[Total endoprosthetic replacement of femur, humerus and tibia]

Improvements in diagnostics and effectiveness of chemotherapy have resulted in most patients with primary malignant bone tumours being candidates for limb salvage surgery. Herewith, the use of modern modular tumour endoprostheses allows for the replacement of all big joints and even entire long bones such as the femur, humerus and tibia. In this article, we focus on individual prerequisites for and challenges with performing a total endoprosthetic reconstruction of the above-mentioned anatomic structures. Additionally, data from the literature with regards to functional outcome, problems and complications are presented.

[Growing Pains : Cause, Significance and Treatment]

BACKGROUND

Leg pain is a common reason for consultation in the children's orthopedic clinic. It can occur across all age groups, although most patients are of pre-school or elementary school age. As there are a series of possibly severe differential diagnoses that might cause such pains in children and adolescents apart from benign pains that occur in the context of growth, a thorough patient history and physical examination are essential.

PATHOGENESIS

Despite extensive research, the cause of benign growing pains has not been elucidated so far. Several possible factors play a role on an anatomical, metabolic or functional basis, ; thus, various theories exist with regard to their origin.

DIAGNOSIS

Growing pains constitute a diagnosis of exclusion. If a possible organic cause of the pains is suspected, an extended diagnosis of the person affected should be made. Growing pains primarily occur at night and are always self-resolving.

THERAPY

With regard to treatment, mild pain medications can be employed in more severely affected patients. It is much more important to inform family members about the benign nature of the condition. Reassuring words and physical relaxation exercises, in addition to massaging and stretching of the leg muscles, can cause a significant reduction in pain without medication.

Neuroinflammation and central PI3K/Akt/mTOR signal pathway contribute to bone cancer pain

BACKGROUND

Pain is one of the most common and distressing symptoms suffered by patients with progression of cancer; however, the mechanisms responsible for hyperalgesia are not well understood. Since the midbrain periaqueductal gray is an important component of the descending inhibitory pathway controlling on central pain transmission, in this study, we examined the role for pro-inflammatory cytokines of the periaqueductal gray in regulating mechanical and thermal hyperalgesia evoked by bone cancer via phosphatidylinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) signals.

METHODS

Breast sarcocarcinoma Walker 256 cells were implanted into the tibia bone cavity of rats to induce mechanical and thermal hyperalgesia. Western blot analysis and ELISA were used to examine PI3K/protein kinase B (Akt)/mTOR and pro-inflammatory cytokine receptors and the levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α).

RESULTS

Protein expression levels of p-PI3K/p-Akt/p-mTOR were amplified in the periaqueductal gray of bone cancer rats, and blocking PI3K-mTOR pathways in the periaqueductal gray attenuated hyperalgesia responses. In addition, IL-1β, IL-6, and TNF-α were elevated in the periaqueductal gray of bone cancer rats, and expression of their respective receptors (namely, IL-1R, IL-6R, and tumor necrosis factor receptor (TNFR) subtype TNFR1) was upregulated. Inhibition of IL-1R, IL-6R, and TNFR1 alleviated mechanical and thermal hyperalgesia in bone cancer rats, accompanied with downregulated PI3K-mTOR.

CONCLUSIONS

Our data suggest that upregulation of pro-inflammatory cytokine signal in the periaqueductal gray of cancer rats amplifies PI3K-mTOR signal in this brain region and alters the descending pathways in regulating pain transmission, and this thereby contributes to the development of bone cancer-induced pain.

Colloids or powders: Which nanoparticle formulations do cells like more?

Understanding the difference in physicochemical properties and biological response between colloidal and powder formulations of identical materials is important before the given materials are used in a medical milieu. In this study we compared a set of biological effects of colloidal and powder formulations of composite nanoparticles comprising superparamagnetic iron oxide cores and silicate/carbon shells. Magnetic dipole interaction between adjacent nanoparticles was more pronounced in their powders than in their colloidal formulations. Nanoparticles delivered as powders were thus more responsive to the magnetic field, but exhibited reduced uptake in bone and brain cancer cells, including K7M2 osteosarcoma line and U87 and E297 glioblastoma lines. Specifically, while the alternate magnetic field elicited a more rapid heat generation in cell culture media supplemented with the magnetic powders, the nanoparticles dispersed in the same media were uptaken by the cancer cells more copiously. The cellular uptake proved to be more crucial in defining the effect on cell survival, given that suspended formulations elicited a greater degree of cancer cell death in the magnetic field compared to the powder-containing formulations. Because of this effect, colloidal formulations were able to target cancer cells more effectively than the powders: they reduced the viability of all three tested cancer cell lines to a significantly greater degree that the viability of the normal, MDCK-MDR1 cell line. It is concluded that better uptake profile can make up for the lower heating rate in the AC field and lead to a more effective magnetic hyperthermia therapy. These results also demonstrate that the direct delivery of ferrofluids is more optimal than the administration of their constitutive particles as powders.

Engineering osteoblastic metastases to delineate the adaptive response of androgen-deprived prostate cancer in the bone metastatic microenvironment

While stromal interactions are essential in cancer adaptation to hormonal therapies, the effects of bone stroma and androgen deprivation on cancer progression in bone are poorly understood. Here, we tissue-engineered and validated an in vitro microtissue model of osteoblastic bone metastases, and used it to study the effects of androgen deprivation in this microenvironment. The model was established by culturing primary human osteoprogenitor cells on melt electrowritten polymer scaffolds, leading to a mineralized osteoblast-derived microtissue containing, in a 3D setting, viable osteoblastic cells, osteocytic cells, and appropriate expression of osteoblast/osteocyte-derived mRNA and proteins, and mineral content. Direct co-culture of androgen receptor-dependent/independent cell lines (LNCaP, C4-2B, and PC3) led cancer cells to display functional and molecular features as observed in vivo. Co-cultured cancer cells showed increased affinity to the microtissues, as a function of their bone metastatic potential. Co-cultures led to alkaline phosphatase and collagen-I upregulation and sclerostin downregulation, consistent with the clinical marker profile of osteoblastic bone metastases. LNCaP showed a significant adaptive response under androgen deprivation in the microtissues, with the notable appearance of neuroendocrine transdifferentiation features and increased expression of related markers (dopa decarboxylase, enolase 2). Androgen deprivation affected the biology of the metastatic microenvironment with stronger upregulation of androgen receptor, alkaline phosphatase, and dopa decarboxylase, as seen in the transition towards resistance. The unique microtissues engineered here represent a substantial asset to determine the involvement of the human bone microenvironment in prostate cancer progression and response to a therapeutic context in this microenvironment.

[Silver coating on tumour prostheses]

BACKGROUND

Modular endoprostheses, so-called "tumour or megaprostheses" are mainly used for limb salvage surgery after resection of malignant soft tissue or a bone tumour. Sometimes, this type of prosthesis is also used for revision surgeries after failed primary joint arthroplasty. Despite continuously improving techniques and quality management systems, periprosthetic infection is one of the most serious complications.

