Sclerostin antibody prevented progressive bone loss in combined ovariectomized and concurrent functional disuse

Ultrasound imaging and regulated mechanotransduction for characteristics, regeneration, and therapeutics of bone

Ultrasound imaging has been widely used in clinical diagnoses, such as B-mode and M-mode ultrasound imaging for cardiovascular, abdomen, OB-Gyn, and other soft tissue and organs in clinical diagnoses. Ultrasound imaging has traditionally been limited in its application to bone because of the high acoustic impedance and density of trabecular and cortical bone structure and density alterations, high wave reflection, absorption, scattering, and low penetration, which result in significant reflection and attenuation of ultrasonic energy in such mineral tissues. Recent advancements in quantitative ultrasound technology have opened new possibilities for noninvasive characteristics of bone quality through transmitted or backscattered signals, offering a radiation-free alternative to traditional imaging modalities like dual-energy X-ray absorptiometry (DEX), X-rays, and CT scans. In addition, low-intensity ultrasound (LIUS) has been studied and applied to promote bone regeneration and fracture healing through induced mechanotransduction in tissue and cells. The field of bone ultrasound encompasses fundamental research on the interaction of elastic waves with cortical and trabecular bone microstructures, the development of innovative imaging methodologies and medical applications such as bone health assessment for osteoporosis diagnosis, therapeutic use of LIUS, and phase aberration correction inside the skull. This work has highlighted recent developments and advancements in ultrasound diagnosis and therapeutics, induced cellular and molecular pathways, and future directions using ultrasound as a promising imaging tool and treatment method.

Affinity targeting of therapeutic proteins to the bone surface-local delivery of sclerostin-neutralizing antibody enhances efficacy

Currently available biotherapeutics for the treatment of osteoporosis lack explicit mechanisms for bone localization, potentially limiting efficacy and inducing off-target toxicities. While various strategies have been explored for targeting the bone surface, critical aspects remain poorly understood, including the optimal affinity ligand, the role of binding avidity and circulation time, and, most importantly, whether or not this strategy can enhance the functional activity of clinically relevant protein therapeutics. To investigate, we generated fluorescent proteins (eg, mCherry) with site-specifically attached small molecule (bisphosphonate) or peptide (deca-aspartate, D10) affinity ligands. While both affinity ligands successfully anchored fluorescent protein to the bone surface, quantitative radiotracing revealed only modest femoral and vertebral accumulation and suggested a need for enhanced circulation time. To achieve this, we fused mCherry to the Fc fragment of human IgG1 and attached D10 peptides to each C-terminus. The mCherry-Fc-D10 demonstrated an ~80-fold increase in plasma exposure and marked increases in femoral and vertebral accumulation (13.6% ± 1.4% and 11.4% ± 1.3% of the injected dose/g [%ID/g] at 24 h, respectively). To determine if bone surface targeting could enhance the efficacy of a clinically relevant therapeutic, we generated a bone-targeted sclerostin-neutralizing antibody, anti-sclerostin-D10. The targeted antibody demonstrated marked increases in bone accumulation and retention (20.9 ± 2.5% and 19.5 ± 2.5% ID/g in femur and vertebrae at 7 days) and enhanced effects in a murine model of ovariectomy-induced bone loss (bone volume/total volume, connectivity density, and structure model index all increased [P < .001] vs untargeted anti-sclerostin). Collectively, our results indicate the importance of both bone affinity and circulation time in achieving robust targeting of therapeutic proteins to the bone surface and suggest that this approach may enable lower doses and/or longer dosing intervals without reduction in biotherapeutic efficacy. Future studies will be needed to determine the translational potential of this strategy and its potential impact on off-site toxicities.

Monthly treatment with romosozumab for 1 year increases bone mineral at the hip, but not the knee, in women with chronic spinal cord injury

Bone loss below the level of neurological lesion is a well-known complication of spinal cord injury (SCI). To date, most research has focused on pharmaceutical intervention using antiresorptives to prevent bone loss during the acute phase of SCI; however, limited research has investigated treatments for established osteoporosis during chronic SCI. Romosozumab, a monoclonal antibody with both antiresorptive and anabolic effects, has demonstrated significant increases in BMD for women with established PMO. Therefore, the purpose of this study was to examine the efficacy of monthly treatment with romosozumab to improve DXA-derived areal BMD at the hip, and CT-derived BMC and strength at the hip and knee in women with chronic SCI and an inability to ambulate. Twelve female participants with chronic SCI were recruited to receive 1 yr of monthly subcutaneous injections of romosozumab (210 mg). DXA and CT scans were taken at baseline, and months 3, 6, and 12 to quantify bone mineral, and finite element (FE) analysis was used to predict bone strength. Longitudinal mixed effects models were employed to determine the impact of treatment on bone properties. After 12 mo of treatment, areal BMD at the lumbar spine and total hip were significantly increased with median changes of 10.2% (IQR: 8.3-15.2%, p<.001) and 4.2% (IQR: 3.4-7.7%, p = .009), respectively. Improvements at the hip were primarily due to increases in trabecular, not cortical, bone and effects were sufficient to significantly increase FE-predicted strength by 20.3% (IQR: 9.5-37.0%, p = .004). Treatment with romosozumab did not lead to any significant improvement in bone mineral at the distal femur or proximal tibia. These findings provide promising results for romosozumab treatment to improve bone mineral and reduce fracture risk at the hip, but not the knee, in women with chronic SCI.

Mechanobiology in cellular, molecular, and tissue adaptation

The use of mechanical biology and biomechanical signal transduction is a novel approach to attenuate biological tissue degeneration, whereas the understanding of specific cellular responses is critical to delineate the underlying mechanism. Dynamic mechanical signals with optimized loading signals, i.e., intensity and frequency, have been shown to have the potential to regulate adaptation and regeneration. Mechanotransduction pathways are of great interest in elucidating how mechanical signals produce such observed effects, including reduced tissue mass loss, increased healing and formation, and cell differentiation. While mechanobiology in the adaptation of cells and tissues is observed and recorded in the literature, its application in disease mechanism and treatment is under development. We would congratulate the opening of the Mechanobiology in Medicine journal, which provides an effective platform for advanced research in basic mechanotransduction and its translation in disease diagnosis, therapeutics, and beyond. This review aims to develop a cellular and molecular understanding of the mechanotransduction processes in tissue regeneration, which may provide new insights into disease mechanisms and the promotion of healing. Particular attention is allotted to the responses of mechanical loading, including potential cellular and molecular pathways, such as mechanotransduction associated with mechanotransduction pathways (e.g., Piezo ion channels and Wnt signaling), immune-response, neuron development, tissue adaptation and repair, and stem cell differentiation. Altogether, these discussed data highlight the complex yet highly coordinated mechanotransduction process in tissue regeneration.

