Non-osseous Tissues Research Articles

Characterization of missense nonsynonymous single-nucleotide polymorphism of runt-related transcription factor-2 gene - An in silico approach.

Single-nucleotide polymorphism (SNP) codes for multiple amino acids, impacting protein functions and disease prognosis. Runt-related transcription factor-2 (RUNX2), a transcription factor linked to osteoblast differentiation, regulates cell proliferation in endothelium and osteoblastic cells. Understanding Runx2's role in nonosseous tissues is rapidly advancing. This study aims to identify harmful SNPs of the RUNX2 gene that may alter disease susceptibility using computational techniques. The study uses various in silico methods to identify nonsynonymous SNPs (nsSNPs) of the RUNX2 gene, which could potentially alter protein structure and functions, with further analyses by I-Mutant, ConSurf, Netsurf 3.0, GeneMANIA, and Have (y)Our Protein Explained. Six missense nsSNPs were identified as potentially harmful, disease-causing, and damaging. Four were found to be unstable, while five were conserved. All six nsSNPs had a coiled secondary structure. Five nsSNPs were found to be destabilized. The RUNX2 gene's deleterious missense nsSNPs were identified by this study, and they may be exploited in future experimental studies. These high-risk nsSNPs might be considered target molecules in therapeutic and diagnostic therapies in teeth and bone development.

Impact of the Host-Microbiome on Osteomyelitis Pathogenesis.

The microbiome is a collection of genomes from microbiota, including all microorganisms in a niche, through direct and indirect interactions with the host. Certain microorganisms can exist in areas conventionally considered to be sterile, such as the bone matrix. Osseous microbiota dysbiosis caused by host-microbiome perturbation or external infections may ultimately lead to osteomyelitis, a bone inflammatory disorder. Our review covers the current discoveries on the impact of host-microbiome on osteomyelitis and some common osseous diseases. Some studies suggest that the microbiotas from both osseous and non-osseous tissues (e.g., blood or gut) impact the pathogenicity of osteomyelitis and other osseous diseases (e.g., rheumatoid arthritis). We believe that this review will provide readers with a better understanding on the role of the microbiome to the host’s bone health.

Heterotopic Ossifications of the Forearm: A Cause of Post-Traumatic Loss of Pronation-Supination

HO is defined by the development of ectopic mature bone within nonosseous tissues. It is a well-described phenomenon that complicates forearm fractures, especially when there is an open fracture, a significant soft tissue injury, and associated neural axis or thermal injury. HO mainly forms near metal hardware and may lead to the formation of radio-ulnar synostosis. CT is superior to plain radiographs, as it identifies the ectopic bone earlier, defines its exact localization, and helps planning the surgical intervention. Radiologic features are variable; in the early stage, CT shows a low-attenuation mass with indistinct surroundings. As the ossification process progresses, zones of mineralization are visible before leading to the formation of mature cortical bone at the periphery (Figure 1 and 2: arrows). Hastings classification describes 5 classes according to how HO affects the forearm range of motion.

Post-Traumatic Heterotopic Ossification With Incidental Hyperparathyroidism

Background: Heterotopic ossification (HO) is a rare disease characterised by abnormal bone growth in non-osseous tissues, causing pain, immobility and impaired quality of life. Although still being elucidated, the underlying pathophysiology may relate to local macrophage-driven inflammation in response to trauma1. Case: A 35-year-old man involved in a motor vehicle accident (MVA) fractured over twenty bones (multiple vertebrae, ribs and complex open book pelvic fracture with shattered left acetabulum) with extensive soft tissue injuries requiring multiple surgeries. Past medical history included a renal calculus three years earlier. His serum corrected calcium on admission was elevated at 2.87mmol/L (2.10-2.60mmol/L). Peri-operative fluid over-resuscitation necessitated boluses of intravenous furosemide, and serum calcium transiently normalised before rapidly incrementing and peaking at 3.04 mmol/L. Serum parathyroid hormone post-operatively was inappropriately high at 9.4pmol/L (1.0–7.0pmol/L) and 25-hydroxyvitamin D low at 24nmol/L (50-150nmol/L). Oral vitamin D replacement was commenced and he received intravenous pamidronate (3x60mg infusions) which briefly restored normocalcaemia. Neck ultrasound and sestamibi scintigraphy demonstrated a left parathyroid adenoma, and he underwent parathyroidectomy. Histology revealed a single parathyroid adenoma. He has been normocalcaemic since surgery. Despite excellent overall recovery, mobility at the left hip remained restricted in all planes of movement. He could not perform simple activities such as putting on his shoe. Plain radiographs showed HO lateral to the left acetabulum, femoral head and neck, with bony bridging to the left ilium on computed tomography. Bone turnover markers (BTMs) measured eleven months post-MVA (and pamidronate) were elevated, with CTX of 750ng/L (100-600ng/L) and P1NP of 207ug/L (15-80ug/L). BTMs gradually reduced over time, plateauing two years post-MVA (CTX 480ng/L and P1NP 103ug/L). Surgery with pre-operative radiotherapy to remove the left hip HO is now planned. Discussion: This man had multiple recognised risk factors for HO, including male sex, trauma followed by immobilisation and pelvic fracture. His hyperparathyroidism may have predisposed HO development through excess calcium-phosphate product promoting soft tissue calcification. Bisphosphonates may also increase the risk2. Elevated BTMs have been demonstrated in the early phase of HO; further research may elucidate whether BTMs can guide timing of surgical intervention relative to the pathophysiological processes driving HO.

