scholarly journals Inhibition of kinase IKKβ suppresses cellular abnormalities induced by the human papillomavirus oncoprotein HPV 18E6

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mojgan Padash Barmchi ◽  
Miranda Thomas ◽  
Jayashree V. Thatte ◽  
Arushi Vats ◽  
Bing Zhang ◽  
...  

AbstractHuman papillomavirus (HPV) is the leading cause of cervical cancer and has been implicated in several other cancer types including vaginal, vulvar, penile, and oropharyngeal cancers. Despite the recent availability of a vaccine, there are still over 310,000 deaths each year worldwide. Current treatments for HPV-mediated cancers show limited efficacy, and would benefit from improved understanding of disease mechanisms. Recently, we developed a Drosophila ‘HPV 18 E6’ model that displayed loss of cellular morphology and polarity, junctional disorganization, and degradation of the major E6 target Magi; we further provided evidence that mechanisms underlying HPV E6-induced cellular abnormalities are conserved between humans and flies. Here, we report a functional genetic screen of the Drosophila kinome that identified IKK$$\beta$$ β —a regulator of NF-κB—as an enhancer of E6-induced cellular defects. We demonstrate that inhibition of IKK$$\beta$$ β reduces Magi degradation and that this effect correlates with hyperphosphorylation of E6. Further, the reduction in IKK$$\beta$$ β suppressed the cellular transformation caused by the cooperative action of HPVE6 and the oncogenic Ras. Finally, we demonstrate that the interaction between IKK$$\beta$$ β and E6 is conserved in human cells: inhibition of IKK$$\beta$$ β blocked the growth of cervical cancer cells, suggesting that IKK$$\beta$$ β may serve as a novel therapeutic target for HPV-mediated cancers.

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Surendra Sharma ◽  
Karl Munger

ABSTRACT Tumor cells overcome the cytostatic and cytotoxic restraints of TP53 tumor suppressor signaling through a variety of mechanisms. High-risk human papillomavirus (HPV)-positive tumor cells retain wild-type TP53 because the HPV E6/UBE3A ubiquitin ligase complex targets TP53 for proteasomal degradation. While restoration of TP53 in tumor cells holds great promise for cancer therapy, attempts to functionally restore the dormant TP53 tumor suppressor in HPV-positive cancer cells by inhibiting the HPV E6/UBE3A ubiquitin ligase complex have not yet been successful. The damage-induced long noncoding RNA, DINO (DINOL), is a TP53 transcriptional target that has been reported to bind to and stabilize TP53, thereby amplifying TP53 signaling. We show that HPV-positive cervical carcinoma cells contain low levels of DINO because of HPV E6/UBE3A-mediated TP53 degradation. Acute DINO expression overrides HPV16 E6/UBE3A-mediated TP53 degradation, causing TP53 stabilization and increased expression of TP53 transcriptional target genes. This causes a marked sensitization to chemotherapy agents and renders cells vulnerable to metabolic stress. Acute DINO expression in HPV-positive cervical cancer cells induces hallmarks of DNA damage response signaling, and TP53 activation involves ATM/CHK2 signaling. DINO upregulation in response to DNA damage is independent of ATM/CHK2 and can occur in cancer cells that express mutant TP53. IMPORTANCE Functional restoration of the TP53 tumor suppressor holds great promise for anticancer therapy. Current strategies are focused on modulating TP53 regulatory proteins. Long noncoding RNAs (lncRNAs) have emerged as important regulators of TP53 as well as modulators of downstream tumor-suppressive transcriptional responses. Unlike many other cancer types, human papillomavirus (HPV)-positive cancer cells retain wild-type TP53 that is rendered dysfunctional by the viral E6 protein. We show that acute expression of the damage-induced long noncoding RNA, DINO, a known TP53 transcriptional target and functional modulator, causes TP53 reactivation in HPV-positive cervical cancer cells. This causes increased vulnerability to standard chemotherapeutics as well as biguanide compounds that cause metabolic stress. Hence, strategies that target DINO may be useful for restoring TP53 tumor suppressor activity in HPV-positive cancers and other tumor types that retain wild-type TP53.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Joseph M. Bay ◽  
Bruce K. Patterson ◽  
Nelson N. H. Teng

The constitutive proliferation and resistance to differentiation and apoptosis of neoplastic cervical cells depend on sustained expression of human papillomavirus oncogenes. Inhibition of these oncogenes is a goal for the prevention of progression of HPV-induced neoplasias to cervical cancer. SiHa cervical cancer cells were transfected with an HPV-16 promoter reporter construct and treated with leukemia inhibitory factor (LIF), a human cytokine of the interleukin 6 superfamily. SiHa and CaSki cervical cancer cells were also assessed for proliferation by MTT precipitation, programmed cell death by flow cytometry, and HPV E6 and E7 expression by real-time PCR. LIF-treated cervical cancer cells showed significantly reduced HPV LCR activation, reduced levels of E6 and E7 mRNA, and reduced proliferation. We report the novel use of LIF to inhibit viral oncogene expression in cervical cancer cells, with concomitant reduction in proliferation suggesting re-engagement of cell-cycle regulation.


