Association of human papillomavirus types 16 and 18 E6 proteins with p53

PTPN14 degradation by high-risk human papillomavirus E7 limits keratinocyte differentiation and contributes to HPV-mediated oncogenesis

High-risk human papillomavirus (HPV) E7 proteins enable oncogenic transformation of HPV-infected cells by inactivating host cellular proteins. High-risk but not low-risk HPV E7 target PTPN14 for proteolytic degradation, suggesting that PTPN14 degradation may be related to their oncogenic activity. HPV infects human keratinocytes but the role of PTPN14 in keratinocytes and the consequences of PTPN14 degradation are unknown. Using an HPV16 E7 variant that can inactivate retinoblastoma tumor suppressor (RB1) but cannot degrade PTPN14, we found that high-risk HPV E7-mediated PTPN14 degradation impairs keratinocyte differentiation. Deletion of PTPN14 from primary human keratinocytes decreased keratinocyte differentiation gene expression. Related to oncogenic transformation, both HPV16 E7-mediated PTPN14 degradation and PTPN14 deletion promoted keratinocyte survival following detachment from a substrate. PTPN14 degradation contributed to high-risk HPV E6/E7-mediated immortalization of primary keratinocytes and HPV⁺ but not HPV^- cancers exhibit a gene-expression signature consistent with PTPN14 inactivation. We find that PTPN14 degradation impairs keratinocyte differentiation and propose that this contributes to high-risk HPV E7-mediated oncogenic activity independent of RB1 inactivation.

Targeting Therapies for the p53 Protein in Cancer Treatments

Half of all human cancers contain TP53 mutations, and in many other cancers, the function of the p53 protein is compromised. The diversity of these mutations and phenotypes presents a challenge to the development of drugs that target p53 mutant cancer cells. This review describes the rationale for many different approaches in the development of p53 targeted therapies: ( a) viruses and gene therapies, ( b) increased levels and activity of wild-type p53 proteins in cancer cells, ( c) p53 protein gain-of-function inhibitors, ( d) p53 protein loss-of-function structural correctors, ( e) mutant p53 protein synthetic lethal drugs interfering with the p53 pathway, and ( f) cellular immune responses to mutant p53 protein antigens. As these types of therapies are developed, tested, and evaluated, the best of them will have a significant impact upon cancer treatments and possibly prevention.

5p and 3p Strands of miR-34 Family Members Have Differential Effects in Cell Proliferation, Migration, and Invasion in Cervical Cancer Cells

The micro RNA (miR)-34 family is composed of 5p and 3p strands of miR-34a, miR-34b, and miR-34c. The 5p strand's expression and function is studied in cervical cancer. The 3p strand's function and regulation remain to be elucidated. To study the function of the passenger strands of miR-34 family members, we overexpressed 5p and 3p strands using a synthetic miRNA in cervical cell lines. Cell proliferation was evaluated using crystal violet. Migration and invasion were tested using transwell assays, Western blot, and zymography. Possible specific targets and cell signaling were investigated for each strand. We found that miR-34a-5p inhibited proliferation, migration, and cell invasion accompanied by matrix metalloproteinase 9 (MMP9) activity and microtubule-associated protein 2 (MAP2) protein reduction. We also found that miR-34b-5p and miR-34c-5p inhibit proliferation and migration, but not invasion. In contrast, miR-34c-5p inhibits MMP9 activity and MAP2 protein, while miR-34b-5p has no effect on these genes. Furthermore, miR-34a-3p and miR-34b-3p inhibit proliferation and migration, but not invasion, despite the later reducing MMP2 activity, while miR-34c-3p inhibit proliferation, migration, and cell invasion accompanied by MMP9 activity and MAP2 protein inhibition. The difference in cellular processes, MMP2 and MMP9 activity, and MAP2 protein inhibition by miR-34 family members suggests the participation of other regulated genes. This study provides insights into the roles of passenger strands (strand*) of the miR-34 family in cervical cancer.

Beta Human Papillomavirus and Associated Diseases

The cutaneous human papillomavirus (HPV), mostly from β- and γ-HPV genus, is ubiquitously distributed throughout the human body and may be part of the commensal flora. The association of β-HPVs and cutaneous squamous cell carcinoma (cSCC) development was initially reported in patients with the rare genetic disorder Epidermodysplasia verruciformis. Likewise, immunosuppressed organ transplant recipients have an increased susceptibility to β-HPV infections in the skin as well as to cSCC development. Although ultraviolet radiation (UVR) is the main risk factor of cSCC, experimental data points toward β-HPVs as co-carcinogens, which appear to be required solely at early stages of skin carcinogenesis by facilitating the accumulation of UVR-induced DNA mutations. Several epidemiological studies relying on different biomarkers of β-HPV infections have also been conducted in immunocompetent individuals to access their association with cSCC development. Additionally, in vivo and in vitro studies are presenting cumulative evidence that E6 and E7 proteins from specific β-HPVs exhibit transforming activities and may collaborate with different environmental factors in promoting carcinogenesis. Nevertheless, further research is crucial to better understand the pathological implications of the broad distribution of these HPVs.

Expression of p-16, Ki-67 and p-53 markers in dysplastic and malignant lesions of the oral cavity and oropharynx

Background:

Understanding the markers for predicting degree of dysplasia and progression to malignancy can help early identification and prompt treatment of patients with oral cancers. In this study, we aim to identify and characterize different tumor suppressor genes such as p-53 and p-16 and proliferation marker Ki-67 in defining stages of dysplasia of oral mucosa and grading of tumor.

Settings and Design:

Oral biopsy tissues (for neoplastic lesions) received for histopathological evaluation were included in the study. The sections were processed for H&E staining, and 112 cases were chosen for immunohistochemical study. The data were analyzed by Chi-square and z-tests using software SPSS.

Results:

We found significant correlation between degree of dysplasia and p-16 immunoexpression with 16.7% of cases showing positivity in oral intraepithelial neoplasia (OIN) I cases as compared to 25% in OIN II and 77.8% in OIN III. Ki-67 immunoexpression correlated significantly with both histological type and grade of tumor with increased expression and intensity seen in malignant cases (66.3%) as compared to benign (10%) and premalignant cases (37%) and higher Ki-67 immunoexpression in poorly differentiated tumors (75%) than well-differentiated tumors (12.2%). Regarding p-53 immunoexpression, positive staining was seen in only malignant cases and premalignant cases.

Conclusions:

Ki-67 and p-16 can be useful as a marker of degree of dysplasia and transformation to malignancy. Ki-67 can also serve as a marker of degree of differentiation of tumors. Hence, they can serve as important ancillary markers to analyze the transition to carcinoma, dysplasia and progression of tumor.

HPV16 E6 promotes cervical cancer cell migration and invasion by downregulation of NHERF1

HPV16 is the predominant type of HPV causing invasive cervical cancer. However, the underlying molecular mechanism of the unparalleled carcinogenic power of HPV16 compared to other types of high-risk (HR)-HPV including HPV18 remains elusive. The PDZ binding motif (PBM) of high-risk HPV E6 plays an important role in neoplasia and progression of cervical cancer. HPV16 E6 rather than HPV18 E6, interacted with NHERF1 by its PBM region, and induced degradation of NHERF1. NHERF1 retarded the assembly of cytoskeleton by downregulation of ACTN4, thereby inhibited the migration and invasion of cervical cancer cells in both cell and mouse model. HPV16 E6 was confirmed to enhance actin polymerization with increased ACTN4 level by downregulation of NHERF1, and result in enhanced migration and invasion of cervical cancer cells. GSEA analysis of cervical cancer specimens also showed that HPV16 E6 rather than HPV18 E6, was significantly associated with actin cytoskeleton assembly. That downregulation of NHERF1 by HPV16 E6 promoted cytoskeleton assembly and cell invasion, was an important cause in cervical cancer carcinogenesis. These findings provided the differential mechanism between HPV16 E6 and HPV18 E6 in the development and progression of cervical cancer, which may partially explain the differences of carcinogenic power between these two types of HR-HPVs.

