Osteonecrosis de maxilares asociada al uso de bifosfonatos: Revisión de 491 casos / Osteonecrosis of the jaws associated with use of bisphosphonates: A review of 491 cases

En los últimos años, el número de pacientes que presenta osteonecrosis maxilar asociada al uso de bifosfonatos (BIONJ) se ha incrementado. Esto es debido al aumento en el consumo de bifosfonatos, los cuales se asocian al tratamiento de carcinomas con metástasis óseas, mieloma múltiple, osteoporosis, osteopenia y enfermedades metabólicas como la enfermedad de Paget. Objetivo: Analizar el número de casos de pacientes que han desarrollado osteonecrosis de maxilares asociado al uso de bifosfonatos, publicados desde Junio del año 2006 hasta Abril 2010. Método: En esta revisión, se consultaron las bases de datos Pubmed-Medline, Scielo e Índice Médico Español, incluyendo límites en la búsqueda, para recopilar los casos de BIONJ que se hayan publicado desde el año 2006 hasta la actualidad. Los artículos seleccionados presentaban casos, en los cuales los pacientes que recibían bifosfonatos desarrollaban BIONJ. Resultados: Se encontraron 491 casos de BIONJ en total, de ellos 49,3% eran mujeres, 32% hombres y 18,7% no se establecía el género. La mayoría de estos casos se presentaron en la mandíbula y asociados particularmente al ácido zolendrónico. Conclusiones: En los próximos años se espera que el número de pacientes que desarrollen esta complicación vaya en aumento, en particular en mujeres, a las cuales se les indica cada vez más esta medicación para el tratamiento de la osteoporosis (AU)

In the last years, the number of patients presenting jaw osteonecrosis associated with the use of bisphosphonates (BIONJ) has increased. This is due to increased consumption of bisphosphonates, which are associated with the treatment of carcinomas with bone metastases, multiple myeloma, osteoporosis, osteopenia and metabolic diseases such as Paget's disease. The aim of this review is to analyze the number of cases of patients who developed jaws osteonecrosis-associated with the use of bisphosphonates, published from June 2006 to April 2010. In this review, we referred to the databases Pubmed-Medline, Scielo and Spanish Medical Index, including limits on the search to collect BIONJ cases published from 2006 up to now. The selected papers presented cases in which the patients who received bisphosphonates developed BIONJ. We found 491 cases of BIONJ in total, of which 49.3% correspond to women, 32% to men and 18.7%, did not establish gender. Most of these cases occurred in the mandible and associated particularly with zoledronic acid. In the coming years it is expected that the number of patients who develop this complication increase, particularly in women, who are more and more prescribed this medication for the osteoporosis treatment (AU)

Identification of dual mTORC1 and mTORC2 inhibitors in melanoma cells: prodigiosin vs. obatoclax.

The PI3K/AKT/mTOR signaling pathway regulates cell proliferation, survival and angiogenesis. The mammalian target of rapamycin (mTOR) is a protein kinase ubiquitously expressed within cells that regulates cell growth and survival by integrating nutrient and hormonal signals. mTOR exists in two complexes, mTORC1 and mTORC2. Hyperactivation of the mTOR protein has been linked to development of cancer, raising mTOR as an attractive target for cancer therapy. Prodigiosin (PG) and obatoclax (OBX), two members of the prodiginines family, are small molecules with anticancer properties which are currently under clinical trials. In the present paper, we demonstrate that mTOR is a molecular target of both prodiginines in melanoma, a highly drug-resistant cancer model. The inhibition of mTORC1 and mTORC2 complexes by PG or OBX resulted in a loss of AKT phosphorylation at S473, preventing its full activation, with no significant effect on T308. The strongest activity inhibition (89%) was induced by PG on mTORC2. Binding assays using Surface Plasmon Resonance (SPR) provide kinetic and affinity data of the interaction of these small molecules with mTOR. In addition, in silico modeling produced a detailed atomic description of the binding modes. These results provide new data to understand the mechanism of action of these molecules, and provide new structural data that will allow the development of more specific mTOR inhibitors for cancer treatment.

New insights on the antitumoral properties of prodiginines.

