Posttreatment monitoring by ASCL1/LHX8 methylation analysis in women with HIV treated for cervical intraepithelial neoplasia grade 2/3

OBJECTIVE

Women with HIV (WWH) have an increased risk to develop recurrent cervical intraepithelial neoplasia grade 2/3 (rCIN2/3) after treatment compared with HIV-negative women. Therefore, appropriate posttreatment monitoring of WWH is important. This study evaluates the performance of ASCL1 and LHX8 methylation analysis as posttreatment monitoring test in WWH treated for CIN2/3, as alternative to cytology or human papillomavirus (HPV) as follow-up test.

DESIGN

Prospective observational cohort study.

METHODS

WWH treated for CIN2/3 by large loop excision of the transformation zone (LLETZ) (n  = 61) were invited for follow-up study visits at 1, 2.5 and 4 years after baseline. Baseline and follow-up cervical scrapes were tested for cytology, HPV and DNA methylation of ASCL1 and LHX8 genes. The performance of these strategies for the detection of rCIN2/3 was evaluated in the first follow-up cervical scrape.

RESULTS

Thirteen (21.3%) rCIN2/3 lesions were detected within 4 years of follow-up. In women without rCIN2/3 in follow-up, methylation levels of ASCL1 and LHX8 decreased significantly after LLETZ treatment (P  = 0.02 and 0.007, respectively). In women with rCIN2/3, methylation levels remained high after LLETZ treatment. The 4-year rCIN2/3 risk was 4.9% (95% CI: 0.6-16.5) for ASCL1/LHX8-negative women, 8.1% (95% CI: 1.7-21.9) for HPV-negative women and 7.7% (95% CI: 2.1-18.5) for cytology-negative women.

CONCLUSION

A negative ASCL1/LHX8 methylation test in follow-up is associated with a low rCIN2/3 risk and could serve as an objective test of cure and well tolerated alternative for HPV and/or cytology screening in the posttreatment monitoring of WWH.

Risk factors associated with HPV persistence after conization in high-grade squamous intraepithelial lesion

OBJECTIVE

Persistence of HPV infection in patients with high-grade squamous intraepithelial lesion (HSIL) undergoing cervical excision is considered strongly associated with the recurrence and progression of cervical dysplasia. This study aims to review potential risk factors for persistence of HPV infection in patients with HSIL, thus optimizing the postoperative monitoring program and clinical treatment.

METHODS

Through literature review, published data about estimated prognostic risk factors for persistence of HPV infection in patients with HSIL after conization within two decades were searched and analyzed, and their references were manually reviewed as well.

RESULTS

Women with persistence of HPV infection after cervical excision were at an extremely high risk of disease recurrence and progression to cervical cancer. Some clinicopathological and even physiological elements involving viral, organic human body and treatment factors, such as human papillomavirus (HPV) 16, high viral load, age older than 50 years and positive surgical margin were of prognostic significance in persistent HPV infection in patients with HSIL, yet some of which still remained controversial.

CONCLUSIONS

Monitoring prognostic factors in women with persistence of HPV infection who have underwent cervical excision for HSIL are of great significance, especially the follow-up within 2 years postoperatively, which significantly improves the clinical outcome.

SOX1 Promoter Hypermethylation as a Potential Biomarker for High-Grade Squamous Intraepithelial Neoplasia Lesion and Cervical Carcinoma: A Meta-Analysis With Trial Sequential Analysis

Background: DNA methylation has been widely assessed as a potential biomarker for the early detection of cervical cancer (CC). Herein, we assessed the associations of SOX1 promoter hypermethylation with squamous intraepithelial lesion and CC.

Methods: Published studies and genome-wide methylation datasets were searched from electronic databases (up to April 2019). The associations of SOX1 hypermethylation with high-grade squamous intraepithelial lesion (HSIL) and CC risks were evaluated by odds ratios (ORs) and 95% confidence intervals (CIs). The summary receiver operator characteristic test was used to assess the diagnostic value of the SOX1 promoter hypermethylation of CC and intraepithelial neoplasia type III or worse (CIN3+). Trial sequential analysis (TSA) was performed to evaluate the stability of results and estimate the required information size (RIS).

