Antibodies against human papillomavirus proteins in Barrett's dysplasia and intramucosal esophageal adenocarcinoma

Relationship between pathogenic microorganisms and the occurrence of esophageal carcinoma based on pathological type: a narrative review

INTRODUCTION

Esophageal cancer (EC) is one of the most common malignant tumors of the upper gastrointestinal tract. The etiology of EC is complicated and increasing evidence has shown that microbial infection is closely related to the occurrence of various malignant tumors. Though many studies have been focused on this subject in recent years, the exact relationship between microbial infection and the occurrence of EC remains unclear.

AREAS COVERED

In this review, we searched all eligible literature reports, summarized the most recent studies in this research field, and analyzed the pathogenic microorganisms associated with EC, providing the latest evidence and references for the prevention of pathogenic microorganism-related EC.

EXPERT OPINION

In recent years, increasing evidence has shown that pathogenic microbial infections are closely associated with the development of EC. Therefore, it is necessary to describe in detail the relationship between microbial infection and EC and clarify its possible pathogenic mechanism, which will shed a light on clinical prevention and treatment of cancer caused by pathogenic microbial infection.

Causal Link of Human Papillomavirus in Barrett Esophagus and Adenocarcinoma: Are We There Yet?

Esophageal cancer is a relatively common malignancy worldwide with a high mortality (5-year survival of <15%). Despite screening, surveillance, improved imaging and treatment, the exponential rise in OAC continues. The strongest risk factors for OAC are chronic heartburn and metaplastic transformation of the lower third of the esophagus (Barrett's esophagus). The risk profile includes Caucasian race, male gender older age, obesity and smoking. Although the tumor risk in BO has been progressively revised downwards, the exponential rise in OAC remains unchecked. This paradox points to an unidentified missing link. Relatively recently, we provided the world's initial data for a strong association of biologically relevant hr-HPV with BD and OAC. Since then, systematic reviews and meta-analysis have documented HPV DNA prevalence rates in OAC of between 13 to 35%. In this review, we provide some evidence for a probable causal relationship between hr-HPV and OAC. This is challenging given the multifactorial etiology and long latency. Increasingly, high-risk HPV (hr-HPV) is regarded as a risk factor for OAC. This discovery will aid identification of a sub-group of high-risk progressors to esophageal cancer by surveillance and the development of effective preventive strategies including vaccination.

Human Papillomavirus Infection and Oropharyngeal and Gastrointestinal Cancers: A Causal Relationship?

The human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. The risk of being infected at least once in a lifetime among both men and women is estimated to be 50%. Although the majority of HPV infections are asymptomatic and improve within 2 years, approximately 10% of individuals develop a persistent infection and have an increased risk of developing carcinomas. The association of HPV and genital cancer is well established. However, there is evidence that HPV may also be associated with other cancers, including those of the gastrointestinal system. The aim of this review is to organize the current evidence of associations between HPV infections and oropharyngeal and gastrointestinal cancers, including the following: oropharyngeal, esophageal, gastric, colorectal, and anal cancers. A comprehensive review of the most up-to-date medical literature concluded that an HPV infection might have a role in the oncogenesis of gastrointestinal tract cancers. HPV may have a causal relationship with oropharyngeal and esophageal squamous cell cancers. However, the association between HPV and gastric and colorectal cancers is weaker. The development of cancer in the oropharyngeal and gastrointestinal tract is usually multifactorial, with HPV having a role in at least a subset of these cancers. HPV infections pose a big challenge due to their burden of infection and their oncogenic potential.

