Leptin, Leptin Receptor, KHDRBS1 (KH RNA Binding Domain Containing, Signal Transduction Associated 1), and Adiponectin in Bone Metastasis from Breast Carcinoma: An Immunohistochemical Study.

Breast cancer patients are at a high risk of complications from bone metastasis. Molecular characterization of bone metastases is essential for the discovery of new therapeutic targets. Here, we investigated the expression and the intracellular distribution of KH RNA binding domain containing, signal transduction associated 1 (KHDRBS1), leptin, leptin receptor (LEPR), and adiponectin in bone metastasis from breast carcinoma and looked for correlations between the data. The expression of these proteins is known in breast carcinoma, but it has not been investigated in bone metastatic tissue to date. Immunohistochemical analysis was carried out on bone metastasis specimens, then semiquantitative evaluation of the results and the Pearson test were performed to determine eventual correlations. KHDRBS1 expression was significantly higher in the nuclei than in the cytosol of metastatic cells; LEPR was prevalently observed in the cytosol and the nuclei; leptin and adiponectin were found in metastatic cells and stromal cells; the strongest positive correlation was between nuclear KHDRBS1 and nuclear LEPR expression. Taken together, our findings support the importance of the leptin/LEPR/KHDRBS1 axis and of adiponectin in the progression of bone metastasis and suggest their potential application in pharmacological interventions.

When primary hyperparathyroidism comes as good news.

SUMMARY: Brown tumors are osteoclastic, benign lesions characterized by fibrotic stroma, intense vascularization and multinucleated giant cells. They are the terminal expression of the bone remodelling process occurring in advanced hyperparathyroidism. Nowadays, due to earlier diagnosis, primary hyperparathyroidism keeps few of the classical manifestations and brown tumors are definitely unexpected. Thus, it may happen that they are misdiagnosed as primary or metastatic bone cancer. Besides bone imaging, endocrine evaluation including measurement of serum parathyroid hormone and calcium (Ca) levels supports the pathologist to address the diagnosis. Herein, a case of multiple large brown tumors misdiagnosed as a non-treatable osteosarcoma is described, with special regards to diagnostic work-up. After selective parathyroidectomy, treatment with denosumab was initiated and a regular follow-up was established. The central role of multidisciplinary approach involving pathologist, endocrinologist and oncologist in the diagnostic and therapeutic work-up is reported. In our opinion, the discussion of this case would be functional especially for clinicians and pathologists not used to the differential diagnosis in uncommon bone disorders. LEARNING POINTS: Brown tumors develop during the remodelling process of bone in advanced and long-lasting primary or secondary hyperparathyroidism. Although rare, they should be considered during the challenging diagnostic work-up of giant cell lesions. Coexistence of high parathyroid hormone levels and hypercalcemia in primary hyperparathyroidism is crucial for the diagnosis. A detailed imaging study includes bone X-ray, bone scintiscan and total body CT; to rule out bone malignancy, evaluation of bone lesion biopsy should include immunostaining for neoplastic markers as H3G34W and Ki67 index. If primary hyperparathyroidism is confirmed, selective parathyroidectomy is the first-line treatment. In advanced bone disease, treatment with denosumab should be considered, ensuring a strict control of Ca levels.

Quality of life, pain, and psychological factors in patients undergoing surgery for primary tumors of the spine.

PURPOSE: Knowledge about quality of life (QOL), pain, and psychological factors in patients with primary tumors of the spine is limited, but is important in planning rehabilitation after surgery. Aims of this study were to assess the preoperative levels and improvement after surgery of these factors, and to identify the predictors of postoperative pain and QOL. METHODS: Patients with primary tumors undergoing spine surgery were matched for sex and age with patients with metastatic tumors. QOL was measured at baseline and three months after surgery with the physical (PCS) and mental (MCS) components SF-12 subscales, pain intensity with a numeric rating scale (NRS), depression with the Beck Depression Inventory (BDI). Preoperative SF-12, NRS, and BDI levels and differences in follow-up improvement in SF-12 and NRS were compared across samples. LASSO regressions were performed to find predictors of follow-up SF-12 and NRS. RESULTS: Patients with primary tumors showed better PCS and NRS, and similar BDI and MCS than patients with metastatic tumors. At follow-up, they showed stronger improvement in the MCS and no improvement in the PCS. All QOL scores were below those of the general population. Follow-up PCS was predicted by baseline PCS and BDI; MCS by baseline MCS; pain intensity by baseline pain intensity and BDI. CONCLUSION: Patients with primary tumors of the spine suffer from moderate levels of physical and mental impairment. Depression influences surgical outcomes.