P53 Codon 72 Polymorphism and Risk for Squamous Cell Carcinoma of the Penis: A Caucasian Case-Control Study

Squamous cell carcinoma of the penis is a rare but often aggressive disease. A large proportion of penile cancers are associated with HPV infection, mainly with HPV high-risk subtypes 16 and 18. From other HPV-related malignancies a link between a functional SNP in the p53 gene (rs1042522, p.Arg72Pro) and a higher disease risk in the presence of HPV is documented. The p53 p.Arg72 variant was described as a risk factor for developing a malignancy in combination with the presence of HPV as the p.72Arg variant is more prone to HPV E6 protein-mediated degradation than the p.72Pro variant. For penile carcinoma there are only sparse data available on this topic. We therefore analyzed the distribution of this p53 codon 72 SNP in a cohort of 107 penile cancer patients and a healthy control group (n=194) using Restriction Fragment Length Polymorphism (RFLP) analysis. After DNA isolation a PCR amplicon including the variant nucleotide was generated. Based on the variant nucleotide this amplicon can be cleaved into two parts or remain unaffected by a restriction enzyme. Subsequent electrophoresis allowed the discrimination of SNP alleles in the investigated sample. Comparison of the allelic variants revealed no significant differences in the distribution of this SNP between cases and controls (p=0,622). There was also no difference in SNP distribution between cases with/without HPV infection (p=0,558) or histologic variants (p=0.339). In order to strengthen the impact of our data we performed a combined analysis of all published data on this topic with our results. This ended up in SNP distribution data from 177 cases and 1149 controls. Overall, there were also no significant differences in the allelic distribution of the p53 codon 72 SNP between either cases and controls (p=0,914) or HPV-positive and HPV-negative cases (p=0,486). From this most comprehensive data available to date we conclude that there is no influence of the p53 codon 72 SNP on the risk of development of penile carcinoma in Caucasians even in the presence of HPV.

Breaking Bad: How Viruses Subvert the Cell Cycle

Interactions between the host and viruses during the course of their co-evolution have not only shaped cellular function and the immune system, but also the counter measures employed by viruses. Relatively small genomes and high replication rates allow viruses to accumulate mutations and continuously present the host with new challenges. It is therefore, no surprise that they either escape detection or modulate host physiology, often by redirecting normal cellular pathways to their own advantage. Viruses utilize a diverse array of strategies and molecular targets to subvert host cellular processes, while evading detection. These include cell-cycle regulation, major histocompatibility complex-restricted antigen presentation, intracellular protein transport, apoptosis, cytokine-mediated signaling, and humoral immune responses. Moreover, viruses routinely manipulate the host cell cycle to create a favorable environment for replication, largely by deregulating cell cycle checkpoints. This review focuses on our current understanding of the molecular aspects of cell cycle regulation that are often targeted by viruses. Further study of their interactions should provide fundamental insights into cell cycle regulation and improve our ability to exploit these viruses.

The prognostic value of p16 and p53 expression for survival after vulvar cancer: A systematic review and meta-analysis

The tumor suppressor proteins p16 and p53 have been suggested to have prognostic value in some human papillomavirus (HPV)-associated cancers, however, this has been less well established for vulvar cancer. The aim of this review and meta-analysis was to examine the prognostic value of p16 and p53 expression status on survival after vulvar squamous cell carcinoma (VSCC). We conducted a thorough systematic literature search of multiple databases to identify studies examining survival after histolocally verified VSCC that were tested for p16 and/or p53. A total of 18 eligible studies were included. Using a fixed-effects model we calculated study-specific and pooled hazard ratios (HRs) of 5-year overall survival (OS). In the analyses of OS, we included 475 VSCC cases tested for p16 expression of which 38% were p16 positive. The pooled HR_p16 was 0.40 (95% CI: 0.29-0.55). In addition, the majority of results from studies with adjusted analyses on the prognostic value of p16 indicated that p16 expression status could be an independent prognostic marker for OS in women diagnosed with VSCC, and the same pattern was seen for disease specific survival (DSS). We also included 310 VSCC cases tested for p53 expression of which 54% were p53 positive. The pooled HR_p53 was 1.81 (95% CI: 1.22-2.68) indicating that p53 positive VSCC have a significantly lower 5-year OS compared to p53 negative. The results in relation to p53 reported from adjusted analyses OS and on DSS and disease free survival were more equivocal. This meta-analysis and review suggests that p53 and especially p16 expression status are of prognostic importance in women diagnosed with VSCC. This may be clinically important in the future design of targeted therapy and when planning the optimal follow-up strategy. Future studies should include the combined use of biomarkers such as p16, p53 and HPV status.

So Now My Patient Has Squamous Cell Cancer: Diagnosis, Staging, and Treatment of Squamous Cell Carcinoma of the Anal Canal and Anal Margin

Squamous cell carcinomas of the anal canal and the anal margin are rare malignancies that are increasing in incidence. Patients with these tumors often experience delayed treatment due to delay in diagnosis or misdiagnosis of the condition. Distinguishing between anal canal and anal margin tumors has implications for staging and treatment. Chemoradiation therapy is the mainstay of treatment for anal canal squamous cell, with abdominoperineal resection reserved for salvage treatment in cases of persistent or recurrent disease. Early anal margin squamous cell carcinoma can be treated with wide local excision, but more advanced tumors require a combination of chemoradiation therapy and surgical excision.

Effect of Productive Human Papillomavirus 16 Infection on Global Gene Expression in Cervical Epithelium

Human papillomavirus (HPV) infection is the world's most common sexually transmitted infection and is responsible for most cases of cervical cancer. Previous studies of global gene expression changes induced by HPV infection have focused on the cancerous stages of infection, and therefore, not much is known about global gene expression changes at early preneoplastic stages of infection. We show for the first time the global gene expression changes during early-stage HPV16 infection in cervical tissue using 3-dimensional organotypic raft cultures, which produce high levels of progeny virions. cDNA microarray analysis showed that a total of 594 genes were upregulated and 651 genes were downregulated at least 1.5-fold with HPV16 infection. Gene ontology analysis showed that biological processes including cell cycle progression and DNA metabolism were upregulated, while skin development, immune response, and cell death were downregulated with HPV16 infection in cervical keratinocytes. Individual genes were selected for validation at the transcriptional and translational levels, including UBC, which was central to the protein association network of immune response genes, and top downregulated genes RPTN, SERPINB4, KRT23, and KLK8 In particular, KLK8 and SERPINB4 were shown to be upregulated in cancer, which contrasts with the gene regulation during the productive replication stage. Organotypic raft cultures, which allow full progression of the HPV life cycle, allowed us to identify novel gene modulations and potential therapeutic targets of early-stage HPV infection in cervical tissue. Additionally, our results suggest that early-stage productive infection and cancerous stages of infection are distinct disease states expressing different host transcriptomes.IMPORTANCE Persistent HPV infection is responsible for most cases of cervical cancer. The transition from precancerous to cancerous stages of HPV infection is marked by a significant reduction in virus production. Most global gene expression studies of HPV infection have focused on the cancerous stages. Therefore, little is known about global gene expression changes at precancerous stages. For the first time, we measured global gene expression changes at the precancerous stages of HPV16 infection in human cervical tissue producing high levels of virus. We identified a group of genes that are typically overexpressed in cancerous stages to be significantly downregulated at the precancerous stage. Moreover, we identified significantly modulated genes that have not yet been studied in the context of HPV infection. Studying the role of these genes in HPV infection will help us understand what drives the transition from precancerous to cancerous stages and may lead to the development of new therapeutic targets.

