Mononuclear Stromal Cells Research Articles

P53 Expression Immuno-histochemistry Index in Stage III Giant Cell Tumor of the Bone

We analyzed the p53 expression of 50 consecutive cases of stage III giant cell tumor to determine the clinico-pathological correlation. There were 29 male patients compared to 21 females. The mean age was 36.42 years and ranged from 19 to 66 years. Tumors were located mainly around the knee (48%) followed by distal radius (28%). Sixteen percent (16%) had local recurrence, and twenty four percent (24%) presented with or eventually developed lung metastasis. There were 3 patients who had both local recurrence and pulmonary metastasis. The expression of p53 antigen was evaluated by immuno-histochemical staining techniques, using the avidin-biotin perioxidase complex method, using an LSAB2 kit (Dako, Glostrup, Denmark). The scoring was done by counting the positively stained cell in the background of 1000 mononuclear stromal cells. Data was analyzed using PASW version 18.0. The mean value of p53 index obtained as a percentage of 1000 background cells was 37.68 (ranged 1.00 – 20.0), with standard deviation of 28.33. The p53 index of recurrent tumor was 65.38 compared to 32.42 of those without recurrence, and was statistically significant (mean difference of 32.97 with p value in independent t test of 0.002). The p53 index was also statistically significant in the presence of pulmonary metastases with the mean value of 66.92 compared to 28.45 of those without metastasis (mean difference of 38.47 with p value in independent t test of 0.001). In conclusion, p53 expression is a good prognostic marker to predict the risk of local recurrence and lung metastasis in the giant cell tumor of the bone.

Clinicopathologic differential diagnosis of giant cell-rich osteosarcoma and giant cell tumor of bone

To study the clinicopathologic features and differential diagnosis of giant cell-rich osteosarcoma (GCRO) and giant cell tumor of bone (GCT). The clinical, radiologic, pathologic and immunohistochemical features of 18 cases of GCRO and 118 cases of GCT were evaluated. The mean age of patients with GCRO was 24.6 years. Fifteen of the 18 cases arose in the metaphysis of long bones. GCRO presented as a large poorly-defined mixed lytic and blastic mass, associated with cortical destruction and formation of large soft tissue component. Histologically, GCRO was characterized by a predominance of numerous osteoclast-like giant cells admixed with scanty osteoid which was formed by neoplastic cells in different levels of anaplasia and pleomorphism. In the 118 cases of GCT studied, the mean age of patients was 34.5 years. Most of them (108 cases) arose in the epiphyseal region of long bones. They usually presented as expansile eccentric and osteolytic lesions. Invasive GCT displayed local cortical destruction. Histologic examination of GCT revealed the presence of large number of osteoclast-like giant cells and mononuclear stromal cells. The mononuclear stromal cells possessed poorly defined cytoplasm, showed little cytological atypia and did not carry atypical mitotic figures. They were positive for p63 (83.9%, 99/118). Reactive bone could be observed at the periphery. GCRO represents a special form of osteosarcoma which shows overlapping clinicopathologic features with invasive GCT. The presence of nuclear atypia, atypical mitoses and osteoid matrix produced directly by neoplastic cells are more in favor of GCRO. These features however may not be demonstrated in full in limited small biopsy samples. It is thus important to analyze all clinical, radiologic and pathologic features before a definitive diagnosis is made.

