A Comprehensive View of the Cancer-Immunity Cycle (CIC) in HPV-Mediated Cervical Cancer and Prospects for Emerging Therapeutic Opportunities.

Cervical cancer (CC) is the fourth most common cancer in women worldwide, with more than 500,000 new cases each year and a mortality rate of around 55%. Over 80% of these deaths occur in developing countries. The most important risk factor for CC is persistent infection by a sexually transmitted virus, the human papillomavirus (HPV). Conventional treatments to eradicate this type of cancer are accompanied by high rates of resistance and a large number of side effects. Hence, it is crucial to devise novel effective therapeutic strategies. In recent years, an increasing number of studies have aimed to develop immunotherapeutic methods for treating cancer. However, these strategies have not proven to be effective enough to combat CC. This means there is a need to investigate immune molecular targets. An adaptive immune response against cancer has been described in seven key stages or steps defined as the cancer-immunity cycle (CIC). The CIC begins with the release of antigens by tumor cells and ends with their destruction by cytotoxic T-cells. In this paper, we discuss several molecular alterations found in each stage of the CIC of CC. In addition, we analyze the evidence discovered, the molecular mechanisms and their relationship with variables such as histological subtype and HPV infection, as well as their potential impact for adopting novel immunotherapeutic approaches.

Long noncoding RNAs (lncRNAs) in cervical carcinogenesis: New molecular targets, current prospects.

Aberrant expression of lncRNAs has been seen as a key factor in a wide range of diseases including cancer. The role of lncRNAs in cervical cancer has not been clearly explained, and has been the subject of recent studies. In this review, we have compiled an updated list of previously reported lncRNAs and established a general profile of these transcripts in accordance with the role they play in cervical carcinogenesis. Thus, information here includes the influence of lncRNAs on cervical tumorigenic process through a disturbance of cellular activities. Additionally, we described recent discoveries about how HPV contributes to lncRNAs expression in cervical cancer and we summarized exploratory studies of strategies adopted to modulate the expression levels of lncRNAs to treat cervical neoplasia, by drawing attention to radio and chemo-resistance. Finally, this paper provides a broad overview that sets out new research directions about the role of lncRNAs in cervical cancer.

Reduced Expression of IL-1ß and IL-18 Proinflammatory Interleukins Increases the Risk of Developing Cervical Cancer.

Background: The objective of this study was to analyze the gene expression profile of the proinflammatory interleukins, (IL-1ß and IL-18) in patients with premalignant lesions and cervical cancer. Methods: Total IL-1ß and IL-18 mRNA was quantified by qPCR to obtain the expression data in cervical tissues. A total of 74 cervical biopsies were obtained from women undergoing a colposcopy. The samples were divided into: normal (19), low level lesions (LSIL) or NIC I (17), high level lesions (HSIL) or CIN II and CIN III (29) and cancer (9). The normal cervical tissue samples were included as controls. The OR and 95% CI were calculated for the determination of the risk of progression between each type of lesion and cancer using logistic regression. Results: The results showed that an increase in the risk of progression of pre-neoplastic lesions to cancer was between 2.5 and 2.08 times higher in women with lower IL-1ß and IL-18 expression, respectively. Conclusions: This study provided evidence that IL-1ß and IL-18 are potential biomarkers that can be explored in further studies for monitoring the evolution of pre-neoplastic lesions and avoiding overtreatment or undertreatment of the patients.

Expression Profile of MicroRNA-203 and its ΔNp63 Target in Cervical Carcinogenesis: Prospects for Cervical Cancer Screening.

BACKGROUND/AIM: Host molecules disturbed by human papillomavirus (HPV) oncoproteins have been shown to be potential biomarkers of cervical carcinogenesis and represent an alternative or supplementary aid to cytological testing and HPV detection. The miR-203 and one of its targets, ΔNp63, are known to be host molecules that interact with each other to control the proliferation and differentiation of keratinocytes; both have been found to be dysregulated in many cancers. As the role of p63 and miR-203 in cervical carcinogenesis is not yet well-understood, we have, thus, decided to evaluate the changes of expression of both in cervical carcinogenesis. MATERIALS AND METHODS: This study was carried out by obtaining quantitative polymerase chain reaction (qPCR) data from cervical biopsies. RESULTS: miR-203 and ΔNp63 displayed a similar expression pattern across cervical tissues and both targets showed statistically significant differences between low-grade squamous intraepithelial lesion (LSIL) x high-grade squamous intraepithelial lesion (HSIL); HSIL x Cancer. Additionally, we did not observe an inverse correlation between ΔNp63 mRNA and miR-203 levels as expected but, rather, a positive correlation between cervical tissues. CONCLUSION: Although preliminary, the expression levels of ΔNp63 mRNA and miR-203 seem to be promising for cervical cancer screening. In addition, positive correlation between miR-203 and ΔNp63 expression suggests the possible existence of some indirect pathways. However, further studies are needed to clarify the role of ΔNp63 and miR-203 in cervical carcinogenesis and, thus, determine how they can be applied in new strategies for diagnosis.

Prospects of molecularly-targeted therapies for cervical cancer treatment.

