New molecular targets against cervical cancer

Evaluation of anticancer activity of Gmelina asiatica leaves, in-vitro and in-silico studies

Cervical cancer poses a major threat to women's health worldwide, constituting the fourth most prevalent cancer among the female population. High-risk variants of human papillomavirus (HPV) with its oncogenic proteins are a necessary cause of cervical cancer. Due to the resistance of cancer cells to the current treatment, there is a need for new medicines with new strategies to treat cervical cancer. Gmelina asiatica Linn. is a medicinal plant with various traditional uses and biological activities. Its anticancer potential against breast cancer and lymphoma has been demonstrated in the literature. In view of this, our study aims to investigate the anticancer activity of Gmelina asiatica leaves against cervical cancer. Various extracts of Gmelina asiatica leaves were prepared by soxhletation and maceration methods. The cytotoxic activity of the extracts was evaluated through in-vitro studies against SiHa cell line using MTT assay and fluorescence imaging. The most potent extract (GAME) phytochemical profile was analysed by UHPLC-HRMS. Further, in-silico studies were performed on its phytoconstituents against E6 oncoprotein, and the DFT studies were conducted on the active component to assess the physicochemical properties. In-vitro studies revealed that methanolic extract (GAME) showed the highest inhibition on the SiHa cell line compared to the other extracts and the control (p < 0.0001). In-silico studies indicated high affinity with stable interaction of the compound 5 (JC5ABDR) at E6 binding sites. This study revealed the importance of Gmelina asiatica plant as a potential source of anticancer molecules with a specific mode of action against cervical cancer.Communicated by Ramaswamy H. Sarma.

The genetic variant rs55986091 HLA-DQB1 is associated with a protective effect against cervical cancer

Introduction

Cervical cancer (CC) is a prevalent malignancy affecting women globally. The primary causative factor of CC is the high-risk oncogenic human papillomavirus (HR-HPV). However, it is noteworthy that not all women infected with HR-HPV develop cancer, indicating the potential involvement of genetic predisposition in the development of CC. This study aims to identify genetic risks and their distribution in groups of women with different epidemiological features of HR-HPV.

Materials and methods

A comparison was conducted among four groups of women, comprising 218 HPV-negative women, 120 HPV-positive women, 191 women diagnosed with cervical intraepithelial neoplasia (CIN) grade 2 or 3, and 124 women diagnosed with CC. The analysis focused on four single nucleotide polymorphisms (SNPs): rs55986091 in HLA-DQB1, rs138446575 in TTC34, rs1048943 in CYP1A1, and rs2910164 in miRNA-146a.

Results

The rs55986091-A allele exhibited a protective effect within the "CC" group when compared to the "HPV-Negative" group (OR = 0.4, 95% CI= 0.25-0.65) using a log-additive model. Additionally, similar protective effects were observed in the "CIN 2/3" group compared to the "HPV-Negative" group (OR = 0.47, 95% CI = 0.28-0.79).

Conclusion

The data obtained emphasize the importance of developing PCR-based diagnostic kits for the identification of SNP alleles, particularly for rs55986091, among HR-HPV-positive women within the Russian population.

BTG2 suppresses the growth and metastasis of cervical squamous cell carcinoma

BACKGROUND

Cervical cancer is the fourth most common malignancy in women, of which cervical squamous cell carcinoma (CESC) is the main pathological type of cervical cancer. B-cell translocation gene 2 (BTG2) protein has been recognized as a tumor suppressor in several cancer types. However, BTG2 expression and molecular function in CESC are unknown.

METHODS

In this study, we first assessed the expression of BTG2 in tumor tissue specimens from CESC patients using immunohistochemical staining and real-time quantitative PCR, and explored the relationship between BTG2 expression status and clinical manifestations. Next, we constructed BTG2 knockdown and overexpression CESC cell lines to observe the effects of BTG2 on CESC proliferation and metastasis at the cellular level. Finally, we employed a nude mouse xenograft tumor model in an in vivo experiment to observe the effect of BTG2 on tumorigenesis in vivo.

RESULTS

The results showed that the expression of BTG2 protein was lower in CESC tissues than in normal tissues, and high BTG2 expression was associated with better survival in CESC patients versus CESC patients. The results of cellular assays confirm that overexpression of BTG2 inhibits the proliferation, migration and metastasis of CESC cells. Nude mouse xenograft tumor model showed that overexpression of BTG2 inhibited tumor growth in vivo, and conversely knockdown of BTG2 promoted tumor growth.

CONCLUSION

In summary, our data suggest that BTG2 acts as a tumor suppressor in CESC and inhibits the growth and metastasis of CESC. BTG2 may serve as a potential prognostic marker in CESC and is expected to provide a therapeutic strategy for patients with CESC.

SLC5A3 is important for cervical cancer cell growth

Novel molecular targets for cervical cancer must be identified. This study examined the role of SLC5A3, a myo-inositol transporter, in the pathogenesis of cervical cancer. Through boinformatics analysis, we showed that the SLC5A3 mRNA levels were upregulated in cervical cancer tissues. The upregulated SLC5A3 mRNA levels were negatively correlated with survival and progression-free interval. Genes co-expressed with SLC5A3 were enriched in multiple signaling cascades involved in cancer progression. In primary/established cervical cancer cells, SLC5A3 shRNA/knockout (KO) exerted growth-inhibitory effects and promoted cell death/apoptosis. Furthermore, SLC5A3 knockdown or KO downregulated myo-inositol levels, induced oxidative injury, and decreased Akt-mTOR activation in cervical cancer cells. In contrast, supplementation of myo-inositol or n-acetyl-L-cysteine or transduction of a constitutively active Akt1 construct mitigated SLC5A3 KO-induced cytotoxicity in cervical cancer cells. Lentiviral SLC5A3 overexpression construct transduction upregulated the cellular myo-inositol level and promoted Akt-mTOR activation, enhancing cervical cancer cell proliferation and migration. The binding of TonEBP to the SLC5A3 promoter was upregulated in cervical cancer. In vivo studies showed that intratumoral injection of SLC5A3 shRNA-expressing virus arrested cervical cancer xenograft growth in mice. SLC5A3 KO also inhibited pCCa-1 cervical cancer xenograft growth. The SLC5A3-depleted xenograft tissues exhibited myo-inositol downregulation, Akt-mTOR inactivation, and oxidative injury. Transduction of sh-TonEBP AAV construct downregulated SLC5A3 expression and inhibited pCCa-1 cervical cancer xenograft growth. Together, overexpressed SLC5A3 promotes growth of cervical cancer cells, representing as a novel therapeutic oncotarget for the devastating disease.

