A functional variant at miRNA-122 binding site in IL-1α 3' UTR predicts risk and HPV-positive tumours of oropharyngeal cancer

microRNAs deregulation in head and neck squamous cell carcinoma

Head and neck (HN) squamous cell carcinoma (SCC) is the eighth most common human cancer worldwide. Besides tobacco and alcohol consumption, genetic and epigenetic alterations play an important role in HNSCC occurrence and progression. microRNAs (miRNAs) are small noncoding RNAs that regulate cell cycle, proliferation, development, differentiation, and apoptosis by interfering in gene expression. Expression profiling of miRNAs showed that some miRNAs are upregulated or downregulated in tumor cells when compared with the normal cells. The present review focuses on the role of miRNAs deregulations in HNSCC, enrolled in risk, development, outcome, and therapy sensitivity. Moreover, the influence of single nucleotide variants in miRNAs target sites, miRNAs seed sites, and miRNAs-processing genes in HNSCC was also revised. Due to its potential for cancer diagnosis, progression, and as a therapeutic target, miRNAs may bring new perspectives in HNSCC understanding and therapy, especially for those patients with no or insufficient treatment options.

HPV shapes tumor transcriptome by globally modifying the pool of RNA binding protein-binding motif

Human papillomavirus (HPV) positive head and neck cancer displayed specific transcription landscape but the underlying molecular mechanisms are not fully determined. Here, we interestingly found that HPV infection could globally elongate the 3’-untranslated regions (3’UTRs) in the majority of alternative polyadenylation (APA)-containing genes. Counterintuitively, the 3’UTR elongation does not affect their resident gene expression. Rather, they significantly increase the number of binding sites for RNA-binding proteins (RBPs) and subsequently upregulate a group of oncogenic genes by absorbing RBPs. A significant fraction of HPV affected genes are regulated through such mechanism that is 3’UTR-mediated recruitment of RBPs. As an example, we observed that HPV infection increases the length of 3’UTR of RBM25 transcript and hence recruits much more RNA binding protein including FUS and DGCR8. Consequently, in the absence of FUS and DGCR8 regulation, PD-1 was rescued and up-regulated after HPV infection. Taken together, our findings not only suggest a novel paradigm of how oncogenic viruses shape tumor transcriptome by modifying the 3’UTR, but also present a previously unrecognized layer of APA—RBP interplay in this molecular hierarchy. Modification of the pool of RBP-binding motif might expand our understandings into virus-associated carcinogenesis.

MicroRNA‑122 downregulates Rho‑associated protein kinase 2 expression and inhibits the proliferation of prostate carcinoma cells

MicroRNA‑122 (miR‑122) has been reported to be involved in the pathogenesis of several types of malignancies; however, its role in prostate carcinoma remains unknown. Thus, the current study aimed to investigate the functionality of miR‑122 in prostate carcinoma. Clinical data of 54 patients with prostate carcinoma who were diagnosed and treated in Union Hospital (Wuhan, China) between January 2011 and January 2013 were retrospectively analyzed. The expression levels of miR‑122 and Rho‑associated protein kinase 2 (ROCK2) in prostate tumor and adjacent healthy tissues of patients, as well as in the serum of prostate carcinoma patients and healthy controls, were detected by reverse transcription‑quantitative polymerase chain reaction. Receiver operating characteristic curve and survival curve analyses were used to examine the diagnostic and prognostic values of serum miR‑122 for prostate carcinoma. In addition, miR‑122 mimic was transfected into prostate carcinoma cells, and the effects on cell proliferation and ROCK2 expression were explored by Cell Counting Kit‑8 and western blot assays, respectively. It was observed that miR‑122 was downregulated and ROCK2 was upregulated in tumor tissues as compared with their levels in adjacent healthy tissues. miR‑122 level in the serum was also markedly lower in prostate carcinoma patients in comparison with that in healthy controls. Furthermore, a low serum level of miR‑122 was found to effectively distinguish the prostate carcinoma patients from healthy controls and to be an indicator of poor survival. In prostate carcinoma cells, miR‑122 overexpression inhibited the proliferation and the expression of ROCK2. Taken together, miR‑122 may inhibit the proliferation of prostate carcinoma cells possibly by downregulating ROCK2 expression.

