Edelmiro Santiago-Osorio

Up-regulation of HLA class-I antigen expression and antigen-specific CTL response in cervical cancer cells by the demethylating agent hydralazine and the histone deacetylase inhibitor valproic acid

BackgroundDNA hypermethylation and histone deacetylation are epigenetic events that contribute to the absence or downregulated expression of different components of the tumor recognition complex. These events affect the processing and presentation of antigenic peptides to CTLs by HLA class-I molecules. In this work evaluated the effect of the DNA hypomethylating agent hydralazine and the histone deacetylase inhibitor valproic acid, on the expression of HLA class-I molecules and on the antigen-specific immune recognition of cervical cancer cells.MethodsCell lines C33A (HPV-), CaSki (HPV-16+) and MS751 (HPV-18+) were treated with hydralazine and valproic acid to assess the expression of HLA class-I molecules by flow cytometry and RT-PCR. Promoter methylation of HLA class-I -A, -B and C, was also evaluated by Methylation-Specific PCR. Primary cervical tumors of four HLA-A*0201 allele patients were typed for HPV and their CTLs stimulated in vitro with the T2 cell line previously loaded with 50 μM of the HPV peptides. Cytotoxicity of stimulated CTLs was assayed against Caski and MS751 cells pre-treated with hydralazine and valproic acid.ResultsValproic acid and hydralazine/valproic acid up-regulated the constitutive HLA class-I expression as evaluated by flow cytometry and RT-PCR despite constitutive promoter demethylation at these loci. Hydralazine and valproic acid in combination but no IFN-gamma hyperacetylated histone H4 as evaluated by ChiP assay. The antigenic immune recognition of CaSki and MS751 cells by CTLs specific to HPV-16/18 E6 and E7-derived epitopes, was increased by VA and H/VA and the combination of H/VA/IFN-gamma.ConclusionThese results support the potential use of hydralazine and valproic acid as an adjuvant for immune intervention in cervical cancer patients whenever clinical protocols based on tumor antigen recognition is desirable, like in those cases where the application of E6 and E7 based therapeutic vaccines is used.

Mesenchymal Stem Cells Derived from Dental Pulp: A Review

The mesenchymal stem cells of dental pulp (DPSCs) were isolated and characterized for the first time more than a decade ago as highly clonogenic cells that were able to generate densely calcified colonies. Now, DPSCs are considered to have potential as stem cell source for orthopedic and oral maxillofacial reconstruction, and it has been suggested that they may have applications beyond the scope of the stomatognathic system. To date, most studies have shown that, regardless of their origin in third molars, incisors, or exfoliated deciduous teeth, DPSCs can generate mineralized tissue, an extracellular matrix and structures type dentin, periodontal ligament, and dental pulp, as well as other structures. Different groups worldwide have designed and evaluated new efficient protocols for the isolation, expansion, and maintenance of clinically safe human DPSCs in sufficient numbers for various therapeutics protocols and have discussed the most appropriate route of administration, the possible contraindications to their clinical use, and the parameters to be considered for monitoring their clinical efficacy and proper biological source. At present, DPSC-based therapy is promising but because most of the available evidence was obtained using nonhuman xenotransplants, it is not a mature technology.

Aging Linked to Type 2 Diabetes Increases Oxidative Stress and Chronic Inflammation

Oxidative stress (OxS) and inflammation are physiopathological mechanisms related to diabetes and aging. We evaluated the additive effect of diabetes and aging on OxS and inflammation in a cross-sectional comparative study of 228 subjects: (1) 56 healthy adults (mean age, 47 ± 7 years); (2) 60 diabetic adults (mean age, 52 ± 6 years); (3) 40 healthy elderly adults (mean age, 67 ± 7 years); and (4) 72 diabetic elderly adults (mean age, 68 ± 7 years). We measured levels of glycosylated hemoglobin (HbA1c), plasma lipid peroxides, superoxide dismutase, glutathione peroxidase, total antioxidants, and tumor necrosis factor-alpha (TNF-α). The results indicate that diabetes is a risk factor for subjects with high serum levels of TNF-α (odds ratio [OR] = 12.1; 95% confidence interval [95% CI], 5.0-28; p < 0.001); this correlation becomes stronger when it is also associated with aging (OR = 14; 95% CI, 3.7-53.7; p < 0.05). Likewise, we observed that diabetes is an independent risk factor for OxS (OR = 2.1; 95% CI, 1.2-3.8; p < 0.05), and a stronger factor in older patients (OR = 3.1; 95% CI, 1.3-7.5; p < 0.05). Our findings suggest that aging, in concert with diabetes, exerts an additive effect on OxS and inflammation.

