Molecular profiling of cervical neoplasia

microRNA-214 suppresses the growth of cervical cancer cells by targeting EZH2

A number of studies have revealed the significance of microRNAs (miRs) in tumorigenesis. Cervical cancer (CC) is one of the most malignant cancer types and is associated with a poor overall survival rate. A previous study demonstrated a critical role of miR-214 in the development of multiple cancer types, but its role in CC remains elusive. In the current study, miR-214 was observed to be downregulated in CC tissues compared with the adjacent non-cancerous tissue. Overexpression of miR-214 reduced the proliferation of CC cells, whereas inhibiting its expression resulted in enhanced proliferation. Furthermore, Enhancer of zeste homolog 2 (EZH2) was demonstrated to be a direct target of miR-214 in CC. An MTT assay demonstrated that upregulating miR-214 expression or knocking down the expression of EZH2 impaired the proliferation of a CC cell line. Low expression of miR-214 was positively associated with tumor differentiation (P=0.037) and tumor stage (P=0.012). Notably, low expression of miR-214 predicted poor prognosis of patients with CC. Consequently, the results of the current study demonstrated that miR-214 functions as a tumor suppressor in CC and may be regarded as a potential therapeutic target in CC.

[Over-expression of miR-519d alters gene expression profiles of cervical cancer SiHa cells]

OBJECTIVE

To investigate the alterations in gene expression profiles of cervical cancer cell line SiHa over-expressing miR-519d.

METHODS

SiHa cells were transfected with a miR-519d mimic or a negative control (NC) and the changes in gene expression profiles were examined using NimbleGen human gene expression microarray. Bioinformatics approaches based on the microarray data were used to identify the targeted genes of miR-519d. Real-time quantitative PCR was employed to confirm the expression of the potential target genes.

RESULTS

A total of 5172 genes were found to be differentially expressed in SiHa cells over-expressing miR-519d, including 2476 up-regulated and 2796 down-regulated genes. We identified 164 potential target genes of miR-519d, and their functions were predicted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway analysis, and STRING database and pSTIING were used to search the key nodes in the protein-protein interactions and transcriptional regulatory networks in cancer. Real-time quantitative PCR confirmed the differential expressions of several candidate target genes.

CONCLUSIONS

Over-expression of miR-519d alters gene expression profiles in SiHa cells. The 164 target genes of miR-519d we identified may provide insights into the role of miR-519d in cervical tumorigenesis.

MicroRNA-10b inhibits proliferation, migration and invasion in cervical cancer cells via direct targeting of insulin-like growth factor-1 receptor

MicroRNAs are deregulated in numerous types of human cancers and have crucial roles in the carcinogenesis and progression of human cancers. MicroRNA-10b (miR-10b) has been studied in several types of human cancer. However, the expression and roles of miR-10b in cervical cancer remain unknown. In the present study, the expression, functions and molecular mechanisms of miR-10b were explored in cervical cancer. The present data revealed that miR-10b was significantly downregulated in cervical cancer tissues and cell lines. In addition, miR-10b overexpression inhibited the proliferation, migration and invasion of cervical cancer cells, while miR-10b under-expression had the opposite effect. Based on bioinformatics analysis, a luciferase reporter assay and western blot analysis, insulin-like growth factor-1 receptor (IGF-1R) was identified as a direct target of miR-10b in cervical cancer. In addition, IGF-1R small interfering RNA-mediated knockdown of IGF-1R also inhibited the proliferation, migration and invasion of the cervical cancer cells. In conclusion, the present study demonstrated that miR-10b serves an important role in cervical cancer progression by targeting IGF-1R.

Amplification and up-regulation of MIR30D was associated with disease progression of cervical squamous cell carcinomas

Background

Cervical squamous cell carcinoma (CSCC) is the most frequent type among cervical cancers. Although the altered miRNA miR-30d expression and the amplified chromosome locus of MIR30D, 8q24, have been reported in somatic cancers, the definitive functional impact of such region especially in CSCC remains under-investigated.