Apoptosis is involved in the action of several (and perhaps all) cancer-chemotherapeutic agents. Prodiginines are a family of natural red pigmented secondary metabolites, produced by different bacteria and most of them are characterized by a common pyrrolylpyrromethene skeleton. The biosynthesis of prodigiosin and derivatives has been extensively studied in Serratia marcescens. S. marcescens is a Gramnegative bacterium belonging to Enterobacteriaceae. Prodiginines show numerous biological activities pointing out immunosuppressive and anticancer properties. Some prodiginines displayed apoptotic effects in vitro and antitumor activity in vivo. Their cytotoxic effect is attributed to the presence of the C- 6 methoxy substituent. The A-pyrrole ring plays a key role in both the copper nuclease activity and the cytotoxicity of prodiginines. Here we review the main characteristics of prodigiosin and their derivatives as well as the most prominent pharmacological activity of prodiginines and related compounds, including novel synthetic PG-derivatives with lower toxicity like GX15-070 (Obatoclax). The molecular targets of prodiginines are discussed and the mechanism of action for these molecules is a current topic in biomedicine with a real therapeutica potential in the clinic.

Immunohistochemical identification of TGF-beta1 at the maxillaries in growing Sprague-Dawley rats and after muscle section.

Growth factors are currently being extensively studied in the literature to ascertain their role during maxillofacial development. Taking into account that few investigations refer to the functions of growth in the maxillaries, our aim was to identify the TGF-beta1 immunohistochemical expression pattern in the maxillaries of growing rats. A secondary aim was to identify this pattern after orofacial function inhibition by muscle section. In the palate and the mandibular symphysis and body, we found that bone was formed through an endomembranous pathway with intense TGF-beta1 staining inside chondroid cells during the maximum development stages. At the midpalatal suture and the mandibular symphysis and condyle, endochondral ossification was detected with an intense expression of TGF-beta1 inside the chondrocytes when major growth occurred. After the muscle had been sectioned, at the mandible the maturation process was accelerated, this change being transitory until muscular function was recovered. However, at the palate, the intervention caused a greater disturbance of the growing pattern, which did not recover normality.

AT514, a cyclic depsipeptide from Serratia marcescens, induces apoptosis of B-chronic lymphocytic leukemia cells: interference with the Akt/NF-kappaB survival pathway.

Clinical treatment of B-cell chronic lymphocytic leukemia (B-CLL) is limited by the progressive drug resistance and nonselectivity of most drugs towards malignant cells. Depsipeptides are present in certain bacteria and display potent antitumor activity. We have studied the effect of the novel cyclodepsipeptide AT514 (serratamolide) from Serratia marcescens on B-CLL cell viability. AT514 induced apoptosis of B-CLL cells from the 21 patients studied, as confirmed by Annexin-V binding and nuclei condensation, with an average IC50 of 13 microM. AT514 was effective in those B-CLL cases resistant to fludarabine, but had no effect on normal PBL. AT514 preferentially activated the intrinsic apoptotic pathway, as evidenced by loss of mitochondrial membrane potential, release of cytochrome c and activation of caspase-9 and -3, but not of caspase-8. Importantly, AT514 interfered with phosphatidylinositol-3 kinase and protein kinase C survival signals since it increased the apoptotic effect of LY294002 and Bisl inhibitors, and induced Akt dephosphorylation at Ser 473. AT514 also decreased NF-kappaB activity by dramatically reducing the levels of p65 in B-CLL. This was confirmed on functional assays using NF-kappaB-luc-transfected Raji cells and transgenic mice. Our results establish that AT514 induces apoptosis of primary B-CLL cells and could be useful for clinical treatment of this malignancy.

Prodigiosin induces apoptosis of B and T cells from B-cell chronic lymphocytic leukemia.

We have previously reported that prodigiosin (2-methyl-3-pentyl-6-methoxyprodigiosene) induces apoptosis in human hematopoietic cancer cell lines with no marked toxicity in nonmalignant cell lines. In this study, we demonstrate that prodigiosin induces apoptosis of B-cell chronic lymphocytic leukemia (B-CLL) cells (n=32 patients). The dose-response for the cytotoxic effect of prodigiosin was analyzed in cells from 12 patients showing an IC(50) of 116+/-25 nM. Prodigiosin induced apoptosis of B-CLL cells through caspase activation. We also analyzed the cytotoxic effect of prodigiosin in T cells from B-CLL samples and no differences were observed with respect to leukemia cells. This is the first report showing that prodigiosin induces apoptosis in human primary cancer cells.