A review of the biomarkers and in vivo models for the diagnosis and treatment of heterotopic ossification following blast and trauma-induced injuries

Heterotopic ossification (HO) is the process of de novo bone formation in non-osseous tissues. HO can occur following trauma and burns and over 60% of military personnel with blast-associated amputations develop HO. This rate is far higher than in other trauma-induced HO development. This suggests that the blast effect itself is a major contributing factor, but the pathway triggering HO following blast injury specifically is not yet fully identified. Also, because of the difficulty of studying the disease using clinical data, the only sources remain the relevant in vivo models. The aim of this paper is first to review the key biomarkers and signalling pathways identified in trauma and blast induced HO in order to summarize the molecular mechanisms underlying HO development, and second to review the blast injury in vivo models developed. The literature derived from trauma-induced HO suggests that inflammatory cytokines play a key role directing different progenitor cells to transform into an osteogenic class contributing to the development of the disease. This highlights the importance of identifying the downstream biomarkers under specific signalling pathways which might trigger similar stimuli in blast to those of trauma induced formation of ectopic bone in the tissues surrounding the site of the injury. The lack of information in the literature regarding the exact biomarkers leading to blast associated HO is hampering the design of specific therapeutics. The majority of existing blast injury in vivo models do not fully replicate the combat scenario in terms of blast, fracture and amputation; these three usually happen in one insult. Hence, this paper highlights the need to replicate the full effect of the blast in preclinical models to better understand the mechanism of blast induced HO development and to enable the design of a specific therapeutic to supress the formation of ectopic bone.

Acquired heterotopic ossification in hips and knees following encephalitis: case report and literature review

BackgroundHeterotopic ossification (HO) is a rare and potentially detrimental complication of soft-tissue trauma, amputations, central nervous system injury (traumatic brain injuries, spinal cord lesions, tumors, encephalitis), vasculopathies, arthroplasties and burn injury, characterized by lamellar bone growth in non-osseous tissues such as the muscle and the joint capsule. Heterotopic ossification associated with encephalitis is rare and the occurrence of excessive, symptomatic heterotopic ossification around bilateral hips and bilateral knees is rarely described in the literature.Case presentationWe present a 47-year-old man with heterotopic ossification in the bilateral hips and bilateral knees that prevented him from walking after being attacked by encephalitis as the case study. He developed severe pain and significantly impaired range of motion of bilateral hips and bilateral knees. Research so far revealed that the management of heterotopic ossification is controversial. After requiring revision surgery resection of heterotopic ossification, reconstruction of the medial collateral ligament and adjunctive pharmacotherapy of 200 mg Celecoxib for 8 weeks after operation, he regained mobility of his joints. On review of X-ray, there was no recurrence of HO and no loosening of rivets which were used in the reconstruction of medial collateral ligament.ConclusionHeterotopic ossification in the bilateral hip joints and bilateral knee joints associated with encephalitis have never been reported previously. Daily functions of heterotopic ossification patients can be hampered by pain, inflammation, reduced mobility, the loss of normal posture and other complications. Further studies of presumptive root causes, the early diagnosis, preventability and optimal therapeutic measures for heterotopic ossification following encephalitis are required. Different patient should be managed with different appropriated protocol based on the risk of individual patient and the institutional experience.

