Skeletal related events in patients with bone metastasis arising from non-small cell lung cancer

Early diagnostic value of ECT whole-body bone imaging combined with PINP and β-CTX for bone metastasis of lung cancer

OBJECTIVE

This research was aimed at investigating the early diagnostic value of emission computed tomograph (ECT) whole-body bone imaging combined with PINP and β-CTX for bone metastasis of lung cancer.

METHODS

Case data of 86 lung cancer patients were categorized into lung cancer with bone metastasis (LCWBM, 46 cases) and lung cancer without bone metastasis (LCWOBM, 40 cases) groups according to the presence or absence of bone metastasis. Patients' general information were collected. ECT whole-body bone imaging was used to detect bone metastases and the grading of the extent of disease (EOD) in both groups, and electrochemiluminescence was utilized to detect the serum levels of PINP and β-CTX. Spearman correlation analysis was employed to evaluate the correlation between EOD grading and PINP and β-CTX levels. Logistic univariate and multivariate regression was implemented to analyze the risk factors of bone metastasis of lung cancer. Receiver operating characteristic (ROC) curve was applied to analyze the diagnostic efficacy of the single test of ECT whole-body bone imaging, PINP, or β-CTX and the combination of the three tests.

RESULTS

The differences in pathological type, clinical stage and EOD grading, the number of positive ECT cases, and the expression levels of PINP and β-CTX between the LCWBM and LCWOBM groups were statistically significant. In LCWBM patients with different EOD grading, the trends of the expression of PINP and β-CTX were grade 3 > grade 2 > grade 1 and grade 0. Further correlation analyses revealed that EOD grading showed a significant positive correlation with the PINP and β-CTX expression levels. Univariate logistic regression analysis demonstrated that adenocarcinoma, TNM stage IV, ECT positivity, and high expression of PINP and β-CTX were associated with bone metastasis of lung cancer, and multivariate logistic regression analysis indicated that ECT positivity, high expression of PINP and β-CTX were independent risk factors for bone metastasis of lung cancer. The area under the curve (AUC) of ECT, PINP, and β-CTX alone for the diagnosis of bone metastasis of lung cancer were 0.872, 0.888, and 0.874, respectively, and the AUC for the combined diagnosis of the three was 0.963, which was greater than that of any one of the individual indices, with a sensitivity of 86.96% and a specificity of 97.50% at a Youden index of 0.845.

CONCLUSION

ECT whole-body bone imaging combined with PINP and β-CTX has high diagnostic value for bone metastasis of lung cancer.

Machine learning based on SPECT/CT to differentiate bone metastasis and benign bone lesions in lung malignancy patients

BACKGROUND

Bone metastasis is a common event in lung cancer progression. Early diagnosis of lung malignant tumor with bone metastasis is crucial for selecting effective treatment strategies. However, 14.3% of patients are still difficult to diagnose after SPECT/CT examination.

PURPOSE

Machine learning analysis of [99mTc]-methylene diphosphate (99mTc-MDP) SPECT/CT scans to distinguish bone metastases from benign bone lesions in patients with lung cancer.

METHODS

One hundred forty-one patients (69 with bone metastases and 72 with benign bone lesions) were randomly assigned to the training group or testing group in a 7:3 ratio. Lesions were manually delineated using ITK-SNAP, and 944 radiomics features were extracted from SPECT and CT images. The least absolute shrinkage and selection operator (LASSO) regression was used to select the radiomics features in the training set, and the single/bimodal radiomics models were established based on support vector machine (SVM). To further optimize the model, the best bimodal radiomics features were combined with clinical features to establish an integrated Radiomics-clinical model. The diagnostic performance of models was evaluated using receiver operating characteristic (ROC) curve and confusion matrix, and performance differences between models were evaluated using the Delong test.

RESULTS

The optimal radiomics model comprised of structural modality (CT) and metabolic modality (SPECT), with an area under curve (AUC) of 0.919 and 0.907 for the training and testing set, respectively. The integrated model, which combined SPECT, CT, and two clinical features, exhibited satisfactory differentiation in the training and testing set, with AUC of 0.939 and 0.925, respectively.

CONCLUSIONS

The machine learning can effectively differentiate between bone metastases and benign bone lesions. The Radiomics-clinical integrated model demonstrated the best performance.