The Clinical Approach Toward Giant Cell Tumor of Bone

We provide an overview of imaging, histopathology, genetics, and multidisciplinary treatment of giant cell tumor of bone (GCTB), an intermediate, locally aggressive but rarely metastasizing tumor. Overexpression of receptor activator of nuclear factor κB ligand (RANKL) by mononuclear neoplastic stromal cells promotes recruitment of numerous reactive multinucleated giant cells. Conventional radiographs show a typical eccentric lytic lesion, mostly located in the meta-epiphyseal area of long bones. GCTB may also arise in the axial skeleton and very occasionally in the small bones of hands and feet. Magnetic resonance imaging is necessary to evaluate the extent of GCTB within bone and surrounding soft tissues to plan a surgical approach. Curettage with local adjuvants is the preferred treatment. Recurrence rates after curettage with phenol and polymethylmethacrylate (PMMA; 8%-27%) or cryosurgery and PMMA (0%-20%) are comparable. Resection is indicated when joint salvage is not feasible (e.g., intra-articular fracture with soft tissue component). Denosumab (RANKL inhibitor) blocks and bisphosphonates inhibit GCTB-derived osteoclast resorption. With bisphosphonates, stabilization of local and metastatic disease has been reported, although level of evidence was low. Denosumab has been studied to a larger extent and seems to be effective in facilitating intralesional surgery after therapy. Denosumab was recently registered for unresectable disease. Moderate-dose radiotherapy (40-55 Gy) is restricted to rare cases in which surgery would lead to unacceptable morbidity and RANKL inhibitors are contraindicated or unavailable.

Diagnostic Efficacy of Radiology in the Diagnosis of Giant Cell Tumour of Bone

Background: Giant cell tumour (GCT) is an aggressive and potentially malignant lesion. Microscopic feature reveals osteoclast like giant cells in a mononuclear stromal cells background. The mononuclear stromal cell is interpreted as neoplastic. Objective: As radiological diagnosis is non invasive and cost effective in comparison to histopathological diagnosis, considering the patients’ compliance, the aim of the study was to observe the diagnostic efficacy of radiology in diagnosis of GCT. Materials and method: This cross sectional study was carried out in the department of Pathology, Delta Hopital Ltd., Dhaka, Bangladesh from July 2011 to December 2012. A total of 30 study subjects were enrolled in the study irrespective of age and sex. Biopsy material and relevant data of clinically suspected cases of GCT along with radiology report were sent from National Institute of Traumatology and Orthopaedic Rehabilitation (NITOR), Dhaka, Bangladesh. Histopathological diagnosis was made by expert pathologists. Results: Mean (±SD) age of the study subjects was 29.20 (±7.34) years with highest number of patients were observed in 3rd decade and female was predominant (60%) with a male female ratio of 1:1.5. Common site of GCT was around knee (50%). Among 30 clinically diagnosed GCT, 25 (83.3%) cases were radiologically diagnosed as GCT, 2 (6.7%) diagnosed as fibrous dysplasia, 1 (3.3%) as chondroblastoma, 1 (3.3%) as simple bone cyst and 1 (3.3%) as aneurysmal bone cyst. However among 30 clinically diagnosed GCT, 28 (93.3%) patients were histopathologically diagnosed as Giant cell lesion and rest 2 (6.7%) patients diagnosed as fibrous dysplasia. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of radiological diagnosis of GCT were found to be 92.6%, 100.0%, 100.0%, 40.0% and 90.0%, respectively. Conclusion: Radiology can be effectively used as a screening tool in diagnosing GCT. DOI: http://dx.doi.org/10.3329/dmcj.v2i1.17791 Delta Med Col J. Jan 2014; 2(1): 13-16

Giant cell tumor of great toe mimicking giant cell reparative granuloma

Giant cell tumor of bone is a benign tumor composed of diffuse osteoclastic giant cells and mononuclear stromal cells. Giant cell tumor of small bones of hands and feet are different in behavior than Giant cell tumor of long bones. Giant cell tumor of toe is very rare (less than 2%), when it involve the toes, it more commonly affects younger age group and is more aggressive in nature. We report a case of Giant cell tumor of distal phalanx of great toe, which was difficult to differentiate radiologically with giant cell reparative granuloma. En bloc resection of the tumor was done and Giant cell tumor was confirmed on histopathology.