AIM OF THE STUDY

Review of the literature in the PubMed data base with the main focus on silver coatings in joint arthroplasty and their effect on infection rate, outcome and patients' safety.

RESULTS

The current literature shows that there is a beneficial role of silver coatings in megaprostheses in terms of revision rates for septic complications, especially following tumour resection with bad soft tissue coverage or in (multimorbid) high-risk patients, compared to uncoated implants.

DISCUSSION

Based on the results of previous publications examining blood or serum silver concentrations or silver levels in urine, silver coatings do not appear to have side effects, except for local argyria. Continuous monitoring of silver levels in blood or serum is still recommended, and additional long-term studies will be necessary to verify the effectiveness and safety of silver coatings.

Mesoporous superparamagnetic hydroxyapatite nanocomposite: A multifunctional platform for synergistic targeted chemo-magnetotherapy

In the present study, the aim was to develop a magneto-responsive nanocomposite for application in drug delivery by the integration of magnetic nanoparticles into an inorganic architecture, hydroxyapatite. The magnetic mesoporous hydroxyapatite nanocomposites, MMHAPs, were synthesized using a template-free method and fully characterized by XRD, FT-IR, TEM, FE-SEM, VSM, ICP, BET, and UV-Vis spectroscopy. MMHAPs exhibited a rod-like shape with a structure of large mesopores and high surface area. A sample of the nanocomposites with well-defined properties, MMHAP(2), was selected as a carrier for delivery of chemotherapy drug, doxorubicin (Dox). Then, it was coated with polyethylene glycol (P) and folic acid (F), providing aqueous stability and tumor targeting, respectively. The evaluation of drug release profile revealed that the release of drug occurs in a time-staggered manner under low pH conditions, which simulate the internal condition of lysosome. More important, a significant drug release was observed under a static magnetic field (SMF), displaying a magnetically triggered release. According to the toxicity assessment, MMHAP(2) did not show any noticeable toxic effect against the tumor cells (Saos-2) and normal cells (HEK-293) up to 100 μg ml^-1 in the presence or absence of SMF. In contrast, the drug-loaded nanocomposite, F.P.D@MMHAP(2), possesses high antitumor efficacy particularly in the presence of SMF. Moreover, it was found that the cellular internalization of F.P.D@MMHAP(2) could be increased by SMF, providing therapeutic efficiency enhancement. The high cytotoxic effect of F.P.D@MMHAP(2) with the help of SMF caused apoptosis in the tumor cells, which was preceded by a disturbance in the intracellular redox state and then caspase activation. Based on the data obtained, F.P.D@MMHAP(2) is a pH- and magneto-responsive platform opening up a new perspective in terms of its exploitation in cancer therapy.

The serum SA levels are significantly increased in sepsis but decreased in cirrhosis

Most of proteins in human blood circulation are glycoproteins with one or more covalently linked N- or O-linked glycans. Sialic acid (SA) generally occurs as the terminal monosaccharide on the glycans. SA in glycoproteins modulates a wide range of physiological and pathological processes and has been routinely measured in hospital since 1950s. Increased serum SA levels have been associated with different types of cancers. However, a systematic comparison of the serum SA levels in different types of human diseases has not been reported. In current study, 160,537 clinical lab test results of serum SA levels from healthy individuals and patients with 64 different types of diseases during the past 5 years in our hospital were retrieved and analyzed. Based on the mean (SD), median, and p (-Log₁₀p) values, we found that patients suffering 55 different types of cancer and noncancer diseases such as sepsis, pancreatitis, bone cancer, rheumatoid arthritis, pancreatic cancer, and encephalitis had significantly (p<0.05, -Log₁₀p>1.30) increased median serum SA levels whereas patients suffering hepatic encephalopathy, cirrhosis, renal cyst, and hepatitis had significantly decreased median serum SA levels compared to that of healthy controls. Moreover, the greatest increase in the mean (SD) and -Log₁₀p values was observed in sepsis and pancreatitis, respectively, but not in cancers. Thus, the regulations of serum SA levels were much more complicated than previously assumed. Understanding the molecular mechanisms behind these observations would make serum SA a useful biomarker to facilitate personalized diagnosis and treatment for patients with different diseases.

Response to PD1 inhibition in conventional chondrosarcoma

Background

Chondrosarcoma is one of the most common malignant bone tumors in adults. Conventional chondrosarcoma represents around 85% of all chondrosarcomas and is notoriously difficult to treat with chemotherapy.

Case presentation

We describe a 67-year-old man with metastatic conventional chondrosarcoma who was treated with nivolumab. Treatment was discontinued after restaging showed increased tumor burden, which later proved to be pseudoprogression. The patient restarted nivolumab and continues to have a near complete response.

Conclusion

Conventional chondrosarcoma may be sensitive to checkpoint inhibitors. Further, this case demonstrates clearly the phenomenon of pseudo-progression in this disease, a factor that must be considered in the design of clinical trials and clinical care. This case supports additional study of immunomodulatory agents in this deadly disease.

Survival of adults with cancers of bone or soft tissue in Europe-Report from the EUROCARE-5 study

BACKGROUND

Five-year relative survival (RS) of adults with bone and soft-tissue cancers in Europe was still <60% by 1995-1999. There was large geographical survival variability, mainly for bone tumours, and survival decreased with increasing age at diagnosis.

METHODS

Data from 87 population-based cancer registries in 29 countries, extracted from the EUROCARE-5 database, were used to provide updated estimates of survival and describe trends in survival of adults with cancers of these sites across Europe. We calculated 5-year RS for patients diagnosed in 2000-2007. We estimated 5-year RS by the period approach to assess changes in survival between 1999-2001, 2002-2004 and 2005-2007, and provide reliable predictions for recently diagnosed patients.

RESULTS

Five-year RS was 60% for adults diagnosed with soft-tissue cancer in 2000-2007 and 53% for those with bone cancer. RS declined with increasing age at diagnosis, especially for bone cancer. Survival from bone cancer varied widely between European regions, from 63 to 62% in Northern and Central Europe to 39% in Eastern Europe. Inter-regional variation was much less for soft-tissue cancer. For both site groupings, there was little evidence of change in five-year RS up to 2002-2004, followed by increases of 3-4% during 2005-2007.

CONCLUSIONS

Outcomes for adults with bone and soft-tissue cancer in Europe began to improve around 2005; new therapeutic developments are expected to result in further progress. Survival improvements already achieved must be brought more fully to elderly patients and those in Eastern Europe. European Reference Networks on rare cancers will have a vital role in future progress.

Risk factors for metastasis at presentation with conventional chondrosarcoma: a population-based study

PURPOSE

The aim of the study was to investigate risk factors for metastasis at diagnosis.