ZIC5 promotes aggressiveness and cancer stemness in cervical squamous cell carcinoma

BACKGROUND

Cervical cancer is one of the major malignancies causing morbidity and mortality in women in developing countries. ZIC5 has been found to be associated with a variety of cancers, yet the expression and molecular function of ZIC5 in cervical squamous cell carcinoma (CESC) is unknown.

METHODS

We examined the expression of ZIC5 in tumors and normal tissues of CESC patients using immunohistochemistry, immunoblotting and fluorescent quantitative PCR, and used statistical methods to explore its relationship with clinical manifestations. Next, we constructed ZIC5 knockdown and overexpression CESC cell lines to observe the effect of ZIC5 on the proliferation and metastasis of CESC cells. Finally, we applied a nude mouse xenograft tumor model to observe the effect of ZIC5 on tumorigenesis in vivo.

RESULTS

Our results showed that the expression of ZIC5 was higher in cancer tissues than in normal tissues. Prognostic analysis showed that ZIC5 expression level was an independent prognostic factor in CESC patients, and the results of Transwell, CCK-8 and wound healing assays confirmed that overexpression of ZIC5 could promote the proliferation and migration of CESC cells. A nude mouse xenograft tumor model showed that knockdown of ZIC5 inhibited tumor growth in vivo. Database, immunoblotting assay and in vitro sphere-forming assay confirmed that ZIC5 could promote the stemness of CESC cells.

CONCLUSION

ZIC5 is a factor that indicates a poor prognosis of CESC patients and promotes stemness in CESC cells. ZIC5 may be a potential biomarker and therapeutic target for CESC patients.

Endothelial cell-specific molecule 1 drives cervical cancer progression

The expression, biological functions and underlying molecular mechanisms of endothelial cell-specific molecule 1 (ESM1) in human cervical cancer remain unclear. Bioinformatics analysis revealed that ESM1 expression was significantly elevated in human cervical cancer tissues, correlating with patients' poor prognosis. Moreover, ESM1 mRNA and protein upregulation was detected in local cervical cancer tissues and various cervical cancer cells. In established and primary cervical cancer cells, ESM1 shRNA or CRISPR/Cas9-induced ESM1 KO hindered cell proliferation, cell cycle progression, in vitro cell migration and invasion, and induced significant apoptosis. Whereas ESM1 overexpression by a lentiviral construct accelerated proliferation and migration of cervical cancer cells. Further bioinformatics studies and RNA sequencing data discovered that ESM1-assocaited differentially expressed genes (DEGs) were enriched in PI3K-Akt and epithelial-mesenchymal transition (EMT) cascades. Indeed, PI3K-Akt cascade and expression of EMT-promoting proteins were decreased after ESM1 silencing in cervical cancer cells, but increased following ESM1 overexpression. Further studies demonstrated that SYT13 (synaptotagmin 13) could be a primary target gene of ESM1. SYT13 silencing potently inhibited ESM1-overexpression-induced PI3K-Akt cascade activation and cervical cancer cell migration/invasion. In vivo, ESM1 knockout hindered SiHa cervical cancer xenograft growth in mice. In ESM1-knockout xenografts tissues, PI3K-Akt inhibition, EMT-promoting proteins downregulation and apoptosis activation were detected. In conclusion, overexpressed ESM1 is important for cervical cancer growth in vitro and in vivo, possibly by promoting PI3K-Akt activation and EMT progression. ESM1 represents as a promising diagnostic marker and potential therapeutic target of cervical cancer.

Triptonide Inhibits the Cervical Cancer Cell Growth via Downregulating the RTKs and Inactivating the Akt-mTOR Pathway

The high incidence and mortality of cervical cancer (CC) require an urgent need for exploring novel valuable therapeutics. Triptonide (TN) is a small molecule monomer extracted from the Chinese herb Tripterygium wilfordii Hook. Our results showed that TN, at only nanomolar concentrations, strongly inhibited growth, colony formation, proliferation, migration, and invasion of established and primary human cervical cancer cells. TN induced apoptosis and cell cycle arrest in cervical cancer cells. Moreover, cervical cancer cell in vitro migration and invasion were suppressed by TN. It was however noncytotoxic and proapoptotic to normal cervical epithelial cells and human skin fibroblast cells. Gene set enrichment analysis (GSEA) of RNA sequencing data of differentially expressed genes (DEGs) in TN-treated cervical cancer cells implied that DEGs were enriched in the receptor tyrosine kinase (RTK) signaling and PI3K-Akt-mTOR cascade. In cervical cancer cells, RTKs, including EGFR and PDGFRα, were significantly downregulated and Akt-mTOR activation was largely inhibited after TN treatment. In vivo, oral administration of TN significantly inhibited subcutaneous cervical cancer xenograft growth in nude mice. EGFR and PDGFRα downregulation as well as Akt-mTOR inactivation was detected in TN-treated HeLa xenograft tumor tissues. Thus, TN inhibits human cervical cancer cell growth in vitro and in vivo. Its anticervical cancer activity was associated with RTK downregulation and Akt-mTOR inactivation.

Identification of Gαi3 as a novel molecular therapeutic target of cervical cancer

Here we studied expression and potential functions of Gαi3 in cervical cancer. The bioinformatics analysis together with the results from local patients' tissues revealed that Gαi3 expression was remarkably elevated in human cervical cancer tissues and different cervical cancer cells, and was associated with poor overall survival and poor disease-specific survival of patients. Gαi3 depletion resulted in profound anti-cervical cancer activity. In primary or immortalized cervical cancer cells, Gαi3 shRNA or CRISPR/Cas9-caused Gαi3 knockout/KO largely hindered cell proliferation and migration, and provoked apoptosis. On the contrast, ectopic Gαi3 overexpression further enhanced cervical cancer proliferation and migration. Akt-mTOR activation in primary cervical cancer cells was significantly reduced after Gαi3 silencing or KO, but was augmented following Gαi3 overexpression. Further studies revealed that the transcription factor GATA4 binding to Gαi3 promoter region was significantly enhanced in cervical cancer tissues and cells. Gαi3 expression was decreased by GATA4 shRNA, but upregulated following GATA4 overexpression. In vivo, the growth of cervical cancer xenografts was robustly suppressed after Gαi3 silencing or KO. Gαi3 depletion and Akt-mTOR inactivation were detected in Gαi3-silenced/-KO cervical cancer xenograft tissues. Together, upregulated Gαi3 is a valuable oncotarget of cervical cancer.

