Genetic polymorphism in the human UGT1A6 (planar phenol) UDP-glucuronosyltransferase: pharmacological implications

Two missense mutations were uncovered in the UGT1A6 (HLUG P1) cDNA which codes for a human phenol-metabolizing UDP-glucuronosyltransferase. The mutant and a wild-type UGT1A6 cDNAs were isolated from a custom synthesized human liver lambda Zap cDNA library. Both an A to G transition at nucleotide 541 (T181 A) and an A to C transversion at nucleotide 552 (R184S) occurred in exon 1 of the UGT1A6 (UGT1F) gene at the UGT1 locus. The two mutations on a single allele created a heterozygous genotype. Newly created BsmI and BsoFI sites at the T181 A and R184S locations, respectively, were confirmed by endonuclease treatment of PCR-generated DNA using the donor-liver genomic DNA as template. Screens with endonuclease treatment showed that 33/98 DNA samples were heterozygous with both mutations on one allele. One other individual also carried the R184S mutation on the second allele. Wild-type UGT1A6 generated a broad plateau of activity from pH 5.0 to pH 8.0 with certain experimental phenols, while activity was 1.3-2.5-fold higher at pH 6.4 than at pH 7.2 for others. UGT1A6*2 (181 A+ and 184S+) metabolized 4-nitrophenol, 4-tert-butylphenol, 3-ethylphenol/4-ethylphenol, 4-hydroxycoumarin, butylated hydroxy anisole and butylated hydroxy toluene, with the pH 6.4 preference, at only 27-75% of the rate of the wild-type isozyme whereas 1-naphthol, 3-iodophenol, 7-hydroxycoumarin, and 7-hydroxy-4-methylcoumarin were metabolized at essentially the normal level. Furthermore, UGT1A6*2 metabolized 3-O-methyl-dopa and methyl salicylate at 41-74% of that of the wild-type, and a series of beta-blockers at 28-69% of the normal level. This evidence suggests that the UGT1A6 enzyme activity is affected by different amino acids depending upon the substrate selection.

Successful control of epidemic diphtheria in the states of the Former Union of Soviet Socialist Republics: lessons learned

Epidemic diphtheria reemerged in the Russian Federation in 1990 and spread to all Newly Independent States (NIS) and Baltic States by the end of 1994. Factors contributing to the epidemic included increased susceptibility of both children and adults, socioeconomic instability, population movement, deteriorating health infrastructure, initial shortages of vaccine, and delays in implementing control measures. In 1995, aggressive control strategies were implemented, and since then, all affected countries have reported decreases of diphtheria; however, continued efforts by national health authorities and international assistance are still needed. The legacy of this epidemic includes a reexamination of the global diphtheria control strategy, new laboratory techniques for diphtheria diagnosis and analysis, and a model for future public health emergencies in the successful collaboration of multiple international partners. The reemergence of diphtheria warns of an immediate threat of other epidemics in the NIS and Baltic States and a longer-term potential for the reemergence of vaccine-preventable diseases elsewhere. Continued investment in improved vaccines, control strategies, training, and laboratory techniques is needed.

Glucuronidation of 7-ethyl-10-hydroxycamptothecin (SN-38) by the human UDP-glucuronosyltransferases encoded at the UGT1 locus

7-Ethyl-10-hydroxycamptothecin (SN-38) is a very promising anticancer drug used for the treatment of metastatic colonrectal cancer. SN-38 is the active metabolite of irinotecan, a semisynthetic anticancer drug derived from 20(S)camptothecin. In this study, we examined the potential for each of the UGT1-encoded isoforms (UGT1A1 and UGT1A3 through UGT1A10) to glucuronidate SN-38. The amount of specific protein for each isoform was determined by Western blot analysis. Although UGT1A1 was previously shown to metabolize this drug, the results of this study show that UGT1A7 glucuronidates this chemical at a 9- to 21-fold higher level at pH 6. 4 and pH 7.6, respectively, than that by UGT1A1. The activity of UGT1A7 is from 8.4- to 19-fold higher at pH 6.4 and 12- to 40-fold higher at pH 7.6 than that by the other 7 UGT1 encoded isoforms. UGT1A7 glucuronidates SN-38 with an apparent Km of 5 microM. Hence, the distribution of this isoform in the gastrointestinal tract has the potential to impact the effectiveness of this chemotherapeutic agent.