The precision prevention and therapy of HPV-related cervical cancer: new concepts and clinical implications

Cervical cancer is the third most common cancer in women worldwide, with concepts and knowledge about its prevention and treatment evolving rapidly. Human papillomavirus (HPV) has been identified as a major factor that leads to cervical cancer, although HPV infection alone cannot cause the disease. In fact, HPV-driven cancer is a small probability event because most infections are transient and could be cleared spontaneously by host immune system. With persistent HPV infection, decades are required for progression to cervical cancer. Therefore, this long time window provides golden opportunity for clinical intervention, and the fundament here is to elucidate the carcinogenic pattern and applicable targets during HPV-host interaction. In this review, we discuss the key factors that contribute to the persistence of HPV and cervical carcinogenesis, emerging new concepts and technologies for cancer interventions, and more urgently, how these concepts and technologies might lead to clinical precision medicine which could provide prediction, prevention, and early treatment for patients.

The implication of CRISPR/Cas9 genome editing technology in combating human oncoviruses

It is evidenced that 20% of all tumors in humans are caused by oncoviruses, including human papilloma viruses, Epstein-Barr virus, Kaposi sarcoma virus, human polyomaviruses, human T-lymphotrophic virus-1, and hepatitis B and C viruses. Human immunodeficiency virus is also involved in carcinogenesis, although not directly, but by facilitating the infection of many oncoviruses through compromising the immune system. Being intracellular parasites with the property of establishing latency and integrating into the host genome, these viruses are a therapeutic challenge for biomedical researchers. Therefore, strategies able to target nucleotide sequences within episomal or integrated viral genomes are of prime importance in antiviral or anticancerous armamentarium. Recently, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) has emerged as a powerful genome editing tool. Standing out as a precise and efficient oncoviruses method, it has been extensively applied in recent experimental ventures in the field of molecular medicine, particularly in combating infections including tumor inducing viruses. This review is aimed at collating the experimental and clinical advances in CRISPR/Cas9 technology in terms of its applications against oncoviruses. Primarily, it will focus on the application of CRISPR/Cas9 in combating tumor viruses, types of mechanisms targeted, and the significant outcomes till date. The technical pitfalls of the CRISPR/Cas9 and the comparative approaches in evaluating this technique with respect to other available alternatives are also described briefly. Furthermore, the review also discussed the clinical aspects and the ethical, legal, and social issues associated with the use of CRISPR/Cas9.

Aurora kinases are a novel therapeutic target for HPV-positive head and neck cancers

OBJECTIVES

Human papilloma virus (HPV) is the main culprit in cancers of the cervix, penis, anus, skin, eye and head and neck. Current treatments for HPV cancers have not altered survival outcomes for 30 years and there is a significant lack of targeted therapeutic agents in the management of advanced HPV-related HNSCC. Here we show that survival and maintenance of HPV-positive HNC cells relies on the continuous expression of the major HPV oncogene, E7, and that Aurora kinases are critical for survival of high-risk HPV-positive HNC cells.

MATERIALS AND METHODS

To assess the role of HPV E7 on HNC cell survival, RNA interference (RNAi) of the E7 gene was initially performed. Using an Aurora kinase inhibitor, Alisertib, the role of Aurora kinases in the carcinogenesis of HPV E7 positive HNC tumour lines was then investigated. An in vivo HNC xenograft model was also utilised to assess loss of tumour volume in response to RNAi E7 gene silencing and Alisertib treatment.

RESULTS

RNAi silencing of the HPV E7 gene inhibited the growth of HPV-positive HNC cells and in vivo tumour load. We show that HPV E7 oncogene expression confers sensitivity to Alisertib on HNC cells where Alisertib-mediated loss in in vitro cell viability and in vivo tumour load is dependent on E7 expression. Moreover, Aurora kinase inhibition induced degradation of MCL-1 in HPV E7-expressing HNC cells.

CONCLUSION

Overall, we show that Aurora kinases are a novel therapeutic target for HPV-positive HNCs. It might be feasible to combine Aurora kinase and MCL-1 inhibitors for future HNC therapies.

Detection of human papilloma virus-E6/E7 proteins of high-risk human papilloma virus in saliva and lesional tissue of oral squamous cell carcinoma patients using nested multiplex polymerase chain reaction: A comparative study

INTRODUCTION

Human papilloma virus (HPV)-associated oral squamous cell carcinoma (OSCC) shows different biological behavior as compared to tobacco-induced OSCC. Mere presence of HPV in OSCC is of no clinical significance; however, the integration of HPV-DNA through E6/E7 gene into the host genome is important as it affects the development and progression of OSCC.

AIM

The aim of this study was to determine the presence of E6/E7 proteins of high-risk (HR) HPV (HPV16 and HPV18) in saliva as well as lesional tissue of OSCC patients and to determine the use of saliva as an alternative to tissue for E6 and E7 proteins in OSCC.

MATERIALS AND METHODS

Histopathologically confirmed 47 cases of OSCC were taken up for the study. The tumor tissue and saliva sample of each patient were obtained to detect the presence of HPV16 and HPV18 along with E6/E7 proteins in both samples by nested multiplex polymerase chain reaction (NMPCR). The data were analyzed using Student t-test (2 tailed) and Wilcoxon signed-ranks test.

RESULTS

In tumor tissue, 40.42% of cases showed HPV16 (19/47) positivity while 34.04% were HPV18 (16/47) positive; whereas, in salivary sample, 31.91% showed HPV16 (15/47) positivity while 25.53% of cases were HPV18 positive (12/47). Mean age of participants was 46.7 years, males showed no significant difference from females in the prevalence of HPV 16/18 with tongue being the most common site for the occurrence. There was no statistically significant difference for HPV16/18 presence in tissue and saliva sample of OSCC. Taking lesional tissue sample as standard, sensitivity and specificity for HPV16 and HPV18 in saliva by NMPCR was estimated at 68.42% and 92.86%, respectively. The accuracy level of NMPCR detection for HPV16 was 82.98% and HPV18 was 65.96%.

CONCLUSION

The study revealed no significant difference in the prevalence of HPV (16/18) among tissue and saliva of OSCC patients in Indian population. The study also found no difference in the level of DNA content of HPV in saliva and tissue indicating that saliva can be used as an alternative predictor of HPV positivity in OSCC.

Epidemiology and biology of cutaneous human papillomavirus

Cutaneous human papillomaviruses (HPVs) include β- and γ-HPVs, in addition to a small fraction of α-HPVs. β-HPVs were first isolated from patients with the rare genetic disorder Epidermodysplasia verruciformis, and they are associated with the development of nonmelanoma skin cancer at sun-exposed skin sites in these individuals. Organ transplant recipients also have greater susceptibility to β-HPV infection of the skin and an increased risk of developing nonmelanoma skin cancer. In both immunosuppressed and immunocompromised individuals, cutaneous HPVs are ubiquitously disseminated throughout healthy skin and may be an intrinsic part of the commensal flora. Functional analysis of E6 and E7 proteins of specific cutaneous HPVs has provided a mechanistic comprehension of how these viruses may induce carcinogenesis. Nevertheless, additional research is crucial to better understand the pathological implications of the broad distribution of these HPVs.

