Inhibitors of epidermal growth factor receptor kinase and of cyclin-dependent kinase 2 activation induce growth arrest, differentiation, and apoptosis of human papilloma virus 16-immortalized human keratinocytes.

Human papilloma virus 16 (HPV 16) is associated with cervical cancer and is therefore considered a major health risk for women. Immortalization of keratinocytes induced by HPV infection is largely due to the binding of p53 and Rb by the the viral oncoproteins E6 and E7, respectively, and is driven to a large extent by a transforming growth factor alpha/amphiregulin epidermal growth factor receptor autocrine loop. In this study, we show that the growth of HPV 16-immortalized human keratinocytes can be blocked by a selective epidermal growth factor receptor kinase inhibitor, AG 1478, and by AG 555, a blocker of cyclin-dependent kinase 2 (Cdk2) activation. AG 1478 induces a massive increase in the Cdk2 protein inhibitors p27 and p21, whereas AG 555 appears to have a different mechanism of action, inhibiting the activation of Cdk2. Growth arrest induced by AG 1478 and AG 555 is accompanied by up to 20% of cells undergoing apoptosis. Following AG 1478 treatment but not AG 555 treatment, up to 50% of cells undergo terminal keratinocyte differentiation as determined by filaggrin expression and by the decline in the expression of cytokeratin 14. The growth-arresting properties of AG 1478 and AG 555 identifies them as possible lead antipapilloma agents.

Monopaternal superfecundation of quintuplets after transfer of two embryos in an in vitro fertilization cycle.

OBJECTIVE: To present the first genetically proven identity of quintuplets in an IVF treatment cycle after transferring only two embryos. DESIGN: Case report. SETTING: IVF unit and obstetrics department of university-affiliated general hospital. PATIENT(S): Twenty-five-year-old patient undergoing IVF treatment for unexplained infertility. INTERVENTION(S): In vitro fertilization with intracytoplasmic sperm injection performed on 50% of oocytes, resulting in successful production of nine early-cleavage embryos. Transfer of two embryos on day 3 and freezing of the remaining embryos. MAIN OUTCOME MEASURE(S): Development of five separate embryonic sacs. Fetal reduction of three embryos at 12 weeks of gestation. RESULT(S): Successful completion of the twin pregnancy and full genetic analysis of the three embryos and the twins that were born at term. CONCLUSION(S): Despite transferring only two embryos, superfecundation occurred, resulting in five embryos. Genetic analysis can be used to determine paternity and identity of all the embryos.

Differential cooperation of a carcinogen with human papillomavirus type 6 and 16 DNAs in in vitro oncogenic transformation.

In contrast to the strong association of human papillomavirus (HPV) type 16 with genital malignancies, HPV 6 has been found essentially in benign genital lesions. In these studies we show that HPV type 6 and 16 DNAs behave differently also in their ability to transform NIH 3T3 cells in cooperation with the carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Although we could show that both HPV-6- and HPV-16-transfected genomes were integrated and expressed in NIH 3T3 cells, only the NIH 3T3 cells which contained the HPV 16 genome became fully transformed after MNNG treatment, as assessed by their ability to form colonies in soft agar and to induce tumors in nude mice. NIH 3T3 cells containing the HPV 6 genome and treated with MNNG did not show this potential. Furthermore, we could detect an increased expression of the E7 gene of HPV 16 in the carcinogen-treated cells containing the HPV 16 genome. These studies indicate that the presence of the HPV 16 genome specifically is also an essential step to in vitro cellular transformation.

Oestrogen stimulates differential transcription of human papillomavirus type 16 in SiHa cervical carcinoma cells.

