SmgGDS is a transient nucleolar protein that protects cells from nucleolar stress and promotes the cell cycle by regulating DREAM complex gene expression.

The chaperone protein and guanine nucleotide exchange factor SmgGDS (RAP1GDS1) is a key promoter of cancer cell proliferation and tumorigenesis. SmgGDS undergoes nucleocytoplasmic shuttling, suggesting that it has both cytoplasmic and nuclear functions that promote cancer. Previous studies indicate that SmgGDS binds cytoplasmic small GTPases and promotes their trafficking to the plasma membrane. In contrast, little is known about the functions of SmgGDS in the nucleus, or how these nuclear functions might benefit cancer cells. Here we show unique nuclear localization and regulation of gene transcription pathways by SmgGDS. Strikingly, SmgGDS depletion significantly reduces expression of over 600 gene products that are targets of the DREAM complex, which is a transcription factor complex that regulates expression of proteins controlling the cell cycle. The cell cycle regulators E2F1, MYC, MYBL2 (B-Myb) and FOXM1 are among the DREAM targets that are diminished by SmgGDS depletion. E2F1 is well known to promote G1 cell cycle progression, and the loss of E2F1 in SmgGDS-depleted cells provides an explanation for previous reports that SmgGDS depletion characteristically causes a G1 cell cycle arrest. We show that SmgGDS localizes in nucleoli, and that RNAi-mediated depletion of SmgGDS in cancer cells disrupts nucleolar morphology, signifying nucleolar stress. We show that nucleolar SmgGDS interacts with the RNA polymerase I transcription factor upstream binding factor (UBF). The RNAi-mediated depletion of UBF diminishes nucleolar localization of SmgGDS and promotes proteasome-mediated degradation of SmgGDS, indicating that nucleolar sequestration of SmgGDS by UBF stabilizes SmgGDS protein. The ability of SmgGDS to interact with UBF and localize in the nucleolus is diminished by expressing DiRas1 or DiRas2, which are small GTPases that bind SmgGDS and act as tumor suppressors. Taken together, our results support a novel nuclear role for SmgGDS in protecting malignant cells from nucleolar stress, thus promoting cell cycle progression and tumorigenesis.

A 30-year experience of Millin's retropubic prostatectomy: Has this classic operation derived by a President of the College in Ireland stood the test of time?

INTRODUCTION: In patients with large gland volume, open prostatectomy/adenoma enucleation remains a valuable surgical option in treating large obstructing prostates. We report our series of open prostatectomies spanning 32 years from a single institution. PATIENTS AND METHODS: We retrospectively reviewed all patients who underwent open prostatectomy between 1980 and 2012. Patient demographical, clinical, pre- and postoperative data and final histology were retrieved from hospital in-patient enquiry system and chart review. RESULTS: A total of 161 patients underwent Millin's prostatectomy by seven surgeons between 1980 and 2012. The mean blood loss was 1,381 mls (range 300-3,675 mls). One-third (34%) of patients (n = 55) received a blood transfusion. The mean weight of prostate tissue removed was 119 g (median 112 g, range 17-372 g). 6.6 % of pathological specimens revealed incidental prostate cancer, of which 78% were well differentiated (Gleason score ≤ 6). The mean weight of prostate tissue removed in patients who received a transfusion was 124 g. Trial of micturition (TOM) was performed at a mean of 9 days (median 9 days, range 5-25 days) with 94% of patients having a successful trial of voiding. 6% of cases early in the series failed to void initially, but did so at later removal of catheter while still in hospital. 45 patients (28%) of patients developed peri- or postoperative complications. There were three deaths (1.9%). CONCLUSION: Open Millin's prostatectomy popularized over half a century ago continues to be a valuable option for the surgical treatment of high-volume prostate glands with excellent outcomes for patients.

The pitfalls of treating anorectal conditions after radiotherapy for prostate cancer.

We present a salutary lesson learned from three cases with significant complications that followed anorectal intervention in the presence of radiation proctitis due to prior radiotherapy for adenocarcinoma of the prostate. After apparent routine rubber band ligation for painful haemorrhoids, one patient developed a colo-cutaneous fistula. Following laser coagulation for radiation proctitis, one patient required a pelvic exenteration for a fistula, while another developed a rectal stenosis. Those diagnosing and treating colonic conditions should be mindful of the increased prevalence of patients who have had radiotherapy for prostate cancer and the potential for complications in treating these patients.

Current concepts in female stress urinary incontinence.

Urinary incontinence is a social burden for up to one-third of the adult female population. Careful assessment, a methodical approach and appropriate treatment can lead to long-term success in the management of these patients. This article gives an outline of current concepts in the evaluation and treatment of stress urinary incontinence.

Carcinosarcoma of the penis.