Epidemic intelligence: a new framework for strengthening disease surveillance in Europe

In a rapidly changing environment, national institutions in charge of health security can no longer rely only on traditional disease reporting mechanisms that are not designed to recognise emergence of new hazards. Epidemic intelligence provides a conceptual framework within which countries may adapt their public health surveillance system to meet new challenges. Epidemic intelligence (EI) encompasses all activities related to early identification of potential health hazards, their verification, assessment and investigation in order to recommend public health control measures. EI integrates both an indicator-based and an event-based component. ‘Indicator-based component’ refers to structured data collected through routine surveillance systems. ‘Event-based component’ refers to unstructured data gathered from sources of intelligence of any nature. All EU member states have long-established disease surveillance systems that provide proper indicator-based surveillance. For most countries, the challenge lies now in developing and structuring the event-based component of EI within national institution in charge of public health surveillance. In May 2006, the European Union member states committed to comply with provisions of the revised International Health Regulations (IHR(2005)) considered relevant to the risk posed by avian and potential human pandemic influenza. This provides for the European Centre for Disease Prevention and Control (ECDC) with an opportunity to guide member states in developing and/or strengthening their national EI , in addition to the ECDC’s task of developing an EI system for the EU.

p16(INK4A) expression is related to grade of cin and high-risk human papillomavirus but does not predict virus clearance after conization or disease outcome

The role of p16(INK4A) as a marker of HR-HPV and in the diagnosis of CIN has been well established, but its predictive value in the clearance of the virus after CIN treatment and its use as a prognostic marker of cervical cancer has not been studied. A series of 302 archival samples, including 150 squamous cell carcinomas (SCCs) and 152 CIN lesions, were subjected to immunohistochemical staining for p16(INK4A) and HPV testing using PCR with three primer sets (MY09/11, GP5/GP6, SPF). Follow-up data were available of 88 SCC patients, and 67 of the CIN lesions had been followed-up with serial PCR after conization. HR-HPV types were closely associated with CIN (OR 19.12; 95%CI 2.31-157.81) and SCC (OR 27.25; 95%CI 3.28-226.09). There was a significant linear relationship between the lesion grade and intensity of p16(INK4A) staining (p = 0.0001). The expression of p16(INK4A) was also closely related to HR-HPV (p = 0.0001). p16(INK4A) staining was a 100% specific indicator of CIN, with 100% PPV, and showed 83.5% sensitivity and 80.1% PPV in detecting HR-HPV. However, p16(INK4A) staining did not predict clearance/persistence of HR-HPV after treatment of CIN. Similarly, despite a slightly more favorable survival in women with strong/intense p16(INK4A) staining in univariate analysis, p16(INK4A) expression was not an independent prognostic predictor in multivariate survival (Cox) analysis. After adjustment for p16(INK4A) staining, HR-HPV, histological grade, International Federation of Gynecology and Obstetrics (FIGO) stage, and age, only the last two were significant prognostic predictors (p = 0.0001 and p = 0.003, respectively). The present data confirm the role of p16(INK4A) as a highly specific marker of CIN and HR-HPV type, but expression of this protein does not seem to be of any prognostic value in cervical cancer or in predicting the clearance of HR-HPV after treatment of CIN. We speculate that different subgroups of cervical cancer are characterized by aberrant p16(INK4A)/cyclin D/Rb pathways that are due to different mechanisms that can be mutually exclusive.

Glucuronidation of benzidine and its metabolites by cDNA-expressed human UDP-glucuronosyltransferases and pH stability of glucuronides

