Gene expression profiles in HPV-immortalized human cervical cells treated with the nicotine-derived carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone

Emerging paradigms: unmasking the role of oxidative stress in HPV-induced carcinogenesis

The contribution of the human papillomavirus (HPV) to cancer is significant but not exclusive, as carcinogenesis involves complex mechanisms, notably oxidative stress. Oxidative stress and HPV can independently cause genome instability and DNA damage, contributing to tumorigenesis. Oxidative stress-induced DNA damage, especially double-strand breaks, aids in the integration of HPV into the host genome and promotes the overexpression of two viral proteins, E6 and E7. Lifestyle factors, including diet, smoking, alcohol, and psychological stress, along with genetic and epigenetic modifications, and viral oncoproteins may influence oxidative stress, impacting the progression of HPV-related cancers. This review highlights various mechanisms in oxidative-induced HPV-mediated carcinogenesis, including altered mitochondrial morphology and function leading to elevated ROS levels, modulation of antioxidant enzymes like Superoxide Dismutase (SOD), Glutathione (GSH), and Glutathione Peroxidase (GPx), induction of chronic inflammatory environments, and activation of specific cell signaling pathways like the Phosphoinositide 3-kinase, Protein kinase B, Mammalian target of rapamycin (PI3K/AKT/mTOR) and the Extracellular signal-regulated kinase (ERK) signaling pathway. The study highlights the significance of comprehending and controlling oxidative stress in preventing and treating cancer. We suggested that incorporating dietary antioxidants and targeting cancer cells through mechanisms involving ROS could be potential interventions to mitigate the impact of oxidative stress on HPV-related malignancies.

ordinalbayes: Fitting Ordinal Bayesian Regression Models to High-Dimensional Data Using R

The stage of cancer is a discrete ordinal response that indicates the aggressiveness of disease and is often used by physicians to determine the type and intensity of treatment to be administered. For example, the FIGO stage in cervical cancer is based on the size and depth of the tumor as well as the level of spread. It may be of clinical relevance to identify molecular features from high-throughput genomic assays that are associated with the stage of cervical cancer to elucidate pathways related to tumor aggressiveness, identify improved molecular features that may be useful for staging, and identify therapeutic targets. High-throughput RNA-Seq data and corresponding clinical data (including stage) for cervical cancer patients have been made available through The Cancer Genome Atlas Project (TCGA). We recently described penalized Bayesian ordinal response models that can be used for variable selection for over-parameterized datasets, such as the TCGA-CESC dataset. Herein, we describe our ordinalbayes R package, available from the Comprehensive R Archive Network (CRAN), which enhances the runjags R package by enabling users to easily fit cumulative logit models when the outcome is ordinal and the number of predictors exceeds the sample size, P > N, such as for TCGA and other high-throughput genomic data. We demonstrate the use of this package by applying it to the TCGA cervical cancer dataset. Our ordinalbayes package can be used to fit models to high-dimensional datasets, and it effectively performs variable selection.

Effect of HPV 16 E6 Oncoprotein Variants on the Alterations of the Proteome of C33A Cells

BACKGROUND/AIM

The E6 genotypic variants of HPV 16 identified in lesions of women with cervical cancer (CC) in Southern of Mexico include the E-G350, AAa, AAc, E-C188/G350, and E-A176/G350, transcriptomic analysis cells transfected with those variants showed to induce differential expression of the host genes involved in the development of CC, the aim of this work was to understand how the over-expression of the E6 oncoprotein and its variants can induce molecular mechanisms that lead to more aggressive HPV 16 phenotypes in cervical cancer and which proteins could be associated with the process.

MATERIALS AND METHODS

Total extracts from C33A, C33A mock, C33A AAa, C33A E-C188/G350, C33A E-A176/G350, and C33A E-prototype cells were analyzed using 2D electrophoresis, PDQuest software and mass spectrometry, validation of results was performed through qPCR.

RESULTS

Statistically significant differential expression of 122 spots was detected, 12 of the identified proteins were associated with metabolism and metabolic programming. Out of these CCT8, ENO and ALDH1A were further validated.