BACKGROUND: Carcinosarcoma of the penis is extremely rare and little is known about its biological behaviour. AIMS: We report the second such case and discuss its histological categorisation and biological behaviour. METHODS: A total penectomy with perineal urethrostomy was performed without lymphadenectomy in an 83-year old presenting with a fungating penile mass. RESULTS: Microscopy of the gross specimen showed a biphasic tumour with both squamous and spindle cell elements. Immunohistochemical staining for epithelial markers showed positivity in the squamous cell elements but was uniformly negative in the spindle component. Immunohistochemistry of the spindle cell element demonstrated mesenchymal markers. The patient refused further treatment and follow up but presented at 26 months with inguinal lymphadenopathy. Biopsy confirmed squamous cell carcinoma metastasis consistent with penile origin. The patient refused further surgery and received pelvic irradiation. He died 6 months later. CONCLUSIONS: This case illustrates the biological behaviour of this rare tumour.

Planning for a national effort to enable and accelerate discoveries in pharmacogenetics: the NIH Pharmacogenetics Research Network.

The Pharmacogenetics Research Network (PGRN) was conceived as a broad network-based approach to research studies in pharmacogenetics and pharmacogenomics, with the central feature of a database that would be hypothesis-generating and open to all scientific investigators. The original working group emphasized the importance of carefully relating phenotypes for drug responses to genotypes, and understanding the relationships functionally and mechanistically. The mission of the PGRN is to advance our knowledge of the genetic basis for variable drug responses. The ultimate goal of the effort is to determine clinically significant sequence variations in order to predict the right choice and dose of medications for individuals and to prepare for implementation of this information to improve health care.

Emphysematous cystitis in an elderly patient with ulcerative colitis.

Emphysematous cystitis is a rare complication of lower urinary tract infections. The disease is characterized by air within the bladder wall and lumen and commonly occurs in middle-aged diabetic women. Intramural bladder gas seen on imaging is pathognomonic for this condition. The severity of the illness varies widely from cases diagnosed incidentally to patients presenting with life-threatening sepsis. We report the case of an 80-year-old non-diabetic man presenting with emphysematous cystitis after a total colectomy for ulcerative colitis.

Ureteral endometriosis and ovarian mucinous cystadenoma presenting with acute pyonephrosis.

BACKGROUND: Endometriosis is a common disease, but ureteral involvement is rare. Nonspecific clinical presentations of ureteral endometriosis may result in diagnostic difficulty. AIM: To discuss the diagnosis and management of such a case. METHODS: To report a case of ureteral involvement with endometriosis and review the literature. RESULTS: The case presented with right lower quadrant pain giving rise to initial diagnostic possibility of acute appendicitis. Subsequent evaluation revealed the diagnosis of right pyonephrosis due to midureteral endometriosis with right ovarian mucinous cystadenoma. CONCLUSION: The diagnosis of ureteral endometriosis requires a high index of clinical suspicion. The importance of ultrasound in the evaluation of acute abdomen in women can not be overemphasised.

RNP localization and transport in yeast.

The localization of mRNAs is used by various types of polarized cells to locally translate specific proteins, which restricts their distribution to a particular sub-region of the cytoplasm. This mechanism of protein sorting is involved in major biological processes such as asymmetric cell division, oogenesis, cellular motility, and synapse formation. With the finding of localized mRNAs in the yeast Saccharomyces cerevisiae, it is now possible to benefit from the powerful yeast laboratory tools to explore the molecular basis of RNA localization. Because mRNA transport and localization in yeast share many features with RNA localization in higher eukaryotes, including the formation of a large ribonucleoprotein (RNP) localization complex, the requirement of a polarized cytoskeleton and molecular motors, and the role of nuclear RNA-binding proteins in cytoplasmic localization, the yeast can be used as a paradigm for unraveling the molecular aspects of this process. This review summarizes the current knowledge on RNP transport and localization in yeast.

Taxol biosynthesis: differential transformations of taxadien-5 alpha-ol and its acetate ester by cytochrome P450 hydroxylases from Taxus suspension cells.

The biosynthesis of the diterpenoid antineoplastic drug Taxol in Taxus species involves the cyclization of the ubiquitous isoprenoid intermediate geranylgeranyl diphosphate to taxa-4(5),11(12)-diene followed by cytochrome P450-mediated hydroxylation (with allylic rearrangement) of this olefin precursor to taxa-4(20),11(12)-dien-5 alpha-ol, and further oxygenation and acylation reactions. Based on the abundances of naturally occurring taxoids, the subsequent order of oxygenation of the taxane core is considered to occur at C10, then C2 and C9, followed by C13, and finally C7 and C1. Circumstantial evidence suggests that the acetylation of taxadien-5 alpha-ol may constitute the third specific step of Taxol biosynthesis. To determine whether taxadienol or the corresponding acetate ester serves as the direct precursor of subsequent oxygenation reactions, microsomal preparations isolated from induced Taxus cells and optimized for cytochrome P450 catalysis were incubated with each potential substrate. Both taxadienol and taxadienyl acetate were oxygenated to the level of a diol and to higher polyols at comparable rates by cytochrome P450 enzymes of the microsomal preparation. Preparative-scale incubation allowed the isolation of sufficient quantities of the diol derived from taxadienol to permit the NMR-based structural elucidation of this metabolite as taxa-4(20),11(12)-dien-5 alpha,13 alpha-diol, which may represent an alternate route of taxoid metabolism in induced cells. GC-MS-based structural definition of the diol monoacetate derived in microsomes from taxadienyl acetate confirmed this metabolite as taxa-4(20),11(12)-dien-5 alpha-acetoxy-10 beta-ol, thereby indicating that acetylation at C5 of taxadienol precedes the cytochrome P450-mediated insertion of the C10-beta-hydroxyl group of Taxol.