Although glucuronidation is considered a necessary step in aromatic amine-induced bladder cancer, the specific enzymes involved are not known. This study assessed the capacity of five different human recombinant UDP-glucuronosyltransferases expressed in COS-1 cells to glucuronidate benzidine, its metabolites and 4-aminobiphenyl. [(14)C]UDP-glucuronic acid was used as co-substrate. UGT1A1, UGT1A4 and UGT1A9 each metabolized all of the aromatic amines. UGT1A9 exhibited the highest relative rates of metabolism with preference for the two hydroxamic acids, N-hydroxy-N-acetylbenzidine and N-hydroxy-N,N'-diacetylbenzidine. UGT1A9 metabolized 4-aminobiphenyl approximately 50% faster than benzidine or N-acetylbenzidine. UGT1A4 N-glucuronidated N'-hydroxy- N-acetylbenzidine at the highest relative rate compared with the other transferases. UGT1A6 was effective in metabolizing only four of the eight aromatic amines tested. UGT1A1 demonstrated more extensive metabolism of the hydroxamic acid, N-hydroxy-N,N'-diacetylbenzidine, and the ring oxidation product, 3-OH-N,N'-diacetylbenzidine, than it did for the other six amines. UGT2B7 was the only product of the UGT2 gene family examined and it metabolized all the aromatic amines at similar low relative levels compared with a preferred substrate, 4-OH-estrone. The K(m) values for N-acetylbenzidine metabolism by UGT1A1 and UGT1A4 were 0.37 +/- 0.14 and 1.8 +/- 0.4 mM, respectively. The O-glucuronide of 3-OH-N,N'-diacetylbenzidine was not hydrolyzed during a 24 h 37 degrees C incubation at either pH 5. 5 or 7.4. Likewise, the O-glucuronide of 3-OH-benzidine was stable at pH 7.4, with 52% remaining at pH 5.5 after 24 h. These results suggest the following relative ranking of transferase metabolism: UGT1A9 > UGT1A4 > > UGT2B7 > UGT1A6 approximately UGT1A1. The relative pH stability of O-glucuronides is consistent with a role in detoxification and excretion of aromatic amines, while the acid lability of N-glucuronides is consistent with delivery of these amines to the bladder epithelium for activation, resulting in DNA adducts which may lead to mutations.

Coding defect and a TATA box mutation at the bilirubin UDP-glucuronosyltransferase gene cause Crigler-Najjar type I disease

Mutations at the bilirubin UDP-glucuronosyltransferase (transferase) gene in a severely hyperbilirubinemic Crigler-Najjar (CN) type I individual was compared with that in a moderately hyperbilirubinemic CN II individual. The CN-I (CF) patient in this study sustained a TATA box insertional mutation which was paired with a coding defect at the second allele, unlike all coding defects previously seen in CN-I patients. The sequence of the mutant TATA box, [A(TA)8A], also seen in the CN-II patient, was compared with that at the wild-type box, [A(TA)7A]. Transcriptional activity with [A(TA)8A] was 10-15% that with the wild-type box when present in the -1.7 kb upstream regulatory region (URR) of the bilirubin transferase UGT1A1 gene which was fused to the chloramphenicol acetyl transferase reporter gene, pCAT 1.7H, and transfected into HepG2 cells. Also, a construct with a TA deletion, [A(TA)6A], was prepared and used as a control; transcriptional activity was 65% normal. The coding region defect, R336W, seen in CF (CN-I) was placed in the bilirubin transferase UGT1A1 [HUG-Br1] cDNA, and its corresponding protein was designated UGT1A1*32. The UGT1A1*32 protein supported 0-10% normal bilirubin glucuronidation when expressed in COS-1 cells. The I294T coding defect seen at the second allele in SM (CN-II) generated the UGT1A1*33 mutant protein which supported 40-55% normal activity with a normal Km (2.5 microM) for bilirubin. The hyperbilirubinemia seen in SM decreased in response to phenobarbital treatment, unlike that seen in CF. Parents of the patients were carriers of the respective mutations uncovered in the offspring. The TATA box mutation paired with a deleterious missense mutation is, therefore, completely repressive in the CN-I patient, and is responsible for a lethal genotype/phenotype; but when homozygous, i.e. paired with itself, as previously reported in the literature, it is far less repressive and generates the mild Gilbert's phenotype.

Up-regulation of proliferating cell nuclear antigen (PCNA) is closely associated with high-risk human papillomavirus (HPV) and progression of cervical intraepithelial neoplasia (CIN), but does not predict disease outcome in cervical cancer

OBJECTIVE

Proliferating cell nuclear antigen (PCNA) is essential for DNA replication of mammalian cells and their small DNA tumour viruses. The E7 oncoprotein of high-risk human papillomavirus (HPV) is known to activate PCNA, shown to be up-regulated in CIN and cervical cancer (CC), but still incompletely studied as an intermediate endpoint marker in this disease.

MATERIAL AND METHODS

As part of our HPV-PathogenISS study, a series of 150 CCs and 152 CIN lesions were examined using immunohistochemical (IHC) staining for PCNA, and tested for HPV using PCR with three primer sets (MY09/11, GP5+/GP6+, SPF). Follow-up data were available from all SCC patients, and 67 of the CIN lesions had been monitored with serial PCR for HPV after cone treatment.