Multicentric, multifocal, and recurrent osteoid osteoma of the hip: first case report.

BACKGROUND: Osteoid osteoma is a benign bone-forming tumour, which very unfrequently has multifocal or multicentric presentation. We report the first known case of a multicentric, multifocal and recurrent osteoid osteoma treated using radiofrequency ablation. CASE PRESENTATION: A 39-year-old man with two-year history of left hip pain was admitted at our Institution. The pain was more intense during the night and partially relieved by salicylates. Pelvis CT demonstrated two lytic lesions (8 and 7 mm, respectively) with surrounding sclerotic reactive bone, both with a central focal area of high attenuation, located in the femoral neck and along the anterior portion of the acetabulum, respectively. Both lesions had clinical and imaging findings consistent with multicentric osteoid osteoma. Thus, the two lesions were biopsied - with pathologic confirmation of osteoid osteoma - and treated using radiofrequency ablation. Hip pain decreased but did not disappear, actually increasing a few months after treatment. CT and MRI were performed showing a smaller lesion (5 mm) with the same imaging features, surrounded by marrow oedema, along the posterior column of the acetabulum. The lesion was considered suspicious for osteoid osteoma, overlooked on previous examinations. Therefore, a diagnosis of multicentric and multifocal osteoid osteoma was established. The new lesion was again treated with radiofrequency ablation with symptom disappearance. However, hip pain relapsed after 18 months, and CT and MRI showed an osteoid osteoma recurrence on the posterior column of the acetabulum, which was biopsied and successfully treated using radiofrequency ablation. CONCLUSIONS: To our knowledge, this is the first reported case of multicentric, multifocal, recurrent osteoid osteoma. Our case report highlights the importance of considering a diagnosis of multifocal osteoid osteoma when dealing with multifocal lytic lesions of the bone and with pain persistence after treatment. It also emphasises the combined role of CT and MRI in this setting.

Is the Posterior-Only Approach Sufficient for Treating Cervical Spine Metastases? The Evidence from a Case Series.

OBJECTIVES: Few studies have evaluated surgical options in the treatment of cervical metastatic disease. The aim of this study is to report the surgical outcomes of patients treated with the posterior-only approach for metastatic cervical disease. METHODS: In this retrospective analysis, all cases treated in our institution from 2009 to 2017 were reviewed. Six (20%) patients had intracompartimental lesions (Tomita 1-3), whereas 24 (80%) patients had extracompartimental lesions (Tomita 4-7), with extensive anterior column involvement. All patients were surgically treated with laminectomy and posterior stabilization. Pain and neurologic function were evaluated before and after surgery. RESULTS: Thirty patients were included (15 female, 15 male), with a mean age of 60.6 ± 11.56 years (range 35-82 years). Lesions were located in 7 patients (23.3%) in the upper cervical spine and in 14 patients (46.6%) and in 9 patients (30,1%) in the mid-cervical and in the cervicothoracic junction, respectively. At a mean follow up of 13.7 ± 14.8 months, 15 (50%) patients died from their disease. Pain decreased in all patients after surgery, (preoperative NRS 5.57 ± 1.81 postoperative Numeric Rating Scale of 2.1 ± 1.0, P < 0.00001). Two patients (6.7%) had significant neurologic worsening after surgery. Two (6.9%) patients had surgical-site infection that required reintervention. No mechanical failures were observed. CONCLUSIONS: In our series, posterior-only fixation provided postoperative pain relief and achieve spinal stability, ultimately improving the quality of life. In conclusion, posterior-approach decompression and stabilization is a safe and feasible procedure in patients with neurologic or mechanical instability for cervical spine metastasis.

Solid bone tumors of the spine: Diagnostic performance of apparent diffusion coefficient measured using diffusion-weighted MRI using histology as a reference standard.