Prevalence and factors associated with the occurrence of pathological fractures and their impact on the overall survival of patients with bone metastases under palliative care

OBJECTIVES

To assess the prevalence and factors associated with the occurrence of pathological fractures and their impact on the overall survival of patients with bone metastases under palliative care.

METHODS

An observational retrospective cohort assessment concerning both male and female patients with cancer presenting with bone metastases referred to a palliative care unit. Sociodemographic and clinical data were obtained before and after care unit referral. Patients were followed up until death or the last follow-up (4 years after referral). Logistic regression models and survival curves employing a log-rank test were applied.

RESULTS

A total of 348 patients were included in the study. Most were <65 years (65%) and female (62%), and the most frequent primary tumour site was the breast (40%). The prevalence of pathological fractures was 28%, more frequent in the axial skeleton (49%), with no association with overall patient survival (p=0.348). Patients with breast cancer exhibited a 2.96-fold higher chance (95% CI: 1.80 to 4.86) of developing a fracture compared with other tumours, and not receiving previous radiotherapy increased the chances of fracture occurrence by 5.60-fold (95% CI: 2.46 to 12.77).

CONCLUSION

A high prevalence of pathological fractures was observed. Presenting with breast cancer and not having undergone previous radiotherapy increase the chances of fracture occurrence, although this is not associated with overall survival in patients under palliative care.

Fatores Prognósticos e Funcionalidade na Síndrome de Compressão Medular Metastática: um Estudo de Coorte

Introdução: A síndrome de compressão medular metastática (SCMM) tem grande potencial de perda irreversível da função motora e sensitiva, sendo considerada uma emergência oncológica. Objetivo: Avaliar o prognostico da SCMM e a funcionalidade dos pacientes com tumores sólidos. Método: Estudo de coorte que incluiu pacientes com câncer que desenvolveram SCMM entre janeiro de 2017 e dezembro de 2018. Os dados clínicos e sociodemográficos foram extraídos dos prontuários físicos e eletrônicos. Analise de sobrevida foi realizada pelo método Kaplan-Meier. Resultados: O estudo abrangeu 90 pacientes que apresentaram SCMM. Ao diagnostico da SCMM, 55,5% dos pacientes não conseguiam realizar marcha. Os pacientes com SCMM após câncer de pulmão tiveram 4,1 vezes maior risco de morrer (IC 95%, 1,79-9,41; p=0,001), os pacientes com tumores geniturinários tiveram 1,9 vezes maior risco de morrer (IC 95%, 1,06-3,45; p=0,02) e os pacientes com outros tipos de tumor tiveram 3,1 vezes maior risco de morrer (IC 95%, 1,58-6,24; p=0,001) quando comparados aos pacientes com SCMM após câncer de mama. Conclusão: Destaca-se a relevância clinica deste estudo ao descobrir que o tipo de tumor primário e um fator preditor independente para sobrevida da SCMM. Ao diagnostico da SCMM, mais da metade dos pacientes não realizam marcha.

Predictors of overall survival in non-small-cell lung cancer patients with metastatic spinal cord compression treated with short-course radiotherapy

Metastatic spinal cord compression (MSCC) is a condition that impacts directly on the patient's prognosis.

OBJECTIVE

The study purpose was to identify predictors of overall survival in non-small-cell lung cancer (NSCLC) patients with MSCC.

METHODS

A cohort study involving NSCLC patients enrolled between 2008 and 2017 was performed. Sixty-four patients treated with short-course radiotherapy were included. Clinical and socio-demographic data were extracted from medical records. Data were analysed using survival analysis and Cox proportional hazard regression analysis.

RESULTS

The median survival time was 2.5 months (95% CI: 1.6-3.5). Patients >60 years had shorter survival than younger patients (HR 1.85; 95% CI 1.06-3.24; p = 0.02), and patients with performance status (PS) >2 had shorter survival than those with PS≤2 (HR 1.93; 95% CI 1.12-3.33; p = 0.01).

CONCLUSION

This study found worse PS and higher age are independent predictors of overall survival in NSCLC patients with MSCC treated with short-course radiotherapy after adjusting the potential confounding factors (PS, age and target therapy).

Impact of different patterns of metastasis in non-small-cell lung cancer patients

Aim: The aim of this study was to evaluate the frequency and median time for the development of metastases and prognosis by metastatic site after the diagnosis of non-small-cell lung cancer (NSCLC). Patients & methods: This cohort study was conducted with 1096 patients diagnosed with NSCLC between 2006 and 2014. Results: The most prevalent site of NSCLC metastases was the respiratory system. The nervous and adrenal systems presented the longest median time for the development of metastases. The 6-month survival varied from 68.2% for liver to 79.9% for the nervous system. Bone metastases were associated with a higher risk of death. Conclusion: The respiratory system was the most prevalent site of metastases. OS and risk of death varied according to the metastatic site.