RESULTS

Expression of PCNA increased in parallel with the grade of CIN, with major up-regulation upon transition to CIN3 (OR 21.77; 95%CI 6.59-71.94) (p = 0.0001). Intense PCNA expression was 100% specific indicator of CIN, with 100% PPV, but suffers from low sensitivity (34.8%) and NPV (10.8%). PCNA expression was also significantly associated to HR-HPV with OR 3.02 (95%CI 1.71-5.34) (p = 0.0001), and this association was not confounded by the histological grade (Mantel-Haenszel common OR = 2.03; 95%CI 1.06-3.89) (p = 0.033). Expression of PCNA did not predict clearance/persistence of HR-HPV after treatment of CIN, and it was not a prognostic predictor in CC in univariate or in multivariate analysis.

CONCLUSIONS

Up-regulation of PCNA was closely associated with HR-HPV and progressive CIN, most feasibly explained by the abrogation of normal cell cycle control by the E7 ongogene, reverting the p21(Cip1)-mediated inhibition of PCNA. However, the fact that PCNA is also expressed in normal squamous epithelium precludes the use of this marker as a potential screening tool for CC.

Infected tibial pseudarthrosis. A 2-year follow up on patients treated by the Ilizarov technique

The Ilizarov technique with a circular external fixator was used in the treatment of infected tibial nonunions. This is a report on 13 patients with a 2-year follow up after removal of the external fixation. There was no debridement of the site of nonunion performed. Union was obtained in all cases. There was no recurrence of infection at follow up. The Ilizarov technique provides the orthopedic surgeon with another alternative in the treatment of complicated tibial nonunions and their associated problems.

Altered coding for a strictly conserved di-glycine in the major bilirubin UDP-glucuronosyltransferase of a Crigler-Najjar type I patient

The characterization (Ritter, J.K., Chen, F., Sheen, Y. Y., Tran, H.M., Kimura, S., Yeatman, M.T., and Owens, I. S. (1992) J. Biol. Chem. 267, 3257-3261) of the single-copy UGT1 gene complex locus encoding both bilirubin and phenol UDP-glucuronosyltransferases (transferase) has been critical to the determination of genetic defects in Crigler-Najjar patients. The complex (UGT1A-UGT1M) codes for at least two bilirubin, three bilirubin-like, and eight phenol transferase isozymes. In the 5' region, a minimum of 13 different exons 1, each with an upstream promoter, are arrayed in series with 4 common exons in the 3' region of the locus. Each exon 1 encodes the amino terminus of a transferase, and the common exons encode the common carboxyl terminus of each isoform. Although a deleterious mutation in a common exon inactivates the entire locus, a deleterious mutation in an exon 1, as we report here for the UGT1A gene in a Crigler-Najjar Type I patient, affects the amino terminus of that single isoform. Recessively inherited mutant alleles for the predominant bilirubin isozyme, the HUG-Br1 protein, substituted Arg for Gly at codon 276 (G276R) in exon 1 of UGT1A abolishing a conserved di-glycine. The mutant HUG-Br1-G276R protein expressed in COS-1 cells had no detectable bilirubin glucuronidating activity at either pH 7.6 or 6.4. Although each of the bilirubin-type isozymes contains a conserved peptide between residues 270 and 288, all UDP-glucuronosyltransferases contain a di-glycine at approximately position 276-277, making it strictly conserved. Structure-function relationship was studied by site-directed mutations of the HUG-Br1 cDNA; G276A, G276Q, G276E, G276I, and P270G mutants were inactive, and V2751- and P285G-altered transferases expressed normal activity. Conservation of residues between the related baculoviral ecdysone UDP-glucosyltransferase and the UDP-glucuronosyltransferases confirms the critical role of the Gly-276 as well as other residues.

Aberrant expression of VEGF-C is related to grade of cervical intraepithelial neoplasia (CIN) and high risk HPV, but does not predict virus clearance after treatment of CIN or prognosis of cervical cancer

AIMS

Increased angiogenesis leads to invasion in cervical cancer. Vascular endothelial growth factors (VEGFs) are involved in angiogenesis, but molecular links to the most important aetiological agent, human papillomavirus (HPV), need clarifying.

MATERIAL/METHODS

Archival samples-150 squamous cell carcinomas (SCCs) and 152 cervical intraepithelial neoplasia (CIN) lesions-were examined immunohistochemically for anti-VEGF-C antibody and for HPV by polymerase chain reaction (PCR). Follow up data were available for all SCC cases, and 67 CIN lesions were monitored with serial PCR to assess HPV clearance/persistence after treatment.