Results: In this meta-analysis of 17 published studies, the SOX1 methylation rates increased among low-grade SIL (LSIL, 27.27%), HSIL (40.75%), and CC (84.56%) specimens. Compared with control specimens, SOX1 promoter hypermethylation progressively increased the risk of HSIL by 4.20-fold (p < 0.001) and CC by 41.26-fold (p < 0.001). The pooled sensitivity of SOX1 methylation was estimated to be 0.85 (95% CI: 0.81–0.88) in differentiating patients with CC, corresponding to a specificity of 0.72 (95% CI: 0.69–0.75) and an area under the curve (AUC) of 0.93. Furthermore, the pooled sensitivity of SOX1 methylation was estimated to be 0.75 (95% CI: 0.72–0.78) in differentiating patients with CIN3+, corresponding to a specificity of 0.71 (95% CI: 0.69–0.73) and an AUC of 0.84. The pooled results of TCGA and GEO datasets showed that all CpG sites in SOX1 were associated with CC and 16 of 19 CpG sites were associated with HSIL. The results of TSA illustrated that the size was sufficient and significant associations were observed.

Conclusion: This meta-analysis indicated that SOX1 promoter hypermethylation might have a potential value in the clinical diagnosis of CC and CIN3+.

A novel miRNA identified in GRSF1 complex drives the metastasis via the PIK3R3/AKT/NF-κB and TIMP3/MMP9 pathways in cervical cancer cells

microRNAs (miRNAs) play an important role in carcinogenesis. Typically, miRNAs downregulate the target expression by binding to the 3′ UTR of mRNAs. However, recent studies have demonstrated that miRNAs can upregulate target gene expression, but its mechanism is not fully understood. We previously found that G-rich RNA sequence binding protein (GRSF1) mediates upregulation of miR-346 on hTERT gene. To explore whether GRSF1 mediate other miRNA’s upregulation on their target genes, we obtained profile of GRSF1-bound miRNAs by Flag-GRSF1-RIP-deep sequencing and found 12 novel miRNAs, named miR-G. In this study, we focused on miR-G-10, which is highly expressed in cervical cancer tissues and cell lines and serum from patients with metastatic cervical cancer. miR-G-10 in cervical cancer cells significantly promoted migration/invasion and anoikis resistance in vitro and lung metastasis in vivo. Furthermore, miR-G-10 bound to the 3′ UTR of PIK3R3 and upregulated its expression to activate the AKT/NF-κB signal pathway in a GRSF1-dependent manner, whereas miR-G-10 suppressed TIMP3 in the AGO2 complex to modulate the MMP9 signaling pathway in cervical cancer cells. Taken together, our findings may provide a new insight into the upregulation mechanism mediated by miRNAs and a potential biomarker for cervical cancer.

Predicting cervical intraepithelial neoplasia recurrence in HIV-infected and -noninfected women by detecting aberrant promoter methylation in the CDH1, TIMP3, and MGMT genes

PURPOSE

Aberrant DNA methylation is present in virtually all types of human cancer. There is no clear evidence that methylation status can predict bad prognosis in patients with CIN recurrence in HIV infected. This study evaluates the relationship between aberrant methylation of CpG islands of CDH1, TIMP3 and MGMT genes and CIN recurrence in HIV-infected and -noninfected women.

METHODS

This is a nested case-control study involving 33 cases with CIN recurrence and 114 controls without recurrence, HIV infected and noninfected, treated with LEEP, between 1999 and 2004. Recurrence diagnosis was established after biopsy. Genes methylation profile was assessed by MSP-PCR technique in formalin-fixed, paraffin-embedded cone specimens. Statistical analysis was performed to compare categorical variables, using χ² test with Yates correction and Fisher's exact test. Multivariate analysis was carried out using logistic regression.

