Senescence and apoptosis in carcinogenesis of cervical squamous carcinoma

Immunohistochemical markers Ki67 and P16 help predict prognosis in locally advanced cervical cancer

OBJECTIVE

To investigate the relationship between Ki-67 and P16 expression levels after neoadjuvant chemotherapy, and the clinicopathological characteristics and prognosis of patients with locally advanced cervical cancer.

METHODS

Patients with FIGO 2009 stage IB2 or IIA2 cervical cancer, who underwent neoadjuvant chemotherapy combined with radical hysterectomy at the First Affiliated Hospital of Chongqing Medical University between January 2015 and December 2019, were identified retrospectively to correlate postoperative Ki-67 and P16 expression levels with clinicopathological factors. The optimal threshold for predicting recurrence was analysed using receiver operating characteristic (ROC) curves for the Ki-67 index, and univariate and multi-factorial Cox regression analysis were used to investigate the association between clinicpathological features including Ki-67 and P16 and recurrence-free survival.

RESULTS

In total, 334 patients were included after screening. The cut-off value of Ki-67 for determining recurrence was 67.5 % according to the ROC curve. On multi-factorial Cox analysis, lymphatic vascular space (p = 0.003) and Ki-67 index (p = 0.005) were shown to increase the risk of recurrence, and were independent prognostic factors for recurrence, while the expression of P16 was not significantly associated with the risk of recurrence (p = 0.097, odds ratio = 0.319). Patients with cervical cancer in the high Ki-67 expression group (Ki-67 ≥ 67.5 %) had lower recurrence-free survival and overall survival than patients in the low Ki-67 expression group (Ki-67 < 67.5 %) (p = 0.001 and 0.036, respectively).

CONCLUSION

The expression levels of Ki-67 and P16 after neoadjuvant chemotherapy for locally advanced cervical cancer correlated with tumour differentiation. High expression of Ki-67 (Ki-67 ≥ 67.5 %) may indicate poorer recurrence-free survival and overall survival.

Eight Aging-Related Genes Prognostic Signature for Cervical Cancer

This study searched for aging-related genes (ARGs) to predict the prognosis of patients with cervical cancer (CC). All data were obtained from Molecular Signatures Database, Cancer Genome Atlas, Gene Expression Integration, and Genotype Organization Expression. The R software was used to screen out the differentially expressed ARGs (DE-ARGs) between CC and normal tissues. A protein-protein interaction network was established by the DE-ARGs. The univariate and multivariate Cox regression analyses were conducted on the first extracted Molecular Complex Detection component, and a prognostic model was constructed. The prognostic model was further validated in the testing set and GSE44001 dataset. Prognosis was analyzed by Kaplan-Meier curves, and accuracy of the prognostic model was assessed by receiver operating characteristic area under the curve analysis. An independent prognostic analysis of risk score and some clinicopathological factors of CC was also performed. The copy-number variant (CNV) and single-nucleotide variant (SNV) of prognostic ARGs were analyzed by the BioPortal database. A clinical practical nomogram was established to predict individual survival probability. Finally, we carried out cell experiment to further verify the prognostic model. An eight-ARG prognostic signature for CC was constructed. High-risk CC patients had significantly shorter overall survival than low-risk patients. The receiver operating characteristic (ROC) curve validated the good performance of the signature in survival prediction. The Figo_stage and risk score served as independent prognostic factors. The eight ARGs mainly enriched in growth factor regulation and cell cycle pathway, and the deep deletion of FN1 was the most common CNV. An eight-ARG prognostic signature for CC was successfully constructed.

Cellular senescence in cancer: clinical detection and prognostic implications

Cellular senescence is a state of stable cell-cycle arrest with secretory features in response to cellular stress. Historically, it has been considered as an endogenous evolutionary homeostatic mechanism to eliminate damaged cells, including damaged cells which are at risk of malignant transformation, thereby protecting against cancer. However, accumulation of senescent cells can cause long-term detrimental effects, mainly through the senescence-associated secretory phenotype, and paradoxically contribute to age-related diseases including cancer. Besides its role as tumor suppressor, cellular senescence is increasingly being recognized as an in vivo response in cancer patients to various anticancer therapies. Its role in cancer is ambiguous and even controversial, and senescence has recently been promoted as an emerging hallmark of cancer because of its hallmark-promoting capabilities. In addition, the prognostic implications of cellular senescence have been underappreciated due to the challenging detection and sparse in and ex vivo evidence of cellular senescence in cancer patients, which is only now catching up. In this review, we highlight the approaches and current challenges of in and ex vivo detection of cellular senescence in cancer patients, and we discuss the prognostic implications of cellular senescence based on in and ex vivo evidence in cancer patients.