A prospective phase II randomized study of docetaxel combined with lobaplatin versus TPF regimen induction chemotherapy followed by concurrent chemoradiotherapy for locally advanced head and neck squamous cell carcinoma

PURPOSE

To compare the toxicity and clinical efficacy of TL (docetaxel + lobaplatin) induction chemotherapy combined with lobaplatin concurrent chemoradiotherapy and TPF (docetaxel + cisplatin + 5-fluorouracil) induction chemotherapy combined with cisplatin concurrent chemoradiotherapy in the treatment of locally advanced head and neck squamous cell carcinoma.

METHODS AND PATIENTS

In total, 128 patients with locally advanced head and neck cancer were prospectively enrolled between August 2016 and April 2021. They were randomly divided into trial group and control group, all using chronological dosage mode. The trial group used TL regimen induction chemotherapy combined with lobaplatin concurrent chemoradiotherapy; the control group used TPF regimen induction chemotherapy and cisplatin concurrent chemotherapy. The endpoints were adverse events and survival rates at 1, 3 and 5 years.

RESULTS

Median follow-up was 42 months (20-71 months). (1) Adverse events: During induction chemotherapy, compared with TPF group, grade 3-4 leukocytes and neutrophils, diarrhea, 1-2 hyperbilirubinemia, nausea / vomiting, oral mucositis, fatigue, anorexia, hyponatremia were significantly lower in TL group (p<0. 05): 6% vs. 35%, 14% vs. 53%, 0% vs. 6%, 15% vs. 40%, 9% vs. 56%, 0% vs. 10%, 3% vs. 13%, 2% vs. 23%, 15% vs. 74%. During chemoradiotherapy, the incidence of hyponatremia, hypokalaemia and grade 1-2 nausea was significantly lower in the TL group (p<0. 05), with 24% vs. 69%, 20% vs. 65% and 24% vs. 44%, respectively. However, more grade 3-4 thrombocytopenia were observed in the TL group (15% vs. 3%, p<0. 05). (2) There was no significant difference in the recent objective response rate (ORR) between patients with TL group and TPF group (p=0.961). (3) There was no statistical difference in 1, 3 and 5 years OS between TL group and TPF group, respectively, (71.0% vs. 67.5%, p=0.573), (56.6% vs. 56.9%, p=0.814), (52.5% vs. 52.9%, p=0.841); 1, 3 and 5 years PFS are: (63.4% vs. 64.0%, p=0.883), (51.1% vs. 54.0%, p=0.705) and (47.3% vs. 45.9%, p=0.887), None of them were significantly different. Multivariate analysis of COX regression showed that T stage (p=0.01) and surgery (p=0.046) were independent factors affecting PFS and OS, respectively. OS subgroup analysis shows that people receiving the TL regimen in postoperative and nodal stage N1 and N2 patients tended to survive longer than those receiving the TPF regimen.

CONCLUSION

Patients with postoperative, N1 or N2 stage locally advanced head and neck squamous cell carcinoma (HNSCC) may have more significant clinical benefits when treated with TL regimen. TL regimen has advantages in reducing toxic side effects and can be used as one of the first-line treatment options.

TRIAL REGISTRATION

ClinicalTrials.gov (No. NCT03117257).

Surgical treatment of carotid blowout syndrome after radiotherapy for head and neck malignant tumors: a single-center experience

To explore the treatments for and manifestations of carotid blowout syndrome (CBS) and to further explore the critical role of high-flow bypass combined with parent artery isolation. The clinical data of nine patients with radiotherapy-related CBS who were admitted to our hospital from March 2020 to March 2023 were retrospectively analyzed. Relevant literature was reviewed. From March 2020 to March 2023, nine CBS patients were admitted to Tianjin Huanhu Hospital, including eight males and one female. Digital subtraction angiography was performed for all the patients; all the pseudoaneurysms were located at the petrous segment of the internal carotid artery. A balloon occlusion test was performed on four patients, which was tolerated by all patients. CT and MRI scans showed seven cases of osteonecrosis combined with infection and two cases of tumor recurrence. Emergency permanent parent artery occlusion was performed on six patients, aneurysm embolization was completed in one case, covered stent implantation was performed in one patient, and three cases were treated by cerebral bypass surgery (including two patients with failed interventional treatment). Rebleeding was found in two patients, and no rebleeding was found in the bypass group. Paralysis was found in three patients, and asymptomatic cerebral infarction without permanent neurologic impairment was found in three patients. Two patients died due to tumor progression. Emergency occlusion surgery is lifesaving in the acute phase of CBS. Endovascular therapy cannot prevent the progression of pseudoaneurysms or lower the recurrence rate of bleeding events. High-flow bypass combined with parent artery isolation is a safe and effective method that may facilitate further surgical treatment. Further research is warranted.

Pharmaceutical treatment of bone loss: From animal models and drug development to future treatment strategies

Animal models are fundamental to advance our knowledge of the underlying pathophysiology of bone loss and to study pharmaceutical countermeasures against it. The animal model of post-menopausal osteoporosis from ovariectomy is the most widely used preclinical approach to study skeletal deterioration. However, several other animal models exist, each with unique characteristics such as bone loss from disuse, lactation, glucocorticoid excess, or exposure to hypobaric hypoxia. The present review aimed to provide a comprehensive overview of these animal models to emphasize the importance and significance of investigating bone loss and pharmaceutical countermeasures from perspectives other than post-menopausal osteoporosis only. Hence, the pathophysiology and underlying cellular mechanisms involved in the various types of bone loss are different, and this might influence which prevention and treatment strategies are the most effective. In addition, the review sought to map the current landscape of pharmaceutical countermeasures against osteoporosis with an emphasis on how drug development has changed from being driven by clinical observations and enhancement or repurposing of existing drugs to today's use of targeted anti-bodies that are the result of advanced insights into the underlying molecular mechanisms of bone formation and resorption. Moreover, new treatment combinations or repurposing opportunities of already approved drugs with a focus on dabigatran, parathyroid hormone and abaloparatide, growth hormone, inhibitors of the activin signaling pathway, acetazolamide, zoledronate, and romosozumab are discussed. Despite the considerable progress in drug development, there is still a clear need to improve treatment strategies and develop new pharmaceuticals against various types of osteoporosis. The review also highlights that new treatment indications should be explored using multiple animal models of bone loss in order to ensure a broad representation of different types of skeletal deterioration instead of mainly focusing on primary osteoporosis from post-menopausal estrogen deficiency.

Is sclerostin antibody an effective agent for alveolar bone regeneration in animal models? A scoping review

Objectives The use of Sclerostin Antibody(Scl-Ab) as a bone anabolic agent has shown significant benefit in bone disorders in preclinical animal models and human clinical trials. Currently available evidence on the use of Scl-Ab in alveolar bone regeneration is limited to animal studies and hence this scoping review encompasses the animal studies conducted to ascertain the effectiveness of Scl-Ab on alveolar bone regeneration. Materials and methods The search strategy was aimed to locate published animal studies in which the treatment arm includes Sclerostin antibody administration for alveolar bone preservation or regeneration. The search terms used were (((Animal model) OR Rodent) AND Alveolar bone defect) AND Anti sclerostin antibody) OR Sclerostin antibody) AND Alveolar bone regeneration) OR Bone regeneration) AND Bone fill. Results Of the 559 results from Medline/PubMed, Scopus, Web of Science, Google scholar and additional articles from the references, six were included in the review. Scl-Ab was found to be effective in improving the bone quality and quantity. It was also observed that Scl-Ab was useful in reduced bone density associated with diseases and conditiona affecting osteoblast activity. Conclusion The review concluded that Scl-Ab promotes alveolar bone augmentation and improves bone quality without surgical interventions.

