De novo protein synthesis by human chondrosarcoma in cell and organ culture: evidence of unusually high collagen production by a neoplastic tissue

Protein synthesis by human chondrosarcoma tissue and normal articular cartilage was studied in organ and primary monolayer cell culture systems. Protein synthesis by cell cultures was evaluated at 2.7 and 21 days after plating. When compared to normal, incorporation of 3H-proline and 35S-methionine into proteins was elevated in chondrosarcoma samples under both culture conditions. Hydroxyproline analyses of tissue hydrolysates indicated that chondrosarcoma samples contained significantly less collagen than normal articular cartilage, yet were incorporating significantly greater amounts of 3H-proline into 3H-hydroxyproline. Collagen production by cell cultures was assessed by digestion of samples with purified clostridial collagenase. Chondrosarcoma cells produced more collagenase-sensitive protein than normal cells at all intervals. SDS polyacrylamide gel analyses of all preparations showed two collagenase-sensitive proteins with apparent molecular weights of 165,000 and 175,000. Decreased synthesis of another major protein, apparent molecular weight 210-220,000 was noted in chondrosarcoma preparations in both culture systems.     

Functional roles of CSPG4/NG2 in chondrosarcoma

CSPG4/NG2 is a multifunctional transmembrane protein with limited distribution in adult tissues including articular cartilage. The purpose of this study was to investigate the possible roles of CSPG4/NG2 in chondrosarcomas and to establish whether this molecule may have potential for targeted therapy. Stable knock‐down of CSPG4/NG2 in the JJ012 chondrosarcoma cell line by shRNA resulted in decreased cell proliferation and migration as well as a decrease in gene expression of the MMP (matrix metalloproteinase) 3 protease and ADAMTS4 (aggrecanase). Chondrosarcoma cells in which CSPG4/NG2 was knocked down were more sensitive to doxorubicin than wild‐type cells. The results indicate that CSPG4/NG2 has roles in regulating chondrosarcoma cell function in relation to growth, spread and resistance to chemotherapy and that anti‐CSPG4/NG2 therapies may have potential in the treatment of surgically unresectable chondrosarcoma.     

Use of MicroRNA biomarkers to distinguish enchondroma from low-grade chondrosarcoma

Establishing a definitive diagnosis between benign enchondroma versus low-grade chondrosarcoma presents a potential challenge to both clinicians and pathologists. microRNAs (small non-coding RNAs) have proven to be effective biomarkers for the identification of tumors and tumor progression. We present analysis, both array and quantitative PCR, that shows consistently and substantially increased expression of two microRNAs, miRs-181a and -138, in low-grade chondrosarcomas compared with enchondromas. The data suggest these microRNAs would provide an analytical distinction between the chondrosarcoma and benign neoplasms that can be performed in formalin-fixed paraffin-embedded specimens. Together with recent publications, these data indicate that miRs-181a and -138 also play a role in tumor development and homeostasis and may provide new targets for the development of much needed therapeutic intervention.     

PAS inclusions,immunoreactive tenascin and proliferative activity in low-grade chondrosarcomas

To distinguish between chondrosarcoma (grade 1--borderline histology) and enchondroma, we examined six chondrosarcomas (grade 1--borderline histology) which looked like benign lesions. Their diagnosis, albeit based on clinical, radiologic and pathologic examinations, was not easily reached. Moreover, we examined six enchondromas and 11 chondrosarcomas, the diagnoses of which were straightforward. All cartilaginous tumors were studied, placing emphasis on PAS-positive intracytoplasmic globules. Anti-Ki67 proliferation-associated nuclear antigen antibody and tenascin antibody were applied. The following features were observed in low-grade chondrosarcomas: (1) masses of hyalin and/or myxoid cartilage invading spaces around the tumor, (2) host lamellar bone trabeculae surrounded by cartilage on all sides, (3) tumoral resorption of bone trabeculae. Intracytopasmic hyalin globules (ICG) were more frequently found in malignant than in benign neoplasm (p = 0.042). Moreover, tenascin matrix immunoreactivity was more likely to be observed in benign than in malignant neoplasm (p = 0.029). Ki67 immunoreactivity was more frequent in characterized than in low-grade chondrosarcomas or in enchondromas, where it was null (p = 0.0044).     