PURPOSE: To assess the diagnostic performance of mean apparent diffusion coefficient (mADC) in differentiating benign from malignant bone spine tumors, using histology as a reference standard. Conventional magnetic resonance imaging (MRI) sequences have good reliability in evaluating spinal bone tumors, although some features of benign and malignant cancers may overlap, making the differential diagnosis challenging. MATERIALS AND METHODS: In all, 116 patients (62 males, 54 females; mean age 59.5 ± 14.1) with biopsy-proven spinal bone tumors were studied. Field strength/sequences: 1.5T MR system; T1 -weighted turbo spin-echo (repetition time / echo time [TR/TE], 500/13 msec; number of excitations [NEX], 2; slice thickness, 4 mm), T2 -weighted turbo spin-echo (TR/TE, 4100/102 msec; NEX, 2; slice thickness, 4 mm), short tau inversion recovery (TR/TE, 4800/89 msec; NEX, 2; slice thickness, 4 mm, IT, 140 msec), axial spin-echo echo-planar diffusion-weighted imaging (DWI) (TR/TE 5200/72 msec; slice thickness 5 mm; field of view, 300; interslice gap, 1.5 mm; NEX, 6; echo-planar imaging factor, 96; no parallel imaging) with b-values of 0 and 1000 s/mm², and 3D fat-suppressed T1 -weighted gradient-recalled-echo (TR/TE, 500/13 msec; slice thickness, 4 mm) after administration of 0.2 ml/kg body weight gadolinum-diethylenetriamine pentaacetic acid. Two readers manually drew regions of interest on the solid portion of the lesion (hyperintense on T2 -weighted images, hypointense on T1 -weighted images, and enhanced after gadolinium administration on fat-suppressed T1 -weighted images) to calculate mADC. Histology was used as the reference standard. Tumors were classified into malignant primary tumors (MPT), bone metastases (BM), or benign primary tumors (BPT). Statistical tests: Nonnormality of distribution was tested with the Shapiro-Wilk test. The Kruskal-Wallis and Mann-Whitney U-test with Bonferroni correction were used. Sensitivity and specificity of the mADC values for BM, MPT, and BPT were calculated. Approximate receiver operating characteristic curves were created. Interobserver reproducibility was evaluated using the intraclass correlation coefficient (ICC). RESULTS: The mADC values of MPT (n = 35), BM (n = 65), and BPT (n = 16) were 1.00 ± 0.32 (0.59-2.10) × 10-3 mm2 /s, 1.02 ± 0.25 (0.73-1.96) × 10-3 mm2 /s, 1.31 ± 0.36 (0.83-2.14) × 10-3 mm2 /s, respectively. The mADC was significantly different between BPT and all malignant lesions (BM+MPT) (P < 0.001), BM and BPT (P = 0.008), and MPT and BPT (P = 0.008). No difference was found between BM and MPT (P = 0.999). An mADC threshold of 0.952 × 10-3 mm2 /s yielded 81.3% sensitivity, 55.0% specificity. Accuracy was 76% (95% confidence interval [CI] = 63.9%-88.1%). Interobserver reproducibility was almost perfect (ICC = 0.916; 95% CI = 0.879-0.942). CONCLUSION: DWI with mADC quantification is a reproducible tool to differentiate benign from malignant solid tumors with 76% accuracy. The mADC values of BPT were statistically higher than that of malignant tumors. However, the large overlap between cases may make mADC not helpful in a specific patient. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1034-1042.

Salvage Revision Surgery After Inappropriate Approach for Primary Spine Tumors: Long Term Follow-Up in 56 Cases.

BACKGROUND: The mainstay treatment of primary malignant bone tumors is wide surgery in the spine. Unfortunately, most cases undergo the first approach in a nonspecialized center; this often means adopting an inappropriate approach with contamination, which consistently decreases the effectiveness of a second surgery. The aim of the present paper is to evaluate recurrence and survival rates after en-bloc resection. METHODS: All patients underwent wide resection by the senior author from January 1997 to December 2013 after the first inappropriate approach was reviewed. Fifty-six patients were included in the present evaluation. Epidemiologic and clinical characteristics, surgeries, early and late complications, and survival rate were reported. RESULTS: The margin obtained was wide, marginal, and intralesional in 9, 28, and 19 cases, respectively. The complication rates were 55.4% and 44.6% for early and late complications, respectively. Most (73.2%) of the patients had complications. The survival rate is 82.1% at 1 year and then decreases 10% each year until 42.1% at 5 years from surgeries. No statistically significant correlation was found between margin and local recurrence and survival. CONCLUSION: In our series, the first inappropriate approach had already compromised patient prognosis, so in case of suspicious primary spine tumor, the patient had to be referred to a specialized center. The margin obtained during salvage surgery does not appear to influence recurrence and survival, probably because it is already compromised by the first surgery. More prospective studies are necessary to confirm our data and verify the impact of the margin obtained during salvage surgery on patients' survival.