2012 ◽  
Vol 87 (3) ◽  
pp. 1586-1595 ◽  
Author(s):  
Siaw Shi Boon ◽  
Lawrence Banks

ABSTRACTCervical cancer develops through the combined activities of the human papillomavirus (HPV) E6 and E7 oncoproteins. A defining characteristic of E6 oncoproteins derived from cancer-causing HPV types is the presence of a PDZ binding motif (PBM) at the extreme carboxy terminus of the protein which is absent from E6 proteins derived from the so-called low-risk HPV types. Within this PBM is also a protein kinase A (PKA) phospho-acceptor site, which is thought to negatively regulate the association of E6 with its PDZ domain-containing substrates. We can now show that phosphorylation of E6 by PKA and/or AKT confers the ability to interact with 14-3-3ζ. The interaction is direct and specific for the high-risk HPV E6 oncoproteins, although there are significant differences in the efficiencies with which HPV-16, HPV-18, and HPV-31 E6 oncoproteins can associate with 14-3-3ζ; this correlates directly with their respective susceptibilities to phosphorylation by PKA and/or AKT. We demonstrate here that the interaction between E6 and 14-3-3ζ also requires integrity of the E6 PBM, and downregulation of 14-3-3ζ results in a marked reduction in the levels of HPV-18 E6 expression in HeLa cells. Using phospho-specific anti-E6 antibodies, we also demonstrate significant levels of E6 phosphorylationin vivo. These studies redefine the potential relevance of the E6 PBM in the development of cervical cancer, suggesting that interaction with 14-3-3ζ, as well as the more well-established interactions with PDZ domain-containing substrates, is likely to be responsible for the biological activities attributed to this region of the high-risk HPV E6 oncoproteins.


Author(s):  
N.A. Shmakova ◽  
G.N. Chistyakova ◽  
I.N. Kononova ◽  
I.I. Remizova

Recently, there has been a steady growth of cervical cancer all over the world, especially in Russia. Patients with cervical cancer have become much younger. At the same time, the human papillomavirus is not only the main factor in the neoplastic process, but it is also one of the most common sexually transmitted infections in the world. The aim of the paper is to assess the prevalence and characteristics of human papillomavirus genotypes in patients with cervical intraepithelial neoplasia. Materials and Methods. During the periodic screening we examined 213 women of a reproductive age with HPV infection. All patients underwent liquid-based cytology and human papillomavirus genotyping by polymerase chain reaction. Results. We revealed that the prevalence of cervical intraepithelial neoplasia among women with papillomavirus infection was 80.3 % (n=171). According to human papillomavirus genotyping, HPV 16 (38 %) and HPV 33 (32 %) prevailed. We also observed positive high correlation between high-grade squamous intraepithelial lesions (HSIL) and HPV 18 (r=+0.759, p=0.001), a negative mean correlation between HPV 45 and low-grade squamous intraepithelial lesions (LSIL) (r=-0.643, p=0.002). A cohort of patients with severe intraepithelial cervical lesions demonstrated high viral load rates. Conclusion. According to the results obtained, we established the dominance of HPV 16 and HPV 33 genotypes in cervical intraepithelial neoplasia. There were significant differences between HSIL and LSIL patients with HPV 18 and HPV 45. There was also a correlation between an increase in the viral load with the severity of the pathological process. Keywords: human papillomavirus, intraepithelial cervical neoplasms, cervical cancer. В последние годы в мире, особенно в России, наблюдается неуклонный рост и «омолаживание» рака шейки матки. При этом вирус папилломы человека является не только основным фактором прогрессирования неопластического процесса, но и одной из наиболее распространенных инфекций, предаваемых половым путем, в мире. Цель. Оценить распространенность и характеристику генотипов папилломавирусной инфекции у пациенток с цервикальными интраэпителиальными неоплазиями. Материалы и методы. Проведено обследование 213 пациенток репродуктивного возраста с ВПЧ-инфекцией, пришедших на профилактический осмотр. Всем женщинам было выполнено цитологическое исследование жидкостным методом и генотипирование вируса папилломы человека методом полимеразной цепной реакции. Результаты. Распространенность цервикальных интраэпителиальных неоплазий среди женщин с папилломавирусной инфекцией составила 80,3 % (171 пациентка). Согласно данным генотипирования вируса папилломы человека превалировал 16-й (38 %) и 33-й типы (32 %). Выявлена положительная высокая корреляционная связь между цервикальными неоплазиями высокой степени онкогенного риска (HSIL) и 18-м типом ВПЧ-инфекции (r=+0,759 при р=0,001), отрицательная средняя корреляционная связь 45-го типа ВПЧ с низкой степенью онкогенного риска (LSIL) (r=-0,643 при р=0,002). Продемонстрированы высокие показатели вирусной нагрузки в когорте пациенток с тяжелыми внутриэпителиальными цервикальными поражениями. Выводы. По результатам полученных данных установлено доминирование 16-го и 33-го генотипов ВПЧ при цервикальных интраэпителиальных неоплазиях с наличием значимых различий между пациентами с HSIL и LSIL в отношении 18-го и 45-го типов, а также связь роста уровня вирусной нагрузки с увеличением степени тяжести патологического процесса. Ключевые слова: вирус папилломы человека, интраэпителиальные новообразования шейки матки, рак шейки матки.


Tumor Biology ◽  
2016 ◽  
Vol 37 (10) ◽  
pp. 13137-13154 ◽  
Author(s):  
Kanchan Vishnoi ◽  
Sutapa Mahata ◽  
Abhishek Tyagi ◽  
Arvind Pandey ◽  
Gaurav Verma ◽  
...  

2007 ◽  
Vol 14 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Jayanthi S. Lea ◽  
Noriaki Sunaga ◽  
Mitsuo Sato ◽  
Geetha Kalahasti ◽  
David S. Miller ◽  
...  

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