Chondrosarcoma of calcanaeum in a 12-year-old male patient: a case report

Chondrosarcoma is distinctly uncommon and tends to be located often in the extremities in young patients more than in its adult counterpart. Cartilaginous tumors involving the small bones of the hands and feet are benign tumors such as enchondromas, chondromyxoid fibroma (CMF), and chondroblastoma. Chondrosarcomas involving calcanaeum in young adults are largely covered in the literature as single case reports. A young 12-yr-male patient presented with complaints of pain and mild swelling in the ankle. Radiological examination revealed a dense irregular lesion in the calcanaeum. Fine-needle aspiration was performed and a possibility of chondrosarcoma was suspected, which later was confirmed on histopathological examination. The cytopathologist should be aware of the occurrence of malignant chondroid tumors in the younger age group at this rare site. Correlation to radiological findings is essential in these cases.     

Synergistic anti-proliferative effects of mTOR and MEK inhibitors in high-grade chondrosarcoma cell line OUMS-27

Chondrosarcoma is a malignant bone tumor that produces cartilaginous neoplastic tissue. Owing to the absence of an effective adjuvant therapy, high-grade chondrosarcoma has a poor prognosis. Therefore, it is important to develop an effective adjuvant therapy to prevent the recurrence and metastasis. Mammalian target of rapamycin (mTOR), a central regulator of cell growth, metabolism, proliferation, and survival, is considered an important target for anticancer drug development. The mitogen activated protein kinase (MAPK) pathway is another highly implicated cellular pathway in cancer and is thought to have compensatory effects in response to the inhibition of the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signaling pathway. We investigated the mechanism of anti-proliferative effect of the mTOR inhibitor rapamycin and MAPK/ERK (MEK) inhibitor PD 0325901, and the combined effect of rapamycin and PD 0325901 on human chondrosarcoma cell line (OUMS-27). Combination therapy with rapamycin and PD 0325901 showed a stronger anti-proliferative effect on OUMS-27 cells than rapamycin monotherapy. We confirmed that the dual inhibition of the PI3K/Akt/mTOR and RAF/MEK/ERK signaling pathways had synergistic anti-proliferative effects in OUMS-27. Our results suggest that combination therapy of mTOR and MEK inhibitor could be an effective therapeutic approach against chondrosarcoma.     

PTEN mutation is rare in chondrosarcoma.

Chondrosarcoma is the second most common primary malignant neoplasm of bone in adults, but the major genetic events involved in the progression of this often-fatal cancer remain to be elucidated. Loss of heterozygosity of chromosome 10q has been reported in 67% of chondrosarcoma. The tumor suppressor gene PTEN is located on chromosome 10q, specifically 10q23, raising the possibility that the loss of PTEN function is responsible for some chondrosarcomas. The authors examined 40 chondrosarcoma tumors and tumor-derived cell lines for alterations in PTEN. Only one mutation resulting in a truncated PTEN protein was detected, which was in a metastasized extraskeletal myxoid chondrosarcoma. Thus, mutated PTEN is an uncommon event in the development of chondrosarcoma. The high frequency of loss of heterozygosity on 10q suggests the presence of additional tumor suppressor genes at these loci.     

S-100 protein immunostaining in the differential diagnosis of chondroblastoma

In an effort to investigate the utility of immunostaining for S-100 protein in the differential diagnosis of chondroblastoma, the expression of S-100 protein in nine chondroblastomas was compared with that in six giant cell tumors, six aneurysmal bone cysts, four giant cell reparative granulomas, six cases of fibrous dysplasia, two cases of osteitis fibrosa cystica, two nonossifying fibromas, and one clear cell chondrosarcoma. Five enchondromas, three typical chondrosarcomas, and one mesenchymal chondrosarcoma were also included as control tumors. The proliferating stromal cells in seven of the nine chondroblastomas stained for S-100 protein, as did the lacunar chondrocytes in all of the enchondromas and chondrosarcomas and rare stromal cells in the clear cell chondrosarcoma. In contrast, none of the other tumefactive bone lesions included in this study demonstrated S-100 protein immunoreactivity. These results suggest that immunohistochemical assessment of S-100 protein may be a method for diagnostically separating chondroblastoma from pathologic entities that could be histologically confused with it in the presence of limited biopsy material. However, clear cell chondrosarcoma would appear to represent an exception to this general statement.     