Methods

One hundred thirty-six cases of CSCC tissues and matched adjacent normal ovarian epithelial tissues were assessed in this study. FISH and qPCR were performed to detect the copy number and microRNA expression of MIR30D gene in the collected samples. In in-vitro study, proliferation of CSCC cells were analyzed using WST-1 assay and invasion abilities of CSCC cells were evaluated by transwell assay. In-vivo study using a model of nude mice bearing tumor was also performed.

Results

Copy number gains of MIR30D were detected in 22.8% (31 out of 136) of CSCC samples. Copy number of MIR30D was positively correlated with tumor progression. CSCCs with lymph node metastases (LNM) also showed more frequencies (36.4%) of MIR30D amplification than those without LNM (18.4%, p < 0.05). CSCCs with increased copy number of MIR30D also showed a positive correlation with miR-30d up-regulation. Inhibition of miR-30d in CSCC cells led to impaired tumor growth and migration.

Conclusions

Copy number amplifications of MIR30D gene and enhanced expression of miR-30d were positively correlated with tumor progression in CSCCs, indicating miR-30d might play an oncomiric role in the progression of CSCC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3201-0) contains supplementary material, which is available to authorized users.

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.

Polymorphism in apoptotic BAX (-248G>A) gene but not in anti-apoptotic BCL2 (-938C>A) gene and its protein and mRNA expression are associated with cervical intraepithelial neoplasia

HPV is associated with cervical cancer and plays a crucial role in tumor formation. Apoptosis is regulated by different pathways involving genes that either promote (BCL2 gene) or inhibit (BAX gene) cell death. Our goal was to determine whether the BCL2-938C>A (rs2279115) and BAX-248G>A (rs4645878) single nucleotide polymorphisms (SNPs) are associated with squamous intraepithelial neoplasia (SIL) risk, and whether their phenotypic expression was impaired in these lesions. Two hundred and thirty-one cases showing SIL were classified as low SIL (LSIL, n = 101) or high SIL (HSIL, n = 130), and control subjects (n = 266) with no gynecologically proven SIL were recruited. No statistical difference in the genotype and allelic frequency of the BCL-2-938C>A polymorphism was observed among the groups. BCL2-938C/A and A/A homozygotes carriers had higher distribution of BCL-2-expressing cells in stroma in the SIL group. BCL2 mRNA-expression was not correlated with BCL2-938C>A SNPs in both groups. We did find a strong association of the BAX GG genotype and risk for SIL. No difference was observed between LSIL and HSIL groups. In BAX-248G/A and A/A homozygote carriers, the number of BAX-expressing cells was lower the epithelium area in SIL. However, mRNA expression was higher in SIL patients than in the control group. In conclusion, our data provide evidence that allele G carriers in the BAX-248G>A promoter SNP may influence the development of SIL. However, this genotype does not influence the SIL outcome. Additionally, we suggest a possible role of HPV infection in the inhibition of the expression of BAX protein, decreasing cell death, and favoring cervical carcinogenesis.

Simultaneous [18F]FDG-PET/MRI: Correlation of Apparent Diffusion Coefficient (ADC) and Standardized Uptake Value (SUV) in Primary and Recurrent Cervical Cancer

Objectives

Previous non–simultaneous PET/MR studies have shown heterogeneous results about the correlation between standardized uptake values (SUVs) and apparent diffusion coefficients (ADCs). The aim of this study was to investigate correlations in patients with primary and recurrent tumors using a simultaneous PET/MRI system which could lead to a better understanding of tumor biology and might play a role in early response assessment.

Methods

We included 31 patients with histologically confirmed primary (n = 14) or recurrent cervical cancer (n = 17) who underwent simultaneous whole-body ¹⁸F-FDG-PET/MRI comprising DWI. Image analysis was performed by a radiologist and a nuclear physician who identified tumor margins and quantified ADC and SUV. Pearson correlations were calculated to investigate the association between ADC and SUV.

