Choosing high-risk screening vs. surgery and the effect of treatment modality on anxiety and breast-specific sensuality in BRCA mutation carriers.

BACKGROUND: We have previously shown that breast cancer surgery affects breast specific sensuality, and that women who undergo mastectomy may have worse sexual function outcomes than those who undergo lumpectomy. It is less clear if patients who undergo prophylactic mastectomy are equally as affected as those with a cancer diagnosis. We sought to compare sexual function outcomes and their relationship to depression and anxiety between BRCA mutation carriers (mBRCA) with and without cancer in order to guide surgical counseling and improve survivorship outcomes. METHODS: A confidential, cross-sectional survey was distributed electronically to mBRCA at least 18 years of age. The survey included investigator-generated questions, the Female Sexual Function Index (FSFI), and the Hospital Anxiety and Depression Scale (HADS) surveys. Responses were analyzed in total and divided into two subgroups: those with and without breast cancer. RESULTS: Sixty-three mBRCA responded (37%) of 170 email addresses were identified, and 77% were postmenopausal. Although more than half of all mBRCA reported that the role of the breast in intimacy was important, most patients without cancer and all of those with cancer experienced an impressive decline in certain breast-specific sensuality parameters postoperatively. Among those without cancer, anxiety scores were not different between those choosing prophylactic mastectomy and high-risk screening (HRS). Sexual function as measured by the FSFI was negatively correlated with depression and anxiety in mBRCA. FSFI scores were not significantly different between those with and without cancer. However, the median FSFI of mBRCA with cancer, those undergoing HRS, and those who underwent prophylactic mastectomy indicated sexual dysfunction. CONCLUSIONS: As the availability of genetic testing increases, more women are found to harbor BRCA mutations and must choose between HRS and prophylactic surgery. Women with BRCA mutations, both with and without breast cancer, are susceptible to derangements in sexual function during the course of both screening or treatment, and this appears to be negatively correlated to depression and anxiety.

Dual function of the UNC-45b chaperone with myosin and GATA4 in cardiac development.

Cardiac development requires interplay between the regulation of gene expression and the assembly of functional sarcomeric proteins. We report that UNC-45b recessive loss-of-function mutations in C3H and C57BL/6 inbred mouse strains cause arrest of cardiac morphogenesis at the formation of right heart structures and failure of contractile function. Wild-type C3H and C57BL/6 embryos at the same stage, E9.5, form actively contracting right and left atria and ventricles. The known interactions of UNC-45b as a molecular chaperone are consistent with diminished accumulation of the sarcomeric myosins, but not their mRNAs, and the resulting decreased contraction of homozygous mutant embryonic hearts. The novel finding that GATA4 accumulation is similarly decreased at the protein but not mRNA levels is also consistent with the function of UNC-45b as a chaperone. The mRNAs of known downstream targets of GATA4 during secondary cardiac field development, the cardiogenic factors Hand1, Hand2 and Nkx-2.5, are also decreased, consistent with the reduced GATA4 protein accumulation. Direct binding studies show that the UNC-45b chaperone forms physical complexes with both the alpha and beta cardiac myosins and the cardiogenic transcription factor GATA4. Co-expression of UNC-45b with GATA4 led to enhanced transcription from GATA promoters in naïve cells. These novel results suggest that the heart-specific UNC-45b isoform functions as a molecular chaperone mediating contractile function of the sarcomere and gene expression in cardiac development.

A novel conserved isoform of the ubiquitin ligase UFD2a/UBE4B is expressed exclusively in mature striated muscle cells.

Yeast Ufd2p was the first identified E4 multiubiquitin chain assembly factor. Its vertebrate homologues later referred to as UFD2a, UBE4B or E4B were also shown to have E3 ubiquitin ligase activity. UFD2a function in the brain has been well established in vivo, and in vitro studies have shown that its activity is essential for proper condensation and segregation of chromosomes during mitosis. Here we show that 2 alternative splice forms of UFD2a, UFD2a-7 and -7/7a, are expressed sequentially during myoblast differentiation of C2C12 cell cultures and during cardiotoxin-induced regeneration of skeletal muscle in mice. UFD2a-7 contains an alternate exon 7, and UFD2a-7/7a, the larger of the 2 isoforms, contains an additional novel exon 7a. Analysis of protein or mRNA expression in mice and zebrafish revealed that a similar pattern of isoform switching occurs during developmental myogenesis of cardiac and skeletal muscle. In vertebrates (humans, rodents, zebrafish), UFD2a-7/7a is expressed only in mature striated muscle. This unique tissue specificity is further validated by the conserved presence of 2 muscle-specific splicing regulatory motifs located in the 3' introns of exons 7 and 7a. UFD2a interacts with VCP/p97, an AAA-type ATPase implicated in processes whose functions appear to be regulated, in part, through their interaction with one or more of 15 previously identified cofactors. UFD2a-7/7a did not interact with VCP/p97 in yeast 2-hybrid experiments, which may allow the ATPase to bind cofactors that facilitate its muscle-specific functions. We conclude that the regulated expression of these UFD2a isoforms most likely imparts divergent functions that are important for myogenisis.

The MPAC domain is a novel mitotically regulated domain, removed by apoptotic protease cleavage during cell death.

The apoptotic proteases, including caspases and granzyme B, have independent evolutionary origins, yet are both highly specific for cleavage after aspartic acid residues and cleave many of the same substrates at closely spaced sites. In addition, many of these substrates are also reversibly regulated during other processes such as the cell cycle. In these studies, we have identified a novel domain (the MPAC domain: Mitotically Phosphorylated, Apoptotically Cleaved) present at the N-terminus of Ufd2a, which is regulated both by cleavage during cell death, and by phosphorylation during mitosis. We have also identified a corresponding domain, at the C-terminus of polyA polymerase (PAP), which is similarly regulated by phosphorylation during mitosis and is delineated by an apoptotic protease cleavage site. The positioning of the apoptotic cleavage site suggests that it represents a novel connector between the regulatory domain and its functional partner(s), providing insights into the structure and function that guided the evolution of the apoptotic proteases.

Ufd2, a novel autoantigen in scleroderma, regulates sister chromatid separation.

The characterization of molecules recognized by patients with autoimmune diseases has provided significant insights into important biological pathways. In these studies, we define Ufd2 (a novel E4 polyubiquitylating enzyme) as a new autoantigen in scleroderma, and show that it regulates chromosome condensation and separation during mitosis in human cells. Ufd2 is regulated by phosphorylation in mitosis. Inhibition of Ufd2 expression results in mitotic arrest at the metaphase-anaphase transition, where cells manifest abnormal chromosome morphology, missegregated chromosomes, irregular spindles, and premature separation of sister chromatids. This is accompanied by premature separase activation, and accumulation of securin in a novel modified form. We further demonstrate that Ufd2 directly and efficiently ubiquitylates securin in vitro and is required for securin polyubiquitylation in vivo. This is the first description of a physiologic substrate for Ufd2, establishing this E4 enzyme as an important regulator of chromosome condensation and separation during mitosis in human cells. Its targeting in scleroderma, together with many other components of the mitotic machinery, reinforces the concept that mitotic cells may be an important focus of the autoimmune response in this disease.