Alessandro De Vita

Development of a patient-derived xenograft (PDX) of breast cancer bone metastasis in a Zebrafish model

Bone metastasis is a complex process that needs to be better understood in order to help clinicians prevent and treat it. Xenografts using patient-derived material (PDX) rather than cancer cell lines are a novel approach that guarantees more clinically realistic results. A primary culture of bone metastasis derived from a 67-year-old patient with breast cancer was cultured and then injected into zebrafish (ZF) embryos to study its metastatic potential. In vivo behavior and results of gene expression analyses of the primary culture were compared with those of cancer cell lines with different metastatic potential (MCF7 and MDA-MB-231). The MCF7 cell line, which has the same hormonal receptor status as the bone metastasis primary culture, did not survive in the in vivo model. Conversely, MDA-MB-231 disseminated and colonized different parts of the ZF, including caudal hematopoietic tissues (CHT), revealing a migratory phenotype. Primary culture cells disseminated and in later stages extravasated from the vessels, engrafting into ZF tissues and reaching the CHT. Primary cell behavior reflected the clinical course of the patient’s medical history. Our results underline the potential for using PDX models in bone metastasis research and outline new methods for the clinical application of this in vivo model.

Current classification, treatment options, and new perspectives in the management of adipocytic sarcomas

Sarcomas are a heterogeneous group of mesenchymal tumors arising from soft tissue or bone, with an uncertain etiology and difficult classification. Soft tissue sarcomas (STSs) account for around 1% of all adult cancers. Till date, more than 50 histologic subtypes have been identified. Adipocyte sarcoma or liposarcoma (LPS) is one of the most common STS subtypes, accounting for 15% of all sarcomas, with an incidence of 24% of all extremity STSs and 45% of all retroperitoneal STSs. The new World Health Organization classification system has divided LPS into four different subgroups: atypical lipomatous tumor/well-differentiated LPS, dedifferentiated LPS, myxoid LPS, and pleomorphic LPS. These lesions can develop at any location and exhibit different aggressive potentials reflecting their morphologic diversity and clinical behavior. Patients affected by LPS should be managed in specialized multidisciplinary cancer centers. Whereas surgical resection is the mainstay of treatment for localized disease, the benefits of adjuvant and neoadjuvant chemotherapy are still unclear. Systemic treatment, particularly chemotherapy, is still limited in metastatic disease. Despite the efforts toward a better understanding of the biology of LPS, the outcome of advanced and metastatic patients remains poor. The advent of targeted therapies may lead to an improvement of treatment options and clinical outcomes. A larger patient enrollment into translational and clinical studies will help increase the knowledge of the biological behavior of LPSs, test new drugs, and introduce new methodological studies, that is, on treatment response.

The Effect of Everolimus in an In Vitro Model of Triple Negative Breast Cancer and Osteoclasts

Metastatic bone disease has a major impact on morbidity of breast cancer (BC) patients. Alterations in mTOR signaling are involved both in cancer progression and in osteoclast differentiation. The purpose of this study was to assess the role of mTOR inhibitor Everolimus (Eve) on osteoclastogenesis induced by triple negative BC cells. To this aim, we developed an in vitro human model of osteoclastogenesis from peripheral blood monocytes co-cultured with the triple negative SCP2 and the hormonal receptor positive MCF7 cell lines. Osteoclastogenesis was evaluated by TRAP staining, evaluation of F actin rings and Calcitonin Receptor expression. Eve significantly reduced differentiation induced by cancer cells and resulted more effective when evaluated in combination with Denosumab and Zoledronic Acid (Zol). Combination with Zol showed a total abrogation of osteoclast differentiation induced by the triple negative cell line, not by MCF7. Finally, we observed that Eve was active in the inhibition of the crosstalk between cancer cells and osteoclasts reproduced by our model, highlighting a new therapeutic choice for the subsetting of triple negative BC patients. We observed a difference in the response to bone-targeted therapy with respect to BC subtypes. Our model may represent a valid platform for preclinical trials on bone-targeted drugs and for the study of the interplay of BC with bone stromal cells.

CSF-1 blockade impairs breast cancer osteoclastogenic potential in co-culture systems.