RESULTS

High risk (HR) HPV types were closely associated with CIN (odds ratio, 19.12; 95% confidence interval, 2.31 to 157.81) and SCC (27.25; 3.28 to 226.09). There was a linear increase of VEGF-C expression-weak in CIN1 and intense in CIN3 and SCC (20.49; 8.69 to 48.26). VEGF-C upregulation was a sensitive (93.5%; 95% CI, 90.1% to 96.9%) marker of HR-HPV type (4.70; 2.17 to 10.21), but lost its significance in multivariate regression-p16(INK4a) and survivin were equally strong independent predictors of HR-HPV. Aberrant expression of VEGF-C did not predict clearance/persistence of HR-HPV after treatment of CIN. In cervical cancer, VEGF-C had no prognostic value in univariate or multivariate survival analysis. After adjustment for HR-HPV, FIGO stage, age, and tumour grade, only FIGO stage and age remained independent prognostic predictors.

CONCLUSIONS

VEGF-C is an early marker of cervical carcinogenesis, with linearly increasing expression starting from low grade CIN. VEGF-C expression is closely related to HR-HPV in cervical lesions, probably because of its p53 independent upregulation by the E6 oncoprotein of HR-HPV.

Genetic defects at the UGT1 locus associated with Crigler-Najjar type I disease, including a prenatal diagnosis

Characterization of the UGT1 gene complex locus encoding both multiple bilirubin and phenol UDP-glucuronosyltransferases (transferases) has been critical in identifying mutations in the bilirubin isoforms. This study utilizes this information to identify the bases of deficient bilirubin UDP-glucuronosyltransferase activity encoded by the UGT1A gene for the major bilirubin isozyme, HUG-Br1, in 3 Crigler-Najjar type I individuals and the genotype of an at-risk unborn sibling of one patient. A homozygous and heterozygous two-base mutation (CCC to CGT) created the HUG-Br1P387R mutant of the major bilirubin transferase in 2 different Crigler-Najjar type I patients, B.G. and G.D., respectively. Both parents of B.G. and his unborn sibling, J.G., were determined to be carriers of the P387R mutation. G.D. also contains the CAA to TAA nonsense mutation (G1n357st). Y.A. has a homozygous CT deletion in codons 40/41. The HUG-Br1P387R mutant protein was totally inactive at the major pH optimum (6.4), but retained 26% normal activity at the minor pH optimum (7.6), which was 5.4% of the combined activities measured at the two pH values.

Required buried alpha-helical structure in the bilirubin UDP-glucuronosyltransferase, UGT1A1, contains a nonreplaceable phenylalanine

A conserved hydrophobic region in the bilirubin-type UDP-glucuronosyltransferase isozyme was first uncovered as a consequence of a deleterious mutation in the UGT1A1 (HUG-Br1) isozyme of a Crigler-Najjar (CN) Type I patient. According to analysis by the RAOARGOS computer program, this hydrophobic region in UGT1A1 is located between residues 159-177 and defines a buried helix centered over position 169-172 with a positive factor of 1.22. Further analysis showed that the planar phenol-type UGT1A6 (HLUG P1) isoform, unlike the steroid-type UGT2B7 (UDPGTh2) isozyme, has a similar conserved hydrophobic region and that the positive factor for its buried helix is 1.14 compared to the threshold of 1.13 for such a structure. The analysis detected the typical membrane-insertion-signal sequence and a membrane-anchoring domain in each isoform. The different amino acid sequence patterns between positions 168-172 for the three types of isoforms and the deleterious mutations in this microregion (MRA) of UGT1A1 in CN-I patients are evidence of a critical and descriminating role for MRA. With the recombinant UGT1A1 enzyme and its mutants, P167G, F170del, F170L, F170I, F170V, F170A, F170Y, F170E, F171L, F171I, F171V, F171A, F171Y, or L175Q, expressed in COS-1 cells, bilirubin glucuronidating activity at both pH 6.4 and 7.6 demonstrated that Phe-170 is not replaceable, whereas Phe-171 can be replaced by Leu without any loss of activity. The less hydrophobic buried helix in the phenolic-type UGT1A6 has a Tyr/Leu at position 170/171; this isoform glucuronidated bilirubin at 1/10 the level of that by UGT1A1 with a Km (bilirubin) of 25 microM compared to that for UGT1A1 of 5. 0 microM.