Results

92 lesions were detected. We found a significant inverse correlation between SUV_max and ADC_min (r = -0.532, p = 0.05) in primary tumors as well as in primary metastases (r = -0.362, p = 0.05) and between SUV_mean and ADC_min (r = -0.403, p = 0.03). In recurrent local tumors we found correlations for SUV_max and ADC_min (r = -0.747, p = 0.002) and SUV_mean and ADC_min (r = -0.773, p = 0.001). Associations for recurrent metastases were not significant (p>0.05).

Conclusions

Our study demonstrates the feasibility of fast and reliable measurement of SUV and ADC with simultaneous PET/MRI. In patients with cervical cancer we found significant inverse correlations for SUV and ADC which could play a major role for further tumor characterization and therapy decisions.

Epigenetic Mechanisms of Human Papillomavirus-Associated Head and Neck Cancer

CONTEXT

Growing evidence suggests that as many as half of all oropharyngeal squamous cell carcinomas (OPSCCs) harbor human papillomavirus (HPV) infections. Despite being more advanced at diagnosis, HPV-positive OPSCCs are associated with a better response to therapy and longer patient survival than HPV-negative OPSCCs. Human papillomavirus-positive OPSCC has also been shown to have distinct host gene expression profiles compared with HPV-negative OPSCC. Recently, this distinction has been shown to include the epigenome. It is well supported that cancers are epigenetically deregulated. This review highlights epigenetic differences between HPV-positive and HPV-negative OPSCCs. The epigenetic mechanisms highlighted include methylation changes to host and viral DNA, and host chromatin modification. We also review the current evidence regarding host DNA methylation changes associated with smoking, and deregulation of microRNA expression in HPV-positive OPSCC.

OBJECTIVE

To provide an overview of epigenetic mechanisms reported in HPV-positive OPSCC, with analogies to cervical cancer, and discussion of the challenges involved in studying epigenetic changes in HPV-associated OPSCC in combination with changes associated with smoking.

DATA SOURCES

Sources were a literature review of peer-reviewed articles in PubMed on HPV and either OPSCC or head and neck squamous cell carcinoma, and related epigenetic mechanisms.

CONCLUSIONS

Epigenetic changes are reported to be a contributing factor to maintaining a malignant phenotype in HPV-positive OPSCC. The epigenetic mechanisms highlighted in this review can be studied for potential as biomarkers or as drug targets. Furthermore, continued research on the deregulation of epigenetic mechanisms in HPV-positive OPSCC (compared with HPV-negative OPSCC) may contribute to our understanding of the clinical and biologic differences between HPV-positive and HPV-negative OPSCC.

Aberrant expression of long noncoding RNAs in cervical intraepithelial neoplasia

OBJECTIVE

Long noncoding RNAs (lncRNAs) are a unique class of messenger RNA-like transcripts of at least 200 nucleotides in length with no significant protein-coding capacity. Aberrant lncRNA expression is emerging as a major component of the cancer transcriptome. Here, we sought to determine if differential lncRNA expression is a feature of the human cervical intraepithelial neoplasia (CIN) transcriptome.

METHODS

Sequence data were derived from 16 long serial analyses of gene expression (L-SAGE) libraries constructed from cervical specimens representing mild (CIN1), moderate (CIN2), and severe (CIN3) histopathologic grades of CIN. A novel lncRNA discovery pipeline was developed to query the expression of lncRNAs within the SAGE data sets.

RESULTS

A total of 2,230,370 sequence tags were delineated from the 16 SAGE libraries, representing the expression of 367,482 unique tags at varying abundance. Using a novel stepwise filtering strategy, we analyzed the cervical SAGE libraries and identified the expression profiles of 1056 lncRNAs in the human cervix. We present the first lncRNA expression profile derived from nonneoplastic cervical tissue and establish that changes in lncRNA expression do occur in cervical intraepithelial lesions. Our analysis also shows statistically significant aberrant expression of lncRNAs in the 3 CIN grades, suggesting that these unique noncoding RNA transcripts may contribute to the development and progression of precursor lesions.

