Targeting ctla-4 directly on melanoma cells: A possible novel perspective in the immunotherapy of cutaneous melanoma

e22138

Background: CTLA-4 (CD152) is an omodimeric membrane glycoprotein which behaves as the major negative regulator of T cell-mediated immune response. CTLA-4 inhibitory function in T cells mainly occurs upon engagement with the B7 ligands expressed on antigen presenting cells, resulting in inhibition of cytokine production and T cell proliferation. CTLA-4 expression has also been documented in established human melanoma cell lines and primary melanoma tumours. The aim of this study was to investigate the expression and functional role of CTLA-4 in primary melanoma cultures derived from biopsies of metastatic melanoma patients. Methods: Seven primary cultures were derived from melanoma samples by mechanical tissue dissociation, enzymatic digestion and filtration of single cell suspensions. Flow cytometry (FACS) with an anti-melanoma (MCSP) mAb was used to assess the growth of melanoma cells. CTLA-4 expression analysis was performed by FACS and real-time PCR. Cytokine secretion and apoptotic cells were evaluated by Elisa and Annexin V/PI staining after treatment with an agonistic anti-CTLA-4 mAb (3D5). The angiogenic property of melanoma culture supernatants was evaluated on mesenchimal stromal cells (msc) isolated from human thoracic aortas. All the study was approved by our Institutional Ethics Committee and patients gave written informed consent. Results: Constitutive CTLA-4 expression was found on all melanoma cultures with variable intensity at both the protein and transcript levels. CTLA-4 expressed by these cells is functional as its ligation, with an anti-CTLA-4 agonistic mAb, is able to induce inhibition of cell proliferation, due to apoptosis induction, and of IL-8, TNF-alpha and VEGF cytokine secretion. Moreover, CTLA-4 ligation down-modulates the ability of melanoma culture supernatants to induce angiogenic differentiation of msc as detected by the acquisition of their endothelial phenotype. Conclusions: Given the physiologic inhibitory function of CTLA-4, our results suggest its possible role in the functional biology of melanoma and open up the possibility of an anti-melanoma immunotherapy based on targeting CTLA-4 directly on tumour cells as this might allow inhibition of tumour cell growth and angiogenesis.

No significant financial relationships to disclose.

The role of oral fluoropyrimidines in the treatment of advanced gastric cancer

Although the incidence of gastric cancer is declining during the second half of the 20th century, it remains the second leading cause of cancer death worldwide. The majority of patients with gastric cancer will require palliative treatment at some point in the course of their disease. Approximately 50% of patients already have advanced incurable disease at the time of initial presentation, and even those who undergo potentially curative resection have high rates of distant as well as local recurrence. Chemotherapy in advanced gastric cancer demonstrated a significant survival benefit over best supportive care alone. Median overall survival increased from 3-5 to 8-12 months. Today, a platinum based regimen is considered as first-line treatment in advanced gastric cancer. Different regimens are investigated and used in routine practice. Similarly to fluorouracil, capecitabine is well tolerated in combination with a range of cytotoxic drugs. As a single agent, it has not undergone large scale randomised studies. S-1, another oral fluoropyrimidine, is a potential challenger to the role of capecitabine, but is lacking phase III data in Western population.

In vitro characterization of the Gd complex of [2,6-pyridinediylbis(methylene nitrilo)] tetraacetic acid (PMN-tetraacetic acid) and of its Eu analogue, suitable bimodal contrast agents for MRI and optical imaging

Gd and Eu complexes of PMN-tetraacetic acid show interesting properties either for MRI or for optical imaging; that is, for the Gd-complex, a high proton relaxivity with favorable water residence time; for the Eu-complex, a luminescence lifetime of 400 micros at room temperature compatible with the use of time-resolved luminescence technique. Both complexes have a good stability in physiological medium.

The need for combination antihypertensive therapy to reach target blood pressures: what has been learned from clinical practice and morbidity-mortality trials?

Pharmacological treatment of hypertension represents a cost-effective way for preventing cardiovascular and renal complications. To benefit maximally from antihypertensive treatment blood pressure (BP) should be brought to below 140/90 mmHg in every hypertensive patient, and even lower (< 130/80 mmHg) if diabetes or renal disease co-exists. Most of the time such targets cannot be reached using monotherapies. This is especially true in patients who exhibit a high cardiovascular risk. The co-administration of two agents acting by different mechanisms considerably increases BP control. Such preparations are not only efficacious, but also well tolerated, and some fixed low-dose combinations have a tolerability profile similar to placebo. This is for instance the case for the preparation containing the angiotensin-converting enzyme inhibitor perindopril (2 mg) and the diuretic indapamide (0.625 mg), a fixed low-dose combination that has recently been shown in controlled interventional trials to be more effective than monotherapies in reducing albuminuria, regressing cardiac hypertrophy and improving macrovascular stiffness. Fixed-dose combinations are becoming more and more popular and are even proposed by current hypertension guidelines as a first-line option to treat hypertensive patients.