease in cyclin D1, p-Akt-S473, p-ERK1/2 and c-Jun expression. Moreover, EM1 treatment also exerts in GBM cells anti-migratory effects and decreases their invasive capacity by a reduction in MMP-9 proteolytic activity. In silico, we demonstrated that EM1 is able to bind to the vitamin D receptor with greater affinity than calcitriol. Finally, we showed that EM1 treatment of nude mice administered at 50ug/kg body weight during 21days neither induces hypercalcemia nor toxicity effects. In conclusion, all the results indicate the potential of EM1 analogue as a promising therapeutic alternative for GBM treatment.

Antitumoral and antimetastatic activity of Maitake D-Fraction in triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) is associated with poor prognosis, high local recurrence rate and high rate of metastasis compared with other breast cancer subtypes. In addition, TNBC lacks a targeted therapy. This scenario highlights the need for novel compounds with high potential for TNBC treatment. In this regard, natural products are important sources of anticancer drugs. D-Fraction, a proteoglucan extracted from the edible and medicinal mushroom Grifola frondosa (Maitake), is a dietary supplement that has been shown to exert both immunostimulatory and immune-independent antitumoral effects on some cancer types. However, its antitumoral potential in TNBC is unknown. Therefore, we employed TNBC cells to investigate if D-Fraction is able to attenuate their aggressive phenotype. We found that D-Fraction decreases MDA-MB-231 cell viability through apoptosis induction and reduces their metastatic potential. D-Fraction increases cell-cell adhesion by increasing E-cadherin protein levels and ß-catenin membrane localization, and increases cell-substrate adhesion. D-Fraction also decreases cell motility by affecting actin cytoskeleton rearrangements, and proteolytic activity of MMP-2 and MMP-9. Furthermore, D-Fraction decreases the invasive capacity of MDA-MB-231 cells. In concordance, D-Fraction retards tumor growth and reduces lung metastases in a xenograft model. Altogether, these results suggest the potential therapeutic role of D-Fraction in aggressive TNBC.

Maitake Pro4X has anti-cancer activity and prevents oncogenesis in BALBc mice.

The understanding of the molecular mechanisms of the immune tolerance induced by the tumoral microenvironment is fundamental to prevent cancer development or to treat cancer patients using immunotherapy. Actually, there are investigations about "addressed-drugs" against cancer cells without affecting normal cells. It could be ideal to find selective and specific compounds that only recognize and destroy tumor cells without damaging the host normal cells. For thousands of years, mushrooms have been used for medicinal purposes because of their curative properties. D-Fraction, an extract of Maitake (from the edible Grifola frondosa mushroom), rich in ß-glucans, exert notable effects in the immune system. Until now, some published articles suggest that Maitake D-Fraction could have anti-tumoral activity, prevent oncogenesis and metastasis in some tumor types. However, there are no clear data about Maitake D-Fraction action on breast cancer prevention and its exact molecular mechanisms are not yet elucidated. The experiments were performed employing 25 female BALBc mice that were treated with and without Maitake D-Fraction Pro4X or Maitake Standard for 15 days by daily intraperitoneal injection. After treatment period, all mice were implanted with murine tumor cells LM3 to induce mammary tumorigenesis. Animals were checked weekly and killed after 46 days of LM3 transplant; percentage of cancer prevention, rate of tumor growing, and overall survival were determined. Under dissection, the internal organs were evaluated histologically and genetically by RT-PCR. We found that 5 mg/kg per day of Maitake D-Fraction Pro4X, administered dairy during 15 days to BALBc mice was able to block more than 60% breast cancer development. However, Maitake Standard prevents oncogenesis in 26% to respect control. In this work, we found that Maitake D-Fraction Pro4X, administered to BALBc mice, prevents breast carcinogenesis, block tumor invasiveness, reduce angiogenesis, and increase overall survival.

The UVB1 Vitamin D analogue inhibits colorectal carcinoma progression.