Efficacy and toxicity of three concurrent chemoradiotherapy regimens in treating nasopharyngeal carcinoma: Comparison among cisplatin, nedaplatin, and lobaplatin

Few studies directly compare efficacy and toxicity among lobaplatin, nedaplatin and cisplatin concurrently with intensity-modulated radiotherapy (IMRT) in nasopharyngeal carcinoma (NPC). Totally 141 treatment-naïve NPC without distant metastasis receiving IMRT concurrent with cisplatin or nedaplatin or lobaplatin were retrospectively enrolled. Their response rate, toxicity and long-term survival were compared. Complete response (CR) rates of concurrent lobaplatin (CR-nasopharynx [CR-nx], 82.7%; CR-cervical lymph node [CR-nd], 94.2%) were lower than those of cisplatin (CR-nx, 89.3%; CR-nd, 98.2%) and nedaplatin (CR-nx, 93.9%; CR-nd, 97.0%), but statistical significance wasn't detected. Estimated five-year overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS) and progression-free survival (PFS) weren't statistically significant between three groups. Multivariable analysis by COX proportional hazards model showed concurrent chemotherapy regimen wasn't an independent prognostic factor. Gastrointestinal toxicity was prevalent in platinum-based concurrent chemotherapy; cisplatin group suffered heavier (≥grade 2) than other two groups. More nephrotoxicity happened in cisplatin group (17.9%) than nedaplatin (9.1%) and lobaplatin (2.0%) groups. Incidence of dermatitis of ≥grade 2 was higher in cisplatin group (60.7%) than nedaplatin (27.3%) and lobaplatin (9.6%) groups. More patients in lobaplatin and nedaplatin groups suffered from any grade thrombocytopenia (P < .001), but incidence of severe thrombocytopenia (≥grade 3) was similar. Economic cost was significant less in lobaplatin group. Cisplatin, nedaplatin and lobaplatin are equally effective when used concurrently with IMRT in NPC. Lobaplatin and nedaplatin have potential to be alternatives to cisplatin in terms of less severe acute side-effects and economic cost.

Anti-sclerostin antibodies and abaloparatide have additive effects when used as a countermeasure against disuse osteopenia in female rats

Prolonged disuse and substantial mechanical unloading are particularly damaging to skeletal integrity. Preclinical studies in rodents and clinical studies have highlighted the need for potent bone anabolic drugs to counteract disuse-induced osteopenia. The aim of present study was to compare the efficacy of romosozumab (Scl-Ab) and abaloparatide (ABL), alone or in combination, to prevent botulinum toxin (BTX) induced bone loss in a rat model. Eighty female Wistar rats were divided into the following six groups: 1. Baseline (n = 12); 2. Control (Ctrl) (n = 12); 3. BTX (n = 12); 4. BTX + Scl-Ab (n = 16); 5. BTX + ABL (n = 12); and 6. BTX + Scl-Ab + ABL (n = 16). Disuse was achieved by injecting 4 IU BTX into the hind limb musculature at study start. Scl-Ab (25 mg/kg) was injected s.c. twice weekly, while ABL (80 μg/kg) was injected s.c. five days a week for four weeks. Hind limb disuse dramatically decreased muscle mass and skeletal integrity and deteriorated the cortical morphology and trabecular microstructure. Treatment with Scl-Ab alone prevented most of the adverse cortical and trabecular effects of disuse, while ABL monotherapy mainly attenuated the disuse-induced loss of femoral areal bone mineral density (aBMD). Moreover, the combination of Scl-Ab and ABL not only counteracted most of the negative skeletal effects of unloading, but also increased aBMD (+10% and +20%), epiphyseal trabecular bone volume fraction (BV/TV) (+25% and +73%), and metaphyseal bone strength (+18% and +30%) significantly above that of Scl-Ab or ABL monotherapy, respectively. The potent and additive osteoanabolic effect of Scl-Ab and ABL, when given in combination, is highly intriguing and underlines that an osteoanabolic bone gain can be maximized by utilizing two pharmaceuticals targeting different cellular signaling pathways. From a clinical perspective, a combination treatment may be warranted in patients where the osteoanabolic effect of either monotherapy is not sufficient, or if a dose-reduction is required due to adverse effects.

Drug discovery of sclerostin inhibitors

Sclerostin, a protein secreted from osteocytes, negatively regulates the WNT signaling pathway by binding to the LRP5/6 co-receptors and further inhibits bone formation and promotes bone resorption. Sclerostin contributes to musculoskeletal system-related diseases, making it a promising therapeutic target for the treatment of WNT-related bone diseases. Additionally, emerging evidence indicates that sclerostin contributes to the development of cancers, obesity, and diabetes, suggesting that it may be a promising therapeutic target for these diseases. Notably, cardiovascular diseases are related to the protective role of sclerostin. In this review, we summarize three distinct types of inhibitors targeting sclerostin, monoclonal antibodies, aptamers, and small-molecule inhibitors, from which monoclonal antibodies have been developed. As the first-in-class sclerostin inhibitor approved by the U.S. FDA, the monoclonal antibody romosozumab has demonstrated excellent effectiveness in the treatment of postmenopausal osteoporosis; however, it conferred high cardiovascular risk in clinical trials. Furthermore, romosozumab could only be administered by injection, which may cause compliance issues for patients who prefer oral therapy. Considering these above safety and compliance concerns, we therefore present relevant discussion and offer perspectives on the development of next-generation sclerostin inhibitors by following several ways, such as concomitant medication, artificial intelligence-based strategy, druggable modification, and bispecific inhibitors strategy.

Osteocytes and Estrogen Deficiency

PURPOSE OF REVIEW

Postmenopausal osteoporosis reduces circulating estrogen levels, which leads to osteoclast resorption, bone loss, and fracture. This review addresses emerging evidence that osteoporosis is not simply a disease of bone loss but that mechanosensitive osteocytes that regulate both osteoclasts and osteoblasts are also impacted by estrogen deficiency.

RECENT FINDINGS

At the onset of estrogen deficiency, the osteocyte mechanical environment is altered, which coincides with temporal changes in bone tissue composition. The osteocyte microenvironment is also altered, apoptosis is more prevalent, and hypermineralization occurs. The mechanobiological responses of osteocytes are impaired under estrogen deficiency, which exacerbates osteocyte paracrine regulation of osteoclasts. Recent research reveals changes in osteocytes during estrogen deficiency that may play a critical role in the etiology of the disease. A paradigm change for osteoporosis therapy requires an advanced understanding of such changes to establish the efficacy of osteocyte-targeted therapies to inhibit resorption and secondary mineralization.