Toxic Effect of Fluoride on Biochemical Parameters and Collagen Metabolism in Osseous and Non-Osseous Tissues of Rats

The present study was carried out to assess the effects of fluoride exposure on collagen metabolism by evaluating the level of hydroxyproline in both osseous and non-osseous tissues along with serum biochemical parameters in rats. Eight week old female rats were divided into two equal groups of six rats each. Rats of group I served as control and received only tap water while those of group II received 200 mg NaF/L in their drinking water ad libitum for a period of 90 days. Significant increase in the level of serum glucose, urea, creatinine, phosphorus and decrease in concentration of calcium and total protein were observed in fluoride exposed rats as compared to respective healthy control rats on different observation periods. Activities of serum aspartate aminotransferase, alanine transaminase and alkaline phosphatase were significantly higher in fluoride exposed rats as compared with respective control rats. On day 90, the increase in hydroxyproline concentration in urine of fluoride exposed rats was 54.75 % over control rats. Hydroxyproline concentration in the muscle (452.10 ± 22.54 µg/gm), liver (238.43 ± 26.16 µg/gm), kidney (1,350.91 ± 27.50 µg/gm), femur (20.21 ± 0.59 mg/gm) and tibia (19.76 ± 0.51 mg/gm) of fluoride exposed rats was significantly reduced as compared to healthy control rats (817.51 ± 32.06 μg/gm, 311.63 ± 10.07 μg/gm, 1,486.33 ± 22.68 μg/gm, 24.18 ± 0.56 mg/gm and 25.44 ± 0.41 mg/gm, respectively) at the end of the 90-day experiment.

Fulminant Heterotopic Ossification After Combat‐related Amputation: A Report of 2 Cases

Heterotopic ossification (HO) is the process of abnormal formation of lamellar bone in nonosseous tissues. In this case presentation, we describe patients with aggressive HO, which becomes symptomatic shortly after injury for which we have suggested the term "fulminant heterotopic ossification." These atypical presentations of fulminant HO highlight the necessity for continued research directed at improved understanding of HO and may suggest a role for early partial surgical excision as a definitive management strategy.

Redefining the activity of a bone-specific transcription factor: Novel insights for understanding bone formation

Redefining the activity of a bone-specific transcription factor: Novel insights for understanding bone formation

RUNX2 in mammary gland development and breast cancer

Runx2 is best known as an essential factor in osteoblast differentiation and bone development but, like many other transcription factors involved in development, is known to operate over a much wider tissue range. Our understanding of these other aspects of Runx2 function is still at a relatively early stage and the importance of its role in cell fate decisions and lineage maintenance in non-osseous tissues is only beginning to emerge. One such tissue is the mammary gland, where Runx2 is known to be expressed and participate in the regulation of mammary specific genes. Furthermore, differential and temporal expression of this gene is observed during mammary epithelial differentiation in vivo, strongly indicative of an important functional role. Although the precise nature of that role remains elusive, preliminary evidence hints at possible involvement in the regulation of mammary stem and/or progenitor cells. As with many genes important in regulating cell fate, RUNX2 has also been linked to metastatic cancer where in some established breast cell lines, retention of expression is associated with a more invasive phenotype. More recently, expression analysis has been extended to primary breast cancers where high levels of RUNX2 align with a specific subtype of the disease. That RUNX2 expression correlates with the so called "Triple Negative" subtype is particularly interesting given the known cross talk between Runx2 and estrogen receptor signaling pathways. This review summaries our current understanding of Runx2 in mammary gland development and cancer, and postulates a role that may link both these processes.