Non Homologous End Joining, a Marker Of Genomic Instability Is Elevated In Multiple Myeloma: A New Prognostic Factor

Genomic instability is a hallmark of several types of solid and hematologic malignancies, including multiple myeloma (MM). Although structural and numerical chromosomal abnormalities are common features of MM cells, the underlying molecular basis of MM genomic instability is still largely unknown. To this aim, we have investigated the activity of non-homologous end joining (NHEJ), which represents the most important mechanism of double-strand breaks (DSBs) repair, in MM cells. First, we developed and validated a dual gene plasmid-based assay utilizing Luciferase (LUC) as a test gene which measures end joining, and Alkaline Phosphatase (SEAP) as a reporter gene to control for transfection efficiency, in either intact cells (in vivo assay) or in cell free extracts (in vitro assay). The first one is a chemiluminescent assay which allows for direct measurement of LUC and SEAP in the supernatant of the cells 24h after electroporation with the plasmid, while the cell free extract method is a customized TaqMan® approach based on a quantitative evaluation of the plasmid rejoining. Both assays revealed a significant increase in NHEJ in all 6 MM cell lines tested compared to normal peripheral blood mononuclear cells (PB-ND) and bone marrow stromal cells (BMSC). We further confirmed the hyper-activation of the NEHJ pathway by analyzing the binding activity of ku86, a key NHEJ-related protein involved in the recognition of the broken DNA ends and in the initiation of the DSBs repair process. Six out of 9 MM cell lines showed a significant increase in ku86-binding activity respect to normal cells. We also found a higher phosphorylation at Ser 2056 of DNA-PK, a ku86-partner whitch plays a key role in NHEJ. Next, we evaluated the NHEJ activity in 35 patient samples using the cell free assay. Interestingly, level of NHEJ activity divided patients into two different groups: one with an NHEJ activity similar to normal cells and the other to the MM cell lines. Preliminary correlation analysis between NHEJ activity and the clinical features of the patients indicated that the MGUS and Smoldering MM subgroup fall into the normal cluster while relapsed/refractory disease to the cell lines one. Finally, using the French (IFM) and the Arkansas (GSE2658) dataset, we demonstrate a significant association between NHEJ pathway-related gene expression and overall survival by the Globaltest analysis. We were also able to find a common NHEJ signature of 6 genes whose expression significantly correlates with patient survival in both the datasets. In conclusion, our data indicate an aberrant activation of NHEJ in MM, highlighting its role in the progression of the disease and suggesting this pathway as an important new prognostic marker in myeloma. Disclosures:No relevant conflicts of interest to declare.