Senolytic Therapy: A Potential Approach for the Elimination of Oncogene-Induced Senescent HPV-Positive Cells

Senescence represents a unique cellular stress response characterized by a stable growth arrest, macromolecular alterations, and wide spectrum changes in gene expression. Classically, senescence is the end-product of progressive telomeric attrition resulting from the repetitive division of somatic cells. In addition, senescent cells accumulate in premalignant lesions, in part, as a product of oncogene hyperactivation, reflecting one element of the tumor suppressive function of senescence. Oncogenic processes that induce senescence include overexpression/hyperactivation of H-Ras, B-Raf, and cyclin E as well as inactivation of PTEN. Oncogenic viruses, such as Human Papilloma Virus (HPV), have also been shown to induce senescence. High-risk strains of HPV drive the immortalization, and hence transformation, of cervical epithelial cells via several mechanisms, but primarily via deregulation of the cell cycle, and possibly, by facilitating escape from senescence. Despite the wide and successful utilization of HPV vaccines in reducing the incidence of cervical cancer, this measure is not effective in preventing cancer development in individuals already positive for HPV. Accordingly, in this commentary, we focus on the potential contribution of oncogene and HPV-induced senescence (OIS) in cervical cancer. We further consider the potential utility of senolytic agents for the elimination of HPV-harboring senescent cells as a strategy for reducing HPV-driven transformation and the risk of cervical cancer development.

ROC-analysis derived immunohistochemical P53 cut-off scores as an adjunct to routine histopathology for better diagnostic compartmentalisation of cervical lesions

Objective

The aim of this study was to evaluate the predictive value of Immunohistochemical p53 cut-off scores as an adjunct to routine histopathology for better diagnosis of cervical lesions.

Materials and Methods

Prospective study carried out for 1 year. After ethical approval and informed consent, a total of 100 cervical tissue samples were analyzed; chronic cervicitis (CC)-15, cervical intraepithelial neoplasia (CIN)-40, and squamous cell carcinoma cervix (SCC)-45 (FIGO 2018 clinical staging). After routine processing of tissue specimen, hematoxylin and eosin (HE) staining was done. Grading of cervical precancerous lesions (CIN) was done as per World Health Organisation criteria as CIN 1,2 or 3. Broder’s grading was assigned for every SCC sample.

Results

Mean p53 scores of CC, CIN, and SCC cases were 0.0, 1.70, and 4.38, respectively, CIN 1, 2, and 3 were 1.07, 1.63, and 2.22, respectively. SCC was differentiated from CIN3 with p53 ≥4.5 as predictor for SCC, sensitivity and specificity were 57.8% and 88.9%, respectively. Overall diagnostic accuracy of the proposed scoring system for differentiating CC, CIN, and SCC was 61%, while the accuracy of previous methods of interpreting p53 immunoreactivity as immunoscore >2 or arbitrary cut-off of >10% cells with nuclear positivity was only 48%.

Conclusion

ROC-derived immunoscore cut-offs can provide the much-needed objectivity and optimal decision thresholds to immunohistochemistry interpretation.

Quick assessment of DNA damage in cervical epithelial cells using a chromatin dispersion test

PURPOSE

This study was aimed to quantify genomic DNA breakages in the cervical epithelium cells of patients diagnosed with different grades of cervical lesions using a quick test based on chromatin dispersion after controlled protein depletion. The association between the progressive stages of cervical dysplasia and the levels of DNA damage, taking into account the presence of papillomavirus human (HPV) infection, was investigated.