Characteristics of recent clinical investigations into systemic therapy against cervical cancer: systematic analysis of trial details from Clinicaltrials.gov

A review that systematically assessed the current state of clinical research into systematic therapy-based interventions against invasive cervical cancer. It analysed registry details of 59 systemic therapy-based cervical cancer trials on ClinicalTrials.gov with study start dates between January 2010 and June 2018. The review characterised the present cervical cancer trial landscape in terms of trial design features, systemic therapy (chemotherapy, targeted therapy, immunotherapy, and repurposed therapy), and disease stages of interest. It also made an attempt to qualitatively synthesise the trial landscape in terms of the nature and trend of research focus, alignment with existing clinical needs, novelty of treatments or concepts pursued, and promise of new treatments.

PPI Modulators of E6 as Potential Targeted Therapeutics for Cervical Cancer: Progress and Challenges in Targeting E6

Advanced cervical cancer is primarily managed using cytotoxic therapies, despite evidence of limited efficacy and known toxicity. There is a current lack of alternative therapeutics to treat the disease more effectively. As such, there have been more research endeavors to develop targeted therapies directed at oncogenic host cellular targets over the past 4 decades, but thus far, only marginal gains in survival have been realized. The E6 oncoprotein, a protein of human papillomavirus origin that functionally inactivates various cellular antitumor proteins through protein–protein interactions (PPIs), represents an alternative target and intriguing opportunity to identify novel and potentially effective therapies to treat cervical cancer. Published research has reported a number of peptide and small-molecule modulators targeting the PPIs of E6 in various cell-based models. However, the reported compounds have rarely been well characterized in animal or human subjects. This indicates that while notable progress has been made in targeting E6, more extensive research is needed to accelerate the optimization of leads. In this review, we summarize the current knowledge and understanding of specific E6 PPI inhibition, the progress and challenges being faced, and potential approaches that can be utilized to identify novel and potent PPI inhibitors for cervical cancer treatment.

Comparison of Snail1, ZEB1, E-Cadherin Expression Levels in HPV-Induced Cervical Cancer

Background:

Molecular profiling techniques are the rapid detection of biomarkers in the human papillomavirus (HPV) infected cells. We aimed to measure the expression level of three cell factors including Snail1, ZEB-1, and E-cadherin in cervical cancer (CC), precancerous and healthy samples, simultaneously, to find potential biomarkers.

Methods:

The expression level of the mentioned cell factors were investigated in 72 CC patients, precancerous patients, and healthy controls by using Real-Time PCR.

Results:

The results demonstrated a significant reduction in the expression level of E-cadherin in cancer and precancerous cases than that in healthy cases; whereas the expression level of ZEB-1 and Snail1 were upregulated in cancer and precancerous samples. The receiver operating characteristic (ROC) analyses shows the highest AUC value emerged for Snail1: 1(95% CI: 1-1) in comparing CC and healthy groups with a sensitivity of 100.0 % and specificity of 100.0%.

Conclusion:

The molecular biomarker Snail1 may be helpful to early diagnosis and prognosis of CC in the HPV-infected human populations. Considering the increased expression level of Snail1 in cancer and precancerous tissue compared to healthy tissue as well as the area under the ROC curve, Snail1 can be used for early detection of CC.

CCNB1 Expedites the Progression of Cervical Squamous Cell Carcinoma via the Regulation by FOXM1

Background

Cervical squamous cell carcinoma (CSCC) is responsible for 80-85% of cervical cancer. Cyclin B1 (CCNB1) represents a hub gene during the development of cervical cancer. However, the oncogenic role of CCNB1 in CSCC remains unclear. Our study aims to explore the mechanism underlying CCNB1 regulation on cell cycle progression in CSCC cells.

Methods

First, we analyzed differentially expressed genes from CSCC dataset GSE63678 and conducted gene function enrichment analysis. Subsequently, CCNB1 expression was knocked down in CSCC cell lines to assess cell proliferation, apoptosis, and cell cycle distribution. After the validation of the binding relationship between forkhead box protein M1 (FOXM1) and the promoter of CCNB1, the effect of FOXM1 on CCNB1 expression and on CSCC cell growth and apoptosis was verified. We further analyzed the histone ChIP-Seq data of CCNB1 in CSCC cells and measured the acetylation levels of the CCNB1 promoter histones.

Results

CCNB1 was overexpressed in CSCC tissues and cells, and CCNB1 silencing inhibited the growth of CSCC cells, and promoted cell cycle arrest and apoptosis. FOXM1 potentiated CCNB1 transcription by binding to its promoter and recruiting CBP/P300, a histone acetyltransferase. Further increasing FOXM1 expression or increasing P300 activity in CSCC cells with CCNB1 knockdown elevated CCNB1 expression and proliferation and cell cycle progression of CSCC cells. Knockdown of CCNB1 activated the p53 pathway in cells.

Conclusion

FOXM1 inhibited the activation of the p53 pathway by recruiting CBP/P300, which promoted the transcription of CCNB1, resulting in the growth and cell cycle progression of CSCC cells.

The SNP rs4846048 of MTHFR enhances the cervical cancer risk through association with miR-522: A preliminary report

BACKGROUND

The present research was designed to explore the association between single nucleotide polymorphisms (SNPs) at the 3'-untranslated region (3'-UTR) of methylenetetrahydrofolate reductase (MTHFR) and the risk of cervical cancer (CC).

METHODS

From May 2015 to October 2016, a total of 197 patients (diagnosed with CC and precancerous lesions, and underwent surgical treatments) were enrolled in the study. Meanwhile, a total of 80 healthy cases were used as the controls. PCR-DNA analysis was used to explore the genotype of the SNPs (rs4846048 and rs55763075) of the MTHFR 3'-UTR as well as the association between allelic frequencies and the CC risk. Then, the role of rs4846048 SNPs in the association of microRNA-522 (miR-522) and MTHFR was evaluated through luciferase reporter assay. Meanwhile, the modulatory influence of miR-522 on cell apoptosis and viability of Hela cells was also detected by flow cytometry and MTT assay.

