Human papillomavirus DNA in cervical lesions from Morocco and its implications for cancer control

Degradation of p53 by HPV16-E6 variants isolated from cervical cancer specimens of Moroccan women

Cervical cancer is the second most diagnosed cancer in Moroccan women. The main etiological factor for developing cervical cancer is the persistent infection with HPV16. Genetic studies have reported the occurrence of amino acid variations within the E6 oncoprotein that promotes host cell transformation by targeting p53 for degradation. To verify the biological effects of E6 polymorphisms towards p53 degradation, HPV16-E6 prototype and 7 variants isolated from cervical cancer biopsies of Moroccan women were evaluated for their activities by transient expression assays using pcDNA3.1-E6 constructs in C33A cell line. Expression of E6 genes in transfected cells was detected with reverse transcription PCR (RT-PCR), then, p53 levels were evaluated by western blot analysis. Significant dissimilarities in p53 degradation activities of HPV16-E6 prototype and intratypic variants were noticed. As compared to the prototype, the highest p53 degradation were exhibited by the African variants Af2-a/r, Af1-d/G295 and Af2-a/G285 (p < 0.001), followed by the European variants E- C442/G350 and E-G350/r (p < 0.01), then, the North American variant NA1-b/r (p < 0.05). The inter-variant differences were statistically significant between Af2-a/r variant and the North American variants NA1-b/r and NA1 (p < 0.05). Thus, the Af2-a/r variant was significantly more active in degrading p53 in our in vitro experiments (p < 0.0001). Our findings support the fact that HPV16-E6 variations have a biological impact on degrading p53, and so, represent a significant carcinogenic potential for developing cervical cancer.

[Cervical cancer: Current situation and management in Morocco]

With more than 3300 new cases and almost 2500 deaths each year, cervical cancer (CC) ranks second among female cancers in Moroccan women. The majority of cases occurs in women aged 50 and over. In absence of a national cancer registry, data published in Morocco are limited to the number of cases recorded in some oncology centers, so the incidence of this cancer is likely much higher than estimated. A Moroccan national program against CC based on the practice of visual inspection after application of acetic acid was set up in 2010, allowing both screening and possibly immediate treatment of (pre)cancerous lesions. However, this program has not been implemented in all regions of the country. The CC develops slowly and most often without any symptoms, and so it is diagnosed at an advanced stage of the disease. Virtually, all CC are associated with persistent infection of high risk human papillomavirus (HPV), particularly HPV16 and 18. For more than ten years, two prophylactic vaccines targeting these two HPV genotypes have been marketed. They have proved their excellent immunogenicity and efficacy and they are well tolerated. However, HPV vaccine is not yet recommended by health authorities in Morocco. In this literature review, we focused on the current situation of CC, the prevalence of HPV infection and the prevention strategies against CC in Morocco.

A Meta-Analysis on Human Papillomavirus Type Distribution among Women with Cervical Neoplasia in the WHO Eastern Mediterranean Region

INTRODUCTION

To date, the human papillomavirus (HPV) vaccine has not been integrated into the national vaccination program of most countries of the WHO Eastern Mediterranean Region (EMRO), except for the United Arab Emirates and Libya. The knowledge of HPV genotype distribution in cervical neoplasia is valuable to predict the impact of current HPV vaccines on cancer prevention and can help the health policymakers to select the most appropriate vaccine types in their countries.

METHODS

Hence, this meta-analysis recapitulates all available data on HPV prevalence and genotypes in women with atypical squamous cells of undetermined significance (ASCUS), cervical intraepithelial neoplasia (CIN) I-III or low- and high-grade squamous intraepithelial lesions (LSIL and HSIL, respectively), and invasive cervical cancer (ICC) in EMRO countries.

RESULTS

The meta-analysis included 5,990 cases of cervical precancer and cancer. The overall HPV prevalence was 85.4, 71.3, 59.2, and 34.8% in women with ICC, CIN II-III or HSIL, CIN I or LSIL, and ASCUS, respectively. HPV 16 was the most common genotype followed by HPV 18, representing 58 and 16.5% in ICC cases, respectively.

