Role of SIRT1 in Chemoresistant Leukemia.

Leukemias of the AML, CML, and CLL types are the most common blood cancers worldwide, making them a major global public health problem. Furthermore, less than 24% of patients treated with conventional chemotherapy (low-risk patients) and 10-15% of patients ineligible for conventional chemotherapy (high-risk patients) survive five years. The low levels of survival are mainly due to toxicity and resistance to chemotherapy or other medication, the latter leading to relapse of the disease, which is the main obstacle to the treatment of leukemia. Drug resistance may include different molecular mechanisms, among which epigenetic regulators are involved. Silent information regulator 2 homolog 1 (SIRT1) is an epigenetic factor belonging to the sirtuin (SIRT) family known to regulate aspects of chromatin biology, genome stability, and metabolism, both in homeostasis processes and in different diseases, including cancer. The regulatory functions of SIRT1 in different biological processes and molecular pathways are dependent on the type and stage of the neoplasia; thus, it may act as both an oncogenic and tumor suppressor factor and may also participate in drug resistance. In this review, we explore the role of SIRT1 in drug-resistant leukemia and its potential as a therapeutic target.

Fruit Extract of Sechium chinantlense (Lira & F. Chiang) Induces Apoptosis in the Human Cervical Cancer HeLa Cell Line.

Sechium edule (Cucurbitaceae) is a commercial species of chayote and is just one of several species in the genus Sechium, whose extracts inhibit proliferation in tumor cell lines. The capacity of the wild species Sechium chinantlense (SCH) as an antitumor agent is unknown, as is the mechanism of action. In the present study, HeLa cervical cancer and HaCaT normal cell lines were treated with SCH and cell proliferation was inhibited in both cell lines in a dose-dependent manner similar to the effect of the antineoplastic agent cisplatin (Cis). Additionally, SCH arrested cell cycle progression but only in HeLa cells and induced apoptosis, as shown by phosphatidylserine translocation and caspase-3 activation, while Cis did so in both cell lines. Exploration of the mechanism of action of SCH in HeLa cells suggests that apoptosis was mediated by the intrinsic signaling pathway since there was no activation of caspase-8, but there was a release of cytochrome-c. These findings suggest that the SCH extract has the potential to selectively kill tumor cells by promoting apoptosis, without harming nontumor cells.

Sodium Caseinate in Combination With Daunorubicin or Cytarabine Improves Survival of Mice With Long-established Leukemia.

BACKGROUND/AIM: Although acute myeloid leukemia (AML) has traditionally been considered an oncological emergency and initiation of therapy is believed to be crucial to minimizing disease-related morbidity and mortality, it has also been suggested that a certain delay in treatment has no negative consequences in terms of response, early mortality, or survival. We aimed to determine the effect of administration of sodium caseinate (SC), a salt of casein, the main milk protein, with cytarabine or with daunorubicin on survival in mice with well-established leukemia. MATERIALS AND METHODS: To assay the time of establishment of leukemia in the bone marrow, Balb/c mice were inoculated with 2.5×10 5 WEHI-3 cells/mouse and after 3, 6 and 9 days were euthanized. Bone marrow mononuclear cells (BM-MNCs) of the femur were obtained and cultured for 120 h with or without rmIL-3 and cell proliferation was evaluated by the crystal violet technique. Then, the effect of administrating SC-cytarabine or SC-daunorubicin on survival rates of mice with well-established leukemia was assayed. Another group of Balb/c mice was inoculated with WEHI-3 cell and after 10 days mice were treated with SC-cytarabine or SC-daunorubicin for 40 days. Survival rates were recorded daily and in surviving mice, the prevalence of bone marrow proliferation after treatment was assayed by the crystal violet technique. RESULTS: The assay on the time of establishment of leukemia shows that in 9 days leukemia cells accumulate in the bone marrow in sufficient quantities to sustain an in vitro culture in the absence of growth factors, and we, thus, used this as a criterion of well-established leukemia. When mice with a burden of leukemic cells of more than 9 days were treated with SC-cytarabine or SC-daunorubicin, this resulted in 55% survival for both treatments, and the proliferation assays showed that the bone marrow retained its normal proliferation capacity. CONCLUSION: SC-cytarabine or SC-daunorubicin treatment prolonged the survival rate of Balb/c mice with a burden of well-established leukemia, and there was no negative impact on bone marrow functionality; however, SC-cytarabine or SC-daunorubicin combination options need to be sought to increase survival beyond 40 days.