High SPARC Expression Starting from Dysplasia, Associated with Breast Carcinoma, Is Predictive for Bone Metastasis without Enhancement of Plasma Levels.

In order to become established in the skeleton, metastatic cells disseminating from the breast carcinoma need to acquire organ-specific traits. There are no effective predictors for who will develop bone metastasis to guide long-term predictive therapy. Our purpose was to individuate events critical for bone colonization to make a molecular classification of breast carcinoma useful for bone-metastasis outcome. In dysplasia adjacent to carcinoma and in pair-matched specimens of bone metastasis we examined SPARC expression and localization as well as Endothelin 1/ETAR signals by immunohistochemistry, and the evaluation of plasma levels of SPARC by ELISA was also performed. In patients with breast carcinoma metastasizing to bone, SPARC and Endothelin 1/ETAR axis were highly expressed from dysplasia until bone metastasis, but the SPARC plasma level was as low as that of normal women, in contrast to patients that never develop bone metastasis, suggesting that circulating SPARC was counter adhesive. Altogether, the early identification of SPARC/Endothelin 1/ETAR in dysplastic lesions would be important to devise therapies preventing metastasis engraftment, since often carcinoma cells spread to distant organs at the time or even before patients present with cancer.

Epithelioid hemangioendothelioma of the spine: results at seven years of average follow-up in a series of 10 cases surgically treated and a review of literature.

PURPOSE: To review a series of ten cases with epithelioid hemangioendothelioma of the spine, that have undergone surgery to describe clinical presentation, results and complications associated with surgical treatment; a review of literature reporting the main characteristics of the cases already published has been reported. METHODS: A review of patients affected by epithelioid hemangioendothelioma surgically treated by the senior author from 1995 to 2012 was carried out. Ten cases were identified and clinical and radiological characteristics, therapy, complications and survival were valued. RESULTS: Wide margin was achieved in two out of ten cases, marginal margin in seven and intralesional margin in one case. Average intraoperative blood loss was about 2,800 ml. Reported complications were one case of cord injury, one of dural tear, two cases of massive blood loss, a case of reconstruction failure, a wound dehiscence with deep infection, a pneumonia episode and a deep vein thrombosis with pulmonary embolism. Average follow-up was 84.4 months. Two local recurrences, after 32 and 37 months and two deaths for metastasis, after 14 and 36 months, were reported. Although several chemotherapy protocols are available for the treatment of EH of soft tissue, they are not relevant for the bone. CONCLUSIONS: Wide surgery is probably associated with a better prognosis. Indeed most deaths and local recurrences reported in literature happened after intralesional surgery or chemotherapy/RT alone. The presenting study suggests that the best approach to achieve long-term local control and a major survival could be wide surgery, nevertheless more cases series are necessary to verify survival rate.

Multilevel en bloc spondylectomy for tumors of the thoracic and lumbar spine is challenging but rewarding.

BACKGROUND: Over the years, en bloc spondylectomy has proven its efficacy in controlling spinal tumors and improving survival rates. However, there are few reports of large series that critically evaluate the results of multilevel en bloc spondylectomies for spinal neoplasms. QUESTIONS/PURPOSES: Using data from a large spine tumor center, we answered the following questions: (1) Does multilevel total en bloc spondylectomy result in acceptable function, survival rates, and local control in spinal neoplasms? (2) Is reconstruction after this procedure feasible? (3) What complications are associated with this procedure? (4) is it possible to achieve adequate surgical margins with this procedure? METHODS: We retrospectively investigated 38 patients undergoing multilevel total en bloc spondylectomy by a single surgeon (AL) from 1994 to 2011. Indications for this procedure were primary spinal sarcomas, solitary metastases, and aggressive primary benign tumors involving multiple segments of the thoracic or lumbar spine. Patients had to be medically fit and have no visceral metastases. Analysis was by chart and radiographic review. Margin quality was classified into intralesional, marginal, and wide. Radiographs, MR images, and CT scans were studied for local recurrence. Graft healing and instrumentation failures at subsequent followup were assessed. Complications were divided into major or minor and further classified as intraoperative and early and late postoperative. We evaluated the oncologic status using cumulative disease-specific and metastases-free survival analysis. Minimum followup was 24 months (mean, 39 months; range, 24-124 months). RESULTS: Of the 38 patients, 34 (89%) were alive and walking without support at final followup. Thirty-one (81%) had no evidence of disease. Two patients died postoperatively and another two died of systemic disease (without local recurrence). Only three patients (8%) had a local recurrence. There were 14 major complications and 22 minor complications in 25 patients (65%). Only one patient required revision of implants secondary to mechanical failure. Two cases of cage subsidence were noted but had no clinical significance. Wide margins were achieved in nine patients (23%), marginal in 25 (66%), and intralesional in four (11%). CONCLUSIONS: In patients with multisegmental spinal tumors, oncologic resections were achieved by multilevel en bloc spondylectomy and led to an acceptable survival rate with reasonable local control. Multilevel en bloc surgery was associated with a high complication rate; however, most patients recovered from their complications. Although the surgical procedure is challenging, our encouraging mid-term results clearly favor and validate this technique. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Four- and five- level en bloc spondylectomy for malignant spinal tumors.