CONCLUSIONS

Through the analysis of L-SAGE libraries constructed from cervical specimens, we provide the first lncRNA expression profile of the cervix and demonstrate aberrant expression in early-stage neoplasia.

Overexpression of myeloid zinc finger 1 suppresses matrix metalloproteinase-2 expression and reduces invasiveness of SiHa human cervical cancer cells

Myeloid zinc finger 1 (MZF1) gene belongs to the Kruppel family of zinc finger transcription factors. MZF1 has been suggested to play an important role in the tumorigenesis, invasion, and apoptosis of various tumor cells. However, the role of MZF1 in human cervical cancer remains unclear. To investigate the molecular mechanisms of MZF1 and its functional role in human cervical cancer cell migration and invasion, we experimented on stable SiHa cells overexpressing MZF1. We found that MZF1 overexpression inhibits the migratory and invasive abilities of SiHa cervical cancer cells. In addition, the overexpression of MZF1 significantly reduces MMP-2 protein and mRNA levels. Luciferase and ChIP assays suggested that MZF1 directly binds to MMP-2 gene regulatory sequences in vivo and suppresses MMP-2 promoter activity in vitro. This study shows that MZF-1 represses MMP-2 transcription and suggests that this repression may be linked to inhibition of human cervical cancer cell migration and metastasis.

Identification of miR-23a as a novel microRNA normalizer for relative quantification in human uterine cervical tissues

Quantitative real-time RT-PCR (RT-qPCR) is being widely used in microRNA expression research. However, few reports detailed a robust identification and validation strategy for suitable reference genes for normalisation in microRNA RT-qPCR studies. The aim of this study was to identify the most stable reference gene(s) for quantification of microRNA expression analysis in uterine cervical tissues. A microarray was performed on 6 pairs of uterine cervical tissues to identify the candidate reference genes. The stability of candidate reference genes was assessed by RT-qPCR in 23 pairs of uterine cervical tissues. The identified most stable reference genes were further validated in other cohort of 108 clinical uterine cervical samples: (HR-HPV- normal, n=21; HR-HPV+ normal, n=19; cervical intraepithelial neoplasia [CIN], n=47; cancer, n=21), and the effects of normalizers on the relative quantity of target miR-424 were assessed. In the array experiment, miR-26a, miR-23a, miR-200c, let-7a, and miR-1979 were identified as candidate reference genes for subsequent validation. MiR-23a was identified as the most reliable reference gene followed by miR-191. The use of miR-23a and miR-191 to normalize expression data enabled detection of a significant dereg-ulation of miR-424 between normal, CIN and cancer tissue. Our results suggested that miR-23a and miR-191 are the optimal reference microRNAs that can be used for normalization in profiling studies of cervical tissues; miR-23a is a novel microRNA normalizer.

The expression of Mcl-1 in human cervical cancer and its clinical significance

Recently, the role of anti-apoptotic Mcl-1 in human carcinogenesis has become an area of great interest as overexpression of the protein has been reported in association with various types of cancer. The aim of this study was to investigate the expression profile of Mcl-1 in cervical cancer and to assess its clinical significance. Immunohistochemistry was used in the detection of Mcl-1 expression as well as the proliferation index of Ki-67, both in cervical cancer and in corresponding normal tissue. Western blotting analysis was also used for the detection of Mcl-1. The data was correlated with clinicopathological features. Survival analysis was performed to assess prognostic significance. Mcl-1 was overexpressed in cervical cancer tissue when compared with corresponding normal tissue. High expression of Mcl-1 was significantly associated with histological grade (P = 0.039), tumor size (P = 0.024) and lymph node involvement (P = 0.002). Overexpression of Ki-67 was associated with lymph node involvement (P = 0.015) and disease stage (P = 0.012). Spearman rank correlation test demonstrated a positive correlation between Mcl-1 and Ki-67 (P < 0.05). Using Kaplan-Meier analysis, a comparison of survival curves of low versus high expressers of Mcl-1 and Ki-67 revealed a highly significant difference in human cervical cancer tissue (P < 0.05), which suggests that overexpression of Mcl-1 and Ki-67 is associated with a poorer prognosis. Our results suggest that Mcl-1 may play an important role in cervical cancer and that it may have potential as a biomarker and therapeutic target. Its evaluation with Ki-67 may provide reliable prognostic information on cervical cancer.