Clonal chromosome abnormalities in enchondromas and chondrosarcomas

We report cytogenetic findings in short-term cell cultures from five enchondromas and four chondrosarcomas. Clonal chromosome aberrations were found in one case of enchondroma, and in all cases of chondrosarcoma. The only enchondroma with nonrandom abnormalities had a reciprocal t(8;17)(q23;p13), and monosomies 9, 19, and/or 22. In contrast to the few karyotypic findings in one of five enchondromas, the four chondrosarcomas were commonly characterized by cytogenetic heterogeneity, with a tendency for increasing karyotypic complexity in higher grade tumors. Two cases, one grade III and one metastasizing grade II chondrosarcoma, revealed hypodiploid stem- and sidelines with loss of chromosomes 6, 10, 13, 14, and 22, as common chromosomal abnormalities, suggesting a distinct karyotypic pattern in a subset of biologically aggressive chondrosarcomas.     

Chondrosarcoma is not characterized by detectable telomerase activity

Reactivation of telomerase, an enzyme which elongates human telomeres, is associated with cell immortilization. In approximately 90% of malignant tumours telomerase activity can be demonstrated, whereas in benign tumours it is mostly absent. Chondrosarcomas are relatively rare malignant cartilaginous neoplasms. A small number of chondrosarcomas located centrally in bone arise secondarily to an enchondroma, while the majority of chondrosarcomas developing from the surface arise within the cartilage cap of an osteochondroma. The histological distinction between a benign lesion and low-grade chondrosarcoma is generally considered difficult. To investigate whether the progression towards chondrosarcoma is characterized by reactivation of telomerase activity, this study determined telomerase activity in ten enchondromas, five osteochondromas, and 37 chondrosarcomas using the TRAP assay. In all tumour samples except one, telomerase activity was absent. By adding tumour lysates to the positive control, an increasing inhibition of telomerase activity was found with an increasing chondroid matrix, suggesting that it may contain inhibitory factors. Inhibition due to endogenous RNAse or Taq-polymerase inhibitors was excluded. The lack of detectable telomerase activity in the high-grade component of a dedifferentiated chondrosarcoma without matrix favours the possibility that telomerase is truly absent. Either its true absence or inhibitory effects disabling telomerase detection exclude the telomerase TRAP assay as a diagnostic tool in the differential diagnosis of benign and low-grade malignant cartilaginous tumours.     

Up-regulation of PTHrP and Bcl-2 expression characterizes the progression of osteochondroma towards peripheral chondrosarcoma and is a late event in central chondrosarcoma

Chondrosarcomas are malignant cartilage-forming tumors arising centrally in bone (central chondrosarcoma) or within the cartilaginous cap of osteochondroma (peripheral chondrosarcoma). For hereditary multiple osteochondromas, two responsible genes, EXT1 and EXT2, have been cloned. Their recently elucidated role in heparan sulfate biosynthesis and Hedgehog diffusion leads to the hypothesis that EXT inactivation affects fibroblast growth factor (FGF) and Indian Hedgehog (IHh)/parathyroid hormone-related peptide (PTHrP) signaling, two important pathways in chondrocyte proliferation and differentiation. The expression of PTHrP, PTHrP-receptor, Bcl-2, FGF2, FGFR1, FGFR3, and p21 is investigated by immunohistochemistry in osteochondromas (n = 24) and peripheral (n = 29) and central (n = 20) chondrosarcomas. IHh/PTHrP and FGF signaling molecules are mostly absent in osteochondromas. Although no somatic EXT mutations were found in sporadic osteochondromas, the putative EXT downstream targets are affected similarly in sporadic and hereditary tumors. In chondrosarcomas, re-expression of FGF2, FGFR1, PTHrP, Bcl-2, and p21 is found. Expression levels increase with increasing histological grade. Up-regulation of PTHrP and Bcl-2 characterizes malignant transformation of osteochondroma because PTHrP and Bcl-2 expression is significantly higher in borderline and grade I peripheral chondrosarcomas compared with osteochondromas. In contrast, up-regulation of PTHrP and Bcl-2 seems to be a late event in central cartilaginous tumorigenesis because expression is mainly restricted to high-grade central tumors.     

