[Corrigendum] Cisplatin in combination with zoledronic acid: A synergistic effect in triple-negative breast cancer cell lines.

Following the publication of the above article, an interested reader drew an anomaly associated with the presentation of Fig. 7 to our attention. Essentially, the panel showing the Cis 0.001 data at T0 for the BRC-230 cell line was the same as that showing the Cis 0.01 data. After having re-examined our data, we realized that an error must have occurred when preparing Fig. 7. A duplication of the photo corresponding to BRC-230 Cis 0.001 T0 was incorrectly placed in the position corresponding to BRC-230 Cis 0.01 T0, while the correct BRC-230 Cis 0.01 T0 figure was erroneously positioned in the BRC-230 Cis 0.01 T1 slot. Fortunately, we had retained all of the data on our computer and were able to find the correct photos representing the conditions of BRC-230 Cis 0.01 T0 and T1. The findings and conclusions of this paper are still supported by our experimental data and are not affected by this error. We sincerely apologize for this oversight and thank the reader for drawing this matter to our attention. We regret any inconvenience caused by our mistake. [the original article was published in the International Journal of Oncology 42: 1263-1270, 2013; DOI: 10.3892/ijo.2013.1809].

Cisplatin in combination with zoledronic acid: a synergistic effect in triple-negative breast cancer cell lines.

Zoledronic acid (ZA) is the most widely used bisphos-phonate to treat cancer-induced bone disease. There is evidence that bisphosphonates have direct antitumor activity and that their combination with anticancer agents can significantly enhance the effect of treatment. We evaluated whether the combination of ZA with different platinum compounds exerts a synergistic effect in breast cancer cell lines and we investigated the mechanisms of action involved. This study was performed on four breast cancer cell lines, MCF-7, SKBR3, MDA-MB-231 and BRC-230, and confirmed on a primary culture obtained from a breast cancer bone metastasis specimen. ZA (50 µM) was administered for 72 h alone or in combination with cisplatin (Cis) or carboplatin. Drug-induced growth inhibition was detected by sulforhodamine B assay, apoptosis and cell cycle regulation were detected by flow cytometry, and protein expression was evaluated by western blot analysis. MCF-7 and SKBR3 showed very low sensitivity to the three drugs tested. The ZA + Cis combination exerted a high antitumor activity in the two triple-negative lines MDA-MB-231 and BRC-230. An important synergistic effect was obtained in MDA-MB-231 and an additive effect was observed in BRC-230. The p21, pMAPK and m-TOR pathways were regulated by this combined treatment, particularly at lower Cis doses. Carboplatin did not show antitumor activity either alone or in combination with ZA. In conclusion, the potential novel treatment schedule identified for triple-negative breast cancer could prove beneficial in view of the limited therapeutic options available for patients and also since the synergism with ZA would enable lower Cis doses to be used, thus reducing toxicity. Although further research in a clinical setting is warranted, our results on cell lines has been confirmed on a human primary bone metastasis culture.

Inhibition of breast cancer cell proliferation in repeated and non-repeated treatment with zoledronic acid.

BACKGROUND: Zoledronic acid is used to treat bone metastases and has been shown to reduce skeletal-related events and exert antitumor activity. The present in vitro study investigates the mechanism of action of Zoledronic Acid on breast cancer cell lines with different hormonal and HER2 patterns. Furthermore, we investigated the efficacy of repeated versus non-repeated treatments. METHODS: The study was performed on 4 breast cancer cell lines (BRC-230, SkBr3, MCF-7 and MDA-MB-231). Non-repeated treatment (single exposure of 168 hrs' duration) with zoledronic acid was compared with repeated treatment (separate exposures, each of 48 hrs' duration, for a total of 168 hrs) at different dosages. A dose-response profile was generated using sulforhodamine B assay. Apoptosis was evaluated by TUNEL assay and biomolecular characteristics were analyzed by western blot. RESULTS: Zoledronic acid produced a dose-dependent inhibition of proliferation in all cell lines. Anti-proliferative activity was enhanced with the repeated treatment, proving to be statistically significant in the triple-negative lines. In these lines repeated treatment showed a cytocidal effect, with apoptotic cell death caused by caspase 3, 8 and 9 activation and decreased RAS and pMAPK expression. Apoptosis was not observed in estrogen receptor-positive line: p21 overexpression suggested a slowing down of cell cycle. A decrease in RAS and pMAPK expression was seen in HER2-overexpressing line after treatment. CONCLUSIONS: The study suggests that zoledronic acid has an antitumor activity in breast cancer cell lines. Its mechanism of action involves the decrease of RAS and RHO, as in osteoclasts. Repeated treatment enhances antitumor activity compared to non-repeated treatment. Repeated treatment has a killing effect on triple-negative lines due to apoptosis activation. Further research is warranted especially in the treatment of triple-negative breast cancer.