Reviewing the role of human papillomavirus in oral cancer using the Bradford Hill criteria of causation

Human papillomavirus is a well-established risk factor for oropharyngeal cancer, although its role in oral cancer is still debated. Inconclusive evidence of its role in oral cancer is due to conflicting data arising from methodological differences, mostly due to the use of diagnostic tests with varying sensitivity and specificity. In addition, there is a lack of experimental data linking HPV to oral cancer. Recent epidemiological studies provide data on HPV prevalence in oral squamous cell carcinoma and other potentially malignant oral disorders. Further, molecular data from in vivo and in vitro models have led to new insights into the role of human papillomavirus in oral cancer. The clinical significance of identifying HPV as an etiology for oral squamous cell carcinoma is that if proven, vaccination could be an effective prevention tool. Further, like oropharyngeal squamous cell carcinoma, prognostic differences may exist between human papillomavirus positive and negative oral squamous cell carcinoma. This manuscript reviews data from the published literature using Bradford Hill criteria of causation to assess the role of human papillomavirus in oral cancer. Due to the advancement in molecular biology, the requirements of each of the Bradford Hill criteria of causation are modified to include integrated data from both epidemiological studies and experimental studies exploring molecular carcinogenesis.

MicroRNA-Related Polymorphisms in Infectious Diseases-Tiny Changes With a Huge Impact on Viral Infections and Potential Clinical Applications

MicroRNAs (miRNAs) are single-stranded sequences of non-coding RNA with approximately 22 nucleotides that act posttranscriptionally on gene expression. miRNAs are important gene regulators in physiological contexts, but they also impact the pathogenesis of various diseases. The role of miRNAs in viral infections has been explored by different authors in both population-based as well as in functional studies. However, the effect of miRNA polymorphisms on the susceptibility to viral infections and on the clinical course of these diseases is still an emerging topic. Thus, this review will compile and organize the findings described in studies that evaluated the effects of genetic variations on miRNA genes and on their binding sites, in the context of human viral diseases. In addition to discussing the basic aspects of miRNAs biology, we will cover the studies that investigated miRNA polymorphisms in infections caused by hepatitis B virus, hepatitis C virus, human immunodeficiency virus, Epstein–Barr virus, and human papillomavirus. Finally, emerging topics concerning the importance of miRNA genetic variants will be presented, focusing on the context of viral infectious diseases.

Comprehensive review of genetic factors contributing to head and neck squamous cell carcinoma development in low-risk, nontraditional patients

BACKGROUND

The past 2 decades have seen an increased incidence of head and neck squamous cell carcinoma (HNSCC) in a nontraditional, low-risk patient population (ie, ≤45 years of age, no substance use history), owing to a combination of human papillomavirus (HPV) infection and individual genetic variation.

METHODS

Articles positing genetic variants as contributing factors in HNSCC incidence in low-risk, nontraditional patients were identified using a PubMed search, reviewed in detail, and concisely summarized herein.

RESULTS

Recent data suggest that common polymorphisms in DNA repair enzymes, cell-cycle control proteins, apoptotic pathway members, and Fanconi anemia-associated genes likely modulate susceptibility to HNSCC development in low-risk, nontraditional patients.

CONCLUSION

At present, there is a lack of robust, comprehensive data on genetic drivers of oncogenesis in low-risk patients and a clear need for further research on genetic alterations underlying the rising incidence of HNSCC in low-risk, nontraditional patients.

Imbalance of a KLF4-miR-7 auto-regulatory feedback loop promotes prostate cancer cell growth by impairing microRNA processing

The microRNA-transcription factor auto-regulatory feedback loop is a pivotal mechanism for homeostatic regulation of gene expression, and dysregulation of the feedback loop is tightly associated with tumorigenesis and progression. However, the mechanism underlying such dysregulation is still not well-understood. Here we reported that Krüppel-like factor 4 (KLF4), a stemness-associated transcription factor, promotes the transcription of miR-7 to repress its own translation so that a KLF4-miR-7 auto-regulatory feedback loop is established for mutual regulation of their expression. Interestingly, this feedback loop is unbalanced in prostate cancer (PCa) cell lines and patient samples due to an impaired miR-7-processing, leading to decreased mature miR-7 production and attenuated inhibition of KLF4 translation. Mechanistically, enhanced oncogenic Yes associated protein (YAP) nuclear translocation mediates sequestration of p72, a co-factor of the Drosha/DGCR8 complex for pri-miR-7s processing, leading to attenuation of microprocessors' efficiency. Knockdown of YAP or transfection with a mature miR-7 mimic can significantly recover miR-7 expression to restore this feedback loop, and in turn to inhibit cancer cell growth by repressing KLF4 expression in vitro. Thus, our findings indicate that targeting the KLF4-miR-7 feedback loop might be a potential strategy for PCa therapy.