Human papillomavirus (HPV) type 16 is highly associated with cervical cancer, but it seems that cofactors such as hormones affect its potential oncogenicity. We have analysed the HPV-16 gene expression in response to sex hormones and glucocorticoids in SiHa cells, a human cervical carcinoma cell line. An eightfold induction of HPV-16 transcripts was obtained in oestrogen-treated SiHa cells. Of the five HPV-16 transcripts detected in these cells only the two major ones, the 4.6 kb and the 4.1 kb mRNA species, were affected by oestrogen. Since the five transcripts span the E6 and E7 open reading frames of the HPV-16 genome, these results suggest that the expression of the various transcripts is differentially controlled, as oestrogen regulates only two of them. We have identified in the HPV-16 genome seven different regions with a high degree of similarity to the oestrogen-responsive element consensus sequence (GGTCANNNTGACC). These sequences are located throughout the entire HPV-16 genome. Progesterone or dexamethasone had no detectable stimulatory effect on the various transcripts of HPV-16 in SiHa cells, up to 24 h after treatment of the cells. Since the E6 and E7 open reading frames have been associated with the oncogenic potential of HPV-16, the effect of oestrogen on the transcription of these viral genes may be of biological relevance in the malignant transformation of HPV-16-infected cervical cells.

Sector retinitis pigmentosa: a fluorescein angiographic study.

Flourescein angiography has been proved to be of value in the study of the chorioretinal abnormaliteis in sector retinitis pigmentosa. The findings from two patients, one being in an early and the other in a more advanced stage were analyzed. The pigment epithelium was found to be disturbed in a larger area than visible by ophthalmoscopy. In the impaired quadrant the retinal vessels were narrowed showing delayed and slow dye transit. Through the discolorated pigment epithelium leaky choriocapillaries were disclosed. Moreover, in the severly affected patient, areas missing choriocapillar perfusion and retinal circulation were also detected.

Papillomaviruses in lesions of the lower genital tract in Israeli patients.

Human papillomaviruses (HPVs) have been strongly associated with benign lesions of the genital tract (condylomata) and with genital cancer of the vulva and cervix. Since the incidence of these lesions in Israel is considered to be low, we have studied the presence of HPV 6, 11, 16 and 18 DNAs in benign, premalignant and malignant tissue samples or gynecological swabs of the lower genital tract. HPV sequences were detected in 48 out of 66 condylomatous lesions (72%), 5/11 grades I-II intraepithelial neoplasia (45%), 4/6 grade III intraepithelial neoplasia (carcinoma in situ) (66.6%) and 8/22 invasive carcinoma (36%). The latter included six cases of vulvar carcinoma which were all negative for HPV sequences. No additional HPV types could be detected in any of the tissue biopsies examined. HPV 18 DNA has been found in one vulvar condyloma where it persisted as an episomal molecule, this being the first report of that specific viral DNA in a condylomatous lesion. In all the benign and premalignant lesions containing HPV, the viral sequences were maintained in an episomal state. In two cases of invasive carcinoma, the HPV 16/18 related sequences were integrated in the cellular genome, but in five cases (three containing HPV 16/18 related DNAs and two containing HPV 6/11 related DNAs) the viral sequences were episomal. HPV 16/18 related sequences detected in one out of three cases of vaginal carcinoma were also found to be episomal. This data indicates that human papillomavirus sequences are indeed found in genital lesions of Israeli patients, although to a lesser extent than in other countries, especially for benign lesions and invasive carcinomas. Although HPVs may have a causative role in the development of genital lesions, also in this low tumor incidence area, other factors should be also considered in the etiology of these lesions.

Simultaneous detection of three common sexually transmitted agents by polymerase chain reaction.