RESULTS

CIN recurrence was more frequent in women with glandular involvement (OR 11.6; 95% CI 2.93-45.89) and compromised surgical margins (OR 2.5; 95% CI 0.87-7.27) in the cervical cone and in HIV-infected women (OR 2.47; 95% CI 0.87-7.05). One methylated allele of CDH1, TIMP3 and MGMT genes was present in 87.9% women with CIN recurrence. Promoter hypermethylation of TIMP3 and MGMT was detected in women with CIN recurrence and without CIN recurrence independent of HIV infection with significant difference between groups (p = 0.04 and p = 0.02, respectively).

CONCLUSIONS

CIN recurrence was associated with glandular involvement and compromised margins in cone biopsy and HIV infection. The presence of CpG islands hemimethylation in TIMP3 and MGMT genes is a promising triage method in CIN recurrence.

Modulation of DNA methylation by human papillomavirus E6 and E7 oncoproteins in cervical cancer

Human papillomaviruses (HPVs) are double stranded circular DNA viruses that infect cutaneous and mucosal epithelial cells. Almost 99% of cervical cancer has a HPV infection. The early oncoproteins E6 and E7 are important in this cellular transformation process. Epigenetic mechanisms have long been known to result in decisive alterations in DNA, leading to alterations in DNA-protein interactions, alterations in chromatin structure and compaction and significant alterations in gene expression. The enzymes responsible for these epigenetic modifications are DNA methyl transferases (DNMTs), histone acetylases and deacetylases. Epigenetics has an important role in cancer development by modifying the cellular micro environment. In this review, the authors discuss the role of HPV oncoproteins E6 and E7 in modulating the epigenetic mechanisms inside the host cell. The oncoproteins induce the expression of DNMTs which lead to aberrant DNA methylations and disruption of the normal epigenetic processes. The E7 oncoprotein may additionally directly bind and induce methyl transferase activity of the enzyme. These modulations lead to altered gene expression levels, particularly the genes involved in apoptosis, cell cycle and cell adhesion. In addition, the present review discusses how epigenetic mechanisms may be targeted for possible therapeutic interventions for HPV mediated cervical cancer.

Upregulation of retinoic acid receptor-β reverses drug resistance in cholangiocarcinoma cells by enhancing susceptibility to apoptosis

Retinoic acid receptor β (RARβ), a known tumor suppressor gene, is frequently silenced in numerous malignant types of tumor. Recent reports have demonstrated that loss of RARβ expression may be responsible, in part, for the drug resistance observed in clinical trials. However, little is known about the role of RARβ in regulating drug sensitivity in patients with cholangiocarcinoma (CCA) with a high risk of mortality and poor outcomes. In the present study, low RARβ expression was observed in the majority of CCA tissues investigated (28/33, 84.8%). In addition, the CCA cell line QBC939, which exhibits low RARβ expression, was found to be significantly resistant to chemotherapeutic agents compared with SK-ChA-1, MZ-ChA-1 and Hccc9810 CCA cell lines, which exhibit high RARβ expression. Furthermore, upregulation of RARβ significantly enhanced the sensitivity of QBC939 cells to common chemotherapeutic agents both in vitro and in vivo. Upregulation of RARβ was shown to increase the expression of proapoptotic genes bax, bak and bim, in addition to caspase-3 activity, and decrease the expression of antiapoptotic genes bcl-2, bcl-xL and mcl-1. As a result, CCA cells were more susceptible to caspase-dependent apoptosis. Taken together, these data suggest that RARβ upregulation rendered CCA cells more sensitive to chemotherapeutic agents by increasing the susceptibility of cells to caspase-dependent apoptosis. These results support the hypothesis that RARβ may be an ideal chemosensitization target for the treatment of patients with drug-resistant CCA.

Novel epigenetic changes in CDKN2A are associated with progression of cervical intraepithelial neoplasia

OBJECTIVE

To conduct a comprehensive mapping of the genomic DNA methylation in CDKN2A, which codes for the p16(INK4A) and p14(ARF) proteins, and 14 of the most promising DNA methylation marker candidates previously reported to be associated with progression of low-grade cervical intraepithelial neoplasia (CIN1) to cervical cancer.