Structural and functional effects of benzimidazole/thioether-copper complexes with antitumor activity on cell membranes and molecular models.

Two cytotoxic copper(II) complexes with N-H and N-methylated benzimidazole-derived ligands (Cu-L(2) and Cu-L(2Me)) were synthesized and made to interact with human erythrocytes and molecular models of their plasmatic membranes. The latter consisted in lipid bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), lipids of the types present in the outer and inner monolayers of the human erythrocyte membrane, respectively. Initial assessment of the interaction of the complexes with DMPC and DMPE consisted of X-ray diffraction studies, which showed preferential interactions with the former. Scanning electron microscopy (SEM) of erythrocytes incubated with solutions of the Cu(II) complexes evidenced deformation of the cells to stomatocytes and knizocytes by Cu-L(2) and Cu-L(2Me) due to interactions with the inner and outer leaflets of the cell membranes, respectively. This was further confirmed by real-time observation of the dose-dependent effects of the complexes on live erythrocytes by defocusing microscopy (DM). The combined observations, including the increased antiproliferative activity of the N-methylated complex Cu-L(2Me) over that of Cu-L(2) is rationalized based on the higher lipophilicity of the former. This property would facilitate passive diffusion of Cu-L(2Me) through the cell membrane, particularly in the initial stages when the DMPC-rich outer leaflet is involved. In contrast, the benzimidazole N-H groups of Cu-L(2) may participate in hydrogen bonding with DMPE polar groups; this result is consistent with the formation of stomatocyte induced by the latter complex.

Effect of Tai Chi versus Walking on Oxidative Stress in Mexican Older Adults

It has recently been reported that the practice of Tai Chi reduces oxidative stress (OxS), but it is not clear whether walking or Tai Chi produces a greater antioxidant effect. The aim of the present study was to evaluate the effect of the practice of Tai Chi and walking on markers for OxS. We carried out a quasi-experimental study with 106 older adults between 60 and 74 years of age who were clinically healthy and divided into the following groups: (i) control group (n = 23), (ii) walking group (n = 43), and (iii) Tai Chi group (n = 31). We measured the levels of lipoperoxides (LPO), antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), and total antioxidant status (TAS) pre- and post-intervention in all subjects. The data were subjected to a covariant analysis. We found lower levels of LPO in the Tai Chi group compared with the walking group (Tai Chi, 0.261 ± 0.02; walking, 0.331 ± 0.02; control, 0.304 ± 0.023 µmol/L; P = 0.05). Likewise, we observed significantly higher SOD activity and lower OxS-score in the Tai Chi group (P < 0.05). Our findings suggest that the practice of Tai Chi produces a more effective antioxidant effect than walking.

Tai Chi Exercise Increases SOD Activity and Total Antioxidant Status in Saliva and Is Linked to an Improvement of Periodontal Disease in the Elderly

The aim of this study was to determine the effect of Tai Chi on biological markers of oxidative stress in saliva and its relationship with periodontal disease (PD) in older adults. We carried out a quasi-experimental study with a sample of 71 sedentary volunteers with PD who were divided into a control group of 34 subjects and an experimental group of 37 subjects who performed Tai Chi 5 days a week for a period of 6 months. PD status was characterized using the Periodontal Disease Index (PDI). Superoxide dismutase (SOD), total antioxidant status (TAS), and TBARS levels of both groups were measured by spectrophotometric methods. In addition, inflammation markers (TNF-α, IL-1β, IL-6, IL-8, and IL-10) were measured by flow cytometry. We found a statistically significant increase in SOD activity (P < 0.001) and TAS concentration (P < 0.05), whereas levels of IL-1β were significantly lower (P < 0.01). Likewise, a statistically significant decrease in the PDI (P < 0.05) was observed in subjects who performed Tai Chi during a period of 6 months. Our findings suggest that the practice of Tai Chi has both antioxidant and anti-inflammatory effects that are linked to the improvement of PD in older adults.

