Chondroblastic Differentiation Research Articles

Rare presentation of a phyllodes tumour with sarcomatous stromal overgrowth and focal heterologous chondroblastic differentiation: a case report

Rare presentation of a phyllodes tumour with sarcomatous stromal overgrowth and focal heterologous chondroblastic differentiation: a case report

Expression of SATB2, RUNX2, and SOX9 and possible osteoblastic and chondroblastic differentiation in chondroblastoma.

Chondroblastoma (CB) is histologically characterized by oval to polygonal-shaped mononuclear neoplastic cells, multinucleated osteoclastic giant cells, and eosinophilic matrix with occasional calcification. Genetically, the majority of CBs harbor H3F3B p.K36M mutation. Despite the historical nomenclature, it has been reported that the matrix of CB is similar to osteoid rather than true cartilage; however, it remains unclear whether neoplastic cells in CB have the potential for osteoblastic differentiation. To clarify this issue, we immunohistochemically examined the expression of osteogenic and chondrogenic markers (SATB2, RUNX2, p63, and SOX9) as well as H3K36M mutant protein in 33 cases of CB. All 33 cases of CB were positive for H3K36M, while SATB2, RUNX2, p63, and SOX9 were expressed in 30/33 (91%), 33/33 (100%), 29/33 (88%), and 31/32 (97%) CB cases, respectively. Our immunohistochemical results suggest that neoplastic cells in CB frequently express both osteogenic and chondrogenic markers and may have an intermediate feature of osteoblastic and chondroblastic nature.

CHONDROBLASTIC OSTEOSARCOMA IN THE MANDIBLE: A CASE REPORT

Osteosarcoma of the jaws is uncommon and mainly occurs as a fast-growing painful swelling in the posterior mandible. The knowledge of clinicopathologic aspects of osteosarcoma is essential for early diagnosis and adequate treatment. The aim of this study is to report a clinical case of chondroblastic osteosarcoma in the posterior left mandible in a 53-year-old male patient with complaint of paresthesia in the left lower lip and a fast-growing swelling in the gingival mucosa. Radiographically, the classical sunray appearance can be observed. Microscopically, we identified atypical polygonal cells with large and hyperchromatic nuclei associated with osteoid material and chondroblastic differentiation. The diagnosis of chondroblastic osteosarcoma was made. The patient was referred to an oncologist for treatment with surgery and chemotherapy.

CNS metastasis secondary to malignant-mixed Müllerian tumor: case report and review of therapeutics

This paper reviews CNS involvement secondary to malignant-mixed Müllerian tumor or uterine carcinosarcoma, a rare aggressive biphasic Müllerian tumor. We report a cerebellar metastasis with epithelial and mesenchymal components, demonstrating heterologous rhabdomyogenic and chondroblastic differentiation. The patient had undergone total abdominal hysterectomy and bilateral salpingo-oophorectomy for palliation of symptomatic chemotherapy-resistant node-positive disease. CNS involvement is rare, and prognostically poor, and suggestively poorer in predominantly sarcomatous metastases. Multimodal therapy is indicated; in solitary metastases, surgical resection or stereotactic radiosurgery is included, followed by whole brain radiotherapy. In unresectable brain metastases, stereotactic radiosurgery and whole brain radiotherapy warrant consideration in up to 2-3 metastases. In multiple metastases, palliative steroid therapy or cranial irradiation may be considered. Combination or platinum-based chemotherapy (i.e., ifosfamide-paclitaxel or carboplatin-paclitaxel) is indicated in all stages, with a role in both disease cure and control-directed management. Targeted therapeutics have thus far not demonstrated significant clinical efficacy.

Chondroblastic osteosarcoma in right thigh of a bitch

Summary A 3 year-old German shepherd bitch was admitted with a severe enlargement of the right thigh. Uncapsulated large mass, 7 cm × 10 cm thickness was found at necropsy surrounding the contour of the thigh muscles along its whole length. Microscopically, the tumor composed of neoplastic cells infiltrating the stroma, with cellular pleomorphism, hyperchromatism, high atypical mitotic figures (2–4 per high power field) and focal areas of osteoid formation. Chondroblastic differentiation was also present where chondroblastic cells consisted of moderately pleomorphic, irregularly arranged polygonal cells with vacuolated cytoplasm, vesiculated nuclei and large nucleoli. Based on these pathological findings, this tumor was diagnosed as chondroblastic osteosarcoma.