Retrospective analysis of massive epistaxis and pseudoaneurysms in nasopharyngeal carcinoma after radiotherapy

OBJECTIVE

Epistaxis after radiotherapy for nasopharyngeal carcinoma (NPC) is a common clinical critical illness, which often leads to death of patients. This article focuses on the relationship between massive epistaxis and pseudoaneurysm after radiotherapy in patients with NPC and discusses clinically relevant treatment strategies.

METHODS

A review was performed in 21 patients with massive epistaxis after radiotherapy for NPC from January 2011 to December 2019, and all of the patients were examined by computed tomography angiography (CTA). We also reviewed the English literature over the past 10 years to analyze the characteristics and related causes of pseudoaneurysms in terms of the clinical stage of NPC, course of radiotherapy, and affected artery. An analysis was performed on the methods of endovascular interventional treatment of such pseudoaneurysms.

RESULTS

Among the 21 patients, 19 cases had bone destruction of the skull base; 13 cases were also found to have tumor recurrence; 15 cases were in stage III or IV of NPC; pseudoaneurysms were observed in 14 cases, of which nine cases had pseudoaneurysms in the internal carotid artery (ICA), and the rest had pseudoaneurysms in the external carotid artery (ECA). These data were consistent with the results of the literature review. Analysis with imaging revealed that the petrous ICA was the common predilection site. There were 11 out of 14 cases of pseudoaneurysms with sentinel hemorrhage in the initial phase. All 14 pseudoaneurysm patients underwent endovascular interventional therapy, but one died from hemorrhagic shock during the procedure. No rebleeding was observed among the other patients during 72 h after intravascular treatment. Nevertheless, regrettably two patients died on the 10th and 17th days after intervention.

CONCLUSION

Pseudoaneurysm, which was a serious complication after radiotherapy in patients with NPC, could cause massive epistaxis with high mortality. The formation of a pseudoaneurysm was closely associated with a high carcinoma stage, re-radiotherapy, and local bone destruction and infection. Most cases had sentinel epistaxis, which was considered the bleeding characteristic. The imaging material prompted that pseudoaneurysm had a predisposition to the petrous part of the ICA, while the preferred therapy was endovascular embolization treatment.

Cross-talk Between Histone and DNA Methylation Mediates Bone Loss in Hind Limb Unloading

Bone loss induced by mechanical unloading is a common skeletal disease, but the precise mechanism remains unclear. The current study investigated the role of histone methylation, a key epigenetic marker, and its cross-talk with DNA methylation in bone loss induced by mechanical unloading. The expression of G9a, ubiquitin-like with PHD and ring finger domains 1 (UHRF1), and DNA methylation transferase 1 (DNMT1) were increased in hind limb unloading (HLU) rats. This was accompanied by an increased level of histone H3 lysine 9 (H3K9) di-/tri-methylation at lncH19 promoter. Then, alteration of G9a, DNMT1, or UHRF1 expression significantly affected lncH19 level and osteogenic activity in UMR106 cells. Osteogenic gene expression and matrix mineralization were robustly promoted after simultaneous knockdown of G9a, DNMT1, and UHRF1. Furthermore, physical interactions of lncH19 promoter with G9a and DNMT1, as well as direct interactions among DNMT1, G9a, and UHRF1 were detected. Importantly, overexpression of DNMT1, G9a, or UHRF1, respectively, resulted in enrichment of H3K9me2/me3 and 5-methylcytosine at lncH19 promoter. Finally, in vivo rescue experiments indicated that knockdown of DNMT1, G9a, or UHRF1 significantly relieved bone loss in HLU rats. In conclusion, our research demonstrated the critical role of H3K9 methylation and its cross-talk with DNA methylation in regulating lncH19 expression and bone loss in HLU rats. Combined targeting of DNMT1, G9a, and UHRF1 could be a promising strategy for the treatment of bone loss induced by mechanical unloading. © 2021 American Society for Bone and Mineral Research (ASBMR).

Effects of Dicer1 targeted by EBV-miR-BART6-5p on biological properties and radiosensitivity of nasopharyngeal carcinoma

OBJECTIVE

To discuss the effects of Epstein-Barr virus (EBV)-encoded BamHI A rightward transcript (BART) microRNA (miR-BART6-5p) by targeting Dicer1 on biological properties and radiosensitivity of nasopharyngeal carcinoma (NPC).

METHODS

NPC patients (n = 96) treated with radiotherapy were collected from Jan 2010 to Jan 2011. Real-time quantitative PCR (qRT-PCR) and western blot were carried out to measure the expression of miR-BART6-5p and Dicer1. Dual luciferase reporter gene assay verified that miR-BART6-5p targeted Dicer1. CCK8, wound-healing, Transwell and Annexin-FITC/PI were employed to evaluate the effects of Dicer1 mediated by miR-BART6-5p on biological characteristics of NPC cells. The radiosensitivity of miR-BART6-5p targeting Dicer1 was assessed in vitro and in vivo.

RESULTS

Increased miR-BART6-5p and decreased Dicer1 were discovered in NPC patients, displaying a close association with T-stage, clinical stage, as well as Pre-DNA of NPC. While elevated Dicer1 and miR-BART6-5p down-regulation in NPC patients were found after effective radiotherapy. Both miR-BART6-5p and Dicer1 were prognostic factors of NPC. Down-regulation of miR-BART6-5p could enhance Dicer1 expression and inhibit NPC cell proliferation, invasion and migration with promoted apoptosis. Clone formation assay also showed miR-BART6-5p down-regulation reduced planting efficiency (PE), which further decreased with the increased dose of irradiation. Injection with miR-BART6-5p inhibitors in nude mice after 6-Gy irradiation contributed to the overexpression of Dicer1 and the inhibition of tumor growth.

CONCLUSIONS

EBV-miR-BART6-5p may target Dicer1 to facilitate proliferation and metastasis of NPC cells and suppress apoptosis, thus being a new target for NPC therapy.

Scl-Ab reverts pro-osteoclastogenic signalling and resorption in estrogen deficient osteocytes

Background

Neutralising antibodies to sclerostin (Scl-Ab) have shown significant potential to induce bone formation and decrease bone resorption, increase strength and substantially reduce fracture risk in animal studies and clinical trials. Mechanical loading negatively regulates sclerostin expression, and sclerostin has been shown to induce RANKL synthesis in osteocytes. However, how Scl-Ab governs osteocyte regulation of osteoclast differentiation and function is not fully understood. We have recently discovered that osteoblasts and osteocytes alter osteoclastogenic signalling (RANKL/OPG) during estrogen-deficiency, and that osteoblast-induced osteoclastogenesis and resorption are exacerbated. However, it is not known whether estrogen deficient osteocytes exacerbate osteoclastogenesis. The aims of this study were to (1) establish whether osteocytes induce osteoclastogenesis and bone resorption during estrogen deficiency in vitro (2) investigate whether the sclerostin antibody can revert osteocyte-mediated osteoclastogenesis and resorption by attenuating RANKL/OPG expression.