METHODS

We analyzed DNA methylation in 68 HIV-seropositive and negative women with incident CIN1, CIN2, CIN3 and invasive cervical cancer, assaying 120 CpG dinucleotide sites spanning APC, CDH1, CDH13, CDKN2A, CDKN2B, DAPK1, FHIT, GSTP1, HIC1, MGMT, MLH1, RARB, RASSF1, TERT and TIMP3 using the Illumina Infinium array. Validation was performed using high resolution mapping of the target genes with HELP-tagging for 286 CpGs, followed by fine mapping of candidate genes with targeted bisulfite sequencing. We assessed for statistical differences in DNA methylation levels for each CpG loci assayed using univariate and multivariate methods correcting for multiple comparisons.

RESULTS

In our discovery sample set, we identified dose dependent differences in DNA methylation with grade of disease in CDKN2A, APC, MGMT, MLH1 and HIC1, whereas single CpG locus differences between CIN2/3 and cancer groups were seen for CDH13, DAPK1 and TERT. Only those CpGs in the gene body of CDKN2A showed a monotonic increase in methylation between persistent CIN1, CIN2, CIN3 and cancers.

CONCLUSION

Our data suggests a novel link between early cervical disease progression and DNA methylation in a region downstream of the CDKN2A transcription start site that may lead to increased p16(INK4A)/p14(ARF) expression prior to development of malignant disease.

HPV infection and p16 promoter methylation as predictors of ASC-US/LSIL progression

BACKGROUND

Although patients found to have atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesions (LSILs) on Papanicolaou (Pap) testing are treated conservatively, 5.2% to 18.8% of them progress to high-grade squamous intraepithelial lesions (HSILs). The objective of the current study was to identify predictors of progression to HSIL and determine what percentage of ASC-US/LSIL cases harbor cervical intraepithelial neoplasia of grade 2 or higher.

METHODS

The current study included 381 consecutive cases with ASC-US/LSIL. After the exclusion of 87 cases because of a history of dysplasia or loss to follow-up, 165 cases with follow-up cytology were used to analyze predictive factors of progression to HSIL, and 129 cases that underwent immediate tissue biopsy were subjected to correlation analysis between cytology and histology. Disease regression was defined as a reversion to normal or benign cellular changes, disease persistence as maintenance at ASC-US/LSIL, and disease progression as progression to HSIL. Data regarding clinical parameters were obtained from medical records. Methylation-specific polymerase chain reaction was performed using cytology samples to evaluate methylation of the p16 promoter.

RESULTS

Of 165 cases, 131 (79.4%) regressed, 23 (13.9%) were persistent, and 11 cases (6.7%) progressed. Human papillomavirus infection was more common in women with disease progression than in those with disease regression or persistence (P = .033). Promoter methylation of p16 in the cytology sample was more common in cases that progressed (5 of 6 cases) than in cases that regressed (0 of 8 cases). Twenty-three of 129 cases (17.8%) were found to harbor cervical intraepithelial neoplasia of grade 2 or higher on immediate tissue biopsy.

CONCLUSIONS

Human papillomavirus infection and p16 promoter methylation might be valuable surrogate markers of disease progression from ASC-US/LSIL to HSIL.

Gene expression changes in progression of cervical neoplasia revealed by microarray analysis of cervical neoplastic keratinocytes