English

We report a rare case of osteogenic sarcoma of zygomatic arch presenting in a 20 year old male patient and a review of world literature on incidence and imaging. Craniofacial osteosarcomas are rare primary malignant bone tumours. This paper presents a case of osteogenic sarcoma of left zygomatic arch, showing erosion of middle aspect of left zygomatic arch with sun-ray spicules noted perpendicular to the cortex with multiple conglomerated new bone formation and associated soft tissue swelling extending inferiorly into the left infratemporal fossa and later diagnosed as osteosarcoma with chondroblastic differentiation. In head and neck, the most common sites of origin are the mandible, maxilla, nasal septum, hard palate and skull vault. More than 50% of craniofascial osteosarcomas arise in the jaw. Mandible is more commonly affected than maxilla. Zygomatic arch is a very rare site of involvement. Osteosarcoma should be considered in the differential diagnosis of lytic lesions with associated soft tissue swelling of zygomatic arch. Only four cases of primary osteogenic sarcoma of zygomatic arch have been reported in the English- language

26-Year-Old Man with a Cerebellar Mass

Medulloblastoma accounts for only 1% of all adult CNS tumors. Recently, we have encountered a case of medulloblastoma in a 26 year old man with divergent differentiation including myoblastic, glial, osteoblastic and chondroblastic differentiation. Here we present the results of immunohistochemical staining using several specific antibodies with a discussion and a review of literature.

Microtopography of titanium suppresses osteoblastic differentiation but enhances chondroblastic differentiation of rat femoral periosteum‐derived cells

Despite the clinical fact that endosseous titanium implants directly contacts periosteum, the behavior and response of the periosteum-derived cells to surface topography of titanium have rarely been studied. This study examines the effect of titanium surface microtopography on osteoblastic and possibly-modulated chondroblastic phenotypes of femoral periosteum-derived cells. Rat femoral periosteum-derived cells were cultured on either relatively smooth, machined titanium surface or acid-etched, micro-roughened titanium surface. The osteoblastic gene expressions, including collagen I, osteopontin and osteocalcin, were downregulated on the acid-etched surface, compared with the machined surface. Alkaline phosphatase and mineralization activities on the acid-etched surface were approximately 20% of those on the machined surface. Instead, chondroblastic specific genes, including collagen II and IX, and sox 9, were exclusively expressed or highly upregulated on the acid-etched surface. Alcian blue stain revealed an extensive deposition of glycosaminoglycan on the acid-etched surface. The cultured matrix on the acid-etched surface lacked the submicron globular structures that were extensively seen on the machined surface, and contained a remarkably increased percentage of sulfur relative to calcium compared with the culture on the machined surface. These results indicated that titanium microroughness suppresses the osteoblastic phenotype and induces or at least considerably enhances the chondroblastic phenotype of the periosteal cells, suggesting the unique role of titanium surface topography in regulating the periosteal cell differentiation. The suppressive effect of titanium microroughness on the periosteal cells toward the osteoblastic linage was contrasted to the known promotive effect on the bone marrow-derived osteoblasts.