Cervical cytology biobanks as a resource for molecular epidemiology

A cervical cytology biobank (CCB) is an extension of current cytopathology laboratory practice consisting in the systematic storage of Pap smears or liquid-based cytology samples from women participating in cervical cancer screening with the explicit purpose of facilitating future scientific research and quality audit of preventive services. A CCB should use an internationally agreed uniform cytology terminology, be integrated in a national or regional screening registry, and linked to other registries (histology, cancer, and vaccination). Legal and ethical principles concerning personal integrity and data safety must be respected strictly. Biobank-based studies require approval from ethical review boards. A CCB constitutes a nearly inexhaustible resource to perform fundamental and applied biologic research. In particular, it can contribute in answering questions on the natural history of HPV infection and HPV-induced lesions and cancers, screening effectiveness, exploration of new biomarkers, and surveillance of short- and long-term effects of the introduction of HPV vaccination. To understand the limitations of CCB, more studies are needed on quality of samples in relation to sample type, storage procedures, and duration of storage.

MicroRNA miR-886-5p inhibits apoptosis by down-regulating Bax expression in human cervical carcinoma cells

OBJECTIVE

MicroRNA (miRNA) plays an essential role in the progression of a variety of cancers, but its role in cervical cancer progression is not well defined. We aimed to test whether special miRNAs and their target mRNAs contribute to cervical cancer progression.

METHODS

The expression profiles of 1145 microRNAs in cervical squamous cell carcinomas (CSCC) and adjacent non-tumor tissues were investigated using an Illumina microRNA microarray platform. Differentially expressed miRNAs were validated by RT-PCR. Downstream target validation was performed for miR-886-5p.

RESULTS

We found that the expression levels of seven miRNAs differed significantly between CSCC tissues and adjacent non-tumor tissues. Forced expression of one miRNA, miR-886-5p, over-expressed in CSCC tissues lowered expression of the pro-apoptotic protein Bax, reduced apoptosis and promoted cell proliferation in H8, an HPV16-immortalized human cervical squamous epithelial cell line. Knockdown of miR-886-5p increased Bax protein and apoptotic cell death in cells of the cervical squamous carcinoma cell line, SiHa.

CONCLUSION

MicroRNA miR-886-5p inhibits apoptosis of cervical cancer cells by down-regulating the production of Bax.

Distribution of CCND1 A870G polymorphism in patients with advanced uterine cervical carcinoma

We examined the distribution of the CCND1 A870G (rs9344) polymorphic variant in patients with cervical cancer (n = 129) and healthy individuals (n = 288) in a sample of a Polish cohort. We showed that patients with advanced cervical cancer bearing the CCND1 A/A and A/G genotypes displayed a 1.811-fold increased risk of cervical cancer (95% CI = 1.150-2.852, p = 0.0098). We also found a significantly higher frequency of the CCND1 870A allele in patients with cancer than in controls, p = 0.0116. Our investigation confirmed that the CCND1 870A gene variant may be a genetic risk factor in the incidence of advanced cervical cancer.