METHODS

A hospital-based unmatched case-control study was conducted during 2018 with a sample of 78 women grouped according to histological diagnosis as follows: 23 women with low grade-squamous intraepithelial lesion (LG-SIL), 34 women with high grade- squamous intraepithelial lesion (HG-SIL), and three women with cervical carcinoma (CC). In parallel, 15 women without cervical lesions were included as a Control cohort. DNA damage levels in cervical epithelial cells were assessed using the chromatin dispersion test (CDT) and controlled in parallel with DNA breakage detection coupled with florescent in situ hybridization (DBD‒FISH) using whole genomic DNA probes.

RESULTS

CDT produces different morphotypes in the cervical epithelium that can be associated with the level of DNA breakage revealed with DBD‒FISH. A significant increase of DNA damage was correlated with the histological progression of the patients and human papillomavirus (HPV) infection.

CONCLUSION

The CDT is a simple, accurate and inexpensive morphological bioassay to identify different levels DNA damage that can be associated with the level of abnormal cells present in the cervical epithelium in patients who commonly present HPV infection.

Systems Pharmacology Study of the Anticervical Cancer Mechanisms of FDY003

Increasing data support that herbal medicines are beneficial in the treatment of cervical cancer; however, their mechanisms of action remain to be elucidated. In the current study, we used a systems pharmacology approach to explore the pharmacological mechanisms of FDY003, an anticancer herbal formula comprising Lonicera japonica Thunberg, Artemisia capillaris Thunberg, and Cordyceps militaris (Linn.) Link, in the treatment of cervical cancer. Through the pharmacokinetic assessment of absorption-distribution-metabolism-excretion characteristics, we found 18 active compounds that might interact with 106 cervical cancer-related targets responsible for the pharmacological effects. FDY003 targets were significantly associated with gene ontology terms related to the regulation of cellular behaviors, including cell proliferation, cell cycle processes, cell migration, cell apoptosis, cell death, and angiogenesis. The therapeutic targets of the herbal drug were further enriched in various oncogenic pathways that are implicated in the tumorigenesis and progression of cervical cancer, including the phosphatidylinositol 3-kinase, mitogen-activated protein kinase, focal adhesion, human papillomavirus infection, and tumor necrosis factor signaling pathways. Our study provides a systematic approach to explore the anticancer properties of herbal medicines against cervical cancer.

Risk Categorization with Different Grades of Cervical Pre-Neoplastic Lesions - High Risk HPV Associations and Expression of p53 and RARβ

Objective:

To identify high risk HPV associations by evaluating linked p16 overexpression and also the expression of p53 and RARβ together with histopathology for risk categorization of cervical pre-neoplastic lesions.

Materials and Methods:

Immunohistochemical staining was performed on 100 cases of cervical pre- neoplastic lesions for expression of biomarkers like p16, p53 and RARβ for comparison with haematoxylin/eosin (HE) findings. All the experimentally generated data were statistically analyzed.

Results:

In this study 70% cases showed overexpression of p16INK4A increasing progressively from CIN I to CIN II but reduced in CIN III (p <0.01). p53 oncoprotein expression was seen in 51% cases, again with increments from CIN I to CIN II with slight reduction in CIN III (p<0.01). Some 24% cases showed negative immunoreactivity for the putative tumor suppressor gene RARβ (p>0.05).

Conclusion:

Our study provides support for the idea that p16 can be used to identify associations with HPV , as well as having potential along with p53 and RARβ for categorizing cervical pre-neoplastic cases having a higher risk of neoplastic conversion. Thus it may be concluded that accurate risk categorization can be achieved with the help of genetic markers as well as histopathology.

Evaluation of p16/Ki-67 dual staining in the detection of cervical precancer and cancer in China