The influence of masseter activity on rat mandibular growth

Many studies have shown that mandibular and condylar growth is affected by compressive forces on mandibular bone and the condyle. It has been reported that chondroblastic differentiation and proliferation in chondrocytes play important roles in condylar growth. However, the influence of reduced compressive force on chondroblastic proliferation and mandibular bone formation is not fully understood. Thirty-six 3-week-old male Wistar rats were used in this study. In the experimental group, the masseter muscles were bilaterally resected to evaluate the influence of masticatory force on mandibular and condylar bone morphology. Six weeks after the operation, while the rats were in the pubertal growth stage, lateral X-rays were taken to analyze the skeletal pattern of the mandible. The form of the condyle and the thickness of the chondroblastic layers were evaluated by toluidine blue staining. Chondroblastic proliferation was identified by insulin-like growth factor-1 receptor (IGF-1r) immunostaining and bone resorption of the condyle was assessed by measuring tartrate-resistant acid phosphatase (TRAP) activity. Lateral X-rays of the mandible showed that rats in the experimental group tended to have large mandibular plane angles. The chondroblastic layer in the condyles of the experimental group rats was thinner than in the control group. The expression of IGF-1r immunopositive cells in the experimental group was significantly lower than in the control chondrocytes, and the number of TRAP-positive cells was significantly higher in the condylar bone of the experimental group. We conclude that masseter muscle activity is closely related to mandibular morphology during growth.

JNK/ERK–AP-1/Runx2 induction “paves the way” to cartilage load-ignited chondroblastic differentiation

Chondro-osteogenesis and subsequently skeletal morphology are greatly influenced by mechanical loads. The exact mechanism(s) by which mechanical stimuli are transduced in chondrocytes remains obscure and appears to be equally complex with similar signal transducing systems. Here we investigated whether and to what extent the MAPK (JNK/ERK)-AP-1/Runx2 signaling pathways are engaged in this phenomenon, and assessed their involvement in the functional biology of articular cartilage. For this purpose, 14-day-old female Wistar rats were divided into 2 groups: the first group was fed hard diet (simulating physiologic temporomandibular joint (TMJ) loading), while the second group was fed soft diet (reduced TMJ loading). On day 21 (experiment initiation day - weaning day), biopsies from condyles of both groups were obtained after 6, 12 and 48 h of functional TMJ loading. Immunohistochemical methodology was employed to evaluate the expression levels of pc-Jun, c-Fos, JNK2, p-JNK, p-ERK and Runx2 due to alteration in functional load. Our data demsonstrate that the protein levels of all the aforementioned molecules were markedly increased in animals fed with the hard diet, throughout the experimental procedure. These results indicate that functional cartilage loading induces the AP-1 and Runx2 transcription factors through the JNK and ERK MAPK cascades. In as much as the above signaling mediators/effectors are considered to be crucial in the differentiation/maturation process of cartilage tissue, we pose that functional mechanical loading of condylar cartilage serves to "fine tune" chondroblastic differentiation/maturation.

Induction of the Sry-related factor SOX6 contributes to bone morphogenetic protein-2-induced chondroblastic differentiation of C3H10T1/2 cells.

Chondrogenesis leads to the formation of mature cartilage and generates initial skeletal elements that serve as templates for endochondral bone formation. Bone morphogenetic proteins (BMPs) are involved in several developmental and organogenetic processes and have been identified as key regulators in chondrogenesis. In the present study we sought to determine the transcriptional mechanisms contributing to the induction of chondrogenic markers by BMP-2. Time-course studies with BMP-2-stimulated C3H10T1/2 cells showed a dose-dependent appearance of Alcian-blue-positive material and up-regulated expression of type-II collagen mRNA. This last effect required new protein synthesis because addition of cycloheximide completely blocked the induction of type-II collagen mRNA. A region encompassing the chondrocyte-specific enhancer, localized in intron I of type-II collagen alpha1 chain (Col2a1) gene, is sufficient to confer BMP-2-dependent transcriptional induction of type-II collagen gene expression. Analysis of the expression levels of chondrogenic Sry-type high-mobility group (HMG) box proteins (SOX) transcription factors demonstrated a time-dependent induction of Sox6 expression by BMP-2 that correlated with the appearance of BMP-2- induced protein complexes bound to the chondrocyte-specific enhancer. Preincubation of nuclear extracts with SOX6 and SOX9 antibodies markedly reduced the intensity of these bands. Forced expression of SOX6 mimicked the BMP-2 effect, whereas coexpression of SOX9 promoted a synergistic interaction between both factors in transcription from the chondrocyte-specific enhancer. Moreover, overexpression of a SOX6 mutated form, devoid of its high-mobility group domain, was sufficient to prevent transcriptional induction of the chondrocyte-specific enhancer by BMP-2. Taken together, these results indicate that SOX6 is an important downstream mediator of BMP-2 signaling in chondrogenesis.