Coxsackievirus A6 Induces Cell Cycle Arrest in G0/G1 Phase for Viral Production

Recent epidemiological data indicate that outbreaks of hand, foot, and mouth disease (HFMD), which can be categorized according to its clinical symptoms as typical or atypical, have markedly increased worldwide. A primary causative agent for typical HFMD outbreaks, enterovirus 71 (EV71), has been shown to manipulate the cell cycle in S phase for own replication; however, it is not clear whether coxsackievirus (CVA6), the main agent for atypical HFMD, also regulates the host cell cycle. In this study, we demonstrate for the first time that CVA6 infection arrests the host cell cycle in G0/G1-phase. Furthermore, synchronization in G0/G1 phase, but not S phase or G2/M phase, promotes viral production. To investigate the mechanism of cell cycle arrest induced by CVA6 infection, we analyzed cell cycle progression after cell cycle synchronization at G0/G1 or G2/M. Our results demonstrate that CVA6 infection promotes G0/G1 phase entry from G2/M phase, and inhibits G0/G1 exit into S phase. In line with its role to arrest cells in G0/G1 phase, the expression of cyclinD1, CDK4, cyclinE1, CDK2, cyclinB1, CDK1, P53, P21, and P16 is regulated by CVA6. Finally, the non-structural proteins of CVA6, RNA-dependent RNA polymerase 3D and protease 3C , are demonstrated to be responsible for the G0/G1-phase arrest. These findings suggest that CVA6 infection arrested cell cycle in G0/G1-phase via non-structural proteins 3D and 3C, which may provide favorable environments for virus production.

The mutational landscape of recurrent versus nonrecurrent human papillomavirus-related oropharyngeal cancer

BACKGROUND

Human papillomavirus-related (HPV-related) oropharyngeal squamous cell carcinomas (OPSCCs) have an excellent response rate to platinum-based chemoradiotherapy. Genomic differences between primary HPV-related OPSCCs that do or do not recur are unknown. Furthermore, it is unclear if HPV-related OPSCCs that recur share a genomic landscape with HPV-negative head and neck cancers (HNCs).

METHODS

We utilized whole exome sequencing to analyze somatic nucleotide (SNVs) and copy number variants (CNVs) among a unique set of 51 primary HPV-related OPSCCs, including 35 that did not recur and 16 that recurred. We evaluated 12 metachronous recurrent OPSCCs (7 with paired primary OPSCCs) and 33 primary HPV-unrelated oral cavity and OPSCCs.

RESULTS

KMT2D was the most frequently mutated gene among primary HPV-related OPSCCs (n = 51; 14%) and among metachronous recurrent OPSCCs (n = 12; 42%). Primary HPV-related OPSCCs that recurred shared a genomic landscape with primary HPV-related OPSCCs that did not recur. However, TSC2, BRIP1, NBN, and NFE2L2 mutations occurred in primary OPSCCs that recurred but not in those that did not recur. Moreover, primary HPV-related OPSCCs that recur harbor features of HPV-unrelated HNCs, notably including MAPK, JAK/STAT, and differentiation signaling pathway aberrations. Metachronous recurrent OPSCCs shared a genomic landscape with HPV-unrelated HNCs, including a high frequency of TP53, CASP8, FAT1, HLA-A, AJUBA, and NSD1 genomic alterations.

CONCLUSION

Overall, primary HPV-related OPSCCs that recur share a genomic landscape with nonrecurrent OPSCCs. Metachronous recurrent OPSCCs share genomic features with HPV-negative HNCs. These data aim to guide future deescalation endeavors and functional experiments.

FUNDING

This study is supported by the American Cancer Society (RSG TBG-123653), funding support for RAH (T32DC00018, Research Training in Otolaryngology, University of Washington), funds to EM from Seattle Translational Tumor Research (Fred Hutchinson Cancer Research Center), and center funds from the Fred Hutchinson Cancer Research Center to EM. UD is supported by the Department of Veterans Affairs, Biomedical Laboratory Research and Development (BLR&D), grant IO1-oo23456, and funds from the Pittsburgh Foundation and PNC Foundation.

Nanoparticles Based on Poly (β-Amino Ester) and HPV16-Targeting CRISPR/shRNA as Potential Drugs for HPV16-Related Cervical Malignancy

Persistent high-risk HPV infection is the main cause of cervical cancer. The HPV oncogene E7 plays an important role in HPV carcinogenesis. Currently, HPV vaccines do not offer an effective treatment for women who already present with cervical disease, and recommended periodical cervical screenings are difficult to perform in countries and areas lacking medical resources. Our aim was to develop nanoparticles (NPs) based on poly (β-amino ester) (PBAE) and HPV16 E7-targeting CRISPR/short hairpin RNA (shRNA) to reduce the levels of HPV16 E7 as a preliminary form of a drug to treat HPV infection and its related cervical malignancy. Our NPs showed low toxicity in cells and mouse organs. By reducing the expression of HPV16 E7, our NPs could inhibit the growth of cervical cancer cells and xenograft tumors in nude mice, and they could reverse the malignant cervical epithelium phenotype in HPV16 transgenic mice. The performance of NPs containing shRNA is better than that of NPs containing CRISPR. HPV-targeting NPs consisting of PBAE and CRISPR/shRNA could potentially be developed as drugs to treat HPV infection and HPV-related cervical malignancy.

High-Risk Human Papillomaviral Oncogenes E6 and E7 Target Key Cellular Pathways to Achieve Oncogenesis

Infection with high-risk human papillomavirus (HPV) has been linked to several human cancers, the most prominent of which is cervical cancer. The integration of the viral genome into the host genome is one of the manners in which the viral oncogenes E6 and E7 achieve persistent expression. The most well-studied cellular targets of the viral oncogenes E6 and E7 are p53 and pRb, respectively. However, recent research has demonstrated the ability of these two viral factors to target many more cellular factors, including proteins which regulate epigenetic marks and splicing changes in the cell. These have the ability to exert a global change, which eventually culminates to uncontrolled proliferation and carcinogenesis.

Cooperation and cheating as innovation: insights from cellular societies

The capacity to innovate is often considered a defining feature of human societies, but it is not a capacity that is unique to human societies: innovation occurs in cellular societies as well. Cellular societies such as multicellular bodies and microbial communities, including the human microbiome, are capable of innovation in response to novel opportunities and threats. Multicellularity represents a suite of innovations for cellular cooperation, but multicellularity also opened up novel opportunities for cells to cheat, exploiting the infrastructure and resources of the body. Multicellular bodies evolve less quickly than the cells within them, leaving them vulnerable to cellular innovations that can lead to cancer and infections. In order to counter these threats, multicellular bodies deploy additional innovations including the adaptive immune system and the development of partnerships with preferred microbial partners. What can we learn from examining these innovations in cooperation and cheating in cellular societies? First, innovation in social systems involves a constant tension between novel mechanisms that enable greater size and complexity of cooperative entities and novel ways of cheating. Second, cultivating cooperation with partners who can rapidly and effectively innovate (such as microbes) is important for large entities including multicellular bodies. And third, multicellularity enabled cells to manage risk socially, allowing organisms to survive in challenging environments where life would otherwise be impossible. Throughout, we ask how insights from cellular societies might be translated into new innovations in human health and medicine, promoting and protecting the cellular cooperation that makes us viable multicellular organisms.This article is part of the themed issue 'Process and pattern in innovations from cells to societies'.

Systemic Therapies for Advanced Squamous Cell Anal Cancer

PURPOSE OF REVIEW

We aim to summarise the available evidence on systemic therapies for advanced anal cancer.

RECENT FINDINGS

There is no universal consensus on the management of this condition and the prognosis remains poor. Nevertheless, significant progress has been recently made including completion of the first, ever-conducted, randomised trial in the first-line setting, investigation of immunotherapy in the refractory setting and use of comprehensive genomic profiling for a better molecular characterisation of this disease and the identification of novel potential targets. The combination of a platinum agent and a fluoropyrimidine is generally considered the standard first-line treatment. Other cytotoxic agents, especially docetaxel and paclitaxel, have shown activity in both the chemotherapy-naive and chemo-refractory setting and are currently being investigated in clinical trials. Finally, further to the promising results of early clinical trials, immunotherapy with checkpoint inhibitors (i.e. nivolumab and pembrolizumab) is likely to become a standard second-line treatment option.