Giant Cell Tumour of the Anterior rib arc Masquerading as a Primary Breast Lump

Sir, A 28-year-old male was referred to our centre for further evaluation of a lump in the right breast. He was being conservatively managed at an outside centre with a presumed clinical diagnosis of gynecomastia. His past, medical and family histories were unremarkable. Clinical examination revealed a well circumscribed, mildly tender, 5 × 4 cm hard lump in the right breast overlying anterior arc of the right third rib, just lateral to the sternochondral junction. The overlying skin was normal; there was insignificant right axillary adenopathy. All hematological and biochemical investigations were within normal limits. A chest skiagram and a subsequent chest computerized tomography demonstrated a 5 × 4 cm expansile, lytic lesion involving the anterior arc of the right third rib with cortical thinning and disruption and with adjacent soft tissue invasion. (Figure 1a) A bone scan revealed an isolated increased uptake in the right third rib. (Figure 1b) A fine needle aspiration and a subsequent trucut biopsy were suggestive of a Giant cell tumour (GCT). Following diagnosis, an anterior thoracotomy and a wide resection of the third rib lesion was performed; the resultant bony defect was bridged with a prolene mesh. (Figure 2a, b) Macroscopic examination revealed an irregular tumour measuring 5.0 × 3.5 × 2.5 cm showing large chondroblastic areas along with areas of osteoid production. The tumour cells were round, slightly elongated with vesicular to hyperchromatic nuclei and moderate cytoplasm. Many osteoclastic giant cells were also seen, the final impression was that of a giant cell tumour rib with reactive osteiod formation. (Figure 3a, b) The patient remains well without evidence of recurrence one and a half years following surgery. Fig. 1 a CT scan showing a 5 × 4 cm expansile, lytic lesion involving the anterior arc of the right third rib with cortical thinning and disruption and with adjacent soft tissue invasion. b A bone scan showing an isolated increased ... Fig. 2 a, b H&EX40- Showing Giant cell tumour rib with reactive osteiod formation. The tumour cells are round to elongated tumour cells with vesicular to hyperchromatic nuclei and moderate cytoplasm, many osteoclastic giant cells are also seen Fig. 3 a Intra operative clinical photograph following removal of the tumour. b Clinical photograph of the specimen Giant cell tumor of bone is a distinct clinical, radiological and pathologic entity accounting for about 4–5 % of all primary bone tumours. It is a benign but locally aggressive neoplasm, classically seen as a purely lytic lesion of the epiphyseal or metaphyseal-epiphyseal region of long tubular bones extending to the articular surface. Around 60 % of the tumours arise around the knee joint, isolated cases have been reported in the scapula, sternum, patella, vertebra, skull, and talus [1]. A rib is an uncommon site for origin of a GCT with a reported incidence of less than one percent. Even in the cases involving the rib, most were located in the posterior arc [1, 2], anterior arc involvement was noted in our patient. The majority of patients with GCT will present with a lytic geographic lesion that destroys the involved bone [3], approximately 20 % are associated with a soft tissue component. Histologically, GCT shows a diffuse proliferation of multinucleated, osteoclast-like giant cells in a background of oval- to spindle-shaped mononuclear stromal cells [4]; the differential diagnosis includes brown tumours, telangiectatic osteosarcoma, malignant fibrous histiocytoma, chondroblastoma, and aneurysmal bone cysts. GCTs are locally aggressive tumors and hence wide excision is usually recommended in all cases [5]. A majority of the patient typically have a benign course, however, a small subset of them (<5 %) show evidence of metastatic involvement, usually to the lung. In conclusion, GCT arising from the chest wall is rare and difficult to diagnose, especially when the tumour is located in the anterior arc of the ribs; the differential diagnosis easily lends itself to a primary breast lump.

Transcription factor ATF3 links host adaptive response to breast cancer metastasis

Host response to cancer signals has emerged as a key factor in cancer development; however, the underlying molecular mechanism is not well understood. In this report, we demonstrate that activating transcription factor 3 (ATF3), a hub of the cellular adaptive response network, plays an important role in host cells to enhance breast cancer metastasis. Immunohistochemical analysis of patient tumor samples revealed that expression of ATF3 in stromal mononuclear cells, but not cancer epithelial cells, is correlated with worse clinical outcomes and is an independent predictor for breast cancer death. This finding was corroborated by data from mouse models showing less efficient breast cancer metastasis in Atf3-deficient mice than in WT mice. Further, mice with myeloid cell-selective KO of Atf3 showed fewer lung metastases, indicating that host ATF3 facilitates metastasis, at least in part, by its function in macrophage/myeloid cells. Gene profiling analyses of macrophages from mouse tumors identified an ATF3-regulated gene signature that could distinguish human tumor stroma from distant stroma and could predict clinical outcomes, lending credence to our mouse models. In conclusion, we identified ATF3 as a regulator in myeloid cells that enhances breast cancer metastasis and has predictive value for clinical outcomes.

Myofibroblastic Differentiation of Stromal Cells in Giant Cell Tumor of Bone: An Immunohistochemical and Ultrastructural Study

The nature of the mononuclear stromal cells (MSCs) in giant cell tumor of bone (GCTB) has not been thoroughly investigated. The purpose of this study was to evaluate the degree and significance of myofibroblastic differentiation in 18 cases of GCTB by immunohistochemistry (IH) and/or electron microscopy (EM). All immunostained cases were found positive for smooth muscle actin (SMA) and/or muscle specific actin (MSA), most in 1–33% of the MSCs. Ultrastructurally, most MSCs were fibroblasts, and a significant number of cells displayed myofibroblastic differentiation. Myofibroblasts are an important component of MSCs in GCTB. The myofibroblastic population may be responsible in part for the production of matrix metalloproteinases (MMPs), which probably play a role in bone destruction, tumor aggression, and recurrence.