Time-dependent pharmacokinetics of 5-fluorouracil and association with treatment tolerability in the adjuvant setting of colorectal cancer.

The authors evaluated the influence of 5-fluorouracil (5-FU) on treatment tolerability in 81 colorectal cancer patients given adjuvant 5-FU intravenously plus folinic acid for 6 cycles. The pharmacokinetics of 5-FU and its inactive metabolite 5-fluoro-5,6-dihydrouracil (5-FDHU) were measured on days 1 and 5 of the first chemotherapy cycle, 5 and 45 minutes after bolus administration. 5-FU clearance was significantly lower on day 5 (62.64 ± 20.16 L/h/m(2)) than on day 1 (74.83 ± 31.61 L/h/m(2)). The lower 5-FU clearance values also predicted the side effects during the entire course of chemotherapy. In particular, patients with low clearance values on day 1 had a further reduction in this parameter on day 5, associated with severe toxicities. In conclusion, 5-FU alters its clearance, which could be partly due to a reduction in 5-FDHU biotransformation. These findings have safety implications for poor metabolizers whose drug clearance may fall below the threshold during repeated treatment cycles.

The role of CXCR4 in the prediction of bone metastases from breast cancer: a pilot study.

OBJECTIVE: The chemokine receptor CXCR4 is involved in tumor growth and homing of cancer cells to distant sites. The aim of our retrospective case-control study was to evaluate whether CXCR4 expression is more effective than conventional markers (estrogen receptor and HER-2) in predicting bone relapse in breast cancer. METHODS: CXCR4 expression was evaluated by immunohistochemical staining in paraffin-embedded tissue sections of primary breast cancers from 20 patients with bone metastases (BM), 10 with visceral metastases (VM) and 10 with no evidence of disease (NED) at a median follow-up of 10.5 years (range 10.1-11.8). RESULTS: Cytoplasmic CXCR4 expression was high in BM patients (45%, 95% CI 23-67), much lower in NED patients (10%, 95% CI 0-29) and negative in the VM group. CXCR4 coexpression in the nucleus and cytoplasm was observed in about half of the BM patients (45%) but never in NED or VM patients (p = 0.013). Conversely, estrogen receptor-positive and HER-2-negative status identified 80 and 95% of bone relapse patients, respectively, but did not discriminate between cases and controls. CONCLUSIONS: Our results suggest a pivotal role of CXCR4 expression as a predictor of BM in primary breast cancer. A larger study is ongoing to confirm these results.

Role of RANK, RANKL, OPG, and CXCR4 tissue markers in predicting bone metastases in breast cancer patients.

UNLABELLED: This is a retrospective study on 40 breast cancer patients, of which 20 have bone metastases, 10 have visceral metastases, and 10 have no evidence of disease, aimed at evaluating the role of CXCR4 and the RANK/RANKL/OPG system to predict bone metastases. CXCR4 expression, alone or in combination with RANK, identified patients destined to relapse to bone. BACKGROUND: The RANK/RANKL/OPG system is active in primary cancers such as breast, prostate, and also in their bone metastases. CXCR4 chemokine receptor is highly expressed in human breast cancer cells and is believed to facilitate the homing of tumor cells to organs such as bone that express high levels of its ligand SDF1. Our study aimed to investigate whether the analysis of these markers with an inexpensive and simple test can help to predict bone metastases in breast cancer patients. PATIENTS AND METHODS: Marker expression was evaluated by immunohistochemical staining in paraffin-embedded tissue sections of primary breast cancers from 40 individuals: 20 patients with bone metastases (BM), 10 with visceral metastases (VM; considered together as the relapsed group), and 10 with no evidence of disease (NED). RESULTS: RANKL was not detected in tumor cells. OPG- and RANK-positive tumors are found with similar frequency in NED (20%) and in relapsed patients (23% and 17%, respectively). However, in the latter subgroup, only RANK positivity was always associated with bone relapse. The frequency of CXCR4-positive tumors was three-fold higher in relapsed (30%) than in NED (10%) patients and positivity was always linked to bone metastases. Considering NED and VM patients together versus BM patients, we observed that CXCR4 expression, alone (P = .008) or in combination with RANK (P < .001), identified patients destined to relapse to bone. CONCLUSION: Our results provide the first clinical evidence to support a pivotal role of combined CXCR4 and RANK expression in predicting bone relapse.