Results

Using conditioned media and co-culture experiments we found increased osteocyte-induced osteoclastogenesis and bone resorption in estrogen deficient conditions. This is the first study to report that administration of Scl-Ab has the ability to revert osteocyte-mediated osteoclastogenesis and resorption by decreasing RANKL/OPG ratio expression and increasing WISP1 expression in estrogen deficient osteocytes.

Conclusions

This study provides an enhanced understanding of the biological changes underpinning decreases in bone resorption following Scl-Ab treatment observed in vivo by revealing that Scl-Ab can reduce pro-osteoclastogenic cell signalling between osteocytes and osteoclasts.

Blockade of IL-6 alleviates bone loss induced by modeled microgravity in mice

This study investigated the effects of blockade of IL-6 on bone loss induced by modeled microgravity (MG). Adult male mice were exposed to hind-limb suspension (HLS) and treated with IL-6-neutralizing antibody (IL-6 nAb) for 4 weeks. HLS in mice led to upregulation of IL-6 expression in both sera and femurs. IL-6 nAb treatment in HLS mice significantly alleviated bone loss, evidenced by increased bone mineral density of whole tibia, trabecular thickness and number, bone volume fraction of proximal tibiae, and ultimate load and stiffness of femoral diaphysis. IL-6 nAb treatment in HLS mice significantly enhanced levels of osteocalcin in sera and reduced levels of deoxypyridinoline. In MC3T3-E1 cells exposed to MG in vitro, IL-6 nAb treatment increased mRNA expression and activity of alkaline phosphatase, mRNA expression of osteopontin and runt-related transcription factor 2, and protein levels of osteoprotegerin and decreased protein levels of receptor activator of the NF-κB ligand. In RAW254.7 cells exposed to MG, IL-6 nAb treatment downregulated mRNA expression of cathepsin K and tartrate-resistant acid phosphatase (TRAP) and reduced numbers of TRAP-positive multinucleated osteoclasts. In conclusion, blockade of IL-6 alleviated the bone loss induced by MG.

Alterations in osteocyte mediated osteoclastogenesis during estrogen deficiency and under ROCK-II inhibition: An in vitro study using a novel postmenopausal multicellular niche model

This study sought to derive an enhanced understanding of the complex intracellular interactions that drive bone loss in postmenopausal osteoporosis. We applied an in-vitro multicellular niche to recapitulate cell-cell signalling between osteocytes, osteoblasts and osteoclasts to investigate (1) how estrogen-deficient and mechanically loaded osteocytes regulate osteoclastogenesis and (2) whether ROCK-II inhibition affects these mechanobiological responses. We report that mechanically stimulated and estrogen-deficient osteocytes upregulated RANKL/OPG and M-CSF gene expression, when compared to those treated with 10 nM estradiol. Osteoclast precursors (RAW 264.7) cultured within this niche underwent significant reduction in osteoclastogenic gene expression (CTSK), and there was an increasing trend in the area covered by TRAP⁺ osteoclasts (24% vs. 19.4%, p = 0.06). Most interestingly, upon treatment with the ROCK-II inhibitor, RANKL/OPG and M-CSF gene expression by estrogen-deficient osteocytes were downregulated. Yet, this inhibition of the pro-osteoclastogenic factors by osteocytes did not ultimately reduce the differentiation of osteoclast precursors. Indeed, TRAP and CTSK gene expressions in osteoclast precursors were upregulated, and there was an increased trend for osteoclast area (30.4% vs. 24%, p = 0.07), which may have been influenced by static osteoblasts (MC3T3-E1) that were included in the niche. We conclude that ROCK-II inhibition can attenuate bone loss driven by osteocytes during estrogen deficiency.

Inhibition of osteoclastogenesis by mechanically stimulated osteoblasts is attenuated during estrogen deficiency

Osteoporotic bone loss and fracture have long been regarded to arise upon depletion of circulating estrogen, which increases osteoclastogenesis and bone resorption. Osteoblasts from human osteoporotic patients also display deficient osteogenic responses to mechanical loading. However, while osteoblasts play an important role in regulating osteoclast differentiation, how this relationship is affected by estrogen deficiency is unknown. This study seeks to determine how mechanically stimulated osteoblasts regulate osteoclast differentiation and matrix degradation under estrogen deficiency. Here, we report that osteoblast-induced osteoclast differentiation (indicated by tartrate-resistant acid phosphatase, cathepsin K, and nuclear factor of activated T cells, cytoplasmic 1) and matrix degradation were inhibited by estrogen treatment and mechanical loading. However, estrogen-deficient osteoblasts exacerbated osteoclast formation and matrix degradation in conditioned medium and coculture experiments. This was accompanied by higher expression of cyclooxygenase-2 and macrophage colony-stimulating factor, but not osteoprotegerin, by osteoblasts under estrogen deficiency. Interestingly, this response was exacerbated under conditions that block the Rho-Rho-associated protein kinase signaling pathway. This study provides an important, but previously unrecognized, insight into bone loss in postmenopausal osteoporosis, whereby estrogen-deficient osteoblasts fail to produce inhibitory osteoprotegerin after mechanical stimulation but upregulate macrophage colony-stimulating factor and cyclooxygenase-2 expression and, thus, leave osteoclast activity unconstrained.

Lobaplatin promotes 125I-induced apoptosis and inhibition of proliferation in hepatocellular carcinoma by upregulating PERK-eIF2α-ATF4-CHOP pathway

We investigated the mechanism underlying the effect of a combination treatment of ¹²⁵I radioactive seed implantation and lobaplatin (LBP) in hepatocellular carcinoma. The effects of administration of HCC cells and subcutaneous tumor model of mice with different doses of ¹²⁵I or a sensitizing concentration of LBP alone, or in combination, on cellular apoptosis and proliferation were analyzed and it was confirmed that LBP promotes ¹²⁵I-induced apoptosis and inhibition of proliferation of HCC. Furthermore, isobaric tag for relative and absolute quantification labeling analyses suggested that ¹²⁵I promoted the apoptosis and inhibition of proliferation of HCC cells by upregulating the expression of PERK-eIF2α-ATF4-CHOP pathway, a well-known apoptosis-related pathway. Moreover, LBP was found to boost the ¹²⁵I-induced upregulation of this pathway and increase the apoptosis. Our data indicate that LBP promotes the apoptotic and anti-proliferative effects of ¹²⁵I and provide a firm foundation for better clinical application of this combination therapy.