To evaluate the gene expression changes involved in neoplastic progression of cervical intraepithelial neoplasia. Using microarray analysis, large-scale gene expression profile was carried out on HPV16-CIN2, HPV16-CIN3, and normal cervical keratinocytes derived from two HPV16-CIN2, two HPV-CIN3 lesions, and two corresponding normal cervical tissues, respectively. Differentially expressed genes were analyzed in normal cervical keratinocytes compared with HPV16-CIN2 keratinocytes and in HPV16-CIN2 keratinocytes compared with HPV16-CIN3 keratinocytes; 37 candidate genes with continuously increasing or decreasing expression during CIN progression were identified. One of these genes, phosphoglycerate dehydrogenase, was chosen for further characterization. Quantitative reverse transcription-polymerase chain reaction and immunohistochemical analysis confirmed that expression of phosphoglycerate dehydrogenase consistently increases during progression of CIN toward cancer. Gene expression changes occurring during CIN progression were investigated using microarray analysis, for the first time, in CIN2 and CIN3 keratinocytes naturally infected with HPV16. Phosphoglycerate dehydrogenase is likely to be associated with tumorigenesis and may be a potential prognostic marker for CIN progression.

HPV-16 exposed mouse embryos: a potential model for pregnancy wastage

PURPOSE

Placentas from spontaneous abortions and preterm deliveries have a higher prevalence of Human papillomavirus (HPV) compared to placentas from elective abortions and term births. The objective was to determine the effects of HPV-16 on the adhesion and implantation properties of early embryo trophoblasts.

METHODS

Two-cell mouse embryos were cultured (medium G2, 5 % CO2, 37 °C) for 72-96 h and exposed to either HPV-16 rich SiHa cell lysates which were refrigerated after mechanical lysis, thawed lysates which had been frozen for freeze/thaw lysis method, or control medium, incubated (4-5 days) and evaluated by microscopy (N = 96 embryos, 3 repeated experiments). Trophoblasts were stained and images were digitized. Adhesion and dimension data were analyzed by Chi-square and t test, respectively.

RESULTS

HPV-16 exposed embryos exhibited less adhesion through reduced implantation compared with the control (combined lysates 53.8 vs. 85.7 %, P < 0.05). Refrigerated and thawed lysate groups had similar reduced implantations (58.3 vs. 50.0 %). Of the embryos with implantation, 100 % in the refrigerated lysates were noted to have loose or abnormal adhesion. This was measured when embryos were noted to be lost after washes with HTF. There was no difference in trophoblast viability among the groups. Total trophoblast area was greater in the HPV-16 exposed frozen lysate group (1,881.8 ± 605.3 vs. control 848.8 ± 298.0 square units, mean ± SEM).

CONCLUSIONS

HPV-16 inhibited trophoblasts adhesion needed for normal implantation, but not embryo development. Total trophoblast spread was increased after HPV-16 exposure suggesting that HPV-16 altered trophoblast migration. These results suggest that HPV-16 may induce abnormal placental growth resulting in pregnancy wastage.

Emerging promise of epigenetics and DNA methylation for the diagnosis and management of women's cancers

Over the last two decades, survival rates from women's cancers (breast, ovarian, endometrial and cervical cancer) have all but modestly improved despite huge efforts from both research and clinical communities. In parallel with this, the field of epigenetics has grown from its infancy into a promising scientific discipline. In particular, DNA methylation analysis has been adopted by oncologists in an attempt to better understand and manage cancer. Now that the epigenetic technological base has caught up, the potential of methylation markers in cancer research is finally being realized. In this review, we present the current status of epigenetic research into women's cancers with a main focus on DNA methylation analysis. We provide an overview of technological development, current markers of risk prediction, early detection, diagnosis, prognosis and response to treatment, and highlight the progression of epigenetic therapies. Finally, we comment on the potential impact of epigenetic analyses on the future of women's health.

Nuclear translocation of β-catenin synchronized with loss of E-cadherin in oral epithelial dysplasia with a characteristic two-phase appearance

AIMS

One of the important histopathological characteristics of oral epithelial dysplasia is a two-phase appearance of rete processes, comprising an upper layer of keratinized cells and a lower layer of basaloid cells, and thereby creating a sharp contrast between these two separate cell populations. The aim of this study was to determine the cellular adhesion status of the basaloid cells.