Effects of the proapoptotic drug prodigiosin on cell cycle-related proteins in Jurkat T cells.

Prodigiosin (PG) is a red pigment produced by Serratia marcescens with immunosuppressive and apoptotic activities. In this study, we sought to examine the effect of PG on cell cycle-related proteins. The antiproliferative activity of PG was tested using human Jurkat leukaemia T cells in culture. PG-inhibited cell proliferation was determined using thymidine incorporation assay. PG-arrested cell cycle was analysed using immunoblot analysis with specific antibodies against cell cycle-related proteins and kinase assays of cdk2. Apoptosis was determined by Hoechst staining and analysis of DNA fragmentation. PG inhibited cyclin E, cdk2, p27 and p21, the induction of the cyclin A-cdk2 and cyclin E-cdk2 kinase activity, and the phosphorylation of Rb in leukaemic Jurkat cells. We confirmed that PG induces apoptosis by the characteristic DNA laddering pattern and condensed nuclei or apoptotic bodies identified by fluorescence microscopy. These results indicate that PG and other family members form a new group of molecules with a common mechanism of action and specific molecular targets, raising the possibility of their therapeutic use as antineoplastic drugs.

The role of fibroblast growth factor (FGF) and type beta transforming growth factor (TGF-beta 1-beta 2-beta 3) during rat craniofacial development.

Growth factors seem to be part of a complex cellular signalling language, in which individual growth factors are the equivalents of the letters that compose words. According to this analogy, informational content lies, not in an individual growth factor, but in the entire set of growth factors and others signals to which a cell is exposed. The ways in which growth factors exert their combinatorial effects are becoming clearer as the molecular mechanisms of growth factors actions are being investigated. A number of related extracellular signalling molecules that play widespread roles in regulating development in both invertebrates and vertebrates constitute the Fibroblast Growth Factor (FGF) and type beta Transforming Growth Factor (TGF beta). The latest research literature about the role and fate of these Growth factors and their influence in the craniofacial bone growth ad development is reviewed.

Transforming growth factor-alpha precursors in human colon carcinoma cells.

Among the proteins of the epidermal growth factor family, transforming growth factor-alpha (TGF-alpha) may be an especially reliable indicator of metastasis or prognosis in human colorectal carcinomas. Moreover, anomalous forms of TGF-alpha have been detected in several tissues of cancer origin, suggesting a role of these forms in the development of the disease. This study was designed to identify the presence of TGF-alpha precursors in different colon cancer cell lines by mean of immunocytochemistry and western blotting techniques. Pro-TGF-alpha was detected in all cell lines tested. Staining for pro-TGF-alpha was observed in cytoplasm. Monoclonal antibody to TGF-alpha detected two bands of 20 and 21 kDa. Polyclonal antibody to pro-TGF-alpha revealed five bands ranging from 15 to 24 kDa. All these proteins were also detected in nonmalignant cells expressing a transfected rat pro-TGF-alpha gene. In conclusions, transformation in these human colon carcinoma cells is not due to the presence of anomalous forms of TGF-alpha precursors.

Prodigiosin-induced apoptosis in human colon cancer cells.

Prodigiosin is a red pigment produced by various bacteria including Serratia marcescens. Colorectal cancer is one of the most frequent malignancies and one of the most frequent causes of cancer death in the Western world. Its treatment is far from satisfactory and the challenge to oncologists is to find novel chemical entities with less toxicity and greater effectiveness than those used in current chemotherapy. Here we characterize the apoptotic action of prodigiosin in colon cancer cells. DLD-1 and SW-620 human colon adenocarcinoma cells, NRK and Swiss-3T3 nonmalignant cells were assayed by the MTT assay, fragmentation pattern of DNA, Hoechst 33342 staining and study of PARP cleavage by Western blot, in order to characterize the prodigiosin-induced apoptosis. Prodigiosin was purified and its structure was confirmed. Metastatic SW-620 cells were more sensitive to prodigiosin (IC50: 275 nM) than DLD-1. We did not observe a significant decrease in the viability of NRK cells. We confirmed that prodigiosin induces apoptosis in both cancer cell lines by the characteristic DNA laddering pattern and condensed nuclei or apoptotic bodies identified by fluorescence microscopy. These results indicate that prodigiosin induces apoptosis in colon cancer cells.

