Antioxidant-induced changes of the AP-1 transcription complex are paralleled by a selective suppression of human papillomavirus transcription

Considering the involvement of a redox-regulatory pathway in the expression of human papillomaviruses (HPVs), HPV type 16 (HPV-16)-immortalized human keratinocytes were treated with the antioxidant pyrrolidine-dithiocarbamate (PDTC). PDTC induces elevated binding of the transcription factor AP-1 to its cognate recognition site within the viral regulatory region. Despite of increased AP-1 binding, normally indispensable for efficient HPV-16 transcription, viral gene expression was selectively suppressed at the level of initiation of transcription. Electrophoretic mobility supershift assays showed that the composition of the AP-1 complex, predominantly consisting of Jun homodimers in untreated cells, was altered. Irrespective of enhanced c-fos expression, c-jun was phosphorylated and became primarily heterodimerized with fra-1, which was also induced after PDTC incubation. Additionally, there was also an increased complex formation between c-jun and junB. Because both fra-1 and junB overexpression negatively interferes with c-jun/c-fos trans-activation of AP-1-responsive genes, our results suggest that the observed block in viral transcription is mainly the consequence of an antioxidant-induced reconstitution of the AP-1 transcription complex. Since expression of the c-jun/c-fos gene family is tightly regulated during cellular differentiation, defined reorganization of a central viral transcription factor may represent a novel mechanism controlling the transcription of pathogenic HPVs during keratinocyte differentiation and in the progression to cervical cancer.

Absence of human papillomavirus DNA in breast cancer as revealed by polymerase chain reaction

Oncogenic human papillomavirus (HPV) types 16 and 18 commonly associated with cervical cancer are found in many epithelial malignancies at extra-genital sites including breast. The transforming gene products of HPV have also been shown to immortalize breast epithelial cells in vitro. But the findings of HPV DNA in breast carcinoma are found to be contradictory. In the present study fine needle aspirate cell (FNAC) samples from 26 breast cancer patients and four breast tumour biopsies were analysed for the presence of HPV 16 and 18 DNA sequences by both polymerase chain reaction (PCR) and Southern blot hybridization. Of 26 fine needle aspirate cell samples and four breast cancer biopsies, not a single sample was found to be positive by either PCR or Southern blot hybridization. The observation of complete absence of HPV DNA sequences in breast cancer refute the possibility of any role for oncogenic genital HPV types 16 and 18 in the pathogenesis of breast cancer.

Detection of human papillomavirus DNA sequences in cancer of the urinary bladder by in situ hybridisation and polymerase chain reaction

OBJECTIVE

To evaluate the prevalence of "high risk" human papillomavirus type 16 (HPV 16) in transitional cell carcinoma of the urinary bladder.

MATERIALS AND METHODS

The study included 10 biopsy specimens from male patients of transitional cell carcinoma of the urinary bladder for the detection of HPV DNA sequences. Specimens were collected from the Urology Clinic of the K.G. Medical College Hospital, Lucknow, India. Detection of HPV DNA was carried out by tissue in situ hybridisation (a single copy gene localisation method) using 3H-labelled HPV DNA probe and also by polymerase chain reaction (PCR) techniques using primers to HPV 16 upstream regulatory region (URR).

RESULTS

Out of 10 cases of transitional cell carcinoma of the urinary bladder, "high risk" HPV 16 DNA was detected only in one (10%) by using in situ hybridisation whereas two cases (20%) were found to be positive by polymerase chain reaction.

CONCLUSION

Our results suggest that the rare occurrence of HPV in bladder carcinoma may not have a causal relation with the viral infection.

Accidents in the aluminium smelting industry

Analysis of the accident records of an aluminium smelting industry, covering about 2,100 employees, over a period of three years, showed a total of 465 accidents of male employees. Out of these, 5 were fatal, 40.86% were from contacts with extreme temperatures, causing burn injury to 42.58%. Hot materials were the agents causing 44.52% of the burn injuries. Molten aluminium constituted 43.96% amongst hot materials. Injury to lower limbs constituted 38.71% and that to upper limbs 36.99%. The accidents occurring to the employees, in the age group of 26-33 years, amounted to 61.72% of the total accidents. The average number of man-days lost per year was 11,153. Average frequency rate of accidents was 30.75 accidents per million man-hours worked. Severity rate of accidents was 2.196 per million man-hours worked. Incident rate per thousand employees was 73.81. Average number of days lost per accidents was 71.95 days and average duration of man-hours between accidents was 32,516. Mean age of the employees, who met with the accidents were 29.53 years. Share of accidents in the second half of each shift was always more than that in the first half, and this average was 66.66%.