RESULTS

The rs4846048 AG and G allele frequencies were significantly higher in CC subgroup compared with the control group. Methylenetetrahydrofolate reductase rs4846048 A/G alleles contributed to miR-522 binding, and miR-522 negatively modulated the expressions of MTHFR. Furthermore, miR-522 overexpression increased cell viability but decreased apoptotic cells in Hela cells.

CONCLUSION

The preliminary report revealed that the SNP rs4846048 of MTHFR enhanced the risk of CC through association with miR-522, which further regulated cell viability and apoptosis in Hela cells.

Expression of Nup93 is associated with the proliferation, migration and invasion capacity of cervical cancer cells

Cervical cancer is a prevalent and devastating malignancy in females worldwide. Nucleoporin 93 (Nup93), a member of the nuclear pore complex, plays an important role in transport across the nuclear pore. Several nucleoporins have been linked to cancer. However, the oncogenic role and underlying mechanism of Nup93 in cervical cancer development have not been reported. In this study, the expression of Nup93 was analyzed by quantitative real-time polymerase chain reaction (qPCR), western blot analysis, and immunohistochemical staining in cervical cancer tissues and cell lines. We found that the expression of Nup93 was higher in cervical cancer samples, compared to normal cervical samples. The knockdown of Nup93 inhibited cell proliferation, migration, and invasion capacity of cervical cancer cells. At the same time, we also found that silencing of Nup93 could inhibit cellular migration and invasion by regulating cytoskeleton actin and Rho family proteins. Nup93 also participated in the IL-6/STAT3 signaling pathway. In addition, down-regulation of Nup93 prevented tumor formation in mice in vivo. Thus, Nup93 may be a carcinogenic gene and serve as a potential therapeutic target for cervical cancer.

Serum and tissue miRNAs: potential biomarkers for the diagnosis of cervical cancer

Background

Finding new biomarkers for the early detection of cervical cancer is an essential requirement in this field. In this study, we aimed to evaluate the expression level of potential biomarkers in progression of cervical cancer in patients with cervical cancer compared to normal subjects.

Methods

The expression levels of tissue and serum miRNAs, including miR-9, miR-192 and miR-205, were investigated in 36 normal, 18 precancer, and 18 cervical cancer samples using real-time polymerase chain reaction.

Results

The results showed the higher significant expressions of miR-9, miR-192 and miR-205 in the tissue of cancer samples than those in the normal samples. Moreover, the miR-192 and miR-205 expression were significantly increased in the cancer group in comparison with the precancer group. Examination of serum samples revealed the increase in the expression level in the cancer groups than in the normal samples, for miR-9, miR-192 and miR-205 and the expressions of miR-9, miR-192 and miR-205 were significantly up-regulated in the precancer group in comparison with the normal group. Also the expression of miR-205 was remarkably increased in the cancer group in comparison with the precancer group. The receiver operating characteristic (ROC) analyses showed the highest area under the curve value for miR-192.

Conclusions

Given the increased expression level of miR-192 in cancer and in precancerous tissue and serum compared with the normal tissue and serum validated by analysing the ROC curve, miR-192 can be used as potential biomarker for the early detection of cervical cancer.

Identification of Key Genes and Pathways in Cervical Cancer by Bioinformatics Analysis

Cervical cancer is a common malignant tumour of the female reproductive system that seriously threatens the health of women. The aims of this study were to identify key genes and pathways and to illuminate new molecular mechanisms underlying cervical cancer. Altogether, 1829 DEGs were identified, including 794 significantly down-regulated DEGs and 1035 significantly up-regulated DEGs. GO analysis suggested that the up-regulated DEGs were mainly enriched in mitotic cell cycle processes, including DNA replication, organelle fission, chromosome segregation and cell cycle phase transition, and that the down-regulated DEGs were primarily enriched in development and differentiation processes, such as tissue development, epidermis development, skin development, keratinocyte differentiation, epidermal cell differentiation and epithelial cell differentiation. KEGG pathway analysis showed that the DEGs were significantly enriched in cell cycle, DNA replication, the p53 signalling pathway, pathways in cancer and oocyte meiosis. The top 9 hub genes with a high degree of connectivity (over 72 in the PPI network) were down-regulated TSPO, CCND1, and FOS and up-regulated CDK1, TOP2A, CCNB1, PCNA, BIRC5 and MAD2L1. Module analysis indicated that the top 3 modules were significantly enriched in mitotic cell cycle, DNA replication and regulation of cell cycle (P < 0.01). The heat map based on TCGA database preliminarily demonstrated the expression change of the key genes in cervical cancer. GSEA results were basically coincident with the front enrichment analysis results. By comprehensive analysis, we confirmed that cell cycle was a key biological process and a critical driver in cervical cancer. In conclusion, this study identified DEGs and screened the key genes and pathways closely related to cervical cancer by bioinformatics analysis, simultaneously deepening our understanding of the molecular mechanisms underlying the occurrence and progression of cervical cancer. These results might hold promise for finding potential therapeutic targets of cervical cancer.

Brd4 inhibition suppresses HPV16 E6 expression and enhances chemoresponse: A potential new target in cervical cancer therapy

Although a vast amount of research underlines the roles of the HR HPV E6 and E7 oncogenes in HPV-induced carcinogenesis of cervical cancer, it remains unclear whether these oncogenes are also involved in the resistance of the cancer against chemotherapy. We examined the role of the HPV16 E6 oncogene in cisplatin resistance by analyzing its expression in newly established cisplatin-sensitive versus -resistant cervical cancer cell lines (CC7, CC10). Resistant variants were obtained by interval exposure treatment with 1-2 μM cisplatin for 8-9 months. Our results demonstrate that the expression level of HPV16 E6 directly correlates with the extent of cisplatin resistance in novel as well as established (SiHa) drug resistant cervical cancer cell lines. Overexpression of HPV16 E6 in cisplatin-naïve cells rendered these cells more resistant to cisplatin. Reducing E6 expression by JQ1 treatment reversed the drug resistant phenotype and strongly enhanced chemoresponse only in HPV-positive cisplatin-resistant variants and not in HPV-negative C33A cervical cancer cells. The level of E6 directly correlated with the extent of cisplatin sensitivity and was shown to be increased in newly established drug-resistant cell line variants, while reducing E6 expression using Brd4-inhibitors enhanced chemoresponse when co-delivered with cisplatin. Inhibition of Brd4 could represent a new therapeutic option by increasing treatment response in cervical cancer cells and might allow lower cisplatin dosages, thus reducing negative side effects.