Upregulation of telomerase (hTERT) is related to the grade of cervical intraepithelial neoplasia, but is not an independent predictor of high-risk human papillomavirus, virus persistence, or disease outcome in cervical cancer

Telomerase activation and telomere maintenance are essential for cell immortalization and represent a rate-limiting step in cancer progression. The E6 oncoprotein of high-risk human papillomavirus (HPV) is known to activate telomerase, but its expression in CIN lesions and its prognostic value in cervical cancer (CC) are still incompletely understood. As part of our HPV-PathogenISS study, a series of 150 CCs and 152 CIN lesions were examined using immunohistochemical (IHC) staining for hTERT (telomerase reverse transcriptase), and tested for HPV using PCR with three primer sets (MY09/11, GP5(+)/GP6(+), SPF). Follow-up data were available from all SCC patients, and 67 CIN lesions had been monitored with serial PCR for HPV after cone treatment. Expression of hTERT was increased in parallel with the grade of CIN, with major up-regulation upon transition to CIN3 (OR 18.81; 95% CI 8.48-41.69; P = 0.0001). Positive hTERT expression was 90% specific indicator of CIN, with 98.7% PPV, but suffers from low sensitivity (57.5%) and NPV (14.3%). hTERT expression was also significantly associated to HR-HPV with OR 3.38 (95% CI 1.90-6.02; P = 0.0001), but this association was confounded by the histological grade (Mantel-Haenszel common OR = 1.83; 95% CI 0.92-3.79; P = 0.086). Expression of hTERT did not predict clearance/persistence of HR-HPV after treatment of CIN, and it was not a prognostic predictor in cervical cancer in univariate or multivariate survival analysis. It was concluded that up-regulation of hTERT was closely associated with HR-HPV, due to activation by the E6 oncoprotein. hTERT is a late marker of cervical carcinogenesis, significantly associated with progression to CIN3. Theoretically, a combination of hTERT assay (showing high SP and PPV) with another test showing high SE and high NPV (e.g. Hybrid Capture 2 for HPV), should provide an ideal screening tool capable of high-performance detection of CIN lesions.

Evidence for overlapping active sites for 17 alpha-ethynlestradiol and bilirubin in the human major bilirubin UDPglucuronosyltransferase

The human major bilirubin UDP glucuronosyltransferase (transferase), HUG-Brl, and its mutants were expressed in the COS-1 cells using cDNA-based pSVL expression units to generate isoforms for the comparison of relative activities with 17 alpha-ethynlestradiol (17 alpha-EE) and bilirubin, its natural substrate. In comparison to bilirubin, 17 alpha-EE was a good substrate for HUG-Br1 under typical assay conditions of pH 7.2, confirming published studies [Ebner, T., et al. (1993) Mol. Pharmacol. 43, 649-654]. It was further shown that the estrogen derivative is 1.2-2-fold more effective as a substrate at pH 6.4 than at pH 7.2. The km for 17 alpha-EE was 40 microM under both pH conditions, while the Vmax values were 400 and 200 pmol per hour per 300 micrograms of protein at pH 6.4 and 7.2, respectively. The pattern of glucuronidation was similar for both bilirubin and 17 alpha-EE. Previously, a ratio of 2-3-fold more activity for bilirubin glucuronidation at pH 6.4 versus 7.6 was established, and km values of 2.5 microM at both pH conditions were determined [Ritter, J.K., et al. (1993) J. Biol. Chem. 268, 23573-23579]. In this study, the generation of 17 alpha-EE and bilirubin beta-glucuronides under both pH conditions was confirmed by the sensitivity of the products to beta-glucuronidase treatment. Concurrent glucuronidation reaction mixtures containing equal amounts of wild-type and mutant proteins demonstrated the following. P270G, V273D, and five different G276 mutants nearly or completely inactivated all glucuronidation at both pH levels. V273Q generated 81-94% of the normal activity for 17 alpha-EE and 42% of the normal activity for bilirubin turnover; H173R gave 37-60% of the normal turnover with both substrates, and V275I produced 15-24% of the normal level of glucuronide with both compounds. The most distinguishing amino acid tested was P176G which was approximately 50% normal for 17 alpha-EE at both pH conditions but was totally inactive for bilirubin. A second substitution, P285G, did not affect 17 alpha-EE turnover but was 50% normal for bilirubin. The parallel effects on the metabolism of both substrates by some mutants and the opposite results from two mutants are evidence for a common set of amino acids for their catalysis with the recruitment of additional amino acids to depend upon the substrate to be metabolized. Hence, amino acid substitutions in the protein are not necessarily universally inactivating.

