The Markers of Bone Turnover in Patients with Lung Cancer

Metformin prevents osteoblast-like potential and calcification in lung cancer A549 cells

In spite of recent advances made in understanding its progression, cancer is still a leading cause of death across the nations. Molecular pathophysiology of these cancer cells largely differs depending on cancer types and even within the same tumor. Pathological mineralization/calcification is seen in various tissues including breast, prostate, and lung cancer. Osteoblast-like cells derived after trans-differentiation of mesenchymal cells usually drive calcium deposition in various tissues. This study aims to explore the presence of osteoblast-like potential in lung cancer cells and its prevention. ALP assay, ALP staining, nodule formation, RT-PCR, RT-qPCR, and western blot analysis experiments were carried out in lung cancer A549 cells to achieve said objective. Expressions of various osteoblast markers (e.g., ALP, OPN, RUNX2, and Osterix) along with osteoinducer genes (BMP-2 and BMP-4) were observed in A549 cells. Moreover, ALP activity and ability leading to nodule formation revealed the presence of osteoblast-like potential in lung cancer cells. Here, BMP-2 treatment increased expressions of osteoblast transcription factors such as RUNX2 and Osterix, enhanced ALP activity, and augmented calcification in this cell line. It was also observed that antidiabetic metformin inhibited BMP-2 mediated increase in osteoblast-like potential and calcification in these cancer cells. The current study noted that metformin blocked BMP-2 mediated increase in epithelial to mesenchymal transition (EMT) in A549 cells. The above findings for the first time unravel that A549 cells possess osteoblast-like potential which drives lung cancer calcification. Metformin might prevent BMP-2 induced osteoblast-like phenotype of the lung cancer cells with concomitant inhibition of EMT to inhibit lung cancer tissue calcification.

Predictive and Prognostic Biomarkers for Lung Cancer Bone Metastasis and Their Therapeutic Value

Lung cancer is the leading cause of cancer-related death worldwide. Bone metastasis, which usually accompanies severe skeletal-related events, is the most common site for tumor distant dissemination and detected in more than one-third of patients with advanced lung cancer. Biopsy and imaging play critical roles in the diagnosis of bone metastasis; however, these approaches are characterized by evident limitations. Recently, studies regarding potential biomarkers in the serum, urine, and tumor tissue, were performed to predict the bone metastases and prognosis in patients with lung cancer. In this review, we summarize the findings of recent clinical research studies on biomarkers detected in samples obtained from patients with lung cancer bone metastasis. These markers include the following: (1) bone resorption-associated markers, such as N-terminal telopeptide (NTx)/C-terminal telopeptide (CTx), C-terminal telopeptide of type I collagen (CTx-I), tartrate-resistant acid phosphatase isoform 5b (TRACP-5b), pyridinoline (PYD), and parathyroid hormone related peptide (PTHrP); (2) bone formation-associated markers, including total serum alkaline phosphatase (ALP)/bone specific alkaline phosphatase(BAP), osteopontin (OP), osteocalcin (OS), amino-terminal extension propeptide of type I procollagen/carboxy-terminal extension propeptide of type I procollagen (PICP/PINP); (3) signaling markers, including epidermal growth factor receptor/Kirsten rat sarcoma/anaplastic lymphoma kinase (EGFR/KRAS/ALK), receptor activator of nuclear factor κB ligand/receptor activator of nuclear factor κB/osteoprotegerin (RANKL/RANK/OPG), C-X-C motif chemokine ligand 12/C-X-C motif chemokine receptor 4 (CXCL12/CXCR4), complement component 5a receptor (C5AR); and (4) other potential markers, such as calcium sensing receptor (CASR), bone sialoprotein (BSP), bone morphogenetic protein 2 (BMP2), cytokeratin 19 fragment/carcinoembryonic antigen (CYFRA/CEA), tissue factor, cell-free DNA, long non-coding RNA, and microRNA. The prognostic value of these markers is also investigated. Furthermore, we listed some clinical trials targeting hotspot biomarkers in advanced lung cancer referring for their therapeutic effects.

[Progress of Biomarkers in Diagnosis of Bone Metastases of Lung Cancer]

中晚期恶性肿瘤容易发生骨转移，随诊疗水平不断提升使其生存期得以延长，骨转移发生率亦随之增加。其中，肺癌是全世界癌症相关死亡的首要原因，晚期肺癌患者骨转移发生率为30%-40%。传统的肺癌骨转移诊断通常依据临床症状、X线、计算机断层扫描（computed tomography, CT）、核磁共振（magnetic resonance imaging, MRI）等影像学及病理，基于血液标记物检测作为骨转移筛查与疗效评估的探索性研究近年多有报道。本文综述了肺癌骨转移诊断标记物的研究进展。

A meta-analysis survey of appropriate bone turnover markers in the detection of bone metastasis in lung cancer

BACKGROUND

A number of studies have investigated the clinical significance of bone turnover markers (BTMs) for the diagnosis of bone metastasis (BM) in lung cancer; however, they led to contradictory results. The aim of this meta-analysis was to investigate whether BTMs differ between lung cancer patients with and without BM.

METHODS

Articles were identified by searching Medline, Embase, Web of Science and Scopus. The studies that were identified were pooled and the weighted mean difference (WMD) and its corresponding 95% confidence interval (CI) were calculated. Subgroup analyses and publication bias detection were also conducted.