Towards a new understanding and classification of chondrogenic neoplasias of the skeleton--biochemistry and cell biology of chondrosarcoma and its variants.

Despite substantial knowledge on the clinicopathology of chondrogenic skeletal neoplasms, only limited insights into the biology of the different tumor variants are available. There are virtually no established molecular markers for identification and classification of these neoplasms. In this paper, we present a systematic review of the biochemistry and cell biology of chondrogenic neoplasms of the bone focussing on our own recent investigations. The hallmark of all differentiated chondrogenic tumors is the presence of neoplastic chondrocytic cells responsible for the formation of the characteristic cartilaginous tumor matrix. These cells can show the full differentiation potential of physiologic chondrocytes depending on the tumor entity investigated. The high phenotypic diversity of physiologic chondrocytes explains the previously poorly understood, striking heterogeneity of the neoplastic cells and their surrounding extracellular matrix not only between different but also within chondrogenic tumors. In our studies, tumor classifications, so far based only on histomorphological criteria, were either confirmed or corrected: mesenchymal chondrosarcomas represent the prototypic neoplasm of pre-chondrogenic undifferentiated cells undergoing multifocal chondrocytic differentiation. Enchondromas, osteochondromas, and conventional chondrosarcomas are neoplasms of multi-phenotypically differentiated chondrocytes. Clear cell chondrosarcomas appear to be neoplasms of hypertrophic chondrocytic cells. A peculiar biology is displayed by dedifferentiated chondrosarcomas, which at least in most cases show neither "anaplasia" nor "dedifferentiation", but most likely "transdifferentiation" of part of the neoplastic cells to a cellular phenotype of a different mesenchymal differentiation lineage. Chondroblastomas do not show any chondroblastic differentiation at all. Our studies delineate molecular markers of chondrogenic neoplasms of the skeleton, which have the potential to be the basis of a new biology-orientated classification of skeletal neoplasms. The expression analysis of extracellular matrix genes, in particular of the collagen types, might be able to play herein a leading role in classification and diagnosis, similar to the cytokeratin subtypes or the CDs (cluster of differentiation) for the classification and diagnosis of neoplasms of the epithelia and the lymphatics.

Early Shifts in Gene Expression during Chondroinduction of Human Dermal Fibroblasts

Treatment options for damaged articular cartilage are limited because of that tissue's poor capacity for repair. Possible approaches to this problem are to stimulate cartilage matrix production in situ or to engineer replacement tissue. Both of these approaches would benefit from a detailed understanding of the molecular mechanisms of chondroblast differentiation. In previous studies, we described a novel in vitro model of postnatal chondroblast differentiation. That model of induced chondrogenesis was used to test the hypothesis that cellular interactions with demineralized bone powder (DBP) would induce specific, early shifts in gene expression, prior to the expression of cartilage matrix genes. Differentially expressed genes were identified by representational difference analysis of human dermal fibroblasts cultured for 3 days with DBP in three-dimensional collagen sponges. Genes that were upregulated by DBP comprised several functional classes, including cytoskeletal elements, protein synthesis and trafficking, and transcriptional regulation. Kinetic analysis of gene expression over 21 days showed that vigilin was transiently upregulated on day 3. In contrast, expression of cartilage signature genes continued to increase. These results are an important step toward complete characterization of the mechanisms by which DBP induces chondroblastic differentiation in postnatal cells.