Inhibitors of Chemoresistance Pathways in Combination with Ara-C to Overcome Multidrug Resistance in AML. A Mini Review.

Acute myeloid leukemia (AML), the most common type of leukemia in older adults, is a heterogeneous disease that originates from the clonal expansion of undifferentiated hematopoietic progenitor cells. These cells present a remarkable variety of genes and proteins with altered expression and function. Despite significant advances in understanding the molecular panorama of AML and the development of therapies that target mutations, survival has not improved significantly, and the therapy standard is still based on highly toxic chemotherapy, which includes cytarabine (Ara-C) and allogeneic hematopoietic cell transplantation. Approximately 60% of AML patients respond favorably to these treatments and go into complete remission; however, most eventually relapse, develop refractory disease or chemoresistance, and do not survive for more than five years. Therefore, drug resistance that initially occurs in leukemic cells (primary resistance) or that develops during or after treatment (acquired resistance) has become the main obstacle to AML treatment. In this work, the main molecules responsible for generating chemoresistance to Ara-C in AML are discussed, as well as some of the newer strategies to overcome it, such as the inclusion of molecules that can induce synergistic cytotoxicity with Ara-C (MNKI-8e, emodin, metformin and niclosamide), subtoxic concentrations of chemotherapy (PD0332991), and potently antineoplastic treatments that do not damage nonmalignant cells (heteronemin or hydroxyurea + azidothymidine).

Improved Survival of Leukemic Mice Treated with Sodium Caseinate in Combination with Daunorubicin without Toxicity.

In recent years, low doses of chemotherapy have been resumed and explored for the treatment of acute myeloid leukemia. Thus, CPX-351, a dual-drug liposomal encapsulation of cytarabine and daunorubicin, was approved by the US Food and Drug Administration, to deliver a synergistic 5 : 1 molar drug ratio into leukemia cells to a greater extent than normal bone marrow cells and significantly enhance survival compared with conventional treatment in older and newly diagnosed AML patients, but overall survival rate remains low; therefore, the need for new therapeutic options continues. Sodium caseinate (SC), a salt of casein, the main milk protein, has cytotoxic effect in leukemia cell lines, but promotes proliferation of hematopoietic normal cells, while its administration in leukemic mice promotes survival for more than 40 days, but bone marrow surviving mice still harbour leukemic cells, but it is not known whether the combination with cytarabine or daunorubicin can improve survival without damaging normal hematopoietic cells. Here, it is shown that, in vitro, the combination of the IC25 of SC-cytarabine or SC-daunorubicin synergizes in the elimination of leukemic cells, with evident induction of apoptosis, while the proliferation of mononuclear cells of bone marrow is not affected. In leukemic mice, the combined administration of SC-daunorubicin or SC-cytarabine promotes the highest survival rate at 40 days; in addition, no autoproliferating cells were detected in the bone marrow of survivors of more than 60 days, evidence of eradication of leukemic cells, but only the bone marrow of mice treated with the SC-daunorubicin combination proliferated in the presence of interleukin-3, which shows that this combination is not toxic to normal bone marrow cells, thus emerging as a possible antileukemic agent.

Dental Pulp Mesenchymal Stem Cells as a Treatment for Periodontal Disease in Older Adults.

Periodontal disease (PD) is one of the main causes of tooth loss and is related to oxidative stress and chronic inflammation. Although different treatments have been proposed in the past, the vast majority do not regenerate lost tissues. In this sense, the use of dental pulp mesenchymal stem cells (DPMSCs) seems to be an alternative for the regeneration of periodontal bone tissue. A quasi-experimental study was conducted in a sample of 22 adults between 55 and 64 years of age with PD, without uncontrolled systemic chronic diseases. Two groups were formed randomly: (i) experimental group (EG) n = 11, with a treatment based on DPMSCs; and a (ii) control group (CG) n = 11, without a treatment of DPMSCs. Every participant underwent clinical and radiological evaluations and measurement of bone mineral density (BMD) by tomography. Saliva samples were taken as well, to determine the total concentration of antioxidants, superoxide dismutase (SOD), lipoperoxides, and interleukins (IL), before and 6 months after treatment. All subjects underwent curettage and periodontal surgery, the EG had a collagen scaffold treated with DPMSCs, while the CG only had the collagen scaffold placed. The EG with DPMSCs showed an increase in the BMD of the alveolar bone with a borderline statistical significance (baseline 638.82 ± 181.7 vs. posttreatment 781.26 ± 162.2 HU, p = 0.09). Regarding oxidative stress and inflammation markers, salivary SOD levels were significantly higher in EG (baseline 1.49 ± 0.96 vs. 2.14 ± 1.12 U/L posttreatment, p < 0.05) meanwhile IL1ß levels had a decrease (baseline 1001.91 ± 675.5vs. posttreatment 722.3 ± 349.4 pg/ml, p < 0.05). Our findings suggest that a DPMSCs treatment based on DPMSCs has both an effect on bone regeneration linked to an increased SOD and decreased levels of IL1ß in aging subjects with PD.