Treatment with hydrogen sulfide donor attenuates bone loss induced by modeled microgravity

The present study was undertaken to explore the therapeutic potential of hydrogen sulfide against bone loss induced by modeled microgravity. Hindlimb suspension (HLS) and rotary wall vessel bioreactor were applied to model microgravity in vivo and in vitro, respectively. Treatment of rats with GYY4137 (a water soluble donor of hydrogen sulfide, 25 mg/kg per day, i.p.) attenuated HLS-induced reduction of bone mineral density in tibiae, and preserved bone structure in tibiae and mechanical strength in femurs. In HLS group, GYY4137 treatment significantly increased levels of osteocalcin in sera. Interestingly, treatment of HLS rats with GYY4137 enhanced osteoblast surface, but had no significant effect on osteoclast surface of proximal tibiae. In MC3T3-E1 cells exposed to modeled microgravity, GYY4137 stimulated transcriptional levels of runt-related transcription factor 2 and enhanced osteoblastic differentiation, as evidenced by increased mRNA expression and activity of alkaline phosphatase. HLS in rats led to enhanced levels of interleukin 6 in sera, skeletal muscle, and tibiae, which could be attenuated by GYY4137 treatment. Our study showed that GYY4137 preserved bone structure in rats exposed to HLS and promoted osteoblastic differentiation in MC3T3-E1 cells under modeled microgravity.

Sustained-release of sclerostin single-chain antibody fragments using poly(lactic-co-glycolic acid) microspheres for osteoporotic fracture repair

Osteoporotic fracture is one of the most common bone diseases in middle and old age, as the most serious consequence of osteoporosis. Sclerostin single‐chain antibody fragments (SCL‐scFv) have been proven to promote bone formation by binding to scleroprotein, a natural antagonist of the Wnt pathway, but it is difficult to rule alone due to the weak permeability and immunogenicity. Herein, we prepared poly(lactic‐co‐glycolic acid) microspheres as a sustained‐release vehicle to prolong the activity of SCL‐scFv. The morphology of microspheres were uniform and nearly sphere, loading efficiency and encapsulation efficiency of SCL‐scFv microspheres were 6.28 ± 1.04% and 48.37 ± 8.11%, respectively. Approximately 90% of the SCL‐scFvs were released from the microspheres over 28 days with initial burst releasing (38%) in the first 4 days. Sustained‐release of active SCL‐scFv from microspheres promoted bone marrow mesenchymal stem cells osteogenic differentiation in vitro and enhanced fracture healing in ovariectomized rats by improving bone mass and bone formation in the fracture region. All these findings demonstrate that the microspheres are able to simultaneously achieve localized long‐term SCL‐scFv controlled release and effectively promote bone formation, which provides a promising approach for osteoporotic fracture.

Retention of osteocytic micromorphology by sclerostin antibody in a concurrent ovariectomy and functional disuse model

Prolonged mechanical unloading in bedridden patients and concurrent hormonal dysregulation represents the cause of one of the severest forms of osteoporosis, a condition for which there are very few efficacious interventions available to date. Sclerostin, a Wnt antagonist, acts as a negative regulator of bone formation. Sclerostin antibody (Scl-Ab)-mediated blockade of sclerostin can dramatically enhance bone formation and reduce bone resorption. This study was designed to investigate the therapeutic effect of the Scl-Ab on severe bone loss induced by concurrent mechanical unloading and estrogen deficiency in a hindlimb-suspended and ovariectomized rat model, and to study the cellular mechanisms underlying severe osteoporosis and Scl-Ab action. Unloading and ovariectomy resulted in severe loss of trabecular and cortical bone mass and strength; Scl-Ab can significantly counteract the deterioration of bone in unloaded and/or ovariectomized rats, with noticeably increased cortical bone formation. Scanning electron microscopy analysis revealed that unloading and ovariectomy lead to multiple morphological and structural abnormalities of osteocytes in cortical bone and the abnormalities were abolished by Scl-Ab administration. This study extends our previous conclusion that Scl-Ab represents a promising therapeutic approach for severe bone loss that occurs after being exposed to estrogen deficiency and prolonged mechanical unloading.

Efficacy of concurrent chemoradiotherapy combined with nimotuzumab for low-risk T4 stage nasopharyngeal carcinoma: A pilot study

BACKGROUND

The purpose of this study was to analyze the efficacy and safety of concurrent chemoradiotherapy combined with Nimotuzumab for low-risk T4 stage nasopharyngeal carcinoma (NPC).

METHODS

This study included 49 low-risk T4 stage NPC patients treated with concurrent chemoradiotherapy plus Nimotuzumab. The IMRT doses were planning target volume (PTV) 70-72 Gy for gross disease in the nasopharynx, and 66-70 Gy for positive lymph nodes. The doses for high risk and low risk region PTV were 60-62 Gy and 54-56 Gy in 31-33 fractions. All patients received a chemotherapy program consisting of Cisplatin 100mg/m2, day 1, Q3w and were treated by Nimotuzumab (Nimotuzumab 200mg, iv, Qw).

RESULTS

All 49 patients completed at least two cycles of chemotherapy and seven weeks of Nimotuzumab. The total efficiency of therapy was 100.0%. The 3-year overall survival (OS), distant metastasis-free survival (DMFS), local-regional control (LRC) and progression-free survival (PFS) rates were 89.7%, 87.8%, 97.9% and 85.7%, respectively. No regional lymph node recurrence was detected. The most serious acute toxicity was mucositis, with prevalence of Grades 0 to IV being 0.0%, 57.1%, 34.7%, 8.2%, and 0.0%, respectively. Late toxicity manifested as Grades I and II xerostomia in 32 and 10 patients.

CONCLUSION

In patients with low-risk T4 stage NPC, concurrent chemoradiotherapy combined with Nimotuzumab yielded an excellent local control rate, and the toxicities were mild and tolerable. Distant metastasis was the main cause of treatment failure.

Dose Escalation of Lobaplatin Concurrent with IMRT for the Treatment of Stage III-IVb NPC: A Phase I Clinical Trial

The maximum tolerated dose (MTD) of lobaplatin as a single agent chemotherapy concurrent with intensity-modulated radiotherapy (IMRT) in Asian population with nasopharyngeal carcinoma (NPC) remains unclear. From June 2016 to December 2017, 17 patients diagnosed with stage III-IVb NPC from an Asian population were prospectively enrolled. Patients were administered lobaplatin with 25-50 mg/m² escalation of dosage on day 1. Every 21 days (days 1, 22, and 43) during radiotherapy, cycles were repeated. We administered radiotherapy as 2.12-2.27 Gy per fraction with five daily fractions each week for 6 to 7 weeks. The evaluation of lobaplatin-related toxic effects was based on the Common Terminology Criteria for Adverse Events version 4.0. During the weekly treatment period, complete blood counts and biochemistry were performed. Dose-limiting toxicities (DLTs) were determined by the following events during any cycle in which lobaplatin was administered. Each dose group consisted of at least three cases. We proceeded to the subsequent dose group in the absence of DLT with a dose increment of 5 mg/m² until DLT occurred. Periods from 1 week prior to the chemotherapy initiation to 3 weeks after the last chemotherapy were defined as DLT observation periods. MTD was determined by the dose that was immediately below the dose that produced DLT. After analysis, DLT occurred in three patients, including a group with two of three patients in 45 mg/m² lobaplatin and another group with one of five patients in 40 mg/m² lobaplatin. No grade 3-4 toxicity was observed in patients treated with lobaplatin <40 mg/m². The tumor response rate at 12 weeks after treatment was 100%. In summary, lobaplatin concurrent with IMRT was active in stage III-IVb NPC, and the MTD for the lobaplatin as single-agent chemotherapy was 40 mg/m² when combined with IMRT in an Asian population. This trial is registered with ClinicalTrials.gov, number NCT03188497.