Induced chondroblastic differentiation of human fibroblasts by three-dimensional culture with demineralized bone matrix

Demineralized bone powder (DBP) implanted in vivo induces endochondral bone formation (osteoinduction). Connective tissue cells migrate to the powders and they begin to produce cartilage matrix. Subsequently, vascularization is stimulated and the cartilage is replaced by bone and marrow. Demineralized bone implants have been used clinically for a variety of osseous reconstructive applications. We designed a novel three-dimensional (3-D) device to examine the mechanism of chondroinduction in vitro. Normal human dermal fibroblasts (hDFs) were cultured in 3-D collagen sponges with and without DBP. The cells migrated through the collagen lattice and they attached to and spread onto particles of demineralized bone. Cells vicinal to the DBP produced cartilage matrix proteoglycans. Induced cells expressed cartilage-specific gene products, type II collagen and aggrecan. Control hDFs did not produce cartilage matrix when cultured in plain collagen sponges. This experimental system has the potential to reveal mechanisms of gene activation and other early steps in postnatal chondro/osteoinduction. Further, these results suggest that it may be possible to engineer human cartilage for transplantation by culturing autogenous dermal fibroblasts with a chondroinductive agent.

Analysis of p53 expression in osteosarcoma of the jaw: Correlation with clinicopathologic and DNA ploidy findings

The objective of this study was to determine whether p53 expression correlated with clinicopathological and DNA ploidy in osteosarcoma of the jaw, a particular subtype of osteosarcoma associated with an older age at presentation, longer median survival, rare metastasis, and death due to uncontrolled local recurrence. Seventeen cases of osteosarcoma of the jaw were stained for p53 using CM1 antibody (Novocastra). Eight cases (47.5%) showed nuclear staining in more than 10% of the neoplastic nuclei. Ploidy analysis showed 13 aneuploid (eight p53+) and three diploid (none p53+) tumors. No significant relationship was found between p53 positivity and clinicomorphological features, DNA ploidy or survival. p53-positive cases were, however, more commonly associated with aneuploidy and chondroblastic differentiation. These results indicate that p53 immunostaining does not seem to provide prognostic information in osteosarcoma of the jaw.

Three-dimensional composite of demineralized bone powder and collagen for in vitro analysis of chondroinduction of human dermal fibroblasts

Implantation of demineralized bone powder (DBP) in muscle or connective tissue stimulates chondrogenesis followed by ectopic bone formation, in this way inducing the differentiation of endochondral bone. A new 3-dimensional in vitro composite sponge was designed to duplicate the packing density of in vivo DBP implants. The composite device, which consists of DBP packed between two layers of a porous collagen lattice, was used to assess the chondroblastic differentiation of human dermal fibroblasts. Important design considerations for this device were biocompatibility, rigidity and ability of cells to penetrate. In this study, collagen concentration and source, irradiation, and lyophilization conditions were varied in fabrication. Human dermal fibroblasts were seeded onto the composite sponge, migrated through the collagen lattice into the packet of DBP, and deposited a metachromatic extracellular matrix amongst the particles of DBP. In contrast, cells cultured in collagen sponges or in composite sponges with inactivated guanidine-extracted DBP did not secrete metachromatic matrix. This new in vitro system will be valuable in defining the mechanism of differentiation by osteoinductive materials and in evaluating the influence of other extracellular components and soluble factors on skeletal differentiation.

T(4;19)(q35;q13.1): A recurrent change in primitive mesenchymal tumors?

We report an apparently balanced t(4;19)(q35;q13.1) as the sole cytogenetic change in a highly malignant extraskeletal sarcoma in a 12-year-old-boy. Tumor cells were negative for all immunocytochemical markers except vimentin and neuron-specific enolase. Electron microscopy indicated chondroblastic differentiation. The tumor was categorized as a malignant sarcoma with differentiation toward extraskeletal mesenchymal chondrosarcoma. Reports of a similar translocation in an embryonal rhabdomyosarcoma (RMS) and in a dedifferentiated sarcoma with both rhabdomyosarcomatous and osteosarcomatous elements suggest that this translocation can arise in a primitive mesenchymal stem cell that can differentiate along at least these three pathways.