Prodigiosin induces cell death and morphological changes indicative of apoptosis in gastric cancer cell line HGT-1.

Gastric cancer is one of the most frequent malignancies and its treatment is far from satisfactory. The challenge to oncologists is the characterization of novel chemical entities with greater effectiveness. Prodigiosin is a red pigment produced by various bacteria including Serratia marcescens. Here we characterize the apoptotic action of prodigiosin in human gastric carcinoma cell line (HGT-1). Cells were assayed by the MTT assay, fragmentation pattern of DNA, Hoechst 33342 staining and study of actin microfilament architecture. Treatment of these cells with prodigiosin showed a constant decrease in viability by apoptosis. Morphological analysis of prodigiosin-treated cells demonstrated that prodigiosin induces cell shrinkage, chromatin condensation, reorganization of actin microfilament architecture, and detachment of cells from the cell culture substrate. Altogether these results suggest that prodigiosin induces apoptosis in HGT-1 human gastric cancer cells and raises the possibility of its use as a new chemotherapeutic drug.

Prodigiosin from the supernatant of Serratia marcescens induces apoptosis in haematopoietic cancer cell lines.

The effects of supernatant from the bacterial strain Serratia marcescens 2170 (CS-2170) on the viability of different haematopoietic cancer cell lines (Jurkat, NSO, HL-60 and Ramos) and nonmalignant cells (NIH-3T3 and MDCK) was studied. We examined whether this cytotoxic effect was due to apoptosis, and we purified the molecule responsible for this effect and determined its chemical structure. Using an MTT assay we showed a rapid (4 h) decrease in the number of viable cells. This cytotoxic effect was due to apoptosis, according to the fragmentation pattern of DNA, Hoechst 33342 staining and FACS analysis of the phosphatidylserine externalization. This apoptosis was blocked by using the caspase inhibitor Z-VAD.fmk, indicating the involvement of caspases. Prodigiosin is a red pigment produced by various bacteria including S. marcescens. Using mutants of S. marcescens (OF, WF and 933) that do not synthesize prodigiosin, we further showed that prodigiosin is involved in this apoptosis. This evidence was corroborated by spectroscopic analysis of prodigiosin isolated from S. marcescens. These results indicate that prodigiosin, an immunosuppressor, induces apoptosis in haematopoietic cancer cells with no marked toxicity in nonmalignant cells, raising the possibility of its therapeutic use as an antineoplastic drug.

Immunolocalization of transforming growth factor-alpha and epidermal growth factor receptor in the rat gastroduodenal area.

The maintenance of gastrointestinal epithelium integrity requires a fine balance between proliferation and differentiation as well as protection against gastric acid secretion. Transforming growth factor-alpha (TGF-alpha) regulates these functions by binding to epidermal growth factor receptor (EGF-R). This study was designed to identify the localization of TGF-alpha and EGF-R in the rat gastroduodenal region. In the stomach, the surface and gastric pit cells showed staining for TGF-alpha antibodies in the cytoplasm and basolateral and apical membranes. TGF-alpha and EGF-R were observed in the supranuclear region of the cells lining the gland. In the duodenum, the enterocytes coexpressed both TGF-alpha and EGF-R in the supranuclear area. The EGF-R was also observed in the apical membrane. Brunner's glands were positive for both TGF-alpha and EGF-R antibodies. Our results demonstrate the coexpression of TGF-alpha and EGF-R in the rat gastroduodenal area, which suggests a functional role for them in the establishment and maintenance of the epithelial renewal.

Immunochemical localization of transforming growth factor-alpha-related protein in the rat kidney.