[Ala4]surfactin, a novel isoform from Bacillus subtilis studied by mass and NMR spectroscopies

When Bacillus subtilis S 499 was grown on a culture medium containing L-alanine as nitrogen source, a mixture of surfactins was obtained. Suitable chromatographic conditions allowed the separation of isoforms. Among these compounds, a new variant of surfactin was isolated and its structure was established by chemical and spectrometric methods, especially by NMR spectrometry. It contains a peptide sequence which differs from that of standard surfactin by the replacement of the L-valine residue by L-alanine residue in position 4. The folding mode of [Ala4]surfactin as deduced from NMR results was compared with that of standard surfactin and the structure/properties relationship issuing from the study of this new isoform is discussed.

BamHI restriction fragment length polymorphism (RFLP) at the human GST3 gene locus

A new restriction fragment length polymorphism (RFLP) detected for the human glutathione S-transferase-pi (GST3) gene with the restriction endonuclease, BamHI (GGATCC) is described. Because of the association of GST isozymes with certain human diseases, the data on involvement of different GST loci, their chromosomal location and information on RFLPs are of potential diagnostic value.

The genetic drift of human papillomavirus type 16 is a means of reconstructing prehistoric viral spread and the movement of ancient human populations

We have investigated the diversity of a hypervariable segment of the human papillomavirus type 16 (HPV-16) genome among 301 virus isolates that were collected from 25 different ethnic groups and geographic locations. Altogether, we distinguished 48 different variants that had diversified from one another along five phylogenetic branches. Variants from two of these branches were nearly completely confined to Africa. Variants from a third branch were the only variants identified in Europeans but occurred at lower frequency in all other ethnic groups. A fourth branch was specific for Japanese and Chinese isolates. A small fraction of all isolates from Asia and from indigenous as well as immigrant populations in the Americas formed a fifth branch. Important patterns of HPV-16 phylogeny suggested coevolution of the virus with people of the three major human races, namely, Africans, Caucasians, and East Asians. But several minor patterns are indicative of smaller bottlenecks of viral evolution and spread, which may correlate with the migration of ethnic groups in prehistoric times. The colonization of the Americas by Europeans and Africans is reflected in the composition of their HPV-16 variants. We discuss arguments that today's HPV-16 genomes represent a degree of diversity that evolved over a large time span, probably exceeding 200,000 years, from a precursor genome that may have originated in Africa. The identification of molecular variants is a powerful epidemiological and phylogenetic tool for revealing the ancient spread of papillomaviruses, whose trace through the world has not yet been completely lost.

Human papillomavirus DNA sequences in adenocarcinoma of the uterine cervix in Indian women

BACKGROUND

Infection with human papillomavirus (HPV) is considered to be the principal causal agent in the development of squamous cell carcinoma of the uterine cervix. Although adenocarcinoma of the cervix originates adjacent to the squamous epithelial neoplastic lesions, the etiopathogenesis of adenocarcinoma is not yet clearly understood. Recent studies have raised more controversy, rather than answering the question of whether specific HPV infection also plays a role in the development of adenocarcinoma of the cervix. Molecular DNA hybridization techniques were used to detect HPV types prevalent in both adenocarcinoma and squamous cell carcinoma of the uterine cervix, which is the most common cancer in Indian women.

METHODS

Histologically confirmed, formaldehyde-fixed, paraffin-embedded tissue sections from 12 cases of adenocarcinoma and 30 cases of squamous cell carcinoma of the uterine cervix were analyzed retrospectively for the presence of HPV DNA types 6b, 11, 16, and 18 by both Southern blot hybridization and in situ hybridization.

RESULTS

Of 12 adenocarcinomas, 5 (41.67%) tumors were positive for HPV DNA: All five cases were positive for HPV 16, and two (16.6%) of these were hybridized again to the HPV 18-specific DNA probe. All tumors were negative for HPV 6b and 11. In addition, no biopsy specimens were positive after hybridization with a mixed probe of HPV 31, 33, 35, 39, and 45. These results were compared to those obtained for 30 squamous cell carcinomas of the cervix. Although 20 (66%) were exclusively positive for HPV 16 and 6 (20%), more tumors were of HPV 16 related types as detected under nonstringent conditions of hybridization, only one (3%) was positive for HPV 18. The results of in situ hybridization were found to be in good agreement with those of Southern blotting.

CONCLUSIONS

HPV 16 is the type present almost exclusively in squamous cell carcinoma of Indian women. A higher frequency of HPV 16 in adenocarcinoma of Indian women, in contrast to HPV 18, as reported from other regions, may be attributed to geographic variation rather than to histologic differences only, and both HPV 16 and 18 may be present in adenocarcinoma of the uterine cervix.