Giant Cell Tumor of Bone

Giant cell tumor (GCT) of bone is one type of giant cell-rich lesion of bone. This benign mesenchymal tumor has characteristic multinuclear giant cells. Mononuclear stromal cells are the physiologically active and diagnostic cell type. Most GCTs are located in the epiphyseal regions of long bones. The axial skeleton-primarily the sacrum-is a secondary site of involvement. Most patients present with pain, swelling, joint effusion, and disability in the third and fourth decades of life. Imaging studies are important for tumor staging and radiographic grading. Typically, these clinically active but slow-growing tumors are confined to bone, with relatively well-defined radiographic borders. Monostotic disease is most common. Metastatic spread to the lungs is rare. Extended intralesional curettage with or without adjuvant therapy is the primary treatment choice. Local recurrence is seen in ≤ 20% of cases, and a second local intralesional procedure is typically sufficient in cases that are detected early. Medical therapies include diphosphonates and denosumab. Denosumab has been approved for use in osteoporosis as well as breast and prostate cancer metastatic to bone. Medical therapy and radiotherapy can alter the management of GCT of bone, especially in multifocal disease, local recurrences, and bulky central/axial disease.

Detection of the Epstein-Barr Virus and DNA-Topoisomerase II-αin Recurrent and Nonrecurrent Giant Cell Lesion of the Jawbones

The aims of this study were to determine whether the expression of Topo II-α correlates with presence of EBV in giant cell lesion of the jawbones and whether it is predictive of clinical biologic behavior of these lesions. Paraffin-embedded tissues from 8 recurrent and 7 nonrecurrent cases of bony GCLs and 9 peripheral giant cell lesions (PGCLs) as a control group were assessed for the expression of EBV and Topo II-α using immunohistochemistry. The results showed positive staining for Topo II-α in mononuclear stromal cells (MSCs) and multinucleated giant cells (MGCs). Student t-test showed that mean Topo II-α labelling index (LI) in recurrent cases was significantly higher than that in non-recurrent cases (P = 0.0001). Moreover, Spearman's correlation coefficients method showed a significant correlation between DNA Topo II-α LI and both of gender and site in these lesions. Moderate EBV expression in relation to the highest Topo II-α LI was observed in two cases of GCT. It was concluded that high Topo II-α LIs could be identified as reliable predicators for the clinical behavior of GCLs. Moreover, EBV has no etiological role in the benign CGCLs in contrast to its role in the pathogenesis of GCTs.

Unusually large peripheral giant cell granuloma- a case report

Peripheral giant cell granuloma (PGCG) is an infrequent exophytic lesion of the oral cavity, also known as giant cell epulis, osteoclastoma, giant cell reparative granuloma, or giant-cell hyperplasia. Lesions vary in appearance from smooth, regularly outlined masses to irregularly shaped, multilobulated protuberances with surface indentations. Ulcerations of the margin is occasionally seen. The lesions are painless, vary in size, and may cover several teeth. It normally presents as a soft tissue purplish-red nodule consisting of multinucleated giant cells in the background of mononuclear stromal cells and extravasated red blood cells. This article reports a peripheral giant cell granuloma arising at maxillary anterior region in 56 years old patient.