Synergism between Wnt3a and Heparin Enhances Osteogenesis via a Phosphoinositide 3-Kinase/Akt/RUNX2 Pathway

A new strategy has emerged to improve healing of bone defects using exogenous glycosaminoglycans by increasing the effectiveness of bone-anabolic growth factors. Wnt ligands play an important role in bone formation. However, their functional interactions with heparan sulfate/heparin have only been investigated in non-osseous tissues. Our study now shows that the osteogenic activity of Wnt3a is cooperatively stimulated through physical interactions with exogenous heparin. N-Sulfation and to a lesser extent O-sulfation of heparin contribute to the physical binding and optimal co-stimulation of Wnt3a. Wnt3a-heparin signaling synergistically increases osteoblast differentiation with minimal effects on cell proliferation. Thus, heparin selectively reduces the effective dose of Wnt3a needed to elicit osteogenic, but not mitogenic responses. Mechanistically, Wnt3a-heparin signaling strongly activates the phosphoinositide 3-kinase/Akt pathway and requires the bone-related transcription factor RUNX2 to stimulate alkaline phosphatase activity, which parallels canonical beta-catenin signaling. Collectively, our findings establish the osteo-inductive potential of a heparin-mediated Wnt3a-phosphoinositide 3-kinase/Akt-RUNX2 signaling network and suggest that heparan sulfate supplementation may selectively reduce the therapeutic doses of peptide factors required to promote bone formation.

Hypercalcaemia and mineralisation of non-osseous tissues in horses due to vitamin-D toxicity.

Summary Five cases of hypercalcaemia due to vitamin-D toxicity are described in horses. A brief survey of the literature on vitamin-D toxicity is given. Of the five horses, two were autopsied and had extensive mineralisation of the nonosseous tissues. Two other horses were treated and treatment was successful in one animal but not in the other. The fifth horse was destroyed by the owner. Zusammenfassung Hypercalzemie und Mineralisation der nicht-knochernen Gewebe bei Pferden infolge Vitamin-D-Vergiftung Funf Falle von Hyperkalzamie und Vitamin-D-Vergiftung bei Pferden sowie eine kurze Literaturubersicht uber Vitamin-D-Vergiftung werden beschrieben. Von den funf Pferden wurden zwei seziert und zeigten eine ausgedehnte Mineralisation der nichtknochernen Gewebe. Zwei Pferde wurden behandelt, das eine mit, das andere ohne Erfolg. Das funfte Pferd wurde durch den Besitzer getotet. Resume Hypercalcemie et mineralisation de tissus non osseux chez des chevaux a la suite d'une intoxication due a la vitamine D On decrit cinq cas d'hypercalcemie et d'intoxication a la vitamine D chez des chevaux et one donne un bref apercu de la litterature concernant l'empoisonnement a la vitamine D. Deux des cinq chevaux ont ete autopsies et ont montre une mineralisation etendue des tissus non osseux. On a traite deux chevaux, l'un avec succes, l'autre sans resultat. Le proprietaire a abattu le cinquieme cheval. Resumen Hipercalcemia y mineralizacion del tejido no oseo en caballos a consecuencia de intoxicacion por vitamina D Se describen cinco casos de hipercalcemia e intoxicacion vitaminica D en caballos, facilitandose tambien una revision bibliografica breve sobre la toxicidad de la vitamina D. De los cinco caballos se autopsiaron dos, los cuales mostraban una mineralizacion extensiva de los tejidos no oseos. Dos caballos fueron tratados, uno con, el otro sin exito. El quinto caballo fue matado por su propietario.

Effect of Osteoporosis on Morphology and Mobility of the Lumbar Spine

Cross-sectional study. The purpose of this study was to examine disc morphology and spinal mobility in subjects with varying degrees of osteoporosis. There was limited information on the effect of osteoporosis on lumbar morphology and spinal mobility. It was also unclear how osteoporosis affects the nonosseous tissues such as the intervertebral disc. Ninety elderly subjects with varying bone mineral densities (22 normal, 28 osteopenia, 40 osteoporosis) were recruited from an osteoporosis clinic. Lateral radiographs and magnetic resonance images of their lumbar spines were obtained. An electromagnetic tracking device was employed to measure the ranges of motion of the whole lumbar spine. Although the thoracic spine had been shown to have decreased anterior vertebral body height in subjects with osteoporosis, this study revealed that the anterior height was increased in the lumbar region. Osteoporosis was associated with expansion of the middle of the disc with corresponding collapse of vertebral bodies, but osteoporosis was found not to be related to either disc preservation or degeneration. No significant change in spinal mobility was observed in patients with osteoporosis. Osteoporosis does not only affect the bone but also the nonosseous tissues. It was found to be associated with expansion of the intervertebral disc, which was likely to be secondary to changes in the vertebral endplate.