Soy protein improves tibial whole-bone and tissue-level biomechanical properties in ovariectomized and ovary-intact, low-fit female rats

BACKGROUND

Osteoporosis and related fractures, decreased physical activity, and metabolic dysfunction are serious health concerns for postmenopausal women. Soy protein might counter the negative effects of menopause on bone and metabolic health due to the additive or synergistic effects of its bioactive components.

OBJECTIVE

To evaluate the effects of ovariectomy (OVX) and a soy-protein diet (SOY) on bone outcomes in female, low-capacity running (LCR) rats selectively bred for low aerobic fitness as a model of menopause.

METHODS

At 27 weeks of age, LCR rats (N = 40) underwent OVX or sham (SHAM) surgery and were randomized to one of two isocaloric and isonitrogenous plant-protein-based dietary treatments: 1) soy-protein (SOY; soybean meal); or, 2) control (CON, corn-gluten meal), resulting in four treatment groups. During the 30-week dietary intervention, animals were provided ad libitum access to food and water; body weight and food intake were measured weekly. At completion of the 30-week intervention, body composition was measured using EchoMRI; animals were fasted overnight, euthanized, and blood and hindlimbs collected. Plasma markers of bone formation (osteocalcin, OC; N-terminal propeptide of type I procollagen, P1NP) and resorption (tartrate-resistant acid phosphatase, TRAP5b; C-terminal telopeptide of type I collagen, CTx) were measured using ELISA. Tibial trabecular microarchitecture and cortical geometry were evaluated using μCT; and torsional loading to failure was used to assess cortical biomechanical properties. Advanced glycation end-product (AGE) content of the femur was measured using a fluorimetric assay, and was expressed relative to collagen content measured by a colorimetric OH-proline assay. Two-factor ANOVA or ANOVCA was used to test for significant main and interactive effects of ovarian status (OV STAT: OVX vs. SHAM) and DIET (SOY vs. CON); final body weight was included as a covariate for body-weight-dependent cortical geometry and biomechanical properties.

RESULTS

OVX had significantly greater CTx than SHAM; SOY did not affect bone turnover markers. OVX adversely affected trabecular microarchitecture as evidenced by reduced BV/TV, trabecular thickness (Tb.Th), trabecular number (Tb.N), and connectivity density (Conn.D), and by increased trabecular separation (Tb.Sp) and structural model index (SMI). SOY increased BV/TV only in ovary-intact animals. There was no effect of OVX or SOY on tibial cortical geometry. In SHAM and OVX rats, SOY significantly improved whole-bone strength and stiffness; SOY also increased tissue-level stiffness and tended to increase tissue-level strength (p = 0.067). There was no effect of OVX or SOY on AGE content.

CONCLUSION

Soy protein improved cortical bone biomechanical properties in female low-fit rats, regardless of ovarian hormone status.

Effects of pharmacologic sclerostin inhibition or testosterone administration on soleus muscle atrophy in rodents after spinal cord injury

Sclerostin is a circulating osteocyte-derived glycoprotein that negatively regulates Wnt-signaling after binding the LRP5/LRP6 co-receptors. Pharmacologic sclerostin inhibition produces bone anabolic effects after spinal cord injury (SCI), however, the effects of sclerostin-antibody (Scl-Ab) on muscle morphology remain unknown. In comparison, androgen administration produces bone antiresorptive effects after SCI and some, but not all, studies have reported that testosterone treatment ameliorates skeletal muscle atrophy in this context. Our purposes were to determine whether Scl-Ab prevents hindlimb muscle loss after SCI and compare the effects of Scl-Ab to testosterone enanthate (TE), an agent with known myotrophic effects. Male Sprague-Dawley rats aged 5 months received: (A) SHAM surgery (T8 laminectomy), (B) moderate-severe contusion SCI, (C) SCI+TE (7.0 mg/wk, im), or (D) SCI+Scl-Ab (25 mg/kg, twice weekly, sc). Twenty-one days post-injury, SCI animals exhibited a 31% lower soleus mass in comparison to SHAM, accompanied by >50% lower soleus muscle fiber cross-sectional area (fCSA) (p<0.01 for all fiber types). Scl-Ab did not prevent soleus atrophy, consistent with the relatively low circulating sclerostin concentrations and with the 91-99% lower LRP5/LRP6 gene expressions in soleus versus tibia (p<0.001), a tissue with known anabolic responsiveness to Scl-Ab. In comparison, TE partially prevented soleus atrophy and increased levator ani/bulbocavernosus (LABC) mass by 30-40% (p<0.001 vs all groups). The differing myotrophic responsiveness coincided with a 3-fold higher androgen receptor gene expression in LABC versus soleus (p<0.01). This study provides the first direct evidence that Scl-Ab does not prevent soleus muscle atrophy in rodents after SCI and suggests that variable myotrophic responses in rodent muscles after androgen administration are influenced by androgen receptor expression.

A randomized and open-label phase II trial reports the efficacy of neoadjuvant lobaplatin in breast cancer

Currently, one sixth of triple-negative breast cancer (TNBC) patients who receive docetaxel (T) and epirubicin (E) as neoadjuvant chemotherapy achieve a pathologic complete response (pCR). This study evaluates the impact of adding lobaplatin (L) to the TE regimen. Here, we show data from 125 patients (63 TE and 62 TEL patients). Four patients did not complete all the cycles. Two-sided P values show that the addition of L (38.7% vs. 12.7%, P = 0.001) significantly increases the rate of pCR in the breast and the axilla (TpCR) and the overall response rate (ORR; 93.5% vs. 73.0%, P = 0.003). The occurrence of grade 3–4 anemia and thrombocytopenia is higher in the TEL group (52.5% vs. 10.0% and 34.4% vs. 1.7% respectively). These results demonstrate that the addition of L to the TE regimen as neoadjuvant chemotherapy improves the TpCR and the ORR rates of TNBC but with increased side effects.

Triple-negative breast cancer (TNBC) is one of the most aggressive and difficult to treat types of breast cancer. Here, a phase 2 clinical trial in TNBC patients reveals that the addition of lobaplatin to docetaxel and epirubicin regime improves pCR and ORR rates with tolerable side-effects.