STUDY DESIGN: Retrospective study. OBJECTIVE: To report results of 4- and 5-level en bloc spondylectomy (EBS) in the treatment of malignant spinal tumors. SUMMARY OF BACKGROUND DATA: EBS is widely used to avoid local recurrence in the treatment of spinal malignant tumors. Four- and 5-level EBS are aggressive procedures associated with complications and morbidity. METHODS: We conducted a retrospective study of all patients treated with minimum 4-level EBS. Patient and surgical data were noted. Radiographs, magnetic resonance images, and computed tomographic scans were studied for local recurrence, graft, and instrumentation failures at subsequent follow-up. Type of excision was classified into intralesional, marginal, and wide margins. Complications were divided into major or minor and were further classified as intraoperative, early, and late postoperative. At the last follow-up, the patients were classified as alive with no evidence of local or systemic disease, alive with evidence of local or systemic disease or both, dead with evidence of local disease, or systemic disease or both, and dead without evidence of local and systemic disease. RESULTS: Nine patients were identified who required a minimum 4-level en bloc resection. Five males and 4 females. Average age was 41.66 years (11-66). There were 8 primary malignant tumors: 3 chordomas, 3 osteosarcomas, 1 chondrosarcoma, 1 primary lung tumor and 1 metastatic alveolar soft part sarcoma. Six were operated with 4-level en bloc and 3 with 5 levels. The mean surgical time was 713 minutes and estimated blood loss was 4.5 L. Mean follow-up was 27.7 months (8-84). At the last follow-up, 6 patients were alive with no evidence of local or systemic disease, 1 alive with evidence of systemic disease, 1 dead with evidence of local disease, or systemic disease or both, and 1 DNLS. Only 1 (11%) patient had a local recurrence. Three patients with Frankel D had full neurological recovery. Histopathological assessment showed marginal margins in 7 patients and wide in 2. There were 9 major and 9 minor complications in 7 patients. Five of 7 patients (71%) with complications, had fully recovered from their complications at the last follow-up. CONCLUSION: Multilevel EBS, can be offered to a patient to prevent local recurrence of disease. Even in experienced hands, the risks of intra- and postoperative complications are high (78%). However, most of the patients with complications, recovered completely (71%). Although the surgery itself may prove beneficial, patients should be well informed regarding the morbidity associated with it. LEVEL OF EVIDENCE: 4.

Microenvironmental stimuli affect Endothelin-1 signaling responsible for invasiveness and osteomimicry of bone metastasis from breast cancer.