Risk factors for skeletal-related events in patients with bone metastasis from breast cancer undergoing treatment with zoledronate

BACKGROUND

Skeletal-related events (SREs) are significant contributors to the morbidity and mortality in patients with bone metastasis from breast cancer. Thus, bone-modifying agents (BMAs) are recommended in this population. However, the baseline risk factors of SREs in patients with bone metastasis from breast cancer receiving BMAs are not well understood.

METHODS

We analyzed the patient-level data from a controlled arm of a clinical trial comparing denosumab with zoledronate in patients with bone metastases from breast cancer (ClinicalTrial.gov ID: NCT00321464) available at Project Data Sphere, a broad-access research platform that collects and curates patient-level data from completed, phase III cancer trials. The primary endpoint was the first SRE after the inclusion to the trial. The time to the first on study SRE was analyzed using Cox proportional hazards model based on patients' baseline characteristics including age, race, ECOG performance status (PS), histology and immunohistochemistry of breast cancer, and urine and serum laboratory data.

RESULTS

Among 756 patients in the zoledronate arm of the trial, we excluded 64 patients with a documented history of osteopenia or osteoporosis. The median age of the patients was 56 years old, the median follow-up was 553 days, and 249 patients (36%) had SREs. The univariate analysis showed that black or African American heritage, ECOG PS > 0, human epidermal growth factor receptor 2 (HER2) positivity, high urine N-telopeptide cross-links / creatinine ratio (NTx/Cre), and elevated serum alkaline phosphatase (ALP) are significant baseline risk factors for SREs. Patients with the characteristics of ECOG PS > 0, HER2 positivity, and elevated ALP also showed a significantly higher hazard ratio of SREs in multivariate analysis.

CONCLUSIONS

We determined risk factors for SREs in patients with bone metastasis from breast cancer.

CaSR Induces Osteoclast Differentiation and Promotes Bone Metastasis in Lung Adenocarcinoma

Objective: Explore the mechanism of CaSR's involvement in bone metastasis in lung adenocarcinoma.

Methods: Immunohistochemistry (IHC) was used to detect the expression of calcium-sensing receptor (CaSR) in 120 cases of lung adenocarcinoma with bone metastasis. Stably transfected cell lines with CaSR overexpression and knockdown based on A549 cells were constructed. The expression of CaSR was verified by western blot and qPCR. The proliferation and migration abilities of A549 cells were tested using cholecystokinin-8 (CCK-8) and Transwell assays, respectively. Western blotting was used to detect the expression of matrix metalloproteinases MMP2, MMP9, CaSR, and NF-κB. The supernatant from each cell culture group was collected as a conditional co-culture solution to study the induction of osteoclast precursor cells and osteoblasts. Western blot and qPCR were used to validate the expression of bone matrix degradation-related enzymes cathepsin K and hormone calcitonin receptor (CTR) and osteoblast-induced osteoclast maturation and differentiation enzyme receptor activator of nuclear factor-κB ligand (RANKL), macrophage colony-stimulating factor (M-CSF), osteoprotegerin (OPG), and PTHrP. Immunofluorescent staining was used to detect F-actin ring formation and osteocalcin expression. Western blot results for NF-κB expression identified a regulatory relationship between NF-κB and CaSR.

Results: CaSR expression in lung cancer tissues was significantly higher than that in adjacent and normal lung tissues. The expression of CaSR in lung cancer tissues with bone metastasis was higher than that in non-metastatic lung cancer tissues. The proliferation and migration ability of A549 cells increased significantly with overexpressed CaSR. The co-culture solution directly induced osteoclast precursor cells and the expression of bone matrix degradation-related enzymes significantly increased. Osteoblasts were significantly inhibited and osteoblast-induced osteoclast maturation and differentiation enzymes were significantly downregulated. It was found that the expression of NF-κB and PTHrP increased when CaSR was overexpressed. Osteoclast differentiation factor expression was also significantly increased, which directly induces osteoclast differentiation and maturation. These results were reversed when CaSR was knocked down.