Sclerostin Antibody Reverses Bone Loss by Increasing Bone Formation and Decreasing Bone Resorption in a Rat Model of Male Osteoporosis

Sclerostin antibody (Scl-Ab) restored bone mass and strength in the ovariectomized rat model of postmenopausal osteoporosis. Increased bone mineral density (BMD) and decreased skeletal fragility fracture risk have been reported in postmenopausal osteoporotic women receiving Scl-Ab. In males, loss of androgen leads to rapid decreases in BMD and an increased risk of fragility fractures. We hypothesized that Scl-Ab could reverse the loss of bone mass and strength caused by androgen ablation in the orchiectomized (ORX) rat model of male osteoporosis. We treated 9-month-old ORX Sprague Dawley rats (3 months after ORX) subcutaneously twice weekly with vehicle or Scl-Ab (5 or 25 mg/kg) for 6 weeks (n = 10 per group). Both doses of Scl-Ab fully reversed the BMD deficit in the lumbar spine and femur and tibia in ORX rats. Microcomputed tomography showed that the bone mass in the fifth lumbar vertebral body, femur diaphysis, and femoral neck were dose-dependently restored by Scl-Ab. The bone strength at these sites increased significantly with Scl-Ab to levels matching those of sham-operated controls and correlated positively with improvements in bone mineral content, demonstrating bone quality maintenance. Dynamic histomorphometry of the tibial diaphysis and second lumbar vertebral body demonstrated that Scl-Ab significantly increased bone formation on periosteal, endocortical, and trabecular surfaces and significantly decreased bone resorption on endocortical and trabecular surfaces. The effects of Scl-Ab on increasing bone formation and decreasing bone resorption led to restoration of bone mass and strength in androgen-deficient rats. These findings support the ongoing evaluation of Scl-Ab as a potential therapeutic agent for osteoporosis in men.

Effects of gene polymorphisms in the endoplasmic reticulum stress pathway on clinical outcomes of chemoradiotherapy in Chinese patients with nasopharyngeal carcinoma

There is considerable inter-individual variabil¬ity in chemoradiotherapy responses in nasopharyngeal carcinoma (NPC) patients receiv¬ing the same or similar treatment protocols. In this study we evaluated the association between the gene polymorphisms in endoplasmic reticulum (ER) stress pathway and chemoradiation responses in Chinese NPC patients. A total of 150 patients with histopathologically conformed NPC and treated with concurrent chemoradiotherapy were enrolled. Genotypes in ER stress pathway genes, including VCP (valosin-containing protein) rs2074549, HSP90B1 rs17034943, CANX (calnexin) rs7566, HSPA5 [heat shock protein family A (Hsp70) member 5] rs430397, CALCR (calcitonin receptor) rs2528521, and XBP1 (X-box binding protein 1) rs2269577 were analyzed by Sequenom MassARRAY system. The short-term effects of primary tumor and lymph node after radiotherapy were assessed based on the Response Evaluation Criteria in Solid Tumors (RECIST) of WHO. And acute radiation-induced toxic reactions were evaluated according to the Radiation Therapy Oncology Group or European Organization for Research and Treatment of Cancer (RTOG/EORTC). The effects of gene polymorphisms on clinical outcomes of chemoradiotherapy were assessed by chi-square test, univariate and multivariate logistic regression analyses. We found that CT and CT+CC genotypes of CANX rs7566 was significantly correlated with primary tumor treatment efficacy at 3 months after chemoradiotherapy and with occurrence of radiation-induced myelosuppression in Chinese NPC patients. CT and CT+CC genotypes of CALCR rs2528521 were significantly correlated with cervical lymph node efficacy at 3 months after chemoradiotherapy. And CC and CT+CC genotypes of VCP rs2074549 were significantly associated with occurrence of myelosuppression. In conclusion, SNPs of VCP rs2074549, CANX rs7566 and CALCR rs2528521 in ER stress pathway genes may serve as predictors for clinical outcomes of chemoradiotherapy in Chinese NPC patients.

Effects of sclerostin antibodies in animal models of osteoporosis

There is an unmet need for therapies that can restore bone strength and reduce fracture risk among patients at high risk of osteoporotic fracture. To address this need, bone-forming therapies that increase osteoblast activity are required to help restore bone structure and strength. Sclerostin is now recognized as a target for osteoporosis therapy. Sclerostin is predominantly secreted by the osteocyte and acts as an extracellular inhibitor of canonical Wnt signaling by binding to the receptors lipoprotein receptor-related protein-4, 5 and 6. Monoclonal antibodies to sclerostin (Scl-Ab) have been used in both clinical and in preclinical studies of osteoporosis with beneficial outcomes for bone density, structure, strength and fracture risk reduction. In this review paper, we summarize the current literature describing the effects of Scl-Ab in animal models of osteoporosis. In addition, we report new pharmacologic data from three animal studies of Scl-Ab: 1) a 12-month study evaluating bone quality in ovariectomized (OVX) rats; 2) a 6-month study evaluating bone structure and strength in adolescent cynomolgus monkeys; and 3) the effects of transition from Scl-Ab to vehicle or the RANKL inhibitor osteoprotegerin-Fc in OVX rats. Together, these results demonstrate that inhibition of sclerostin by Scl-Ab increased bone formation, and decreased bone resorption, leading to improved bone structure, bone mass and bone strength while maintaining bone quality in multiple animal models of osteoporosis. Further, gains in bone mass induced by Scl-Ab treatment were preserved by antiresorptive agents such as a RANKL inhibitor as a follow-on therapy. The bone-forming effects of Scl-Ab were unaffected by pre- or co-treatment with a bisphosphonate, and were restored following a treatment-free period after initial dosing. These data support the clinical development of Scl-Ab for treatment of conditions with low bone mass such as postmenopausal and male osteoporosis.

Sost, independent of the non-coding enhancer ECR5, is required for bone mechanoadaptation

Sclerostin (Sost) is a negative regulator of bone formation that acts upon the Wnt signaling pathway. Sost is mechanically regulated at both mRNA and protein level such that loading represses and unloading enhances Sost expression, in osteocytes and in circulation. The non-coding evolutionarily conserved enhancer ECR5 has been previously reported as a transcriptional regulatory element required for modulating Sost expression in osteocytes. Here we explored the mechanisms by which ECR5, or several other putative transcriptional enhancers regulate Sost expression, in response to mechanical stimulation. We found that in vivo ulna loading is equally osteoanabolic in wildtype and Sost^-/- mice, although Sost is required for proper distribution of load-induced bone formation to regions of high strain. Using Luciferase reporters carrying the ECR5 non-coding enhancer and heterologous or homologous hSOST promoters, we found that ECR5 is mechanosensitive in vitro and that ECR5-driven Luciferase activity decreases in osteoblasts exposed to oscillatory fluid flow. Yet, ECR5^-/- mice showed similar magnitude of load-induced bone formation and similar periosteal distribution of bone formation to high-strain regions compared to wildtype mice. Further, we found that in contrast to Sost^-/- mice, which are resistant to disuse-induced bone loss, ECR5^-/- mice lose bone upon unloading to a degree similar to wildtype control mice. ECR5 deletion did not abrogate positive effects of unloading on Sost, suggesting that additional transcriptional regulators and regulatory elements contribute to load-induced regulation of Sost.