芹菜素对体外培养软骨肉瘤细胞增殖的抑制作用

目的探讨芹菜素对体外培养软骨肉瘤细胞株的作用。方法采用细胞培养技术,分别用0、20、40、80μmol/L芹菜素加入到培养的软骨肉瘤细胞株中,分别在培养24、48、72 h后,通过光学显微镜观察软骨肉瘤细胞株的形态学变化,采用四唑盐(MTT)比色法观察软骨肉瘤细胞株的生长情况。结果 40及80μmol/L芹菜素对软骨肉瘤的生长呈剂量和时间依赖性抑制。结论芹菜素有一定的抗软骨肉瘤活性,抑制软骨肉瘤细胞体外生长。     

Absence of IHH and retention of PTHrP signalling in enchondromas and central chondrosarcomas

Enchondromas and conventional central chondrosarcomas are, respectively, benign and malignant hyaline cartilage-forming tumours that originate in the medulla of bone. In order to gain a better understanding of the molecular process underlying malignant transformation of enchondroma, and to investigate whether there is a biological difference between conventional central cartilaginous tumours and those of enchondromatosis or with phalangeal localization, a series of 64 enchondromas (phalanx, n = 21; enchondromatosis, n = 15) and 89 chondrosarcomas (phalanx, n = 17; enchondromatosis, n = 13) was collected. Indian Hedgehog (IHH)/parathyroid hormone related peptide (PTHrP) signalling, an important pathway in chondrocyte proliferation and differentiation within the normal growth plate, was studied by immunohistochemical analysis of the expression of PTHrP, PTHR1, Bcl-2, p21, cyclin D1, and cyclin E. Quantitative real-time PCR for IHH, PTCH, SMO, and GLI2 was performed on a subset of tumours. The data show that IHH signalling is absent in enchondromas and central chondrosarcomas, while PTHrP signalling is active. There was no difference in the expression of any of the molecules between 35 enchondromas and 26 grade I central chondrosarcomas, indicating that PTHrP signalling is not important in malignant transformation of enchondroma. Higher expression of PTHR1 and Bcl-2 was associated with increasing histological grade in chondrosarcoma, suggesting involvement in tumour progression. No difference was found between samples from enchondromatosis patients and solitary cases, suggesting no difference in PTHrP signalling. A small subset of phalangeal chondrosarcomas demonstrated down-regulation of PTHrP, which may be related to its more indolent clinical behaviour. Thus, in both enchondromas and central chondrosarcomas, PTHrP signalling is active and independent of IHH signalling, irrespective of the presence or absence of enchondromatosis.     

NKX3.1 a useful marker for mesenchymal chondrosarcoma: An immunohistochemical study

IntroductionMesenchymal chondrosarcoma is a rare subtype of chondrosarcoma. The tumor has a characteristic bimorphic pattern with areas of poorly differentiated small round cell component and interspersed islands of well differentiated hyaline cartilage. Histological diagnosis of mesenchymal chondrosarcoma is very challenging especially in small biopsies when tumor presents with little cartilaginous component. In such cases, it is very difficult to distinguish mesenchymal chondrosarcoma from other round blue cell tumors like Ewing's sarcoma, rhabdomyosarcoma, small cell osteosarcoma and desmoplastic round blue cell tumor. Immunohistochemically, mesenchymal chondrosarcoma stains positive for NKX2.2, CD99, S100 and SOX9. This immunoprofile is non-specific and overlaps with other round blue cell tumors. Till recently, there was no reliable immunohistochemical marker to differentiate mesenchymal chondrosarcoma from other round blue cell tumors.NKX3.1, though widely used as a diagnostic biomarker for prostatic adenocarcinoma, has been recently proposed by Yoshida et al. (2020) as a unique marker of mesenchymal chondrosarcoma and EWSR1-NFATC2 sarcoma.ObjectiveThe aim of our study was to further explore utility of NKX3.1 as a diagnostic marker of mesenchymal chondrosarcoma.Material & methodsWe applied NKX3.1 immunohistochemistry to 21 cases of mesenchymal chondrosarcoma and 32 cases of other round blue cell tumors.Results14 out of 21 cases (66.7%) of mesenchymal chondrosarcoma stained positive for NKX3.1 with nuclear expression in small round component. Cartilaginous component was predominantly negative. All other round blue cell tumors showed negative results.ConclusionBased on our study results we suggest that NKX3.1 is a useful immunohistochemical marker in differentiating mesenchymal chondrosarcoma from its histological mimics.     