Infection with Human Papillomavirus 18 Promotes Alkylating Agent-Induced Malignant Transformation in a Human Esophageal Cell Line

The relationship between human papillomavirus (HPV) and esophageal cancer (EC) has been controversial, which may be caused by the difference in geographic regions of sample origin. Thus, we conducted a case-control study to find that HPV increased the risk of esophageal cancer, and the HPV18 detection rate is the highest (24.2%) among patients with EC, suggesting that HPV18 could be the most risk subtype of HPV infected. We then identified high-risk HPV18 and N-methyl-N'-nitro-N-nitroso-guanidine (MNNG) to establish a model on the viral etiology cooperating with environmental carcinogens. Het-1A cells containing HPV18 were continuously exposed to MNNG or not; then the morphological phenotype and function assays were performed in 25th passage cells. MNNG promoted the proliferation and invasion abilities and inhibited apoptosis both in Het-1A-HPV18 and control group. However, the Het-1A-HPV18 had a stronger change in phenotypic features and formed more transformed foci in soft agar. Further, Western blot found p53 and p21 were down-regulated, and expression of c-Myc, MMP-2, and MMP-9 and Bcl-2/Bax ratio were up-regulated. Our results revealed that MNNG was easier to induce malignant transformation of Het-1A cells transfected with HPV18. It is good evidence for the close relationship between HPV and the etiology of EC, providing foundation for further study in molecular mechanism and specific intervention targets.

Immunodiagnosis and Immunotherapeutics Based on Human Papillomavirus for HPV-Induced Cancers

Infection with human papillomavirus (HPV) is one of the main causes of malignant neoplasms, especially cervical, anogenital, and oropharyngeal cancers. Although we have developed preventive vaccines that can protect from HPV infection, there are still many new cases of HPV-related cancers worldwide. Early diagnosis and therapy are therefore important for the treatment of these diseases. As HPVs are the major contributors to these cancers, it is reasonable to develop reagents, kits, or devices to detect and eliminate HPVs for early diagnosis and therapeutics. Immunological methods are precise strategies that are promising for the accurate detection and blockade of HPVs. During the last decades, the mechanism of how HPVs induce neoplasms has been extensively elucidated, and several oncogenic HPV early proteins, including E5, E6, and E7, have been shown to be positively related to the oncogenesis and malignancy of HPV-induced cancers. These oncoproteins are promising biomarkers for diagnosis and as targets for the therapeutics of HPV-related cancers. Importantly, many specific monoclonal antibodies (mAbs), or newly designed antibody mimics, as well as new immunological kits, devices, and reagents have been developed for both the immunodiagnosis and immunotherapeutics of HPV-induced cancers. In the current review, we summarize the research progress in the immunodiagnosis and immunotherapeutics based on HPV for HPV-induced cancers. In particular, we depict the most promising serological methods for the detection of HPV infection and several therapeutical immunotherapeutics based on HPV, using immunological tools, including native mAbs, radio-labelled mAbs, affitoxins (affibody-linked toxins), intracellular single-chain antibodies (scFvs), nanobodies, therapeutical vaccines, and T-cell-based therapies. Our review aims to provide new clues for researchers to develop novel strategies and methods for the diagnosis and treatment of HPV-induced tumors.

Human papillomavirus infection in esophageal squamous cell carcinoma and esophageal adenocarcinoma: a concise review

The causal link between high-risk human papillomavirus (hr-HPV) infection and cervical, anogenital, and some oropharyngeal malignancies has been established by both molecular and epidemiological data. The association between HPV and esophageal squamous cell carcinoma (ESCC) remains controversial, as is the true prevalence of HPV infection in ESCC. The wide range in reported rates reflects variability in the primary literature, with some larger scale case-control studies suggesting the infection rates range from 0% to 78%. Interactions between HPV and the Barrett's metaplasia-dysplasia-carcinoma sequence have been explored, and these studies have shown some conflicting data. Overall, systematic reviews have reported the prevalence of HPV-positive DNA in esophageal adenocarcinoma patients of between 13% and 35%. Postulated reasons for discrepancies in HPV prevalence rates in esophageal cancer include variations in testing methodology and assay sensitivities; technical issues, including the lack of a gold-standard primer; types of specimens utilized (fresh-frozen versus formalin-fixed tissue); geographical variation; cross-contamination; and small sample sizes. Thus, efforts must be undertaken to (1) standardize HPV testing, ideally in a central laboratory and utilizing tests that detect viral transcriptional activity; (2) avoid cross-contamination; and (3) recruit large numbers of patients to accurately ascertain HPV rates in esophageal malignancy.