Background This study aimed to evaluate the clinical performance of p16/Ki-67 dual staining in the detection of cervical intraepithelial neoplasia grade 2 or 3 or worse (CIN2+/CIN3+) in Chinese women. Methods Cervical exfoliated cells were collected from 537 eligible women and were used for liquid-based cytology (LBC), p16/Ki-67 dual staining, and human papillomavirus (HPV) DNA testing. All women received colposcopy with biopsies taken at abnormal sites. Histopathological diagnoses were used as the gold standard. Results p16/Ki-67 staining had a positivity rate of 43.58% overall; the rate increased significantly with histological severity (p <0.001). The sensitivities of p16/ki-67 for detecting CIN2+ and CIN3+ were 88.10% and 91.30%, respectively. Compared with high-risk HPV (HR-HPV), sensitivity of p16/Ki-67 was lower for detecting CIN2+ (88.10% versus 95.71%), but similar for detecting CIN3+ (91.30% versus 96.27%). Specificities of p16/Ki-67 were 85.02% for detecting CIN2+ and 76.86% for detecting CIN3+, values similar to those for LBC (84.71% for CIN2+, 80.05% for CIN3+) but higher than those for HR-HPV (62.77% for CIN2+, 71.25% for CIN3+). All the tests performed better in women>30 years. With respect to the performance of triage for women with ASC-US, sensitivities of p16/Ki-67 were 86.36% for detecting CIN2+ and 83.33% for detecting CIN3+, values similar to those of HR-HPV. However, specificities of p16/Ki-67 were both higher than those of HR-HPV (85.96% versus 67.54% for CIN2+, 79.84% versus 62.90% for CIN3+). Conclusion P16/Ki-67 dual staining could probably provide an optional method for China's national cervical cancer screening, and could also be considered as an efficient method of triage for managing women with ASC-US.

Recent Advances on the Molecular Mechanism of Cervical Carcinogenesis Based on Systems Biology Technologies

Cervical cancer is one of the common malignancies in women worldwide. Exploration of pathogenesis and molecular mechanism of cervical cancer is pivotal for development of effective treatment for this disease. Recently, systems biology approaches based on high-throughput technologies have been carried out to investigate the expression of some genes and proteins in genomics, transcriptomics, proteomics, and metabonomics of cervical cancer. Compared with traditional methods，systems biology technology has been shown to provide large of information regarding prognostic biomarkers and therapeutic targets for cervical cancer. These molecular signatures from system biology technology could be useful to understand the molecular mechanisms of cervical cancer development and progression, and help physicians to design targeted therapeutic strategies for patients with cervical cancer.

Morphoproteomics, E6/E7 in-situ hybridization, and biomedical analytics define the etiopathogenesis of HPV-associated oropharyngeal carcinoma and provide targeted therapeutic options

BACKGROUND

Human papillomavirus (HPV) has been identified as an etiopathogenetic factor in oropharyngeal squamous cell carcinoma. The HPV E6 and E7 oncogenes are instrumental in promoting proliferation and blocking differentiation leading to tumorigenesis. Although surgical intervention can remove such tumors, the potential for an etiologic field effect with recurrent disease is real. A downstream effector of E7 oncoprotein, enhancer of zeste homolog 2 (EZH2), is known to promote proliferation and to pose a block in differentiation and in turn, could lead to HPV-induced malignant transformation. However, the EZH2 pathway is amenable to low toxicity therapies designed to promote differentiation to a more benign state and prevent recurrent disease by inhibiting the incorporation of HPV into the genome. This is the first study using clinical specimens to demonstrate EZH2 protein expression in oropharyngeal carcinoma (OPC).

METHODS

The study included eight patients with oropharyngeal carcinoma, confirmed p16INK4a- positive by immunohistochemistry (IHC). The tissue expression of E6/E7 messenger RNA (mRNA) was measured by RNAscope® in-situ hybridization technology. Expression of EZH2, Ki-67, and mitotic indices were assessed by morphoproteomic analysis. Biomedical analytics expanded the results with data from Ingenuity Pathway Analysis (IPA) and KEGG databases to construct a molecular network pathway for further insights.

RESULTS

Expression of E6 and E7 oncogenes in p16INK4a- positive oropharyngeal carcinoma was confirmed. EZH2 and its correlates, including elevated proliferation index (Ki-67) and mitotic progression were also present. Biomedical analytics validated the relationship between HPV- E6 and E7 and the expression of the EZH2 pathway.

CONCLUSION

There is morphoproteomic and mRNA evidence of the association of p16INK4a-HPV infection with the E6 and E7 oncogenes and the expression of EZH2, Ki-67 and mitotic progression in oropharyngeal carcinoma. The molecular network biology was confirmed by biomedical analytics as consistent with published literature. This is significant because the biology lends itself to targeted therapeutic options using metformin, curcumin, celecoxib and sulforaphane as therapeutic strategies to prevent progression or recurrence of disease.