Transforming growth factor-alpha (TGF-alpha) is a 50-amino acid polypeptide synthesized as part of a larger precursor of 159 amino acids. Its expression has been reported in normal and neoplastic kidney. In this report, we characterized a renal TGF-alpha-immunoreactive protein, which we named TGF-alpha-related protein (TGF-alpha-RP). It was found to be present in the final part of the collecting tubules of the normal rat kidney. Western blotting analysis of kidney samples revealed a protein of 38 kD and pI = 5.5. In nonreducing conditions immunoreaction for this protein decreased and a TGF-alpha-immunoreactive protein of 150 kD was observed. The expression of TGF-alpha-RP seems to be highly conserved in the kidney of mammals and chickens. Therefore, TGF-alpha-RP may have an important role in the normal development and function of the kidney.

Epidermal growth factor receptor (EGF-R) localization in the apical membrane of the enterocytes of rat duodenum.

The maintenance of gastrointestinal epithelium integrity requires a fine balance between proliferation and differentiation as well as protection against gastric acid secretion. Some growth factors, such as epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha), bind to epidermal growth factor receptor (EGF-R) to exert these functions. The exact location of EGF-R within the duodenal area is controversial and still not completely known. Immunohistochemical and Western blot techniques using a monoclonal anti-EGF-R antibody were performed on the adult rat duodenum. The duodenal enterocytes expressed EGF-R in the apical membrane and in the supranuclear area along the length of the villuos. The Lieberkhüm crypts and Brunner's glands also showed a positive immunostaining. By Western blot analysis we identified in the duodenal scrape a band with an apparent molecular weight of 175 kDa. Our results suggest a functional role for the luminal EGF and/or TGF-alpha in the establishment and maintenance of the epithelial renewal, probably by stimulation of cell proliferation, differentiation and migration.

Immunochemical study of transforming growth factor-beta in the kidney of the rat and chicken.

Transforming growth factor-beta (TGF-beta) is a homodimeric polypeptide of 25 kDa, which regulates cell growth and differentiation and influences extracellular matrix metabolism. Using immunochemical techniques, we identified TGF-beta in the loops of Henle and the collecting and Bellini ducts of rat kidney and in the loops of Henle of chicken kidney. Furthermore, we detected two TGF-beta-immunoreactive proteins on kidney blots of the rat of 12.5 and 47 kDa, and three on chicken kidney blots of 12.5, 34, and 47 kDa. We suggest that the precursor forms of rat and chicken TGF-beta 2 or beta 3, chicken TGF-beta 4, and the mature form of all of them are expressed in the collecting and Bellini ducts of rat kidney and the loops of Henle of rat and chicken kidney.

Immunochemical study of a transforming growth factor-alpha-related protein in the chicken kidney.

A number of polypeptides are involved in renal growth and physiology. Both transforming growth factor-alpha (TGF-alpha) protein and mRNA are expressed in kidney cells during embryonic and adult stages, and exert mitogenic activity on kidney cells in culture. We studied the immunolocalization of a TGF-alpha-related protein at the ultra-structural level and found it in the basolateral membranes of dark cells from distal tubules of the chicken kidney. By Western blotting techniques, we identified a protein complex composed of a least two TGF-alpha immunoreactive subunits of 40 and 88 kDa, respectively. Both subunits were sensitive to elastase digestion, and released TGF-alpha immunoreactive products. In addition, TGF-alpha immunoreaction was found in primary culture of chicken kidney cells. These findings suggest that the TGF-alpha-related protein complex plays a very specific role in proliferation and/or differentiation of kidney cells.

Immunoelectron microscopic localisation of transforming growth factor alpha in rat colon.

Transforming growth factor alpha (TGF alpha) is a polypeptide, which binds to the epidermal growth factor receptor to carry out its function related to cell proliferation and differentiation. The ultrastructural localisation of TGF alpha was studied in both the proximal and the distal colon. The columnar cells, lining the surface epithelium of the proximal colon, showed a strong immunoreactivity in the polyribosomes and in the interdigitations of the lateral membrane. The columnar cells of the crypts and the goblet cells in both the proximal and the distal colon showed the immunostaining in the cis and trans cisternae of the Golgi apparatus. TGF alpha seems to be processed differently in the surface columnar cells and in the crypt columnar cells and goblet cells. Moreover, it probably has different roles in proliferation and differentiation.