CONCLUSION

This meta-analysis showed that the introduction of current HPV vaccines into national vaccination programs and the establishment of comprehensive screening programs in EMRO countries is beneficial by preventing 74.5% of cervical neoplasia.

Virus-associated human cancers in Moroccan population: From epidemiology to prospective research

Eight human viruses have been classified by the International Agency for Research on Cancer as carcinogenic or probably carcinogenic for humans. Infection with high risk human papillomaviruses, hepatitis B and C viruses, Epstein-Barr virus (EBV), human T-Cell Lymphotropic Virus Type 1 (HTLV-1), Human herpesvirus 8 (HHV-8), Merkel cell polyomavirus and human immunodeficiency virus-1 (HIV1) alone or in combination with other agents are the main etiologic factors of many cancers. This review highlights some aspects of virus-associated human cancers, potentially responsible for >14,000 malignancies per year in Morocco. Given that not all individuals infected with these viruses develop cancer, somatic alterations, genetic predisposition, and lifestyle or environmental factors obviously play potentializing roles modulating viral activity. These viral, host genetic signatures and lifestyle interactions may represent a reservoir of biomarkers for early detection, prevention of cancer and rationale-based therapy.

[Acceptability of human papilloma virus vaccine: parent survey]

Le but de ce travail est d'évaluer les connaissances des parents des filles en âge de vaccination sur le vaccin anti virus du papillome humain (HPV), leur acceptabilité du vaccin et les facteurs associés au refus. Nous avons mené une enquête auprès des parents de filles âgées de 8 à 15 ans, suivies pour diverses pathologies au service de pédiatrie du CHU Mohamed VI de Marrakech, Maroc, portant sur le profil des parents, leur connaissances sur le cancer du col de l'utérus, l'HPV, et le vaccin anti HPV, l'acceptabilité de vacciner leur filles et les arguments liés au refus. Quatre vingt seize questionnaires ont été inclus dans l'analyse. Le cancer du col est considéré fréquent pour 58% des parents. Seuls 5% connaissaient le vaccin anti HPV. Leur source d'information à tous était les médias. Personne n'avait d'idée sur le coût du vaccin et sa tolérance. Aucune fille n'était vaccinée contre l'HPV. Soixante trois pour cent des parents voudraient bien vacciner leurs filles, ce taux a augmenté à 82% après sensibilisation des parents. Treize pour cent des parents étaient hésitants alors que 24% ont refusé de vacciner pour cause d'effets secondaires majoritairement (51%). Les parents refusant le vaccin étaient en majorité de sexe masculin, de niveau socio-économique et culturel moyen, et ignoraient le virus et le vaccin dans 91% des cas. Cette étude a permis de soulever les éléments de réticences face au vaccin anti HPV afin d'optimiser les stratégies de communication auprès des parents.

Naturally occurring capsid protein variants L1 of human papillomavirus genotype 16 in Morocco

HPV L1 protein is a corner stone in HPV structure, it's involved in the formation of the viral capsid; widely used as a systematic material and considered as the main component in vaccines development and production. The present study aims to characterize genetic variation of L1 gene of HPV 16 specimens and to evaluate in silico the impact of major variants on the epitope change affecting its conformational structure. A fragment of L1 gene from 35 HPV 16 confirmed specimens were amplified by PCR and sequenced. Overall, five amino acids residues changes were reported: T390P in 16 specimens, M425I and M431I in 2 cases, insertion of Serine at 460 and aspartic acid deletion at position 477 in all analyzed cases. The 3D generated model showed that T389P amino acid substitution is located in the H-I loop; the two substitutions M424I and M430I are both located in the H2 helice. The Serine insertion and aspartic acid deletion are located in the H4 helice and B-C loop, respectively. Superimposition of sequences' structures showed that they share a very similar conformation highlighting that the reported amino acids variations don't affect the structure of the L1 protein. However T389P, located in the H-I loop identified as an immunogenetic region of L1 capsid, was reported in 51.4% of cases could interact with vaccines induced monoclonal antibodies suggesting a potential impact on the efficacy of available anti-HPV vaccines.