Microarray profile of micro-ribonucleic acid in tumor tissue from cervical squamous cell carcinoma without human papillomavirus

AIMS

Micro-ribonucleic acid (miRNA) are noncoding RNA molecules of 21 to 24 nt that regulate the expression of target genes in a post-transcriptional manner. Evidence indicates that miRNA play essential roles in embryogenesis, cell differentiation and pathogenesis of human diseases. This study describes a comparison between the microRNA profile of human-papillomavirus-negative cervical squamous cell carcinoma patients and controls, in order to develop further understanding of the pathogenesis of cervical squamous cell carcinomas.

METHODS

MiRNA were isolated from tumor tissues of five human-papillomavirus-negative cervical squamous cell carcinoma patients and five healthy controls in order to perform miRNA microarray chip analysis. The chip results were then confirmed by northern blot analysis.

RESULTS

A total of 27 miRNA differentially expressed between the squamous cell carcinoma patients and the healthy controls were identified.

CONCLUSION

This work indicates that these miRNA may be potential diagnosis biomarkers and probable factors involved in the pathogenesis of cervical squamous cell carcinomas.

Use of and attitudes and knowledge about pap smears among women in Kuwait

OBJECTIVE

To estimate the lifetime prevalence of Pap smear among women in Kuwait and to assess their knowledge about and attitude toward Pap smears.

METHODS

This was a descriptive cross-sectional study using a multistage cluster sampling method. We interviewed 299 women attending polyclinics in Kuwait using a self-administered questionnaire. Factors related to history of having a Pap smear, knowledge level, and willingness to participate in a screening program were evaluated.

RESULTS

The lifetime prevalence of Pap smear was found to be 37% (95% CI 33-43). Forty-four percent of women in our study had a Pap smear only once in their lives. History of having at least one Pap smear was significantly related to such factors as age, total family income, marital status, history of cervical infection, and knowledge. The level of knowledge about cervical cancer varied among the participants. Forty-six percent of women were uncertain about the symptoms of cervical cancer. About half the women recognized cervical infection, smoking, and having multiple sexual partners as risk factors for cervical cancer; however, only 10% recognized early sexual intercourse as a risk factor. Willingness to participate in a future screening program varied significantly according to educational level, employment status, and total family income.

CONCLUSIONS

Although cervical cancer incidence and mortality are relatively low in Kuwait, they may be underreported in the absence of a screening program. Moreover, lifetime prevalence of having a Pap smear was found to be considerably lower in Kuwait compared with developed countries.

Stabilization of mismatch repair gene PMS2 by glycogen synthase kinase 3beta is implicated in the treatment of cervical carcinoma

Background

PMS2 expression loss was reported in a variety of human. However, its importance has not been fully understood in cervical carcinoma. The aim of this study was to determine the expression of PMS2 in cervical carcinoma and evaluate the significance of mismatch repair gene PMS2 regulated by glycogen synthase kinase 3β (GSK-3β) in chemosensitivity.

Methods

We examined PMS2 and phosphorylated GSK-3β(s9) expression in cervical carcinoma tissues using immunohistochemical staining. Furthermore, we detected PMS2 expression in HeLa cells and evaluate the interaction with GSK-3β after transfection with GSK-3β by small interference RNA (siRNA), co-immunoprecipitation and immunoblotting. We also evaluated the effect of PMS2 transfection on HeLa cells' chemosensitivity to cisplatin treatment.

Results

We found significant downregulation of PMS2 in cervical carcinoma, which was negatively associated with phosphorylated GSK-3β (s9). Furthermore, we demonstrated GSK-3β transfection was able to interact with PMS2 and enhance PMS2 production in HeLa cells, and increased PMS2 production was responsible for enhanced chemosensitivity.

Conclusions

Our results provide the evidence that stabilization of PMS2 production by GSK-3β was important to improve chemosensitization, indicating the significance of GSK-3β-related PMS2 downregulation in the development of cervical carcinoma and in developing a potential strategy for chemotherapy.