Metastatic bone disease has a major impact on the morbidity and mortality of breast cancer patients, and studies on bone metastasis biology have led to the development of the most widely used drugs for bone metastases treatment: zoledronate (Zol) and denosumab (Den). The aim of the present study was to assess the effect of soluble mediators produced by breast cancer cells on human osteoclast maturation in a co-culture model. We also tested the ability of zoledronate, denosumab and 5H4, an antibody directed against CSF-1, to interfere with the osteoclastogenic potential of breast cancer. The study was performed on the triple negative cell line MDA-MB-231 and on human osteoclasts obtained from the differentiation of peripheral blood monocytes of a healthy volunteer. Osteoclastogenesis was evaluated by TRAP assay after 14days of differentiation with 10% MDA-MB-231-conditioned media or with CSF-1 and RANKL. Den, Zol and 5H4 were administered after 7days of differentiation. MDA-MB-231-conditioned media doubled the differentiation of monocytes into osteoclasts. MDA-MB-231 secreted CSF-1, especially when cells were cultured to confluence. Induced osteoclasts were sensitive to bone-targeted drugs: Den and 5H4 blocked osteoclast differentiation and survival, while Zol induced osteoclast apoptosis. Osteoclasts differentiated by breast cancer cells were less sensitive to Zol than those induced by differentiation factors, whereas sensitivity to Den was similar. Conversely, breast cancer-induced osteoclast activation resulted in a higher sensitivity to 5H4. A significant increase in CSF-1 secretion was observed in osteoclast precursors after treatment with the highest concentration of Den. Further research is ongoing to evaluate the efficacy of 5H4 combination with Den.

Activity of Eribulin in a Primary Culture of Well-Differentiated/Dedifferentiated Adipocytic Sarcoma

Eribulin mesylate is a novel, non-taxane, synthetic microtubule inhibitor showing antitumor activity in a wide range of tumors including soft tissue sarcomas (STS). Eribulin has been recently approved for the treatment of metastatic liposarcoma (LPS) patients previously treated with anthracyclines. This work investigated the mechanism of action of this innovative antitubulin agent in well-differentiated/dedifferentiated LPS (ALT/DDLPS) which represents one of the most common adipocytic sarcoma histotypes. A primary culture of ALT/DDLPS from a 54-year-old patient was established. The anticancer activity of eribulin on the patient-derived primary culture was assessed by MTT and tunel assays. Eribulin efficacy was compared to other drugs approved for the treatment of STS. Cell migration and morphology were examined after exposure to eribulin to better understand the drug mechanism of action. Finally, Western blot analysis of apoptosis and migration proteins was performed. The results showed that eribulin exerts its antiproliferative effect by the arrest of cell motility and induction of apoptosis. Our results highlighted the activity of eribulin in the treatment of ALT/DDLPS patients.

Update on the role of trabectedin in the treatment of intractable soft tissue sarcomas

Soft tissue sarcomas (STS) represent a variety of tumors of mesenchymal origin, accounting for about 1% of all adult cancers. This group of tumors comprises over 60 different histotypes with different biology showing different sensitivity to therapeutic agents. For decades, the standard first-line systemic treatment of metastatic STS has comprised anthracycline based-chemotherapy. Second-line therapy options include agents such as ifosfamide, gemcitabine, and pazopanib, but the optimal sequential therapy for the management of metastatic disease has yet to be defined. Trabectedin is one of the new molecules approved for patients in progression after first-line chemotherapy with anthracyclines or for those unfit for these agents. The compound is characterized by multiple potential mechanisms of action combining cytotoxic, targeted, and immunological effects. This article takes an in-depth look at the role of trabectedin in the management of metastatic STS, including L-sarcoma and non-L-sarcoma.

Metronomic capecitabine in gastroenteropancreatic neuroendrocrine tumors: a suitable regimen and review of the literature.

Background We present a retrospective analysis of metronomic capecitabine in metastatic gastroenteropancreatic neuroendrocrine tumors (GEP-NETs). A review of the literature is also presented. Methods From January 2007 to December 2013, ten patients with metastatic GEP-NETs (four pancreatic and six ileal) who progressed after treatment with somatostatin analogs and other cytotoxic agents received oral capecitabine 1,500 mg/day continuously. The median patient age was 68 (range 29–82) years. The median treatment duration was 8 months. Results Five (50%) patients achieved a partial radiographic response, four (40%) showed stable disease, and one (10%) progressed. Median overall survival was 56 months. Three of the four pancreatic patients achieved a partial radiographic response that lasted for a median of 15.5 months; overall survival and progression-free survival in this subgroup was 58 and 6 months, respectively. Conclusion Data in the literature show that capecitabine has only occasionally been used as a single agent, with increased toxicity. Only one study using single-agent capecitabine reported a progression-free survival of 9.9 months and overall survival of 36.5 months, without an objective response or major toxicity. In our experience, metronomic capecitabine was well tolerated, although minor side effects may have been underestimated due to the retrospective nature of our study. This regimen also seems to be feasible in elderly people. Although high response rates and prolonged response duration indicate the potential efficacy of this treatment, our results should be interpreted cautiously because of the small number of patients involved. Capecitabine was most effective in the pancreatic subgroup, which would seem to be more sensitive to chemotherapy.