METHODS

We collected patients diagnosed with conventional chondrosarcoma between 1983 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) database. Each patient was classified as having metastatic or localized disease. Univariate and multivariate logistic regression analyses were applied to determine which characteristics were risk factors for metastasis at diagnosis.

RESULTS

Two thousand three hundred forty-nine patients were collected and 180 patients had metastasis at presentation. Data on age, gender, primary site, grade, and tumour size were enrolled into the multivariate logistic analysis. Greater age (60 years or older: OR = 1.872, 95% CI, 1.206 to 2.904), axial or craniofacial location (spine: OR = 1.775, 95% CI, 1.188 to 2.651; thoracic cage: OR = 2.034, 95% CI, 1.321 to 3.134; craniofacial bones: OR = 5.507, 95% CI, 3.001 to 10.107), higher grade (grade II: OR = 1.849, 95%CI, 1.181 to 2.895; grade III: OR = 4.016, 95%CI, 2.513 to 6.418), and larger tumour size (size over 10 cm: OR = 7.135, 95%CI, 2.130 to 23.893) were associated with an increased risk of metastasis at presentation.

CONCLUSIONS

Conventional chondrosarcoma patients with greater age, axial or craniofacial tumour location, higher grade, and larger tumor size were more likely to have metastasis at diagnosis.

Lectin-conjugated pH-responsive mesoporous silica nanoparticles for targeted bone cancer treatment

A novel multifunctional nanodevice based in doxorubicin (DOX)-loaded mesoporous silica nanoparticles (MSNs) as nanoplatforms for the assembly of different building blocks has been developed for bone cancer treatment. These building blocks consists of: i) a polyacrylic acid (PAA) capping layer grafted to MSNs via an acid-cleavable acetal linker, to minimize premature cargo release and provide the nanosystem of pH-responsive drug delivery ability; and ii) a targeting ligand, the plant lectin concanavalin A (ConA), able to selectively recognize, bind and internalize owing to certain cell-surface glycans, such as sialic acids (SA), overexpressed in given tumor cells. This multifunctional nanosystem exhibits a noticeable higher internalization degree into human osteosarcoma cells (HOS), overexpressing SA, compared to healthy preosteoblast cells (MC3T3-E1). Moreover, the results indicate that small DOX loading (2.5 µg mL^-1) leads to almost 100% of osteosarcoma cell death in comparison with healthy bone cells, which significantly preserve their viability. Besides, this nanodevice has a cytotoxicity on tumor cells 8-fold higher than that caused by the free drug. These findings demonstrate that the synergistic combination of different building blocks into a unique nanoplatform increases antitumor effectiveness and decreases toxicity towards normal cells. This line of attack opens up new insights in targeted bone cancer therapy.

STATEMENT OF SIGNIFICANCE

The development of highly selective and efficient tumor-targeted smart drug delivery nanodevices remains a great challenge in nanomedicine. This work reports the design and optimization of a multifunctional nanosystem based on mesoporous silica nanoparticles (MSNs) featuring selectivity towards human osteosarcoma cells and pH-responsive antitumor drug delivery capability. The novelty and originality of this manuscript relies on proving that the synergistic assembly of different building blocks into a unique nanoplatform increases antitumor effectiveness and decreases toxicity towards healthy cells, which constitutes a new paradigm in targeted bone cancer therapy.

Oxidative stress in ageing and disease development studied by FT-IR spectroscopy

FT-IR spectroscopy was used to investigate the effect of oxidative stress and to approach the mechanism on cancer bone demineralization, aortic valve mineralization and heterotopic ossification on disease development. The FT-IR spectra obtained from paediatric, adult bone and ex vivo irradiated adult healthy bone with a dose of 20Gy were compared with those of healthy bone. The increase of band intensity changes of vasCH_2,vsCH₂ in the region 3000-2850cm^-1 depended on aging, the disease progression and the dose of irradiation. The bands at 3080cm^-1 and 1744cm^-1, which originate from olefinic terminal bond (v=CH) and ester carbonyl group (vROCO), respectively, indicate the influence of oxidative stress on lipid degradation and peroxidation, respectively. The new bands at about 1690cm^-1 and 1516cm^-1 denote the presence of β-sheet conformation of the proteins due to the diseases, confirming the increasing amount of lipophilic environment and fibril formation. Comparison of the FT-IR spectra of calcified aortic valve and hip heterotopic ossification with that of normal bones showed that in the bone-like formation the peroxide anion free radicals play an important role in the disease.

Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics

Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is relatively poor, with 5 year OSA survival rates in people not having improved in decades. For dogs, 1 year survival rates are only around ~ 45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human OSA. Finally, the current position of canine OSA genetic research is discussed and areas for additional work within the canine population are identified.

Tumor Syndromes That Include Bone Tumors: An Update

Tumor syndromes, including bone neoplasias, are genetic predisposing conditions characterized by the development of a pattern of malignancies within a family at an early age of onset. Occurrence of bilateral, multifocal, or metachronous neoplasias and specific histopathologic findings suggest a genetic predisposition syndrome. Additional clinical features not related to the neoplasia can be a hallmark of specific genetic syndromes. Mostly, those diseases have an autosomal dominant pattern of inheritance with variable percentage of penetrance. Some syndromic disorders with an increased tumor risk may show an autosomal recessive transmission or are related to somatic mosaicism. Many genetic tumor syndromes are known. This update is specifically focused on syndromes predisposing to osteosarcoma and chondrosarcoma.

Plasma-induced selectivity in bone cancer cells death

BACKGROUND

Current therapies for bone cancers - either primary or metastatic - are difficult to implement and unfortunately not completely effective. An alternative therapy could be found in cold plasmas generated at atmospheric pressure which have already demonstrated selective anti-tumor action in a number of carcinomas and in more relatively rare brain tumors. However, its effects on bone cancer are still unknown.

METHODS

Herein, we employed an atmospheric pressure plasma jet (APPJ) to validate its selectivity towards osteosarcoma cell line vs. osteoblasts & human mesenchymal stem cells.

RESULTS

Cytotoxicity following direct interaction of APPJ with cells is comparable to indirect interaction when only liquid medium is treated and subsequently added to the cells, especially on the long-term (72h of cell culture). Moreover, following contact of the APPJ treated medium with cells, delayed effects are observed which lead to 100% bone cancer cell death through apoptosis (decreased cell viability with incubation time in contact with APPJ treated medium from 24h to 72h), while healthy cells remain fully viable and unaffected by the treatment.

CONCLUSIONS

The high efficiency of the indirect treatment indicates that an important role is played by the reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the gaseous plasma stage and then transmitted to the liquid phase, which overall lead to lethal and selective action towards osteosarcoma cells. These findings open new pathways for treatment of metastatic bone disease with a minimally invasive approach.