Upregulation of nuclear factor-kappaB (NF-kappaB) is related to the grade of cervical intraepithelial neoplasia, but is not an independent predictor of high-risk human papillomavirus or disease outcome in cervical cancer

Nuclear factor-kappaB (NF-kappaB) has a pivotal function in controlling a wide variety of gene functions, and has shown to be constitutively activated in many human cancers. The molecular links of NF-kappaB to oncogenic human papillomavirus (HPV) in cervical intraepithelial neoplasia (CIN) lesions and its prognostic value in cervical cancer (CC) are incompletely understood. As part of our HPV-PathogenISS study, a series of 150 squamous-cell carcinomas (SCCs) and 152 CIN lesions were examined using immunohistochemical staining for NF-kappaB, and tested for HPV using PCR with three primer sets (MY09/11, GP5+/GP6+, and SPF). Follow-up data were available from all SCC patients, and 67 CIN lesions had been monitored with serial PCR for HPV clearance/persistence after cone treatment. Cytoplasmic NF-kappaB expression was associated with CIN3/cancer at OR 3.55 (95% CI, 1.79-7.05), while nuclear NF-kappaB expression had an OR of 21.90 (95% CI, 2.96-161.74) (P = 0.0001). Strong nuclear expression was a rare event (8.8%) also in CC, but it was related to high-risk human papillomavirus (HR-HPV) detection, with OR 2.15 (95% CI, 1.08-4.30) (P = 0.022). This association was confounded, however, by the histological grade (Mantel-Haenszel common OR = 1.46; 95% CI, 0.70-3.03) (P = 0.308). Cytoplasmic or nuclear NF-kappaB expression did not predict clearance/persistence of HR-HPV after treatment of CIN, and neither one proved to be a prognostic predictor in CC. Overexpression of cytoplasmic NF-kappaB is significantly associated with progression to CIN3 and cancer. This is paralleled by only a slight increase in nuclear expression of NF-kappaB, which could be explained by the mechanisms whereby HR-HPVs escape from the transcriptional control of NF-kappaB, i.e., E7-mediated impaired nuclear translocation of cytoplasmic NF-kappaB, and E6-conditioned attenuated NF-kappaB (p65)-dependent transcriptional activity.

Down-regulated nucleoside diphosphate kinase nm23-H1 expression is unrelated to high-risk human papillomavirus but associated with progression of cervical intraepithelial neoplasia and unfavourable prognosis in cervical cancer

OBJECTIVE

One of the factors leading to an invasive phenotype is the nm23 family of metastases-associated genes. Of the six known members, nm23-H1 is the most frequently studied potential anti-metastatic gene in cervical cancer. However, the possible molecular links to oncogenic human papillomavirus (HPV) are completely unexplored as yet.

MATERIALS AND METHODS

As a part of the HPV-Pathogen Istituto Superiore di Sanità study, a series of 150 squamous cell carcinomas (SCCs) and 152 cervical intraepithelial neoplasia (CIN) lesions were examined by immunohistochemical staining for nm23-H1, and tested for HPV by polymerase chain reaction (PCR) with three sets of primers (MY09/11, GP5(+)/GP6(+) and short PCR fragment). Follow-up data were available on all patients with SCC, and 67 CIN lesions were monitored by serial PCR for clearance or persistence of HPV after cone treatment.

RESULTS

A linear decrease (p = 0.001) was observed in nm23-H1 expression, starting from CIN1 (85% with normal expression), with the most dramatic down regulation on transition from CIN2 (70% normal) to CIN3 (39%) and further to SCC (25%). Reduced expression was associated with CIN3 or cancer at an odds ratio 8.72 (95% confidence interval 4.13 to 18.41). Nm23-H1 was of no use as a marker of the high-risk human papillomavirus (HR-HPV) type, and it did not predict clearance or persistence of HR-HPV after treatment of CIN. Importantly, nm23-H1 expression was a significant prognostic factor in cervical cancer, reduced expression being associated with lower survival (p = 0.022) in univariate analysis. In the multivariate (Cox) regression model, however, only the International Federation of Gynecology and Obstetrics stage (p = 0.001) and age (p = 0.011) remained independent prognostic predictors.

