A single nucleotide polymorphism in the 3?untranslated region of theCDKN2A gene is common in sporadic primary melanomas but mutations in theCDKN2B,CDKN2C,CDK4 andp53 genes are rare

Abstract

Ten patients with advanced B-cell lymphoma were treated with a single locoregional injection of CD3CD19 bispecific and costimulating CD28 monospecific antibodies to activate tumor-infiltrating T-lymphocytes. Antibodies were administered at 4 different dose levels (30 g, 270 g, 810 g, 1,600 g of each antibody) either by intratumoral or intralym-phatic injection. Most patients developed responses within different compartments of the immune systems (T cells, NK cells) subsequent to the antibody application. Comparative studies in 2 patients of which treated as well as untreated lymph nodes were available revealed the up-regulation of T-cell activation markers induced by the antibody injection. Additionally, in 1 patient the induction of apoptosis of lym-phoma B cells in the antibody-treated lymph node was observed. Specificity analyses of peripheral blood T cells by means of IFN-ELISpot measurement indicated the recruitment of idiotype-specific T cells, as in 1 out of 3 investigated patients an increased T-cell response toward autologous id-iotype peptides could be demonstrated. We conclude that a single injection of CD3CD19 bispecific antibodies is capable to induce an activation of autologous T lymphocytes if simultaneous costimulatory signaling by CD28 antibodies is provided. Furthermore, our data suggest that at least in some patients lymphoma-specific T cells can be recruited by this immunotherapeutic approach toward B-cell lymphoma. Among the immunotherapeutic approaches toward malignant diseases of B-cell origin, strategies aiming at the activation of T lymphocytes are most promising as these are known to be highly specialized effector cells of the cellular immune system mediating key functions such as cytotoxicity, cytokine production, regulation of other effector cells, and immunological memory. The central role of T lymphocytes in the regulation of the immune system is the rationale for the therapeutic use of professional antigen-presenting cells (APC), namely dendritic cells (DC), that can process and present tumor-associated antigens (TAA) and thus are able to activate tumor-specific T lymphocytes. 1 APC-based approaches for the induction of anti-tumoral T-cell responses are therefore being tested in clinical studies in several human malignancies including B-cell lymphomas and myeloma. 2,3 Tumor-specific T-cell activation by non-cellular immunothera-peutic agents avoids the requirement to generate autologous DC ex vivo for every individual patient. In this view, CD3-based bispe-cific antibodies (CD3anti-TAA) may be used alternatively or in addition to vaccination protocols with DC as they can stimulate T cells in a tumor-specific manner as well. 4 As the application of CD3anti-TAA bispecific antibodies alone will result in an insufficient activation or even apoptosis of the effector cells, 5 the additional stimulation of the effector T cells is an indispensable demand. To address this problem, we used locoregional (i.e., intratumoral) injections of CD3CD19 bispecific antibodies targeting the B-cell anti...

Germline mutations of the INK4a-ARF gene in patients with suspected genetic predisposition to melanoma

“…This polymorphism has previously been reported to be present in 11% of CEPH parents (Ueki et al, 1994), and found to be associated with familial melanoma risk in Queensland (Aitken et al, 1999), but not with sporadic melanomas (Kumar et al, 2001). The C/T polymorphism at nucleotide 540 in the 3 0 UTR was detected in 14 patients (allelic frequency 8.4%), at a frequency lower than the one previously found in sporadic melanoma (14%) (Kumar et al, 2001).…”

Malignant melanoma: genetics and therapeutics in the genomic era

“…These findings provided the smoking gun fingering this protein as a bona fide melanoma suppressor (for review, see Chin 2003). In addition to the 25%-40% of melanoma-prone families and 0.2%-2% of sporadic melanoma patients harboring INK4A mutations in the coding region (Aitken et al 1999;Tsao et al 2000), polymorphism in both 5Ј and 3Ј untranslated regions (UTRs) that alter translation or possibly regulate message stability of INK4A as well as promoter and splicing mutations of INK4A have since been identified in association with 9p21-linked melanomaprone families (Liu et al 1999;Kumar et al 2001; for review, see Sharpless 2004). In line with this, mice with specific Ink4a inactivation did show increased susceptibility to carcinogen-induced and spontaneous melanoma (Krimpenfort et al 2001;Sharpless et al 2001); however, the phenotype observed was relatively weak.…”

Low frequency of BRAF and CDKN2A mutations in endometrial cancer

“…Mutations and polymorphisms in the CDKN2A and BRAF genes were detected using single-strand conformation polymorphism and direct DNA sequencing methods as described previously. 23 Homozygous deletions at the CDKN2A locus were detected by real-time PCR method using ABI PRISM 7700 sequence detection system (Applied Biosystems, Foster City, CA). CDKN2A fragment (target) and GAPDH fragment (reference) were co-amplified and measured in real-time mode.…”