Association between the stages of cervical cancer and chromosome 1 aneusomy

DBD-FISH Using Specific Chromosomal Region Probes for the Study of Cervical Carcinoma Progression

Genomic instability is an important biomarker in the progression of cervical carcinoma. DBD-FISH (DNA breakage detection-fluorescence in situ hybridization) is a sensitive method that detects strand breaks, alkali-labile sites, and incomplete DNA excision repair in cells of the cervical epithelium. This technique integrates the microgel immersion of cells from a vaginal lesion scraping and the DNA unwinding treatment with the capacity of FISH integrated into digital image analysis. Cells captured within an agarose matrix are lysed and submerged in an alkaline unwinding solution that generates single-stranded DNA motifs at the ends of internal DNA strand breaks. After neutralization, the microgel is dehydrated and the cells are incubated with DNA-labeled probes. The quantity of a hybridized probe at a target sequence corresponds to the measure of the single-stranded DNA produced during the unwinding step, which is equivalent to the degree of local DNA breakage. DNA damage does not show uniformly throughout the entire DNA of a cell; rather, it is confined to specific chromosomal sites. In this chapter, an overview of the technique is supplied, focusing on its ability for assessing the association between DNA damage in specific sequences and in the progressive stages of cervical carcinoma.

Use of micronucleus assays for the prediction and detection of cervical cancer: a meta-analysis

Cervical cancer (CC) is the fourth most common cancer in women; the survival rates depend strongly on its early detection. The Pap test is the most frequently used diagnostic tool, but due to its limited sensitivity/specificity, additional screening tests are needed. Therefore, we evaluated the use of micronucleus (MN) assays with cervical cells for the prediction and diagnosis of CC. MN reflects structural and numerical chromosomal aberrations. A search was performed in Pubmed, Scopus, Thomson ISI and Google Scholar. Subsequently, meta-analyses were performed for different grades of abnormal findings in smears and biopsies from patients which were diagnosed with CC. Results of 21 studies in which findings of MN experiments were compared with data from Pap tests show that higher MN frequencies were found in women with abnormal cells that are indicative for increased cancer risks. MN frequency ratios increased in the order inflammation (2.1) < ASC-US and ASC-H (3.3) < LGSIL (4.4) < HGSIL (8.4). Furthermore, results are available from 17 investigations in which MN were scored in smears from patients with neoplasia. MN rates increased with the degree of neoplasia [CIN 1 (4.6) < CIN 2 (6.5) and CIN 3 (10.8)] and were significantly higher (8.8) in CC patients. Our meta-analysis indicates that the MN assay, which is easy to perform in combination with Pap tests, may be useful for the detection/prediction of CC. However, standardization (including definition of the optimal cell numbers and stains) and further validation is necessary before the MN test can be implemented in routine screening.

Impact of infections, preneoplasia and cancer on micronucleus formation in urothelial and cervical cells: A systematic review

Approximately 165,000 and 311,000 individuals die annually from urothelial (UC) and cervical (CC) cancer. The therapeutic success of these cancers depends strongly on their early detection and could be improved by use of additional diagnostic tools. We evaluated the current knowledge of the use of micronucleus (MN) assays (which detect structural and numerical chromosomal aberrations) with urine- (UDC) and cervix-derived (CDC) cells for the identification of humans with increased risks and for the diagnosis of UC and CC. Several findings indicate that MN rates in UDC are higher in individuals with inflammation and schistosomiasis that are associated with increased prevalence of UC; furthermore, higher MN rates were also found in CDC in women with HPV, Candidiasis and Trichomonas infections which increase the risks for CC. Only few studies were published on MN rates in UDS in patients with UC, two concern the detection of recurrent bladder tumors. Strong correlations were found in individuals with abnormal CC cells that are scored in Pap tests and histopathological abnormalities. In total, 16 studies were published which concerned these topics. MN rates increased in the order: inflammation < ASC-US/ASC-H < LSIL < HSIL < CC. It is evident that MNi numbers increase with the risk to develop CC and with the degree of malignant transformation. Overall, the evaluation of the literature indicates that MNi are useful additional biomarkers for the prognosis and detection of CC and possibly also for UC. In regard to the diagnosis/surveillance of UC, further investigations are needed to draw firm conclusions, but the currently available data are promising. In general, further standardization of the assays is needed (i.e. definition of optimal cell numbers and of suitable stains as well as elucidation of the usefulness of parameters reflecting cytotoxicity and mitotic activity) before MN trials can be implemented in routine screening.