HPV: Molecular pathways and targets

Infection of high-risk human papillomaviruses (HPVs) is a prerequisite for the development of cervical carcinoma. HPV infections are also implicated in the development of other types of carcinomas. Chronic or persistent infection of HPV is essential but HPV alone is inadequate, additional endogenous or exogenous cues are needed along with HPV to induce cervical carcinogenesis. The strategies that high-risk HPVs have developed in differentiating epithelial cells to reach a DNA-synthesis competent state leading to tumorigenic transformation are basically due to overexpression of the E6 and E7 oncoproteins and the activation of diverse cellular regulatory or signaling pathways that are targeted by them. Moreover, the Wnt/β-catenin/Notch and phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathways are deregulated in various cancers, and have also been implicated in HPV-induced cancers. These are basically related to the "cancer hallmarks," and include sustaining proliferative signals, the evasion of growth suppression and immune destruction, replicative immortality, inflammation, invasion, metastasis and angiogenesis, as well as genome instability, resisting cell death, and deregulation of cellular energetics. These information could eventually aid in identifying or developing new diagnostic, prognostic biomarkers, and may contribute to design more effective targeted therapeutics and treatment strategies. Although surgery, chemotherapy and radiotherapy can cure more than 90% of women with early stage cervical cancer, the recurrent and metastatic disease remains a major cause of cancer mortality. Numerous efforts have been made to design new drugs and develop gene therapies to treat cervical cancer. In recent years, research on treatment strategies has proposed several options, including the role of HPV E5, E6, and E7 oncogenes, which are retained and overexpressed in most of the cervical cancers and whose respective oncoproteins are critical to the induction and maintenance of the malignant phenotype. Other efforts have been focused on antitumor immunotherapy strategies. It is known that during the development of cervical cancer, a cascade of abnormal events is induced, including disruption of cell cycle control, perturbation of antitumor immune response, alteration of gene expression, deregulation of microRNA and cancer stem cell and stemness related markers expression could serve as novel molecular targets for reliable diagnosis and treatment of HPV-positive cancers. However, the search for new proposals for disease control and prevention has brought new findings and approaches in the context of molecular biology indicating innovations and perspectives in the early detection and prevention of the disease. Thus, in this article, we discuss molecular signaling pathways activated by HPV and potential targets or biomarkers for early detection or prevention and the treatment of HPV-associated cancers.

Metastatic Anal Cancer and Novel Agents

Squamous cell carcinoma of the anal canal (SCCA) represents an orphan disease. Although prior infection with human papilloma virus is associated with the development of SCCA, knowledge of this relationship has proven ineffective in identifying therapeutic agents that have activity in the management of metastatic SCCA. Combination chemotherapy with traditional cytotoxic agents has demonstrated efficacy in multiple small series. However, immune checkpoint blockade agents have demonstrated efficacy for patients with refractory metastatic SCCA; these agents hold promise in the horizon for patients with metastatic SCCA. Clinical trials should be considered for oncologists to manage patients with metastatic SCCA.

The role of human papillomavirus on the prognosis and treatment of oropharyngeal carcinoma

Human papillomavirus positive oropharyngeal cancer (HPV-positive OPC) is a distinct subtype of head and neck carcinoma (HNC) distinguished from HPV-negative HNC by its risk factor profile, clinical behavior, and molecular biology. Compared to HPV-negative HNC, HPV-positive OPC exhibits significantly better prognosis and an enhanced response to treatment. Recognition of the survival benefit of HPV-positive tumors has led to therapeutic de-intensification strategies aiming to mitigate treatment-related toxicities while maintaining high response rates. In this review, we summarize key aspects of oral HPV infection and the molecular mechanisms of HPV-related carcinogenesis. We review the clinical and molecular characteristics of HPV-positive OPC that contribute to its improved prognosis compared to HPV-negative HNC. We also discuss current and emerging treatment strategies, emphasizing potential mechanisms of treatment sensitivity and the role of therapeutic de-intensification in HPV-positive OPC. Lastly, we examine literature on the management and prognosis of recurrent/metastatic HPV-positive OPC with a focus on the role of salvage surgery in its management.

mTOR co-targeting strategies for head and neck cancer therapy

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. There is an urgent need to develop effective therapeutic approaches to prevent and treat HNSCC. Recent deep sequencing of the HNSCC genomic landscape revealed a multiplicity and diversity of genetic alterations in this malignancy. Although a large variety of specific molecules were found altered in each individual tumor, they all participate in only a handful of driver signaling pathways. Among them, the PI3K/mTOR pathway is the most frequently activated, which plays a central role in cancer initiation and progression. In turn, targeting of mTOR may represent a precision therapeutic approach for HNSCC. Indeed, mTOR inhibition exerts potent anti-tumor activity in HNSCC experimental systems, and mTOR targeting clinical trials show encouraging results. However, advanced HNSCC patients may exhibit unpredictable drug resistance, and the analysis of its molecular basis suggests that co-targeting strategies may provide a more effective option. In addition, although counterintuitive, emerging evidence suggests that mTOR inhibition may enhance the anti-tumor immune response. These new findings raise the possibility that the combination of mTOR inhibitors and immune oncology agents may provide novel precision therapeutic options for HNSCC.

Association of an intact E2 gene with higher HPV viral load, higher viral oncogene expression, and improved clinical outcome in HPV16 positive head and neck squamous cell carcinoma

To assess the relationship of E2 gene disruption with viral gene expression and clinical outcome in human papillomavirus (HPV) positive head and neck squamous cell carcinoma, we evaluated 31 oropharyngeal and 17 non-oropharyngeal HPV16 positive carcinomas using two PCR-based methods to test for disruption of E2, followed by Sanger sequencing. Expression of HPV16 E6, E7 and E2 transcripts, along with cellular ARF and INK4A, were also assessed by RT-qPCR. Associations between E2 disruption, E2/E6/E7 expression, and clinical outcome were evaluated by Kaplan-Meier analysis for loco-regional recurrence and disease-specific survival. The majority (n = 21, 68%) of HPV16 positive oropharyngeal carcinomas had an intact E2 gene, whereas the majority of HPV16 positive non-oropharyngeal carcinomas (n = 10, 59%) had a disrupted E2 gene. Three of the oropharyngeal tumors and two of the non-oropharyngeal tumors had deletions within E2. Detection of an intact E2 gene was associated with a higher DNA viral load and increased E2/E6/E7, ARF and INK4A expression in oropharyngeal tumors. Oropharyngeal carcinomas with an intact E2 had a lower risk of loco-regional recurrence (log-rank p = 0.04) and improved disease-specific survival (p = 0.03) compared to tumors with disrupted E2. In addition, high E7 expression was associated with lower risk of loco-regional recurrence (p = 0.004) as was high E6 expression (p = 0.006). In summary, an intact E2 gene is more common in HPV16 positive oropharyngeal than non-oropharyngeal carcinomas; the presence of an intact E2 gene is associated with higher HPV viral load, higher viral oncogene expression, and improved clinical outcome compared to patients with a disrupted E2 gene in oropharyngeal cancer.