CONCLUSION

CCT8 and ALDH1A were found to be over-expressed in C33A AAa and C33A E-A176/G350, compared to the E prototype. Both proteins could be associated with a most aggressive phenotype due to their relationship with metabolism, protein folding and stemness, mechanisms associated to E6 that could be useful in the design of new therapies.

Chemopreventive Role of Apigenin against the Synergistic Carcinogenesis of Human Papillomavirus and 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone

Tobacco smoke and human papillomavirus (HPV) are both crucial causes of cancer, and their cooperative carcinogenesis has drawn more attention in recent years. Apigenin (AP), a typical flavonoid abundantly found in flowers of plants, vegetables, and fruits, has been demonstrated to exert an anti-carcinogenic effect on various types of cancer. In this study, we investigated the capability of AP against malignant transformation and DNA damage of immortalized human esophageal epithelial (SHEE) cells induced by the synergism of HPV18 and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The results indicated that the enhancement of migration, invasion, and proliferation ability of SHEE cells induced by HPV and NNK could be effectively inhibited by AP. Moreover, the levels of pyridyloxybutylated (POB)-DNA adducts induced by NNK via P450-catalyzed metabolic activation could also be significantly suppressed by AP. Further analyses on the molecular mechanism revealed that AP inhibited the synergistic carcinogenesis of NNK and HPV on SHEE cells by reducing the expression of mutp53, CDK4, Cyclin D1, and p-Rb (Ser 780), increasing caspase-3 activity, thereby arresting the cell cycle at G1 phase and promoting apoptosis of SHEE cells. We hypothesize that the decrease in NNK-induced POB-DNA adduct levels is related to the deactivation of P450 by AP, which needs to be confirmed in future studies. This study highlights that AP may be employed as a promising chemopreventive agent against cancers in smokers with an HPV infection.

Co-carcinogenesis: Human Papillomaviruses, Coal Tar Derivatives, and Squamous Cell Cervical Cancer

Cervical cancer (CC) is the fourth most common cancers among women worldwide. Human papillomaviruses (HPVs) play a major role in the etiology of CC, with several lines of epidemiologic and experimental evidence supporting a role for non-viral (co-carcinogens) and host genetic factors in controlling the risk for progression to neoplasia among HPV-infected individuals. The role of co-carcinogens in the development of CC is significant in the developing world where poor sanitation and other socio-economic conditions increase the infectious cancer burden. Here, we discuss how exposure to environmental factors such as coal tar derivatives from cigarette smoking, tar-based sanitary products, and inhaled smoke from biomass-burning stoves, could activate host pathways involved in development of HPV-associated squamous cell cancers in resource-limited settings. Understanding interactions between these pathways with certain oncogenic HPV genotypes may guide implementation of strategies for control and treatment of HPV-associated cancers that develop in populations at high risk of exposure to various co-carcinogens.

An insight into the complex roles of metallothioneins in malignant diseases with emphasis on (sub)isoforms/isoforms and epigenetics phenomena

Metallothioneins (MTs) belong to a group of small cysteine-rich proteins that are ubiquitous throughout all kingdoms. The main function of MTs is scavenging of free radicals and detoxification and homeostating of heavy metals. In humans, 16 genes localized on chromosome 16 have been identified to encode four MT isoforms labelled by numbers (MT-1-MT-4). MT-2, MT-3 and MT-4 proteins are encoded by a single gene. MT-1 comprises many (sub)isoforms. The known active MT-1 genes are MT-1A, -1B, -1E, -1F, -1G, -1H, -1M and -1X. The rest of the MT-1 genes (MT-1C, -1D, -1I, -1J and -1L) are pseudogenes. The expression and localization of individual MT (sub)isoforms and pseudogenes vary at intra-cellular level and in individual tissues. Changes in MT expression are associated with the process of carcinogenesis of various types of human malignancies, or with a more aggressive phenotype and therapeutic resistance. Hence, MT (sub)isoform profiling status could be utilized for diagnostics and therapy of tumour diseases. This review aims on a comprehensive summary of methods for analysis of MTs at (sub)isoforms levels, their expression in single tumour diseases and strategies how this knowledge can be utilized in anticancer therapy.