A novel HPV 16 L1-based chimeric virus-like particle containing E6 and E7 seroreactive epitopes permits highly specific detection of antibodies in patients with CIN 1 and HPV-16 infection

BackgroundThe presence of IgG antibodies to HPV-16 L1-virus like particles (VLPs) in serum has been reported as a result of persistent exposure to the virus and as a marker of disease progression. However, detection of VLP-specific antibodies in sera does not always indicate a malignant lesion as positive results may also be due to a nonmalignant viral infection. Furthermore, malignant lesions are associated with an increased antibody titer for E6 and E7 proteins. The aim of this study was to develop an ELISA using a novel chimeric virus-like particle (cVLP) encoding an L1 protein fused with a string of HPV-16 E6 and E7 seroreactive epitopes to its C-terminus to be used for detection of HPV-16 specific antibodies in patients with cervical intraepithelial lesion grade 1 (CIN 1).ResultsThe sera of 30 patients with CIN 1 who also tested positive for HPV-16 DNA and of 30 age-matched normal donors negative for HPV infection were tested for the presence of IgG antibodies specific for either VLP-L1 (HPV-16 L1), gVLP (derived from Gardasil), or cVLP by ELISA. The cVLP-reactive sera yielded two distinct groups of results: (H) reactivity levels that presented very strong cVLP-specific titers, and (L) reactivity levels with significantly lower titers similar to those obtained with VLP-L1 and gVLP antigens. Additionally, the sera that presented the higher cVLP titers closely matched those that had significantly stronger reactivity to E6 and E7 epitopes. Interestingly, the samples with the highest titers corresponded to patients with the higher numbers of sexual partners and pregnancies. On the other hand only 4 out of the 12 sera that harbored antibodies with VLP neutralizing ability corresponded to the group with high cVLP antibody titers.ConclusionWe report for the first time that chimeric particles containing HPV-16 L1 protein fused with E6 and E7 seroreactive epitopes enable much better detection of IgG antibodies in the sera of CIN 1 patients positive for HPV-16 infection than those obtained with VLPs containing only the HPV-16 L1 protein. We also found that the sera with higher cVLP antibody titers corresponded to patients with more sexual partners and pregnancies, and not always with to those with a high neutralizing activity. This novel assay could help in the development of a tool to evaluate cervical cancer risk.

Tai Chi diminishes oxidative stress in Mexican older adults

ObjectiveTo determine the effect of Tai Chi on oxidative stress in a population of elderly Mexican subjects.DesignIt was carried out a quasi-experimental study with a sample of 55 healthy subjects randomly divided into two age-matched groups: (i) a control group with 23 subjects and (ii) an experimental group with 32 subjects. The experimental group received daily training in Tai Chi for 50 min.MeasurementsIt was measured before and after 6-month of exercise period: thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), superoxide dismutase (SOD), and glutathione peroxidase (GPx).ResultsIt was found that the experimental group exhibited a statistically significant decrease in glucose levels, total cholesterol, low-density lipoprotein cholesterol (LDLC), and systolic blood pressure, as well as an increase in SOD and GPx activity and TAS compared with the control group (p < 0.05).ConclusionsOur findings suggest that the daily practice of Tai Chi is useful for reducing OxS in healthy older adults.

Mesenchymal Stem Cells of Dental Origin for Inducing Tissue Regeneration in Periodontitis: A Mini-Review

Periodontitis is a chronic disease that begins with a period of inflammation of the supporting tissues of the teeth table and then progresses, destroying the tissues until loss of the teeth occurs. The restoration of the damaged dental support apparatus is an extremely complex process due to the regeneration of the cementum, the periodontal ligament, and the alveolar bone. Conventional treatment relies on synthetic materials that fill defects and replace lost dental tissue, but these approaches are not substitutes for a real regeneration of tissue. To address this, there are several approaches to tissue engineering for regenerative dentistry, among them, the use of stem cells. Mesenchymal stem cells (MSC) can be obtained from various sources of adult tissues, such as bone marrow, adipose tissue, skin, and tissues of the orofacial area. MSC of dental origin, such as those found in the bone marrow, have immunosuppressive and immunotolerant properties, multipotency, high proliferation rates, and the capacity for tissue repair. However, they are poorly used as sources of tissue for therapeutic purposes. Their accessibility makes them an attractive source of mesenchymal stem cells, so this review describes the field of dental stem cell research and proposes a potential mechanism involved in periodontal tissue regeneration induced by dental MSC.

Fruit Extract from A Sechium edule Hybrid Induce Apoptosis in Leukaemic Cell Lines but not in Normal Cells

The antiproliferative potential of a crude extract from the chayote hybrid H-837-07-GISeM® and its potential for apoptosis induction were assessed in leukaemic cell lines and normal mouse bone marrow mononuclear cells (BM-MNCs). The extract strongly inhibited the proliferation of the P388, J774, and WEHI-3 cell lines (with an IC50 below 1.3 μg·mL−1), reduced cell viability, and induced apoptotic body production, phosphatidylserine translocation, and DNA fragmentation. However, the extract had no effect on BM-MNCs. We postulate that these properties make the extract a good candidate for an anti-tumour agent for clinical use.