Molecular genetics of osteosarcoma

Osteosarcoma is the predominant form of bone cancer, affecting mostly adolescents. Recent progress made in molecular genetic studies of osteosarcoma has changed our view on the cause of the disease and ongoing therapeutic approaches for patients. As we draw closer to gaining more complete catalogs of candidate cancer driver genes in common forms of cancer, the landscape of somatic mutations in osteosarcoma is emerging from its first phase. In this review, we summarize recent whole genome and/or whole exome genomic studies, and then put these findings in the context of genetic hallmarks of somatic mutations and mutational processes in human osteosarcoma. One of the lessons learned here is that the extent of somatic mutations and complexity of the osteosarcoma genome are similar to that of common forms of adult cancer. Thus, a much higher number of samples than those currently obtained are needed to complete the catalog of driver mutations in human osteosarcoma. In parallel, genetic studies in other species have revealed candidate driver genes and their roles in the genesis of osteosarcoma. This review also summarizes newly identified drivers in genetically engineered mouse models (GEMMs) and discusses our understanding of the impact of nature and number of drivers on tumor latency, subtypes, and metastatic potentials of osteosarcoma. It is becoming apparent that a synergistic team composed of three drivers (one 'first driver' and two 'synergistic drivers') may be required to generate an animal model that recapitulates aggressive osteosarcoma with a short latency. Finally, new cancer therapies are urgently needed to improve survival rate and quality of life for osteosarcoma patients. Several vulnerabilities in osteosarcoma are illustrated in this review to exemplify the opportunities for next generation molecularly targeted therapies. However, much work remains in order to complete our understanding of the somatic mutation basis of osteosarcoma, to develop reliable animal models of human disease, and to apply this information to guide new therapeutic approaches for reducing morbidity and mortality of this rare disease.

Bufalin attenuates cancer-induced pain and bone destruction in a model of bone cancer

Bufalin is a natural anti-inflammatory small molecule. Given the close relationship between inflammation and cancer, many scholars have studied the effect of bufalin on cancer in vitro, but in vivo research is still lacking. A murine bone cancer model was used in this study. We conducted pain sensitive test on mice with bone cancer, by nocifensive behavior, mechanical allodynia, and thermal hyperalgesia. Serum levels of bone loss markers with bufalin treatment were measured by ELISA. Expressions of osteoprotegerin (OPG) and receptor activator of NF-κB ligand (RANKL) were analyzed in bufalin-treated mice by real-time PCR and Western blot. Cannabinoid 2 receptor (CB2) inverse agonist AM630 was administrated to mice with bone cancer together with bufalin. Bufalin relieved cancer-induced pain and bone destruction in the murine bone cancer model. Serum levels of bone loss markers after bufalin treatment were reduced. Bufalin upregulated OPG and downregulated RANKL. The CB2 receptor inverse agonist, AM630, reduced the pain relief of bufalin treatment in the mouse bone cancer model. This study demonstrates that bufalin relieves cancer-induced pain and bone destruction, which is mediated through the CB2 receptor.

Systemic Therapy Outcomes in Adult Patients with Ewing Sarcoma Family of Tumors

Background

The Ewing sarcoma family of tumors (ESFT) is a rare but curable bone neoplastic entity. The current standard of care involves chemotherapy and local disease control with surgery or radiation regardless of the extent of disease at presentation. Data that document the effectiveness of the current approach in the adult patient population are limited.

Methods

We performed a retrospective review including all ESFT patients older than 19 years of age who received systemic therapy between January 2002 and December 2013 at our institution. The main study outcome was overall survival; secondary outcomes were objective response rate, disease-free survival, and progression-free survival.

Results

Eighteen patients with ESFT were identified. The median overall survival for the entire group was 20.65 months (range 0.43–114.54). In patients with localized disease, the 1-, 2-, and 3-year survival rates were 90, 80, and 70%, respectively. Age was not correlated with overall survival (r = 0.58, p = 0.76). The 3-year disease-free survival rate was 70%. In patients with metastatic disease, the 1-year survival rate was 40%. In patients treated in the neoadjuvant and palliative setting with chemotherapy, we observed an objective response rate of 61.54%. The time to progression in patients with metastatic disease treated with chemotherapy ranged from 0.69 to 4.93 months.

Conclusion

In this group of adult patients with ESFT treated with multimodality therapy, the outcomes were similar to those reported in well-known larger clinical trials that typically included younger patients. Age was not associated with worse survival.

Cervical osteochondroma with neurological symptoms: literature review and a case report

INTRODUCTION

Osteochondromas are common benign tumors of bone and spinal involvement is uncommon. Solitary spinal osteochondromas may produce a wide variety of symptoms depending on their location and relationship to adjacent neural structures.

CASE PRESENTATION

Herein, we present a case of solitary osteochondroma arising from the posterior arch of C1, causing left-sided ascending numbness and paresthesia and difficulty walking. The lesion was totally resected through a posterior approach. Histopathological examination confirmed the diagnosis of benign osteochondroma.

DISCUSSION

Spinal cord compression is uncommon in spinal osteochondromas because in most cases the tumor grows out of the spinal column. To prevent neurological compromise, complete surgical removal is mandatory when an intraspinal osteochondroma with cord compression is diagnosed, which also helps to prevent recurrence. Our literature review of similar cases indicates that despite the old belief that C2 is the most commonly involved vertebra for osteochondromas, C1 is actually the most commonly involved vertebra in the cervical region.

Risk of bone tumors in children and residential proximity to industrial and urban areas: New findings from a case-control study

Few epidemiologic studies have explored risk factors for bone tumors in children, and the role of environmental factors needs to be analyzed. Our objective was to ascertain the association between residential proximity to industrial plants and urban areas and risk of bone tumors in children, taking into account industrial groups and toxic pollutants released. A population-based case-control study of childhood bone cancer in Spain was carried out, covering 114 incident cases obtained from the Spanish Registry of Childhood Tumors (between 1996 and 2011), and 684 controls individually matched by sex, year of birth, and autonomous region of residence. Distances from the subject's residences to the 1271 industries and the 30 urban areas (towns) with ≥75,000 inhabitants located in the study area were computed. Unconditional logistic regression models were fitted to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance (from 1km to 3km) to industrial and urban areas, with adjustment for matching variables and sociodemographic indicators. Excess risk (OR; 95%CI) of bone tumors in children was detected for children close to industrial facilities as a whole (2.33; 1.17-4.63 at 3km) - particularly surface treatment of metals (OR=2.50; 95%CI=1.13-5.56 at 2km), production and processing of metals (OR=3.30; 95%CI=1.41-7.77 at 2.5km), urban waste-water treatment plants (OR=4.41; 95%CI=1.62-11.98 at 2km), hazardous waste (OR=4.63; 95%CI=1.37-15.61 at 2km), disposal or recycling of animal waste (OR=4.73; 95%CI=1.40-15.97 at 2km), cement and lime (OR=3.89; 95%CI=1.19-12.77 at 2.5km), and combustion installations (OR=3.85; 95%CI=1.39-10.66 at 3km)-, and urban areas (4.43; 1.80-10.92). These findings support the need for more detailed exposure assessment of certain toxics released by these facilities.

