Ascorbic acid induces either differentiation or apoptosis in MG-63 osteosarcoma lineage

BACKGROUND/AIM

Osteosarcoma originates from mesenchymal stem cells with impaired bone differentiation. In the present study we investigated the effect of ascorbic acid (AsA) on osteogenic differentiation and apoptosis of the MG-63 osteosarcoma cell line.

MATERIALS AND METHODS

We evaluated the expression of runt-related transcription factor-2 (RUNX2) and secreted phosphoprotein 1 (SPP1) genes by real-time Polymerase Chain Reaction (PCR) and of endogenous bone morphogenetic protein-2 (BMP2) and osteocalcin proteins by immunohistochemistry. We analyzed osteoblast maturation by phosphatase alkaline synthesis and calcium deposition, and apoptosis by (TUNEL) test and Annexin staining.

RESULTS

Our results showed that RUNX2 and SPP1 gene expression was increased in cells treated with low concentrations of AsA with respect to untreated cells. At higher concentrations, AsA induced apoptosis of osteosarcoma cells, possibly with the involvement of p21.

CONCLUSION

Our findings support the ability of AsA to induce both differentiation, by affecting the target involved in early and late phases of osteogenic maturation, and apoptosis in poorly-differentiated osteosarcoma cells.

Runx-2 gene expression is associated with age-related changes of bone mineral density in the healthy young-adult population

Bone mineral density (BMD) and peak bone mass (PBM) are important determinants of skeletal resistance. The development of bone densitometry improved the possibility of studying BMD and the influence of genetic and environmental factors on bone. Heredity factors are important for BMD, and Runx-2 is accepted as a regulator of osteoblasts and bone formation. The aim of our study was to evaluate the behavior of Runx-2 during skeletal maturity in the healthy young-adult population. We analyzed spine and hip BMD in 153 volunteers, 98 women and 55 men, using dual-energy X-ray absorptiometry. In a subgroup of these volunteers, a sample of peripheral blood was taken to perform gene expression analysis of Runx-2 both in peripheral mesenchymal stem cells (MSCs; 28 subjects) and in peripheral mononuclear cells (PBMCs; 140 subjects). In our work BMD was comparable in both genders after puberty, then became higher in men than women during the third and fourth decades. PBM was achieved in the third decade in women and in the fourth in men. More interestingly, Runx-2 gene expression highly correlated with BMD in both genders. MSCs and PBMCs showed the same gene expression profile of Runx-2. In conclusion, PBM is reached earlier in females, BMD becomes higher in males later in life, and BMD and PBM are strictly associated with Runx-2. In addition, PBMC should be considered an important source for gene expression analysis in bone diseases.

Runx2 mRNA expression in the tissue, serum, and circulating non-hematopoietic cells of patients with thyroid cancer

CONTEXT

Runx2, a master gene of osteogenic differentiation, is also expressed in nonosseous cancer cells. Microcalcifications are characteristic of papillary thyroid carcinoma and represent a useful find for diagnosis. However, the molecular expression of osteogenic differentiation transcription factor Runx2 has been poorly investigated in this tumor.

OBJECTIVE

The aim of this study was to investigate Runx2 mRNA expression in normal and pathological thyroid tissue, serum, and circulating non-hematopoietic cells.

SETTING

The study was performed in the Endocrine Unit of Internal Medicine of "Azienda Ospedaliera Universitaria Integrata of Verona" (Verona, Italy).

PATIENTS

We enrolled 12 patients with a papillary thyroid carcinoma (PTC), who had undergone total thyroidectomy performed by the same surgeon. The results, obtained by real-time RT-PCR, were compared with biological samples obtained from 13 sex- and age-matched normal donors.

RESULTS

Our data demonstrated that Runx2 mRNA is overexpressed (7.81-fold expression) in pathological thyroid tissue than in normal tissue (P < 0.05). Runx2 mRNA overexpression was also observed in serum and circulating non-hematopoietic cells of PTC patients with respect to normal donors (5.91-fold expression, P < 0.001; 3.82-fold expression, P < 0.05, respectively). We also observed that patients with microcalcifications expressed significantly higher levels of Runx2 mRNA in serum with respect to patients without microcalcifications (P < 0.05).

CONCLUSION

This study can open up new research perspectives in the diagnosis and follow-up of PTC, even if further and larger cohort studies will be necessary to validate the Runx2 expression as biomarkers in thyroid cancer.