Adverse effect of smoking on prognosis in human papillomavirus-associated oropharyngeal carcinoma

BACKGROUND

The purpose of this retrospective study was to identify prognostic factors in a cohort of patients with oropharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT).

METHODS

Medical records of 142 patients treated with (chemo)radiotherapy between September 2005 and September 2011 were reviewed and the human papillomavirus (HPV) status was determined by polymerase chain reaction (PCR) analysis. Potential prognostic factors for 3-year locoregional control and overall survival (OS) were evaluated.

RESULTS

HPV-positive patients (n = 82) had locoregional control and OS of 78% and 79%, respectively. Significant prognostic factors on multivariate analysis were smoking (p = .03) for locoregional control and OS, and comorbidity (p = .04) for OS. Further stratification was done according to smoking behavior in HPV-positive patients. Locoregional control in current smokers was 67% compared to 86% in never smokers and former smokers, respectively (p = .02).

CONCLUSION

Smoking was the only modifiable prognostic factor in HPV-positive patients. Therefore, active stop-smoking programs must be integrated in the routine management of patients to maximize treatment results. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1780-1787, 2016.

A genome-wide association study identifies novel single nucleotide polymorphisms associated with dermal shank pigmentation in chickens

Shank color of domestic chickens varies from black to blue, green, yellow, or white, which is controlled by the combination of melanin and xanthophylls in dermis and epidermis. Dermal shank pigmentation of chickens is determined by sex-linked inhibitor of dermal melanin (Id), which is located on the distal end of the long arm of Z chromosome, through controlling dermal melanin pigmentation. Although previous studies have focused on the identification of Id and the linear relationship with barring and recessive white skin, no causal mutations have yet been identified in relation to the mutant dermal pigment inhibiting allele at the Id locus. In this study, we first used the 600K Affymetrix Axiom HD genotyping array, which includes ~580,961 SNP of which 26,642 SNP were on the Z chromosome to perform a genome-wide association study on pure lines of 19 Tibetan hens with dermal pigmentation shank and 21 Tibetan hens with yellow shank to refine the Id location. Association analysis was conducted by the PLINK software using the standard chi-squared test, and then Bonferroni correction was used to adjust multiple testing. The genome-wide study revealed that 3 SNP located at 78.5 to 79.2 Mb on the Z chromosome in the current assembly of chicken genome (galGal4) were significantly associated with dermal shank pigmentation of chickens, but none of them were located in known genes. The interval we refined was partly converged with previous results, suggesting that the Id gene is in or near our refined genome region. However, the genomic context of this region was complex. There were only 15 SNP markers developed by the genotyping array within the interval region, in which only 1 SNP marker passed quality control. Additionally, there were about 5.8-Mb gaps on both sides of the refined interval. The follow-up replication studies may be needed to further confirm the functional significance for these newly identified SNP.

The ALDH7A1 genetic polymorphisms contribute to development of esophageal squamous cell carcinoma

Although the entire etiology of esophageal squamous cell carcinoma (ESCC) is still unclear, alcohol drinking has been identified as a major environmental risk factor. The aldehyde dehydrogenase (ALDH) superfamily members are major enzymes involved in the alcohol-metabolizing pathways. Accumulating evidences demonstrated that ALDH7A1, one of ALDH superfamily members, degrades and detoxifies acetaldehyde generated by alcohol metabolism and have been associated with development and prognosis of multiple cancers. However, it is still unknown if ALDH7A1 single nucleotide polymorphisms (SNPs) contribute to ESCC susceptibility. In this study, we examined the association between sixteen ALDH7A1 SNPs and risk of developing ESCC. Genotypes were determined in 2,098 ESCC patients and 2,150 controls (three independent hospital-based case-control sets from different regions of China). Odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated by logistic regression. Our data demonstrated that only the ALDH7A1 rs13182402 SNP confer susceptibility to ESCC (For AG genotype, OR = 0.75, 95 % CI = 0.66-0.91, P = 4.8 × 10(-6); for GG genotype, OR = 0.59, 95 % CI = 0.41-0.88, P = 0.003). These results are consistent to the biological functions of ALDH7A1 during alcohol metabolism and carcinogenesis.