Osteosarcoma Overview

Osteosarcoma (OS) is the most common primary malignancy of bone and patients with metastatic disease or recurrences continue to have very poor outcomes. Unfortunately, little prognostic improvement has been generated from the last 20 years of research and a new perspective is warranted. OS is extremely heterogeneous in both its origins and manifestations. Although multiple associations have been made between the development of osteosarcoma and race, gender, age, various genomic alterations, and exposure situations among others, the etiology remains unclear and controversial. Noninvasive diagnostic methods include serum markers like alkaline phosphatase and a growing variety of imaging techniques including X-ray, computed tomography, magnetic resonance imaging, and positron emission as well as combinations thereof. Still, biopsy and microscopic examination are required to confirm the diagnosis and carry additional prognostic implications such as subtype classification and histological response to neoadjuvant chemotherapy. The current standard of care combines surgical and chemotherapeutic techniques, with a multitude of experimental biologics and small molecules currently in development and some in clinical trial phases. In this review, in addition to summarizing the current understanding of OS etiology, diagnostic methods, and the current standard of care, our group describes various experimental therapeutics and provides evidence to encourage a potential paradigm shift toward the introduction of immunomodulation, which may offer a more comprehensive approach to battling cancer pleomorphism.

Targeted drug delivery of near IR fluorescent doxorubicin-conjugated poly(ethylene glycol) bisphosphonate nanoparticles for diagnosis and therapy of primary and metastatic bone cancer in a mouse model

BACKGROUND

Most primary and metastatic bone tumors demonstrate increased osteoclast activity and bone resorption. Current treatment is based on a combination of surgery, radiotherapy and chemotherapy. Severe side effects are associated with chemotherapy due to use of high dosage and nonspecific uptake. Bisphosphonates have a strong affinity to Ca2+ ions and are widely used in the treatment of bone disorders.

RESULTS

We have engineered a unique biodegradable bisphosphonate nanoparticle (NPs) bearing two functional surface groups: (1) primary amine groups for covalent attachment of a dye/drug (e.g. NIR dye Cy 7 or doxorubicin); (2) bisphosphonate groups for targeting and chelation to bone hydroxyapatite. In addition, these engineered NPs contain high polyethyleneglycol (PEG) concentration in order to increase their blood half life time. In vitro experiments on Saos-2 human osteosarcoma cell line, demonstrated that at a tenth of the concentration, doxorubicin-conjugated bisphosphonate NPs achieved a similar uptake to free doxorubicin. In vivo targeting experiments using the NIR fluorescence bisphosphonate NPs on both Soas-2 human osteosarcoma xenograft mouse model and orthotopic bone metastases mCherry-labeled 4T1 breast cancer mouse model confirmed specific targeting. In addition, therapeutic in vivo experiments using doxorubicin-conjugated bisphosphonate NPs demonstrated a 40% greater inhibition of tumor growth in Saos-2 human osteosarcoma xenograft mouse model when compared to free doxorubicin.

CONCLUSIONS

In this research we have shown the potential use of doxorubicin-conjugated BP NPs for the targeting and treatment of primary and metastatic bone tumors. The targeted delivery of doxorubicin to the tumor significantly increased the efficacy of the anti-cancer drug, thus enabling the effective use of a lower concentration of doxorubicin. Furthermore, the targeting ability of the BP NPs in an orthotopic xenograft mouse model reinforced our findings that these BP NPs have the potential to be used for the treatment of primary and metastatic bone cancer.

Cancer stem cells in osteosarcoma

Osteosarcoma is the most common primary bone tumour in children and adolescents and advanced osteosarcoma patients with evidence of metastasis share a poor prognosis. Osteosarcoma frequently gains resistance to standard therapies highlighting the need for improved treatment regimens and identification of novel therapeutic targets. Cancer stem cells (CSC) represent a sub-type of tumour cells attributed to critical steps in cancer including tumour propagation, therapy resistance, recurrence and in some cases metastasis. Recent published work demonstrates evidence of cancer stem cell phenotypes in osteosarcoma with links to drug resistance and tumorigenesis. In this review we will discuss the commonly used isolation techniques for cancer stem cells in osteosarcoma as well as the identified biochemical and molecular markers.

Design and synthesis of pyrimidinyl acyl thioureas as novel Hsp90 inhibitors in invasive ductal breast cancer and its bone metastasis

Invasive ductal carcinoma is the most common breast malignancies tumors and has tendency to bone metastases. Many oncogenic client proteins involved in formation of metastatic pathways. Stabilization, regulation, and maintenance of these oncogenic client proteins are provided with Heat Shock Protein 90 (Hsp90). Hsp90 perform these processes through its ATP binding and subsequent hydrolysis energy. Therefore, designing Hsp90 inhibitors is a novel cancer treatment method. However, many Hsp90 inhibitors have solubility problems and showed adverse effects in clinical trials. Thus, we designed and synthesized novel pyrimidinyl acyl thiourea derivatives to selectively inhibit Hsp90 alpha in human invasive ductal breast (MCF-7) and human bone osteosarcoma (Saos-2) cell lines. In vitro experiments showed that the compounds inhibited cell proliferation, ATP hydrolysis, and exhibited cytotoxic effect on these cancer cell lines. Further, gene expression was analyzed by microarray studies on MCF-7 cell lines. Several genes that play vital roles in breast cancer pathogenesis displayed altered gene expression in the presence of a selected pyrimidinyl acyl thiourea compound. Molecular docking studies were also performed to determine interaction between Hsp90 ATPase domain and pyrimidinyl acyl thiourea derivatives. The results indicated that the compounds are able to interact with Hsp90 ATP binding pocket and inhibit ATPase function. The designed compounds powerfully inhibit Hsp90 by an average of 1 μM inhibition constant. And further, the compounds perturb Hsp90 N terminal domain proper orientation and ATP may not provide required conformational change for Hsp90 function as evidenced by in silico experiments. Therefore, the designed compounds effectively inhibited both invasive ductal breast carcinoma and bone metastasis. Pyrimidinyl acyl thiourea derivatives may provide a drug template for effective treatment of invasive ductal breast carcinoma and its bone metastasis as well as new therapeutic perspective for drug design.

Mitochondrial genome of a multiple myeloma bone cancer disease model rat strain (Muridae; Rattus)

We sequenced the complete mitochondrial genome sequencing of a multiple myeloma bone cancer disease model rat strain for the first time. The total length of the mitogenome was 16,302 bp and coding 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes.

Differences in electrophysiological properties of functionally identified nociceptive sensory neurons in an animal model of cancer-induced bone pain

Background

Bone cancer pain is often severe, yet little is known about mechanisms generating this type of chronic pain. While previous studies have identified functional alterations in peripheral sensory neurons that correlate with bone tumours, none has provided direct evidence correlating behavioural nociceptive responses with properties of sensory neurons in an intact bone cancer model.