HPV and cofactors for invasive cervical cancer in Morocco: a multicentre case-control study

Background

Limited national information is available in Morocco on the prevalence and distribution of HPV-sub-types of cervical cancer and the role of other risk factors. The aim was to determine the frequency of HPV-sub-types of cervical cancer in Morocco and investigate risk factors for this disease.

Methods

Between November 2009 and April 2012 a multicentre case-control study was carried out. A total of 144 cases of cervical cancer and 288 age-matched controls were included. Odds-ratios and corresponding confidence-intervals were computed by conditional logistic regression models.

Results

Current HPV infection was detected in 92.5% of cases and 13.9% of controls. HPV16 was the most common type for both cases and controls. Very strong associations between HPV-sub-types and cervical cancer were observed: total-HPV (OR = 39), HPV16 (OR = 49), HPV18 (OR = 31), and multiple infections (OR = 13). Education, high parity, sexual intercourse during menstruation, history of sexually transmitted infections, and husband’s multiple sexual partners were also significantly associated with cervical cancer in the multivariate analysis.

Conclusions

Our results could be used to establish a primary prevention program and to prioritize limited screening to women who have specific characteristics that may put them at an increased risk of cervical cancer.

Human papillomavirus genotypes distribution among Gabonese women with normal cytology and cervical abnormalities

BACKGROUND

Cervical cancer is one of the most common tumors affecting women with a disproportionate mortality occurring in developing countries. Despite the high prevalence of cervical cancer and cervical neoplasia in Gabon, few studies have been performed to evaluate the prevalence and determinants of HPV infection in this country. The aim of this study was to determine the HPV prevalence and distribution in a population of Gabonese women with normal cytology and cervical abnormalities.

METHODS

A total of 200 cervical samples collected in the "Departement d'Anatomie et de Cytologie Pathologiques" of the "Faculté de Medecine et des Sciences de la Santé" in Libreville, Gabonwere analyzed. Cytological status was classified according to Bethesda 2001. Nested polymerase chain reaction (PCR) using consensus degenerate PCR primers (MY09/11 and GP5+/6+) was performed for the detection of HPV DNA and HPV typing was done by DNA sequencing.

RESULTS

Cytological analysis showed that 87 % of women had normal cytology (n = 174/200). Among the 26 women with cytological abnormalities, predominance (61.5 %; 16/26) of low grade squamous intraepithelial lesion (LSIL) was found and no cervical cancer case was detected. Overall, HPV DNA was detected in 60 % of women (120/200). With respect to the cytological status, HPV DNA was found in 57.5 % of women with normal cervix and 76.9 % of women with abnormal cytology. HPV genotyping was performed on 114 HPV positive cases and revealed the presence of 11 distinct genotypes: 16, 18, 33, 31, 56, 6, 66, 70, 35, 45 and 81. The high risk type HPV 16 was the most common genotype found in all cytological categories. Six HPV positive samples could not be typed by DNA sequencing, probably due to multiple HPV infection. Evaluation of possible risk factors showed that HPV infection was related positively with number of sexual partners (≥3, OR = 2.3; 95 % CI, 1.3-4.3), history of sexually transmitted infection (Chlamydia, OR = 1.9; 95 % CI, 1.01-3.4) and marital status (single, OR = 2.0; 95 % CI, 1.1-3.5).

CONCLUSION

The prevalence of HPV infection among Gabonese women is high. Our findings highlight the need to set up a national program to fight cervical cancer, combining Pap smear test and HPV testing, to improve cervical cancer prevention in Gabon.

Analysis of mutations in the E6 oncogene of human papillomavirus 16 in cervical cancer isolates from Moroccan women

BACKGROUND

Worldwide, cervical cancer is the second most common cancer in women. High-risk human papillomavirus (HPV) play a crucial role in the etiology of cervical cancer and the most prevalent genotype is HPV16. HPV 16 intratypic variants have been reported to differ in their prevalence, biological and biochemical properties. The present study was designed to analyze and identify HPV type 16 E6 variants among patients with cervical cancer in Morocco.

METHODS

A total of 103 HPV16 positive samples were isolated from 129 cervical cancer cases, and variant status was subsequently determined by DNA sequencing of the E6 gene.