CONCLUSIONS

Down-regulated nm23-H1 expression is markedly associated with progression from CIN2 to CIN3, and predicts poor prognosis in cervical cancer. Nm23-H1 down regulation is probably orchestrated by mechanisms independent of HR-HPV oncoproteins and is possibly related to the emergence of a proteolytic phenotype.

Polyoma virus BK and renal dysfunction in a transplanted population

INTRODUCTION

Reactivation of polyoma virus BK (BKV) is increasingly recognized as a cause of severe renal-allograft dysfunction. The aim of the present study was to evaluate prevalence of BKV infection and activity in a population of kidney (KT) and liver (LT) transplant patients and search for a possible correlation with renal dysfunction.

METHODS

We studied 118 patients for BKV viruria and, when present, for BKV viremia. We also assessed HCV status.

RESULTS

Among 16 patients with BKV viruria (5 LT and 11 KT), eight showed BKV viremia (one LT and seven KT). Among BKV viruria-positive patients, three LT recipients were HCV-positive. All LT BKV viruria-positive patients showed normal renal function with a mean serum creatinine (sCr) blood level of 0.9 mg% and a mean blood urea nitrogen (BUN) value of about 36 mg%. The mean transplant age was 2.5 years. In contrast, KT BKV viruria-positive patients showed impaired renal function which was slightly worse in patients who also displayed BKV viremia, namely, a mean sCr blood level 1.7 mg% and a mean BUN value about 80 mg%. The mean transplant age was 7 years.

CONCLUSION

Based on these findings, it seems that BKV viruria in renal allograft recipients may be associated with viremia and related to nephropathy that may lead to allograft rejection. The study will be completed with a 2-year follow-up of positive patients to assess the possible relationship between BKV active infection and eventual decrease of renal function and loss of transplanted organ.

Respiratory viruses and influenza-like illness: a survey in the area of Rome, winter 2004-2005

Limited information is available on the viral aetiology of influenza-like illness (ILI) in Southern European countries. Hereby we report the main findings of a survey conducted in the area of Rome during the 2004-2005 winter season.ILI cases were defined as individuals with fever >37.5 degrees C and at least one constitutional symptom and one respiratory symptom, recruited during the survey period. Influenza and other respiratory viruses were identified using polymerase chain reaction (PCR) on throat swabs. Basic individual information was collected through a standard form. Of 173 ILI cases enrolled, 74 tested positive for one virus, and two tested positive for two viruses. Overall, 33.5% of the cases were positive for influenza viruses, 5.2% for adenoviruses, 3.5% for parainfluenza viruses, 1.7% for coronaviruses, and 1.2% for the respiratory syncitial virus. The proportion of influenza virus detection was higher in the 'high influenza activity' period. The distribution of viral agents varied across age groups, influenza viruses being more likely to be detected in younger patients. Viral pathogens were identified in less than 50% of ILI cases occurred during a high activity influenza season. The detection of other than influenza viruses was sporadic, without evidence of large outbreaks due to specific agents.

Follicle-stimulating hormone, testosterone, and hypoxia differentially regulate UDP-glucuronosyltransferase 1 isoforms expression in rat sertoli and peritubular myoid cells

Uridine diphosphoglucuronosyltransferases (UGTs) are detoxifying enzymes responsible for the metabolism of endogenous and xenobiotics compounds. UGT isoforms are widely distributed in rat tissues showing a constitutive and inducible gene expression. However, little information is available concerning UGTs expression in testis. The UGT1A1, UGT1A2, and UGT1B1 mRNAs expression in whole rat testis, in Sertoli and peritubular myoid cells in basal conditions, and after hormonal and hypoxic stimulation were investigated by reverse transcriptase-polymerase chain reaction (RT-PCR). Constitutive expression of each UGT1 isoform was present in rat testis with higher levels of UGT1A2. UGT transcripts were also detected in Sertoli and peritubular myoid cells. After FSH stimulation, Sertoli cells showed an increase in UGT1B1 mRNA expression, whereas the levels of UGT1A1 and UGT1A2 resulted unmodified. The main effect induced by testosterone was a decrease of UGT1B1 mRNA expression in peritubular myoid cells, whereas in Sertoli cells an increase in UGT1A1 and UGT1B1 was observed. In hypoxic conditions, a reduction in UGTs mRNA levels was detected in both cell types. These findings suggest that rat UGT1 isoforms are regulated in testis by hormonal and environmental factors. Thus, it was speculated that alterations in UGTs expression and/or activity may be involved in the pathogenesis of testis injury.