Cervical cancer is the third most common cancer among women worldwide and is responsible for 275.000 deaths each year. The development of cervical cancer has been linked to cell cycle disturbances caused by persistent expression of high- risk HPV oncoproteins (E5, E6 and E7), which modulate the expression of host genes and cellular microRNAs. An estimated 5 million women throughout the world are currently infected by HPV and several of them will develop invasive cervical cancer. Despite failures in conventional screening tests, approved therapies have no direct effect on HPV infection. In view of this, effective therapy for cervical cancer is still urgently needed, particularly in developing countries where more than 85% of fatal cases occur. In this paper we review the current molecular targeted therapies which are being explored and may have a significant impact on the treatment of HPV- related cervical dysplasia and carcinoma.

Quantifying mRNA and microRNA with qPCR in cervical carcinogenesis: a validation of reference genes to ensure accurate data.

A number of recent studies have catalogued global gene expression patterns in a panel of normal, tumoral cervical tissues so that potential biomarkers can be identified. The qPCR has been one of the most widely used technologies for detecting these potential biomarkers. However, few studies have investigated a correct strategy for the normalization of data in qPCR assays for cervical tissues. The aim of this study was to validate reference genes in cervical tissues to ensure accurate quantification of mRNA and miRNA levels in cervical carcinogenesis. For this purpose, some issues for obtaining reliable qPCR data were evaluated such as the following: geNorm analysis with a set of samples which meet all of the cervical tissue conditions (Normal + CIN1 + CIN2 + CIN3 + Cancer); the use of individual Ct values versus pooled Ct values; and the use of a single (or multiple) reference genes to quantify mRNA and miRNA expression levels. Two different data sets were put on the geNorm to assess the expression stability of the candidate reference genes: the first dataset comprised the quantities of the individual Ct values; and the second dataset comprised the quantities of the pooled Ct values. Moreover, in this study, all the candidate reference genes were analyzed as a single "normalizer". The normalization strategies were assessed by measuring p16INK4a and miR-203 transcripts in qPCR assays. We found that the use of pooled Ct values, can lead to a misinterpretation of the results, which suggests that the maintenance of inter-individual variability is a key factor in ensuring the reliability of the qPCR data. In addition, it should be stressed that a proper validation of the suitability of the reference genes is required for each experimental setting, since the indiscriminate use of a reference gene can also lead to discrepant results.

Molecular targets of HPV oncoproteins: potential biomarkers for cervical carcinogenesis.

Cervical cancer is the second most common cancer among women worldwide and is responsible for 275,000 deaths each year. Persistent infection with high-risk human papillomavirus (HR-HPV) is an essential factor for the development of cervical cancer. Although the process is not fully understood, molecular mechanisms caused by HPV infection are necessary for its development and reveal a large number of potential biomarkers for diagnosis and prognosis. These molecules are host genes and/or proteins, and cellular microRNAs involved in cell cycle regulation that result from disturbed expression of HR-HPV E5, E6 and E7 oncoproteins. One of the current challenges in medicine is to discover potent biomarkers that can correctly diagnose cervical premalignant lesions and standardize clinical management. Currently, studies are showing that some of these molecules are potential biomarkers of cervical carcinogenesis, and it is possible to carry out a more accurate diagnosis and provide more appropriate follow-up treatment for women with cervical dysplasia. In this paper, we review recent research studies on cell cycle molecules deregulated by HPV infections, as well as their potential use for cervical cancer screening.

Production of Equine Infectious Anemia Virus (EIAV) antigen in Pichia pastoris.

Equine Infectious Anemia (EIA) is a persistent lentivirus infection of horses which causes a chronic clinical condition with worldwide importance in veterinary medicine. The p26 protein is usually prepared for use as an antigen in serological tests for EIA diagnosis since it is a well-conserved gene sequence and very immunogenic. In view of the ability of yeast to make post-translational modifications of proteins, this study was carried out to allow Pichia pastoris to be used for the expression of a synthetic codon-optimized EIAV p26 gene. The gene was cloned into pPICZαA vector after appropriate enzymatic digestion. P. pastoris clones transformed with the pPICZαAp26 construction were induced to produce the recombinant p26 protein (rp26) under the regulation of alcohol oxidase 1 promoter by adding methanol to the culture medium. The p26 gene expression was detected by RT-PCR and the production of rp26 was confirmed by dot blotting, Western blotting, ELISA and AGID. The P. pastoris expression system was capable of producing a functional EIAV p26 protein that can be used directly in the functionality tests without requiring laborious purification or recovery steps. This is the first reported study of EIAV p26 protein production in yeast cells.

Susceptibility to cervical cancer: an overview.

Cervical cancer is the second most common cancer in females worldwide. It is well-established that Human Papillomavirus (HPV) infections play a critical role in the development of cervical cancer. However, a large number of women infected with oncogenic HPV types will never develop cervical cancer. Thus, there are several external environment and genetic factors involved in the progression of a precancerous lesion to invasive cancer. In this review article, we addressed possible susceptible phenotypes to cervical cancer, focusing on host genome and HPV DNA variability, multiple HPV infections, co-infection with other agents, circulating HPV DNA and lifestyle.