Reversible sideroblastic anemia associated with the tetracycline analogue COL-3

Transient/reversible ring sideroblasts in bone marrow of patients post cytotoxic therapies for primary malignancies

The diagnosis of therapy-related myelodysplastic syndrome (t-MDS) in the absence of increased myeloblasts or cytogenetic abnormalities is challenging. The presence of ring sideroblasts (RS) in this setting is often used to support the diagnosis of t-MDS. In this study, we reviewed 843 patients initially classified as therapy-related myeloid neoplasm in our hospital over 10 years. Nineteen (2.3%) patients had a normal karyotype, <5% bone marrow (BM) blasts, and ≥15% RS (17-70%), forming this study group. After reviewing clinical charts and follow-up BM specimens, we confirmed the diagnosis of MDS in 13 patients, but in 6 patients the blood counts returned to normal and RS and associated dyserythropoiesis disappeared in the follow-up BM biopsy. With a median follow-up of 21 months, none of these 6 patients died of BM causes. Compared with t-MDS cases, the 6 patients with transient/reversible RS showed comparable numbers of RS and BM blasts, but infrequent dysplasia involving non-erythroid lineages. We conclude that the presence of ≥15% RS in the post-therapy setting is not necessarily indicative of a clonal stem cell neoplasm. Four patients with transient/reversible RS received α-interferon therapy which may contribute to RS formation in this setting.

Plasma Cell Leukemia Occurring in a Patient with Thrombocythemia Treated with Hydroxyurea and Busulphan

Plasma cell leukemia (PCL) is a rare aggressive lymphoproliferative disease with a short median survival and a very poor prognosis. We report the case of a 63-year-old man who developed a PCL after 5 years of chemotherapy with hydroxyurea and busulphan for Essential thrombocythemia (ET). The karyotype showed a deletion of chromosome 7 and the plasma cells cytofluorimetric examination revealed a high expression of Multidrug Resistance related P-glycoprotein (PGP). After the second cycle of VAD chemotherapy the patient had a severe pneumonia and died with refractory PCL. This is a rare example of the coexistence of a chronic myeloproliferative and lymphoproliferative diseases in the same patient, and to the best of our knowledge, the first reported in the literature involving PCL and ET. Moreover, this case shows the possibility of secondary malignancies developing in patients treated with busulphan and hydroxyurea for chronic myeloproliferative disorders.

Tumour vascularization: sprouting angiogenesis and beyond

Tumour angiogenesis is a fast growing domain in tumour biology. Many growth factors and mechanisms have been unravelled. For almost 30 years, the sprouting of new vessels out of existing ones was considered as an exclusive way of tumour vascularisation. However, over the last years several additional mechanisms have been identified. With the discovery of the contribution of intussusceptive angiogenesis, recruitment of endothelial progenitor cells, vessel co-option, vasculogenic mimicry and lymphangiogenesis to tumour growth, anti-tumour targeting strategies will be more complex than initially thought. This review highlights these processes and intervention as a potential application in cancer therapy. It is concluded that future anti-vascular therapies might be most beneficial when based on multimodal anti-angiogenic, anti-vasculogenic mimicry and anti-lymphangiogenic strategies.

Influence of the microenvironment on melanoma cell fate determination and phenotype

Tumor cells communicate bidirectionally with the surrounding microenvironment, sending and receiving topographical and molecular cues that direct diverse cellular phenomena, including differentiation, growth, and invasion. The microenvironment has long been acknowledged as a facilitator of melanoma progression, and recent studies have illuminated tumor-associated factors, including hypoxia and the extracellular matrix, as important mediators of melanocyte transformation and transdifferentiation. Although these findings portray the microenvironment as a perilous obstacle to the successful treatment of advanced melanomas, it is important to note that certain molecular milieus may be capitalized on as potential treatment modalities. Indeed, our group and others have elucidated the unique ability of embryonic microenvironments to normalize aggressive melanoma cells toward a more benign melanocytic phenotype. The microenvironment therefore presents a novel target for the treatment and ultimately the prevention of melanoma progression and metastasis.

Sideroblastic anemia due to linezolid in a patient with a left ventricular assist device

An acquired form of sideroblastic anemia has been described in association with several drugs, especially anti-microbial agents. A case of sideroblastic anemia is presented in a patient with a left ventricular assist device drive-line infection who was receiving linezolid, an antibiotic used for serious infections with gram-positive organisms. This patient's anemia resolved after discontinuation of the drug; he subsequently underwent an uncomplicated orthotopic heart transplant with no recurrence of anemia. As linezolid has been shown to have hematologic side effects, blood count monitoring is recommended in patients receiving this drug for long-term therapy.

Development of matrix metalloproteinase inhibitors in cancer therapy

The matrix metalloproteinases represent an attractive target for cancer treatment, and a number of matrix metalloproteinase inhibitors are undergoing clinical trials. The results of these studies will establish whether any of these compounds are therapeutically useful. Independent of the conclusions from the first generation of studies, the field of matrix metalloproteinase inhibitors remains attractive for creative and innovative research. In the future, the development of novel, less toxic, and more effective matrix metalloproteinase inhibitors, and the combination of conventional agents with these novel anticancer agents will constitute the main focus of research efforts.

Matrix metalloproteinases in cancer: prognostic markers and therapeutic targets

Degradation of extracellular matrix is crucial for malignant tumour growth, invasion, metastasis and angiogenesis. Matrix metalloproteinases (MMPs) are a family of zinc-dependent neutral endopeptidases collectively capable of degrading essentially all matrix components. Elevated levels of distinct MMPs can be detected in tumour tissue or serum of patients with advanced cancer and their role as prognostic indicators in cancer is studied. In addition, therapeutic intervention of tumour growth and invasion based on inhibition of MMP activity is under intensive investigation and several MMP inhibitors are in clinical trials in cancer. In this review, we discuss the current view on the feasibility of MMPs as prognostic markers and as targets for therapeutic intervention in cancer.