Giant Cell Tumor of Bone: Review, Mimics, and New Developments in Treatment

Giant cell tumor (GCT) of bone is generally a benign tumor composed of mononuclear stromal cells and characteristic multinucleated giant cells that exhibit osteoclastic activity. It usually develops in long bones but can occur in unusual locations. The typical appearance is a lytic lesion with a well-defined but nonsclerotic margin that is eccentric in location, extends near the articular surface, and occurs in patients with closed physes. However, GCT may have aggressive features, including cortical expansion or destruction with a soft-tissue component. Fluid-fluid levels, consistent with secondary formation of aneurysmal bone cysts, are seen in 14% of cases. GCT can mimic or be mimicked by other benign or malignant lesions at both radiologic evaluation and histologic analysis. Rarely, GCT is associated with histologically benign lung metastases or undergoes malignant degeneration. In the past, the mainstay of treatment was surgical, primarily consisting of curettage with cement placement, with recurrence rates of 15%-25%. Recurrence is suggested by development of progressive lucency at the cement-bone interface. Other complications include pathologic fracture and postoperative infection. Denosumab, a monoclonal antibody that targets the osteoclastic activity of GCT, has produced 90% tumor necrosis in early studies, results indicative of promise as a potential adjuvant therapy.

Aberrant Non-Homologous End Joining in Multiple Myeloma: A Role in Genomic Instability and As Potential Prognostic Marker.

AbstractAbstract 2932Multiple Myeloma (MM) is a hematologic malignancy characterized by a complex combination of structural and numerical chromosomal abnormalities. However, the underlying molecular basis of the genomic instability remains largely unknown. The ability to repair DNA damages, especially double-strand breaks (DSBs), is essential to suppress genetic instability. Non-homologous end joining (NHEJ) is one of the most important mechanisms responsible for repair of these breaks. Since both impaired and aberrant NHEJ seem to be linked to genomic instability in solid as well as other hematologic tumors, we have investigated its altered function in MM. To confirm involvement of an aberrant NHEJ pathway in MM genomic instability, we measured the end joining (EJ) capacity of 6 different MM cell lines using a plasmid based assay containing both the test gene (Luciferase - LUC) measuring end joining as well as a reporter gene (Alkaline Phosphatase - SEAP) to control for transfection efficiency. MM and normal control cells were transfected with this plasmid and the LUC and SEAP activity was detected directly in the supernatant of the cells at 24 h. Increased EJ activity was observed in all the MM cell lines tested compared to peripheral blood mononuclear cells (PBMCs) and bone marrow stromal cells (BMSCs) from healthy donor. To confirm the role of the NHEJ pathway in this increased DNA EJ activity, nuclear extracts from 9 different MM cell lines were used to determine the DNA-binding-activity of Ku86, a key protein of this repair mechanism involved in the recognition of the broken DNA ends and in the initiation of the DSBs repair process. As in EJ activity, all the MM cell lines showed an increased Ku86 binding respect to normal cells confirming the aberrant activation of the NHEJ pathway in MM cells. Interestingly, we did not observe significant differences in Ku86 level in nuclear extracts between PBMCs and MM cell lines suggesting that the difference in the Ku86 DNA-binding-activity was likely a functional and not due to disparity in the protein levels. We further investigated the link between this aberrant NHEJ activity and MM genomic instability using an immune-fluorescent based assay for DSBs. We observed an increased constitutive DNA damage in the absence of treatment with DSB-inducing agents in 5 of 6 MM cell lines compared with normal PBMCs. Most importantly, we noticed a direct correlation between the basal level of DSBs and the Ku86-binding-affinity. Furthermore, all the MM cell lines showed little or no ability to repair ionizing radiation (IR)-induced DNA damage compared to normal cells as well as no change in the Ku86-binding-affinity after stimulation suggesting that the aberrant NHEJ pathway in MM might represent a response to the constitutive endogenous DNA damage in these cells. We have also observed that 2 key NHEJ genes (Ku86 and Artemis) are overexpressed in MM compared to MGUS and normal plasma cells and their overexpression correlates with a shortened overall survival in MM suggesting that an hyper-activation of this pathway could have a potential role in MM progression and prognosis. Ongoing experiments are assessing the NHEJ activity in primary MM cells to correlate with clinical outcome. In conclusion, our data suggests that an aberrant NHEJ in the context of a constitutive endogenous DNA damage might contribute to the high frequency of chromosome abnormalities in MM cells, thus potentially playing a central role in the tumor progression and as an important prognostic marker in this disease. Disclosures:Anderson:Onyx: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees. Munshi:Celgene: Consultancy; Millenium: Consultancy; Merck: Consultancy; Onyx: Consultancy.