Conclusions: CaSR can positively regulate NF-κB and PTHrP expression in A549 cells with a high metastatic potential, thereby promoting osteoclast differentiation and maturation, and facilitating the occurrence and development of bone metastasis in lung adenocarcinoma.

[Predictive factors for skeletal-related events in lung cancer]

INTRODUCTION

Skeletal-related events (SRE) are common in patients with bone metastatic lung cancer and have a negative impact on quality of life and survival. The objective of this study is to identify predictive factors for SRE occurrence among this population.

METHODS

We conducted a 3-year retrospective study including 100 lung cancer patients with bone metastasis.

RESULTS

Eighty-two patients presented at least one SRE (69.5% at baseline). The median occurrence for SRE was 4.5 months and severe bone pain was the most common SRE (56%). The alkaline phosphatase serum level>120IU/L (hazard ratio [sHR]=2.8; 95% confidence interval (CI) [1.5-5.4]; P=0.002) and calcemia>2.6mmol/L ([sHR]=9.7; 95% CI [5.1-18.4]; P<0.001) were identified as risk factors for SRE occurrence while the presence of an initial SRE was associated with a decrease of this risk ([sHR]=0.2; 95% CI [0.1-0.4]; P<0.001).

CONCLUSION

The elevated alkaline phosphatase serum level and hypercalcemia are risk factors for SRE occurrence in bone metastatic lung cancer patients and should be used as biomarkers to adapt current medical practice for these patients.

Incidence and Risk Factors for Bone Metastasis in Non-Small Cell Lung Cancer

Background: Bone is a frequent site of metastasis from various primary cancers including with Non-Small Cell Lung Cancer. The aim of this study was to investigate the incidence and risk factors for Bone Metastasis in patients with Non-Small Cell Lung Cancer. Methodology: A cohort study was carried out in patients diagnosed with Non-Small Cell Lung Cancer between 2006 and 2014 in a single cancer centre. A descriptive analysis of the population was compiled based on mean ± standard deviation (SD) for continuous variables and percentage (%) for categorical variables. Univariate and multivariate Cox proportional hazards regression analyses were carried out to quantify the relationship between independent variables and the outcome variable (Bone Metastasis). Results: During the study period 1025 patients were diagnosed with Non-Small Cell Lung Cancer. Bone Metastasis was detected in 136 patients (13.2%) with a mean interval between Non-Small Cell Lung Cancer diagnosis and Bone Metastasis of 8.07 months (95% CI: 7.68 8.45). Multivariate analysis revealed that younger age (HR 0.97; 95%CI, 0.95–0.99; p=0.002), adenocarcinoma (HR 1.51; 95%CI, 1.06–2.15; p=0.021) and treatment with chemotherapy, radiotherapy or chemotherapy combined with radiotherapy (HR 3.73; 95%CI, 2.30–6.05; p<0.001) were associated with the occurrence of Bone Metastasis. Conclusion: The incidence of Bone Metastasis was 13.2%. Younger age, histological subtype adenocarcinoma and treatment with chemotherapy, radiotherapy or chemotherapy combined with radiotherapy are independent risk factors for Bone Metastasis.

Bone metastases and skeletal-related events: incidence and prognosis according to histological subtype of lung cancer

AIM

Estimate the incidence of bone metastases (BM) and skeletal-related events according to the histological subtype of lung cancer and its impact on patient survival.

PATIENTS & METHODS

Retrospective cohort study was carried out with patients diagnosed with lung cancer. Cumulative incidence, Kaplan-Meier survival analysis and the risk of death were estimated.

RESULTS

In non-small-cell lung cancer (NSCLC), the cumulative incidence of BM during follow-up was 23.8% at 24 months; in small-cell lung cancer, it was 18.5%. The presence of BM in patients with NSCLC was associated with an increased risk of death (hazard ratio: 1.25; 95% CI: 1.04-1.49; p = 0.013).

CONCLUSION

This study revealed a high incidence of BM and skeletal-related events. BM was associated with a poor prognosis in NSCLC patients.

Bone turnover markers and novel biomarkers in lung cancer bone metastases

CONTEXT

Lung cancer still remains the leading cause of cancer-related mortality worldwide. Bone is one of preferred metastatic sites for lung cancer cells. So far, both accurate diagnosis and effective treatment of lung cancer bone metastases are difficult.