Involvement of Human Papillomaviruses in Cervical Cancer

Human papillomaviruses (HPV) are the first viruses to have been acknowledged to prompt carcinogenesis, and they are linked with cancers of the uterine cervix, anogenital tumors, and head and neck malignancies. This paper examines the structure and primary genomic attributes of HPV and highlights the clinical participation of the primary HPV serotypes, focusing on the roles that HPV-16 and 18 play in carcinogenesis. The mechanisms that take place in the progression of cervical neoplasia are described. The oncogenic proteins E6 and E7 disrupt control of the cell cycle by their communication with p53 and retinoblastoma protein. Epidemiological factors, diagnostic tools, and management of the disease are examined in this manuscript, as are the vaccines currently marketed to protect against viral infection. We offer insights into ongoing research on the roles that oxidative stress and microRNAs play in cervical carcinogenesis since such studies may lead to novel methods of diagnosis and treatment. Several of these topics are surfacing as being critical for future study. One particular area of importance is the study of the mechanisms involved in the modulation of infection and cancer development at cervical sites. HPV-induced cancers may be vulnerable to immune therapy, offering the chance to treat advanced cervical disease. We propose that oxidative stress, mRNA, and the mechanisms of HPV infection will be critical points for HPV cancer research over the next decade.

The sphingosine kinase 2 inhibitor ABC294640 inhibits cervical carcinoma cell growth

ABC294640 is a specific sphingosine kinase 2 (SphK2) inhibitor. The anti-cervical carcinoma activity by ABC294640 was tested in this study. ABC294640 inhibited in vitro growth of the established (C33A and HeLa lines) and primary human cervical carcinoma cells. The SphK2 inhibitor also induced G1-S arrest and apoptosis in cervical carcinoma cells. It was yet non-cytotoxic to SphK2-low human cervical epithelial cells. ABC294640 inhibited SphK activation, causing sphingosine-1-phosphate depletion, signal transducer and activator of transcription 3 in-activation and ceramide production. Bcl-2 is a key resistance factor of ABC294640. Pharmacological Bcl-2 inhibition or Bcl-2 shRNA potentiated ABC294640-induced C33A cell growth inhibition and apoptosis. On the other hand, exogenous over-expression of Bcl-2 attenuated ABC294640's cytotoxicity against C33A cells. In vivo, ABC294640 administration inhibited C33A xenograft tumor growth in mice. Co-administration of the Bcl-2 inhibitor GDC-0199 further potentiated ABC294640's anti-tumor activity. Together, we suggest that ABC294640 might have translational value for the treatment of human cervical carcinoma.

Experiences of cervical cancer patients in rural Ghana: An exploratory study

Even though cervical cancer is quite a prevalent disease in Ghana, there is hardly any study on this disease. This paper sought to explore the experiences of cervical cancer patients living with the disease with emphasis on their knowledge about the disease before and after the diagnosis. Qualitative data were collected through in-depth interviews with cervical cancer patients undergoing treatment in a specialised cancer treatment health facility in rural Ghana. Cervical cancer patients had inadequate knowledge about the disease, its symptoms, risk factors, treatment and prevention prior to being diagnosed of the disease. These patients were diagnosed late because they usually sought treatment elsewhere before reporting to health facilities. They experienced physical, psychological, economic and social disruptions in their daily lives, which affected their quality of life. It is evident that lack of knowledge about cervical cancer constitutes a threat to its prevention and treatment. Intensive health education through the mass media and community health promotion outreaches can be a sure way of creating adequate knowledge about cervical cancer in Ghana. Treatment and care for cervical cancer patients should incorporate counselling sessions, which should take into consideration the different levels of disruption the women experience and the implications for their wellbeing and management of the condition.

The value of local registry data for describing cervical cancer management and outcomes over three decades in Australia

Registry data on invasive cervical cancers (n = 1,274) from four major hospitals (1984-2012) were analysed to determine their value for informing local service delivery in Australia. The methodology comprised disease-specific survival analyses using Kaplan-Meier product-limit estimates and Cox proportional hazards models and treatment analyses using logistic regression. Five- and 10-year survivals were 72% and 68%, respectively, equating with relative survival estimates for Australia and the USA. Most common treatments were surgery and radiotherapy. Systemic therapies increased in recent years, generally with radiotherapy, but were less common for residents from less accessible areas. Surgery was more common for younger women and early-stage disease, and radiotherapy for older women and regional and more advanced disease. The proportion of glandular cancers increased in-step with national trends. Little evidence of variation in risk-adjusted survival presented over time or by Local Health District. The study illustrates the value of local registry data for describing local treatment and outcomes. They show the lower use of systemic therapies among residents of less accessible areas which warrants further investigation. Risk-adjusted treatment and outcomes did not vary by socio-economic status, suggesting equity in service delivery. These data are important for local evaluation and were not available from other sources.

URI promotes the migration and invasion of human cervical cancer cells potentially via upregulation of vimentin expression

URI is known to act as an oncoprotein in several tumors. Our previous studies have shown that URI is associated with the migration process in cervical and gastric cancer cells, but the mechanisms remain to be determined. Given the fact that URI positively regulates vimentin expression, we therefore investigated how URI regulated vimentin expression affects the migration and invasion of cells from two human cervical cancer cell lines HeLa and C33A, which differentially express URI. We have shown that knock-down of URI in HeLa cells using URI siRNA caused decreased vimentin mRNA and protein levels along with attenuated cell motility. Meanwhile, overexpression of URI by transfection of PCMV6-URI in C33A cells resulted in increased vimentin expression and enhanced cell migration and invasion. We have also used TGF-β to induce vimentin expression, which enhanced the cell migration and invasion abilities affected by URI, while inhibition of vimentin by siRNA attenuated URI's effect on cell migration and invasion. In addition, we have performed luciferase reporter and ChIP assays, and the results support that URI indirectly enhances the activity of vimentin promoter. Taken together, our results suggest that URI plays essential roles in the migration and invasion of human cervical cancer cells, possibly via targeting vimentin expression.