Nuclear targeting of the betanodavirus B1 protein via two arginine-rich domains induces G1/S cell cycle arrest mediated by upregulation of p53/p21

The molecular functions of betanodavirus non-structural protein B and its role in host cell survival remain unclear. In the present study, we examined the roles of specific nuclear targeting domains in B1 localization as well as the effect of B1 nuclear localization on the cell cycle and host cell survival. The B1 protein of the Red spotted grouper nervous necrosis virus (RGNNV) was detected in GF-1 grouper cells as early as 24 hours post-infection (hpi). Using an EYFP-B1 fusion construct, we observed nuclear localization of the B1 protein (up to 99%) in GF-1 cells at 48 hpi. The nuclear localization of B1 was mediated by two arginine-rich nuclear targeting domains (B domain: ⁴⁶RRSRR⁵¹; C domain: ⁶³RDKRPRR⁷⁰) and domain C was more important than domain B in this process. B1 nuclear localization correlated with upregulation of p53 and p21^(wef1/cip1); downregulation of Cyclin D1, CDK4 and Mdm2; and G1/S cell cycle arrest in GF-1 cells. In conclusion, nuclear targeting of the RGNNV B1 protein via two targeting domains causes cell cycle arrest by up-regulating p53/p21 and down-regulating Mdm2, thereby regulating host cell survival.

Eradication of cervical cancer in vivo by an AAV vector that encodes shRNA targeting human papillomavirus type 16 E6/E7

The major causative agent of cervical cancer is human papilloma virus (HPV); the viral proteins E6 and E7 induce carcinogenesis through the inactivation of the host tumor-suppressor gene. Therefore, the stable expression of specific inhibitors of E6 and E7 in cancer cells is expected to provide effective treatment for cervical cancer without affecting normal tissue. In this study, we propose a novel therapeutic approach using an adeno-associated virus (AAV) vector encoding short hairpin RNA (shRNA) against the onco-proteins E6 and E7 (shE6E7) of HPV type 16 (HPV-16), termed AAV-shE6E7. Three different HPV-16-positive cervical cancer cell lines (BOKU, SiHa and SKG-IIIa cells) were tested for gene transfer efficiency using serotypes of AAV vectors. For in vitro analysis, the cells were transduced AAV-shE6E7; alternatively, in vivo studies were performed via the administration of a direct injection of AAV-shE6E7 into cervical cancer cell-derived tumors in mice. The high gene transfer efficiency was observed using AAV2 in all three cervical cancer cell lines. Following transduction, we observed apoptosis, G₁ phase arrest and cell growth inhibition. Additionally, in the transduced cells, the E6, E7 and p16 expression levels decreased, whereas the expression levels of p53, p21 and pRb levels were enhanced. The growth of subcutaneously transplanted tumors was markedly inhibited by the single administration of AAV2-shE6E7, and the tumors were almost completely eradicated without any adverse effects. These results provided evidence of the utility of AAV2-shE6E7 as a novel treatment approach for cervical cancer.

Identification of Head and Neck Cancer Subtypes Based on Human Papillomavirus Presence and E2F-Regulated Gene Expression

Human papillomavirus (HPV) is present in a subset of head and neck squamous cell carcinomas (HNSCCs). The cell cycle regulatory Rb-E2F pathway is a major target of HPV and is perturbed by these viruses in cell culture and animal models, as well as in human tumors. In this study, we examined differences in the Rb-E2F pathway displayed by HPV-positive (HPV+) and HPV-negative (HPV-) HNSCC tumors. We created a computational approach that effectively categorizes gene expression as unchanged, downregulated, or upregulated by comparing the gene's mRNA levels in the tumor to the corresponding mRNA levels across normal tissue samples. Our findings suggest that there are three major HNSCC subtypes, defined by differences in the presence of HPV and in E2F-regulated gene expression. Most HPV+ HNSCC tumors show upregulation of E2F-regulated genes, which is consistent with inactivation of Rb by the virus-encoded E7 protein. In contrast, many HPV- HNSCCs show little or no change in the Rb-E2F pathway. However, we also identified a set of tumors that show alterations in the Rb-E2F pathway in the absence of HPV. Thus, one class of HPV- HNSCCs arise without significant alterations of the Rb-E2F pathway, while a second class of tumors appear to deregulate this pathway independently of the presence of HPV. IMPORTANCE Cancer is a complex disease that can be caused by a multitude of factors. HNSCC is complicated because some of these cancers are clearly associated with HPV, while others have no viral involvement. Determining the pathways that are commonly altered in both types of HNSCC, as well as those that are unique to viral and nonviral tumors, is important for a basic understanding of how these cancers arise and progress and critical to the development of targeted therapies. In this work, we show that all HPV-associated tumors have increased expression of E2F target genes, indicating that the tumor suppressor function of Rb is blocked. Importantly, Rb is also inhibited in a subset of nonviral tumors, suggesting that mutations present in these cancers mimic the action of the HPV E6 and E7 oncogenes.

Human papillomavirus E6 protein enriches the CD55(+) population in cervical cancer cells, promoting radioresistance and cancer aggressiveness

Accumulating evidence indicates that the human papillomavirus (HPV) E6 protein plays a crucial role in the development of cervical cancer. Subpopulations of cells that reside within tumours are responsible for tumour resistance to cancer therapy and recurrence. However, the identity of such cells residing in cervical cancer and their relationship with the HPV-E6 protein have not been identified. Here, we isolated sphere-forming cells, which showed self-renewal ability, from primary cervical tumours. Gene expression profiling revealed that cluster of differentiation (CD) 55 was upregulated in primary cervical cancer sphere cells. Flow-cytometric analysis detected abundant CD55(+) populations among a panel of HPV-positive cervical cancer cell lines, whereas few CD55(+) cells were found in HPV-negative cervical cancer and normal cervical epithelial cell lines. The CD55(+) subpopulation isolated from the C33A cell line showed significant sphere-forming ability and enhanced tumourigenicity, cell migration, and radioresistance. In contrast, the suppression of CD55 in HPV-positive CaSki cells inhibited tumourigenicity both in vitro and in vivo, and sensitized cells to radiation treatment. In addition, ectopic expression of the HPV-E6 protein in HPV-negative cervical cancer cells dramatically enriched the CD55(+) subpopulation. CRISPR/Cas9 knockout of CD55 in an HPV-E6-overexpressing stable clone abolished the tumourigenic effects of the HPV-E6 protein. Taken together, our data suggest that HPV-E6 protein expression enriches the CD55(+) population, which contributes to tumourigenicity and radioresistance in cervical cancer cells. Targeting CD55 via CRISPR/Cas9 may represent a novel avenue for developing new strategies and effective therapies for the treatment of cervical cancer. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Perturbation of RNA Polymerase I transcription machinery by ablation of HEATR1 triggers the RPL5/RPL11-MDM2-p53 ribosome biogenesis stress checkpoint pathway in human cells

Ribosome biogenesis is an energy consuming process which takes place mainly in the nucleolus. By producing ribosomes to fuel protein synthesis, it is tightly connected with cell growth and cell cycle control. Perturbation of ribosome biogenesis leads to the activation of p53 tumor suppressor protein promoting processes like cell cycle arrest, apoptosis or senescence. This ribosome biogenesis stress pathway activates p53 through sequestration of MDM2 by a subset of ribosomal proteins (RPs), thereby stabilizing p53. Here, we identify human HEATR1, as a nucleolar protein which positively regulates ribosomal RNA (rRNA) synthesis. Downregulation of HEATR1 resulted in cell cycle arrest in a manner dependent on p53. Moreover, depletion of HEATR1 also caused disruption of nucleolar structure and activated the ribosomal biogenesis stress pathway - RPL5 / RPL11 dependent stabilization and activation of p53. These findings reveal an important role for HEATR1 in ribosome biogenesis and further support the concept that perturbation of ribosome biosynthesis results in p53-dependent cell cycle checkpoint activation, with implications for human pathologies including cancer.

A novel intracellular antibody against the E6 oncoprotein impairs growth of human papillomavirus 16-positive tumor cells in mouse models

Single-chain variable fragments (scFvs) expressed as “intracellular antibodies” (intrabodies) can target intracellular antigens to hamper their function efficaciously and specifically. Here we use an intrabody targeting the E6 oncoprotein of Human papillomavirus 16 (HPV16) to address the issue of a non-invasive therapy for HPV cancer patients.