S100A8/A9 induces apoptosis and inhibits metastasis of CasKi human cervical cancer cells

S100 proteins, a family of Ca(2+)-binding proteins, have been linked to several human diseases in recent years. Deregulated expression of S100 proteins, including S100A9 and its partner S100A8, was reported to be associated with neoplastic disorders. In our previous study using serial analysis of gene expression, we identified decreased expressions of S100A9 and S100A8 in human cervical squamous cell carcinoma. To investigate the functions of S100A8 and S100A9 in cervical cancer, we purified recombinant S100A8 and S100A9 proteins and treated CaSki human cervical cancer cells with these proteins. We found that S100A8/A9 induced apoptosis and inhibited migration of CaSki cells; S100A8/A9 also reduced the expression of matrix metalloproteinase (MMP)-2 in CaSki cells. In summary, this study suggests that S100A8 and S100A9 have inhibitory effects on the proliferation of CaSki carcinoma cells by inducing cell apoptosis and on the invasiveness of CaSki cells.

MicroRNA-21 promotes cell proliferation and down-regulates the expression of programmed cell death 4 (PDCD4) in HeLa cervical carcinoma cells

MicroRNAs are involved in cancer-related processes. The microRNA-21(miR-21) has been identified as the only miRNA over-expressed in a wide variety of cancers, including cervical cancer. However, the function of miR-21 is unknown in cervical carcinomas. In this study, we found that the inhibition of miR-21 in HeLa cervical cancer cells caused profound suppression of cell proliferation, and up-regulated the expression of the tumor suppressor gene PDCD4. We also provide direct evidence that PDCD4-3'UTR is a functional target of miR-21 and that the 18bp putative target site can function as the sole regulatory element in HeLa cells. These results suggest that miR-21 may play an oncogenic role in the cellular processes of cervical cancer and may serve as a target for effective therapies.

Gene expression profiling in cervical cancer: identification of novel markers for disease diagnosis and therapy

Cervical cancer, a potentially preventable disease, remains the second most common malignancy in women worldwide. Human papillomavirus is the single most important etiological agent in cervical cancer. HPV contributes to neoplastic progression through the action of two viral oncoproteins E6 and E7, which interfere with critical cell cycle pathways, p53, and retinoblastoma. However, evidence suggests that HPV infection alone is insufficient to induce malignant changes and other host genetic variations are important in the development of cervical cancer. Advances in molecular biology and high throughput gene expression profiling technologies have heralded a new era in biomarker discovery and identification of molecular targets related to carcinogenesis. These advancements have improved our understanding of carcinogenesis and will facilitate screening, early detection, management, and personalised targeted therapy. In this chapter, we have described the use of high density microarrays to assess gene expression profiles in cervical cancer. Using this approach we have identified a number of novel genes which are differentially expressed in cervical cancer, including several genes involved in cell cycle regulation. These include p16ink4a, MCM 3 and 5, CDC6, Geminin, Cyclins A-D, TOPO2A, CDCA1, and BIRC5. We have validated expression of mRNA using real-time PCR and protein by immunohistochemistry.

Gene discovery in cervical cancer : towards diagnostic and therapeutic biomarkers

Cervical cancer is a potentially preventable disease; however, it remains the second most common malignancy in women worldwide. The human papillomavirus (HPV) is the single most important etiological agent in cervical cancer. HPV contributes to neoplastic progression through the action of two viral oncoproteins E6 and E7, which interfere with critical cell cycle pathways, tumor protein p53, and retinoblastoma protein. However, evidence suggests that HPV infection alone is insufficient to induce malignant changes, and other host genetic variations are important in the development of cervical cancer. Advances in molecular biology and high throughput technologies have heralded a new era in biomarker discovery and identification of molecular targets related to carcinogenesis. These advancements have improved our understanding of carcinogenesis and will facilitate screening, early detection, management, and personalized targeted therapy. A number of these developments and molecular targets associated with cervical cancer will be addressed in this review.

Comparative study of four candidate strategies to detect cervical cancer in different health care settings

AIM

Considering the differing but potentially supplementary properties of visual inspection of the cervix with acetic acid (VIA) and the cytological examination (CYTO) of cervical smears for the screening of cervical cancers, we examined the performance of these two tests and their combinations for the screening of cervical cancer in different health care settings.