The present study was undertaken to clarify the function(s) of Endothelin-1 and its receptors ETAR and ETBR in osteolytic-bone metastasis from breast cancer, and their regulation by hepatocyte and transforming growth factors (HGF, TGF-ß) and hypoxia. The aim was to evaluate the adaptability of bone metastasis to microenvironmental stimuli through Endothelin-1-mediated epithelial-mesenchymal transition (EMT), or the reverse process MET, and through osteomimicry possible key features for bone colonization. We compared low (MCF-7) and high (MDA-MB231) invasive-breast carcinoma cells, and 1833-bone metastatic clone, with human pair-matched primary breast-carcinomas and bone metastases. Parental MDA-MB231 and the derived 1833-clone responded oppositely to the stimuli. In 1833 cells, TGF-ß and hypoxia increased Endothelin-1 release, altogether reducing invasiveness important for engraftment, while Endothelin-1 enhanced MDA-MB231 cell invasiveness. The Endothelin-1-autocrine loop contributed to the cooperation of intracellular-signaling pathways and extracellular stimuli triggering MET in 1833 cells, and EMT in MDA-MB231 cells. Only in 1833 cells, HGF negatively influenced transactivation and release of Endothelin-1, suggesting a temporal sequence of these stimuli with an initial role of HGF-triggered Wnt/ß-catenin pathway in metastatization. Then, Endothelin-1/ETAR conferred MET and osteomimetic phenotypes, with Runt-related transcription factor 2 activation and metalloproteinase 9 expression, contributing to colonization and osteolysis. Findings with human pair-matched primary ductal carcinomas and bone metastases gave a translational significance to the molecular study. Endothelin-1, ETAR and ETBR correlated with the acquisition of malignant potential, because of high expression already in the in situ carcinoma. These molecular markers might be used as predictive index of aggressive behavior and invasive/metastatic phenotype.

Hypoxia inducible factor-1 is activated by transcriptional co-activator with PDZ-binding motif (TAZ) versus WWdomain-containing oxidoreductase (WWOX) in hypoxic microenvironment of bone metastasis from breast cancer.

The hypoxic microenvironment of bone marrow favours the bone metastasis process. Hypoxia inducible factor (HIF)-1α is hallmark for hypoxia, correlating with poor prognosis and radio/chemotherapy resistance of primary-breast carcinoma. For bone metastasis, the molecular mechanisms involved in HIF-1α expression and HIF-1 (α/ß heterodimer)-transcription factor activity are scarcely known. We studied the role played by HIF-1 in the cross-talk between neoplastic and supportive-microenvironmental cells. Also, WWdomain-containing oxidoreductase (Wwox) and transcriptional co-activator with PDZ-binding motif (TAZ) were taken into consideration evaluating whether these Hippo-pathway effectors affect bone-metastatic phenotype through HIF-1 activity. Considering bone-metastasis specimens, nuclear HIF-1α-TAZ co-localisation occurred in neoplastic and supportive cells, such as fibroblasts and endotheliocytes. Based on these data, the functional importance was verified using 1833-bone metastatic clone under hypoxia: nuclear HIF-1α and TAZ expression increased and co-immunoprecipitated, activating HIF-1-DNA binding and transactivation. In contrast, Wwox localised at perinuclear level in neoplastic cells of bone metastasis, being almost absent in supportive cells, and Wwox-protein expression diminished in hypoxic-1833 cells. Thus, TAZ regulation of HIF-1 activity might be important for bone-secondary growth, participating in metastasis-stroma cross-talk. Further, TAZ and HIF-1α-protein levels seemed correlated. In fact, blocking cyclooxygenase-2 with NS398 in hypoxic-1833 cells, not only HIF-1α decreased but also molecular-mechanism(s) upstream of the Hippo pathway were triggered: LATS-dependent TAZ phosphorylation seemed responsible for TAZ nucleus/cytoplasm translocation and degradation. In the 1833-xenograft model, NS398 largely prevented the outgrowth of bone-metastatic cells, probably related to remarkable-extracellular matrix assembly. We gained clinical insight into HIF-1α and TAZ as candidate biomarkers for bone avidity, relevant for early-therapeutic intervention against bone metastasis.

Bone metastatic process of breast cancer involves methylation state affecting E-cadherin expression through TAZ and WWOX nuclear effectors.