Revisiting the Genomic and Transcriptomic Landscapes from Female Malignancies Could Provide Molecular Markers and Targets for Precision Medicine

AIMS

Gynaecological malignancies such as breast, ovarian and cervical cancers have become an important public health problem. Detection of molecular alterations in cancer research is fundamental since it can reveal specific pathogenic patterns and genes that could serve as markers. Our aim was to characterize common genomic and transcriptomic signatures for the three gynaecologic malignancies with the highest incidence and mortality to try to identify new molecular markers, therapeutic targets and molecular signatures.

METHODS

Here we analysed a total of 723 microarray libraries corresponding to equal number of breast, ovary and cervical cancer and non-cancer patient samples. Copy number variation (CNV) was carried out using 428 libraries and transcriptomic analysis using the 295 remaining samples.

RESULTS

Our results showed that breast, ovary and cervical malignancies are characterized by gain of 1q chromosome. At transcriptomic level, they share 351 coding and non-coding genes, which could represent core transcriptome of gynaecological malignancies. Pathway analysis from the resulting gene lists from CNV and expression showed participation in cell cycle, metabolism, and cell adhesion molecules among others.

CONCLUSIONS

Chromosome 1q characterize the gynaecological malignancies, which could harbour a richness of genetic repertoire to mine for molecular markers and targets, particular gynaecologic expression profile, containing FANCI, FH and MIR155HG among others, could represent part of the transcriptomic core for diagnostic test and attractive therapeutic targets. It may not be long before every human cancer sample is profiled for a detections test to ascertain a molecular diagnosis and prognosis and to define an optimal and precise treatment strategy.

Using low-coverage whole genome sequencing technique to analyze the chromosomal copy number alterations in the exfoliative cells of cervical cancer

Objectives

We analyzed the chromosomal-arm-level copy number alterations (CNAs) in the cervical exfoliative cell and tissue samples by using the low-coverage whole genomic sequencing technique.

Methods

In this study, we retrospectively collected 55 archived exfoliated cervical cell suspension samples and the corresponding formalin-fixed and paraffin-embedded tissue section samples including 27 invasive cervical cancer and 28 control cases. We also collected 19 samples of the cervical exfoliative cells randomly from women to verify the new algorithm model. We analyzed the CNAs in cervical exfoliated cell and tissue samples by using the low-coverage next generation of sequencing.

Results

In the model-building study, multiple chromosomal-arm-level CNAs were detected in both cervical exfoliated cell and tissue samples of all cervical cancer cases. By analyzing the consistency of CNAs between exfoliated cells and cervical tissue samples, as well as the heterogeneity in individual patient, we also established a C-score algorithm model according to the chromosomal-arm-level changes of 1q, 2q, 3p, 7q. The C-score model was then validated by the pathological diagnosis of all 74 exfoliated cell samples (including 55 cases in model-building group and 19 cases in verification group). In our result, a cutoff value of C-score >6 showed 100% sensitivity and 100% specificity in the diagnosis of cervical cancer.

Conclusion

In this study, we found that CNAs of cervical exfoliated cell samples could robustly distinguish invasive cervical cancer from cancer-free tissues. And we have also developed a C-score algorithm model to process the sequencing data in a more standardized and automated way.

The Role of Chromosomal Instability in Cancer and Therapeutic Responses

Cancer is one of the leading causes of death, and despite increased research in recent years, control of advanced-stage disease and optimal therapeutic responses remain elusive. Recent technological improvements have increased our understanding of human cancer as a heterogeneous disease. For instance, four hallmarks of cancer have recently been included, which in addition to being involved in cancer development, could be involved in therapeutic responses and resistance. One of these hallmarks is chromosome instability (CIN), a source of genetic variation in either altered chromosome number or structure. CIN has become a hot topic in recent years, not only for its implications in cancer diagnostics and prognostics, but also for its role in therapeutic responses. Chromosomal alterations are mainly used to determine genetic heterogeneity in tumors, but CIN could also reveal treatment efficacy, as many therapies are based on increasing CIN, which causes aberrant cells to undergo apoptosis. However, it should be noted that contradictory findings on the implications of CIN for the therapeutic response have been reported, with some studies associating high CIN with a better therapeutic response and others associating it with therapeutic resistance. Considering these observations, it is necessary to increase our understanding of the role CIN plays not only in tumor development, but also in therapeutic responses. This review focuses on recent studies that suggest possible mechanisms and consequences of CIN in different disease types, with a primary focus on cancer outcomes and therapeutic responses.