RESULTS

A final analysis of 1720 subjects (707 patients with BM and 1013 patients without BM) was performed from 16 cohort studies. From the pooled data in the meta-analysis, the total alkaline phosphatase (TALP) (104.35 U/l [95% CI 33.36-175.34]), bone-specific ALP (BALP) (13.24 μg/l [95% CI 8.50-17.98] or 6.84 U/l [95% CI 2.98-10.70]), C-terminal cross-linked telopeptide of type I collagen (ICTP) (5.07 μg/l [95% CI 3.58-6.56]) and N-terminal cross-linked telopeptide of type I collagen (NTX) (5.08 nM bone collagen equivalent/l [95% CI 2.82-7.33]) were significantly lower among BM patients than non-BM patients. Subgroup analyses detected that the serum level of tartrate-resistant acid phosphatase isoform 5b was significantly reduced in Caucasian patients with BM (-0.64 U/l [95% CI -1.02 to -0.25]), while increased in Asian patients with BM (2.69 U/l [95% CI 0.08-5.31]), compared to patients without BM.

CONCLUSIONS

The present meta-analysis suggested that serum measurement of TALP, BALP, ICTP and NTX might be helpful in detecting BM in lung cancer.

Use of urinary markers in cancer setting: A literature review

INTRODUCTION

In bone metastases, the disruption of normal bone processes results in increased resorption and formation rates, which can often be quantitatively measured by biomarkers in the urine and blood. The purpose of this review is to summarize relevant studies of urinary markers used as a diagnostic and/or prognostic tool, as well as its potential and advances in directing therapy.

METHODS

A literature search was conducted using Ovid MEDLINE (1950 to July 2014), EMBASE (1950 to 2014 week 30) and Cochrane Central Register of Controlled Trials (3rd Quarter 2014) to identify studies that detailed the use of urinary markers in the cancer setting, specifically involving markers for bone metastases. Search terms included "urinary markers", "cancer", and "bone metastases".

RESULTS

A total of 35 articles, with 24 original studies, were identified. In general, urinary markers can be used to detect early signs of bone metastases prior to skeletal imaging, but still must be used in conjunction with imaging to avoid false positive results. The use of urinary markers, such as N-telopeptide, as a prognostic tool remains controversial, but can provide information on the relative risk of skeletal related events (SREs), disease progression, as well as death. Finally, while urinary markers have shown to be potentially useful in confirming the efficacy of bone metastases treatments, exploring the appropriate dosages for treatment, and directing therapy, it is still unclear to what extent urinary markers should be reduced by.

CONCLUSION

The potential use of urinary markers in the management of bone metastases is promising as it can allow for earlier and more convenient detection of bone metastases in comparison to other techniques. However, additional studies involving prospective clinical trials are suggested to further examine the potential of urinary markers in developing appropriate treatment strategies and endpoints, especially in developing a clearer protocol on the extent urinary markers should be reduced by to correlate with achievement of clinical benefit.

Response of Bone Resorption Markers to Aristolochia longa Intake by Algerian Breast Cancer Postmenopausal Women

Aristolochia longa is widely used in traditional medicine in Algeria to treat breast cancer. The aim of the present study was to investigate the response of bone resorption markers to A. longa intake by Algerian breast cancer postmenopausal women. According to the A. longa intake, breast cancer patients were grouped into A. longa group (Al) (n = 54) and non-A. longa group (non-Al) (n = 24). 32 women constituted the control group. Bone resorption markers (from urine) pyridinoline (PYD) and deoxypyridinoline (DPD) were determined by HPLC. Serum and urinary creatinine, uric acid, and urea were measured. 1 g of A. longa intake resulted in significant rise of renal serum markers and a pronounced increase of bone resorption markers. The intake of A. longa roots is detrimental for kidney function and resulted in high bone resorption, maybe due to the reduction in renal function caused by the aristolochic acids contained in the roots.

Prognostic significance of bone markers in patients with lung cancer metastatic to the skeleton: a review of published data

The presence of bone metastases significantly affects clinical outcome and quality of life parameters in patients with lung cancer. In this review, we aimed to evaluate the predictive value of markers of bone turnover in skeletal morbidity and clinical parameters, including disease-free survival (DFS) and overall survival (OS), in patients with lung cancer metastatic to the skeleton who were receiving bisphosphonate treatment. A comprehensive overview of all articles published from 1995 to date in 3 medical databases (PubMed, Scopus, and Cochrane) was performed using the keywords bone markers and lung cancer. Most bone formation markers (including bone alkaline phosphatase [bALP], osteocalcin [OC], and osteoprotegerin [OPG]), most bone absorption markers (including urinary calcium, osteopontin [OPN], receptor activator of nuclear factor κ-B ligand [RANKL], tartrate-resistant acid phosphatase isoform-5b [TRACP 5b]), and the metabolites of type I collagen had elevated concentrations in patients with lung cancer and bone metastases compared with patients without skeletal involvement. Two large studies showed that urinary N-terminal telopeptide (NTX) levels are a valid diagnostic method for early detection of bone metastases and a more consistent prognosticator than bALP. Treatment with zoledronic acid reduces NTX, TRACP-5b, RANKL, and OPG levels. Furthermore posttherapeutic reduction of urinary NTX levels seems to correlate with lower risk of skeletal-related events (SREs). Levels of markers of bone remodeling reflect the presence of bone metastases and may contribute to early detection of occult skeletal disease or monitor the effect of bisphosphonate treatment. However their ability to predict SREs, as well as DFS and OS, remains debatable.