METHODS AND RESULTS

Immunohistochemistry for β-catenin, E-cadherin and their related molecules was carried out in surgical specimens of two-phase epithelial dysplasia of the oral mucosa. The lower-half basaloid cells and the upper keratinized cells were microdissected separately, and extracted DNA samples were subjected to methylation-specific polymerase chain reaction amplification for E-cadherin. β-Catenin was immunolocalized within the nuclei and cytoplasm of Ki67-positive lower-half basaloid cells, as well as on the cell membrane of upper parakeratotic cells. The basaloid cells of the lower-half were also positive for matrix metalloproteinase-7 and cyclin D1, β-catenin target gene products, α-dystroglycan, tenascin-C, and perlecan, but not for E-cadherin. The promoter region of the E-cadherin gene was hypermethylated.

CONCLUSIONS

The solid proliferation of lower-half E-cadherin-free basaloid cells is enhanced by Wnt signalling cascades, as well as by the intraepithelial extracellular matrix or its bound growth factors.

Type-specific HPV prevalence in cervical cancer and high-grade lesions in Latin America and the Caribbean: systematic review and meta-analysis

Background

Cervical cancer is a major public health problem in Latin America and the Caribbean (LA&C), showing some of the highest incidence and mortality rates worldwide. Information on HPV type distribution in high-grade cervical lesions (HSIL) and invasive cervical cancer (ICC) is crucial to predict the future impact of HPV16/18 vaccines and screening programmes, and to establish an appropriate post-vaccinal virologic surveillance. The aim was to assess the prevalence of HPV types in HSIL and ICC in studies in LA&C.

Methods and Findings

We performed a systematic review, following the MOOSE guidelines for systematic reviews of observational studies, and the PRISMA statement for reporting systematic reviews and meta-analyses. Inclusion criteria were at least ten cases of HSIL/ICC, and HPV-type elicitation. The search, without language restrictions, was performed in MEDLINE, Cochrane Library, EMBASE, LILACS from inception date to December 2009, proceedings, reference lists and consulting experts. A meta-analysis was performed using arc-sine transformations to stabilize the variance of simple proportions. Seventy-nine studies from 18 countries were identified, including 2446 cases of HSIL and 5540 of ICC. Overall, 46.5% of HSIL cases harbored HPV 16 and 8.9% HPV18; in ICC, 53.2% of cases harbored HPV 16 and13.2% HPV 18. The next five most common types, in decreasing frequency, were HPV 31, 58, 33, 45, and 52.

Study's limitations comprise the cross-sectional design of most included studies and their inherent risk of bias, the lack of representativeness, and variations in the HPV type-specific sensitivity of different PCR protocols.

Conclusions

This study is the broadest summary of HPV type distribution in HSIL and ICC in LA&C to date. These data are essential for local decision makers regarding HPV screening and vaccination policies. Continued HPV surveillance would be useful, to assess the potential for changing type-specific HPV prevalence in the post-vaccination era in Latin America.

Promoter hypermethylation of CDH13, DAPK1 and TWIST1 genes in precancerous and cancerous lesions of the uterine cervix

Aberrant DNA methylation is an early event in carcinogenesis and could serve as an additional molecular marker for the early diagnosis. The study was performed to investigate the promoter methylation of DAPK1, CDH13, and TWIST1 genes in uterine cervix lesions in an effort to examine whether this epigenetic event is involved in the process of cervical carcinogenesis, and whether it might be used as a molecular marker of cervical lesions. We conducted a retrospective study of 60 uterine cervix specimens, including 8 normal tissue samples, 10 benign lesions, 28 precancerous lesions (CIN1-3), and 14 squamous cell carcinomas (SCC). DNA hypermethylation was investigated using methylation-specific PCR. Immunohistochemistry was used to find p16(INK4A) overexpression. No hypermethylated promoters were detected in normal tissues and benign lesions. However, promoter hypermethylation of CDH13, TWIST1, and DAPK1 increased progressively from CIN1 to cancer, reaching values higher than 50% for cancer. DAPK1 and CDH13 displayed a significantly increased frequency of promoter methylation with progressively more severe cervical neoplasia (p<0.05). A statistically significant association was observed between p16(INK4A) expression and hypermethylation of DAPK1, TWIST1, and CDH13 (p<0.0001). Hypermethylation of CDH13, DAPK1, and TWIST1 promoters is an early event in the initiation and progression of cervix neoplasia. CDH13, DAPK1, and TWIST1 genes are potential biomarkers of cervical cancer risk.