Casein and Peptides Derived from Casein as Antileukaemic Agents.

Milk is a heterogeneous lacteal secretion mixture of numerous components that exhibit a wide variety of chemical and functional activities. Casein, the main protein in milk, is composed of α-, ß-, and κ-caseins, each of which is important for nutritional value and for promoting the release of cytokines, also are linked to the regulation of haematopoiesis and immune response and inhibit the proliferation and induce the differentiation of leukaemia cells. It has been shown that the digestive process of caseins leads to the release of bioactive peptides that are involved in the regulation of blood pressure and the inhibition or activation of the immune response by serving as agonists or antagonists of opioid receptors, thus controlling the expression of genes that exert epigenetic control. Later, they bind to opioid receptor, block nuclear factor κ-beta, increase the redox potential, and reduce oxidative stress and the pro-inflammatory agents that favour an antioxidant and anti-inflammatory environment. Therefore, the bioactive peptides of casein could be compounds with antileukaemia potential. This review provides a summary of current knowledge about caseins and casein peptides on the immune system as well as their roles in the natural defence against the development of leukaemia and as relevant epigenetic regulators that can help eradicate leukaemia.

El Sodium caseinate and alfa-casein inhibit proliferation of the mouse myeloid cell line 32D clone 3 (32Dcl3) via TNF-α / El caseinato de sodio y la caseína α inhiben la proliferación de la línea celular mieloide de ratón 32D clone 3 (32Dcl3) mediante el TNF-α.

Introduction: Sodium caseinate (CS) and its components (alpha-casein, beta-casein, and kappa-casein) have been shown to inhibit the proliferation of the mouse hematopoietic 32D clone 3 (32Dcl3) cell line and induce its differentiation into macrophages. It is well-known that alpha-casein induces IL-1ß production and that this cytokine inhibits the proliferation via the production of tumor necrosis factor alpha (TNF-alpha), but it is not known if CS and the caseins inhibit the proliferation via TNF-alpha production. Objective: To evaluate if CS and alpha-casein, beta-casein and kappa-casein inhibit the proliferation on 32Dcl3 cell line via TNF-alpha. Materials and methods: We used different concentrations of CS, alpha-casein, betacasein and kappa-casein in 32Dcl3 cells to evaluate cell proliferation. We assessed cell viability by MTT, induction to apoptosis by flow cytometry, and TNF-alpha synthesis by ELISA. Additionally, we performed anti-TNF-alpha neutralization assays on 32Dcl3 cells treated with CS and alpha-casein and we evaluated proliferation. Results: The results showed that CS, alpha-casein, beta-casein, and kappa-casein reduced proliferation of the 32Dcl3 cell line without affecting the viability and that only CS and alpha-casein induced apoptosis and the release of TNF-alpha. The 32Dcl3 cells treated with CS and alpha-casein reestablished their proliferation by using anti-TNF-alpha antibodies. Conclusion: TNF-alpha was the main responsible for the inhibition of proliferation in 32Dcl3 cells treated with CS or alpha-casein.