Immunohistochemical expression of estrogen receptors in chondrosarcomas and enchondromas

Immunohistochemical expression of estrogen receptors alpha and beta was studied in chondrosarcomas and enchondromas and was correlated with chondrosarcoma grade, type, and dedifferentiation. Estrogen receptor alpha was studied in 37 chondrosarcomas, 10 enchondromas, and 2 extraskeletal myxoid chondrosarcomas. Estrogen receptor beta was studied in 23 chondrosarcomas, 6 enchondromas, and 2 extraskeletal myxoid chondrosarcomas. Ventana prediluted monoclonal anti-ER alpha (clone 6F11) and Biogenex prediluted polyclonal anti-ER beta were used on the Ventana ES autostainer and BenchMark XT IHC/ISH, respectively. Percent of cell staining and intensity (+, ++, or +++) was evaluated. Overall, 61% of conventional chondrosarcoma and 60% of enchondroma were positive for estrogen receptor alpha. Low-grade chondrosarcoma expressed estrogen receptor alpha more frequently than high-grade chondrosarcoma (P相似文献   

ULTRASTUCTURE OF CARTILAGINOUS TUMORS AND S-100 PROTEIN IN THE TUMORS: With Reference to the Histogenesis of Chondroblastoma, Chondromyxoid Fibroma and Mesenchymal Chondrosarcoma

Twelve cartilaginous tumors were studied by electron microscopy and the presence of S-100 protein was studied immunohistochemically in order to clarify the cell origin of chondroblastoma, chondromyxoid fibroma, and mesenchymal chondrosarcoma. Three chondroblastomas were characterized by round or ovoid tumor cells with some cytoplasmic processes, well-developed organelles and thick fibrous laminae in the nuclear membrane, occasional multinucleated giant cells and scanty chondroid matrix. S-100 protein was demonstrated in the tumor cells and some multinucleated giant cells. Two chondromyxoid fibromas revealed tumor cells of varied shapes with character istic cartilaginous differentiation and abundant chondroid matrix. Spindle tumor cells showed the ultrastructural features of cartilage cells rather than of fibroblasts and S-100 protein was also demontratrated in their cytoplasm. Chondroblastoma and chondomyxoid fibroma were considered to arise from chondrocytes. Mesenchymal chondrosarcoma ultrastructurally exhibited round tumor cells with cartilaginous nature in cartilage islands. Poorly-differentiated portions were composed of primitive round or elongated cells with occasionally admixed round cells with ultrastructural features of cartilaginous differentiation. S-100 protein was demonstrated in the cells in cartilage islands and in single cells admixed in poorly-differentiated portions. These results support the hypothesis of primitve mesenchymal origin with a tendency to differentiate toward cartilage cells. ACTA PATHOL. JPN. 34: 1285–1300, 1984.     

白藜芦醇通过PI3K/Akt通路及线粒体途径抑制软骨肉瘤

 目的：探讨白藜芦醇抑制软骨肉瘤的机制及对线粒体途径和PI3K/Akt通路的影响。方法：SW1353软骨肉瘤细胞培养至对数生长期后设对照组和白藜芦醇处理组,药物处理组用25、50和100 μmol/L白藜芦醇处理24 h、48 h或72 h。采用CCK8法检测SW1353软骨肉瘤细胞的活力,Hoechst 33258荧光染色观察细胞凋亡,Western blotting检测activated caspase-3、Bcl-2、Bax、Akt和p-Akt蛋白在细胞中表达情况,细胞划痕实验观察细胞迁移情况。结果：白藜芦醇处理后细胞活力下降,呈时间-剂量依赖性（P<0.01）。Hoechst  33258染色检测可见药物处理组有明显的细胞凋亡核象。Western blotting检测显示药物处理组activated caspase-3和Bax蛋白表达上调,Bcl-2蛋白和p-Akt蛋白表达下调,总Akt改变不显著。细胞划痕试验显示,白藜芦醇能显著抑制SW1353细胞的迁移。结论：白藜芦醇能够诱导软骨肉瘤凋亡,部分是通过线粒体途径及PI3K/Akt信号通路发挥作用。