Vitamin D has been shown to display a wide variety of antitumour effects, but their therapeutic use is limited by its severe side effects. We have designed and synthesized a Gemini vitamin D analogue of calcitriol (UVB1) which has shown to display antineoplastic effects on different cancer cell lines without causing hypercalcemia. The aim of this work has been to investigate, by employing in silico, in vitro, and in vivo assays, whether UVB1 inhibits human colorectal carcinoma progression. We demonstrated that UVB1 induces apoptotic cell death and retards cellular migration and invasion of HCT116 colorectal carcinoma cells. Moreover, the analogue reduced the tumour volume in vivo, and modulated the expression of Bax, E-cadherin and nuclear ß-catenin in tumour animal tissues without producing toxic effects. In silico analysis showed that UVB1 exhibits greater affinity for the ligand binding domain of vitamin D receptor than calcitriol, and that several characteristics in the three-dimensional conformation of VDR may influence the biological effects. These results demonstrate that the Gemini vitamin D analogue affects the growth of the colorectal cancer and suggest that UVB1 is a potential chemotherapeutic agent for treatment of this disease.

The alkynylphosphonate analogue of calcitriol EM1 has potent anti-metastatic effects in breast cancer.

The active form of vitamin D3, calcitriol, plays a major role in maintaining calcium/phosphate homeostasis. In addition, it is a potent antiproliferative and prodifferentiating agent. However, when effective antitumor doses of calcitriol are employed, hypercalcemic effects are observed, thus precluding its therapeutic application. To overcome this problem, structural analogues have been designed with the aim at retaining or even increasing the antitumor effects while decreasing its calcemic activity. This report shows the biological evaluation of an alkynylphosphonate vitamin D less-calcemic analogue in a murine model of breast cancer. We demonstrate that this compound has potent anti-metastatic effects through its action over cellular migration and invasion likely mediated through the up-regulation of E-cadherin expression. Based on the current in vitro and in vivo results, EM1 is a promising candidate as a therapeutic agent in breast cancer.

BRCA1 polymorphism in breast cancer patients from Argentina.

Breast cancer is the most common type of cancer in females in Argentina, with an incidence rate similar to that in the USA. However, the contribution of the BRCA1 or BRCA2 mutation in breast cancer incidence has not yet been investigated in Argentina. In order to evaluate which BRCA1 polymorphisms or mutations characterize female breast cancer in Argentina, the current study enrolled 206 females with breast cancer from several hospitals from the southeast of Argentina. A buccal smear sample was obtained in duplicate from each patient and the DNA samples were processed for polymorphism analysis using the single-strand conformational polymorphism technique. The polymorphisms in BRCA1 were investigated using a combination of 15 primers to analyze exons 2, 3, 5, 20 and 11 (including the 11.1 to 11.12 regions). The BRCA1 mutations were confirmed by direct sequencing. Samples were successfully examined from 154 females and, among these, 16 mutations were identified in the BRCA1 gene representing 13.9% of the samples analyzed. One patient was identified with a polymorphism in exon 2 (0.86%), four in exon 20 (3.48%), four in exon 11.3 (3.48%), one in exon 11.7 (0.86%), two in exon 11.8 (1.74%), one in exon 11.10 (0.86%) and one in exon 11.11 (0.86%). The most prevalent alteration in BRCA1 was located in exon 11 (11 out of 16 patients; 68.75%). The objective of our next study is to evaluate the prevalence of mutations in the BRCA2 gene and analyze the BRCA1 gene in the healthy relatives of BRCA1 mutation carriers.

Validation of the Test Your Memory (F-TYM Test) in a French memory clinic population.