Telomerase mRNA detection in serum of patients with prostate cancer

Telomerase functions as a reverse transcriptase enzyme in the process of telomere synthesis and telomerase activity have been detected in a large part of neoplastic tissues, whereas in normal somatic cells they were low or undetectable. The aim of this study was to investigate the telomerase mRNA detection in the serum of patients with a prostate tumor by using real-time reverse transcription PCR. The results were compared with biological samples obtained by age-matched normal donors and by patients with cardiovascular or metabolic diseases. Our data demonstrated that telomerase mRNA is detectable in the serum of patients with prostate cancer whereas it is not amplifiable in normal donors. This marker, assayed with the molecular method of quantitative PCR in serum, may be useful for diagnosing and monitoring prostate cancer patients.

The effect of risedronate on osteogenic lineage is mediated by cyclooxygenase-2 gene upregulation

Introduction

The purpose of this study was to evaluate the effects of risedronate (Ris) in the modulation of bone formation in rats with glucocorticoid (GC)-induced osteoporosis by histomorphometric, immunohistochemical and gene expression analyses.

Methods

We analyzed structure, turnover and microarchitecture, cyclooxygenase 2 (COX-2) levels and osteocyte apoptosis in 40 female rats divided as follows: 1) vehicle of methylprednisolone (vGC) + vehicle of risedronate (vRis); 2) Ris 5 μg/Kg + vGC; 3) methylprednisolone (GC) 7 mg/Kg + vRis; 4) GC 7 mg/Kg +Ris 5 μg/Kg. In addition, we evaluated cell proliferation and expression of COX-2 and bone alkaline phosphatase (b-ALP) genes in bone marrow cells and MLO-y4 osteocytes treated with Ris alone or in co-treatment with the selective COX-2 inhibitor NS-398 or with dexametasone.

Results

Ris reduced apoptosis induced by GC of osteocytes (41% vs 86%, P < 0.0001) and increased COX-2 expression with respect to controls (Immuno-Hystochemical Score (IHS): 8.75 vs 1.00, P < 0.0001). These positive effects of Ris in bone formation were confirmed by in vitro data as the viability and expression of b-ALP gene in bone marrow cells resulted increased in a dose dependent manner.

Conclusions

These findings suggest a positive effect of Ris in bone formation and support the hypothesis that the up-regulation of COX-2 could be an additional mechanism of anabolic effect of Ris.

Zoledronic acid decreases mRNA six-transmembrane epithelial antigen of prostate protein expression in prostate cancer cells

BACKGROUND

Zoledronic acid (Zol) is used successfully to inhibit bone resorption in tumor bone disease of various human cancer. Zol inhibits the mevalonate pathway and other potential targets include the inhibition of tyrosine phosphatase activity, disruption of metalloproteinase, secretion and down-regulation of the catalytic subunit of telomerase (hTERT). The six-transmembrane epithelial antigen of prostate protein (STEAP) is a new marker highly expressed at all phases of prostate cancer.

AIM

Here, we analyzed for the first time the effect of Zol on STEAP gene expression in prostate cancer cells.

MATERIAL AND METHODS

We evaluated the effects of Zol in STEAP gene expression by RT real time PCR in androgen-sensitive (LNCaP) and androgen-non-sensitive (PC3 and DU145) cell lines. To confirm the pro-apoptotic effect of Zol, we also analyzed the caspase-3 gene expression, that resulted up-regulated in cancer cell apoptosis.

RESULTS

Zol strongly decreased cell viability and lowered STEAP gene expression in a dose-dependent manner. In addition, this effect was accompanied by an increase of apoptotic index and an up-regulation of caspase-3 gene expression.

CONCLUSION

Zol may affect cancer cells also by targeting the gene expression of STEAP.

Circulating mesenchymal stem cells with abnormal osteogenic differentiation in patients with osteoporosis

OBJECTIVE

While the role of osteoclasts in bone loss has been well investigated, the involvement of osteoblast-lineage cells has not been completely elucidated. Several genes contribute to normal osteoblastic differentiation from mesenchymal stem cells (MSCs), but an understanding of their role in the pathogenesis of osteoporosis is still lacking. The present study was undertaken to evaluate a possible alteration of osteogenic gene expression as a mechanism contributing to bone loss.

METHODS

We studied the osteogenic differentiation process in MSCs obtained from the peripheral blood of 31 patients with osteoporosis and 20 normal donors. The cells were evaluated by colony-forming unit-fibroblastic assay and cultured in osteogenic medium to analyze the transcription factors runt-related transcription factor 2 (RUNX-2) and Sp7 and the bone-related genes COL1A1, SPARC, and SPP1 after 3, 8, and 15 days of differentiation. In addition, to determine possible differences between the 2 groups in terms of osteoclastic and osteoblastic activation, we quantified the osteoprotegerin (OPG) and RANKL levels in the supernatants of osteoblastic culture.