Introducción. Se ha demostrado que el caseinato de sodio y sus componentes (caseínas α, ß y κ) inhiben la proliferación de la línea celular hematopoyética de ratón 32D clone 3 (32Dcl3) e inducen su diferenciación hacia macrófagos. Se sabe que la caseína α induce la producción de IL-1ß y que esta última citocina inhibe la proliferación celular mediante la producción del factor de necrosis tumoral alfa (TNF-α), pero se desconoce si el caseinato de sodio y las caseínas inducen la producción de TNF y si este es el responsable de la inhibición de la proliferación. Objetivo. Evaluar si el caseinato de sodio y las caseínas α, ß y κ inhiben la proliferación de la línea celular 32Dcl3 mediante la producción de TNF-α. Materiales y métodos. Se usaron diferentes concentraciones de caseinato de sodio y de las caseínas α, ß y κ en las células 32Dcl3. Posteriormente, se evaluaron la viabilidad celular mediante una prueba con el MTT [3-(4,5-dimetiltiazol-2-ilo)-2,5-difeniltetrazol], la inducción de apoptosis con la citometría de flujo y la síntesis del TNF-α con el ELISA. Además, se hicieron pruebas de neutralización con anti-TNF-α en células 32Dcl3 tratadas con caseinato de sodio y caseína α, y se evaluó la proliferación celular. Resultados. Se encontró que el caseinato de sodio y las caseínas α, ß y κ reducían la proliferación de la línea celular 32Dcl3 sin afectar la viabilidad, y que solo el caseinato y la caseína α inducían la apoptosis y la liberación al medio de TNF-α. La proliferación de células 32Dcl3 tratadas con caseinato y caseína α se restableció al usar anticuerpos anti-TNF-α. Conclusión. El TNF-α fue el principal responsable de la inhibición de la proliferación en las células 32Dcl3 tratadas con caseinato de sodio o caseína α.

Mesenchymal Stem Cells for Periodontal Tissue Regeneration in Elderly Patients.

Mesenchymal stem cell (MSC) grafting is a highly promising alternative strategy for periodontal regeneration in periodontitis, which is one of the primary causes of tooth loss in the elderly. However, aging progressively decreases the proliferative and differentiation potential of MSCs and diminishes their regenerative capacity, which represents a limiting factor for their endogenous use in elderly patients. Therefore, tissue regeneration therapy with MSCs in this age group may require a cellular source without the physiological limitations that MSCs exhibit in aging. In this sense, exogenous or allogeneic MSCs could have a better chance of success in regenerating periodontal tissue in elderly patients. This review examines and synthesizes recent data in support of the use of MSCs for periodontal regenerative therapy in patients. Additionally, we analyze the progress of the therapeutic use of exogenous MSCs in humans.

Retrieval of a periodontally compromised tooth by allogeneic grafting of mesenchymal stem cells from dental pulp: A case report.

Objective To report a case of successful allogeneic grafting of mesenchymal dental pulp stem cells (DPSCs) as preliminary findings in a patient with periodontal disease enrolled into clinical trial ISRCTN12831118. Methods Mesenchymal stem cells from the dental pulp of a deciduous tooth from a 7-year-old donor were separated from the pulp chamber and processed via enzymatic digestion and centrifugation. DPSCs were passaged and cultured on a 35 × 13 mm culture dish in minimum essential medium-alpha, without supplementation. After reaching 80% confluency, 5 x 106 allogeneic DPSCs in 250 µl phosphate buffered saline were seeded onto a dry scaffold of lyophilized collagen-polyvinylpyrrolidone sponge placed in the left lower premolar area of a 61-year-old patient with periodontal disease. Surgical access to the lower premolar area was achieved using the flap technique. Results At 3 and 6 months following allogeneic graft, the patient showed no sign of rejection and exhibited decreases in tooth mobility, periodontal pocket depth and bone defect area. Bone mineral density had increased at the graft site. Conclusions Regenerative periodontal therapy using DPSCs of allogeneic origin may be a promising treatment for periodontal disease-induced bone defects.

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.

Chemical analyses and in vitro and in vivo toxicity of fruit methanol extract of Sechium edule var. nigrum spinosum.

CONTEXT: Sechium edule (Jacq.) Sw. (Cucurbitaceae) is used in ethnomedicine, but the diversity of the varietal groups of this species has not often been considered. This is important because we previously reported that different variety of species exhibit different activities across different tumor cell lines. OBJECTIVE: This study investigates the chemical composition and biological activities of extracts obtained from S. edule var. nigrum spinosum. MATERIALS AND METHODS: The leukemia P388 cell line and mononuclear bone marrow cells (MNCBMs) were treated with the extract at a concentration ranging from 40 to 2370 µg/mL for cytotoxicity and viability assays. CD-1 mice were treated with 8-5000 mg/kg extract and monitored every hour for the first 24 h and subsequently for seven days for signs of toxicity (LD50). In addition, the chromatographic profile of the extract was determined by HPLC. RESULTS: The extract inhibits the proliferation of both P388 cells and MNCBMs, with IC50 values of 927 and 1911 µg/mL, respectively, but reduced the viability and induced the apoptosis of only leukemia cells. The LD50 was higher than 5000 mg/kg, and this concentration did not alter the blood chemistry or cell count but doubled the mitotic index in the bone marrow. The HPLC showed the presence of cucurbitacins, phloridzin, naringenin, phloretin, apigenin, and gallic, chlorogenic, vanillic, p-hydroxybenzoic, caffeic, and p-coumaric acids. DISCUSSION AND CONCLUSION: Sechium edule var. nigrum spinosum contains bioactive compounds that explain the antiproliferative and nutraceutical activities, and its lack of physiological side effects constitutes an added value to a widely consumed vegetable.