OBJECTIVE

This review aimed to evaluate roles of bone turnover markers (BTMs), microRNAs (miRNAs), dickkopf1 (DKK1) and insulin like growth factor binding protein 3 (IGFBP-3) in lung cancer bone metastases.

METHODS

We searched articles about these four biomarkers in lung cancer bone metastases mainly in PubMed.

RESULT

The levels of bone specific alkaline phosphatase (BALP), cross-linked carboxy-terminal telopeptide of type-I collagen (ICTP) and N-terminal telopeptides of type-I collagen (NTX) were reported to be significantly increased in lung cancer patients with bone metastases. ALP, NTX and bone sialoprotein were thought to be associated with prognosis of lung cancer patients with bone metastases. MiRNA-335, miRNA-33a, miRNA-21, DKK1 and IGFBP-3 were revealed to be novel biomarkers in lung cancer bone metastases.

DISCUSSION AND CONCLUSION

Current researches have revealed that BTMs, miRNAs, DKK1 and IGFBP-3 may be useful in diagnosis, prognosis evaluation or treatment of lung cancer bone metastases. More studies about these biomarkers in lung cancer bone metastases are needed.

Skeletal-related events and overall survival of patients with bone metastasis from nonsmall cell lung cancer - A retrospective analysis

Because of improving treatments and survival, 40% to 58% of patients with bone metastases from nonsmall cell lung cancer (NSCLC) will suffer from at least one skeletal-related event (SRE), affecting their quality of life, but the natural history of SRE is poorly understood. The study aimed to examine the factors involved in SRE-free survival (SRS) and overall survival (OS) of patients with NSCLC and bone metastases.This was a retrospective study of 211 patients with bone metastasis from NSCLC and treated at the Tumor Hospital Affiliated to Harbin Medical University between January 2007 and January 2012. OS and SRS were evaluated by the Kaplan-Meier method. The factors associated with SRS and OS were examined using multivariate Cox analyses.The 1 year OS was 55.9% and the median OS was 30 months (range, 1-98 months). Multivariate analyses showed that clinical staging at initial diagnosis (P < .001) and SRE (P = .033) were independently associated with OS, and clinical staging at initial diagnosis (P = .009), bone pain (P = .008), primary tumor radiotherapy (P < .001), and chemotherapy (P = .031) were independently associated with SRS. Stage I, II, and III patients under biphosphonate therapy fared better than those without biphosphonate treatment, but there was no difference for stage IV patients.The identification of factors associated with OS and SRS of patients with NSCLC and bone metastases should provide new clues for a better management of these patients.

Epidermal growth factor receptor is associated with the onset of skeletal related events in non-small cell lung cancer

Background

Bone metastasis and skeletal related events (SREs) are common in non-small cell lung cancer (NSCLC). Patients with mutant epidermal growth factor receptor (EGFR) could benefit from tyrosine kinase inhibitors (TKIs). However, it is unclear whether SRE is influenced by EGFR status. We aimed to evaluate the correlation of EGFR status and TKIs with the incidence of SREs.

Methods

We conducted a retrospective study of stage IV NSCLC patients with bone metastasis. Incidence rate of SREs was collected and was compared using chi-square test. Logistic-regression analysis was used to identify the risk factors predicting the incidence of SREs.

Results

410 eligible patients were enrolled in the study. 49.0% were detected with EGFR mutation. 49.8% of patients received EGFR-TKIs therapy prior to the onset of SREs. 42.7% experienced at least one SRE. Patients who were treated with TKIs held lower incidence of SREs than patients who were not treated with TKIs (23.5% vs 61.7%, p<0.001). Multivariate analysis showed that poor performance status (OR 5.550, 95%CI 2.290-13.450; p<0.001) and mutant EGFR (OR 3.050, 95%CI 1.608-5.787, p=0.001) were independent risk factors predicting the onset of SREs, while the usage of TKIs (OR 0.102, 95%CI 0.054-0.193, p<0.001) was a protective factor of SREs in NSCLC patients with bone metastasis.

Conclusions

This study indicates that the incidence of SREs is common in both patients with and without EGFR mutation. Poor performance ability and mutant EGFR imply higher risks of SREs, while the usage of TKIs may be a protective factor of SREs.

