3-(2-Chloropropyl amide)-4-methoxy-N-phenylbenzamide inhibits expression of HPV oncogenes in human cervical cancer cell

Fang Han,Yuhuan Li,Jiandong Jiang,Zhuorong Li,Huiqiang Wang,Yanping Li,Qiaoni Lu,Linlin Ma

doi:10.1186/s12985-017-0806-5

Abstract

BackgroundHuman papillomaviruses (HPVs) are the primary causative agents for cervical cancer, and HPV oncoproteins E6 and E7 are known to be the main reason for the onset and maintenance of the malignancies. Therefore, inhibition of viral E6 and E7 oncoproteins expression represents a viable strategy to cervical cancer therapies. This study is to evaluate the antiviral effect of a novel N-Phenylbenzamide derivative, 3-(2-Chloropropyl amide)-4-methoxy-N-phenylbenzamide (L17), against HPV16 in vitro and identify its associated mechanism of action in cervical cancer cells.MethodsThe cytotoxic effect of L17 was assessed by MTT assay. The mRNA and protein levels of E6 and E7 oncogenes were analyzed by quantitative real-time reverse transcription PCR (qRT-PCR) and Western blot, respectively. p53 and Rb protein levels were also detected by Western blot. The effect of L17 on cell cycle was analyzed by flow cytometry.ResultsThe cytotoxic effect of L17 was greater in cervical carcinoma cells than in normal cells. L17 significantly reduced the expression of HPV16 E6 and E7 mRNA and protein, at least partly by enhancing degradation of HPV16 E6 and E7 mRNA. Moreover, reduced expression of E6 and E7 induced by L17 resulted in the up-regulation of p53 and Rb expression, which subsequently induced CaSki cells arrest at G0/G1 phase.ConclusionsL17 has antiviral activity through suppressing E6 and E7 oncogene expression and could inhibit CaSki cell proliferating by inducing cells arrest at G0/G1 phase at nontoxic concentration, implying that L17 might be exploited as a candidate agent for HPV-associated cervical cancer prevention and treatment.

Highlights

Human papillomaviruses (HPVs) are the primary causative agents for cervical cancer, and human papillomavirus (HPV) oncoproteins E6 and E7 are known to be the main reason for the onset and maintenance of the malignancies
In our screening for drug candidates exhibiting inhibitory activity against HPV, we found that a novel N-Phenylbenzamide derivative, 3-(2-Chloropropyl amide)4-methoxy-N-phenylbenzamide, named 3-(2Chloropropylamide)-4-methoxy-N- phenylbenzamide (L17), was active in inhibiting the expression of HPV oncoproteins E6 and E7
We studied the effects of L17 on the expression of HPV oncoproteins E6 and E7, which are associated with the development of cervical cancer

Summary

Introduction

Human papillomaviruses (HPVs) are the primary causative agents for cervical cancer, and HPV oncoproteins E6 and E7 are known to be the main reason for the onset and maintenance of the malignancies. Inhibition of viral E6 and E7 oncoproteins expression represents a viable strategy to cervical cancer therapies. E6 protein can facilitate tumor suppressor protein p53 degradation via the ubiquitin proteolytic pathway, which shortens the half-life of p53 and reduces its concentration, leading to the overrides at the G1/S and G2/M checkpoints [14, 15]. This is the major cause of chromosomal instability and leads to the mutation of the HPV-positive cells. Inhibition of viral E6 and E7 oncoprotein expression represents a viable strategy that might restore growth control in tumor cells or sensitize cells to cancer therapies

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