Bone metastases detection by circulating biomarkers: OPG and RANK-L.

Osteoprotegerin (OPG) is a decoy receptor of the receptor activator of nuclear factor-κB ligand (RANK-L) and plays an important role in the formation of metastatic bone lesions. We evaluated the usefulness of circulating OPG and RANK-L for the detection of bone metastases. We enrolled 143 individuals in the study: 30 healthy donors (HD) and 113 breast cancer patients. Among patients, 49 had no evidence of disease (NEDP), 54 had bone metastases (BMP) at first diagnosis, and 10 had visceral metastases (VMP). Both transcripts were determined in peripheral blood samples using quantitative PCR. Receiver operating characteristic (ROC) curve analysis was used to calculate the diagnostic accuracy of OPG, RANK-L, CEA and CA15-3. OPG and RANK-L median values were significantly lower in BMP (median 0.5, range 0.1-5.7, p<0.001 and median 0.5, range 0.1-4.5, p=0.024, respectively) compared to NEDP (median 1.7, range 0.4-8.9 and median 0.8, range 0.2-3.8, respectively), regardless of the number and type of bone lesions or the presence of visceral metastases. The area under the ROC curve (NEDP vs. BMP) was higher for OPG (82.5, 95% CI 74.5-90.6) than for RANK-L (69.2, 95% CI 59.0-79.40). Specificity for OPG was 87.7% (95% CI 75.7-94.2) and sensitivity was 74.1% (95% CI 60.4-85.0), both values increasing when considered together with CEA and CA15-3. For VMP, OPG and RANK-L were expressed in only one patient. Our results highlight the potentially important role of circulating OPG in the diagnosis of bone metastases. A confirmatory study on a larger case series is ongoing.

Pathogenesis of osteoblastic bone metastases from prostate cancer.

Prostate cancer is the second leading cause of cancer-related death in men. A typical feature of this disease is its ability to metastasize to bone. It is mainly osteosclerotic, and is caused by a relative excess of osteoblast activity, leading to an abnormal bone formation. Bone metastases are the result of a complex series of steps that are not yet fully understood and depend on dynamic crosstalk between metastatic cancer cells, cellular components of the bone marrow microenvironment, and bone matrix (osteoblasts and osteoclasts). Prostate cancer cells from primary tissue undergo an epithelial-mesenchymal transition to disseminate and acquire a bone-like phenotype to metastasize in bone tissue. This review discusses the biological processes and the molecules involved in the progression of bone metastases. Here we focus on the routes of osteoblast differentiation and activation, the crosstalk between bone cells and tumor cells, and the molecules involved in these processes that are expressed by both osteoblasts and tumor cells. Furthermore, this review deals with the recently elucidated role of osteoclasts in prostate cancer bone metastases. Certainly, to better understand the underlying mechanisms of bone metastasis and so improve targeted bone therapies, further studies are warranted to shed light on the probable role of the premetastatic niche and the involvement of cancer stem cells.

Multidisciplinary approach to the treatment of bone metastases: Osteo-Oncology Center, a new organizational model.

AIMS AND BACKGROUND: Bone metastases are responsible for high morbidity in cancer patients. The frequency of pain and other serious complications associated with such metastases depends on the site and type of lesions and preventive therapy. The present paper aims to inform the scientific community about a new organizational health care model specifically designed for patients with bone metastases, in the hope of stimulating the creation of similar initiatives whose goals are to decrease the high morbidity of this pathology, reduce the frequency of complications, limit psychophysical distress of patients, and improve quality of life. METHODS: In January 2005, an Osteo-Oncology Center was opened in our institute to provide multidisciplinary care (19 specialists involved) for patients with bone metastases, to train physicians, and to conduct research in the field. RESULTS: In its first three years of activity, 601 multidisciplinary team consultations were made and a total of 425 patients were seen. The most frequent primary tumor site was the lung in males and the breast in females. Upon presentation at the Center, 79% of patients reported experiencing a level of pain (median pain intensity, 3.69) that interfered with normal daily activities. An anonymous questionnaire was also completed on the quality of the service provided: 75% of patients were very satisfied, 23% were satisfied, 1% responded "I don't know", and only 1% expressed dissatisfaction. CONCLUSIONS: Our preliminary results confirm the usefulness of a multidisciplinary center for the management of patients with bone metastases, especially in terms of decreasing psychophysical suffering.