Adela Carrillo-García

Geographical variation in human papillomavirus prevalence in Mexican women with normal cytology

OBJECTIVE To determine the prevalence of human papillomavirus (HPV) infection and genotype distribution in Mexican women with similar lifestyles from two geographical regions who receive medical care from the Mexican Navy Health System, and to identify the associated sociodemographic and reproductive characteristics. METHODS Cervical swabs from 671 women, beneficiaries of the Mexican Navy Health System, from two distinct southern coast regions of Mexico, were analyzed. Data were obtained regarding sociodemographic variables and sexual and reproductive history. For HPV detection and typing, PCR with general primers and direct sequencing were performed on extracted DNA. Association with clinical variables was evaluated. RESULTS Most patients had a normal cytology or low-grade intraepithelial neoplasia. A high prevalence of HPV was found (43.6%), with a significant difference between the two regions studied from the southwest Pacific coast of Mexico (37.6% in Acapulco, Guerrero vs. 49.7% in Lázaro Cárdenas, Michoacán). Some differences were also found associated to HPV type distribution, particularly related to genotypes 18, 58, and 53. Factors influencing these differences could not be identified with the analysis of typical risk factors linked to the acquisition of an HPV infection. CONCLUSIONS Regional differences in HPV prevalence and distribution show an apparent geographic boundary between the studied populations that deserves further analysis, taking into account other factors such as those related to the sexual partners.

Impact of human papillomavirus coinfections on the risk of high-grade squamous intraepithelial lesion and cervical cancer.

OBJECTIVE The molecular and epidemiologic effect of human papillomavirus (HPV) coinfections in the risk of developing cervical cancer is yet unclear. The aim of this study was to determine the frequency HPV coinfections at different stages of cervical lesions in the development of cervical cancer and the impact of HPV specific type interactions on high-grade squamous intraepithelial lesions (HSIL) and invasive cervical cancer (ICC) risk. METHODS HPV testing was performed in 931 cervical samples diagnosed as: negative for intraepithelial lesion or malignancy (NILM); low-grade squamous intraepithelial lesion (LSIL); HSIL; and ICC. For HPV detection and typing two sets of primers from the L1 region were used in the polymerase chain reaction method (PCR) (MY09/MY11/HMB01 and L1C1/L1C2.1/L1C2.2) and HPV type was determined by PCR product sequence. To look for multiple HPV infections, the E6 nested multiplex PCR method was performed in all DNA samples. Odds ratios were calculated as indexes of the strength of the association between the sample category (LSIL/NILM or ICC/HSIL) and the presence of a given viral combination. RESULTS In HPV positive samples, coinfections are as common in ICC/HSIL as in LSIL/NILM (47.12% and 40.17%, respectively). There is an increased risk to ICC/HSIL when multiple high-risk HPV types are present. The coinfection of HPV68 with HPV16 increases the risk of ICC/HSIL (OR=14.54, P=0.012, after multivariate adjustment), related to the presence of HPV16 or HPV68 alone. CONCLUSIONS These results sustain that specific HPV coinfections confer an increased risk to develop ICC/HSIL.

High-risk human papillomavirus (HPV) DNA sequences in metaplastic breast carcinomas of Mexican women