Innovative approaches to establish and characterize primary cultures: an ex vivo 3D system and the zebrafish model

ABSTRACT Patient-derived specimens are an invaluable resource to investigate tumor biology. However, in vivo studies on primary cultures are often limited by the small amount of material available, while conventional in vitro systems might alter the features and behavior that characterize cancer cells. We present our data obtained on primary dedifferentiated liposarcoma cells cultured in a 3D scaffold-based system and injected into a zebrafish model. Primary cells were characterized in vitro for their morphological features, sensitivity to drugs and biomarker expression, and in vivo for their engraftment and invasiveness abilities. The 3D culture showed a higher enrichment in cancer cells than the standard monolayer culture and a better preservation of liposarcoma-associated markers. We also successfully grafted primary cells into zebrafish, showing their local migratory and invasive abilities. Our work provides proof of concept of the ability of 3D cultures to maintain the original phenotype of ex vivo cells, and highlights the potential of the zebrafish model to provide a versatile in vivo system for studies with limited biological material. Such models could be used in translational research studies for biomolecular analyses, drug screenings and tumor aggressiveness assays. Summary: Patient-derived primary cells maintain their original phenotype when cultured on 3D scaffolds, and their in vivo behavior can be effectively studied with innovative zebrafish models.

First-line chemotherapy in patients with metastatic gastroenteropancreatic neuroendocrine carcinoma

Background and aim To investigate the efficacy of platinum-based chemotherapy in patients with metastatic gastroenteropancreatic neuroendocrine carcinoma (mGEP-NEC) and define predictive and prognostic factors. Methods Twenty mGEP-NEC patients were treated with cisplatin or carboplatin/etoposide between April 2010 and October 2014. Both large-cell and small-cell histologies were included. Cisplatin 25 mg/m2 was administered on days 1–3 followed by etoposide 100 mg/m2 on days 1–3 every 21 days. Carboplatin 300 mg/m2 was administered on day 1 followed by etoposide 100 mg/m2 on days 1–3. Results Of the 19 evaluable patients, 13 obtained a partial response, four showed stable disease, and two progressed. Median overall survival (mOS) was 13.5 months and median progression-free survival (mPFS) was 10.9 months. Gallium-68 positron emission tomography/computerizsed tomography-positive patients had a higher, albeit not significantly, OS than those with negative results (75% vs 34.3% at 18 months; P=0.06). mPFS was 19.3 and 6.3 months (P<0.01) in mGEP-NEC patients with Ki67 ≤55% or >55%, respectively. mOS was 8.1 months in the latter group but was not reached in the Ki67 ≤55% group (P-value =0.039). Patients with a lower body mass index (BMI) had a better prognosis in terms of both OS and PFS. Patients with BMI ≥25 had a mOS of 11.7 months (P=0.0293) and a mPFS of 6.2 months (P=0.0057). Conclusion Platinum-based chemotherapy showed good efficacy in mGEP-NEC patients. Those with Ki67 ≤55%, positive Gallium-68 positron emission tomography/computerized tomography and BMI <25 had a better prognosis.

Myxofibrosarcoma primary cultures: molecular and pharmacological profile:

Background: Myxofibrosarcoma (MFS), formerly considered as a myxoid variant of malignant fibrous histiocytoma, is the most common sarcoma of the extremities in adults and is characterized by a high frequency of local recurrence. The clinical behavior of MFS is unpredictable and the efficacy of chemotherapy is still not well documented. Furthermore, given the relatively recent recognition of MFS as a distinct pathologic entity its cellular and molecular biology has still not been extensively studied in patient-derived preclinical models. We examined the molecular biology and treatment outcomes of high-grade, patient-derived MFS primary cultures. Methods: A total of three patient-derived MFS primary cultures were analyzed. We evaluated the role of CD109 expression and also looked for a correlation between transforming growth factor-beta (TGF-β) expression and sensitivity of the primary cultures to different drugs. Results: CD109 was a promising marker for the identification of more aggressive high-grade MFS and a potential therapeutic target. The results also highlighted the potential role of TGF-β in chemoresistance. Pharmacological analysis confirmed the sensitivity of the cultures to chemotherapy. The most active treatments were epirubicin alone and epirubicin in combination with ifosfamide, the latter representing the current standard of care for soft tissue sarcomas (STSs), including MFS. Conclusions: Our results provide a starting point for further research aimed at improving the management of MFS patients undergoing chemotherapy.