OBJECTIVE: Human papillomaviruses, herpes simplex viruses, and Chlamydia trachomatis are very common infections of the genital tract. The purpose of our study was to develop a polymerase chain reaction-based assay for the simultaneous detection of these organisms from a single genital swab. STUDY DESIGN: To prove the technical feasibility of a simultaneous polymerase chain reaction assay for these organisms, a mixture of deoxyribonucleic acids extracted from cells infected by these three agents was amplified in the same tube with three different sets of primers corresponding to specific regions of the human papillomavirus genome, the herpes simplex virus 1 and 2 genomes, and the Chlamydia trachomatis plasmid, respectively. Then genital swabs from patients with suspected infection by one or more of these agents were assayed by polymerase chain reaction for the presence of herpes simplex virus, human papillomavirus, and Chlamydia trachomatis independently and simultaneously. Most of the samples were analyzed in parallel by other methods: herpes simplex virus by culture., Chlamydia trachomatis by culture and antigen staining, and human papillomavirus by the filter in situ hybridization method. RESULTS: Analysis of the polymerase chain reaction products amplified from the deoxyribonucleic acid mixture revealed three bands corresponding to the respective amplified region of each microorganism. A total of 391 genital swabs were assayed independently by polymerase chain reaction for the presence of herpes simplex virus (113 samples), human papillomavirus (200 samples), and Chlamydia trachomatis (78 genital swabs and four urethral swabs). Forty-nine were herpes simplex virus positive (47 by culture), 45 were human papillomavirus positive (43 by filter in situ hybridization), and one sample was positive for Chlamydia trachomatis, both by polymerase chain reaction and by culture. Ninety-two of the 391 samples were analyzed simultaneously by polymerase chain reaction for the presence of the three agents. The correlation between the results obtained independently and simultaneously was of the order of 100%: 29 were positive for herpes simplex virus, 16 were positive for human papillomavirus, and one was positive for Chlamydia trachomatis, in one sample we could detect both human papillomavirus and herpes simplex virus. CONCLUSIONS: The polymerase chain reaction simultaneous assay is a quick and efficient way of detecting herpes simplex virus, human papillomavirus, and Chlamydia trachomatis from a single genital swab. This method can greatly simplify the diagnostic procedures in the laboratory.

Lupus miliaris disseminatus faciei--the DNA of Mycobacterium tuberculosis is not detectable in active lesions by polymerase chain reaction.

There has been a controversy as to the origin of lupus miliaris disseminatus faciei (LMDF). It was originally thought to be associated with tuberculosis, due to its histopathological similarity. Recently, this association has been doubted, although there remain reported cases of LMDF associated with Mycobacterium tuberculosis. Three patients with the clinical and histopathological features of LMDF are described. Skin from these patients was analysed by polymerase chain reaction (PCR) using two different oligoprimers for the detection of 123 bp and 165 bp DNA fragments specific for M. tuberculosis complex. With these two PCR systems, no M. tuberculosis DNA was detected in any of the LMDF patients. It was present in all positive controls and absent in all negative controls. In this study we could not demonstrate an association between LMDF and tuberculosis.

Tyrphostins that suppress the growth of human papilloma virus 16-immortalized human keratinocytes.

Human papilloma virus 16 (HPV16) is considered to be the causative agent for cervical cancer, which ranks second to breast cancer in women's malignancies. In an attempt to develop drugs that inhibit the malignant transformation of HPV16-immortalized epithelial cells, we examined the effect of tyrphostins on such cells. We examined the effect of tyrphostins from four different families on the growth of HPV16-immortalized human keratinocytes (HF-1) cells. We found that they alter their cell cycle distribution, their morphology, and induce cell death by apoptosis. The effects of tyrphostins on HF-1 cells are different from their effects on normal keratinocytes. Growth suppression by AG555 and AG1478 is accompanied by 30% apoptosis in HF-1 cells, but this is not observed in normal keratinocytes. Tyrphostin treatment produces distinctive morphological changes in HF-1 cells and in normal keratinocytes; however, the culture organization of normal keratinocytes is less disrupted. These differential effects of the tyrphostins on HPV16-immortalized keratinocytes compared with their effects on normal keratinocytes suggests that these compounds are suitable candidates for the treatment of papilloma. Previous and present results indicate that group 1 tyrphostins, which inhibit Cdk2 activation, and group 2 tyrphostins, represented by AG1478, a potent epidermal growth factor receptor kinase inhibitor, induce cell cycle arrest; and, in the case of HF-1 cells, apoptosis and differentiation. Cells accumulate in the G(1) phase of the cell cycle at the expense of S and G(2) + M. These compounds block the growth of normal keratinocytes without inducing apoptosis or differentiation, causing them to accumulate in G(1). AG17, which belongs to group 4, exerts its antiproliferative effect mainly by increasing the fractions of cells in G(1) with a concomitant decrease in the fraction of cells in S and G(2) + M.