BackgroundMetaplastic carcinoma, an uncommon subtype of breast cancer, is part of the spectrum of basal-like, triple receptor-negative breast carcinomas. The present study examined 20 surgical specimens of metaplastic breast carcinomas, for the presence of high-risk Human papillomavirus (HPV), which is suspected to be a potential carcinogenic agent for breast carcinoma.MethodsMastectomy specimens from patients harboring metaplastic breast carcinoma, as defined by the World Health Organization (WHO), and who attended the Instituto Nacional de Cancerologia in Mexico City, were retrieved from the files of the Department of Pathology accumulated during a 16-year period (1995–2008). Demographic and clinical information was obtained from patients’ medical records. DNA was extracted from formalin-fixed, paraffin-embedded tumors and HPV type-specific amplification was performed by means of Polymerase chain reaction (PCR). Quantitative Real-time (RT) PCR was conducted in HPV positive cases. Statistically, the association of continuous or categorical variables with HPV status was tested by the Student t, the Chi square, or Fisher’s exact tests, as appropriate.ResultsHigh-risk HPV DNA was detected in eight (40%) of 20 metaplastic breast carcinomas: seven (87.5%) HPV-16 and one (12.5%) HPV-18. Mean age of patients with HPV-positive cases was 49 years (range 24–72 years), the same as for HPV-negative cases (range, 30–73 years). There were not striking differences between HPV + and HPV– metaplastic carcinomas regarding clinical findings. Nearly all cases were negative for estrogen, progesterone and Human epidermal growth factor receptor 2 (HER2), but positive for Epidermal growth factor receptor (EGFR).ConclusionsHigh-risk HPV has been strongly associated with conventional breast carcinomas, although the subtle mechanism of neoplastic transformation is poorly understood. In Mexican patients, the prevalence of HPV infection among metaplastic breast carcinomas is higher than in non-metaplastic ones, as so the HPV viral loads; notwithstanding, HPV viral loads show wide variation and remain even lower than cervical and other non-cervical carcinomas, making it difficult to assume that HPV could play a key role in breast carcinogenesis. Further studies are warranted to elucidate the meaning of the presence of high-risk HPVDNA in breast carcinomas.

KCNH1 potassium channels are expressed in cervical cytologies from pregnant patients and are regulated by progesterone

Potassium voltage-gated channel, subfamily H (eag-related), member 1 (KCNH1) potassium channels are potential tumour markers and cancer therapeutic targets and are up-regulated by oestrogens and human papilloma virus (HPV) oncogenes. However, the role of KCNH1 in normal tissues is poorly understood, and its expression in pregnancy is unknown. We wondered whether KCNH1 channels are expressed in cervical cells from pregnant patients and whether progesterone (P4) regulates KCNH1. The association with HPV was also investigated. KCNH1 protein expression was studied by immunocytochemistry in liquid-based cervical cytologies; 93 samples were obtained from pregnant patients at different trimesters, and 15 samples were obtained from non-pregnant women (controls). The presence of HPV was studied by PCR with direct sequencing and nested multiplex PCR. HeLa cervical cancer cells were transfected with human progesterone receptor-B (PR-B) and treated with P4. KCNH1 mRNA expression in these cultures was studied by real-time PCR. KCNH1 protein was detected in 100% of the pregnancy samples and in 26% of the controls. We found 18 pregnant patients infected with HPV and detected 14 types of HPV. There was no association between the percentage of cells expressing KCNH1 and either the presence or type of HPV. P4 induced KCNH1 mRNA and protein expression in cells transfected with human PR-B. No regulation of KCNH1 by P4 was observed in non-transfected cells. We show for the first time the expression of an ion channel during human pregnancy at different trimesters and KCNH1 regulation by P4 in human cells. These data raise a new research field for KCNH1 channels in human tissues.

Frequency and genotype distribution of multiple human papillomavirus infections in cancer of the head and neck in a Mexican population.

OBJECTIVE The aim of this study was to determine the frequency and genotype distribution of single and multiple human papillomavirus (HPV) infections in head and neck squamous cell carcinomas (HNSCCs) in a Mexican population and to assess their associations with smoking and drinking habits and clinicopathologic characteristics. STUDY DESIGN A cross-sectional study was performed on a sample of patients diagnosed with HNSCCs. Tumor DNA was amplified using polymerase chain reaction with HPV consensus and multiplex primers. The associations among HPV status, survival, and clinical characteristics were analyzed. RESULTS Sixteen of the 43 HNSCCs were HPV positive. HPV16 was the most prevalent type, with single infections present in 5 cases, whereas another 5 cases were combined with HPV56 infection. There was a significant association between HPV infection and oropharyngeal cancers. HPV positivity was associated with overall survival at a nearly significant P level of 0.06. CONCLUSIONS Our data support the importance of HPV infection in oropharyngeal cancer, with a trend toward higher survival in HPV-positive cases.