Effect of inhibitor of poly (ADP-ribose) polymerase in blood lymphocyte cultures of untreated leprosy patients

Poly (ADP-ribose) polymerase is a cellular repair enzyme synthesised following damage to DNA. 3-Aminobenzamide (3-AB) is an inhibitor of this repair enzyme. To study repair efficiency in leprosy patients, who usually show a significantly higher frequency of spontaneous chromosome aberrations and sister-chromatid exchanges (SCEs), their blood lymphocyte cultures were treated with 3-AB. A marginal increase in the frequency of chromosome aberrations was observed following treatment with 3-AB in controls as well as in patient groups. There was also no significant difference in the frequency of SCEs in control cultures with or without 3-AB. A significant increase in the frequency of SCEs was observed in lymphocyte cultures of paucibacillary (PB) and multibacillary (MB) patients treated with 3-AB when compared with controls. Observation of a significant increase in the frequency of SCEs in 3-AB-treated cultures over the untreated value indicates that DNA damage caused in leprosy patients following mycobacterial infection is not repaired because of the presence of the inhibitor of repair enzyme.

A simple method for elimination of unspecific amplifications in polymerase chain reaction

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Analysis by polymerase chain reaction of the physical state of human papillomavirus type 16 DNA in cervical preneoplastic and neoplastic lesions

Integration of human papillomavirus (HPV) DNA into the host cell genome is believed to be essential for malignant progression. However unambiguous detection of the physical state of HPV is a difficult and time-consuming procedure. To resolve this issue a simple, rapid and highly sensitive technique of polymerase chain reaction (PCR) has been utilized for detecting the physical state of HPV-16 DNA. Investigations were carried out in 122 cervical specimens comprising the whole spectrum of cervical lesions starting from cervical dysplasia to invasive carcinoma including HPV-16-positive normal controls. A pair of oligonucleotide primers specific to the E2 open reading frame, which is often deleted or disrupted following HPV integration, was used for the study. Distinction between episomal and integrated forms of viral DNA was accomplished by detecting amplification of the E2-specific fragment (1139 bp) in the PCR product. The PCR results were compared with those obtained by the conventional methods of Southern blotting, two-dimensional gel electrophoresis and chromosomal in situ hybridization; a high degree of agreement was observed between the methods. The findings indicate that although integrated forms of HPV-16 DNA were detected in more than 70% of cervical cancer specimens, integration was less frequent (23%) in severe dysplasia and carcinoma in situ. Only 2.5% of cases showed both episomal and integrated forms of HPV-16 DNA. The difference between episomal and integrated forms was statistically significant (P less than 0.01). The absence of integration in about 30% of cancer cases suggests that integration of HPV may not be necessary for malignant progression and alternative mechanism(s) of malignant transformation may occur without HPV integration. The PCR test thus provides an effective complement to Southern blotting and two-dimensional gel electrophoresis for accurate detection of the integration of HPV DNA.

A high frequency of human papillomavirus DNA sequences in cervical carcinomas of Indian women as revealed by Southern blot hybridization and polymerase chain reaction

Ninety-six colposcopically directed biopsies from squamous epithelial carcinoma of the uterine cervix and 22 age-matched normal control biopsy specimens were examined by both Southern blot hybridization and polymerase chain reaction (PCR) for the presence of different human papillomavirus (HPV) DNA types. Cancer of the uterine cervix, which is the most common malignant disease in Indian women, showed a high frequency (98%) of HPV as compared to those reported from other parts of the world. HPV type 16 was found to be the dominant (64%) type while the frequency of HPV type 18 was very low (3%). On individual typing of HPV, no biopsy was found to contain any other known HPV types under stringent conditions of hybridization except a single case of HPV type 11. Only one case of double infection with HPV types 16 and 18 was recorded. Under low stringency conditions of hybridization with a mixed probe of HPV types 16 and 18, 29 additional biopsies were found to be positive. Southern blot hybridization alone detected HPV DNA in 92% of the cases but none in the controls. By PCR, six (6.25%) more cases and four (18.18%) healthy women were found to be positive for HPVs. Analysis of the physical state of HPV 16 indicated integration in about 70% of carcinoma cases while 30% of them were in episomal form. The findings suggest that infection with HPV is an important etiologic factor for the development of cervical cancer, that a number of such tumours may arise without HPV infection, and that integration of the viral DNA into host genome is not always essential for malignant progression.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple and rapid method of high quantity DNA isolation from cervical scrapes for detection of human papillomavirus infection