The presence of methylation of the p16INK4A gene and human papillomavirus in high-grade cervical squamous intraepithelial lesions

Methylation is a chemical modification in which a methyl group (CH3) is added to the cytosine in the promoter region of the gene. It involves a very frequent epigenetic event that is found in many human cancers. Currently, there is no consensus on whether methylation of the p16 gene could be used as a biomarker in cervical intraepithelial neoplasia. The authors studied the presence of methylation of the p16 gene and human papillomavirus (HPV) DNA, and a possible relationship between them in high-grade squamous intraepithelial lesions of the cervix. This case-control study analyzed 27 high-grade squamous intraepithelial lesion samples and 20 normal cytology samples. To detect p16 methylation, methylation-specific polymerase chain reaction was used, and for HPV DNA detection the polymerase chain reaction was performed by using MY09/MY11 and GP5+/GP6+ consensus primers. The presence of methylation of the promoter region of the p16INK4a gene was detected in 55.6% of the samples from the case group, whereas it was detected only in 20% of the samples from the control group (P=0.005). HPV DNA was found in 66.7% of the samples from the case group, whereas only 15% from the control group (P=0.0001). The relationship between the presence of methylation of the p16 gene and HPV DNA did not prove statistically significant in the case group (P=0.67) or the control group (P=0.51). In conclusion, the presence of methylation of the p16 gene constituted an occurrence that was early but independent of the presence of HPV DNA.

HPV16 E7 oncogene expression in normal human epithelial cells causes molecular changes indicative of an epithelial to mesenchymal transition

Cancer-associated epithelial to mesenchymal transition (EMT) is crucial for invasion and metastasis. Molecular hallmarks of EMT include down-regulation of the epithelial adhesion protein E-cadherin and de-novo expression of N-cadherin and the mesenchymal intermediate filament proteins vimentin and fibronectin. Expression of HPV16 E7 in normal human epithelial cells caused increased levels of vimentin and fibronectin, whereas the epithelial adhesion protein E-cadherin was expressed at decreased levels. Similar expression patterns of vimentin, fibronectin and E-cadherin were also detected in cells expressing HPV16 E6 and E7 or the entire HPV16 early transcriptional unit. HPV16 E6 and E7 were each able to induce N-cadherin expression. Interestingly, these changes in expression levels of EMT-associated proteins are not similarly reflected at the level of mRNA expression, suggesting that HPV16 oncoproteins also modulate EMT through non-transcriptional mechanisms. Hence, HPV16 oncoproteins may contribute to malignant progression through EMT induction.

Colposcopy to evaluate abnormal cervical cytology in 2008

The rates of cervical cancer in the United States are low in comparison with developing nations. Whereas the Papanicolaou smear has performed well in terms of detecting both precursors of squamous cell carcinoma and squamous cell carcinoma of the cervix, this test has been less successful at identifying those women with the highest-risk premalignant disease. The use of human papillomavirus testing has also contributed to the improved sensitivity of screening for cervical cancer. In light of this, the colposcopy clinic retains high referral rates yet has poor diagnostic accuracy. Unfortunately, patients are triaged to follow-up for abnormal Papanicolaou smears based on algorithms that rely on the less evidence-based techniques of colposcopy. Therefore, the need to improve the specificity of colposcopic-guided biopsy remains. The colposcopic procedure is highlighted in this review and evaluated in terms of current literature on technique, the colposcopic impression, cervical biopsy, and methods proposed to enhance appreciation of the highest-risk lesions. By outlining certain flaws in technique and discussing the proposal of new tests to supplement the current standard of care, this review aimed to highlight the need for future research to maintain sensitivity but improve the specificity of colposcopy.