Cytomorphology of giant cell tumor of bone in pleural fluid

Cytomorphology of giant cell tumor of bone in pleural fluid

Prediction of metastatic breast cancer in non-sentinel lymph nodes based on metalloprotease-1 expression by the sentinel lymph node

AimsSentinel lymph node (SLN) biopsy is the current standard axillary approach for patients with clinically node-negative breast cancer. If the SLN is positive, is still also standard in most centres to proceed with a complete axillary dissection to predict the remaining nodes affectation, despite of SLN is the only positive lymph node in 50–68% of cases. If we could identify them, these patients could be spared a complete axillary dissection. MethodsElevated expression of specific matrix metalloproteases (MMPs) and their inhibitors (TIMPs) by stromal mononuclear inflammatory cells (MICs) of primary tumours is significantly associated with distant metastasis development in breast cancer. In the present study we first identified candidate MMPs/TIMPs associated with axillary metastasis in a preliminary group (n=50), and subsequently examined the potential of their expression in the SLN for predicting the status of the remaining nodes, in 105 patients with intraoperative SLN-assessment. ResultsMMP-1 expression by MICs from SLNs was significantly associated with metastatic spread to non-SLNs. Moreover, in all cases with negative MMP-1 expression by MICs from SLNs, the remaining non-SLNs were not affected (p<0.0001). Therefore, we demonstrate that MMP-1 expression by MICs from SLNs had 100% sensitivity, 100% negative-predictive value and 61.5% specificity to predict non-SLNs status. ConclusionThis is the first time that tumour spread to the remaining axillary nodes has been predicted from molecular features of the SLN(s). If confirmed in larger studies, patients could be spared the morbidity associated with an unnecessary complete lymphadenectomy.

Highlights of This Issue

The taxanes paclitaxel and docetaxel are widely used for the treatment of solid tumors. Recently, it was shown that cigarette smoking can influence the metabolism and toxicity profile of some important anticancer drugs. de Graan and colleagues designed a study to assess the influence of smoking on the metabolism and toxicities of taxane therapy. The pharmacokinetics of paclitaxel and docetaxel were not altered by smoking, but interestingly, smokers were found to have less hematologic toxicity during anticancer treatment.Approximately 5% to 10% of gastrointestinal stromal tumors (GIST) have pathogenetic activating mutations of the platelet-derived growth factor receptor (PDGFRA) tyrosine kinase. The most common variant, PDGFRA D842V, is resistant to currently approved tyrosine kinase inhibitors (TKI). Treatment of PDGFRA D842V–mutant GIST with conventional TKIs results in markedly inferior clinical outcomes compared with treatment of KIT-mutant GIST. Heinrich and colleagues identified crenolanib as a potent inhibitor of PDGFRA D842V with an IC50 of approximately 10 nmol/L (making it 100–150 times more potent than imatinib). Based on these results, a phase II study of crenolanib for advanced PDGFRA D842V–mutant GIST has been initiated (NCT01243346).Giant-cell tumor of bone (GCTB) is an aggressive osteolytic tumor characterized by osteoclast-like giant cells and their precursors that express RANK and mononuclear stromal cells that express the ligand RANKL, a key mediator of osteoclast activation. Denosumab binds to RANKL, eliminating giant cells, inhibiting bone destruction, and shifting the bone turnover balance in favor of bone formation. Branstetter and colleagues report that histologic evidence confirms these effects and shows that denosumab-induced interruption of the dysregulated overexpression of RANKL reduces tumor growth and promotes differentiation to normal tissue. This unique biologic mechanism is clinically relevant for GCTB treatment and for future cancer research.Docetaxel is extensively metabolized in the liver, but mechanisms by which the drug is taken up into hepatocytes remain unclear. de Graan and colleagues designed a translational study to investigate the influence of the OATP1B uptake transporters on docetaxel metabolism in transfected cell models, transporter knockout mice, and patients with inherited, reduced-function variants in the genes encoding these transporters. These findings shed new light on factors affecting the elimination of this widely used drug and provide a framework for future investigations aimed at tailoring drug dosage in cancer patients.

