Immune defects in breast cancer patients after radiotherapy.

The purpose of this study was to evaluate the immune status of women with stage I-III breast cancer after receiving external beam radiotherapy (RT). Fourteen stage I-III, estrogen or progesterone receptor-positive or-negative (FER/PR +\-), postsurgical breast cancer patients undergoing a standard course of chemotherapy and radiation were studied. Complete blood counts (CBC) with differential, phagocytic activity, natural killer (NK) cell functional activity, and tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma cytokine activity were measured immediately before and for the six weeks following the completion of radiation therapy. Fatigue levels after completion of RT were measured using the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale. Nonparametric statistical methods (Wilcoxon rank and Spearman correlations) were used to analyze the data. Compared with postchemotherapy, following the completion of RT, these breast cancer patients showed lymphopenia, low functional activity of natural killer lymphocytes, decreased monocyte phagocytic activity, and decreased TNF-alpha production but no neutropenia, no anemia, and no change in interferon-gamma production. Lymphocyte count did not return to normal by the end of the 6-week post-RT observation period. The severity of lymphopenia and low natural killer cell activity was related to RT area but not radiation dose. Patients did not report significant fatigue levels for the 6 weeks after completing RT. Significant decreases in the numbers and functions of cells from both the innate and adaptive immune system were detected following a standard course of radiation therapy for the treatment of breast cancer. Immune deficits in lymphocyte populations and TNF-alpha production, should they persist, may have consequences for immune response to residual or recurrent malignancy following completion of conventional treatment. The use of adjunctive immune therapies which target these specific defects may be warranted in the post-treatment period.

The amphioxus Hox cluster: characterization, comparative genomics, and evolution.

The amphioxus Hox cluster is often viewed as "archetypal" for the chordate lineage. Here, we present a descriptive account of the 448 kb region spanning the Hox cluster of the amphioxus Branchiostoma floridae from Hox14 to Hox1. We provide complete coding sequences of all 14 previously described amphioxus sequences and give a detailed analysis of the conserved noncoding regulatory sequence elements. We find that the posterior part of the Hox cluster is so highly derived that even the complete genomic sequence is insufficient to decide whether the posterior Hox genes arose by independent duplications or whether they are true orthologs of the corresponding gnathostome paralog groups. In contrast, the anterior region is much better conserved. The amphioxus Hox cluster strongly excludes repetitive elements with the exception of two repeat islands in the posterior region. Repeat exclusion is also observed in gnathostomes, but not protostome Hox clusters. We thus hypothesize that the much shorter vertebrate Hox clusters are the result of extensive resolution of the redundancy of regulatory DNA after the genome duplications rather than the consequence of a selection pressure to remove nonfunctional sequence from the Hox cluster.

No more than 14: the end of the amphioxus Hox cluster.

The Hox gene cluster has been a key paradigm for a generation of developmental and evolutionary biologists. Since its discovery in the mid-1980's, the identification, genomic organization, expression, colinearity, and regulation of Hox genes have been immediate targets for study in any new model organism, and metazoan genome projects always refer to the structure of the particular Hox cluster(s). Since the early 1990's, it has been dogma that vertebrate Hox clusters are composed of thirteen paralogous groups. Nonetheless, we showed that in the otherwise prototypical cephalochordate amphioxus (Branchiostoma floridae), the Hox cluster contains a fourteenth Hox gene, and very recently, a 14(th) Hox paralogous group has been found in the coelacanth and the horn shark, suggesting that the amphioxus cluster was anticipating the finding of Hox 14 in some vertebrate lineages. In view of the pivotal place that amphioxus occupies in vertebrate evolution, we thought it of considerable interest to establish the limits of its Hox gene cluster, namely resolution of whether more Hox genes are present in the amphioxus cluster (e.g., Hox 15). Using two strategies, here we report the completion and characterization of the Hox gene content of the single amphioxus Hox cluster, which encompasses 650 kb from Hox1 to Evx. Our data have important implications for the primordial Hox gene cluster of chordates: the prototypical nature of the single amphioxus Hox cluster makes it unlikely that additional paralogous groups will be found in any chordate lineage. We suggest that 14 is the end.