Prevalence of micronuclei in exfoliated uterine cervical cells from patients with risk factors for cervical cancer

CONTEXT AND OBJECTIVE

Pap smears are the most common and inexpensive screening method for cervical cancer. We analyzed micronucleus prevalence in exfoliated cervical mucosa cells, to investigate associations between increased numbers of micronuclei and risk factors for cervical cancer.

DESIGN AND SETTING

Analytical cross-sectional study, at Instituto de Pesquisa em Oncologia (IPON).

METHODS

Exfoliated cervical cells were obtained from 101 patients between September 2004 and November 2005. Patients' ages, habits (passive or active smoking, alcoholism and numbers of sexual partners), age at first sexual intercourse, contraceptive methods used, histories of sexually transmitted diseases, use of hormone replacement therapy, numbers of pregnancies and abortions, inflammatory cytology and cervical intraepithelial neoplasia (CIN) were obtained. Cells were collected using Ayre spatulas, transferred to vials containing 0.9% saline solution for micronucleus tests and analyzed at 1000x magnification. The number of micronuclei in 1,000 epithelial cells per patient sample was counted.

RESULTS

Comparisons between groups with active (7.9 +/- 7.8) and passive (7.2 +/- 10.6) smoking versus no smoking (3.7 +/- 5.1); with/without alcoholism (7.8 +/- 1.4 and 6.9 +/- 10.1); with/without inflammatory cytology (10.7 +/- 10.5 and 1.3 +/- 1.7); and with CIN I, II and III and no CIN (respectively 4.3 +/- 4.3, 10.6 +/- 5.3, 22.7 +/- 11.9 and 1.3 +/- 1.4) found elevated micronucleus prevalence (P < 0.05).

CONCLUSIONS

We concluded that the prevalence of micronuclei in exfoliated uterine cervical cells was greater in patients with one or more risk factors for uterine cervical cancer than in patients without risk factors.

DNA methylation: a promising target for the twenty-first century

BACKGROUND

Over the last few years DNA methylation and its involvement in diseases such as cancer has become of great interest for applied research. Since reversal of aberrant DNA methylation may influence the behavior of tumors, the methylation of DNA CpG sites is a potential target for the development of inhibitors for use in cancer treatment.

OBJECTIVE/METHODS

We briefly review the structural and mechanistic features of DNA methylation, including a structural analysis of the three main human DNA methyltransferases and some (pre)clinical results.

RESULTS/CONCLUSION

Despite side effects, data obtained to date still support the vision that DNA-methylation, possibly associated with the use of histone deacetylases (HDACs) and/or artificial transcription factors (ATFs), is a promising target for improving anticancer therapy in the 21st century.

T lymphocytes (CD3) may participate in the recurrence of cervical intraepithelial neoplasia grade III

OBJECTIVE

Data from the literature demonstrate that the local and systemic immune responses seem to play an important role in the progression of cervical intraepithelial neoplasia (CIN). Our aim was to investigate whether recurrences among CIN III patients might be related to the presence of local lymphocytes, macrophage and enzyme iNOS.

METHODS

We analyzed 35 patients with CIN III who underwent conization and followed up for a minimum of 4 years. Using immunohistochemistry, the presence of T lymphocytes (CD3, CD8 and CD45RO), B lymphocytes (CD20), macrophages (CD68) and the expression of the enzyme iNOS were investigated. The quantity of marked cells is graded as: 0, absence of cells; 1, rare cells; 2, moderate number of cells; 3, many cells. For statistical purposes, we took the scores 0 and 1 to indicate weak marking and the scores 2 and 3 to indicate strong marking.

RESULTS

We found strong positive expression of CD3-positive T lymphocytes among CIN III patients with recurrence following conization (100 vs. 50% without recurrence, p=0.02). We did not find any statistical differences in the expression of CD20, CD68, CD45RO, CD8 or iNOS.

CONCLUSIONS

It is concluded that strong positive findings of CD3 T lymphocytes were related to recurrence following conization due to CIN III.