An exclusively nuclear RNA-binding protein affects asymmetric localization of ASH1 mRNA and Ash1p in yeast.

The localization of ASH1 mRNA to the distal tip of budding yeast cells is essential for the proper regulation of mating type switching in Saccharomyces cerevisiae. A localization element that is predominantly in the 3'-untranslated region (UTR) can direct this mRNA to the bud. Using this element in the three-hybrid in vivo RNA-binding assay, we identified a protein, Loc1p, that binds in vitro directly to the wild-type ASH1 3'-UTR RNA, but not to a mutant RNA incapable of localizing to the bud nor to several other mRNAs. LOC1 codes for a novel protein that recognizes double-stranded RNA structures and is required for efficient localization of ASH1 mRNA. Accordingly, Ash1p gets symmetrically distributed between daughter and mother cells in a loc1 strain. Surprisingly, Loc1p was found to be strictly nuclear, unlike other known RNA-binding proteins involved in mRNA localization which shuttle between the nucleus and the cytoplasm. We propose that efficient cytoplasmic ASH1 mRNA localization requires a previous interaction with specific nuclear factors.

She2p is a novel RNA-binding protein that recruits the Myo4p-She3p complex to ASH1 mRNA.

In Saccharomyces cerevisiae, Ash1p is a specific repressor of transcription that localizes exclusively to daughter cell nuclei through the asymmetric localization of ASH1 mRNA. This localization requires four cis-acting localization elements located in the ASH1 mRNA, five trans-acting factors, one of which is a myosin, and the actin cytoskeleton. The RNA-binding proteins that interact with these cis-elements remained to be identified. Starting with the 3' most localization element of ASH1 mRNA in the three-hybrid assay, element E3, we isolated a clone corresponding to the C-terminus of She3p. We also found that She3p and She2p interact, and this interaction is essential for the binding of She3p with element E3 in vivo. Moreover, She2p was observed to bind the E3 RNA directly in vitro and each of the ASH1 cis-acting localization elements requires She2p for their localization function. By tethering a She3p-MS2 fusion protein to a reporter RNA containing MS2 binding sites, we observed that She2p is dispensable for She3p-MS2-dependent RNA localization.

Structural elements required for the localization of ASH1 mRNA and of a green fluorescent protein reporter particle in vivo.

The sorting of the Ash1 protein to the daughter nucleus of Saccharomyces cerevisiae in late anaphase of the budding cycle correlates with the localization of ASH1 mRNA at the bud tip [1] [2]. Although the 3' untranslated region (3' UTR) of ASH1 is sufficient to localize a reporter mRNA, it is not necessary, a result which indicates that other sequences are involved [1]. We report the identification of three additional cis-acting elements in the coding region. Each element alone, when fused to a lacZ reporter gene, was sufficient for the localization of the lacZ mRNA reporter to the bud. A fine-structure analysis of the 3' UTR element showed that its function in mRNA localization did not depend on a specific sequence but on the secondary and tertiary structure of a minimal 118 nucleotide stem-loop. Mutations in the stem-loop that affect the localization of the lacZ mRNA reporter also affected the formation of the localization particles, in living cells, composed of a green fluorescent protein (GFP) complexed with lacZ-ASH1-3' UTR mRNA [3]. A specific stem-loop in the 3' UTR of the ASH1 mRNA is therefore required for both localization and particle formation, suggesting that complex formation is part of the localization mechanism. An analysis on one of the coding-region elements revealed a comparable stem-loop structure with similar functional requirements.

Localization of ASH1 mRNA particles in living yeast.

ASH1 mRNA localizes to the bud tip in Saccharomyces cerevisiae to establish asymmetry of HO expression, important for mating type switching. To visualize real time localization of the mRNA in living yeast cells, green fluorescent protein (GFP) was fused to the RNA-binding protein MS2 to follow a reporter mRNA containing MS2-binding sites. Formation and localization of a GFP particle in the bud required ASH1 3'UTR (untranslated region) sequences. The SHE mutants disrupt RNA and particle localization and SHE 2 and 3 mutants inhibit particle formation as well. Both She3myc and She1myc colocalized with the particle. Video microscopy demonstrated that She1p/Myo4p moved particles to the bud tip at 200-440 nm/sec. Therefore, the ASH1 3'UTR-dependent particle serves as a marker for RNA transport and localization.