Infection with human papillomavirus (HPV) is an important etiological factor in the development of cervical cancer, and detection of the viral genome is of prognostic importance, particularly for preneoplastic lesions. We developed a simple, easy and efficient non-organic method of DNA extraction from cervical scrapes for reliable detection of HPV DNA sequences. The method involves incubation of cell nuclei in higher concentration of proteinase K at 65 degrees C for 2.5 h. Following prolonged incubation at higher temperature, the enzyme is autoinactivated and the DNA isolated can be used directly for analysis without further purification. The recovery of DNA is more than 95% and it can be easily cleaved by restriction enzymes and is suitable for amplification by the polymerase chain reaction (PCR). The whole procedure is carried out in a single Eppendorf tube and a large number of specimens can be processed at a time without any error of handling. DNA extracted from a single smear sample is sufficient to conduct as many as four different molecular biology tests. This provides an opportunity for verification of sensitivity, specificity and reliability of each test for diagnosis of HPV infection without resorting to biopsy.

Isolation and characterization of a new variant of surfactin, the [Val7]surfactin

Reinvestigation of surfactin, a previously studied peptidolipid surfactant from Bacillus subtilis, by fast-atom-bombardment mass spectrometry and 1H-NMR spectroscopy, as well as by chemical methods, revealed the presence of a closely related second constituent. This new compound, [Val7]surfactin, differs from the known surfactin by the C-terminal amino acid residue which is valine instead of leucine.

Cytogenetic studies in leprosy patients before and after chemotherapy

The frequencies of chromosome aberrations and sister chromatid exchanges (SCEs), cell proliferation kinetics and mitotic indices were studied in peripheral blood lymphocyte cultures of leprosy patients both before and after chemotherapy. The differences in the frequencies of chromosome aberrations and SCEs between controls, paucibacillary and multibacillary patients were found to be statistically highly significant (P less than 0.001). The extent of cytogenetic damage seemed to depend on the severity of the disease. Lymphocytes of untreated leprosy patients showed a low mitotic index and a slow rate of cell proliferation. Following combined treatment with dapsone and rifampicin there was an increase, but to a lesser degree (P less than 0.01), in the frequency of SCEs and chromosome aberrations while the drug combination of dapsone, rifampicin and clofazamine had a nonmutagenic effect on chromosomes of the patient. Furthermore, after drug treatment, the cell proliferation rate and mitotic indices in paucibacillary patients were comparable to that of controls. These results indicate the clastogenic potency of Mycobacterium leprae and the remedial effects that follow therapeutic drug treatment.

Effects of lepromatous leprosy (LL) serum factor(s) on normal blood lymphocytes

To investigate the clastogenic activity of sera from leprosy patients, normal peripheral blood lymphocytes were cultured in both inactivated and noninactivated lepromatous leprosy (LL) sera. An increase in the frequency of chromosome aberrations was observed in normal lymphocyte cultures supplemented with both inactivated (5.2%) and noninactivated (5.0%) LL serum compared to that of cultures supplemented with normal human AB+ serum (2.4%). An enhanced frequency of sister chromatid exchanges (SCEs) was also observed in normal lymphocyte cultures supplemented with both inactivated (8.2 +/- 3.85) (mean +/- S.D.) and noninactivated (8.3 +/- 4.61) LL serum compared to that of controls (6.8 +/- 3.45). The normal blood lymphocyte cultures with LL serum have revealed a slow cell-cycle kinetics at a 48-hr incubation period, but a slightly faster proliferation rate was observed at 72 hr compared to cultures supplemented with normal human AB+ serum, indicating a depressive effect of LL serum on normal blood lymphocyte proliferation. The results obtained from the inactivated LL serum showed that the factor(s) which induce chromosomal damage, depress the mitotic index and the cell proliferation rate were not destroyed at 56 degrees C. These results are the first documentation of cytogenetic effects of LL sera on normal human peripheral blood lymphocytes.

Risk factors related to biological behaviour of precancerous lesions of the uterine cervix

In a study of factors related to cervical carcinogenesis, a cohort of 1,107 cervical dysplasia along with 1,077 controls matched for age and parity were followed up prospectively. During the follow up 75 dysplasia cases progressed to carcinoma in situ. The overall rate of progression of dysplasia to malignancy was observed to be 15.7% at the end of 108 months of follow-up. The analysis of progression rates in relation to various factors revealed significantly higher progression rates for initially higher grade of dysplastic lesions, and early age at consummation of marriage (ACM). The other factors, such as religion, literacy status of the patient, number of pregnancies, presence of cervical erosion, history of fetal loss and positivity to HSV-II antibodies, did not reveal statistical significance. The case-control comparison for detection of HPV 16/18 by in situ hybridisation revealed the presence of HPV 16/18 sequences in 67.3% of the dysplasia subjects progressed to carcinoma in situ while 27.3% of precancerous cases regressed to normalcy. The difference was found to be statistically significant (P less than 0.001).