A functional variant at miRNA-122 binding site in IL-1a 3' UTR predicts risk of recurrence in patients with oropharyngeal cancer

IL-1α, an important regulator of immune and inflammation responses, has been implicated in cancer development and prognosis. An insertion (Ins)/deletion (Del) polymorphism (IL-1α rs3783553) in the 3′ UTR of IL-1α may disrupt a binding site for miRNA-122 and may affect its transcription level. Thus, this polymorphism may cause interindividual variation in immune and inflammation responses and thus may lead to different susceptibility to treatment response and prognosis of such patients. We evaluated the association of IL-1α rs3783553 polymorphism with risk of recurrence of squamous cell carcinoma of the oropharynx (SCCOP) in a cohort of 1008 patients. Log-rank test and univariate and multivariable Cox models were used to evaluate associations. Compared with patients with Del/Del homozygous genotype, the patients with Ins/Del+Ins/Ins variant genotypes had worse disease-free survival (log-rank P < 0.0001) and increased risk of SCCOP recurrence (HR, 2.4, 95% CI, 1.7-3.3) after multivariable adjustment. Furthermore, among patients with HPV16-positive tumors, the patients with Ins/Del+Ins/Ins variant genotypes of the IL-1α polymorphism had worse disease-free survival (log-rank P < 0.0001) and much higher recurrence risk than those with Del/Del homozygous genotype of this polymorphism (HR, 16.3, 95% CI, 5.0-52.7). Our findings suggest that IL-1α rs3783553 polymorphism may modulate the risk of SCCOP recurrence in patients, particularly for patients with HPV16-positive tumors. However, larger studies are needed to validate these results.

A functional variant at the miRNA binding site in E2F1 gene is associated with risk and tumor HPV16 status of oropharynx squamous cell carcinoma

Human papillomavirus (HPV) activates E2F1-driven transcription via the E7-RB1-E2F pathway. Genetic polymorphisms in the 3' untranslated region (UTR) targeted by miRNAs can affect the regulation of target genes and individual cancer risk. Thus, we hypothesized that a polymorphism at the 3'UTR miRNA binding site of E2F1 gene (rs3213180) was associated with risk of oral squamous cell carcinoma (OSCC) and tumor HPV status of oropharynx squamous cell carcinoma (OPSCC). We determined the E2F1rs3213180 polymorphism and HPV16 L1 serology of 325 OSCC patients and 335 controls, and tumor HPV16 status of 552 OPSCC. Logistic regression models were used to calculate associations of E2F1rs3213180 polymorphism with risk of HPV-associated OSCC and tumor HPV status of OPSCC. The risk of HPV-associated OSCC was modified by the E2F1rs3213180 polymorphism. Patients with both HPV seropositivity and the Ins/Del or Ins/Ins genotype of E2F1rs3213180 had the highest risk of OSCC, while the lowest risk was detected in patients with HPV seronegativity and the Del/Del genotype. A similar and more prominent effect was detected in OPSCC, but not in oral cavity squamous cell carcinoma (OCSCC) patients. Notably, that effect trend was pronounced in never-smokers and never-drinkers. Furthermore, the patients with the E2F1rs3213180 Ins/Del or Ins/Ins genotype were 2.9 times more likely to have HPV-positive tumors than those with the Del/Del genotype. Our results suggest that the E2F1rs3213180 polymorphism may influence susceptibility to HPV-associated OSCC, particularly for OPSCC, never-smokers and never-drinkers, but not for patients with OCSCC. Additional larger population and functional studies are warranted to confirm our findings. © 2016 Wiley Periodicals, Inc.

Genetic variants within microRNA-binding site of RAD51B are associated with risk of cervical cancer in Chinese women

RAD51B plays a central role in homologous recombinational repair (HRR) of DNA double-strand breaks (DSBs), which is important to prevent genomic instability, a hallmark of cancer. Recent studies suggested that common genetic variants of RAD51B may contribute to cancer susceptibility. In this study, we aimed to investigate whether potentially functional variants within miRNA-binding sites of RAD51B are associated with risk of cervical cancer. A total of 1486 cervical cancer patients and 1536 cancer-free controls were enrolled, and two genetic variants, rs963917 (A > G) and rs963918 (T > C), were genotyped in all participants. Using multivariate logistic regression analyses, we found that G allele of rs963917 conferred lower risk of cervical cancer compared to A allele (adjusted OR = 0.89, 95% CI = 0.80-0.99, P = 0.039). Similarly, rs963918 allele C was associated with a decreased risk for cervical cancer compared with allele T (adjusted OR = 0.84, 95% CI = 0.74-0.94, P = 0.004). Haplotype analyses showed that haplotype GC was also correlated with lower risk (OR = 0.83, 95% CI = 0.73-0.95, P = 0.005) compared with the most common haplotype AT. In summary, our study suggested that miRNA-binding site genetic variants of RAD51B may modify the susceptibility to cervical cancer, which is important to identify individuals with differential risk for this malignancy and to improve the effectiveness of preventive intervention.