Results

In a rat model of prostate cancer-induced bone pain, we confirmed tactile hypersensitivity using the von Frey test. Subsequently, we recorded intracellularly from dorsal root ganglion neurons in vivo in anesthetized animals. Neurons remained connected to their peripheral receptive terminals and were classified on the basis of action potential properties, responses to dorsal root stimulation, and to mechanical stimulation of the respective peripheral receptive fields. Neurons included C-, Aδ-, and Aβ-fibre nociceptors, identified by their expression of substance P. We suggest that bone tumour may induce phenotypic changes in peripheral nociceptors and that these could contribute to bone cancer pain.

Conclusions

This work represents a significant technical and conceptual advance in the study of peripheral nociceptor functions in the development of cancer-induced bone pain. This is the first study to report that changes in sensitivity and excitability of dorsal root ganglion primary afferents directly correspond to mechanical allodynia and hyperalgesia behaviours following prostate cancer cell injection into the femur of rats. Furthermore, our unique combination of techniques has allowed us to follow, in a single neuron, mechanical pain-related behaviours, electrophysiological changes in action potential properties, and dorsal root substance P expression. These data provide a more complete understanding of this unique pain state at the cellular level that may allow for future development of mechanism-based treatments for cancer-induced bone pain.

Negative and Positive Consequences of Cancer Treatment Experienced by Long-term Osteosarcoma Survivors: A Qualitative Study

BACKGROUND

Our study aimed to explore how survivors of osteosarcoma of the lower extremity experience physical and psychosocial late effects several years after undergoing arduous treatment. A qualitative, phenomenological and hermeneutic approach was applied.

MATERIALS AND METHODS

Osteosarcoma survivors (n=8) previously treated at the Norwegian Radium Hospital, Oslo University Hospital, participated in the study. In-depth and semi-structured interviews were conducted. The interviews were analyzed using inductive thematic analysis.

RESULTS

Three to ten years after diagnosis, the majority of participants had experienced both negative and positive consequences following treatment. Changes in activity and exclusion from participation in different areas were the most challenging consequences. Several of their experiences are similar to those described by people with disabilities.

CONCLUSION

It is important to understand osteosarcoma survivors' own experiences in order to assist those who struggle to reorient in life and to construct a new identity for themselves.

Impaired Immune Function in Patients Undergoing Surgery for Bone Cancer

BACKGROUND

Natural killer (NK) cells undergo quantitative and functional changes after oncological surgery.

PATIENTS AND METHODS

After Institutional Review Board approval, the count and function of NK cells from patients with malignant bone tumors were assessed only days 1, 3, 5 and during first postoperative visit, and compared with preoperative values. The serum concentrations of interleukins (IL)-2, -4 and -6 were also measured before and after surgery.

RESULTS

Complete clinical and laboratory data were analyzed from 17 patients with different bone malignancies. The number of NK cells significantly decreased postoperatively as well as their function. The maximum deterioration in their function occurred 5 days postoperatively. The serum concentrations of IL-2 and IL-4 did not change perioperatively. In contrast, a significant increase in the concentrations of IL-6 was observed on day 1, 3 and 5 postoperatively.

CONCLUSION

A significant inflammatory response and innate immune suppression occurred after surgery for malignant bone tumors.

Epigallocatechin-3-gallate attenuates bone cancer pain involving decreasing spinal Tumor Necrosis Factor-α expression in a mouse model

Tumor metastasis to bone often elicits a wide array of symptoms, in which pain is a significant factor in catastrophic complications of bone cancer. The complete understanding of bone cancer-related pain is still unknown, while several pathophysiological components have been suggested, from tumor-stimulated osteolysis, nerve compression, stimulations of ion channels, and locally generated inflammatory cytokines. In particular, it has been shown that pro-inflammatory cytokine TNFα-mediated actions are necessary for the development of bone cancer pain. As a member of catechin family in green tea extracts, EGCG (Epigallocatechin-3-gallate) can reduce excess free radicals and attenuate overactive inflammatory signaling including TNFα. In addition, EGCG or its related molecules have been used to control neuropathic pain in various preclinical settings. However, its potential use in bone cancer-caused pain has not yet been reported. Here we show that treating a mouse model of bone cancer by EGCG, results in a dramatic reduction in pain behavior and a significant decrease of TNFα expression within the spinal cord of tumor-bearing mice. Thus, this study reveals an anti-nociceptive role for EGCG in the progression of pain caused by tumor bone metastasis, and highlights a potential scheme by using anti-TNFα as a therapeutic option for osteolytic pain.

Helical coil electrode radiofrequency ablation designed for application in osteolytic vertebral tumors--initial evaluation in a porcine model

BACKGROUND CONTEXT

Radiofrequency ablation (RFA) is emerging as a complementary treatment for vertebral metastases. Traditional RFA induces frictional heating leading to local tissue necrosis but often yields small, incomplete, and inhomogeneous zones of ablation in bone. We have developed a new bone-specific RFA electrode that uses a nontraditional frequency (27.12 MHz) and geometry (helical), exploiting a magnetic field and an electric field to generate larger and more comprehensive treatment zones.

PURPOSE

The purpose of the study was to evaluate the feasibility and safety of the Bone Coil RFA electrode in the spine.

STUDY DESIGN

This is a preclinical in vivo study based on basic science.

METHODS

Under institutional approval, six healthy Yorkshire pigs received a sham and an RF treatment in two adjacent cervical vertebrae. To deploy the Bone Coil RFA device in dense porcine vertebrae, a surgical approach was required; an irrigated coring drill bit created a cylindrical path in the vertebral bodies through which the RFA electrodes were placed. The electronic circuit was completed by four grounding pads. Treatment was delivered for 10 minutes at 20 W (n=1), 25 W (n=1), and 30 W (n=4). To monitor the thermal rise and for safety, fiber-optic probes recorded temperatures in the center of each coil and near the spinal foramen. After the procedure, animals were monitored for 2 weeks. Magnetic resonance imaging (MRI) was completed immediately after treatment and at 14 days. Magnetic resonance image segmentation and histology were used to evaluate the ablation volume.

RESULTS

Comprehensive treatment of the porcine vertebrae was demonstrated by temperature monitoring, MRI, and histology. Large zones of RF ablation were obtained (RF: 3.72±0.73 cm3 vs. sham: 1.98±0.16 cm3, p<.05), confined within the vertebral body. Internal temperatures were elevated with RF (66.1 °C-102.9 °C), without temperature rise outside of the vertebrae (38.2 °C ± 1.5 °C). Mobility, neurological responses, and behavior were normal, consistent with preprocedural examination. Magnetic resonance imaging best visualized ablation at Day 14. Histology revealed comprehensive homogeneous coagulative necrosis with little peripheral sign of repair.