Relationship of IL-17A and IL-17F genetic variations to cervical cancer risk: a meta-analysis

Aim: We performed a meta-analysis to determine a more precise relationship of IL-17A and IL-17F polymorphisms with cervical cancer risk. Materials & methods: PubMed, CNKI and Wan Fang databases were searched for studies on these associations using STATA version 10.0 software. Results: Five studies were included. The AG and AA genotypes and A allele of IL-17A rs2275913 were correlated with an elevated risk of cervical cancer. The TT genotype and T allele of IL-17A rs3748067 and the CC genotype and C allele of IL-17F rs763780 carried a moderate risk of cervical cancer, when compared with the wild-type genotype. Conclusion: IL-17A and IL-17F polymorphisms therefore have the potential to act as predictive biomarkers for cervical cancer risk.

Rosiglitazone enhances radiosensitivity by inhibiting repair of DNA damage in cervical cancer cells

Radiation therapy (RT) is one of the main treatment modalities for cervical cancer. Rosiglitazone (ROSI) has been reported to have antiproliferative effects against various types of cancer cells and also to induce antioxidant enzymes that can scavenge reactive oxygen species (ROS) and thereby modify radiosensitivity. Here, we explored the effect of ROSI on radiosensitivity and the underlying mechanisms in cervical cancer cells. Three cervical cancer cell lines (ME-180, HeLa, and SiHa) were used. The cells were pretreated with ROSI and then irradiated. Expression of proteins of interest was detected by western blot and immunofluorescence. Intracellular production of ROS was measured by H₂DCFDA. Radiosensitivity was assessed by monitoring clonogenic survival. Expression of antioxidant enzymes (catalase, superoxide dismutases) was increased by ROSI in HeLa and SiHa cells, but not in ME-180 cells. With ROSI pre-treatment, cell survival after irradiation remained unchanged in HeLa and SiHa cells, but decreased in ME-180 cells. Radiation-induced expression of γ-H2AX was increased and that of RAD51 was decreased by ROSI pre-treatment in ME-180 cells, but not in HeLa cells. ROSI increases radiosensitivity by inhibiting RAD51-mediated repair of DNA damage in some cervical cancer cell lines; therefore, ROSI is a potential inhibitor of RAD51 that can be used to enhance the effect of RT in the treatment of some cervical cancers.

HER Family Receptors are Important Theranostic Biomarkers for Cervical Cancer: Blocking Glucose Metabolism Enhances the Therapeutic Effect of HER Inhibitors

Persistent HPV infection alone is not sufficient for cervical cancer development, which requires additional molecular alterations for tumor progression and metastasis ultimately leading to a lethal disease. In this study, we performed a comprehensive analysis of HER family receptor alterations in cervical adenocarcinoma. We detected overexpression of HER protein, mainly HER2, which was an independent prognostic marker for these patients. By using in vitro and in vivo approaches, we provided evidence that HER inhibitors, allitinib and lapatinib, were effective in reducing cervical cancer aggressiveness. Furthermore, combination of these drugs with glucose uptake blockers could overcome the putative HIF1-α-mediated resistance to HER-targeted therapies. Thus, we propose that the use of HER inhibitors in association with glycolysis blockers can be a potentially effective treatment option for HER-positive cervical cancer patients.

ISG15 inhibits cancer cell growth and promotes apoptosis

Cervical cancer is one of the most common causes of cancer-related mortality in women in developing countries. Interferon (IFN)-α has been widely used in the treatment of various types of cancer, including cervical cancer, and IFN-stimulated gene 15 (ISG15), an ubiquitin-like protein, is upregulated by IFN-α treatment. The anti-virus and antitumor effects of ISG15 have been reported; however, its mechanism of action have not yet been fully elucidated. In this study, HeLa cells were used as a model system to investigate the roles of ISG15 in IFN-α-mediated cancer cell growth inhibition and induction of apoptosis. The results revealed that both p53 and p21 were upregulated in HeLa cells treated with IFN-α or in the HeLa cells overexpressing ISG15. In addition, the expression levels of ubiquitin-like modifier-activating enzyme 7 (UBA7, also known as UBE1L; ISG15 E1-activating enzyme), UBCH8 (ISG15 E2-conjugating enzyme) and HERC5 (ISG15 E3-ligase) were elevated in the HeLa cells treated with IFN-α. The levels of p53 in the HeLa cells were attenuated by transient transfection with small interfering RNA (siRNA) targeting ISG15 (ISG15-siRNA). Cell viability was inhibited by both IFN-α treatment and ISG15 overexpression. However, these effects were significantly diminished when p53 was knocked down, suggesting that the effects of inhibitory effects of ISG15 on HeLa cell growth and the induction of apoptosis were p53-dependent. Taken together, these results suggest the existence of the IFN-α/ISG15/p53 axis in cervical cancer cells and any strategies manipulating the levels of ISG15 may thus prove to be effective in the treatment of cervical cancer.

Knowledge, Awareness and Attitude on HPV, HPV Vaccine and Cervical Cancer among the College Students in India

BACKGROUND

Infection of specific high risk Human papillomaviruses (HPVs) is known to cause cervical cancer and two prophylactic vaccines have been developed against two major high risk HPV types 16 and 18 for prevention of cervical cancer. Because of societal, religious and ethical issues associated with the vaccination of adolescent girls in India together with lack of awareness about HPV and HPV vaccines, no successful HPV immunization program has been employed in India.

OBJECTIVE

To determine knowledge, awareness and attitude of college students on HPV, HPV vaccine and cervical cancer.

METHOD

A questionnaire-based survey was conducted in a total of 1580 undergraduate students between the age group 16-26 years comprising 684 girls and 876 boys.

RESULTS

Out of a total of 1580 students, girls had more knowledge about cervical cancer (82.45%, p<0.001), HPV (45.61%, p<0.001) and HPV vaccines (44%, p<0.001) when compared to those in boys. However, knowledge about the types of HPV and vaccines was poor. Interestingly, students from biology-major had more knowledge and awareness about cervical cancer (81.89%, p<0.001) and HPV (46.58%, <0.001) when compared to non-biology students. Girls from both biology and non-biology group had higher awareness compared to boys. Analysis of odds ratio (ORs) along with 95% CI showed older girls with 1.2 to 3 fold (p<0.05) higher knowledge than boys. All students agreed that girls should get vaccinated against HPV (p<0.001).

CONCLUSION

It is suggested that there is a need for educational intervention and awareness campaigns to augment HPV immunization program for control of cervical cancer in India.