The Genomics, Epigenomics, and Transcriptomics of HPV-Associated Oropharyngeal Cancer--Understanding the Basis of a Rapidly Evolving Disease

Human papillomavirus (HPV) has been shown to represent a major independent risk factor for head and neck squamous cell cancer, in particular for oropharyngeal carcinoma. This type of cancer is rapidly evolving in the Western world, with rising trends particularly in the young, and represents a distinct epidemiological, clinical, and molecular entity. It is the aim of this review to give a detailed description of genomic, epigenomic, transcriptomic, and posttranscriptional changes that underlie the phenotype of this deadly disease. The review will also link these changes and examine what is known about the interactions between the host genome and viral genome, and investigate changes specific for the viral genome. These data are then integrated into an updated model of HPV-induced head and neck carcinogenesis.

An insertion/deletion polymorphism in the interleukin-1A 3'untranslated region confers risk for gastric cancer

OBJECTIVE

The aim of the study was to evaluate whether the insertion/deletion polymorphism (rs3783553) locating in the 3' untranslated region (3'UTRs) of IL-1A was related to the risk of gastric cancer (GC) in a Chinese population and explore the possible molecular mechanism.

METHODS

Genomic DNA was extracted from peripheral venous blood of 519 GC patients and 536 healthy control individuals. The IL-1A rs3783553 polymorphism was genotyped by using a polymerase chain reaction assay. The vectors containing the insertion or deletion allele were constructed, and luciferase assay was used to detect the effect of the polymorphism on the transcriptional activity of IL-1A.

RESULTS

Strong evidence of association was observed between the IL-1A rs3783553 polymorphism and susceptibility to GC in the study. In addition, the `TTCA' insertion allele of rs3783553 disrupts the binding site for miR-122 and miR-378, thereby increasing transcription of IL-1α in vitro.

CONCLUSION

These findings suggest that functional polymorphism rs3783553 in IL-1A could contribute to GC susceptibility, possibly or at least partially through affecting the transcriptional activity of IL-1A.

Association between an insertion/deletion polymorphism in IL-1A gene and cancer risk: a meta-analysis

Purpose

Previous studies have reported the association of an insertion/deletion (Ins/Del) polymorphism (rs3783553) in the 3′ untranslated region of interleukin-1A (IL-1A) with the risk of cancer, such as oral squamous cell carcinoma, nasopharyngeal carcinoma, and cervical carcinoma. However, the results are still inconsistent. The present meta-analysis aimed to clarify the association of IL-1A rs3783553 polymorphism with cancer risk.

Methods

All eligible studies were selected from PubMed, Web of Science, and Chinese National Knowledge Infrastructure up to September 2, 2015. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate cancer risk.

Results

A total of ten case–control studies with 4,514 cases and 6,689 controls were included this meta-analysis. We found that IL-1A rs3783553 polymorphism was significantly associated with cancer risk (Ins/Ins + Ins/Del vs Del/Del: OR =0.79, 95% CI =0.67–0.92; Ins/Ins vs Del/Del: OR =0.61, 95% CI =0.47–0.79; Ins/Ins vs Ins/Del + Del/Del: OR =0.67, 95% CI =0.55–0.83; Ins vs Del: OR =0.81, 95% CI =0.72–0.92). In the stratified analyses, significant effects were found among Asian populations (Ins/Ins + Ins/Del vs Del/Del: OR =0.81, 95% CI =0.69–0.95) and cervical carcinoma (Ins/Ins vs Del/Del: OR =0.51, 95% CI =0.34–0.76; Ins/Ins vs Ins/Del + Del/Del: OR =0.52, 95% CI =0.35–0.78).

Conclusion

Our meta-analysis suggests that the IL-1A rs3783553 polymorphism contributes to susceptibility to cancer. However, well-designed studies with larger sample sizes are required to verify the results.