CONCLUSIONS

The Bone Coil RFA device created large intravertebral ablation volumes with no neurologic sequelae. Radiofrequency thermal ablation (clearly distinguished from the much smaller effects arising from core drilling) corresponded to the homogeneous necrosis visible on histology.

[Surgical treatment of osteochondromas: indication in "Strategic Exostosis"]

OBJECTIVE

The osteochondromas represents is the most frequent benign lesion interesting the bone tissue. This lesion, often asymptomatic, can arise through mechanical, irritative or painful syndromes: "strategic exostosis".

MATERIALS AND METHODS

In our present study we retrospectively evaluated 65 Caucasian patients, which have been treated surgically for symptomatic solitary exostosis from March 2004 to Jan 2011. The most frequent symptom referred by patient has been represented by pain. The others complains were related to nervous compression, esthetic injury and a reduction of range of motion. By using the VAS score we evaluated the post-operative bone pain at 3, 12 and 24 months. At the end of follow up we evaluated by a validated questionnaire the grade of patient satisfaction.

RESULTS

No major surgical complication were found. The rate of disease recidivism was null. Only a small group of patient referred a persisting pain in the lesion area during the two years follow up. In this subgroup the rate of satisfaction was obviously reduced.

CONCLUSIONS

In our opinion the surgical treatment of strategic exostosis, is safe and it should be recommended, since it allows to eliminate the noise with a low incidence of complications. The large majority of out patients were satisfied of the clinical improvement they experienced.

Mitochondrial genome of a spontaneous multiple myeloma bone cancer model mouse C57BL/KaLwRij strain

We sequenced the complete mitochondrial genome of a multiple myeloma bone cancer model mouse C57BL/KaLwRij strain for the first time. The total length of the mitogenome was 16,297 bp, with 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes. This mitochondrial genome sequence contains 127 SNPs compared with the house mouse reference sequence.

What do we know about survivorship after treatment for extremity sarcoma? A systematic review

OBJECTIVE

The varied presentations and treatments of extremity bone and soft tissue sarcoma mean that the issues faced by survivors are diverse and complex. The aim of this systematic review was to investigate what is known about this topic with a view to identifying areas for further research or service development.

METHODS

This was a review of the English language literature identified from Medline and Ovid and hand searches published between January 2000 and September 2012. Results were compiled according to physical, psychological and social domains of survivorship.

RESULTS

Of 182 studies identified, 22 met the inclusion criteria. There is a wide range of outcome measures used and a need for more objective measures. Unsurprisingly, survivors of extremity sarcoma typically demonstrate lower levels of physical functioning than healthy controls. In addition, survivors demonstrate a substantial psychological morbidity.

CONCLUSIONS

Services for survivors of extremity sarcoma should include rehabilitation and psychological support, sexual health services, expert pain management, and support to return to work.

Targeting receptor tyrosine kinases in osteosarcoma and Ewing sarcoma: current hurdles and future perspectives

Osteosarcoma (OS) and Ewing sarcoma (ES) are the two most common types of primary bone cancer, which mainly affect children and young adults. Despite intensive multi-modal treatment, the survival of both OS and ES has not improved much during the last decades and new therapeutic options are awaited. One promising approach is the specific targeting of transmembrane receptor tyrosine kinases (RTKs) implicated in these types of bone cancer. However, despite encouraging in vitro and in vivo results, apart from intriguing results of Insulin-like Growth Factor-1 Receptor (IGF-1R) antibodies in ES, clinical studies are limited or disappointing. Primary resistance to RTK inhibitors is frequently observed in OS and ES patients, and even patients that initially respond well eventually develop acquired resistance. There are, however, a few remarks to make concerning the current set-up of clinical trials and about strategies to improve RTK-based treatments in OS and ES. This review provides an overview concerning current RTK-mediated therapies in OS and ES and discusses the problems observed in the clinic. More importantly, we describe several strategies to overcome resistance to RTK inhibitors which may significantly improve outcome of OS and ES patients.

Evaluation of a bipolar-cooled radiofrequency device for ablation of bone metastases: preclinical assessment in porcine vertebrae

BACKGROUND CONTEXT

Cancer spread to the spine affects bone stability and can lead to pathologic fracture and neurologic impairment. Radiofrequency ablation (RFA) recently has gained popularity in treating skeletal tumors. Conventional RFA devices use a monopolar design, which limits the ability to comprehensively treat large tumors in bony tissues and may pose risks to adjacent critical normal neurologic tissues when applied to vertebrae. New bipolar-cooled radiofrequency (BCRF) may generate larger controlled lesions without the same degree of risk to adjacent structures.

PURPOSE

The purpose of this study was to evaluate the feasibility, efficacy, and safety of RFA with the use of a new bone-specific, BCRF probe in a porcine vertebral model and to evaluate the ability of magnetic resonance (MR) imaging to represent histologic outcomes of RFA treatment.

STUDY DESIGN

Basic science: preclinical in vivo study.

METHODS

RFA was evaluated in three noncontiguous lumbar vertebrae in six Yorkshire pigs (25-30 kg). Via a transpedicular approach for probe placement, two vertebrae received BCRF treatment and one vertebrae served as a sham control. MR imaging and neurological assessments were conducted pre- and posttreatment as well as immediately before animal sacrifice (n=3 at day 0, n=3 at day 14). MR ablation zones were compared with hematoxylin and eosin-stained histological sections.

RESULTS

With BCRF, large reproducible zones of ablation were achieved, confined within the vertebrae, without damage to adjacent tissues or the spinal cord. All animals demonstrated normal consistent neurologic behavior pre- and posttreatment. External tissue temperatures around targeted vertebrae were not increased. MR imaging after 14 days was more effective in demonstrating ablation effects than images on day 0, with radiologic findings most apparent on T2-weighted sequences. Histologic analysis of samples corresponded well to the zones of ablation observed on MR images (R=0.9, p<.01).

CONCLUSIONS

The study demonstrated feasibility, safety, and effectiveness of BCRF ablation of vertebral bone. This motivates ongoing preclinical evaluation in diseased models to further explore the potential for its use in clinical treatment of metastatic vertebrae.