A scFv against the HPV16 E6 was selected by Intracellular Antibody Capture Technology and expressed as I7nuc in the nucleus of HPV16-positive SiHa, HPV-negative C33A and 293T cells. Colocalization of I7nuc and recombinant E6 was observed in different cell compartments, obtaining evidence of E6 delocalization ascribable to I7nuc. In SiHa cells, I7nuc expressed by pLNCX retroviral vector was able to partially inhibit degradation of the main E6 target p53, and induced p53 accumulation in nucleus. When analyzing in vitro activity on cell proliferation and survival, I7nuc was able to decrease growth inducing late apoptosis and necrosis of SiHa cells.

Finally, I7nuc antitumor activity was demonstrated in two pre-clinical models of HPV tumors. C57BL/6 mice were injected subcutaneously with HPV16-positive TC-1 or C3 tumor cells, infected with pLNCX retroviral vector expressing or non-expressing I7nuc. All the mice injected with I7nuc-expressing cells showed a clear delay in tumor onset; 60% and 40% of mice receiving TC-1 and C3 cells, respectively, remained tumor-free for 17 weeks of follow-up, whereas 100% of the controls were tumor-bearing 20 days post-inoculum. Our data support the therapeutic potential of E6-targeted I7nuc against HPV tumors.

Loss of Genome Fidelity: Beta HPVs and the DNA Damage Response

While the role of genus alpha human papillomaviruses in the tumorigenesis and tumor maintenance of anogenital and oropharyngeal cancers is well-established, the role of genus beta human papilloviruses (β-HPVs) in non-melanoma skin cancers (NMSCs) is less certain. Persistent β-HPV infections cause NMSCs in sun-exposed skin of people with a rare genetic disorder, epidermodysplasia verruciformis. However, β-HPV infections in people without epidermodysplasia verruciformis are typically transient. Further, β-HPV gene expression is not necessary for tumor maintenance in the general population as on average there is fewer than one copy of the β-HPV genome per cell in NMSC tumor biopsies. Cell culture, epidemiological, and mouse model experiments support a role for β-HPV infections in the initiation of NMSCs through a "hit and run" mechanism. The virus is hypothesized to act as a cofactor, augmenting the genome destabilizing effects of UV. Supporting this idea, two β-HPV proteins (β-HPV E6 and E7) disrupt the cellular response to UV exposure and other genome destabilizing events by abrogating DNA repair and deregulating cell cycle progression. The aberrant damage response increases the likelihood of oncogenic mutations capable of driving tumorigenesis independent of a sustained β-HPV infection or continued viral protein expression. This review summarizes what is currently known about the deleterious effects of β-HPV on genome maintenance in the context of the virus's putative role in NMSC initiation.

Betanodavirus B2 protein triggers apoptosis and necroptosis in lung cancer cells that suppresses autophagy

The betanodavirus B2 protein targets the mitochondria and acts as a "death factor", but its effect on lung cancer cells is unknown. We examined the effect of the B2 protein on triggering apoptosis or necroptosis via P53-dependent and P53-independent pathways and increased in suppression of autophagy. The B2 protein targets the mitochondria of A549 (P53+/+) and H1299 (P53-/-) lung cancer cells due to a specific signal sequence (41RTFVISAHAA50). This triggers generation of reactive oxygen species within the mitochondria, and a minor stress response in A549 cells, but a strong stress response in H1299 cells. We examined the molecular mechanism of this cell death pathway, and found that B2 protein induces the P53/Bax-mediated apoptotic pathway in A549 cells, and that a P53 specific inhibitor (pifithrin-α) switches this response to RIP3-mediated necroptosis. On the other hand, B2 induces RIP3-mediated necroptosis pathway in H1299 cells, and a necroptosis inhibitor (necrostatin-1) switches this response to the apoptotic pathway. Both types of cell death signals inhibited autophagy via a tightly increased balance of beclin-1 and Bcl-2. Thus, B2 protein triggers P53-dependent apoptosis in A549 cells and ROS/RIP3-mediated necroptosis in H1299 cells, and crosstalk of these pathways limits initiation of autophagy. These findings provide new insights into the possible control and treatment of lung cancer.

Insight into novel biomarkers in penile cancer: Redefining the present and future treatment paradigm?

INTRODUCTION

Biomarkers are increasingly used in the diagnosis and management of various malignancies. Selected biomarkers may also play a role in management of certain cases of penile carcinoma. In this article, we provide an overview of the clinical role of such markers in the management of penile cancer.

METHOD

This is a nonsystematic review of relevant literature assessing biomarkers in penile carcinoma.

RESULTS

Evidence of infections with human papillomavirus and its surrogate markers may have important prognostic value in patients with localized or metastatic penile cancer. Squamous cell carcinoma antigen, p53, C-reactive protein, Ki-67, proliferating cell nuclear antigen, cyclin D1, as well as other markers have been studied with various degree of evidence in support of clinical utility in penile cancer.

CONCLUSIONS

No single marker may have all the answers, and future research should focus on genomic analysis of individual penile tumors, attempting to identify specific targets for treatment.

Human papillomavirus genotype affects metastatic rate following radiotherapy in patients with uterine cervical cancer

Human papillomavirus (HPV) infection is well known as a major etiological risk factor associated with carcinogenesis in uterine cervical cancer. However, few reports have investigated the association between HPV genotype and outcome in patients with uterine cervical cancer following radiotherapy (RT). The aim of the present study was to investigate the association between the HPV genotype and clinical outcome following RT in Japanese patients with uterine cervical cancer. Between November 2001 and August 2006, 157 Japanese women with uterine cervical cancer were treated with RT or concurrent chemoradiotherapy with curative intent. Pretreatment, formalin-fixed, paraffin-embedded biopsies were obtained from 83 patients. HPV genotypes were determined using the polymerase chain reaction method. Patients were categorized, according to HPV L1 protein sequence homology, into the HPV α-9 (HPV 16, 31, 33, 52, and 58), HPV α-7 (HPV 18, 39, 45, 59, and 68) or 'other' (HPV 51 and 56) groups. Associations between HPV genotype and clinical outcome following RT were evaluated. A total of 54 (65.1%) tumors were HPV α-9-positive, 13 (15.7%) were HPV α-7-positive, 2 (2.4%) were categorized under 'other' and 14 (16.9%) were HPV-negative. There were no significant differences in age, FIGO stage, regional lymph node metastases rate at diagnosis, or concurrent chemotherapy administration between the HPV α-9 and α-7 groups. The median follow-up period was 52 months (range, 2-156 months). The 5-year disease-free survival rates were 54.5 and 30.8% in the HPV α-9 and α-7 groups, respectively (P=0.034), and the 5-year distant metastasis rates were 38.0 and 69.2%, respectively (P=0.015). There were no significant differences in the 5-year local control or overall survival (OS) rates between the two groups. HPV genotype affected the 5-year distant metastatic rate, however not the 5-year local control or OS rate in patients with uterine cervical cancer following RT.

Delineation of the HPV11E6 and HPV18E6 Pathways in Initiating Cellular Transformation

Although high-risk human papillomaviruses (HPVs) are the major risk factors for cervical cancer they have been associated with several other cancers, such as head and neck and oral cancers. Since integration of low-risk HPV11 DNA has been demonstrated in esophageal tumor genomes, this study compared the effects of low-risk HPV11E6 and high-risk HPV18E6 on cellular gene expression. The HPV11E6 and HPV18E6 genes were cloned into an adenoviral vector and expressed in human keratinocytes (HaCaT) in order to investigate early events and to eliminate possible artifacts introduced by selective survival of fast growing cells in stable transfection experiments. HPV11E6 had very little effect on p21 and p53 gene expression, while HPV18E6 resulted in a marked reduction in both these proteins. Both HPV11E6 and HPV18E6 enabled growth of colonies in soft agar, but the level of colony formation was higher in HPV18E6 infected cells. DNA microarray analysis identified significantly differentially regulated genes involved in the cellular transformation signaling pathways. These findings suggest that HPV11E6 and HPV18E6 are important in initiating cellular transformation via deregulation of signaling pathways such as PI3K/AKT and pathways that are directly involved in DNA damage repair, cell survival, and cell proliferation. This study shows that the low-risk HPV11E6 may have similar effects as the high-risk HPV18E6 during the initial stages of infection, but at a much reduced level.