Risk factors for bone metastasis in completely resected non-small-cell lung cancer

Aim: We assessed risk factors for bone metastasis in patients with completely resected non-small-cell lung cancer (NSCLC). Materials & methods: A total of 374 NSCLC patients who had undergone a complete resection from January 2008 to May 2012 were included in this retrospective study. The Kaplan–Meier method and multivariate Cox regression analysis were used to evaluate risk factors for bone metastasis. Results: A total of 47 (47/374; 12.6%) patients developed bone metastasis up until the last follow-up time. The patients with bone metastasis included 33 adenocarcinoma patients and 6 (4.9%) squamous cell carcinoma patients (p = 0.001). There were 17 (10.2%) patients with pathological stage (P-stage) I disease, 9 (9.5%) patients with P-stage II disease and 21 (18.8%) patients with P-stage III disease (p = 0.007) among all the bone metastasis patients. For patients without or with bone metastasis, the overall survival ratio at 3 years was 71.6% compared with 46.8% (p < 0.0001), respectively. Conclusion: Adenocarcinoma and P-stage III disease were related to a high risk of bone metastasis.

Epidermal growth factor receptor mutations should be considered as a prognostic factor for survival of patients with pathological fractures or painful bone metastases from non-small cell lung cancer

Aims

This study aims to assess first, whether mutations in the epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma (kRAS) genes are associated with overall survival (OS) in patients who present with symptomatic bone metastases from non-small cell lung cancer (NSCLC) and secondly, whether mutation status should be incorporated into prognostic models that are used when deciding on the appropriate palliative treatment for symptomatic bone metastases.

Patients and Methods

We studied 139 patients with NSCLC treated between 2007 and 2014 for symptomatic bone metastases and whose mutation status was known. The association between mutation status and overall survival was analysed and the results applied to a recently published prognostic model to determine whether including the mutation status would improve its discriminatory power.

Results

The median OS was 3.9 months (95% confidence interval (CI) 2.1 to 5.7). Patients with EGFR (15%) or kRAS mutations (34%) had a median OS of 17.3 months (95% CI 12.7 to 22.0) and 1.8 months (95% CI 1.0 to 2.7), respectively. Compared with EGFR-positive patients, EGFR-negative patients had a 2.5 times higher risk of death (95% CI 1.5 to 4.2). Incorporating EGFR mutation status in the prognostic model improved its discriminatory power.

Conclusion

Survival prediction models for patients with symptomatic bone metastases are used to determine the most appropriate (surgical) treatment for painful or fractured lesions. This study shows that NSCLC should not be regarded as a single entity in such models. Cite this article: Bone Joint J 2017;99-B:516–21.

Basigin-2 upregulated by receptor activator of NF-κB ligand enhances lung cancer-induced osteolytic lesions

BACKGROUND

Lung cancer bone metastasis causes poor prognosis. Basigin-2, a novel cancer-associated biomarker, is upregulated in lung cancer and has been linked with tumor progression. But little is known about the role of basigin-2 in lung cancer bone metastasis and osteolytic lesion.

METHODS

Basigin-2 expression was evaluated in biopsy tissue specimens of 20 lung cancer patients with bone metastases via immunohistochemistry. Invasion assay and MTT proliferation assay were performed to test the invasion and proliferation of lung cancer cell after modulated basigin-2 expression. The osteoclastic activity of basigin-2 was detected in tibia cancer model by injected of lung cancer cells. The regulation role of receptor activator of NF-κB ligand (RANKL) on basigin-2 and its downstream molecules were measured by real-time quantitative RT-PCR, gelatin zymography and western blot analysis.

RESULTS

We found that basigin-2 was highly expressed in lung cancer bone metastases. Then, we demonstrated that basigin-2 could promote lung cancer cells invasion, metastasis and proliferation through upregulating metalloproteinases-2 (MMP-2), MMP-9 and vascular endothelial growth factor (VEGF) expression. The lung cancer cells overexpressing basigin-2 strongly induced the osteolytic lesions in immunodeficient mice, which were reduced by treatment with basigin-2 blocking antibody. Furthermore, we explored the enhanced basigin-2 molecular mechanism in lung cancer bone metastasis. Our results indicated the RANKL, pivotal for the control of bone resorption, could increase basigin-2 and its downstream molecules MMP-2, MMP-9 and VEGF expression in vitro.

CONCLUSIONS

Basigin-2 upregulated by RANKL induces MMPs and VEGF, which may increase lung cancer cell metastasis ability and support osteoclastic activity. Thus, our data suggest important roles for basigin-2 in lung cancer-induced osteolytic lesion and implicate this protein potential application as a target for lung cancer bone metastasis therapy.