Human papillomavirus dysregulates the cellular apparatus controlling the methylation status of H3K27 in different human cancers to consistently alter gene expression regardless of tissue of origin

High-risk human papillomaviruses (HPV) cause cancer at multiple distinct anatomical locations. Regardless of the tissue of origin, most HPV positive (HPV+) cancers show highly upregulated expression of the p16 product of the cyclin-dependent kinase inhibitor 2A (CDKN2A) gene. Paradoxically, HPV+ tumor cells require continuous expression of this tumor suppressor for survival. Thus, restoration of normal p16 regulation has potential therapeutic value against HPV induced cancers. Normally, p16 transcription is tightly controlled at the epigenetic level via polycomb repressive complex-mediated tri-methylation of histone 3 lysine 27 (H3K27me3). Although a mechanism by which HPV induces p16 has been proposed based on tissue culture models, it has not been extensively validated in human tumors. In this study, we used data from over 800 human cervical and head and neck tumors from The Cancer Genome Atlas (TCGA) to test this model. We determined the impact of HPV status on expression from the CDKN2A locus, the adjacent CDKN2B locus, and transcript levels of key epigenetic regulators of these loci. As expected, HPV+ tumors from both anatomical sites exhibited high levels of p16. Furthermore, HPV+ tumors expressed higher levels of KDM6A, which demethylates H3K27me3. CpG methylation of the CDKN2A locus was also consistently altered in HPV+ tumors. This data validates previous tissue culture studies and identifies remarkable similarities between the effects of HPV on gene expression and DNA methylation in both cervical and oral tumors in large human cohorts. Furthermore, these results support a model whereby HPV-mediated dysregulation of CDKN2A transcription requires KDM6A, a potentially druggable target.

Expression/localization patterns of sirtuins (SIRT1, SIRT2, and SIRT7) during progression of cervical cancer and effects of sirtuin inhibitors on growth of cervical cancer cells

Sirtuins belong to the family of class III histone deacetylases; its role in neoplasia is controversial as both tumor-suppressive and promoting functions have been reported. There are very few reports available, where expressions of sirtuin isoforms are comprehensively analyzed during neoplasia. Therefore, in the present study, the expression of SIRT1, SIRT2, and SIRT7 during different stages of cervical cancer progression was analyzed. The normal cervical epithelium showed feeble expression of sirtuin isoforms, SIRT1, SIRT2, and SIRT7. A significant increase in SIRT1 expression was noted in the cytoplasm as well as in the nucleus of proliferative layers of cervical epithelium in squamous intraepithelial lesions (SIL); however, in the squamous cell carcinomas (SCC), a heterogeneous pattern of SIRT1 expression varying from low to high was noted. A progressive increase in the expression of both SIRT2 and SIRT7 was noted during cancer progression in the following order: normal < preneoplasia < cancer. Cervical cancer cell lines, HeLa and SiHa, showed higher levels of SIRT1 and SIRT2 in comparison to the immortalized cell counterpart, HaCaT. Specific inhibitors of SIRT1 (Ex527) and SIRT2 (AGK2) impaired the growth of the cervical cancer cells, SiHa, but not of the HaCaT cells. SIRT1 inhibition caused cell death, while SIRT2 inhibition resulted in cell cycle arrest. In conclusion, we report the overexpression of SIRT2 and SIRT7 proteins in cervical cancer and suggest probable application of sirtuin inhibitors as therapeutic targets. Further, a specific increase in the levels of SIRT1 in intraepithelial lesion makes it a promising candidate for identification of preneoplastic changes.

Immunohistochemical expression of apoptosis regulators in squamous cell carcinoma of the cervix and their association with human papillomavirus 16/18 subtypes

BACKGROUND

Human papillomavirus (HPV) infection is an important aetiological factor in squamous cell carcinoma (SCC) of the cervix. Limited studies have been focused on the differences between carcinogenesis of SCCs with and without HPV infection.

AIMS

The main goal of this study is to determine the expression of some of the apoptotic pathway regulators, including P53, Bax and Bcl2 in SCCs with and without high risk HPV 16/18 infection.