Clinical and Immunologic Biomarkers for Histologic Regression of High-Grade Cervical Dysplasia and Clearance of HPV16 and HPV18 after Immunotherapy

Purpose: As previously reported, treatment of high-grade cervical dysplasia with VGX-3100 resulted in complete histopathologic regression (CR) concomitant with elimination of HPV16/18 infection in 40.0% of VGX-3100-treated patients compared with only 14.3% in placebo recipients in a randomized phase IIb study. Here, we identify clinical and immunologic characteristics that either predicted or correlated with therapeutic benefit from VGX-3100 to identify parameters that might guide clinical decision-making for this disease.Experimental Design: We analyzed samples taken from cervical swabs, whole blood, and tissue biopsies/resections to determine correlates and predictors of treatment success.Results: At study entry, the presence of preexisting immunosuppressive factors such as FoxP3 and PD-L1 in cervical lesions showed no association with treatment outcome. The combination of HPV typing and cervical cytology following dosing was predictive for both histologic regression and elimination of detectable virus at the efficacy assessment 22 weeks later (negative predictive value 94%). Patients treated with VGX-3100 who had lesion regression had a statistically significant >2-fold increase in CD137⁺perforin⁺CD8⁺ T cells specific for the HPV genotype causing disease. Increases in cervical mucosal CD137⁺ and CD103⁺ infiltrates were observed only in treated patients. Perforin⁺ cell infiltrates were significantly increased >2-fold in cervical tissue only in treated patients who had histologic CR.Conclusions: Quantitative measures associated with an effector immune response to VGX-3100 antigens were associated with lesion regression. Consequently, these analyses indicate that certain immunologic responses associate with successful resolution of HPV-induced premalignancy, with particular emphasis on the upregulation of perforin in the immunotherapy-induced immune response. Clin Cancer Res; 24(2); 276-94. ©2017 AACR.

KDM6A addiction of cervical carcinoma cell lines is triggered by E7 and mediated by p21CIP1 suppression of replication stress

Expression of E7 proteins encoded by carcinogenic, high-risk human papillomaviruses (HPVs) triggers increased expression of the histone H3 lysine 27 demethylase KDM6A. KDM6A expression is necessary for survival of high-risk HPV E7 expressing cells, including several cervical cancer lines. Here we show that increased KDM6A in response to high-risk HPV E7 expression causes epigenetic de-repression of the cell cycle and DNA replication inhibitor p21^CIP1, and p21^CIP1 expression is necessary for survival of high-risk HPV E7 expressing cells. The requirement for KDM6A and p21^CIP1 expression for survival of high-risk HPV E7 expressing cells is based on p21^CIP1’s ability to inhibit DNA replication through PCNA binding. We show that ectopic expression of cellular replication factors can rescue the loss of cell viability in response to p21^CIP1 and KDM6A depletion. Moreover, we discovered that nucleoside supplementation will override the loss of cell viability in response to p21^CIP1 depletion, suggesting that p21^CIP1 depletion causes lethal replication stress. This model is further supported by increased double strand DNA breaks upon KDM6A or p21^CIP1 depletion and DNA combing experiments that show aberrant re-replication upon KDM6A or p21^CIP1 depletion in high-risk HPV E7 expressing cells. Therefore, KDM6A and p21^CIP1 expression are essential to curb E7 induced replication stress to levels that do not markedly interfere with cell viability.

High-risk human papillomaviruses (HPVs) are associated with approximately five percent of all human cancers, including virtually all cervical cancers as well as a large percentage of anal, vaginal, vulvar, penile, and oropharyngeal cancers. The HPV E6 and E7 proteins are the major oncogenic drivers in these tumors, and persistent expression of E6 and E7 is required for the maintenance of the transformed state. While E6 and E7 lack intrinsic enzymatic activities, and thus are difficult to directly target therapeutically, they biochemically interact with, functionally modify, or alter expression of key host cellular signaling proteins. HPV16 E7 triggers increased expression of the KDM6A histone demethylase, and KDM6A expression becomes necessary for the survival of HPV16 E7 expressing cells. Here we show that the requirement for persistent KDM6A expression is mediated by the cell cycle and DNA replication inhibitor p21^CIP1 in that p21^CIP1 expression is necessary for survival of E7 expressing cells. Remarkably, this is based on the ability of p21^CIP1 to inhibit cellular DNA replication by binding PCNA. Our results suggest that increased KDM6A and p21^CIP1 expression serves to curb HPV16 E7-induced replication stress to levels that are conducive to DNA replication but do not cause death of HPV infected cells.

Nicotinamide Phosphoribosyl Transferase a Reliable Marker of Progression in Cervical Dysplasia

BACKGROUND/AIM

Nicotinamide phosphoribosyl transferase (Nampt) catalyses the rate-limiting step of the mammalian nicotinamide adenine dinucleotide (NAD) salvage pathway. Nampt is highly expressed in several epithelial and mesenchymal neoplasms, where is promotes cell-cycle progression ans chemotherapy resistance. To our knowledge, alterations in Nampt expression have not been examined in cervical intraepithelial neoplasia (CIN) or squamous cell carcinoma (SCC).

MATERIALS AND METHODS

We performed immunohistochemical analysis for Nampt using tissue microarrays on 14 samples of benign cervical squamous epithelium and 15 CIN I, 15 CIN II, and 13 samples of CIN III. The SCCs included 5 low-grade, 67 intermediate-grade, and 81 high-grade tumors.

RESULTS

Nampt levels increased with increased CIN grades were compared to benign cervical squamous epithelium. Similarly, Nampt levels increased with increasing SCC grade.

CONCLUSION

Nampt expression is a reliable marker of progression in cervical dysplasia and SCC.

Current Approaches to Diagnosis and Treatment of Ductal Carcinoma In Situ and Future Directions

The presentation and treatment of ductal carcinoma in situ (DCIS) has changed substantially over the years. While previously an incidental pathologic finding in more advanced, palpable tumors, the institution of screening mammography has repositioned this disease entity as one largely diagnosed as a non-palpable lesion, often prior to any invasive disease. As DCIS is a precursor to invasive carcinoma, evolution in the approach to treatment has followed in the footsteps of that for invasive disease, including breast conservation therapy, adjuvant radiation, and use of antihormonal therapy. Survival outcomes for DCIS are very high and more recent literature has investigated tailoring therapeutic approaches to avoid overtreatment. Two important areas of ongoing clinical debate concerning overtreatment include use of preoperative MRI and the role of adjuvant radiation. The heterogeneity of the disease makes it difficult to differentiate lesions that would benefit from more aggressive treatment from those in which overtreatment could be avoided. Clinical characteristics, such as histologic appearance, age at diagnosis, and margin status at tumor excision have been established as moderate predictors of disease recurrence, but none has provided strong enough evidence as to guide consensus decisions on adjuvant therapy. Continuing research seeks to define the genetic and molecular characteristics that can predict disease course and serve as the potential targets for novel therapeutic agents. While several markers have shown promise in differentiating tumor aggressiveness, there is still much to be discovered about the precise mechanisms of disease progression and how this can be applied clinically to optimize treatment.