Improvement of Cardiac Contractile Function in Rats with Postinfarction Cardiosclerosis after Transplantation of Mononuclear and Multipotent Stroma Bone Marrow Cells

We compared the efficiency of autologous mononuclear cells and multipotent stromal cells of the bone marrow after their non-selective intracoronary transplantation on day 30 after acute coronary infarction in rats. Improvement of hemodynamic parameters of myocardial contractility (rates of left ventricular pressure rise and drop) in comparison with the initial values and deceleration of postinfarction prolongation of QRS and QT intervals were observed in rats of the experimental group in contrast to controls in 4 weeks after transplantation. These functional changes were more intensive after transplantation of multipotent stromal cells and were accompanied by more pronounced morphological signs of reverse myocardial remodeling: thickening of the scarred left ventricular wall, shrinkage of the scar, and decrease in left ventricular dilatation index.

Analysis of giant cell tumour of bone cells for Noonan syndrome/Cherubism‐related mutations

Giant cell tumour of bone (GCTB) is an osteolytic tumour which contains numerous osteoclast-like giant cells and a proliferation of mononuclear stromal cells (MSC). Giant cell-rich osteolytic lesions can also develop in the jaw bones in Noonan syndrome, a cherubism-like developmental abnormality that is transmitted in an autosomal dominant fashion, often because of mutation in the PTPN11 or BRAF genes. We screened GCTBs for mutations in PTPN11 and BRAF to determine whether GCTBs develop through alterations of genes involved in Noonan syndrome. MSC were isolated from 10 GCTBs. Chromosome banding analysis of these cells revealed telomeric associations (tas) in 7 of the 10 cases. Thus, the cultured cells expressed a cytogenetic abnormality typically found in short-term cultures from GCTBs. Sequencing of DNA extracted from the seven GCTB-derived MSC cultures displaying tas did not identify any mutation in PTPN11 or in exons 9-15 of BRAF. Our findings indicate that the molecular pathways involved in GCTB development are different from those causing Noonan syndrome. The method for isolating and culturing GCTB stromal cells described in this study generated a population of MSC that contained tas, indicating that it is useful for obtaining stromal cells from GCTB and other giant cell-rich lesions, such as giant cell reparative granuloma, for genetic and other studies.

Role of bone marrow transplantation for correcting hemophilia A in mice

AbstractTo better understand cellular basis of hemophilia, cell types capable of producing FVIII need to be identified. We determined whether bone marrow (BM)–derived cells would produce cells capable of synthesizing and releasing FVIII by transplanting healthy mouse BM into hemophilia A mice. To track donor-derived cells, we used genetic reporters. Use of multiple coagulation assays demonstrated whether FVIII produced by discrete cell populations would correct hemophilia A. We found that animals receiving healthy BM cells survived bleeding challenge with correction of hemophilia, although donor BM-derived hepatocytes or endothelial cells were extremely rare, and these cells did not account for therapeutic benefits. By contrast, donor BM-derived mononuclear and mesenchymal stromal cells were more abundant and expressed FVIII mRNA as well as FVIII protein. Moreover, injection of healthy mouse Kupffer cells (liver macrophage/mononuclear cells), which predominantly originate from BM, or of healthy BM-derived mesenchymal stromal cells, protected hemophilia A mice from bleeding challenge with appearance of FVIII in blood. Therefore, BM transplantation corrected hemophilia A through donor-derived mononuclear cells and mesenchymal stromal cells. These insights into FVIII synthesis and production in alternative cell types will advance studies of pathophysiological mechanisms and therapeutic development in hemophilia A.