STUDY DESIGN

Cross sectional study.

METHODS

A total of 42 paraffin-embedded blocks with the histopathological diagnosis of invasive SCC with determined HPV 16/18 status were selected; half of them were HPV positive and the rest were negative. Afterwards, immunohistochemistry stained slides for p53, Bcl2 and Bax were evaluated with H-score, multiplicative and Additive Quick score by two pathologists; in cases of controversy about the results, the mean results were recorded.

RESULTS

Mean results and percentage of expression of our three markers were significantly higher in the HPV 16/18 infected group than in uninfected individuals: Respectively, the mean score for Bcl2, Bax and p53 staining according to H-scoring method was 68.5, 234, 106.4 in the HPV 16/18 infected group and 4.5, 218.8, 5.07 in the uninfected group; and the Multiplicative Quick score was 4, 14.6, 8.2 in the HPV 16/18 infected group and 3, 12.3, 3.5 in the uninfected group.

CONCLUSION

High risk HPVs possibly act in favour of apoptotic pathway inactivation. The significant difference in apoptotic pathway between SCCs with and without high risk HPVs suggests a different early carcinogenesis pathway.

Ocular expression and distribution of products of the POAG-associated chromosome 9p21 gene region

It has recently been shown that there are highly significant associations for common single nucleotide polymorphisms (SNPs) near the CDKN2B-AS1 gene region at the 9p21 locus with primary open angle glaucoma (POAG), a leading cause of irreversible blindness. This gene region houses the CDKN2B/p15^INK4B_,CDKN2A/p16^INK4A and p14ARF (rat equivalent, p19^ARF) tumour suppressor genes and is adjacent to the S-methyl-5′-thioadenosine phosphorylase (MTAP) gene. In order to understand the ocular function of these genes and, therefore, how they may be involved in the pathogenesis of POAG, we studied the distribution patterns of each of their products within human and rat ocular tissues. MTAP mRNA was detected in the rat retina and optic nerve and its protein product was localised to the corneal epithelium, trabecular meshwork and retinal glial cells in both human and rat eyes. There was a very low level of p16^INK4A mRNA present within the rat retina and slightly more in the optic nerve, although no protein product could be detected in either rat or human eyes with any of the antibodies tested. P19^ARF mRNA was likewise only present at very low levels in rat retina and slightly higher levels in the optic nerve. However, no unambiguous evidence was found to indicate expression of specific P19^ARF/p14^ARF proteins in either rat or human eyes, respectively. In contrast, p15^INK4B mRNA was detected in much higher amounts in both retina and optic nerve compared with the other genes under analysis. Moreover, p15^INK4B protein was clearly localised to the retinal inner nuclear and ganglion cell layers and the corneal epithelium and trabecular meshwork in rat and human eyes. The presented data provide the basis for future studies that can explore the roles that these gene products may play in the pathogenesis of glaucoma and other models of optic nerve damage.

Functional regulatory role of STAT3 in HPV16-mediated cervical carcinogenesis

Signal transducer and activator of transcription 3 (STAT3) is an oncogenic transcription factor constitutively active and aberrantly expressed in cervical cancer. However, the functional role of STAT3 in regulation of HPV's viral oncogene expression and downstream events associated with cervical carcinogenesis is not known. Our present study performed on HPV16-positive cervical cancer cell lines (SiHa and CaSki) and primary tumor tissues revealed a strong positive correlation of constitutively active STAT3 with expression of HPV16 E6 and E7 oncoproteins and a negative association with levels of p53 and pRB. Pharmacologic targeting of STAT3 expression in cervical cancer cell lines either by STAT3-specific siRNA or blocking its tyrosine phosphorylation by AG490 or curcumin led to dose-dependent accumulation of p53 and pRb in cervical cancer cells. Interestingly, the suppression of STAT3 expression or activation was associated with the gradual loss of HPV16 E6 and E7 expression and was accompanied by loss of cell viability. The viability loss was specifically high in HPV16-positive cells as compared to HPV negative C33a cells. These findings substantiate the regulatory role of STAT3 in HPV16-mediated cervical carcinogenesis. Leads obtained from the present study provide a strong rationale for developing novel STAT3-based approaches for therapeutic interventions against HPV infection to control cervical cancer.