SOX2 as a new regulator of HPV16 transcription

Persistent infections with high-risk human papillomavirus (HPV) constitute the main risk factor for cervical cancer development. HPV16 is the most frequent type associated to squamous cell carcinomas (SCC), followed by HPV18. The long control region (LCR) in the HPV genome contains the replication origin and sequences recognized by cellular transcription factors (TFs) controlling viral transcription. Altered expression of E6 and E7 viral oncogenes, modulated by the LCR, causes modifications in cellular pathways such as proliferation, leading to malignant transformation. The aim of this study was to identify specific TFs that could contribute to the modulation of high-risk HPV transcriptional activity, related to the cellular histological origin. We identified sex determining region Y (SRY)-box 2 (SOX2) response elements present in HPV16-LCR. SOX2 binding to the LCR was demonstrated by in vivo and in vitro assays. The overexpression of this TF repressed HPV16-LCR transcriptional activity, as shown through reporter plasmid assays and by the down-regulation of endogenous HPV oncogenes. Site-directed mutagenesis revealed that three putative SOX2 binding sites are involved in the repression of the LCR activity. We propose that SOX2 acts as a transcriptional repressor of HPV16-LCR, decreasing the expression of E6 and E7 oncogenes in a SCC context.

Type‐specific persistence and clearance rates of HPV genotypes in the oral and oropharyngeal mucosa in an HIV / AIDS cohort

BACKGROUND Oral high-risk human papillomavirus (HR-HPV) infections are frequent and persistent among the HIV-positive population and are associated with an increased risk for head and neck cancer (HNC). In this study, we sought to determine the incidence, persistence and clearance of HPV infections in oral and oropharyngeal samples from HIV/AIDS subjects. METHODS A longitudinal, observational and analytical study was performed with an ongoing cohort of HIV/AIDS subjects in Mexico City (September 2013-February 2015). The study was approved by institutional committees, and demographic and clinical data were registered. At the baseline and three-month visits, oral examinations and cytobrush samples were obtained. DNA was purified, quantified and used to detect an HPV-L1 gene fragment by nested PCR, using MY09/MY11 and GP5 + /GP6 + primers. HPV DNA products were purified, sequenced and typed according to HPV databases. Risk factors were assessed, and a multivariate modelling approach was used to determine independent effects. RESULTS This study included 97 HIV/AIDS individuals (91% men [86.4% of which are men who have sex with men], median age: 36 years, 72.2% under HAART). From the baseline visit, HPV was observed in 55.7% (HR-HPV: 26.8%; HPV-18: 24.1%), with a higher HPV-positive samples for smokers (61.1 vs 32.6%, P = .005). The three-month overall HPV incidence was 33.9%; type-specific HPV persistence was 33.3% (HR-HPV: 13.3%); and 13 of the 33 (39.4%) baseline HPV-positive individuals cleared the infection (HR-HPV: 53.8%). CONCLUSIONS Although HR-HPV persistence was low, and clearance of the infection was observed in most cases, a close follow-up is necessary, given the increase in HNC among HIV-subjects, particularly HPV-related cancer.

Regulation of Cellular Metabolism by High-Risk Human Papillomaviruses

The alteration of glucose metabolism is one of the first biochemical characteristics associated with cancer cells since most of these cells increase glucose consumption and glycolytic rates even in the presence of oxygen, which has been called “aerobic glycolysis” or the Warburg effect. Human papillomavirus (HPV) is associated with approximately 5% of all human cancers worldwide, principally to cervical cancer. E6 and E7 are the main viral oncoproteins which are required to preserve the malignant phenotype. These viral proteins regulate the cell cycle through their interaction with tumor suppressor proteins p53 and pRB, respectively. Together with the viral proteins E5 and E2, E6 and E7 can favor the Warburg effect and contribute to radio- and chemoresistance through the increase in the activity of glycolytic enzymes, as well as the inhibition of the Krebs cycle and the respiratory chain. These processes lead to a fast production of ATP obtained by Warburg, which could help satisfy the high energy demands of cancer cells during proliferation. In this way HPV proteins could promote cancer hallmarks. However, it is also possible that during an early HPV infection, the Warburg effect could help in the achievement of an efficient viral replication.