We investigated the involvement of Hippo-related pathways in bone metastasis from breast cancer, by evaluating E-cadherin expression downstream of WWdomain-containing oxidoreductase (Wwox) and transcriptional co-activator with PDZ-binding motif (TAZ). These nuclear effectors functioned in a context-specific fashion on transcriptome, depending on breast-cancer aggressiveness and methylation state. Wwox and E-cadherin were found in human specimens of bone metastasis but not in primary-ductal breast carcinoma, while TAZ showed a characteristic localisation in metastasis nuclei. Wwox and E-cadherin were higher in 1833-metastatic clone with bone avidity than in parental-MDA-MB231 cells, while only metastatic cells presented TAZ. In 1833 cells, a complex interplay of transcriptional signalling controlled E-cadherin transactivation. Wwox and TAZ activated Hypoxia inducible factor-1 (HIF-1) binding to E-cadherin promoter, while Peroxisome proliferator-activated receptor γ (PPARγ) intervened in E-cadherin transactivation favouring and preventing Wwox and TAZ functions, respectively. Methylation impinged on Hippo-related pathways through Wwox and TAZ, modifying metastatic phenotype. The protract exposure to 5-azacytidine (Aza), by affecting methylation state modified the shape of 1833 cells, becoming mesenchymal as that of MDA-MB231 cells and reduced spontaneous-Matrigel invasion. The underlying-molecular mechanisms were diminutions of E-cadherin, Wwox, matrix metalloproteases 2 and 9, HIF-1- and PPARγ-activities, inversely correlated to Snail and nuclear-TAZ accumulations. Exogenous WWOX restored 1833-Aza invasion. Thus, 1833-Aza cells permitted to study the role played by methylation in metastasis plasticity, being E-cadherin loss part of an entire-gene reprogramming. Of note, bone-metastasis formation in 1833-Aza xenograft was partially impaired, prolonging mice survival. In conclusion, the methylation-heritable changes seemed important for cancer progression to establish bone metastasis engraftment/growth, by affecting steps requiring homotipic and/or heterotypic-adhesive properties and matrix degradation.

Bone formation and resorption markers as diagnostic tools for bone metastases evaluation.

Bone metastases are a frequent complication of several types of cancers. Since bone metastases are difficult to diagnose with the current available approaches, there is a demand for new methods for assessing bone response. In this context, biochemical markers of bone remodeling may provide useful information on bone turnover that, in turn, may reflect disease activity in bone. In this study we tested a panel of bone remodeling markers (distinguishing between bone formation and bone resorption ones) in different groups of cancer patients, so as to evaluate the potential clinical role of the examined bone remodeling markers in the early diagnosis of metastases formation and progression. Among the bone resorption markers, tartrate resistant acid phosphatase 5b (TRAP5b) resulted the most specific for the metastatic tumor stage. Both the bone formation markers we analyzed displayed a direct correlation (positive for bone-specific alkaline phosphatase [BAP] and negative for osteocalcin [OC]) with tumor disease progression, ranging from healthy controls to primary tumor and, ultimately, to the metastatic stage. Taken together our results suggest that these markers can be valuable tools to be used, in parallel with traditional methods of metastases diagnosis, in order to monitor more in detail the pathological effect of metastases progression in bone tissue.

Nuclear co-localization and functional interaction of COX-2 and HIF-1α characterize bone metastasis of human breast carcinoma.

The aim of this article is to identify nuclear co-localization of COX-2 and HIF-1α in human-bone metastasis of breast cancer, index of transcriptionally activated cells and functional for gene expression. In particular, we verified whether hypoxia exerted a direct role on metastasis-gene expression or through COX-2 signaling, due to the relevance for clinical implications to individuate molecular targets for diagnosis and therapy. The experiments were performed in vitro with two metastatic clones, 1833 and MDA-231BO, and the parental MDA-MB231 cells, in vivo (1833-xenograft model), and in human-bone metastasis specimens. In 1833 cells in vitro, COX-2 signaling pathway was critical for nuclear HIF-1α-protein expression/translocation, mechanisms determining HIF-1 activity and gene expression. The data were corroborated by immunohistochemistry in human-bone metastasis specimens. COX-2 and HIF-1α showed wide co-localization in the nucleus, indicative of COX-2-nuclear import in transcriptionally activated metastatic cells and consistent with COX-2-HIF-1α functional interaction. A network of microenvironmental signals controlled COX-2 induction and HIF-1 activation downstream. In fact, hypoxia through HGF and TGF-ß1 autoregulatory loops triggered a specific array of transcription factors responsible for COX-2 transactivation. The novelty was that HGF and TGF-ß1 biological signals were produced by hypoxic metastatic cells and, therefore, the microenvironment seemed to be modified by metastatic-cell engraftment in the bone. In agreement, HIF-1α expression in bone marrow supportive cells occurred in metastasis-bearing animals. Altogether, the data supported the pre-metastatic-niche theory. Our observations might be useful to design therapies against bone metastasis, by affecting the phenotype changes of metastatic cells occurring at the secondary growth site through COX-2-HIF-1 interaction.