Situation of HPV16 E2 gene status during radiotherapy treatment of cervical carcinoma

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.

Carbon-ion irradiation overcomes HPV-integration/E2 gene-disruption induced radioresistance of cervical keratinocytes

To date, only few data exist on mechanisms underlying the human papillomavirus (HPV)-associated irradiation response. It has been suggested, that the viral E2 gene plays an important role in that context. The aim of the current study is to compare the effect of photon- and carbon-ion (12C)-radiation therapy (RT) on cells with different HPV and E2 gene status. We hypothesized that 12C-RT might overcome the radioresistance of E2 gene-disrupted cells. We analyzed four different cell lines that differed in HPV status or E2 gene status. Cells were irradiated with either photons or 12C. Clonogenic survival, cell cycle and expression of Rb and p53 were analyzed. Radiosensitivity seemed to be dependent on E2 gene status and type of RT. 12C-RT led to lower surviving fractions, indicating higher radiosensitivity even in cells with disrupted E2 gene. The observed relative biological effectiveness (RBE) of 12C-RT for C33a/Caski and W12/S12 was 1.3/4 and 2.7/2.5, respectively. Cell cycle regulation after both photon- and 12C-RT was dependent on HPV status and on E2 gene status. Furthermore, the effect of RT on expression of p53 and Rb seemed to be dependent on E2 gene status and type of RT. We showed that 12C-RT overcomes HPV-integration induced radioresistance. The effect of RT on cell cycle regulation as well as on expression of p53 and Rb seemed to be dependent on HPV status, E2 gene status and type of RT. Differences in Rb expression and cell cycle regulation may play a role for enhanced radiosensitivity to 12C-RT of cells with disrupted E2 gene.

Human papillomavirus-associated cancers: A growing global problem

Human papillomavirus (HPV) infection is linked with several cancers such as cancer cervix, vagina, vulva, head and neck, anal, and penile carcinomas. Although there is a proven association of HPV with these cancers, questions regarding HPV testing, vaccination, and treatment of HPV-related cancers continue to remain unanswered. The present article provides an overview of the HPV-associated cancers.

Molecular Detection of Human Papillomavirus and Viral DNA Load after Radiotherapy for Cervical Carcinomas

Aims and background

Infection with high-risk types of human papillomavirus (HPV) is a necessary cause for cervical carcinoma. Radiation therapy together with surgery is the most effective treatment. The purpose of this study was to investigate the molecular basis of the response to radiotherapy in cervical cancer cells.

Methods and study design

Tumor cells were obtained from biopsies of 44 cervical cancers, collected before and after radiotherapy. The presence of HPV was analyzed by polymerase chain reaction (PCR) using primers specific for the L1 region.

Results

The prevalence of HPV was 70.4%, with HPV16 being the most common (54.5%) and HPV18 the second (15.9%). Our analyses show that ionizing radiation does not influence HPV detection, as the percentage of HPV-positive biopsies was similar in patients before and after radiotherapy (HPV16 60% vs. 51.7% and HPV18 20% vs. 13.7%, respectively). However, the detection of HPV did vary by tumor stage, with the highest proportion observed in late-stage tumors (HPV16 and HPV18 in 80% and 60% of stage III tumors, respectively). We also found that HPV viral load is influenced by radiotherapy and tumor stage, with the highest viral loads in late-stage tumors (stage III) after 1 day since radiotherapy (p<0.05). According to Kaplan-Meier curves, higher HPV viral load was associated with significantly shortened progression-free survival (p = 0.04).

Conclusions

Our data provide prospective evidence that ionizing radiation can affect the HPV viral load and this might offer the best strategies for assessment of therapeutic efficacy.