CHD1L: a novel oncogene

Comprehensive sequencing efforts have revealed the genomic landscapes of common forms of human cancer and ~ 140 driver genes have been identified, but not all of them have been extensively investigated. CHD1L (chromodomain helicase/ATPase DNA binding protein 1-like gene) or ALC1 (amplified in liver cancer 1) is a newly identified oncogene located at Chr1q21 and it is amplified in many solid tumors. Functional studies of CHD1L in hepatocellular carcinoma and other tumors strongly suggested that its oncogenic role in tumorigenesis is through unleashed cell proliferation, G1/S transition and inhibition of apoptosis. The underlying mechanisms of CHD1L activation may disrupt the cell death program via binding the apoptotic protein Nur77 or through activation of the AKT pathway by up-regulation of CHD1L-mediated target genes (e.g., ARHGEF9, SPOCK1 or TCTP). CHD1L is now considered to be a novel independent biomarker for progression, prognosis and survival in several solid tumors. The accumulated knowledge about its functions will provide a focus to search for targeted treatment in specific subtypes of tumors.

ALDH7A1 expression is associated with recurrence in patients with surgically resected non-small-cell lung carcinoma

AIM

The purpose of this study was to describe the prognostic significance of ALDH7A1 in surgically treated non-small-cell lung carcinoma. (NSCLC).

MATERIALS & METHODS

We immunohistochemically analyzed ALDH7A1 expression in surgically resected NSCLC from 89 patients using a tissue microarray.

RESULTS

ALDH7A1 staining was positive in 43 patients and negative in 44 patients, with two tumor sections missing. For stage I NSCLC patients, ALDH7A1 positivity was associated with decreased recurrence-free and overall survival. Multivariate analysis demonstrated that ALDH7A1-expressing NSCLC tumors had a significantly higher incidence of lung cancer recurrence compared with patients with ALDH7A1-negative tumors, although there was no association with overall survival.

CONCLUSION

For patients with NSCLC, low ALDH7A1 expression was associated with a decreased incidence of cancer recurrence. Specifically in stage I patients, negative staining for ALDH7A1 was associated with improved recurrence-free and overall survival, suggesting a predictive role in surgically treated patients.

Cigarette smoking, cyclooxygenase-2 pathway and cancer

Cigarette smoking is a major cause of mortality and morbidity worldwide. Cyclooxygenase (COX) and its derived prostanoids, mainly including prostaglandin E2 (PGE2), thromboxane A2 (TxA2) and prostacyclin (PGI2), have well-known roles in cardiovascular disease and cancer, both of which are associated with cigarette smoking. This article is focused on the role of COX-2 pathway in smoke-related pathologies and cancer. Cigarette smoke exposure can induce COX-2 expression and activity, increase PGE2 and TxA2 release, and lead to an imbalance in PGI2 and TxA2 production in favor of the latter. It exerts pro-inflammatory effects in a PGE2-dependent manner, which contributes to carcinogenesis and tumor progression. TxA2 mediates other diverse biologic effects of cigarette smoking, such as platelet activation, cell contraction and angiogenesis, which may facilitate tumor growth and metastasis in smokers. Among cigarette smoke components, nicotine and its derived nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are the most potent carcinogens. COX-2 and PGE2 have been shown to play a pivotal role in many cancers associated with cigarette smoking, including cancers of lung, gastric and bladder, while the information for the role of TxA2 and PGI2 in smoke-associated cancers is limited. Recent findings from our group have revealed how NNK influences the TxA2 to promote the tumor growth. Better understanding in the above areas may help to generate new therapeutic protocols or to optimize the existing treatment strategy.