RESULTS

Isolates from patients were grouped into the European (E), African (Af) and North-American (NA1) phylogenetic clusters with a high prevalence of E lineage (58.3%). The Af and NA1 variants were detected in 31.1% and 11.6% of the HPV16 positive specimens, respectively, whereas, only 3% of cases were prototype E350T. No European-Asian (EA), Asian (As) or Asian-American (AA) variants were observed in our HPV16-positive specimens. At the amino acid level, the most prevalent non-synonymous variants were L83V (T350G), H78Y (C335T), E113D (A442C), Q14D (C143G/G145T) and R10I (G132T), and were observed respectively in 65%, 41.8%, 38.8%, 30.1% and 23.3% of total samples.Moreover, HPV16 European variants were mostly identified in younger women at early clinical diagnosis stages. Whereas, HPV16 Af variants were most likely associated with cervical cancer development in older women with pronounced aggressiveness.

CONCLUSION

This study suggests a predominance of E lineage strains among Moroccan HPV 16 isolates and raises the possibility that HPV16 variants have a preferential role in progression to malignancy and could be associated with the more aggressive nature of cervical cancer.

Molecular detection and genotyping of human papillomavirus in cervical carcinoma biopsies in an area of high incidence of cancer from Moroccan women

Cervical cancer is a leading cause of cancer-related deaths in developing countries, and the human papillomavirus (HPV) is linked etiologically to cervical cancer. Eighty nine cervical carcinoma biopsies collected from women visiting the Oncologic Center in Casablanca (Centre Hospitalier Universitaire Ibn Rochd, Morocco) for cervical cancer symptoms, were screened for HPV DNA by polymerase chain reaction amplification with subsequent typing by hybridization with specific oligonucleotides for HPV types 16, 18, 31, 33, 45, and 59. Using very high stringency hybridization the HPV types could be easily distinguished. After preliminary clinical sorting, 92% (82/89) of the samples were found to be HPV-positive. Among the samples infected by a single HPV, type 16 was the most frequent 36.6% (30/82) of the positive samples, followed by HPV 18; 19.5% (16/82). Double or even multiple infections by the different HPV types were also detected (35.5% of the positive samples); dual infections were the more frequent, with the following combinations of HPVs: HPV16/HPV18 (21% of the positives samples) and HPV16/HPV45 (8.5%).

Prevalence of cervical neoplastic lesions and Human Papilloma Virus infection in Egypt: National Cervical Cancer Screening Project

Background

Data from Egyptian studies provide widely varying estimates on the prevalence of pre-malignant and malignant cervical abnormalities and human papilloma virus (HPVs) infection. To define the prevalence and risk factors of pre-invasive and invasive cervical cancer (cacx), a community based full-scale cross sectional, household survey including 5453 women aged between 35 and 60 years was conducted.

Methods

The study period was between February 2000 and December 2002. Initially, conventional Papanicolaou (Pap) smears were evaluated using the Bethesda system (TBS), followed by colposcopic guided biopsy (CGB) for all epithelial abnormalities (EA). In a third step, HPV was tested on all EA by in-situ hybridization (ISH) using first the broad spectrum HPV probe recognizing HPVs 6, 11, 16, 18, 30, 31, 35, 45, 51 and 52 followed by subtyping with probes 6/11, 16/18 and 31/33. Lastly, unequivocal cases were immunostained for herpes simplex type-2 (HSV-2), cytomegalovirus (CMV), and human immunodeficiency virus (HIV).