METHODS

In this cross-sectional diagnostic test performance evaluation study of 4235 female subjects in the reproductive age group, we assessed the screening performance of four strategies: VIA alone, CYTO alone, VIA and CYTO combined in a parallel fashion, and VIA and CYTO combined in tandem. Subjects were recruited from three settings: Hospital, Urban Community and Rural Community. Colposcopy was used as the reference standard. Screening performance was assessed using sensitivity, specificity, post-test probabilities and likelihood ratios (LR), diagnostic odds, area under receiver operating characteristic curve and LR chi(2).

RESULTS

Both VIA and CYTO when used alone had a low sensitivity but high specificity, especially in the Rural Community setting. A combination of the results of VIA and CYTO improved the diagnostic accuracy but the strategy using a parallel combination of VIA and CYTO was the most accurate. In general, all screening strategies using VIA and CYTO showed a modest screening performance.

CONCLUSIONS

In the settings of varying levels of health care and low resources, caution is needed for a generalized use of VIA for cervical cancer screening. Further evaluation of the cost-effective ways of combining VIA and CYTO is needed in these circumstances.

A simple array platform for microRNA analysis and its application in mouse tissues

MicroRNAs (miRNAs) are a novel class of small noncoding RNAs that regulate gene expression at the post-transcriptional level and play a critical role in many important biological processes. Most miRNAs are conserved between humans and mice, which makes it possible to analyze their expressions with a set of selected array probes. Here, we report a simple array platform that can detect 553 nonredundant miRNAs encompassing the entire set of miRNAs for humans and mice. The platform features carefully selected and designed probes with optimized hybridization parameters. Potential cross-reaction between mature miRNAs and their precursors was investigated. The array platform was used to analyze miRNAs in the mouse central nervous system (CNS, spinal cord and brain), and two other non-CNS organs (liver and heart). Two types of miRNAs, differentially expressed organ/tissue-associated miRNAs and ubiquitously expressed miRNAs, were detected in the array analysis. In addition to the previously reported neuron-related miR-124a, liver-related miR-122a, and muscle-related miR-133a, we also detected new tissue-associated miRNAs (e.g., liver-associated miR-194). Interestingly, while the majority of pre-miRNAs were undetectable, miR690, miR709, and miR720 were clearly detected at both mature and precursor levels by the array analysis, indicating a limited cross-reaction between pre-miRNAs and their mature miRNAs. The reliability of this array technology was validated by comparing the results with independent Northern blot analyses and published data. A new approach of data normalization based on Northern blot analysis of one ubiquitously expressed miRNA is introduced and compared with traditional approaches. We expect this miRNA array platform to be useful for a wide variety of biological studies.

Human papillomavirus testing and molecular markers of cervical dysplasia and carcinoma

Cervical cancer is the second most common cancer in women worldwide. Human papillomavirus (HPV) is the etiologic agent for the vast majority of premalignant and malignant lesions, and high-risk HPV types can be detected in almost all cases of cervical dysplasia and carcinoma. HPV testing has been widely adopted for the triage of patients after a cervical cytology screening test (Papanicolaou smear or liquid-based cervical cytology such as ThinPrep or SurePath) interpretation of atypical squamous cells of undetermined significance (ASCUS), and HPV testing is increasingly used for screening in conjunction with cervical cytology. Although cervical cytology is a highly effective screening test for cancer, it has limited specificity for clinically significant lesions in cases with low-grade cytologic abnormalities. Up to a quarter of all patients may have a false-negative result on the basis of cervical cytology testing alone. This review focuses on HPV testing methods and molecular markers and their clinical relevance. HPV testing and surrogate molecular markers of HPV infection (p16INK4a) may help identify cases that are associated with underlying high-grade premalignant or malignant lesions and may also reduce aggressive treatment of patients with low-grade lesions.