The Test Your Memory (TYM) test has been proposed for screening dementia. We present a French version and its validation in memory clinics. F-TYM was administered to 201 patients with memory complaints visiting five secondary referral hospital centers. Final diagnosis was dementia in 34%, amnestic mild cognitive impairment (MCI) in 32%, non-amnestic MCI in 11%, absence of cognitive disorder in 23% and F-TYM scores were respectively (M ± SD) 30.9 ± 7.6, 40.5 ± 6.3, 44.3 ± 4.5 and 43.5 ± 6.6 (p < .0001). F-TYM showed high correlation with MMSE (r = .78), excellent internal consistency, no effect of educational level, sex, or mood but a significant effect of age (p = .004). A F-TYM score ≤ 39 had 0.90 sensitivity and 0.70 specificity for diagnosis of dementia. F-TYM was unable to discriminate MCI and patients without cognitive disorders. F-TYM could be proposed for screening of dementia in patients with memory complaints.

Genes related to suppression of malignant phenotype induced by Maitake D-Fraction in breast cancer cells.

It is already known that the Maitake (D-Fraction) mushroom is involved in stimulating the immune system and activating certain cells that attack cancer, including macrophages, T-cells, and natural killer cells. According to the U.S. National Cancer Institute, polysaccharide complexes present in Maitake mushrooms appear to have significant anticancer activity. However, the exact molecular mechanism of the Maitake antitumoral effect is still unclear. Previously, we have reported that Maitake (D-Fraction) induces apoptosis in breast cancer cells by activation of BCL2-antagonist/killer 1 (BAK1) gene expression. At the present work, we are identifying which genes are responsible for the suppression of the tumoral phenotype mechanism induced by Maitake (D-Fraction) in breast cancer cells. Human breast cancer MCF-7 cells were treated with and without increased concentrations of Maitake D-Fraction (36, 91, 183, 367 µg/mL) for 24 h. Total RNA were isolated and cDNA microarrays were hybridized containing 25,000 human genes. Employing the cDNA microarray analysis, we found that Maitake D-Fraction modified the expression of 4068 genes (2420 were upmodulated and 1648 were downmodulated) in MCF-7 breast cancer cells in a dose-dependent manner during 24 h of treatment. The present data shows that Maitake D-Fraction suppresses the breast tumoral phenotype through a putative molecular mechanism modifying the expression of certain genes (such as IGFBP-7, ITGA2, ICAM3, SOD2, CAV-1, Cul-3, NRF2, Cycline E, ST7, and SPARC) that are involved in apoptosis stimulation, inhibition of cell growth and proliferation, cell cycle arrest, blocking migration and metastasis of tumoral cells, and inducing multidrug sensitivity. Altogether, these results suggest that Maitake D-Fraction could be a potential new target for breast cancer chemoprevention and treatment.

Maitake (D fraction) mushroom extract induces apoptosis in breast cancer cells by BAK-1 gene activation.

For many years mushrooms have been used empirically in traditional medicine to treat several diseases. Study of the maitake mushroom, with its immunomodulatory and antitumoral properties, has led to the isolation of several bioactive compounds. One of these, D fraction, is known to reduce tumor cell viability. This study examined the effect of isolated D fraction on viability and apoptosis of human breast cancer cells (MCF7). These cells were treated with maitake (D fraction) extract at 18 µg/mL, 36 µg/mL, 91 µg/mL, 183 µg/mL, or 367 µg/mL or were left untreated (control) for 24 hours. MCF7 incubation with the maitake extract resulted in decreased cell viability [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay] in a dose-dependent manner. Apoptosis was statistically significantly increased in a dose-dependent manner at every concentration tested (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assay). Upon incubation with D fraction, a microarray assay revealed upregulation of BAK-1 and cytochrome c transcripts, 2 proteins directly involved in the apoptotic pathway. Reverse transcriptase polymerase chain reaction studies confirmed these findings; BAK-1 was one of most overexpressed gene, as observed by microarray assay. These findings confirm the apoptotic effect of maitake D fraction in breast cancer cells and further highlight the involvement of cytochrome c release to the cytoplasm. Cytoplasmic release of cytochrome c, another player in the apoptotic pathway, was also increased after incubation with D fraction in a dose-dependent manner. This finding indicates that the effect of this compound involves mitochondrial dysfunction. The identification of the molecular mechanisms by which D fraction exerts its effects is crucial for the development of preventive and therapeutic strategies for cancer.