An Optimization-Driven Analysis Pipeline to Uncover Biomarkers and Signaling Paths: Cervix Cancer

Establishing how a series of potentially important genes might relate to each other is relevant to understand the origin and evolution of illnesses, such as cancer. High-throughput biological experiments have played a critical role in providing information in this regard. A special challenge, however, is that of trying to conciliate information from separate microarray experiments to build a potential genetic signaling path. This work proposes a two-step analysis pipeline, based on optimization, to approach meta-analysis aiming to build a proxy for a genetic signaling path.

5-bp Classical Satellite DNA Loci from Chromosome-1 Instability in Cervical Neoplasia Detected by DNA Breakage Detection/Fluorescence in Situ Hybridization (DBD-FISH)

We aimed to evaluate the association between the progressive stages of cervical neoplasia and DNA damage in 5-bp classical satellite DNA sequences from chromosome-1 in cervical epithelium and in peripheral blood lymphocytes using DNA breakage detection/fluorescence in situ hybridization (DBD-FISH). A hospital-based unmatched case-control study was conducted in 2011 with a sample of 30 women grouped according to disease stage and selected according to histological diagnosis; 10 with low-grade squamous intraepithelial lesions (LG-SIL), 10 with high-grade SIL (HG-SIL), and 10 with no cervical lesions, from the Unidad Medica de Alta Especialidad of The Mexican Social Security Institute, IMSS, Mexico. Specific chromosome damage levels in 5-bp classical satellite DNA sequences from chromosome-1 were evaluated in cervical epithelium and peripheral blood lymphocytes using the DBD-FISH technique. Whole-genome DNA hybridization was used as a reference for the level of damage. Results of Kruskal-Wallis test showed a significant increase according to neoplastic development in both tissues. The instability of 5-bp classical satellite DNA sequences from chromosome-1 was evidenced using chromosome-orientation FISH. In conclusion, we suggest that the progression to malignant transformation involves an increase in the instability of 5-bp classical satellite DNA sequences from chromosome-1.

Chromosome aberrations in peripheral blood lymphocytes of high-risk HPV-infected women with HGSIL

Genomic instability is one of the main characteristics of malignant tumors, including HPV-induced cervical cancer. The aim of this study was to explore the use of assessing chromosome aberrations (CA) in peripheral blood lymphocytes as a biomarker for genomic instability in high-risk HPV-infected women with high-grade squamous intraepithelial lesions (HGSIL). A total of 120 women were recruited for this study, following cytology/colposcopy evaluation and HPV DNA detection. The study groups consisted of 30 HPV(+) women with histologically confirmed cervical intraepithelial neoplasia grade 2/3 and 30 HPV(+) women with carcinoma in situ (CIS). Two control groups, including 30 women HPV(-) and 30 women HPV(+), were recruited among women who were reported as cytology negative. Lymphocyte cell cultures were established for 52 hr, and 100 complete metaphase cells were evaluated per subject for CA analysis. The results show that women with CIS had significantly higher frequencies of both aneuploidy (0.67 +/- 0.20 vs. 0.14 +/- 0.08, P = 0.020) and tetraploidy (0.88 +/- 0.23 vs. 0.17 +/- 0.08, P = 0.013) in comparison with HPV(-) controls. These findings suggest the usefulness of peripheral blood lymphocytes to detect genomic instability associated with HPV-induced HGSIL.

Chromosome 11 aneusomy in esophageal cancers and precancerous lesions- an early event in neoplastic transformation: An interphase fluorescence in situ hybridization study from south India

AIM: To detect aneusomic changes with respect to chromosome 11 copy number in esophageal precancers and cancers wherein the generation of cancer-specific phenotypes is believed to be associated with specific chromosomal aneuploidies.

METHODS: We performed fluorescence in situ hybridization (FISH) on esophageal tissue paraffin sections to analyze changes in chromosome 11 copy number using apotome-generated images by optical sectioning microscopy. Sections were prepared from esophageal tumor tissue, tissues showing preneoplastic changes and histologically normal tissues (control) obtained from patients referred to the clinic for endoscopic evaluation.

RESULTS: Our results demonstrated that aneusomy was seen in all the cancers and preneoplastic tissues, while none of the controls showed aneusomic cells. There was no increase in aneusomy from precancers to cancers.

CONCLUSION: Our results suggest that evaluation of chromosome 11 aneusomy in esophageal tissue using FISH with an appropriate signal capture-analysis system, can be used as an ancillary molecular marker predictive of early neoplastic changes. Future studies can be directed towards the genes on chromosome 11, which may play a role in the neoplastic transformation of esophageal precancerous lesions to cancers.