Identification of SEC62 as a potential marker for 3q amplification and cellular migration in dysplastic cervical lesions

Background

Chromosome 3 amplification affecting the 3q26 region is a common genomic alteration in cervical cancer, typically marking the transition of precancerous intraepithelial lesions to an invasive phenotype. Though potential 3q encoded target genes of this amplification have been identified, a functional correlation of potential oncogenic function is still missing. In this study, we investigated copy number changes and the expression level of SEC62 encoded at 3q26.2 as a new potential 3q oncogene in dysplastic cervical lesions and analyzed its role in cervical cancer cell biology.

Methods

Expression levels of Sec62 and vimentin were analyzed in liquid based cytology specimens from 107 women with varying grades of cervical dysplasia ranging from normal cases to cancer by immunofluorescence cytology. Additionally, a subset of 20 representative cases was used for FISH analyses targeting SEC62. To further explore the functional role of Sec62 in cervical cancer, HeLa cells were transfected with a SEC62 plasmid or SEC62 siRNA and analyzed for their proliferation and migration potential using real-time monitoring and trans-well systems as well as changes in the expression of EMT markers.

Results

FISH analyses of the swabbed cells showed a rising number of SEC62 gains and amplifications correlating to the grade of dysplasia with the highest incidence in high grade squamous intraepithelial lesions and squamous cell carcinomas. When analyzing the expression level of Sec62 and vimentin, we found a gradually increasing expression level of both proteins according to the severity of the dysplasia. In functional analyses, SEC62 silencing inhibited and SEC62 overexpression stimulated the migration of HeLa cells with only marginal effects on cell proliferation, the expression level of EMT markers and the cytoskeleton structure.

Conclusions

Our study suggests SEC62 as a target gene of 3q26 amplification and a stimulator of cellular migration in dysplastic cervical lesions. Hence, SEC62 could serve as a potential marker for 3q amplification, providing useful information about the dignity and biology of dysplastic cervical lesions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2739-6) contains supplementary material, which is available to authorized users.

MicroRNA-138 inhibits proliferation, migration and invasion through targeting hTERT in cervical cancer

A growing body of evidence suggests that microRNA-138 (miR-138) functions as a tumor suppressor, and is involved in tumor initiation, development and metastasis in certain types of human cancers. However, the function and underlying molecular mechanism of miR-138 in cervical cancer remains unclear. Therefore, the purpose of the present study was to investigate the clinical significance of miR-138 expression in cervical cancer, and to evaluate its role and underlying mechanisms in cervical cancer. The present study indicated that miR-138 expression was significantly downregulated in cervical cancer tissues and cell lines, and that the low miR-138 expression was negatively associated with advanced FIGO stage and lymph node metastasis (P<0.01). Functional analyses indicated that the overexpression of miR-138 in cervical cancer cells inhibited cell proliferation, migration and invasion, induced cell apoptosis in vitro, and suppressed tumor growth in a nude mice model. Luciferase reporter assays confirmed that human telomerase reverse transcriptase was a novel target gene of miR-138. The findings of the present study suggested that miR-138 could be a potential candidate for cervical cancer therapeutics.

Oxymatrine inhibits the proliferation of CaSki cells via downregulating HPV16E7 expression

Treatment of recurrent and metastatic cervical cancer remains a challenge, especially in developing countries, which lack efficient screening programs. HPV16E7 has been reported to play an important role in the development of cervical cancer. In recent years, oxymatrine, which was traditionally used as anti-malarial agent, has been shown to inhibit tumor growth with low toxicity to normal cells. In the present study, we investigated the mechanisms underlying the antitumor effect of oxymatrine in cervical cancer. The CCK-8 assay was used to compare the proliferation of untreated and oxymatrine-treated cervical cancer CaSki cells. Flow cytometry was applied to observe the effect of oxymatrine on apoptosis and the cell cycle distribution of CaSki cells. We used qRT-PCR and western blot analysis to determine the mRNA level and protein level of HPV16E7. The HPV16E7 siRNA inhibition was also performed to confirm the effect of downregulating HPV16E7 on the proliferation in CaSki cells. Our results revealed that oxymatrine-treated cells showed time-dependent and dose-dependent inhibition of proliferation and a significant increase in apoptosis. Oxymatrine arrested CaSki cells in G0/G1 phase and S phase while decreased the cells in G2/M phase. The expression of HPV16E7 was significantly downregulated in oxymatrine-treated cells compared with control cells. Knock-down of HPV16E7 effectively inhibited the proliferation of CaSki cells. In conclusion, our data suggest that oxymatrine inhibits cervical cancer growth via downregulation of HPV16E7. Oxymatrine can be considered to be a potential preventive and therapeutic target for cervical cancer.

Human papillomavirus vaccine trials and tribulations: Clinical perspectives

Human papillomavirus (HPV) affects hundreds of millions of people worldwide and is associated with both benign and malignant neoplasms in men and women. It is a double-stranded DNA virus with an icosahedral capsid. Forty HPV types are known to infect mucosal keratinocytes. If not cured by the immune system, the infection can lead to genital warts, mucosal dysplasia, or cancer. The most common oncogenic types are 16 and 18. The vaccine to prevent HPV and its associated morbidity and mortality has existed since 2006. Several variations protect against an increasing number of HPV types. The recommended vaccination age is before sexual exposure; administration of the vaccine to children has been controversial. This continuing medical education review evaluates the current HPV vaccines available to clinicians. Part I focuses on the debate over who should be vaccinated, at what age, and in which populations.

Clinicopathological significance of Notch1 expression in cervical cancer patients: a meta-analysis

Aim: Notch1 expression remains incompatible and contradictory with previous findings on cervical cancer. The purpose of this study is to evaluate the association between Notch1 and cervical cancer. Methods: Available studies were searched from diverse databases and Review Managers 5.3 software was used to perform analysis. Results: A total of 798 samples were included in this meta-analysis. The Notch1 expression in cancer tissues was higher than that in precancer (p = 0.0003) and normal tissues (p < 0.02). However, the difference of Notch1 expression between cancer cases and precancer cases has no statistical significance (p = 0.35). Moreover, lymph node metastasis (p = 0.02) was associated with higher Notch1 expression in cervical cancer. Conclusion: Notch1 over-expression indicated aggressive biological behaviors.