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.

Sodium Caseinate (CasNa) Induces Mobilization of Hematopoietic Stem Cells in a BALB/c Mouse Model.

BACKGROUND Hematopoietic stem cells transplantation has high clinical potential against a wide variety of hematologic, metabolic, and autoimmune diseases and solid tumors. Clinically, hematopoietic stem cells derived from peripheral blood are currently used more than those obtained from sources such as bone marrow. However, mobilizing agents used in the clinic tend to fail in high rates, making the number of mobilized cells insufficient for transplantation. We investigated whether sodium caseinate induces functional mobilization of hematopoietic stem cells into peripheral blood of Balb/c mice. MATERIAL AND METHODS Using a mouse model, we administrated sodium caseinate or Plerixafor, a commercial mobilizing agent, and analyzed counts of hematopoietic stem cells in peripheral blood, and then cells were transplanted into lethally irradiated mice to restore hematopoiesis. All assays were performed at least twice. RESULTS We found that sodium caseinate increases the number of mononuclear cells in peripheral blood with the immunophenotype of hematopoietic stem cells (0.2 to 0.5% LSK cells), allowing them to form colonies of various cell lineages in semisolid medium (p<0.05). This effect is similar to that of Plerixafor, and cells transplanted into lethally irradiated mice can restore hematopoiesis at higher percentages than mononuclear cells mobilized by Plerixafor (40% vs. 20%, respectively). Further, a secondary transplant rescued a separate group of irradiated mice from death, proving definitive evidence of hematopoietic reconstitution after hematopoietic stem cells transplantation. Data are presented as mean ± standard deviation. To determine significant differences between the data, one-way ANOVA and the Tukey test were used. CONCLUSIONS Collectively these results show the utility of sodium caseinate as a mobilizer of hematopoietic stem cells and its potential clinical application in transplantation settings.

Sodium caseinate induces increased survival in leukaemic mouse J774 model.

BACKGROUND: Acute myeloid leukaemia is a neoplastic disease of haematopoietic stem cells. Although there have been recent advances regarding its treatment, mortality remains high. Consequently, therapeutic alternatives continue to be explored. In the present report, we present evidence that sodium caseinate (CasNa), a salt of the principal protein in milk, may possess important anti-leukaemic properties. MATERIALS AND METHODS: J774 leukaemia macrophage-like cells were cultured with CasNa and proliferation, viability and differentiation were evaluated. These cells were also inoculated into BALB/c mice as a model of leukemia. RESULTS: We demonstrated that CasNa inhibits the in vitro proliferation and reduces viability of J774 cells, and leads to increased survival in vivo in a leukaemic mouse model. CONCLUSION: These data indicate that CasNa may be useful in leukaemia therapy.

Antineoplastic activity of rinvanil and phenylacetylrinvanil in leukaemia cell lines.

In the search for novel chemotherapeutic agents for cancer treatment, capsaicin has been shown to inhibit proliferation and induce apoptosis in various types of cancer cell line, including leukaemia cell lines. The capsaicin analogues, rinvanil and phenylacetylrinvanil (PhAR), share a binding affinity for vanilloid receptors and may have biological activities similar to capsaicin; however, their anticancer potential has not yet been reported. This study analyses the antineoplastic activities of rinvanil and PhAR in leukaemia versus normal cells. P388, J774 and WEHI-3 leukaemia cell lines, as well as mouse bone marrow mononuclear cells, were cultured with varying concentrations of rinvanil and PhAR. Following this, proliferation and apoptosis were determined by the sulforhodamine B (SRB) assay and DNA ladder. Cultured leukaemia cell lines and mouse bone marrow mononuclear cells demonstrated a dose-dependent inhibition of proliferation, while non-diseased cells were less sensitive to the cytotoxic effect of capsaicin, rinvanil and PhAR. Rinvanil and PhAR also induced apoptosis in leukaemia cell lines but not in bone marrow. Given the lower IC50 values for apoptosis induction in leukaemia cells compared with that of normal cells, PhAR is a promising selective anticancer agent.