Silencing of the DEK gene induces apoptosis and senescence in CaSki cervical carcinoma cells via the up-regulation of NF-κB p65

The human DEK proto-oncogene has been found to play an important role in autoimmune disease, viral infection and human carcinogenesis. Although it is transcriptionally up-regulated in cervical cancer, its intracellular function and regulation is still unexplored. In the present study, DEK and IκBα [inhibitor of NF-κB (nuclear factor κB) α] shRNAs (short hairpin RNAs) were constructed and transfected into CaSki cells using Lipofectamine™. The stable cell line CaSki-DEK was obtained after G418 selection. CaSki-IκB cells were observed at 48 h after psiRNA-IκB transfection. The inhibitory efficiency of shRNAs were detected by RT (reverse transcription)-PCR and Western blot analysis. The proliferation activity of cells were measured using an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay, cell apoptosis was measured using an Annexin V/PI (propidium iodide) kit, the cell cycle was analysed by flow cytometry and cell senescence was detected using senescence β-galactosidase staining. The intracellular expression of NF-κB p65 protein was studied by cytochemistry. The expression levels of NF-κB p65, p50, c-Rel, IκBα and phospho-IκBα protein were analysed by immunoblotting in whole-cell lysates, cytosolic fractions and nuclear extracts. The protein expression and activity of p38 and JNK (c-Jun N-terminal kinase) were also assayed. In addition, the NF-κB p65 DNA-binding activity was measured by ELISA. Following the silencing of DEK and IκBα, cell proliferation was inhibited, apoptosis was increased, the cell cycle was blocked in the G0/G1-phase with a corresponding decrease in the G2/M-phase, and cell senescence was induced. All of these effects may be related to the up-regulation of NF-κB p65 expression and its nuclear translocation.

p16INK⁴a and p14ARF mRNA expression in Pap smears is age-related

Expression of high-risk HPV oncogenes results in a strong overexpression of cellular protein p16(INK4a). Immunohistochemical staining for p16(INK4a) is widely used as diagnostic marker. However, p16(INK4a) upregulation was also described as a biomarker of age. Here we analyzed p16(INK4a) expression in cervical smears to investigate if patient age may influence p16(INK4a)-based cervical cancer diagnosis. p14(ARF) was analyzed as a related supportive biomarker. Cervical scrapes were taken and stored in RNAlater. Total RNA was extracted, and cDNA was analyzed for expression of p16(INK4a) and p14(ARF) relative to β-actin, by real-time reverse transcriptase PCR SYBR-Green I assays. Patient-derived smears referred as HSIL (n=45) had 6.27-fold higher p16(INK4a) mRNA expression than smears of cytologically normal and HPV-negative persons (n=48). Expression of p14(ARF) was 4.87-fold higher. When women with normal diagnoses were stratified for age, a significantly enhanced p16(INK4a) (2.88-fold) and p14(ARF) (1.9-fold) expression was observed as a consequence of ageing. A significant age-dependent upregulation was also observed in older HSIL patients (2.54-fold). Our study revealed significantly enhanced expression of p16(INK4a)/p14(ARF) mRNA in cervical scrapes referred to as HSIL compared with normal women. An age-dependent bias has to be considered when quantifying these tumor suppressor genes, with respect to cervical cancer development.

Deceiving high-grade cervical dysplasias identified as human papillomavirus non-16 and non-18 types by Invader human papillomavirus assays