RESULTS

Circulating MSCs were increased in osteoporosis patients compared with normal donors. In contrast, gene expression analysis revealed down-regulation of RUNX2, Sp7, COL1A1, SPARC, and SPP1 in patients with osteoporosis, associated with a lower OPG:RANKL ratio.

CONCLUSION

These results suggest that an alteration of osteoblastic differentiation may contribute to the pathogenesis of osteoporosis. The noninvasive approach used in the present study could be proposed as a useful tool for studying mesenchymal involvement in bone diseases.

Gene expression analysis in osteoblastic differentiation from peripheral blood mesenchymal stem cells

MSCs are known to have an extensive proliferative potential and ability to differentiate in various cell types. Osteoblastic differentiation from mesenchymal progenitor cells is an important step of bone formation, though the pattern of gene expression during differentiation is not yet well understood. Here, to investigate the possibility to obtain a model for in vitro bone differentiation using mesenchymal stem cells (hMSCs) from human subjects non-invasively, we developed a method to obtain hMSCs-like cells from peripheral blood by a two step method that included an enrichment of mononuclear cells followed by depletion of unwanted cells. Using these cells, we analyzed the expression of transcription factor genes (runt-related transcription factor 2 (RUNX2) and osterix (SP7)) and bone related genes (osteopontin (SPP1), osteonectin (SPARC) and collagen, type I, alpha 1 (COLIA1)) during osteoblastic differentiation. Our results demonstrated that hMSCs can be obtained from peripheral blood and that they are able to generate CFU-F and to differentiate in osteoblast and adipocyte; in this study, we also identified a possible gene expression timing during osteoblastic differentiation that provided a powerful tool to study bone physiology.

STEAP mRNA detection in serum of patients with solid tumours

STEAP was identified by the strategy of suppression subtractive hybridizations in Los Angeles prostate cancer xenografts. It is expressed in prostate and other cancers, and not in most normal tissue; it can be used as a marker to evaluate biological samples from individuals suspected of having a disease associated with STEAP dysregulation, such as cancers, and may provide prognostic information useful in defining appropriate therapeutic options. The aim of this study was to test the STEAP mRNA detection in the serum of patients with different malignant tumours by using Real-Time reverse transcription PCR. The results were compared with biological samples obtained by age-matched non-malignant donors. Our data demonstrated that STEAP mRNA is detectable in serum of patients with different solid tumours whereas it is not amplifiable in non-malignant donors. This marker revealed with the molecular method of quantitative PCR in serum, may be useful to discriminate normal and cancer patients.

The effects on hTERT gene expression is an additional mechanism of amino-bisphosphonates in prostatic cancer cells

Many studies have demonstrated various effects of bisphosphonates on several cancer cells and it is accepted that their anti-tumor activity is related to interference with the mevalonate pathway. In addition, it is well known that gene expression of hTERT, the catalytic subunit of the telomerase, is elevated in prostatic cancer. In the prostate cancer cell lines we investigated the effects on hTERT gene expression of several bisphosphonates. We also evaluated whether the observed levels of expression were affected by the exposure to an analogue of the geranylgeranylpyrophosphate, the geranylgeraniol used to recover the mevalonate pathway. Our results showed that the amino-bisphosphonates down-regulate hTERT gene expression and that combined treatment with geranylgeraniol and zoledronate was able to revert only partially the effects on viability; on the contrary, hTERT gene down-regulation was not affected by the restoration of the mevalonate pathway. These results support the hypothesis that prostatic cancer cells are targeted by amino-bisphosphonates also through a different mechanism from the mevalonate pathway.

Considerations on the epidemiology of the Seveso accident

A historical analysis of the Seveso accident and a critical evaluation of the investigations carried out up to now on the subject are reported. On the basis of several considerations, a definition of the magnitude and of the true consequences of the contamination by dioxin and other not clearly identified chemicals, which affected a large area of Northern Italy on July 10 1976, is also attempted.

[Neuropsychopharmacological effects of TCDD]

It has been found that TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), in rats, endoperitoneally or orally administered at dose of 1-10 mcg/kg, provokes irritability, aggressivity and restlessness (increase of spontaneous crossings in the shuttle box). The TCDD does not modify the conditioned avoidance (C.A.) or the conflictual situation. In "vitro" the TCDD stimulates directly the striatal and hypothalamic adenylate cyclase of rat. The TCDD increases the stimulation produced by dopamine on striatal adenylate cyclase. Haloperidol (dopamine antagonist) inhibits the stimulation produced by TCDD. TCDD does not significantly modify the stimulation by hystamine on hypothalamic adenylate cyclase. Cimetidine (H2) antagonist) causes a remarkable increase of the TCDD stimulating effect.