Heterotopic Ossification in the Maxillary Sinus

We report a case of heterotopic ossification of the maxillary sinus in a 30-year-old female who was treated surgically in our department. Heterotopic ossification (HO) refers to the formation of mature lamellar bone in nonosseous tissues. We present the radiographic and computed tomographic appearance, and discuss the surgical treatment, histopathologic results, and differential diagnosis. To the best of our knowledge, no other case of HO of the maxillary sinus has been reported yet.

Heterotopic ossification: Review of histologic findings and tissue distribution in a 10-year experience

Heterotopic ossification (HO) within tissues involved by a pathologic process is a well-recognized phenomenon. It is most frequently observed in atherosclerotic plaques, in soft tissue around joints, and in the central nervous system. Less frequently, carcinomas and some benign neoplasms will undergo heterotopic ossification. We performed a retrospective review of our experience with HO over a 10-year period to determine the frequency and tissue site distribution of heterotopic ossification. A computerized review of surgical pathology records of approximately 126,000 reports revealed 85 cases in which heterotopic ossification, ectopic bone or metaplastic bone was specifically mentioned in the surgical pathology diagnosis. Twenty-two cases were neoplasms of non-osseous tissues, and 63 cases were non-neoplastic lesions. Immunohistochemical staining for bone morphogenic proteins (BMP) 1, 4, and 6 was performed. Fourteen cases showed staining for BMP-1, 22 cases showed staining for BMP-4, and five cases showed weak staining for BMP-6. HO is a relatively infrequent finding and is more commonly seen in degenerative and reparative conditions than in neoplasms.

Tumoral calcinosis: New insights for the rheumatologist into a familial crystal deposition disease

A growing body of evidence points to extraosseous calcification (calcification occurring in nonosseous tissues) as a major cause of morbidity and mortality in humans. The term familial tumoral calcinosis encompasses a number of rare recessive diseases, often associated with increased reabsorption of phosphate through the renal proximal tubule, which manifests with periarticular or acral calcium deposition. Recently, the molecular pathogenesis of this group of disorders has been elucidated, leading to the identification of several proteins playing pivotal roles in the regulation of extraosseous calcification. This report reviews these advances as well as the potential implications of these discoveries for the management of acquired conditions associated with abnormal calcification.

Effects of continuous activation of vitamin D and Wnt response pathways on osteoblastic proliferation and differentiation

The Wnt pathway regulates cell proliferation and differentiation in development and disease, with a number of recent reports linking Wnt to control of osteoblast differentiation and bone mass. There is also accumulating evidence for interaction between the Wnt and nuclear receptor (NR)-mediated control pathways in non-osseous tissues. Calcitriol (1,25D 3), which is the active hormonal ligand for the vitamin D receptor (VDR), a member of the NR superfamily, induces osteoblastic cell cycle arrest and expression of genes involved in matrix mineralization in vitro, with over-expression of VDR in mature osteoblasts increasing bone mass in mice. To determine whether the vitamin D and Wnt control pathways interact in osteoblastic regulation, we investigated the treatment effects of 1,25D 3 and/or lithium chloride (LiCl), which mimics canonical Wnt pathway activation, on osteoblast proliferation and differentiation. Treatments were initiated at various stages in differentiating cultures of the MC3T3-E1 osteoprogenitor cell line. Treatment of subconfluent cultures (day 1) with either agent transiently increased cell proliferation but decreased viable cell number, with additive inhibition after combined treatment. Interestingly, although early response patterns of alkaline phosphatase activity to 1,25D 3 and LiCl were opposite, mineralized nodule formation was virtually abolished by either treatment initiated at day 1 and remained very low after initiating treatments at matrix-formation stage (day 6). By contrast, mineralized nodule formation was substantial but reduced if 1,25D 3 and/or LiCl treatment was initiated at mineralization onset (day 13). Osteocalcin production was reduced by all treatments at all time points. Thus, vitamin D and/or canonical Wnt pathway activation markedly reduced mineralization, with additive inhibitory effects on viable cell number. The strength of the response was dependent on the stage of differentiation at treatment initiation. Importantly, the inhibitory effect of LiCl in this committed osteoblastic cell line contrasts with the stimulatory effects of genetic Wnt pathway activation in human and mouse bone tissue. This is consistent with the anabolic Wnt response occurring at a stage prior to the mature osteoprogenitor in the intact skeleton and suggests that prolonged or repeated activation of the canonical Wnt response in committed cells may have an inhibitory effect on osteoblast differentiation and function.