PAK4 confers the malignance of cervical cancers and contributes to the cisplatin-resistance in cervical cancer cells via PI3K/AKT pathway

Background

Multiple protein or microRNA markers have been recognized to contribute to the progression and recurrence of cervical cancers. Particular those, which are associated with the chemo- or radio-resistance of cervical cancers, have been proposed to be promising and to facilitate the definition for cervical cancer treatment options.

Methods

This study was designed to explore the potential prognosis value of p21-activated kinase (PAK)-4 in cervical cancer, via the Kaplan–Meier analysis, log-rank test and Cox regression analysis, and then to investigate the regulatory role of PAK4 in the cisplatin resistance in cervical cancer cells, via the strategies of both PAK4 overexpression and PAK4 knockout.

Results

It was demonstrated that PAK4 was upregulated in cervical cancer tissues, in an association with the cancer’s malignance variables such as FIGO stage, lymph node or distant metastasis and the poor histological grade. The high PAK4 expression was also independently associated with poor prognosis to cervical cancer patients. Moreover, PAK4 confers cisplatin resistance in cervical cancer Hela or Caski cells. In addition, the PI3K/Akt pathway has been implicated in the PAK4-confered cisplatin resistance. And the PI3K/Akt inhibitor, LY294002, markedly deteriorated the cisplatin-mediated viability reduction of Hela or Caski cells, indicating the involvement of PI3K/Akt pathway in the cisplatin resistance in cervical cancer cells.

Conclusion

This study has confirmed the significant prognostic role of PAK4 level in cervical cancer patients and has recognized the regulatory role in cervical cancer progression. Moreover, our study has indicated that PAK4 also confers the chemoresistance of cervical cancer cells in a PI3K/Akt-dependent way. Thus, our study indicates PAK4 as a promising marker for cervical cancer treatment.

MicroRNA-491-5p suppresses cervical cancer cell growth by targeting hTERT

MicroRNAs (miRNAs) are small non-coding RNAs that have been shown to regulate a variety of biological processes by targeting messenger RNA. MicroRNA-491-5p (miR-491-5p), an important miRNA, has been demonstrated to be involved in the processes of initiation and progression in several tumors. However, the precise biological function of miR-491-5p and its molecular mechanism in cervical cancer cells remain elusive. The present study was carried out to investigate the clinical significance and prognostic value of miR-491-5p expression in cervical cancer, and to evaluate the role of miR-491-5p and the underlying molecular mechanisms involved in cervical cancer. The results showed that miR-491-5p expression was significantly downregulated in cervical cancer tissues when compared with the corresponding adjacent normal tissues (P<0.001), and the value was negatively associated with advanced International Federation of Gynecology and Obstetrics (FIGO) stage, high histological grading and lymph node metastasis (P<0.01). The enforced expression of miR-491-5p in cervical cancer cells significantly inhibited proliferation, migration and invasion, induced cell apoptosis, and suppressed the tumor growth of the mouse model of HeLa cells. In addition, the dual-luciferase reporter assay revealed that human telomerase reverse transcriptase (hTERT) was identified as a novel target gene of miR-491-5p. Notably, it was found that miR-491-5p regulated the PI3K/AKT signaling pathway. These results suggested that targeting miR-491-5p is a strategy for blocking the development of cervical cancer.

Butein suppresses cervical cancer growth through the PI3K/AKT/mTOR pathway

Cervical cancer is the second most common women carcinoma worldwide and the fourth leading cause of cancer-associated mortality in women. Butein, a bioactive flavonoid isolated from numerous native plants, has been shown to induce apoptosis and inhibits migration and invasion in numerous human cancer cells. However, to the best of our knowledge, the effect of butein on human cervical cancer cells has not been reported. The present study aimed to determine the effect of butein on cell growth, apoptosis, migration and invasion and identify the associated molecular mechanism involved using HeLa human cervical cancer cells in vitro, and on tumor growth in a nude mouse model. It was found that butein notably inhibited cell viability, colony formation, migration and invasion, induced cell cycle at the G2/M stage and cell apoptosis, as well as enhanced caspase-3, -8 and -9 activity in HeLa cells in a dose-dependent manner. When administered intraperitoneally, butein inhibited the tumor growth of human cervical cancer xenograft tumors in the nude mouse model. Additionally, treatment with butein significantly increased reactive oxygen species (ROS) generation and reduced the phosphorylation of PI3K, AKT and mTOR expression, which contributes to the inhibition of the tumor growth of cervical cancer and reduction of oxidative stress. These findings suggested that butein serves as a potential therapeutic agent for the treatment of cervical cancer.

URI expression in cervical cancer cells is associated with higher invasion capacity and resistance to cisplatin

Cervical cancer is a common and devastating female cancer worldwide. The etiology of cervical cancer has been largely attributed to human papillomavirus (HPV) infection and activation of the P13K/AKT/mTOR (mammalian target of rapamycin) pathway. However, the limited HPV-directed therapy, as well as therapeutic approach targeting P13K/AKT/mTOR pathway, has not yet been established or effective. A deeper understanding of cervical carcinogenesis and finding of novel candidate molecules for cervical cancer therapeutics is largely warranted. The unconventional prefoldin RPB5 interactor (URI or URI1), a known transcription factor involving the TOR signaling pathway, has recently been implicated a role in multiple tumorigenesis. We recently reported significant upregulation of URI in precancerous cervical intra-epithelial neoplasia (CIN) and invasive cervical cancer, suggesting its role in cervical carcinogenesis. However, the effect and underlying mechanism of URI in cervical cancer development have never been elucidated. Here, we aimed to investigate the in vitro effect of URI on cervical cancer using two cervical cancer cell lines CaSki and C33A, which are HPV-positive and HPV-negative respectively. We have shown that forced over-expression of URI in C33A and CaSki cells markedly promoted cell growth, while down-regulation of URI mediated by siRNA inhibited cell proliferation. We have found that URI over-expression enhanced resistance of cervical cancer cells to cisplatin. In contrast, knockdown of URI promoted apoptosis by influencing cell response to cisplatin, supporting URI as an oncogenic protein for cervical cancer cells. We have also shown that URI promoted the migration and invasive capacity of cervical cancer cells by up-regulation of Vimentin, a mesenchymal cell migration marker relating to the epithelial-mesenchymal transition (EMT) program. Our data support an important function of URI in the biological behavior of cervical cancer cells and provide novel mechanistic insights into the role of URI in cervical cancer progression and possibly, metastasis.