TGF-β and basement membrane matrigel stimulate the chondrogenic phenotype in osteoblastic cells derived from fetal rat calvaria

Primary cultures of fetal rat calvarial cells contain a spectrum of osteogenic phenotypes including undifferentiated mesenchymal cells, osteoprogenitor cells, and osteoblasts. We recently demonstrated that rat calvarial osteoblast-like cells grown on basement membrane undergo profound morphological changes resembling a canalicular network in bone. In the present study, we examined the effect of reconstituted basement membrane Matrigel on chondroblastic versus osteoblastic differentiation of different cell subpopulations obtained by five consecutive enzymatic digestions of rat calvarial cell populations. We found that the appearance of canalicular cell processes decreased with the later digests. When cells from the fourth and fifth digest were grown on top of Matrigel for 7 days, the majority of the cell aggregates displayed chondrocytic characteristics but none of the cells became hypertrophic. When individual chondroblastic cell aggregates were subsequently transferred from Matrigel to plastic, they started expressing types I and X collagens, alkaline phosphatase, and osteocalcin. Within the next 7 days (days 8-14 of the experiment), the majority of cells increased in size, and at day 17 on plastic (day 24 of the experiment) mineralized bone nodules formed. The chondroblastic differentiation of calvarial cells grown on Matrigel could be inhibited by a specific transforming growth factor-beta 1 (TGF-beta 1) but not by a TGF-beta 2 antibody. Addition of recombinant TGF-beta 1 to similar cultures promoted the appearance of chondroblastic cell aggregates. The cartilage phenotype could not, on the contrary, be promoted by growing the cells on other extracellular matrices such as a collagen I gel. We suggest that TGF-beta 1 in concert with the basement membrane extracellular matrix induces chondroblastic differentiation of rat calvarial osteoprogenitor cells.

Human Osteogenic Protein-1 Induces Chondroblastic, Osteoblastic, and/or Adipocytic Differentiation of Clonal Murine Target Cells

Osteogenic protein-1 (OP-1, BMP-7), a bone morphogenetic protein in the transforming growth factor-β superfamily, induces endochondral bone formationin vivo,but the mechanism of action of OP-1 in osteogenesis is not yet established. Three murine clonal cell lines in different stages of differentiation exhibit graded responses to recombinant human OP-1: the mouse embryonal carcinoma ATDC5 cell, with potential for chondroblastic differentiation; the osteoblast-like MC3T3-E1 cell derived from mouse calvaria; and the multipotent fibroblastic C3H10T12 cell derived from mouse embryo connective tissue. We show that OP-1 acts on early stage mesenchymal progenitor cells (ATDC5, C3H10T12) to induce chondroblastic differentiation, while OP-1 strongly enhances the osteoblastic phenotype of committed osteoblasts (MC3T3-E1), possibly explaining its induction of the endochondral ossification cascadein vivo.Markers of osteoblastic, chondroblastic, and adipocytic differentiation are compared. OP-1 is strongly mitogenic for ATDC5, showing dose-dependent (2.5–80 ng/ml) induction of Alcian blue staining, alkaline phosphatase activity, and mRNA expression for collagen types II and IX, and matrix Gla protein. MC3T3-E1 cells do not proliferate or stain with Alcian blue in response to OP-1, but express elevated levels of alkaline phosphatase and osteocalcin. While low-dose OP-1 treatment of C3H10T12 induces only adipocyte-like cells filled with lipid droplets, a high dose (500 ng/ml) causes the same cells to also exhibit chondrocytic properties. Thus, OP-1 can induce differentiation along elements of the endochondral ossification pathway according to the stage and potential of the target cell.

Periosteal osteosarcoma. Histologic characteristics, preparation technique, growth pattern and differential diagnosis

Periosteal osteosarcoma is a distinct bone tumor entity with characteristic morphological features within the group of juxtacortical osteosarcoma. Periosteal osteosarcoma is predominantly located in the long tubular bones, especially in the tibia and femur and is situated on the outer circumference of the tumor-bearing bone (saucerization phenomenon). In contrast to parosteal osteosarcoma, periosteal osteosarcoma is less differentiated and is believed to have a worse prognosis. In this work the histological features are described with predominantly chondroblastic differentiation of 14 cases with periosteal osteosarcoma. A horizontal preparation technique of periosteal osteosarcoma specimens allows comparison with computed tomography and is the optimal method to detect an invasion of the medullary cavity. Further studies are necessary to clarify if neoadjuvant chemotherapy could improve the prognosis of certain patients.