Bone Formation in Non-Osseous Tissues of Biphasic HA/β-TCP Bioceramics Sintered by Different Ways

In order to improve the bioactivity of calcium phosphate bioceramics, biphasic HA/β-TCP (BCP) bioceramics were prepared by the microwave sintering and the microwave plasma sintering. Bone-like apatite formation of the resulting samples was investigated in simulated body fluid (SBF). The samples were also implanted in dorsal muscles of healthy dogs for 1.5and 3 months. All samples after taking out were examined by histological observation. Bone formation in different sintering ways and temperatures was investigated in details. Better osteoinductivity was found in samples sintered by the microwave and microwave plasma instead of the conventional furnace, as well as by lower temperature (1050 oC) instead of higher temperature (1150 oC). It accounts for that the increase in degradability of materials sintered by microwave and microwave plasma or lower temperature leads to the better of bone-like apatite formation and bone formation due to fine grains and lower crystallinity.

A comparison of bone formation in biphasic calcium phosphate (BCP) and hydroxyapatite (HA) implanted in muscle and bone of dogs at different time periods

Physicochemical modification could implement synthetic materials into osteoinductive materials, which induce bone formation in nonosseous tissues. We hereby studied the relevance between the osteogenic capacities of osteoinductive materials in nonosseous tissues and in osseous sites. Biphasic calcium phosphate ceramic (BCP) and hydroxyapatite ceramic (HA) were implanted in femoral muscles and femoral cortical bone of dogs for 7, 14, 21, 30, 45, 60, 90, 180, and 360 days, respectively. Two dogs were used in each time point. In each dog, four cylinders (phi5x6 mm) per material were implanted in femoral muscles and 2 cylinders (phi5x6 mm) per material in femoral cortical bone. The harvested samples were processed for both histological and histomorphometric analyses. Bone was observed in BCP implanted in femoral muscles since day 30, while in HA since day 45. Quantitatively, more bone was formed in BCP than in HA at each time point after day 30 (p<0.05). The earlier and more bone formed in BCP than in HA suggests BCP a higher osteoinductive potential than HA in muscle. In femoral cortical bone defects, a bridge of bone in the defect with BCP was observed at day 21, while with HA at day 30. At days 14, 21, and 30, significantly more bone was formed in BCP than in HA (p<0.05). The results herein show that osteogenic capacities of osteoinductive materials in nonosseous tissues and osseous sites are correlated: the higher the osteoinductive potential of the material, the faster the bone repair.

Splicing Variants of Osteocalcin-mRNA in Haematological Malignancies.

Osteocalcin (OCN) is defined as a marker for osteoblasts but incompletely spliced variants as characterised by intron retention may also occur in non-osseous tissues including tumour cells. Bone marrow of haematological diseases was shown to harbour a stem cell candidate common to MSC (mesenchymal stem cells) and HSC (haematopoietic stem cells), which expressed OCN. In this study, we analysed cells from bone marrow samples obtained from 4 patients with AMLs, one patient with CML at blast crisis, one CML patient in chronic phase and 7 patients with myeloproliferative disease (MPD), as well as stem cells from peripheral blood and bone marrow obtained from healthy donors. In attempt to find out whether the presence of such stem cells is associated with disease status, sequential bone marrow samples from a patient with acute myeloid leukaemia (AML/M2Eo) were analysed at 6 time points including diagnosis, remission (= months 4, 5 and 17 after diagnosis) and relapse (months 29 and 41 after diagnosis). RT-PCR analyses were performed to characterise spliced and unspliced mRNA variants of OCN and to quantify mRNA levels of c-KIT and the Runt-transcription factors AML1 and AML3, known to regulate gene expression of c-KIT and OCN. Results of immunostaining for c-KIT and OCN showed that positive signals for OCN were detected only in those bone marrow smears, which expressed spliced OCN-mRNA, i.e. the bone marrow samples from the AML/M2Eo-patient in the relapse phase, the 2 samples of AML/M2, the sample of CML at blast crisis. The same samples and all others, which were positive for the unspliced OCN-mRNA, were also positive for c-KIT (both at the protein and at the mRNA level) as well as for AML1- and AML3-mRNA, however, at lower quantities. Our data indicate an association of OCNs expression with haematological malignancies at disease stages with activated bone marrow stem cells.