High-grade cervical intraepithelial lesions (HGCINs) are easily diagnosed by established histologic criteria. However, we encountered problematic cases that are difficult to diagnose because features intermediate between dysplasia and metaplasia are present. p16 and Ki-67 immunostains proved HGCIN in these difficult and unusual cases. Because these are unusual cases of cervical dysplasia, we decided to type the human papillomavirus (HPV) using the Invader HPV test with analyte-specific reagents developed by Third Wave Technologies (Madison, WI, USA) (a new HPV screening assay applicable to tissue and amenable to rapid, sensitive, and specific detection of 14 high- to intermediate-risk HPV types) and a panel of immunostains. Results of these difficult cases are compared with classic HGCIN cases. We searched our pathology files over a period of 16 months for high-grade squamous intraepithelial lesion, cervical intraepithelial neoplasia II, cervical intraepithelial neoplasia III, and p16. To identify cases of difficult HGCIN with features intermediate between dysplasia and metaplasia, we reviewed all surgical cases of HGCIN that required p16 and Ki-67 diagnosis confirmation. Cases of interest were also stained with ProExC. Human papillomavirus screening and HPV 16/18 typing were performed by the Invader assays as described previously. Ten cases of classic HGCIN were easily diagnosed by hypercellularity, significant atypia, mitotic figures, and diffuse staining by p16, Ki67 and ProExC. The Invader assay identified HPV 16 (A9 positive/HPV16 positive) in 7 of 10 cases; the 3 others were A7 positive/not HPV18 (1) and A9 positive/not HPV16 (2). Eight cases of difficult HGCIN were identified. These showed only mild-to-moderate cellularity, a lack of significant atypia, absent-to-rare mitotic figures, and diffuse staining by p16, Ki-67, and ProExC. Human papillomavirus DNA was detected in 5 of 8 cases: only 1 was A9 positive/HPV16 positive, 1 was A5/A6 positive, 1 was A7 positive/not HPV18, and 2 were A9 positive/not HPV16. Three remaining cases demonstrated sufficient DNA to be analyzed by the Invader assay, but results were negative. This is a poorly recognized unusual group of cervical HGCIN with features intermediate between dysplasia and metaplasia that is easily confused by histologic examination. Immunostains prove the high-grade nature of these lesions, and Invader assay demonstrates association with HPV types other than 16/18 (ie, other HPV types detected by Invader assay). In this study, we present an unusual group of cases of high-grade dysplasia, not recognized by hematoxylin and eosin but identified by Ki67 and P16. It is very important to emphasize that this unusual group of high-grade dysplasias is associated with high-risk HPV but with types other than 16/18.

Effect of human papillomavirus on cell cycle-related proteins p16, Ki-67, Cyclin D1, p53, and ProEx C in precursor lesions of cervical carcinoma: a tissue microarray study

In-depth study of cell cycle proteins and human papillomavirus (HPV) genotyping can provide useful information about the malignant potential of precursor lesions of cervical carcinoma (CC). Immunostaining of cell cycle-related proteins (p16, cyclin D1, Ki-67, p53, and ProEx C) was evaluated using tissue microarrays, and HPV genotypes were identified in 144 cervical tissue specimens encompassing normal or benign epithelial lesions, low- and high-grade squamous intraepithelial lesions (LSIL and HSIL, respectively), and CC. In addition, 14 cases with atypical immature metaplasia (AIM) were included to compare their immunohistochemical features with those of well-established precursor lesions. Expression of p16, Ki-67, and ProEx C was most associated with the severity of dysplasia. Positive expression of p16, Ki-67, and ProEx C and negative expression of p53 seem to be related to HPV-16 infection. AIM cases show an immunohistochemical pattern more similar to LSIL than to HSIL. Immunohistochemical assessment of cell cycle proteins may help to distinguish normal and benign conditions of the cervix from precursor lesions of CC.

Characterization of TRIM31, upregulated in gastric adenocarcinoma, as a novel RBCC protein

To explore the molecules associated with gastric adenocarcinoma, we used the gene expression profile database of various human tissues and identified TRIM31 upregulated in both patients with chronic gastritis and stomach cancer. TRIM31 is a new member of RBCC proteins composed of RING finger, B-box and coiled-coil domains. We characterized TRIM31 biochemically and found it possess properties in common with other RBCC proteins, such as occurrence of alternative splicing transcripts, in vitro autoubiquitylating activity and a tendency to homo-oligomerize. The primary localization site of TRIM31 is the cytoplasm but some fraction is potentially associated with the mitochondria. TRIM31 overexpression suppresses colony formation of HCT116 cells while knockdown of its expression with short interfering RNAs (siRNAs) consistently tends to enhance growth of AsPC-1 cells slightly. Thus, TRIM31 is a characteristic RBCC protein with the ability to regulate cell proliferation negatively and may be a potential biomarker of gastric cancer as it is overexpressed from the early stage of gastric carcinogenesis.