Results

EA representing 7.8% (424/5453), were categorized into atypical squamous cell of undetermined significance (ASCUS) (34.4%), atypical glandular cell of undetermined significance (AGCUS) (15.3%), combined ASCUS and AGCUS (3.1%), low grade squamous intraepithelial lesions (SIL) (41.0%), high grade SIL (5.2%) and invasive lesions (1%). CGB of EA (n = 281) showed non neoplastic lesions (12.8%), atypical squamous metaplasia (ASM) (19.2%), cervical intraepithelial neoplasia I (CIN) (44.4%), CIN II (4.4%), CINIII (2.8%), endocervical lesions (5.2%), combined squamous and endocervical lesions (10.0%), invasive squamous cell carcinoma (SCC) (0.02%) and extranodal marginal zone B cell lymphoma (MZBCL) (0.02%). The overall predictive value of cytology was 87% while the predictive value for high grade lesions was 80%. On histological basis, HPVs were present in 94.3% of squamous lesions while it was difficult to be identified in endocervical ones. ISH revealed positivity for pan HPV in 65.9% of the studied biopsies (n = 217), with incorporation of the viral genome HPV 6/11, 16/18 and 31/33 in 11.1%, 33.3% and 17.1% respectively. Multiple HPVs infections were identified in 0.02%.

Conclusion

Pre-invasive high grade lesions and invasive cervical carcinoma represent 0.5% and 0.04% respectively in Egyptian women. HPV mostly 16/18 as a risk factor (p < 0.001), was frequently associated with mixed infections (p < 0.001) and bilharzial infestation (p < 0.001).

High-risk HPV types in Tunisia. A pilot study reveals an unexpectedly high prevalence of types 58 and 82 and lack of HPV 18 among female prostitutes

"High-risk" HPVs (HR-HPV) have sharply different prevalences and there is evidence to suggest this may vary according to regions. Accurate description of HR-HPV circulation is a key feature for the rational design of prevention and screening campaigns. To gain insight into HR-HPV circulation in Tunisia, a pilot study was carried out on 64 healthy prostitutes working in the Tunis area. HPV detection and typing were carried out by MY09/MY11 PCR and restriction fragment length polymorphism (RFLP). A selected set of samples was also assayed by Gp5+/Gp6+ PCR and typed by direct sequencing. Out of 64 women, 28 were HPV positive. HPV-16 and HPV-58, both members of the genus Alpha-Papillomavirus, species 9, accounted for 10 and 7 cases with a prevalence rate of 38% and 27%, respectively. HPV-82, a member of species 5, ranked third with four cases (approximately 15%). Types 31, 33, 35; all members of species 9 were each detected once (approximately 4%) while neither HPV-18 nor related members of species 7 were detected. Type 72 and 83, both members of species 3, were the only low-risk types, each detected only once (4% each). Two samples could not be typed. The prevalence of HPV types appeared sharply different from that of neighboring areas. Should the existence of epidemiological pockets be confirmed by larger, more detailed studies, screening and vaccine campaigns will have to be designed carefully taking into account the actual epidemiological context of the target population.

Cervical carcinoma in Algiers, Algeria: Human papillomavirus and lifestyle risk factors

We conducted a hospital-based case-control study in Algiers, Algeria. A total of 198 cervical carcinoma (CC) cases (including 15 adeno- and adenosquamous carcinomas) and 202 age-matched control women were included. Human papillomavirus (HPV) DNA in cervical cells was evaluated using a PCR assay. Odds ratios and corresponding confidence intervals were computed by means of unconditional multiple logistic regression models. HPV infection was detected in 97.7% of CC cases and 12.4% of control women (OR = 635). Nineteen different HPV types were found. HPV 16 was the most common type in both CC cases and control women, followed by HPV 18 and 45. Twelve types (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 66 and 73) were found as single infections in CC cases. Multiple HPV infections did not show a higher odds ratio for CC than single infections. In addition to HPV infection, husband's extramarital sexual relationships with other women (OR = 4.8) or prostitutes (OR = 3.2), residing in a rural environment for most of one's life (OR = 4.9) and indicators of poor sanitation or poor hygiene were the strongest risk factors for CC. Oral contraceptive use was unrelated to CC risk, while multiparity emerged as a significant risk factor after adjustment for sexual habits. Intrauterine device users showed a lower CC risk than nonusers. The role of major risk factors, except inside toilet, was confirmed in the analysis restricted to HPV-positive women. The distribution of HPV types in CC cases and control women in Algeria is more similar to the one found in Europe than the one in sub-Saharan Africa, where HPV 16 is less prevalent. A vaccine against HPV 16 and 18 may be effective in more than 3/4 of CCs in Algeria.