Overexpression of steroid receptor coactivator-3 in bone cancers: an in vivo immunohistochemical study with tissue microarray

Bone tissue is steroid-responsive and profoundly regulated by steroids and/or their receptors. Bone cancers (either primary or metastatic) belong to the most dangerous tumors. Previous studies have demonstrated overexpression of steroid receptor coactivator-3 (SRC-3) in many cancers, such as breast cancer, prostate cancer, thyroid cancer, functioning in the regulation of cancer cell proliferation, invasion, and metastasis. However, so far, the expression and function of SRC-3 in bone cancers have not yet been clarified. In this study, nickel-intensified immunohistochemistry was conducted using a commercial tissue microarray (with 94 cases of bone cancer tissue and 10 normal bone tissues), and the 4-scoring system was employed to evaluate the expression levels of SRC-3 immunoreactivity. The results showed that in normal bone tissue, levels of SRC-3 are almost negative (score=0), the total positivity (score=1-3) of SRC-3 immunoreactivities in bone cancers was 74.47%. There were no significant differences in gender, status (malignant or benign) or (mean) age (p>0.05). The percentage of positivity was 77.78% in osteogenic tumors, 58.82% in cartilage tumors, 70% in giant cell tumors, 100% in hematopoietic tumors, 77.78% in miscellaneous lesions, and 75% in miscellaneous tumors. Age related differences of SRC-3 immunoreactivities were detected in cartilage tumors and giant cell tumors (p<0.05). The above results clearly demonstrated a high frequency of overexpression of SRC-3 immunoreactivities in different bone cancers, indicating its potential roles in the prognosis and treatment of these cancers.

Protocadherin20 promotes excitatory synaptogenesis in dorsal horn and contributes to bone cancer pain

The majority of patients with metastatic bone disease experience moderate to severe pain. Bone cancer pain is usually progressive as the disease advances, and is very difficult to treat due to the poor understanding of the underlying mechanisms. Recent studies demonstrated that synaptic plasticity induces spinal cord sensitization and contributes to bone cancer pain. However, whether the synaptic plasticity is due to modifications of existing synapses or the formation of new synaptic connections is still unknown. Here we showed that a carcinoma implantation into a rats' tibia induced a significant increase in the number of excitability synapses in the dorsal horn, which contributes to the development of bone cancer pain. Previous studies identified that non-clustered protocadherins play significant roles in neuronal development and other implications in neurological disorders. In the present study, we showed that Protocadherin20 was significantly increased in the dorsal horn of cancer-bearing rats, while knockdown of Protocadherin20 with RNAi lentivirus reversed bone cancer-induced pain behaviors and decreased excitatory synaptogenesis in ipsilateral dorsal horn. In an in vitro study, we showed that knockdown of Protocadherin20 inhibited neurite outgrowth and excitatory synapse formation of dorsal neurons. These findings indicate that Protocadherin20 is required for the development of bone cancer pain probably by promoting the excitability synaptogenesis.

New dicoumarol sodium compound: crystal structure, theoretical study and tumoricidal activity against osteoblast cancer cells

BACKGROUND

Enormous interest had been paid to the coordination chemistry of alkali and alkaline metal ions because of their role inside body viz; their Li(+)/Na(+) exchange inside the cell lead to different diseases like neuropathy, hypertension, microalbuminuria, cardiac and vascular hypertrophy, obesity, and insulin resistance. It has been presumed that alkali metal ions (whether Na(+) or K(+)) coordinated to chelating ligands can cross the hydrophobic cell membrane easily and can function effectively for depolarizing the ion difference. This unique function was utilized for bacterial cell death in which K(+) has been found coordinated valinomycin (antibiotic).

RESULTS

Distinct sodium adduct (1) with dicoumarol ligand, 4-Hydroxy-3-[(4-hydroxy-2-oxo-4a,8a-dihydro-2H-chromen-3-yl)-phenyl-methyl]-chromen-2-one (L) is isolated from the saturated solution of sodium methoxide. Single crystal X-ray diffraction studies of the adduct reveals that sodium is in the form of cation attached to a methoxide, methanol and a dicoumarol ligand where carbonyl functional groups of the coumarin derivative are acting as bridges. The sodium compound (1) is also characterized by IR, (1)H-NMR, and (13)C{(1)H}-NMR spectroscopic techniques. The composition is confirmed by elemental analysis. DFT study for 1 has been carried out using B3LYP/6-13G calculations which shown the theoretical confirmation of the various bond lengths and bond angles. Both the compounds were studied subsequently for the U2OS tumoricidal activity and it was found that L has LD50 value of 200 μM whereas the sodium analog cytotoxicity did not drop down below 60%.

CONCLUSION

A sodium analogue (1) with medicinally important dicoumarol ligand (L) has been reported. The crystal structure and DFT study confirm the formation of cationic sodium compound with dicoumarol. The ligand was found more active than the sodium analog attributed to the instability of 1 in solution state. Coumarin compound with sodium was observed to be less cytotoxic than the ligand, its LD50 value never dropped below 60%.

Perspectives on cancer stem cells in osteosarcoma

Osteosarcoma is an aggressive pediatric tumor of growing bones that, despite surgery and chemotherapy, is prone to relapse. These mesenchymal tumors are derived from progenitor cells in the osteoblast lineage that have accumulated mutations to escape cell cycle checkpoints leading to excessive proliferation and defects in their ability to differentiate appropriately into mature bone-forming osteoblasts. Like other malignant tumors, osteosarcoma is often heterogeneous, consisting of phenotypically distinct cells with features of different stages of differentiation. The cancer stem cell hypothesis posits that tumors are maintained by stem cells and it is the incomplete eradication of a refractory population of tumor-initiating stem cells that accounts for drug resistance and tumor relapse. In this review we present our current knowledge about the biology of osteosarcoma stem cells from mouse and human tumors, highlighting new insights and unresolved issues in the identification of this elusive population. We focus on factors and pathways that are implicated in maintaining such cells, and differences from paradigms of epithelial cancers. Targeting of the cancer stem cells in osteosarcoma is a promising avenue to explore to develop new therapies for this devastating childhood cancer.

Anti-RANKL therapy for bone tumours: Basic, pre-clinical and clinical evidences

Bone remodelling is related to coordinated phases of bone resorption and bone apposition allowing the maintenance of bone integrity, the phosphocalcic homoeostasis all along the life and consequently the bone adaptation to mechanical constraints or/and to endocrine fluctuations. Unfortunately, bone is a frequent site of tumour development originated from bone cell lineages (primary bone tumours: bone sarcomas) or from nonosseous origins (bone metastases: carcinomas). These tumour cells disrupt the balance between osteoblast and osteoclast activities resulting in a disturbed bone remodelling weakening the bone tissue, in a strongly altered bone microenvironment and consequently facilitating the tumour growth. At the early stage of tumour development, osteoclast differentiation and recruitment of mature osteoclasts are strongly activated resulting in a strong bone matrix degradation and release of numerous growth factors initially stored into this organic/calcified matrix. In turn these soluble factors stimulate the proliferation of tumour cells and exacerbate their migration and their ability to initiate metastases. Because Receptor Activator of NFκB Ligand (RANKL) is absolutely required for in vivo osteoclastogenesis, its role in the bone tumour growth has been immediately pointed out and has consequently allowed the development of new targeted therapies of these malignant diseases. The present review summarises the role of RANKL in the bone tumour microenvironment, the most recent pre-clinical and clinical evidences of its targeting in bone metastases and bone sarcomas. The following sections position RANKL targeted therapy among the other anti-resorptive therapies available and underline the future directions which are currently under investigations.